The Tokyo Electric Power Company (TEPCO) today postponed plans to add extra cooling to reactor number 1 – thought to be the most damaged reactor – by flooding the containment vessel that surrounds the reactor vessel with almost 8,000 tonnes of water.
The unprecedented flooding plan is seen as a potential solution to the fact that leaks are hampering cooling of the reactor vessel, and possibly leaving fuel rods exposed. The same procedure is being considered for the plant’s two other stricken reactors.
But engineers are holding back from executing the plan following tests yesterday, Nikkei.com reports, because of concerns that adding water to the containment vessel might create a negative pressure inside it that would draw in air and so perhaps trigger a hydrogen explosion. The weight of the water could also stress the containment vessel and lead to structural damage if an aftershock hit the reactor. Any leaks in the containment vessel could also worsen local contamination; attempts to remove highly contaminated water from the reactor basements continue to stall with more water leaking back into them than is being pumped out.
Nikkei.com also reported that concerns about a possible leak in the fuel pond at reactor 4 have resurfaced.
US supercomputer centres are offering Japanese colleagues compute time in a show of solidarity. The NSF’s Teragrid reports on how its centres are trying to help with the emergency response in Japan by offering supercomputing resources.
Keith Baverstock, a radiobiologist at the University of Eastern Finland’s Kuopio Campus, has an editorial in the BMJ calling for the health lessons from nuclear accidents to be more thoroughly explored. He doesn’t seem impressed with the international response to the Fukushima accident here.
India has decided to delay approval of four new reactors, the Wall Street Journal reported today, signalling perhaps a tougher regulatory line.