Thursday 22 August 2013

The worsening situation at Fukushima Daiichi


Radioactive Leaks in Japan Prompt Call for Overseas Help
The operator of the crippled nuclear plant at Fukushima said it’s losing its two-year battle to contain radioactive water leaks and emphasized for the first time it needs overseas expertise to help contain the disaster.


21 August, 2013


Tokyo Electric Power Co. (9501) is grappling with the worst spill of contaminated water since the March 2011 earthquake and tsunami caused a meltdown at the Fukushima Dai-Ichi plant. The call for help from Zengo Aizawa, a vice president at the utility, follows a leak of 300 metric tons of irradiated water. Japan’s nuclear regulator labeled the incident “serious” and questioned Tepco’s ability to deal with the crisis. Prime Minister Shinzo Abe made similar comments earlier this month.


We will revamp contaminated-water management to tackle the issue at the Fukushima Dai-Ichi plant and seek expertise from within and outside of the country,” Aizawa said at a press conference last night in Tokyo. “There is much experience in decommissioning reactors outside of Japan. We need that knowledge and support.”


In Vienna, the International Atomic Energy Agency said it’s prepared to help. Besides radiated water, the site north of Tokyo has more than 73,000 cubic meters of contaminated concrete, 58,000 cubic meters of irradiated trees and undergrowth, and 157,710 gallons of toxic sludge, according to the utility.


The tanks holding highly radioactive water cover an area equal to 37 football fields, and the utility is clearing forest to make room for more. There are 480 filters clogged with cesium. Each weigh 15 tons and are warehoused in what the utility calls temporary storage, though it will take hundreds of years for the radiation to decay.

Biggest Concern’

Japan’s nuclear watchdog has ratcheted up concern about more leaks of highly radioactive water from the hundreds of storage tanks at the Fukushima atomic plant.


The possibility of leaks from other tanks “is the biggest concern,” said Nuclear Regulation Authority Chairman Shunichi Tanaka at a press conference yesterday. “This will need to be handled carefully on the assumption that one incident could bring another.”


Late last night, Tepco said water leaking from the storage tank probably ran into the ocean. It cited high radiation readings in a drainage ditch.


At least one commissioner at the regulator questioned the accuracy of data being released by Tepco and whether the incident had been fully reported. The leak, along with a separate spill of 300 tons of radioactive water a day into the Pacific Ocean, is raising doubts about the utility’s ability to handle the 40-year task to decommission the nuclear site.


Tepco’s Effort

Tepco is providing the regulator with information, company spokesman Yoshikazu Nagai said by phone, declining to comment further. The company’s shares fell as much as 15 percent in Tokyo yesterday, their biggest intraday slide since June 5.


Japan’s government has ordered an investigation into the safety of hundreds of other tanks storing contaminated water in Fukushima, the site of the world’s worst civilian nuclear disaster since the Chernobyl reactor exploded in 1986.


There are 226 tanks of similar bolted design to the leaking unit with the same 1,000-ton capacity at the site, said Tatsuya Shinkawa, director of the nuclear accident response office in the government’s Agency for Natural Resources and Energy, which called for the probe.


Nuclear incidents and accidents are ranked by order of severity on the International Nuclear and Radiological Event Scale or INES, which has seven categories and was set up by the International Atomic Energy Agency.


Leaking Tanks

On Aug. 19, Tepco said about 300 tons of highly radioactive water had leaked from a storage tank and was ranked as category one on INES, the lowest.
Japan’s NRA raised that to category three yesterday, or a “serious incident.” The 2011 meltdown of the three reactors at Fukushima is in the highest severity category of seven on the INES scale, the same as Chernobyl.


This INES evaluation is based on the 300-ton leak, but I really wonder if we can trust data provided by Tepco,” Toyoshi Fuketa, a commissioner at the NRA, said at a meeting in Tokyo. “I really wonder if we should judge based on Tepco’s data.”
In two separate incidents this month, workers were exposed to radioactive releases at the plant.


Prime Minister Abe has said that Tepco alone isn’t able to handle the clean-up, promising more government funds without detailing how they’d be used.


Overseas Concern

INES is a means to measure nuclear accidents in terms of their effects on health and the environment, according to the International Atomic Energy Agency. Each of its seven steps represents a ten-fold increase in severity. The IAEA last night said it takes the leaks in Japan “seriously” and that it “remains ready to provide assistance on request,” according to a statement on its website.


A seven rating means there has been a “major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures,” according to the INES fact sheet.


Japan’s regulator raised the INES rating on the water leak based on radiation levels reported by the utility this week and on an evaluation of measures at the plant to prevent such incidents. The IAEA will be the final arbiter of where the leak will sit on the severity scale.


New York Times: “Potential for huge spill” of highly radioactive liquid from many Fukushima tanks at same time, says nuclear design expert

Top Officials: Leaks from more tanks are “the biggest concern… We are extremely concerned”





21 August, 2013


Fox News, Aug 21, 2013: Four other tanks of the same design have had similar leaks since last year. The incidents have shaken confidence in the reliability of hundreds of tanks that are crucial for storing what has been a continuous flow of contaminated water. “We are extremely concerned,” [Nuclear Regulation Authority deputy secretary-general Hideka Morimoto] told reporters Wednesday.


New York Times, Aug 20, 2013: The new leak raises disturbing questions about the durability of the nearly 1,000 huge tanks Tepco has installed about 500 yards from the site’s shoreline. [...] Hiroshi Miyano, an expert in nuclear system design at Hosei University in Tokyo, said that the tanks would be vulnerable to earthquake or tsunami, with the potential for a huge spill. [...] At some point, Tepco will have no choice but to start releasing some of the water, said Dr. Miyano, the expert in nuclear system design. The continued problems have heightened public scrutiny of Tepco and have made it harder to build public consensus around any release of water, he said. “That just makes the problem worse, with no viable solution,” he said.





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