Wednesday, May 30, 2012

4 More Thermocouples May Be Going Bad in Reactor 2 at #Fukushima I Nuke Plant

It looks like four more thermocouples inside the Reactor 2 Containment Vessel are failing:

  • return air drywell cooler(TE-16-114A)

  • return air drywell cooler(TE-16-114D)

  • supply air D/W cooler(TE-16-114F#1)

  • supply air D/W cooler(TE-16-114H#1)

The locations of these thermocouples can be (sort of) figured out with this TEPCO document, as of April 25, 2012 (I put the red rectangles around the failing thermocouples):

TEPCO's handout for press, 5/29/2012 lists "Thermometers which indicated large fluctuation". Temperatures have been fluctuating in a meaningful way (increase or decrease in large steps) since May 28 (red rectangles added to indicate the large fluctuations; click on the table for a better image):

But do not worry. TEPCO has a plan to send human workers inside the Reactor 2 building again to somehow install new thermocouples. According to the reference document for the Working Group meeting on May 28, 2012 (pages 10 to 17), the installation work should start sometime in August, after the decontamination of the 1st floor of the Reactor 2 building is complete by mid July. The trial decontamination has already been done by the workers to compare different methods (strippable paint is most effective, so is the radiation shield), and they have just stated the actual decontamination in the environment where the highest radiation level is 4,400 millisieverts/hour (on the surface of the penetration X-34, near the location that TEPCO wants to insert a new thermocouple).

I don't know why there is no robot by now that can do such a work.

Unlike Reactor 4, where carbon-based human workers routinely enter and work in the radiation levels measured in microsievert/hour, Reactors 1, 2 and 3 have much higher radiation levels measured in millisievert or even sievert/hour. Upper floors of Reactors 1, 2 and 3 are too radioactive for human workers, and even the robot (Quince) was left stranded in Reactor 2's 3rd floor because of high radiation that precluded the rescue mission.


Anonymous said...

"I don't know why there is no robot by now that can do such a work" --the Radiation is too high and makes the equipment fail. Carbon Based Humans however, are able to continue working..for a bit. Also, ads out in Brazil asking for more Fukushima temp workers(30,000 yen) the success of the decontamination efforts (sarcasm).

If workers return to their home countries..wonder if they are knowingly returning with high radiation levels. Probably not.

arevamirpal::laprimavera said...

@anon above,

"ads out in Brazil asking for more Fukushima temp workers(30,000 yen)"??

Do you have additional info on that? Thanks.

doitujin said...

it's from fukushima diary, but is it really true?

Anonymous said...

well if it's from there, probably not.

Steve From Virginia said...

RE: Fukushima reactor units 1,2 and 3 too radioactive for entry to upper floors ...

Lead bricks. Tepco/Japgov should have been on top of this starting 3/12/11. They need lead bricks and lots of them.

TechDud said...

@Anonymous - "well if it's from there, probably not"
Why do you say that about him?

@Steve From Virginia
Lead bricks violate environmental legislation.
What is truly at issue though is whom shall place them were they to be deemed necessary?
Did i misunderstand your desired use for these bricks?

TechDud said...

An odd thing was presented to me in order to publish my previous comment.

Half of the new captcha can be easily defeated. It's google's street-view trying to determine street addresses.

For instance; the image of a street address is presented. Use incorrect information for that image, and correct info for the traditional captcha & it accepts the result every single time!

Google's "Do no evil" should have read "We Do Evil"

Anonymous said...

@TechDud, that site is not known for accuracy for the news or the translation. Nevertheless, he seems to be collecting good donation money from clueless readers.

TechDud said...


These are provocative things to say. Do you have any supporting evidence, or is this simply your opinion?

PS: My apologies to the Admin for straying off-topic. I am grateful for anyone brave enough to relay fact, not fear &/or conjecture.

TechDud said...


That is a provocative thing to say. Do you have any supporting evidence to show any inaccuracy, or is this simply your opinion?

PS: I apologize to the Admin for straying far off-topic. I respect those brave enough to relay fact, not fear &/or conjecture.

Anonymous said...

TechDud, it's not provocative at all, and it's not my personal opinion either. It's a fact, and the examples are just too many to cite. That blog was screaming Reactor 4 was falling apart last year, when he mistook the dismantling operation as something unplanned happening. That "rumor" sure spread. It's one thing after another, rumor mongering.

arevamirpal::laprimavera said...

(This site welcomes generous donations, too....)

TechDud said...

@Admin - my apologies for the double-post.

@Anonymous - I had not read that. Can you cite examples with links, please? So far you seem long on accusations, and short on evidence.

Anonymous said...

did you know these articles are being blocked from posting on Facebook. I have tried to share this information but told the URL has been blocked due to spam??

Anonymous said...

@TechDud, do you read and understand Japanese? If you do I'll dig up links. Otherwise, no point, because you would have no way of knowing if the translation is wrong or not.

TechDud said...


I may not be fluent in Japanese, yet Google Translate can interpret much of what is written. I understand what it cannot do is translate the context of what is written. There are likely other limitations.

If there exists a more faithful service, please enlighten me.

Please, do "dig up links". Do this, not just for me, yet for other readers as well, many of whom can "read and understand Japanese".

Speaking of context, Mochizuki Iori may have been ill at the time. I say this not to make any excuse, only in the interest of proper context.
"When I was in Japan, I was so sick. I started having diarrhea since last summer. got sore throat and fatigue. From autumn to winter, I started caughing and couldn’t stop in December. I took double dose of coughing meds.
I became fine soon as I came to Europe. I really appreciate my host family."

In addition, i note his decision to have "I removed all the advertisement from the blog because it’s annoying and too distracting. so I’ll be happy if someone nicely makes me donation.
Fukushima Diary is attacked every 15 mins and run on 4 servers."

If he was simply after money, why halt advertisements?

Anonymous said...

@TechDud - FukushimaDiary is widely known as the most paranoid site concerning Fukushima. It is hardly a secret.

TechDud said...

Hopefully TEPCO splurges on 4-wire thermocouples.
Maybe they will attempt to place more sensors.
Strain gauges on critical structural areas of SFP's might show initiative.

Anonymous said...

It won't be TEPCO any more pretty soon. The Japanese government will effectively take over the company. Goshi Hosono himself can go and install them at 4 sieverts/hour location. Will do him good.

Anonymous said...

Fukushima Diary dude gets $2300 in one month in donation? Geez...

TechDud said...

It would seem that people are voting with their dollars, so to speak.

TechDud said...

PS: Having a government nationalize a technical company during these delicate hours scares me. Governments seem to have 'perfected' the reverse-Midas effect! Do not let them touch your gold!

Anonymous said...

TechDud, thank you for your ringing endorsement that this blog is worthless. Nice touch.

Atomfritz said...


Tepco uses 2-wire thermocouples.

There was a handout some time ago in which Tepco described the thermocouple diagnosis procedure, it clearly showed that the thermocouples are 2-wire.

Anonymous said...

you'll all be sleeping peacefully soon, you're so miserable geez, and I welcome more sites about fukushima not less, you act like 3 or so is too many, you sound like communists.

Unknown said...

What's up! :)

While Thermocouples can measure their own temperatures, it is worth noting that they can err especially if they have just been in use. Other factors that can lead to inaccurate temperature readings include when the insulation between the two wires losses its resistance due to thermal conditions or moisture.

TSPL - INDIA said...

A good post with detailed information. High Temperature thermocouples are the most effective and trusted instrument to measure temperature.

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