Samples of groundwater taken from monitoring holes around the sunken reservoirs at the Fukushima No. 1 nuclear plant are proving radioactive, Tokyo Electric Power Co. said Saturday.
Strontium and other radioactive elements were detected in samples taken from 13 of the 22 observation holes dug around the reservoirs, which were built to hold water tainted during the cooling of the reactors, Tepco said.
Some of the reservoirs are leaking.
The amount of radioactive material in the samples is small and within the range of normal fluctuations, Tepco said, but it is not known whether there is any link between the radiation and the reservoir leaks.
The utility said that 0.03 to 0.048 becquerels per milliliter of the radioactive materials was detected in Friday’s groundwater samples. A similar amount was detected in water taken from two holes when the utility reanalyzed the samples to confirm the previous readings.
The observation holes range from 5 to 15 meters deep.
Great wall of Fukushima?
A government panel has begun studying ways to prevent more radioactive water from accumulating at the Fukushima No. 1 power plant, including a plan to build underground walls around the damaged reactor buildings to stop groundwater from entering.
About 400 tons of groundwater seep into the plant every day, entering the lengthy and complicated cooling loop set up to control the damaged reactors. The process leaves the groundwater tainted with radiation.
Tokyo Electric Power Co. is attempting to deal with the water buildup by building storage tanks. It also constructed a dozen wells to intercept and pump out some of the groundwater as it creeps from the mountains to the sea.
But the panel, which includes Tepco and government officials, hopes to find a more fundamental solution because it is running out of storage capacity.
Proposals made by Taisei Corp. and Kajima Corp. Friday included building a subterranean wall around the reactor buildings using a claylike material.
Tepco considered building a wall on the mountain side of the plant after the March 2011 earthquake and tsunami, but abandoned the plan because of the risk that radioactive water flooding the buildings might be leaking into the soil.
The Fukushima water problem recently drew more attention after some of the plant’s giant storage reservoirs for contaminated water were found to be leaking.
Reconstruction minister Takumi Nemoto plans to make a four-day trip to Ukraine starting May 3 to tour the site of the 1986 Chernobyl disaster.
He will be the first Cabinet member to visit Chernobyl since the Fukushima crisis. His itinerary will include a tour of the defunct nuclear plant’s radioactive waste disposal sites, a viewing of a limited access area at the plant, and meetings with local officials.
Nemoto said at a news conference Friday that he wants to find “common points and differences” regarding the disasters, and to learn from Russia’s efforts to recover so the lessons can be applied to Fukushima’s case.