Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[elektrownik]

Tepco's request to NISA to keep unit 2's double doors open : http://www.nisa.meti.go.jp/english/press/2011/06/en20110609-5.pdf (in English)

in order to implement calibration of water level gauges of the Reactor Pressure Vessel and the Primary Containment Vessel

Is there water level sensor in drywell ?

 

[zapperzero]

Hold a second and sorry if it is just another stupid comment on my part, but if it wasn't the containment that vectored the detonation (second phase), for that amount of vertical energy to be generated you'd need fusion level releases of energy from the SPF, since the pool is such a poor vertical vectoring structure. Is it conceivable that the pressure wave from the first detonation could have triggered a fusion reaction? Or am I having a serious senior moment here?

Why is it poor? Anyway, no fusion... if it were that easy, we'd have done it by now and there would not be any nuclear plants in existence :D.

 

[zapperzero]

On the other hand, is it much more surprising than the presence of contaminated water at Fukushima Daiichi unit 6 ? Or at any garden pond or swimming pool in the nearby cities and villages ?

Yes, it is. The fact that it is inside a building MUST have protected it from fallout. So, it MUST have been contaminated when it came in.

EDIT: For once, I tend to believe TEPCO.

 

[etudiant]

Yes, it is. The fact that it is inside a building MUST have protected it from fallout. So, it MUST have been contaminated when it came in.

EDIT: For once, I tend to believe TEPCO.

The TEPCO scenario as outlined seems very implausible, imho.
The initial tsunami which flooded the plant was clean, unless the ocean off the plant was already seriously contaminated.
There has been no subsequent flooding and the only additional seawater intake is for the cooling.
Again, if that cooling water is contaminated and leaking in the plant, it might be an explanation, but it would require the water off the site to be very active.
The easiest explanation would seem to be that something is amiss at DaiNi, fortunately much less so that at DaiIchi.

 

[tsutsuji]

Is there water level sensor in drywell ?

I checked the Japanese version (attachment No. 1 of http://www.meti.go.jp/press/2011/06/20110608002/20110608002.html ), and I think there is no translation mistake. I have no clue about the real meaning of that sentence.

Yes, it is. The fact that it is inside a building MUST have protected it from fallout. So, it MUST have been contaminated when it came in.

EDIT: For once, I tend to believe TEPCO.

Contaminated ground water may have seeped in through new earthquake-created cracks in concrete, or through cracks older than the earthquake. We had a discussion about these possibilities for Fukushima Daiichi unit 6 at https://www.physicsforums.com/showthread.php?p=3336401#post3336401 .

The TEPCO scenario as outlined

Outlined by whom ? Did Tepco publish a press release on this topic ? Did Tepco provide any scenario ?

The third sentence from the bottom of http://jp.ibtimes.com/articles/19498/20110608/1307540621.htm translates as "This time, the contaminated water intended for sea discharge is believed to be something produced by normal operation and not by any damage of the nuclear power facilities".

http://www3.nhk.or.jp/news/html/20110608/t10013401701000.html describes the water intended for discharge as being sea water from the tsunami wave which accumulated in places such as the turbine buildings and the reactor buildings and has since been moved into tanks (the move into tanks is mentioned only in the video, not in the text). It says that the Cesium (concentration ? yearly amount ?) is 30 times above the allowed standard (video only), and the Cobalt 60 concentration is 1.5 times above the allowed standard (text only) without providing any clue as to where this Cobalt is coming from. The video worries for the cesium only while the text worries for the cobalt only : this is a bit strange.

Keiji Miyazaki, a professor emeritus of reactor engineering at Osaka University, said the reported radioactivity levels and composition of isotopes in the water suggested any issue at the plant was relatively small.
(...)
The 3,000 tons of water—a bit more than would fit into an Olympic swimming pool—contains radioactive cobalt 58 and 60 isotopes, iodine 131 and manganese 54, Tepco said Wednesday. Their levels are below the legal limit for discharge water set in Japan, whose limits tend to be stricter than other international standards.

However, levels of cesium 134 and 137 isotopes in the water—at 2 and 3 becquerels per cubic centimeter, respectively—exceeded the legal limits of 0.06 and 0.09 becquerels.
(...)
Neither body [NISA or Tepco] addressed why the water remained onsite, however.(...) NISA said it was possible the water could have corroded some piping, causing leakage of radioactive materials.

JUNE 9, 2011 Second Japanese Plant to Dump Tainted Water by Mitsuru Obe : http://online.wsj.com/article/SB10001424052702304259304576373150813737000.html

A Yomiuri article mentioned at https://www.physicsforums.com/showthread.php?p=3345550#post3345550 took the view that the cesium flew from Daiichi to Daini.

 

[Bioengineer01]

The debris was scattered on top of the fuel assembly tops. They all looked in place to me. The rectangular patterns are quite distinctive. The only thing is that we only saw about two - three square feet of the top of the assemblies. The key in the video is to look quickly at the very beginning. As the bubbles come up and block the lens you can see the pattern of the top of the assemblies at the top and left of center. That rectangular pattern was consistent with the pattern in the reactor 4 SFP.

http://www.dailykos.com/story/2011/05/11/974605/-Up-Date-with-SFP-3-Video

My concern with TEPCO is mostly centered about what they don't show. I build that data by following the reporting of temperature in Unit 3 in detail, around the middle of May, every time there was a big increase they stopped reporting it until they were able to control and decrease it then they restarted reporting again. That was not random, thus it created a pattern in my mind that says: "critical information that is "bad" will not be reported until they must report it. I use that learning point to filter what I see reported and look for what they must have and is not being reported.

 

[Bioengineer01]

Wow, that's quite a difference. It took me a while to even see the slight difference in one of the glyphs. The translation I came up with is from "copy and paste" directly from the document into Google. For some reason the character/glyph/kanji is not correct. The good news is I won't be wasting a lot of time in the future on this activity. Natural language translation have a long way to go.

Out of topic but very important, I use google translate only for languages that I know to make the translation task easy. DO not use it for anything important if you don't know both languages. 100% of the time the interpretation of the translated text is Wrong, unless the phrases are extremely simple. And I am talking about similar languages like Spanish English French Portuguese Italian, not Chinese or Japanese

 

[Bioengineer01]

old jim, thanks for the link, i devoured it... :)

Look, they reported 720k TBq in just 10k cubic meters of water.

Anyway, the way most important point is that this contamination for most part did NOT get fixed/trapped/caught in land soil as at Chernobyl, but will be ionically distributed over the whole world.
Really, immobile cesium stuck in soil of a "death zone" is not really a threat. Dissolved cesium in ionic form contaminating the oceans... ...this is a worldwide threat.

But I fear that this point will get noticed only a few years later, when it gets difficult to find fish below acceptable radiation levels.
Then this could become a global problem.

I completely agree with your assessment of the long term biological impact of this release, it is a LOT worse than Chernobyl because as you say, it will bioaccumulate.

But I had the hell of a time getting accurate estimates of the isotopic contents of the trench water and their energy profile. The only number I got and I quoted was 5.4 Megabecquerels/cm^3. That is 54,000 TeraBecquerels in 10,000 Tons of water, not 720k Terabecquerels in 10k Tons. Can you give me a reference for your data point?

 

[Bioengineer01]

If I'd get a cookie every time I have to explain the differences between those activity numbers, I could probably build a castle out of them by now.

You CAN'T compare the 720 TBq activity for the basement water and the 760k TBq airborne release.

The 760k TBq airborne release is an estimate which only covers I131 and C137 isotopes. Furthermore, it's a converted value. Basically it's (I131 release in Tbq * 1 + C137 release in TBq * 40). The real, measurable activity of those 770k TBq is in fact 160k TBq I131 and 15k TBq C137.
Everything regarding converting values is described in the INES Manual. Page 5 and page 15f.

The 720k TBq water number is NOT converted. It's a normal addition of the activity of the three isotopes I131, C134 and C137 in the basement water. So it's way more than the airborne release. If all those isotopes in the basement get released into the environment, Chernobyl won't be the biggest radioactive release in human history any more...

Yes, THANKS, I knew that I was forgetting something when I was asked to redo my Napkin calculation yesterday night. Should have gone to bed and replied this morning, sorry, the numbers in my calculation need to be corrected. If you assume that the 5.4 MBq/cm^3, the you need to use an assumed isotopic ration for estimating each isotope and then multiply the activities of each isotope by the corresponding factors from INES manual as above to adjust the total release that I estimated as 38,000 TBq become 177,000 TBq assuming that 35.5 TBq was I-131 and 3.55 TBq was Cs-137 at the time of release.

 

[ThomS]

The link reports a NOT FOUND error by the remote server

Not surprising really. TBS is a television/news channel here in Japan. Most TV station news websites change frequently, meaning that the news they post today will more than likely be removed so that other "new" news can be put on their site.

Poster Jim Lagerfeld (I think) also commented in this thread on that bit of news and translated more than I did.

 

[joewein]

A question about the turbine hall condensers. I recall reading that when the offline cooling system failed and they started injecting water using temporary pumps (fire fighting pumps?), they ran out of fresh water after an hour and it took a while before they decided to use seawater instead.

Later, when the turbine hall basements were flooded with radioactive water from the cooling efforts after the meltdowns they wanted to pump that water into the condenser storage tanks and found them to be full.

I read that the unit 1 storage tank has a capacity of 1600 t while units 2-5 hold 3000 t each.

Does this mean TEPCO would have had access to as much as 7600 t of fresh water in the turbine halls of units 1-3 without realizing it? At the current 500 t a day that would have lasted them two weeks.

I realize they may still have had a problem using it for cooling because of the high RPV pressure until they vented that the temporary pumps had problems coping with.

Would the condenser storage water have made a difference and if so, why was it not used? Was its (slight?) radioactivity an issue? Does this tell us anything about TEPCO's (lack of) emergency planning?

 

[clancy688]

But I had the hell of a time getting accurate estimates of the isotopic contents of the trench water and their energy profile. The only number I got and I quoted was 5.4 Megabecquerels/cm^3. That is 54,000 TeraBecquerels in 10,000 Tons of water, not 720k Terabecquerels in 10k Tons. Can you give me a reference for your data point?

Here it is: http://www.tepco.co.jp/cc/press/betu11_j/images/110603a.pdf (page 8)

Out of the 720k TBq, 140 TBq account for C137. A little comparison: The Chernobyl core had a total C137 inventory of 280 TBq (of which only 40% escaped).

 

[Bioengineer01]

TEPCO made an own estimate of the amount which flowed through that crack into the sea.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110421e2.pdf



Sigh...

One page earlierer I explained why you can't compare those official airborne release values to any other activity values. Why do people keep ignoring my posts? https://www.physicsforums.com/showpost.php?p=3348281&postcount=9472

Btw, do you have those "official Chernobyl values as reported 90 days after that crisis started"? I'd be interested in them...

I rushed to answer the request and didn't have the time to finish reading the thread, my mistake, I had taken that into account in my original napkin calculations, but i didn't have the napkin :), so I tried to redo them in a rush and forgot about your point that is critically important. I am not an expert on the subject but had read about errors made in the original leaks reports and how they had to be corrected to I-131 as the baseline isotope, to account for the larger time impact of the longer lived isotopes. I also understand that my calculation fails to consider the decay of I-131 when released or accurate measurements from each basement and an individual estimate for the leaks through cracks in the foundations of each, plus all other isotopes not CS and I.

With respect to the official Soviet reports and the many many many... later reports quoting different numbers I found them searching in google, you will find similar stories of cover up to the ones now being reported about TEPCO, the parallels are just too close for comfort. Rather than me going back and finding one of those links, I highly recommend that you do the search, it will be very illustrative to your understanding of where we are in the disclosure cycle of the current crisis.

 

[Bioengineer01]

Why is it poor? Anyway, no fusion... if it were that easy, we'd have done it by now and there would not be any nuclear plants in existence :D.

Great news!

Poor because the ration of the area of the mouth of the pool to its depth is far from ideal for creating a vectored explosion. You ideally need a gun barrel type structure, like the RPV or the PCV

 

[Bandit127]

Great news!

Poor because the ration of the area of the mouth of the pool to its depth is far from ideal for creating a vectored explosion. You ideally need a gun barrel type structure, like the RPV or the PCV

Possibly a gun barrel length to width ratio might be ideal - I am not an expert.

But things designed to 'shape' (i.e. vector) explosions commonly have a L/W ratio of 1:1 or 2:1

 

[Joe Neubarth]

I believe the original reference was to this:


I think Joe means starting at 0:27 if you look in the upper left corner you see the top of a few of the fuel assemblies. I'm with the dkos user and MiceAndMen here; I can't tell much of anything about the state of the fuel from that brief imagery.

I also didn't feel I could tell much about the actual state of the assemblies in the SPF4 video either. The tops of the assemblies seemed to be somewhat intact. Can't draw conclusions about lower down where the fuel itself is, but at least it wasn't all in shambles.

Thank you. MY observation was that the top of the fuel modules were visible at the depth in the water where they should have been located, regardless of the debris. If there had been an explosion as Artie Gunderson claimed, those modules should have been blown out of the pool like a shotgun blast. Since they were still visable, I believe Artie's conjecture is wrong.

 

[Pu239]

I had a question from another forum:

What actually happens if the #4 spent fuel pool collapses?

1. If they collapse in a heap - danger of repeated criticalities?
2. Radiation will become too high for workers to be on site.
3. Very serious situation leading to higher levels of radiation

Also, live video shows #4 continually steaming (I assume it's not smoke) - more noticeable at night. What causes this steam?

It must be SFP-related since there is no active core.

 

[elektrownik]

I must back to old thermal images case again, we have big problem here - in thermal images there was heat source in core location, sometimes its temperature was 1/3 bigger than SFP location. I asked about this here and some peoples told me that it could be damaged SFP gate and that water flow from SFP to RPV, but we all saw on SFP 4 video that gate is undamaged, so now, how it is possible that there is heat source in unit 4 core location ?
[PLAIN]http://img535.imageshack.us/img535/3165/gggss.png

 

[causeceleb]

I must back to old thermal images case again, we have big problem here - in thermal images there was heat source in core location, sometimes its temperature was 1/3 bigger than SFP location. I asked about this here and some peoples told me that it could be damaged SFP gate and that water flow from SFP to RPV, but we all saw on SFP 4 video that gate is undamaged, so now, how it is possible that there is heat source in unit 4 core location ?

and furthermore, whenever Building #4 is steaming the steam comes from 2 distinct locations:
1) the front middle of the building (location of the reactor)
2) the south wall middle area, which is the location of the SFP

so, once again, why is there steam coming out of the area of the reactor in Bdg. #4

 

[radio_guy]

and furthermore, whenever Building #4 is steaming the steam comes from 2 distinct locations:
1) the front middle of the building (location of the reactor)
2) the south wall middle area, which is the location of the SFP

so, once again, why is there steam coming out of the area of the reactor in Bdg. #4

one thing nagging me about all that is wondering if the core of #4 was fully unloaded.. or if they were a little behind and just said oh yeah.. we did it. expecting to have it completed shortly?

 

[elektrownik]

Tepco webcam what the...
http://www.tepco.co.jp/nu/f1-np/camera/

 

[causeceleb]

one thing nagging me about all that is wondering if the core of #4 was fully unloaded.. or if they were a little behind and just said oh yeah.. we did it. expecting to have it completed shortly?

well, of course, the implication in what i am saying is that, contrary to what TEPCO says,
there was in fact fuel in #4 reactor and it's for certain that the primary containment
lid (yellow cap) was off and stored...

 

[elektrownik]

Tepco doesn't tell us also about unit 5 pressure stress test during earthquake until last gov report... so who know... maybe there was fuel in unit 4.

 

[causeceleb]

Tepco webcam what the...
http://www.tepco.co.jp/nu/f1-np/camera/

yes, here at 2:48 a.m. Japan time Bdg. #4 is steaming like mad, and the "extra cloud of fog"
is being caused by all of that excessive steam.

 

[elektrownik]

yes, here at 2:48 a.m. Japan time Bdg. #4 is steaming like mad, and the "extra cloud of fog"
is being caused by all of that excessive steam.

I never saw so much steam from unit 4

 

[causeceleb]

I never saw so much steam from unit 4

this is about the 3rd time I've seen it. i think it happens whenever they water
the corium in the reactor at the same time they water the SFP.

 

[elektrownik]

I see 2 sources of steam in unit 4:

 

[clancy688]

There's also a plume coming out of Unit 2. It's hard to see, though.

 

[radio_guy]

this is about the 3rd time I've seen it. i think it happens whenever they water
the corium in the reactor at the same time they water the SFP.

in unit 4? according to tepco there are no fuel rods in the reactor since it was all offloaded.

edit: are they using one of the first ever webcams made with a horribly small picture and huge compression a like 9FPS.

if they wanted people to guess and debate over minor things due to low quality to keep their minds off the actual problem they are doing a great job.

 

[ManuBZH]

I see 2 sources of steam in unit 4:

Well, the one of the right is clearly unit 4, but I see the one on the left as coming from unit 3.
Isn't all this fog weather related? And the plume is simply visible because of the fog... I'm no weather expert but I'm not sure there is something suspicious here (even if it looks so).