Japan Fukushima nuclear thread
Discussion
This thread is for people pontificating about the performance of the various agencies involved, and who want to discuss the nuclear aspect.
All other non-nuclear discussion should be directed to this thread:
http://www.pistonheads.com/xforums/topic.asp?h=0&a...
To start the latest reactor status from the International Atomic Energy Authority is here:
http://www.iaea.org/newscenter/news/tsunamiupdate0...
All other non-nuclear discussion should be directed to this thread:
http://www.pistonheads.com/xforums/topic.asp?h=0&a...
To start the latest reactor status from the International Atomic Energy Authority is here:
http://www.iaea.org/newscenter/news/tsunamiupdate0...
IAEA said:
1. Current Situation
The situation at the Fukushima Daiichi plant remains very serious.
The restoration of off-site power continues and lighting is now available in the central control rooms of Units 1, 2 and 3. Also, fresh water is now being injected into the Reactor Pressure Vessels (RPVs) of all three Units.
Radiation measurements in the containment vessels and suppression chambers of Units 1, 2 and 3 continued to decrease. White "smoke" continued to be emitted from Units 1 to 4.
Pressure in the RPV showed a slight increase at Unit 1 and was stable at Units 2 and 3, possibly indicating that there has been no major breach in the pressure vessels.
At Unit 1, the temperature measured at the bottom of the RPV fell slightly to 142 °C. At Unit 2, the temperature at the bottom of the RPV fell to 97 °C from 100 °C reported in the Update provided yesterday. Pumping of water from the turbine hall basement to the condenser is in progress with a view to allowing power restoration activities to continue.
At Unit 3, plans are being made to pump water from the turbine building to the main condenser but the method has not yet been decided. This should reduce the radiation levels in the turbine building and reduce the risk of contamination of workers in the turbine building restoring equipment.
No notable change has been reported in the condition of Unit 4.
Water is still being added to the spent fuel pools of Units 1 to 4 and efforts continue to restore normal cooling functions.
Units 5 and 6 remain in cold shutdown.
We understand that three workers who suffered contamination are still under observation in hospital.
The situation at the Fukushima Daiichi plant remains very serious.
The restoration of off-site power continues and lighting is now available in the central control rooms of Units 1, 2 and 3. Also, fresh water is now being injected into the Reactor Pressure Vessels (RPVs) of all three Units.
Radiation measurements in the containment vessels and suppression chambers of Units 1, 2 and 3 continued to decrease. White "smoke" continued to be emitted from Units 1 to 4.
Pressure in the RPV showed a slight increase at Unit 1 and was stable at Units 2 and 3, possibly indicating that there has been no major breach in the pressure vessels.
At Unit 1, the temperature measured at the bottom of the RPV fell slightly to 142 °C. At Unit 2, the temperature at the bottom of the RPV fell to 97 °C from 100 °C reported in the Update provided yesterday. Pumping of water from the turbine hall basement to the condenser is in progress with a view to allowing power restoration activities to continue.
At Unit 3, plans are being made to pump water from the turbine building to the main condenser but the method has not yet been decided. This should reduce the radiation levels in the turbine building and reduce the risk of contamination of workers in the turbine building restoring equipment.
No notable change has been reported in the condition of Unit 4.
Water is still being added to the spent fuel pools of Units 1 to 4 and efforts continue to restore normal cooling functions.
Units 5 and 6 remain in cold shutdown.
We understand that three workers who suffered contamination are still under observation in hospital.
Yes, that makes no sense at all!
Tank_slapper gave a good analogy:
If you are standing in the rain:
so they should have been only aware of Becquerels in that context - i.e. counts/second.
From http://www.antirad.com/units.htm
Tank_slapper gave a good analogy:
If you are standing in the rain:
Becquerels is similar to the amount of rain that is falling.
Grays is how much of the rain hits you.
Sieverts is how wet that rain makes you.
so they should have been only aware of Becquerels in that context - i.e. counts/second.
From http://www.antirad.com/units.htm
units said:
Dosage units:
Gray (Gy) = 1 Joule/kg
Sievert (Sv) = Gray x QF, where QF is a "quality factor" based on the type of particle.
QF for electrons, positrons, and xrays = 1 QF = 3 to 10 for neutrons, protons dependent upon the energy transferred by these heavier particles.
QF = 20 for alpha particles and fission fragments.
The Sievert is a measure of biological effect.
and Gray (Gy) = 1 Joule/kg
Sievert (Sv) = Gray x QF, where QF is a "quality factor" based on the type of particle.
QF for electrons, positrons, and xrays = 1 QF = 3 to 10 for neutrons, protons dependent upon the energy transferred by these heavier particles.
QF = 20 for alpha particles and fission fragments.
The Sievert is a measure of biological effect.
units said:
Converting older units:
1 rad = 1 centigray = 10 milligrays ( 1 rad = 1cGy = 10 mGy )
1 rem = 1 centisievert = 10 millisieverts ( 1 rem = 1cSv = 10 mSv )
1 mrad = 10 uGy
Nominal background radiation absorbed dose of 100 mrad/year = 1 mGy/yr.
Perhaps the journo got the figure from the damage to (2 of) the workers feet, it's still misquoted but if so I understand why he linked it to the water!1 rad = 1 centigray = 10 milligrays ( 1 rad = 1cGy = 10 mGy )
1 rem = 1 centisievert = 10 millisieverts ( 1 rem = 1cSv = 10 mSv )
1 mrad = 10 uGy
Nominal background radiation absorbed dose of 100 mrad/year = 1 mGy/yr.
MOTORVATOR said:
The other thing we have not successfully answered under the noise of how well the plant did given it's been hit by an earthquake is what energy actually hit the plant.
I'll go find the link but the plants were not designed for a particular earthquake size but rather an accelerative energy immediately under the plant which someone decided equalled 8.2. Obviously the energy dissipates the further away the epicentre so do we actually know if it was hit by something exceeding it's design?
Also the length of the quake at 5 minutes was quite stunning, I can imagine pipes having a bad time with that persistent shaking. I have not seen any word from TEPCO or the IAEA that the plant actually survived the shaking - many just assume it did. For instance what caused the damage in Reactor 4? I'll go find the link but the plants were not designed for a particular earthquake size but rather an accelerative energy immediately under the plant which someone decided equalled 8.2. Obviously the energy dissipates the further away the epicentre so do we actually know if it was hit by something exceeding it's design?
I'll keep looking!
More info from the IAEA
http://www.iaea.org/newscenter/news/tsunamiupdate0...
http://www.iaea.org/newscenter/news/tsunamiupdate0...
IAEA_28thMar said:
Overall at the Fukushima Daiichi plant, the situation is still very serious.
NISA informed the IEC that a meeting is planned with TEPCO to determine the origin and path of water in the turbine buildings of Units 1 to 4. As seen with the contaminated workers, high dose rates in the turbine buildings and contaminated water in the basements can hamper recovery efforts.
The pumping of contaminated water from the basement floor of Unit 1's turbine building into its main condenser is in progress, whereas at Unit 2 that process has not begun because the steam condenser is full. At Unit 3, the pumping of contaminated water and in particular where it is going, are under consideration. The issue is also being examined for Unit 4.
Temperatures measured at the feed water nozzle and at the bottom of the Reactor Pressure Vessel (RPV) continue to decrease slightly at Units 1 and 2, except the temperature at the feed water nozzle of Unit 1's RPV, which has slightly increased to 274 °C.
A positive development is that the pumping of fresh water into the reactor pressure vessel of Unit 1 is to switch from the use of fire trucks to temporary electrical pumps running on offsite power on 29 March. At Unit 2, this switch was carried out on 27 March, with a diesel generator as backup in case offsite power is interrupted. Fresh water is also being injected continuously into the reactor pressure vessel of Unit 3, albeit currently pumped by fire trucks. The switch to temporary electrical pumps for this unit is planned for today.
On 27 March at Unit 3, water was sprayed into the spent fuel pool using a concrete pump truck, and seawater was also pumped in through the spent fuel cooling system. It is planned to start pumping fresh water into the spent fuel pool tomorrow.
It is also planned to commence pumping freshwater into the spent fuel pool of Unit 4 from tomorrow.
So it looks like still no/little instrumentation, a leak in #3 and #1 heating up (274°C sounds a bit hot for water..)NISA informed the IEC that a meeting is planned with TEPCO to determine the origin and path of water in the turbine buildings of Units 1 to 4. As seen with the contaminated workers, high dose rates in the turbine buildings and contaminated water in the basements can hamper recovery efforts.
The pumping of contaminated water from the basement floor of Unit 1's turbine building into its main condenser is in progress, whereas at Unit 2 that process has not begun because the steam condenser is full. At Unit 3, the pumping of contaminated water and in particular where it is going, are under consideration. The issue is also being examined for Unit 4.
Temperatures measured at the feed water nozzle and at the bottom of the Reactor Pressure Vessel (RPV) continue to decrease slightly at Units 1 and 2, except the temperature at the feed water nozzle of Unit 1's RPV, which has slightly increased to 274 °C.
A positive development is that the pumping of fresh water into the reactor pressure vessel of Unit 1 is to switch from the use of fire trucks to temporary electrical pumps running on offsite power on 29 March. At Unit 2, this switch was carried out on 27 March, with a diesel generator as backup in case offsite power is interrupted. Fresh water is also being injected continuously into the reactor pressure vessel of Unit 3, albeit currently pumped by fire trucks. The switch to temporary electrical pumps for this unit is planned for today.
On 27 March at Unit 3, water was sprayed into the spent fuel pool using a concrete pump truck, and seawater was also pumped in through the spent fuel cooling system. It is planned to start pumping fresh water into the spent fuel pool tomorrow.
It is also planned to commence pumping freshwater into the spent fuel pool of Unit 4 from tomorrow.
Good question!
According to Answers.com:
Maybe here the issue of gamma is not as big as alpha/beta radiation?
According to Answers.com:
answers said:
Roentgens are units of radiation exposure used for x-rays and gamma rays. They are defined in terms of the number of ions produced in one cubic centimeter of air by the radiation.
Improve Answer
Read more: http://wiki.answers.com/Q/What_are_roentgens#ixzz1...
So like Grays for air perhaps.Improve Answer
Read more: http://wiki.answers.com/Q/What_are_roentgens#ixzz1...
Maybe here the issue of gamma is not as big as alpha/beta radiation?
Condieboy said:
Globs said:
So it looks like still no/little instrumentation, a leak in #3 and #1 heating up (274°C sounds a bit hot for water..)
Not when it's pressurised as it is, and although there seems to have been a partial meltdown of the core it seems the cooling circuit has remained intact, minimising the escape of fission products.On the 26th "The temperature measured at the bottom of the RPV is stable at 144 °C", today they say "the temperature at the feed water nozzle of Unit 1's RPV, which has slightly increased to 274 °C" so these are looking at different areas in the reactor.
So #1 seems to be intact like you say.
Japan Confirms Plutonium in Soil Samples at Fukushima Daiichi.
A bit of scaremongering going on: http://dcbureau.org/201103281314/Bulldog-Blog/plut... but it does seem that the integrity of the MOX fuel has been compromised, and the RPV is fractured/compromised badly enough for it to get out.
IAEA said:
After taking soil samples at the Fukushima Daiichi nuclear power plant, Japanese authorities today confirmed finding traces of plutonium that most likely resulted from the nuclear accident there. The Nuclear and Industrial Safety Agency told the IAEA that the Tokyo Electric Power Company (TEPCO) had found concentrations of plutonium in two of five soil samples.
It's all a bit vague as to where these samples were taken, but I guess it's from reactor #3.A bit of scaremongering going on: http://dcbureau.org/201103281314/Bulldog-Blog/plut... but it does seem that the integrity of the MOX fuel has been compromised, and the RPV is fractured/compromised badly enough for it to get out.
Fume troll said:
TheRegister said:
Here's a roundup of the latest facts
Given that article is dated the 25th, whereas the International Energy Authorities website is updates more than once a day I guess I'll go with the IAEA as my source 
I also have a tiny suspicion that the IAEA may have more knowledge of nuclear reactors than a publication staffed by people more used to upgrading Windows XP...
If you want even closer information I'd suggest NISA, their press releases can be found on this page: http://www.nisa.meti.go.jp/english/index.html, or more specifically about the soil samples here: http://www.nisa.meti.go.jp/english/files/en2011032... which includes a link to the TEPCO site.
Still, I'm sure if I have a serious NAT routing issue TheRegister would be the place to look.
BTW TheRegisters figures are at odds with those of the IAEA:
I assume IT guys think dosimeters are worn in people's socks. I hope the workers concerned recover.
TheRegister said:
(25th March) First up, three technicians working to restore electrical power in the plant's No 3 reactor building stood in some water while doing so. Their personal dosimetry equipment later showed that they had sustained radiation doses up to 170 millisievert. Under normal rules when dealing with nuclear powerplant incidents, workers at the site are permitted to sustain up to 250 millisievert before being withdrawn. If necessary, this can be extended to 500 millisievert according to World Health Organisation guidance.
None of this involves significant health hazards: actual radiation sickness is not normally seen until a dose of 1,000 millisievert and is not common until 2,000. Additional cancer risk is tiny: huge numbers of people must be subjected to such doses in order to see any measurable health consequences. In decades to come, future investigators will almost certainly be unable to attribute any cases of cancer to service at Fukushima.
None of this involves significant health hazards: actual radiation sickness is not normally seen until a dose of 1,000 millisievert and is not common until 2,000. Additional cancer risk is tiny: huge numbers of people must be subjected to such doses in order to see any measurable health consequences. In decades to come, future investigators will almost certainly be unable to attribute any cases of cancer to service at Fukushima.
IAEA said:
(28th March) At noon today in Japan, the three workers mentioned in previous briefings were released from the National Institute of Radiological Sciences where they had been kept under observation. The result of analyses performed indicates that the level of localised exposure received by two of them is between 2,000 and 3,000 millisievert (i.e. somewhat lower than the previous estimate of 2,000 to 6,000 millisievert).
So TheRegister assumes 170mSv, 3 days later it turns out to be between 2000mSv - 6000mSv.I assume IT guys think dosimeters are worn in people's socks. I hope the workers concerned recover.
Fume troll said:
Not sure what point you were making...?
Cheers,
FT.
I was making the point that TheRegister was as wildly inaccurate as the rest of the media. The fact it only said the worker got 170mSv instead of the actual 2000-3000mSv is an illustration of that - out by a factor of over 12.Cheers,
FT.
As you seem to think I'm anti-nuclear could you please point out a single post I have made that is anti-nuclear? Thanks in advance.
Some people seem to think wanting the facts and a robust critique of TEPCO and it's strange insistence on placing it's backup diesel generators on the beach is the reaction of an anti-nuclear person;- if that's the case everyone who thought that the Allegro had faults and the management of British Leyland was bad would be car haters.
Fume troll said:
Not at all, just surprised at your rapid dismissal and sarcastic treatment of the entire article. Is the example above the only part of the article you disagree with? If so it's not done too bad a job has it? 
Cheers,
FT.
My example above was just the first incorrect thing I saw, near the top, it did not bode well for the rest of the article;- confusing a dosimeter reading (probably clipped onto a top shirt pocket) with feet wet is a feeble mistake. Cheers,
FT.
That kind of article does nothing for the nuclear industry IMO, I prefer to stick to the known facts and speculation about the condition of the reactors and plant rather than the 'we'll all going to die' or 'no one is going to die' articles.
What is true however is that due to TEPCOs poor choice of site many people whose homes are unaffected by the tsunami haven't been allowed home for over two weeks now.
You need to realise that there are many chemicals in the world that are significantly more dangerous than radiation, in fact more dangerous to such an extent that most radiation can be safely ignored, but exclusion zones do affect lives.
hairykrishna said:
Did you read my post? It's whole body vs feet/legs.
Sorry Hairy, yes I did read your post and disagreed with none of it 
Your explanation while not incompatible with the register article was rather more informative, also only two workers got wet feet according to the IAEA, not three.
I suppose the register article is better than the average media one but I still prefer information from closer to the source.
BTW any idea how the HPA detect such low levels of Iodine 131 in the UK?
llewop said:
Timescales: At Chernobyl the sarcophagus was built within a year, so completed by the end of 1986, they continued to operate the other reactors until 2000 when unit 3 (the one twined with unit 4 that exploded) was shut down. As for a 'replacement' for the sarcophagus...we're working on it
That was a stunning feat of engineering, given the huge size and rather hostile environment, the Japanese case would be rather easier to entomb I suspect.That replacement sarcophagus for Chernobyl was supposed to have cost $5bn but they never seemed to have the money. It's immensely irritating that so much radioactive dust is contained by a rusty, leaky structure and so many times the cost of doing it properly have been blown on the stupid religion of AGW.
llewop said:
I'm being thick: AGW?
Not sure where you got your cost estimate from, not that it matters, but somewhat out from the figures I've seen.
AGW = Anthropogenic Global WarmingNot sure where you got your cost estimate from, not that it matters, but somewhat out from the figures I've seen.
That cost estimate was from some website or video I watched a while ago, it was one figure of many though.
It's not going to be cheap as it's fecking huge and dangerous - have you any estimates?
I think they patched it up not so long ago:
Looking again at the Chernobyl pictures it does seem that we have nothing to fear from the Japanese ones, a meltdown almost seems small potatoes compared to this:
It is striking however that we have lived through a long period where a reactor goes 'pop' or 'fizz' often enough to keep the widespread adoption of nuclear power a matter of concern. This leads me to think that most of the 'bad press' is generated by the operators themselves in mis-handling or mis-designing those plants. For instance if the RMBK didn't have such a huge positive void coefficient (a defect 'ignored'/operated around until the disaster) and if TEPCO has not put their (backup) generators of the beach we'd be much better placed for power.
Interesting stuff. I expect diesel particulates have far more effect than radon, and smoking far more than that - very difficult to quantify.
I think some people are better build to withstand radiation too - susceptibilty appears to vary from person to person.
I was reading a couple of fascinating articles about what happens when you get too close to powerful sources, you probably know them already but I'll link them here for people who don't.
The first is the Goiania Accident, September 13, 1987, a piece of medical equipment is abandoned, for legal reasons it gets neglected and after a while someone steals it for scrap. Then a whole bunch of people are attracted to the glowing blue source and play with it and use it as body paint..
http://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
The second is the 'Demon core' a bunch of people playing around with a ball of plutonium and some beryllium hemispheres. Fun while it lasted but unbelievably cocky, Louis Slotin was balancing criticality by the wedging a flat screwdriver between the top neutron reflector and certain death. He slipped and got a fatal dose in probably under a second - he passed away 9 days after.
http://en.wikipedia.org/wiki/Demon_core
In Japan it looks like the temperature of Unit 1 is falling, the rest seems to be a game of pumping in water at the top and sucking it out of the bottom, I wonder how long it will be until they can so a proper survey of the pipework and joints.
I think some people are better build to withstand radiation too - susceptibilty appears to vary from person to person.
I was reading a couple of fascinating articles about what happens when you get too close to powerful sources, you probably know them already but I'll link them here for people who don't.
The first is the Goiania Accident, September 13, 1987, a piece of medical equipment is abandoned, for legal reasons it gets neglected and after a while someone steals it for scrap. Then a whole bunch of people are attracted to the glowing blue source and play with it and use it as body paint..
http://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
The second is the 'Demon core' a bunch of people playing around with a ball of plutonium and some beryllium hemispheres. Fun while it lasted but unbelievably cocky, Louis Slotin was balancing criticality by the wedging a flat screwdriver between the top neutron reflector and certain death. He slipped and got a fatal dose in probably under a second - he passed away 9 days after.
http://en.wikipedia.org/wiki/Demon_core
In Japan it looks like the temperature of Unit 1 is falling, the rest seems to be a game of pumping in water at the top and sucking it out of the bottom, I wonder how long it will be until they can so a proper survey of the pipework and joints.
From the IAEA:
http://www.slideshare.net/iaea/summary-of-reactor-...
Reactor 2's core is severely damaged (the worst there) and all three reactors still have rods half uncovered, so I guess the main progress is that time has passed and it's decayed a bit.
Containment integrity of 2 and 3 is 'damage suspected' and of 1 is unknown. Still no instrumentation at unit 3. All now have freshwater injection.
I wonder what the cores look like inside. Three mile island looked like this:
- worse than people expected (the picture is a sonar survey).
http://www.slideshare.net/iaea/summary-of-reactor-...
Reactor 2's core is severely damaged (the worst there) and all three reactors still have rods half uncovered, so I guess the main progress is that time has passed and it's decayed a bit.
Containment integrity of 2 and 3 is 'damage suspected' and of 1 is unknown. Still no instrumentation at unit 3. All now have freshwater injection.
I wonder what the cores look like inside. Three mile island looked like this:
- worse than people expected (the picture is a sonar survey).
http://rt.com/news/island-japans-radioactive-water...
Holes reported in #2 containment - I assume due to one of the large explosions at the site.
Reactor #1 is the only one intact now, because it's the only one holding pressure. Reactor #2 and #3 have cracks in the RPV and #2 in the outer containment too it seems.
I guess all those people saying how great the containment systems were are going to have to modify their world view of containment integrity when faced with the force of steam explosions.
I guess now concrete has failed (it probably had no time to set) expanding foam will be used. I suspect the manual on how-to-patch-up-a-failed-containment-during-a-meltdown has not been written yet..
They do not quote for all outlets but these seem high to me - due to mixing perhaps? Units 5 and 6 should have no radioactive output.
Holes reported in #2 containment - I assume due to one of the large explosions at the site.
Reactor #1 is the only one intact now, because it's the only one holding pressure. Reactor #2 and #3 have cracks in the RPV and #2 in the outer containment too it seems.
I guess all those people saying how great the containment systems were are going to have to modify their world view of containment integrity when faced with the force of steam explosions.
I guess now concrete has failed (it probably had no time to set) expanding foam will be used. I suspect the manual on how-to-patch-up-a-failed-containment-during-a-meltdown has not been written yet..
They do not quote for all outlets but these seem high to me - due to mixing perhaps? Units 5 and 6 should have no radioactive output.
IAEA said:
On the 30 March, 180 000 Bq/l of I-131 and 15 000 Bq/l of Cs -137 were detected in the vicinity of the discharge water outlet of Unit 4.
The data reported for 27th - 30th March indicated that the levels at 30 m from the common discharge point of Units 5 and 6 were relatively constant at 45 000 - 55 000 Bq/l for I-131 and 10 000 - 15 000 Bq/l for Cs-137.
The data reported for 27th - 30th March indicated that the levels at 30 m from the common discharge point of Units 5 and 6 were relatively constant at 45 000 - 55 000 Bq/l for I-131 and 10 000 - 15 000 Bq/l for Cs-137.
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.
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