Fukushima prefectural police said on 2 October that they had referred former and current officials of Tokyo Electric Power Company (Tepco) to prosecutors over the pollution caused by the 2011 nuclear accident at Fukushima Daiichi NPP.
A group of residents filed a criminal complaint two years ago against the utility and 32 top officials over the leaks of highly radioactive wastewater from the nuclear plant into the sea. The group says the company and the executives failed to properly manage storage tanks of contaminated water or build underground walls to block the flow.
The police did not disclose whether they had asked prosecutors to indict those named in the documents. The officials and the utility were listed as suspected violators of the pollution law for failing to prevent the leakage of highly radioactive water into the Pacific Ocean. Among those named in the papers are Tepco President Naomi Hirose and former chairman Tsunehisa Katsumata.
TEPCO executives were negligent in converting the temporary tanks holding contaminated water on the plant site to safer ones, according to the police. That failure had led to the leakage of about 300t of contaminated water from the temporary tanks by July 2013. The executives are also accused of delaying the installation of walls to prevent groundwater from flowing into the reactor buildings. As a result 300-400t of contaminated water a day leaked from the reactor buildings between June 2011 to September 2013.
Meanwhile, at the end of September, the prefectural government again called on Tepco to address the outflow of radioactive rainwater into the ocean after a heavy rainfall. The prefecture's crisis management section chief Takao Kikori called on the utility to speed up the work to reroute the drainage system into the plant's port. Most of the port area is surrounded by breakwaters and other barriers.
The official also told the Tepco officials to make greater efforts to prevent contaminated water from flowing into the ocean. Tepco representative Naohiro Masuda said the firm is considering pumping up rainwater further upstream from the drain in question and redirecting it to other drains flowing into the port.
Tepco and the government announced on 28 September that storage tanks for radioactively contaminated water at at the NPP will be increased by 14,000t by April next year. this is intended to prepare for additional contaminated water in case impermeable walls currently under construction at the plant turn out to be less effective than expected. The walls are meant to prevent an influx of groundwater into nuclear reactor buildings by freezing underground soil surrounding those buildings.
Currently, there are underground water storage tanks and other tanks with a combined capacity of some 950,000t. As of 24 September, contaminated water had taken up some 700,000t of the capacity, leaving around 250,000t still available. Tepco is planning to install 20 additional tanks with a capacity of 700t each at two vacant lots on the plant's premises.