Wednesday, May 18, 2011

18/05 Timetable to end nuclear crisis too optimistic

A timetable for bringing an end to radiation leaks from the tsunami-hit Fukushima No. 1 Nuclear Power Plant and paying compensation to those affected by the accident -- which the government's task force has just announced -- suggests that the plant operator and the government had been too optimistic about the prospects for ending the crisis.

Tokyo Electric Power Co. (TEPCO), the operator of the plant, which had released a roadmap a month ago for placing the crippled plant under control, has since unveiled a revised version. The roadmap focuses specifically on cooling down the reactors, sealing off radioactive substances and monitoring the reactors.

In contrast, the government's timetable covers a wider range of measures -- including the evacuation of residents from affected areas, health inspections, decontamination of soil tainted with radiation, securing jobs for residents of crisis-hit areas and compensation for victims.

In particular, measures to lessen health hazards that radioactive substances can cause, specific relief measures for evacuees and prospects of when they can go home are important matters of concern for many people. The government should have shown these issues much earlier. The government is urged to promptly implement various measures that meet the needs of residents affected by the crisis.

The review of the roadmap for getting the reactors under control, based on which other measures have been worked out, has raised various questions. TEPCO has not changed its original schedule for bringing the affected reactors to a stable condition, known as a "cold shutdown," and reducing the amount of water contaminated with radiation in them. The government has approved TEPCO's original schedule.

TEPCO began to release initial data on May 16 showing what actually happened to the Fukushima No. 1 Nuclear Power Plant immediately after the Great East Japan Earthquake occurred on March 11. The data has suggested that the meltdown occurred at its No. 1, 2 and 3 reactors and that their pressure vessels were damaged.

Nuclear fuel is believed to have melted in the reactors, and dropped to the bottom of the pressure vessels, causing radioactive water to leak into their containment vessels. The containment vessels are also feared to be damaged and are leaking a massive amount of radioactive water. Moreover, there is a possibility that nuclear fuel that has melted has leaked into the containment vessels.

The government and TEPCO should have suspected that such trouble occurred even without the initial data. TEPCO's initial roadmap was based on its overly optimistic perception of the state of affairs at the plant, and needs to be thoroughly reviewed.

It is a matter of course that TEPCO has been forced to abandon filling the containment vessels with water to seal off the pressure vessels. However, questions remain as to how to install heat exchanges to the crippled reactors and ensure that water is cycled inside them in order to permanently place them under control. Another problem is how to promptly shield the reactors in a bid to prevent radioactive water from leaking into the soil and contaminating underground water and the sea.

The government and TEPCO need to accurately grasp the state of affairs at the reactors, work out specific countermeasures and explain them to the public. If their efforts to place the reactors under control are based on their overly optimistic prospects because they want evacuees to return home as early as possible, it will be counterproductive.

Needless to say, it is an important task to improve the work environment for workers struggling to place the nuclear plant under control and to secure skilled workers. TEPCO has incorporated measures to improve the working environment at the plant in its revised roadmap, while the government has shown specific measures to improve health management for the workers. The government and TEPCO should steadily implement these measures.

(Mainichi Japan) May 18, 2011

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