Hydrogen Buildup Spurs More Concern At Japanese Nuclear Plant

Tokyo -- Engineers began injecting non-flammable nitrogen into the No. 1 reactor at the crippled Fukushima Daiichi nuclear power plant Thursday to counter a buildup of potentially explosive hydrogen, the plant's owner reported.

The Tokyo Electric Power Company said the danger of another hydrogen explosion, like the one that blew the roof and upper walls off the reactor building in March, was "extremely low." But it warned that more hydrogen could build up in the damaged reactor and that it planned a similar procedure for reactors 2 and 3.

Hydrogen buildup is a symptom of overheated fuel rods in the cores of the reactors, which plant workers have been struggling to keep under control since the March 11 earthquake and tsunami.

Another hydrogen explosion blew apart the No. 3 reactor building three days after the quake, and a suspected hydrogen explosion is believed to have damaged the No. 2 reactor the following day.