Japan injects nitrogen into nuke reactor to prevent blast

Workers injected nitrogen gas into the containment vessel of the plant's No 1 reactor in process that could take several days, according to the embattled utility firm.

But following the firm managing to stem the flow of radioactive water from flowing freely into the Pacific Ocean yesterday, the latest move was described by Japan's nuclear safety agency as "preventative."

"It is necessary to inject nitrogen gas into the containment vessel and eliminate the potential for a hydrogen explosion," Hidehiko Nishiyama, Deputy-General of Japan's Nuclear and Industrial Safety Agency told a press briefing.

Nishiyama added that the risk of further hydrogen explosions that previously blew apart reactor buildings No 1 and No 3, causing dangerous levels of radioactive substances to be released into the atmosphere, was "extremely low."

That said, due to fears that the outside casing of the reactor vessel has been damaged, while an explosion remains unlikely, the scenario has not been completely ruled out, the nuclear safety agency said.

"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," a TEPCO official was quoted as saying Thursday.

A total of 6,000 cubic meters of the inert gas will be pumped into the No. 1 reactor and TEPCO will repeat the process for reactors No.2 and No.3, in a bid to make the six-reactor complex more stable, officials said.

TEPCO have said, to the condemnation of neighboring countries like South Korea, that they intend to pump a further 10,000 tonnes of radioactive water into the Pacific Ocean by this weekend, to free up yet more storage space at the complex to shift more highly-contaminated water into the facility's containment units.

Hence domestic and international fears remain rife as the utility firm has confirmed that 70 percent of the No 1 reactor's fuel rods, 30 percent of the No 2 reactor's fuel rods and 25 percent of the nuclear fuel rods at the No 3 reactor have been damaged.

Previous hydrogen explosions were caused as a result of high levels of hydrogen accumulating following melted nuclear fuel rods reacting with steam produced from the reactors' coolant water.

A seawater sample taken near the No 2 reactor water intake on Saturday showed a radioactive iodine-131 concentration of 7.5 million times the maximum level permitted under law. Kazinform cites. See www.chinadaily.com.cn for full version