MOX fuel fabrication technology in J-MOX

Osaka, Shuichi*; Yoshida, Ryoichi*; Yamazaki, Yukiko*; Ikeda, Hiroyuki*

Japan Nuclear Fuel Ltd. (JNFL) has constructed JNFL MOX Fuel Fabrication Plant (J-MOX) since 2010. The MIMAS process has been introduced in the powder mixing process from AREVA NC considering a lot of MOX fuel fabrication experiences at MELOX plant in France. The feed material of Pu for J-MOX is MH-MOX powder from Rokkasho Reprocessing Plant (RRP) in Japan. The MH-MOX powder is a mixed oxide consisting of 50 wt% plutonium oxide and 50 wt% uranium oxide produced by direct denitration of Pu and U nitric acid solution utilizing microwave heating (MH) technology which was developed by Japan Atomic Energy Agency (JAEA). The compatibility of the MH-MOX powder with the MIMAS process was positively evaluated and confirmed in our previous study. The MIMAS process has two mixing steps. In the first step, which is called "Primary Blend", the feed materials (MH-MOX powder, UO powder and recycled scrap powder) are mixed and homogeneous powder which contains approximately 30 wt% of Pu is obtained. In the second step, which is called "Secondary Blend", the primary blend powder is diluted with UO powder to a certain Pu content. This paper describes the influences of the UO powder and the recycled scrap powder on the MOX pellet density.