Final report spent nuclear fuel retrieval system primary cleaning development testing

Developmental testing of the primary cleaning station for spent nuclear fuel (SNF) and canisters is reported. A primary clean machine will be used to remove the gross sludge from canisters and fuel while maintaining water quality in the downstream process area. To facilitate SNF separation from canisters and minimize the impact to water quality, all canisters will be subjected to mechanical agitation and flushing with the Primary Clean Station. The Primary Clean Station consists of an outer containment box with an internally mounted, perforated wash basket. A single canister containing up to 14 fuel assemblies will be loaded into the wash basket, the confinement box lid closed, and the wash basket rotated for a fixed cycle time. During this cycle, basin water will be flushed through the wash basket and containment box to remove and entrain the sludge and carry it out of the box. Primary cleaning tests were performed to provide information concerning the removal of sludge from the fuel assemblies while in the basin canisters. The testing was also used to determine if additional fuel cleaning is required outside of the fuel canisters. Hydraulic performance and water demand requirements of the cleaning station were also evaluated. Thirty tests are reported in this document. Tests demonstrated that sludge can be dislodged and suspended sufficiently to remove it from the canister. Examination of fuel elements after cleaning suggested that more than 95% of the exposed fuel surfaces were cleaned so that no visual evidence of remained. As a result of testing, recommendations are made for the cleaning cycle. 3 refs., 16 figs., 4 tabs.