Ultrasonic cleaning system for centrifugal extractors employed in reprocessing plants

In fast reactor fuel reprocessing, the centrifugal contactors (CE) are used for the separation of U (VI) and Pu (IV) from radioactive spent fuel dissolver solution. It was found that the rotating bowls of CE are prone to failure after several campaigns due to the deposition of the insoluble present in the dissolver solution. In view of this, it was proposed to develop a method for cleaning CE bowls for reusing the bowl, reducing the high active solid waste volume and limiting exposure to plant personnel. In this context, the centrifugal extractor rotating bowl was chocked with a simulated solution of zirconium molybdate, considered as a potential insoluble material formed during the dissolution of spent fuel. It was prepared by mixing zirconyl nitrate and ammonium molybdate in the ratio of 2:1. Since Zr and Mo are formed as fission products, these elements likely combine and precipitate as zirconium molybdate in the acid solution representing HLLW