Comparative study for minor actinide transmutation in various fast reactor core concepts (1)

Oki, Shigeo 

Comparative study for various core concepts is being carried out in a frame work of the study for minor actinide (MA) transmutation using a fast reactor. Different fuel types (Oxide, Nitride, Metal) and coolants (Sodium, Lead) were investigated. It is found that neither nitride nor metal-fueled core has significantly more excellent efficiency for MA transmutation comparing with an oxide-fueled core when the basic performance of these cores as a power reactor are fixed. The MA transmutation Properties of lead-cooled fast reaetor (BREST-300) and sodium-cooled fast reactor (3800MWth large core) were compared. The sodium-cooled reactor surpasses BREST-300 on the MA transmutation rate. Meanwhile, it is found that BREST-300 is excellent from the viewpoint of loading much more MA in the core to attain larger MA transmutation amount. The effect of MA to coolant void reactivity is considered by the sensitivity analysis. It is found that the lead void reactivity has different sensible energy regions on MA nuclides from those for the sodium void reactivity.