Corrosion of aluminum-cald spent fuel in reactor basin water storage

Aluminum-clad fuel and target materials have been in reactor basin water storage at the Savannah River Site (SRS) for times exceeding five years. This extended storage is the result of decisions to suspend processing of nuclear materials for Defense at SRS and other Department of Energy locations. During this interim storage period, significant pitting corrosion of the aluminum clad has resulted in exposure of the uranium core leading to the release of cesium-137 and other fission products to the basin water. An aggressive Basin Management Program has been implemented at SRS in response to the corrosion issue. This intense effort to clean the basins, deionize the water, and control the cesium activity appears to be making positive progress. Basin corrosion tests underway in K-Disassembly Basin in 1994 show no corrosion of the aluminum clad after 6 months exposure to current basin conditions compared to tests in 1992 which showed corrosion penetrating the cladding in 45 days. Sim-ilar tests in P and L-Disassembly Basins show no corrosion after 8 months in basin water storage. This paper reviews the results of the corrosion test program and describes the changes implemented by the Basin Management Program leading to improvements in the interim storage of Spent Nuclear Fuel at SRS