Activities of design studies on innovative small and medium LWRs in JAERI

原研における革新的中小型軽水炉の設計研究

岩村 公道; 落合 政昭

Iwamura, Takamichi; Ochiai, Masaaki

原研では、持続可能性,エネルギー利用の多様化等の革新的原子炉の目的を達成するため、2種類の中小型軽水炉の研究開発を実施中である。一つは、受動安全性を具備した低減速スペクトル炉で、炉心は中性子の減速を抑えるためMOX燃料稠密炉心から構成され、電気出力は330MW,運転サイクル26ヶ月,転換比1.01,負のボイド反応度係数,60GWd/tの燃焼度を達成した。もうひとつは地域熱供給や海水脱塩等を目指した分散型小型炉で、改良舶用炉MRXをバージに搭載して熱と電気の供給を行う設計と、需要地の地下に立地して熱供給を行う小型炉の設計を実施した。

JAERI has developed two types of small and medium size Light Water Reactors to meet the goals of innovative nuclear reactors such as sustainability and diversification of energy utilization. One is the Reduced-Moderation light Water Reactor (RMWR) with passive safety features. The reactor core consists of MOX fuel assemblies with tight lattice arrangement to increase the conversion ratio by reducing the moderation of neutron energy. The core design of 330MWe output with the operational cycle of 26 months was accomplished. A breeding ratio of 1.01, negative void coefficient and natural circulation cooling of the core were realized under the discharged burn-up of 60GWd/t. The other is the Passive Safe small Reactor for Distributed energy systems (PSRD) to diversify the nuclear energy utilization. An innovative advanced marine reactor (MRX) is used to supply the small grid electricity or electricity and heat co-supply by installing it on a barge. A small integral LWR for underground deployment is also studied for exclusive use of heat supply to household or office.