New Radiation Hotspots Found at Fukushima Daiichi; Operator’s Struggle to Control Highly Radioactive Water Suffers New Setbacks

Updated September 1, 2013, 11:35 a.m. ET

New Radiation Hotspots Found at Fukushima Daiichi

Operator’s Struggle to Control Highly Radioactive Water Suffers New Setbacks

KANA INAGAKI

TOKYO—The operator of the troubled Fukushima Daiichi nuclear complex said over the weekend that its struggles to control highly radioactive water had suffered new setbacks. The company announced the discovery of contaminated spots in new parts of the compound where the water is stored, while radiation levels jumped to highly dangerous levels in another part of that area where readings were previously lower.Tokyo Electric Power Co. 9501.TO +0.60% said it found on Saturday and Sunday high radiation levels in five locations near storage tanks installed to collect the 400 tons of contaminated water pumped out daily from the radioactive reactor buildings, indicating the possibility of new leaks from the tanks, or some other unexplained difficulties in containing the water.

Three of the measurements came in spots where contamination hadn’t previously been detected. The other two hot spots registered sharp increases from previous measurements.

Two of the readings showed extremely high levels of radiation, one as high as 1,800 millisieverts per hour, another nearby at 1,700. Those are among the highest levels reported at the plant since the early days after a tsunami knocked out power on March 11, 2011, triggering one of the world’s worst nuclear disasters. Exposure to such a level of radiation would kill a person within four hours, Tepco said.

Tepco has increased patrols and radiation readings after finding last month that 300 metric tons, or 79,000 gallons, of highly radioactive water had leaked from a hastily built storage tank. The Japanese government recently stepped in to take a more direct role in stemming the crisis at Fukushima Daiichi, which suffered triple meltdowns after the 2011 earthquake and tsunami knocked out backup power at the site.

The continuing reports of new radiation readings at Fukushima Daiichi underscore the difficulties Tepco and the government have in bringing the stricken compound under control.

For nearly two years, they say they have minimized the biggest danger of the crippled complex, the possibility of a new meltdown. But they have fallen behind on dealing with the hundreds of tons of groundwater coming into contact daily with the radioactive reactor buildings, sticking the bulk of it in storage tanks on the compound. Storage tanks hastily set up during plant emergencies have started springing leaks, and Tepco can’t replace them with sturdier ones fast enough.

While disclosing the new findings over the weekend, Tepco officials played down the significance of any new risks.

“We’re not taking the latest findings lightly and we understand that it’s a critical challenge,” Tepco spokesman Yoshikazu Nagai said Sunday. “But we’re not in a situation where the 300 tons of leaked water [detected so far from the storage tanks] will increase to 600 or 900 tons.”

Tepco said water levels of tanks nearby the five contaminated spots haven’t fallen, suggesting the water hasn’t leaked. Mr. Nagai said drain valves connected to the storage tanks are closed and that the tanks are built atop a concrete foundation, which the company says is waterproof, suggesting not much water has leaked outside the complex and into the ocean nearby. In the case of the 79,000-gallon leak, Tepco suspects the water leaked from a tank’s drain valve that was open.

Regarding one of the new hot spots reported Saturday, Tepco said Sunday that it appeared to be caused by the fact that one drop of contaminated water is leaking every 90 seconds from a pipe linking two storage tanks. Late Sunday, Tepco said it appeared that the leak had stopped after it tightened bolts.

As for the sharp rise in the radioactivity at one of the hot spots, Tepco said that while workers measured 1,800 mSv/h at a spot that was around five centimeters from the tank’s base, the reading dropped sharply to 15 mSv/h when moving 50 centimeters away from the base, a level considered much less dangerous.

By wearing special gloves or using aluminum sheets, the radiation can be blocked, according to the operator. Still, the level is incredibly high since 100 mSv is the level at which cancer risks are seen as rising and equivalent to double the maximum dosage that workers at the plant are allowed in an entire year.

The continuous water problems have prompted Tepco and the government to continue seeking new solutions. The Japanese government is now studying an expensive, untested proposal to install a subterranean ring of ice to stem the spread of radioactive water. Prime Minister Shinzo Abe has said the government would now take the lead from Tepco after Japan’s nuclear watchdog recently assessed the leak to be a “serious incident” or level 3 on an international nuclear accident scale of zero to seven.

Radiation readings spike at water tank at Japan’s ruined nuclear plant

1:54am EDT

(Adds quotes, reading measurements)

By Tetsushi Kajimoto

TOKYO, Sept 1 (Reuters) – Radiation near a tank holding highly contaminated water at Japan’s crippled Fukushima nuclear plant has spiked 18-fold, the plant’s operator said on Sunday, highlighting the struggle to bring the crisis under control after more than two years.

Radiation of 1,800 millisieverts per hour – enough to kill an exposed person in four hours – was detected near the bottom of one storage tank on Saturday, Tokyo Electric Power Co , also known as Tepco, said.

An Aug. 22 readings measured radiation of 100 millisieverts per hour at the same tank. Japanese law has set an annual radiation exposure safety threshold of 50 millisieverts for nuclear plant workers during normal hours.

Last month, Tepco revealed that water from the tank was leaking. Japan’s nuclear regulator later raised the severity of the leak from a level 1 “anomaly” to a level 3 “serious incident” on an international scale for radiation releases.

The Fukushima Daiichi power plant north of Tokyo was devastated by a tsunami on March 11, 2011 that resulted in fuel-rod meltdowns at three reactors, radioactive contamination of the air, sea and food and the evacuation of 160,000 people.

It sparked the worst nuclear crisis since Chernobyl a quarter of a century earlier.

While there were no new leaks found at the tank, a Tepco spokesman said another leak had been detected from a pipe connecting two other tanks nearby.

“We have not confirmed fresh leakage from the tank and water levels inside the tank has not changed,” the Tepco spokesman said. “We are investigating the cause.”

Tepco said the radiation measured was beta rays, which would be easier to protect against than gamma rays.

The Tepco spokesman also said the higher level of radiation from the latest reading was partly because investigators had used a measuring instrument capable of registering greater amounts of radiation.

Instruments used previously had only been capable of measuring radiation up to 100 millisieverts, but the new instruments were able to measure up to 10,000 millisieverts.

Radiation of 220 millisieverts was also recorded near an adjacent storage tank, where a reading of 70 had been registered last month.

Radiation of 230 millisieverts was detected from the new leak from the pipe connecting two nearby tanks, a new measurement of 70 was taken from another, separate storage tank.

Those tanks are built of steel plates stuck together by bolts – the same structure as the tank that was found last month to have leaked 300 tonnes of highly toxic water.

With no one seeming to know how to bring the crisis to an end, Tepco said last week it would invite foreign decommissioning experts to advise it on how to deal with the highly radioactive water leaking from the site.

Japan has also signalled it might dip into a $3.6 billion emergency reserve fund to help pay for the clean-up of a situation the chief cabinet secretary has described as “deplorable”.

Its nuclear regulator has also expressed fear that the disaster was beyond Tepco’s ability to cope in some respects.

Foreign Minister Fumio Kishida visited Chernobyl in Ukraine, the site of the 1986 disaster, hoping to apply lessons learned there to Fukushima.