BURN-UP SENSITIVITY ANALYSIS OF MINOR ACTINIDE TRANSMUTATION FAST REACTOR

摘要

In order to effectively transmute MAs, fast reactors are promising because large amount of MAs can be loaded and high transmutation rate can be achieved compared with light water reactors. Research and developments of MAs transmutation using fast reactors are conducted in whole world. The projects titled as "Study on Minor Actinides Transmutation Using Monju Data" supported by the Ministry of Education, Culture, Sports, Science and Technology has been launched as one of the national project in Japan. In the project, the burn-up sensitivity analysis and the evaluation of the prediction uncertainties were performed in order to predict the MAs transmutation rates in the MAs loaded fast reactor with the sodium-plenum. The target neutronics characteristics were criticality and number density. As the numerical results of the criticality, large differences of the sensitivities between the BOC and the EOC were obtained. The uncertainties of the criticality were 0.753%dk/k at the BOC and 0.679%dk/k at EOC by JENDL-4.0. The main contribution was uncertainties of fuel nuclides. In the case of number density, the capture cross section of target nuclide and the Pu-239 fission cross section had large contribution to burn-up sensitivity coefficient of the target nuclide number density. The uncertainties of Np-237 and Am-241 number density were 1.479% and 2.301%, respectively. In addition, we recommend specific improvement of cross section covariance and energy region of the covariance in order to reduce the uncertainties by error of JENDL-4.0.