02-17283. Interim Management of Nuclear Materials

AGENCY:

Department of Energy.

ACTION:

Supplemental record of decision.

SUMMARY:

On December 12, 1995, the U.S. Department of Energy (DOE) issued a Record of Decision (ROD) and Notice of Preferred Alternatives, 60 FR 65300 (December 19, 1995), for the final environmental impact statement, Interim Management of Nuclear Materials (IMNM EIS) (DOE/EIS-0220, October 1995), at the Savannah River Site (SRS), Aiken, South Carolina. As part of that ROD, DOE decided to stabilize plutonium-239 solutions stored in H-Canyon by one of three methods: processing to metal in FB-Line, processing to oxide in H-Area facilities, or vitrification in F-Canyon. In that same ROD, the Department announced that “a subsequent Record of Decision will be issued to specify the final strategy for stabilizing the plutonium-239 solutions” (60 FR 65302). DOE issued a Supplemental ROD on September 6, 1996 (61 FR 48474, September 13, 1996), selecting the Process to Metal alternative for managing the H-Canyon plutonium-239 solutions. DOE subsequently amended this decision (62 FR 61099, November 14, 1997) and instead selected the Process to Oxide alternative for managing these solutions.

Now, after further review of stabilization costs, schedules, and program requirements, DOE has decided to implement the Processing and Storage for Vitrification in the Defense Waste Processing Facility alternative as well as the Process to Oxide alternative previously selected for the management of the H-Canyon plutonium solutions. The environmental impacts of the newly-selected alternative were analyzed in the IMNM EIS. This alternative includes the transfer of the solutions to the SRS high-level waste (HLW) system, vitrification of the liquid HLW in the Defense Waste Processing Facility, and storage of the resultant canisters in appropriate waste storage facilities at the SRS pending disposal in a geologic repository.

FOR FURTHER INFORMATION:

For further information on the interim management of nuclear materials at the SRS, to receive a copy of the final IMNM EIS or the IMNM ROD(s), contact: Andrew R. Grainger, National Environmental Policy Act (NEPA) Compliance Officer, U.S. Department of Energy, Savannah River Operations Office, Building 730B, Room 2418, Aiken, South Carolina 29802, [phone]. Internet: [e-mail].

For further information on the DOE NEPA process, contact: Carol M. Borgstrom, Director, Office of NEPA Policy and Compliance (EH-42), U.S. Department of Energy, 1000 Independence Avenue, SW., Washington, DC 20585, [phone], or leave a message at [phone].

SUPPLEMENTARY INFORMATION:

Background

NEPA Reviews and Decisions

The U.S. Department of Energy (DOE) prepared a final environmental impact statement, Interim Management of Nuclear Materials (IMNM EIS) (DOE/EIS-0220, October 1995), in accordance with the National Environmental Policy Act (NEPA), Council on Environmental Quality regulations implementing NEPA, and DOE implementing procedures. The IMNM EIS assessed the potential environmental impacts of actions necessary to safely manage nuclear materials at the SRS, near Aiken, South Carolina, until decisions on their future use or ultimate disposition are made and implemented. The IMNM EIS grouped the nuclear materials at the SRS into three categories: Stable, Programmatic (three material types), and Candidates for Stabilization (seven material types). Some of the “Programmatic” and all of the “Candidates for Stabilization” materials could have presented environmental, safety and health vulnerabilities in their then-current storage condition. For materials that could present environmental, safety, or health vulnerabilities within approximately 10 years of the NEPA analysis (performed in 1995), the implementation of the IMNM EIS action alternatives would allow safe storage of plutonium and uranium materials pending decisions and actions on the ultimate disposition of the materials.

The IMNM EIS analyzed several alternatives, including the No Action alternative (Continued Storage), for the interim management of eleven (11) types of nuclear materials at the SRS. All of the alternatives, except No Action, would support DOE's objective of removing nuclear materials from vulnerable conditions and from vulnerable facilities in preparation for facility decontamination and decommissioning. For ten of these material types (all but Stable), DOE evaluated the impacts of the Processing for Storage and Vitrification in the Defense Waste Processing Facility alternative. The previously-issued IMNM RODs include decisions to undertake stabilization and processing actions for all ten nuclear material types categorized as “Candidates for Stabilization” and “Programmatic.” DOE decided to continue existing actions for the “Stable” nuclear material category.

On December 12, 1995, DOE issued a Record of Decision (ROD) and Notice of Preferred Alternatives [60 FR 65300, published December 19, 1995], on the interim management of several categories of nuclear materials at the SRS. As part of that ROD, DOE decided to stabilize plutonium-239 solutions stored in H-Canyon by one of three methods: processing to metal in FB-Line, processing to oxide, or by vitrification in F-Canyon. In that same ROD, DOE announced that a subsequent ROD would be issued to select a final strategy for managing these solutions. Accordingly, DOE issued a Supplemental ROD on September 6, 1996 (61 FR 48474, September 13, 1996), selecting the Process to Metal alternative for managing the H-Canyon plutonium-239 solutions. DOE subsequently amended this decision (62 FR 61099, November 14, 1997) and instead selected the Process to Oxide alternative for managing these solutions.

Potential Environmental Impacts

The IMNM EIS analyzed potential impacts of alternatives for managing all SRS nuclear materials, both those materials that were expected to present environment, safety, or health vulnerabilities, as well as those determined to be stable. Summaries of potential impacts from the alternatives are presented in the IMNM EIS, Table 2-2 through Table 2-12 (pp. 2-48 through 2-58).

The IMNM EIS indicated that there would be minimal environmental impacts from the implementation of any alternative (including stabilization in the Defense Waste Processing Facility) in the areas of geologic, ecological, cultural, 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. The existing SRS workforce would support any construction projects and other activities required to implement any of the alternatives, and thus negligible socioeconomic impacts would be expected from implementing any of the alternatives.

Emissions of hazardous air pollutants and releases of hazardous liquid effluents from any of the alternatives would be very small and well within, often by several orders of magnitude, applicable standards and existing regulatory permits for the SRS facilities. DOE expects minimal impacts from any of these releases. Similarly, for any of the IMNM EIS alternatives, potential transuranic waste, mixed hazardous waste, and low-level solid waste generated would be handled by existing waste management (treatment, storage, and disposal) facilities at the SRS.

Processing for Storage and Vitrification in the Defense Waste Processing Facility

While the IMNM EIS indicates that potential environmental impacts from any of the nuclear material management alternatives are small, those management alternatives requiring the processing of nuclear material through the large chemical separations facilities (F- or H-Canyon and FB- or HB-Line), or processing plutonium materials for vitrification in the Defense Waste Processing Facility, would have the greatest environmental impacts during the time that dissolving, processing or conversion activities are underway, as compared to the time when these facilities are merely storing nuclear materials. The plutonium within the H-Canyon plutonium solutions had already been dissolved and transferred to storage tanks at the time the IMNM EIS was prepared. The impacts of storage of these solutions were fully evaluated in the IMNM EIS.

The IMNM EIS describes several technical challenges that would have to be overcome in order to stabilize plutonium solutions using the HLW system and the Defense Waste Processing Facility. Since the preparation of the IMNM EIS, technical and operational developments have led DOE to reassess this alternative for the H-Canyon plutonium solutions. As a result, DOE has determined that the two primary challenges described in the IMNM EIS, prevention of nuclear criticality for significant quantities of plutonium solutions, and management of the solutions in the SRS Tank Farm, have now been overcome. Specifically, the reassessment indicates that: (1) Gadolinium is a suitable alternate neutron poison for quantities of plutonium of a criticality concern; (2) gadolinium is compatible with the existing Canyon and HLW processes; (3) very little dilution is expected to be required, so that there would be only a slight increase in the number of waste canisters required to be produced at the Defense Waste Processing Facility; and (4) the transferred plutonium solution could be sent directly from H-Canyon to the Defense Waste Processing Facility feed tank and vitrified with the subsequent sludge batch, thereby bypassing the Tank Farm.

For that portion of the H-Canyon plutonium solutions managed under this approach, implementation of the Processing and Storage for Vitrification in the Defense Waste Processing Facility alternative would avoid the impacts of processing the solutions through HB-Line, and the impacts of the subsequent packaging and storage of the resultant plutonium oxide. Additionally, by vitrifying the plutonium in HLW canisters at the Defense Waste Processing Facility, the plutonium would be stabilized in a form suitable for ultimate disposition in a geologic repository. In the IMNM EIS, DOE evaluated the impacts of the Processing and Storage for Vitrification in the Defense Waste Processing Facility for the H-Canyon plutonium solutions, and found the potential impacts to be similar to the impacts of the Process to Metal or the Process to Oxide alternatives.

Environmentally Preferable Alternative

The IMNM EIS indicated that while certain management alternatives are expected to result in lower environmental impacts than others, a single alternative was rarely estimated to have lower impacts for all environmental factors evaluated by DOE. The health effects from any of the alternatives are all low and well within regulatory limits. In its December 1995 ROD (60 FR 65300), DOE indicated that the environmentally preferable alternative for the H-Canyon plutonium solutions was the “Vitrification (F-Canyon)” alternative. This alternative would have involved use of equipment that would have been installed in a portion of F-Canyon for vitrification of certain programmatic material. However, DOE subsequently cancelled this project (66 FR 55166, November 1, 2001) due to project cost growth and schedule extension. Of the remaining alternatives, DOE believes that the Process to Oxide alternative is the environmentally preferable alternative for the H-Canyon plutonium solutions. The Process to Oxide alternative would result in the smallest health effects and less HLW, low-level radioactive waste, and saltstone waste, although it would result in greater volumes of transuranic and mixed waste than the Processing for Storage and Vitrification in the Defense Waste Processing Facility alternative.

Decision

After review of plutonium stabilization costs, facility operation schedules, and programmatic requirements, including preparation of material for disposition, DOE is supplementing its November 1997 Supplemental ROD (62 FR 61099) in regard to stabilization of plutonium solutions stored in H-Canyon. DOE will stabilize these solutions using either the Processing and Storage for Vitrification in the Defense Waste Processing Facility alternative, as described and evaluated in the IMNM EIS, or the previously selected Process to Oxide alternative. Under the newly-selected alternative, the solutions will be transferred to the HLW system prior to vitrification with HLW in the Defense Waste Processing Facility.

Using both of these methods will allow DOE to optimize the use of the HB-Line Phase II facility for plutonium-239 and neptunium-237 stabilization. Implementation of this additional management method will reduce the amount of plutonium that would need to be processed to meet the plutonium storage standard (DOE-STD-3013), reduce vault storage space requirements for plutonium and the associated storage container, lower vault surveillance and maintenance costs, and enable the plutonium to be ultimately disposed of in a geologic repository. There is no programmatic need for the plutonium contained in these solutions.

Issued at Washington, DC, June 26, 2002.

Jessie Hill Roberson,

Assistant Secretary for Environmental Management.