DRY SPENT FUEL CASK MONITORING BY %F-SOURCE-DRIVEN FREQUENCY ANALYSIS MEASUREMENTS

If devel~ a nondestmctive method would be useful for veriljing canister contents without requiring the canister to be opened. This paper addresses the application of the 2s2Cf-sourcedriven fkquenq analysis measurements for verification of the fissile material content of sealed spent fuel canisters. The cross-power spectml density (CPSD) between the 252Cf source in an ionization chamber and exlemal neutron detectors depends only on the induced fission rate in the fissile system and is independent of inherent sources. Thus the source-todetector CPSD is ideal for determimtion of fksile material content of spent fhel. This paper evaluates the application of this method to a 125-ton spent fbel canister that contained 21 pressurized-water reactor fuel elements. The results demonstrate that the fissile material content of a sealed spent fuel canister could be obtained using the ‘2Cf frequency analysis method if calibration standards were available. The reds also indicate that a measurement could be performed in less than a day for burnups up to 36 GWd/MTU and in less time for lower bumups.