Radiation level rises faster than expected in Fukushima absorption machine
Temporary storage tanks for low- and middle-level radioactive water from Tokyo Electric Power Co.'s Fukushima Dai-ichi Nuclear Power Station's No.1, No.2, No.3 and No.4 reactors are seen at the grounds of the plant in Fukushima prefecture.

Tokyo - The operator of Japan's stricken Fukushima nuclear power plant said on Saturday it had suspended an operation to clean up radioactive water only hours after it had begun because radiation levels rose dramatically.

Tokyo Electric Power Company had undertaken the operation at the plant, disabled by the March 11 earthquake and tsunami, to avert spillage into the sea of large, growing pools of radioactive water.

A statement issued by the company, known as TEPCO, said the suspension, five hours after the operation began, was prompted by a sharp rise in radiation in a part of the system intended to absorb cesium.

"At the moment, we haven't specified the reason," a TEPCO spokesman told a news conference. "So we can't say when we can resume the operation. But I'd say it's not something that would take weeks."

The official said teams working at the plant believed the radiation rise could be linked to sludge flowing into the machinery intended to absorb cesium. Another cause could be pipes surrounding it.

But a resumption, he said, was critical to deal with the highly radioactive water - officials say 110,000 metric tones, the equivalent of 40 Olympic swimming pools - is stored there.

"Unless we can resume the operation within a week, we will have problems in disposing of the contaminated water," the official said.

"But if this is caused by the reasons we are thinking, we can resume the operation within a week."

The official said TEPCO foresaw no delay in its overall plan to bring the Fukushima Daiichi plant fully under control by the end of the year. The plan calls for a shutdown of its three unstable reactors by January 2012.

Comment: Is the above statement implying there are three 'other' reactors to be shut down, other than the three in total melt down?

The cleanup operation had got underway on Friday after being delayed by a series of glitches at the plant, 150 miles northeast of Tokyo.

TEPCO, with help from French nuclear group Areva, U.S. firm Kurion and other companies, has been test-running a system in which radioactive water is decontaminated and re-used to cool the reactors.

But in a setback that delayed the plan by about a week it said water had leaked from a facility used to absorb cesium on Thursday.

TEPCO official Junichi Matsumoto told reporters that the operator was aiming to use some of the cleaned water to cool the reactors within the next few days, which would not require the pumping in of fresh water.

In early April, the utility dumped about 10,000 tons of water with low-level radioactivity into the ocean, prompting criticism from neighbors China and South Korea.

Even if the water treatment were successful, TEPCO would next face the problem of dealing with highly radioactive sludge that will be left over from the decontamination process. It is unclear where the sludge will be stored in the long-term.

Despite the mounting challenges, TEPCO aims to complete initial steps to limit the release of further radiation from the plant and to shut down its three unstable reactors by January 2012.

TEPCO announced Friday, as expected, that it had not made significant changes to its timeline.

The operator said that storing high radiation sludge likely to result from the treatment of contaminated water and improving the conditions for their workers during the approaching summer were extra areas it was looking into.

Measures for the workers include access to more doctors and body counters that measure exposure to radiation and new resting areas away from the summer heat, Tepco said.

The ultimate goal is to bring the reactors to a state of "cold shutdown," where the uranium at the core is no longer capable of boiling off the water used as a coolant.

That would allow officials to move on to cleaning up the site and eventually removing the fuel, a process that could take more than a decade.