Full scale testing of the WVDP canister decontamination system

The West Valley Demonstration Project (WVDP) will solidify a liquid high level waste (HLW) stream by vitrification. The vitrified waste will be stored in approximately 300 stainless steel canisters, which require exterior surface decontamination prior to shipment to a repository or retrievable storage facility. The proposed canister decontamination system at the WVDP uses a dilute solution of nitric acid and cerium (+4) to chemically mill the exterior surface of the filled and sealed cansiters. Laboratory scale testing of this proposed system at the Pacific Northwest Laboratory (PNL) has proven the effectiveness of the basic chemical reactions in removing a predictable amount of the canister's surface along with embedded surface contamination. Full scale testing of this unique system has been completed by the WVDP and has confirmed the system operating parameters. Additionally, a preliminary review of the test data has suggested modifications to the reference process and changes to canister surface finishes