Tokyo Electric Power (TEPCO) reported a leakage of 300 metric tons of contaminated water with high levels of radiation from a drain valve of a storage tank in the H4 area at the Fukushima Daiichi nuclear power plant in Japan.
Nuclear Regulation Authority (NRA) commissioner Toyoshi Fuketa said that NRA, which rated the incident as level 1, or an anomaly, on 20 August 2013, raised the severity level of the incident to the third, or a serious incident, on the seven-level International Nuclear and Radiological Event Scale.
"This INES evaluation is based on the 300-ton leak, but I really wonder if we can trust data provided by Tepco. I really wonder if we should judge based on Tepco's data," Fuketa added.
The company, which is investigating the cause of the leak, reported that it found puddles both inside and outside the drain valve of the dike, and detected High ß ray and ? ray densities in the outside puddle.
The company claims that water from puddle detected outside the drain valve has not flowed into a public drainage ditch; and thus it considers that water has not flowed out into the sea.