Masamichi Obata

Advanced Drying System to Meet Radiolysis Criteria of Metallic Waste

High dose rate metal waste from core internals, such as BWR channel boxes or control rods are stored in spent fuel pool or site bunker pool. Waste form for final disposal of these high dose rate metal wastes should eliminate water to prevent hydrogen gas generation which can be caused by radiolysis of water. Toshiba’s newly developed drying system for high dose rate metal wastes enable very low content of water even if the waste have a powder layer. Toshiba will provide the total system to fabricate the waste form for high dose rate metal wastes. An operational condition to dry the B4C control rod which is the typical waste with powder layer was estimated based on experimental data.Copyright

Discrimination Monitors for Various Kinds of Waste to Be Down Graded

During operation and maintenance, or decommissioning of nuclear power plant, various kind of waste should be treated, and exposure control is also required. These wastes have a wide range of contamination, different composition of nuclides, and a different shape, so each measurement instrument would be optimized for its use especially for very low level radioactivity measurement. TOSHIBA provides appropriate equipment for any needs to discriminate the very low and non radioactive waste to save cost of waste disposal, based on our original and innovative technology. For alpha emitting nuclides, we are ready to supply instruments based on ionized particle measurement technology. For beta, gamma-emitting nuclides, we are ready to customize a shape of detector based on our original plastic scintillation material. Some examples are introduced.Copyright

Solidification of Simulated Liquid Waste of Primary Loop Resin Elution Process of PWR

Primary loop resin waste is eluted by sulfuric acid in The Kansai Electic Company Mihama, Takahama and Ohi nuclear power station. Waste solution from this elution process is planned to be solidified by cement. This study bring out a range of chemical composition and crud concentration of waste solution from this elution process, and examine the properties of alumina cement solidification process and solidified material. Test for sulfate ion, borate, lithium, ammonium ion was carried out. Volume reduction ratio of over 0.5 was achieved for 5 to 25wt% of sulfate ion and <5,000ppm of borate. Lithium ion restrained the solidification delay by borate. Also, ammonium ion shows no significant effect. Based on this study, we concluded that the aluminum cement is applicable to all range of composition of waste solution from the resin elution process. This study is a part of committed work of The Kansai electric company.© 2010 ASME

Drying System for Radioactivated Metal Waste From Nuclear Power Station

High dose rate metal waste from core internals, such as BWR channel boxes or control rods are stored in fuel pool or site bunker pool. Waste form for final disposal of these high dose rate metal wastes should eliminate water to prevent hydrogen gas which can be caused by radiolysis of water. Toshiba’s newly developed drying system for high dose rate metal wastes enable short drying time and easy maintenance. Toshiba will provide the total system to fabricate the waste form for high dose rate metal wastes.Copyright