Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Dancewithbear]

When I read that first (some Russian professor's suggestion if I remember) I thought gee, that's an out of the box idea. The problem I see (and I'm not an expert) are how do u cool the molten tin? In Chernobyl it would act as a heat sink to the huge concrete building, I guess. But here - the RPV is isolated. Where would that heat go?
As someone suggested here, Chernobyl was probably an easier problem to solve once it burned down. Hell, the core was all over so a more dissipated source of heat than a BWR.

Now if the RPV would be breached & core was on concrete I would see value in such an idea: drop tin in the containment to dissipate the heat. Let's all hope it won't be the case here...

Edit: after reading Fred's quote, it makes some sense. Tin is the heat sink from fuel to RPV, then water cools that.

Could you fill the RPV with LM and let the heat transfer to the flooded containment through the RPV wall? I don't know.. is there a heat exchanger in the RPV for say steam to the turbine?

 

[Reno Deano]

Why is it that in case of a shut down they bypass the turbine and route the steam directly to the condenser ?

Faster steam (heat) removal from the reactor and cooling of the steam. Extract steam is still used to run HPSI and LPSI, if needed. Plus if loose particles are considered (you never immediately know what caused a shut down) you would want to protect the next costly item in the plant and the item that gets the plant income.

 

[Bodge]

Latest SEA Water analysis (unfortunately only available in Japanese at the time...) Source Nisa
http://k.min.us/ijHnOk.jpg

edited with English version from tepco http://www.tepco.co.jp/en/press/corp-com/release/11032603-e.html
[PLAIN]http://k.min.us/ijHpSg.jpg

@AntonL
Sewage pipes does not mean SFP but pipes linking the core to the turbine

Why do Tepco use E-notation to express these numbers? They are nonsensical to the vast majority. Why not say 50,000 bec/litre of Iodine-131 for example? (per IAEA 26th March)

Can somebody please explain their way of expressing numbers? I understand normalised scientific notation, e.g. 5x10^4

Edit: Tepco are discussing cubic centimeters, IAEA litres: 1000/1 difference

 

[Joe Neubarth]

Apologies - I meant 0.30 micro sieverts per hour. That is the current level of radiation in Tokyo at the upper level of private measurers. The officlai levels seem around half that.

The following is micrograys per hour over the past few weeks

http://ftp.jaist.ac.jp/pub/emergency/monitoring.tokyo-eiken.go.jp/monitoring/past_data.html

Thanks

I'm 63. Because of two tumors I have had three CAT scans in the past two years. I do not even know what the dose rate if for a CAT scan, but I am willing to bet that I have received a lot more radiation from those CAT scans than you will be exposed to in Tokyo in the next year. I am still alive and the tumors are benign. I have a theory that a little radiation is good for you as it gives your body something to do.

 

[Dancewithbear]

When I read that first (some Russian professor's suggestion if I remember) I thought gee, that's an out of the box idea. The problem I see (and I'm not an expert) are how do u cool the molten tin? In Chernobyl it would act as a heat sink to the huge concrete building, I guess. But here - the RPV is isolated. Where would that heat go?
As someone suggested here, Chernobyl was probably an easier problem to solve once it burned down. Hell, the core was all over so a more dissipated source of heat than a BWR.

Now if the RPV would be breached & core was on concrete I would see value in such an idea: drop tin in the containment to dissipate the heat. Let's all hope it won't be the case here...

Edit: after reading Fred's quote, it makes some sense. Tin is the heat sink from fuel to RPV, then water cools that.

Any thoughts about using Liquid Gallium for the Spent Pool cooling. Gallium melts at ~29.76C (85.57F) and boiling point at 2204C/3999F.

I think you could easily add a heat exchanger to the spent pool.

 

[britinjapan]

I'm 63. Because of two tumors I have had three CAT scans in the past two years. I do not even know what the dose rate if for a CAT scan, but I am willing to bet that I have received a lot more radiation from those CAT scans than you will be exposed to in Tokyo in the next year. I am still alive and the tumors are benign. I have a theory that a little radiation is good for you as it gives your body something to do.

Thanks for that! All the best on your health Sir!

I imagine though that external and internal (ingested) radiation is a little different - so I`m avoiding drinking water for the moment...cheers (good reason to drink beer!)

 

[Bodge]

Just thought, re. my last post on E notation - does E equal 10 ?

 

[Bodge]

Cheers Joe, sounds like you've had a good old dose of gamma there - gives you superpowers in the end ;)

 

[downwinder]

I've heard the mention of Cs-137, but there is normally Cs-134. I'm not sure why it is not included. I have also heard that some radioiodine is in the water. Children should not drink water with radionuclides present.

The amount of Cs-137 and Cs-134 is predictable by the fission yield curves. In this situation where we have fresh fission products the ratio should be constant. see this link.
http://en.wikipedia.org/wiki/Nuclear_fission_product"

 

[Astronuc]

Just thought, re. my last post on E notation - does E equal 10 ?

Yes E is used instead of 10^. It's quite common, especially to those who are familiar with Fortran.

 

[Joe Neubarth]

Thanks for that! All the best on your health Sir!

I imagine though that external and internal (ingested) radiation is a little different - so I`m avoiding drinking water for the moment...cheers (good reason to drink beer!)

Indeed! Japan has some darn good beers. They rival some of the best beers in the world.

 

[Bodge]

Please can somebody tell me the theoretical decay heat remaining in reactors 1-3, assuming all all fuel remains within the RPV?

Also, what are the consequences of the fact that the fuel from reactor 4 was only transferred to the spent fuel pool in December?

What levels of Pu-239 will be in play in each reactor and SPF? Will this effect chances for fission (I've been thinking about the "13 neutron rays" {sic} observed by Tepco).

To those who understand all these questions and more, the situation at Fukushima must be clear.. if data has been reliable..


I understand fortran notation now, but am confident in saying that will be the limit of my understanding of fortran!

 

[AntonL]

news coming in KYODO News

NEWS ADVISORY: Radioactive iodine 1,850 times limit in sea near plant, up from Fri.
11:31 27 March
NEWS ADVISORY: Pool of water at No.2 reactor may be from reactor core: safety agency
11:29 27 March
NEWS ADVISORY: Pool of water at Fukushima's No.2 reactor contains high radioactivity

NHK TV reports 10,000,000 million times as in normal reactorNEWS ADVISORY: Over 1,000 millisieverts per hour found in water at No.2 reactor
12:00 27 March

 

[Joe Neubarth]

news coming in KYODO News

NEWS ADVISORY: ...


NEWS ADVISORY: Over 1,000 millisieverts per hour found in water at No.2 reactor
12:00 27 March

So why don't they just say One Sievert per hour? In one hour you can get very sick. In four hours, half of the people thus exposed would be dead.

Those three workers received between two to six sieverts to their legs. I doubt that they will be able to keep their legs, but the estimate could be way off.

 

[intric8]

Could someone please clarify the specific isotope(s) responsible for the beta emissions coming from h20 in the plant? Understanding the beta energy (ie, .5 mev vs 10 mev) is crucial to calculating actual exposures to skin and at depth (≅ 1cm) for those whose feet were exposed.

The puddle was later measured at 400 mSv per hour, presumably mixed gamma/beta but unverified.

 

[AntonL]

NEWS ADVISORY: Over 1,000 millisieverts per hour found in water at No.2 reactor
12:00 27 March

and here is the analysis

 

[KateB]

and here is the analysis

Anyone else concerned about the large quantities of Barium nuclides in 2 and 3? Seems like a lot of that should be gone. Granted, it's only a little over one half life, but still a sizable amount. The Tc-99m is concerning also...

Edit: for the Barium, I was thinking we should be seeing more La-140, but I supposed it could have decayed to Cerium, which isn't shown...
But the Tc-99m is still concerning. Especially without any translation of Molybdenum values (which I am assuming at this point is low enough to not be in consideration...)

 

[intric8]

Assuming these levels remain persistently high, at some point the continuity in this effort will be severely disrupted. Fukushima engineers will start dropping out fast.

 

[M. Bachmeier]

Anyone else concerned about the large quantities of Barium nuclides in 2 and 3? Seems like a lot of that should be gone. Granted, it's only a little over one half life, but still a sizable amount. The Tc-99m is concerning also...

I was just about to ask about the short lived isotopes. What kind of half lives are we talking about?

 

[KateB]

I was just about to ask about the short lived isotopes. What kind of half lives are we talking about?

Ba-140 12.8 days -> La-140 1.6 days -> Ce 140

Tc-99m 6 hours -> Ru-99
Tc-99m only occurs as a product of fission of Uranium, one way or another, as far as I know.

Edit: NOT an expert. Just a student.

 

[M. Bachmeier]

Ba-140 12.8 days -> La-140 1.6 days -> Ce 140

Tc-99m 6 hours -> Ru-99
Tc-99m only occurs as a product of fission of Uranium, one way or another, as far as I know.

(EDIT)*** Uncertain of facts concerning possible fission products re: #3 ***
Isn't that the second indication of a fission product, the first being associated with #3? Are these guys pushing the water too fast?

 

[M. Bachmeier]

Another thought is, how are they going to be able to fix a leak with radiation levels that high?

 

[KateB]

Isn't that the second indication of a fission product, the first being associated with #3? Are these guys pushing the water too fast?

I am not sure that the rate is all that important, just that it is there at all, but I am not an expert. My reasoning is that it is because it means the control rods are useless if fission is happening, which it might well not be, and water present would just act like a neutron moderator more so than a coolant. My unprofessional opinion is that heavily borated water should be pushed, if it hasn't been already. And thankfully they have fresh water, as who knows what radioactive isotopes could be/possibly were induced with all the elements present in sea water...

Edit: I think what you are referring to are the CL-38 isotopes that were found, which **may** indicate fission, but it isn't clear whether that is an error or not.

 

[AntonL]

Are these guys pushing the water too fast?

I speculated this on 25th - https://www.physicsforums.com/showpost.php?p=3209639&postcount=1218"

 

[Bodge]

Incredibly worrying translation posted on Greenpeace Japan's twitter from a very recent TEPCO press-conference:

""We don't have equipment to measure plutonium, so we are thinking of asking experts." (TEPCO on presser, 12:31 local time)"

The "presser" was a determined journalist asking about what is in the water pools in buildings.

Also, I think Reactor 2 is now confirmed RPV breach due to levels of Cs-134 measured outside of core.

 

[M. Bachmeier]

I speculated this on 25th - https://www.physicsforums.com/showpost.php?p=3209639&postcount=1218"

Right now I'm also very concerned about Tc-99m from #2 and what probably was CL-38 from #3. Add to this fresh water...

 

[Bodge]

Assuming these levels remain persistently high, at some point the continuity in this effort will be severely disrupted. Fukushima engineers will start dropping out fast.

The problem for disaster management is that at doses over 1Sv, congnitive function declines.

 

[AntonL]

Another thought is, how are they going to be able to fix a leak with radiation levels that high?

by a fusion of middle age and new technology

lead plated body armour and robotic muscle suits

http://www.youtube.com/watch?v=S7HKD-FWKkE&feature=related

 

[M. Bachmeier]

by a fusion of middle age and new technology

lead plated body armour and robotic muscle suits

Nice idea, but I don't think it will be ready in time.

 

[Bodge]

Why would 'special equipment' be needed to detect Plutonium isotopes??

unconfirmed translation from twitter: Tepco may have just stated that the device they need is at Daiini

 

[M. Bachmeier]

Why would 'special equipment' be needed to detect Plutonium isotopes??

Tepco may have just stated that the device they need is at Daiini

I wonder if they're talking about detection in air?

 

[Reno Deano]

by a fusion of middle age and new technology

lead plated body armour and robotic muscle suits

They will probably use high pressure grout and remote application. Same way they do geothermal wells to shut them off.

 

[Bodge]

I wonder if they're talking about detection in air?

It is ridiculous for them to say they haven't checked yet. IMO

 

[KateB]

(EDIT)*** Uncertain of facts concerning possible fission products re: #3 ***
Isn't that the second indication of a fission product, the first being associated with #3? Are these guys pushing the water too fast?

Ha! Oops, silly me, I was still zeroed in on the possibility of fission and interpreted your question as being in regards to it; I guess I should have supposed that the integrity of the system under that kind of water load may be just as important.

 

[83729780]

and here is the analysis

these releases are coincident with the injection of fresh water, which can accommodate more solutes

ps: 2.9 trillion becquerels I-134 per liter!

 

[|Fred]

Associated Press corrected the following: the 1 sievert reading is for air, not water.
source: http://www.cbsnews.com/stories/2011/03/26/ap/asia/main20047576.shtml
having said that the article is still soso mixing sv and sv/h and sv/y

2.9 trillion becquerels I-134 per liter! => assuming the fission stopped on the 14th that would be some thing in the range of 2.9*10^9= N *(0.5)^((27-14)*24))
2,419*10^103 atom of I-134 just for this liter (some one clever should be able to calculate the weight of that)

 

[KateB]

these releases are coincident with the injection of fresh water, which can accommodate more solutes

ps: 2.9 trillion becquerels I-134 per liter!

(pps: at a half life of under an hour, unless there are some odd isotopes in there...)

 

[Passionflower]

Perhaps someone knowledgeable could explain to me why they haven't started closing these plants up with concrete? How much longer do we need to wait?
Does anyone perhaps expect something could be salvaged in those plants?

 

[AntonL]

Here is a nice slide explaining the isotopes found in a reactor

first column during or immediately after the reaction
second column after a couple of days in SFP and released if damage to fuel rods
last column the ones you should be careful of

 

[|Fred]

>slide explaining the isotopes found in a reactor
If the reactor is working properly I thought that the isotopes were contained in the Zircaloy casing

 

[Gilles]

sorry I may have missed some posts but has the "Cl-38" mystery been solved or any hint for that ? Astronuc said that they could have been a typo and a confusion with "Cs -138" - there are also some reports of "Co-58" , is it a possibility? if Cl-38 has been indeed produced (despite the absence of Na-24 or Cl-36, but are all nuclides really listed in these reports), is it possible to explain the needed neutron flux without some parts of the reactor being near-critical , at least during some time?

 

[AntonL]

>slide explaining the isotopes found in a reactor
If the reactor is working properly I thought that the isotopes were contained in the Zircaloy casing

The isotopes in the upper section (gas) are the ones normally found in working reactor as the gas can leak out, the others should be contained in the fuel rods.

 

[AtomicWombat]

Refering to https://www.physicsforums.com/showpost.php?p=3210895&postcount=1342" and below plan the building is about 125 meters long (google earth)
then the flooded area is about 1650 m21 40cm
2 100cm
3 150cm
4 80cm
confirms that the source of the water is from unit 3 and has leaked into the neighbouring
units through cable tunnels. The cable tunnels would be fire proofed between the buildings
restricting the flow hence the varied heights

at the time of measurement volume of water is about 6000m3

From the IAEA:
http://www.iaea.org/newscenter/news/2011/fukushimafull.html"
March 22
"Unit 3
Unit 3 experienced an explosion on 14 March that destroyed the outer shell of the building's upper floors. The blast may have damaged the primary containment vessel and the spent fuel pool. Concerned by possible loss of water in the pool, authorities began spraying water into the building in an effort to replenish water levels. First, helicopters dropped seawater on 17 March, and every day since then, including 21 March, emergency workers have sprayed water from fire trucks and other vehicles, so far spraying at least 3,742 tonnes."

March 24
"Japanese authorities today reported that three workers at the Fukushima Daiichi nuclear power plant were exposed to elevated levels of radiation. The three were working in the turbine building of reactor Unit 3 and have received a radiation dose in the range of 170-180 millisieverts.
Two of the workers have been hospitalized for treatment of severely contaminated feet, which may have suffered radiation burns. The workers had been working for about three hours in contact with contaminated water.
The IAEA is seeking additional information."

There were also reports that authorities were unable to maintain water levels in reactor 3, which I cannot source at the moment.

So we know where all the water went!

 

[|Fred]

just as a reminder side by side first analysis of Unit 3 and general one
[PLAIN]http://i.min.us/imbXPu.jpg

 

[Borek]

Perhaps someone knowledgeable could explain to me why they haven't started closing these plants up with concrete? How much longer do we need to wait?
Does anyone perhaps expect something could be salvaged in those plants?

I am perhaps not much more knowledgeable, but I don't think it will be a valid solution at this stage. I guess you think about something similar to Chernobyl sarcophagus. First, it takes months of preparations, it is not a thing that can be done fast. Second, before sarcophagus is built whatever is inside is still in potential contact with environment, so it won't stop radiation leaks for months. Third, and perhaps the most important part - building a sarcophagus around the buildings before the situation inside is known and stable, is just asking for more troubles, as you don't know how the situation can evolve.

 

[jensjakob]

"The water would be sent to condensers"
http://www.jaif.or.jp/english/aij/member/2011/earthquakereport32.pdf

Depending on the volume of water - I wonder:
1. Will it be fed into the reactorside of the condenser?
of
2. Will it be feed to the seawater side - sending it into the ocean?

 

[AntonL]

"The water would be sent to condensers"
http://www.jaif.or.jp/english/aij/member/2011/earthquakereport32.pdf

Depending on the volume of water - I wonder:
1. Will it be fed into the reactorside of the condenser?
of
2. Will it be feed to the seawater side - sending it into the ocean?

and feed it back to the reactors as cooling water no
sending it to the see yes
so feeding it to the condenser sounds better and they have fairly unrestricted access to the sea to cater for huge amounts of cooling water during normal operation

The condensers are the three blocks
[ Tu]rbi[ine] B[uild]ing
and blue flooded area by earlier press release.

 

[jensjakob]

A bit more about the basement-water:
http://mdn.mainichi.jp/mdnnews/news/20110327p2g00m0dm063000c.html

My questions:
1. What will they do with it?
2. What are the quantities?
3. Does it keep on coming?
4. Notice the part about needing "more pumps"

 

[jensjakob]

Hmmmm. Interesting math from another forum:
"
Also note the misleading numbers in the story--it's comparing apples to oranges: they say the detected level of 1,000 millisieverts per hour is four times the occupational limit of 250 millisieverts set by the government. But the 250 set by the government is the ANNUAL limit, while the 1,000 is the HOURLY amount.
"

Comments?

 

[Gilles]

it's not comparing apples to oranges, it's comparing elephants to mice ...