Saturday, May 21, 2011

19/05 EDITORIAL: Long road ahead to get Fukushima reactors under control


It has been a month since Tokyo Electric Power Co. announced its action plan for bringing the crippled Fukushima No. 1 nuclear power plant under control. But we now fear the utility may not be able to keep to its schedule.

TEPCO on May 12 disclosed selective reactor data that was gathered immediately after the accident. The data suggests that every one of the three reactors in operation probably had a meltdown. This is extremely grave.

We cannot see the inside of each reactor, but we assume the fuel became a molten amorphous mass and partially leaked out from the bottom of the pressure vessel, and collected in the containment vessel.

But why did it take TEPCO as long as two months to put all this data together? Surely, this was the sort of information the company should have used immediately after the accident to assess the general state of the reactors and figure out the best and fastest response.

But TEPCO's excuse was that it didn't have all the data it needed to assess the situation accurately. This not only makes the utility unreliable as the party responsible for the accident, but also raises serious questions about its handling of information disclosure.

Many outside experts were of the opinion that a meltdown must have occurred not long after the plant was incapacitated. Yet, both TEPCO and the Nuclear and Industrial Safety Agency kept using the expression "reactor core damage," perhaps to lead the public into underestimating what was really happening.

Had TEPCO taken a harder look at the situation at hand, it could have foreseen the possibility of a hydrogen buildup--which led to explosions of facilities at the plant--and prevented its workers from exposure to radiation-contaminated water.

TEPCO must now brace itself for much more formidable challenges in the days ahead. In the case of the Three Mile Island meltdown in 1979, it took about three years before the reactor core could be photographed, and more than 10 years to complete the cleanup process.

TEPCO's revised action plan, revealed on May 17, is not much of an improvement over the original. According to the initial idea, TEPCO was to flood the No. 1 and No. 3 reactor units over three months to keep them cooled stably.

But the utility had to abandon the flooding operation for the No. 1 reactor when its containment vessel was found to be leaking too much water. The No. 2 unit's pressure control room in the containment vessel was damaged, which requires pouring concrete into the vessel at first. The No. 3 unit, both inside and outside, is littered with considerable radioactive debris, which is hindering work.

Given the severity of the accident and the resulting extensive damage, it certainly will not be easy for TEPCO to meet its goal of stabilizing the reactors "in six to nine months."

But Fukushima evacuees are holding their collective breath as they watch the process, since any progress in the execution of TEPCO's action plan will give them some indication of when they may be able to go home. Once the reactors are stabilized, the evacuees can start planning their homecoming.

But bringing the three melted-down reactor cores under control and disposing of them will be a long, arduous battle.

--The Asahi Shimbun, May 18

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