Core design study on actinide-burning fast reactors

アクニチド燃焼高速炉の炉心設計研究

大木 繁夫 

Oki, Shigeo

As one of the options for future nuclear reactor use, this study deals with actinide-burning fast reactor core design based on the knowledge accumulated during the development of Japan Sodium-cooled Fast Reactor (JSFR). The 750-MWe JSFR core was chosen as a reference, and its modification to the pancake-type core was investigated. Plutonium degradation during multiple recycling, a key point in core design for burning mode, was considered. It was found that a large fuel pin diameter and high burnup as in JSFR is still preferable for better core economic performance with a transuranic (in particular, plutonium and minor-actinide (MA)) consumption rate of 200-300 kg/GWe y. The possible MA content in core fuel was evaluated depending on the nuclide composition as 5-3 wt% in heavy metal. These actinide-burning capabilities were acceptable for incinerating both plutonium and MA stockpiles in a hypothetical burning-mode scenario evaluation. This paper describes the relationship between the core design parameters and the actinide-burning capabilities, offering useful information for future optimization of core design and scenario studies.