After a series of blunders, miscalculations and unresolved problems, Tokyo Electric Power Co. adopted a new strategy to avoid a total collapse of its system for handling radioactive water at its crippled nuclear plant.
TEPCO is running out of storage space for water used in the nonstop process of cooling the melted and spent fuel at the Fukushima No. 1 nuclear plant. Exacerbating the storage problem is the groundwater that keeps flowing into the plant’s buildings.
The company has dug 12 wells to the west of the reactor buildings, where it plans to pump up groundwater before it can enter the facilities and become contaminated.
“We would like to release that water into the ocean if we can gain the understanding of the relevant officials,” Toshihiko Fukuda, who heads TEPCO’s Nuclear Quality and Safety Management Department, said at a May 7 news conference.
Currently, surface tanks at the Fukushima No. 1 plant hold about 280,000 tons of radioactive water. An additional 100,000 tons are believed to be flooding the basements of the No. 1 to No. 4 reactor buildings as well as the turbine buildings.
After the leaks were discovered in the underground storage tanks, TEPCO transferred about 8,000 tons of radioactive water from the faulty tanks to surface tanks by May 6. The remaining 16,000 tons or so will remain in the underground tanks until new surface tanks are completed in late May, according to TEPCO’s plan.
An estimated 120 tons of radioactive water leaked into the ground from the faulty underground tanks. Officials of TEPCO and the Japan Atomic Energy Agency say the contaminated water could mix with groundwater and reach the ocean in 10 years at the earliest.
TEPCO officials have yet to determine the cause of the leaks. One factor may have been the fact that they did not follow Environment Ministry guidelines for industrial waste.
The underground storage tanks were protected by a double layer of polyethylene waterproof sheets and a 6.4-millimeter-thick sheet of bentonite, a clay-like substance.