From the BBC:
How To Avoid Talking Politic
Technicians are battling to stabilise a third reactor at a quake-stricken Japanese nuclear plant that has been rocked by a second blast in three days.Sea water is being pumped into reactor 2 at the Fukushima Daiichi plant after its fuel rods were fully exposed twice.
International nuclear watchdogs said there was no sign of a meltdown but one minister said a melting of rods was "highly likely" to be happening.
The second hydrogen explosion in three days rocked a stricken Japanese nuclear plant Monday, sending a massive cloud of smoke into the air and injuring 11 workers. Hours later, the U.S. said it had shifted its offshore forces away from the plant after detecting low levels of radiation.
The aircraft carrier USS Ronald Reagan was about 100 miles offshore when it detected the radiation, which U.S. officials said was about the same as one month's normal exposure to natural background radiation in the environment.
It was not clear if the leak happened during Monday's explosion. That blast was felt 25 miles away, but the plant's operator said radiation levels at the reactor were still within legal limits.
The explosion at the plant's Unit 3, which authorities have been trying to cool with sea water after a system failure in the wake of Friday's massive earthquake and tsunami, triggered an order for hundreds of people to stay indoors, said Chief Cabinet Secretary Yukio Edano. The two disasters left at least 10,000 people dead.
Operators knew the sea water flooding would cause a pressure buildup in the reactor containment vessel -- and potentially lead to an explosion -- but felt they had no choice if they wanted to avoid a complete meltdown. In the end, the hydrogen in the released steam mixed with oxygen in the atmosphere and set off the blast.
The inner containment shell surrounding the Unit 3 reactor was intact, Edano said, allaying some fears of the risk to the environment and public. But the outer building around the reactor appeared to have been devastated, with only a skeletal frame remaining.
Tokyo Electric Power Co., which operates the plant, said radiation levels at Unit 3 were well under the levels where a nuclear operator must file a report to the government.
A similar explosion occurred Saturday at the plant's Unit 1, injuring four workers, causing mass evacuations and destroying much of the outer building.
Shortly after Monday's explosion, Tokyo Electric warned it had lost the ability to cool another reactor, the plant's Unit 2. Takako Kitajima, a company official, said plant workers were preparing to inject sea water into the unit to cool the reactor, a move that could lead to an explosion there as well.
More...
