Robots Find High Radiation as Tepco Lays Out Plan to End Crisis

Bloomberg BusinessWeek: Robots Find High Radiation as Tepco Lays Out Plan to End Crisis
April 19 (Bloomberg) -- Robots sent into two buildings at Japan’s crippled Fukushima Dai-Ichi nuclear station detected radiation still too toxic for humans as the plant operator set out a plan to end the crisis in six to nine months.

Measurements show one hour inside the No. 3 reactor building would expose humans to more than one-fifth of the radiation Japan has said is the most workers can endure in a year, the atomic safety agency said yesterday. People haven’t been in the buildings since a 15-meter (49-foot) surge following a magnitude-9 quake on March 11 knocked out cooling equipment, sparking the worst disaster since Chernobyl in 1986.

A sustained drop in radiation at the tsunami-damaged plant could be achieved within three months, Tokyo Electric Power Co. said in a statement laying out its plans. Following that, a cold shutdown, where core reactor temperatures fall below 100 degrees Celsius (212 degrees Fahrenheit), may be achieved within six months, it said.

The six-to-nine month timeframe “seems mindbogglingly long given the urgency,” said Michael Friedlander, a nuclear engineer who is chief risk officer at APG Asset Management in Hong Kong. The utility should aim to have the crisis in hand in two to three months, he said. “They’re managing expectations and don’t want to make a commitment they can’t deliver on.”

In the next three months, Tepco, as the utility is known, plans to fill the reactor containment vessels at the No. 1 and No. 3 units with water, the company said in its April 17 statement. The utility will seal the vessel of the No. 2 reactor, which is likely damaged, before flooding it.

Leaking Into Sea

“If we flood the damaged vessel, the leak of contaminated water will increase,” Tepco Vice President Sakae Muto told reporters in Tokyo April 17. “We will continue injecting water with care and monitor the volume of water leaked.”

The water pumped so far has overflowed into basements and trenches, with some of it leaking into the ocean.

“It is vitally important that Tepco succeeds in shifting the cooling process to a closed loop system,” said Philip White, international liaison officer at the Citizens’ Nuclear Information Center in Tokyo. “In the current situation, where water poured in one end leaks out the other, there is the constant danger that highly radioactive water will run off into the sea.”

Seventy percent of people in Japan disapprove of the way Prime Minister Naoto Kan’s government has handled the nuclear crisis, the Nikkei newspaper said yesterday, citing a telephone survey it carried out with TV Tokyo Corp. Japan’s Chief Cabinet Secretary Yukio Edano said the plan outlined by Tepco to end the nuclear crisis is “an important step.”

Robots, Radiation

Two iRobot Corp. robots sent April 17 to check whether humans could reenter the site found radiation levels as high as 49 millisieverts per hour in the No. 1 reactor building, and up to 57 millisieverts in the No. 3 building, the Nuclear and Industrial Safety Agency said.

The cumulative maximum level for nuclear workers was raised to 250 millisieverts from 100 millisieverts by Japan’s health ministry on March 15. Exposure totaling 100 millisieverts over a year is the lowest level at which any increase in cancer is evident, according to the World Nuclear Association in London.

Tepco shares fell 0.4 percent to 467 yen in Tokyo yesterday. The stock is down almost 80 percent since the quake and tsunami, which left about 28,000 people dead or missing.

Tepco plans to inject nitrogen into the containment vessels of the No. 2 and No. 3 reactors by the end of April, Muto said. The utility injected the inert gas into the No. 1 unit this month to prevent hydrogen explosions.

‘Makes No Sense’

“Injecting nitrogen doesn’t hurt, but it makes no sense -- it just makes it look like you’re doing something,” said Friedlander, who spent 13 years working in nuclear plant management in the U.S. “It’s a question of resources and the people; those people could be better utilized.”

Three to six months after the initial phase of its plan, Tepco will attempt a cold shutdown of reactors No. 1, 2 and 3, the company said. Reactors 4, 5 and 6 were shut at the time of the disaster. The utility will also cover the No. 1, 3 and 4 reactor buildings as a temporary measure to reduce radiation emissions after the structures were damaged by hydrogen blasts last month, according to the statement.

Japan’s government plans to tell families evacuated from the area within ninth months whether they can return home, Trade Minister Banri Kaieda said in a briefing in Tokyo.

The government this month widened a 20-kilometer evacuation zone to include the towns of Iitate, Katsurao and Namie. Radiation no longer poses “significant” health risks beyond an 80-kilometer radius, the U.S. State Department said.