Slashdot Mirror

That was the regulatory regime beforehand, and it resulted in the most colossal waste of money ever: Shoreham

The combined (construction & operating) license regulatory regime is intended specifically to prevent such wasteful endevours, The design, construction, and operation of the facility is approved largely upfront to ensure the plant can actually be operated when it's built.

Ok, I see where the confusion is, I've led you to believe it's all about aircraft impacts however that is not the main issue. Aircraft resistance is a consequence of what the real issue is.

Ah! Took you long enough. ;) From the very beginning I was saying that 'all' reactor domes can tank being hit by an aircraft due to their strength, required in order to contain the pressure from the reactor in a worst case scenario. You kept talking about aircraft.

So, yes, it does matter whether the dome can tank it's own reactor, that's the primary design consideration, after all. However, I'll break away from you at 'thermal containment ratio', because the issue is quite a bit more complicated than merely throwing more concrete at the problem.

Ask yourself WHY the dome needs to contain so much pressure. The answer boils down to heat(snerk). If you can reduce the amount of heat produced, that reduces the pressure. If you can dispose of more heat, the pressure is reduced. AP1000, from my reading, does a lot to increase passive cooling in a worst case scenario, and it starts out at about 60% of the heat production of an EPR, being a smaller reactor. It's a bit like an internal combustion engine - a small one can easily use air cooling, like most motorcycle engines. Get over a certain size and you need water cooling.

I'd also be careful - are you arguing against the current or original AP1000 design? The DOE told them the dome they wanted was inadequate, so they went back and beefed it up. The beefed up dome passed scrutiney.

This means that TMI has the highest possibility for containing a reactor explosion such as what occurred in Fukushima. Reduce the amount of concrete below the amount of thermal energy in the reactor and you may as well not have a concrete dome at all. It just makes people feel better. AP1000's thermal containment ratio is below that of the reactor (IIRC) and certainly much less than TMI.

I'd double check how recent your source is. Also, Fukushima's domes exploded not because of heat, but because of actual explosion - under high heat situations there's a catalytic response with zirconium cladding which cracks the water in the dome into hydrogen and oxygen. Which built up, was eventually sparked off, causing explosions. In the previous thread I brought up hydrogen recombiners for this reason. The AP1000 addresses hydrogen production in this document, where they have hydrogen igniters to ensure that the hydrogen is burned off before it reaches explosive concentrations, in areas away from the containment structure.

All US reactors were required to have hydrogen management systems even before Fukushima. They all got checked again afterwards.

I'm critical of information from the manufacturers of reactors. I've never heard a company say bad things about their products and I don't expect reactor manufacturers to be any different. Independent studies and law are generally more reliable. Westinghouse want to sell nuclear reactors.

That's fine, but in that case at least come up with a independent review of the saftey systems that identifies specific problems.

That new reactors should be underground is the first and there are about 30 other recommendations like control room design and implementation of EPR like features. If you want the watered down version [nrc.gov], and no, AP-1000 has none of them.

EPR reactors aren't built underground either, that sounds like a rather silly requirement actually. Being underground makes reaching the reactor more difficult in case of an incident.

AP1000 has a lot of problems because new features introduce new failure modes.

Which shouldn't be an automatic failure, unless we want to NEVER improve anything.

Planes not being a threat to even AP1000 domes

Ok, I see where the confusion is, I've led you to believe it's all about aircraft impacts however that is not the main issue. Aircraft resistance is a consequence of what the real issue is.

Thermal Containment ratio which is the amount of concrete compared to the energy in the reactor at anyone time. So it doesn't matter if a reactor dome can tank an aircraft, what matters is if it can tank the reactor that it contains. I was referring to TMI because it has the *highest* Thermal Containment ratio of reactors as a consequence of it being in a flight path.

This means that TMI has the highest possibility for containing a reactor explosion such as what occurred in Fukushima. Reduce the amount of concrete below the amount of thermal energy in the reactor and you may as well not have a concrete dome at all. It just makes people feel better. AP1000's thermal containment ratio is below that of the reactor (IIRC) and certainly much less than TMI.

Dude, the wiki, westinghouse's site [westinghousenuclear.com], etc... All mention extensive safety systems, including how they've changed some things up to improve safety

I'm critical of information from the manufacturers of reactors. I've never heard a company say bad things about their products and I don't expect reactor manufacturers to be any different. Independent studies and law are generally more reliable. Westinghouse want to sell nuclear reactors.

I think the problem I'm having with your assertion that the AP1000 includes 'none' of the recommended safety measures is that by all research I've done, it includes them quite extensively. So I think you need to be more specific about what safety measures you think it doesn't have, that it should.

That new reactors should be underground is the first and there are about 30 other recommendations like control room design and implementation of EPR like features. If you want the watered down version, and no, AP-1000 has none of them.

Searching the web, I primarily get that the EPR is not as good or economical as the AP1000. But like I've said earlier, I'm actually neutral on the two designs. ... AP1000 has a core damage frequency of 5.09e-7 per plant years, EPR is rated at 6.1e-7 per plant year ...

AP1000 has a lot of problems because new features introduce new failure modes. Of the math regarding CDF that you quoted the NRC had this to say in SECY-05-0227 FINAL RULE — AP1000 DESIGN CERTIFICATION: The applicant’s estimates of risk do not account for uncertainties either in the CDF or in the offsite radiation exposures resulting from a core damage event. The uncertainties in both of these key elements are fairly large because key safety features of the AP1000 design are unique and their reliability has been evaluated through analysis and testing programs rather than operating experience. In addition, the estimates of CDF and offsite exposures do not account for the added risk from earthquakes. - however they approved it anyway.

Challenge your assumptions here Firethorn, AP-1000 is not a good design.

Whilst you say these containment buildings sneer at plane impacts, well, EPR builds *another* concrete building around that one, has four separate buildings to control radio-isotopes in the event of an accident and, a core catcher, which isn't present in the AP-1000 at all. EPR is also resistant to impacts from *Military* aircraft. Powerful and good, but not cheap.

Do I talk about why AP-1000 is crap? Corrosion is the biggest issue from my understanding and the reduced accessibility to inspect key parts of the reactor. CDF has little to do with what volu

Planes not being a threat to even AP1000 domes

Ok, I see where the confusion is, I've led you to believe it's all about aircraft impacts however that is not the main issue. Aircraft resistance is a consequence of what the real issue is.

Thermal Containment ratio which is the amount of concrete compared to the energy in the reactor at anyone time. So it doesn't matter if a reactor dome can tank an aircraft, what matters is if it can tank the reactor that it contains. I was referring to TMI because it has the *highest* Thermal Containment ratio of reactors as a consequence of it being in a flight path.

This means that TMI has the highest possibility for containing a reactor explosion such as what occurred in Fukushima. Reduce the amount of concrete below the amount of thermal energy in the reactor and you may as well not have a concrete dome at all. It just makes people feel better. AP1000's thermal containment ratio is below that of the reactor (IIRC) and certainly much less than TMI.

Dude, the wiki, westinghouse's site [westinghousenuclear.com], etc... All mention extensive safety systems, including how they've changed some things up to improve safety

I'm critical of information from the manufacturers of reactors. I've never heard a company say bad things about their products and I don't expect reactor manufacturers to be any different. Independent studies and law are generally more reliable. Westinghouse want to sell nuclear reactors.

I think the problem I'm having with your assertion that the AP1000 includes 'none' of the recommended safety measures is that by all research I've done, it includes them quite extensively. So I think you need to be more specific about what safety measures you think it doesn't have, that it should.

That new reactors should be underground is the first and there are about 30 other recommendations like control room design and implementation of EPR like features. If you want the watered down version, and no, AP-1000 has none of them.

Searching the web, I primarily get that the EPR is not as good or economical as the AP1000. But like I've said earlier, I'm actually neutral on the two designs. ... AP1000 has a core damage frequency of 5.09e-7 per plant years, EPR is rated at 6.1e-7 per plant year ...

AP1000 has a lot of problems because new features introduce new failure modes. Of the math regarding CDF that you quoted the NRC had this to say in SECY-05-0227 FINAL RULE — AP1000 DESIGN CERTIFICATION: The applicant’s estimates of risk do not account for uncertainties either in the CDF or in the offsite radiation exposures resulting from a core damage event. The uncertainties in both of these key elements are fairly large because key safety features of the AP1000 design are unique and their reliability has been evaluated through analysis and testing programs rather than operating experience. In addition, the estimates of CDF and offsite exposures do not account for the added risk from earthquakes. - however they approved it anyway.

Challenge your assumptions here Firethorn, AP-1000 is not a good design.

Whilst you say these containment buildings sneer at plane impacts, well, EPR builds *another* concrete building around that one, has four separate buildings to control radio-isotopes in the event of an accident and, a core catcher, which isn't present in the AP-1000 at all. EPR is also resistant to impacts from *Military* aircraft. Powerful and good, but not cheap.

Do I talk about why AP-1000 is crap? Corrosion is the biggest issue from my understanding and the reduced accessibility to inspect key parts of the reactor. CDF has little to do with what volu

1. AP1000 = Gen3, Gen3 != AP1000, though good catch, I did say gen3. Though I'll note that was in a different reply chain.

That's where the 'authorized' ventings are defined. All NPPs vent radio-isotopes into the atmosphere every 2 weeks during normal operations, because they need to. That is a fact of operating the technology.

No, they don't. Venting steam(from the primary loop) is an Emergency event. Citation that they actually vent that often, not that they are merely 'allowed' to. I've searched, and it's not mentioned that I found.

You keep asking me for citations, why? Do you think I am bullshitting you? What does it mean that I provide it? Will you correct your assumptions against this new knowledge or maintain your assuptions in face of the fact?

What I do depends on the qualities of the citations. For example, you haven't provided a source that says NPPs actually vent radioisotopes every two weeks, merely that they *can*. When I ask for citations, it's because from my knowledge it's different. I'm not saying you're lying, but I want to know the source of your knowledge.

No, they are not because you cannot retrofit improvements to a Nuclear reactor, the same way I can install a four valve head where there previously was a 2 valve head,

The scale is different, but you can sure can retrofit improvements into a nuclear reactor. Let's see, safety improvement available, but not installed for Fukushima: Hydrogen recombiners, otherwise known as PARS. From what I remember reading, US reactors have them, having been retrofitted decades ago. Quite a few reactors have been 'up rated', to the point that for quite a while we were actually producing more electricity and increasing nuclear capacity despite not actually building any new reactors, even shutting down a few. Many reactors have been upgraded with more efficient turbines.

Besides all that, you're missing the point I think - I'm not talking about retrofitting improvements, I'm talking about incorporating improvements into the design of NEW plants.

The "refinements' are made to reduce material input costs, specifically, concrete.

That's certainly part of it. Doesn't mean that the containment dome isn't still strong as all heck. They've also reduced the amount of pipping and valves needed, and otherwise simplified and made the systems more robust.

Unless you can provide your own citations you will find that AP1000 is the only one that is approved by law (also very interesting).

Not according to the NRC. There's quite a few certified.

ABWR, System80+, AP600, AP1000, ESBWR. Under review: US EPR, US-APWR, APR1400

These are the 'major' reactors. There are smaller power units around.

Several reactors in the United States are BWR Mark I containments. Newer designs have enhanced safety measures, and there have been many upgrades since the accident, but they can operate safely for design basis accidents. The tsunami was far beyond design basis.

Fourth, the nuke plant has long term radioactive waste problems the former doesn't.

That can be addressed by recycling the fuel, but IIRC, there are weapons treaties that complicate that. Coal use emits more radioactive material into the environment than what is used by the nuclear power industry, so I wouldn't say that it doesn't have a radioactive waste problem. It's a different problem. http://pbadupws.nrc.gov/docs/M...

Stop reading the tabloids and get your information straight. The "600,000 gallons of tritium steam" is pure crap. The steam that was released was steam from the secondary water loop which run the steam turbines. You should learn a little about how these nuclear plants actually work if you are so worried about them. You see, there are 2 main water loops, the primary water loop which goes into the reaction chamber and is heated by the nuclear reaction, and the secondary loop which is heated by the hot water from the primary loop (think like a car radiator where there are pipes running back and forth to disperse the heat to all the metal fins and into the air, but instead of there being just one long tube in the radiator, there are 2 separate tubes, one with the highly heated water from the reaction, the other with cool water that just came from the cooling tower).

So in other words, water that doesn't touch the reactor was vented as steam. So instead of reading tabloids and other such sources that simply are trying to sell a paper or generate a click on an article, you might want to read the real information like an official report or given how bad the reporting on the incident was, a official corrections release by the government showing how bad the reporting was in certain "press" coverage of the incident:

Official NRC Letter of Corrections to Editor of New York Daily News

Again, since you live there, you should know that there is a history of New York not liking nuclear plants. In fact, New York hates them so much that the state of New York refused to sign any evacuation plans for a plant, causing the operator to not be able to turn it on. Approx 16% of every dollar Long Island Electric collects is being used to pay for that plant still to this day, along with a 5% rate increase every year for 10 years straight that happened all because of how anti-nuclear New York had become.

Note the last line of the article: http://www.scientificamerican....

Laymen article: http://www.quora.com/How-long-... ... spent fuel is in pools for about 10 years.

That is more interesting: http://www.nrc.gov/waste/spent...

This is a german article: http://de.m.wikipedia.org/wiki...Ãrme (contains umlaut a) ... http://en.wikipedia.org/wiki/D... the numbers vary a bit, the german one has a table in the middle, saying after a month the heat is 0.13% and after three months it is 0.07%

The next paragraph after that table states: fuel rods create enough decay heat to melt themselves _months_ after shutdown, if they are not cooled obviously.

Well, to get real numbers I guess we need a anti radiation suit, wait for the next melt down, and measure our selves ^_^ would you volunteer for the first two weeks?

Pilgrim is a reliable station still going strong after many years.

Lol @ reliable. Pilgrim has been on the NRC's worst-ten shit list for a few years now.

The same day the storm hit, the NRC sent Pilgrim a letter.
http://pbadupws.nrc.gov/docs/ML1502/ML15026A069.pdf

Overall, the NRC has determined that your act ions have not provided the assurance level to fully meet all of the inspection objectives and have correspondingly determined that Pilgrim will remain in the Degraded Cornerstone of the Action Matrix by the assignment of two parallel White PI inspection findings. [Green, White, Yellow, Red, in increasing order of severity] [...] . Additionally, for one of the
root cause evaluations, inspectors determined that Entergy failed to investigate a deficient condition in accordance with corrective action program (CAP) requirements to ensure they fully understood all of the causes of one of the [four unplanned] scram events [that happened in 2013].

Reliable != multiple unplanned SCRAMs per year.

Anyways, on January 27, while the reactor was SCRAMing, these three things happened:

The High Pressure Coolant Injection System had to be secured due to failure of the gland seal motor.
The station diesel air compressor failed to start.
One of the four safety relief valves could not be operated manually from the control room.

Those safety relief valves are the ones that get used to vent pressure after the coolant injection system fails.

Pilgrim has problems. On top of all those problems, locals are spitting mad because the disaster plans fail to include scenarios like "giant blizzard shuts down all the roads and nobody can evacuate."

Ok, how do you start upgrading? Oh yeah, you decommission the old one! So your whole argument makes very little sense...

If only it were that simple. See this NRC backgrounder on decommissioning nuclear power plants and 26 CFR 1.468A-5. It is a fund owned by customers, held in trust for complete plant dissolution. It cannot be borrowed from or against or used to upgrade the plant, even if this would result in a longer useful life. Typically these funds are held conservatively, though there have been attempts to tax them to higher heaven or play risky games.

Don't get me wrong, decommissioning funds are a good idea in general for industry, especially for anything involving radioactivity or stored chemicals. But you have to ask yourself for anything, such as my water or sewer plant example, is it likely that we will really want this thing to close and completely disappear in (x) years? If the answer is NO, the return-on-investment burden costs everyone money over it's lifetime because it stifles renovation and innovation. The higher cost and lower profit margin repels good stewards and attracts bad ones (like Dominion). Just as for life insurance, it's not healthy for any one or thing that is truly useful to be considered worth more dead than alive.

If anyone would attempt to impose such a trust to coal generating plants over a pre-determined lifespan with subsequent greenfield decommissioning, you'd hear some real noise. Then when those numbers change, aside from CO2 everyone might conclude that nuclear IS cheaper than coal, today!

"The useful is as beautiful as the beautiful." ~apologies to The Little Prince

I second. Drills are the way to identify and correct flaws, as well as to identify areas for improvement. It is unfortunate that it took a one-two punch to turn around Japan's nuclear culture, but hopefully they come out stronger, as we had following the Three Mile Island Unit 2 event in 1979. Here in the U.S., even now, emergency drills at nuclear power plants continue to optimize emergency processes, and to test a plant's (including and especially its staff's) response to a significant adverse event. The typical drill postulates a series of malfunctions that inevitably lead to a radiation release, which then triggers an evacuation. This latter part is designed to exercise local and state resources as well.

After Fukushima, the paradigm got turned a bit on its head: instead of a nuclear plant event causing the emergency, it's a natural calamity that degrades and destroys infrastructure that could lead to a radiation release. As a result, the lessons learned prompted at least one order, which requires all U.S. plants to be ready for events that are beyond their current design bases. In other words, if your plant was designed for a Category 3 hurricane, be ready to handle one that's much more devastating. As you might expect, this is no small expense, but the U.S utilities have committed to making the preparations, and you can find descriptions of these on the NRC website.

I second. Drills are the way to identify and correct flaws, as well as to identify areas for improvement. It is unfortunate that it took a one-two punch to turn around Japan's nuclear culture, but hopefully they come out stronger, as we had following the Three Mile Island Unit 2 event in 1979. Here in the U.S., even now, emergency drills at nuclear power plants continue to optimize emergency processes, and to test a plant's (including and especially its staff's) response to a significant adverse event. The typical drill postulates a series of malfunctions that inevitably lead to a radiation release, which then triggers an evacuation. This latter part is designed to exercise local and state resources as well.

After Fukushima, the paradigm got turned a bit on its head: instead of a nuclear plant event causing the emergency, it's a natural calamity that degrades and destroys infrastructure that could lead to a radiation release. As a result, the lessons learned prompted at least one order, which requires all U.S. plants to be ready for events that are beyond their current design bases. In other words, if your plant was designed for a Category 3 hurricane, be ready to handle one that's much more devastating. As you might expect, this is no small expense, but the U.S utilities have committed to making the preparations, and you can find descriptions of these on the NRC website.

Nice cherry-picking of material to support an insupportable postulate.

From your own goddam citation: "The approximately 2 million people around TMI-2 during the accident are estimated to have received an average radiation dose of only about 1 millirem above the usual background dose. To put this into context, exposure from a chest X-ray is about 6 millirem and the area's natural radioactive background dose is about 100-125 millirem per year for the area. The accident's maximum dose to a person at the site boundary would have been less than 100 millirem above background."

That is NOT SIGNIFICANT compared to normal variation in natural background radiation. It so happens the area around TMI has an unusually low NBR. The average NBR in the US is 300 mrem/y. The area with the highest NBR in the inhabited world is Ramsar, Iran, with 600 mrem/y. But you don't see anyone evacuating there do you?

Give up the hysterical exaggeration.

"A significant release of radiation from the plant's auxiliary building, performed to relieve pressure on the primary system and avoid curtailing the flow of coolant to the core, caused a great deal of confusion and consternation. In an atmosphere of growing uncertainty about the condition of the plant, the governor of Pennsylvania, Richard L. Thornburgh, consulted with the NRC about evacuating the population near the plant. Eventually, he and NRC Chairman Joseph Hendrie agreed that it would be prudent for those members of society most vulnerable to radiation to evacuate the area. Thornburgh announced that he was advising pregnant women and pre-school-age children within a five-mile radius of the plant to leave the area." http://www.nrc.gov/reading-rm/... describes one of the meltdowns. Perhaps "significant" and "uncontained" means something different to you?

"except for meetings on security subjects that include sensitive information" http://www.nrc.gov/security/fa...

"...except for meetings on security subjects that include sensitive information..." TRUST US! Sleeping guards, sweep it under the rug.... http://www.nrc.gov/security/fa...

Ok, where's the reference then?

I see when I googled, an estimate for "large" "loss of coolant accidents" around 5*10^-6 per year per plant. That sounds like your number. It's worth noting that the accident category in question hasn't happened yet since they're speaking of loss of coolant from pipe corrosion and mechanical failure in a plant with proper maintenance and the following of procedures, not the many other sorts of loss of coolant accidents that can happen to a nuclear plant (such as the real world examples caused by earthquakes, incompetence, and poor maintenance).

Did you just make this shit up? Completely false.

Sorry bro, you are full of shit.

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

References:
http://www.epa.gov/radtown/nuc...
http://en.wikipedia.org/wiki/N...
http://www.radiationanswers.or...
http://www.iaea.org/Publicatio...
http://en.wikipedia.org/wiki/N...
http://www.radiationanswers.or...
http://www.nrc.gov/about-nrc/r...

It is funny how people's definitions of "safe" change depending on the subject.

Note how I didn't say it was unsafe. You made that up and then used it as a straw man. My point was actually that it is safe, but that the rule has developed based on more than just the relative safety of that one number.

No containment can contain a meltdown, if it wasn't built to do so. The BWR containments, as used in Fukushima Daiichi, just weren't, because it wasn't deemed necessary. Nureg/CR-6042 made it pretty clear that the focus back in the early 1960ies was on definitively preventing "catastrophic deaths". Preventing contamination just wasn't the goal. From the perspective they had, it was sufficient if meltdowns were unlikely. This has changed, but at least in the US and Japan, the power plants weren't changed to accomodate this.

And I'm not cherrypicking my sources. Any of the well known and often discussed reports like Wash-1400 or Nureg-1150 make it very clear that such BWR containments would overpressurize and leak soon after a meltdown due to hydrogen generation (hydrogen can't be condensed, unlike water steam), leading to widespread contamination after a meltdown. That's not merely a chance, but a certainty. (Whether a meltdown can be prevented is a different matter.) All three also clearly state that flooding and tsunamis (in Wash-1400 "tidal waves") are a potential cause for a meltdown, despite the redundancy of safety equipment, because they cause a full station blackout.

All this is quite different in other containments. Pressure water reactors typically have a large dry containment, that is capable of containing a meltdown, at the very least long enough for most contaminants to settle down in the containment and not outside of it. (Without power to run any pumps, it takes some 20 hours for 99% of the Cesium to settle down. With power, you can run containment sprays and do it in a bit more than half an hour. BWR Mark I/II containments generally don't have such sprays.) Newer BWR containments are also much larger and much more capable of containing a meltdown.

Other countries such as Sweden, France and Germany fitted filtered containment vents to their nuclear power plants in 1980(Sweden) and 1988 (Germany/France). Which would have prevented any significant fallout, because the containments wouldn't overpressurize.

No containment can contain a meltdown, if it wasn't built to do so. The BWR containments, as used in Fukushima Daiichi, just weren't, because it wasn't deemed necessary. Nureg/CR-6042 made it pretty clear that the focus back in the early 1960ies was on definitively preventing "catastrophic deaths". Preventing contamination just wasn't the goal. From the perspective they had, it was sufficient if meltdowns were unlikely. This has changed, but at least in the US and Japan, the power plants weren't changed to accomodate this.

And I'm not cherrypicking my sources. Any of the well known and often discussed reports like Wash-1400 or Nureg-1150 make it very clear that such BWR containments would overpressurize and leak soon after a meltdown due to hydrogen generation (hydrogen can't be condensed, unlike water steam), leading to widespread contamination after a meltdown. That's not merely a chance, but a certainty. (Whether a meltdown can be prevented is a different matter.) All three also clearly state that flooding and tsunamis (in Wash-1400 "tidal waves") are a potential cause for a meltdown, despite the redundancy of safety equipment, because they cause a full station blackout.

All this is quite different in other containments. Pressure water reactors typically have a large dry containment, that is capable of containing a meltdown, at the very least long enough for most contaminants to settle down in the containment and not outside of it. (Without power to run any pumps, it takes some 20 hours for 99% of the Cesium to settle down. With power, you can run containment sprays and do it in a bit more than half an hour. BWR Mark I/II containments generally don't have such sprays.) Newer BWR containments are also much larger and much more capable of containing a meltdown.

Other countries such as Sweden, France and Germany fitted filtered containment vents to their nuclear power plants in 1980(Sweden) and 1988 (Germany/France). Which would have prevented any significant fallout, because the containments wouldn't overpressurize.

Link? I know that NRC hasn't reported any incidents before 1999 http://www.nrc.gov/reading-rm/... . The wikipedia page speaks of incidents which are just recently declassified http://en.wikipedia.org/wiki/N... (footnote 43) and were not disclosed to the public by the DOE (see rocketdyne )
That being said, (and fwiw) Nuclear power as safe, clean energy. However doesn't take away the value of the research paper as to potential threat posed by insiders. Even if it has never happened, it still would be horrible consequences if it did.

No, you won't read the same thing around Fukushima, even if the paper is correct, because there has been no release of Strontium-90 to begin with. Mind you, there is some in the cooling water, but not in the fallout. One of the advantages to have an intact, though leaking, containment is that only volatile components can escape from it. Strontium is not among the volatile components, only noble gasses, Iodine and Caesium. You can keep most of the Caesium inside the containment, if you either have a containment spray system (which the BWR Mark I and Mark II don't have). In this case it takes about 15-20 minutes to remove 90% of it from the containment air. Without the spray, it takes about 8-10 hours to fall out inside the containment.

Unfortunately, GE said about the Mark I containment all the way back in 1966 (part 1, page 50) that it would definitively leak very soon after a meltdown, unlike PWR containments (which also have containment sprays). The old BWR containments were designed around 1960 to prevent "catastrophic death tolls", in case of any accident. Back in their time, they were not designed to prevent fallout in the surrounding area. This came later. In order to prevent those with a Mark I or Mark II, you need reinforced, passively activated, filtered containment vents. Those are required by law in Germany, France and Sweden in all nuclear power plants, including PWRs. Not so in the US or Japan for that matter. In the US, the general rule is that nuclear power plant operators are required to keep their plants up to date, but are explicitly not required to perform major changes to the plant. So, there is a lot of grandfathering going on. Installing filtered vents, seems to constitute such a "major change".

In short: Nuclear power plants are exactly as safe as they are designed to be. And they are designed to be as safe as whatever law (that currently applies to them) requires them to be. Fukushima Daiichi worked exactly as required, it's just that the requirements they were held to by the law weren't exactly stellar.

At least none in the designated evacuation buildings deemed to be safe and high enough, where hundreds upon hundreds of people died. Where are the eyewitness reports of how those were crushed? (Oh right.) Where are the accusations of mayors and emergency planners who are responsible for the deaths of thousands of people?

One thing is for sure. You don't care about people. You don't care about their lives, as was made abundantly clear on wikipedia. You don't care about what people lost. Some 400.000 people lost everything, in many cases even friends and relatives, not to mention everything in their households. Documents, photos, clothes. Their homes? That goes without saying. And that's the problem.

I wanted to make the suggestion that everyone of the 100,000 or so people affected by the nuclear accident be paid half a million dollars. A family of four would get $2,000,000. Enough to start a new life. The problem is not the cost. $50bn is about a year's worth of coal, oil and gas being imported to replace nuclear power in Japan. The problem is the other 400,000 who will rightfully say that their losses were so much worse, that they should easily be entitled to get even more money.

Yes, it's a terrible accident and an avoidable one as well. It has been known since 1966 (p.50) that the Mark I BWR containment is unable to withstand a meltdown under any conditions, because it is too small. In case of a meltdown you either vent the containment in a controlled manner, or it leaks uncontrolled. Japan only saw the need to install filtered containment vents in any of its nuclear power plants in 2013 ... they must have had a problem in one of their nuclear plants or something. Strangely enough, neither Germany or France needed that kind of reminder to get to that point. They did it a quarter of a century before that. (And yes, it was after Chernobyl. But it's not like the Japanese never heard about that one.)

Probably from TMI. Read the timeline on the link below for more information:

http://www.nrc.gov/reading-rm/...

Note that the reactor stayed covered in place for about 4 years, and the catastrophe was not anywhere near as bad as Fukushima. Can't even imagine how long it will be until Chernobol is cleaned up.

Most of the worst stuff has been moved to the Idaho National Laboratory, where it sits in long term storage (and will until someone figures out if they want to recycle the fuel or bury it). I imagine the actual reactor site is pretty safe today but will require monitoring for an indefinite time.

The NRC's job is safety. That's it. They have people stationed at power plants, and their only job is to ask questions and enforce policies such that the plant operates safely. With that beaten home, let's get to some specifics.

The biggest concern for the current fleet of U.S. reactors (mostly all Generation II designs) in terms of long operation is embrittlement of the reactor pressure vessel (RPV) due to radiation damage (mostly neutronic). Embrittlement of the RPV comes into play when severe accident responses (for either Design Basis Accidents (DBAs) or Beyond Design Basis Accidents (BDBAs)) dictate fast, extreme cooling of the RPV that can lead to pressurized thermal shock (PTS) events. The biggest hurdle toward getting approval is proving which-and-every way to a high confidence level that a PTS breach of the RPV will not occur from this embrittlement. If plants cannot do this, the NRC will not issue a license extension because the plant cannot prove its safety. If you care to read more on it, consult 10 CFR 50.61 for details (or the whole thing at the10 CFR 50 Part Index.

Are there other requirements? Yes (see the 10 CFR 50 index above). However, this is the one aspect I wanted to expound upon since turbomachinery has been replaced/upgrade, fuel is refreshed every 18 months or so, and piping is constantly checked. But I wanted to stress the safety issue. The NRC has 100% no qualms about telling a plant "no" if that plant cannot prove it is safe to operate.

The NRC's job is safety. That's it. They have people stationed at power plants, and their only job is to ask questions and enforce policies such that the plant operates safely. With that beaten home, let's get to some specifics.

The biggest concern for the current fleet of U.S. reactors (mostly all Generation II designs) in terms of long operation is embrittlement of the reactor pressure vessel (RPV) due to radiation damage (mostly neutronic). Embrittlement of the RPV comes into play when severe accident responses (for either Design Basis Accidents (DBAs) or Beyond Design Basis Accidents (BDBAs)) dictate fast, extreme cooling of the RPV that can lead to pressurized thermal shock (PTS) events. The biggest hurdle toward getting approval is proving which-and-every way to a high confidence level that a PTS breach of the RPV will not occur from this embrittlement. If plants cannot do this, the NRC will not issue a license extension because the plant cannot prove its safety. If you care to read more on it, consult 10 CFR 50.61 for details (or the whole thing at the10 CFR 50 Part Index.

Are there other requirements? Yes (see the 10 CFR 50 index above). However, this is the one aspect I wanted to expound upon since turbomachinery has been replaced/upgrade, fuel is refreshed every 18 months or so, and piping is constantly checked. But I wanted to stress the safety issue. The NRC has 100% no qualms about telling a plant "no" if that plant cannot prove it is safe to operate.

They specifically include "byproduct materials" in their definition (along with "source materials" and "special nuclear materials", the weapons grade stuff you refer to), which includes just about every radioisotope with commercial or medical applications...

http://www.nrc.gov/materials.h...

i believe VY has been shut down for a while

According to NRC status Vermont Yankee was at 100% yesterday. Stop making stuff up and guess working your way through energy issues please. Thanks.

Government good, business bad. +85 Insightful!! Yay

Radioactive materials get stolen routinely in the US. Troxler gauges are portable devices used to measure moisture content and material density. Like anything else found at a construction site, these are subject to frequent theft. Usually they go missing in a stolen vehicle, trailer or whatnot. Reselling devices that are individually licensed by the NRC isn't really feasible; nobody wants a hot Troxler gauge.

You may read about these events here. Moisture gauges aren't anywhere near as dangerous as Cobalt isotopes, but these events are reported and the thefts are pursued vigorously and the equipment is usually recovered. If an actual category-1 device went missing in the US the pursuit would be brief.

We generally know who the miscreants are among us, and when Government can be bothered to deal with them because the stakes are high it doesn't take long.

Have you read NUREG 1150, the NRC accident study that includes Peach Bottom? 18 hours after station blackout, core melting will start. The most likely risk is a fire knocking out power. "This means that the dominant plant damage states will be driven by events that fail a multitude of systems (i.e., reduce the redundancy through some common-mode or support system failure) or events that only require a small number of systems to fail in order to reach core damage. The station blackout plant damage state satisfies the first of these requirements in that all systems ultimately depend upon ac power, and a loss of offsite power is a relatively high probability event. The total probability of losing ac power long enough to induce core damage is relatively high, although still low for a plant with Peach Bottom's design. "

That's the problem. Lose power with that class of plant, and there will be a meltdown. That's what happened at Fukushima. The reactor survived the earthquake and tsnuami, but the backup power system wiring did not. They had 13 backup generators and a trailer-mounted generator, but some of the backup generators and the power connection point were flooded, and they had the wrong cables for the trailer-mounted generator.

Here's a description without the hype. This has a small containment vessel, only slightly larger than the reactor pressure vessel. It's a vacuum bottle setup - there's normally a vacuum between the pressure vessel and the containment, as insulation. In an emergency, the reactor vents into the containment vacuum, which allows more heat conduction to the outside. The outside water pool is just a big heat sink.

Most containment vessels are much bigger than the reactor vessel. One of the problems with the reactors at Fukushima was that the containment wasn't big enough to contain the overpressure produced in a hydrogen explosion. Presumably there's some justification for the small containment vessel in this new design.

Insurance for nuclear power plants is set up by the government, but it is funded by the plant operators:

http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/funds-fs.html

It is true there's a top limit per incident, but that's true of any insurance policy.

I think this could be a hoax. It's not a scientific paper, not in a peer-reviewed journal's letter section. It appears via a Google circles posting from Kerry Emanuel who is a well-known, though partially reformed, climate denier. It looks like the Google+ account the letter is published in was just created. Plus, the facts are either skimpy & wrong. Saying we cannot ramp up solar & wind power fast enough, but can ramp up nuclear, is directly in opposition to what's happening. Solar installations are going up by double-digit percentage points each year, and meanwhile we haven't had a new nuclear power plant in over 40 years. The only pair that is underway (which is pictured in the Yahoo! story) is years from completion. There are only 19 permit applications active for new nukes in the US, and the power industry (which is notoriously risk-averse) has for decades shied away from their huge liability and expense.

If only there was a place where we could scrutinize the scrutiny!

Oh wait, there is! NRC Scrutiny

Agreed; there is no impact on safety. On one hand, I'm glad we won't be paying their over bloated, $277/hour pay rates. Yes, folks, regardless of who is doing the work or what they are doing, the commercial entities are required to reimburse the NRC at a rate of $277 per hour. http://www.nrc.gov/reading-rm/doc-collections/news/2013/13-012.pdf
On the other hand, it's all for naught as they will likely be back-paid for their free vacation. That, and a variety of improvements and life extensions will get strung out even longer. Alas.

In a shocking and atypical display of foresight (notably absent in, say, chronically underfunded "Pension funds", back when those existed), the NRC actually requires plant operators to sock away enough money to decommission the plant when they are finished with it, even if they become insolvent.

I assume that they didn't really want to be stuck with a bunch of glow-in-the-dark superfund sites....

nuclear and other power plants should not be allowed construction without adequate consideration of cleanup cost. as it stands, superfund is a joke

Superfund has absofuckinglutely nothing to do with cleaning up nuclear plants.
I'm surprised there are so many people who modded up a fundamentally wrong post.

http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/decommissioning.html

Decommissioning Funds

Each nuclear power plant licensee must report to the NRC every two years the status of its decommissioning funding for each reactor or share of a reactor that it owns. The report must estimate the minimum amount needed for decommissioning by using the formulas found in 10 CFR 50.75(c). Licensees may alternatively determine a site-specific funding estimate, provided that amount is greater than the generic decommissioning estimate. Although there are many factors that affect reactor decommissioning costs, generally they range from $300 million to $400 million. Approximately 70 percent of licensees are authorized to accumulate decommissioning funds over the operating life of their plants. These owners -- generally traditional, rate-regulated electric utilities or indirectly regulated generation companies -- are not required today to have all of the funds needed for decommissioning. The remaining licensees must provide financial assurance through other methods such as prepaid decommissioning funds and/or a surety method or guarantee. The staff performs an independent analysis of each of these reports to determine whether licensees are providing reasonable "decommissioning funding assurance" for radiological decommissioning of the reactor at the permanent termination of operation.

Before a nuclear power plant begins operations, the licensee must establish or obtain a financial mechanism -- such as a trust fund or a guarantee from its parent company -- to ensure that there will be sufficient money to pay for the ultimate decommissioning of the facility.

Not that it's entirely relevant to GP's post against new nuclear plants, but half of the nuclear plants operating in America started operation from 1969-1977. (See Table 8.)

Power plants aren't always the most modern of things, given the huge capital costs in construction and various environmental regulations (e.g. the Clean Air Act) that require any plant making "major modifications" to conform to current emissions regulations which place a financial hurdle for upgrades.

However, you are right that Windscale is mostly irrelevant to discussion of modern nuclear power because it happened due to Cold War short-cutting to produce nuclear weapons. An accident like that would never happen in a modern, civilian plant.

No, there are only 100 commercial reactors and only 93 of them are running right now. http://www.nrc.gov/reading-rm/doc-collections/event-status/reactor-status/ps.html

• http://en.wikipedia.org/wiki/List_of_civilian_radiation_accidents
• http://www.nrc.gov/reading-rm/doc-collections/event-status/event/
• http://www.nrc.gov/reading-rm/doc-collections/event-status/event/en.html

• http://en.wikipedia.org/wiki/List_of_civilian_radiation_accidents
• http://www.nrc.gov/reading-rm/doc-collections/event-status/event/
• http://www.nrc.gov/reading-rm/doc-collections/event-status/event/en.html

We are exposed to Natural radiation all the time
http://www.nrc.gov/reading-rm/basic-ref/glossary/background-radiation.html

Background radiation
The natural radiation that is always present in the environment. It includes cosmic radiation which comes from the sun and stars, terrestrial radiation which comes from the Earth, and internal radiation which exists in all living things. The typical average individual exposure in the United States from natural background sources is about 300 millirems per year

Please spend your last $11.1 million on a facility that is never going to become operational. Make sure the money goes to companies financing political lobbysts.

Fact Sheet on Licensing Yucca Mountain

That Bloomberg story is about the reactor pressure vessel or RPV, the part the contains the reactor core. These authors write poorly and got it wrong calling it the "containment vessel."

This Slashdot story is about the AP-1000 containment vessel, not the RPV. The vessel is 36 meters wide and 65 meters tall. Nothing on Earth can make a single piece of forged steel that large.

The RPVs specified for the AP-1000 are unusual. RPVs are traditionally welded.

Reactor pressure vessels, which contain the nuclear fuel in nuclear power plants, are made of thick steel plates that are welded together.

RPVs for other common reactor designs such as CANDU or VVER are welded assemblies. Often forged steel steel rings are stacked and welded. Some RPVs use large forged plates and are axially welded.

Note that although the bottom of the AP-1000 RPV is a single piece it still has a separate head; the top of the RPV is gasketed and bolted to the vessel like every other PWR or BWR. It has to be to (re)fuel the reactor.

Your town has a billion dollars and wants to build a nuclear power station. You've been asked to recommend what kind. Give a recommendation with evidence to support safety, reliability, fuel cycle handling, economics, probability of success, etc.

Does the project include making contingency plans in case something like tritium leaking into the groundwater happens, or is it just a Libertarian nuclear power love fest assignment?

The only entities that can afford to build a nuclear power plant such as Entergy, Duke, PG&E always end up doing the double whammy of cutting back on maintenance just as the plants start to age out. Then, they quickly spin off the plant ownership to a separate division, then a separate DBA, then quietly sell it or convert it to a wholly separate no-liability company just as the expensive chickens of total rebuilt or shutdown come home to roost.

Looks like somebody watched a little bit too much Captain Planet as a kid.

As an aside, the folks running SONGS for PG&E decided to redesign the tube bundles when they had to be replaced. They arrogantly redesigned them - without even telling the NRC, mind you - to get more [Jeremy Clarkson] Power! [/JC], but only managed to make them wear out in mere months due to so much vibration the tubes eroded each other.

How do you define "arrogantly redesign"? They made a design change which was within the scope of 10 CFR 50.59.

Analyses conducted in the late 1970s concluded that the Mark I would almost certainly result in disaster in the event of sustained power loss - and it did.

Yeah... unfortunately, the containment failures at Fukushima matched the models pretty well. I've posted it before, but the following document is illuminating... see the section titled "BWR 3/4 Perspectives", including the parts regarding station blackout (SBO), transients with loss of coolant injection, and transients with loss of decay heat removal (DHR).

http://www.osti.gov/bridge/purl.cover.jsp?purl=%2F205567-BJIEKT%2Fwebviewable%2F

I still don't understand why TEPCO didn't install hardened containment vents back in the '90s. If they had, things would have gone very differently. They must have known about NRC Generic Letter 89-16.

https://forms.nrc.gov/reading-rm/doc-collections/gen-comm/gen-letters/1989/gl89016.html

The other thing I don't understand is why Unit 1 didn't handle the situation better than the others. It should have because it has an Isolation Condenser instead of Reactor Core Isolation Cooling... I'm not sure that anyone has yet explained what happened with this.

Are we nuclear yet? For us to do that, we have to take the maintenance of these plants out of the hands of potential Homer Simpsons.

Similar to the core concept here in question, be careful not to mix media bias with technological facts. Comparing the average American nuclear worker to Homer Simpson is not accurate.

Information about American nuclear plant operators.

Aside from the actual day-to-day operation, the maintenance of the American nuclear plants is above and beyond what is necessary.

Operational Maintenance

Are we nuclear yet? For us to do that, we have to take the maintenance of these plants out of the hands of potential Homer Simpsons.

Similar to the core concept here in question, be careful not to mix media bias with technological facts. Comparing the average American nuclear worker to Homer Simpson is not accurate.

Information about American nuclear plant operators.

Aside from the actual day-to-day operation, the maintenance of the American nuclear plants is above and beyond what is necessary.

Operational Maintenance