Tuesday, October 18, 2011

Criteria for 'cold shutdown' of Fukushima nuclear plant remain vague and ambiguous - 17th Oct 2011

The government and Tokyo Electric Power Co. (TEPCO) unveiled a revised roadmap to contain the crippled nuclear reactors at the Fukushima No. 1 Nuclear Power Plant on Oct. 17, clearly stipulating that they would aim for a stable condition called a "cold shutdown" of the reactors by the end of this year, but the criteria used to thrash out the work schedule are vague and ambiguous.

It is still not clear whether they can judge that they have achieved a cold shutdown only by checking the temperatures of the bottoms of reactor pressure vessels. On the assessment of the amounts of radioactive substances being released from the nuclear reactors, the government and TEPCO, the operator of the troubled Fukushima nuclear complex, must come up with more detailed data than "provisional figures" in order to say definitely that they have "achieved" a cold shutdown. Furthermore, the government and TEPCO failed to show any direction on the timing of lifting of evacuation advisories -- the final goal of the nuclear disaster response roadmap, let alone prospects for measures that should be taken after a cold shutdown is achieved. Read More