Friday, April 29, 2011

#Fukushima I Nuke Plant: Murphy Wins, TEPCO Stops "Water Entombment" Experiment on Reactor 1

After the pressure inside the Containment Vessel of the Reactor 1 dropped down very, very close to the atmospheric pressure, TEPCO decided to stop the experiment of pumping extra water into the Pressure Vessel of the Reactor 1.

The idea was to pump extra water into the Pressure Vessel, which then would leak extra water into the Containment Vessel, which then would be filled with water to the level that's high enough to cool the fuels inside the Pressure Vessel.

For now, the idea of turning the "unintended" water entombment into the "intended" is out.

Snippets from Asahi Shinbun (9:58PM JST 4/29/2011):


On April 29 TEPCO reduced the amount of water being injected to the Reactor 1 [Pressure Vessel] from 10 tonnes/hr back to 6 tonnes/hr for the "water entombment" experiment to fill the Containment Vessel with water, because the temperature and the pressure dropped [more than expected]. TEPCO will continue to observe the changes.

 当初は、注水量を毎時14トンまで増やす予定だった。ところが、温度や圧力が予想以上に低下。注水を増やす前の132度、1.5気圧が、29日午前5時 現在では113度、1.1気圧になった。注水によって格納容器内を満たしていた水蒸気が冷やされて水になり、圧力が下がったとみられる。

The plan, initially, was to increase the amount of water to 14 tonnes/hr. However, the temperature and the pressure [of the Containment Vessel] dropped more than expected. The temperature of 132 degrees Celsius and the pressure of 1.5 atmospheric pressure before the experiment dropped to 113 degrees Celsius and 1.1 atmospheric pressure at 5:00AM on April 29. The steam inside the Containment Vessel is thought to have turned into water with the injection of cold water, lowering the pressure.

 圧力が1気圧を下回ると、酸素を含む外気が吸い込まれ、格納容器内にたまった水素が爆発を起こしかねない。爆発を防ぐための窒素の注入も進めているため 「水素の濃度は1%未満とみられ、爆発のリスクはさほど高くない」とはいうものの、48時間が過ぎた29日午前10時すぎの段階で、注水量を元に戻すこと にした。

If the pressure drops below 1 atmospheric pressure, the outside air that contains oxygen may get sucked inside the Containment Vessel, and cause a hydrogen explosion. As nitrogen gas is being injected, TEPCO thinks "the concentration of hydrogen is less than 1%, and the risk of explosion is not that high." Still, TEPCO decided to reduce the amount of water back to 6 tonnes/hr at 10:00AM on April 29, 48 hours after the start of the experiment.

It was good that the temperature dropped, but the pressure drop was the Murphy..

Here are the precise numbers for the Containment Vessel dry well pressure (from the Plant Parameter sheets from NISA, the latest is linked). It did come awfully close to the atmospheric pressure:

1 atmospheric pressure = 0.1013 MPa

April 29 11:00AM: 0.105 MPa
April 28 5:00AM: 0.125 MPa
April 27 5:00AM: 0.155 MPa (when the experiment started)


Anonymous said...

Robbie001 sez:

I guess it's a good thing they called it an "experiment" or people might get the idea they don't know what they're doing. This is probably a blessing in disguise I don't have a lot of faith in anything TEPCO plans.

BTW, I found this article about a Japanese science adviser resigning his position over the governments mis-handling of the Fukushima crisis but I could only find one article about it and a Facebook page that alludes to it. Does anyone know if this article is true and if so do they have more information about it?

"Advisor To Japanese PM To Resign Over Government's Nuclear Crisis Response

TOKYO, April 30 (Bernama) -- Toshiso Kosako, an advisor to Japanese Prime Minister on the nuclear crisis said that he will resign in protest following government's impromptu in handling the Fukushima Daiichi power plant crisis, Kyodo News reported Friday.

It is extremely rare for an intellectual adviser appointed by the prime minister to resign in protest at measures the government has taken.

Kosako said the government has belittled the laws and regulations, and expressed disappointment over the present moment measures taken to solve this crisis."

arevamirpal::laprimavera said...

It is true, and Japanese tweets about Fukushima crisis are all over the news. It was apparently announced at a press conference in the Japanese Diet building, attended only by the members of the press club and the resignation is not widely reported.

I've found the entire statement to the press when he announced the resignation, from NHK blog. I'll try to translate later, but if you read Japanese, it's here:

maybe I'd better copy it before NHK forces the Science division to take down the blog post.

Anonymous said...

Robbie001 sez:

WOW! Thanks for your efforts. I'd love just to hear a loose translation of what this man has to say. I wonder how many seconds it is going to take for the JNuc/JGov conglomerate to mount a discrediting/disinformation campaign against this poor guy? I see this man as every bit the hero a person working at Fukushima is. This guy has committed career suicide to take a stand and you've got to respect that. How many people are going to jeopardize a cushy job and "peer" acceptance on a whim?

Toshiso Kosako is the kind of human that renews my faith in mankind. He reminds me of the WWII story of Sugihara Chiune a Japanese diplomat who against direct orders of his government was instrumental in saving thousands of Jewish refuges in Europe.

"From July 18 to August 28, 1940, aware that applicants were in danger if they stayed behind, Sugihara began to grant visas on his own initiative, after consulting with his family. He ignored the requirements and issued the Jews with a ten-day visa to transit through Japan, in direct violation of his orders. Given his inferior post and the culture of the Japanese Foreign Service bureaucracy, this was an extraordinary act of disobedience."

"You want to know about my motivation, don't you? Well. It is the kind of sentiments anyone would have when he actually sees refugees face to face, begging with tears in their eyes. He just cannot help but sympathize with them. Among the refugees were the elderly and women. They were so desperate that they went so far as to kiss my shoes, Yes, I actually witnessed such scenes with my own eyes. Also, I felt at that time, that the Japanese government did not have any uniform opinion in Tokyo. Some Japanese military leaders were just scared because of the pressure from the Nazis; while other officials in the Home Ministry were simply ambivalent.

People in Tokyo were not united. I felt it silly to deal with them. So, I made up my mind not to wait for their reply. I knew that somebody would surely complain about me in the future. But, I myself thought this would be the right thing to do. There is nothing wrong in saving many people's lives....The spirit of humanity, philanthropy...neighborly friendship...with this spirit, I ventured to do what I did, confronting this most difficult situation—and because of this reason, I went ahead with redoubled courage."

杉原 千畝,

Anonymous said...

Robbie001 sez:

Just because people like Mr. Sugihara are so little known I'd like to add a small excerpt from the PBS documentary "Sugihara: Conspiracy of Kindness" (available @ netflix).

YUKIKO SUGIHARA (wife): I wasn't frightened by the crowd. They all looked so sad. Some women were looking right at me with great sorrow. Some of them had their hands together begging. I could see how they came there depending on us.

NARRATOR: Sugihara was faced with an agonizing decision.

To disobey his government would surely bring punishment and disgrace. Also, assisting Jews in these anti-Semitic times could lead to grave consequences.

To the Soviets, now in control of Lithuania, emigrants were considered traitors, and aiding their passage was a capital offense. In addition, Japan's future ally, the Nazis, were now closing in from the west.

YUKIKO SUGIHARA (wife): If we were in Germany and we did something like that, my husband, myself, my children could all be taken away by the Nazis. I didn't know what they would do to us ... maybe they'd kill us.

NARRATOR: Despite the possible risk to himself and his family, Sugihara was persuaded by the desperate stories of the refugees.

SUGIHARA (QUOTE): Those people told me the kind of horror they would have to face if they didn't get away from the Nazis and I believed them. There was no place else for them to go. They trusted me. If I had waited any longer, even if permission came it might have been too late.

NARRATOR: Finally, at the end of July 1940, Sugihara agreed to issue the transit visas. ...

SUGIHARA (QUOTE): I may have disobeyed my government but if I didn't I would be disobeying God.

Anonymous said...

Robbie001 sez:

Here's a little more news on Toshiso Kosako I must say the more I hear from him the more I respect him.

"In particular, Kosako protested against the government's decision to revise the maximum permissible level of radiation exposure among children up to 20 millisieverts per year, saying, "Should I approve that decision, I would no longer be a researcher. I would not want my children to be exposed to that amount of radiation."

Kosako revealed the Cabinet did not accept his advice that outdoor school activities for elementary and junior high school students near the crippled power station be restricted to prevent them from being exposed to over 1 millisievert of radiation per year.

"It is quite rare for nuclear power plant workers dealing with radioactive materials to be exposed to 20 millisieverts of radiation per year. I cannot allow infants and children to be exposed to such high levels of radiation from an academic as well as humanitarian point of view."

M. Simon said...

Very interesting situation. They can only maintain pressure if the water is boiling. This seems odd given nitrogen and water pumping options. Assuming they are faced with a bunch of bad choices and they are not complete idiots (which can't be completely ruled out) the situation must be a lot worse than they are letting on. And if they are complete idiots? Worse for sure.

Anonymous said...

The resignation of Mr. Kosako is being very widely reported. All major news services are reporting on it, and continue to reference it widely. Kosako's views, and Professor Takeda's views are always attract attention. As well they should.

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