Thursday, 19 May 2016

Unreported massive release of radiation 36 years ago!

Unreported Release

by Karl Johanson

36 years ago today, a major release of radioactive material took place in Washington State. The explosive event which lead to the release, killed 61 people and was covered extensively by the news media. However, the release of radioactive material was never mentioned in this coverage. The amount of radioactive material released can only be roughly approximated, but the following is a fair estimate.

  • Actinium-227 13 grams
  • Thorium-228 18 grams
  • Radium-228 60 grams
  • Lead-210 300 grams
  • Protactinium-231 20 kilograms
  • Radium-226 22 kilograms
  • Thorium-230 1,000 kilograms
  • Uranium-234 32,000 kilograms
  • Uranium-235 420,000 kilograms
  • Uranium-238 60,000,000 kilograms
  • Thorium-232 170,000,000 kilograms
  • Potassium-40 300,000,000 kilograms
  • Rubidium-87 337,000,000 kilograms

In addition to the above, the following radioactive isotopes were released in trace amounts:

  • Astatine 215, 216, 218 & 219
  • Bismuth 210, 211, 212, 214 & 215
  • Francium 223
  • Lead 211, 212 & 214
  • Plutonium 239 & 244
  • Polonium 210, 211, 212, 214, 215, 216 & 218
  • Radon 219, 220, & 222
  • Thallium 206, 2207, 208 & 210
  • Thorium 227

Many of the listed isotopes are the daughter isotopes of Uranium 238, Uranium 235 and Thorium 232.

This amount of radioactive material is (very roughly) what one would expect to find in any 4 cubic kilometres of the Earth's crust. The event which expelled this material, involved a release of energy roughly 500 times that of the nuclear bomb used on Nagasaki. 500 hectares of land was devastated and shockwaves shook houses more than 30 kilometres away. Around 25% of the material was emitted as dust, which remained in the atmosphere for some time. The remainder precipitated out fairly rapidly over the nearby countryside.

To add some interesting perspectives on this amount of material, consider the following.

  • 420,000 kilograms of Uranium 235 is enough to make more than 100,000 nuclear weapons.
  • The US government is studying Yucca Mountain in Nevada with intent to store around 70,000 tonnes of spent nuclear fuel there.
  • Some claimed that roughly 40,000 kilograms of depleted uranium (almost pure Uranium 238) was used in the Gulf war and that it represented 500,000 "potential deaths". (I make no commentary here on the ethics of weapon use in general, nor of the ethics of the use of this specific weapon.) I'm curious what those people would estimate the number of "potential deaths" would be from the emission of around 1,000 times as much Uranium 238.
  • If you've heard and believed the mistaken claim that releasing 1 pound of plutonium would kill every human on Earth, consider the following. The 22 kilograms of Radium 226 (just one isotope from the above list) would have a specific level of alpha radiation equivalent to just over 350 kilograms (770 pounds) of Plutonium 239. Radium is also far more likely to form readily aspiratable particles and is more readily absorbed by the human body when ingested. Somehow, that powdered radium left more than 7 billion humans alive.

If you're at all curious, the event which released somewhere around the above estimated amount of material, happened on May 18, 1980 and was, of course, the eruption of Mount Saint Helens. Eleven years later, on June 13, 1991, Mt. Pinatubo released roughly one and a quarter times as much material (radioactive and otherwise) as Mount Saint Helens.

I would never suggest that a natural event emitting any given material should be used as ‘justification’ of humans releasing large amounts of similar materials. Nor does Saint Helens’ and Pinatubo’s emission of Lead and Uranium ‘justify’ the use of such things as Lead or Uranium bullets in any given situation. I do suggest however, that the Saint Helens and the Pinatubo examples (and dozens of other recent eruptions) are useful data points on the road to understanding the complex issue of the possible effects of releases of radioactive material.

Thursday, 12 May 2016

Nuclear Winter?

The nuclear winter meme3 originated in 1982 as a development of the, then, climate models. Carl Sagan (an anti-nuclear war advocate, and science popularist) was an advocate and contributed to a book sub-titled: "Nuclear Winter and the End of the Arms Race".1 I find it very interesting that there are two climate change nuclear criticisms:

  1. Nuclear winter - resulting from atomic war
  2. Climate change caused by atomic power

I already refuted the 2nd nuclear-caused climate change idea, but that's something most scientists and technically educated people can do at a glance. What about the first? Will a small nuclear war really exterminate humanity via climate change as the nuclear critics say? Obviously not. What about a massive nuclear war where every bomb is exploded and war is global: all over the planet? This, at least, is almost a scientific debate. British scientists considered nuclear winter scaremongering.5

The rest of this post below is an extract from "Nuclear War Survival Skills", by Cresson H. Kearny,2 but the best available refutation of the meme is now 30 old: Nuclear Winter Reappraised in Foreign Affairs.4. Which led to a debate with Carl Sagan.6


Unsurvivable "nuclear winter" surely will follow a nuclear war. The world will be frozen if only 100 megatons (less than one percent of all nuclear weapons) are used to ignite cities. World-enveloping smoke from fires and the dust from surface bursts will prevent almost all sunlight and solar heat from reaching the earth's surface. Universal darkness for weeks! Sub-zero temperatures, even in summertime! Frozen crops, even in the jungles of South America! Worldwide famine! Whole species of animals and plants exterminated! The survival of mankind in doubt!


Unsurvivable "nuclear winter" is a discredited theory that, since its conception in 1982, has been used to frighten additional millions into believing that trying to survive a nuclear war is a waste of effort and resources, and that only by ridding the world of almost all nuclear weapons do we have a chance of surviving.

Non-propagandizing scientists recently have calculated that the climatic and other environmental effects of even an all-out nuclear war would be much less severe than the catastrophic effects repeatedly publicized by popular astronomer Carl Sagan and his fellow activist scientists, and by all the involved Soviet scientists. Conclusions reached from these recent, realistic calculations are summarized in an article, "Nuclear Winter Reappraised", featured in the 1986 summer issue of Foreign Affairs, the prestigious quarterly of the Council on Foreign Relations. The authors, Starley L. Thompson and Stephen H. Schneider, are atmospheric scientists with the National Center for Atmospheric Research. They showed " that on scientific grounds the global apocalyptic conclusions of the initial nuclear winter hypothesis can now be relegated to a vanishing low level of probability."

Their models indicate that in July (when the greatest temperature reductions would result) the average temperature in the United States would be reduced for a few days from about 70 degrees Fahrenheit to approximately 50 degrees. (In contrast, under the same conditions Carl Sagan, his associates, and the Russian scientists predicted a resulting average temperature of about 10 degrees below zero Fahrenheit, lasting for many weeks!)

Persons who want to learn more about possible post-attack climatic effects also should read the Fall 1986 issue of Foreign Affairs. This issue contains a long letter from Thompson and Schneider which further demolishes the theory of catastrophic "nuclear winter." Continuing studies indicate there will be even smaller reductions in temperature than those calculated by Thompson and Schneider.

Soviet propagandists promptly exploited belief in unsurvivable "nuclear winter" to increase fear of nuclear weapons and war, and to demoralize their enemies. Because raging city firestorms are needed to inject huge amounts of smoke into the stratosphere and thus, according to one discredited theory, prevent almost all solar heat from reaching the ground, the Soviets changed their descriptions of how a modern city will burn if blasted by a nuclear explosion.

Figure 1.6 pictures how Russian scientists and civil defense officials realistically described - before the invention of "nuclear winter" - the burning of a city hit by a nuclear weapon. Buildings in the blasted area for miles around ground zero will be reduced to scattered rubble - mostly of concrete, steel, and other nonflammable materials - that will not burn in blazing fires. Thus in the Oak Ridge National Laboratory translation (ORNL-TR-2793) of Civil Defense. Second Edition (500,000 copies), Moscow, 1970, by Egorov, Shlyakhov, and Alabin, we read: "Fires do not occur in zones of complete destruction . . . that are characterized by an overpressure exceeding 0.5 kg/cm2 [- 7 psi]., because rubble is scattered and covers the burning structures. As a result the rubble only smolders, and fires as such do not occur."

Fig. 1.6. Drawing with Caption in a Russian Civil Defense Training Film Strip. The blazing fires ignited by a surface burst are shown in standing buildings outside the miles-wide "zone of complete destruction," where the blast-hurled "rubble only smolders."

Translation: [Radioactive] contamination occurs in the area of the explosion and also along the trajectory of the cloud which forms a radioactive track.

Firestorms destroyed the centers of Hamburg, Dresden, and Tokyo. The old-fashioned buildings of those cities contained large amounts of flammable materials, were ignited by many thousands of small incendiaries, and burned quickly as standing structures well supplied with air. No firestorm has ever injected smoke into the stratosphere, or caused appreciable cooling below its smoke cloud.

The theory that smoke from burning cities and forests and dust from nuclear explosions would cause worldwide freezing temperatures was conceived in 1982 by the German atmospheric chemist and environmentalist Paul Crutzen, and continues to be promoted by a worldwide propaganda campaign. This well funded campaign began in 1983 with televised scientific-political meetings in Cambridge and Washington featuring American and Russian scientists. A barrage of newspaper and magazine articles followed, including a scaremongering article by Carl Sagan in the October 30, 1983 issue of Parade, the Sunday tabloid read by millions. The most influential article was featured in the December 23,1983 issue of Science (the weekly magazine of the American Association for the Advancement of Science): "Nuclear winter, global consequences of multiple nuclear explosions," by five scientists, R. P. Turco, O. B. Toon, T. P. Ackerman, J. B. Pollack, and C. Sagan. Significantly, these activists listed their names to spell TTAPS, pronounced "taps," the bugle call proclaiming "lights out" or the end of a military funeral.

Until 1985, non-propagandizing scientists did not begin to effectively refute the numerous errors, unrealistic assumptions, and computer modeling weakness' of the TTAPS and related "nuclear winter" hypotheses. A principal reason is that government organizations, private corporations, and most scientists generally avoid getting involved in political controversies, or making statements likely to enable antinuclear activists to accuse them of minimizing nuclear war dangers, thus undermining hopes for peace. Stephen Schneider has been called a fascist by some disarmament supporters for having written "Nuclear Winter Reappraised," according to the Rocky Mountain News of July 6, 1986. Three days later, this paper, that until recently featured accounts of unsurvivable "nuclear winter," criticized Carl Sagan and defended Thompson and Schneider in its lead editorial, "In Study of Nuclear Winter, Let Scientists Be Scientists." In a free country, truth will out - although sometimes too late to effectively counter fast-hitting propaganda.

Effective refutation of "nuclear winter" also was delayed by the prestige of politicians and of politically motivated scientists and scientific organizations endorsing the TTAPS forecast of worldwide doom. Furthermore, the weakness' in the TTAPS hypothesis could not be effectively explored until adequate Government funding was made available to cover costs of lengthy, expensive studies, including improved computer modeling of interrelated, poorly understood meteorological phenomena.

Serious climatic effects from a Soviet-U.S. nuclear war cannot be completely ruled out. However, possible deaths from uncertain climatic effects are a small danger compared to the incalculable millions in many countries likely to die from starvation caused by disastrous shortages of essentials of modern agriculture sure to result from a Soviet-American nuclear war, and by the cessation of most international food shipments.

  1. A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, by Carl Sagan, Richard Turco;
  2. Nuclear War Survival Skills, by Cresson H. Kearny
  3. Nuclear winter (wikipedia)
  4. Thompson, Starley L & Schneider, Stephen H Nuclear Winter Reappraised in Foreign Affairs, Vol. 64, No. 5 (Summer, 1986), pp. 981-10055. doi:10.2307/20042777.
  5. "Home Office dismissed nuclear winter threat as scaremongering, files show", Guardian 30 Nov 2014.
  6. The Nuclear Winter Debate, by Carl Sagan, Richard Turco, George W. Rathjens, Ronald H. Siegel, Starley L. Thompson and Stephen H. Schneider; Foreign Affairs, Vol. 65, No. 1 (Fall, 1986), pp. 163-178, DOI: 10.2307/20042868

Monday, 2 May 2016

Don’t criticize what you can’t understand

Your old road is rapidly agin’
Please get out of the new one if you can’t lend your hand
For the times they are a-changin’
If only Jim Green (national anti-nuclear campaigner for Friends of the Earth, Australia), had listened to Bob Dylan. Poor Jim hasn't much of a clue about science so he does not know what he's talking about. He attempts to criticise thorium powered nuclear reactors here but does a bad job because he does not know much about the technology pathways being promoted. For instance, let's just look at his WNA quotation. There's so much wrong with it:
"A great deal of testing, analysis and licensing and qualification work is required before any thorium fuel can enter into service. This is expensive"
-- The anti-nuclear movement are the reason for this. We could have zero-carbon, cheaper energy, thorium reactors working in a few years were it not for the catalogue of regulation and agencies (official and unofficial) blocking the development of better nuclear power.
"Other impediments to the development of thorium fuel cycle are the higher cost of fuel fabrication"
-- Liquid fuels like molten salts could be far cheaper. Such fuels require no fabrication. Liquid molten salt fuels are proposed for nearly every thorium reactor
"the cost of reprocessing to provide the fissile plutonium driver material"
-- Thorium reactors do not need plutonium to start. They could start with uranium-235. That will only require enrichment; which is what currently happens.
"the high cost of fuel fabrication (for solid fuel)"
-- Nearly all the thorium reactor plans are for molten salt reactors - not solid fuel reactors. Such liquid fuels have no 'fabrication'.
"Separated U-233 is always contaminated with traces of U-232"
-- were it to be true, that would be a good thing. It would make the U-233 made in thorium reactors proof against weapons proliferation. According to weapons experts as only 50 ppm U-232 will make uranium-233 unsuitable for weapons. Reprocessing can be run either entirely robotically, or manually behind safe screens. As was demonstrated for the IFR over 2 decades ago, and as done at some reprocessing plants today. Contaminating U-232 will pose no problem. Au contraire, several reactor designers want to make sure their fuel will contain such U-232!

Note: Thorium reactors work by breeding thorium-232 to uranium-233.

   Th-232 + n -> Th-233; 
   Th-233 + e- -> Pa-233; Th-233 ½-life: 22 min
   Pa-233 + e- -> U-233;  Pa-233 ½-life: 27 days

Uranium-233 is the fissionable material. The product 'bred' from thorium (Th-232). The other materials: Th-233, and Pa-233 are just steps along the way. U-233 behaves differently to other materials. When its nucleus is hit by a neutron, it is generally not captured to increase the atomic weight, causing transmutation [i.e. U-233 + n -> U-234 ]. Instead, U-233 is fissionable. It splits in two when hit by a neutron. One atom becomes two smaller, energetic, atoms, plus 2 or 3 neutrons, plus electromagnetic rays. This is where the energy in nuclear fission is made: from the release of nuclear binding energy. This fission is the reaction we want. We do not want fissionable materials to be wasted by capturing a neutron to increase in atomic mass. With such neutron capture both the potentially fissionable atom (e.g. U-233) and a neutron are wasted, because U-234 is not fissionable. There are only 3 isotopes available to us which are fissionable by 'thermal' (moderated) neutrons: U-233, U-235, and Pu-239. U-233 is the best of them. In the thermal neutron spectrum U-233 has the best neutronics all all fissionable materials:

Notice the final two columns in this table. With U-233 only 7.7% of neutrons are wasted by capture ( U-233 + n -> U-234 ). The U-234 made does not fission. Proportionally U-235 wastes almost twice as many neutrons and plutonium wastes more than 3 times as many by capture. Uranium-233 also shows a much better neutron economy over a wider neutron energy range than either U-235, or Pu-239 (see chart below). The average eta value (number of neutrons produced for every neutron absorbed) for U-233 = 2.27 in a standard PWR compared to 2.06 for U-235 and 1.84 for Pu-239. Eta must be at least 2 for breeding (to sustain the reaction) because 1 neutron is needed to cause another fission and 1 to breed another U-233 (from Th-232). In practice a breeder reactor needs eta much larger than 2 because many neutrons are lost (absorbed by the reactor, the moderator, or captured by U-233, or even by the intermediate Pa-233.

Thorium has far less toxic waste

There is another thorium advantage: any U-234 made can eventually absorb another neutron to make U-235, so it gets a 2nd chance to fission.

The consequence of this is that the thorium/uranium-233 fuel cycle has a waste stream which is far less radioactive after the fission products have decayed. It contains very little long-lasting radioactive transuranics. The chart below has logarithmic scales. Thorium transuranics show the green curve. All kinds of fission include the blue curve (fission products). The point where the blue curve crosses the dotted orange line happens after 300 years. After this point, thorium waste will be as safe as natural uranium ore, which is generally considered safe. In contrast radioactivity of uranium/plutonium waste from a conventional reactor such as a PWR, or BWR will not fall below uranium ore radioactivity levels for hundreds of thousands of years at best (red).