I thought this was a very interesting piece.
The Athsma Society of Canada appeared at the public hearing over the relicensing of the Bruce nuclear power plant (one of the largest in the world) to discuss how they see the use of reliable, cheap, non-polluting atomic energy as vital to the interests of their constituency. Well worth a watch – or, really, a listen, since there aren’t any figures.
While I believe nuclear to be our best energy option and wouldn’t mind living in the vicinity of a modern plant, to call it non-polluting is misleading at best.
All current nuclear power plants produce waste material of varying degrees of danger. Such waste is pollution. But then, mankind (and all other animals) can not exist without producing a significant waste stream (pollution)
I will take this waste stream over any one of the following:
- the surface water pollution from strip mining to support a similar size plant.
- the combination of CO2 released and contaminants scrubbed from the stack.
- the damage to landscape and wildlife habitat from strip mining.
- the deaths that occurr at rail crossings supporting coal plants.especially when combined with rest of the supporting industrial deaths.
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The Asthma Society’s concern is air pollution, & nuclear plants simply don’t discharge any noticeable quantity of lung-irritating substances into the air. In a more general way, I think it is reasonable to call fission non-polluting, at least in the context of sources of industrial-scale energy, for these reasons :
- The quantity of waste material generated, per unit energy sent out, is very small. Canadian nuclear plants, using unenriched (natural) uranium, require one tonne of uranium for each seven gigawatt-days of electricity produced. (With a breeder cycle, this number can be reduced by something like 99%.) A coal-burning plant requires about 40 000 tonnes of fuel for the same production, plus several tonnes of air for each tonne of fuel.
- The waste material is in a form which is easily contained and isolated from the environment – if it doesn’t get into the biosphere, it’s hard to call it pollution. By contrast, most or all of the waste material from combustion is discharged directly into the environment.
- The small proportion of waste which is sometimes discharged by some types of plants consists largely of tritium. This substance is already present in the environment (produced by cosmic rays) ; because it is a form of hydrogen, it dilutes rapidly, so that measured concentrations away from the plant site are generally not appreciably higher than background. Because it is so diluted by nonradioactive hydrogen, & because of the low energy of its beta decay, its biological effects in the environment are scientifically known to be effectively nil.
- Radioactive wastes, unlike most other types of industrial wastes, spontaneously lose toxicity over time.
One of my arguments for more atomic power is fewer unit coal trains, with the result of increased available railway capacity & improved on-time performance, allowing more intermodal freight movment, leading to fewer trucks on the road, & thus fewer traffic delays (with attendant pollution, & more subtle causes of harm to human health) & also fewer deadly road accidents. No matter how careful & professional the truck drivers are, the sheer size & inertia of their vehicles is inherently unsafe in mixed traffic with passenger automobiles.
Institute the following rate schedule:
Customers within 5 mi of reactor: free electricity
Customers within 10 mi of reactor: 75% discount
Customers within 15 mi of reactor: 50% discount
Customers within 20 mi of reactor: 25% discount
People will be clamoring for a plant…
As I recall, breeder reactors produce much less in terms of waste product than normal cycle reactors. There was a big fuss back in the 70s and they were banned. Might be totally wrong on this point, but seems like we should investigate them.
Also, burning coal releases more radioactive material into the air than a fission reactor. This is on top of the non-radioactive pollutants.
It’s a tough call: nuclear reactors are hard to “stop” immediately when problems arise (cf. Fukushima Daichi). Better designs will mitigate this. Perhaps bury the whole reactor complex in underground caves and retire them in place after they have been decommissioned?
A number of first-generation plants have been decommissioned & the sites returned to “green field” status, where you wouldn’t know anything had been there. In the USA, some of these sites have an inconspicous fenced-in concrete pad somewhere, on which sit concrete casks containing all the spent fuel the plant ever produced. In other countries, there is typically a national mechanism for dealing with spent fuel.
There have been a number of experiments with breeder reactors, in the USA & elsewhere. The uranium-plutonium fast breeder has had various economic problems, but the technology appears viable. One of the more interesting experiments was the conversion of the Shippingport pressurized-water-reactor into a throium-uranium thermal breeder, a modification which could be applied to any LWR (the main type of power reactor in the world). Currently, the major barrier in the adoption of breeder technologies is what are called “non-proliferation technical safeguards”, measures supposedly intended to impede the making of off-label atom bombs, but which place considerable obstacles in the way of peaceful atomic energy. Considering that access to energy is a major factor in international conflict, & that countries which are at peace with their neighbours have little incentive to develop nuclear armaments, I doubt the soundness of this policy.
Breeders were controversial because they produce lots of plutonium which is a primary fuel for nuclear weapons.
If fission reactors have a future, it will be thorium.
When evaluating different source, all of the waste should be considered. But again, I agree that a properly designed modern plant is our current best choice for energy.
Also, when there is an accident, nuclear plants do release a considerable am mount of ‘air pollution’. Look, today at least, I am not looking to argue with anyone, but no one is served by glossing over the negatives of any option.
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As with many things in the realm of atomic power, this is a more complicated question than it may at first appear.
The plutonium from power reactors of any kind, thermal converters (produce less than they consume) or fast breeders (produce more than they consume) indifferently, is not very suitable for bombs, although for different reasons. Thermal-reactor plutonium contains a proportion of 240-Pu, which has a high spontaneous fission rate, requiring a very sophisticated bomb design to assure reliability. Fast-reactor plutonium contains a proportion of 238-Pu, the stuff used for spacecraft radioisotopic thermoelectric generators & such applications, which is a problem when it comes to wrapping the bomb core up in beryllium tamper, chemical explosives, et cetera.
Likewise, it is completely possible to use uranium-233, produced from thorium, in a bomb. It’s less effective than 235-U or 239-Pu, but it does work. Of course, depending on the specifics of the production process, there is gamma radiation from 232-U to make fabrication difficult, & spontaneous fission from 234-U to reduce reliability.
But, regardless of the facts, when you say “plutonium” people have a tendency to freak out. That’s one of the things I’m trying to combat by my educational efforts. I suppose I should do my “Introduction to Atomic Energy” series again some time soon.
Apples and oranges…
The general public reads “plutonium” and thinks “bad.” It may not all be suitable for use in weapons, but it is all chemically poisonous as well as being radioactive.
Thorium reactors are best in my mind not because of WMD potential or lack thereof, but they are safer in case of an accident - far less prone to “melt down,” etc.
As a nuclear fuel, thorium can be used in a variety of reactor designs, some better, some worse. The Chernobyl design, RBMK-1000, wouldn’t be much safer if operated on uranium-233 diluted with thorium than on 235-U diluted with 238-U. Similarly, the molten-salt-type reactor which many “thorium advocates” prefer can be operated using uranium-plutonium fuel, & there are proposals to do just that (eg the “WAMSR”).
Thorium has basically two advantages. Firstly, it produces virtually none of the long-lived, highly-energetic transuranic elements which are produced by irradiation of uranium-238 with thermal neutrons. Secondly, 233-U produces enough excess neutrons with thermal fission that you can breed fuel with slow neutrons, making for much greater flexibility in plant design. Most existing power reactors could be converted to a thorium-based breeder cycle right now, without waiting for any new designs to come on line.
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Interesting that a makerspace from Grand Junction, Colorado makes its presence in the forum while we happen to be discussing nuclear power. Much of western Colorado has rich deposits of uranium and vanadium. Until the Manhattan Project, uranium had been mostly discarded as waste material. It had few uses other than as a coloring agent for glass and ceramics.
Uranium tailings, the remains from the original mining of vanadium and later uranium, were often put into huge piles near mills where the ore is processed. Some of it was used for road and building construction before the danger of radioactivity was recognized. The problem became widely known in the early 70s and many homes in Grand Junction had to be jacked up and the material removed from the foundation (pier and beam.) Some concrete walls had to be replaced. Some streets had to be torn up and repaved. The stuff was even found in sandboxes in some school playgrounds.
If you ever see me glowing in the dark, you now know why. I spent some time in Grand Junction in the 60s.
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Aside from the graphite fire at Chernobyl, I am hard-pressed to think of anything answering to the description.
But when something is four thousand times safer than its major competitor, I guess it seems to me that exaggerating the negatives is far more of a problem than glozing them over. (That’s 160 deaths per terawatt-hour from coal, versus 0.04 from fission.)
I have a couple of nice pieces of uranium glass myself. One I’m planning to convert into a little lamp using UV LEDs or something like that – very cute to have the light coming from the shade, not the “bulb”!
Not to mention a quantity of “radium beads” marketed in Japan for people to use to get that natural hot-spring feeling in their home baths. And then there’s the “Nico-Clean”, which claims to be radioactive but isn’t! It’s this amazing quack product which allegedly makes cigarettes safer to smoke by irradiating them in the pack.
The question of radioactive building materials is an interesting one.
Obviously there are, for instance, the granites used in many public buildings (such as the Texas Capitol), which contain enough uranium, thorium, & daughter products that they’d be condemned under NRC regulations if they showed up at a power plant site ; or the homes built by people in the vicinity of Ramsar, Iran, using the native travertine stone, which is uncommonly active due to radium from the hot springs there (the area is underlain by a rich bed of uraniferous minerals). Less obvious is the use of phosphate-rock waste for producing wallboard — uranium is often recovered as a secondary product from phosphate mining. Then there have been the incidents where cobalt-60 sources have wound up being incorporated into steel used, for instance, for rebar in a large apartment complex in Taipei. This has been an object of study for years, not least because its inhabitants have shown an uncommonly low cancer incidence.
Of course, this gets at the question of what appropriate action levels are for remediation. As long as the exposures are small, in the range where there is no solid correlation between radiation dose & health effects, I’d say it’s right to ask what are the costs & consequences of “doing something” versus “doing nothing”.
That Ted talk utilizes some subjective analysis. In particular it is comparing inferred deaths. Which translates to if you expose X number of people to a substance you will end up with Y deaths. While the science for that is sound, there have been ample instances of such approaches being applied mistakenly, or wilfully so. As a result, the general population seems to find such things less ‘reliable’. Just look at the number of smokers we still have.
However, when exposed to atomic ‘air pollution’ the death rate is nearly 100% (when over a certain level), and nearly immediate (as opposed to decades in the future). People have no reason to doubt the reliability of any claims to ‘atomic danger’ and several good reason to doubt any official assurance that it is ‘safe’. After all we could talk for hours about how the US government exposed people to dangerous and lethal levels of radiation, all while assuring them it was safe.
Captain’s Log: Stardate 2015.09.29
Look, today at least, I am not looking to argue with anyone,
Making a special entry based on this comment. Ever since the last recent lunar eclipse of notoriety, most everyone at DMS has been “getting along” with each other.
I am suspicious.
To stay on topic, I am speculating that some unknown form of atomic radiation was released into the atmosphere and has affected certain sectors of our planet.
Also, I have no asthma.
JAG “Walter Has Been Replaced By A Pod Person” MAN
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