Hitachi Ltd. has stored 91 kg of spent nuclear fuel near a residential area in Kawasaki for almost three decades, sources said Monday.
The sources said 598 spent nuclear fuel rods are being kept in a pool for testing at Hitachi’s nuclear training center. They said no harmful effects on the surrounding environment have been detected.
The rods came from the center’s Hitachi Training Reactor, which halted operations in 1975 and was dismantled the following year. It has stored the rods at the Ozenji Hitachi Training Reactor Center in Kawasaki’s Asao Ward ever since.
The sources said Hitachi wants to reprocess the fuel rods as soon as possible to prevent them from falling into the wrong hands. However, no clear schedule has been set, they said.
A Hitachi spokesman confirmed that the spent fuel is being stored at the facility.
Hitachi, in cooperation with the Education, Culture, Sports, Science and Technology Ministry and other entities, is considering reprocessing the spent fuel at the Tokai Works reprocessing plant, operated by the Japan Nuclear Cycle Development Institute in Tokai, Ibaraki Prefecture.
Experts have meanwhile said that reprocessing the spent fuel would be meaningless because it has little value as a resource.
The Hitachi Training Reactor was a small reactor that had thermal output of 100 kilowatts and used uranium dioxide as fuel at a concentration of 10 percent.
Hitachi had been negotiating with the U.S. Department of Energy and some companies in Europe and the United States about having them take over the rods. However, it could not reach an agreement due to a range of problems, including profitability and the difficulties of handling radioactive waste.
Reprocessing the spent fuel at the reprocessing plant in Tokai — Hitachi’s last resort — also comes with hurdles, because Hitachi would need to lower the uranium concentration of the rods to 4 percent or lower.
If Hitachi decides to send the spent fuel to Tokai, the uranium concentration would have to be lowered at another plant in Ibaraki before the rods could be transported to the Tokai Works. In that case, it would likely take four or five years before reprocessing could begin.