Radioactive iodine in seawater near Japan's crippled Fukushima nuclear plant tested five million times the legal limit, the facility's operator said today, as authorities for the first time imposed radiation safety standards for fish in the tsunami-hit region.
The plant's operator, Tokyo Electric Power Company (TEPCO), which last week said toxic water was leaking from a cracked concrete pit near the No.2 reactor, said the seawater samples taken on Saturday last contained 300,000 becquerels of iodine 131 per cubic cm or 7.5 million times the legal limit, which dropped yesterday to 5 million times than usual.
The samples taken yesterday also contained cesium 137 which was 1.1 million times the legal limit, more than three weeks after the monster magnitude-9 quake and tsunami hit Japan's northeast leaving nearly 30,000 people dead or unaccounted for.
A day after TEPCO began dumping toxic water into the Pacific Ocean, Chief Cabinet Secretary Yukio Edano said the government has imposed a legal limit of 2,000 becquerels per kg for radioactive iodine in seafood.
"As there is no limit set for radioactive iodine in fish, the government has decided to temporarily adopt the same limit (2,000 becquerels per kg) as for vegetables," he said.
The new standards were announced after a type of fish was caught last Friday off the coast of Ibaraki Prefecture that contained high levels of radioactive iodine 131. The small fish contained 4,080 becquerels per kg of iodine 131.
Japan's Nuclear and Industrial Safety Agency said it believes the radioactive substances that seeped into sea are from nuclear fuel which leaked from the reactor into the water and flowed out.
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A total of 60,000 tonnes of radioactive water is believed to be flooding the basement of reactor buildings and underground trenches connected to them at the crisis-hit Fukushima plant, authorities said.
TEPCO yesterday started pumping out low-level radioactive water as an emergency step to secure room for storage of more highly contaminated water. It aims to dump a total of 11,500 tonnes of low-level tainted water into the sea by the weekend.
An estimated 3,430 tonnes of such low radioactive water had so far been discharged into the Pacific Ocean from the plant on the coast, TEPCO was quoted as saying by Kyodo.
Industry Minister Banri Kaieda said that contamination of the sea would pose no major health risk, but apologised for raising concerns among the public, especially fishermen.
TEPCO was also trying to stop the leakage into the sea of highly radioactive water believed to be originating from the No.2 reactor's core, where fuel rods have partially melted.
The water containing radioactive iodine-131 more than 10,000 times the legal concentration limit has been leaking from a cracked seaside pit connected to the No. 2 reactor turbine building.