Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Joe Neubarth]

Sorry Anton, but I must ask a dumb question. If there were a leak of a melted core near the bottom, does it have to be corium? I only ask because fuel rods are different. Some things melt at different temperatures.

In past reactor meltdowns, the Zirconium ran together with the Uranium and collected at the bottom of the reactor vessel or flowed out through steam releases like at Chernobyl. For them to be together, they melted and flowed about the same time.

 

[PietKuip]

Let us assume that the numbers http://www.nisa.meti.go.jp/english/files/en20110325-6.pdf are correct and that there really is a megabecquerel of Cl-38 per cm^3 in that water.

Suppose this is the steady state concentration in a certain neutron flux. Then the number of neutrons absorbed is equal to the number of decays. Let is suppose this is sea water, 3 % NaCl by weight. That is 30 milligrams of NaCl per cubic centimeter. Less than 1 millimole.

The cross section for neutron absorption of Cl-37 is 33 barns = 33 x 10^-24 cm. Only about a quarter of the chlorine consists of this isotope. So the total cross section is 10^23 x 10^-3 x 33.10^-24 = 10^-3 cm^2.

So one needs a neutron flux of about 10^9 neutrons per cm^2 per second to get this kind of induced radioactivity. That is several orders of magnitudes below what one has in a working reactor. But the activity found may also be several orders of magnitude below steady state.

Please correct me if there is a major error in this estimate.

Edit: Cl-37 has a cross section of 0.423 barns; I underestimated the neutron flux by two orders of magnitude.

 

[Reno Deano]

None of the experts on BWRs (from NRC training center) has contributed to this and shouldn't. If by mistake their feelings or assumptions were to get out before being fed to the IAEA, TEPCO or the Japanese Gov't they (NRC) would be in deep kimche.

See NRC's updates on assistance: http://www.nrc.gov/japan/japan-info.html"

 

[Joe Neubarth]

Let us assume that the numbers http://www.nisa.meti.go.jp/english/files/en20110325-6.pdf are correct and that there really is a megabecquerel of Cl-38 per cm^3 in that water.

Suppose this is the steady state concentration in a certain neutron flux. Then the number of neutrons absorbed is equal to the number of decays. Let is suppose this is sea water, 3 % NaCl by weight. That is 30 milligrams of NaCl per cubic centimeter. Less than 1 millimole.

The cross section for neutron absorption of Cl-37 is 33 barns = 33 x 10^-24 cm. Only about a quarter of the chlorine consists of this isotope. So the total cross section is 10^23 x 10^-3 x 33.10^-24 = 10^-3 cm^2.

So one needs a neutron flux of about 10^9 neutrons per cm^2 per second to get this kind of induced radioactivity. That is several orders of magnitudes below what one has in a working reactor. But the activity found may also be several orders of magnitude below steady state.

Please correct me if there is a major error in this estimate.

If you are right and it looks like you are not wrong, we can be thankful the the producing element of all of those neutrons is spread over a wide area.

 

[KateB]

None of the experts on BWRs (from NRC training center) has contributed to this and shouldn't. If by mistake their feelings or assumptions were to get out before being fed to the IAEA, TEPCO or the Japanese Gov't they (NRC) would be in deep kimche.

See NRC's updates on assistance: http://www.nrc.gov/japan/japan-info.html"

This explains why no answers are easily forthcoming.

 

[Reno Deano]

I would recommend dumping charcoal over the areas where they believe the Iodine is emanating from. But, if wet it may loose it efficiency for trapping Iodine and other halogens. Using exhaust fans and Hepa filters and charcoal beds would be another method to control Iodine and fission product releases releases. Radioactive isotopes within the basement of turbine building could be from clogged drains and radwaste tank back ups. The turbine building also has drains to reactor building waste tanks. The turbines (and other associated systems) on BWRs do have buildup of radioactive corrosion products from the reactor via the steam used to power them. Doubtful, but if the MSIVs were to have been damaged there could be direct flow from the reactor to the Turbine building.

 

[|Fred]

In past reactor meltdowns, the Zirconium ran together with the Uranium or flowed out through steam releases like at Chernobyl. .

It was my understanding that meldown was basically the lost of part of the primary containment ie Ziralloy casing ; leading to a liquification of the fuel.
Once no longer in it's casing fission product (isotop) are free in the RCV, if they are noble gaz they are in the air, if they disolve in water they are in the water .. It is my undestanding that heavy metal isotops and stuff like Uranium can not be released through steam.. They need to be oxidized to break free in smoke.

I would recommend dumping charcoal

Yes.. Let's just do that and light a match.

 

[KateB]

Let us assume that the numbers http://www.nisa.meti.go.jp/english/files/en20110325-6.pdf are correct and that there really is a megabecquerel of Cl-38 per cm^3 in that water.

Suppose this is the steady state concentration in a certain neutron flux. Then the number of neutrons absorbed is equal to the number of decays. Let is suppose this is sea water, 3 % NaCl by weight. That is 30 milligrams of NaCl per cubic centimeter. Less than 1 millimole.

The cross section for neutron absorption of Cl-37 is 33 barns = 33 x 10^-24 cm. Only about a quarter of the chlorine consists of this isotope. So the total cross section is 10^23 x 10^-3 x 33.10^-24 = 10^-3 cm^2.

So one needs a neutron flux of about 10^9 neutrons per cm^2 per second to get this kind of induced radioactivity. That is several orders of magnitudes below what one has in a working reactor. But the activity found may also be several orders of magnitude below steady state.

Please correct me if there is a major error in this estimate.

Just to clarify (33 * 10^-24) * 10^-3 * 10^23? wouldn't that be 33 * 10^-4? (even lower values?)
I think that the prevalence of Cl-37 is less than 1/4 in sea water, though I don't believe it is low enough to cause a huge variation of your figures. BUT, and a BIG BUT. We have the issue of the steam leaving the salt behind creating a much larger percentage of NaCl to water, how does this change your estimation if at all?

 

[Joe Neubarth]

It was my understanding that meldown was basically the lost of part of the primary containment ie Ziralloy casing ; leading to a liquification of the fuel.
Once no longer in it's casing fission product (isotop) are free in the RCV, if they are noble gaz they are in the air, if they disolve in water they are in the water .. It is my undestanding that heavy metal isotops and stuff like Uranium can not be released through steam.. They need to be oxidized to break free in smoke.


Yes.. Let's just do that and light a match.

Well, technically, a melting of the Zirconium alloy would technically be a limited meltdown, it would be very difficult to keep the Uranium pellets in place. My understanding of past meltdowns was that at the bottom of the reactor (TMI) there was a good mixture between the fuel and the zirconium as well as trace amounts of Inconel and steel and chromium and so on and so forth.

 

[PietKuip]

Just to clarify (33 * 10^-24) * 10^-3 * 10^23? wouldn't that be 33 * 10^-4? (even lower values?)
I think that the prevalence of Cl-37 is less than 1/4 in sea water, though I don't believe it is low enough to cause a huge variation of your figures. BUT, and a BIG BUT. We have the issue of the steam leaving the salt behind creating a much larger percentage of NaCl to water, how does this change your estimation if at all?

It does not matter, this is just the grossest estimate of what a minimum neutron flux would be to achieve this level of activation of seawater. For that, the brine would have had to be in this neutron flux for about one half-life (30 minutes). And not have had time for decay. And not have been diluted. That is not realistic.

It seems that there was no water in that basement the day before. Suppose it had leaked in from the reactor 6 hours before they analyzed it. That is 12 half-times, and the activity would be 4000 times higher than when they measured the spectrum.

The uncertainties are gigantic, but something is very wrong. If the NISA numbers are correct, that reactor is still critical.

 

[Astronuc]

Astronuc,

Are specialized teams in the US being organized officially, or unofficially through contact with the Japanese Govt and Tepco to provide virtual and on-site support hardware, etc... for containment of the reactors ?

Have you or anyone you know who shares your expertise been involved with any of the teams in Japan to address this crisis, and have any of them reviewed or joined in the discussions here in this thread or other related threads on PF ?

The reason for my query is that as each day passes, it appears to me, a layman looking from the outside in that things could get worse. The window(s) of opportunity appear to be filled with more roadblocks as each day passes.

Thanks...

Rhody...

I understand that there is at least one team from the NRC.

I can only comment here on what is published. It may get to the point where I can't comment.

 

[KateB]

It does not matter, this is just the grossest estimate of what a minimum neutron flux would be to achieve this level of activation of seawater. For that, the brine would have had to be in this neutron flux for about one half-life (30 minutes). And not have had time for decay. And not have been diluted. That is not realistic.

It seems that there was no water in that basement the day before. Suppose it had leaked in from the reactor 6 hours before they analyzed it. That is 12 half-times, and the activity would be 4000 times higher than when they measured the spectrum.

The uncertainties are gigantic, but something is very wrong. If the NISA numbers are correct, that reactor is still critical.

My estimation also, let's hope the figures are incorrect.
edit: disclaimer: from NOT an expert at all

 

[Astronuc]

Let us assume that the numbers http://www.nisa.meti.go.jp/english/files/en20110325-6.pdf are correct and that there really is a megabecquerel of Cl-38 per cm^3 in that water.

Suppose this is the steady state concentration in a certain neutron flux. Then the number of neutrons absorbed is equal to the number of decays. Let is suppose this is sea water, 3 % NaCl by weight. That is 30 milligrams of NaCl per cubic centimeter. Less than 1 millimole.

The cross section for neutron absorption of Cl-37 is 33 barns = 33 x 10^-24 cm. Only about a quarter of the chlorine consists of this isotope. So the total cross section is 10^23 x 10^-3 x 33.10^-24 = 10^-3 cm^2.

So one needs a neutron flux of about 10^9 neutrons per cm^2 per second to get this kind of induced radioactivity. That is several orders of magnitudes below what one has in a working reactor. But the activity found may also be several orders of magnitude below steady state.

Please correct me if there is a major error in this estimate.

The report of Cl-38 is very puzzling. If they were getting activation of Cl-37 (t_1/2 = 37.24 min), then they should be getting more Cl-36 (t_1/2 = 3E5 yr). More importantly, they should be getting Na-24 (t_1/2 = 15 hr).

I'm wondering if Cl-38 is a mistype, and it should be Cs-138 (t_1/2 = 33.41 min) from Xe-138(t_1/2 = 14.08 min). That would make more sense. See attached figure.

 

[PietKuip]

The report of Cl-38 is very puzzling. If they were getting activation of Cl-37 (t_1/2 = 37.24 min), then they should be getting more Cl-36 (t_1/2 = 3E5 yr). More importantly, they should be getting Na-24 (t_1/2 = 15 hr).

I'm wondering if Cl-38 is a mistype, and it should be Cs-138 (33.41 min) from Xe-138(t_1/2 = 14.08 min). That would make more sense. See attached figure.

Yes, fission products would make more sense.

But neutron induced activity is a product of parent abundances, absorption cross sections, decay constants, and gamma yields. One does not get a lot of activity from a Cl-36 because the half-life is so much longer.

 

[KateB]

The report of Cl-38 is very puzzling. If they were getting activation of Cl-37 (t_1/2 = 37.24 min), then they should be getting more Cl-36 (t_1/2 = 3E5 yr). More importantly, they should be getting Na-24 (t_1/2 = 15 hr).

I'm wondering if Cl-38 is a mistype, and it should be Cs-138 (33.41 min) from Xe-138(t_1/2 = 14.08 min). That would make more sense. See attached figure.

They did not report any other isotopes derived from NaCL, and while I hope you are correct about the typo, is it possible that they don't report nuclides that could come from overlapping sources?

[STRIKE]Aaaaand Pure speculation of course, but perhaps they reported the CL-37 as it would induce the least amount of panic as it would have the lowest values? [/STRIKE]

Edit: I should keep my thoughts on motivation out of this, I apologize. I will keep my speculating toward the physical realm.

 

[rhody]

I understand that there is at least one team from the NRC.

I can only comment here on what is published. It may get to the point where I can't comment.

Thanks, I understand, because of implications and command authority. Are there any folks from the teams in Japan here on the forum ?

Rhody...

 

[PietKuip]

I'm wondering if Cl-38 is a mistype, and it should be Cs-138 (t_1/2 = 33.41 min) from Xe-138(t_1/2 = 14.08 min). That would make more sense.

Same isotope is in http://www.meti.go.jp/press/20110326001/20110326001-2.pdf" .

 

[Astronuc]

Same isotope is in http://www.meti.go.jp/press/20110326001/20110326001-2.pdf" .

Probably the same source.

I just think Cl-38 is problematic for a number of reasons. That's why I wonder if it's a typo, and there is a propagation of this error.

 

[Bodge]

None of the experts on BWRs (from NRC training center) has contributed to this and shouldn't. If by mistake their feelings or assumptions were to get out before being fed to the IAEA, TEPCO or the Japanese Gov't they (NRC) would be in deep kimche.

See NRC's updates on assistance: http://www.nrc.gov/japan/japan-info.html"

For what it's worth, I believe Jaczko himself has been "leaking info" since the 16th.

Check the c-span archives, even after his blunt comments on the 16th he still releases new info; info that is not now reported by the media in such a prominent manner.

Now he seems much more guarded, but importantly, he still stands by the earlier assertations he made.

The figures I mentioned earlier from yesterdays IAEA report re. high beta/gamma contamination 32km NW of Daiitchi are not to be found in any media reports or releases by the Japanese authorities.

It seems the IAEA, the NRC (subtly) and France's IRSN are the only important organisations talking about the more worrying evidence that has been found.

Of course communications crisis management is essential and responsible in this case.

 

[Bodge]

Hidehiko Nishiyama, deputy director-general of the Japan Nuclear and Industrial Safety Agency, 1st raised the possibility of a crack in the RPV on Thursday. [NISA press conference]

On Friday the NYT ran its piece:

"A senior nuclear executive who insisted on anonymity but has broad contacts in Japan said that there was a long vertical crack running down the side of the reactor vessel itself. The crack runs down below the water level in the reactor and has been leaking fluids and gases, he said."

Now on Saturday 10:26 JST, Kyodo reports:

"Early Friday, concern grew that the high-level radiation leak detected with the workers' exposure could indicate possible damage to the No. 3 reactor vessel, but the government's nuclear safety agency later denied the possibility, saying no data, such as on the pressure level, suggest the reactor vessel has cracked or been damaged."

Confusing much?Hidehiko Nishiyama, deputy director-general of the Japan Nuclear and Industrial Safety Agency, 1st raised the possibility of a crack in the RPC on Thursday.

On Friday the NYT ran it's piece:

"A senior nuclear executive who insisted on anonymity but has broad contacts in Japan said that there was a long vertical crack running down the side of the reactor vessel itself. The crack runs down below the water level in the reactor and has been leaking fluids and gases, he said."

Now on Saturday 10:26 JST, Kyodo reports:

"Early Friday, concern grew that the high-level radiation leak detected with the workers' exposure could indicate possible damage to the No. 3 reactor vessel, but the government's nuclear safety agency later denied the possibility, saying no data, such as on the pressure level, suggest the reactor vessel has cracked or been damaged."

Confusing much? NYT deceived?

 

[Bodge]

Probably the same source.

I just think Cl-38 is problematic for a number of reasons. That's why I wonder if it's a typo, and there is a propagation of this error.

Certainly possible and would speak to the wider confusion between countries. Food for thought.

 

[KateB]

Kyodo news reporting that the workers that sustained burns to their feet were exposed to between 2-6 SIEVERTS of radiation. Does this mean that the water was at 2-6 Sv/hr or that the absorbed dose was 2-6 Sv?
http://english.kyodonews.jp/news/2011/03/81122.html

It reports them walking, which seems...painfully difficult under those numbers?

 

[KateB]

Probably the same source.

I just think Cl-38 is problematic for a number of reasons. That's why I wonder if it's a typo, and there is a propagation of this error.

Looking at his second link, that seems highly unlikely; as the Japanese characters for Cesium number 4, and for Chlorine are a very complicated set of 2 characters. Doesn't seem like a typo likely to be made in Japanese...
Though I still certainly hope you are correct.

 

[Reno Deano]

It was my understanding that meldown was basically the lost of part of the primary containment ie Ziralloy casing

Fisson product release barriers are 1:the fuel pellet construction; 2: fuel rod cladding (Ziralloy alloy tubes); 3: Reactor Pressure Vessel; 4: Primary containment around the RPV; and then the reactor accident systems. Individual fuel rods fail occassional so they are not the "primary" containment for fission products.

 

[TCups]

Kyodo news reporting that the workers that sustained burns to their feet were exposed to between 2-6 SIEVERTS of radiation. Does this mean that the water was at 2-6 Sv/hr or that the absorbed dose was 2-6 Sv?
http://english.kyodonews.jp/news/2011/03/81122.html

It reports them walking, which seems...painfully difficult under those numbers?

If they are using the term correctly, as I understand it, absorbed dose, I believe. Which seems plausible if the had skin burns apparent when they were still on site the same day.

So, in this range, (per wiki):

Symptom benchmarks

Symptoms of acute radiation (within one day):[16]
0 – 0.25 Sv (0 – 250 mSv): None

0.25 – 1 Sv (250 – 1000 mSv): Some people feel nausea and loss of appetite; bone marrow, lymph nodes, spleen damaged.

1 – 3 Sv (1000 – 3000 mSv): Mild to severe nausea, loss of appetite, infection; more severe bone marrow, lymph node, spleen damage; recovery probable, not assured.

3 – 6 Sv (3000 – 6000 mSv): Severe nausea, loss of appetite; hemorrhaging, infection, diarrhea, peeling of skin, sterility; death if untreated.

6 – 10 Sv (6000 – 10000 mSv): Above symptoms plus central nervous system impairment; death expected.

Above 10 Sv (10000 mSv): Incapacitation and death.

 

[M. Bachmeier]

If they are using the term correctly, as I understand it, absorbed dose, I believe. Which seems plausible if the had skin burns apparent when they were still on site the same day.

So, in this range, (per wiki):

Symptom benchmarks

Symptoms of acute radiation (within one day):[16]
0 – 0.25 Sv (0 – 250 mSv): None

0.25 – 1 Sv (250 – 1000 mSv): Some people feel nausea and loss of appetite; bone marrow, lymph nodes, spleen damaged.

1 – 3 Sv (1000 – 3000 mSv): Mild to severe nausea, loss of appetite, infection; more severe bone marrow, lymph node, spleen damage; recovery probable, not assured.

3 – 6 Sv (3000 – 6000 mSv): Severe nausea, loss of appetite; hemorrhaging, infection, diarrhea, peeling of skin, sterility; death if untreated.

6 – 10 Sv (6000 – 10000 mSv): Above symptoms plus central nervous system impairment; death expected.

Above 10 Sv (10000 mSv): Incapacitation and death.

From the same source:

"The National Institute of Radiological Sciences, where the three arrived earlier in the day for highly specialized treatment, said the two were exposed to 2 to 6 sieverts of radiation below their ankles, whereas exposure to 250 millisieverts is the limit set for workers dealing with the ongoing crisis, the worst in Japan's history."

The statement implies total absorbed, but it also implies that the exposure was limited to there ankles and below.

 

[AntonL]

If they are using the term correctly, as I understand it, absorbed dose, I believe. Which seems plausible if the had skin burns apparent when they were still on site the same day.

but remember the exposure was localised and not complete body as would be for wiki symptons.

As the third worker seems to be OK the exposure seems to be alpha radiation as the boots have protected him.
If this is the case then radiation damage is to the skin only. http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radact.html"
[PLAIN]http://www.deq.idaho.gov/inl_oversight/radiation/images/alpha_beta.jpg

2 Nucelar plant workers hospitalized
Medical radiation experts say 2 of the 3 workers exposed to high levels of radiation at the Fukushima Daiichi nuclear power plant may need to receive treatment for burns.

The 3 workers underwent close examination at the National Institute of Radiological Sciences in Chiba Prefecture.

At a news conference on Friday, doctors from the institute said that 2 of the workers were standing in radioactive water for about 2 hours and were partially exposed to strong radiation, between 2,000 and 6,000 millisieverts.

The doctors said the workers' skin show no signs of injury but they fear that symptoms may develop within 3 weeks' time. If this occurs, the workers will receive the same treatment used for burns.

The doctors also indicated that so far, the internal symptoms are not serious enough to require special treatment.

As for the other worker, who was wearing waterproof boots and has no symptoms of internal radiation exposure, the doctors say he will not likely develop a skin disorder.

The director of the institute, Makoto Akashi, says the 2 workers should be able to carry on with their daily lives without discomfort. He added the 3 workers will be discharged early next week.
Saturday, March 26, 2011 04:22 +0900 (JST)

 

[M. Bachmeier]

Has anyone seen the new wiki:

http://en.wikipedia.org/wiki/Fukushima_I_nuclear_accidents

Seems to be well organized with lots of detail.

 

[downwinder]

If we look at the decay of Cl 38 it is a pure beta emitter. This means that if an analysis of this isotope was performed a chemical separation of the sample would be required for the analysis to take place because there are to many competing beta emitters to provide an accurate analysis. I really doubt that they would do this complex analysis at this point. The only way that Cl 38 can be present at this late date is for neutron activation of the salt water coolant. I suspect this is an error - if it isn't big problem.

The presence of intermittent neutron emissions is of concerns as this would suggest that fission reactions are taking place. It the neutron emissions are indeed pulsed or periodic it is quite possible that fuel integrity has indeed been compromised and favorable geometric conditions are being formed and moderator (or other) depletion may be taking place to stop the reaction. This is typical of criticality accidents.

Regarding all the Zr-95 reported values, it is also a fission product with a high fission yield so I don't think that the presence of Zr-95 necessarily means cladding melt down although I think that has happened from the data I have seen. The presence of high I-131 leads me to points to a failure of one of the reactors vs the storage pool fuel. If we only had more data...

 

[Bob S]

here are the result of the water analysis found in the basement of the Turbine unit 1 ( source nisa)

[PLAIN]http://k.min.us/imbXPu.jpg[/QUOTE]
Using these values, this represents about 15 Curies per square meter in 15-cm deep standing water. Didn't these workers in the basement get any radiation safety training and protective equipment? Their radiation detectors must have been screaming. The news reports imply that their doses (probably at chest level) were about 18 rads (180 millisieverts). The dose rate at the water surface was about 40 rads/hr (400 millisieverts/hr).

Bob S

 

[AntonL]

Possibility is being raised by NISA/Tepco that the accumulated water in units 1,2,3 and 4 is from leaking or blocked drainage and that water highly likely from SPF and not reactors.

Using machine translation:

Radioactive material, exposure to sewage leaks or damaged Unit 3 reactor fuel
Fukushima Daiichi Nuclear Power Station Tokyo Electric Power (Ookuma Town, Fukushima
Prefecture Futabachō) worker exposures occurred in the Unit 3 turbine building (nuked), the
Nuclear and Industrial Safety Agency Ministry of Economy yesterday, the reactor showing
the view of likely leaking radioactive material is damaged fuel. 1 found that water has
accumulated high amounts of radiation as it legs. TEPCO stopped working underground
cabling. Came out repair work may be delayed even more power.

　NISA and TEPCO said, three workers are exposed, while laying the cable to the Unit 3
turbine building, was believed to be soaked in water at your feet. The radioactivity was
detected from the water approximately 10,000 times stronger than normal cooling water in
nuclear reactors.

　NISA is this water from spent nuclear fuel storage pools, which look likely to be higher in a
nuclear reactor from leaking. The water was suspected to contain radioactive cesium-137
and fuel corruption.

　Since the furnace from the ambient pressure is maintained, not have major damage or
cracks in reactor pressure vessel, it might have drifted out of steam and water from broken
pipes, etc.. Building a nuclear reactor next to the turbine building. Workers had their
basement, but not direct access, you can come and go through the door on the first floor.　Unit 1 also found in the pools. Water collected from a puddle in the basement 24 of the
Unit 1 turbine building, 3.8 million becquerels per cubic centimeter and a No. 3 hit the same
level (unit of radioactivity), radioactivity was detected.

 

[KateB]

If we look at the decay of Cl 38 it is a pure beta emitter. This means that if an analysis of this isotope was performed a chemical separation of the sample would be required for the analysis to take place because there are to many competing beta emitters to provide an accurate analysis. I really doubt that they would do this complex analysis at this point. The only way that Cl 38 can be present at this late date is for neutron activation of the salt water coolant. I suspect this is an error - if it isn't big problem.

Correct me if I'm wrong, but doesn't beta decay have signature energies for each nuclide measurable in MeV; isn't it a simple matter of equipment for the purpose? (Beta scintillation spectrometer or such?)

 

[AntonL]

Ten fold increase in sea water contamination within 24 hours,

Again a machine translation

Fukushima Daiichi nuclear power plant at 1250 times the standard concentration of radioactive material from the water
12 hours 33 minutes 26 March 2011


　TEPCO 26, 25, from seawater collected in the morning near the Fukushima Daiichi Nuclear Power Station, 1250.8 safety standards is found at most levels of radioactive material falls times announced.

　According to TEPCO, on the southern coast about 330 meters from the outlet of the first nuclear power plant at 8:30 am were examined 0.5 to 25 liters of water collected, the Nuclear Reactor Regulation Law is established by iodine-131 1250.8 standard times, were detected. Jumped to 10 times when the Sun 2:30 pm 21. Strengthen the surveillance was increased to twice the measure once a day so far.

　According to the Nuclear and Industrial Safety Agency Ministry of Economy, drinking 500 ml of water to this level temporarily, exposed the extent mSv an amount to limit the annual public (nuked) but, iodine-131 is half to half the radiation dose 8 days shorter period. Changes in the number of 30 kilometers away had not been confirmed.

　In addition, the reference cesium 134 117.3 times, 79.6 times the cesium-137 was detected.

 

[M. Bachmeier]

Lack of data from Japan distresses nuclear experts

Nuclear scientists and policy experts say the quality and quantity of information coming out of Fukushima has left gaping holes in their understanding of the nuclear disaster nearly two weeks after it began.


http://www.latimes.com/news/nationworld/world/la-sci-japan-quake-secrecy-20110325,0,3610246.story

 

[AntonL]

In the last days we discussed bullets (debris at high velocity) smashing through
neighbouring roofs let's call these bombs, being material blasted high into the sky and
falling at high equally high velocity. Penetration holes can be seen on turbine building no
3 and in the latest SDF video from two days back, showed steam escaping through holes
of unit 2 roof - possibly also a bombs from rector 3 explosion.

What we have not discussed are these bombs falling into the SPF and destroying the
spent fuel rods and unit 3 also had 200 brand new rods. In this case the Zirconium
jackets could be destroyed and fission products exposed to the water in the pools

 

[KateB]

Lack of data from Japan distresses nuclear experts

Nuclear scientists and policy experts say the quality and quantity of information coming out of Fukushima has left gaping holes in their understanding of the nuclear disaster nearly two weeks after it began.


http://www.latimes.com/news/nationworld/world/la-sci-japan-quake-secrecy-20110325,0,3610246.story

If they are withholding information, that is really too bad; considering hundreds of brilliant minds are better than their relatively small amount. The world has a stake in this too.

 

[AntonL]

Lack of data from Japan distresses nuclear experts

Nuclear scientists and policy experts say the quality and quantity of information coming out of Fukushima has left gaping holes in their understanding of the nuclear disaster nearly two weeks after it began.http://www.latimes.com/news/nationworld/world/la-sci-japan-quake-secrecy-20110325,0,3610246.story

So its official now what we have been saying this all along

and in #1176 I wrote:
I personally feel that Tepco engineers are overextended, paralyzed and firefighting,
instead of having a set clear path of action with small deviations to solve the problem.
The question now arises if nuclear reactor accidents should be co-managed internationally,
an new task for the United Nations as they are the only body to enforce this.

and in #1195 I wrote:
All I want to say is that nuclear accident management need to be rethought and taken out
of the control of the operator. It would be of interest if the big nuclear nation to have a
national emergency manual that structures the accident management that takes immediate
effect with military like precision.

 

[Fresno Phil]

Speaking of lack of data, if you haven't seen the official reports from NISA, they are here:

http://www.meti.go.jp/press/

Specifically, the "Plant Parameter" reports have a wealth of data:

http://www.meti.go.jp/press/20110326002/20110326002-3.pdf

If you understand plant construction and physics, these tell quite a story.

The first line is amount of water injection: 700 litres/minute, which equals ~1000 tonnes/day

The second line is water coverage over fuel rods (negative is uncovered)

Third line is reactor vessel pressure (anybody know why 2 & 3 are negative?)

Fifth line is primary containment vessel temperature (unit 1 is 200 degrees still!)

Next is DW/SC pressure. This is the interesting one. I assume DW is dry-well, and it shows that Nos 2 & 3 are at or close to 0.1Mpa (abs), which is of course atmospheric pressure at sea level. For some reason nobody in the press has caught the fact that since Tuesday both units 2 and 3 have apparently lost pressure, and TEPCO didn't feel like telling them I guess.

Unit 2's S/C (suppression chamber I assume) pressure is listed as "downscale", which means unreadable. Unit 1's torus pressure is identical with the primary container vessel pressure, and Unit 3's torus pressure is oddly almost twice the drywell pressure.

CAMS is radiation monitoring and should be self-explanatory.

The next two lines list operating pressure and max pressure for the drywell.

 

[M. Bachmeier]

In the last days we discussed bullets (debris hat high velocity) smashing through
neighbouring roofs let's call these bombs, being material blasted high into the sky and
falling at high equally high velocity. Penetration holes can be seen on turbine building no
3 and in the latest SDF video from two days back, showed steam escaping through holes
of unit 2 roof - possibly also a bombs from rector 3 explosion.

What we have not discussed are these bombs falling into the SPF and destroying the
spent fuel rods and unit 3 also had 200 brand new rods. In this case the Zirconium
jackets could be destroyed and fission products exposed to the water in the pools

That makes sense, but the big blast in #3 might still have something to do with containment. Also, not confirmed, but reports say evacuation zone increased from 20 to 30 km on a voluntary basis, but transportation will be supplied.

 

[M. Bachmeier]

So its official now what we have been saying this all along

Well at least there's a consensus (as reported) that the information flow is inadequate. Some additional details bring the reasons into perspective, but don't justify it.

 

[AntonL]

Speaking of lack of data, if you haven't seen the official reports from NISA, they are here:

http://www.meti.go.jp/press/

Specifically, the "Plant Parameter" reports have a wealth of data:

http://www.meti.go.jp/press/20110326002/20110326002-3.pdf

If you understand plant construction and physics, these tell quite a story.

The first line is amount of water injection: 700 litres/minute, which equals ~1000 tonnes/day

The second line is water coverage over fuel rods (negative is uncovered)

Third line is reactor vessel pressure (anybody know why 2 & 3 are negative?)

Fifth line is primary containment vessel temperature (unit 1 is 200 degrees still!)

Next is DW/SC pressure. This is the interesting one. I assume DW is dry-well, and it shows that Nos 2 & 3 are at or close to 0.1Mpa (abs), which is of course atmospheric pressure at sea level. For some reason nobody in the press has caught the fact that since Tuesday both units 2 and 3 have apparently lost pressure, and TEPCO didn't feel like telling them I guess.

Unit 2's S/C (suppression chamber I assume) pressure is listed as "downscale", which means unreadable. Unit 1's torus pressure is identical with the primary container vessel pressure, and Unit 3's torus pressure is oddly almost twice the drywell pressure.

CAMS is radiation monitoring and should be self-explanatory.

The next two lines list operating pressure and max pressure for the drywell.

Fresno Phil I note this is your first post, WELCOME , but stop being an alarmist and stop exaggerating the figures this is a serious forum and we are trying to to stay with facts.

If you took time and read any of the previous post you will note that we all understand these figures and they are availabe in english too http://www.nisa.meti.go.jp/english/files/en20110325-3-3.pdf

700 litres per minute appears nowhere in your linked document

To explain the negative pressure please study the difference between gauge and absolute pressures or simply add .101 MPa to convert to MPa_g to MPa_abs

That the Dry Well is near atmospheric pressure is a good sign and is normal condition as that indicates that the reactor vessel is holding

 

[Fresno Phil]

Fresno Phil I note this is your first post, WELCOME , but stop being an alarmist and stop exaggerating the figures this is a serious forum and we are trying to to stay with facts.

700 litres per minute appears nowhere in your linked document

Actually if you add 120 +340 + 240 you get 700.

That the Dry Well is near atmospheric pressure is a good sign and is normal condition as that indicates that the reactor vessel is holding

That would be the non-alarmist position, yes.

But if these containment vessels are supposed to be holding steam, a 1 ATM pressure reading indicates that they are not.

Note #1's drywell is ~2.7 ATM. THAT'S what containing steam looks like.

Reactor vessel pressures are negative for 2 & 3 so it's hard to say the steam is being retained there.

 

[M. Bachmeier]

Reactor vessel pressures are negative for 2 & 3 so it's hard to say the steam is being retained there.

I read a report somewhere that indicated that pressure sensing equipment for units 2 and 3 might not be operable or reliable.

 

[M. Bachmeier]

International Business Times
Is confirming a voluntary evacuation of people in the 20-30 km range, also regional governments are being provided instructions on evacuation procedures in case they are needed.

http://www.ibtimes.com/articles/126961/20110325/japan.htm

 

[AntonL]

Actually if you add 120 +340 + 240 you get 700.

That would be the non-alarmist position, yes.

Sorry - maybe I was a bit too hard on you

Rest assured we are all alarmed what is happening, but we try to remain rational.

statements should be referenced with a link to the source
or clearly marked as a proposal or hypothesis

 

[PietKuip]

If we look at the decay of Cl 38 it is a pure beta emitter. This means that if an analysis of this isotope was performed a chemical separation of the sample would be required for the analysis to take place because there are to many competing beta emitters to provide an accurate analysis. I really doubt that they would do this complex analysis at this point.

There are also gammas, see http://nucleardata.nuclear.lu.se/nucleardata/toi/nuclide.asp?iZA=170038" . High probabilities (30 %) of emissions at 1.643 and 2.167 MeV. It is very easy to detect.

The only way that Cl 38 can be present at this late date is for neutron activation of the salt water coolant. I suspect this is an error - if it isn't big problem.

I agree. But the info is still there at http://www.nisa.meti.go.jp/english/index.html" . It is insane. They should publish the gamma spectrum.

 

[|Fred]

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

 

[Fresno Phil]

The above seawater analysis is 330m from the south water outlet that serves 1-4 (5 & 6 use the north outlet I believe). They carried 500ml to Fukushima Dai Ni plant for analysis.

Column 1 is detected amount, Column 2 is Detection Margin Amount, I believe Column 3 is the legal maximum for nuclear plants, and Column 4 is the ratio of 1 over 3.

 

[|Fred]

Thank you Phil
could you please confirm my translation of this:
原子炉圧力容器へ淡水注入中 <= injection of "tap" water "tap" as in not seawater
Now (26th 8:00 JST) all 3 reactors are getting fresh water
In the past they stated
原子炉圧力容器へ海水注入中 note the symbol after the へ it changed from 海 (sea) to 淡 (Light)

Source latest http://www.meti.go.jp/press/20110324006/20110324006-1.pdf

 

[AntonL]

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

and how do you explain water in reactor building 4.
and all happening at the same time?

sounds like an exterior catchment/retainment tank for fire fighting water, sprinkler systems etc being full and now overflowing into the basements. These catchment/retainment tanks are used under normal circumstance to collect fire fighting run off water such that it can be filtered and cleared before releasing into the environment. With all the water being pumped into the SFP one or two could be overflowing due to other breaches in the pool and draining into these tanks through the provided drains. Also spent fuel rods could be damaged from exposure to air and by the effect of the crashing heavy debry from the explosion into the pool smashing the rods, thus fission elements could well be in direct contact with the cooling water.