Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[NUCENG]

TEPCO management knew about the tsunami threat and did nothing:

http://mdn.mainichi.jp/mdnnews/news/20110825p2g00m0dm050000c.html

I said this in a posting two weeks ago and received a warning from Astronuc to "refrain from such noise" and my posting was deleted. Now it is official "noise".

We discussed this on the Management and Government Performance Thread in May and it has come up again there today. Tsutsuji has added some excellent references showing that this was true. I have to believe there was more to the deletion of your post than a simple statement. The mentors have deleted posts and locked threads that I disagreed with, but they are doing a tough job and they have their reasons.

 

[NUCENG]

I am double posting this link here and on the Fukushima Management and Government Performance thread. It has technical information about robots as well as a potential indication of censorship.

--------------------------------------------------------------------------------

Here is a link to a story about one of the robot operators at Fukishima. This is a summary because a blog the operator was writing has been deleted. Perhaps another example of trying to prevent communication in a world where the internet makes that impossible and foolish.

http://spectrum.ieee.org/automaton/robotics/industrial-robots/fukushima-robot-operator-diaries

 

[skodises2]

Well, that didn't take long. I get a 404 error from that link: "Page Not Found". And I am a 25+ year member of the IEEE... Hope somebody got a snapshot of it before it was taken down.

 

[Borek]

NUCENG posted incorrect link in this post, it is corrected now.

 

[NUCENG]

NUCENG posted incorrect link in this post, it is corrected now.

Ooops. Thanks Borek!

 

[LabratSR]

Analysis Results From The Spent Fuel Pools

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110825_02-e.pdf


Background Concerning The Evaluation Of Wave Sources

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110825_01-e.pdf

 

[Bodge]

Analysis Results From The Spent Fuel Pools

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110825_02-e.pdf


Background Concerning The Evaluation Of Wave Sources

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110825_01-e.pdf

As per usual, just three isotopes measured.

There will be dozens of others and they never tell us the levels. I don't believe that they are not testing for strontium, cobalt and the actinides.

Also, ph 9.2 in SPF 3 seems a little high compared to the others: why is this? TIA

 

[joewein]

ph 9.2 in SPF 3 seems a little high compared to the others: why is this? TIA

Because of the amount of broken concrete rubble in the pool of unit 3, which is highly alkaline. Cement reacts with CO2 at the surface of the concrete, but inside there's still a lot of CaO that will raise pH when exposed.

 

[rmattila]

As per usual, just three isotopes measured.

There will be dozens of others and they never tell us the levels. I don't believe that they are not testing for strontium, cobalt and the actinides.

You don't measure isotopes separately, but rather measure the entire gamma spectrum and then recognize different isotopes from the spectrum by their signature gamma peaks. Strontium is not a gamma emitter, so it requires a separate (and rather lengthy) beta analysis to be detected.

If you know the measurement arrangements and get the raw gamma spectrum, you could make the spectrum analysis anywhere around the world, as there are several organizations with very sophisticated analysis capabilities.

 

[tsutsuji]

http://www.tepco.co.jp/en/press/corp-com/release/11082602-e.html Yesterday, near unit 3, most likely, "an oil pipeline for cooling was damaged by accidental removal of an oil pipeline for radiator of the transformer during the removal work of debris". Picture available at http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110825_06-e.pdf

http://www.yomiuri.co.jp/science/news/20110826-OYT1T00779.htm A pump carrying water from the Kurion system to the Areva system made an automatic stop at 2:21 PM, 26 August. Tepco is investigating the cause of the overload. [If it is a "temporary stop", as Yomiuri says, it could mean that the pump has already been restarted. However, there is no such hint in Tepco's latest press release at http://www.tepco.co.jp/nu/f1-np/press_f1/2011/htmldata/bi1714-j.pdf which also says the (Kurion) adsorption system is stopped]

 

[tsutsuji]

I have begun to read the big Fukushima Daini report that was published on 12 August : http://www.tepco.co.jp/cc/press/betu11_j/images/110812b.pdf

I think the 16 diagrams on pages 33 to 40 (pdf page numbers) explaining what happened at the four units at four different dates are quite helpful to figure out what happened, and to easily compare the lucky unit 3 with the more unlucky other units.

Unit 1, 11 March after quake, before tsunami: page 33 top
Unit 1, 11 March after tsunami: page 33 bottom
Unit 1, 14 March recovery of RHRS and RHRC pumps, start of RHR pump B (S/P cooling): page 34 top
Unit 1, 14 March 17:00 cold shutdown: page 34 bottom

Unit 2, 11 March after quake, before tsunami: page 35 top
Unit 2, 11 March after tsunami: page 35 bottom
Unit 2, 14 March recovery of RHRS and RHRC pumps, start of RHR pump B (S/P cooling): page 36 top
Unit 2, 14 March 18:00 cold shutdown: page 36 bottom

Unit 3, 11 March after quake, before tsunami: page 37 top
Unit 3, 11 March after tsunami: page 37 bottom
Unit 3, 12 March start of reactor cooling: page 38 top
Unit 3, 12 March 12:15 cold shutdown: page 38 bottom

Unit 4, 11 March after quake, before tsunami: page 39 top
Unit 4, 11 March after tsunami: page 39 bottom
Unit 4, 14 March RHRS and RHRC pumps, plant status upon recovery of power supply (S/P spray): page 40 top
Unit 4, 15 March 7:15 cold shutdown: page 40 bottom

The key to the English acronyms is given on pages 763, 764, 765 and 766.

I attach below an English translation of the first diagram (Unit 1, 11 March after quake, before tsunami: page 33 top)

The most important clue is that equipment in use is colored in red. Idle equipment is blue, and unusable equipment is shown with a black "X" symbol.

Yellow boxes are backup electric power supplies (power cables or mobile diesel generators)

 

[tsutsuji]

The Kurion system was restarted :

http://www.tepco.co.jp/en/press/corp-com/release/11082702-e.html "At 4:54 pm we resumed the instruments by switching to transfer pump (B) for cesium absorption treated water. At 5:45, it reached normal volume of flow."

Third and last instalment of the earthquake safety study, now for units 2, 5 and 6:

http://www.tepco.co.jp/en/press/corp-com/release/11082605-e.html English (summary only)
http://www.tepco.co.jp/cc/press/betu11_j/images/110826c.pdf (65 pages, not translated into English) page 50 shows a series of pictures inside unit 5.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110824e13.pdf Water treatment weekly report for the 17 - 23 August week. 6,780 m³ (or 80,7% of 50 m³/h*24hours*7days=8400 m³) have been treated, including 1,760 m³ treated by SARRY.

 

[rmattila]

Radiation measurement results from unit 4 emergency gas treatment system:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110827_02-e.pdf

It appears that the filters have a clearly higher level of activity on the side of the common exhaust stack of units 3/4, and a smaller activity on the unit 4 side. If the filters are identical, this would apparently support the theory of unit 3 hydrogen finding its way to unit 4 through the common stack connection.

 

[ernal_student]

I am sorry that I have been unable to contribute in recent weeks, but I have been abroad and will have to go on another extended trip before long.

By the way, if I may ask, I would like to ask whether anybody sees any major problems (data that have been shown to be invalid or invalid conclusions) in the following summarizing article:
http://www.gaia-health.com/articles501/000517-fukushima-no-return-home.shtml

Thank you in advance for your help.

 

[LabratSR]

I am sorry that I have been unable to contribute in recent weeks, but I have been abroad and will have to go on another extended trip before long.

By the way, if I may ask, I would like to ask whether anybody sees any major problems (data that have been shown to be invalid or invalid conclusions) in the following summarizing article:
http://www.gaia-health.com/articles501/000517-fukushima-no-return-home.shtml

Thank you in advance for your help.

For me, a simple Google search of the authur told me all I need to know.

http://www.naturalnews.com/Author32.html

 

[zapperzero]

Radiation measurement results from unit 4 emergency gas treatment system:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110827_02-e.pdf

It appears that the filters have a clearly higher level of activity on the side of the common exhaust stack of units 3/4, and a smaller activity on the unit 4 side. If the filters are identical, this would apparently support the theory of unit 3 hydrogen finding its way to unit 4 through the common stack connection.

It would support the theory of air on one side being less radioactive than air on the other side.

 

[hbjon]

How's the battle with the fuku monster going? Giant Robot activate? Thanks in advance for the tireless work you all do.

 

[etudiant]

Has anyone developed a scenario that explains the sizable emission of plutonium/neptunium from the site?

According to the NISA report of June 6 (hat tip to EX SKF, http://ex-skf.blogspot.com/ ) the accident has dispersed 3.2x10**9 bequerels of plutonium.
While this is not a lot, it does raise the question of how this non volatile material was mobilized for dispersal. Other than molten fuel vaporizing, are there other plausible explanations?

 

[zapperzero]

Has anyone developed a scenario that explains the sizable emission of plutonium/neptunium from the site?

According to the NISA report of June 6 (hat tip to EX SKF, http://ex-skf.blogspot.com/ ) the accident has dispersed 3.2x10**9 bequerels of plutonium.
While this is not a lot, it does raise the question of how this non volatile material was mobilized for dispersal. Other than molten fuel vaporizing, are there other plausible explanations?

Well, they are both (in their metal form) somewhat soluble in water. During the meltdown, some of the metal oxide gets reduced and seawater is mildly alkaline. I don't know if it's the only mechanism, but some of the plutonium mst have left with the steam.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20110829/index.html Today 10 workers are going to enter inside Fukushima Daini unit 4 primary containment vessel. They are going to check radiations, temperatures, check if anything is broken, preparing for future work there. It is the first time people enter inside a Fukushima Daini primary containment vessel since 11 March.

How's the battle with the fuku monster going? Giant Robot activate? Thanks in advance for the tireless work you all do.

On the Fukuichi live camera, you can see that the two lower levels steel truss beams have already been assembled surrounding Fukushima Daiichi unit 1 : http://www.tepco.co.jp/en/nu/f1-np/camera/index-e.html (you can compare with the structure diagram on http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110614e17.pdf )

While the new SARRY system had its trouble on 26 August, at the Kurion system :

Vessels in the Water Treatment Facility were exchanged (the Water Treatment Facility was not suspended) (from 11:01 to 13:58, August 26).
http://www.nisa.meti.go.jp/english/press/2011/08/en20110829-2-1.pdf

Without even suspending one of the two lines (or half of the facility)? Remembering the early days of the Kurion system when it was said that flushing had to be performed during long hours before vessel change, I was not aware they were now able to perform vessel change at the Kurion system without suspending the whole facility.

http://sankei.jp.msn.com/region/news/110829/fks11082912150003-n1.htm A thermometer located at the junction between the RPV and the RPV cap at Fukushima Daiichi unit 2 is displaying 120°C on 29 August instead of 72°C on 28 August. As the other thermometers and pressure gauges are OK, the thermometer is probably having a dysfunction.

 

[Cire]

Well the Daini plants reached cold shutdown.

As of 3:00 pm on August 29, the reactors of Unit 1 to 4 are in cold
shutdown (please refer to the appendix). We will continue to make our
endeavors to further stabilize each plant of cold shutdown.

 

[joewein]

Yes, but the last Daini unit to reach cold shutdown was on http://www.tepco.co.jp/en/press/corp-com/release/11031501-e.html", not anything that happened recently.

I am curious if TEPCO is still planning on restarting operations at Daini (maybe after a few years) even though it's almost 10 km inside the Daiichi exclusion zone.

I am curious what other purpose the inspection of the containment serves. Are they suspecting internal damage?

 

[joewein]

Well, they [plutonium/neptunium, JW] are both (in their metal form) somewhat soluble in water. During the meltdown, some of the metal oxide gets reduced and seawater is mildly alkaline. I don't know if it's the only mechanism, but some of the plutonium mst have left with the steam.

Plutonium and neptunium (as well as uranium) are http://www.meta-synthesis.com/webbook/36_eneg/electroneg.html" than hydrogen, so even if their metallic form was present while there was still steam around, they should get reoxidated by steam similar to the zirconium reaction.

In fact plutonium is more electropositive than zirconium (in the fuel rod cladding), so it might grab oxygen from zirconium that had reacted with steam already. On the other hand, metallic plutonium boils at a lower temperature than metallic zirconium, so that might shift the balance the other way.

If any metallic plutonium was evaporated in the core, I expect it would react back to oxide with the steam and turn into an oxide aerosol before it has a chance to meet liquid water again.

 

[etudiant]

Plutonium and neptunium (as well as uranium) are http://www.meta-synthesis.com/webbook/36_eneg/electroneg.html" than hydrogen, so even if their metallic form was present while there was still steam around, they should get reoxidated by steam similar to the zirconium reaction.

In fact plutonium is more electropositive than zirconium (in the fuel rod cladding), so it might grab oxygen from zirconium that had reacted with steam already. On the other hand, metallic plutonium boils at a lower temperature than metallic zirconium, so that might shift the balance the other way.

If any metallic plutonium was evaporated in the core, I expect it would react back to oxide with the steam and turn into an oxide aerosol before it has a chance to meet liquid water again.

Thank you for this quite illuminating comment.
It makes a lot more sense than the stories of fuel fragments flung for miles, but in a real way is more troublesome. It implies that the emissions from a meltdown are even more lethal than the relatively short lived cesium contamination. Cesium is excreted by adults in a couple of months, whereas plutonium tends to stay in the body afaik, barring heroic measures such as chelation therapy.

 

[zapperzero]

Plutonium and neptunium (as well as uranium) are http://www.meta-synthesis.com/webbook/36_eneg/electroneg.html" than hydrogen, so even if their metallic form was present while there was still steam around, they should get reoxidated by steam similar to the zirconium reaction.

In fact plutonium is more electropositive than zirconium (in the fuel rod cladding), so it might grab oxygen from zirconium that had reacted with steam already. On the other hand, metallic plutonium boils at a lower temperature than metallic zirconium, so that might shift the balance the other way.

If any metallic plutonium was evaporated in the core, I expect it would react back to oxide with the steam and turn into an oxide aerosol before it has a chance to meet liquid water again.

I was thinking about a scenario where quenching with seawater succeeded - the surface of the corium would have come in contact with liquid water. Much lower temps and availability of anions (esp. hydroxil) would change the picture yu're painting somewhat.

Re boiling point: for Pu it is over 3200 while Zr is around 4300. You must be thinking of melting points - 640 and 1855 respectively.

EDIT: there's even a paper, for those of you who have access
http://www.sciencedirect.com/science/article/pii/S0969804301000975

LATER EDIT: chemical analysis of the water they are recirculating would tell us more.

 

[tsutsuji]

http://www.asahi.com/national/jiji/JJT201108290140.html 2 workers have been exposed to 23.4 and 17.1 mSv of beta radiations while changing filters at the desalination facility yesterday. The condition of a third worker is not known yet.

http://www3.nhk.or.jp/news/html/20110830/t10015234611000.html While it is above the 15 mSv planned exposure, it is less than the legal limit of 1000 mSv in emergency situations for beta rays. The workers were changing filters with gum gloves. Tepco will check if anything is wrong either with the working method or with the equipment.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20110830/1230_hibakuryou.html The Ministry of Health and Labour will cancel by next Autumn the decision taken in March to allow worker exposure up to 250 mSv / year. The limit will come back to 100 mSv like before the accident. No worker has been tested above 100 mSv since April.

Decommisionning Fukushima Daiichi:

It is believed that raising water levels inside the reactor has been difficult because of a hole in the bottom of the vessel. It will be necessary to plug the hole, and continue filling the vessel with water while extracting the melted fuel. How to fill the vessel with water is still being debated.
http://mdn.mainichi.jp/mdnnews/news/20110828p2a00m0na002000c.html

 

[Bandit127]

http://www3.nhk.or.jp/news/html/20110830/t10015234611000.html While it is above the 15 mSv planned exposure, it is less than the legal limit of 1000 mSv in emergency situations for beta rays.

Thanks for your valuable contribution as always.

I suspect this should be 100 mSv though.

 

[SteveElbows]

Dose equivalent rates inside Daini reactor 4 containment have been published, and don't appear unusual to me:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110830_04-e.pdf

Looks like they have found a problem with a pump at Daini reactor 2:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110830_03-e.pdf

http://www.tepco.co.jp/en/press/corp-com/release/11083014-e.html

 

[SteveElbows]

What happened with the plan to spray water into reactor 3 from a different point? I've not seen it mentioned since they announced they were going to try it, and I certainly haven't seen temperatures falling.

 

[tsutsuji]

[URL]http://www.tepco.co.jp/en/news/110311/images/110830_4t.jpg[/URL]
http://www.tepco.co.jp/en/news/110311/images/110830_4.jpg

http://mainichi.jp/select/jiken/news/20110607ddm003040107000c.html :

It was discovered that the 13 km long Yunotake fault which runs in Iwaki city 40 km south of Fukushima Daini was activated by aftershocks of the 11 March earthquake. The problem is that this fault had been overlooked in past earthquake safety designs. NISA instructs all NPP operators to review their earthquake safety assessments to ensure similar faults elsewhere are not being overlooked.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20110831/0515_katsudansou.html Replying to the NISA request concerning the 11 April aftershock, Tepco has checked the faults around Fukushima Daiichi and Daini and found 5 faults, including the South-North running Hatakegawa fault West of the plants (1), and faults on the sea bed South-East of the plants (2) where Earth crust deformation was confirmed whereas this had previously been dismissed. Tepco is confident that the faults cannot produce earthquakes stronger than the plants' earthquake resistance design can resist, but will conduct detailed surveys about the faults, including the use of boring techniques.

(1) a map of this fault is available on pages 53,54,55 (pdf numbers 54,55,56) of http://www.tepco.co.jp/nu/material/files/ga08080401.pdf (2008)
(2) http://www.tepco.co.jp/nu/material/files/ga08080401.pdf (2008) p. 64-68

http://www.47news.jp/CN/201108/CN2011083001000448.html The Yunotake fault is included in the 5 faults reported by Tepco. Concerning the Japco and Jaea facilities in Tokai-Mura, 9 faults were reported to NISA. All in all, 5+9=14 faults were reported to NISA.