Japan Fukushima nuclear thread
Discussion
Other news about the leak at #2 reactor:
http://english.aljazeera.net/news/asia-pacific/201...
As far as I can tell we have reactor #1 which is in a Three-mile-island state, I.e. it's melted down but still contained. Then we have #2 which has melted down and got out of the containment. #3 is the same as far as I can see but with perhaps less spillage, then #4 melted down outside the containment as that's where the fuel was.
http://english.aljazeera.net/news/asia-pacific/201...
Aljazeera said:
Japanese officials grappling to end the nuclear crisis at the earthquake and tsunami-damaged Fukushima plant are focusing on a crack in a concrete pit that is leaking highly radioactive water into the ocean from a crippled reactor.
"There have been two attempts now to stem the flow of water from a pit near reactor No. 2," Al Jazeera's Wayne Hay, reporting from Tokyo, said on Sunday.
"In the first they [power plant workers] tried to use cement but that failed, in the second they tried to use a polymeric material, a kind of powder, but at the moment that is not working either," he said.
"Officials at TEPCO [the company that operates the plant] say they are not giving up yet on this product they will test it again on Monday. If it isn't working then, it is not clear what step 3 will be to try and stem the flow of this water.
"But even if they do stop the water flowing out of this pit, the water shouldn't be there in the first place, this is a pit that contains cables, so how do they stop that, that's the next question."
The water has been leaking into the sea from a 20-centimetre crack detected at a pit in the reactor where power cables are stored. TEPCO said the pit is connected to the No. 2 reactor's turbine building and a tunnel-like underground trench, in which highly radioactive water has been spotted so far.
Solution 'could take months'
Operators of the plant are no closer to regaining control of damaged reactors, as fuel rods remain overheated and high levels of radiation are flowing into the sea.
Radiation 4,000 times the legal limit has been detected in seawater near the plant and a floating tanker was to be towed to Fukushima to store contaminated seawater.
But until the plant's internal cooling system is reconnected radiation will flow from the plant.
Nuclear safety agency spokesman Hidehiko Nishiyama on Sunday offered the first sense of how long it might take to bring an end to the nuclear crisis.
"It would take a few months until we finally get things under control and have a better idea about the future,'' Nishiyama said.
Without instrumentation it's difficult to say what's going on inside any reactor, especially ones that were shaken to pieces, had their cooling removed and then were subject to steam/gas explosions. "There have been two attempts now to stem the flow of water from a pit near reactor No. 2," Al Jazeera's Wayne Hay, reporting from Tokyo, said on Sunday.
"In the first they [power plant workers] tried to use cement but that failed, in the second they tried to use a polymeric material, a kind of powder, but at the moment that is not working either," he said.
"Officials at TEPCO [the company that operates the plant] say they are not giving up yet on this product they will test it again on Monday. If it isn't working then, it is not clear what step 3 will be to try and stem the flow of this water.
"But even if they do stop the water flowing out of this pit, the water shouldn't be there in the first place, this is a pit that contains cables, so how do they stop that, that's the next question."
The water has been leaking into the sea from a 20-centimetre crack detected at a pit in the reactor where power cables are stored. TEPCO said the pit is connected to the No. 2 reactor's turbine building and a tunnel-like underground trench, in which highly radioactive water has been spotted so far.
Solution 'could take months'
Operators of the plant are no closer to regaining control of damaged reactors, as fuel rods remain overheated and high levels of radiation are flowing into the sea.
Radiation 4,000 times the legal limit has been detected in seawater near the plant and a floating tanker was to be towed to Fukushima to store contaminated seawater.
But until the plant's internal cooling system is reconnected radiation will flow from the plant.
Nuclear safety agency spokesman Hidehiko Nishiyama on Sunday offered the first sense of how long it might take to bring an end to the nuclear crisis.
"It would take a few months until we finally get things under control and have a better idea about the future,'' Nishiyama said.
As far as I can tell we have reactor #1 which is in a Three-mile-island state, I.e. it's melted down but still contained. Then we have #2 which has melted down and got out of the containment. #3 is the same as far as I can see but with perhaps less spillage, then #4 melted down outside the containment as that's where the fuel was.
From http://www.nisa.meti.go.jp/english/files/en2011040...
And this is in the most intact reactor they have!
By the time this is done the site will have thrown out more dangerous radioactive products than Chernobyl, by quite a margin. Only the Pacific is saving them greater damage, but people who live in the exclusion zone can kiss goodbye to moving back.
TEPCO chose to ignore 8 years of warnings about inadequate tsunami defences here - and this is the result, my view is that is criminal negligence, you could argue that it's a simple mistake but that's the case with all negligence isn't it?
Also all sorts of stories about criticality events occurring in Unit 1, which indicates to me an almost total meltdown in that reactor. So we have three total meltdowns, a fuel pool meltdown and serious contamination of the pacific.
NISA said:
<Unit 1> ・ TEPCO reported to NISA the event (Inability of water injection of the
Emergency Core Cooling System) falling under the Article 15 of the Act on Special Measures Concerning Nuclear Emergency Preparedness. (16:36 March 11th)
・ Operation of Vent (10:17 March 12th) ・ Seawater injection to the Reactor Pressure Vessel (RPV) via the Fire
Extinguish Line was started. (20:20 March 12th)
DTemporary interruption of the injection (01:10 March 14th) ・ The sound of explosion in Unit 1 occurred. (15:36 March 12th) ・ The amount of injected water to the Reactor Core was increased by
utilizing the Feedwater Line in addition to the Fire Extinguish Line. (2m3/h→18m3/h). (02:33 March 23rd) Later, it was switched to the Feedwater Line only (around 11m3/h). (09:00 March 23rd)
・ Lighting in the Central Operation Room was recovered. (11:30 March 24th)
・ Fresh water injection to RPV was started. (15:37 March 25) ・ As the result of concentration measurement in the stagnant water on the basement floor of the turbine building, 2.1×10^5Bq/cm3 of 131I (Iodine) and 1.8×10^6Bq/cm3 of 137Cs (Caesium) were detected as major
radioactive nuclides.
Holy crap. Emergency Core Cooling System) falling under the Article 15 of the Act on Special Measures Concerning Nuclear Emergency Preparedness. (16:36 March 11th)
・ Operation of Vent (10:17 March 12th) ・ Seawater injection to the Reactor Pressure Vessel (RPV) via the Fire
Extinguish Line was started. (20:20 March 12th)
DTemporary interruption of the injection (01:10 March 14th) ・ The sound of explosion in Unit 1 occurred. (15:36 March 12th) ・ The amount of injected water to the Reactor Core was increased by
utilizing the Feedwater Line in addition to the Fire Extinguish Line. (2m3/h→18m3/h). (02:33 March 23rd) Later, it was switched to the Feedwater Line only (around 11m3/h). (09:00 March 23rd)
・ Lighting in the Central Operation Room was recovered. (11:30 March 24th)
・ Fresh water injection to RPV was started. (15:37 March 25) ・ As the result of concentration measurement in the stagnant water on the basement floor of the turbine building, 2.1×10^5Bq/cm3 of 131I (Iodine) and 1.8×10^6Bq/cm3 of 137Cs (Caesium) were detected as major
radioactive nuclides.
And this is in the most intact reactor they have!
By the time this is done the site will have thrown out more dangerous radioactive products than Chernobyl, by quite a margin. Only the Pacific is saving them greater damage, but people who live in the exclusion zone can kiss goodbye to moving back.
TEPCO chose to ignore 8 years of warnings about inadequate tsunami defences here - and this is the result, my view is that is criminal negligence, you could argue that it's a simple mistake but that's the case with all negligence isn't it?
Also all sorts of stories about criticality events occurring in Unit 1, which indicates to me an almost total meltdown in that reactor. So we have three total meltdowns, a fuel pool meltdown and serious contamination of the pacific.
Globs said:
Holy crap.
And this is in the most intact reactor they have!
By the time this is done the site will have thrown out more dangerous radioactive products than Chernobyl, by quite a margin. Only the Pacific is saving them greater damage, but people who live in the exclusion zone can kiss goodbye to moving back.
TEPCO chose to ignore 8 years of warnings about inadequate tsunami defences here - and this is the result, my view is that is criminal negligence, you could argue that it's a simple mistake but that's the case with all negligence isn't it?
Also all sorts of stories about criticality events occurring in Unit 1, which indicates to me an almost total meltdown in that reactor. So we have three total meltdowns, a fuel pool meltdown and serious contamination of the pacific.
Despite Fox news getting excited about reports of a blue glow from Cherenkov radiation there seems to be no firm evidence of criticality - the IAEA think that it's not happening. The closest to a credible suggestion that it has been is this chap doing a neutron flux calculation based on Cl-38 levels; http://lewis.armscontrolwonk.com/files/2011/03/Cau...And this is in the most intact reactor they have!
By the time this is done the site will have thrown out more dangerous radioactive products than Chernobyl, by quite a margin. Only the Pacific is saving them greater damage, but people who live in the exclusion zone can kiss goodbye to moving back.
TEPCO chose to ignore 8 years of warnings about inadequate tsunami defences here - and this is the result, my view is that is criminal negligence, you could argue that it's a simple mistake but that's the case with all negligence isn't it?
Also all sorts of stories about criticality events occurring in Unit 1, which indicates to me an almost total meltdown in that reactor. So we have three total meltdowns, a fuel pool meltdown and serious contamination of the pacific.
The rest of the inventory measured at the same time don't match up though, which likely indicates an error in the Cl-38 measurement rather than criticality.
I've seen no evidence that the exclusion zone is contaminated to any significant degree, and independent people are certainly looking for it. Suggestions that people can 'kiss goodbye to moving back" is no more than scaremongering.
Contamination of the ocean, likely short term and localised, yes.
Just to keep us up to date over here Globs.
Plant does not survive eight times design for earthquake.
http://www.world-nuclear.org/info/inf18.html
Plant does not survive eight times design for earthquake.
http://www.world-nuclear.org/info/inf18.html
Fume troll said:
Globs said:
By the time this is done the site will have thrown out more dangerous radioactive products than Chernobyl, by quite a margin.
Where's that piece of information from?I have taken the current rate and amount from the New Scientist article posted above, and multiplied that by the 'months' figure that was quoted by some Japanese nuclear bod.
Have you read the NS article? I'd be interested in your take on this, assuming for instance they manage to have it all damped down by July.
Globs said:
From me.
I have taken the current rate and amount from the New Scientist article posted above, and multiplied that by the 'months' figure that was quoted by some Japanese nuclear bod.
Have you read the NS article? I'd be interested in your take on this, assuming for instance they manage to have it all damped down by July.
Yes, it says: "Japan's damaged nuclear plant in Fukushima has been emitting radioactive iodine and caesium at levels approaching those seen in the aftermath of the Chernobyl accident in 1986."I have taken the current rate and amount from the New Scientist article posted above, and multiplied that by the 'months' figure that was quoted by some Japanese nuclear bod.
Have you read the NS article? I'd be interested in your take on this, assuming for instance they manage to have it all damped down by July.
It then mentions that "The difference between this accident and Chernobyl, they say, is that at Chernobyl a huge fire released large amounts of many radioactive materials, including fuel particles, in smoke. At Fukushima Daiichi, only the volatile elements, such as iodine and caesium, are bubbling off the damaged fuel"
I.e. not the zirconium-95, niobium-95, lanthanum-140, cerium-144 and the transuranic elements, including neptunium, plutonium and the minor actinides which Chernobyl produced.
It is estimated that Chernobyl threw about 6 t of fragmented fuel into the atmosphere; I don't think that has happened in Japan yet.
Admittedly the Cs and I are probably the most likely to have an effect on human health, but I'm not convinced they will have much effect here.
Cheers,
FT.
Posted here for LLewop.
Source.
http://www.meti.go.jp/english/electricity_supply/i...
I haven't looked through them all to see how much they are varying but the last few days seems relatively stable and it seems they only started 20th March. Edit, Now I have.
20/03/2011 8.35
21/03/2011 7.26
22/03/2011 6.38
23/03/2011 5.48
24/03/2011 4.92
25/03/2011 3.98
26/03/2011 3.89
27/03/2011 3.54
28/03/2011 3.18
29/03/2011 3.31
30/03/2011 2.89
31/03/2011 2.72
01/04/2011 2.68
02/04/2011 2.75
03/04/2011 2.49
04/04/2011 2.3
05/04/2011 2.27
06/04/2011 2.27 Actually just a reprint of the previous day??
Source.
http://www.meti.go.jp/english/electricity_supply/i...
I haven't looked through them all to see how much they are varying but the last few days seems relatively stable and it seems they only started 20th March. Edit, Now I have.
20/03/2011 8.35
21/03/2011 7.26
22/03/2011 6.38
23/03/2011 5.48
24/03/2011 4.92
25/03/2011 3.98
26/03/2011 3.89
27/03/2011 3.54
28/03/2011 3.18
29/03/2011 3.31
30/03/2011 2.89
31/03/2011 2.72
01/04/2011 2.68
02/04/2011 2.75
03/04/2011 2.49
04/04/2011 2.3
05/04/2011 2.27
06/04/2011 2.27 Actually just a reprint of the previous day??
Edited by MOTORVATOR on Thursday 7th April 14:00
An attempt at context for the dose rate levels in the map. For most of the areas the numbers are to be honest in the range of normal background, so rather than look at them all, Toyko is just under 0.1 uSv/hour - which gives an annualised dose of something like 750-800 uSv/year. The annual figure quoted I expect is including all factors and not that far from the UK figure of 2.7 mSv (2700 uSv). I did find a better breakdown after the debate the other day, so for simplicity will use that (UK figures) for the general levels across the whole country:
figures in uSv
The dose rate measured would probably be the cosmic and gamma together, so from the table above about 700 - so on par with the Japanese figures. Radon we've discussed on the thread, fallout and disposals ditto, occupational speaks for itself - internal: don't forget we are all a little bit radioactive so are irradiating ourselves and each other all the time! Most of it is K-40 potassium.
The dose rate in Fukushima province is obviously an average as way way higher than that in and around the plant and even some quite high values reported on the IAEA monitoring reports. That dose rate alone would give the occupational dose limit in a year, so I'd imagine would be a need in some areas for relocation - as has already been indicated in reports from Japan.
I'll try and sort out the table later - got to dash to get confused for an hour!
ETA:
table sorted: source btw is Health Protection Agency report HPA-RPD-001: Ionising Radiation Exposure of the UK Population 2005 review
Also to add to the doses for Fukushima province: annual dose extrapolation from current dose rate probably shouldn't be linear: there are probably short lived isotopes contributing to the dose rate, I've got the curves for it somewhere, or used to have. What actually would determine whether relocation would be recommended for the public would be on averted dose: what dose do you save by doing it: so comparing the annual dose in, say Fukushima vs the dose for living in Toyko instead: on those figures you'd save about 20 mSv in the first year, neglecting to correct the linear calculation.
figures in uSv
| Group | Source | dose (uSv) | percent |
|---|---|---|---|
| Natural | Cosmic | 330 | 12% |
| Gamma | 350 | 13% | |
| Internal | 250 | 9% | |
| Radon | 1300 | 49% | |
| Man made | Medical | 410 | 15% |
| Occupation | 6 | 0% | |
| Fallout | 6 | 0% | |
| Disposal | 0.9 | 0% | |
| Consumer Products | 0.1 | 0% | |
| Total | 2653 | 100% |
The dose rate measured would probably be the cosmic and gamma together, so from the table above about 700 - so on par with the Japanese figures. Radon we've discussed on the thread, fallout and disposals ditto, occupational speaks for itself - internal: don't forget we are all a little bit radioactive so are irradiating ourselves and each other all the time! Most of it is K-40 potassium.
The dose rate in Fukushima province is obviously an average as way way higher than that in and around the plant and even some quite high values reported on the IAEA monitoring reports. That dose rate alone would give the occupational dose limit in a year, so I'd imagine would be a need in some areas for relocation - as has already been indicated in reports from Japan.
I'll try and sort out the table later - got to dash to get confused for an hour!
ETA:
table sorted: source btw is Health Protection Agency report HPA-RPD-001: Ionising Radiation Exposure of the UK Population 2005 review
Also to add to the doses for Fukushima province: annual dose extrapolation from current dose rate probably shouldn't be linear: there are probably short lived isotopes contributing to the dose rate, I've got the curves for it somewhere, or used to have. What actually would determine whether relocation would be recommended for the public would be on averted dose: what dose do you save by doing it: so comparing the annual dose in, say Fukushima vs the dose for living in Toyko instead: on those figures you'd save about 20 mSv in the first year, neglecting to correct the linear calculation.
Edited by llewop on Thursday 7th April 18:47
hairykrishna said:
Despite Fox news getting excited about reports of a blue glow from Cherenkov radiation there seems to be no firm evidence of criticality - the IAEA think that it's not happening. The closest to a credible suggestion that it has been is this chap doing a neutron flux calculation based on Cl-38 levels; http://lewis.armscontrolwonk.com/files/2011/03/Cau...
The rest of the inventory measured at the same time don't match up though, which likely indicates an error in the Cl-38 measurement rather than criticality.
I've seen no evidence that the exclusion zone is contaminated to any significant degree, and independent people are certainly looking for it. Suggestions that people can 'kiss goodbye to moving back" is no more than scaremongering.
Contamination of the ocean, likely short term and localised, yes.
I know you know that is not the case, but it's perhaps worth pointing out to someone not familiar that Cherenkov does not = criticality. What you wrote suggests otherwise. The rest of the inventory measured at the same time don't match up though, which likely indicates an error in the Cl-38 measurement rather than criticality.
I've seen no evidence that the exclusion zone is contaminated to any significant degree, and independent people are certainly looking for it. Suggestions that people can 'kiss goodbye to moving back" is no more than scaremongering.
Contamination of the ocean, likely short term and localised, yes.
llewop said:
An attempt at context for the dose rate levels in the map. For most of the areas the numbers are to be honest in the range of normal background, so rather than look at them all, Toyko is just under 0.1 uSv/hour - which gives an annualised dose of something like 750-800 uSv/year. The annual figure quoted I expect is including all factors and not that far from the UK figure of 2.7 mSv (2700 uSv). I did find a better breakdown after the debate the other day, so for simplicity will use that (UK figures) for the general levels across the whole country:
figures in uSv
Natural Cosmic 330 12%
Gamma 350 13%
Internal 250 9%
Radon 1300 49%
Man made Medical 410 15%
Occupation 6 0%
Fallout 6 0%
Disposal 0.9 0%
Consumer Products 0.1 0%
Total 2653 100%
The dose rate measured would probably be the cosmic and gamma together, so from the table above about 700 - so on par with the Japanese figures. Radon we've discussed on the thread, fallout and disposals ditto, occupational speaks for itself - internal: don't forget we are all a little bit radioactive so are irradiating ourselves and each other all the time! Most of it is K-40 potassium.
The dose rate in Fukushima province is obviously an average as way way higher than that in and around the plant and even some quite high values reported on the IAEA monitoring reports. That dose rate alone would give the occupational dose limit in a year, so I'd imagine would be a need in some areas for relocation - as has already been indicated in reports from Japan.
I'll try and sort out the table later - got to dash to get confused for an hour!
Thanks for that LLewop. figures in uSv
Natural Cosmic 330 12%
Gamma 350 13%
Internal 250 9%
Radon 1300 49%
Man made Medical 410 15%
Occupation 6 0%
Fallout 6 0%
Disposal 0.9 0%
Consumer Products 0.1 0%
Total 2653 100%
The dose rate measured would probably be the cosmic and gamma together, so from the table above about 700 - so on par with the Japanese figures. Radon we've discussed on the thread, fallout and disposals ditto, occupational speaks for itself - internal: don't forget we are all a little bit radioactive so are irradiating ourselves and each other all the time! Most of it is K-40 potassium.
The dose rate in Fukushima province is obviously an average as way way higher than that in and around the plant and even some quite high values reported on the IAEA monitoring reports. That dose rate alone would give the occupational dose limit in a year, so I'd imagine would be a need in some areas for relocation - as has already been indicated in reports from Japan.
I'll try and sort out the table later - got to dash to get confused for an hour!
As you say the figures are probably averaged over the area so don't really give an indication to what final effect it will have on evacuees.
I've been trying to track down a figure for those displaced by tsunami and those by radiation evacuation and not really got a firm answer.
BBC States.
"NUMBER OF PEOPLE EVACUATED
More than 163,000 people were in shelters around the country following evacuation, the National Police Agency said. The government has set up an evacuation area around Tokyo Electric Power Co's quake-stricken nuclear plant in Fukushima 150 miles north of Tokyo, with a 12-mile radius. More than 70,000 people lived in the largely rural area within the zone. It is unclear how many of them have been evacuated, but most are believed to have left. Another 136,000 people were within a zone extending a further six miles in which residents are recommended to leave or stay indoors. "
I'm not sure if the 163,000 is just radiation event and tsunami displacements are on top of it.
If it's in addition then there are a shedload more homes to be found if they cannot return in the near future.
Interesting bit of trivia I picked up on the way. Radon concentrations in groundwater were seen to increase by up to a factor of ten in the months preceeding the Kobe quake and are now seen as a precursor. Don't know whether air concentrations could do the same.
Edited by MOTORVATOR on Thursday 7th April 17:37
Edited by MOTORVATOR on Thursday 7th April 17:45
rhinochopig said:
hairykrishna said:
Despite Fox news getting excited about reports of a blue glow from Cherenkov radiation there seems to be no firm evidence of criticality - the IAEA think that it's not happening. The closest to a credible suggestion that it has been is this chap doing a neutron flux calculation based on Cl-38 levels; http://lewis.armscontrolwonk.com/files/2011/03/Cau...
The rest of the inventory measured at the same time don't match up though, which likely indicates an error in the Cl-38 measurement rather than criticality.
I've seen no evidence that the exclusion zone is contaminated to any significant degree, and independent people are certainly looking for it. Suggestions that people can 'kiss goodbye to moving back" is no more than scaremongering.
Contamination of the ocean, likely short term and localised, yes.
I know you know that is not the case, but it's perhaps worth pointing out to someone not familiar that Cherenkov does not = criticality. What you wrote suggests otherwise. The rest of the inventory measured at the same time don't match up though, which likely indicates an error in the Cl-38 measurement rather than criticality.
I've seen no evidence that the exclusion zone is contaminated to any significant degree, and independent people are certainly looking for it. Suggestions that people can 'kiss goodbye to moving back" is no more than scaremongering.
Contamination of the ocean, likely short term and localised, yes.
hairykrishna said:
Bugger, quite right, it does read like that. Cherenkov just means there are charged particles.
I thought it was caused by fast particles travelling in a liquid faster than light, which is sort of nothing to do with criticality (although criticality events appear to have blue flashes - which may be Cherenkov in fluids but are probably air ionisation in the dry as light will almost be at it's terminal speed there.As for the pollution I think the actual radioactivity (total gamma+particles) is largely irrelevant for everyone except for the plant team, the damage will be done by particles being ingested and sitting there disrupting stuff until they eventually decay.
Then the bigger damage is the exclusion zone - a zone of 20km (radius?) stops over 600 square km of land use which must affect a lot of people, and when they do go back they may be afraid of ingesting anything grown in that area.
Globs said:
I thought it was caused by fast particles travelling in a liquid faster than light, which is sort of nothing to do with criticality (although criticality events appear to have blue flashes - which may be Cherenkov in fluids but are probably air ionisation in the dry as light will almost be at it's terminal speed there.
Yes - that's right. Very intense Cherenkov (in water) tends to be a good indicator of criticality though, because you get a lot of charged particles. Edited by hairykrishna on Thursday 7th April 20:53
Trying to pin down the source of stories about the generation of Chlorine-38, lots of people are saying this but no real source for the story has been identified.
So either they are making it all up (but it's very specific info) or it's true - which means it must have some type of cause.
http://japanfocus.org/-Arjun-Makhijani/3509
So either they are making it all up (but it's very specific info) or it's true - which means it must have some type of cause.
http://japanfocus.org/-Arjun-Makhijani/3509
hairykrishna said:
Globs said:
I thought it was caused by fast particles travelling in a liquid faster than light, which is sort of nothing to do with criticality (although criticality events appear to have blue flashes - which may be Cherenkov in fluids but are probably air ionisation in the dry as light will almost be at it's terminal speed there.
Yes - that's right. Very intense Cherenkov (in water) tends to be a good indicator of criticality though, because you get a lot of charged particles. Edited by hairykrishna on Thursday 7th April 20:53
http://ieeexplore.ieee.org/Xplore/login.jsp?url=ht...
http://www.sciencedirect.com/science?_ob=ArticleUR...
Slightly off topic, has anyone seen it first hand? I was lucky enough a few years back in a UK core pond - I bullied my guide to turn the lights off and it really is quite an eerie site. Without the background knowledge, I can understand why 'nuclear' scares people.
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