Fukushima nuclear plant will be turned into a training base, said TEPCO, according to Japanese media. The company also discovered loose bolts in a storage tank which are believed to have caused the daily leak of 300 tons of toxic water into the ocean.
Tokyo Electric Power Company (TEPCO), the plant’s former operator which is now responsible for the clean-up, is considering turning the crippled Fukushima Daiichi plant into a "decommissioning center," sources told Asahi Shimbun newspaper on Friday.
The new role of the crippled plant is to be discussed within the framework of the Fukushima rebuilding plan at the end of 2013.
Three of the plant’s reactors suffered a nuclear meltdown in March 2011 after the Great East Japan Earthquake and resulting tsunami hit the region. The plant is comprised of six separate water reactors. At the time of the earthquake, reactor number 4 had been de-fueled and reactors 5 and 6 were in cold shutdown for planned maintenance, thereby managing to avoid meltdowns.
Japanese Prime Minister Shinzo Abe told TEPCO on Thursday to decommission reactor numbers 5 and 6.
Japan’s economy, trade and industry minister, Toshimitsu Motegi, said on Friday that "we will consider various possibilities for the future" for the two reactors. He also noted that they would be utilized to proceed with the decommissioning of reactor numbers 1 to 4.
The decision to decommission means TEPCO will no longer need the manpower to maintain the equipment that would be used if the reactors were to begin working in the future.
Reactors 5 and 6 are similar in structure to the 1 to 4 reactors and workers could use them as training facilities, Asahi Shimbun reported.
New techniques, including the use of remote-controlled robots to remove melted fuel from the 1 to 3 reactor cores, are to be developed, according to the newspaper. The reactors could also be used for training exercises to repair core containment vessels and investigate the situation within the cores.
Moreover, according to Asahi, storage tanks for the radioactive water which continues to increase in volume could be located in the area of the 5 and 6 reactors.
The nuclear facility has been accumulating radioactive water as groundwater passing through the plant becomes contaminated. The protective barriers installed to prevent the flow of contaminated water into the ocean have proved ineffective. Around 300 tons of contaminated groundwater has seeped into the Pacific Ocean daily since the nuclear disaster occurred in 2011, according to estimations from Japan’s Ministry of Industry.
On Friday, TEPCO discovered five loose bolts on the bottom panels near the eastern edge of a tank holding contaminated water, Asahi reported.
The utility company added that it monitored radiation levels in earth samples taken from a hole drilled beside the storage tank. The maximum radiation level was estimated at 1.7 millisieverts per hour at a depth of 30 centimeters below the ground surface. The safe level of radiation is 1-13 millisieverts per year.
Sealed sections which block openings along junctions in the tank were found bulging in eight areas, while packing sections below the sealants were also protruding in several areas, TEPCO said.
Thus, radioactive water may have seeped into the soil through cracks formed in the concrete-covered ground surface.
According to TEPCO, the tank was disassembled and relocated before the radioactive water leak occurred, but it is not yet clear whether findings are connected with the massive leak. TEPCO is currently dismantling the storage tank in order to further investigate the matter.