# Radiological Criteria for License Termination

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A97-17752

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** July 21, 1997
- **Citation:** 62 FR 39058

## Text

SUMMARY: The Nuclear Regulatory Commission (NRC) is amending its
regulations regarding decommissioning of licensed facilities to provide
specific radiological criteria for the decommissioning of lands and
structures. The final rule is intended to provide a clear and
consistent regulatory basis for determining the extent to which lands
and structures can be considered to be decommissioned. The final rule
will result in more efficient and consistent licensing actions related
to the numerous and complex site decommissioning activities anticipated
in the future.

EFFECTIVE DATE: This regulation becomes effective on August 20, 1997.
However, licensees may defer rule implementation until August 20, 1998.

FOR FURTHER INFORMATION CONTACT: Cheryl A. Trottier, Office of Nuclear
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, telephone: (301) 415-6232, e-mail CAT[email protected]; Frank
Cardile, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, telephone: (301) 415-6185; e-
mail [email protected]; Dr. Carl Feldman, Office of Nuclear Regulatory
Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555-
0001, telephone: (301) 415-6194, e-mail [email protected]; or Christine M.
Daily, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, telephone: (301) 415-6026, e-
mail [email protected].
SUPPLEMENTARY INFORMATION:
I. Introduction
II. Background
III. Overview of Public Comments
IV. Summary of Public Comments, Responses to Comments, and Changes
From Proposed Rule
A. Overall license termination approach and criteria for
unrestricted use (proposed rule Secs. 20.1402 and 20.1404).
1. Proposed rule content.
2. Criteria for unrestricted use, including total effective dose
equivalent, as low as reasonably achievable, and decommissioning
objective.
3. General comments on the dose criterion.
4. Average member of the critical group.
B. Criteria for restricted use (proposed rule Secs. 20.1402(d)
and 20.1405).
1. Proposed rule content.
2. Comments on acceptability of restricted use for
decommissioned sites.
3. Response.
4. Summary of rule revisions on restricted use.
C. Alternate criteria for license termination.
1. Codifying provisions for certain facilities that the proposed
rule suggested exempting.
2. Exclusion of uranium/thorium mills proposed in
Sec. 20.1401(a).
3. Other exemptions.
D. Groundwater protection criteria (proposed rule Sec. 20.1403).
1. Proposed rule content.
2. Use of Environmental Protection Agency drinking water
standards in NRC's regulation.
E. Public participation (proposed rule Secs. 20.1406 and
20.1407).
1. Proposed rule content.
2. General requirements on notification and solicitation of
comments (proposed rule Sec. 20.1406(a)).
3. Additional requirements on public participation (including
those for restricted use, for alternate criteria, and for use of
site-specific advisory boards (proposed rule Sec. 20.1406(b)).
4. Specific questions on functioning of site-specific advisory
boards.
F. Other procedural and technical issues.
1. State and NRC compatibility.
2. Grandfathering sites with previously approved plans (proposed
rule Sec. 20.1401(b)).
3. Finality of decommissioning and future site reopening
(proposed rule Sec. 20.1401(c)).
4. Minimization of contamination (proposed rule Secs. 20.1401(d)
and 20.1408).
5. Provisions for readily removable residual radioactivity.
6. Separate standard for radon.
7. Calculation of total effective dose equivalent over 1000
years to demonstrate compliance with dose standard.
G. Other comments.
1. Definitions (proposed rule Sec. 20.1003).
2. Need for regulatory guidance.
3. Need for flexibility.
4. Consistency with NRC's timeliness rule.
5. Comments from power reactor decommissioning rulemaking.
6. Mixed waste, hazardous waste, and naturally occurring and
accelerator-produced radioactive material.
7. Recycle.
8. The rulemaking process.
V. Agreement State Compatibility
VI. Relationship Between the Generic Environmental Impact Statement
and Site-Specific Decommissioning Actions
VII. Final Generic Environmental Impact Statement: Availability
VIII. Paperwork Reduction Act Statement
IX. Regulatory Analysis
X. Regulatory Flexibility Certification
XI. Backfit Analysis
XII. Small Business Regulatory Enforcement Fairness Act

I. Introduction

The Nuclear Regulatory Commission is amending its regulations
regarding decommissioning of licensed facilities to provide specific
radiological criteria for the decommissioning of lands and structures.
This action is necessary to ensure that decommissioning will be carried
out without undue impact on public health and safety and the
environment.
These criteria apply to the decommissioning of licensed facilities
and facilities subject to the NRC's jurisdiction. The Commission will
apply these criteria in determining the adequacy of remediation of
residual radioactivity resulting from the possession or use of source,
byproduct, and special nuclear material. The criteria apply to
decommissioning of nuclear facilities that operate through their normal
lifetime and to those that may be shut down prematurely.
The intent of this rulemaking is to provide a clear and consistent
regulatory basis for determining the extent to which lands and
structures must be remediated before decommissioning of a site can be
considered complete and the license terminated. The Commission believes
that inclusion of criteria in the regulations will result in more
efficient and consistent licensing actions related to the numerous and
frequently complex site remediation activities anticipated in the
future. The Commission has reassessed residual contamination levels
contained in existing guidance based on changes in basic radiation
protection standards, improvements in remediation and radiation
detection technologies, decommissioning experience, public comments
received on rule drafts and public comments presented at workshops held
as part of the rulemaking effort and public comments received on the
proposed rule.
The NRC has previously applied site release criteria for
decommissioning on a site-specific basis using existing guidance.
Although site-specific situations will still occur, the Commission
believes that codifying radiological criteria for decommissioning in
the regulations will allow the NRC to more effectively carry out its
function of protecting public health and the environment at
decommissioned sites by providing for more efficient use of NRC and
licensee resources, consistent application across all types of
licenses, and a predictable basis for decommissioning planning.

[[Page 39059]]

II. Background

On August 22, 1994 (59 FR 43200), the NRC published a proposed rule
for comment in the Federal Register to amend 10 CFR part 20 of its
regulations ``Standards for Protection Against Radiation'' to include
radiological criteria for license termination. The public comment
period closed on January 20, 1995. Comments received on the proposed
rule were summarized in NUREG/CR-6353. A workshop was held on December
6-8, 1994, to solicit additional comments related to site-specific
advisory boards as described in the proposed rule. Comments received
during that workshop were summarized in NUREG/CR 6307 1. A
workshop was also held on September 29, 1995, to specifically discuss
methods for implementing the rule. Additionally, communication with the
public on the proposed rule was maintained through the Electronic
Bulletin Board system.
---------------------------------------------------------------------------

\1\ Copies of NUREGS may be purchased from the Superintendent of
Documents, U.S. Government Printing Office, P.O. Box 37082,
Washington, DC 20013-7082. Copies are also available from the
National Technical Information Service, 5285 Port Royal Road,
Springfield, VA 22161. A copy is also available for inspection and/
or copying at the NRC Public Document Room, 2120 L Street, NW.
(Lower Level), Washington, DC.
---------------------------------------------------------------------------

III. Overview of Public Comments

Over 100 organizations and individuals submitted comments on the
proposed rule. The commenters represented a variety of interests.
Comments were received from Federal and State agencies, electric
utility licensees, material and fuel cycle licensees, citizen and
environmental groups, industry groups, native American organizations,
and individuals. The commenters offered from 1 to over 50 specific
comments and represented a diversity of views. The commenters addressed
a wide range of issues concerning all parts of the rule. The reaction
to the rule in general and to specific provisions of the rule was
varied. Viewpoints were expressed both in support of and in
disagreement with nearly every provision of the rule.

IV. Summary of Public Comments, Responses to Comments, and Changes From
Proposed Rule

The following sections describe the principal public comments
received on the proposed rule (organized according to the major subject
areas and sections of the proposed rule), present NRC responses to
those comments, and explain principal changes to the proposed rule
(where they occur) in response to those comments. The comments are
organized according to the following major subject areas and sections
of the proposed rule and are presented in the following subsections:
(a) Overall license termination approach (unrestricted use,
restricted use, exemptions, and alternate criteria), and specific
issues on criteria for unrestricted use (including total effective dose
equivalent (TEDE), as low as is reasonably achievable (ALARA),
objective of decommissioning, average member of critical group);
(b) Specific issues on criteria for restricted use (bases for using
restricted use, reliance on institutional controls, 1 mSv (100 mrem)
TEDE cap, engineered barriers, financial assurance);
(c) Specific issues on exemptions and alternate criteria for
license termination (facilities with large volumes of low level wastes,
uranium and thorium mills, exemptions);
(d) Groundwater protection criteria (use of Environmental
Protection Agency (EPA) drinking water standards of 40 CFR 141 in NRC's
regulation);
(e) Public participation (means of notification, site-specific
advisory boards (SSABs));
(f) Other procedural and technical issues (state compatibility,
grandfathering, finality, minimization of contamination, readily
removable residual radioactivity, radon, calculation of TEDE over 1000
years to demonstrate compliance with dose standard); and
(g) Other comments (definitions, regulatory guidance; timeliness
rule; wastes; recycle; rulemaking process).
The comments received from both public comment and the workshops
have been factored into the Commission's decisionmaking on the final
rule and into the technical basis for guidance documents implementing
the final rule. The description of changes to the final rule made as a
result of the comments in each of the major subject areas follows each
comment/response section.

A. Overall License Termination Approach and Criteria for Unrestricted
Use (Proposed Rule Secs. 20.1402 and 20.1404)

A.1 Proposed Rule Content
The proposed rule (Sec. 20.1402(d)) presented an overall approach
for license termination involving either of two basic methods, i.e.,
unrestricted use or restricted use of sites after license termination.
The proposed rule indicated that unrestricted use was generally
preferred, but that restricted use was also permitted because it was
recognized that there may be cases where achieving unrestricted use
would not be reasonable.
Specific requirements for use of each of these two basic methods
were presented in the proposed rule. The preamble to the proposed rule
also indicated that there may be certain licensees that would seek
exemptions from the decommissioning criteria of the proposed rule,
although it did not codify this exemption path.
Section IV.A.2 reviews in detail the development of unrestricted
use criteria; and, in doing so it also indicates, in general, how the
overall approach for license termination has been reexamined to
consider public comments. Specific issues and requirements regarding
other areas, specifically restricted use, exemptions, and alternate
criteria, are discussed in more detail in Sections IV.B and IV.C of
this preamble.
Section 20.1402(a) of the proposed rule indicated that the
objective of decommissioning is to reduce residual radioactivity in
structures, soils, groundwater, and other media at the site so that the
concentration of each radionuclide that could contribute to residual
radioactivity is indistinguishable from the background radiation
concentration for that nuclide. Section 20.1402(a) further noted that,
as a practical matter, it would be extremely difficult to demonstrate
that such an objective had been met and that a site release limit for
unrestricted use was being proposed.
Section 20.1404 of the proposed rule indicated that a site would be
considered acceptable for unrestricted use if the residual
radioactivity that is distinguishable from background radiation results
in TEDE to an average member of the critical group of 0.15 mSv/y (15
mrem/y) and has been reduced to levels that are ALARA.
Section 20.1402(d) of the proposed rule indicated that release for
unrestricted use of a facility is the preferred approach but that the
alternative of release for restricted use would also be allowed if its
use were justified (see Section IV.B).
A.2 Criteria for Unrestricted Use, Including TEDE, ALARA, and
Decommissioning Objective
A.2.1 Comments. Some commenters (including EPA) agreed that 0.15
mSv/y (15 mrem/y) is an acceptable criterion because it is attainable,
provides a margin of safety, and isn't unjustifiably costly. The
Department of Energy (DOE) agreed that 0.15 mSv/y (15 mrem/y) could be
acceptable if reasonable scenarios were considered although it
preferred 0.25 mSv or 0.3 mSv/y (25 or 30 mrem/y) with ALARA. However,
most commenters did not agree with the

[[Page 39060]]

0.15 mSv/y (15 mrem/y) criterion. Some opposed 0.15 mSv/y (15 mrem/y)
as being too high and preferred alternatives that reduced the
contamination level to lower levels, including preexisting background.
The majority of commenters opposed 0.15 mSv/y (15 mrem/y) as being too
low and gave alternatives that generally included increasing the limit
to 0.25, 0.3, 0.5, or 1 mSv/y (25, 30, 50, or 100 mrem/y) with further
reduction based on ALARA. The categories of reasons given by commenters
opposing 0.15 mSv/y (15 mrem/y) as either too high or too low included
potential health impacts or the lack of demonstrable health effects at
these levels, consistency with national and international standards,
effect of multiple sources, consistency with other NRC/EPA regulations,
analysis of costs vs. benefits, ability to measure, effect on disposal
capacity, effect on sites with naturally occurring radioactive material
(NORM), and responsibility for cleanup of sites.
The proposed rule indicated that licensees would be expected to
demonstrate that doses are ALARA below the proposed 0.15 mSv/y (15
mrem/y) dose criterion. Some commenters endorsed ALARA analyses in
specific cases to determine if doses should be reduced below 0.15 mSv/y
(15 mrem/y) and recommended that a value of 0.03 (or less) mSv/y (3 (or
less) mrem/y) be the ALARA objective. Some of these commenters also
requested that the NRC explicitly mandate that technical and economic
analyses be performed. Other commenters indicated that ALARA principles
and analyses should not be required to determine if cleanup should be
performed to reduce doses below 0.15 mSv/y (15 mrem/y) because the
costs are large in comparison with the small reduction in risk. Several
commenters indicated, alternatively, that ALARA should be allowed above
0.15 mSv/y (15 mrem/y) and that the rule should allow ALARA analyses to
be used to permit a licensee to release its site at a value higher than
0.15 mSv/y (15 mrem/y) (up to 1
mSv/y (100 mrem/y)) if ALARA calculations support this alternative.
Another commenter disagreed and recommended that ALARA analyses be
applied only to demonstrate if additional cleanup is required below
0.15 mSv/y (15 mrem/y). Some commenters stated that guidance should be
provided describing how ALARA should be achieved, how doses would be
quantified, how models and parameters would be selected, what $/person-
rem value would be used, how nonradiological risks would be considered,
how net risks would be evaluated, how flexibility would be
incorporated, what degree of simplification of complex models would be
incorporated, and what final criteria would be used.
The proposed rule also contained, in Sec. 20.1402(a), a
decommissioning objective of reducing residual radioactivity to levels
that are indistinguishable from background. Section 20.1402(a) further
noted that such an objective may be difficult to meet as a practical
matter. Many commenters opposed establishment of the decommissioning
objective because it is arbitrary, serves no purpose for industrial
sites, is costly and a waste of resources, is unlikely to be achieved,
and cannot be measured. Some commenters supported establishing the
proposed objective because it is reasonable from a health standpoint.
Others suggested alternative objectives such as ALARA or using a dose
that is indistinguishable from the variation in background.
A.2.2 Response. The preamble to the proposed rule described three
broad considerations as providing the overall rationale for the
proposed rule's approach to license termination. The first two
considerations were related to health and safety, i.e., level of risk
and need for a constraint or margin of safety below the 1 mSv/y (100
mrem/y) public dose limit of 10 CFR part 20 to account for the
potential effect of multiple sources of radiation exposure. The third
consideration was related to practicality and reasonableness of costs.
The preamble to the proposed rule noted that the risk implied by use of
the proposed 0.15 mSv/y (15 mrem/y) dose is comparable to other
standards and practices of EPA and NRC for areas of unrestricted access
in the vicinity of facilities, and that the proposed 0.15 mSv/y (15
mrem/y) standard provides a substantial margin of safety (constraint)
for a single source below the 1 mSv/y (100 mrem/y) public dose limit in
10 CFR part 20 to account for the potential exposure of a member of the
public to other sources. This ``constraint'' approach was noted as
being consistent with generic constraint recommendations made by
national and international scientific bodies such as the International
Commission on Radiation Protection (ICRP) and the National Council on
Radiation Protection and Measurements (NCRP). Requirements related to
ALARA, the decommissioning objective, and restricted use were included
in the rule based on the NRC staff analysis in the Draft Generic
Environmental Impact Statement (GEIS) (NUREG-1496) that showed that the
costs of reducing exposures to, or in some cases below, a 0.15 mSv/y
(15 mrem/y) criterion would not generally be unduly burdensome for most
licensees, although in those cases where the costs would present an
unreasonable burden, release of the site with restrictions placed on
its use would provide an alternative means for achieving the same level
of protection. Achieving levels of less than 0.15 mSv/y (15 mrem/y),
including achieving the decommissioning objective, was generally seen
as not cost-effective because increasingly larger volumes of concrete
and soil would have to be removed at a greater net risk due to deaths
from transportation accidents and because more difficult survey
measurements would have to be made with little net benefit in dose
reduction.
The NRC considered alternatives suggested in public comments and
reexamined the rationale of the proposed rule. A summary of that
reexamination, along with a description of particular comments on the
rationale, is contained in the following subsections.
A.2.2.1 Level of risk and consistency with other EPA/NRC
standards. Some commenters criticized the health risk associated with a
0.15 mSv/y (15 mrem/y) limit as too high thereby providing inadequate
public protection. In particular, they objected to the NRC's reliance
on ICRP and NCRP because recent research (including findings in the
aftermath of the 1986 Chernobyl accident and in the 1990 report on
Biological Effects of Ionizing Radiation (the BEIR V report)) showed
risks to be higher than ICRP or NCRP indicated, or suggested other
sources for limits, including a British standard and a National Academy
of Sciences statement on radiation safety. Commenters also indicated
that 0.15 mSv/y (15 mrem/y) was too high because it is higher than
other NRC or EPA standards such as those for operating reactors.
The majority of commenters criticized 0.15 mSv/y (15 mrem/y) as too
low for reasons which included that it is far below the level at which
health effects have been observed in studies, that the risks associated
with other EPA and NRC standards (including 10 CFR parts 20, 60 and 61,
40 CFR parts 190 and 191, and EPA's radon action level) are higher, and
that it is based on the linear non-threshold theory which is not
appropriate for setting such standards. These commenters also
criticized the relationship of the risks implied by this rule to those
implied by standards for chemical hazards.
In general, many commenters stated that the NRC should work closely
with

[[Page 39061]]

the EPA in developing its decommissioning regulations to assure that
there are no conflicting or duplicate requirements and that the
acceptable risk levels and associated requirements developed by the two
agencies are compatible or the same. DOE noted that a nonuniform
approach could significantly impact the DOE environmental restoration
program and that NRC/EPA regulations will have an impact beyond NRC
licensees. There was some commenter disagreement as to whether EPA or
NRC should take the lead in issuance of exposure standards. In its
comments on the NRC's proposed rulemaking, the EPA supported the 0.15
mSv/y (15 mrem/y) limit.
In response, the NRC has considered recent information and
recommendations in ICRP Publication 60 and NCRP No. 116. These
documents are developed by recognized experts in the fields of
radiation protection and health effects and contain reviews of current
significant research in radiation health effects. The NCRP is a
nonprofit corporation chartered by the U.S. Congress to develop and
disseminate information and recommendations about protection against
radiation and to cooperate with the ICRP and other national and
international organizations with regard to these recommendations. The
ICRP has continued to update and revise its estimates of health effects
of radiation since its inception in 1928. In its deliberations, ICRP
maintains relationships with United Nations health and labor
organizations.
In addition, the NRC evaluated the proposed Federal Radiation
Protection Guidance for Exposure of the General Public (FRG) as
published for comment on December 23, 1994 (59 FR 66414), in which the
EPA, under its charter, made recommendations to the President of the
United States concerning recommended practices for protection of the
public and workers from exposure to radiation.
Recent recommendations contained in ICRP 60, NCRP No. 116, and the
proposed FRG are essentially similar. Use of these sources for
formulating basic radiation protection standards is consistent with
NRC's general approach regarding risk decisions as is noted in the
preamble to issuance of 10 CFR part 20 on May 21, 1991 (56 FR 23360).
The NRC considers it reasonable and appropriate to use the findings of
these bodies in developing criteria for license termination to apply to
its licensees.
The ICRP and NCRP and EPA have reviewed current, significant
studies made by other health research bodies, such as the National
Academy of Sciences-National Research Council's Committee on the
Biological Effects of Ionizing Radiation (BEIR) and the United Nations
Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and
have developed recommendations regarding limitations on exposure to
radiation. In particular, the BEIR Committee conducted major reviews of
the scientific data on health risks of low levels of ionizing radiation
in 1972, 1980, 1988, and 1990, and similar reviews were published by
UNSCEAR in 1977, 1982, 1986, and 1988. As noted in the proposed FRG,
these studies have provided more certainty about radiation risks at
high doses and dose rates. Using that information and assumptions of
linearity with low dose/dose rate reduction factors, BEIR V contains
updated risk factors.
Concerning recent information from the Chernobyl accident noted by
a commenter, there are still ongoing studies of the effects of the
accident. A report published by the principal international
organization studying health effects from the accident, the
Organization for Economic Co-operation and Development (OECD), entitled
``Chernobyl: Ten Years On; Radiological and Health Impact,'' summarized
the findings regarding health impacts by noting that scientific and
medical observation of the population has not revealed any increase in
cancers or other radiation induced disease that could be attributable
to the Chernobyl accident. The only area where an increase was noted
was for thyroid cancer. However, these effects most likely resulted
from the release of short-lived radioiodine from the accident and the
affinity of the thyroid gland for iodine. Similar effects would not be
applicable in decommissioning because radioactive iodine is not
expected to be a significant contaminant. The report further notes
that, while studies continue on long term effects, it is unlikely that
the exposure to contaminants in the environment will lead to
discernible radiation effects in the general population. Thus, this
research does not appear to indicate that the findings of the ICRP and
NCRP will be shown to underestimate risks.
Specifically with regard to the risk level, some of the commenters
stated that the risk of fatal cancers from 0.15 mSv/y (15 mrem/y) is
too high in comparison with risk goals in the range 1 x 10-4
to 1 x 10-6 used by EPA in Comprehensive Environmental
Response, Compensation and Liability Act (CERCLA) regulations. Other
commenters disagreed and stated that precedents from earlier NRC
rulemakings support a level of risk significantly greater than that and
more appropriately in a range of 1 x 10-2 to
1 x 10-3 (e.g., the level of lifetime risk corresponding to
the 1 mSv/y (100 mrem/y) public dose limit of 10 CFR Part 20, that is
NRC's basic standard for public safety, is about
1.5 x 10-3). Several of these commenters also criticized
0.15 mSv/y (15 mrem/y) as too low because the linear non-threshold
model overestimates the risk and should not be used in the analysis. In
response to comments on the risk level, constant exposure over a 30-
year time period to dose levels of about 0.15-0.25 mSv/y (15-25 mrem/
y), results in an estimated lifetime risk of fatal cancer of about
2.3 x 10-4 to 3.8 x 10-4 which is at the upper
end of the acceptable risk range suggested by EPA in their comments on
NRC's proposed rule but lower than that in NRC's public dose
limits.2 These estimates are based on use of the linear non-
threshold model for calculating risk estimates. In response to specific
comments on use of the linear non-threshold model in estimating risk,
use of the linear non-threshold model for estimating incremental health
effects per radiation dose incurred is considered a reasonable
assumption for regulatory purposes by international and national
scientific bodies such as ICRP and NCRP. The principal international
and national radiological protection criteria, including the NRC's, are
based on this assumption as a measure of conservatism. NRC's policy
regarding use of the linear non-threshold model was stated in the
preamble to the issuance of 10 CFR part 20 (56 FR 23360; May 21, 1991)
noting that the assumptions regarding a linear non-threshold dose
effect model are appropriate for formulating radiation protection
standards. Although this matter continues to be the subject of further
consideration at this time, there is not sufficient evidence to
convince the NRC to alter its policy as part of this rulemaking.
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\2\ The risks are estimated assuming a risk coefficient of
5 x 10-4 per rem and a 30-year lifetime exposure that is
used by EPA in estimating risk from contaminated sites based on the
assumption that it is unlikely that an individual will continue to
live or work in the same area for more than 30 years. Such an
estimate is seen as providing a conservative estimate of potential
risk because land use patterns are generally such that persons
living at or near a site will not continuously receive the limiting
dose, and, for most of the facilities covered by this rule, the TEDE
is controlled by relatively short-lived nuclides of half-lives of 30
years or less for which the effect of radioactive decay will, over
time, reduce the risk significantly (e.g., at reactors where much of
the contamination is from Co-60 with a half-life of 5.3 years).
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To provide some perspective on the conservatism of considering dose
criteria in the range of 0.15-0.25 mSv/

[[Page 39062]]

y (15-25 mrem/y), it should be noted that, as described in the Final
GEIS (NUREG-1496) prepared in support of this rulemaking, these levels
are small when compared to the average level of natural background
radiation in the United States (about 3 mSv/y (300 mrem/y)) and the
variation of this natural background across the United States. In
addition, although as noted above NRC is not altering its policy
regarding use of the linear non-threshold model as part of this
rulemaking, there is uncertainty associated with estimating risks at
such dose levels. This uncertainty occurs because evidence of radiation
dose health effects has only been observed at high dose levels (200 mSv
(20,000 mrem) and above) and significant uncertainty in risk estimation
is introduced when extrapolating to the very low dose levels being
considered in this rulemaking. The health effects resulting from even a
dose of 1 mSv (100 mrem) are uncertain. The BEIR Committee stated in
its 1990 report (BEIR V) that ``Studies of populations chronically
exposed to low-level radiation, such as those residing in regions of
elevated natural background radiation, have not shown consistent or
conclusive evidence of an associated increase in the risk of cancer.''
The risk associated with a dose criterion in the range of about
0.15-0.25 mSv/y (15-25 mrem/y) is generally consistent with the risk
levels permitted in the performance objectives for low-level waste
facilities in 10 CFR 61.41, and for fuel cycle facilities and for spent
fuel and high level waste in EPA's 40 CFR 190 and 191. In addition,
doses in the range of 0.15-0.25 mSv/y (15-25 mrem/y) are comparable to
current NRC practices for decommissioning of reactors and certain
materials facilities and fuel cycle facilities. Specifically, reactors
have been decommissioned in accordance with Regulatory Guide 1.86 and
with an NRC license termination letter to Stanford University (April
21, 1982, Docket No. 50-141). Materials facilities have been released
in accordance with the levels for external radiation for beta/gamma
exposure in NRC's Policy and Guidance Directive FC 83-23. In addition,
a dose criterion in the range of 0.15-0.25 mSv/y (15-25 mrem/y) is
generally at the low end of the range of values estimated for Option 1
of the 1981 Branch Technical Position (BTP) for sites with uranium and
thorium and used for Ra-226 in 10 CFR 40, Appendix A, for uranium mill
contamination.
A.2.2.2 Effect of multiple sources and margin of safety below 1
mSv/y (100 mrem/y). Some commenters suggested that 0.15 mSv/y (15 mrem/
y) is too low and indicated that the NRC limit was inconsistent with
ICRP and NCRP especially with regard to considerations of multiple
sources of exposure, and that it would be unusual for an individual to
be exposed to multiple sources approaching the 1 mSv/y (100 mrem/y)
limit. These commenters suggested that 25-30 percent of 1 mSv (100
mrem) is an adequate margin to account for multiple sources.
In response, and by way of background, it is noted that the NCRP in
its publication No. 116 (Chapter 15) recommends that, for continuous
exposure, the effective dose to members of the public not exceed 1 mSv/
y (100 mrem/y) from all man-made sources, other than medical and not
including natural background sources. Similarly, ICRP, in Table 6 of
ICRP Publication 60, recommends a limit of 1 mSv/y (100 mrem/y) as the
dose limit for the public, and recommendation No. 3 of the draft EPA
Federal Radiation Protection Guidance (FRG) indicates that the combined
radiation doses incurred in any single year from all sources of
exposure (excluding medical and natural background) should not normally
exceed 1 mSv (100 mrem) and that continued or chronic exposure of an
individual over substantial portions of a lifetime at or near 1 mSv/y
(100 mrem/y) should be avoided. Consistent with these bodies, the NRC
issued 10 CFR part 20 (56 FR 23360) in 1991 that established a public
dose limit of 1 mSv/y (100 mrem/y) in 10 CFR 20.1301.
These national and international bodies also note and agree that,
although the limit for the public dose should be 1 mSv/y (100 mrem/y)
from all man-made sources combined, it would seem appropriate that the
amount that a person would receive from a single source should be
further reduced to be a fraction of the limit to account for the
possibility that an individual may be exposed to more than one source
of man-made radioactivity, thus limiting the potential that an
individual would receive a dose at the public dose limit.
Recommendations from these bodies, as well as from the NRC's Advisory
Committee on Nuclear Waste (ACNW), regarding what the fraction from a
source should be are:
(a) NCRP No. 116, Chapter 15, notes that no single source or set of
sources under one's control should result in an individual being
exposed to more than 0.25 mSv/y (25 mrem/y). This fraction was
presented as a simple alternative to having a site operator (where a
site could expose individuals to levels greater than 0.25 mSv/y (25
mrem/y)) investigate all man-made exposures that an individual at the
site would be exposed to so as to demonstrate that the total dose does
not exceed 1 mSv/y (100 mrem/y). The clear implication in this simple
alternative is that, if individual sources are constrained to 0.25 mSv/
y (25 mrem/y), NCRP believes it likely, given the low potential for
multiple exposures, that the public dose limits will be met. Further
reductions considering ALARA would still be considered by NCRP No. 116.
(b) ICRP 60, Section 5.5.1, in discussing the principles of
constraints and limits, notes that it is appropriate to select dose
constraints applied to each source to allow for contributions from
other sources so as to maintain doses below the 1 mSv/y (100 mrem/y)
limit. ICRP 60 does not contain numerical guidance on dose constraints
for particular practices, but notes that cumulative exposures to
individuals from existing sources near 1 mSv/y (100 mrem/y) are rarely
a problem primarily because of the widespread use of source-related
dose constraints.
Further explanation of the fundamental concepts of ICRP 60 are
contained in the paper, ``The ICRP Principles of Radiological
Protection and Their Application to Setting Limits and Constraints for
the Public from Radiation Sources,'' by Professor Roger Clarke,
Chairman of the ICRP (January 12, 1995; a copy is available in the file
for this rulemaking in the NRC Public Document Room, 2120 L Street NW.
(Lower Level), Washington, DC). The paper notes that the constraint
approach derives from the optimization principle of radiation
protection in which, for any source, individual doses should be ALARA
and also be constrained by restrictions on doses to individuals (i.e.,
dose constraints). The paper further notes that a constraint is an
individual related criterion applied to a single source to ensure that
the overall dose limits are not exceeded, and that a dose constraint
would therefore be set at a fraction of the dose limit as a boundary on
the optimization of that source. Based on the principles presented in
the paper, the constraint recommended in the paper for a decommissioned
site is 0.3 mSv/y (30 mrem/y) and that further optimization through the
ALARA principle is appropriate. As is the case for NCRP No. 116, the
implication of the paper and ICRP 60 is that the constraint level is a
boundary on the dose from this source and is sufficient to assure that
members of the public are not exposed to levels in excess of the public
dose limit. The rationale for this is expressed in Section 5.5.1 of
ICRP 60 where it is noted that the critical group

[[Page 39063]]

is not normally exposed to the constraint level from more than one
source although it may be exposed to some dose level less than the
constraint level from more than one source.
(c) The proposed FRG in recommendation No. 4 indicates that
individual sources should have ``authorized limits'' set at a fraction
of the 1 mSv/y (100 mrem/y) limit for all sources combined. The draft
FRG notes that the basis for this recommendation is the various
categories of activities using radiation that can lead to exposure to
members of the public, and also notes the need for broad assumptions
about future activities involving radiation use.
The draft FRG does not recommend a level for any one source
although it does note that setting such a fraction will necessarily be
a broad judgment based on a general observation of the characteristics
of existing activities, projections for continuing those activities in
the future, and the potential for other uses in the future that can be
identified now. Thus, the draft FRG notes that, in the case of
authorized limits for broad categories of sources, the judgments will
often necessarily be broad and may lead to somewhat higher values, with
further implementation of the ALARA process left to management of
individual sources within a category. The draft FRG does not indicate
how this judgment is to be made although it cites authorized standards
for certain sources that currently exist, including 40 CFR part 190 for
the nuclear fuel cycle, Appendix I to 10 CFR part 50 for power
reactors, 10 CFR part 61, and 40 CFR part 141. All of these set
authorized fractions at 25 percent or less of the 1 mSv/y (100 mrem/y)
public dose limit. NRC, in its comments on EPA's draft FRG, questioned
what was the appropriate fraction of the public dose limit in 10 CFR
part 20 that should be used in setting constraints that would become
``authorized'' limits.
(d) In its review of how the principles and recommendations of the
ICRP, NCRP, and FRG are relevant to the proposed NRC rule, NRC's
Advisory Committee on Nuclear Waste (ACNW) noted that 0.15 mSv/y (15
mrem/y) represented an unnecessarily conservative fraction of the 1
mSv/y (100 mrem/y) annual limit. The ACNW agreed that the need to
partition the annual recommended dose limit among several sources to
which a person is likely to be exposed appears justifiable and noted
that no explicit guidance from the various national and international
bodies on this subject exists. ACNW stated that a constraint of 25
percent or 30 percent of the 1 mSv/y (100 mrem/y) limit appears more
justified and appropriate based on the likelihood that no more than 3
or 4 separate regulated sources will affect the critical group at any
instance. ACNW further noted that the selection of 0.15 mSv/y (15 mrem/
y), that represents about \1/7\ of the annual limit, assumes that a
person will encounter a simultaneous dose from seven different
regulated sources and that this appears to them to be unjustified,
particularly because the ALARA principle accompanies all such NRC
regulatory actions.
The recommendations of the previously cited organizations can be
summarized as suggesting that a constraint value should be set as part
of the process of optimizing the dose from a particular source and that
this constraint value should be set as a boundary value below which
further optimization or ALARA principles should be employed. The
recommendations also appear to suggest that setting a source constraint
of 25-33 percent of the annual dose limit of 1 mSv/y (100 mrem/y) is
appropriate and adequate to ensure that the dose limit is met, and do
not tend to lend support to 0.15 mSv/y (15 mrem/y) as the appropriate
fraction to which to constrain the dose from an individual source
because it is not likely that a critical group will be exposed to as
many as seven sources. Thus, the recommendations appear to indicate
that the constraint value should be set using a more reasonable
approach.
In discussing the bases for the 0.15 mSv/y (15 mrem/y) dose
criterion in the proposed rule, the Commission noted in the preamble
(at 59 FR 43219; August 22, 1994) that 0.15 mSv/y (15 mrem/y) would
provide a ``substantial'' margin of safety and be appropriate for
decommissioned facilities. As part of its review of the public
comments, the Commission considered the recommendations of the
standards-setting bodies previously cited. Further, in making a
judgment on the appropriate value of the fraction, the Commission also
considered principles of optimization, numbers and types of sources,
potential for exposure of critical groups to more than one source at
the constraint value, and assumptions regarding the manner in which a
critical group would be exposed. NRC reviewed the assumptions of the
Draft and Final GEIS regarding exposure pathways and also NUREG/CR-5512
upon which the Draft and Final GEIS are based. NUREG/CR-5512 provides
an analysis of exposure pathways for critical groups at decommissioned
facilities. The principal limiting scenarios include: (a) Full time
residence and farming at a decommissioned site, (b) exposure while
working in a decommissioned building, and (c) renovation of a newly
decommissioned building. These principal limiting exposure scenarios
are intended to overestimate dose and also tend to be somewhat mutually
exclusive; i.e., a person living near a decommissioned nuclear facility
would only receive a dose near the constraint level if his living
pattern includes full-time residency and farming at the site. This
living pattern would make it difficult for the member of this critical
group to also be a member of the critical group from other licensed or
decommissioned sources. Conversely, a person having less residency than
a full time farmer (e.g., apartment dweller, homeowner who works away
from the site) might receive doses from other sources but would receive
less than the constraint value from the decommissioned site because the
exposure time and the number of pathways would be reduced. Thus, given
the assumptions regarding living patterns made in evaluating compliance
with the constraint level, it is difficult to envision an individual
receiving levels approaching constraint levels from more than one
licensed or decommissioned source. It is also likely that individuals
at a decommissioned site will actually be exposed to doses
substantially below the constraint level because of ALARA
considerations and because of the nature of the cleanup process itself,
i.e., the process of scabbling of concrete removes a layer of concrete
which likely contains a large fraction of the remaining radioactivity,
and the process of soil excavation is a gross removal process that is
also likely to remove large fractions of the radioactivity. For
example, the Final GEIS indicates that, for the reference cases
analyzed, removal of a layer of concrete by scabbling will result in
doses at levels from 2 to more than 10 times lower than a constraint
value. In addition to consideration of decommissioned sources, it is
also difficult to envision that an individual could come in contact
with more than a few other sources as part of normal living patterns.
For example, the NCRP in NCRP No. 93, ``Ionizing Radiation Exposure of
the Population of the United States,'' September 1987, reviewed likely
radiation exposures to the public from consumer products, air
emissions, and fuel cycle facilities (including nuclear power plants)
and found that, in general, exposure to the public is a small fraction
of 1 mSv/y (a few mrem/y). Recent experience on

[[Page 39064]]

nuclear power plant emissions and dose commitments (NUREG/CR-2850)
tends to support the conclusions of NCRP No. 93 about power plant
exposures.
NRC's generic evaluation of uses of and doses from various sources,
including decommissioned sources, supplemented by the recommendations
of the standards setting bodies and advisory committee noted above,
suggests that the substantial added margin of safety provided by the
0.15 mSv/y (15 mrem/y) value may be too restrictive for its intended
purpose of constraining doses from this category of sources in
establishing an appropriate boundary constraint. Rather, the evaluation
leads NRC to conclude that 25 percent of the public dose limit is a
sufficient and ample fraction to use as the limitation for
decommissioned sources.
Thus, the Commission concludes that a generic dose constraint or
limitation for decommissioning sources of 0.25 mSv/y (25 mrem/y) for
unrestricted release of a site is reasonable from the standpoint of
providing a sufficient and ample margin of safety for protection of
public health and safety. It is recognized that this conclusion
reflects a judgment regarding the likelihood of individuals being
exposed to multiple sources with cumulative doses approaching 1 mSv/y
(100 mrem/y) rather than an analysis based on probability distributions
for such exposures. However, considering the kinds of occupancy time
typically assumed for the average member of the critical group at a
site, it is highly unlikely that individuals could realistically be
expected to experience exposures to other sources with a cumulative
effect approaching 1 mSv/y (100 mrem/y).
A.2.2.3 Cost and practicality of standard. Comments received on
cost and practicality were analyzed to determine whether such an
analysis can provide additional information related to the criteria of
this rule. This analysis includes how, and to what level, ALARA efforts
should be made, how the proposed decommissioning objective of returning
a site to background should be applied, and what provisions should
there be (e.g., restricted use) for sites where it is unreasonable or
unwise to attain the unrestricted dose criterion.
Some commenters criticized the proposed rule for including
considerations of cost-effectiveness, objecting to using cost in
decisionmaking. Other commenters criticized the rule because, although
they favored use of cost-benefit analyses in decisionmaking, they
believed that the cost-benefit analysis in the draft GEIS and draft
Regulatory Analysis (RA) was inadequate to justify a 0.15 mSv/y (15
mrem/y) dose criterion because it used an improper approach (i.e.,
combining the building and soil analysis). They also believed that it
underestimated the amount of contamination at reference facilities, as
well as the costs of remediation and final site closeout surveys.
The Commission considered the concerns of commenters who criticized
inclusion of cost as a consideration in decisionmaking. NRC methods and
policy regarding cost considerations are stated in NUREG/BR-0058, Rev.
2, and call for preparation of an appropriate regulatory analysis in
support of regulatory decisions. NUREG/BR-0058 does note that costs
cannot be considered for regulatory actions necessary to ensure
adequate protection of the health and safety of the public; however, it
further notes that costs can be a factor in those cases where there may
be more than one way to reach a level of adequate protection. Thus, the
analysis in the GEIS and RA was prepared in support of the rulemaking
to provide additional information to decisionmakers about the rule
criteria being considered.
The Commission has also considered the concerns of those commenters
that criticized the analysis of costs and risks as incomplete and
inadequate and reviewed information submitted in support of those
comments. In general, some of the major comments suggested, and
provided data on, the following:
(a) Additional data from actual decommissionings should be included
that would consider variations in site contamination characteristics,
including the concentration and volume of contamination and the profile
of the contamination with depth;
(b) Reevaluation of remediation and survey costs should be
conducted, including consideration of variation in waste burial
charges, remediation methods, and survey procedures;
(c) Separate analyses of the cost-effectiveness of soil removal and
building removal should be performed. A commenter illustrated that
separate analyses would clarify differences between costs and impacts
of cleanup of soils and structures that were not obvious in the Draft
GEIS. Commenters also suggested deleting the ``knee-in-curve'' approach
as not clearly illustrating the information regarding costs and impacts
for cleanup of both soils and structures; and
(d) Potential alternative uses of the site lands and facilities
should be considered to provide a higher level of realism in the dose
estimates. These alternative uses can result in variations in direct
exposure and ingestion pathways and in the number of persons exposed
and thus the collective exposure and net health effects.
Based on the comments and information received, additional
information has been added to the GEIS. Data on contamination submitted
by the commenters were reviewed, compared with other existing data,
including that in the Draft GEIS, and incorporated into the Final GEIS
as appropriate. The Final GEIS thus considers additional soil
contamination data as well as soil and building contamination
comparable to that in the draft GEIS. It also considers the range of
disposal costs and survey methods and costs presented in the Draft
GEIS, as well as those suggested in the comments. The Commission agrees
with the commenters that consideration of soil and buildings separately
can provide added information. Thus the Final GEIS has used the
analysis of the Draft GEIS, that contained the data for performing
separate analyses, and has presented the data more clearly in revised
tables. In addition, the ``knee-in-curve'' figures, that provided
general information about behavior of costs and impacts associated with
cleanup, have been replaced with a simpler set of tables similar to the
presentation in the Draft Regulatory Analysis, in Tables 6.1 and 6.2.
In response to comments suggesting that the Final GEIS consider more
realistic post decommissioning uses, the Final GEIS considers a range
of possible uses, including residential farming, denser residential
use, industrial/office use, and higher building occupancy rates.
Given the range of possible parameters, scenarios, and site-
specific situations, the Final GEIS concludes, in a manner similar to
the Draft GEIS, that there is a wide range of cost-benefit results
among the different facilities and within facility types and that there
is no unique algorithm that decisively produces an ALARA result for all
facilities. Despite these difficulties, the Final GEIS and RA provide
the following results that can be helpful for gaining insight in making
decisions regarding ALARA, the decommissioning objective, and whether
restricted use should be permitted:
(a) Achieving, as an objective of ALARA, reduction to preexisting
background. The objective of returning a site to preexisting background
conditions is consistent with the concept of returning a site to the
radiological condition that existed before its use. However, the
question of whether this objective, as a goal of ALARA, should be
codified by rule depends on a variety of factors,

[[Page 39065]]

including cost, practicality (e.g., measurability) of achieving the
objective, and the type of facility involved.
As noted in Section 7.3.1 of the Draft GEIS, decommissioning is
expected to be relatively easy for a certain class of non-fuel-cycle
nuclear facilities (i.e., those that use either sealed radioactive
sources or small amounts of short-lived nuclides), because there is
usually no residual radioactive contamination to be cleaned up and
disposed of, or, if there is any, it should be localized or it can be
quickly reduced to low levels by radioactive decay. Decommissioning
operations will generally consist of disposing of a sealed source or
allowing licensed short-lived nuclides to decay in storage, submitting
Form NRC-314, and demonstrating (either through radiation survey or
other means such as calculation of reduction of the contamination level
by radioactive decay) compliance with the requirements for license
termination. Because contamination at these facilities is expected to
be negligible or to decay to negligible levels in a short time,
achieving an objective of returning these facilities to background
would not appear to be an unreasonable objective of ALARA.
However, in general, for those nuclear facilities where
contamination exists in soils and/or structures, the Final GEIS
analysis shows, in a manner similar to the Draft GEIS, that achieving
an ALARA decommissioning objective of ``return to a preexisting
background'' is not reasonable as it may result in net detriment or
because cost cannot be justified because detriments and costs
associated with remediation and surveys tend to increase significantly
at low levels, while risk reduction from radiation exposure from
criteria near background is marginal.
(b) ALARA analysis for soil contamination. Soil contamination can
exist onsite at nuclear facilities because of a variety of reasons
including spills or leaks, deposition from airborne effluents, or
burial or placement of system byproducts or other waste materials in
onsite soils. The level of soil contamination for the large majority of
NRC-licensed facilities (>6000) is either zero or minimal (it is
expected that the large majority of Agreement State licensees would
have similar contamination). Certain facilities (e.g., power reactors,
fuel facilities, industrial facilities) may have greater soil
contamination, and certain of these facilities have been identified as
having extensive soil contamination (albeit generally at relatively low
levels) and have been placed in the Site Decommissioning Management
Plan (SDMP) (see NUREG-1444, October 1993). These sites warrant
specific NRC attention regarding their decommissioning.
For the generic scenarios considered, the results of the Final GEIS
evaluation indicate that there is a wide range of possible cost-benefit
ratios. Nevertheless, there appears to be a strong indication that
removing and transporting soil to waste burial facilities to achieve
exposure levels at the site at or below a 0.25 mSv/y (25 mrem/y)
unrestricted use dose criterion is generally not cost-effective when
evaluated using NRC's regulatory analysis framework presented in NUREG/
BR-0058 and NUREG-1530. Further, even for a range of cleanup levels at
or above a 0.25 mSv/y (25 mrem/y) criterion, there can also be cases
where costs are unreasonable in comparison to benefits realized.
(c) ALARA analysis for structures containing contamination.
Building floors and walls at nuclear facilities can be contaminated for
a variety of reasons, including system leaks, spills, tracking, and
activation. The large majority of NRC licensed facilities have zero or
limited building contamination. Generally, contamination does not
penetrate the surface of concrete and can be readily removed by water
jets or concrete scabbling. If the building is reused for some new
industrial, office, or other use after license termination, persons can
be in direct contact with the decommissioned floors and walls.
For the range of generic situations considered, the results of the
Final GEIS evaluation indicate that there is a wide range of possible
cost-benefit ratios. It appears that cleanup of concrete to levels at
or below 0.25 mSv/y (25 mrem/y) can be cost effective, depending on the
number of individuals projected to be occupying a building, when using
the decisionmaking guidelines of NUREG/CR-0058 and NUREG-1530.
A.2.3 Conclusions regarding overall approach to license
termination and unrestricted dose criterion. Based on the above
discussion, the Commission has concluded that the overall license
termination approach of this final rule should include:
An unrestricted use dose criterion of 0.25 mSv/y (25 mrem/
y) applicable on a generic basis without site-specific analysis;
Considerations regarding ALARA, including the
decommissioning objective;
A tiered approach of unrestricted use and allowing
restricted use if certain provisions are met; and
Codifying alternate criteria in the rule to alleviate the
need for exemptions in certain difficult site-specific circumstances.
The reasons for these conclusions are discussed in the following
subsections.
A.2.3.1 An unrestricted use dose criterion of 0.25 mSv/y (25 mrem/
y) applicable on a generic basis without site-specific analysis. For
the reasons described above, the Commission is establishing a dose of
0.25 mSv/y (25 mrem/y) as an acceptable criterion for release of any
site for unrestricted use without further analysis of the potential for
exposures from other man-made sources excluding medical. The Commission
concludes that a generic dose constraint or limitation for
decommissioning sources of 0.25 mSv/y (25 mrem/y) for unrestricted use
of a site appears reasonable from the standpoint of providing a
sufficient and ample margin of safety in protection of public health
and safety. This conclusion reflects the Commission's judgment that the
likelihood of individuals being exposed to multiple sources with
cumulative doses approaching 1 mSv/y (100 mrem/y) is quite small. This
conclusion is based on consideration of the kinds of occupancy times
generally expected for the average member of the critical group at
typical decommissioned sites and the low probability that individuals
could realistically be expected to experience significant exposures to
other sources, particularly with a cumulative effect approaching 1 mSv/
y (100 mrem/y). In view of these perspectives, the Commission believes
that a generic dose criterion of 0.25 mSv/y (25 mrem/y) provides a
sufficient and ample, although not necessary, margin to protect the
public.
A.2.3.2 Considerations regarding ALARA, including the
decommissioning objective. The ICRP, NCRP, and draft FRG all suggest
that, in addition to setting a constraint value for an individual
source, achievement of exposures that are ALARA should continue to be
considered as a means of optimization. For this reason and because the
generic analysis of the Final GEIS tends to indicate that achieving
doses below 0.25 mSv/y (25 mrem/y) may be ALARA for some cases, the
rule continues to require an ALARA evaluation below the unrestricted
dose criterion.
It would be useful if the analyses in the Final GEIS could have
arrived at a value of ALARA for all facilities or classes of facilities
so that no further estimate of ALARA would be needed in site-specific
cases. However, it was not feasible for the Commission to use the

[[Page 39066]]

results of the Final GEIS to determine a generic optimum ALARA dose
because of the variety of possible scenarios, assumptions, parameters,
and site-specific conditions that could exist. Nevertheless, the Final
GEIS does contain information about certain trends in impacts and costs
of decommissioning that can be useful in preparation of regulatory
guidance supporting site-specific ALARA provisions. In particular, it
is clear from the Final GEIS that removal of soil to achieve dose
levels below the 0.25 mSv/y (25 mrem/y) dose criterion is generally
unlikely to be cost-effective, whereas it may be for concrete in
certain cases. It is also clear that removal of soil or concrete to
``pre-existing background'' levels is generally not cost effective.
Thus, for those facilities where soil or building contamination
exists, it would be extremely difficult to demonstrate that an
objective of return to background had been achieved. Therefore it is
concluded, as was previously done in the proposed rule, that for these
sites use of the unrestricted dose criterion with appropriate ALARA
considerations would be appropriate. For restricted use, the Final GEIS
suggests that although removal of soil to achieve dose levels below
0.25 mSv/y (25 mrem/y) may not be cost-effective, other simple and less
costly measures to restrict the use of the site such as fencing or
barrier plantings may be cost-effective and should be considered as
part of the ALARA process. For groundwater contamination, as discussed
later in Section IV.D, ALARA considerations should consider the
situation where populations use groundwater plumes from a facility as
drinking water.
In actual situations, it is likely that, even if no specific
analysis of ALARA were required for soil and concrete removal, the
actual dose will be reduced to below 0.25 mSv/y (25 mrem/y) because of
the nature of the removal process. For example, the process of
scabbling of concrete removes a layer of concrete that likely contains
a large fraction of the remaining radioactivity, and the process of
soil excavation is a gross removal process that also is likely to
remove large fractions of the radioactivity.
To clarify the concept of ALARA, the regulatory guidance to be
prepared will refer to the existing requirements of Secs. 20.1003 and
20.1101 where ALARA is defined to include considerations of the state
of technology, economics of improvement in relation to the state of
technology, economics of improvements in relation to benefits to the
public health and safety, and other societal and socio-economic
considerations. Although preparation of guidance is in a preliminary
stage, it is anticipated that this guidance would likely indicate that
ALARA during decommissioning should include typical good practice
efforts (e.g., floor and wall washing, removal of readily removable
radioactivity in buildings or in soil areas), as well as ALARA analyses
for buildings to levels less than 0.25 mSv/y (25 mrem/y) based on the
number of individuals projected to be occupying the building, but that
an ALARA analysis below 0.25 mSv/y (25 mrem/y) for soil removal would
not need to be done. It is expected that use of the dose criterion of
the final rule and the regulatory guidance on ALARA would achieve
consistency with current practices where it is cost-effective to do so.
The Commission also believes that, in any ALARA analysis conducted
to support decisions about site cleanup, all reasonably expected
benefits and detriments resulting from the cleanup activities should be
taken into consideration in balancing costs and benefits. An example of
such a detriment would be transportation deaths that might occur as
contaminated waste is transported away from the site.
A.2.3.3 Tiered approach of unrestricted use and allowing
restricted use if certain provisions are met. It appears reasonable to
retain the basic structure presented in the proposed rule and allow for
both unrestricted and restricted use of sites. Allowance of restricted
use is appropriate because there can be situations where restricting
site use can provide protection of public health and safety by reducing
the TEDE to 0.25 mSv/y (25 mrem/y) in a more reasonable and cost-
effective manner than unrestricted use. This protection is afforded by
limiting the time period that an individual spends onsite or by
restricting agricultural or drinking water use. For many facilities,
the time period needed for restrictions can be fairly short; i.e., long
enough to allow radioactive decay to reduce radioactivity to levels
that permit release for unrestricted use. For example, at reactors,
manufacturing facilities, or broad scope licensees, where the principal
contaminants can have half-lives of 5-30 years (e.g., Co-60, Cs-137),
restricting site use for about 10-60 years can result in achieving
unrestricted use levels. Thus, it continues to be appropriate to allow
restricted use if accompanied by provisions that ensure the
restrictions remain in place to achieve a dose of 0.25 mSv/y (25 mrem/
y). Considerations for assuring that restrictions remain in place and
that public health and safety is protected are discussed further in
Section IV.B. In addition, because restricting site use can affect the
local community, Sections IV.B and IV.E indicate that licensees should
seek advice from such affected parties and, in seeking that advice,
provide for: (1) Participation by representatives of a broad cross
section of community interests, (2) an opportunity for a comprehensive,
collective discussion on the issues, and (3) a publicly available
summary of the results of all such discussions.
A.2.3.4 Codifying alternate site-specific criteria in the rule to
alleviate the need for exemptions in special circumstances. The
preamble to the proposed rule recognized that there could be certain
difficult sites presenting unique decommissioning problems where
licensees would seek exemptions from the rule's requirements. However,
as noted in Section IV.C below, because the Commission finds that it
would be preferable to deal with those facilities under the aegis of a
rule rather than as exemptions, the Commission has included in its
final rule a provision under which the Commission may terminate a
license using alternate criteria in certain specific cases. In allowing
such a provision, it is nevertheless the Commission's judgment that:
(1) It is generally preferable for sites to reduce doses to 0.25 mSv/y
(25 mrem/y) due to the uncertainty over the number of sources where
nuclides may be present for a long time-frame; (2) the large majority
of sites can reduce doses to less than 0.25 mSv/y (25 mrem/y) through
restricting site use; and (3) permitting large numbers of licensees to
propose alternate criteria is not advisable because it would be
contrary to one of the goals of this rulemaking to achieve more
efficient and consistent licensing actions. Therefore, the Commission
has limited the conditions under which a licensee could apply for
alternate criteria and expects that its use would be rare. A licensee
proposing to terminate a license at a site-specific level above 0.25
mSv/y (25 mrem/y) would be required to:
(a) Provide assurance that public health and safety would continue
to be protected by means of a complete and comprehensive analysis of
possible sources of exposure so that it is unlikely that the dose from
all potential man-made sources combined, other than medical, would
exceed the 1 mSv/y (100 mrem/y) public dose limit of 10 CFR part 20;

[[Page 39067]]

(b) Employ, to the extent practical, restrictions on site use for
minimizing exposures at the site using the provisions for restricted
use outlined in Section IV.B, below; and
(c) Reduce doses to ALARA levels.
(d) Seek advice from affected parties regarding this approach and,
in seeking such advice, provide for: (1) Participation by
representatives of a broad cross section of community interests who may
be affected by the decommissioning, (2) an opportunity for a
comprehensive, collective discussion on the issues, and (3) a publicly
available summary of the results of all such discussions, and
(e) Obtain the specific approval of the Commission. The Commission
will make its decision on allowing use of alternate criteria in
specific cases only after consideration of the NRC staff's
recommendations that will address any comments provided by the
Environmental Protection Agency and any public comments submitted
regarding the decommissioning or license termination plan.
A description of these circumstances and potential resolutions on a
site-specific basis, short of exempting a facility from this rule,
appears in Section IV.C.
If license termination still cannot be met even under alternate
criteria, it may be necessary for the site (or a portion thereof) to be
kept under license in order to ensure that exposures to the public are
appropriately monitored. The evaluation of the maintenance of a site or
a portion thereof under a continued license is outside the scope of
this rulemaking because this rule contains provisions addressing
radiological criteria that apply to termination of a license.
A.2.4 Summary of rule revisions on unrestricted use and plans for
implementation. The final rule has been modified to indicate that the
dose criterion for unrestricted use is 0.25 mSv/y (25 mrem/y).
Requirements that a licensee consider how the ALARA requirements of 10
CFR part 20 can be applied to achieve a dose below the dose criterion
have been retained.
Regulatory guidance is planned on how to meet these existing ALARA
requirements. In addition, to assist in implementing the dose
criterion, regulatory guidance will also be issued to provide clear
guidance to licensees on how to demonstrate compliance with the dose
criterion by using either:
(a) Screening analyses that use relatively simple approaches for
demonstrating compliance; or
(b) Site-specific modeling for more complex sites and
contamination. Regulatory guidance will also be issued to provide clear
guidance on statistical tests and survey methods available to licensees
for demonstrating compliance.
The Commission is retaining the distinguishable from background
provision in the final rule to allow release of sites when residual
contamination, if any, cannot be distinguished from background on a
statistical basis using proper survey techniques. In particular, at the
levels of the dose criterion, concentrations of uranium and thorium in
soil are extremely low and may not be distinguishable from background
on a statistical basis even when using proper survey techniques.
A.3 General Comments on the Dose Criterion
A.3.1 Comments. Comments were received on the 0.15 mSv/y (15 mrem/
y) dose criterion that questioned its effect on disposal capacity, the
relationship to naturally occurring radioactive material (NORM), and
the issue of fixing the responsibility for cleanup.
A.3.2 Response. Some commenters were concerned about the effect of
0.15 mSv/y (15 mrem/y) criterion on disposal capacity. As noted in
Section IV.A.2.2, several of the assumptions, models, and approaches in
the GEIS and Regulatory Analysis have been revised to include
additional data and alternate waste disposal costs. A complete
discussion of these revisions and analysis of disposal capacity is in
the Final GEIS and the Regulatory Analysis.
Some commenters questioned the relationship of this rule to NORM.
In response, the criteria of this rule apply to residual radioactivity
from activities under a licensee's control and not to naturally
occurring background radiation. Issues related to NRC-licensed sites
containing materials that occur in nature are discussed in Sections
IV.B and IV.C.
There is a wide variety of sites containing NORM subject to EPA
jurisdiction and not licensed by the NRC. The extent to which criteria
in this rule would apply to these sites would be based on a separate
evaluation although certain aspects of the rule, for example control of
sites with restrictions imposed, could be similar. For further
discussion, see also Section IV.G.6.
With regard to responsibility for cleanup, several commenters
stated that the 0.15 mSv/y (15 mrem/y) limit is too high because
licensees should have to clean up contamination that they created.
Because these are final licensing actions before releasing the site to
the public, they stated that only a lower criterion such as return to
background would adequately protect the public. In response, the NRC
agrees with the need to fix responsibility for decommissioning of
licensed sites. The planning and financial assurance requirements
adopted June 27, 1988 (53 FR 24018), recognized the responsibility of
licensees to plan for the cleanup of their sites and to provide
adequate financial assurance for that cleanup. Similarly in this
regulation, licensees are not permitted to release a facility for
unrestricted or restricted public use unless the dose criteria
stipulated in the rule have been satisfied. As noted in the Final GEIS,
further cleanup to levels such as background is not generally
reasonable because it results in very little additional health benefit
with very large costs incurred and could result in an increase in the
overall risk associated with cleanup of a particular site when all
factors (e.g., estimated fatalities due to transportation accidents
during transport of radioactive wastes) are considered. Therefore, for
the reasons discussed in Section IV.A.2.2, the criteria in the final
rule are considered appropriate to protect public health and safety and
to permit release of the sites and termination of license.
A.4 Average Member of the Critical Group
A.4.1 Comment. Some commenters agreed with provisions of the rule
that would apply the dose limit to an average member of the critical
group rather than to the ``reasonably maximally exposed (RME)
individual'' because it is consistent with ICRP and provides an
appropriate protection standard. Other commenters objected to use of
``an average member of the critical group.'' These commenters favored
applying the dose limit to the most exposed person rather than to an
average person. They asserted that this would be consistent with the
approach used for other licensed activities and environmental
protection.
A.4.2 Response. Section 20.1003 of the proposed rule defined the
term ``critical group'' as the group of individuals reasonably expected
to receive the greatest exposure to residual radioactivity for any
applicable set of circumstances. For example, if a site were released
for unrestricted use, the critical group would be the group of
individuals reasonably expected to be the most highly exposed
considering all reasonable potential future uses of the site. As noted
in the preamble to the proposed rule (at 59 FR 43218; August 22, 1994),
NUREG/CR- 5512 defines the critical group as an individual or
relatively homogeneously exposed

[[Page 39068]]

group expected to receive the highest exposure within the assumptions
of a particular scenario and the dosimetric methods of 10 CFR part 20.
The average member of the critical group is an individual who is
assumed to represent the most likely exposure scenario based on
prudently conservative exposure assumptions and parameter values within
model calculations. For example, the critical group for the building
occupancy scenario can be the group of regular employees working in a
building that has been decontaminated. If a site were converted to
residential use, the critical group could be persons whose occupations
involve resident farming at the site, not an average of all residents
on the site.
Although the terms ``critical group'' and ``average member'' are
new terms in NRC regulations, they are consistent with ICRP practice of
defining and using a critical group when assessing individual public
dose from low levels of radioactivity similar to those expected from a
decommissioned site. ICRP recommends that such analyses should consider
exposure to individuals representative of those expected to receive the
highest dose using cautious but reasonable assumptions. This approach
has been adopted in the proposed FRG and is also consistent with the
recommendations of the National Academy of Sciences on the Yucca
Mountain Standards (August 1995).
A.4.3 Summary of rule revisions. Based on this discussion, the
proposed rule has not been changed.

B. Criteria for Restricted Use (Proposed Rule Secs. 20.1402(d) and
20.1405)

B.1 Proposed Rule Content
As described in the proposed rulemaking and restated in Section
IV.A.2.2, there are potential situations under which termination of a
license under restricted conditions could be used in the
decommissioning of a site. Proposed Sec. 20.1405 indicated that a site
would be considered acceptable for license termination under restricted
conditions if the licensee:
(1) Made provisions for institutional controls that provide
reasonable assurance that the TEDE to the average member of the
critical group would not exceed the unrestricted use dose criterion;
(2) Reduced residual radioactivity at the site so that, if the
controls were no longer in effect, there is reasonable assurance that
the TEDE would not exceed 1 mSv/y (100 mrem/y);
(3) Demonstrated that complying with the unrestricted use dose
criterion would be prohibitively expensive, result in net public or
environmental harm, or not be technically achievable;
(4) Obtained advice on the restrictions from the affected community
by convening a site-specific advisory board, and;
(5) Provided financial assurance to ensure the controls remain in
place.
B.2 Comments on Acceptability of Restricted Use for Decommissioned
Sites
A variety of comments was received on the restricted use option.
The major comment categories are listed below. Although the comment
categories address somewhat separate issues, they are listed and
answered together to develop a unified response on the issue of
restricted use.
B.2.1 The general concept of restricted use. Some commenters
agreed with the proposal to permit restricted use of decommissioned
sites because it may be financially impractical to reach unrestricted
levels, especially if health and safety considerations do not warrant
it and because restricted release allows realistic land uses to be
considered. Some commenters opposed the concept of any planned
restricted release of decommissioned sites because of concerns over the
durability and effectiveness of institutional controls, and because
license termination should be a final action with full licensee
responsibility for site disposition and cleanup costs previously
considered.
B.2.2 The need for licensees to demonstrate that restricted use is
appropriate for their sites. In allowing restricted use, the proposed
rule would have required licensees to demonstrate the appropriateness
of restricting site use for their particular situation by showing that
it would be ``prohibitively expensive,'' ``technically unachievable,''
or cause ``net public or environmental harm'' to achieve unrestricted
use (proposed Sec. 20.1405(a)). Some commenters supported the
restricted use of sites but indicated that the proposed requirements
for demonstrating its appropriateness were unreasonably restrictive.
These commenters stated that the provisions in proposed Sec. 20.1405(a)
were structured so narrowly that few sites would be able to qualify for
license termination under restricted conditions. Commenters stated that
these terms should be explained, deleted, or replaced with a less
onerous requirement allowing restricted use if justified by an ALARA
analysis or if there were continued ownership and industrial use of the
site.
B.2.3 The durability of institutional controls. Several commenters
opposed or expressed concern about the ability of institutional
controls to provide needed protection of public health and safety at
decommissioned sites because they cannot be enforced indefinitely into
the future and can be struck down or become ineffective. Other
commenters favored reliance on more flexible institutional controls and
recommended that the rule should not assume that they will eventually
fail. Approaches for using institutional controls were suggested
including Federal Government ownership of sites or legislative
solutions for complex sites similar to the National Waste Policy Act
(NWPA) of 1982.
B.2.4 The 1 mSv/y (100 mrem/y) cap if institutional controls fail.
Some commenters stated that the proposed 1 mSv/y (100 mrem/y)
restriction is unreasonably low when used to assess the worst case
scenario. They recommended that the rule should not stipulate that a
licensee must assume that all institutional controls will eventually
fail. Alternatively, they recommended that a 5 mSv/y (500 mrem/y)
backup limit be allowed if restrictions such as institutional controls
or engineered features fail. The commenters believed that a 5 mSv/y
(500 mrem/y) limit is consistent with other regulations, since
residential use of an industrial site is unlikely, and failure of
controls is speculative. Several commenters objected to the last
sentence of proposed Sec. 20.1405(d), that stated that licensees may
not assume any benefits from an earthen cover, other earthen barriers,
or engineered controls in complying with the 1 mSv/y (100 mrem/y) cap
unless specifically authorized by the Commission and recommended that
the sentence be deleted. Some commenters recommended that the rule
specify the extent to which licensees may take credit for engineered
barriers. Other commenters stated that 1 mSv/y (100 mrem/y) is too high
and that a lower value (e.g., 0.15, 0.3, 0.5, 0.75 mSv/y (15, 30, 50,
or 75 mrem/y)) should be applied because institutional controls are
uncertain, concerns over health effects would exist, and doses in
excess of 40 CFR Part 190 are unreasonable. Some commenters agreed with
establishing a maximum TEDE of 1 mSv/y (100 mrem/y) in the event
institutional controls are no longer in effect.
B.2.5 Financial assurance for restricted use. Some commenters
questioned the need for financial assurance provisions and suggested
that more flexibility be provided for

[[Page 39069]]

licensees. Other commenters questioned whether the financial assurance
provisions were adequate. One commenter stated that there should be
more detail on financial assurance provided in the rule.
B.3 Response
B.3.1 The general concept of restricted use. Current NRC
regulations pertaining to decommissioning, issued on June 27, 1988 (53
FR 24018), do not contain provisions for release of a facility for
restricted use but limit a licensee's options in decommissioning to
release of a facility for unrestricted use. Experience with
decommissioning of facilities since 1988 has indicated that for certain
facilities, achieving unrestricted use might not be appropriate because
there may be net public or environmental harm in achieving unrestricted
use, or because expected future use of the site would likely preclude
unrestricted use, or because the cost of site cleanup and waste
disposal to achieve unrestricted use is excessive compared to achieving
the same dose criterion by restricting use of the site and eliminating
exposure pathways. The input received from the rulemaking workshops
held from January through May 1993 confirmed this experience and
indicated that restricted use of a facility, if properly designed and
if proper controls were in place, was a reasonable means for
terminating licenses at certain facilities.
Current NRC-licensed sites that might request restricted use are
largely industrial sites. It is reasonable for them to remain
industrial because of their locations and previous siting
considerations. Nevertheless, there may be instances where, if a site
had high cultural value, such considerations would be presented as part
of the public input that is part of the process of restricted use (see
Section IV.E) and could be considered as a socioeconomic effect under
the ALARA process.
The proposed rule thus provided for both unrestricted and
restricted use of sites. Both the Draft and Final GEIS provide
discussions of the environmental impact of decommissioning for the
reference sites and of the costs related to decommissioning. From this
it may be concluded that release of certain facilities for restricted
use is an appropriate option assuming the presence of the specific
provisions described below to ensure that appropriate controls are in
place so that the restrictions on use remain in effect.
B.3.2 The need for licensees to demonstrate that restricted use is
appropriate for their sites. As described in Section IV.B.3.1, the
proposed rule allowed restricted use because release of a site under
restricted conditions can be an appropriate method of decommissioning
from both health and safety, and cost-benefit bases, especially for
certain facilities with soil contamination. Nevertheless it did so
under the philosophy (stated in Sec. 20.1402(d)) that, in general,
termination of a license for unrestricted use is preferable because it
requires no additional precautions or limitations on use of the site
after licensing control ceases, in particular for those sites with
long-lived nuclides. In addition, there may be societal or economic
benefits related to future value of the unrestricted use of the land to
the community. Thus, Sec. 20.1405(a) of the proposed rule stated the
provisions the NRC would consider in evaluating a request for
termination of a site under restricted conditions, including that it is
``prohibitively expensive'' or there is ``net public or environmental
harm'' in achieving unrestricted release.
The Commission continues to believe that unrestricted use is
generally preferable for the reasons noted. However, the NRC has
reexamined the provisions for allowing restricted use because of the
potential benefits. In explaining the provision of ``prohibitive''
cost, the proposed rule noted (at 59 FR 43220) that costs to achieve
unrestricted use may be ``excessive,'' indicating that this means there
may be situations where removal and disposal of large quantities of
material is simply ``not reasonable'' from a cost standpoint.
Consistent with this, the proposed rule noted in Sec. 20.1402(d) that
the Commission expected licensees to make every reasonable effort to
achieve unrestricted release. The specific cost that would be
considered excessive, not reasonable, or prohibitive was not included
in the proposed rule. This value depends on costs of unrestricted and
restricted use, and on an evaluation of these alternatives using the
regulatory analysis framework presented in NUREG/BR-0058 and NUREG-
1530. NUREG/BR-0058 provides a decisionmaking tool for deciding between
regulatory alternatives. As noted in the discussion below, restricted
use with appropriate institutional controls (accompanied by sufficient
provisions for ensuring their effectiveness) can provide protection of
public health and safety because the dose level will be reduced to the
same 0.25 mSv/y (25 mrem/y) criterion as for unrestricted use. Thus,
use of the guidelines in NUREG/BR-0058 is appropriate for determining
whether restricted use should be permitted. Therefore, the Commission
has modified the rule to incorporate an ALARA standard rather than
prohibitive costs as the basis for selecting restricted use. To support
a request for restricted use, a licensee would perform an ALARA
analysis of the risks and benefits of all viable alternatives and
include consideration of any detriments. This could include estimated
fatalities from transportation accidents that might occur as the result
of transport of wastes from cleanup activities, and societal and
socioeconomic considerations such as the potential value to the
community of unrestricted use of the land.
The proposed rule also noted that because the net public or
environmental damage through removal, transport, and disposal of
materials could be larger than the benefit in dose reduction at the
site, it may be more reasonable for the material to remain onsite. The
Final GEIS illustrates when it may be inappropriate, when considering
such relative impacts, to completely remediate a site to an
unrestricted level that assumes activities such as farming or
residence, and then, as would be the case for a number of currently
licensed sites, actually employ a commercial or industrial use that
would eliminate significant pathways of exposure. Specific examples
include reactors or other materials facilities where the dose is
controlled by relatively short-lived nuclides (e.g., Co-60 and Cs-137
with half-lives of 5.3 and 30 years, respectively) that will decay to
unrestricted dose levels in a finite time period of institutional
control (e.g., about 10-60 years). For these facilities, there may be
net public or environmental harm from removing and transporting soil to
achieve unrestricted use compared to restricting use for a period of
time associated with a reasonable decay period (see the Final GEIS,
Chapter 6). Thus, the consideration of potential detriments from
cleanup activities and the possibility of net harm have been retained
in the final rule. Both terms, net public harm and net environmental
harm, are retained in the final rule to indicate that a licensee's
evaluation should consider the radiological and nonradiological impacts
of decommissioning on persons who may be impacted, as well as the
potential impact on ecological systems from decommissioning activities.
B.3.3 The durability of institutional controls. As described in
Sections IV.B.3.1 and IV.B.3.2, use of restrictions that employ
institutional controls appears appropriate in specific

[[Page 39070]]

situations. However, an important question raised in the public
comments relates to the durability of institutional controls, i.e.,
whether the controls provide reasonable assurance that the exposure
will be limited to the dose criterion in the rule over the periods in
question.
For many types of decommissioned sites released under restricted
conditions where potential doses to an individual are caused by
relatively short-lived nuclides, the radiation exposure that could
potentially be received were controls to fail will gradually decrease
to below the unrestricted dose criterion so the restrictions on use
would no longer be necessary. Examples of facilities with nuclides of
this type include reactors or materials facilities for which the
principal dose contributing nuclides after decommissioning are Co-60 or
Cs-137 (half-lives 5.3 and 30 years, respectively), or other similarly
short-lived nuclides. The Commission has considered the effectiveness
of institutional controls for up to 100 years in similar contexts such
as low-level waste disposal sites. Because decommissioned facilities
will have minimal contamination compared to large volumes buried at
low-level disposal sites, the Commission believes that institutional
controls using relatively simple deed restrictions can provide
reasonable assurance that the TEDE will be below the 0.25 mSv/y (25
mrem/y) dose criterion with restrictions in place.
In a limited number of cases, in particular those involving large
quantities of uranium and thorium contamination, the presence of long-
lived nuclides at decommissioned sites will continue the potential for
radiation exposure beyond the 100-year period. More stringent
institutional controls will be required in these situations, such as
legally enforceable deed restrictions and/or controls backed up by
State and local government control or ownership, engineered barriers,
and Federal ownership, as appropriate. Federal control is authorized
under Section 151(b) of the National Waste Policy Act (NWPA). Requiring
absolute proof that such controls would endure over long periods of
time would be difficult, and the Commission does not intend to require
this of licensees. Rather, institutional controls should be established
by the licensee with the objective of lasting 1000 years to be
consistent with the time-frame used for calculations (and discussed in
Section IV.F.7). Having done this, the licensee would be expected to
demonstrate that the institutional controls could reasonably be
expected to be effective into the foreseeable future.
To provide added assurance that the public will be protected, the
final rule incorporates provisions (Sec. 20.1405(c)) for financial
assurance to ensure that the controls remain in place and are effective
over the period needed. With these provisions, the Commission believes
that the use of reliable institutional controls is appropriate and that
these controls will provide a high level of assurance that doses will
not exceed the dose criterion for unrestricted use.
Although the Commission believes that failure of active and passive
institutional controls with the appropriate provisions in place will be
rare, it recognizes that it is not possible to preclude the failure of
controls. Therefore, in the proposed rule, the Commission included a
requirement that remediation be conducted so that there would be a
maximum value (``cap'') on the TEDE from residual radioactivity if the
institutional controls were no longer effective in limiting the
possible scenarios or pathways of exposure. The cap included in the
proposed rule was 1 mSv/y (100 mrem/y), which is the public dose limit
codified in 10 CFR part 20. Public comments on the proposed rule
suggested other values for the cap, both higher than and lower than the
proposed value. The analysis of those comments, and their potential
effect on the institutional controls used, is discussed in Section
IV.B.3.4.
The Commission believes, based on the discussion in this section on
the viability of controls and on the provisions for financial assurance
and for a ``cap,'' described in Sections IV.B.3.4 and IV.B.3.5, that
the provision for restricted use and institutional controls will
provide a high level of assurance that public health and safety will be
protected. Licensees seeking restricted use will be required to
demonstrate, to NRC's satisfaction, that the institutional controls
they propose are comparable to those discussed above, are legally
enforceable, and are backed by financial assurance. Licensees will also
be required to demonstrate that the cap will be met. The Commission
believes that the provision for restricted use should be retained in
the final rule.
B.3.4 The 1 mSv/y (100 mrem/y) cap if institutional controls fail.
A ``cap'' of 1 mSv/y (100 mrem/y), corresponding to the public dose
limit, was proposed in Sec. 20.1405(d) of the proposed rule. Various
possible ``cap'' values were suggested by the commenters, both lower
than (e.g., values such as 0.15, 0.3, or 0.85 Sv/y (15, 30, or 85 mrem/
y)) or higher than the proposed cap.
The Commission has reviewed the comments suggesting that the
specific cap value be set at levels other than 1 mSv/y (100 mrem/y).
The rationale for setting the cap at 1 mSv/y (100 mrem/y) presented in
the proposed rule (at 59 FR 43221) was that the value of the cap
coincides with NRC's public dose limit of 10 CFR Part 20. This value
was premised on the assumption that circumstances could develop in
which the restrictions might no longer be effective in limiting the
exposure scenarios or pathways. Although this occurrence need not be
assumed for planning purposes, a safety net is needed to prevent
exposures in excess of the public dose limits. A cap using the public
dose limits would provide an additional level of protection in the
unlikely event that restrictions were not effective. Although, as noted
in Section IV.A.2, the Commission has used a fraction of the public
dose limit in setting the 0.25 mSv/y (25 mrem/y) dose limit for
decommissioning, it indicated in the proposed rule that, in the case of
the ``cap'' or ``safety net,'' it did not believe that fractionation,
i.e., setting a cap value less than 1 mSv/y (100 mrem/y), would be
necessary because:
(a) The 1 mSv/y (100 mrem/y) cap is less than values suggested in
the proposed FRG for members of the public in unusual circumstances and
less than values used for other types of facilities where some type of
institutional control is used;
(b) The Commission believes that failure of all site restrictions
at decommissioned sites is a highly unlikely event; and
(c) Radioactive decay for relatively short-lived nuclides (e.g.,
Co-60 and Cs-137), that are the principal dose contributing
contaminants at the large majority of NRC licensed facilities, will
actually reduce the dose level over a period of time for most sites
that will provide an additional margin of safety equivalent to
fractionation of the limit.
The rationale for setting a cap value at 1 mSv/y (100 mrem/y)
continues to appear appropriate. In addition, setting a cap at a lower
value does not appear warranted because: (1) It appears arbitrary to
assume that the same person would be an average member of the critical
group both near a facility where there was failure of controls and near
another decommissioned facility; and (2) the failure of restrictions
would be infrequent and therefore it is likely that the overall
lifetime risk to the critical group would still be maintained at levels
comparable to unrestricted use

[[Page 39071]]

while providing a more cost-effective use of resources.
Although the Commission did not fractionate the cap, it did include
in the proposed rule, and continues to include in the final rule, a
provision that would require exposures to be below the cap to a degree
that is ALARA. The purpose of this requirement is that licensees would
not simply leave behind contamination corresponding to the value of the
cap but would evaluate the level below the cap that is cost effective
and reduce the contamination to that level. This will provide a
requirement that will effectively fractionate the doses and result in
doses not dissimilar from those suggested by the commenters if it is
cost-effective to do so. This approach is consistent with the current
requirements in 10 CFR part 20.
Based on its experience with sites with difficult contamination
issues, in particular those sites treated in NRC's SDMP, and as
described in the Final GEIS, the Commission anticipates that there may
be sites where compliance with the 1 mSv/y (100 mrem/y) cap could cause
impacts resulting from cleanup to that level (e.g., estimated
industrial or traffic fatalities associated with removing or
transporting waste) that exceed the benefits of averting radiation
exposure (thus causing a net detriment to public health or the
environment) or that diminish the net benefit to where costs of cleanup
would be prohibitive compared to the net benefit. Although the NRC
recognizes that it is always the licensee's responsibility to clean up
the contamination that it has caused, the appropriate course of action
should not result in net public or environmental harm from a cleanup,
and it is not clear that it is beneficial if resources are spent in a
manner prohibitive in relation to other benefits which could be
achieved, or if a licensee is put into a financial position where it
cannot continue to perform the cleanup safely.
Although a cap higher than 1 mSv/y (100 mrem/y) would result in
using a value in excess of the public dose limit in Sec. 20.1301(a),
existing requirements in Sec. 20.1301(c) permit levels up to values of
5 mSv/y (500 mrem/y), provided that a licensee would apply to the
Commission for permission to operate at that level, submit reasons why
it is necessary, and indicate procedures to maintain doses ALARA. The
proposed FRG, Recommendation No. 4, states that the dose from all
sources should not exceed 1 mSv/y (100 mrem/y) although it may be
exceeded temporarily in unusual situations that are not expected to
recur.
Based on this existing requirement, the Commission has incorporated
a specific provision in the final rule under which a licensee could
propose exceeding the 1 mSv/y (100 mrem/y) cap in unusual site-specific
circumstances if, in addition to the normal provisions of restricted
use, it also met the following additional stringent provisions:
(a) A licensee would have to demonstrate that it cannot meet the 1
mSv/y (100 mrem/y) cap because of net public or environmental harm or
prohibitive costs by means of a site-specific evaluation of the issues
associated with complying with the 1 mSv/y (100 mrem/y) cap. The NRC
expects that only a very few facilities (e.g., sites with soil
contaminated with naturally occurring radionuclides in small
radioactivity levels but large volumes, certain SDMP sites) could
provide sufficient rationale for seeking a higher cap. Although the
proposed rule contained a reference to the use of prohibitive cost, it
did not quantify or define these costs beyond noting that they would be
excessive or unreasonable. The Commission believes it appropriate to
consider a prohibitive cost to be one that would be an order of
magnitude greater than that contained as part of the decisionmaking
guidelines in NUREG/BR-0058, although a lower factor may be appropriate
in specific situations when a licensee could become financially
incapable of carrying out decommissioning safely;
(b) Under these circumstances, the licensee would be required to
reduce contamination so doses would be no greater than the 5 mSv/y (500
mrem/y) value currently contained in Sec. 20.1301(a). Also, the actual
dose level to which the licensee would have to clean the site would be
less than that value based on an ALARA evaluation of the site. This
provision is consistent with existing requirements in Sec. 20.1301(c)
that permit levels up to values of 5 mSv/y (500 mrem/y) for specific
cases;
(c) Durable institutional controls must be in place. These controls
could include significant engineered barriers and/or State, local, or
Federal Government control of sites or maintenance of site deed
restrictions so that site access is controlled. Under Section 151(b) of
the NWPA of 1982, the DOE has already been authorized to take
possession of waste disposal sites in certain situations. A similar
provision in Section 151(c) was used as the vehicle to transfer custody
of the Amax site from Amax to DOE;
(d) A licensee would make provisions for a verification of the
continued effectiveness of institutional controls at the site every 5
years after license termination to ensure that the institutional
controls are in place and the restrictions are working, and that there
is financial assurance to reestablish controls if the recheck indicates
otherwise. This 5-year recheck is consistent with 10 CFR Part 20 and
also with the FRG, Recommendation No. 4, that states that in some
unusual situations the 1 mSv/y (100 mrem/y) may be exceeded temporarily
in situations that are not anticipated to recur. It is also consistent
with the approach for institutional controls used in CERCLA that allows
for release of sites without a cap providing there is continuous
checking on the status of the controls.
The NRC would retain the authority to take appropriate action in
those unusual situations when both the 5 mSv/y (500 mrem/y) cap was in
effect and the controls had failed. This action might include oversight
of actions needed to reinstate the controls and any necessary cleanup
and/or monitoring actions.
B.3.5 Financial assurance. As a second provision for ensuring that
the institutional controls provide protection of public health and
safety, financial assurance requirements were included to ensure that
funds will be available to enable an independent third party, including
a governmental custodian of a site, to implement and ensure continued
effectiveness of institutional controls. Some commenters questioned
whether these provisions were necessary while others questioned whether
they went far enough. In response, the Commission continues to believe
the proposed provisions are reasonable and adequate for their purpose.
The provisions are consistent with financial assurance requirements
currently in 10 CFR Parts 30, 40, 50, 61, 70, and 72 which call for
financial assurance to provide funds for decommissioning in cases when
licensees might otherwise be financially unable to remediate a site.
Reference to an independent third party is necessary in the regulations
because after the license is terminated, the licensee may no longer be
the party ensuring the effectiveness of the controls. Because the
purpose of this provision is to provide broad requirements for
financial assurance necessary to ensure that the controls continue to
limit the dose, more specific details are not included in the rule. The
level of detail in the rule is similar to that in other similar NRC
regulations on financial assurance. As requested by a commenter, the
funding provisions include a trust fund (or similar funding mechanism)
for

[[Page 39072]]

surveillance and enforcement of the institutional controls. The
financial assurance requirements must be in place before the license is
terminated and be flexible enough to allow for the necessary site-
specific details.
B.4 Summary of Rule Revisions on Restricted Use
Based on the discussions above, restricted use has been retained in
the final rule. Based on its analyses in the Final GEIS and its
experiences with actual decommissioned sites, the Commission recognizes
that, although unrestricted use is generally preferred, restricted use
(when properly designed in accordance with the rule's provisions
discussed in Section IV.B.3) can provide a cost-effective alternative
to unrestricted use for some facilities and maintain the dose to the
average member of the pertinent critical group at the same level. Thus,
the Commission has replaced the prohibitively expensive provision for
justifying restricted use with a reasonable cost provision. The net
harm provision remains the same. The general cap value has been
retained at 1 mSv/y (100 mrem/y) as has the requirement that licensees
reduce the actual level of contamination to levels as far below the cap
as is ALARA, where appropriate. The rule has been modified to allow for
exceeding the 1 mSv/y (100 mrem/y) cap in site-specific situations and
under specific provisions. No change has been made to the financial
assurance provisions of the rule.
A number of comments were also received on public participation
aspects of restricting site use. The final rule will require that
licensees proposing to decommission by restricting use of a site shall
seek advice from individuals and institutions in the community who may
be affected by the decommissioning and that, in seeking that advice,
the licensee shall provide for: (1) Participation by representatives of
a broad cross section of community interests who may be affected by the
decommissioning; (2) an opportunity for a comprehensive, collective
discussion on the issues by the participants represented; and (3) a
publicly available summary of the results of all such discussions,
including a description of the individual viewpoints of the
participants on the issues and the extent of agreement and disagreement
among the participants on the issues. The details of the comments
received and the rationale for the public participation aspects of the
final rule are discussed in Section IV.E.

C. Alternate Criteria for License Termination

C.1 Codifying Provisions for Certain Facilities That the Proposed Rule
Suggested Exempting
C.1.1 Proposed rule content. The preamble to the proposed rule
noted that there were several existing licensed sites where public
health and the environment may best be protected by use of alternate
criteria, although these situations were not codified in the proposed
rule; rather, it was thought that these facilities might seek
exemptions (under Sec. 20.2301) from the criteria of this rule.
C.1.2 Comments. Some commenters recommended that the rule should
not apply to any facility that possesses large volumes of low-level
contaminated wastes (including SDMP sites) and should provide a
specific exemption or exemption procedures for the ``tens'' of existing
facilities for which application of the proposed criteria is
inappropriate and too restrictive. Commenters suggested that guidance
is needed on sites that should be turned over to the Federal Government
after license termination and sites that should be kept under license.
Commenters also recommended that NRC ask Congress to amend the NWPA of
1982 to allow Federal ownership of extensively contaminated sites.
Other commenters objected to exempting facilities from the proposed
radiological criteria and stated that the rule should cover all
decommissioning cases.
C.1.3 Response. For the very large majority of NRC-licensed sites,
the Commission believes that the 0.25 mSv/y (25 mrem/y) unrestricted
and restricted use dose criterion in the rule is an appropriate and
achievable criterion for decommissioning.
However the Commission is concerned about the possible presence of
certain difficult sites presenting unique decommissioning problems.
Licensees of these sites who would have sought exemptions to the
proposed rule's criteria would have had to follow processes similar to
the other facilities covered by the rule. In addition, licensing
efficiency, consistency of application of requirements, and oversight
of these facilities can best be achieved by codifying application of
criteria to all facilities. Therefore, the Commission believes that it
is preferable to codify provisions for these facilities under the aegis
of the rule rather than requiring licensees to seek an exemption
process outside the rule as was contemplated in the proposed
rulemaking.
In addition, as discussed in Section IV.A, the Commission has
concluded that for any site where the 0.25 mSv/y (25 mrem/y) dose
criterion is met, there will be a very low likelihood that individuals
who use the site will be exposed to multiple man-made sources combined,
excluding medical, with cumulative doses approaching 1 mSv/y (100 mrem/
y). Thus, the discussion in Section IV.A of this notice establishes
this level as a sufficient and ample, but not necessary, margin of
safety.
Based on these considerations, the Commission has included in the
final rule a provision under which the Commission may terminate a
license using alternate criteria in its final rule. The Commission
expects the use of alternate criteria to be confined to rare
situations. Therefore, for the reasons previously listed in Section
A.2.3.4, the Commission has limited the conditions under which a
licensee would apply to the NRC for, or be granted use of, alternate
criteria to unusual site-specific circumstances subject to the
following provisions:
(a) A licensee must provide assurance that, for the site under
consideration, it is unlikely that the dose to an average member of the
critical group for that site from all potential man-made sources
combined, other than medical, would exceed the 1 mSv/y (100 mrem/y)
public dose limit of 10 CFR Part 20. The Commission envisions that a
licensee proposing to use alternate criteria will have to provide a
complete and comprehensive analysis that would build upon generic
considerations such as those discussed in Section IV.A.2, and also
include site-specific considerations. To guide the Commission in its
review of such analyses, the NRC is continuing to develop generic
information on the potential for exposure to radioactivity from various
sources, including decommissioned sources, to supplement currently
available knowledge, and is planning to make this information publicly
available through publication of a NUREG report. Site-specific factors
that the Commission might review in such cases could include soil and
aquifer characteristics, the nature of the critical groups likely to
use the site, the detailed nature of the contamination patterns at the
site, and the characteristics of residual radionuclides remaining at
the site, including considerations related to whether the nuclides are
long-lived or short-lived;
(b) A licensee will employ, to the extent practical, restrictions
on site use for minimizing exposure at the site using the provisions
for restricted use

[[Page 39073]]

outlined in IV.B, above, and in Sec. 20.1403;
(c) A licensee will indicate that a comprehensive analysis had been
performed of the risks and benefits of all viable alternatives and
consideration of any detriments, such as transportation fatalities that
might occur as the result of cleanup activities, to reduce the residual
radioactivity at the site to levels that are ALARA;
(d) A licensee will seek advice from affected parties regarding
this approach. In seeking such advice, the licensee will provide for:
(1) Participation by representatives of a broad cross section of
community interests who may be affected by the decommissioning; (2) an
opportunity for a comprehensive, collective discussion on the issues by
the participants represented; and (3) a publicly available summary of
the results of all such discussions, including a description of the
individual viewpoints of the participants on the issues and the extent
of agreement and disagreement among the participants on the issues (the
rationale for these public participation aspects are discussed in more
detail in Section IV.E); and
(e) A licensee will obtain the specific approval of the Commission
for the use of alternate criteria. The Commission will make its
decision after consideration of the NRC staff's recommendations that
will address any comments provided by the Environmental Protection
Agency and any public comments submitted regarding the decommissioning
or license termination plan.
If the license termination conditions under alternate criteria
cannot be met, it may be necessary for the site (or portion thereof) to
be kept under license to ensure that exposures to the public are
appropriately monitored. The evaluation of maintenance of a site or a
portion of that site under continued license is outside the scope of
this rulemaking because this rule contains provisions, including
radiological criteria, that apply to termination of a license.
With regard to the comment on the NWPA, it should be noted that
Section 151(b) of the NWPA already authorizes ownership by the U.S.
Department of Energy, if NRC makes certain determinations. Therefore,
no further legislation is needed to grant this authority. The rule
language has been clarified to ensure that this authority may be
implemented by NRC and DOE.
C.1.4 Summary of revisions to rule on codifying provisions for
certain facilities. The rule has been modified to include the use of
alternate criteria in specialized circumstances and under the
provisions described above.
C.2 Exclusion of Uranium/Thorium Mills Proposed in Sec. 20.1401(a)
C.2.1 Proposed rule content. The proposed rule stated that, for
uranium mills, the criteria of the rule apply to the facility but do
not apply to the disposal of uranium mill tailings or to soil cleanup.
The proposed rule referred to 10 CFR Part 40, Appendix A, where
criteria already exist (Sec. 20.1401(a)).
C.2.2 Comments. Comments on the proposed rule generally agreed
with the exclusion for disposal of mill tailings and soil cleanup.
Commenters also recommended that the rule exempt conventional thorium
and uranium mill facilities and in situ leach (ISL) (specifically
uranium solution extraction) facilities from the scope of coverage
because they stated that the decommissioning of these sites is covered
by Appendix A to 10 CFR part 40 and 40 CFR part 192.
C.2.3 Response. Currently, there are regulations applicable to
remediation of both inactive tailings sites, including vicinity
properties, and active uranium and thorium mills. Under the Uranium
Mill Tailings Radiation Control Act (UMTRCA) of 1978, as amended, EPA
has the authority to set cleanup standards for uranium mills and, based
on that authority, issued regulations in 40 CFR part 192 which contain
remediation criteria for these facilities. NRC's regulations in 10 CFR
part 40, Appendix A, apply to the decommissioning of its licensed
facilities and conform to EPA's standards for uranium mills. At ISLs,
the decommissioning activities are similar to those at uranium mills
and consist mainly of the cleanup of byproduct material as defined in
Section 11e.(2) of the Atomic Energy Act of 1954, as amended.
Thus, applicable cleanup standards already exist for soil cleanup
of radium in 10 CFR part 40, Appendix A, Criterion 6(6). Radium is the
main contaminant at mills in the large areas (20-400 hectares (50 to
1000 acres) for uranium mills) where windblown contamination from the
tailings pile has occurred, and at ISLs (in holding ponds). These
standards require that the concentration of radium in those large areas
not exceed the background level by more than 0.19 Bq/gm (5 pCi/gm) in
the first 15 cm (6 inches) of soil, and 0.56 Bq/gm (15 pCi/gm) for
every 15 cm (6 inches) below the first 15 cm (6 inches). Cleanup of
radium to these concentrations would generally result in doses higher
than the unrestricted use dose criterion of this rulemaking, although,
in actual practice, cleanup of uranium mill tailings results in radium
levels lower than the 10 CFR part 40 standards, and radium is usually
removed to background levels during cleanup of uranium and thorium to
the levels in existing NRC guidance documents.
However, in other mill and ISL site areas proximate to locations
where radium contamination exists (e.g., under the mill building, in a
yellow cake storage area, under/around an ore pad, and at ISLs in soils
where spray irrigation has occurred as a means of disposal), uranium or
thorium would be the radionuclide of concern. A difficulty in applying
10 CFR part 40, Appendix A, as a standard for uranium and thorium, is
that it does not have any cleanup standards for soil contamination from
radionuclides other than radium. Application of the decommissioning
dose criterion of the final rule to these areas (while retaining the 10
CFR 40, Appendix A, standard for radium) would result in a situation
where the cleanup standard of that small portion of the mill site would
be lower than the standard for the large windblown tailings areas where
radium is the nuclide of concern. This would result in situations of
differing criteria being applied across essentially the same areas and
would be a problem for contamination existing both in uranium mill
soils and buildings.
The Commission has considered the most appropriate means to address
requirements for cleanup at uranium and thorium mills and ISLs
(collectively referred to as UR facilities) for unrestricted release of
the site other than tailings disposal and reclamation subject to the
requirements of 10 CFR part 40, Appendix A. One way would be to include
criteria for UR facilities as part of this rulemaking. However, as
noted above, there are complexities associated with decommissioning of
these unique facilities which could cause practical problems in
applying the standards of this rulemaking to UR facilities. Therefore,
the Commission has decided to exclude UR facilities from the scope of
this rulemaking.
To allow for full consideration by the Commission and affected
parties of the issues associated with decommissioning UR facilities and
of the regulatory options listed above, the Commission is publishing a
separate notice in this Federal Register reopening the comment period
to specifically request additional comment on the regulatory options
for decommissioning criteria for UR facilities. The Commission is not
reopening the comment period for any other issue discussed in this
Federal

[[Page 39074]]

Register notice. In the interim, the Commission will continue its
current practices for decommissioning UR facilities.
C.2.4 Summary of rule revisions for uranium/thorium mills. The
Commission is excluding uranium/thorium mills from the scope of this
rulemaking and is publishing a separate notice requesting additional
comment on the specific standard for license termination of UR
facilities.
C.3 Other Exemptions
C.3.1 Comments. Commenters suggested certain other exemptions

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A97-17752. Public record. Not legal advice.