Charybdisjim All American 5486 Posts user info edit post |
So I'm sure most of you will have seen the video of the explosion at the Japanese nuclear facility damaged during the earthquake and Tusnami yesterday. As soon as I saw it I was pretty sure I knew what had happened.
It appears to be a catastrophic failure of the containment building due to the increased pressure within the dome being suddenly pushed beyond failure point when hydrogen ignited inside containment. What is worse is that the source of the hydrogen build up is most likely from the following. First the core became partially uncovered/dry (dry is relative as it would still be bathed in high-quality steam). This portion of the core eventually exceeded 1200 C and the cladding began to chemically change from zircalloy to a partially a compound of zirconium and fuel rod material. Zirconium and steam at that temperature can have a self sustaining exothermic reaction that produces hydrogen gas.
Large portions of the uncovered section of the cladding in the core would be quickly converted to brittle residue and an aerosolized mixture of hydrogen and particles of cladding, fuel, and lattice. Since pressure vessels are quite tough this would not necessarily compromise its thick steel walls. The pressure inside it would also be prevented from reaching dangerous levels by emergency valves which are venting into the containment building (which was already compromised.) Under less catastrophic conditions, electric fans and other systems would circulate air inside containment to prevent hydrogen build up/bubble formation and sprayers would be helping to keep pressure down.
These systems have failed however as emergency backup power was down, external grid power was lost, and the sprayers finite supply of gravity fed water would have run dry. From the video it appears the hydrogen bubble and aerosolized corium mixture ignited and partially collapsed the containment building. This is pretty bad- it's what they were worried could happen but did not at three mile island. It is not a hot nor energetic enough explosion to produce the plume seen at chernobyl but it is certainly bad.
By the time people read this my guess at what happened from watching 12 seconds of video showing the explosion might turn out to be far worse than reality. I hope that is the case, but it really looks as bad as I think it is.
Anyways - this had me thinking about the portion of our nuclear plants located on fault zones. Some of those plants have a similar over-reliance on active safety systems and could suffer similar problems during supper-massive earthquakes. Why do we not have a firm commitment to phase out older plants in fault zones as we gradually build newer passively-safe plants in seismically stable locations AND to upgrade the grid to make the increased distance of transmission economical? I mean even a very long-term and very conservative time-line would be better than what we have - defacto perpetual use of obsolete designs in fault zones.
Actually I find our lack of a long term roadmap to modernize and improve our nuclear power systems and close (as much as possible) our fuel cycle to be frustrating. I know we won't fix it all overnight, but we do posess the technology and plant designs to build passively safe plants which can be built less expensively than the previous generation, run more efficiently, and safely weather catastrophic accident conditions for 3 or more days without operator action. We also have the technology to help close our fuel cycle (reduces end waste volume and longevity) significantly now but it's illegal to do so - even if done in ways that do not produce weapons grade material. Adittionally we are developing particle beam spalation technology (as is the EU) that can be used potentially to safely transmute waste and produce enough electrical power to pay for itself in the process.
Why do we not at least have a firm commitment to move towards these things, even if very gradually. 3/12/2011 6:09:23 AM |
Nighthawk All American 19623 Posts user info edit post |
NIMBY and promotion of alternative energies from the environmental left is why we have no forward motion to speak of on nuclear power production. Their pie in the sky notion that we can power the entire world on solar/wind plants with natural gas as a fallback is ridiculous.
And it sounds like TEPCO has had issues with falsifying safety reports at their nuclear plants. The CEO had to resign in 2002 over this. God only knows what they have gotten away with. You would think as a country that had two atomic bombs exploded over it, they would appreciate the danger of radiation and be more safety conscious.
Bottom line this is terrible for the nuclear industry. If people really want to save the world and go green with the electric grid, the baseload must be handled by nuclear fission until fusion reactors are able to takeover at some point in the future. Fission is the only reliable way to generate large amounts of electricity constantly and with no carbon footprint. Obviously the President doesn't support this as he has closed Yucca Flats, at the cost of billions of taxpayer dollars to energy companies. If we would not have let the environmentalists push us around on nuclear power since Three Mile Island, we could have a progressive roadmap to phasing out older plants and pushing forward with many of the safer passive cooling reactor assemblies.
[Edited on March 12, 2011 at 7:41 AM. Reason : ] 3/12/2011 7:40:10 AM |
kdogg(c) All American 3494 Posts user info edit post |
This is Chernobyl all over again, save for the reason it occurred.
God help the people of Japan and the rest of the world as we figure out how to deal with this.
I think the Japanese are smarter (and more concerned with their own people) than the Russians to handle this. 3/12/2011 8:44:04 AM |
Chance Suspended 4725 Posts user info edit post |
What videos are you talking about, I don't have the dummy tube on, just looking on the internets.
This, posted minutes ago, says it wasn't a major melt down yet
http://www.cnn.com/2011/WORLD/asiapcf/03/12/japan.nuclear/ 3/12/2011 8:59:46 AM |
HockeyRoman All American 11811 Posts user info edit post |
Quote : | "the environmental left" |
Hold your horses there, sparky. That may have been the old way it was conveyed as to how environmentalists thought back in the 70s and 80s but given the alternatives of oil and coal that's hardly the case now. Granted, I can only speak for me but environmental conservation is my number one priority and I am all for the expansion of nuclear technology and the advancement of fusion for the future. I've often championed the cause that fusion should be this generation's "space race". So you'd be wise to withhold your blanket accusation and blame. One could also argue that big oil has ginned up this notion that environmentalists are against it in order to protect their interests without looking like the bad guys.3/12/2011 9:30:22 AM |
Charybdisjim All American 5486 Posts user info edit post |
Yeah the biggest direct competitor for nuclear power is coal. It's not (yet) solar nor any other sustainable energy source. Ultimately though - terestrial power generation will likely be covered primarily by a combination of solar, wind, and tidal generation coupled with gen III+ and gen IV nuclear reactors for base load and gase turbine facilities for on demand peak power production.
Of course if we don't progress towards an improved grid and a closed fuel cycle and can't phase out these older poorly placed plants then you can cut nuclear out of that list and replace it with "something else" 3/12/2011 9:56:47 AM |
Nighthawk All American 19623 Posts user info edit post |
The Left WAS in the past extremely against the proliferation of nuclear power, as they saw it as an extension of the nuclear arms race. Greenpeace and the NRDC are very anti-nuclear power, and they probably donate a LOT more to the Democrats than to the Republicans. So yes, the environmentalists generally align with the left, and the anti-nuclear groups also align with environmental groups and the left.
More recently there has been more splintering due to the fact that nuclear is the only option that can deliver huge amounts of power with no CO2 output, but the more liberal folks in the left are the one opposing the expansion and upgrading of nuclear plants in this country. The president has been flip-flopping on the issue, with expansions in the licensing process, while at the same time killing Yucca Mountain Waste Repository to appease Harry Reid. You may have seen the light on this, but I don't think Republicans need nearly as much convincing that nuclear is worth the small risks versus Democrats. 3/12/2011 10:08:30 AM |
LoneSnark All American 12317 Posts user info edit post |
Keep in mind that the free market has declared Nuclear Power Plants a terrible investment because of the limitless liability potential. Now that we know this, the only way to build a Nuclear Power Plant is under government liability protection, which is not something I would defend. 3/12/2011 10:15:37 AM |
Chance Suspended 4725 Posts user info edit post |
^ My next question was somewhat related to that....is there any sort of a Nuke Plant moratorium here or is it more the government has made the economics so bad you just don't see anyone wanting to build?
Quote : | "because of the limitless liability potential" |
What does this entail?3/12/2011 10:18:12 AM |
Charybdisjim All American 5486 Posts user info edit post |
^ It's more that building a nuclear plant is a decade+ long process. You have to hope that changes in party politics, regional politics, regional population density/location, as well as the increasing number of plants run well beyond their prime do not all conspire to sink the expensive and fragile project during that long time frime.
In Japan there were a total of about 11 ABWR reactors scheduled to be in-construction by 2008. Two of them were built and completed and allowed for decomissioning of some of the oldest plants. 3 more were started but halted before they were brought online - due to anti-nuclear sentiments, political changes, and economic concerns. Two of those would have been online before now and allowed for the decomissioning of 2-3 of these older plants. The remaining ABWRs have either been cancelled or are "on order" indefinately.
Would those 2 halted plants that were nearly complete have allowed for this particular reactor to be decomissioned or in the process of being decomissioned by now? Maybe, but probably not - there are a lot of plants that might have be decomissioned instead and it does not happen overnight.
The thing is though you can't run these aging plants indefinately. You either have to replace them with newer nuclear plants that are safer and better able to weather the disasters you can expect or might be able to imagine - or- you have to replace them with something else. If you don't start to decomission 40+ year old plants built before the lessons learned over that time, particularly if they're sitting next to active fault lines, it's like playing russian roulette by yourself. You will eventually lose.
The same is true for our own aging nuclear plants - particularly those on the west coast. We need to either begin to phase the oldest out and replace them with safer more modern plants (preferably located in safer areas) or we need to phase them out and replace them with something else. Transporting power efficiently from farther away would require an overhaul in our electrical grid but that's probably something we should do anyways too. Either way, they aren't built to last forever - either modernize them, replace them with newer reactor complexes in better locations, or replace them with something else. That or keep pulling the trigger. 3/12/2011 10:48:07 AM |
Chance Suspended 4725 Posts user info edit post |
But, there is nothing that prevented this plant from weathering the disaster. We have triple (and sometimes more) redundancy in aircraft that carry 20 people, why not for nuke plants? Why do they only have enough batteries to run the plant for 8 hrs? Why not enough to allow it to properly cool? I imagine we take care of this with new designs, but I doubt it's terribly expensive to retrofit old designs. 3/12/2011 12:00:40 PM |
UberCool All American 3457 Posts user info edit post |
Quote : | "but I doubt it's terribly expensive to retrofit old designs." |
you'd be amazed at how bloody expensive it is to do modifications at a nuclear plant (in the US, anyway). it ain't cheap.3/12/2011 12:11:52 PM |
Chance Suspended 4725 Posts user info edit post |
It's expensive to buy some extra batteries, enough to run pumps for 3 days, and put them on site in the event your back up generators don't work? 3/12/2011 12:21:49 PM |
CarZin patent pending 10527 Posts user info edit post |
Well, the one thing that bothers me about the media coverage is the complete lack of knowledge they (and often their 'experts') have about radiation and exposure doses. 1000x background radiation isnt great, but you arent to get cancer from being exposed to that level. For example, background radiation at my house is about .014 millirem per hour (or .14 microsievert). If it is 1000 times that level, that amounts to 14 millirem (140 microsieverts). Most people get dosed about 350 millirem (3500 microsieverts) a year. I believe nuclear workers have a work dose max of around 3-5 REM a year (someone can correct me). So, if the background radiation is 1000x background, you'll get your yearly dose if you stay in that area for 1 day.
Compare that to a full body CAT scan, and you will receive 1/3 the CAT scan dosage. So people get dosed with far more radiation in far less times with a CAT scan.
This doesnt mean long term exposure isnt an issue, but the current levels arent an issue for the people in the immediate exposure area.
Now, if the plant melts down, and it sends a lot of dust all over the place from the core, thats an entirely different issue.
I wish we'd actually get measurements of exposure areas.
[Edited on March 12, 2011 at 1:11 PM. Reason : .] 3/12/2011 1:01:53 PM |
skokiaan All American 26447 Posts user info edit post |
Isn't the Japanese reactor a light water one that can't melt down? 3/12/2011 1:16:18 PM |
Nighthawk All American 19623 Posts user info edit post |
^I really enjoyed the fact that the professional opinion on nuclear reactors that was oft cited yesterday was somebody (can't find the source now) who was part of a movement to disassemble all nuclear weapons and nuclear reactors in the world. I'm sure he would never try to scare folks by giving only the worst case scenario, instead of giving a list of all possible scenarios and their likelihood of outcome. More sensationalism by the media.
Appears the TEPCO has stated that the containment building blew, but the reactor and all its equipment is fine and they have just decided to pump seawater on it and likely kill the whole reactor in the process. Still better than a meltdown though, even if they have to deactivate the unit.
Ah good, Greenpeace has chimed in:
Quote : | "Greenpeace is calling for the phase out of existing reactors, and no construction of new commercial nuclear reactors. Governments should invest in renewable energy resources that are not only environmentally sound but also affordable and reliable." |
God forbid you have a cloudy day with no wind, or you are gonna be fucked.
[Edited on March 12, 2011 at 1:20 PM. Reason : ]3/12/2011 1:16:26 PM |
CarZin patent pending 10527 Posts user info edit post |
Quote : | "^I really enjoyed the fact that the professional opinion on nuclear reactors that was oft cited yesterday was somebody (can't find the source now) who was part of a movement to disassemble all nuclear weapons and nuclear reactors in the world. I'm sure he would never try to scare folks by giving only the worst case scenario, instead of giving a list of all possible scenarios and their likelihood of outcome. More sensationalism by the media. " |
Absolutely. I was aware of that group, and told my wife about it. We were watching Fox. They gave he pro nuclear guy 30 secs, and the anti nuke guys 5 minutes.
Much of what he said, except for his opinions on exposure level, wasnt too far off, however.
I like nulear energy, and think its use is unavoidable, but when it shits the bed, it shits it bad.3/12/2011 1:18:26 PM |
The E Man Suspended 15268 Posts user info edit post |
can't have a day with no tides 3/12/2011 1:38:55 PM |
Steven All American 6156 Posts user info edit post |
CarZin, 3-5 Rem/Yr is correct.
I have not been keeping up with what is going on over there with the power plant due to how mad i get listening to news reporters sound like complete idiots and then you have the no-nuke protestors....
but apparently there emergency cooling system power supply failed? do they not have back-up to the back-up? dual redundancy so-to-speak? i do not know how most civilian power plants are designed... 3/12/2011 1:41:41 PM |
aaronburro Sup, B 53062 Posts user info edit post |
Quote : | "is there any sort of a Nuke Plant moratorium here or is it more the government has made the economics so bad you just don't see anyone wanting to build?" |
Well, the problem was that the anti-nuke left sued anyone and everyone who even mentioned the word "nuclear" for so long that it killed the nuclear industry.
Quote : | "But, there is nothing that prevented this plant from weathering the disaster. We have triple (and sometimes more) redundancy in aircraft that carry 20 people, why not for nuke plants?" |
In the US we actually do have such redundancies. I think we are going to learn that this company was skimping on safety requirements. Moreover, keep in mind that this plant was a 1960s-era plant, designed in the infancy of the industry. I will say, though, that running a plant without a functioning diesel generator is reckless, pure and simple. I hope they weren't doing that. Even still, not to have a seismically sound diesel generator set up is still absurd, especially in that area
Quote : | "Why do they only have enough batteries to run the plant for 8 hrs?" |
One problem with such batteries is that you can't simply stockpile them and wait for a rainy day. Over time, the batteries degrade, so you have to buy new ones. Kinda sux. But it is very expensive.
[Edited on March 12, 2011 at 1:52 PM. Reason : ]3/12/2011 1:51:21 PM |
Nighthawk All American 19623 Posts user info edit post |
^^Just like air travel. Its great until something goes bad, and then it REALLY goes bad. The few tragedies really overshadow the millions of people that fly and put in tons of miles with no problems whatsoever. 3/12/2011 1:51:44 PM |
aaronburro Sup, B 53062 Posts user info edit post |
Quote : | "do they not have back-up to the back-up? dual redundancy so-to-speak?" |
US reactors most certainly do. Nighthawk can correct me if I am wrong, but I think that each reactor has to have 2 diesel generators on standby, and these generators must be tested like every 3 months. I don't know what Japanese requirements are, but the US doesn't play around with this stuff. And, I'm sure battery backups are also required. What I don't get at the Japanese plant is why they don't try to link up the diesels from the other reactors to this reactor, assuming the other reactors had them.
again, I think what we are going to find is that this plant, and its operator in general, really skimped on what was necessary for safe operation, and they finally got caught. What we'll then see is the stark contrast at American plants as far as design and operation requirements3/12/2011 1:56:10 PM |
skokiaan All American 26447 Posts user info edit post |
^pure nonsense (coming from jingoism? )
They actually have 13 backup generators, which failed because of the tsunami. You assume that american design and operation requirements can handle that?
And they have already flown in backup generators (no thanks to your expert advice or command of the facts available).
[Edited on March 12, 2011 at 2:14 PM. Reason : Same way their buildings are much stronger than ours. just complete fucking nonsense from you] 3/12/2011 2:11:40 PM |
Snewf All American 63368 Posts user info edit post |
so I'm about 160 miles from Fukushima
hmmm I'll probably be safe 3/12/2011 2:17:25 PM |
ScubaSteve All American 5523 Posts user info edit post |
for the same country that doesnt allow US nuclear subs in it's harbors, I doubt they would be so lacks on nuclear power plants on their island. This seems like it might be one of those cases where everything fails and you can't engineer away 100% of the risk. 3/12/2011 2:58:13 PM |
ladysman3621 Veteran 325 Posts user info edit post |
On the International Nuclear and Radiological Event Scale(INES) this accident rates a level 4 on a 7 point scale where Chernobyl rates 7 and 3 mile island rates 5. I mean this sucks for sure but I wouldn't worry too much about it. It is important to note that there a two containment structures which house the reactor vessel. The explosion occurred between the primary(innermost) containment structure and the secondary. So if push comes to shove there are still fission product barriers intact. In the end they are probably going to flood the vessel and primary containment, call it a day, then write unit 1 off as a really, really, really, really, really, really expensive and useless space heater.
As to the question about why the nuclear industry doesnt have multiple layers of safety systems...they obviously do otherwise this accident would have gone down similar to Chernobyl. So far the only injuries that resulted from this are two employees with a couple of broken bones. As of a few hours after the explosion, the dose levels at the site boundary are on the order of 7 millirem per hour, which, while non-zero, its nothing to cry home about. This will likely drop dramatically when they stop venting. 3/12/2011 3:07:10 PM |
ladysman3621 Veteran 325 Posts user info edit post |
On a fun side note, as Charybdisjim points out, a hydrogen explosion can be easily explained via the exothermic metal-water reaction that takes place when zircalloy reaches the magic temperature of 2200 F (i.e. "meltdown"). Partial meltdown has probably already happened. 3/12/2011 3:43:04 PM |
moron All American 34141 Posts user info edit post |
Quote : | "again, I think what we are going to find is that this plant, and its operator in general, really skimped on what was necessary for safe operation, and they finally got caught. What we'll then see is the stark contrast at American plants as far as design and operation requirements " |
so... you're praising government regulations...?3/12/2011 3:51:50 PM |
moron All American 34141 Posts user info edit post |
Quote : | "Keep in mind that the free market has declared Nuclear Power Plants a terrible investment because of the limitless liability potential. Now that we know this, the only way to build a Nuclear Power Plant is under government liability protection, which is not something I would defend." |
If that is your analysis then the most logical conclusion is that this is one of the cases where the free market fails.3/12/2011 4:22:50 PM |
Chance Suspended 4725 Posts user info edit post |
Nah, just that failing companies be allowed to fail. If a worse scenario would have happened where it Chernobyl'd, at least we'd be happy knowing we have that little bit of extra liberty despite the complete wasting for...forever...of a square miles of Japanese country side and maybe a few deaths and cancer cases. 3/12/2011 4:22:58 PM |
aaronburro Sup, B 53062 Posts user info edit post |
^^^ in this case, yes. it seems quite sensible to require operators of a potentially dangerous machine like this to follow rules in order to do so. I know I wouldn't want some random guy on the street to be putting together his own nuclear reactor in his backyard with a couple steel pipes and a 55-gallon drum. 3/12/2011 5:11:07 PM |
Steven All American 6156 Posts user info edit post |
Quote : | "One problem with such batteries is that you can't simply stockpile them and wait for a rainy day. Over time, the batteries degrade, so you have to buy new ones. Kinda sux. But it is very expensive." |
you wouldnt necessarily just be stock piling them? i know on submarines they always have a constant 5-9amp trickle discharge...im pretty sure that is what conserves them, im no sub guy nor will i ever say i know that much about electricity.
aaronburro, we have 4 emergency diesel generators. effectively 2 per reactor. reason i asked was because of Japan's "fear" of nuclear power, i would assume they would have some ridiculous safety system.
scubasteve, nuclear subs have visited their harbors. We have a CVN stationed in Yokosuka, JA
CarZin, and correcting what i said earlier...5 rem/yr nte 3 rem/qtr3/12/2011 5:52:37 PM |
Shaggy All American 17820 Posts user info edit post |
Quote : | "If that is your analysis then the most logical conclusion is that this is one of the cases where the free market fails. " |
In a truely free market they'd be able to construct their reactors wherever they wanted and not need to worry about anyone shutting them down prematurely.
Im not saying thats the way to go but a large burden of governmental regulations is not the same as a free market. Create regulations around safety but provide financial and other guarantees to offset the added risks.
Plus, if we hadn't let morons stop the construction of new reactors 40 years ago the free market would have provided much more modern, efficient, and safer designs.
The entire green movement should be pushed aside and ignored for future prosperity and progress.3/12/2011 7:08:08 PM |
A Tanzarian drip drip boom 10995 Posts user info edit post |
Quote : | "It's expensive to buy some extra batteries, enough to run pumps for 3 days, and put them on site in the event your back up generators don't work?" |
The batteries would be the cheap part.
Any sort of ambitious modernization project at a US nuclear plant is tremendously expensive, in no small part due to regulatory processes that must be navigated and the uncertainties and time associated with those processes. As a result, utilities tend to maintain what they have rather than upgrade--they nurse along obsolete equipment rather than install something more reliable and modern (and consequently safer).
I do believe nuclear plants should be government regulated. But, when it's easier to nurse along 60's and 70's crap (that's no longer commercially supported) than it is to install modern technology (much of which is already in wide use in other industries), that's a good indication the process is broken.
(None of this is to say that US plants are particularly unsafe. Just that they could be much more reliable and much safer.)
I believe I heard on the news that the design basis earthquake in Japan is a 7 something. So even if there was a super-duper quadruple triple redundant backup system, it has as much chance surviving an 8.9 earthquake as the existing systems.3/12/2011 9:17:31 PM |
LoneSnark All American 12317 Posts user info edit post |
Quote : | "If that is your analysis then the most logical conclusion is that this is one of the cases where the free market fails." |
Why? If they are in fact pricing risk correctly, then having the government subsidize their construction makes us all poorer, as the negligible benefits do not outweigh the very real potential costs.3/13/2011 1:16:43 AM |
Chance Suspended 4725 Posts user info edit post |
Can anyone point out specific (or even vaguely specific, lulz) regulations that are driving the costs up? It's sort of taken as a given but is that really the case?
Quote : | "scubasteve, nuclear subs have visited their harbors. We have a CVN stationed in Yokosuka, JA" |
...it's the weapons they don't let back into their waters.3/13/2011 9:02:11 AM |
The Dude All American 6502 Posts user info edit post |
This might sound terrible but I look at this proof that nuclear is safer than people think (assuming that this doesn't get much worse). This is a worst case scenario event and yet the operators so far have manage to minimize the public dose to a completely reasonable level. I've heard reports that the PEAK radiation levels have reached 1557 micro-sieverts/hr or 155.7 mrem/hr. That is nothing and can in no way endanger the public health. I would have no problem standing in a room with a 155.7 mrem field. You also have to take into account that this dose rate is significantly less the further you move away from the plant.
The events that have taken place at Fukushima are seemingly unimaginable, however, these are the type of events that operators train for. This plant was near the center of an 8.9 earthquake, they lost offsite power, a tsunami took out emergency backup power and a H2 explosion destroyed the building outside their drywell. This also includes multiple smaller system and equipment failures that have occurred during this time. I don't think people begin to realize what these operators and this plant is going through right now.
Quote : | "US reactors most certainly do. Nighthawk can correct me if I am wrong, but I think that each reactor has to have 2 diesel generators on standby, and these generators must be tested like every 3 months. I don't know what Japanese requirements are, but the US doesn't play around with this stuff. And, I'm sure battery backups are also required. " |
What aaronburro says is mostly true. We do have 2 diesels on standyby and they are required to be tested every month. We have 2 sets of 125 VDC safety emergency batteries designated only to assist in safe shutdown. These will last 8 hours total. We also have multiple sets of non safety batteries to assist in other non essential backup operations.
Quote : | "again, I think what we are going to find is that this plant, and its operator in general, really skimped on what was necessary for safe operation, and they finally got caught. What we'll then see is the stark contrast at American plants as far as design and operation requirements" |
This plant is an American plant. It is a GE BWR. I also doubt you'll find that they skimped on nearly anything safety related. Unfortunately what they did do is build a nuclear plant right on the ocean smack dab in the middle of a faultiline.
Quote : | " CarZin, and correcting what i said earlier...5 rem/yr nte 3 rem/qtr" |
This is an NRC limit. Our company limit is 2 rem/year. A typical nuclear worker will not receive anything close to that. As an operator who's in the plant every work day I receive on average about 50 mrem per year (this number would be more at a BWR).
[Edited on March 13, 2011 at 10:31 AM. Reason : yo]3/13/2011 10:19:47 AM |
UberCool All American 3457 Posts user info edit post |
Quote : | "Can anyone point out specific (or even vaguely specific, lulz) regulations that are driving the costs up? It's sort of taken as a given but is that really the case? " |
in american nuclear facilities, any components that are nuclear safety-related (QA-1) have to have special pedigrees. basically, they have to have been put through extra-rigorous testing and qualification, etc, and there are a limited number of manufacturers willing to make them. so cost is high.
also, if you want to upgrade anything (ie, modify a plant), you can't just do it; you have to go through a rigorous design process to make sure everything you do is safe and effective. you also have to make sure it conforms to your plant's licensing basis, as defined to the NRC. sometimes, a change is safe and effective, but you have to change your licensing basis...so you have to ask the NRC for permission. needless to say, the whole process can get very expensive.3/13/2011 10:59:58 AM |
CarZin patent pending 10527 Posts user info edit post |
Quote : | "I've heard reports that the PEAK radiation levels have reached 1557 micro-sieverts/hr or 155.7 mrem/hr. That is nothing and can in no way endanger the public health." |
Well, lets be fair. There is no short term risk being exposed to that level, but this is not a level you want to live in or have long term exposure to.
I think I'd start to hurry out of an area once you got to the 500-1000mr/Hr. Once you get to those levels, there are known health effects at short term exposure (72 hours).
I think if I saw 155.7 mrem on my geiger counter, I'd be looking to get further away in the event things could get worse, and at this point, things could get worse.
[Edited on March 13, 2011 at 11:29 AM. Reason : .]3/13/2011 11:21:31 AM |
Steven All American 6156 Posts user info edit post |
Quote : | "This is an NRC limit. Our company limit is 2 rem/year." |
mine is 100 mrem/yr, nte 25 mrem a qtr. but in some circumstances you can be extended up to 2 rem, but that is rare.
Quote : | "...it's the weapons they don't let back into their waters." |
ballistic missile submarines are not allowed in foreign ports anyways. the security on one of those is fucking crazy.3/13/2011 1:16:30 PM |
moron All American 34141 Posts user info edit post |
So the radiation they are detecting is because the venting facility exploded because there was no power for the fans?
Quote : | "At Daini, TEPCO is preparing to initiate a "partial discharge of air containing radioactive materials" to "fully secure safety" at all four reactors.
Casualty reports at Daiichi include two workers injured during the earthquake, radiation exposure to one worker, and four workers "injured and transported to the hospital" as a result of Saturday's explosion.
At Daini, according to TEPCO, as of Saturday afternoon "A seriously injured worker is still trapped in the crane operating console of the exhaust stack and his breathing and pulse cannot be confirmed. Currently, the rescue efforts are under way.” " |
http://www.theregister.co.uk/2011/03/13/japanese_nuclear_site_update/
[Edited on March 13, 2011 at 1:55 PM. Reason : ]3/13/2011 1:29:35 PM |
eleusis All American 24527 Posts user info edit post |
nuclear power in this country needs monumental changes in order for the G&T companies to take it seriously. Until we're allowed to cycle load and recycle spent fuel, there is no reason to dump money into nuclear when natural gas keeps getting cheaper and more plentiful. Only being able to use nukes for base load makes them much less attractive than natural gas and coal as a fuel source.
Utilities like Dominion and Duke made up for the inability to cycle load on their nukes by building massive pumped storage hydro facilities. Unfortunately, the areas where these units can be built is limited, and they have their own environmental concerns that make present day permitting almost impossible. We're making some good advances with compressed air storage systems, but they are nowhere near the energy storage capacity of pumped storage. I believe they suffer from higher efficiency losses too, because pumped hydro facilities make up for some of their efficiency and evaporation losses through rainfall adding to the top reservoir.
The issues that occurred in Japan this week definitely didn't help matters, but I don't think anyone in this country was really taking nuclear power seriously beforehand. 3/13/2011 2:56:06 PM |
DaBird All American 7551 Posts user info edit post |
interesting conversation. way over my head, but interesting. 3/13/2011 2:58:45 PM |
moron All American 34141 Posts user info edit post |
That's what happens at an engineering school i guess...
I wonder if we were a liberal arts school, would our normal policy discussions go like this...? 3/13/2011 4:10:17 PM |
A Tanzarian drip drip boom 10995 Posts user info edit post |
Quote : | "also, if you want to upgrade anything (ie, modify a plant), you can't just do it; you have to go through a rigorous design process to make sure everything you do is safe and effective. you also have to make sure it conforms to your plant's licensing basis, as defined to the NRC. sometimes, a change is safe and effective, but you have to change your licensing basis...so you have to ask the NRC for permission. needless to say, the whole process can get very expensive." |
Which is fine, in and of itself. But it gets frustrating and expensive when the NRC doesn't really know what the NRC wants.3/13/2011 5:57:50 PM |
UberCool All American 3457 Posts user info edit post |
^truth 3/13/2011 6:10:54 PM |
Smath74 All American 93278 Posts user info edit post |
this event in japan has scientifically proved that nuclear plants are naturally unsafe and should never be built. i support a plan to phase them out over a 6 year period and think that they should all be closed sooner than that. 3/13/2011 10:14:39 PM |
BEU All American 12512 Posts user info edit post |
I agree. I will go ahead and cut all power usage in my house to make up for the loss of power generation......
Any structure is naturally unsafe on top of a 8.9 quake and a tsunami.
In Japan it would be almost impossible to phase anything out in 6 years. They have to many of them, and you cant replace the power output with anything anywhere near that time frame.
Nuclear is necessary, just doesn't need to be built at the intersection of 3 tectonic plates. 3/13/2011 11:18:53 PM |
BEU All American 12512 Posts user info edit post |
Those plants are also the first generation of plants. The oldest, and didnt have the lessons learned from years of design revisions to improve on it. 3/13/2011 11:22:25 PM |
Charybdisjim All American 5486 Posts user info edit post |
Yeah I'm more in favor of phasing out the old plants while replacing them with higher capacity passively-safe new plants. Many of the Gen III+ designs (some of which have been built in europe and japan) would not have seen this sort of dramatic failure in the same situation. There are designs which require no external power nor even moving parts to circulate coolant - they use gravity and the reactor's own heat to do the job.
I do not think we should get rid of nuclear power. I think we should have a long term commitment to modernizing our nuclear power plants - which are a crucial part of our base load power production. We also need to commit to modernizing our power grid so that the newer safer plants we should be replacing the old ones with can be built in more ideal locations than on top of a major fault line. Many of the current and near-future designs also produce far more power than the aging designs currently in use. This means that if you built them while decommissioning the old plants and include burner reactors or accelerator driven waste transmutation systems into the mix you would:
1) Increase the total ammount of power produced by nuclear energy 2) Not increase the number of nuclear plants in operation 3) Decrease the number of nuclear plants in operation near fault zones and other areas of concern 4) Reduce the volume of waste produced as well as reduce the level of hazard presented by the waste you do produce (transmutation for the win)
Failing that though - it might be nice to set up a system for facilitating the upgrade and improvement of existing plants. Some sensible upgrades are rendered so costly by the procedures involved with what might otherwise be an inexpensive way to add safety that they are just not worth doing. If that could be made easier while also not compromising safety- well that would be a good thing.
It has to be frustrating for nuclear energy safety experts that one of the principle effects of anti-nuclear power pressure has been to increase the length of time that aging plants remain in operation. Popular pressure and economic pressure makes it too difficult for some utilities to construct newer, more efficient, higher capacity plants so they can not do without the base-load capacity provided by even some of their oldest existing plants. Allowing companies or helping companies to build new plants will also allow for the decommissioning of old ones. Fighting the construction of new plants forces them to keep the old plants open longer and longer and actually increases the long term risk of nuclear accidents.
[Edited on March 14, 2011 at 12:25 AM. Reason : ] 3/14/2011 12:20:56 AM |