#Fukushima I Nuke Plant: TEPCO Has Started to Expel Hydrogen Gas from the Pipe Leading to Reactor 1 CV

Remember that pipe filled with 63% hydrogen gas (the rest was nitrogen gas, according to TEPCO) that leads to the Containment Vessel of Reactor 1?

TEPCO is removing the gas from the pipe right now. They started at about 2 hours ago (12 noon on October 8, 2011 Japan Standard Time), according to NHK News Japanese (12:57PM JST 10/8/2011):

東京電力福島第一原子力発電所１号機で、格納容器につながる配管に高濃度の水素がたまっている問題で、東京電力は、８日正午すぎから水素を抜き取る作業を始めました。東京電力は、作業は配管に窒素を入れて水素の濃度を下げながら行うため、爆発のおそれはないとしています。

Regarding the hydrogen gas in the pipe that leads to the Containment Vessel of Reactor 1 at Fukushima I Nuclear Power Plant, TEPCO started the operation to expel the gas from the pipe at noon on October 8. TEPCO says there is no danger of explosion as the nitrogen gas will be injected in the pipe to lower the concentration of the hydrogen gas.

福島第一原発１号機では、先月下旬格納容器につながる配管に水素がたまっていることが分かり、東京電力が配管の水素濃度を測定したところ、６１％から６３％と全体の３分の２近くを占める高い濃度だったことが分かりました。この配管の中に酸素はないとみられ、今のところ、爆発のおそれはないとしていますが、今後の復旧作業で配管を切断する計画があるため高濃度の水素が外部に放出されると爆発するおそれがあるとして、８日正午すぎ、配管から水素を抜き取る作業を始めました。水素を抜き取る作業は、配管の中に窒素を入れて、水素の濃度を下げるとともに、発火につながる静電気が起こりにくい特殊なホースをつなぎ込んで、建屋の外に放出するということで、爆発するおそれはないとしています。東京電力は、２号機と３号機についても配管などの水素濃度を調べるよう国から指示を受けていて、今後、１号機と同じように調査を行うことにしています。

In late September it was discovered that the hydrogen gas was in the pipe that leads to the Containment Vessel of Reactor 1. When TEPCO measured the concentration of the gas, it was very high between 61 and 63%. It is considered that there is no oxygen in the pipe, and there is no danger of explosion so far, according to TEPCO. The company plans to cut the pipe later, and to eliminate the danger of explosion if the hydrogen gas in the pipe is released it started to expel the gas at noon on October 8. Nitrogen gas will be injected in the pipe to lower the concentration of the hydrogen gas there, and a special hose that suppresses static electricity which could trigger explosion will be attached to expel the gas outside the building. There will be no danger of explosion, TEPCO says. TEPCO has been ordered by the national government to check the concentration of hydrogen gas in the similar pipes in Reactors 2 and 3, which the company has said it will do in the near future.

TEPCO hasn't said anything definite about where this hydrogen gas came from, other than saying it may be the remaining gas from zirconium (in the cladding) and steam reaction when the fuel was melted down. The company doesn't seem eager to find out.

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