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Plutonium is Forever

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Re: Plutonium is Forever

#81

Post by Tichy »

InclinedPlane wrote: post #64
anamax wrote: post #55

Earlier quoted context omitted.

> Whether you measure by hour or by mile air travel is still comparatively safe The problem with that measure is that air accidents don't correlate with either hours or miles, but with takeoffs and landings. The comparable incident for cars is probably intersections. Yes, each plane trip involves only one takeoff and landing while each car trip usually involves multiple intersections, but that just means that simple…

What's important for humans is whether spending time in an airplane or in a car is more dangerous and whether choosing to use an airplane or a car for a trip is more dangerous. In either case the airplane is safer than the car.

As was explained, it is a function of the number of takeoffs and landings. Therefore it only holds because airplane trips tend to be a lot longer than trips with other vehicles.

Re: Plutonium is Forever

#82

Post by iuytghyjuyh »

tedunangst wrote: post #75
ChuckMcM wrote: post #45

Earlier quoted context omitted.

Sigh, its not 'one of the most challenging technologies' its actually rather simple which is why it was developed in the 1940's, a 'challenging' technology would be genetically engineered life forms, only recently managed [1]. Not only are synthetic life forms more technologically challenging, if they escape from the lab the planet is designed to provide them with an environment that allows them to replace all existi…

Actually, if you ingest mercury (the metal), it's not that bad for you. Basically goes right through. It's mercury vapor and various compounds that are dangerous. The ABC article doesn't have enough info to identify what's really in the coal ash. http://www.ncbi.nlm.nih.gov/pubmed/16973445

Although if your heat the mercury to 1200C in the presence of hydrocarbons, sulfur and a bunch of other elements and then spray it out of the stack as water vapor you are likely to generate some biologically accessible Hg compound

Re: Plutonium is Forever

#83

Post by iuytghyjuyh »

borism wrote: post #72
InclinedPlane wrote: post #71

Earlier quoted context omitted.

"But it also so much more dangerous when nuclear accidents happen than anything else." This is a facile assumption but it's almost certainly false. The Banqiao dam disaster killed 25,000 people directly, and destroyed 6 million buildings (it caused 145,000 further deaths due to famine). Such a disaster far outstrips even Chernobyl, which was about as maximally bad as any nuclear reactor accident can be (runaway fissi…

now please factor in duration and affected area and population into account when talking about severity of nuclear accidents, the same way you factored in hours and miles when you wrote about aviation safety.

But do you factor in the deaths in Iraq into the cost of oil fired power stations? And flooding in Bangladesh and sea level rises as part of the CO2 cost of coal?

Re: Plutonium is Forever

#84

Post by iuytghyjuyh »

pjscott wrote: post #79
3am wrote: post #61

Earlier quoted context omitted.

Germany?

They've temporarily shut off all their nuclear plants constructed before 1980. They need to get power from somewhere , and nuclear power has the lowest number of deaths per terawatt-hour of any currently-viable competing energy source. Coal pollutes the atmosphere and kills miners (among other things). Natural gas has an unpleasant tendency to explode during handling, and is considerably more expensive than coal. And…

The German solution is to burn their dirty high sulfur coal in Poland. Most German coal is stripped mined so unless you fall of the bucket excavator there aren't many miners killed.

It does pollute the atmosphere - but the winds blow east so it's the polish, then Belarus, then Ukrainian atmopsheres so who gives a s

Re: Plutonium is Forever

#85

Post by afterburner »

mchouza wrote: post #25
Duff wrote: post #16

Now I'm starting to get worried. This has been up for 2 hours, and typically the "atomic trolls" would have at least 5-6 comments up about how all of this is nothing to worry about. So I guess this is truly bad.

I'm no "atomic troll" and radioactive contamination at Fukushima is potentially a significant problem. But the detected plutonium levels are almost insignificant compared to the detected Cs-137 contamination (whose half-life is 30 years, not months): http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/im... (Pu) http://www.mext.go.jp/component/english/__icsFiles/afieldfil... (Cs-137) The activity of Cs-137 is o…

The plutonium leak confirms a meltdown and containment breach. That is what is significant.

Re: Plutonium is Forever

#86

Post by lutorm »

bjelkeman-again wrote: post #73
bjelkeman-again wrote: post #69

Earlier quoted context omitted.

Recent research with one of the least radioactive isotopes of plutonium (plutonium-242, which has a half-life of 376,000 years) indicates that plutonium in the body may contribute to the development of tumors. In general, however, plutonium isotopic mixtures that are commonly encountered in the nuclear fuel cycle, nuclear weapons programs, or thermoelectric generator applications exhibit much higher radiological toxi…

This abstract: http://www.rrjournal.org/doi/abs/10.2307/3578993 (albeit a bit hard to read if you don't parse TeX) seems to say that of 144 beagle dogs who inhaled plutonium oxide, 93 died of bone tumors, 46 of lung tumors and 2 of liver tumors. Although I can't figure out from the abstract what the dose was.

They say it's 0.6-60 Gy. If my calculation is correct, to get a 10Gy dose over ~2.5 years due to the 5.15Mev alphas from Pu239, that would mean they contained 6.7e-8 kg Pu239 / kg body mass, i.e. .06mg/kg body mass. So it's fair to say that it's pretty bad. Unless I dropped a factor N_A or something... ;-)

Re: Plutonium is Forever

#87

Post by caf »

joeburke wrote: post #47
pasbesoin wrote: post #30

This disaster has caused me to revisit my concerns regarding nuclear energy. # One of the most challenging technologies ever developed, is under the control of politicians and bankers. A recipe in itself for technical disaster. # Public concerns, under this regime, end up being counter-productive. "No new nukes" means extending the life of the oldest, most vulnerable technology. # Human society has demonstrated no st…

Please, let's keep the fear mongering down. This is the first incident of this kind in 40 years and the number of casualties will probably not exceed a few hundreds. Coal alone killed over 100,000 people over the past century.

Three Mile Island was 32 years ago.

Re: Plutonium is Forever

#88

Post by caf »

chris_j wrote: post #34
raleec wrote: post #26

I plead ignorance. Why does a nuclear power station need an external power source? Obviously there is a good reason, but my sleep deprived brain can't fathom it.

Very simply, when a nuclear reactor stops, the fission products in the fuel rods continue to decay and therefore continue to generate heat. A lot of heat. An external power source is needed to take that heat away from the fuel. Failing to keep the reactor cool can potentially be rather catastrophic. There is lots of information online. Why not start here: http://en.wikipedia.org/wiki/Nuclear_safety#Failure_modes_of..…

Spent fuel rods even continue to generate a nontrivial amount of heat months after they've been removed from the reactor - one of the problems at Fukushima is the spent fuel pools (which are located near the top of the reactor buildings, outside the secondary containment).

Re: Plutonium is Forever

#89

Post by kragen »

lutorm wrote: post #86
bjelkeman-again wrote: post #73

Earlier quoted context omitted.

This abstract: http://www.rrjournal.org/doi/abs/10.2307/3578993 (albeit a bit hard to read if you don't parse TeX) seems to say that of 144 beagle dogs who inhaled plutonium oxide, 93 died of bone tumors, 46 of lung tumors and 2 of liver tumors. Although I can't figure out from the abstract what the dose was.

They say it's 0.6-60 Gy. If my calculation is correct, to get a 10Gy dose over ~2.5 years due to the 5.15Mev alphas from Pu239, that would mean they contained 6.7e-8 kg Pu239 / kg body mass, i.e. .06mg/kg body mass. So it's fair to say that it's pretty bad. Unless I dropped a factor N_A or something... ;-)

.06mg/kg is a pretty small lethal dose. That's probably entirely due to the radioactivity. Tetraethyl lead has a lethal dose of something like 1.2mg/kg http://www.inchem.org/documents/pims/chemical/organlea.htm which is 20 times higher. But that's organic lead, which is rapidly absorbed; lead oxide is something like 600 mg/kg, ten thousand times higher than the dose you calculated for plutonium. But, in that case we're comparing the ingested dose to the dose absorbed; you'd have to ingest about 150mg/kg of PuO₂ to absorb 0.06mg/kg of it.

Also, though, the fatal dose of another heavy metal like lead might be lower than the LD₅₀ reported, because LD₅₀ tests normally don't give the experimental animals several years to die.

So, in conclusion, it seems like accurately comparing plutonium poisoning to poisoning by other heavy metals requires more knowledge than I have. Good thing the NRC's on the job.

Re: Plutonium is Forever

#90

Post by orangecat »

caf wrote: post #87
joeburke wrote: post #47

Earlier quoted context omitted.

Please, let's keep the fear mongering down. This is the first incident of this kind in 40 years and the number of casualties will probably not exceed a few hundreds. Coal alone killed over 100,000 people over the past century.

Three Mile Island was 32 years ago.

Three Mile Island was 32 years ago.

Which killed how many people?

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