The operator of the crippled Fukushima Daiichi nuclear power plant on Tuesday continued its emergency operation to dump 11, 500 tons of water tainted with low-level radiation into the Pacific Ocean to secure enough storage space for more highly radioactive water at the complex.
The work began Monday evening, and about 3,430 tons had been already discharged by Tuesday noon. Of the total, 10,000 tons come from the plant’s central waste processing facility, and 1,500 tons from near the No. 5 and No. 6 reactors, according to TEPCO.
The utility said contaminated water being released into the sea contains up to 500 times the legal limit for radioactive material, but it stressed that the release would not harm marine life or seafood safety.
“Even if people ate fish from the affected sea water every day for one year, their radiation exposure would be 0.6 millisieverts, or about a quarter of the annual normal radiation from natural sources,” TEPCO said in a press conference.
Chief Cabinet Secretary Yukio Edano said the dumping radioactive water into the sea is “regrettable but unavoidable.”
“It is a relative and unavoidable decision based on the options available, as we put priority on preventing more highly contaminated water from flowing into the sea,” the top government spokesman said. Edano said the government should properly monitor developments and take all possible measures to ensure radioactive water won’t spread in the sea.
The Fukushima plant, 230 km north of Tokyo, was severely damaged by tsunami triggered by the March 11 earthquake and tsunami that hit the northeastern region. The twin natural disasters knocked out the plant’s cooling systems, leading to suspected partial meltdowns in three of its six reactors and continued radiation leaks.
TEPCO has been also struggling to halt the flow of highly radioactive water soaking from various parts of the Fukushima plant into the Pacific Ocean. The buildup of highly contaminated water has been severely delaying TEPCO’s efforts to restore the reactors’ cooling functions, which are crucial to overcome the world’s worst radiation crisis since Chernobyl in 1986.
The operator is stepping up efforts to stop highly radioactive water leaking into the ocean from a 20-centimeter crack in the pit connected to the No. 2 reactor’s turbine building. Since Saturday, workers have poured concrete, sawdust, paper and water-absorbing polymers in the pipes, but the contaminated water is still flowing from the pit.
TEPCO said today it detected radioactive iodine-131 at 7.5 million times higher than the legal limit in samples taken on Saturday around the No. 2 reactor’s water.
Meanwhile, South Korea expressed concern over the issue, public broadcaster NHK reported.
South Korea’s Foreign Affairs and Trade Ministry conveyed its concern to Japan’s Foreign Ministry on Monday evening through its embassy in Tokyo, according to NHK.
The South Korean ministry pointed out that release of contaminated wastewater could be a violation of international law, the report said, adding that Seoul has been increasingly worried about radioactive contamination of tap water and farm products.
There is growing criticism in South Korea that Japan failed to notify neighboring countries in advance about the release of contaminated water.
Small amounts of radioactive material have been detected in South Korea after the Fukushima nuclear complex, 230 kilometers north of Tokyo, started to release radioactive materials on March 12. The power station with six reactors was hit hard by the record 9.0-magnitude quake and tsunami that rocked the northeastern region on the previous day.