Fast reactor core design studies to cope with TRU fuel composition changes in the LWR-to-FBR transition period

軽水炉-高速炉移行期のTRU組成変動に対応した高速炉炉心設計研究

川島 克之; 丸山 修平   ; 大木 繁夫 ; 水野 朋保

Kawashima, Katsuyuki; Maruyama, Shuhei; Oki, Shigeo; Mizuno, Tomoyasu

高速炉で軽水炉使用済燃料回収TRUを受け入れる際には、予想されるTRU組成の変動を考慮して炉心特性を評価しておく必要がある。本検討では、出力750MWeのFaCT中型炉MOX燃料炉心(高内部転換型炉心)において、種々の軽水炉使用済燃料回収TRU組成、並びにそれらを高速炉でリサイクルしたときのTRU組成に対する炉心特性の依存性とその炉心設計範囲を明らかにした。

750 MWe MOX fuel fast reactor core design efforts have been made to cope with the TRU fuel composition changes expected during LWR-to-FBR transition period, in which a various kind of TRU fuel compositions are available depending on the characteristics of the LWR spent fuels and a way of recycling them. It is shown that among the core neutronics characteristics, the burnup reactivity and the safety parameters such as sodium void reactivity and Doppler coefficient are significantly influenced by the TRU fuel composition changes. As a result, a general characteristic in the FaCT core design to cope with TRU fuel composition changes is grasped and the design envelopes are identified in terms of the burnup reactivity and the safety parameters.