FUKUOKA (Kyodo) — Radiation dosages 47 times higher than acceptance levels have been detected from vitrified radioactive waste at a storage facility in Rokkasho, Aomori Prefecture, Kyushu Electric Power Co. said Thursday.
The spent fuel came from nuclear reactors operated by Kyushu Electric Power Co.Up to 190 becquerels of both beta and gamma rays were detected from the surface of three of 28 canisters of waste from spent nuclear fuel reprocessed in Britain. The storage facility’s acceptance level is set at 4 becquerels, Kyushu Electric said, adding there has been no leakage of radiation.
Japan Nuclear Fuel Ltd., which operates the High-Level Radioactive Waste Storage Center in Aomori, northeastern Japan, is looking into why three of the vitrified waste canisters are emitting radiation at such levels.
Kyushu Electric said the vitrified waste was a by-product of the reprocessing in Britain of spent nuclear fuel shipped there by it and two other Japanese power companies. Radioactivity readings were below the criteria before shipments from Britain, it said.
The radiation readings were registered in a safety check of vitrified waste delivered to the Rokkasho facility on Sept. 15.
So far, the radiation level fell below 4 becquerels for one of the three worrisome canisters and workers continue decontaminating the remaining two, Kyushu Electric said.
Nine regional electric power companies and Japan Atomic Power Co. ship spent nuclear fuel from their nuclear reactors to Britain or France for reprocessing. After reprocessing, the high-level radioactive waste is vitrified, shipped back to Japan and stored at the facility in Rokkasho, where a number of other nuclear power-related facilities are located.
(Mainichi Japan) October 13, 2011