Fukushima Worker On Fukushima Reactor 2 Endoscope Operation: Radiation Resistant Camera Built To Withstand 1000 Sieverts Broken! (Photos)

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Result of endoscope operation on 1/19/2012 (Fukushima Diary, Jan. 19, 2012):

The water level turned out to be lower then 4.000m at the most.

Even the radiation resistant endoscope for 1000Sv got too much noise.

Tepco inserted 2m of the endoscope to reactor2 from the hole called X53 on 1/19/2012. The operation took 6 Tepco employees and 28 workers from subcontract companies. The maximum dose of the worker was 3.07 mSv.

As the result, they could not see the water surface. Because the radiation level was too high, endoscope had too much noise to capture the clear image.

The heat gauge on the endoscope measured 44.7℃ at 9:13. The heat gauge set inside of around X53 measured 42.6℃, so Tepco judged the heat gauges inside are not completely broken.

Unexpectedly, inside was not too steamy but because the evaporated water kept dropping inside, it also prevented the camera from capturing clear image.

The coating inside of the reactor was damaged and ripped off like squama.

From the gap of the pressure between inside of the reactor and suppression chamber, Tepco assumed the water level could be above the grating cover, but they could not see the water at least above the cover.

The height of the cover is around 4.0m from the bottom of the reactor. At least the water level is lower than there.

Actual Fukushima worker analyzes the main problem is the extremely high level of radiation.

@Happy20790
ハッピー
ただいまっ(^O^)今日は手足先の寒さも感じないで仕事出来たでし。2号機PCVの中見えたね。オイラが思ってたよりよく見えてた。もっとクモクモで見 えないと思ってたからね。今日は水面まで見れなかったのは残念だけど、中が見れただけでも良かったと思う。ただ気になるのは線量なんだ。

<Translation>

I’m back :) Today was warm, didn’t feel icy in my hands and feet. We managed to see inside of the PCV of reactor2. The image was clearer than I thought. I thought the inside might be more steamy. That’s sad not to be able to see the water surface, but it was an improvement for sure. but I’m concerned about the radiation level.

<End>

Happy20790 ハッピー
続き1:今日使ったカメラが確か1000SVの耐放カメラだと思うんだけど、かなりノイズ出てたから中は相当線量高い感じがするんだよね。通常の定検中も炉内に水中カメラ入れるんだけど線量の高い上部格子板(トップガイド)に近づいたらノイズが凄いんだ。

<Translation>

The camera we used today can resist for 1000Sv, but even the camera got so much noise (the white spots), the radiation level is really high. At usual reactor test, we put water-resistant camera into the reactor but it gets too much noise when the camera goes close to the highly radioactive place called top guide.

<End>

Happy20790 ハッピー
続き2:余り長い時間見てるとカメラ素子が壊れてしまうんだ。今日のはそんな感じだったからなぁ…。今後詳細に調べるならもっと高性能なカメラが必要だね。だけど燃料デブリに近づいて見れるカラーカメラだと1億円以上するんじゃないのかなぁ…。

<Translation>

If you put the camera at too radioactive place for too long, the camera gets broken. Today the endoscope became like that. To get more detailed image, we would need a more protective camera. It would cost 100 million yen to buy the camera what can get close to the fuel debris with color image.

<End>

Happy20790 ハッピー
続き3:次はちょっと治具を検討開発しなきゃだけど、今回のペネを使って線量測定して欲しい。線量がわからないと対策も打てないし…。本当はX-6ペ ネ付近からカメラが入れられればいいんだけどね。そしたらCRD昇降ブリッジ伝いにペデスタル内にアクセス出来るんだけど…。

<Translation>

For the next time, we need to develop new equipment. We shall use the same hole to measure the radiation level next time. We can’t even tell what to do if we don’t know the radiation level inside.

<End>

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