Nondestructive assay of plutonium in spent nuclear fuel assembly in water pool

Hayakawa, Takehito; Shizuma, Toshiyuki; Hajima, Ryoichi; Kikuzawa, Nobuhiro ; Nishimori, Nobuyuki; Seya, Michio; Fujiwara, Mamoru

We propose a new nondestructive assay method for U, Pu, and minor actinides in spent nuclear fuel assembly in a water pool. Nuclear fuel materials are detected using nuclear resonance fluorescence (NRF) with laser Compton scattering (LCS) -rays, which are generated by collision of high energy electrons and laser photons. This method can identify each isotope of interest hidden in heavy shields such as lead plates with a thickness of several centimeters. A simulation calculation shows that we can detect 1% fraction Pu in all the fuel rods with statistical error lower than 2% using the proposed high flux LCS -ray source in the measurement time of 4000s.