Transmutation scenarios after closing nuclear power plants

Nishihara, Kenji  ; Tsujimoto, Kazufumi ; Oigawa, Hiroyuki 

With consideration of the phase-out option from NP utilization in Japan, an ADS for Pu transmutation is designed and scenario analysis is performed. The ADS is designed based on the existing ADS design for MA transmutation, and the 6-batch ADS is selected as a reference design for scenario analysis. In the scenario analysis, once-through scenario of LWR spent fuel is referred as a conventional scenario with a LWR-MOX utilization scenario. As the transmutation scenario, three cases of transmuters that are only-FR, only-ADS and both-FR+ADS are analyzed. The numbers of necessary transmuters are obtained as 15 to 32, and, the necessary period for transmutation as 180 to 240 years. Benefit on repository by reduction of Pu and MA is reduction of repository area by a factor of five and of decay time of toxicity by a magnitude of order. The FR+ADS scenario is considered to be a modest solution, though the ADS scenario is preferable if rapid transmutation is required.