Japan tackles hydrogen buildup amidst radiation concerns

Nitrogen pumped into reactor to prevent hydrogen explosion; Nuclear experts say damaged reactors far from being under control.

Nuclear spacesuits 311 (photo credit: REUTERS)
Nuclear spacesuits 311
(photo credit: REUTERS)
TOKYO - Japan pumped nitrogen gas into a crippled nuclear reactor on Thursday, trying to prevent an explosive buildup of hydrogen gas.
Engineers worked through the night injecting nitrogen into the containment vessel of reactor No.1 at Fukushima Daiichi power plant, following success in stopping highly radioactive water leaking into the sea at another reactor in the complex.
"It is necessary to inject nitrogen gas into the containment vessel and eliminate the potential for a hydrogen explosion," an official of plant operator Tokyo Electric Power (TEPCO) told a news briefing.
The possibility of another hydrogen explosion like those that ripped through reactors No.1 and No.3 early in the crisis, spreading high levels of radiation into the air, was "extremely low," he said.
But TEPCO suspected that the outside casing of the reactor vessel was damaged, said the official.
"Under these conditions, if we continue cooling the reactors with water, the hydrogen leaking from the reactor vessel to the containment vessel could accumulate and could reach a point where it could explode," he added.
A second TEPCO official said 6,000 cubic meters of nitrogen gas would be pumped into reactor No.1 and the utility was preparing nitrogen gas injections for reactors No.2 and No.3 in the six-reactor plant as a safety precaution .
Although TEPCO succeeded after days of desperate efforts to plug the leak at reactor No.2, they still need to pump 11.5 million liters (11,500 tonnes) of contaminated water back into the ocean because they have run out of storage space at the facility. The water was used to cool overheated fuel rods.
Nuclear experts said the damaged reactors were far from being under control almost a month after they were hit by a massive earthquake and tsunami on March 11.