Nuclear

[JonS]

You don't consider a radiation burn to be a health complication caused by a spill of radio active material. Fair enough, I suppose - see no evil, and all that.

I do.

[Elmar Bijlsma]

Talk about being selective with your threat perception!

You base your scaremongering on 2 guys with burned feet as a result of a very rare accident involving a quake/tsunami combo. Yet you skimp over the other energy sources' far, far greater and regular death toll.

You can pretty much compare any power source and nuke power is still coming out smelling of roses in terms of environmental damage, human health and in some cases even in terms of radiation(!) Everyone involved at the Fukushima plant could drop dead tomorrow and nuclear power would still beat the coal safety record by a whopping great margin.

Lets be clear about the current threat to the population at large:

You can fly to Japan, eat the most radioactive spinach you can find for a month and then fly back home. If you then happen to catch cancer from the trip, it is more likely to have been caused by the flights to and fro.

All the figures being bandied about on news are real impressive, but if you go investigate what they mean it turns out the danger is in most cases fairly limited and short term.

The thing to watch out for is Caesium-137 but I'm getting confused signals on how severe and widespread it is.

[JonS]

I'm not scaremongering, read my posts again. I've made no statement for or against nuclear power, and I'm also not trying to pretend I know what the hell is going on over there. Any scaremongering you've 'read' in my posts are your own internal projections.

OM is trying to paint a rosy picture that despite a very substantial nuclear incident, coupled with an absolute dearth of analysis or studies, longitudinal or otherwise, that there have been no health complications due to the various spills/releases of radioactive materials. That is an absolute stament, not a comparative one.

I don't think that's true, even in the direct sense which the burned workers represent, and I'll be astonished if those two or three are found to be the only ones once the Japanese move beyond Response and into Recovery. Then there's the indirect health consequences, such as the farmer who committed suicide after his farm was quarantined due to contamination.

[JonS]

Yet you skimp over the other energy sources' far, far greater and regular death toll. You can pretty much compare any power source and nuke power is still coming out smelling of roses in terms of environmental damage, human health and in some cases even in terms of radiation(!) Everyone involved at the Fukushima plant could drop dead tomorrow and nuclear power would still beat the coal safety record by a whopping great margin.

I'm not skimping anything. But, for the sake of your own argument, could you point me to the coal disaster that resulted in a 3,000+km² exclusion zone that remained in place for at least 25 years?

[Stalins Organ]

whever evaluating the dangers of Nuclear power I always find it disturbing to come back to the number of fatalities caused by/in hte fossil fuel industry - eg 29 miners killed here on the West Coast last year, and I think a simlar nubmer in hte US somewhere shortly before then too??

I would hate to guess how many coal miners have been killed in, say, the 50 years since Nuclear power has been really "popular".

Along with 11 oil workers in the Gulf last year, 11 on Petrobras 36 in 2001, and going back further 167 on Piper Alpha, 22 on KAB 101 in 1994, Alexander L. Kielland killing 123 in 1980, Ocean Ranger in 1982 killing 84, Sea Gem in 1965 killing 13.

And then there's all the oil spills and their effects on lives and environments, and just general industrial accidents in & on oil facilities, pipelines, service stations, etc. plus people killed or injured by fires fueled by petro-chemicals, and the bilions of tons of air pollution from our addiction to the black stuff.

and all that is more-or-less socially acceptable - oh sure we wring our hands about it a bit - but the vast majority of us are happy to drive to work, to fly between cities, to have our global-economy delivered on shipping that burns heavy oil and is delivered on trucks.

So I hope you will forgive me if I currently think that the "concern" about the nuclear situation in Japan is just a little hysterical!

[Elmar Bijlsma]

I'm not skimping anything. But, for the sake of your own argument, could you point me to the coal disaster that resulted in a 3,000+km² exclusion zone that remained in place for at least 25 years?

Does it have to be coal? Because in the power generation business only hydro-electric dams comes close. The Three Gorges Dam comes in at under half that area but did manage to force 1.2m+ people out of their homes and has dealt massive ecological damage to the area. And there is dihydrogen monoxide all over the place now and we all know how lethal that is!

[JonS]

You set the terms;

nuclear power would still beat the coal safety record by a whopping great margin

[Elmar Bijlsma]

And then you shifted the goals by making that safety record solely about surface area evacuated over a span of time. If you start messing with the goalposts I'll change the shape of the field.

[Stalins Organ]

I'm not skimping anything. But, for the sake of your own argument, could you point me to the coal disaster that resulted in a 3,000+km² exclusion zone that remained in place for at least 25 years?

Coal seam fires worldwide, thousands of them....many unreported...chinese ones are probably the worst ....generating as much as 40 tons of mercury perannum.

Then there's the outpot from yuor average coal fired station, which might not make any given area uninhabitable, but the idea that it is harmless is patent nonsense - in an average year a 500MW station emits:

3,700,000 tons of CO2

10,000 tons of SO2

10,200 tons of NOx

720 tons of CO

220 tons of hydrocarbons

170 lbs of mercury

225 lbs of arsenic

114 lbs of lead

all that pollution is not making he planet a nicer place to live, and quite frankly it's killing a lot more people each year than Chernobyl ever will!

So how keen are you to do without your coal generated electricity??

[JonS]

And then you shifted the goals by making that safety record solely about surface area evacuated over a span of time. If you start messing with the goalposts I'll change the shape of the field.

Is the area evacuated relevant to safety?

[JonS]

So how keen are you to do without your coal generated electricity??

Very, but you are, as usual, being an ass.

Not all coal plants were created equal, and even if they were Coal/Nuclear are not the only two sides on this coin.

[Other Means]

I'm not scaremongering, read my posts again. I've made no statement for or against nuclear power, and I'm also not trying to pretend I know what the hell is going on over there. Any scaremongering you've 'read' in my posts are your own internal projections.

OM is trying to paint a rosy picture that despite a very substantial nuclear incident, coupled with an absolute dearth of analysis or studies, longitudinal or otherwise, that there have been no health complications due to the various spills/releases of radioactive materials. That is an absolute stament, not a comparative one.

I don't think that's true, even in the direct sense which the burned workers represent, and I'll be astonished if those two or three are found to be the only ones once the Japanese move beyond Response and into Recovery. Then there's the indirect health consequences, such as the farmer who committed suicide after his farm was quarantined due to contamination.

Well if you know of more, do tell. I'm sure you're not just basing your argument or prejudice.

[__Yossarian0815[jby]]

It was used as a coolant as well, I believe. Could be wrong - willing to learn, imagine that.

The 56 number wasn't given by the Soviets.

Book.

Review.

If you read the links I've posted you'll see the workers have got a great chance of zero happening.

A lie is a lie. You can´t have thousands of people working without protection under extreme radiation conditions without most of them dying as a result. Please spare me any weaselly lawyer definitions of how those thousand deaths don´t count because of some arbitrary definition somebody thought up.

An example: Recently I read an article saying that it´s not that terrible that thousands of children got thyroid cancer post chernobyl because thyroid cancer can be treated well.

[JonS]

Well if you know of more, do tell. I'm sure you're not just basing your argument or prejudice.

I don't know more, that's the thing. But then, neither do you.

On the other hand, only one of us is trying to paint a picture of sweetness and light. What I do know is that pretty much every attempt to portray the Fukushima disasters as trivial or inconsequential or under control over the past couple of weeks has susequently been shown to be somewhat optimistic, to put it mildly. This is a big deal, and it's going to have serious consequences for Japan for a long time. They already have a compromised national electrical supply. It also looks like they're going to lose a chunk of their already quite small country to an exclusion zone. Their land-based food supply is at least partially compromised, and fishing off the east coast looks like being a non-starter for some time. Tourism is taking it in the shorts too.

All those things have happened because Japan is so reliant on nuclear, not because coal is more or less or differently dangerous. They happened because nuclear has unique risks, and pooh-poohing them or writing them off as hysteria doesn't help the deate. Nuclear power is asolutely wonderful, right up until it goes pear-shaped, at which point it seems that some just want to continue talking about how wonderful it is.

TEPCO won't be carrying the costs for the mess they allowed to occur. To them it's all an externality. In fact, for the operator of a nuclear power plant, this is probably the cheapest of all decomissioning methods.

[__Yossarian0815[jby]]

There are some significant risks to nuke power, sure. But coal/oil is ultimately unsustainable and has shown to be far more dangerous in any case.

How is nuclear sustainable? Neither Uranium nor Thorium exist in endless amounts. The more you expand nuclear the shorte it´ll be around.

And the renewables have so far fallen woefully short in capacity and costs. (In The Netherlands it is joked that windfarms are more dependant on subsidies then wind)

Nothing can compete with fossil fuels on a cost basis.

Nuke power is the best of a bad bunch. We certainly have not got the option to get rid of it all together. Alternative techs sufficient for our needs are just too far off. And we best get building new reactors soon because in most countries I know off age is creeping up on the existing ones.

I think we agree. If nuclear is to have a chance, the 1970s plants have to be replaced first, especially the russian models without containments.

[Other Means]

I do know Jon. It would be all over the news. It's not. No one is hurt. There has been a bad industrial accident but apart from a worker killed in a crane during the tsunami, no-one is dead.

Or do you have some special facts you're not sharing with the group?

A lie is a lie. You can´t have thousands of people working without protection under extreme radiation conditions without most of them dying as a result. Please spare me any weaselly lawyer definitions of how those thousand deaths don´t count because of some arbitrary definition somebody thought up.

And the truth is the truth. The statement is 56 dead. There's dead and there's alive. You can't really get clearer.

[ironbar]

125 dead- by product of mine operation

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

Fly ash contamination

http://www.postandcourier.com/news/2008/oct/26/coals_time_bomb59266/

Cancer clusters in anthracite mining regions

http://southernstudies.org/2008/10/energy-watch-public-health-authorities.html

The last link is the most interesting to me as Schuylkyll County Pa, is where I grew up, where both sets of grandparents settled after leaving the old countries.

[dieseltaylor]

Other Means - you really are batting on a very very sticky wicket. To base your deaths figure at a very narrow point in time makes all your postings seem fantastical. Even more so when the death figures for Chernobylare highly suspect even 6 months after the blast let alone 3 years or 20 years.

And what about land no longer truly habitable by humans? In Japan there is not lots of spare land as there is in Russia.

1. Basically Cesium-137 has now been found 25 miles from Fukushima at such dangerously high concentrations that they far exceed the threshold of land abandonment used by the Soviet Union following the Chernobyl catastrophe (http://www.nytimes.com/2011/03/31/w...). This is raising questions of whether the evacuation zone around Fukushima should now be expanded.

The New Scientist article from yesterday reports

"

So far 70,000 people have been evacuated from a 20-kilometre-radius zone centred on the Fukushima Daiichi nuclear plant – but that may only be the beginning. The International Atomic Energy Agency (IAEA) says that radioactive contamination outside the evacuation zone has exceeded levels at which people should relocate. But the Japanese government says it will not widen the zone.

Radiation within the evacuation zone is so high, it is reportedly hindering workers trying to recover bodies left by the tsunami of 11 March. A further 30,000 people are expected to be evacuated from an area outside the evacuation zone but within 30 kilometres of Fukushima Daiichi, where people have been advised to leave or stay inside.

MEXT, the Japanese science ministry, has been monitoring radioactive iodine and caesium, considered most harmful to health, in soil 25 to 58 kilometres from the plant since 18 March. The IAEA says these deposits are very patchy, so it averages them across larger areas. This reveals average values of from 0.2 to 25 megabecquerels per square metre for iodine-131, and 0.02 to 3.7 MBq/m2 for caesium-137. The highest values are in a relatively small area north-west of the plant, as New Scientist reported this week.

Yet the numbers the IAEA is averaging show local hotspots that are far higher, and it is these, rather than averages, that people might encounter. The accumulated readings published today by MEXT show levels as high as 18 MBq/m2 in Iitate village, 40 kilometres from the plant, and 17.6 MBq/m2 just outside the 30-kilometre zone.

Time to go?

Even the averages are worrying, however. In Iitate, the IAEA says the average level of caesium-137 is double its "operational criteria for evacuation" – 1 MBq/m2 of caesium-137. After the 1986 Chernobyl accident, the level of caesium contamination at which evacuation was mandatory was 1.48 MBq/m2. The IAEA advised Japanese authorities "to carefully assess the situation".

In reply, chief cabinet secretary Yukio Edano told reporters that the situation did not "immediately require such action", although the levels of radiation might pose a risk "over the long term".

Others aren't so sure: the two highest caesium hotspots also carried 45 MBq/m2 and 57 MBq/m2, respectively, of iodine-131, and others also had high levels of iodine-131. Other short-lived radioisotopes may also be present – possibly enough, a radiation expert who did not wish to be named told New Scientist, to warrant temporary relocation of local inhabitants.

Notice that the use of averages screens out the dnagerous areas - rather like the USSR did for its hotspots. Imagine how dismissive one would be if the national average number of road accidents was used to declare there were no accident blackspots. Baloney.

http://www.nytimes.com/2011/03/18/health/research/18cancer.html

For the length of time that damage to human lives continues.

[dieseltaylor]

Regarding coal and waste, it is a newish technology but it is to burn it in situ. See here:

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

This would remove some of the current objections.

SO taking historical coal problems is not a guide to the necessary future use.

Perhaps those who are quoting the kill rate of other power generation technologies ought to bear in mind currently how few nuclear plants there are and the comparatively short time span they have been in operation.

I am not suggesting nuclear power is of no use now and in the future. What I am finding difficult to live with is the jumping in by proponents lauding how safe it is and quoting some very biased figures.

[Bigduke6]

The RBMK reactor at Chernobyl was "moderated" by graphite control rods, meaning the deeper you shoved the rods into the core, the more damping on the nuclear reaction.

Since the nuclear reaction produces heat which is usually used to produce steam to drive turbines, the control rods will reduce heat produced by the nuclear reaction, thereby eventually causing the reactor to cool.

Therefore, provided you are not being a strict nuclear geek, it is more or less correct to say the RBMK is graphite cooled. But moderated is the preferred term, as the nuclear reactor scientists prefer to use "moderation" to describe what you use to control the actual nuclear reaction. Moderation is what keeps the nuclear materials in the reactor from going critical and melting down.

"Cooling" to describe what you use to keep the heat produced by the nuclear reaction low enough so that you don't catch something on fire or have a steam explosion.

It is worth noting here that, if your cooling goes fubar, then almost automatically you are going to have problems moderating your nuclear reaction, so cooling is considered extremely important to preventing meltdowns as well. As we have seen in Japan.

The dedicated cooling system in Chernobyl system was to a large extent a primitive and unique type. As I understand it, its cooling was performed primarily with water pumped through and around the nuclear core. This was the same water that was made into steam to turn the turbines, so in one way you had a very efficient closed loop, water gets heated, it turns into steam, spins the turbines, loses heat, turns back into water, flows back into the nuclear core, where it helps keep it cool until it is turned into steam again.

For the record, and again as I understand it, water is a pretty good moderator of nuclear reactions, although not as good as graphite. Therefore, water levels in the reactor are another moving part you have to watch if you are an RBMK engineer trying to make electricity safely.

But the main thing is, as they said in Buckaroo Banzai, this is a very bad design. The reason this is bad is that these control rods are pretty durn long, like 6 meters, and so when you stick them in the holes in the reactor core they go into, when they go down they displace water. Which is cooling the reactor and indeed to some extent also moderating its nuclear reaction. So, if you jam a bunch of graphite rods into a RBMK reactor - like what you might do if you thought the reaction was getting out of control - you might just get a counterproductive effect. Control rods go in, water is displaced, and until the rod's presence takes effect on the neurons flying around in the core, the reactor is likely to get hotter and react faster. This effect is most pronounced if the reactor is running at very low power which, surprise, was one of the things the engineers did when they ran their test.

As it turns out engineers operating a similar reactor in Estonia in 1983 figured out the RBMK could produce this counter-intuitive result under the right conditions, but they kept the nuclear reaction under control. The Soviet government made their findings secret and the Chernobyl crew supposedly was not aware of what had happened in Estonia.

So think about it. The RBMK has graphite rods and it is inherent in the design that if you reduce the power, switch off the safety equipment, and then shove a bunch of rods into the core, you run a risk of triggering a very fast jump in nuclear reaction which, if you don't control it quick, could accelerate increase exponentially and that is what gets you a meltdown, steam explosions, and radioactive emissions. If you really manage to trigger a fast rise in reaction, you run the risk of not even being able to jam all the control rods into the core, as they're graphite and graphite can indeed catch fire from the heat generated by a runaway nuclear core.

None of this would have been possible, had the Chernobyl crew left the safety equipment on, it would not have been possible to power down to the extent they did, remove as many control rods as they did, stick back in as many control rods as quickly as they did, or wait as long as they did (about 90 seconds as opposed to the 10 seconds or less it should have taken) to respond to suddenly rising volume of nuclear reaction.

The Russians are the only people left operating these reactors, and they're modified with more or less proper containment structures around them, more control rods that move into the core from more directions, backups to the cooling system backups, and probably most of all the safety equipment is much harder to switch off.

It is not correct to say the Russians operate reactors inherently likely to cause an accident; after all the reactors (they're at Smolensk and Kursk) are hardly likely to feel a meaningful earthquake, never mind tsnunami. Shutting the reactors down, from my perspective, would not really make things particularly safer, you know the Russians are going to get the electricity lost from somewhere else, and personally I am not sure the pollution and extraction-related deaths from the coal would be less of a burden on the Russian state or its neighbors, than a proper nuclear accident. But I don't know.

What I do know is the Russians need electricity and they aren't going to take orders. Whether we like it or not, nuclear power is in the former Soviet Union for the very long term, and unless I miss my guess that goes for East Europe and France at least as well. I see discussions about doing away with nuclear power as futile. It would be a good idea to do away with cars and make every one ride trains and bicycles, that isn't happening either.

[__Yossarian0815[jby]]

The RBMK reactor at Chernobyl was "moderated" by graphite control rods, meaning the deeper you shoved the rods into the core, the more damping on the nuclear reaction.

Since the nuclear reaction produces heat which is usually used to produce steam to drive turbines, the control rods will reduce heat produced by the nuclear reaction, thereby eventually causing the reactor to cool.

Therefore, provided you are not being a strict nuclear geek, it is more or less correct to say the RBMK is graphite cooled. But moderated is the preferred term, as the nuclear reactor scientists prefer to use "moderation" to describe what you use to control the actual nuclear reaction. Moderation is what keeps the nuclear materials in the reactor from going critical and melting down.

I´m not a nuclear geek, but this is all wrong. The moderator (slows down neutrons) is what enables the chain reaction. Water is also a moderator, hence the need to add boric acid (captures neutrons) to the cooling water in Fukoshima, because water is restarting the chain reaction. Meltdown is simply the failure to remove the heat produced in the chain reaction.

[Bigduke6]

I stand corrected, "moderation" is control of the nuclear process so that the neutrons are released systematically, so that a nuclear reaction can be sustained. The mistake was due to a poor translation by me from the Russian, mea culpa.

For the record, a control rod is made of a material that absorbs neutrons and prevents them from continuing the nuclear reaction. So the more control rods affecting the nuclear core, the slower (well, less energy generated) by the nuclear reaction. Get enough control rods into the core, and there is no sustained nuclear chain reaction, there are just neutrons coming off the fuel rods that aren't causing any meaningful fission anywhere else.

I don't know about water and moderating the RBMK. The engineers I talked to made clear that water was a material that damped down the nuclear reaction, and that shoving a bunch of control rods into the core was dangerous, as the sudden displacement of water from the core could cause a jump in the nuclear chain reaction. The graphite control rods under normal circumstances would compensate, but as it was explained to me if the RMBK reactor was at very low power the loss of neutron absorption by water in the control rod channels would not be immediately compensated by the graphite control rods replacing them.

In other words, low power, ram a bunch of control rods into the core, and you run the risk of an extreme jump in the nuclear chain reaction, perhaps too extreme to keep under control.

[Michael Emrys]

..."moderation" is control of the nuclear process so that the neutrons are released systematically, so that a nuclear reaction can be sustained.

Well...sort of, but imprecisely expressed I think. Water, or any moderator, slows down fast neutrons so that they can be captured in the nuclei of fissionable isotopes that will then fission. Draining the water out theoretically would slow down the reaction because the fast neutrons could not be captured. But in a reactor where the same water is the coolant, you might get a meltdown anyway.

The engineers I talked to made clear that water was a material that damped down the nuclear reaction...

That's something I never heard of before. Are you sure you were understanding each other correctly?

Michael

[Stalins Organ]

Very, but you are, as usual, being an ass.

Good argument.....

Not all coal plants were created equal,

Neither are all nuclear plants.

and even if they were Coal/Nuclear are not the only two sides on this coin.

Not for us, but in many places they are - it seems unlikely that France will ever generate enough "renewable" electricity to replace it's nukes...or at least not within the lifetime of anyone alive now, nor China generate enough to replace its coal.

But hey - I'm being an ass, so that makes up for it....right??

[Bigduke6]

ME,

It appears that I understood what the engineer was saying, but he dumbed down the explanation, which considering the person he was talking to (me) made some sense. However, you're right, I clearly confused cooling with damping down the nuclear reaction, so I owe you one.

Here's the appropriate bit of WIKI:

the control rods have a 4.5 meters long graphite section at the end, separated by a 1.25 meters long telescope (which creates a water-filled space between the graphite and the absorber), and a boron carbide neutron absorber section. The role of the graphite section, known as "displacer," is to enhance the difference between the neutron flux attenuation levels of inserted and retracted rods, as the graphite displaces water that would otherwise act as a neutron absorber, although much weaker than boron carbide; a control rod channel filled with graphite absorbs fewer neutrons than when filled with water, so the difference between inserted and retracted control rod is increased. When the control rod is fully retracted, the graphite displacer is located in the middle of the core height, with 1.25 meters of water at each of its ends. The displacement of water in the lower 1.25 meters of the core as the rod moves down causes a local increase of reactivity in the bottom of the core as the graphite part of the control rod passes that section. This "positive scram" effect was discovered in 1983 at the Ignalina Nuclear Power Plant; however, the matter was soon forgotten.

So correct me if I'm wrong, but the deal (well one of them) with the RBWK at Chernobyl was that it had these funky graphite control rods that telescoped, and if fully contracted then significant water flows into the control rod channels, this is significant because the presence of the water in the bottom end of the channel increases the reactivity of the nuclear core.

Which peculiar effect engineers at the Ingalina plant in Lativa found out in 1983, but since the Soviet government suppressed the information, the Chernobyl engineers were not aware of it. (Although I have my suspicions the grapevine did, but who knows?)