Sunday, March 25, 2012

TEPCO at Atomic Energy Society of Japan: Reactor 2 May Have Leaked Radioactive Materials from Heat-Damaged Containment Vessel Seal

4 TEPCO researchers attending the Spring Conference of the Atomic Energy Society of Japan (AESJ) made their presentation on the first day of the Conference on March 19.

From Fukushima Minpo (3/25/2012; part):

ただ、東電が新たに示した事実もあった。事故発生から5日目の昨年3月15日に原発周辺の放射線量が急上昇したことへの見解だった。東電は「2号機の原子炉格納容器の上部にあるシール(封印箇所)が熱で損傷し、放射性物質が漏れ出した可能性が高い」との見方を示した。

However, there was a new piece of information from TEPCO, which was TEPCO's opinion [hypothesis] about the rapid rise of radiation levels around Fukushima I Nuclear Power Plant on March 15, 2011, 5 days after the start of the nuclear accident. TEPCO said, "It is highly likely that the seal[s?] on the upper part of the Reactor 2 Containment Vessel was damaged by the heat, and radioactive materials leaked from there."

 ただ、発表終了後、報道陣の質問に対して、東電の担当者は「どう漏れたか、はっきりしたことはまだ分かっていない」と最終的な結論は出ていないことを説明した。

But after the presentation, one of the researchers answered the questions from the press and said "The detailed mechanism of the leak is still not known", and that there was no final conclusion reached yet.

 事故発生から1年が経過したが、東電や政府は原子炉の格納容器や圧力容器の内部を正確に把握できていない。東電の発表には「推定される」「思われる」などの語句がたびたび使われた。事故の原因や進展経過を十分に解明するには、依然として判断材料が乏しいことをうかがわせた。

It has been one year since the start of the accident, but TEPCO and the national government still haven't figured out what's been going on inside the Containment Vessels and Pressure Vessels of the reactors. TEPCO often used the words "to be presumed" or "to be considered" in the presentation. It seems there is still not enough information to fully understand the cause of the accident and how it progressed.

11 comments:

Anonymous said...

Still no concrete answers to so many things ... boy, we really got that nuclear power technology down! AND we made it safe. Congratulations definitely seem to be in order to our accomplishments. (Not to take away credit where credit is due, i.e., the workers dealing with the mess since the accident.)

Anonymous said...

The more you spread information like this, the more it will get beaten into the brains of those who: 1) dont care, 2) dont know, 3) pretend they know, 4) ignorant of it all (dont worry be happy moto)...

They will not be able to continue lying, and covering up, and pushing this issue to the back burner. pretty soon US/CAN will have to radiation check their foods.

its all about getting us used to Hell in small amounts.

Keep up the infowar against these elitist scums! STOP THE NWO!

arevamirpal::laprimavera said...

@anon at 5:42PM, can you tell me what "information" you are talking about?

Anonymous said...

In the US government documents that came out with FOIA and was picked up by ENENEWS.COM, the NRC folks (both onsite Fukushima and US office)believes that the core had been ejected from one or two of the Fuku reactor vessels. The transcript was clear that the NRC analysis of the released isotopes suggested containment breach. They were already discussing this back in spring 2011.

arevamirpal::laprimavera said...

ENENEWS picked up what Enformable.com had been writing, combing through the FOIA documents.

Anonymous said...

Lets just thank you all.

Keep up the good work.

Anonymous said...

Actually, no, these and several others were only on enenews:

http://enenews.com/nrc-be-fission-products-pellets-parking-lot-fukushima-plant-doesnt-make-sense-fuel-rods-be-intact

http://enenews.com/nrc-admits-radiological-material-dispersed-in-various-forms-around-plant-most-likely-from-inside-reactors-isotopes-indicative-of-core-damage

Atomfritz said...

Would be interesting to know if the article is talking about the midnight radiation spike on 3/15 or the later ones.

Just a few thoughts:
If radioactive steam escaped through the reactor lid into the reactor hall, wouldn't it have been condensed/cleaned by the water in the reactor pool?
Would then mostly non-condensing gases have escaped into the reactor hall and then to the outside via the blowout panel?
Could this possibly explain the low radiation level of 0.2 sievert Quince2 recently found in the reactor hall?
Has there been any measurement of the activity of the reactor pool water above the lid, which then could be very very radioactive?

elbows said...

@Atomfritz

What rector pool are you talking about? I don't know of any water above the lid, the reactor well & surrounding upper containment is only filled with water during refuelling and certain maintenance operations. During operation of the reactor the reactor vessel obviously has water in it, but this was gone by the 15th.

Substances that leak from the top of the containment will get into the air of the upper floors of th building, some will stick to walls, floor and equipment but the rest will have entered the environment via the opened blowout panel.

Anyway I think we are seeing articles about drywell failure because they didn't find huge and extensive or explosive damage to the torus (although some damage there is still possible).

We can speculate that reactor 2 caused more environmental contamination than the other reactors not simply because of the location of the containment failure, but because no wet-venting happened at this reactor. At reactors 1 & 3 the wet venting caused quite a lot of the radioactive substances to become trapped in the water of the suppression chamber. So when the containment failed not so much bas stuff was released. But at reactor 2 lots of this material was still in the drywell, it never got scrubbed by the suppression pool. And the containment probably failed while it was under high pressure, so these substances could leak out in considerable quantities.

Someone on the physics forum noticed that the EXIF times tam for the following picture was March 15th at 08:58am. If this time is accurate then this photo was taken at the time that drywell pressure was decreasing, site radiation was increasing, and many site workers had been temporarily evacuated.

http://www.tepco.co.jp/en/news/110311/images/110412_1f_tsunami_6.jpg

elbows said...

Doh, multiple typo's in my above post, corrections below:

rector pool = reactor pool.

not so much bas stuff = not so much bad stuff

EXIF times tam = EXIF timestamp

Atomfritz said...

elbows, thank you for your very interesting comment!

The photo is really interesting. It looks like heavy blowout from the blowout window, not like the usual fog. And it shows quite a lot of radiation distortion, way more than the pictures of the 500mSv junk pile area etc. So it could really be caused from the gamma emission of the steam pouring out of the RB. (The photographer must have been a cool guy, as it probably is quite hot to get so close to such a blowout. If wind changes for a moment one could quickly find oneself be engulfed in multi-sievert steam...)

Noticed that the thread about #2 on the PF really kicked off now, reading that stuff now for new insights, maybe posting some more after... (here the link for people new to the topic: http://physicsforums.com/showthread.php?t=507252 )

P.S.: please don't care so much about occasional typos. Happens to every of us, so what...

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