Wednesday, April 27, 2011

#Fukushima I Nuke Plant: 1120 Milli-Sieverts/Hr Inside the Reactor 1 Bldg, But "Water Entombment" Has Started Anyway

(Picture from TEPCO: Packbot in Reactor 1 reactor building, 4/24/2011)

That high level of radiation would indicate the highly radioactive water from the Pressure Vessel may be leaking outside the Containment Vessel, but TEPCO has decided to go ahead with the plan.

From Yomiuri Shinbun (1:17 PM JST 4/27/2011):


On April 27, TEPCO started the test to increase the amount of water being injected into the Pressure Vessel of the Reactor 1 at Fukushima I Nuclear Power Plant.


The purpose of the test is to observe the change in water level by increased water injection. It is a step toward the "water entombment" that will involve filling the Containment Vessel with water to cool the Pressure Vessel.


The amount of water was increased from the previous 6 tons/hour to 10 tons/hour at 10:00AM on April 27. It is to be increased to 14 tons/hour starting at 4:00PM for 18 hours, and then to be decreased to 6 tons/hour again in the morning of April 28. After that, the robots will go in to check whether there is any leak.

 東電は、26日のロボットを使った事前調査で、建屋内の数値としては最高の毎時1120ミリ・シーベルトの放射線量を記録した場所があったことを 明らかにした。原子炉からの高濃度の汚染水が漏れている可能性があるが、東電は約2時間にわたる調査で漏れ箇所が発見できなかったとして、水棺作業の実施 を決断した。

TEPCO disclosed that during the preliminary survey of the reactor building using the robots on April 26 there was a location that registered 1,120 milli-sieverts/hour, the highest so far for the radiation level inside the plant buildings. It is possible that the highly radioactive water is leaking from the reactor, but TEPCO decided to go ahead with the "water entombment" after no leak was found during the 2-hour survey.

Total 312 tons of water is to be injected before the test is over. We'll find soon enough if there's more Murphy..


Anonymous said...

Robbie001 sez

The NRC assessment of reactor #1 said between the salt and the fuel damage cooling in RPV #1 was severely impeded. I think water entombment is their last and only option but I can see an aftershock causing major problems. And then there is always that pesky leak that isn't allowing them to do a full nitrogen purge. I could see part of the experiment is trying to find the source of the N purge leak. I wonder how all the various valves, gaskets and seals will hold up if they are shook under excess water weight?

BTW, Rolling Stone has a pretty good article on the cozy relationship the NRC has with the nuclear industry and its disturbing effect on reactor safety in the US.

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