EVALUATION OF WEST VALLEY HIGH-LEVEL WASTE TANK LAY-UP STRATEGIES

摘要

The primary objective of the task summarized in this paper was to demonstrate a methodology forrnevaluating alternative strategies for preclosure lay-up of the two high-level waste (HLW) storage tanks atrnthe West Valley Demonstration Project (WVDP). Lay-up is defined as the period between operationalrnuse of tanks for waste storage and final closure.rnThe U.S. Department of Energy (DOE) is planning to separate the environmental impact statement (EIS)rnfor completion of closure of the WVDP into two separate EISs. The first EIS will cover only wasternmanagement and decontamination. DOE expects to complete this EIS in about 18 months. The secondrnEIS will cover final decommissioning and closure and may take up to five years to complete.rnThis approach has been proposed to expedite continued management of the waste and decontaminationrnactivities in advance of the final EIS and its associated Record of Decision on final site closure.rnFinal closure of the WVDP site may take 10 to 15 years; therefore, the tanks need to be placed in a safe,rnstable condition with minimum surveillance during an extended lay-up period.rnThe methodology developed for ranking the potential strategies for lay-up of the WVDP tanks can bernused to provide a basis for a decision on the preferred path forward. The methodology is also applicablernto determining preferred lay-up approaches at other DOE sites. Some of the alternative strategiesrnidentified for the WVDP should also be considered for implementation at the other DOE sites. Each siternhas unique characteristics that would require unique considerations for lay-up.