Ocean dumps of leaking water at Fukushima ‘unavoidable’ says Japanese nuclear regulator

ingressimage_fukushimatanks.png Photo: eandt.theiet.org

“I’m afraid that it is unavoidable to dump or release the water into the sea” after it is purified to levels recognized as safe under international standards, Shunichi

Tanaka, chairman of the newly-constituted Nuclear Regulatory Agency (NRA) told a news conference, as quoted by Agence France Presse.

Tepco has long struggled to deal with the massive amounts of water used to cool reactors that went into meltdown after being struck by an earthquake and tsunami on March 11, 2011.

Neighboring countries and local fishermen have expressed concern at the mooted release from the plant, where contaminated water was already believed to have escaped into sea.

“The situation at Fukushima is changing everyday,” Tanaka said, according to AFP. “Fukushima Daiichi has various risks. The accident has yet to be settled down.”

“It’s time to call in international oversight,” said Nils Bøhmer, Bellona’s general director and nuclear physicist, who, with other Bellona staff, has visited Fukushima.

“They need international help because irradiated water is now leaking and more will soon be dumped into the Pacific Ocean  and the environment is by far not the best solution  –this is an international issue,” he said.

Original radiation measurements 18 times too low

Tanaka’s announcement comes a day after the regulatory body said that radiation levels of the leakage at Fukushima Daiichi are 1,800 millisieverts per hour – 18 times higher than previously thought. New measurements of the leakage indicate that the radioactivity levels are lethal after a mere four hours of exposure.

Tanaka has also raised concerns that more tanks of irradiated water at the site are leaking.

The new measurements of radioactivity in the leakage add to the mounting confusion of reports that for the past two weeks have been issued by Tokyo Electric Power Co, or Tepco, the plant’s operator, which until now has been unable to quantify the dangers of the leaks.

Alarmingly, regulatory officials confirmed Monday that part of the new leakage from the storage tanks has likely already escaped into the Pacific Ocean.  For its part, Tepco has yet to determine the cause of the leaks or exactly where the water has gone, according to a company spokesman who spoke with Bellona via email said Monday.

Tanaka, told reporters Sunday that a small leak and signs of other possible leaks have been spotted at several other Fukushima Daiichi’s 1,000 water storage tanks, Asashi Shimbun reported.

Denouncing Tepco’s “careless management” of contaminated water, Tanaka told reporters: “We need to give them very strict instructions.”

Tepco plagued by leaks

Early in August, Tepco belatedly confirmed reports that a lower level activity mixture of groundwater and water being used to cool melted fuel lying deep inside the damaged reactors was seeping into the sea at a rate of about 300 tonnes a day.

Experts said those leaks – which are separate from the most recent incidents – might have started soon after the plant was struck by a powerful 11-meter tsunami almost three years ago.

The tsunami smashed into the plant after Japan’s north-east coast was rocked by a magnitude 9.0 earthquake. The waves killed almost 19,000 people, while the resulting three-reactor meltdown at Fukushima Daiichi forced some 160,000 people to abandon their homes. Most have not been able to return.

All of Fukushima Daiichi’s primary and back up cooling systems were destroyed when the tsunami hit. This has necessitated the constant pumping of water to cool the reactors and spent nuclear fuel storage pools via improvised means.

Unfolding of the current leaks

Eleven days ago, Tepco reported radioactive water had leaked from a storage tank into the ground.

The 1,000 tanks, which regulators say are of shoddy quality, had been trucked in to deal with flood waters resulting from the tsunami as well as the ad hoc cooling efforts for the plant’s three melted down reactors. Water was dumped on the plant by water cannons and seawater dropped from helicopters.

That water has now become a highly irradiated swamp that has hobbled decommissioning efforts – estimated to take some 40 years – from moving forward.

Tepco needs international help

Tepco has issued wan appeals for international help, but those have been somewhat drowned out by the regulator’s fury at the utility’s mishandling of the leaks, as well as promises by Japan’s Ministry of Economy, Trade and Industry (METI) to take over responsibility for cleaning up the Fukushima Daiichi site.

But this may prove an awkward fit: METI oversaw Japan’s previous nuclear regulatory agency, the Nuclear and Industrial Safety Agency (NISA), which was as complicit as METI in spreading disinformation to the Japanese and the world public about the Fukushima crisis until it was replaced earlier this year by the NRA.

“The new Japanese regulator may be a little too young to handle this problem, a little too green,” said Bøhmer.

But Bøhmer also said that METI’s relationship to the nuclear industry in Japan is too tarnished by its past misdeeds to be an effective oversight monitor for the colossal radioactive cleanup job.

Sloppy tank monitoring

Tepco admitted during a meeting of the NRA last Wednesday that only two workers had initially been assigned to check more than 1,000 storage tanks on the site twice daily. Neither of the workers carried dosimeters to measure their exposure to radiation, and some inspections had not been properly recorded.

The firm responded to growing criticism of its handling of the water problem by increasing the number of workers patrolling the tanks from the current total of eight to 50.

How serious are the leaks?

Tepco  initially reported on August 21 that one of these tanks had leaked some 300 tons of radioactive water into the ground, and sought to raise the crisis level of the accident from a Level 1 (“anomaly”) to a Level 3 (“serious incident”) on the seven-level International Nuclear Event Scale (INES).

Last Wednesday, Tanaka agreed to back the Level 3 assignment, but castigated Tecpo for botching their evaluation of the tank leaks, questioning whether the incident deserved a Level 3 rating. Chernobyl and the initial Fukushima meltdowns both rated a Level 7 on the INES scale. A final assignment level assignment for the leaks will be established by the International Atomic Energy Agency.

The NRA now says readings taken near the leaking tank on Saturday showed radiation was high enough to prove lethal within four hours of exposure.

New radioactivity reports

Tepco had initially reported said the leaking water was around 100 millisieverts an hour.

But it came to light over the weekend that the equipment used to take the measurements could only read up to 100 millisieverts. Using more sensitive devices, the new measurements taken near the bottom of the leaking tank are show to be 1,800 millisieverts an hour.

The new reading will have direct implications for radiation doses received by workers who spent several days trying to stop the leak last week, said Bøhmer.

In addition, Tepco says it has discovered a leak on another pipe emitting radiation levels of 230 millisieverts an hour, the BBC reported Monday.

The current leak is the fourth major leak from storage tanks at Fukushima since 2011 and the worst so far in terms of volume.

Charles Digges