Via Kyodo News :
" Tokyo Electric Power Co. on Thursday started injecting nitrogen into one of the reactors at the crippled Fukushima Daiichi nuclear power complex to reduce the potential risk of a hydrogen explosion, while it succeeded in stopping highly radioactive water leaking into the Pacific Ocean from the plant the previous day.
Nitrogen, an inert gas, was injected into the No. 1 reactor's containment vessel, a process that could take several days. Hidehiko Nishiyama, a spokesman for the government's Nuclear and Industrial Safety Agency, denied there is an ''immediate danger'' of explosion and described the injection as ''a preventive measure.''
In addition to the task of maintaining the relative stability of all six reactors at the nuclear complex in Fukushima Prefecture, the utility firm known as TEPCO has also been engaged in efforts to stop highly radioactive water from leaking into the sea and cleaning up contaminated water within the plant."