Fukushima No. 1 loss of coolant due to earthquake
Fukushima No. 1 loss of coolant due to earthquake
(OP)
I'm sure we're all anxiously waiting for some technically accurate news, so if you hear anything credible, please post it here.
Latest report that I have says that the reactor is shutdown, but coolant pumps are not running because of the power outage and failure of their auxillary generator. 2800 people evacuated - is that just the plant workers, or is that civillians? The government says there is no leak, but residents within 3 km of the reactor were told to stay inside.
The quake also caused a conventional fire and leak at the Onagawa plant. I bet you most of us on this list don't care so much about that, so please leave those reports off this thread.
Does anybody know how well these plants can thermosiphon?
Latest report that I have says that the reactor is shutdown, but coolant pumps are not running because of the power outage and failure of their auxillary generator. 2800 people evacuated - is that just the plant workers, or is that civillians? The government says there is no leak, but residents within 3 km of the reactor were told to stay inside.
The quake also caused a conventional fire and leak at the Onagawa plant. I bet you most of us on this list don't care so much about that, so please leave those reports off this thread.
Does anybody know how well these plants can thermosiphon?





RE: Fukushima No. 1 loss of coolant due to earthquake
ht
And here's my personal favorite...
http
I bet they're running out of internet as well, we better ship some of that over too!
RE: Fukushima No. 1 loss of coolant due to earthquake
The pressure in the reactor is up 1.5 times the normal pressure.
The radiation is ?100? times the normal level.
The exclusion zone has bee increased from 6 to 10 kilometers.
None of the cooling towers are operating.
RE: Fukushima No. 1 loss of coolant due to earthquake
The evening news journalists are now discussing it as if they knew something about it. HA!
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
Regards,
Van
RE: Fukushima No. 1 loss of coolant due to earthquake
The most affected unit is Fukushima Dai-ichi unit #1. It is a 460 MW BWR reactor built in the 1960's. Some news reports also refer to unit #2, but the reports are very conflicting about that.
There is lots of confusion among reporters between the containment structure and the pressure vessel. One of those is over twice its normal operating pressure and very hot. They are venting gas or steam, but it is unclear whether it is being vented from the coolant loop into the atmosphere, from containment into the atmosphere, or from the coolant loop into containment.
Radiation levels in the control room are 1000 times normal, but the reporters don't say if this is irradiation or airborne contamination, or what "normal" is. But the plant is now doing rapid shift changes, so that gives you some idea. One report said 250-500 mrem/hr.
The evacuation zone has grown to a 3km radius, and the stay-in zone has grown to a 10km radius. There are multiple reports talking about dozens of ships and hundreds of planes being sent to help the nuclear accident, but I'm guessing that's really just part of the general earthquake relief effort.
I've tried to trim out the speculative stuff, but it's still hard at this stage.
RE: Fukushima No. 1 loss of coolant due to earthquake
Have been looking at those areal views showing the off gas towers. I climbed one to the top. I remember it being a white knuckle experience. Looks even taller now. That kind of prank would get me kicked out of the country today.
RE: Fukushima No. 1 loss of coolant due to earthquake
It gives status of each nuclear plant.
http://www.nisa.meti.go.jp/english/index.html
RE: Fukushima No. 1 loss of coolant due to earthquake
What really happens is that the emergency cooling system pumps are driven by the remaining steam from the plant. The motor operated valves in the system, and only those !, and the control systems are supplied from the batteries.(UPS systems)
When steam power runs out you will be in big trouble. That is why the emergency diesel generator sets must be back on line as soon as possible and the engineers at the plant are working hard on this.
RE: Fukushima No. 1 loss of coolant due to earthquake
There is still a stream of "experts" telling the news cameras that an explosion is impossible, that even the melting of fuel is impossible, and the media dutifully reports on it since every story must have two sides. But it sounds to me like the worst has happened.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
The earthquake hit at 14:46, local time.
World Nuclear News reports that the backup diesel generators started as planned, but failed an hour later.
A 10 m tall tsunami hit Sendai airport at 15:55 local time.
The Fukushami reactors are right on the coast according to Google maps, maybe 2-3 m above sea level.
So I would put money on the tsunami taking out the diesels.
RE: Fukushima No. 1 loss of coolant due to earthquake
USS Ronald Regan is headed over there and has the capability of providing power to on shore facilities. Wonder is that is the plan.
RE: Fukushima No. 1 loss of coolant due to earthquake
Radiolysis in a nuclear reactor normally produces hydrogen and oxygen, which is continuously burned by electric recombiners. A number of possible failures could cause the recombiners to fail or be insufficient, resulting in accumulation of hydrogen. Hydrogen explosions are a common feature of nuclear meltdown scenarios.
They flew in more than enough generators a long time ago, but the problem is that you need a lot of copper and some fast electricians to run lines that can carry megawatts of power to the pumps. They did not succeed.
They say the reactor core vessel is intact, but it's a BWR, and I'm guessing some of the coolant piping is damaged. They say core pressure is decreasing, which would be consistent with a coolant pipe leak. The core vessel is in a containment well below ground level. A possible contingency in this scenario would be to flood the well with ocean water and boric acid. Some people speculate that the boric acid would be the "coolant" that Hillary Clinton mentioned.
RE: Fukushima No. 1 loss of coolant due to earthquake
HAZOP at www.curryhydrocarbons.ca
RE: Fukushima No. 1 loss of coolant due to earthquake
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: Fukushima No. 1 loss of coolant due to earthquake
The hydrogen and oxygen itself gradually transmutes into radioactive isotopes by neutron capture while the reactor is running. The oxygen isotopes are all either stable or have very low half-life so they are not normally a health concern. The hydrogen isotope tritium has a half-life of 12 years, which is right in that sweet-spot that does the most damage if inhaled. But the tritium concentrations usually only reach hazardous levels in heavy water reactors, which the Fukushima reactor is not.
Tritium is lighter than air and floats away into space quickly, so fugitive emissions are normally not a concern. But if it recombines with oxygen or carbon, either through the explosion, fire, or just natural atmospheric recombination, the resulting water or hydrocarbon molecules are radioactive and easily absorbed into the body. There are regulations that limit how much that happens.
RE: Fukushima No. 1 loss of coolant due to earthquake
"there are regulations that limit how much that happens"- I think we may be past the effect of regulations by now, at this particular plant.
If the end result is a large plume of cesium contaminating downwind countries , or some other drastic result, it could have a huge impact on food supplies, cost of food, and reconsideration of continued operation of other similar reactors ( and that is a lot of installed capacity !).
If nothing else good comes out of this experience, other plants will need to learn from this event, and be modified accordingly, if feasible.
RE: Fukushima No. 1 loss of coolant due to earthquake
Wrote this on a separate, more political website for those (non-engineers) to read. Please extend your throughts.
Large amounts of Hydrogen - non-radioactive, regular but highly purified medium-pressure hydrogen gas at 35 to 50 psig - is used inside all of the medium to large generators worldwide to cool the inside of the generators from their electrical resistance to the 48,000 volt high-flow currents in the copper and iron. This hydrogen cooling system is supplied from large numbers of very high-pressure hydrogen bottle banks at 3000 - 3600 psig. (200+ bar, for you metric types.)
These hydrogen tanks are OUTSIDE the containment buildings - because they are non-radioactive and are a turbine building service system that does NOT connect to any reactor systems. The turbine, however, is lightly contaminated internally from residual particles deposited from the primary coolant because these power plants are boiling water reactors, and the turbines (not the primary coolant containment systems) ARE outside the containment concrete presssure-tight (blockhouse) domes.
If the high-pressure hydrogen tanks blew they would blow up like this (outside, with great dust blast and a sound wave) but the blast would NOT damage the reactor or the piping INSIDE the containment building. However, radioactive contamination to nearby injured workers is very likely. Any blast this size blows h*ll out of the turbine complex -> Ain't no power coming from this plant for a while.......
The small amount of hydrogen inside the containment dome that people were worried about at Three Mile Island WAS from decay and release of the melted fuel and decomposition of fuel element cladding. But the net pressure buildup from fission decay product gasses and this hydrogen inside the TMI dome was exaggerated at the time, and venting to relieve that pressure at TMI was the wrong decision by the government.
RE: Fukushima No. 1 loss of coolant due to earthquake
I haven't actually seen reports of hydrogen.
Regarding potential sources of hydrogen in the core, normal hydrolisis is not a big concern, but there is a zirconium-water reaction at high temperatures which can produce hydrogen.
See page 2 of 3 here
http://canteach.candu.org/library/20044507.pdf
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
I've looked at a lot of pictures and videos of the accident, before, during and after, and I am quite convinced that it is the reactor building that blew up. There are reports that the containment structure is unharmed, but I'm think that's just a product of the language barrier and non-technical reporters. And political bloggers spouting nonsense.
Maybe they mean the pressure vessel is intact, or maybe they just mean the containment well still holds water, which allows it to be flooded with ocean water and boric acid. But the "containment structure," in the sense that english-speaking nuclear engineers use the term, appears to have failed.
RE: Fukushima No. 1 loss of coolant due to earthquake
ABB has a whole range of these with the appropriate Gas Analyzer Systems for Hydrogen-cooled Alternators. Go to their site to find examples of these generators.
When you follow this link (copy/paste)
ht
or search with "cooling large generators" in Google you will find enough info on this subject.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
When they say the containment structure is unharmed, they are referring to the inner steel containment shell. Some reports I've read indicated the outer containment concrete was damaged, but the steel lining was still intact. In other words, the containment structure is still providing it's function of containing the atmosphere and maintaining pressure boundary so that any releases to the environment are done on purpose, to control containment pressure. The fact the containment pressure is higher than normal indicates the containment structure is working, though with less concrete reinforcement than designed.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
I still think it was the reactor building that blew up, not the turbine hall.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
above roof , any coloring could be a lense effect of hot gas ,
Hot Hydrogen will explode very suddenly mixed with Air .
This appears before Dust shoots out , from building collapse !
RE: Fukushima No. 1 loss of coolant due to earthquake
HAZOP at www.curryhydrocarbons.ca
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
well worth the read
http:
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
rmw
PS: ByrdJ, you seem to get out too much :)
RE: Fukushima No. 1 loss of coolant due to earthquake
ht
RE: Fukushima No. 1 loss of coolant due to earthquake
Being somewhat familar with a BWR plant, I find fermi's discriptions to be accurate
RE: Fukushima No. 1 loss of coolant due to earthquake
http://ww
The nuclear accident has claimed its first fatality. A different worker has received a dose of 10.6 rem.
They're saying that the outer concrete building does not act as containment. There's another concrete containment structure nested inside it that is still standing. They have a couple of nice diagrams of it.
RE: Fukushima No. 1 loss of coolant due to earthquake
byrdJ, Whew..... I never knew who she was, but I was worried that you might be a fan..... :) LOL
I am afraid that overall this is strike 3 for Nuclear power in the USA. Maybe not elsewhere in the world, but here, sorry, but yes. TMI was strike 1, Chernoyble strike 2, and this is probably the end of Nuclear power as a generally accepted form of power generation for as long as any of us will live to see it. The sierra clubbies must be dancing in the street.
As an engineer, I hate it, but that is reality with our fickle public and their ability to be manipulated by the media.
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
http://en.wikipedia.org/wiki/Sievert
If my math is right, the hourly dose at the site boundary would be
500 uS * 1E-6 S / (uS) * 100Rem/S = 0.05 Rem/hr = 50 mRem/hr
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
What is a reference level... similar to a design limit?
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
Guess he never heard of fission products. Amazing.
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
Nice link.
I read a lot of Fermi's stuff, but most of it is based on normal procedures and that includes normal emergency procedures.
I tripped a power plant once and put a whole (islanded) city in the black and one take-away I will never forget is how helpless the plant was with no power.
Yes, the DC pumps protected the turbine as it coasted down, and yes, I had a boiler full of steam (every safety on the blasted thing was screaming), and yes, there was air (while it lasted), but there was no cooling water and with no heat sink, I couldn't use the steam to drive anything even if I could have manipulated the valves. The air didn't last long enough for the operators to dash next door and get the stand-by combustion turbine (black start - air) cranked.
The city didn't begin to recover until a portabale trailer mounted trailer mounted compressor owned by the sewer dep't was brought in to provide air to start the standby CT. The situation in Japan is much more complicated than that.
I make the above point to say that once the auxiliary generators are defunct all bets are off and normal emergency procedures are out the door.
Who knows what is really going on in the hell that is their world right now?
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
It is truly amazing they can't do better than that.
As a small proof of this circus, I took a picture of my TV (attached). You can see one of the two banners at the bottom reads "Bill Nye: Cesium is used to slow and control nuclear reactions".
By the way it is true that Cesium does absorb some neutrons, but it's not like it's something that is built into the reactor ("used") and certainly not part of the control rods. It is a fission product which appears as a result of nuclear fission. There would be some trace amounts present in the coolant of even a healthy reactor, and if fuel cladding is breached, then much more.
I'd love to find a link to that interview on youtube. It has not much information value but a whole lot of entertainment video.
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
rmw,
I shutdown anywhere 1 to 5 power boilers several times, with radiation. My deeds were th prelude to Con Edison's loos Big Bertha.
RE: Fukushima No. 1 loss of coolant due to earthquake
http://www
If they follow the same pattern as the last two articles, they'll be updating this every couple of hours.
RE: Fukushima No. 1 loss of coolant due to earthquake
http
If you compare to this diagram, it looks like the crane deck is gone, but the concrete is largely still standing:
http://
RE: Fukushima No. 1 loss of coolant due to earthquake
http://en.
And further, could it be that the SoS Hillary Clinton referred to helping the Japanese out with Borid Acid when she referred some time ago that the US would sent "coolant" to Japan?
RE: Fukushima No. 1 loss of coolant due to earthquake
#3 is going through the same cycle as #1 and they are mentioning possible H2 explosion as happened in #1.
Lets hope the #3 outer building is frangible like #1. I pickup that the the failure mode of the building was not d design, but a happening.
How effective is Boric Acid compared to Metallic Boron. They used Boron Metal at Chernobyl as the melted core was exposed.
RE: Fukushima No. 1 loss of coolant due to earthquake
HAZOP at www.curryhydrocarbons.ca
RE: Fukushima No. 1 loss of coolant due to earthquake
[*]Anti-nukes will say it proves nuclear power is dangerous.
[*]Pro-nukes will say look at how superbly the reactors did absorbing the most severe one-two punch imaginable, with only a very modest release of radioactivity... and that release was intentional to reduce pressure to preserve integrity of the containment pressure boundary.
Neither will mean much until the unit is stable and we understand the full extent of any release and we have a full understanding of what happened.
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
http://
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: Fukushima No. 1 loss of coolant due to earthquake
I have marked the "after" screen shot and added a picture of the plant in side view and have attached these to this message.
What you can see on the "after" picture is that the water did not go very far on land at the plant as there is a large raised area behind the plant which must be about 10m. I have marked the max waterlevel on the road. Most of the waves will have been disolved by the breakers in front of the plant and the structures in front which are badly damaged as you can see. Notice the parking lot on the top left of the picture which on the "after" is full of cars. I have also included a "before" and "after" screen shot of the village just north of the plant which is heart breaking to see when you think how many people must have died there.
RE: Fukushima No. 1 loss of coolant due to earthquake
Regards,
Van
RE: Fukushima No. 1 loss of coolant due to earthquake
CNN just reported an explosion at no 3. I found a brief mention here:
http://twitter.com/REUTERSFLASH
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
http://ww
RE: Fukushima No. 1 loss of coolant due to earthquake
IAEA reports an explosion at unit 3.
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: Fukushima No. 1 loss of coolant due to earthquake
I am sure to the public that conjures up an image of the "explosion" having ripped the containment vessel assunder and there are the fuel rods exposed to the open air like a gutted deer carcass.
I don't think the public will be able to understand the sensationalism vs. what is actually going on. Another nail in the coffin.
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
The reactors are BWRs -- they have a steel containment building surrounded by a concrete/sheet metal reactor building. From the TV pictures, it appears that the reactor buildings for Units 1 and 3 have been damaged. However, from the various descriptions, it doesn't sound like the containment buildings are damaged.
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
Assuming the media got it partially correct : Where does the hydrogen that caused the explosions come from, a corrosion reaction ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
http://w
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
http://ansnuclearcafe.org/
Richard www.6sproductivitycom.com
RE: Fukushima No. 1 loss of coolant due to earthquake
http:
Blacksmith37- What do you prefer instead- Aluminium, Lead or Magnesium which are comparable or better metals for neutron cross section?
RE: Fukushima No. 1 loss of coolant due to earthquake
ht
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
NHK stated that this last explosion was the second one in @2 reactor.
RE: Fukushima No. 1 loss of coolant due to earthquake
percentages of each but the phrase a substantial amount of lutonium was present. This fue lsi only ussed in @2 reactor.
RE: Fukushima No. 1 loss of coolant due to earthquake
There's a lot that is getting lost in translation. These plants don't have suppression or containment pools (they have torii).
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
ht
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
http://www.nrc.gov/reactors/generic-bwr.pdf
Here's the site for the Japan Nuclear and Industrial Safety Agency and their press releases. They give a lot of technical information about radiation levels and plant parameters.
http://www.nisa.meti.go.jp/english/
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
Fukushima Daiichi Unit #1 (439 MWe):
http://ww
Fukushima Daiichi Unit #2 (760 MWe):
http://ww
Fukushima Daiichi Unit #3 (760 MWe):
http://ww
RE: Fukushima No. 1 loss of coolant due to earthquake
I hope a less serious comment will not be frowned upon. It is after all pi day.
For anyone who wants a chuckle courtesy of Bill Nye (bless his heart) and CNN, see the video at 4:40 to 5:30 and at 9:45 here:
http://www.youtube.com/watch?v=af-41E5mndk
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
http:
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
At the risk of removing any doubt about my intelligence for any that were wondering, I am going to ask a couple of things about this whole mess. But first, EP, I really wish I could go to that you-tube video but that is blocked on our network here at work. I really could use a chuckle. This whole thing is making me sick.
Ok the questions: Assuming the reactor vessel is not breached and containing all the neutrons, is there a possibility in the event of a complete fuel meltdown into one big "puddle" creating a fission explosion? I guess is there sufficient quantity of fuel there to attain critical mass? Seems to me I read a long time ago that if you were to put 110 lbs of U235 in a lead box and put a lid on it, it would go critical almost instantly and boom....Please dont hold me to that amount and that element, just the concept. It was a very long time ago.
Also, does anybody know what created that fire in unit 4? All I get from the news sites is speculation.
Thanks in advance
Scott
I really am a good egg, I'm just a little scrambled!
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
First part is what is know as the TEPCO scandals in Japan.
Time line on the Fukushima Nuclear Plant.
ht
http:
I understand that these reactors are Light Water Reactors which are not the same as the BWR reactors in the US.
RE: Fukushima No. 1 loss of coolant due to earthquake
I will not give you an outright "no" to a fission explosion because there is room to get tripped up in definitions. Spontaneous fission is still occurring, and that is what is producing all that heat and pressure and hydrogen. So fission is indirectly responsible for those hydrogen explosions, and might also cause a pressure explosion. But there is no risk of a meltdown causing criticality and restarting a chain reaction, which is what a true nuclear explosion would be.
As to Cloa's comment, the control rods at Fukushima Dai-ichi unit #1 are boron carbide and hafnium. I believe they would float on top of the uranium in the event of a meltdown, so they would not be effective. Past accidents, such as at Chernobyl, have taught us that pure carbon is an undesirable material in a reactor.
RE: Fukushima No. 1 loss of coolant due to earthquake
http://w
The good news: It seems the fire was at unit 4, and is out, not a concern.
The bad news: There remains big concern for the failure of the unit 2 torus:
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
Would it be something like 3 times Tchernobyl in the case of the worst scenario possible?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
Now, my question is about the radiation levels at the plant. These 50 or so workers are being exposed to what I believe is a lethal dosage of radiation. Is the PPE they have sufficient to protect them from harm or are they already walking(working)dead? If so, what would be the maximum levels that they could safely work in with the proper PPE? A personal example is my arc flash protection I wear, it is rated for an 8 calorie blast, so I stay out of panels where there is potential for greater than that. Believe me, I have no desire to be in an 8 Cal blast either, but that is where my protection stops. We are not issued the 40 calorie "space suits" at my plant.
One more question if I may. What kind of radiation is this? Alpha, beta, gamma and how fast does it travel a given distance (when not propelled by an explosion)? I believe that if it were xray or gamma, it would travel at speed of light. Please correct me on all of this as you see fit.
Once again, thanks to all of you for your responses.
Scott
I really am a good egg, I'm just a little scrambled!
RE: Fukushima No. 1 loss of coolant due to earthquake
"Four hundred times more radioactive material was released than had been by the atomic bombing of Hiroshima. However, compared to the total amount released by nuclear weapons testing during the 1950s and 1960s, the Chernobyl disaster released 100 to 1000 times less radioactivity. The fallout was detected over all of Europe except for the Iberian Peninsula.
The initial evidence that a major release of radioactive material was affecting other countries came not from Soviet sources, but from Sweden, where on the morning of 28 April workers at the Forsmark Nuclear Power Plant (approximately 1,100 km (680 mi) from the Chernobyl site) were found to have radioactive particles on their clothes"
unquoted
So yes definitely I want to roughly compare to figure out the environmental and Health potential consequence of Fukushima.
By Nuclear Fuel I mean combustible or Nuclear Materials. Sorry for my english I am not native english speaker.
RE: Fukushima No. 1 loss of coolant due to earthquake
As I understand, it is now possible to treat some exposures that were at one time considered lethal.
RE: Fukushima No. 1 loss of coolant due to earthquake
Here are links to digital globe that has excellent images from after the latest explosion at reactor 3. The damage to this building seems more extensive then to the building of reactor 1 after the explosion there.
htt
h
The 50 or so operators/engineers/staff (from the 800 normal) that remain in the plant have an impossible task. With the levels of radiation present they should be out of the place within 30min but 2 hours max. When they don't they will get radiation sickness and die. They can hardly cope with all the new incidents like the fire in the building of reactor 4. (which was already shut down over a longer period). When the operators are forced to leave the plant will be on its own and.......
Think of this: when you go for nuclear energy you should be able to maintain a high level of security, technical know how and safe storage of spent nuclear fuel for at least the next 10.000 year. Now take the 10.000 year and flip that back to the past and imagine where you are. (You will end up way before the Egyptian dynasties)
RE: Fukushima No. 1 loss of coolant due to earthquake
These reactor are General Electric Mark I reactors. There are 23 of these in the US.
RE: Fukushima No. 1 loss of coolant due to earthquake
Please don't be shy; it wasn't a stupid question. You can look further up through this thread to see a stupid answer on my part, and that's much worse.
Radiation is probably the most complex hazard that humans work with, so it's very hard to give simple answers. To start with, there are two broad types of radiation exposure: internal, for example breathing in radioactive dust, or external, like getting a sunburn from solar irradiation. The suits they wear provide protection against internal contamination but do little against external irradiation. The suits themselves are useful against almost any level of contamination, but their effectiveness depends primarily on the work practices of the user. For example, forgetting to shave can make your respirator ineffective. Carelessness while changing out of them can send surface contaminants airborne where you can breathe them. Your level of radiation protection training is the number one thing that determines what level of radiation you can work with safely, not the quality of the suit.
It's hard to tell how much dose the workers have received. There have been a variety of numbers and statements published by the press that are completely inconsistent and can only be explained as journalistic errors. As best as I could gather as of March 14th, somewhere between zero and four workers may have received a lethal dose. One of those was physically trapped and may have died from conventional causes long before the radiation got him. The other three, if the reports are accurate, are being treated. I have not seen nearly enough information for further medical prognosis, either positive or negative.
I suspect that most of the workers on site are receiving doses well in excess of occupational limits but far below lethal levels. Any amount of radiation will increase your lifetime risk of cancer proportional to the does you take. The highest dose number I have seen so far was 106,000 microsieverts, which carries with it a 0.6% chance of cancer and other health effects. But there may be other numbers I haven't seen, and the situation is still deteriorating. Please check the FAQ section later, and I will try to address this.
Alpha, beta and gamma radiation are all present in this accident. All of them travel at the speed of light, but they get weaker with distance. (Alpha and beta are actually slightly slower, but not by much.) The particles, droplets and gases that emit this radiation travel at whatever speed the wind or water currents will take them. You can probably see that this is a really complicated problem.
RE: Fukushima No. 1 loss of coolant due to earthquake
With the recent escalation of events, do we need to consider the risk to the spent fuel bays? According to the diagram, spent fuel is stored within the reactor building secondary containment; is this correct? This is the part of the building that blew up on units 1 and 3, leaving those bays exposed to the atmosphere. Spent nuclear fuel needs to be kept underwater and cooled for a few years after removing from the reactor. If those pools drain or evaporate off their water, the zirconium cladding on the spent fuel can catch fire. Is this what happened in unit 4? How much fuel would be in those bays?
RE: Fukushima No. 1 loss of coolant due to earthquake
So much for safe storage of spent fuel rods.
RE: Fukushima No. 1 loss of coolant due to earthquake
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fukushima No. 1 loss of coolant due to earthquake
http://www.nirs.org/factsheets/bwrfact.htm
RE: Fukushima No. 1 loss of coolant due to earthquake
According to the media, the earthquake alarm tripped these reactors into shutdown mode, or some of them and one was down for maintenance.
The problem, we are told, is that the Tsunami damaged the diesel generators and the batteries were unable to cope.
Is there something more? It seems to me that even if the generators were wiped out, portable generators could be brought in within the time frame here and since this is a coastal station which receives much of its supplies and equipment by sea, the suggestion has been that ships docking there could provide power though it might take some doing to jury rig a connection.
So I have to think that the generator failure is not the primary problem.
So OK, the control rooms are damaged, but the first objective is tor restore water circulation... so it is a matter of powering some pumps and valves.
At the moment they are said to be flooding the reactors with sea water... they've power for that but are they flooding the reactors or simply pouring water over the containment? (which suggests the cooling water installation has suffered something else?)
Need to replace pumps? Airlift in.
So something in the media doesn't gell. It may well be my understanding.
So what am I missing?
JMW
www.ViscoAnalyser.com
RE: Fukushima No. 1 loss of coolant due to earthquake
We will likely need to wait for the "root cause analysis report" that would be issued maybe a year from now to have something more reliable than guesses. And the publically available version will likely be edited in some manner, but that is the price we pay everyday, for "consensus'.
Some reports claim the diesels were taken out by water contamination of the fuel- which would also likely damage the fuel injectors. Other possiblities include water entering the snorkel air intake.
The pumps and motors may use seal water, normally assumed to be filtered clean fresh water, and that assumption may have been violated and now whaterver the seal water or cooling water had contaced is likely fouled/ damaged by salt water / debris contamination.seized bearing etc follows quickly.
But one thing we can be certain- everyone involved is working at max dedication to solve this ASAP, and it is best to give them whatever support they need to succeed.
RE: Fukushima No. 1 loss of coolant due to earthquake
htt
RE: Fukushima No. 1 loss of coolant due to earthquake
(Disclaimer: what follows is from my Navy career which ended many years ago. I believe it to still be current)
To put that in perspective, the occupational limit in the US nuclear industry is 3,000 mrem (30,000 microsieverts) per quarter or 5,000 mrem (50,000 microsieverts) per year. This is based on a presumed "safe" level that does not add substantially to long-term cancer risks.
The Navy's limits when I was in were 300 mrem (3000 microsieverts) per quarter or 500 mrem (5000 microsieverts) per year.
Acute physical damage starts to occur at short-term exposure levels in the 50-100 rem (500,000-1,000,000 microsieverts) range. If the exposure level rises to 300-500 rem (3,000,000-5,000,000 microsieverts) the short-term survival odds drop to 50% or less..
At Fukushima, they reported a spike to 822 mrem (8217 microsieverts) at the perimeter, then decreasing to some level markedly lower. A worker would exceed his/her quarterly exposure limit in about four hours in that environment.
What we don't know is the source of the radiation. The significant decline indicates (to me) that it originated from a point source rather than area contamination. If it was from a point source, the exposure levels closer to the source go up as the square of the distance. If that is the case, workers nearer to the source will exceed their limit that much quicker.
It is possible that reducing the number of workers on site is a measure intended to miinimize exposure.
In any case, our hearts must go out to the workers at that site. They have suffered personal losses like everyone else who lives in the surrounding area, yet they are at work trying to keep a bad situation from becoming much worse.
Kevin Snyder
SW2010 x64 SP3
Win 7 Pro
Core2 Quad Q6600 2.4Ghz 8Gb
NVIDIA Quadro FX570
3D Connexion SpacePilot Pro
RE: Fukushima No. 1 loss of coolant due to earthquake
Yes you are missing something here: As I posted in the OilDrum thread, is that the auxiliary station service electrical supply was wiped out by the Tsunami, that is all the electrical equipment at a an elevation of few meters above Sea Level was flooded out by corrosive salt water, and was therefore rendered inoperable, and could not be re-energized from whatever source.
We are talking of 4.16 KV systems (possibly 6KV), 480V, and lower voltage systems. The outdoor sea water pumps. plainly visible in the aerial views. on all 4 units were flooded out, as well as the Diesels (several MW) and even the two fuel tanks for the Diesel station were carried away.
Al electrical equipment was rendered useless, instantaneously, that was flooded out by salt water. Unrepairable. Only replaceable.
Even the reportably "brought in gensets" could not be connected to the existing (ruined) switchgear.
Evidently some other MV large motors (feed pumps?) were also flooded out and were therefore made uselass, rendering the reactors without any cooling supply. This is conjecture on my part, not having seen any any elevation drawings or one-line electrical diagrams of the station. Such information would be useful in further analysis of the situation.
rasevskii
RE: Fukushima No. 1 loss of coolant due to earthquake
In this rather lengthy paper there drawing of the different Pressure Suppression water system on the reactor..
The case is thus or somewhat similar:
POGO
ht
RE: Fukushima No. 1 loss of coolant due to earthquake
Would anyone venture a guess what's going on with this fire in unit 4?
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
I can take a guess, but I'd rather hear someone else guess what this represents.
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
There was some Congressman on TV calling for all the US nuclear plants to be shutdown.
If I could only harvest all the hot going out today I could run a very big turbine. I've come to the conclusion that a bow tie makes one an expert.
Also today an expert said shutdown the nukes and use a renewable energy source, natural gas and others. He wouldn't name the others.
A person stated that all we needed was a smart electrical grid which would replace the Nukes. I've seen some numbers on a smart grid but nothing like the 20% from nukes.
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
"On Wednesday morning, the Japanese government raised the permitted radiation exposure for plant workers by 2.5 times to allow them to work longer, according to NHK TV".
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
htt
I know 130kev = 0.13MeV is a fairly low energy gamma compared to certain like the N-16 6 MeV gamma. Are most fission product gammas also above 0.13 mev (?)
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
http://w
RE: Fukushima No. 1 loss of coolant due to earthquake
Radiation suits protect primarily against internal radiation exposures, although it does also block external alpha and beta. Personal protection against external gamma is generally not worth the weight. See my radiation protection thread for an explanation of the difference between internal and external exposure.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
Reports continue to say "injecting sea water".
The pressure vessel was full of water to start with. So where is all this water going?
There was some venting of steam, but how much water could that account for?
RE: Fukushima No. 1 loss of coolant due to earthquake
Each unit is specially designed to be easily transported by C-17 military aircraft and all members of the 249th are fully trained on their operation and service.
Wonder why these units are not deployed there?
RE: Fukushima No. 1 loss of coolant due to earthquake
Suppose the control of the situation is lost, and all reactors are lost with all nuclear material releasing radiations to atmosphere making a whole area of 500 km diameter having no more acceptable levels of radiation for any human being.
Question is : who will keep operating the remaning nuclear facilities in the affected critical 500 km area? are theses facilities equipped to withstand fulong shutdown period full autonomous mode?
RE: Fukushima No. 1 loss of coolant due to earthquake
guizmy, I am not aware of any plausible scenario where a 500 km evacuation zone would be warranted for civillians, and a similar sized evacuation zone for nuclear workers is ludicrous. The appearance of Godzilla would seem more likely to me.
guizmy's second question is interesting, but I do not know the answer.
RE: Fukushima No. 1 loss of coolant due to earthquake
There appears to be a complete news blackout on the detailed status of anything at Fukushima. Some reports say that the workers are operating in complete station blackout conditions. It may be too late in any case for more generators to be sent in. I think that we have been talking about a complete loss of all station service due salt water intrusion into all equipment at near seawater level.
That would have been 4.16 KV (or 6Kv) and all lower voltage level equipment that was lost.
It is obvious that the outdoor seawater pump motors were all flooded out, and the Diesels in a building near the lower right had the same fate. Imagine the damage as the salt water flooded into the energized and operating plant...
In any case two fuel tanks seen in the Before views were not there in the After views.
Latest reports talk of reduced staff due high radiation levels.
BTW what KW are these Diesels that you refurbished? Are they 4160 60HZ or reconnectable for 50Hz and other voltage...(unless that is secret of course.) You said 5KV, was that a typo?
Obviously detailed incident info belongs to the plant owner, as would be in any organization. We can only conjecture based on our field experience in similar installations.
rasevskii
RE: Fukushima No. 1 loss of coolant due to earthquake
You can access all the press releases at this website:
http://www.nisa.meti.go.jp/english/
There have obviously been communication failures, but I'm guessing that the workers on site are a little to busy to do interviews right now.
RE: Fukushima No. 1 loss of coolant due to earthquake
I get the feeling that the reason there is not any emergency power hooked up by now is Japan has not accepted the help? Matter of national pride maybe? I can't be the only guy with the means to do this sort of thing. The Ronald Regan is steaming off the coast and I would think they have the capabilities to do this sort of thing. Haliburton? FEMA? Someone?
RE: Fukushima No. 1 loss of coolant due to earthquake
Sorry, I should not have said that. I was thinking only of the electrical side. Thanks for the link. I had not seen that before.
rasevskii
RE: Fukushima No. 1 loss of coolant due to earthquake
And yes, bringing in helicopters to fight a fire was certainly envisioned long ago. They are frequently used in conventional fires, they were used in Chernobyl, and I myself had speculative conversations about them with some of my peers on the very day of the earthquake. I'm sure I wasn't alone, and the mission plans would have been drawn up long ago, just in case.
Communication needs to be better than this, it's true! I think most nuclear professionals understand the need for accuracy and completeness of information. That's why I'm here on this forum trying to help in my own way. But I also think some of the difficulties can be attributed to language barriers, journalistic errors, and outside factors related to the earthquake and tsunami.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
Am I reading this wrong, or is this yoyo saying that cesium and iodine do NOT harm the body?
Scott
I really am a good egg, I'm just a little scrambled!
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
Thanks for this link:
http://www.nisa.meti.go.jp/english/
Very informative.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fukushima No. 1 loss of coolant due to earthquake
I apologize if this post seems harsh, but I am just a little tired of vague details, speculation, and conjecture that I am getting from public sources, not including this forum of course. The links here are the best yet. And, I guess I am tired as well....these 7-12's are wearing on me. Once again, SORRY.
Good night for now,
Scott
I really am a good egg, I'm just a little scrambled!
RE: Fukushima No. 1 loss of coolant due to earthquake
You are not the only one that poses the same questions about how much CMA, large scale, is going on. I was listening to a Professor from MIT discuss the same problem about the available information and who is privy to it. He hit the IAEA very hard because as of yesterday they were not involved in any form and had no people in the loop. He also didn't like the position of the NRC for their comments, like we have it under review and so on. Whether this was by design or circumstance, that is the question. This type behaviour reminds me of the many times while working on problem or project when things start to go wrong in any sense there is nobody to be found. Let things turn around and get on track you have a hell of a time getting a seat on the front row.
As you state I too personally think that the information has not been updated and transparent as it needs to be. Whether or not a person can participate in the resolution of the problem materially is not the issue, but for people in the Nuclear Industry first hand information could be very valuable in any event going forward. If a person is skilled and dedicated in their job they act like a tickler file going forward. I can't count the times a short remark about a previous event turns on the light. The problem now is no one outside the circle will get the actual scenario of the event, only the opinions by one given in very sanitized version.
My favorite example of a dedicated employee was a Continuous Polymerization process operator who was cognizant of everything that went on around her while on the job. Though not officially in the loop her comments about a series of events prior to a particular failure were about 90% of resolving the problem. How she worked was shown one day when she ask me what was the purpose of that metal tag sticking through the insulation on pressure vessels the only person who ask me that question in 40 yeas working around them.
RE: Fukushima No. 1 loss of coolant due to earthquake
It would also help if the electric utility had been able to provide someone who could translate the technical stuff for the journalists and politicians. When you get to the point where the prime minister exclaims "What the hell is going on?" on national TV, I think it's clear that TEPCO bears some responsibility for inadequate communications.
RE: Fukushima No. 1 loss of coolant due to earthquake
htt
There is zero containment around this fuel which was removed from the reactor #4 in December and stored in a giant open air swimming pool in the building that has been destroyed by a hydrogen explosion.
RE: Fukushima No. 1 loss of coolant due to earthquake
http:/
RE: Fukushima No. 1 loss of coolant due to earthquake
The situation at Fukushima is now going completely out of hand with high levels of radiation which even prevent high flying choppers to release their loads of water.
The US is now sending an unmanned robot plane that can hover above the plant to get a good look inside to see the condition. Hope the electronics of that plane can handle the radiation levels.
In the meantime Japan is loosing so much electrical power due to the damages and shutdowns of various other plants that a total black-out of large cities like Tokyo gets closer and closer. The Japanese Governement has urged citizens to cut down on electricity.
In the north, like from Sendai, people are massively escaping the threat of a nuclear dissaster. At the moment the wind is more or less from the west (off land) but when that turns to north-east people living in the larger Tokyo area will be in big trouble.
htt
RE: Fukushima No. 1 loss of coolant due to earthquake
Just a thought...
RE: Fukushima No. 1 loss of coolant due to earthquake
The choppers would have to fly really low in order to dump their water (or other substance) accurately. And it seems plausible that the radiation beams and plumes of smoke would be much stronger in the vertical direction, through a missing roof, than horizontally through thick concrete walls. It means that an important contingency is unavailable, but there are others.
If the wind shifts, that may increase internal exposure hazards. In the worst-case scenarios, that may contribute to a statistical rise in the incidence of cancers and other health effects in the coming years. This rise would likely only be detectable through epidemiological studies. It is too early to quantify the harm, but it is conceivable that the power shortages might wind up having more significant public health effects than the radiation.
RE: Fukushima No. 1 loss of coolant due to earthquake
There are now 130 new personel at the plant, nuclear experts, engineers, rescue, military.
Several fire trucks are pumping water into the spent fuel pool and the best news, they have restored one of the emergency diesels so they now have power to the pumps to cool the cores. Unless something unexpected happens, it looks like the worst is behind us.
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
I would guess that the zirconium oxide coating (where intact) would be resistant, not sure about bare zirconium or other metals exposed to this brine solution. No one is worried about a crud burst here, or long term effects. But are there short term aggressive corrosion vectors that could come into play? (I hope not, and hope this is a rhetorical question)
I don't remember much of my reactor plant chemistry from when I was in the Navy, but chloride concentrations in the ppm range made us go ballistic as far as the secondary side of the steam generators were concerned (because of chloride pitting of the stainless steel tubes). The appropriate measurement unit for chlorides in the Fukushima plants is probably close to pounds per gallon...
Kevin Snyder
SW2010 x64 SP3
Win 7 Pro
Core2 Quad Q6600 2.4Ghz 8Gb
NVIDIA Quadro FX570
3D Connexion SpacePilot Pro
RE: Fukushima No. 1 loss of coolant due to earthquake
What's needed is access, assessment, disassembly, repair, re-assembly, and testing of connections, doors, debris field, piping and tubing.
Can't do that robotically. Pulling even an empty 2-inch 50 mm) hose through a debris-filled corridor with even only one or two twists or bends will require several hundreds pounds of force - no small robot can do that.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
The US has officially told the Japanese that we are not receiving enough information. This report also stated part of the problem was Japanese trying DIY on the event and failed miserably. Supposedly the reason that the pumps were not brought in earlier is part of the DIY syndrome.
The sowed some closeup pictures of the reactors and the damage is more than just a little or only this or that was damaged.
RE: Fukushima No. 1 loss of coolant due to earthquake
I was just curious.
I'll bet aux turbines are built on the turbine deck in future seaside Nuke plants, especially in earthquake prone zones.
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
Great big things. Size of a house. I don't remember the manufacturer anymore.
You might put a turbine genset on the main turbine deck, but you'd have to be crazy to put one of these up there. You'd shake things to pieces.
RE: Fukushima No. 1 loss of coolant due to earthquake
And, foundations can be designed to isolate vibrations. I just spent a week on a cruse ship and if I hadn't other wise known that there were some massive recip diesels driving the gen sets, I never would have known by feeling vibrations transmitted through the hull.
They certainly have some pretty massive other pieces of equipment on the turbine deck - again thinking of main turbine-generators and at times the turbine driven BFP's.
I think it can be done.
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
htt
RE: Fukushima No. 1 loss of coolant due to earthquake
htt
RE: Fukushima No. 1 loss of coolant due to earthquake
The load pickup schedule is very fast. If I remember correctly first load was picked up in lless than 9 seconds. The cooling system is continually heated and lube oil is circulating all the time.
There would be dual seperate compressed air starters with air injected into the cylinders. Combustion turbines can't start that fast.
RE: Fukushima No. 1 loss of coolant due to earthquake
How do they get around that fast start requirement?
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
rmw
RE: Fukushima No. 1 loss of coolant due to earthquake
I don't think anyone has linked this before- as well as nuclear risks there is a bit of presentation on Fukushima's present state and while fission due to plutonium pooling was stated as a possibility, that possibility is now discounted as the dangerous fuel rods seem to have collapsed (with no nuclear explosion) so a fission reaction is unlikely. The expert says that a final solution for Fukushima is going to be difficult, a salt pile is growing in the reactors, there is a lot of debris and top access is difficult with the heavy radiation so covering the top is difficult. It might need explosives to allow the rods to fall lower. Fortunately military helicopters are getting close now to water bomb, Japanese are accepting international assistance. Maybe a few more helicopter could clean it up a bit and cover the top.
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
HAZOP at www.curryhydrocarbons.ca
RE: Fukushima No. 1 loss of coolant due to earthquake
My plant here in Ontario has 4, 15,000 KW non seismic all with separate fuel source and 2 CTs for emergency that are seismic and 5MW each
RE: Fukushima No. 1 loss of coolant due to earthquake
frankiee - CT's but no DG's? How fast do the CT's start up?
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
http://ww
Some rough calculations suggest the numbers are big enough to kill you by acute radiation poisoning within days if you drink an undiluted sip.
RE: Fukushima No. 1 loss of coolant due to earthquake
It seems like we should be able to draw some conclusions from examining the isotopes. For example if one plant has higher long-lived isotopes, that favors spent fuel pool as a source while if one has higher short-lived isotopes, that favors reactor as a source. But at first glance, I didn't see any simple pattern like that.
I looked for the highest concentration of anything on the chart. Looks like Unit 2 I134 at 2.9E9y Bq/cm3 and a half-life of only 53 minutes. With such a short half-life, that can't be left over from power operation... must be a decay daughter. What decay chain gives us I134?
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
http://w
So you would actually have to drink a tumbler or so of the stuff to guarantee death. Or go wading through it for a few hours.
I've got to say I'm relieved. Not because of the toxicity level, but because the presence of any significant amount of I-134 would have indicated very bad stuff about the internal state of that reactor.
RE: Fukushima No. 1 loss of coolant due to earthquake
The reports of rain showing radioactivity got me to thinking about what levels of radioactivity were seen in rainwater during the atmospheric testing era. In reality it may not have been measured design as the instrument's of the day with any accuracy were lab instruments and quite bulky. For measuring low levels of radioactivity the "Cutie Pie"" was about the only thing outside the labs. I remember going to class on the operation of the meter we were told to always keep the polyethylene cap on the meter due to high levels of Beta Radiation occasionally seen.
RE: Fukushima No. 1 loss of coolant due to earthquake
What limit?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
Iodine-134 only has a half-life of 53 minutes, and it is not a decay daughter of any long-life fission product. Therefore the presence of iodine-134, if it had been real, would have indicated that the reactor resumed criticality in the last few days, and/or that some new physics was taking place. Very unexpected and very bad. But it was just a lab error.
RE: Fukushima No. 1 loss of coolant due to earthquake
http://www
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
Earlier I saw some news agency's cartoon animation showing that the drywell had been flooded, but discounted it in light of a preponderance of reports suggesting that seawater was being introduced to the reactor vessel only.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
How can you determine that fuel has melted through the reactor vessel based on radiation levels?
What does the RPV provide 4" steel = 1/10 thickness?
Does anyone know the contact raditation reading for a spent fuel bundel out of water?
Could abnormal radiation levels occur due to a shift in the fuel when it melted to the bottom of the vessel?
What about the CRDM's and the undervessel support structure?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
Whoops, I was wrong ....you were right. 2" of lead of 4" of steel or 24" of water is about a tenth thickness.
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
External gamma shielding basically comes down to mass - a pound of tungsten provides no more protection than a pound of lead. Some applications use tungsten because it's denser, non-toxic and can somehow be mixed more easily with flexible plastics. No doubt there exists some tungsten aprons out there, but that weight would still slow you down too much to be useful. Better to get your job done quickly and get out of the radiation field. Also, lead aprons can become contaminated and carry the contamination around with you.
RE: Fukushima No. 1 loss of coolant due to earthquake
http
http://www.tepco.co.jp/en/news/110311/index-e.html
Lots of pictures at the second URL (which can be reached from the first one; look under "Press Release")
Under the first URL, you can find the location of the monitoring points and the associated radiation levels at those points.
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
http://www
Temperature > 100C, should have positive pressure at saturation.
Some kind of instrument error?
=====================================
(2B)+(2B)' ?
RE: Fukushima No. 1 loss of coolant due to earthquake
I have no more information than what was provided here on a publicly available website, so your guess is as good as mine. Might it be due to the different locations where the readings are being taken?
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
ww
The highest RPV temperatures reported in all documents are from the main feedwater nozzle. This nozzle is relatively high on the RPV and is probably dry. I'm guessing that cooling water is only being injected through the Low Pressure Coolant Injection (LPCI) system, which feeds the recirculation loops below the main feedwater nozzle.
There's another set of published temperatures for the bottom head of the RPV, and these are around 110-120 C. We can expect the boiling point to be elevated by a couple metres of head and a lot of salt left behind from the seawater cooling. On top of that there could be some metastable superheating happening, or heat conduction could be keeping the metal temperature higher than the water temperature. And then there's always the possibility of sensor failure(s) as well.
RE: Fukushima No. 1 loss of coolant due to earthquake
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
http://ww
RE: Fukushima No. 1 loss of coolant due to earthquake
A bunch of amazing pictures, including the ones shown above.
Patricia Lougheed
******
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.
RE: Fukushima No. 1 loss of coolant due to earthquake
Now I just need something to download them all so it doesn't take me a week of watching them all crawl down the screen..
Keith Cress
kcress - http://www.flaminsystems.com
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
3-Mile Island melted at least the upper half of the fuel rods, due to lack of cooling water. Moron operator keept turning off pumps when they automatically came on. He was trained in-house by the utility. First-rate Navy-trained operators cost too much for them, so they got a $6-billion cleanup bill.
At Fukushima, they lost offsite power due to the eatrhquake, and internal power due to automatic shutdown because of the earthquake. Then the 6-15 foot tall wave drown out their diesel generators. Pathetic engineering, as this was a readily forseeable scenario. Japan holds tsunami drills all the time.
Without power, the decay heat of the used fuel boils off the water. If you don't replace the water, the fuel melts. One small firetruck could have delivered enough make-up water by suctioning from the seawater intake canal, and pumping into the the steam system. It all would have run back into the reactor. The firetruck method has actually been tried at a BWR before: look up "Brown's Ferry fire".
My guess is that the main problem in Japan was an inability to make a decision in a timely manner. The Japanese culture is to mull problems over for days, hold several meetings, discuss it over drinks, and finally achieve some sort of consensus -- in a week or three.
"Reactor desparately needs water NOW -- pump water into reactor. Only have seawater, and it will ruin the entire system -- system will be ruined tomorrow by the impending meltdown -- start pumping seawater."
It just took them too long to acknowledege the inevitable. And we in the USA may have that same lack of alacrity in a big emergency, if the utilities persist in training for Normal Ops, and leaving out ugly emergencies. The Navy trains for the hard stuff first, thus they develop superb operators.
"It ain't Rocket Science, it's just a big teakettle with some pecularities"
RE: Fukushima No. 1 loss of coolant due to earthquake
HAZOP at www.curryhydrocarbons.ca
RE: Fukushima No. 1 loss of coolant due to earthquake
Robots don't work in real nuclear disaster situations.
RE: Fukushima No. 1 loss of coolant due to earthquake
RE: Fukushima No. 1 loss of coolant due to earthquake
Keith Cress
kcress - http://www.flaminsystems.com