Disaster in JapanJapan facing a nuclear catastrophe

Published 14 March 2011

Initial estimates say that the Magnitude 9.0 earthquake and tsunami killed about 10,000 people and made hundreds of thousands homeless; Japan is facing another threat: radioactive contamination from four damaged nuclear power plants; the tremor damaged the cooling systems in the reactors, forcing the companies operating the plants to flood the reactors with corrosive sea water and boric acid; one containment vessel was destroyed in an explosion, and in order to prevent more explosion, radioactive-contaminated hydrogen had to be released, increasing the radioactive levels to unsafe levels; more than 200,000 people living in the vicinity of the reactors were evacuated; the government has began distributing iodine pills to citizens (the pills are used to protect the thyroid gland from the effects of radiation); the difficulties at the nuclear power plants mean that rotating power outages will be imposed across Japan as of Monday

Smoke pillar following explosion at Fukushima plant // Source: 174.143.24.167

Four days after a magnitude 9.0 earthquake and ensuing tsunami struck Japan, killing an estimated 10,000 people and leaving many more destitute, the country is still struggling to avert nuclear disaster, with problems reported at four separate nuclear power plants (two of the plants are located in the same facility – the Fukushima-Daiichi plant).

Fukushima-Daiichi plant. The Tokyo Electric Power Company (Tepco) is continuing attempts to cool down two reactors at the Fukushima-Daiichi plant 240 kilometers north-east of Tokyo, where a dramatic explosion destroyed the roof of the building housing reactor No. 1 on Saturday. In an emergency measure, seawater mixed with boric acid has been introduced to reactors Nos. 1 and 3 in an attempt to cool the reactors’ cores and kill the nuclear fission reaction more quickly.

The decision to flood the reactor’s core with corrosive sea water, experts say, is an indication of how desperate the situation is: it means that Tepco has probably decided to scrap the plant (the plant, in any event, is 40-year old).

It is not clear how much progress has been made, although nuclear power experts canvassed by Reuters were cautiously optimistic that the situation was being brought under control. New Scientist reports that the Japanese government has acknowledged that fuel roads at one or both reactors may not have been fully submerged for a time, and may have melted or become deformed as a result, but that would fall short of a complete meltdown and does not necessarily constitute a risk to the public unless the situation worsens.

Tokai nuclear power station. Japan’s nuclear safety agency also faces an emergency at Tokai nuclear power station, 120 kilometers from Tokyo in Ibaraki Prefecture, where one of two cooling systems has stopped. The Japan Atomic Power Company, which operates the plant, says that the remaining systems are working effectively and the reactor core is cooling smoothly.

Onagawa nuclear plant. At a third nuclear plant, in Onagawa, Miyagi Prefecture, an initial report of elevated radiation levels led to a low-level emergency being declared, but Tohoku Electric, the company that runs the Onagawa plant, said the cooling systems at all three reactors are functioning properly. The BBC reported that the increase in radiation was brief, with one possibility being that it originated at the Fukushima plant.

NS notes that the site causing greatest concern is reactor No. 3 at Fukushima-Daiichi, whose plutonium-uranium fuel mix poses a greater radiological risk than