(423c) Performance Assessment for the Low Activity Waste and Intermediate Level Vaults (LAWV and ILV) at the Savannah River Site

Low Activity Waste (LAW) generated at the Savannah River Site (SRS) that exceeds disposal limits for burial in ground trenches is being disposed of in the LAW Vault (LAWV) located in E-Area. The LAWV is a large, above-grade, reinforced concrete structure 643 ft long, 145 ft wide, and 27 ft high at the roof crest. It is divided into 12 cells designed to contain more than 12,000 B-25 boxes. Intermediate level waste generated at SRS is being disposed of in the Intermediate Level Vault (ILV) also located in E-Area. The ILV is a largely below-grade, reinforced concrete vault with a footprint of 279 ft by 48 ft and consists of two modules: the Intermediate Level Tritium (ILT) module, which contains two 26-ft deep cells, and the Intermediate Level Non-Tritium (ILNT) module, which contains seven 28.4-ft deep cells. At the end of radwaste-generating operations at SRS, both LAWV and ILV will be closed, sealed, and covered with an earthen closure cap for long-term disposition.

Groundwater models have been developed for the ILV and LAWV using the PORFLOW software package with the purpose of evaluating dose to members of the public following site closure and thereby producing waste disposal limits. Modeling results are presented and discussed in this paper.