Fukushima reactor readings raise reheating concern via the guardian

Temperature inside No 2 reactor may have risen to 82C, and Tepco reportedly steps up cooling efforts

Concern is growing that the Fukushima Daiichi nuclear power plant in Japan is no longer stable after temperature readings suggested one of its damaged reactors was reheating.

The plant’s operator, Tokyo Electric Power (Tepco), said the temperature inside No 2 reactor – one of three that suffered meltdown after last year’s earthquake and tsunami – may have reached 82C on Sunday.

Tepco said there was no evidence that the melted fuel inside had reached criticality. The utility reportedly increased the amount of cooling water being injected into the reactor along with a boric acid solution, which is used to prevent the fuel from undergoing sustained nuclear reactions.

Confirmation that the temperature has risen above 80C could force the government to reverse its declaration two months ago that the crippled plant was in a safe state known as cold shutdown.

Cold shutdown is achieved when the temperature inside the reactors remains below 100C and there is a significant reduction in radiation leaks. Given that Tepco assumes a margin of error of 20C, the actual temperature could have risen to 102C.

Continue reading at Fukushima reactor readings raise reheating concern