Dry spent fuel cask monitoring by (sup 252)Cf-source-driven frequency analysis measurements

摘要

If developed, a nondestructive method would be useful for verifying canister contents without requiring the canister to be opened. This paper addresses the application of the (sup 252)Cf-source-driven frequency analysis measurements for verification of the fissile material content of sealed spent fuel canisters. The cross-power spectral density (CPSD) between the (sup 252)Cf source in an ionization chamber and external neutron detectors depends only on the induced fission rate in the fissile system and is independent of inherent sources. Thus the source-to-detector CPSD is ideal for determination of fissile material content of the spent fuel. This paper evaluates the application of this method to a 125 ton spent fuel canister that contained 21 pressurized-water reactor fuel elements. The results demonstrate that the fissile materials content of a sealed spent fuel canister could be obtained using the (sup 252)Cf frequency analysis method if calibration standards were available. The results 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 burnups.