By Steven Mufson
The Washington Post
Monday, March 14, 11

Japan stepped closer to a full blown nuclear catastrophe Tuesday after the third explosion in four days appeared to have damaged equipment inside the reactor, apparently creating a path for the escape of radioactive materials, and a fire broke out at a separate reactor where spent fuel and hydrogen ignited. Tokyo Electric Power Co., owner of the seaside nuclear complex, ordered the evacuation of all but the 50 most essential workers and the Japanese Prime Minister addressed the nation urging people within 19 miles to stay indoors and remain calm.

Officials from Tokyo Electric Power, the plant owner, said the 6:14 a.m. explosion took place in the unit 2 reactor at or near the suppression pool, which collects water and radioactive elements from the containment vessel.

Experts said that, unlike the two previous explosions that destroyed outer buildings, this one might have damaged valves and drain pipes, possibly creating a path for radioactive materials to escape.

The explosion — more serious than the earlier blasts — was followed by a brief drop in pressure in the vessel and a spike in radioactivity outside the reactor to levels more than eight times what people ordinarily receive in a year, the company said. Tokyo Electric, which over the weekend said it had 1,400 people working at the complex, said it was evacuating all nonessential personnel, leaving about 50 people there. Read the rest of this entry »