Criteria for the Certification and Determination of the Waste Isolation Pilot Plant's Compliance With Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes
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Part II
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 194
Criteria for the Certification and Determination of the Waste Isolation
Pilot Plant's Compliance With Environmental Standards for the
Management and Disposal of Spent Nuclear Fuel, High-Level and
Transuranic Radioactive Wastes; Proposed Rule
Proposed Rules
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 194
[FRL-5142-4]
RIN 2060-AE30
Criteria for the Certification and Determination of the Waste
Isolation Pilot Plant's Compliance With Environmental Standards for the
Management and Disposal of Spent Nuclear Fuel, High-Level and
Transuranic Radioactive Wastes
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing
criteria for certifying and determining whether the Department of
Energy's Waste Isolation Pilot Plant (WIPP) complies with disposal
standards set forth in 40 CFR part 191 (Environmental Standards for the
Management and Disposal of Spent Nuclear Fuel, High-Level and
Transuranic Radioactive Wastes). EPA is required to promulgate these
criteria under the 1992 Waste Isolation Pilot Plant Land Withdrawal Act
(WIPP LWA). These criteria will be used by the Agency in ascertaining
whether the WIPP disposal system complies with the disposal standards.
DATES: Comments on today's proposal must be received by May 1, 1995.
Public hearings on today's proposal will be held in New Mexico. A
separate annoucement will be published in the Federal Register to
provide public hearing information.
ADDRESSES: Comments should be submitted, in duplicate, to: Docket No.
A-92-56, Air Docket, room M-1500 (LE-131), U.S. Environmental
Protection Agency, 401 M Street SW., Washington, DC 20460. See
additional docket information in the Supplementary Information.
sal will be held in New Mexico. A
separate annoucement will be published in the Federal Register to
provide public hearing information.
ADDRESSES: Comments should be submitted, in duplicate, to: Docket No.
A-92-56, Air Docket, room M-1500 (LE-131), U.S. Environmental
Protection Agency, 401 M Street SW., Washington, DC 20460. See
additional docket information in the Supplementary Information.
FOR FURTHER INFORMATION CONTACT: Mary Kruger or Martin Offutt;
telephone number (202) 233-9310; address: Criteria and Standards
Division, Mail Code 6602J, U.S. Environmental Protection Agency, 401 M
Street SW., Washington, DC 20460. An addendum to the supplementary
information provided in today's notice is located in Docket No. A-92-
56. For copies of this addendum and the Background Information Document
and Economic Impact Analysis prepared for this proposed rule, contact
Mary Kruger at the above phone number and address.
SUPPLEMENTARY INFORMATION: As discussed below, the scope of today's
proposal is limited to proposed criteria for certifying and determining
whether the Waste Isolation Pilot Plant (WIPP) in New Mexico complies
with the disposal standards set forth in 40 CFR part 191. Accordingly,
comments should be similarly limited in scope; e.g., comments should
not address the Agency's recently promulgated radioactive waste
disposal standards--40 CFR part 191 (58 FR 66398, December 20, 1993)--
or whether WIPP should be used as a disposal facility.
The U.S. Department of Energy (DOE) is developing the Waste
Isolation Pilot Plant (WIPP) near Carlsbad in southeastern New Mexico
as a potential deep geologic repository for the disposal of defense
transuranic (TRU) radioactive waste currently being stored on Federal
reservations in Washington, Ohio, Idaho, New Mexico, Tennessee, South
Carolina, Nevada and Colorado
ed as a disposal facility.
The U.S. Department of Energy (DOE) is developing the Waste
Isolation Pilot Plant (WIPP) near Carlsbad in southeastern New Mexico
as a potential deep geologic repository for the disposal of defense
transuranic (TRU) radioactive waste currently being stored on Federal
reservations in Washington, Ohio, Idaho, New Mexico, Tennessee, South
Carolina, Nevada and Colorado. TRU waste consists of materials
containing one or more elements having atomic numbers greater than 92,
in concentrations greater than 100 nanocuries of alpha-emitting TRU
isotopes per gram of waste, with half-lives greater than 20 years. Most
TRU waste consists of items that have become contaminated as a result
of activities associated with the production of nuclear weapons, e.g.,
rags, equipment, tools, and organic and inorganic sludges. TRU waste is
often mixed with hazardous chemical constituents.
Before beginning disposal of radioactive waste at the WIPP, DOE
must demonstrate that the WIPP complies with the Environmental
Protection Agency's (EPA) radioactive waste standards at 40 CFR part
191 (Environmental Standards for the Management and Disposal of Spent
Nuclear Fuel, High-Level and Transuranic Radioactive Wastes).
On October 30, 1992, the Waste Isolation Pilot Plant Land
Withdrawal Act (WIPP LWA) was enacted (Pub. L. 102-579). The WIPP LWA
contains numerous provisions pertaining to EPA's role in overseeing
DOE's activities at the WIPP, including requirements for the
development and implementation of the 40 CFR part 191 disposal
standards as they are applied to the WIPP. Specifically, section 8(a)
of the WIPP LWA reinstated all of the remanded disposal standards
except those aspects of the individual and ground-water protection
requirements which the court found problematic in NRDC v. U.S. EPA. The
WIPP LWA requires EPA to certify and determine whether or not the WIPP
will comply with the Agency's final radioactive waste disposal
standards
plied to the WIPP. Specifically, section 8(a)
of the WIPP LWA reinstated all of the remanded disposal standards
except those aspects of the individual and ground-water protection
requirements which the court found problematic in NRDC v. U.S. EPA. The
WIPP LWA requires EPA to certify and determine whether or not the WIPP
will comply with the Agency's final radioactive waste disposal
standards. ``Certification'' refers to any initial certification of
compliance of DOE's application for the WIPP with subparts B and C of
40 CFR part 191 (see section 8(d) of the WIPP LWA). ``Determination''
refers to any subsequent decisions by the Agency (required every 5
years by the WIPP LWA) of whether the WIPP continues to be in
compliance with subparts B and C of 40 CFR part 191 (see section 8(f)
of the WIPP LWA). In order to certify or determine compliance, the
Agency will be issuing criteria for assessing compliance with the final
disposal standards, as required by section 8(c) of the WIPP LWA. On
February 11, 1993, as a first step in the development of compliance
criteria, EPA issued an Advance Notice of Proposed Rulemaking (ANPR)
soliciting comments on issues associated with the development of
compliance criteria. (58 FR 8029.) The next step in the evolution of
these criteria is occurring today with the issuance of proposed
compliance criteria.
Objective and Implementation of Today's Proposed Criteria
as a first step in the development of compliance
criteria, EPA issued an Advance Notice of Proposed Rulemaking (ANPR)
soliciting comments on issues associated with the development of
compliance criteria. (58 FR 8029.) The next step in the evolution of
these criteria is occurring today with the issuance of proposed
compliance criteria.
Objective and Implementation of Today's Proposed Criteria
Under authority of the WIPP LWA, the Agency is proposing criteria
for certifying and determining whether the Department of Energy's (DOE)
Waste Isolation Pilot Plant (WIPP) will comply with the Agency's
radioactive waste disposal standards set forth in 40 CFR part 191. The
WIPP LWA specifies that underground emplacement of transuranic wastes
for disposal at the WIPP may not commence unless and until EPA
certifies that the WIPP facility will comply with 40 CFR part 191,
subparts B and C. If the Agency certifies compliance, the WIPP LWA
requires EPA to subsequently conduct periodic determinations of
continued compliance throughout waste disposal operations at the WIPP.
Criteria contained in today's notice address any initial certification
of compliance as well as any subsequent determinations of continued
compliance. When final compliance criteria are promulgated as Agency
regulations, EPA will be responsible for assuring that the requirements
are properly implemented.
Importantly, today's proposal is limited to consideration of the
WIPP's compliance with the disposal regulations found in subparts B and
C of 40 CFR part 191 (which include containment requirements, assurance
requirements, individual protection requirements, and ground-water
protection requirements). These compliance criteria do not address
compliance with the management and storage regulations found in subpart
A of 40 CFR part 191. The Agency plans to issue guidance
addressing implementation of subpart A at a later date
and
C of 40 CFR part 191 (which include containment requirements, assurance
requirements, individual protection requirements, and ground-water
protection requirements). These compliance criteria do not address
compliance with the management and storage regulations found in subpart
A of 40 CFR part 191. The Agency plans to issue guidance
addressing implementation of subpart A at a later date.
The Agency also wishes to make clear that today's proposal does not
address compliance with all of the requirements of the WIPP LWA.
Rather, today's proposal is limited to those requirements of the WIPP
LWA which pertain to the WIPP's compliance with the disposal standards
in 40 CFR part 191. For example, today's proposal does not address the
WIPP's compliance with EPA regulations developed pursuant to the
Resource Conservation and Recovery Act (RCRA) or any other
environmental laws or regulations. EPA intends to address compliance
with the balance of these additional laws and regulations through
compliance plans being developed by EPA's Region VI. For more
information regarding the Region's activities, please write to EPA
Region VI, 1445 Ross Avenue, Dallas, Texas 75202-2733; Attn: Chuck
Byrum.
EPA has prepared a document entitled ``Implementation Strategy for
the Waste Isolation Pilot Plant Land Withdrawal Act of 1992'' (EPA 402-
R-93-002, March 1993) which explains in more detail the Agency's roles
and responsibilities under the WIPP LWA. For more information
concerning the Implementation Strategy Document, please write to the
Policy and Public Information Section, Office of Radiation and Indoor
Air, U.S. EPA, Mail Code 6602J, 401 M St., S.W., Washington, D.C. 20460
or call the EPA WIPP Information Line at 1-800-331-WIPP.
Additional Docket Information
in more detail the Agency's roles
and responsibilities under the WIPP LWA. For more information
concerning the Implementation Strategy Document, please write to the
Policy and Public Information Section, Office of Radiation and Indoor
Air, U.S. EPA, Mail Code 6602J, 401 M St., S.W., Washington, D.C. 20460
or call the EPA WIPP Information Line at 1-800-331-WIPP.
Additional Docket Information
The Agency is currently maintaining the following public
information dockets: (1) Docket No. A-92-56, located in room 1500
(first floor in Waterside Mall near the Washington Information Center),
U.S. Environmental Protection Agency, 401 M Street, S.W., Washington,
D.C. 20460 (open from 8:00 a.m. to 4:00 p.m. on weekdays); (2) EPA's
docket in the Government Publications Department of the Zimmerman
Library of the University of New Mexico located in Albuquerque, New
Mexico (open from 8:00 a.m. to 9:00 p.m. on Monday through Thursday,
8:00 a.m. to 5:00 p.m. on Friday, 9:00 a.m. to 5:00 p.m. on Saturday,
and 1:00 p.m. to 9:00 p.m. on Sunday); (3) EPA's docket in the Fogelson
Library of the College of Santa Fe in Santa Fe, New Mexico located at
1600 St. Michaels Drive (open from 8:00 a.m. to 12:00 midnight on
Monday through Thursday, 8:00 a.m. to 5:00 p.m. on Friday, 9:00 a.m. to
5:00 p.m. on Saturday, 1:00 p.m. to 9:00 p.m. on Sunday); and (4) EPA's
docket in the Municipal Library of Carlsbad, New Mexico located at 101
S. Halegueno (open from 10:00 a.m. to 9:00 p.m. on Monday through
Thursday, 10:00 a.m. to 6:00 p.m. on Friday and Saturday, and 1:00 p.m.
to 5:00 p.m. on Sunday). As provided in 40 CFR part 2, a reasonable fee
may be charged for photocopying docket materials.
Description of Proposed Criteria
The proposed criteria consist of four subparts. Each of these
subparts is discussed in more detail below.
Subpart A--General Provisions
o 9:00 p.m. on Monday through
Thursday, 10:00 a.m. to 6:00 p.m. on Friday and Saturday, and 1:00 p.m.
to 5:00 p.m. on Sunday). As provided in 40 CFR part 2, a reasonable fee
may be charged for photocopying docket materials.
Description of Proposed Criteria
The proposed criteria consist of four subparts. Each of these
subparts is discussed in more detail below.
Subpart A--General Provisions
Subpart A is chiefly concerned with identifying the purpose, scope
and applicability of the criteria, defining terms, setting forth
requirements regarding communications, addressing conditions of
compliance certification and determinations, incorporating publications
by reference, and providing for alternative provisions if future
information indicates a need to modify the criteria. The specific
provisions of Subpart A are discussed below.
Purpose, Scope, and Applicability
Under Section 7(b) of the WIPP LWA, the DOE cannot dispose of
transuranic waste at the WIPP until the EPA certifies that the WIPP is
in compliance with the Agency's radioactive waste disposal standards
set forth in 40 CFR part 191. In addition, under Section 8(f) of the
WIPP LWA, not later than five years after initial receipt of waste for
disposal at the WIPP, and every five years thereafter until the end of
the decommissioning phase (as defined in section 2 of the WIPP LWA),
DOE is required to submit to the Administrator documentation of
continued compliance with the Agency's disposal standards. EPA is
proposing to specify that these criteria will apply to any
certification of compliance or determination of continued compliance
under these sections of the WIPP LWA
rs thereafter until the end of
the decommissioning phase (as defined in section 2 of the WIPP LWA),
DOE is required to submit to the Administrator documentation of
continued compliance with the Agency's disposal standards. EPA is
proposing to specify that these criteria will apply to any
certification of compliance or determination of continued compliance
under these sections of the WIPP LWA. The Administrator will review any
compliance applications (hereinafter, the term ``compliance
applications'' refers to applications for certification of compliance
under section 8(d) of the WIPP LWA as well as applications for
determinations of continued compliance under section 8(f) of the WIPP
LWA) and will utilize these criteria to ascertain whether such
applications demonstrate compliance with subparts B and C of 40 CFR
part 191. The Administrator's certification or determination of
compliance for the WIPP facility will depend on satisfying the specific
requirements of each section of these criteria.
Definitions
In an effort to be consistent with the disposal standards set forth
in 40 CFR part 191, the Agency is proposing that, unless otherwise
indicated, all terms in the criteria have the same meaning as terms
found in the disposal regulations.
Communications
The Agency is proposing to specify that any compliance applications
shall be addressed to the Administrator and shall be signed by the
Secretary. Any other communications concerning compliance applications
for the WIPP shall, likewise, be addressed to the Administrator and
shall be signed by the Secretary or the Secretary's authorized
representative.
Conditions of Compliance Certification and Determination
roposing to specify that any compliance applications
shall be addressed to the Administrator and shall be signed by the
Secretary. Any other communications concerning compliance applications
for the WIPP shall, likewise, be addressed to the Administrator and
shall be signed by the Secretary or the Secretary's authorized
representative.
Conditions of Compliance Certification and Determination
EPA is proposing that any certification or determination issued by
the Agency pursuant to the WIPP LWA may include any conditions that the
Administrator finds necessary to support a compliance certification or
determination. In addition, EPA is proposing that any certification or
determination of compliance be potentially subject to modification,
suspension, or revocation for cause. The Agency believes that such
conditions are necessary in order to guard against the possibility that
the disposal system does not perform as expected (i.e., according to
predictions contained in compliance applications).
Any certification or determination of the WIPP's compliance will be
based upon the information contained in any compliance application
submitted to the Administrator and upon other available information
relevant to the application. So long as the contents of the application
remain valid, the current certification or determination will remain
valid. However, if the information contained in the application becomes
invalid due to unanticipated developments, then the basis for the
certification or determination may no longer be valid, and
modification, suspension, or revocation of the certification or
determination may be in order. Any modification, suspension, or
revocation of a compliance certification will be subject to Agency
rulemaking
owever, if the information contained in the application becomes
invalid due to unanticipated developments, then the basis for the
certification or determination may no longer be valid, and
modification, suspension, or revocation of the certification or
determination may be in order. Any modification, suspension, or
revocation of a compliance certification will be subject to Agency
rulemaking.
EPA is proposing to include these conditions because the Agency
believes it is important to have a mechanism which enables a
certification or determination to be modified, suspended, or revoked if
new information comes to light which suggests that the WIPP is no
longer performing or may no longer perform as predicted.
It would not be prudent to wait until submission of documentation of
continued compliance (potentially up to five years later) before taking
steps to mitigate against potential malfunctioning of the disposal
system. Delay would allow a situation which could result in a violation
continuing to exist or, perhaps, worsen. Hence, EPA is proposing these
conditions in order to be able to take action quickly to address
serious issues raised as to whether the WIPP is in compliance with the
disposal regulations.
The Agency is not specifying, in today's proposal, the particular
actions which may be required to be undertaken if modification or
suspension were invoked. EPA has not done so because the Agency
believes that it is inappropriate to specify particular actions prior
to knowing the precise circumstances in which the actions would be
undertaken. Since all of the scenarios in which the conditions might be
invoked would be difficult to predict, specification of the actions
necessary to mitigate against the consequences of all such scenarios
becomes even more difficult. EPA, therefore, is proposing that
decisions about the appropriate actions shall be based upon the nature
and gravity of the given scenario at the time it occurs
ertaken. Since all of the scenarios in which the conditions might be
invoked would be difficult to predict, specification of the actions
necessary to mitigate against the consequences of all such scenarios
becomes even more difficult. EPA, therefore, is proposing that
decisions about the appropriate actions shall be based upon the nature
and gravity of the given scenario at the time it occurs. In some cases
this might entail instituting remedial actions or even removal of
waste, while in other cases it might simply involve temporarily halting
waste emplacement. Thus, actions will be evaluated on a case by case
basis. The Agency solicits comment on this approach.
While the Agency is not specifying the particular actions which may
be required in the event of a modification or suspension, the Agency is
proposing that, in the event of a revocation (where presumably all
attempts at remedial action have failed), the Department shall
retrieve, to the extent practicable, any waste emplaced in the disposal
system. The Agency solicits comment on this proposal.
The Agency is proposing that upon written request of the
Administrator (after any certification or determination of compliance
has been issued), the Department shall submit information to enable the
Administrator to determine whether cause exists to modify, revoke, or
suspend any certification or determination. Moreover, the EPA is
proposing that the Department shall provide the requested information
to the Administrator within 30 days of receipt of the Administrator's
request. By requiring such a quick response time, the Agency can be
assured that if circumstances arise which warrant suspension,
modification, or revocation, the potential consequences of such
circumstances can be mitigated early and safety can, therefore, be
increased
he Department shall provide the requested information
to the Administrator within 30 days of receipt of the Administrator's
request. By requiring such a quick response time, the Agency can be
assured that if circumstances arise which warrant suspension,
modification, or revocation, the potential consequences of such
circumstances can be mitigated early and safety can, therefore, be
increased. As an additional measure to ensure that the Administrator is
kept apprised of any developments at the WIPP which might warrant
modification, suspension, or revocation of any certification or
determination of compliance, the Agency is proposing that the
Department report, within ten days of discovery, any significant
changes in conditions pertaining to the disposal system that depart
from the application and which formed the basis of any certification or
determination. Moreover, the Agency is requiring that a written report
of all changes in conditions and/or activities pertaining to the
disposal system that depart from the application and which formed the
basis of any certification or determination be submitted to the Agency
at least once every six months. If the Department plans to
intentionally make any significant changes in conditions or activities
pertaining to the disposal system, all such changes must be approved by
the Administrator prior to being made. The Administrator will consider
whether the planned change will invalidate the terms of the
certification or determination in assessing whether approval should be
given.
EPA is proposing to require the reporting of changes in WIPP
conditions or activities once every six months to assure that the
Agency is kept apprised of such changes but in a manner which is not
overly burdensome to the Department in submitting the information or to
the Agency in reviewing it
ate the terms of the
certification or determination in assessing whether approval should be
given.
EPA is proposing to require the reporting of changes in WIPP
conditions or activities once every six months to assure that the
Agency is kept apprised of such changes but in a manner which is not
overly burdensome to the Department in submitting the information or to
the Agency in reviewing it.
EPA is also proposing to require that if the Department determines
that a release of waste from the disposal system in excess of what is
permitted under the disposal regulations has occurred or is likely to
occur, the Department shall immediately suspend emplacement of waste in
the disposal system and notify the Administrator within 24 hours of
discovery of such a release. Following such notification, the
Administrator may request additional information and will determine
whether to modify, suspend, or revoke any previously issued
certification or determination of compliance. The EPA is proposing this
requirement to ensure that the Administrator is quickly apprised of any
changes in the disposal system's performance from the projections
included in any compliance applications.
Publications Incorporated by Reference
EPA is proposing that the following four documents be incorporated
by reference: (1) The Nuclear Regulatory Commission's NUREG 1297 ``Peer
Review for High-Level Nuclear Waste Repositories''; (2) The American
Society of Mechanical Engineers' (ASME) NQA-1-1989 edition ``Quality
Assurance Program Requirements for Nuclear Facilities''; (3) ASME NQA-
2a-1990 addenda (part 2.7) to ASME NQA-2-1989 edition ``Quality
Assurance Requirements of Computer Software for Nuclear Facility
Applications''; and (4) ASME NQA-3-1989 edition ``Quality Assurance
Program Requirements for the Collection of Scientific and Technical
Information for Site Characterization of High-Level Nuclear Waste
Repositories.'' The Agency is proposing to incorporate all of these
documents because EPA believes that each is app
n ``Quality
Assurance Requirements of Computer Software for Nuclear Facility
Applications''; and (4) ASME NQA-3-1989 edition ``Quality Assurance
Program Requirements for the Collection of Scientific and Technical
Information for Site Characterization of High-Level Nuclear Waste
Repositories.'' The Agency is proposing to incorporate all of these
documents because EPA believes that each is appropriate for use at the
WIPP. More detailed information about the contents of each document is
provided below in the sections dedicated to the particular topic
covered by the various documents. Documents incorporated by reference
are also available for inspection in the Office of the Federal
Register.
Alternative Provisions
Although the Agency believes that the criteria being proposed today
are appropriate based upon current knowledge and information, the
possibility that future information may indicate necessary
modifications to the criteria can not be ruled out.
In recognition of this possibility, today's proposed criteria set
forth procedures under which the Administrator may develop
modifications to this part, should the need arise. Any such
modifications would proceed through the notice-and-comment rulemaking
process under the Administrative Procedure Act (5 U.S.C. 553). The
proposed criteria stipulate that such a rulemaking would require a
public comment period of at least 120 days, including public hearings
in New Mexico.
Subpart B--Compliance Certification and Determination Applications
Subpart B of the proposed compliance criteria addresses: (1) The
completeness and accuracy of compliance applications; (2) the filing
and distribution requirements for such applications and any associated
reference materials; (3) the contents of a complete application; and
120 days, including public hearings
in New Mexico.
Subpart B--Compliance Certification and Determination Applications
Subpart B of the proposed compliance criteria addresses: (1) The
completeness and accuracy of compliance applications; (2) the filing
and distribution requirements for such applications and any associated
reference materials; (3) the contents of a complete application; and
(4) the criteria for updating certification applications.
Each of these sections is discussed below.
Completeness and Accuracy of Compliance Applications
The Agency proposes to require that any applications submitted to
the Administrator for a certification or determination of compliance be
complete and accurate. Since the statutory review period for
applications is only one year for certification and six months for
determinations, it is essential that all of that time be devoted to
substantive evaluation of the information contained in the
applications. Therefore, the Agency is proposing that the statutory
review periods not begin until the Administrator has determined that
the application is complete, accurate, and in accordance with the
compliance criteria. The Administrator will notify the Secretary in
writing once this determination is made.
Submission of Compliance Applications
In order to meet EPA's needs for reviewing and docketing any
compliance applications, the Agency proposes to require that 30 paper
copies of applications be filed with the Administrator (one original
and 29 printed copies), unless otherwise specified by the
Administrator. This number of copies is necessary because the Agency
plans to place copies of compliance applications in various public
dockets and the complexity of the application material will require
multiple reviewers
the Agency proposes to require that 30 paper
copies of applications be filed with the Administrator (one original
and 29 printed copies), unless otherwise specified by the
Administrator. This number of copies is necessary because the Agency
plans to place copies of compliance applications in various public
dockets and the complexity of the application material will require
multiple reviewers. The phrase ``unless otherwise specified by the
Administrator'' is meant to allow for the possibility of alternative
requirements for submission of compliance applications in the event
that new submission methods are developed; e.g., electronic submission
requirements.
Submission of Reference Materials
The Agency recognizes that compliance applications will likely
include references to other sources of information. Accordingly,
today's proposal requires submission to the Administrator of ten paper
copies of any referenced material unless otherwise specified by the
Administrator. This is necessary due to the limited time period for
review and due to the needs of multiple reviewers, including the
public. Again, the phrase ``unless otherwise specified by the
Administrator'' signals that the Administrator may require an
alternative method for submission of reference materials if a more
appropriate system (e.g., an electronic submission system) is
developed. Regardless of what system is ultimately used, submissions
need not include referenced material from standard textbooks (e.g.,
physics or chemical handbooks).
Content of Compliance Certification Applications
' signals that the Administrator may require an
alternative method for submission of reference materials if a more
appropriate system (e.g., an electronic submission system) is
developed. Regardless of what system is ultimately used, submissions
need not include referenced material from standard textbooks (e.g.,
physics or chemical handbooks).
Content of Compliance Certification Applications
The Agency is proposing to specify information which must be
included in any compliance certification application. The proposed
criteria require descriptions of the WIPP disposal system and
surrounding environment, and the components and results of long-term
compliance assessments. The items listed, however, are not intended to
be an exhaustive identification of the necessary elements of a complete
application. Rather, the proposed criteria identify what the Agency
considers to be major elements of a complete compliance application.
Note that other major submission requirements are discussed elsewhere
in the criteria and are too numerous to list here (such as
documentation requirements for use of expert judgment and for waste
characterization).
In the future, the Agency will be issuing a detailed guide as a
supplement to the 40 CFR part 194 compliance criteria. This guide will
provide additional detailed information on the expected format and
content of a complete compliance application. The Agency is not
including such a detailed itemization in today's proposal because EPA
needs more information about factors important to the disposal system's
ability to contain waste before such detailed submission requirements
can be identified.
As an example of the type of information which may be necessary for
inclusion in a complete application, but which EPA is not specifying in
today's proposal due to the fact that there is currently an incomplete
understanding of its effect on the disposal system, is an analysis and
identification of higher permeability marker beds in the host rock
ed submission requirements
can be identified.
As an example of the type of information which may be necessary for
inclusion in a complete application, but which EPA is not specifying in
today's proposal due to the fact that there is currently an incomplete
understanding of its effect on the disposal system, is an analysis and
identification of higher permeability marker beds in the host rock.
(Marker beds are stratified units with distinctive characteristics
making them an easily recognized geologic horizon.) At present, there
is some information about the existence of these marker beds in the
host rock, but little knowledge about how they may affect the transport
of radionuclides and the flow of ground water. As further study is done
of these marker beds, it is possible that they may be discovered to
have a great impact on the WIPP's ability to comply with the disposal
standards of 40 CFR part 191. It is also possible that they will be
discovered to have little or no impact. Depending on the results of
further study, then, EPA will decide whether information about the
higher permeability beds needs to be included in compliance
applications and if so, how much information. EPA solicits comment on
this approach.
Content of Compliance Determination Application(s)
As required by section 8(f) of the WIPP Land Withdrawal Act, DOE
must submit documentation of continued compliance every five years
after any initial certification is granted for the WIPP until the end
of the decommissioning phase, when all shafts and rooms at the WIPP are
backfilled and sealed. To avoid duplication of information already
submitted to the Administrator as part of any previous compliance
applications, EPA proposes to require that only relevant new
information be submitted as documentation of continued compliance. This
documentation must update the information contained in previous
applications and apprise the Agency of new developments regarding the
WIPP disposal system and its performance
information already
submitted to the Administrator as part of any previous compliance
applications, EPA proposes to require that only relevant new
information be submitted as documentation of continued compliance. This
documentation must update the information contained in previous
applications and apprise the Agency of new developments regarding the
WIPP disposal system and its performance. Information included in
previous applications may be summarized and referenced.
Subpart C--Compliance Certification and Determination
Subpart C sets forth general and specific requirements for
certifying and determining compliance with the provisions of the
disposal regulations found in subparts B and C of 40 CFR part 191. The
provisions of Subpart C are discussed in detail below.
General Requirements
Inspections
Today's proposal provides for EPA inspections to help ensure that
WIPP-related activities and pertinent records described in any
compliance applications are implemented as described. Inspections,
including, random, unannounced inspections of WIPP-related activities
and records, will assist EPA in assuring the validity of information
used to support compliance applications. In conducting such
inspections, EPA will comply with applicable access control measures
for security, radiological protection and personal safety, but shall
otherwise have unfettered access to WIPP-related activities and
records.
To facilitate EPA's ability to inspect as warranted, EPA is
proposing that, upon request, the Department provide the
Administrator's inspectors with rent-free office space convenient to
the WIPP disposal system. Additionally, records shall be made
immediately available to Agency inspectors where
possible, and in no circumstances shall the furnishing of records be
extended beyond 30 days from the initial request.
As an additional matter, the Agency believes that on occasion, EPA
personnel may need to conduct sampling and analysis or monitoring of
the disposal system
ient to
the WIPP disposal system. Additionally, records shall be made
immediately available to Agency inspectors where
possible, and in no circumstances shall the furnishing of records be
extended beyond 30 days from the initial request.
As an additional matter, the Agency believes that on occasion, EPA
personnel may need to conduct sampling and analysis or monitoring of
the disposal system. Such sampling may include split sampling, in which
portions of samples taken by the DOE shall be furnished to EPA for
analysis. Through split sampling, EPA can independently verify the
results of DOE analyses. Moreover, by taking such samples, EPA will be
better equipped to evaluate the quality of data being produced, as well
as gain a better understanding of the disposal system.
EPA proposes that its inspection privileges be broad enough to
allow the Agency to inspect activities that may provide information
used to support compliance application(s) and are deemed by the
Administrator or the Administrator's authorized representative to be
relevant to a compliance certification or determination. This may
include, but is not necessarily limited to, examination of quality
assurance procedures, waste characterization activities, experimental
programs, computer operations, and data collection activities, insofar
as all of these items may affect the WIPP's ability to comply with the
40 CFR part 191 disposal regulations. Significantly, under today's
proposal, EPA inspections would be limited to locations to which the
Department has rights of access but would not be limited to activities
which occur at the WIPP facility. As discussed above, if an activity
can potentially affect the WIPP's ability to comply with the Agency's
disposal regulations, it shall be subject to potential inspection by
EPA personnel. For instance, EPA may inspect WIPP-destined waste
generation and storage sites because waste characterization activities
often occur at these sites.
Quality Assurance
ies
which occur at the WIPP facility. As discussed above, if an activity
can potentially affect the WIPP's ability to comply with the Agency's
disposal regulations, it shall be subject to potential inspection by
EPA personnel. For instance, EPA may inspect WIPP-destined waste
generation and storage sites because waste characterization activities
often occur at these sites.
Quality Assurance
To help assure that calculations of compliance with 40 CFR part
191, subparts B and C, are based upon sound data and information, the
Agency proposes to include compliance criteria addressing quality
assurance (QA). EPA is proposing that the Department implement a QA
program that meets the requirements of the American Society of
Mechanical Engineer's (ASME) ``Quality Assurance Program Requirements
for Nuclear Facilities'' (NQA-1-1989 Edition), ASME's ``Quality
Assurance Requirements of Computer Software for Nuclear Facility
Applications'' (NQA-2a-1990 addenda, part 2.7 to ASME NQA-2-1989
edition), and ASME's ``Quality Assurance Program Requirements for the
Collection of Scientific and Technical Information on Site
Characterization of High-Level Nuclear Waste Repositories'' (NQA-3-1989
edition--excluding Section 2.1 (b) and (c)). EPA is proposing to use
the ASME standards referenced above because it appears they offer the
most comprehensive and specific set of QA requirements for all
compliance-related elements of the disposal system. EPA solicits
comment on whether these standards are the most appropriate to use for
this purpose.
With respect to data collected prior to the implementation of the
ASME standards, EPA is proposing that such data be acceptable for the
purpose of supporting any applications for compliance certification if
it can be demonstrated to have been collected: (1) Under a QA program
that is equivalent in scope and implementation to the NQA series, or
e the most appropriate to use for
this purpose.
With respect to data collected prior to the implementation of the
ASME standards, EPA is proposing that such data be acceptable for the
purpose of supporting any applications for compliance certification if
it can be demonstrated to have been collected: (1) Under a QA program
that is equivalent in scope and implementation to the NQA series, or
(2) through a method otherwise approved by the Administrator for use at
the WIPP. Today's proposal does not include any specific criteria
identifying how such equivalence should be demonstrated, nor is there
any specification about what the Agency will consider in approving QA
plans. The Agency intends to issue guidance on this topic in the
future.
The Agency is proposing to allow a flexible approach on quality
assurance for data collected prior to implementation of the ASME NQA
series because the Agency recognizes that unless a method exists for
qualifying such ``old data,'' the efforts in collecting such ``old
data'' will be wasted. It is likely that a large portion of the data
submitted in support of an application for certification of compliance
will be ``old data.'' To prohibit the inclusion of such data if the
data can be demonstrated to be of equivalent quality to ``new data,''
or is sufficiently reliable for approval by the Administrator, would be
unreasonable because data that are sufficiently reliable should be
included in the analysis. The Agency solicits comment on this approach
an application for certification of compliance
will be ``old data.'' To prohibit the inclusion of such data if the
data can be demonstrated to be of equivalent quality to ``new data,''
or is sufficiently reliable for approval by the Administrator, would be
unreasonable because data that are sufficiently reliable should be
included in the analysis. The Agency solicits comment on this approach.
The ASME NQA-1-1989 edition sets forth requirements for the
``establishment and execution of quality assurance programs for the
siting, design, construction, operation, and decommissioning of nuclear
facilities.''
The NQA-2(a)-1990 addenda (part 2.7) to ASME NQA-2-1989 edition
standard is directed toward establishing requirements for ``the
development, procurement, maintenance, and use of computer software, as
applied to the design, construction, operation, modification, repair,
and maintenance of nuclear facilities.'' More specifically, it applies
to computer software ``used to produce or manipulate data which is used
directly in the design, analysis, and operation of structures, systems,
and components.''
The NQA-3-1989 edition standard sets forth quality assurance
requirements for ``the collection of scientific and technical
information for site characterization of high-level nuclear waste
repositories.'' The requirements apply to ``activities which could
affect the quality of scientific and technical information collected as
part of the site characterization phase of high-level nuclear waste
repositories * * * [which include] as a minimum: (a) Readiness reviews;
for ``the collection of scientific and technical
information for site characterization of high-level nuclear waste
repositories.'' The requirements apply to ``activities which could
affect the quality of scientific and technical information collected as
part of the site characterization phase of high-level nuclear waste
repositories * * * [which include] as a minimum: (a) Readiness reviews;
(b) peer reviews; (c) data and sample management; (d) data collection
and analysis; (e) coring; (f) sampling; (g) in situ testing; and (h)
scientific investigations.''
EPA is proposing criteria which require submission of information
which demonstrates that QA programs have been established and executed
for aspects of the WIPP disposal system important to the containment of
waste in the disposal system. QA programs must address elements such as
models used to support applications for certification of compliance,
waste characterization, monitoring, field measurements, design of the
disposal system (and actions taken to ensure compliance with design
specification), use of expert judgment, and other factors important to
the containment of radionuclides in the disposal system. EPA solicits
comment on the appropriateness of the items listed above and on any
other items which should be specifically included in such a list. The
Agency also is proposing that applications for certification of
compliance address how quality indicators such as data accuracy,
precision, representativeness, completeness, comparability, and
reproducibility have been or will be achieved in the collection of
compliance data and information.
As a final matter, the Agency is proposing to conduct its own
examination of DOE QA programs and plans through select inspections,
management system reviews, and audits. This is to help assure that QA
plans are implemented appropriately.
Models and Computer Codes
pleteness, comparability, and
reproducibility have been or will be achieved in the collection of
compliance data and information.
As a final matter, the Agency is proposing to conduct its own
examination of DOE QA programs and plans through select inspections,
management system reviews, and audits. This is to help assure that QA
plans are implemented appropriately.
Models and Computer Codes
Computer models are needed to assess whether the WIPP disposal
system will comply with the 40 CFR part 191 disposal regulations. In
order for these computer models to perform their
functions with acceptable accuracy, they must be based
upon appropriate conceptual, mathematical, and numerical models.
In order to ensure that the conceptual, mathematical, numerical,
and computer models used to support compliance applications are
appropriate for use in certifying whether the WIPP complies with the
disposal regulations, EPA proposes to require that detailed information
about these models be submitted to the Agency as part of any compliance
certification applications. EPA proposes to assess the appropriateness
of the models and any computer codes used to represent them based on
the following factors: Whether conceptual models reasonably represent
the disposal system; whether mathematical models incorporate equations
and boundary conditions which reasonably represent mathematical
formulations of the conceptual models; whether numerical models provide
numerical schemes which enable mathematical models to obtain stable
solutions; whether computer models accurately implement the numerical
models (i.e., are free of coding errors and produce stable and accurate
solutions); and whether the models, data, and computer codes have been
properly peer reviewed. EPA solicits comment on these factors and
whether other factors should be included
rovide
numerical schemes which enable mathematical models to obtain stable
solutions; whether computer models accurately implement the numerical
models (i.e., are free of coding errors and produce stable and accurate
solutions); and whether the models, data, and computer codes have been
properly peer reviewed. EPA solicits comment on these factors and
whether other factors should be included. For instance, should EPA
require information which demonstrates that there is agreement between
the model results and any measured and observed data? Or, if it can be
demonstrated that models and computer codes are sufficiently
conservative, is such demonstration unnecessary?
In addition, EPA is proposing to require that the American Society
of Mechanical Engineer's NQA-2a-1990 addenda (part 2.7 to ASME NQA-2-
1989 edition) be used to help ensure that models and codes are fully
and clearly documented.
In order to determine whether the conceptual models used to support
a compliance certification application offer the best representation of
the disposal system, EPA is proposing to require a complete listing and
description of conceptual models considered but not used to support
such application. In addition, EPA is proposing to require a complete
listing of conceptual model(s) considered but not used to support
compliance certification applications, a description of such model(s),
and an explanation of the reason(s) why such model(s) was/were not
used. An examination of conceptual models requires an assessment as to
whether the theories represented in conceptual models are appropriate
and whether other theories may be more or equally appropriate. For this
reason, EPA is proposing that the DOE identify and describe all
conceptual models that the Department considered and provide
justification why some were selected and others were not
used. An examination of conceptual models requires an assessment as to
whether the theories represented in conceptual models are appropriate
and whether other theories may be more or equally appropriate. For this
reason, EPA is proposing that the DOE identify and describe all
conceptual models that the Department considered and provide
justification why some were selected and others were not. The Agency
solicits comments on this approach and on whether any particular
theories should be represented in conceptual models used to support
compliance certification applications.
EPA is proposing to require that documentation include such items
as: Descriptions of the theoretical backgrounds of each model, the
method of analysis and assessment, scenario construction, data
collection procedures, and code structures and source codes. In
addition, the Agency is proposing that user's manuals be submitted that
include the following information: discussions of the limits of
applicability of each model; detailed instructions for running the
codes including hardware and software requirements; input and output
formats with detailed explanations of each input and output variable
and parameter; listings of input and output files with a sample
computer run; reports on code verification, benchmarking, validation
and quality assurance procedures. The Agency is also proposing to
require the submission of programmer's manuals and any necessary
licenses. Programmer's manuals typically include such things as the
mathematical formulations included in the model, computational
algorithms and modeling structures.
In addition, because the WIPP disposal system is very complex, it
is likely that some of its characteristics correlate to one another. If
this correlation is not reflected in modeling efforts, then the models
may fail to portray the realities of the system and significant errors
in performance assessment results can occur
cluded in the model, computational
algorithms and modeling structures.
In addition, because the WIPP disposal system is very complex, it
is likely that some of its characteristics correlate to one another. If
this correlation is not reflected in modeling efforts, then the models
may fail to portray the realities of the system and significant errors
in performance assessment results can occur. Covariance, a measurement
of the tendency of random variables to vary together, is used to
evaluate this possibility. Therefore, EPA is proposing that information
be provided which indicates whether and how models and codes handle
covariance of model input parameters. If models do not consider
covariance, EPA would expect to be provided with an explanation of why
covariance was not considered and the potential impact of instead
treating variables independently. EPA solicits comments on this
approach and on the alternatives of (1) requiring covariance to be
included in models and codes and, (2) requiring covariance to be
included unless justification can be provided that the independent
treatment of variables would cause models to predict greater releases
than if covariance is taken into account.
Finally, EPA proposes that copies of the models and software, data
files, source codes, licenses, or other materials necessary to run the
models on EPA's own computers (or on DOE computers if EPA computers are
unable to run the models) be provided to the Agency within 30 days of a
request by the Administrator or the Administrator's authorized
representative. Additional requirements for models are covered in the
quality assurance and peer review sections of today's proposal.
Waste Characterization
materials necessary to run the
models on EPA's own computers (or on DOE computers if EPA computers are
unable to run the models) be provided to the Agency within 30 days of a
request by the Administrator or the Administrator's authorized
representative. Additional requirements for models are covered in the
quality assurance and peer review sections of today's proposal.
Waste Characterization
In order to make meaningful predictions about the performance of
the WIPP over long periods of time, it is necessary to have a good
understanding of the characteristics of the waste proposed to be
emplaced in the disposal system. The potential for releasing
radionuclides from the disposal system can be directly affected by the
chemical, radiological, and physical composition of the waste. These
factors, therefore, can affect the ability of the WIPP to comply with
the 40 CFR part 191 disposal standards and, consequently, must be
examined as part of any certification or determination of compliance.
Currently, the waste inventory to be potentially disposed of at the
WIPP consists of: (1) A large volume of stored (``existing'') waste
with varying degrees of adequacy of accompanying documentation
regarding its composition and properties; and (2) an estimated larger
volume of ``to-be-generated'' waste about which there is uncertain
knowledge of its expected composition and properties.
For the purpose of gaining a complete understanding of the waste
proposed for disposal at the WIPP, EPA is proposing to require
submittal of a detailed description of the waste's chemical, physical,
and radiological contents including a description of the activity in
curies of each radionuclide contained in such waste. Such description
shall be used in assessing compliance with subparts B and C of 40 CFR
part 191
ning a complete understanding of the waste
proposed for disposal at the WIPP, EPA is proposing to require
submittal of a detailed description of the waste's chemical, physical,
and radiological contents including a description of the activity in
curies of each radionuclide contained in such waste. Such description
shall be used in assessing compliance with subparts B and C of 40 CFR
part 191.
To identify waste characteristics important to the containment of
waste in the disposal system, EPA is proposing that DOE undertake a
study to determine the effect of various characteristics on the
performance of the disposal system. The characteristics studied shall
include, but need not be limited to: (1) waste form; (2) free liquid
content and liquid saturation; (3) pyrophoric and
explosive material content, and (4) characteristics affecting the
solubilization and mobilization of radionuclides, formation of
colloidal suspensions containing radionuclides, production of gas from
the waste, nuclear criticality, and generation of heat in the disposal
system. The impact of non-radioactive hazardous components of the waste
should also be assessed as such components have the capacity to
influence radionuclide transport. The results of this study shall be
provided to EPA along with documentation of the methodology and
information describing the importance of particular characteristics of
the waste. These results shall dictate the breadth of characterization
to be performed.
Once the waste characteristics that are important to the disposal
system's ability to isolate radionuclides have been identified, the
waste shall be categorized based on those characteristics that would be
expected to make all waste within a particular category behave
similarly in the disposal system. For example, if the curie content of
a given radionuclide in the waste is determined to be important to the
disposal system's ability to contain radionuclides, it might be used as
part of a system of categorization
ified, the
waste shall be categorized based on those characteristics that would be
expected to make all waste within a particular category behave
similarly in the disposal system. For example, if the curie content of
a given radionuclide in the waste is determined to be important to the
disposal system's ability to contain radionuclides, it might be used as
part of a system of categorization. Waste having a high curie content
of that nuclide could comprise one category, while waste having a low
curie content of that nuclide could comprise another category.
Similarly, if a given waste form is found to be important, categories
could be made for various waste forms such as sludges and solids. EPA
proposes that a detailed description shall be provided which identifies
the characteristics of each category of waste established.
A variety of methods for characterizing waste exists including
sampling and analysis, radioassay, and examination of waste generation
documentation and associated records (often referred to as ``process
knowledge''). Today's proposal does not specify any particular method
for characterizing the waste. Nevertheless, regardless of which method
or combination of methods is selected for waste characterization
activities, the Agency is proposing to require that each method be
identified and described. Moreover, the uncertainty associated with
each method shall be identified, and if information about the processes
and materials that generated the waste is used as a basis for waste
characterization, the DOE shall be required to substantiate such
characterization.
The manner in which the Agency proposes that waste characterization
shall be accomplished is explained below. The DOE will examine each
important characteristic of the waste and determine a value or range of
values for that characteristic
ses
and materials that generated the waste is used as a basis for waste
characterization, the DOE shall be required to substantiate such
characterization.
The manner in which the Agency proposes that waste characterization
shall be accomplished is explained below. The DOE will examine each
important characteristic of the waste and determine a value or range of
values for that characteristic. Since DOE must demonstrate that the
WIPP complies with the containment, individual, and ground-water
protection requirements of 40 CFR part 191 for the whole range of
values for each waste characteristic, the larger the range, the greater
the uncertainty associated with a claim that WIPP complies. DOE can
reduce the range of values for each characteristic through enhanced
information gathering until the range is small enough such that DOE is
reasonably confident that the resulting probability for compliance will
meet the containment, individual, and ground-water protection
requirements of 40 CFR part 191. Thus, DOE has a great deal of
flexibility in the amount of characterization required. However,
whatever value or range of values DOE selects for each characteristic
must be considered in compliance assessments of the WIPP. In assessing
compliance, DOE shall consider all combinations of waste
characteristics and the resulting impact on the disposal system's
behavior.
EPA is proposing that waste not be emplaced in the repository
unless its characteristics fall within the ranges of values for those
characteristics used in compliance assessments. To assure that only
waste whose characteristics fall within the given range of values is
emplaced, the Agency is proposing that a system of controls be
established, including measurements, sampling, and recordkeeping for
the waste, such that the actual characteristics of waste will be
identified before the waste is emplaced in the WIPP
or those
characteristics used in compliance assessments. To assure that only
waste whose characteristics fall within the given range of values is
emplaced, the Agency is proposing that a system of controls be
established, including measurements, sampling, and recordkeeping for
the waste, such that the actual characteristics of waste will be
identified before the waste is emplaced in the WIPP. Compliance
applications shall provide an identification and description of these
controls along with an analysis of the uncertainty associated with
them.
As a final measure to assure proper waste characterization, the
Agency is proposing that EPA audits and inspections will be used to
verify the waste characterization requirements of this part.
Future State Assumptions
Demonstrating compliance with 40 CFR part 191, subparts B and C,
involves the use of computer models based on conceptual models which
project, over an extended period of time, the transport of
radionuclides from the disposal system to the accessible environment
and resulting radiation doses to individual members of the public.
Because of the long-term nature of these evaluations, uncertainty of
values for many parameters important to the analysis may be very large.
Environmental conditions and living habits of future populations and
individuals may change in significant and unforeseeable ways over the
lengthy timeframes that will be analyzed for compliance.
In light of the difficulty of assigning appropriate values with
confidence, the Agency is proposing to specify certain assumptions
about the future for use in long-term modeling. The Agency is proposing
that, unless otherwise specified, any certification of compliance shall
assume that characteristics of the future remain what they are today.
EPA believes such an approach will enable compliance assessment to
focus on more predictable and more significant features of disposal
system performance
pecify certain assumptions
about the future for use in long-term modeling. The Agency is proposing
that, unless otherwise specified, any certification of compliance shall
assume that characteristics of the future remain what they are today.
EPA believes such an approach will enable compliance assessment to
focus on more predictable and more significant features of disposal
system performance. For instance, EPA is proposing that such an
approach not be used to characterize the long-term geologic,
hydrologic, or climatologic conditions of the system and its vicinity.
With regard to consideration of climatic conditions, the Agency is
proposing to require predictions about climate, but within a specified
framework. Specifically, EPA is proposing to limit the consideration of
climate effects to the effects of increased and decreased precipitation
on the disposal system. This would include predictions of temperature,
which affects evapotranspiration, and other factors.
With respect to human technology and behavior, EPA has tentatively
concluded that it would be fruitless to attempt any predictions about
the future that would be useful over 10,000 years. The one constant in
human history is change--in social organization, economic activity, and
technology. Thus, at first glance it seems highly anomalous to assume
that future states will be like the present. However, as noted, EPA
believes that there is no reasonable way to predict in any definitive
way what changes will take place in the future. In effect, then, EPA is
proposing to employ present conditions as default values for future
states because it has no better choices, and because this approach at
least has the advantage of providing readily ascertainable and
verifiable values.
The Agency solicits comment on its approach to future states
assumptions and the Agency's treatment of geology, hydrology, and
climate considerations. Suggestions of alternatives to the proposed
approach are also solicited.
Expert Judgment
states because it has no better choices, and because this approach at
least has the advantage of providing readily ascertainable and
verifiable values.
The Agency solicits comment on its approach to future states
assumptions and the Agency's treatment of geology, hydrology, and
climate considerations. Suggestions of alternatives to the proposed
approach are also solicited.
Expert Judgment
EPA recognizes that expert judgment may be used to support disposal
system compliance analyses. EPA is proposing that use of
expert judgment be limited to those situations where data is not
reasonably attainable through data collection or experimentation.
To assure that the Agency is aware of all cases in which expert
judgment is used, EPA is proposing that any compliance certification
application clearly identify all instances in which such judgment is
used and the names and professional affiliations of experts involved.
Moreover, documentation shall be included which describes the process
for expert judgment elicitation, the results of expert elicitation, and
the reasoning behind those results. Documentation shall also be
provided of interviews used to elicit judgments from experts,
deliberations and formal interactions among experts, background
information provided to experts, and the questions or issues presented
for elicitation of expert judgment. Access to this information will
help the Agency assess the quality and appropriateness of expert
judgment as well as DOE's interpretation and use of that judgment.
Although EPA has not specified any particular methods for expert
judgment elicitation in today's proposal, the Agency does believe that
some restrictions and guidelines for the selection of individuals for
expert judgment are appropriate
to this information will
help the Agency assess the quality and appropriateness of expert
judgment as well as DOE's interpretation and use of that judgment.
Although EPA has not specified any particular methods for expert
judgment elicitation in today's proposal, the Agency does believe that
some restrictions and guidelines for the selection of individuals for
expert judgment are appropriate. The restrictions which EPA is
proposing today include prohibitions on: selecting individuals who are
members of the team of investigators requesting the judgment or the
team of investigators who will use the judgment; selecting individuals
who maintain a supervisory role or who are supervised by (directly or
indirectly) those who will utilize the judgment; and selecting a
membership of which no more than one-third consists of individuals who
are employed directly by the Department or its contractors (unless it
can be shown that this is impracticable because of a lack or
unavailability of qualified independent experts, in which case at least
one-half of the membership must be non-DOE personnel). University
professors with grants from the Department not related to work on the
WIPP and the New Mexico Environmental Evaluation Group are not
considered employees or contractors of the Department for purposes of
this part. Additionally, compliance applications shall provide
information which demonstrates that the expertise of any individuals
involved in expert judgment is consistent with the level of knowledge
required by the question or issue presented to that individual.
Furthermore, the Agency is requiring that at least five individuals
be used in any expert elicitation process, unless a lack or
unavailability of experts can be demonstrated
ons shall provide
information which demonstrates that the expertise of any individuals
involved in expert judgment is consistent with the level of knowledge
required by the question or issue presented to that individual.
Furthermore, the Agency is requiring that at least five individuals
be used in any expert elicitation process, unless a lack or
unavailability of experts can be demonstrated. Also, any compliance
certification application shall include a discussion explaining the
relationship between the information presented, the questions asked,
the judgment of any expert panel or individual, and the purpose for
which the expert judgment is being used. The Agency is proposing all of
the above requirements to assure that expert judgment is elicited in a
manner that is as objective and informed as possible.
As a final means of helping to assure the appropriateness of expert
judgment, EPA is proposing that the elicitation process afford an
opportunity for presentation to the experts of the scientific and
technical views of outside groups and individuals. This provision is
being proposed in today's notice because the Agency believes it will
help to provide experts involved in elicitations with a fuller range of
information and view points upon which to base their judgments.
The Agency considered several different approaches to the use of
expert elicitation and concluded that though each was appropriate for a
specific type of situation, none were appropriate for all types of
situations. For example, one approach identified would require that the
average of all values elicited by an expert panel be used as the final
judgment. This may be appropriate if the issue presented to an expert
panel lends itself to meaningful averaging of values. For instance, if
an expert panel is asked to determine the rate of rainfall in the
Delaware Basin over 10,000 years, the range of answers that would be
obtained from the various experts would be expressed in numbers that
could be meaningfully averaged
used as the final
judgment. This may be appropriate if the issue presented to an expert
panel lends itself to meaningful averaging of values. For instance, if
an expert panel is asked to determine the rate of rainfall in the
Delaware Basin over 10,000 years, the range of answers that would be
obtained from the various experts would be expressed in numbers that
could be meaningfully averaged. However, if an expert panel is asked to
determine whether the possibility of a meteor hitting the WIPP site is
likely, the answers would be expressed in terms of yes or no, which
cannot be meaningfully averaged. Hence, depending on the situation,
this approach may not be appropriate.
Given the above, EPA believes that it may not be useful to specify
a particular method. However, the Agency solicits comments on
alternative approaches to incorporating the results of expert judgment
elicitations into compliance assessment.
Peer Review
Peer review is widely used as a means of validating technical data,
processes and assumptions. Peer review involves a group of experts who
are convened to review work conducted by their peers to determine
whether the work was performed appropriately and in keeping with the
purpose intended.
Since a large part of compliance applications will consist of data
and descriptions of methods for producing data, EPA believes that peer
review can be helpful as a means of validating the information
contained in such applications. Therefore, the Agency proposes that
peer review be used to support compliance applications. Specifically,
EPA proposes to require peer review of any information contained in any
compliance certification application regarding the evaluation of
engineered barriers, consideration of processes and events that may
affect the disposal system's performance, quality assurance programs
and plans, models and computer codes and including data used to support
them, and waste characterization activities
lly,
EPA proposes to require peer review of any information contained in any
compliance certification application regarding the evaluation of
engineered barriers, consideration of processes and events that may
affect the disposal system's performance, quality assurance programs
and plans, models and computer codes and including data used to support
them, and waste characterization activities. Peer review can build
additional confidence in the soundness of these important aspects of a
compliance certification.
EPA proposes that peer review be conducted in a manner which is
compatible with the Nuclear Regulatory Commission's NUREG-1297 ``Peer
Review for High-Level Nuclear Waste Repositories,'' which is
incorporated by reference in today's proposal. This document provides
guidance on the definition of peer review, the acceptability of peers,
and the conduct and documentation of peer review.
Containment Requirements
The Agency's disposal regulations found in 40 CFR part 191 include
requirements for containment of radionuclides. These containment
requirements specify numerical requirements limiting the cumulative
release of radionuclides over 10,000 years. The specific release limits
are found in Appendix A of the disposal regulations. The containment
requirements specify that there be less than one chance in ten of
cumulative releases exceeding the limits specified in Appendix A and
less than one chance in 1,000 of cumulative releases exceeding ten
times those limits.
Application of Release Limits
release of radionuclides over 10,000 years. The specific release limits
are found in Appendix A of the disposal regulations. The containment
requirements specify that there be less than one chance in ten of
cumulative releases exceeding the limits specified in Appendix A and
less than one chance in 1,000 of cumulative releases exceeding ten
times those limits.
Application of Release Limits
The containment requirements of 40 CFR part 191 specify that
releases from a disposal system to the accessible environment can not
exceed release limits set forth in Appendix A, Table 1. Information
about the curie content will be needed for calculation of the release
limits. However, because the curie content of the waste inventory will
vary over time due to natural ingrowth and decay of radionuclides, a
question arises concerning when the curie content of the
waste should be fixed for purposes of calculating the release limits.
The EPA is proposing that the expected curie activity 100 years
after disposal of the waste in the WIPP be used in calculating
applicable release limits. The Agency is proposing this approach
because EPA believes that 100 years represents a long enough period of
time for most of the radioactive material with short half-lives to
decay to low levels. The remaining activity after the 100-year period
will largely be the result of radioactivity from waste with long half-
lives. Such waste may pose the most danger to human health and the
environment and, therefore, should be the focus of attention.
The Agency solicits comment on the appropriateness of the above-
mentioned approach and on alternative time frames for fixing the curie
content.
Scope of Performance Assessments
e 100-year period
will largely be the result of radioactivity from waste with long half-
lives. Such waste may pose the most danger to human health and the
environment and, therefore, should be the focus of attention.
The Agency solicits comment on the appropriateness of the above-
mentioned approach and on alternative time frames for fixing the curie
content.
Scope of Performance Assessments
In today's notice, the Agency is proposing criteria which indicate
that performance assessments shall consider both natural and human-
initiated processes and events that may affect the disposal system.
However, EPA is also proposing that performance assessments need not
consider processes, events, or sequences of processes and events
(sometimes referred to as ``scenarios'') that have less than one chance
in 10,000 of occurring over 10,000 years.
EPA is proposing the above requirements because section 13 of 40
CFR part 191 requires the implementing agencies to evaluate compliance
through performance assessments. One method of displaying results of
performance assessments required under section 13 of 40 CFR part 191 is
to assemble ``complementary cumulative distribution functions'' (CCDF).
CCDFs are assembled by first calculating the probability of each
release scenario and associating a consequence (e.g., release of
radionuclides) with each probability. Once the paired probability and
consequence estimates are made, they are combined into the CCDF by
ranking them in the order of decreasing consequences. The first point
on the curve would represent the large consequence of a low probability
scenario. The second point on the curve would represent the probability
of the first scenario added to the probability of a second scenario
h probability. Once the paired probability and
consequence estimates are made, they are combined into the CCDF by
ranking them in the order of decreasing consequences. The first point
on the curve would represent the large consequence of a low probability
scenario. The second point on the curve would represent the probability
of the first scenario added to the probability of a second scenario.
Since the probability of scenarios occurring is cumulative, scenarios
with probabilities lower than one chance in 1,000 must be incorporated
into probability distributions assembled under section 13 of 40 CFR
part 191 to see if the results are significant with regard to
compliance assessment.
Importantly, not all scenarios considered by the Department will
necessarily be included in calculations of compliance with the 40 CFR
part 191 disposal standards. Some scenarios may be eliminated from
incorporation into performance assessments because assumptions will be
made about such scenarios which indicate that the probability or
consequences of such scenarios are outside of the scope of the
requirements of 40 CFR part 191. In an effort to understand which
scenarios were considered in performance assessments, EPA is proposing
that information be provided which identifies all potential processes,
events, or sequences of processes and events that may occur during the
regulatory time frame and that may affect the disposal system, as well
as information which identifies those processes, events, or sequences
of processes and events actually included in performance assessment
results.
Consideration of Human-Initiated Processes and Events
provided which identifies all potential processes,
events, or sequences of processes and events that may occur during the
regulatory time frame and that may affect the disposal system, as well
as information which identifies those processes, events, or sequences
of processes and events actually included in performance assessment
results.
Consideration of Human-Initiated Processes and Events
Compliance with the containment requirements of 40 CFR part 191
requires consideration of the effects of human-initiated processes and
events on the disposal system. The Agency believes that the most
productive consideration of inadvertent human-initiated processes and
events concerns those realistic possibilities that may be usefully
mitigated by disposal system design, site selection, or use of passive
institutional controls. Therefore, the Agency is proposing that
inadvertent and intermittent drilling for resources (other than those
resources provided by the waste in the disposal system or any
engineered barriers designed to isolate such waste) be the most severe
scenario for human-initiated processes and events.
Further, the Agency is limiting the consideration of human-
initiated processes and events to drilling events because mining events
were not included in EPA's analyses that supported the final rule of 40
CFR part 191 as promulgated in 1985.
The Agency has chosen to divide human-initiated processes and
events into two distinct categories, ``human intrusion'' and ``human
activity,'' and is proposing a separate process to establish the
drilling rate for each. ``Human intrusion'' includes those drilling
events that reach the level of the waste in the disposal system or
below. Such events would include, but would not be limited to,
exploration for and development of oil and natural gas resources
vents into two distinct categories, ``human intrusion'' and ``human
activity,'' and is proposing a separate process to establish the
drilling rate for each. ``Human intrusion'' includes those drilling
events that reach the level of the waste in the disposal system or
below. Such events would include, but would not be limited to,
exploration for and development of oil and natural gas resources. The
second category of human-initiated processes and events, ``human
activity,'' includes all drilling events that may affect the disposal
system, but do not reach the level of the waste in the disposal system.
Such drilling events may include, but would not be limited to,
exploration for potash, withdrawal of water--whether for purposes of
drinking, irrigating or controlling dust--and drilling for other
resources. Note that a given resource may exist at levels above and
below the level of the waste in the disposal system and may therefore
be included in establishing the rates for both human intrusion and
human activity.
EPA is proposing that consideration be given to the record of
human-initiated processes and events in the Delaware Basin over the
past 50 years. The Agency believes that the 50-year time frame is
appropriate because it represents a period during which information
regarding human-initiated processes and events in the Delaware Basin
can be reasonably obtained.
Importantly, by making assumptions about the frequency of human-
initiated processes and events in the vicinity of the WIPP and holding
them constant throughout the future, scenarios in which such events
cease because, for instance, resources eventually become depleted would
no longer be considered. However, the Agency recognizes that as one
resource becomes depleted, the decrease in exploratory or production
operations may be compensated for by the increase in drilling
operations for another
vicinity of the WIPP and holding
them constant throughout the future, scenarios in which such events
cease because, for instance, resources eventually become depleted would
no longer be considered. However, the Agency recognizes that as one
resource becomes depleted, the decrease in exploratory or production
operations may be compensated for by the increase in drilling
operations for another. Rather than engage in speculation about which
resources will become more valuable in the future, and which will
become depleted, EPA believes it is preferable to assume that current
rates of drilling for each individual resource will remain constant.
The Agency solicits comment on this approach.
As stated above, the Delaware Basin is being proposed as the area
for examination of the record of human-initiated processes and events.
The Delaware Basin is an elongated depression that extends from just
north of Carlsbad, New Mexico, southward into Texas. The Agency
solicits comment on how, precisely, the Delaware Basin should be
defined. The Agency believes that the Delaware Basin is an appropriate
region because the WIPP is situated within it and, as a region, it
represents the largest contiguous area which shares similar geologic
and hydrologic conditions with the WIPP site. However, EPA solicits
comments on whether a different area should be used (such as a subset
of the Delaware Basin).
It is important to note that the Agency is proposing to require a
separate examination of each type of human-initiated
process and event. The reason for this requirement is to account for
the fact that each type of drilling has a distinct rate and unique
properties, resulting in a different effect on the disposal system for
each type of drilling. For example, oil drilling is conducted at a
different depth, rate and with a different drilling technique than
water drilling and is, therefore, more likely to penetrate the
repository than water drilling
equirement is to account for
the fact that each type of drilling has a distinct rate and unique
properties, resulting in a different effect on the disposal system for
each type of drilling. For example, oil drilling is conducted at a
different depth, rate and with a different drilling technique than
water drilling and is, therefore, more likely to penetrate the
repository than water drilling. Accordingly, the analyses for each
resource must be conducted individually.
In assessing the consequences of human-initiated processes and
events, the Agency is proposing that such processes and events be
assumed to occur at random intervals in time and space throughout the
regulatory time frame. The consequences of each human-initiated process
and event shall be calculated in terms of the projected impact on the
WIPP disposal system. If more than one human-initiated process or event
is predicted to occur, the consequences of any processes and events
which occur subsequent to initial ones shall take into account any
impacts on the disposal system from such previous disruptions. This is
done to take into account the fact that every drilling event introduces
potential changes to the disposal system. For example, a disposal
system with man-made pathways interconnecting aquifers underlying the
disposal system with ground water above the disposal system may react
differently than a disposal system that has never been disturbed. In
other words, the cumulative consequences of all human-initiated
processes and events shall be taken into account in performance
assessment results.
For the purpose of performance assessments, the Agency is proposing
different criteria for establishing the frequency of ``human
intrusion'' and the frequency of ``human activity''. While both are
based on the historical record of resource exploration over the past 50
years in the Delaware Basin, an upper and lower limit is placed on the
rate of human intrusion
rformance
assessment results.
For the purpose of performance assessments, the Agency is proposing
different criteria for establishing the frequency of ``human
intrusion'' and the frequency of ``human activity''. While both are
based on the historical record of resource exploration over the past 50
years in the Delaware Basin, an upper and lower limit is placed on the
rate of human intrusion. The rate of human activity, however, is not
limited to a set range.
Specifically, the rate of human intrusion is determined by first
identifying and examining past occurrences of human intrusion in the
Delaware Basin over the past 50 years for all resources.
The sum of the individual rates of human intrusion for each
resource then becomes the rate of human intrusion to be used in
performance assessments, provided that the sum is not less than 25 and
not greater than 62.5 boreholes per square kilometer per 10,000 years.
In the event that the calculated total rate is less than 25, then the
rate of human intrusion to be used in performance assessments should be
adjusted upward proportionally to yield a total rate of 25 boreholes
per square kilometer per 10,000 years. Thus, if the oil drilling rate
is 8 and the natural gas drilling rate is 2, both values are adjusted
upward by a factor of 2.5 to yield a rate of 20 for oil and 5 for
natural gas. Likewise, if the calculated total rate exceeds 62.5, then
the rate of each type of human intrusion should be adjusted downward
proportionally to yield a maximum rate of 62.5 boreholes per square
kilometer per 10,000 years to be used in performance assessments.
By placing an upper and lower limit on the rate of human intrusion,
the Agency is adhering to the assumptions that the Agency made in
developing the technical basis used for formulating the containment
requirements of the final disposal regulations as promulgated in 1985
ally to yield a maximum rate of 62.5 boreholes per square
kilometer per 10,000 years to be used in performance assessments.
By placing an upper and lower limit on the rate of human intrusion,
the Agency is adhering to the assumptions that the Agency made in
developing the technical basis used for formulating the containment
requirements of the final disposal regulations as promulgated in 1985.
As part of the development of the disposal regulations, the Agency
estimated the range of future human intrusion and human activity for
the general case of a repository in bedded salt, the geologic setting
of the WIPP. Assumptions were made about the presence near a repository
of different types of resources--including oil, gas, minerals and
water--though it was assumed that the most significant resources
present would be oil and gas. Using drilling data from the contiguous
48 states as a rough guide, the Agency estimated that a region of
bedded salt would experience 25 to 62.5 boreholes per square kilometer
per 10,000 years. Because the depths at which oil and gas, the only
significant resources assumed to be present, are located typically
exceed 10,000 feet the estimated range applies only to the rate of
human intrusion. Thus, by proposing a human intrusion range of 25 to
62.5 boreholes per square kilometer per 10,000 years, the Agency is
grounding the criteria on the same basis as 40 CFR part 191. Discussion
of the assumptions as developed for the 1985 final rule of 40 CFR part
191 can be found in ``Technical Support of Standards for High-Level
Radioactive Waste Management, Volume D'' (EPA 520/4-79-007D) and
``Addendum to Volumes C and D'' (EPA 520/4-79-007E).
The Agency is proposing that, should the Department wish to forego
the process of analyzing the historical rates of human intrusion events
in the Delaware Basin, the Department shall assume the maximum rate of
62.5 boreholes per square kilometer per 10,000 years
or High-Level
Radioactive Waste Management, Volume D'' (EPA 520/4-79-007D) and
``Addendum to Volumes C and D'' (EPA 520/4-79-007E).
The Agency is proposing that, should the Department wish to forego
the process of analyzing the historical rates of human intrusion events
in the Delaware Basin, the Department shall assume the maximum rate of
62.5 boreholes per square kilometer per 10,000 years. The Agency is
further proposing that the rate of human intrusion may be reduced in
accordance with the criteria found in Sec. 194.41, active institutional
controls, and Sec. 194.43(c), passive institutional controls. A
complete discussion of reduction of the human intrusion rate can be
found in the discussion of those two portions of the criteria.
For consideration of ``human activity'' in performance assessments,
the Agency is proposing that the historical record of drilling be
examined, but without placing pre-set limits on the rates.
Specifically, the rate of human activity is determined by first
identifying and examining past occurrences of human activity in the
Delaware Basin over the past 50 years for all resources. The sum of the
individual rates for each resource then becomes the rate of human
activity to be used in performance assessment.
The Agency is placing no limits on the rate of human activity, in
contrast to the treatment of the rate of human intrusion. This
divergent treatment is consistent with the final rule of 40 CFR part
191, which was based on an estimate of 25 to 62.5 boreholes per square
kilometer per 10,000 years for the general case of a repository in
bedded salt in the vicinity of few resources other than oil and natural
gas. Because the depths at which oil and natural gas reserves are
located typically exceed 10,000 feet, the estimated range of 25 to 62.5
boreholes per square kilometer per 10,000 years applies to the case of
human intrusion only. Hence, no limit, upper or lower, is placed on the
rate of human activity
of a repository in
bedded salt in the vicinity of few resources other than oil and natural
gas. Because the depths at which oil and natural gas reserves are
located typically exceed 10,000 feet, the estimated range of 25 to 62.5
boreholes per square kilometer per 10,000 years applies to the case of
human intrusion only. Hence, no limit, upper or lower, is placed on the
rate of human activity.
The Agency recognizes that for some resources such as water, the
use of that resource may depend upon the quality of the specific
reservoir of that resource that is being exploited. A given reservoir
of water, for example, may not be of potable quality but may still be
usefully withdrawn for controlling dust. Therefore it may be possible
to show that certain resources found within the controlled area differ
in quality from the same resource as found in rest of the Delaware
Basin. For such resources, it could potentially be demonstrated that
the resource would normally be exploited for different purposes at a
different rate within the controlled area, and further that there is
reason to believe that such practices would continue. The Agency is
proposing that if such a case can be made in compliance applications,
then when examining the historical record of human activity associated
with that resource, only that human activity that has been associated
with resources of quality similar to that found within the
controlled area need be considered. Consider a
hypothetical example in which the water resources in the controlled
area were found not to be of potable quality, and this were
demonstrated and documented in the application for certification of
compliance. Then, when examining the history of drilling for water in
the Delaware Basin, the Department would need only consider boreholes
created for water uses other than drinking, e.g., irrigation and
control of dust.
The Agency is further proposing that the rate of human activity may
be reduced in accordance with the criteria found in Sec
cumented in the application for certification of
compliance. Then, when examining the history of drilling for water in
the Delaware Basin, the Department would need only consider boreholes
created for water uses other than drinking, e.g., irrigation and
control of dust.
The Agency is further proposing that the rate of human activity may
be reduced in accordance with the criteria found in Sec. 194.41, active
institutional controls, and in Sec. 194.43(c), passive institutional
controls. A complete discussion of reduction of the human activity rate
can be found under the discussion of those two portions of the
criteria.
In assessing the consequences of human-initiated processes and
events, the Agency is proposing that assumptions pertaining to
characteristics of such processes and events be based on
characteristics associated with current practice in the Delaware Basin.
This approach is consistent with the approach the Agency is proposing
for future state assumptions. For example, assumptions related to the
type and amount of any drilling fluids, borehole depths, diameters, and
seals should be assumed to remain consistent with the current practice
in the Delaware Basin. For the specific case of borehole seals, EPA is
further proposing that boreholes shall be assumed to be sealed at the
rate boreholes have been sealed over the past 50 years in the Delaware
Basin and that natural processes will degrade or otherwise affect the
permeability of boreholes over the regulatory time frame.
The Agency has chosen in today's proposal to differ from the
Appendix C ``Guidance for Implementation'' which accompanied 40 CFR
part 191 because EPA believes that the approach outlined above for
assessing the likelihood and consequences of human-initiated processes
and events is more appropriate for the WIPP than the method discussed
in the guidance. Today's proposal is specific to the WIPP; the
guidance, on the other hand, is generic
differ from the
Appendix C ``Guidance for Implementation'' which accompanied 40 CFR
part 191 because EPA believes that the approach outlined above for
assessing the likelihood and consequences of human-initiated processes
and events is more appropriate for the WIPP than the method discussed
in the guidance. Today's proposal is specific to the WIPP; the
guidance, on the other hand, is generic. Moreover, the guidance only
took into account drilling frequencies for oil and gas. The Agency
believes that other human activities, such as drilling for potash and
drilling for water, are equally important for consideration at the
WIPP, as they too have the potential to affect the disposal system.
Therefore, today's proposal requires consideration of all human actions
that could affect a waste disposal system. However, the Agency solicits
comment on its proposed approach and the appropriateness of differing
from the Appendix C guidance.
Results of Performance Assessments
The Agency proposes to establish criteria for assessing the results
of performance assessments required under the containment requirements
of 40 CFR part 191. The Agency is proposing to require that the results
of performance assessments be displayed as complementary cumulative
distribution functions or ``CCDFs.'' These CCDFs would display the
releases of radionuclides over 10,000 years after disposal--summed and
normalized according to Table 1, Note 6 of 40 CFR part 191--on the
horizontal axis and the probability of releases occurring on the
vertical axis.
In conducting performance assessments, there will be many parameter
values that can affect the results of such assessments. For instance,
gas generation by the waste, radionuclide solubilities, permeability of
the host rock, and the porosity and transmissivity of surrounding
aquifers entail parameter values that can affect the results of such
performance assessments. These values may be difficult to quantify
particularly over a 10,000-year period
y parameter
values that can affect the results of such assessments. For instance,
gas generation by the waste, radionuclide solubilities, permeability of
the host rock, and the porosity and transmissivity of surrounding
aquifers entail parameter values that can affect the results of such
performance assessments. These values may be difficult to quantify
particularly over a 10,000-year period. Therefore, the Agency is
proposing to require the development of probability distributions for
parameter values in order to represent the probability of different
values of the parameter occurring.
The Agency is further proposing to require that, in generating
CCDFs, computational techniques be developed that sample randomly
across the full range of probability distributions developed for
uncertain disposal system parameter values used in performance
assessments. In so doing, it is possible to convey the influence of
parameter uncertainty upon the resulting CCDFs. Random sampling
techniques can select a predetermined number of values from a
parameter's probability distribution, the collection of which will
represent the range of the distribution in successive stages of
calculation.
The Agency is proposing to require that the entire range or
``family'' of CCDFs generated as a result of these sampling techniques
be included in compliance applications. By requiring that all CCDFs be
submitted, the Agency can evaluate whether given the conditions that
exist at the disposal system, the disposal system could fail to comply
with section 13 of 40 CFR part 191 in some of the CCDFs. By noting the
number of total CCDFs generated that fail to comply, the Agency will
gain insight into the performance of the disposal system over the
10,000-year time frame.
The Agency is proposing to place statistical criteria on the number
of CCDFs generated
that
exist at the disposal system, the disposal system could fail to comply
with section 13 of 40 CFR part 191 in some of the CCDFs. By noting the
number of total CCDFs generated that fail to comply, the Agency will
gain insight into the performance of the disposal system over the
10,000-year time frame.
The Agency is proposing to place statistical criteria on the number
of CCDFs generated. The Agency is proposing to require that the number
of CCDFs generated be large enough such that the maximum CCDF generated
exceeds the 99th percentile of the population of CCDFs with at least a
0.95 probability. A 95% confidence level is commonly recognized as
being a good indicator of statistical acceptability. The Agency
believes that the effect of this approach will be that the number of
CCDFs generated will be large enough to ensure that a full range of
realizations have been generated. EPA estimates that this will require
several hundred realizations, although the number submitted in
compliance with this requirement may ultimately be larger or smaller.
The Agency is proposing to require that the mean CCDF of the
population of CCDFs meets the requirements of section 13(a) of 40 CFR
part 191 with at least a 95 percent level of statistical confidence.
The mean CCDF is calculated from a ``family'' of CCDFs whose parameters
have an associated uncertainty to them, as discussed above. As a
result, the mean will have its own associated uncertainty. This
uncertainty around the location of the mean reduces the level of
assurance with which we can state that the mean CCDF is in compliance
with section 13 of 40 CFR part 191. One way of attaining statistical
confidence in the mean is to determine how reproducible the mean is if
recalculated. For example, first generate an ensemble of a certain
number of CCDFs and calculate the mean. Next, generate an entirely new
ensemble of the same number of CCDFs and compare the mean calculated
for this new set to that of the first set
iance
with section 13 of 40 CFR part 191. One way of attaining statistical
confidence in the mean is to determine how reproducible the mean is if
recalculated. For example, first generate an ensemble of a certain
number of CCDFs and calculate the mean. Next, generate an entirely new
ensemble of the same number of CCDFs and compare the mean calculated
for this new set to that of the first set. If the number of CCDFs
generated is a statistically representative portion of the infinite
population of CCDFs, then the two calculated means will likely agree.
By placing a statistical confidence requirement on the mean of the
CCDFs, the Agency hopes to ensure that a mean that is in compliance
would upon recalculation from a new ensemble of CCDFs, still be in
compliance. The Agency is proposing to require a 95 percent level of
statistical confidence that the mean meets the requirements but
solicits comment on other levels of confidence which may be more
appropriate.
Before selecting the mean as the compliance indicator, the Agency
examined three options. The first option, the mean CCDF
or expected value, was selected because of its ability to convey a
sense of the whole ensemble of CCDFs generated. In calculating the
mean, all CCDFs--those representing best case results, those
representing worst case results, and everything in between--are
included. Since it cannot be known which CCDF represents actual
performance over the 10,000 year regulatory period, it is deemed wise
to include the influence of all generated CCDFs.
The Agency also examined the median CCDF. The median CCDF would be
indicative of the central tendency of the majority of the CCDFs and
would not exhibit the influence of high or low consequence CCDFs as
strongly as the mean CCDF. Specifically, the influence of high
consequence CCDFs that do not meet the requirements of section 13(a) of
40 CFR part 191 would be discounted by the median. In the Agency's
view, this makes the median CCDF less suitable as a compliance
indicator
e central tendency of the majority of the CCDFs and
would not exhibit the influence of high or low consequence CCDFs as
strongly as the mean CCDF. Specifically, the influence of high
consequence CCDFs that do not meet the requirements of section 13(a) of
40 CFR part 191 would be discounted by the median. In the Agency's
view, this makes the median CCDF less suitable as a compliance
indicator.
The Agency also examined the possibility of using a percentile
value as a compliance indicator. The Agency has considered and rejected
percentile values at or below 50 on grounds that such values would not
provide adequate confidence of achieving the desired protection of
public health. As for higher values, the Agency believes that it would
be extremely difficult to justify any specific higher value.
The Agency solicits comment on the appropriateness of the mean or
some other CCDF as a basis for compliance. The Agency solicits comments
on using some possible combination of CCDFs as a basis for compliance;
e.g., requiring that the mean and the median meet the requirements of
section 13(a) of 40 CFR part 191.
Another issue upon which the Agency solicits comment is on the
alternative of basing compliance on one single realization, rather than
on a multitude of them as discussed above and then using that
realization to determine compliance with the containment requirements.
Instead of sampling from a given range of variables for each parameter
and generating a new realization curve each time this is done, it has
been suggested that all possible values for each parameter should be
selected in creating a single curve. In this way, all the information
is folded into one realization which either complies or does not. The
advantage in this technique is that the issue of the appropriateness of
the mean, median, or other percentile is obviated. The disadvantage is
that it is difficult to see exactly which parameters caused the curve
to behave in a particular way
r should be
selected in creating a single curve. In this way, all the information
is folded into one realization which either complies or does not. The
advantage in this technique is that the issue of the appropriateness of
the mean, median, or other percentile is obviated. The disadvantage is
that it is difficult to see exactly which parameters caused the curve
to behave in a particular way.
Regardless of the method ultimately used to determine compliance
with the numerical requirements of section 13 of 40 CFR part 191, a
``reasonable expectation of compliance'' with the containment
requirements cannot be achieved until a demonstration has been made
that the qualitative requirements set forth in sections 21 through 27
of today's proposal have also been met. A ``reasonable expectation of
compliance'' with the containment requirements shall not be based
solely upon a statistical estimate of radionuclide releases to the
accessible environment. Instead, the Agency will consider the full
record of information submitted in compliance applications and will
examine the methods and assumptions which were used to support the
development of radionuclide release estimates. For example, the EPA
will consider such factors as the reasonableness of the processes and
events incorporated into performance assessments, the appropriateness
of any expert elicitation used to provide input to models, the adequacy
of peer review, and the quality of other data inputs. Only after a
demonstration has been made that all of the requirements set forth in
sections 21 through 27 of today's proposal have been met and that the
numerical requirements of section 13 of 40 CFR part 191 have been
satisfied, will a ``reasonable expectation'' of compliance with the
containment requirements be achieved.
Assurance Requirements
review, and the quality of other data inputs. Only after a
demonstration has been made that all of the requirements set forth in
sections 21 through 27 of today's proposal have been met and that the
numerical requirements of section 13 of 40 CFR part 191 have been
satisfied, will a ``reasonable expectation'' of compliance with the
containment requirements be achieved.
Assurance Requirements
In addition to the numerical requirements set forth in the Agency's
radioactive waste disposal standards, section 14 of the standards
contains a set of qualitative requirements to help assure that the
desired level of protection is achieved. These assurance requirements
address: (1) Active institutional controls; (2) monitoring; (3) passive
institutional controls; (4) engineered barriers; (5) consideration of
the presence of resources; and (6) removal of waste.
Active Institutional Controls
According to the disposal standards:
Active institutional controls over disposal sites should be
maintained for as long a period of time as is practicable after
disposal; however, performance assessments that assess the isolation
of the wastes from the accessible environment shall not consider any
contributions from active institutional controls for more than 100
years after disposal.
As defined in 40 CFR part 191, ``active institutional control''
means: ``(1) Controlling access to a disposal site by any means other
than passive institutional controls; (2) performing maintenance
operations or remedial actions at a site; (3) controlling or cleaning
up releases from a site; or (4) monitoring parameters related to
disposal system performance.''
With the above requirements in mind, today's proposal requires that
any application for certification of compliance contain detailed
descriptions of proposed active institutional controls, their location
and the period of time they are proposed to remain active
a site; (3) controlling or cleaning
up releases from a site; or (4) monitoring parameters related to
disposal system performance.''
With the above requirements in mind, today's proposal requires that
any application for certification of compliance contain detailed
descriptions of proposed active institutional controls, their location
and the period of time they are proposed to remain active. Any credit
assumed for reduced human activity in the vicinity of the WIPP or
reduced releases of radionuclides must be supported by such
descriptions but, as indicated in the disposal standards, in no case
shall it be assumed that active institutional controls will be
effective in preventing or reducing releases beyond 100 years after
disposal.
Monitoring
Since the predictions associated with long-term compliance with the
disposal standards of 40 CFR part 191 are inherently uncertain, final
disposal standards issued in 1985 included a provision requiring
monitoring of disposal systems to help assure that they are performing
as predicted. The proposed disposal standards issued in 1982 had not
included such a requirement. However, several commenters (including
most of the States) urged addition of a requirement for long-term
monitoring of a repository after disposal to guard against unexpected
failures. Accordingly, further information was sought on this idea. The
Agency surveyed the capabilities and expectations of long-term
monitoring approaches. As explained in the preamble to the 1985
disposal standards (50 FR 38081, September 19, 1985):
Evaluating this information led the Agency to several
conclusions:
(1) Perhaps most importantly, the techniques used for monitoring
after disposal must not jeopardize the long-term isolation
capabilities of the disposal system. Furthermore, plans to conduct
monitoring after disposal should never become an excuse to relax the
care with which systems to isolate these wastes must be selected,
designed, constructed, and operated.
Agency to several
conclusions:
(1) Perhaps most importantly, the techniques used for monitoring
after disposal must not jeopardize the long-term isolation
capabilities of the disposal system. Furthermore, plans to conduct
monitoring after disposal should never become an excuse to relax the
care with which systems to isolate these wastes must be selected,
designed, constructed, and operated.
(2) Monitoring for radionuclide releases to the accessible
environment is not likely to be productive. Even a poorly performing
geologic repository is very unlikely to allow measurable releases to
the accessible environment for several hundreds of years or more,
particularly in view of the engineered controls needed to comply
with 10 CFR Part 60. A monitoring system based only on
detecting radionuclide releases--a system which would
almost certainly not be detecting anything for several times the
history of the United States--is not likely to be maintained for
long enough to be of much use.
(3) Within the above constraints, however, there are likely to
be monitoring approaches which may, in a relatively short time,
significantly improve confidence that a repository is performing as
intended. Two examples are of particular interest. One involves the
concept of monitoring ground-water sources at a variety of distances
for benign tracers intentionally released to the ground water in the
repository; this approach can evaluate the delay involved in ground-
water movement from the repository to the environment and can serve
to validate expectations of the performance expected from the
system's natural barriers. Another concept involves monitoring the
small uplift of the land surface over the repository in order to
validate predictions of the system's thermal behavior. Both of these
approaches can be carried out without enhancing pathways for the
wastes to escape from the repository.
he environment and can serve
to validate expectations of the performance expected from the
system's natural barriers. Another concept involves monitoring the
small uplift of the land surface over the repository in order to
validate predictions of the system's thermal behavior. Both of these
approaches can be carried out without enhancing pathways for the
wastes to escape from the repository.
Based on these conclusions and the public comments on this
question, the Agency included a provision (in the assurance
requirements of the final disposal standards) for long-term monitoring
after disposal: ``Disposal systems shall be monitored after disposal to
detect substantial and detrimental deviations from expected
performance. This monitoring shall be done with techniques that do not
jeopardize the isolation of the wastes and shall be conducted until
there are no significant concerns to be addressed by further
monitoring.''
Accordingly, EPA is proposing criteria for complying with the
monitoring requirements in the disposal standards. EPA is proposing
that monitoring programs be designed to detect the movement of
radionuclides toward the accessible environment at the earliest
practicable time. Such monitoring programs shall be consistent with
monitoring required under applicable federal hazardous waste
regulations and shall be done with techniques that do not jeopardize
the containment of waste in the disposal system. Due to the long-term
nature of the potential hazard associated with disposal of transuranic
radioactive waste, any unpredicted detection of movement of
radionuclides away from the disposal system and toward the accessible
environment would be cause for concern that an exceedance of what is
permitted under the disposal regulations is likely to occur. If
releases are detected early enough, remedial action can be implemented
before radionuclides reach the accessible environment
uranic
radioactive waste, any unpredicted detection of movement of
radionuclides away from the disposal system and toward the accessible
environment would be cause for concern that an exceedance of what is
permitted under the disposal regulations is likely to occur. If
releases are detected early enough, remedial action can be implemented
before radionuclides reach the accessible environment.
EPA is proposing in today's criteria that any compliance
certification application include a detailed plan for monitoring the
performance of the WIPP after disposal. At a minimum, this plan shall:
Identify parameters that will be monitored and how baseline states will
be determined; indicate how each parameter will be used to evaluate the
performance of the disposal system; and discuss the length of time over
which each parameter will be monitored to detect deviations from
expected performance. Radionuclide monitoring programs should be
consistent with applicable federal hazardous waste monitoring programs
in order to minimize duplication of monitoring efforts. The Agency
solicits comments on this approach.
In addition to monitoring after closure of the disposal system
(i.e., when all of the shafts to the repository are backfilled and
sealed), EPA proposes that, to the extent practicable, pre-closure
monitoring of parameters which may affect the long-term performance of
the disposal system after closure shall also be conducted. The Agency
believes that such monitoring can provide important information about
the disposal system and that such information can contribute to a
better understanding of how the disposal system is likely to perform
after closure. Furthermore, such information can be used to verify
assumptions (about the disposal system) which form the basis of a
compliance assessment
hall also be conducted. The Agency
believes that such monitoring can provide important information about
the disposal system and that such information can contribute to a
better understanding of how the disposal system is likely to perform
after closure. Furthermore, such information can be used to verify
assumptions (about the disposal system) which form the basis of a
compliance assessment.
The Agency is proposing to require that, as a part of the pre-
closure monitoring plan for the WIPP, monitoring of parameters which
can affect the containment of waste in the disposal system shall be
conducted to the extent practicable. The Agency believes that the
following parameters can affect the containment capability of the WIPP:
Brine quantity, flux, composition, and spatial distribution; gas
quantity and composition; and temperature distribution. Since there may
be additional disposal system parameters important to the containment
of waste, EPA is proposing that DOE undertake a study to determine the
effect of various disposal system parameters on the performance of the
disposal system. Such study shall consider whether a disposal system
parameter should be monitored because the parameter either provides
information regarding the disposal system's ability to contain waste or
regarding the ability to predict the future performance of the disposal
system. The parameters studied shall include, but need not be limited
to: Backfilled mechanical state including porosity, permeability, and
degree of compaction and reconsolidation; extent of deformation of the
surrounding roof, walls, and floor of the disposal room; and initiation
or displacement of major brittle deformation features in the roof or
surrounding rock. The results of the study shall be provided to EPA
along with documentation of the methodology and information describing
the importance of each disposal system parameter studied. The results
of such study shall dictate the breadth of monitoring of disposal
system parameters
he disposal room; and initiation
or displacement of major brittle deformation features in the roof or
surrounding rock. The results of the study shall be provided to EPA
along with documentation of the methodology and information describing
the importance of each disposal system parameter studied. The results
of such study shall dictate the breadth of monitoring of disposal
system parameters.
The parameters specifically mentioned above and in the proposed
criteria were identified as important to the containment capability of
the WIPP by the Agency in its comments to the Department (dated October
19, 1989) regarding the Test Phase Plan for the WIPP. In those
comments, EPA recommended that the Department implement monitoring
systems in disposal rooms that would be ``indicative of waste system
performance'' (Recommendation 7). In response to EPA's comments, the
DOE agreed to conduct a feasibility study on underground monitoring of
the WIPP.
EPA solicits comment on whether monitoring should be required for
the specific parameters listed above, on whether additional or other
parameters should be specified, and on the feasibility of continuing
such monitoring after disposal (i.e., after the repository has been
backfilled and sealed). Additionally, the Agency solicits comment on
whether EPA should require the use of specific monitoring methods.
Passive Institutional Controls
The assurance requirements of 40 CFR part 191 require that
``disposal systems shall be designated by the most permanent markers,
records, and other passive institutional controls practicable to
indicate the dangers of the wastes and their location.'' Section 14(c)
of 40 CFR part 191
comment on
whether EPA should require the use of specific monitoring methods.
Passive Institutional Controls
The assurance requirements of 40 CFR part 191 require that
``disposal systems shall be designated by the most permanent markers,
records, and other passive institutional controls practicable to
indicate the dangers of the wastes and their location.'' Section 14(c)
of 40 CFR part 191. The standards define ``passive institutional
controls'' as ``(1) permanent markers placed at a disposal site, (2)
public records and archives, (3) government ownership and regulations
regarding land or resource use, and (4) other methods of preserving
knowledge about the location, design and contents of a disposal
system.''
In light of the requirement for use of passive institutional
controls set forth in 40 CFR part 191, the Agency is proposing that any
application for certification of compliance include detailed
descriptions of the measures that will be employed to preserve
knowledge about the location, design, and contents of the
disposal system. At a minimum, it is proposed that such measures will
include: (1) Identification of the controlled area by markers that have
been designed, fabricated and emplaced to be as permanent as
practicable; and (2) placement of records in the archives and land
record systems of local, state, and Federal Government agencies, and
international archives, that would be likely to be consulted by
individuals in search of unexploited resources
measures will
include: (1) Identification of the controlled area by markers that have
been designed, fabricated and emplaced to be as permanent as
practicable; and (2) placement of records in the archives and land
record systems of local, state, and Federal Government agencies, and
international archives, that would be likely to be consulted by
individuals in search of unexploited resources.
The Agency proposes that the type of information contained in
records shall include: The location of the controlled area and the
disposal system; the design of the disposal system; the nature and
hazard of the waste; geologic, geochemical, hydrologic, other site data
pertinent to the containment of waste in the disposal system, and the
results of tests, experiments, and other analyses relating to backfill
of excavated areas, shaft sealing, waste interaction with the disposal
system, and any other tests, experiments, or analyses pertinent to the
containment of waste in the disposal system. EPA solicits comments on
the appropriateness of this list and on whether additional or other
items should be specified. Any application for certification of
compliance shall include detailed descriptions of the proposed controls
as well as information regarding the period of time those controls are
expected to endure and be understood.
A question arises with regard to the extent to which the Agency
should allow performance assessments to consider contributions from
passive institutional controls in reducing the likelihood of human-
initiated processes and events that may affect the disposal system.
While the disposal regulations address contributions from active
institutional controls (see above discussion of active institutional
controls), they do not specifically address contributions from passive
institutional controls
to consider contributions from
passive institutional controls in reducing the likelihood of human-
initiated processes and events that may affect the disposal system.
While the disposal regulations address contributions from active
institutional controls (see above discussion of active institutional
controls), they do not specifically address contributions from passive
institutional controls. The Agency may be willing to consider such
contributions if a persuasive case can be made that the passive
institutional controls can be expected to endure and act as a deterrent
to potential intruders. In no instance, however, will passive
institutional controls be assumed to eliminate the likelihood of human-
initiated processes and events entirely. Furthermore, contributions
from passive institutional controls may vary over time. For example,
the effectiveness of passive institutional controls may decrease over
the regulatory time frame. The Agency solicits comment on the extent--
if any--to which contributions from passive institutional controls
should be considered in performance assessments.
Because of the uncertainty concerning the effectiveness of passive
institutional controls in terms of influencing human activity, EPA must
carefully scrutinize information about such controls. The Agency has
considered the fact that markers exist in the world today that are
thousands of years old. This would tend to support the view that
passive institutional controls can survive for very long periods of
time. Nevertheless, it is possible that markers have been created in
the past and were destroyed or disintegrated. The actual percentage of
surviving markers is thus unknown. It could be very small, meaning that
an unrealistically large number of markers would have to be placed at
the WIPP in order to assure survival. Further uncertainty in the
effectiveness of markers derives from the possibility that even if
markers survive, it does not mean they will necessarily be understood
by future generations
ed. The actual percentage of
surviving markers is thus unknown. It could be very small, meaning that
an unrealistically large number of markers would have to be placed at
the WIPP in order to assure survival. Further uncertainty in the
effectiveness of markers derives from the possibility that even if
markers survive, it does not mean they will necessarily be understood
by future generations.
Institutional controls have been known to fail. The New Mexico
Environmental Evaluation Group (EEG) has documented instances in the
recent past where institutional controls have failed at the WIPP.
According to EEG, both the DOE and the Department of the Interior's
Bureau of Land Management ``failed to implement the procedures
described by the DOE as crucial to protecting the site from inadvertent
human intrusion in twenty-two of the twenty-five applications to drill
oil and gas wells filed while a Memorandum of Understanding was legally
binding and the WIPP facility was in a state of full readiness to
receive waste.'' (EEG letter to EPA dated February 23, 1994). This
indicates that even today, and even with governmental entities
responsible for implementation of controls, such controls are not,
necessarily, reliable. The unknown nature of future societies and
governmental institutions compounds the uncertainty.
Engineered Barriers
The assurance requirements of 40 CFR part 191 require that disposal
systems ``use different types of barriers to isolate the wastes from
the accessible environment.'' Additionally, the disposal standards
mandate that ``Both engineered and natural barriers shall be used.'' 40
CFR part 191 defines the term ``barrier'' as ``any material or
structure that prevents or substantially delays movement of water or
radionuclides toward the accessible environment
sposal
systems ``use different types of barriers to isolate the wastes from
the accessible environment.'' Additionally, the disposal standards
mandate that ``Both engineered and natural barriers shall be used.'' 40
CFR part 191 defines the term ``barrier'' as ``any material or
structure that prevents or substantially delays movement of water or
radionuclides toward the accessible environment. For example, a barrier
may be a geologic structure, a canister, a waste form with physical and
chemical characteristics that significantly decrease the mobility of
radionuclides, or a material placed over and around waste, provided
that the material or structure substantially delays movement of water
or radionuclides.''
If selected and designed properly, engineered barriers can
significantly reduce the potential for waste migration away from the
disposal system. They can be an effective mechanism for improving the
performance of the WIPP and for reducing the uncertainty inherent in
long-term projections about the ability of the disposal system to
comply with the quantitative requirements of 40 CFR part 191.
While the disposal standards require use of engineered barriers,
they do not specify how many or what kinds of engineered barriers must
be used. The Agency is, therefore, proposing criteria for selecting
engineered barriers.
In today's notice, EPA is proposing that DOE complete a study of
engineered barrier alternatives and their benefits and costs. The
results of such study shall be used to justify both the selection and
rejection of engineered barriers at the WIPP. Moreover, the study shall
be peer reviewed. For example, EPA believes that the National Academy
of Sciences may be able to provide an appropriate forum for peer review
of the study envisioned in today's proposed criteria. The Agency
believes that the credibility of the study of engineered barrier
alternatives and resulting selection of engineered barriers for the
WIPP disposal system is critically important
udy shall
be peer reviewed. For example, EPA believes that the National Academy
of Sciences may be able to provide an appropriate forum for peer review
of the study envisioned in today's proposed criteria. The Agency
believes that the credibility of the study of engineered barrier
alternatives and resulting selection of engineered barriers for the
WIPP disposal system is critically important.
The specific engineered barriers proposed to be evaluated include,
but are not limited to: Cementation, shredding, supercompaction,
incineration, vitrification, improved waste canisters, grout and
bentonite backfill, melting of metals, alternative configurations of
waste placements in the disposal system, and alternative disposal
system dimensions. These specific engineered barriers were selected by
the Agency because they have already begun to be considered by DOE's
Engineered Alternatives Task Force (EATF) (see July, 1991 EATF Report
on Engineered Alternatives for the WIPP, DOE/WIPP 91-007) and appear to
represent potentially promising alternatives. EPA solicits comment on
the appropriateness of specifying the above-mentioned engineered
barriers as the subject of the study and on whether alternative
barriers should be specified.
The Agency is proposing that the following factors be considered in
benefit/cost analysis of the above-mentioned engineered barriers: the
ability of the engineered barrier to prevent or
substantially delay the movement of water or radionuclides toward the
accessible environment; the impact on worker exposures to radiation (at
the WIPP and off-site) both during and after incorporation of
engineered barriers; the increased ease or difficulty in removing the
waste from the disposal system; the increased or reduced risk of
transporting the waste to the disposal system; the increased or reduced
uncertainty in compliance assessment; the increased or reduced public
confidence in the performance of the disposal system; the increased or
reduced total system costs; the impact,
on of
engineered barriers; the increased ease or difficulty in removing the
waste from the disposal system; the increased or reduced risk of
transporting the waste to the disposal system; the increased or reduced
uncertainty in compliance assessment; the increased or reduced public
confidence in the performance of the disposal system; the increased or
reduced total system costs; the impact, if any, on other waste disposal
programs from the incorporation of engineered barriers; and the effect
on mitigating the consequences of human-initiated processes and events.
It would be inappropriate to limit the study only to the impact of
engineered barriers on the performance of the WIPP. If this were done,
the possibility would exist that an engineered barrier may be selected,
for example, which marginally improves the disposal system's
performance, yet results in much higher environmental risks at
treatment sites. This increase in risk would contravene the Agency's
objective of protecting human health and the environment. EPA solicits
comment on this approach to selecting engineered barriers and on
whether an alternative list of factors should be specified for
consideration.
The Agency proposes that the benefit/cost study described above
include separate analyses for different categories of waste potentially
destined for disposal at the WIPP. The Agency believes that benefits
and costs of engineered barriers can differ depending on whether they
are applied to existing waste that is already packaged, existing waste
that is not yet packaged or is in need of repackaging, or to-be-
generated waste. Therefore, the Agency is proposing that these
different categories of waste be analyzed separately.
Finally, EPA is proposing that engineered barrier alternatives be
considered both alone and in combination. In this way, assurance can be
had that the full range of alternative applications of engineered
barrier systems has been considered
r is in need of repackaging, or to-be-
generated waste. Therefore, the Agency is proposing that these
different categories of waste be analyzed separately.
Finally, EPA is proposing that engineered barrier alternatives be
considered both alone and in combination. In this way, assurance can be
had that the full range of alternative applications of engineered
barrier systems has been considered.
Importantly, today's proposal requires the results of the benefit/
cost study to be included in any compliance application and for the
results to be used to justify the selection or rejection of any
engineered barrier. This will help the Agency understand why particular
barriers were selected while others were not, as well as help the
Agency to evaluate the appropriateness of such selections.
The Agency solicits comments on other potential approaches to the
treatment of engineered barriers in the WIPP compliance criteria. In
particular, the Agency is interested in receiving comment on the option
of specifying a performance standard for engineered barriers similar to
that specified by the Nuclear Regulatory Commission in 10 CFR part 60
regulations for disposal of high-level radioactive waste. Under this
approach, a maximum radionuclide release rate would be established for
the engineered barrier system. Engineered barriers selected for the
disposal system would have to contain radionuclide releases within the
established rate.
Consideration of the Presence of Resources
by the Nuclear Regulatory Commission in 10 CFR part 60
regulations for disposal of high-level radioactive waste. Under this
approach, a maximum radionuclide release rate would be established for
the engineered barrier system. Engineered barriers selected for the
disposal system would have to contain radionuclide releases within the
established rate.
Consideration of the Presence of Resources
Section 14 of 40 CFR part 191 includes the following requirement:
``Places where there has been mining for resources, or where there is a
reasonable expectation of exploration for scarce or easily accessible
resources, or where there is a significant concentration of any
material that is not widely available from other sources, should be
avoided in selecting disposal sites. Resources to be considered shall
include minerals, petroleum or natural gas, valuable geologic
formations, and ground waters that are either irreplaceable because
there is no alternative source of drinking water available for
substantial populations or that are vital to the preservation of unique
and sensitive ecosystems. Such places shall not be used for disposal of
the wastes covered by this part unless the favorable characteristics of
such places compensate for their greater likelihood of being disturbed
in the future.''
EPA is proposing that any application for certification of
compliance shall include information which demonstrates that the
favorable characteristics of the WIPP compensate for the presence of
resources and the likelihood of human-initiated processes and events as
a result of the presence of those resources. If, after full
consideration of the potential effects of resource recovery activities
the WIPP is still predicted to meet the requirements of 40 CFR part
191, then the Agency will assume that the requirements of this part and
section 14(e) of 40 CFR part 191 have been fulfilled. The Agency
solicits comment on this approach.
Removal of Waste
ts as
a result of the presence of those resources. If, after full
consideration of the potential effects of resource recovery activities
the WIPP is still predicted to meet the requirements of 40 CFR part
191, then the Agency will assume that the requirements of this part and
section 14(e) of 40 CFR part 191 have been fulfilled. The Agency
solicits comment on this approach.
Removal of Waste
Another assurance requirement included in the 40 CFR part 191
disposal standards involves the removal of waste from the disposal
system. Specifically, 40 CFR part 191 mandates that: ``Disposal systems
shall be selected so that removal of most of the wastes is not
precluded for a reasonable period of time after disposal.'' In order to
address this requirement, EPA is proposing criteria to require a plan
for removing waste from the disposal system using the best technology
available at the time of application.
Individual and Ground-Water Protection Requirements
The Agency incorporated requirements in 40 CFR part 191 for the
protection of individuals and ground-water. The individual protection
requirements of 40 CFR part 191 limit annual committed effective doses
of radiation to members of the public to no more than 15 millirem. The
ground-water protection requirements limit releases to ground water to
no more than the limits set by the maximum contaminant level for
radionuclides (MCL) established in 40 CFR part 141 under section 1412
of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300g-1. Both of these
requirements are concerned with human exposure to radionuclides from
disposal systems and, like the containment requirements of 40 CFR part
191, both limit such exposure for 10,000 years
o
no more than the limits set by the maximum contaminant level for
radionuclides (MCL) established in 40 CFR part 141 under section 1412
of the Safe Drinking Water Act (SDWA), 42 U.S.C. 300g-1. Both of these
requirements are concerned with human exposure to radionuclides from
disposal systems and, like the containment requirements of 40 CFR part
191, both limit such exposure for 10,000 years.
The proposed criteria address the following issues: the definition
of a protected individual, the consideration of exposure pathways, the
consideration of underground sources of drinking water, the scope of
compliance assessments, and the basis for a determination of compliance
with these requirements (results of compliance assessments).
With regard to identifying protected individuals, the Agency is
proposing to require that assessments regarding individual exposures to
radiation from the disposal system be based upon the assumption that
individuals reside at the point on the surface of the accessible
environment where they would be expected to receive the highest
exposure from radionuclide releases from the disposal system. This
helps ensure that the individual most likely to receive the highest
exposure from the disposal system is accounted for and protected.
In assessing individual doses, the Agency proposes to require
consideration of all potential pathways (associated with undisturbed
performance) for radionuclide transport. The pathways which need to be
considered include land-surface pathways (including direct radiation
exposure), surface or ground-water pathways, and air pathways, as well
as combinations of the above. Furthermore, consistent
with the Agency's approach under the Safe Drinking Water Act (42
U.S.C.A. sections 300(f) to 300j-26), it should be assumed that
individuals consume two liters of water per day from any underground
source of drinking water in the accessible environment
direct radiation
exposure), surface or ground-water pathways, and air pathways, as well
as combinations of the above. Furthermore, consistent
with the Agency's approach under the Safe Drinking Water Act (42
U.S.C.A. sections 300(f) to 300j-26), it should be assumed that
individuals consume two liters of water per day from any underground
source of drinking water in the accessible environment.
EPA is proposing today that any underground sources of drinking
water in the accessible environment which are likely to be affected by
the disposal system over 10,000 years be considered in WIPP compliance
applications. Such consideration should include an analysis of the
interconnection and commingling of bodies of ground water with
underground sources of drinking water, as well as ground-water flow
rates and direction.
According to 40 CFR part 191, calculations of compliance with the
individual and ground-water protection requirements must consider the
undisturbed performance of the disposal system. 40 CFR part 191 defines
``undisturbed performance'' as: ``the predicted behavior of a disposal
system, including consideration of the uncertainties in predicted
behavior, if the disposal system is not disrupted by human-intrusion or
the occurrence of unlikely natural events.'' The Agency solicits
comment on whether there is a need for further clarification of the
analysis of undisturbed performance, e.g.; is there a need to identify
what constitutes an ``unlikely'' natural event or what probability of
occurrence renders an event ``likely'' or ``unlikely?''.
EPA is proposing that any application for certification of
compliance shall include information which identifies the processes,
events, or sequences of processes and events considered in compliance
analyses. Moreover, EPA is proposing that documentation be provided
which justifies the inclusion/non-inclusion of particular processes,
events, or sequences of processes and events in compliance assessment
results
hat any application for certification of
compliance shall include information which identifies the processes,
events, or sequences of processes and events considered in compliance
analyses. Moreover, EPA is proposing that documentation be provided
which justifies the inclusion/non-inclusion of particular processes,
events, or sequences of processes and events in compliance assessment
results.
Once the processes, events, or sequences of processes and events
have been identified, they shall be incorporated into compliance
assessments of the disposal system. The disposal standards require
compliance assessments to include consideration of the uncertainties
associated with the undisturbed performance of the disposal system. To
do this, it is necessary to identify all disposal system parameters
that can affect the performance of the WIPP, as well as to identify the
uncertainty associated with each parameter.
When the disposal system parameters and their accompanying
uncertainty have been identified, EPA is proposing that probability
distributions be developed for each such parameter. A probability
distribution is a function which assigns a probability of occurrence to
each value for a given parameter.
The Agency is proposing that, in compiling compliance assessment
results, computational techniques be used which draw random samples
from across the full range of probability distributions for parameter
values used in compliance assessments. This will help assure that all
possible values of a parameter have been considered in compiling
compliance assessment results.
EPA is proposing that the range of estimated radiation doses to
individuals (as generated through use of the computational techniques
referred to above), and the range of estimated radionuclide
concentrations in ground water must be large enough such that the
maximum estimate generated exceeds the 99th percentile of the
population of estimates with at least a 95% probability
essment results.
EPA is proposing that the range of estimated radiation doses to
individuals (as generated through use of the computational techniques
referred to above), and the range of estimated radionuclide
concentrations in ground water must be large enough such that the
maximum estimate generated exceeds the 99th percentile of the
population of estimates with at least a 95% probability. The
``population of estimates'' refers to the set of all possible estimates
that can be generated from all disposal system parameter values used in
compliance assessments. A single estimate, in effect, samples this
population. This is similar to the requirement for the number of CCDFs
which must be generated for purposes of compliance with the containment
requirements. The Agency is proposing to include this provision for the
purpose of ensuring that there is a 95% probability that 99% of all
possible values have been exceeded by the maximum estimate generated.
In order to assure that all pertinent information is provided to
the Agency, EPA is proposing to require that compliance applications
display the full range of estimated radiation doses and the full range
of estimated radionuclide concentrations.
Finally, the Agency is proposing to require that any compliance
certification application provide information which demonstrates that
there is at least a 95% level of statistical confidence that the mean
and the median of the full range of estimated radiation doses and of
the full range of estimated radionuclide concentrations meet the
requirements set forth in sections 15 and 16 of 40 CFR part 191. The
mean estimate provides a measure of compliance that expresses the
average impacts of the disposal system on individuals and ground water
as well as the probabilities of uncertain disposal system parameter
values. The median estimate provides a measure of compliance that
expresses the central tendency of a population of estimates
irements set forth in sections 15 and 16 of 40 CFR part 191. The
mean estimate provides a measure of compliance that expresses the
average impacts of the disposal system on individuals and ground water
as well as the probabilities of uncertain disposal system parameter
values. The median estimate provides a measure of compliance that
expresses the central tendency of a population of estimates.
Specifically, the median represents the point that a calculated
estimate would be equally likely to fall above or below. Insofar as
both statistics contain useful information, the Agency is proposing an
approach that assures that both meet the limits of the individual and
ground-water protection requirements.
The Agency solicits comments on the above approach for evaluating
the results of compliance assessment.
Subpart D--Public Participation
The Agency intends to involve the public throughout the Agency's
regulatory oversight at the WIPP. Accordingly, today's proposal
contains a set of criteria for public participation in any compliance
certification or determination.
In today's proposal, the Agency is proposing to continue to
maintain the four public information dockets listed in the
Supplementary Information section of this part. All materials relevant
to any compliance certification or determination or to any decision
regarding modifications, suspensions, or revocations of such compliance
certifications and determinations will be placed in the proposed
dockets.
The Agency believes that maintaining dockets is useful because they
can greatly increase communication between EPA and all interested
parties. The Agency intends to maintain all dockets in conformance with
EPA's ``Uniform Rulemaking Docket Guidance'' to the extent practicable.
This guidance is widely used within the Agency and helps to ensure that
public participation in Agency rulemakings is optimized.
The Agency also proposes to hold public hearings on proposed
compliance criteria within the State of New Mexico
nterested
parties. The Agency intends to maintain all dockets in conformance with
EPA's ``Uniform Rulemaking Docket Guidance'' to the extent practicable.
This guidance is widely used within the Agency and helps to ensure that
public participation in Agency rulemakings is optimized.
The Agency also proposes to hold public hearings on proposed
compliance criteria within the State of New Mexico. These hearings will
provide an opportunity for members of the public, beyond submission of
written comments, to express their views to EPA in the rulemaking
process.
With respect to applications for compliance certification, the
Agency is proposing that, upon receipt of an application for
certification of compliance, it will publish a notice in the Federal
Register announcing that an application for certification of compliance
has been received and soliciting comment on that application. This
notice in the Federal Register will be an Advance Notice of Proposed
Rulemaking (ANPR), as it will also announce the Agency's intent to
conduct a rulemaking to certify whether the WIPP will
comply with the disposal regulations. The Agency is proposing this
approach in order to afford the public an opportunity for early input
into EPA's certification decision. The alternative might have been
simply putting the application in the docket and receiving comments
from the public through a more informal means. However, the Agency
believes that this approach would not necessarily lead to as much
public input relevant to its decision. Hence, the more formal approach
is proposed.
Upon completion of a review of the application for certification of
compliance, the Agency also proposes to publish in the Federal Register
a Notice of Proposed Rulemaking announcing the Administrator's proposed
decision on whether the WIPP facility will comply with the disposal
regulations and soliciting comment on such proposal
to its decision. Hence, the more formal approach
is proposed.
Upon completion of a review of the application for certification of
compliance, the Agency also proposes to publish in the Federal Register
a Notice of Proposed Rulemaking announcing the Administrator's proposed
decision on whether the WIPP facility will comply with the disposal
regulations and soliciting comment on such proposal. The notice will
provide a comment period of at least 120 days and will announce the
opportunity for public hearings in New Mexico (including times and
procedures for registering to testify).
The Agency will publish a Notice of Final Rule in the Federal
Register announcing the Administrator's decision on certifying whether
the WIPP facility will comply with the disposal regulations.
Additionally, a document summarizing major comments and issues arising
from comments received on the Notice of Proposed Rulemaking, as well as
the Administrator's response to such comments and issues, will be
prepared and made available for inspection in Agency dockets.
Similar to the process outlined above for applications for
compliance certification (and for the same reasons), when EPA receives
documentation of continued compliance as required under 8(f) of the
WIPP LWA, the Agency will publish a notice in the Federal Register
announcing the Administrator's intent to determine whether the WIPP
facility continues to be in compliance with the disposal regulations.
Copies of any documentation received will be made available for
inspection in Agency dockets and comments will be solicited for at
least 30 days after receipt. Once the Agency has considered all
comments received, the Administrator will make a determination
regarding WIPP's continued compliance and publish that decision in the
Federal Register.
Questions for Comment
he disposal regulations.
Copies of any documentation received will be made available for
inspection in Agency dockets and comments will be solicited for at
least 30 days after receipt. Once the Agency has considered all
comments received, the Administrator will make a determination
regarding WIPP's continued compliance and publish that decision in the
Federal Register.
Questions for Comment
The Agency is requesting comment on today's proposed criteria for
the certification and determination of the WIPP's compliance with the
40 CFR part 191 disposal standards and on the proposed approaches
taken. EPA generally invites comment on whether today's proposal
addresses all issues related to any EPA certification or determination
of WIPP's compliance with the disposal regulations in 40 CFR part 191.
Effective Date
The effective date of these compliance criteria, once finalized,
will be 30 calendar days after date of publication of the final rule in
the Federal Register.
Regulatory Analyses
Executive Order 12866
Under Executive Order 12866 (58 FR 51735 (October 4, 1993)) the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant regulatory action'' as
one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more
or adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with
an action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements,
grants, user fees, or loan programs or the rights and obligations of
recipients thereof; or
my, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with
an action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements,
grants, user fees, or loan programs or the rights and obligations of
recipients thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Pursuant to the terms of Executive Order 12866, it has been
determined that this rule is a ``significant regulatory action''
because it raises novel policy issues arising out of legal mandates. As
such, this action was submitted to OMB for review. Changes made in
response to OMB suggestions or recommendations will be documented in
the public record.
Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires each
Federal agency to consider the effects of their regulations on small
entities and to examine alternatives that may reduce these effects. The
nature of this action is to propose criteria for the certification of
compliance of the WIPP with the Agency's radioactive waste disposal
standards set forth in 40 CFR Part 191. Since the preparation of
applications for compliance will only be conducted by DOE, and since
any ensuing disposal and information gathering activities will only be
carried out by DOE, the Agency certifies that this regulation will not
have a significant impact on a substantial number of small entities.
Paperwork Reduction Act
The EPA has determined that this proposed rule contains no
information requirements as defined by the Paperwork Reduction Act (42
U.S.C. 3501 et seq.).
List of Subjects in 40 CFR Part 194
mation gathering activities will only be
carried out by DOE, the Agency certifies that this regulation will not
have a significant impact on a substantial number of small entities.
Paperwork Reduction Act
The EPA has determined that this proposed rule contains no
information requirements as defined by the Paperwork Reduction Act (42
U.S.C. 3501 et seq.).
List of Subjects in 40 CFR Part 194
Environmental protection, Administrative practice and procedure,
Nuclear materials, Plutonium, Radiation protection, Radionuclides,
Uranium, Transuranics, Waste treatment and disposal.
Dated: January 11, 1995.
Carol M. Browner,
Administrator.
A new part 194 is hereby proposed to be added to title 40, Code of
Federal Regulations, as follows:
PART 194--CRITERIA FOR THE CERTIFICATION AND DETERMINATION OF THE
WASTE ISOLATION PILOT PLANT'S COMPLIANCE WITH ENVIRONMENTAL
STANDARDS FOR THE MANAGEMENT AND DISPOSAL OF SPENT NUCLEAR FUEL,
HIGH-LEVEL AND TRANSURANIC RADIOACTIVE WASTES
Subpart A--General Provisions
Sec.
194.1 Purpose, scope, and applicability.
194.2 Definitions.
194.3 Communications.
194.4 Conditions of compliance certification and determination.
194.5 Publications incorporated by reference.
194.6 Alternative provisions.
Subpart B--Compliance Certification and Determination Applications
194.11 Completeness and accuracy of compliance applications.
194.12 Submission of compliance applications.
194.13 Submission of reference materials.
194.14 Content of compliance certification application.
194.15 Content of compliance determination application(s).
Subpart C--Compliance Certification and Determination
General
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