is nuclear power really really dangerous?
power - is nuclear power really really dangerous? is
the second of a series of briefing documents on the problems of power consumption,
posed by the steady depletion of fossil fuels and most particularly of pumpable
One of a grouping of documents on global concerns at abelard.org.
|on energy||on global warming|
housing and making living systems ecological
sustainable futures briefing documents
|Tectonics: tectonic plates - floating on the surface of a cauldron|
Too often, nuclear power is dismissed on the basis of urban legend and
mis-information. If our energy desires for the future were secure, or
if fossil fuels were without considerable drawbacks, then the question
‘is nuclear power
really really dangerous?’
would be no great issue. However, in the absence of nuclear power or else
radically new technology, our energy future is far from assured. It is,
therefore, very important that nuclear power generation be studied with
Here is a rough outline of radioactive substances, together with some very basic detail. Further background is available at Ionising radiation and health - risk analysis. See also this dicussion article.
A half-life means the time a radioactive material will take to lose half its radiation properties. For example, with iodine-131 that time is approximately 8 days. Thus after 8 days, half of its radiating material will have returned to (I think) ordinary, standard, non-radioactive iodine-126.
Often, radioactive substances go through several forms before returning to base. Uranium (with an atomic number of 92) eventually becomes decays to lead! The same goes for all elements with atomic numbers higher than 83. These include the trans-uranic elements, which are those elements with atomic numbers higher than that of uranium.
Uranium consists naturally of a mixture of
Some reactors, like the Canadian-designed Candu and the British Magnox reactors, use natural uranium as their fuel. Most present day reactors (Light Water Reactors or LWRs) use enriched uranium where the proportion of the U-235 isotope has been increased from 0.7% to about 3 – 5%. (For comparison, uranium used for nuclear weapons must be enriched to at least 90% U-235.) Note carefully that the fuel for nuclear reactors is totally unsuitable and irrelevant to weapon production.
Plutonium, in the abstract,
is not a highly radioactive substance, though clearly it (and uranium)
must be treated with due caution. All plutonium isotopes are radioactive.
The most important is plutonium-239 because it is fissionablethat
is, it can start a chain reaction; in effect, it can blow up.
(Note that the radioactive material used in power stations is not fissionable,
although such a power station can be converted to use for manufacturing
fissionable plutonium isotopes. The IEAE
supervises the industry.) Plutonium-239
has a relatively long half-life of 24,360 years.
The best summary I know of on fast breeders and plutonium is in chapter 13 of the online book by Bernard L Cohen, The Nuclear Energy Option. I have some extracts here: Plutonium is part of the solution, rather than a problem. The whole book is stuffed with useful information.
Critical mass (the amount that will spontaneously blow up when brought together) must be considered when handling quantities of plutonium of more than 300 grams (2/3 lb). The critical mass of plutonium-239 is only about one-third that of uranium-235. Uranium-238 is non-fissile; that is, it will not blow up if you have a lumpof itit does not have a critical mass.
It is a common misperception to imagine that a long half-life equates to high radioactivity, the reverse is the case. The higher the half-life, the more stable and less radioactive the substance: in other wordsit leaks, or radiates, its radioactivity more slowly. The lower the half-life, the more unstable and the more radioactive is the substance.
The heat radiated by radioactive decay can be converted to electricity for long-lived, lightweight power sources in navigation buoys, remote weather stations, space vehicles, etc.
Notice the tendency of strontium-90 to be stored in the body, which adds greatly to the dangers. Of course, plutonium can also lodge in the body, particularly in bone marrow.
half-life: 30 years.
Then we have
But it is not all bad news
Note the advantage that, with an eight-day half-life, effectively radiation will stop after a few weeks.
half-life about three times the age of the Earth, say 14, billion years.
Thorium power stations are still only in development stages. A thorium power station would not produce plutonium, and so would not interest terrorists, the major source of political security risks. A thorium power station would also have considerably less highly radioactive waste to need disposal. It also works by a different method than those using uranium, and instead would probably be an accelerator-driven system (or ADS) reactor. A uranium-based reactor functions by having a continuous and spontaneous chain-reaction, which is kept under control, but can go out of control, resulting in a disastrous melt-down of its radioactive core. An ADS reactor requires a stream of neutrons applied from an exterior souce to stimulate its reaction. If the stream is stopped, so also does the reaction.
The Prestige disaster has been referred to, reasonably, as Europes Chernobyl. As part of my ongoing investigation into human energy desires, I shall use the example of Chernobyl, the worlds worst nuclear power station accident.
I am fairly convinced that most of the fears regarding nuclear power are overblown. By taking this worst case and examining it in a similar manner to abelard.orgs reports on the Prestige, I intend to test this supposition. Here is an item claiming only low-level effects detectable in the aftermath of Chernobyl.
is an article on the continuing clear up costs at Chernobyl.
Note that the panic responses in Goiana, Brazil, were much more of a problem than the real damage or threat. It is essential that populations are better informed concerning radioactivity.
Also from the second of the four articles referenced above:
Reactors on the Chernobyl site were operating until recently; since when I think they have been closed down. (To be checked.)
A more recent report on Davis-Besse, without the hysteria:
This gives the impression the US nuclear industry is still not managed adequately, see also sloppy nuclear safety facilities in the USA.
Despite this scaremongering reference to the accident at Three Mile Island-2 [TMI] in this article, no one is known to have been killed or injured by, or because of, the incident. The reactor that failed has been made safe, while the reactor alongside will continue to function until it reaches the end of its operating life. Then both reactors will be decommissioned.
I have done an illustrative case study of a media article to show clumsy reporting of nuclear power issues.
Chernobyl is by far the worst reactor accident so far. As far as is known, there were only thirty fatalities within the plant at the time of the accident and up to 2000 non-fatal thyroid cancer cases among children in the surrounding region. Apparently, these cancers could have been avoided if it were not for Soviet mismanagement. Note here, as with TMI, other reactors on the site continued to operate until recently.
You will notice that both these incidents, Chernobyl and TMI, constantly are grossly exaggerated but both have been, and now are being, handled effectively.
Link to a November 2007 article in Der Speigel Online article (translated from the German). This item is on the widespread exaggerations made regarding radioactive contamination and deaths from the 1945 nuclear bombs dropped on Japan, on plant disasters in the USSR and East Germany and on old ‘dirty’ working methods, principally in the USSR.
In the meanwhile, it is calculated that diesel fumes cause over 8000 deaths from asthma each and every year in the USA alone. (Less than one percent of US cars are diesel. Therefore, this figure applies only to heavy equipment.) To this, add a multitude of probable carcinogens found in fossil hydrocarbons and their combustion products.
A major study is being done within the European Union on the dangers of ingesting radioactive materials, if they then lodge in the body. It is probable that this is far more dangerous than brief exposure, or contamination that can be washed off or excreted. For more on what is known about the comparative health dangers of radioactive materials, visit RussP.org.
The first four items listed on the cited page are informative on the extremely low (and well understood) dangers of radiation dispersal. The articles, which appear to have been précised from books, are written in a most clumsy manner.
The third item, on plutonium toxicity, appears to me to be very relevant to expressed worries concerning depleted uranium, as it discusses ingestion of airborne particles.
Keep in mind that uranium is much less radioactive even than plutonium.
This document accords with my growing suspicion, mentioned at the start of this briefing document, that the problems with fossil fuel powered electrical generation are considerably greater than those of nuclear-driven power generation. For want of contrary information, I am now going to assume this is so while I investigate further.
From the document above:
[The World Nuclear Association site has a large number of very useful, basic documents on the industry. Two useful paths for access to their data are here and here. See also their page, Sustainable Energy, for a useful, general statement.]
Next for investigation is a European Union report: the ExternE Project.
You can find a simple summary of some of the basic approved reactor designs here.
and reality in resource limitation
As I read into the current situation, I am increasingly convinced that substituting for fossil fuel use is highly desirable, whether or not we are in process of immediate over-resource use of fossil fuels.
Fossil fuels are mostly filthy. They are concentrated in a politically unpleasant region and, because they are cheap, they represent a strategic objective which is likely to generate international friction.
It is becoming time to revisit nuclear power. Because of its ability to enable nuclear weapons production, this will require world-wide supervision of the nuclear industry. This supervision has unpleasant political centralisation implications as far as I am concerned, it may however, be necessary to face those problems. (There is already a fairly robust system in place.)
Advanced nuclear plants can allow both the production of electricity and by running the plant at sufficient temperatures, using the heat directly to split hydrogen from water, thus achieving 40 – 50% efficiency from a nuclear power plant.
This PDF file is a simplified series of slides on the last item. It is a serious pain to download, as you may well have to sit over it and, to completely call down the document, click the vertical scroll bar as many times as there are pages!
A survey of the best dual-use designs of nuclear reactors is available from this link (67-page PDF).
Known reserves of uranium, the radioactive material used to fuel nuclear power stations, are classified according to the quality of concentration and, therefore, the cost of extraction and processing.
|Typical natural concentrations of uranium (U)||
(ppm = parts per million).
|‘High-grade’ ore - 2% U||20,000 ppm U|
|‘Low-grade’ ore - 0.1% U||1,000 ppm U|
|Granite||4 ppm U|
|Sedimentary rock||2 ppm U|
|Earth’s continental crust||(av) 2.8 ppm U|
|Seawater||0.003 ppm U|
|Known recoverable resources* of uranium|
|tonnes U||percentage of world|
|Russian Fed.||131,000||4%||* Reasonably Assured Resources plus Estimated Additional Resources - category 1, to US$ 80/kg U, 1/1/01, from OECD NEA & IAEA, Uranium 2001: Resources, Production and Demand. Brazil, Kazakhstan, Uzbekistan and Russian figures above are 75% of in situ totals.|
source: World Nuclear Association
Nuclear resource use applies to the small percentage of electricity generation which is by nuclear reactor, currently approximately 15-20% of electricity production. Therefore, to meet even present levels of electricity production with nuclear methods would require five times the uranium consumption.
World uranium production is now approximately 35,000 tonnes, whereas usage is approximately 60,000 tonnes. This shortfall appears to be met by recycling old bomb material and by using up past over-production, maybe about half and half, though I do not yet have good figures. To meet this difference would obviously require another doubling of production.
While nuclear power is not some easy fix for all our problems, it is of extreme importance.
How long nuclear power will last depends, critically, on fast breeder reactors. According to some sources, there is approximately 100 times more energy resources available if fast-breeder reactors are used, than if normal nuclear reactors are used. (I am using the more conservative figure of 60 times in the calculation below.)
Based on present known reserves, assuming fast-breeder technology, my guesses are approximately as follows:
Further details of how I arrived at these assessments can be found at delivery of power, with other background reasoning here, energy economics - extraction efficiency and costs.
Aside from the potential for weapon proliferation, I am pretty well convinced that nuclear power is vastly safer than popular hysteria would suggest, and that it is also has the advantage of being much safer and cleaner than fossil fuels. More on proliferation can be found here.
There are potential, sun-driven, energy resources; I shall look at those as I have the time and energy.
The IEAE is the controlling body for the supervision of feeder materials for potential bomb making. It has wide powers, duties and discretion. Violations of agreements are reported to the UNO and to the International Court of Justice. The IAEA gets involved in monitoring arms agreements. It is a powerful international body. The IAEA is heavily involved in the North Korean hassle and in the inspection teams in Iraq.
fusion project [22 April 2005]
At last an end to the faffing around regarding where to put the intended international experimental fusion installation. Glory knows why the USA and Japan do not also just act, the amounts of money are tiny for the parties involved.
web address for the segment above is
In London, in 1893, there were 300,000 horses, that is approaching 3 million
tonnes of manure on the London streets each year.
Note that the one cubic metre that Lovelock offered to take is the equivalent of 6.6 million tones of carbon.
With regard to the mountain, take note that most of is not solidified. It is pumped into the air where it remains for about 100 years, and that is not to consider the rest of the mess strewn around.
There is also radiation from slag heaps. Some claim considerably more than from nuclear stations (I have not detailed confirmation of this). Slag heaps pose other problems and dangers, such as the disaster of Aberfan in South Wales where a school-house was engulfed. Similar fears stalk the coal fields of the Appalachians and other areas.
For more detail on risk analysis, particular in the context of the nuclear industry.
email abelard at abelard.org
© abelard, 2002, 13 october
the address for this document is http://www.abelard.org/briefings/nuclear.htm