Savannah River Operations Office; Interim Management of Nuclear Materials at the Savannah River Site

DEPARTMENT OF ENERGY

Savannah River Operations Office; Interim Management of Nuclear

Materials at the Savannah River Site

AGENCY: Department of Energy.

ACTION: Supplemental Record of Decision.

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SUMMARY: The U.S. Department of Energy (DOE) prepared a final

environmental impact statement (EIS), ``Interim Management of Nuclear

Materials'' (DOE/EIS-0220, October 20, 1995), to assess the potential

environmental impacts of actions necessary to manage nuclear materials

at the Savannah River Site (SRS), Aiken, South Carolina, until

decisions on their ultimate disposition are made and implemented.

On December 12, 1995 (60 FR 65300), DOE issued a Record of Decision

(ROD) and Notice of Preferred Alternatives on the interim management of

several categories of nuclear materials at the SRS. DOE is now issuing

its decisions on actions that will stabilize two additional categories

of materials at the SRS, which present environment, safety and health

vulnerabilities in their current storage condition or may present

vulnerabilities within the next 10 years. The decisions on the

stabilization of two additional categories of nuclear materials,

neptunium-237 solution and targets, and H-Canyon plutonium-239

solutions, are not being made at this time.

Mark-16 and Mark-22 Fuels

DOE has decided to stabilize the Mark-16 and Mark-22 fuels by

processing them in the SRS canyon facilities and blending down the

resulting highly enriched uranium (HEU) to low enriched uranium (LEU).

The LEU solution will be stored or converted to an oxide in the FA-

Line. Neptunium-237 separated during the stabilization processing of

the Mark-16 and Mark-22 fuels will be stabilized with the other SRS

neptunium. The Department is still considering which of the management

options for neptunium to implement.

Other Aluminum-Clad Targets

DOE has decided to stabilize the ``other aluminum-clad targets'' by

dissolving them in the SRS canyon facilities and transferring the

resulting nuclear material solution to the high level waste tanks for

future vitrification in the Defense Waste Processing Facility (DWPF).

FOR FURTHER INFORMATION CONTACT: For further information on the interim

management of nuclear materials at the SRS or to receive a copy of the

Final EIS, the Facility Utilization Strategy study, the initial ROD and

Notice, or this supplemental ROD contact: Andrew R. Grainger, NEPA

Compliance Officer, U.S. Department of Energy, Savannah River

Operations Office, P.O. Box 5031, Aiken, South Carolina 29804-5031,

(800) 242-8259, Internet: [email protected].

For further information on the DOE National Environmental Policy

Act (NEPA) process, contact: Carol M. Borgstrom, Director, Office of

NEPA Policy and Assistance, EH-42, U.S. Department of Energy, 1000

Independence Avenue, SW., Washington, DC 20585, (202) 586-4600, or

leave a message at (800) 472-2756.

SUPPLEMENTARY INFORMATION:

I. Background

The U.S. Department of Energy (DOE) prepared the final

environmental impact statement (EIS), ``Interim Management of Nuclear

Materials'', (DOE/EIS-0220, October 20, 1995), to assess the potential

environmental impacts of actions necessary to manage nuclear materials

at the Savannah River Site (SRS), Aiken, South Carolina, until

decisions on their ultimate disposition are made and implemented.

The Final EIS identified continued storage (i.e., No Action) as the

preferred alternative for the Mark-16 and Mark-22 fuels and the ``other

aluminum-clad targets'' until DOE could complete additional reviews of

costs, schedules, and technical uncertainties associated with dry

storage techniques for failed fuel.

On December 12, 1995 (60 FR 65300), DOE issued a Record of Decision

(ROD) and Notice of Preferred Alternatives on the interim management of

several categories of nuclear materials at the SRS. At that time, DOE

announced new preferred alternatives for the management of the Mark-16

and Mark-22 fuels (processing and blending down to LEU) and the ``other

aluminum-clad targets'' (processing and storage for vitrification in

the DWPF). In addition, DOE indicated that neptunium-237 solution and

targets would be stabilized through either processing to oxide or

vitrification, and that plutonium-239 solutions in H-Canyon would be

stabilized through processing to metal, processing to oxide, or

vitrification. For each of these material categories, only one

stabilization method will be implemented. The stabilization alternative

chosen is dependent upon whether the materials would be stabilized in

the SRS's F- or H-Canyon, as discussed in a DOE staff study, Facility

Utilization Strategy for the Savannah River Site Chemical Separation

Facilities (December 1995). DOE is still considering the facility

utilization strategy study and other related information.

[[Page 6634]]

II. Alternatives Evaluated in the Final EIS

DOE evaluated the following alternatives for managing the Mark-16

and Mark-22 fuels and the other aluminum-clad targets at the SRS: (A)

Continuing Storage (i.e., ``No Action'' within the context of NEPA),

(B) Processing to Oxide, (C) Blending Down to Low Enriched Uranium, (D)

Processing and Storage for Vitrification in the DWPF, and (E) Improving

Storage. The following is a brief description of the alternatives

evaluated.

A. Continuing Storage (No Action)

This alternative was evaluated for the fuels and targets considered

in this supplemental ROD. Under this alternative, DOE would continue to

store the materials in their current physical and chemical form. DOE

would relocate, repackage, or re-can materials stored in basins to

consolidate the material or to respond to an immediate safety problem.

Periodic sampling, destructive and non-destructive examination,

weighing, visual inspection and similar activities would continue in

order to monitor the physical and chemical condition of the nuclear

material. Repackaging would include removing materials from a damaged

storage container and placing them in a new container or placing the

damaged container in a larger container. Re-canning would primarily

entail placing damaged or degraded fuel or targets in metal containers,

sealing the containers, and keeping them in wet storage.

Many activities would be required by DOE irrespective of the

management alternative used. For example, DOE would maintain facilities

in good working condition and would continue to provide utilities

(water, electricity, steam, compressed gas, etc.) and services

(security, maintenance, fire protection, etc.) for each facility.

Training activities would ensure that personnel maintain the skills

necessary to operate the facilities and equipment. DOE would continue

with ongoing projects to alleviate facility-related vulnerabilities

associated with storage of the materials and projects to upgrade or

replace aging equipment (ventilation fans, etc.).

B. Processing to Oxide

For purposes of this supplemental ROD, this alternative is only

relevant to the Mark-16 and Mark-22 fuels. DOE would dissolve and

process the Mark-16 and Mark-22 fuels containing HEU in the H-Canyon

and would convert the resulting HEU solution to HEU oxide. To provide

conversion capability, DOE would complete the partially constructed

Uranium Solidification Facility (USF) in H-Canyon. The HEU oxide would

be packaged and stored in a vault in USF.

C. Blending Down to Low Enriched Uranium

This alternative is only relevant to the Mark-16 and Mark-22 fuels.

Mark-16 and Mark-22 fuels containing HEU would be transported to H-

Canyon and/or F-Canyon by rail casks, and dissolved in nitric acid. If

processed through F-Canyon, due to criticality constraints, the

dissolved fuel material would be blended down to LEU prior to

separation from fission products and other materials. If processed

through H-Canyon, the dissolved fuel material would be separated from

fission products and other materials and subsequently blended down to

LEU. In either case, the HEU would be blended at the SRS with existing

depleted or natural uranium to produce LEU solutions. The LEU solutions

would be stored or converted to an oxide using FA-Line. The oxide would

be stored in drums in existing facilities or in a new warehouse to be

constructed at the SRS. Decisions on a potential new warehouse at the

SRS will be made after or coincident with the ROD for the disposition

of surplus HEU. The Disposition of Surplus Highly Enriched Uranium

Final EIS is expected to be issued in mid 1996.

D. Processing and Storage for Vitrification in the DWPF

This alternative could apply to both the Mark-16 and Mark-22 fuels

and the other aluminum-clad targets considered in this supplemental

ROD. DOE would perform research and development work to develop a

method for chemically adjusting solutions that would result from the

dissolution of the Mark-16 and Mark-22 fuels, and the other aluminum-

clad targets in order to transfer them to the high level waste tanks in

F- or H-Area. The research and development work would be to ensure

nuclear criticality safety due to the large amounts of uranium-235

contained in the fuels, and to evaluate the effects of the nuclear

materials on the systems and facilities used to store and treat the

liquid high level waste.

Upon completion of the studies, DOE would transport the fuel and

targets stored in the water-filled basins by rail casks to F- or H-

Canyon and would dissolve them in nitric acid. The resulting solutions

from dissolution would be chemically adjusted and transferred to the

high level waste tanks via underground pipelines. The solutions would

be mixed with the existing volume of high level waste stored in the F-

and H-Area tanks. The bulk of the radioactivity in the solutions would

eventually be immobilized in borosilicate glass by the DWPF. The glass

would be contained within stainless steel canisters that would be

stored in a facility adjacent to the DWPF pending geologic disposal by

DOE. The bulk of the liquid would be immobilized by the Saltstone

facility into a grout containing very low levels of radioactivity. The

grout would be poured into concrete vaults located at the Saltstone

facility.

E. Improving Storage

This alternative could be applicable to both the Mark-16 and Mark-

22 fuels and the other aluminum-clad targets. For this alternative, DOE

would remove the Mark-16 and Mark-22 fuels and the other aluminum-clad

targets from the basins and place them in dry storage. Because of

technical uncertainties (e.g., potentially pyrophoric hydrides of

uranium, elimination of potential reactive material) associated with

the dry storage of failed fuel and targets, DOE would perform

additional research to demonstrate the feasibility of drying and

placing the materials into canisters for storage. Work related to the

dry storage of LEU and commercial spent nuclear fuel has already been

done in the United States and other countries. This work has not been

focused on the storage of aluminum-clad HEU fuels. In conjunction with

this work, DOE would design and construct a Dry Storage Facility at

SRS.

A typical dry storage facility would be a Modular Dry Storage

Vault. This facility would consist of four major components: a

receiving/unloading area, fuel storage canisters, a shielded container

handling machine, and a modular vault for storing the fuel in storage

canisters. As a variation, canisters could be stored in dry storage

casks rather than a vault. The degraded fuel and target materials would

be removed from the basins and dried, canned or placed directly in

canisters; the cans or canisters would be filled with an inert gas to

inhibit further corrosion; if cans were used they would be loaded into

storage canisters. This process could be varied as dictated by the

condition of the material. After the fuel or targets were loaded in a

canister, a machine would transport the canister to the modular storage

vault. The vault would consist of a large concrete structure with an

array of vertical tubes to hold the canisters. The canister

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transport machine would move into the vault and load the canister into

a storage tube. A shielded plug would be placed on top of the tube. The

transport machine and the vault storage tubes would be heavily shielded

to reduce the effects of radiation from the canister. To use dry

storage casks, the machine would transport the canister to a cask

(horizontal or vertical) and discharge the canister into the cask, and

then the cask would be sealed.

DOE evaluated the potential environmental impacts associated with

two variations for implementing this alternative. The first involved

the use of a traditional project schedule for the design and

construction of the Dry Storage Facility, estimated to take about ten

years. The second was an accelerated schedule for design and

construction, estimated to take about five years. Until the Dry Storage

Facility was completed, DOE would store the materials in existing

basins, as described under Continued Storage (No Action).

III. Environmental Impacts of Alternatives

The Final EIS for the Interim Management of Nuclear Materials

analyzed the potential environmental impacts that could result from

implementation of the candidate management alternatives. DOE has

concluded that there would be minimal environmental impact from

implementation of any of the alternatives for any of the material

groups in the areas of geologic resources, ecological resources

(including threatened or endangered species), cultural resources,

aesthetic and scenic resources, noise, and land use. Impacts in these

areas would be limited because facility modifications or construction

of new facilities would occur within existing buildings or

industrialized portions of the SRS. DOE anticipates that the existing

SRS workforce would support any construction projects and other

activities required to implement any of the alternatives. As a result,

DOE expects negligible socioeconomic impacts from implementation of any

of the alternatives.

Management alternatives requiring the use of the large chemical

separations facilities (the canyons) would have greater environmental

impacts (e.g., radiological, waste generation) during the time

dissolving, processing or conversion activities are underway than when

these facilities are storing nuclear materials. After materials have

been stabilized, impacts of normal facility operations related to

management of those materials would decline, and potential impacts of

accidents associated with those materials would be reduced with certain

kinds of accidents eliminated (e.g., solution spills or releases).

Potential health effects from normal operations from any of the

alternatives, including those involving the operation of the canyon

facilities, would be low and well within regulatory limits.

Alternatives requiring the use of the canyons are: Processing to Oxide,

Blending Down to Low Enriched Uranium, and Processing and Storage for

Vitrification in the DWPF.

The Improving Storage alternatives generally have lower impacts in

the near term because they involve only heating, drying and repackaging

the nuclear materials. These alternatives involve the use of new

facilities, such as a Dry Storage Facility. New facilities would

incorporate improved designs for remote handling, shielding,

containment, air filtration, etc.; these improvements could reduce

worker exposures and releases to the environment below levels

associated with existing storage basins and vaults.

Annual impacts from normal operations and potential accidents

associated with nuclear material storage would be reduced after

material stabilization alternatives are implemented. Due to the

substantial influence actively operating facilities have upon potential

environmental impacts, stabilization alternatives requiring longer

periods of time to complete are estimated to have relatively higher

impacts from normal operation and potential accidents than alternatives

requiring less time to complete.

Continuing Storage (or ``No Action'') alternatives would result in

low annual environmental impacts, but the impacts would continue for an

indefinite period of time. Stabilization alternatives typically would

result in slightly higher annual environmental impacts than ``No

Action'' in the near-term, but upon completion of the stabilization

action would result in lower annual impacts. Under Continuing Storage

alternatives, no actions would be taken to chemically or physically

stabilize the storage conditions and reduce the potential for

accidents. All of the stabilization alternatives, upon completion of

the actions required, would reduce the potential for accidents and

associated consequences. Several of the stabilization alternatives

would involve a short-term increase in the risks from accidents until

the required actions are completed.

Emissions of hazardous air pollutants and releases of hazardous

liquid effluents for any of the alternatives would be within applicable

federal standards and existing regulatory permits for the SRS

facilities. Similarly, high level liquid waste, transuranic waste,

mixed hazardous waste and low level solid waste generated by

implementation of any of the alternatives would be handled by existing

waste management facilities. All of the waste types and volumes are

within the capability of the existing SRS waste management facilities

for storage, treatment or disposal.

SRS facilities that will be used to stabilize and store the nuclear

materials incorporate engineered features to limit the potential

impacts of facility operations to workers, the public and the

environment. All of the engineered systems and administrative controls

are subject to DOE Order requirements to ensure safe operation of the

facilities. No other mitigation measures have been identified;

therefore DOE need not prepare a Mitigation Action Plan.

IV. Other Factors

In addition to comparing the environmental impacts of implementing

the various alternatives, DOE considered other factors in making the

decisions announced in this supplemental ROD. These other factors

included: (1) the need to construct and operate modified or new

facilities (e.g., a Dry Storage Facility) and the reliability of old

facilities, (2) nonproliferation concerns, involving potential impacts

to U.S. nonproliferation policy as affected by both the operation of

certain facilities and the attractiveness of the managed nuclear

materials for potential weapons use, (3) implementation schedules, (4)

technology availability, (5) labor availability and core competency,

(6) level of custodial care for the continued safe management of the

nuclear materials, (7) cost and budget considerations, (8) technical

uncertainty (i.e., dry storage of failed HEU fuels), and (9) comments

received during the scoping period for the EIS on the Interim

Management of Nuclear Materials, and comments received on the Draft and

Final EISs.

V. Environmentally Preferable Alternatives

As described in the Final EIS for Interim Management of Nuclear

Materials, certain management alternatives are expected to result in

lower environmental impacts than others. However, a single alternative

was rarely estimated to have lower impacts for all environmental

factors evaluated by DOE. For example, an

[[Page 6636]]

alternative might be expected to result in lower releases of hazardous

pollutants to air or water than the other alternatives, but might

generate slightly higher amounts of radioactive waste. DOE reviewed the

environmental impacts estimated for the alternatives evaluated for the

Mark-16 and Mark-22 fuels and the other aluminum-clad targets, and

identified the following as the environmentally preferable alternative

for each material category. The health and environmental effects from

any of the alternatives are all low and well within regulatory limits.

Mark-16 and Mark-22 Fuels and Other Aluminum-Clad Targets--Improving

Storage (Accelerated Schedule)

Improving Storage, on an accelerated schedule, is the

environmentally preferable alternative for the fuels and targets. This

alternative is estimated to result in the lowest radiological doses to

the offsite public with doses to the SRS workers comparable to the

other alternatives; has the lowest estimates of air and water

emissions; and, results in the generation of the least amount of high

level, transuranic, mixed, and low level waste.

VI. Decision

As indicated in the ROD and Notice issued December 12, 1995, DOE

received several comments from stakeholders on issues related to the

interim management of nuclear materials at the SRS. These comments

dealt principally with: (1) The method to be used for the management of

spent nuclear fuel, and (2) the operational status and potential plans

for the F- and H-Canyon processing facilities. Subsequent to issuing

the initial ROD and Notice, DOE received a letter from the

Environmental Protection Agency (EPA), Region IV, on the Final EIS

offering additional comments for consideration in making the decisions

on the stabilization of the SRS nuclear materials. EPA identified, as

did the Final EIS, processing to oxide as the preferred alternative for

stabilizing the neptunium-237 and plutonium-239 materials. EPA stated

that the principal advantage over the environmentally preferable

vitrification alternative is that shipping nuclear material solutions

across the SRS would not be required. For the Mark-16 and Mark-22

fuels, EPA recommended that the fuels be blended to LEU and processed

to an oxide. EPA recommended that DOE proceed with the construction of

a dry storage facility on an accelerated basis for storing the other

aluminum-clad targets because this alternative would take a shorter

time to implement.

After careful consideration of the issues and public comments,

along with the analyses of environmental impacts and other factors, DOE

has made the following decisions for the interim management of Mark-16

and Mark-22 fuels, and other aluminum-clad targets:

Mark-16 and Mark-22 Fuels--Blending Down to Low Enriched Uranium

DOE has decided to stabilize the Mark-16 and Mark-22 fuels through

processing in the canyon facilities, blending down the HEU to LEU. DOE

will dissolve depleted uranium oxide in the FA-Line as necessary to

blend down the HEU to LEU.

DOE will remove the Mark-16 and Mark-22 fuels from the water-filled

basins in which they are stored and transport them to the canyon

facilities using the existing SRS rail casks. All of the cask shipments

will be confined within the boundaries of the SRS, occurring near the

center of the site. The fuel assemblies will be dissolved in nitric

acid. If processed through the F-Canyon, the resulting HEU solution

will be blended down to LEU and then separated from fission products

and other materials. If processed through the H-Canyon, the resulting

HEU solution from dissolution will be separated from fission products

and other materials and then blended down to LEU. DOE will transfer

depleted or natural uranium solutions to the canyon facilities for

blending with the HEU from the fuels. The LEU solution will be stored

or converted to an oxide in FA-Line. The LEU solution or oxide will be

stored at the SRS until disposition decisions are made. Dependent upon

the timing of future DOE decisions, the uranium from the Mark-16 and

Mark-22 fuels could be dealt with in conjunction with the disposition

of other HEU (by commercial sale, etc.).

Neptunium-237 will be separated from the fuel during the

stabilization process. This material will be managed in conjunction

with the other neptunium at the SRS. The Department is still

considering which of the management options for neptunium-237 and

plutonium-239 to implement.

DOE selected this stabilization alternative for several reasons.

Stabilization of the fuels with their removal from basin wet storage

and elimination of the wet storage vulnerabilities through processing

can be accomplished two to seven years earlier than the improved

storage alternative. Improving storage on an accelerated schedule is

the environmentally preferable alternative. Blending down to LEU

reduces the HEU inventory and eliminates nonproliferation and security

issues associated with the indefinite storage of HEU fuel which is not

self-protecting. (Self-protecting fuel is highly radioactive, so that

substantial shielding (or distance) is required to prevent unhealthy

radiological effects from handling or storage conditions; non self-

protecting fuel could be contact-handled and therefore is of greater

theft or sabotage concern.) Cost and cost uncertainties also have

played a significant role in the selection of this stabilization

action. Near-term annual costs to process and blend down the HEU to LEU

are estimated at $20 million to $95 million less than for the improved

storage alternatives. Substantial uncertainty exists concerning the

disposition of dry-stored (improved storage) HEU spent fuel, while less

uncertainty exists with the stabilization of the fuels through blending

down to LEU and the storage and disposition of the resulting waste

through the DWPF. Life-cycle cost evaluations favor blending down to

LEU ($38 million to greater than $1 billion advantage)[Facility

Utilization Strategy, Attachment 2]. Although potential safety, health

and environmental impacts evaluated in the Final EIS are lower in the

interim period for the improved storage alternatives than the selected

blending down to LEU alternative, the potential impacts from any of the

stabilization alternatives are shown to be very low and well below any

regulatory or management control limits. It is anticipated, however,

that the secondary impacts associated with the eventual or periodic

need to handle stored spent fuel for management or disposal purposes

may increase over time the potential impacts of the improved storage

alternatives.

Other Aluminum-Clad Targets--Processing and Storage for Vitrification

in the DWPF

DOE has decided to implement the processing and storage for

vitrification in the DWPF alternative for the other aluminum-clad

targets stored in the reactor disassembly basins at the SRS. DOE will

remove the targets stored in the reactor disassembly basins and

transport them to the canyon facilities by SRS rail casks. The targets

will be dissolved in a canyon, the resulting solutions chemically

adjusted and transferred to the adjacent underground high level waste

tanks. The solutions will be stored in the high level waste tanks until

they are processed in conjunction with the other high level waste in

the tanks. The high level waste will eventually be vitrified in the

DWPF. The resulting stainless steel

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canisters of glass produced from the DWPF process will be stored in a

facility adjacent to the DWPF pending geological disposal by DOE.

DOE selected this stabilization alternative for several reasons.

These targets are in a variety of physical forms and shapes and contain

no or small amounts of fissile materials; primarily they contain such

materials as thorium, cobalt, and thulium. Their dissolution and

transfer for vitrification in the DWPF will place these physically and

chemically diverse materials into a uniform medium suitable for future

emplacement in a geologic repository. Improved storage (the

environmentally preferable alternative) would require the development

of one or more packaging configurations for repository emplacement.

Although vitrification in the DWPF will not occur for several years,

processing and storage for vitrification in the DWPF can be implemented

one to six years earlier than the improved storage alternatives. This

will remove the targets in their deteriorating condition from the

reactor disassembly basins, precluding further release of radioactivity

to the basin water. Near-term costs are considerably less for the

processing alternative as compared with the improved storage

alternative. As with the Mark-16 and Mark-22 fuels, potential safety,

health and environmental impacts for the improved storage alternatives

are lower than the selected stabilization alternative of processing and

storage for vitrification in the DWPF. However, the potential impacts

from any of the stabilization alternatives are acceptable and well

below any regulatory or management control limits.

VII. Conclusion

While the Final EIS focuses on the interim management of nuclear

materials at the SRS, the decisions associated with the safe management

of these materials directly affect the operational status of the

nuclear material processing facilities at the Site. The decisions in

this supplemental ROD and the initial ROD and Notice are structured to

effect the earliest completion of actions necessary to stabilize or

convert nuclear materials into forms suitable for safe storage and

prepare the facilities for subsequent shutdown and deactivation. The

actions being implemented will support efficient, cost-effective

consolidation of the storage of nuclear materials and, to a great

extent, will result in stabilization of the nuclear materials and

alleviation of associated vulnerabilities within the timeframe

recommended by the DNFSB.

The stabilization decisions utilize existing facilities and

processes to the extent practical; can be implemented within expected

budget constraints and with minimal additional training to required

personnel; rely upon proven technology; use an integrated approach; and

represent the optimum use of facilities to stabilize the materials in

the shortest amount of time. Only minor modifications of the canyon

facilities will be required, and these were also supported by the

decisions made in the initial ROD and Notice.

Several years will be required to achieve stabilization of the

nuclear materials within the scope of this and the initial ROD.

Stabilization of the candidate nuclear materials at SRS will entail the

operation of many portions of the chemical processing facilities.

Consistent with DNFSB Recommendation 94-1, this will preserve DOE's

capabilities related to the management and stabilization of other

nuclear materials until programmatic decisions are made.

In summary, the Department has structured its decisions on interim

actions related to management of the nuclear materials at SRS to

achieve stabilization as soon as possible.

Issued at Washington, DC, February 8, 1996.

Thomas P. Grumbly,

Assistant Secretary for Environmental Management.

[FR Doc. 96-3884 Filed 2-20-96; 8:45 am]

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