Radwaste reduction technology for spent resins

Aizawa, Hideyuki*; Katagiri, Genichi*; Sano, Kazuya; Higashiura, Norikazu

Fuji Denki Homu Peji and Fuji Denki America Sha Homu Peji (Internet), 11 Pages, 2012/04

http://www.americas.fujielectric.com/engineers-room/white-papers

In a nuclear power plant, spent IXR (hereafter called SR), low-level radioactive waste, is produced from water purification systems in association with the operation of the plant. These SR are different in a radioactive concentration depending on purification systems, and SR which is relatively higher in the radioactivity concentration is stored in the nuclear power plant. Stored amounts continue to increase year after year. In Japan, it is planned that SR will be buried in the ground in the future as a "waste solid" which is solidified in a specific metal container. In terms of securing long-term soundness of the waste solids, it is said the solidification of the SR is required after stabilization treatment is performed. Moreover, SR with high radioactivity concentration requires higher disposal expenses; therefore, the reduction of the disposal volume is required in terms of cost-cutting. To realize these requirements, processing technologies are required which satisfy both the volume reduction and stabilization of the SR at once. Fuji Electric is continuing to develop LPOP technology and the equipment (FRR: Fuji Resin Reducer) as technologies to respond to these requirements. LPOP treatment is a technology enabling realization of both volume reduction and stabilization of SR which is low-level radioactive waste. Fuji Electric post the overview of LPOP technology and the results of mineralization of ion exchange resin and solidification tests executed for the purpose of evaluating the effect of LPOP treatment aiming the burial disposal on our website.

Development of inspection and repair techniques in reactor vessel of the experimental fast reactor "Joyo" and of visual inspection device to observe in-vessel structures

Saito, Takakazu; Imaizumi, Kazuyuki; Oka, Kiyoshi; Aizawa, Hideyuki*; Katagiri, Genichi*

FAPIG, (179), p.3 - 9, 2009/07

The experimental fast reactor Joyo is the first sodium cooled fast reactor in Japan. In-vessel visual inspections have been conducted with an obstacle on the in-vessel storage rack in Joyo. Because of the high radiation dose in the reactor vessel, radiation-resistant fiberscope was applied to Joyo. The radiation-resistant fiberscope was inserted into the reactor vessel thorough the inspection hole and fuel handling hole on rotating plugs. In order to observe the top of the subassemblies and in-vessel storage rack, an I-shape device which had a downward and side view monitoring radiation-resistant fiberscopes was used. To observe the bottom face of the upper core structure, a remote handling visual device whose tip could bend into an L-shape was developed to insert the radiation-resistant fiberscope into the 70 mm gap between the bottom of the upper core structure and the top of the subassemblies. The observations of the top of the subassemblies and in-vessel storage rack were conducted from October 2007 to February 2008. The bottom face of the upper core structure was observed in July 2008. The number of photographs of the entire bottom face of the upper core structure reached approximately 35,000. Confirmation was made that the remote handling device equipped with the radiation-resistant fiberscope would achieve the expected performance. These observations results provided useful information on incident investigations. In addition, fundamental findings and the experience gained during this study, which included the design of equipment, operating procedures, resolution, lighting adjustments, photograph composition and the durability of the radiation-resistant fiberscope under radiation exposure, provided valuable insights into possible further improvements and verifications for in-vessel visual observation techniques in an sodium fast reactor.

Inspection and repair techniques in reactor vessel of sodium cooled fast reactor, 2-2; Development of visual inspection device to observe in-vessel structures

Imaizumi, Kazuyuki; Tobita, Shigeharu; Saito, Takakazu; Katagiri, Genichi*; Aizawa, Hideyuki*; Yaginuma, Yoshihiro*

no journal, , 

no abstracts in English

Basic test for making waste package for spent resin disposal, 1; Volume reduction and stabilization process by low pressure oxygen plasma process for spent resin

Mizui, Hiroyuki; Otani, Hiroshi; Higashiura, Norikazu; Onozaki, Kimihiro*; Katagiri, Genichi*; Endo, Nobuyuki*; Ogawa, Hideo*; Kaneda, Yoshihisa*

no journal, , 

The applicable prospect for spent resin disposal including inhibitor was acquired by basic test of using low pressure oxygen plasma method.

Development of a water stoppage technique using the photo-curable resin for decommissioning

Shimada, Kozue; Ooka, Makoto; Maekawa, Yasunari*; Tomizuka, Chiaki; Katagiri, Genichi*; Aoyagi, Katsuhiro*; Shibata, Takuya; Koyama, Shinichi

no journal, ,