Correlation for evaluation of spent fuel composition of MA mixed metal fuel

Kojima, Kensuke; Okumura, Keisuke ; Arita, Yuji*

Dry processing is assumed for reprocessing of minor actinide mixed metal fuels discharged from fast reactors. In wet processing, spent fuel composition has been measured by a method of sampling fuel solution. However, the method is difficult for dry processing to be applied. Thus, a new method is required for dry processing. The new method was considered as predicting nuclide inventories from measured isotopic ratio of fission products of noble gas accumulated in plenum region of fuel rod with use of correlations between the inventories and the isotopic ratio. In order to evaluate the correlations, burn-up calculations were carried out for various configurations based on FaCT core with the metal fuels. Using the calculated data, correlation functions were newly formulated. As results of applying isotopic ratios Kr/Kr and Xe/Xe to the functions, the predicted inventories show good agreement with those of burn-up calculations for major 21 nuclides.