Nuclear Common Sense

Inside front cover

Inside front cover

FRONT COVER Hands Up for Nuclear Science ! Staff and graduate students of the Research School of Nuclear Science at the Australian National University in Canberra. The research school is one of the few places in Australia where nuclear science is studied and taught at advanced level. Their enthusiasm is obvious. As the inevitable events predicted in this book unfold, graduates in nuclear science and engineering will be absolutely essential for assisting a change for the better in Australia's vulnerable future prospects. It is impossible to overstate the vital importance of high level trained personnel to replace those now retiring or about to retire, but far too few are currently in training. The current shortage of science and mathematics students in secondary schools will not help the situation, remembering that the better part of ten years is needed to train a nuclear scientist or engineer to make a useful contribution to a highly technological enterprise such as nuclear electricity production. Photo courtesy of Prof. George Dracoulis, Head, Nuclear Science, ANU.

Nuclear Common Sense Opportunity for Prosperity

Colin Keay PhD DSc

The Enlightenment Press 2003

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ABOUT THE AUTHOR The author is a retired physicist and astronomer who, as an associate professor at the University of Newcastle for 24 years, taught nuclear and reactor physics to senior classes. During his professional career as a university scientist he encountered under laboratory and research conditions radioactive substances and high-voltage electricity, learning to respect each for their lethal hazards. He considers it paradoxical that most people are comfortable with electricity, happily harbouring its deadly dangers in every home, while on the other hand nuclear radiation usually sends chills up the spine, notwithstanding the fact that radioactivity and nuclear radiations are harmlessly present all around us. There can be no such thing as a truly nuclear-free zone anywhere in the known universe. This booklet outlines a golden opportunity for Australia to take full advantage of nature's gifts and emerge as one of the most prosperous countries in the world. It brings some facts to bear on one of the most contentious issues facing Australia and to confront the exaggerated scares so often presented by the media and various irresponsible organisations. If Australians can conquer irrational fears on nuclear issues our future is bright. But not if anti-nuclear activists keep us in the dark, both mentally and electrically. The author has no past or present connection with the nuclear industry. All he desires is a better future for his grandchildren.

Copyright ©2003 by Colin S Keay. All rights reserved. First published in Australia by The Enlightenment Press ISBN 0-9578946-3-5 Printed by Longworth & Goodwin Pty Ltd, NSW 2305 Second printing (2005)

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INTRODUCTION Australia is said to be the Lucky Country. Our national anthem extols the benefits of living on our island continent. There are, however, a couple of crucial advantages that usually do not rate a mention. If, in coming decades they are sensibly exploited they could make Australia the most prosperous - and politically moral country in the world. The trouble is, there are too many organisations who see the benefits we are about to discuss in an implacably negative light. What are these benefits? In the first place, Australia has more uranium ore than any other country in the world - something like one third of the proved global total. "Keep it in the ground!" cry the anti-nukes, without thought of the dangers of doing what they urge. The second factor is that Australia has the oldest stable rock provinces in the world, ideal for safe nuclear waste disposal. But the Pangea proposal, which sought to utilise this fact, has been politically buried despite being endorsed by senior Australian scientists1. Just as there are very few Australians with the qualifications and skills to undertake brain surgery, so too are there few with the training and knowledge to make sensible judgements about nuclear science and engineering. Especially in the case of nuclear waste management and, for that matter, the nuclear fuel cycle in general. Far too many instant experts - with little experience in nuclear matters - appeal to purely emotive responses through the use of pejorative terms like 'nuclear sewage', which have no justification whatever. This book is an appeal to common sense based on understanding the real issues. A case will be presented for Australia to take the moral high ground in a world beset by the evil of nuclear weapons, but hungry for safe, clean nuclear energy. Australia is in a unique position to make the Nuclear Non-proliferation Treaty work as it should by exercising effective control of the nuclear fuel cycle from mining to ultimate waste disposal. What's more, we could stop exporting uranium ore because once it leaves our shores we have little control over its end use. We can do much better by processing it ourselves. Opponents of nuclear electricity claim it has three unresolved problems: weapon proliferation; waste disposal (including reactor decommissioning); and disastrous accidents. The problems are all 1

e.g. "N-dumps: why waste a chance?", Sir Gustav Nossal, The Australian 11 December 1998.

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socio-political - not technological. It is the purpose of this book to show that such fears are quite unjustified and that solutions to all three of these allegedly 'unresolved' problems are well within reach. Briefly speaking, this book aims to show that the three imagined stumbling blocks completely disappear if we mine uranium and manufacture fuel assemblies which we then lease to countries needing reactor fuel to produce nuclear electricity. An essential condition of the lease is that the rods muct be returned here to salvage their plutonium content and thereby satisfy requirements of the Nuclear Non-Proliferation Treaty (NNPT) which ban military use of the plutonium. The plutonium is recycled through the use of mixed oxide (MOX) reactor fuel and kept out of the waste stream. And we limit the scope for nuclear disasters by leasing the fuel rods only for use in reactors of proven safe design. Not only is this a highly moral stance to adopt in a world needing safe, clean electricity production but it makes Australia much less vulnerable to attack by countries having envious eyes on our massive resources of uranium. Remember that Japan's imperialist ambitions leading to their entry into the second world war were driven by a desire to secure overseas raw materials essential to fulfil their dreams of industrial expansion. These days they need reactor fuel. Furthermore, nuclear power is the only proven way of meeting the terms of the Kyoto Protocol for the reduction of greenhouse gases. The so-called hydrogen economy using fuel cells is touted as the best method for powering transport vehicles. But producing the hydrogen in sufficient quantity for widespread use will not come from solar or wind power. J G Ballard, developer of the hydrogenpowered Ballard buses succesfully operating in some North American cities, is on record as statng that nuclear power is the only viable option. Another global problem solvable by nuclear power is desalination. Australia in particular has an urgent need for desalination on a scale that only nuclear power can meet. For years the Soviets successfully operated a desalination plant at Shevchenko, on the Caspian Sea, powered by a breeder reactor. Anti-nuclear activists don't like to talk about this long-term success story. So there we are. Wise use of nuclear energy can solve many of the world's pressing needs if approached with an open mind. To clarify the way this desirable state of affairs can be brought about we need to first of all take a careful look at the nuclear fuel cycle.

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NUCLEAR FUEL CYCLE

1 Mining U Ore

2 Convert to UF6

3 Enrichment

4 Depleted Uranium

6 Fuel Rods

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7 Nuclear Power Reactor

8 MOX Fuel

Spent Fuel

10 Salvage Pluton'm

9 Reprocessing

11 Salvaged Uranium

13 Final Disposal

12 Hi-level Waste

The nuclear fuel cycle shown is a comprehensive one identifying the stages and processes that may be involved in a real situation. For one reason or another, depending on the type of power reactor,

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one or more stages may be bypassed, but we shall consider them all.

1 MINING Due to relentless agitation, including endless demonstrations and blockades, Australians are deeply divided on the issue of uranium mining. The indigenous people are likewise split on the issue. At Jabiluka in the Northern Territory the Gugadji tribe favour mining while the Mirrar tribe oppose it. The number of mines has been limited by federal policy and in at least two states, New South Wales and Victoria, activists have succeeded in persuading their parliaments to pass legislation banning not only uranium mining but even the act of prospecting for it. With modern techniques the dangers of uranium mining are minimal. The health of the miners is continually monitored, especially their radiation exposure2, and there is little industrial trouble. Unlike coal mining, its safety record is exemplary. The mined uranium ore is generally milled (purified) close to the mine and concentrated into yellowcake (U3O8) for delivery. It is not highly radioactive. Tailings (leftover material) from a mine contain radioactive daughter isotopes from the uranium. A hostile letter to a newspaper editor about uranium mining and the resulting tailings contains the assertion “No country has yet discovered how to treat these cancerous insidious substances. ” 3 It is not really a problem. As the radioactive isotopes in the tailings were originally in the ore body anyway, there is no good reason why they could not be put back in the mine and left to fade away, which they would do because there is no longer any parent uranium to replenish them.

2 CONVERSION Natural uranium contains only 0.7% of the U-235 isotope which is the one readily fissionable by slow (thermal) neutrons. Most power reactors require a higher percentage of U-235 (compared to the less fissionable U-238 in the ore) so enrichment of U-235 to several percent (usually 3% to 5%) is necessary. The processes for doing this require the uranium to be in the form of a gas. Surprisingly for such a heavy atom as uranium, there is a gaseous 2 3

See "Nuclear Radiation Exposed, Enlightenment Press 2001 Newcastle Herald, 24 October 1997.

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form. Uranium combines with fluorine (which fortunately has only one isotope, thereby keeping the compound from having more mass variation) to form UF6 (uranium hexafluoride) molecules which are gaseous at 60 degrees celsius.

3 ENRICHMENT After more than half a century of experience the currently favoured technique for enriching uranium is the high-speed centrifuge method. It is around forty times more efficient than the earlier diffusion method and therefore demands much less energy. Within a spinning rotor, the heavier U-238 is flung outwards further than the lighter U-235. The greater the velocity the greater the separation of enriched and depleted fractions. A cascade of centrifuges can effect enrichment to a degree dependent on the number of stages. Australia had at one time a good start in uranium enrichment work (see Hardy 1996). A research and development program conducted by the Australian Atomic Energy Commission (AAEC, now ANSTO) was terminated by a political decision in 1983, after it had demonstrated an economical program for enriching U-235 to 3%, which is enough for some power reactors. At one time there were serious plans for building an enrichment plant on the Spencer Gulf in South Australia to add value to uranium exports. A golden opportunity to establish a major value-added export industry was thrown away after the necessary research and development for it had essentially been completed. Other methods of uranium enrichment include the old and very inefficient diffusion technique which is now quite obselete and the newer laser techique which is not as promising as was initially hoped.

4 DEPLETED URANIUM The fraction left over from the enrichment process is depleted uranium, mainly U-238. It is still useful as further reactor fuel because in a breeder reactor it can be converted into fissionable plutonium, thereby releasing almost one hundred times the energy than by using only the U-235. Because of this, using depleted uranium to boost certain types of military weapons is an unconscionable waste of a valuable energy resource. Incidentally,

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the level of radioactivity of depleted uranium is forty percent lower than natural uranium which we ingest in tiny amounts with our food anyway. It makes a small contribution to the natural level of inherent radioactivity of everyone, humans and animals alike.

5 MIXED OXIDE (MOX) FUEL A combination of (depleted) uranium oxide and plutonium oxide forms Mixed OXide (MOX) fuel, which in many power reactors is just as useful as fuel consisting only of enriched uranium. It has been so employed for over forty years and is a very practical means of gaining the usable energy from plutonium while getting rid of it! And it is a great way of safely utilising military stocks of plutonium.

6 FUEL ELEMENT FABRICATION Generally in power reactors the fuel is an oxide in the form of a ceramic that can withstand high temperatures without disintegrating. The ceramic rods or pellets are usually housed in zirconium alloy tubes or 'pins'. A bundle of such tubes forms a fuel element having a size and cross-sectional form dictated by the structure of the reactor.

7 NUCLEAR POWER REACTOR Of the 440 or so power reactors in the world, the vast majority are the tried and proven Pressurised (PWR) or Boiling (BWR) Water Reactors which use ordinary water to moderate (slow down) the neutrons to initiate fission and also act as a heat transfer fluid. Some others use heavy water (deuterium oxide) as moderator and a few use a gas as the heat transfer fluid. There are also some fast breeder reactors that make very efficient use of their fuel, breed more fuel as outlined earlier, and can also incinerate certain radioactive wastes. It is impossible for a power reactor to explode like a nuclear bomb. The Chernobyl disaster was a steam explosion caused by an excursion of power under conditions the operators had not been warned about. That ignited a chemical fire in the graphite moderator within the reactor core, causing widespread dispersal of the radioactivity.

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The Chernobyl reactor had little protection for its highly radioactive core. In the West, power reactors are required to have several layers of defence against release of radioactivity: these include the use of refractory fuel - confined within stout cladding in a core within a thick steel vessel - all contained within a reinforced concrete dome with walls up to three metres thick. That is why only a trifling amount of radioactive gas escaped from the major core meltdown at Three Mile Island - causing no casualties.

8 SPENT FUEL After two or three years, when the fuel elements are spent and removed from the reactor core, they are sent to a cooling pond close by until their intense short-lived radiaoactivity from the fission products has had time to die away. They could remain there for decades without problems as long as there is enough pond space to accommodate them. As the activity dies away the fuel elements become easier to transport and handle.

9 REPROCESSING This is the most complex operation in the fuel cycle as it involves the remote handling of highly radioactive materials. However it has been undertaken for almost seventy years with remarkably good safety. And of course much has been learned over that timespan to make the process easier and more efficient. As in aviation, progress does not stand still. Since 1960 the tried and proven Purex solvent-extraction process has been most commonly adopted at most facilities around the world. As the flow chart indicates, the plutonium (10) and unfissioned uranium (11) may be separated out from the spent fuel for further use, leaving for disposal a residue somewhat less in weight and volume. The fissionable elements are regarded as valuable resources in France and Japan, but not in the USA where, as a result of regarding their spent fuel (8) as waste they have greater amounts requiring disposal.

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The plutonium, having an isotope mix rendering it unsuitable for weapons, is ideal as a fuel to be mixed in (5) with the uranium in new fuel-rods, particularly in fast breeder reactors which can cope better with the difficult to utilise even-numbered isotopes of plutonium. The spent uranium can be sent back to an enrichment plant (3) to reclaim the small amount of fissile uranium-235 remaining in it.

12, 13 HIGH-LEVEL WASTE AND ITS DISPOSAL One of the most deeply ingrained anti-nuclear myths4 is that there is no safe way to get rid of nuclear waste. It is frequently used as if it is a trump card in discussions and debates on the subject of nuclear power. Generally the opposing argument runs something like this: “Well maybe the statistics prove you right about the safety of the nuclear industry, the fact remains there is no safe way to get rid of nuclear wastes .” In an otherwise first-rate international best-seller by author Dava Sobel, there is a false analogy intended to bolster the story: “One would imagine that Harrison grew up well aware of the longitude problem - just as any alert schoolchild nowadays knows that cancer cries out for a cure and there’s no good way to get rid of nuclear waste.”5 If these were the only people parroting that insidious falsehood there would be little harm done. However the anti-nuclear propagandists have, by ceaseless repetition, drummed this lie into the minds of everyone not in full possession of the facts. Years ago this situation prompted Beckmann (1979) to cite what he calls “five well kept secrets: 1. It is utterly untrue that no method of nuclear waste disposal is known; 2. It is utterly untrue that nuclear wastes must be guarded for thousands of years; 3. The paramount issue that is being covered up is a simple comparison: Is nuclear waste disposal a significant advantage in safety, public health, and environmental impact over the wastes of fossil -fired 4

This and many other anti-nuclear lies and disinformation are gathered and exposed in the author's booklet "Nuclear Energy Fallacies - Forty Reasions to Stop and Think". 5 Sobel, D, “Longitude”, Fourth Estate, London, p67, 1995

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power plants (let alone industrial wastes in general ) or not? 4. Much of the answer to the question above is contained in two simple statistics: For the same power, nuclear wastes are some 3.5 million times smaller in volume; and in the duration of their toxicity, the advantage ranges from a few percent to infinity. 5. Nuclear power does not add any radioactivity to the Earth; on the contrary, it reduces the radioactivity that Mother Nature would otherwise be producing .” In his last point, Beckmann is referring to a long-term reduction of radioactivity compared to the gradual decay of parent elements. We will now look further into the points raised by Beckmann. The most intractable problems of radioactive waste disposal are neither physical nor technical. They are legal, political and sociological. An eminent environmental lawyer, Michael Gerrard, who has represented litigants on both sides of these issues, has drawn heavily on his own broad experience to write Whose Backyard, Whose Risk, a comprehensive work which addresses the non-scientific ramifications of the disposal of wastes of all types. Noting the complete failure of the US Government to establish safe disposal sites for high-level nuclear wastes, mainly of military origin, Gerrard considers that the current socio-political approach is at fault. He proposes a radical new approach whereby communities are invited to host waste disposal facilities - “a method that, experience surprisingly shows, can attract numerous offers.” It is a matter of community psychology. No region wants a waste disposal facility foisted onto it and the affected communities react by raising all sorts of objections. However if the same people are offered compensatory benefits by choosing to host such a facility their reaction is much more likely to be receptive. Although his data refers to the United States, Gerrard (1996) cites figures which give some idea of the amounts of various types of waste that have to be dealt with. From his table it is clear that the amounts of industrial and municipal wastes are much greater than radioactive wastes, although the activity of spent fuel (high-level radioactive waste) is very much greater. Because the amounts of radioactive wastes are tens of thousand times less than normal community wastes their disposal sites can be much smaller, even allowing for adequate radiation shielding and isolation from the biosphere.

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The challenge of radioactive waste disposal is not so much that presented by the wastes themselves as it is to define the level of safety that will be acceptable. Objectors demand nothing less than absolute safety, which is an unattainable goal in any endeavour.

Waste stream Naturally occurring radioactive materials that are mined*

Annual production (tons) Approx. 50,000,000,000

Industrial wastes

430,000,000

Municipal solid waste (MSW)

180,000,000

Sewage sludge

8,500,000

MSW incineration ash

5,500,000

Medical waste Low-level radioactive waste Spent nuclear fuel

500,000 36,000 1,900

* Most of this is residue from phosphate mining, oil and gas production and other extractive industries. Perhaps as much as ten percent would be in tailings from uranium mining. (US data from Gerrard, 1996)

That fact of life does not deter them. Somehow they expect that the wastes must be totally removed from the face of the Earth. This, in turn, has encouraged hare-brained solutions such as rocketing high-level nuclear wastes into the Sun! In reality the disposal of nuclear wastes, even high-level wastes, is not a serious problem. Those who argue otherwise overlook the fact that the radioactivity they contain did not come from nowhere. It is directly derived from radioactive elements already present in the biosphere, as Beckmann and others have made clear. The isotopes in reactor wastes may be temporarily more active, which obviously makes them more dangerous, but, like a barbecue plate left aside to cool until it no longer sears and can be readily handled, high-level radioactive wastes are stored safely in cooling ponds for a time until they can be more easily dealt with.

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Beckmann also cites another example of anti-nuclear mythology, namely the ridiculous assertion that high-level nuclear wastes containing plutonium will have to be guarded for centuries to stop terrorists gaining access to it and reclaiming the plutonium for bomb manufacture. This scenario is quite absurd because the plutonium in high-burnup reactor fuel is not only unsuitable for bombs6 but the handling and reprocessing problems are immense unless the terrorists have ready access to a highly sophisticated facility designed with remote handling equipment to safely deal with such materials. Another myth is that, given the plutonium, any competent person could build a bomb in a garage workshop. Those making such a claim have no idea of the complexity of the task.

LOW-LEVEL WASTES Before continuing on with a discussion of high-level nuclear waste disposal, a few words about dealing with low-level radioactive wastes. They are much less of a problem than many other wastes, such as the safe disposal of home computer components and the immense volumes of industrial wastes. Some of these have half-lives of infinity because they are stable and never decay away to become harmless. Even so, low-level radioactive waste has caused much angst in many communities where groundless fears have been encouraged by irresponsible scare campaigns. Nobel Laureate (Medicine 1977) Rosalyn Yalow7 pointed out that a human body contains natural radioactivity of an amount that had a laboratory animal received as much, and died with that amount still in its body, current regulations would require that animal to be sealed in a drum and transported to a radioactive waste disposal site, “thereafter to occupy needlessly space that should be reserved for measurably hazardous material.” This is yet another example of the application of ridiculously conservative regulations governing radioactive waste disposal. Even so rigid controls are essential, but they must be sensible and not excessive.

Because power reactor wastes contain too much of the plutonium-240 isotope which has a high spontaneous fission rate rendering a bomb unreliable and inefficient (see Cohen 1990). 6

Disposal of Low-Level Radioactive Waste: Perspective of the Biomedical Community” in “Radioactive Waste”, NCRP Proceedings No 7, Bethesda MD 1986 7

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Yalow pointed out that disposal of wastes from medical experiments involving the use of radioisotopes was costing almost twenty million dollars a year when the amounts of radioactivity were absurdly small. Disposal by incineration would, for a city like New York, release radioactivity amounting to only a few percent of that falling on the city in the form of carbon-14 and tritium (hydrogen-3) produced naturally by cosmic rays all the time as they hit the atmosphere. Usually shallow burial of low-level wastes is a safe enough method of disposal where laws permit it. Incineration is also appropriate for combustibles in many instances for the reasons Rosalyn Yalow discussed. Quite frequently the distinction between low- and high-level nuclear wastes is ignored or confused by the media. High-level wastes contain 99% of the radioactivity from a nuclear installation, while low-level wastes account for 99% of the volume. Beckmann (1979) cites an article and photograph from Time Magazine in 1977 which fails to note the difference and thereby sows the seeds of doubt in the minds of its readers. It is thanks to such irresponsible reporting that two of the six sites in the United States licensed for the burial of low-level wastes were closed due to intense local opposition after they had operated without any public health problems for more than a decade (Eisenbud 1987). To quote Gerrard (1996) once more, “The search for scientific rationality in the siting process is illusory as long as important constituencies are unhappy with the scientific results.” The general public distrust bland scientific reassurances about site safety because they suspect them to be biassed by commercial or political influences. Many honest scientists despair that the public give greater credence to alarmist junk science on important issues such as nuclear waste disposal. The sensationalist media delight to spread horrific claims while ignoring the actual facts, and the 'better safe than sorry' argument has been done to death. Recently, right here in Australia, a decision to store low-level nuclear wastes at a remote site in the north of South Australia drew intense criticism. A street-poll in Adelaide showed ninety percent condemned the proposal. It is relevant to notice that if the low-level wastes requiring disposal were mixed in with the reburied tailings at Roxby Downs, nearby in the north of South Australia, the amount of radioactivity per unit volume would be less than in the mined material before the uranium was extracted from it!

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Some perceptive people have pointed out that yellowcake has been transported along roads in South Australia with little hullabaloo, but the transport of low-level waste of lower radioactivity (and contained in approved protective canisters) has been roundly condemned. Before leaving the topic, there is another curious double standard with respect to materials having low levels of radioactivity. The radiation dose rate allowable from such materials originating from non-nuclear industries is in some countries as much as thirty times the dose rate allowable from exposure to materials from the nuclear industry!

HIGH LEVEL WASTE DISPOSAL Moving on to the disposal of high-level nuclear waste from civil power reactors, it is nowhere near as great a problem as antinuclear activists would have us believe. After three years storage in a cooling pond close by the reactor in the power station the radioactivity of the spent fuel rods has diminished to less than one percent of the amount on exit from the reactor. The fuel rods are then cool enough to be transferred to dry storage within air-cooled shielding. After forty years the radioactivity has diminished to less than one thousandth of the original level and permanent disposal becomes an option. However there is no hurry and there are benefits to be had by reprocessing high-level waste to extract useful radioisotopes. Edward Teller argues we should abolish the idea of nuclear waste. “Let’s call it by-products and use it” he maintains8. Russian scientist Professor Victor Orlov agrees9, saying “There are no great problems here, It is a very practical question because actinides (the heavier radi oactive elements) burn quite well in fast reactors. We should take them from the nuclear waste and return them to the fast reactors, and they will burn in the reactor, turning into fission products, And if we take the fission products long-lived technetium and iodine - God almighty provided in such a way that they will also burn in the fast reactor, so these fission products can be burned. Most (other) fission products decay fairly quickly. You can put them together under controlled observation 8 9

21st Century Science and Technology, Vol 6, No 1, 1993. Same source.

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where they will decay on their own down to the level of the natural uranium mined from the earth. Then you can return it to the earth...” Professor Orlov goes on to advocate that fission products such as strontium and cesium, which have intermediate half-lives, should be used for radiation treatments of various kinds, citing their use in China for irradiating rice seeds to gain larger harvests. There are many positive ways of looking at the situation with high-level nuclear wastes. In the case of nuclear energy from uranium, each fission releases a little over 200 MeV of energy as heat compared with the sum total of around 50 MeV released through the natural step-by-step decay processes. So taking a longterm view, nuclear fission rids the globe of the energy of radioactivity four times more effectively than nature herself! Before we examine the finer points of high-level nuclear waste disposal and the options that are available we need to know exactly what it is. When expended fuel rods are withdrawn from a nuclear reactor they are highly radioactive due almost entirely to the fission products held within them by the fuel cladding. As we said earlier, they are transferred immediately to cooling ponds close to the reactor where one may gaze down through several meters of clear water to see the ethereal blue glow of the Cerenkov radiation produced by high energy electrons as they are slowed down and absorbed by the water. Since the total volume of rods is not large, a single pool can contain the used rods from several years of reactor operation. As mentioned above, temporary storage and cooling reduces the level of radioactivity contained within the fuel rods by a huge factor due to the rapid decay of the most radioactive fission products such as iodine-131 and strontium-90. Further storage for a few decades allows the concentrated waste to cool thermally and lose radioactivity sufficiently to either make reprocessing easier or permit vitrification. Of course if the waste is diluted by mixing it with non-radioactive material the disposal can be speeded up. Economics and reduced storage space requirements favour leaving the waste in concentrated form for as long as possible. In 1990 the US National Academy of Sciences concluded that continued at-reactor storage of spent fuel should be safe for at least one hundred years (Gerrard 1996). That is taking the pessimistic view that the purely political objections to safe geological disposal have not been overcome by then.

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NATURE’S ANSWERS If, for some reason, it is deemed imperative that something must be done to permanently isolate high level nuclear wastes there exist disposal options so extraordinarily safe that only the most unreasonable and unlikely circumstances could lead to failure. It is probably fair to state that no other aspect of nuclear power generation has so deeply engaged the concern of those responsible for the health and safety of the public and the protection of the environment. To them it has been a considerable reassurance that one of the most astonishing demonstrations of the effectiveness of underground storage of nuclear reactor wastes was conducted by nature nearly two billion years ago at Oklo in Central Africa (see Wilson 1996). The discovery of the Oklo reactor was made by the French who were mining the rich deposits of uranium in the southeast of the Gabon Republic, formerly a French colony. In 1972 their testing laboratories found a deficiency of the U-235 isotope in the uranium they were intending to enrich. After ruling out contamination from used reactor fuel they performed isotope assays on batches of newly mined uranium. To their great surprise they found some samples of ore contained as little as half of the normal fraction which, everywhere else in the world, is a precise 0.7202 percent U-235. Field work at Oklo soon turned up sample cores proving, by the presence of decayed fission products, that there were six lensshaped zones in the uranium ore body where natural nuclear reactors had functioned nearly two billion years ago. This amazing phenomenon has been described as “surely one of the most exciting scientific discoveries of the decade .”10. The six or more natural reactors at the site achieved a level of fuel utilisation (called 'burn-up') about as good as that of a modern light-water reactor. Field studies revealed that a thick vein of rich uranium ore had been permeated by fresh water in sufficient quantity to moderate and thereby slow down enough neutrons to spontaneously initiate chain reactions and keep them ticking over for up to half a million years. It was important that the vein be thick to reduce the number of neutrons managing to escape and by doing so failing to maintain the chain reaction. The power levels remained low due to the selfregulation provided by the water, which, wherever it formed steam, shut down the reaction in the vicinity until the heat escaped and 10

Weinberg, A, “Assessing the Oklo Phenomenon”, Nature, Vol 266, p 266, 17 March 1977

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fissioning could resume. Due to the confining pressure of overlying strata there was no risk of a steam explosion. The fission products were formed in the presence of flowing water, which would have removed the radioactive gases and some of the more soluble species. Most of the other fission products and the actinides (elements heavier than lead formed by normal radioactive decay and not by fission) remained entirely within the reaction zone. Another example of nature showing the way is at the Morro do Ferro near the top of a hill in the State of Minas Gerais, Brazil. It is one of the most radioactive localities on Earth. It is a highly weathered deposit of thorium and rare-earth elements which has been invaded by ground water and eroded to the surface (Eisenbud and Gesell, 1997). Studies have shown that the 30,000 tonnes of thorium remain in situ despite the weathering. Since ions of thorium and the rare-earth element lanthanum behave like plutonium and other trans-uranic ions, the Morro do Ferro example fails to support claims that ground-water will be a problem for the safe disposal of high-level nuclear wastes. A feature that Oklo and the Morro do Ferro have in common is the presence of abundant clay minerals which prevent the escape of the radioactive elements. The lesson is clear and simple - blocks of waste, vitrified or encapsulated by any of the methods we are about to discuss, should be enclosed in clay if underground burial is adopted. Yet activists continue to wail that there is no safe way to dispose of nuclear wastes. Nonsense. Nature has shown the way to achieve this goal and has essentially validated the approach that was adopted by the nuclear power industry long before Oklo was discovered. This was, and still is, the strategy of storing used fuel rods under water until the short-lived (and hence most active) fission products have decayed, then where possible reprocessing the rest to extract useful elements such as unconsumed uranium and plutonium for further use as fuel, then encapsulating the remainder for eventual permanent disposal. 'Eventual' is the operative word. As long as the quantities are not large, about one cubic meter for every year of operation of a 600 MW(e) reactor, it is advantageous to store the high-level waste for as long as convenient in order to reduce the activity of the volume that needs to be isolated from the biosphere by vitrification and burial or whatever. Because the time-scale for this is several decades or longer, there has not been enough time to conduct definitive experiments to see what shortcuts might be found, so a conservative approach has

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generally been adopted (except by the military, whose inferior methods of waste storage are not what we are discussing here). To gain some perspective we shall shortly take a close look at the horrendous extent of the military waste problem, which is about one hundred times that from civil nuclear power production.

VITRIFICATION Tipping high-level radioactive wastes into a vat of molten glass and letting it solidify was the first attempt at containing them. Depending on the extent of dilution, the resulting glass blocks are radioactive to a greater or lesser degree. The problem with vitrification in glass stems from the fact that glass has some of the properties of a very viscous fluid and the wastes are not firmly locked in place. They can be leached out. When the first wastes were produced from the Chalk River reactor in Canada, some of it was vitrified and the resulting block of glass was placed in a stream of running water, with geiger counters placed downstream to measure the radioactivity released. The results were encouraging. The leach rate was low enough for the radioactivity of the flowing water to remain within acceptable limits. The glass retained its integrity, like pieces of glass cast in ancient times and salvaged in good condition from under the ocean. However it has been found that the type of glass used is most important. With common soda glass the sodium can be detached in the course of time by heat and irradiation from the nuclear waste dissolved within it. Over long periods the degraded glass becomes susceptible to corrosive attack, particularly if the blocks of waste are stored in salt formations and water gains entry. Borosilicate glass does not suffer this problem. But during storage periods of thousands of centuries another process becomes important. If highlevel wastes are vitrified in any kind of glass there must be some kind of buffer material, such as a clay, between the glass and the metal container enclosing it. Otherwise tracks produced by alpha particles from waste decay etch the metal and render it more prone to corrosion in the presence of water, and especially salt water. So there are problems with vitrification in glass, but they are being recognised and know-how to overcome them is steadily accumulating. Vitrification of high-level waste in borosilicate glass has been adopted by several countries, notably France where a plant at Marcoule has been operating since 1978. By 1982 it had produced

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264 tonnes of vitrified waste, which I would think includes military wastes as well as that from the few civilian power reactors operating by that time. The final product is in the form of cylinders of glass encased in stainless steel, 1.5 or 3 metres long and 30 centimetres in diameter.11 But there is no urgency for final disposal since the dangerous radioactivity is completely immobilised. The main French vitrification plant is now situated at La Hague. In 1991 a highly automated vitrification facility was opened at Sellafield in Great Britain. In the Sellafield process highly radioactive liquid wastes are piped into a slowly revolving furnace, mixed with suitable chemicals (including common sugar!) heated to 850 degrees celsius and reduced to a coffee-like brown powder. The powder is then mixed with three times its volume of glass flakes and again heated in a furnace, this time to 1150 degrees to melt the glass and produce a molten mix which can then be poured into stainless steel containers to solidify. When it has cooled sufficiently the container is placed in a transport flask and moved by rail to a well-ventilated building where it is loaded into a storage channel. It can stay there indefinitely because the total volume of containers is not great. Eventually the containers may be moved to a deep underground repository if that form of disposal is mandated, or it may be reprocessed sometime in the future to reclaim valuable elements such as radium.

COPPER ENCAPSULATION This novel method of isolating high-level nuclear waste has been developed in Sweden. It relies on the long-term integrity of a thick copper containment vessel. The Swedes plan to bury the vessels deep in a stable rock formation, surrounding them with clay material to inhibit access by ground water and slow the release of radioactive material in the unlikely event that the vessels fail in some way. At the Aspo Hard Rock Laboratory construction of a test repository is well advanced. The facility is a 3,600 metres long underground laboratory tunnel, five metres in diameter, reaching a depth of 450 metres in the bedrock. An elevator gives access to the repository area from service facilities above ground, where wastes can be temporarily stored prior to final disposal in containment vessels. Sites for final nuclear waste disposal in deep geological repositories have been narrowed to two from an initial eight 11

“Radioactive Wastes”, International Atomic Energy Agency, Vienna 1983.

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locations where their municipalities have voted acceptance. The two, at Oskarshamn and Osthammer (close to the Forsmark nuclear power station) were selected for their suitable bedrock properties.

SYNROC Due to its superior retention properties and impermeability to water the Australian invention of Synroc (Synthetic rock) is the Rolls Royce of encapsulation methods for permanently immobilising high level nuclear wastes. The Russians and Chinese are examining its unique advantages. The process (but not the name!) has been licensed to ANSTO where a small pilot plant has been built at Lucas Heights. Synroc was developed in 1979 by the late Professor Ted Ringwood of the Australian National University. He spent many years studying the abilities of countless minerals to trap within their crystal structures the wide variety of radioactive components in high level waste from nuclear reactors. He came up with a recipe for a crystalline ceramic composed of minerals known as titanates because they are all based on titanium. The mixture Professor Ringwood found to be most effective is a combination of four simple minerals known to mineralogists as rutile, hollandite, perovskite and zirconolite. These provide a highly stable crystal lattice structure which immobilises the actinides and hazardous fission products from nuclear reactors. The zirconolite takes up the actinides (the heavy radioactive decay products of uranium and plutonium); the perovskite locks in the dangerous strontium-90 while the hollandite takes care of barium, cesium and rubidium. The rutile binds them all together. To create the ceramic, four parts of the component mineral ingredients are mixed with one part of high level waste (which dilutes the radioactivity by twenty percent anyway) and the mixture is dried, calcined in a furnace at 750C, then hot pressed at 1150C to produce a dense, hard block of Synroc. The wastes are so tightly locked into the mineral structure of the rock that after two months the rate at which the wastes leach out is down to only one thousandth that of wastes vitrified in borosilicate glass (which, as the French will argue, is still a very good option). The leach rate is higher to start with, about one tenth that of the vitrified wastes, until a small residue of less tightly bound waste is flushed out. It is worth noting that by this stage the leach rate is down to one tenth

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that of the common radioactive mineral, granite (as used in many kitchen benchtops!). After two months the loaded synroc is ready for burial. After about a thousand years, depending on how much the original waste has been allowed to stand and how much it is diluted, the synroc will be no more radioactive than the ore from which the original uranium was mined. It can be dropped down a drill shaft in a stable rock formation and forgotten. Scare stories about it being so dangerous it must be guarded for millions of years are just that scare tactics - even when the waste contains a typical amount of unsalvaged plutonium.

UNDERGROUND DISPOSAL There is nowhere on this planet where nuclear wastes can be stored without raising a chorus of complaint by anti-nuclear activists. Even if repositories are chosen in rock provinces of proven stability for billions of years, as at the Swedish sites mentioned earlier, there will still be the incessant “What if .... ?” objections, citing the most absurd failure scenarios. In the eons of time before the dying Sun wipes out all life on this planet, who, with the technology to tunnel deep into basement rock formations where the wastes repose, is likely to do so without continuously watching what emerges from their boring machine and monitoring radiation levels whenever abnormal strata are encountered? Besides, in a few hundred years after burial the radioactivity of the highest level wastes will be no greater than that of a rich new radioactive ore body which they could easily strike at any number of locations. Obviously encapsulated high level nuclear wastes should not be buried near geotechnically active regions, such as fault lines, volcanos and tectonic plate margins, with the exception of subduction zones which we will come to later. There are plenty of places in the world that satisfy these conditions. Australia currently holds the record, snatched from Canada, for the oldest terrestrial rocks. Rocks from northwestern Australia have been dated at a shade under four billion years. Rocks in the Canadian shield are only slightly younger and it would surprise nobody if the Russians discover some almost as old on their vast continent. The Chinese too have access to extremely old rock provinces in the west of their country, where it is believed they already plan to dispose of their nuclear wastes.

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As mentioned earlier, the Swedes and the Finns as well, are pressing ahead with nuclear waste disposal in deep bedrock repositories within their own national boundaries, with fading objections from anti-nuclear activists. There is no shortage of suitable sites and it is pleasing to note that there are some far-sighted people in Australia who are investigating the best ones. The Federal Bureau of Resource Sciences, as custodians of a massive amount of seismic information, has a project for offering advice on possible locations for new low-level waste repositories. “This exercise .... uses a range of data on geology, populations, economic value and existing infrastructure to come up with a number of possible locations...(for the repository) ” Of course this groundwork, so to speak, will provide an invaluable basis for the selection of a future repository for high-level nuclear wastes if, and when, a decision is made to create one on the Australian continent.

OCEAN DISPOSAL The first reaction to this method is usually one of horror that such a proposal should be so much as mentioned. In fact the oceans are a vast repository of radioactive materials to the extent that the recovery of uranium from sea-water is a practical proposition, but not at present an economic one because there are only about three parts per billion of uranium in sea-water. Even so the world’s oceans contain about four billion tonnes of uranium. The Japanese have successfully obtained uranium from the sea and are keeping the technique up their sleeves in case they are for any reason cutoff from their normal supplies. They have built a plant at Nio, 550 km southwest of Tokyo, to extract as much as a thousand tonnes of uranium a year from the sea. Other nations are also experimenting with similar schemes. Uranium is not the only radioactive element in ocean water and in the light of the vast quantities that exist there the addition of quite large quantities of man-made nuclear wastes could go completely unnoticed if it were not for the extraordinary sensitivity of nuclear measurement devices which can record events atom-by-atom. Once high-level radioactive wastes are immobilised by vitrification, encapsulation or mineral entrapment (Synroc) - it hardly matters which - they can be taken to suitable locations near the edges of the deepest oceanic trenches and simply dropped overboard. Suitable trenches are found off the coasts of the

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Philippines, Japan, Russia (beside the Kurile island chain) and the United States (beside the Aleutians). Not to mention near to 'nuclear free' New Zealand! The deep ocean trenches occur at places where tectonic plates are slowly but irresistably colliding. For example, at the Kermadec trench to the north of New Zealand. When an oceanic plate meets a less dense continental plate the ocean plate slides under the continental plate - a process known as subduction. Subduction at colliding plate margins can be at the rate of up to 10 centimetres per year and the crustal material is carried as deep as 700 kilometres into the Earth’s mantle.12 At the subduction trenches there is a piling up of light sediments which are not dense enough to plunge into the Earth’s mantle under the irresistable pressures of ocean-floor spreading (Encrenaz, 1991). Therefore the trick in this method of disposal is to drop the canisters of immobilised waste into the edge of the sediment pile-up on the oceanic side of the subduction trench. The greater density of the waste will ensure that it will work its way down through the less-dense sediments to rest on the denser seafloor rock which is forced down into the mantle. Once on its way, no conceivable human intervention will recover it and its complete safety and removal from the biosphere is assured. Another approach to undersea disposal of high-level nuclear wastes is that proposed by a former member of the anti-nuclear Union of Concerned Scientists, C D Hollister. Many kilometres down under the oceans there are vast abyssal plains of little value to the marine ecology since they are almost devoid of either plant or animal life. These plains are like submerged mud-flats hundreds of metres thick, composed of chocolate-coloured clays having the consistency of peanut butter, overlaying the crustal rock below. Hollister argues that a relatively straightforward deep sea drilling rig could bore holes in the mud to allow waste canisters to be deposited and sealed in place. The clays act as an excellent sealant and greatly inhibit the mobility of the wastes should the canisters leak their contents. Because seventy percent of the Earth’s surface is ocean, and the abyssal plains extend across most of the sea floor, there is more than enough area available to permanently bury all the radioactive wastes ever likely to be produced by a nuclearpowered global civilisation over many thousands of years. Of course the greatest impediments to the disposal of radioactive wastes in the sea would have to be political. Treaties and agreements, such as the London Dumping Convention of 1972, 12

Dewey, J F, “Plate Tectonics” Scientific American, Vol 226, No 5, 56-68, May 1972.

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which were legitimately designed to eliminate or minimise harm to the oceanic ecology, will be invoked to block such actions quite regardless of the fact that the maximum possible leach rates from properly immobilised radioactive wastes will make a negligible contribution to existing levels of sea-water radioactivity. In clear violation of these agreements Russia has scuttled several damaged nuclear submarines in the Arctic Sea and dumped low level nuclear wastes into the Sea of Japan (Gerrard 1996). Summing up, regardless of politically inspired treaties, it would seem that the best way of disposing of the 300 nuclear submarines estimated to be obsolete by the year 2000 (Gerrard 1996) would be to remove their fuel rods and scuttle them over the subduction trench closest to their home ports. Their valuable fuel rods could be reprocessed for use in civil power reactors - swords into ploughshares approach - and any unusable high level nuclear wastes could be encapsulated and buried either in the barren ocean plains or in land repositories. In my view, nature has given us an ideal solution to the problem of high-level waste disposal after having shown us at Oklo that it is not such a big problem after all said and done. Not so different from ocean disposal is another scheme for which Synroc is particularly well suited. If the Antarctic Treaty is amended to allow it, blocks of high-level waste could be simply dumped on the Antarctic ice plateau. Their heat of radioactive decay would melt the ice below them and they would slowly sink harmlessly several kilometres to the bedrock below, the ice refreezing over the top of them as they sink, sealing them in permanently. If it was deemed they should be recoverable, a tether cable would allow them to be hauled back to the surface as long as they were still generating sufficient heat. There is enough space under the Antarctic ice to accommodate tens of thousands of years production of high-level nuclear waste with total isolation from the biosphere.

NUCLEAR WASTE INCINERATOR A much less controversial solution may be close at hand. Recently an innovative proposal for getting rid of high-level nuclear waste was announced by one of the world’s leading physicists. Nobel laureate Carlo Rubbia (Physics prize 1984) has developed a proposal for a prototype cyclotron-activated nuclear reactor which will burn up the waste, stripping it of most of its radioactivity.

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Professor Rubbia, an Italian who headed the European laboratory for particle physics (CERN) until 1993, has worked on this controversial project for over a decade. The proposal has now gained prominence due to it being recommended in a French parliamentary report, and lately by apparently obtaining funding to build a large prototype for the Spanish government. A 100 MW prototype was quoted earlier at US$ 175 million. "Our goal is to generate cheap nuclear energy which cannot cause accidents, does not produce radioactive waste and does not propagate plutonium", he said. "Our machine eats all its own garbage". The device is variously known as an 'energy amplifier' and a 'Rubbiatron'. It combines an accelerator with a reactor core of thorium (or natural uranium) mixed with high-level nuclear waste, all cooled by liquid lead. A high-energy proton beam from the accelerator is directed on to the fuel to convert plentiful thorium-232 to uranium-233 and initiate a fast-neutron breeder reaction which then generates heat (and hence electricity to run the accelerator with plenty to spare). The chain reaction is only sustained while the proton bombardment continues, burning the high-level waste to leave simply a residue of easily disposable low-activity waste. The European Community has funded experiments carried out at CERN which have demonstrated the breakdown of both transuranic elements such as plutonium and radioactive fission products such as technetium-99.13

MILITARY WASTES Before leaving the subject of high-level nuclear waste, mention should be made of military nuclear waste (besides the submarine propulsion reactors discussed above). Those countries with nuclear weapon programs are by far the worst offenders and the ones to be worried about rather than the comparatively trivial amounts of high-level nuclear wastes resulting from civil nuclear power reactors. The country with the best cleanup record is France which has two facilities in operation to deal with wastes from both its military and civil nuclear programs. The worst offender is the former Soviet Union, whose incredibly messy military nuclear program generated an enormous quantity of high-level wastes. According to a pie-chart published in the American Institute of Physics journal "Physics Today" about ten 13

Nature 3/4/97

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years ago14, the Russian releases of radioactive material into the environment were approximately 1130 Mc (million curies) from Tomsk-7, 450 Mc from Krasnoyarsk-26 and 130 Mc from the Mayak military reprocessing plants. Compare the above figures with the grand total of 2.8 Mc altogether from their ocean discharges, mining tailings, power reactor wastes and the dispersed core material from the destroyed Chernobyl reactor. All of these amount to little more than one percent of the military releases. Other nuclear weapon states have similar problems, perhaps not on such a huge scale. But it is surely apparent that military wastes are a major problem because they are so much greater in quantity than those from all the civil power reactors in the world. It is not within the scope of this book to discuss the disposal of military nuclear waste except to emphasise that centuries of civil nuclear power reactor operation would hardly begin to rival the current extent of the military-generated wastes in the world. It is not proposed that Australia should become involved in military nuclear waste disposal.

DECOMMISSIONING OF NUCLEAR FACILITIES Another of the myths of nuclear power is the frequently voiced canard that no nuclear power stations have ever been successfully decommissioned. That might have been so in the early days of nuclear power technology, but it is no longer true. The problems of decommissioning a reactor at the end of its life are relatively simple and cheap in contrast to the complexities encountered in cleaning up after an accident that spreads radioactive materials throughout a plant. The Three Mile Island cleanup took ten years and cost over a billion dollars (Eisenbud and Gesell 1997). To date, 70 commercial power reactors and upwards of 250 research reactors have been retired from operation along with a number of other fuel-cycle facilities. Some of these have already been completely dismantled and their sites returned to 'green field' status with no restrictions on subsequent land use. Years of experience in decommisioning nuclear reactors and related facilities have validated the techniques for dismantling them and safely disposing the associated radioactive wastes. Most components of a nuclear power station do not become radioactive or are contaminated at very low levels. Much of the recovered materials are recyclable. As a result, decommissioning costs have 14

Which I have in the form of an undated lecture transparency.

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fallen to the point where they amount to less than five percent of the total cost of electricity generation and are fully included in the tariffs paid by consumers. Even when this cost overhead is included the price of nuclear electricity is fully competitive with that from any other source. In fact it should be remembered that nuclear electricity production is the only major industry on this planet that takes full financial and physical responsibility for the disposal and clean-up of all of its operating and decommissioning wastes. When a nuclear reactor reaches the end of its operating life, usually 30 or more years, it is decommissioned in three stages, as defined by the International Atomic Energy Agency. The first stage, obviously, is withdrawal of the fuel which accounts for 99 percent of the radioactivity in the reactor. The removed fuel is treated exactly like any spent fuel: allowed to cool in storage ponds and later reprocessed to separate reusable products from that which becomes waste. Then the ancilliary reactor systems such as heat exchangers are drained, operating systems such as control rods are disconnected, and all valves and access openings are sealed shut. For the next five years or so while the remaining one percent of its radioactivity decays the entire facility is essentially mothballed and kept under constant surveillance to ensure that it remains completely safe and presents no hazard to its neighbours. In the second stage of decommissioning the equipment and buildings outside the reactor vessel and its shielding are demolished to allow restricted re-use of the site. The reactor remains sealed in what is known as a 'safe storage' condition while its internal radioactivity further decays away. This residual radioactivity is largely due to unavoidable activation products. These are formed in the steel structures exposed for many years to high neutron fluxes. The intense neutron bombardment creates neutron-rich isotopes of the iron, nickel, cobalt and carbon atoms in the steel and these exhibit high levels of gamma radioactivity during their fairly short half-lives. During this time the defunct reactor is regularly inspected to monitor the integrity of its seals and ensure that there is no danger to adjacent activities at the site. The third and final stage involves the complete dismantling of the reactor core and removal of any residual radioactivity for disposal by appropriate means. The extent of the final clean-up depends on the intended re-use of the site. For some purposes it doesn’t matter if fairly low levels of radioactivity remain. If the removal of radioactive materials is so complete that only pre-

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existing radiation levels are restored, the site is said to be restored to 'green field' status. The time taken to complete all three stages of decommissioning varies widely for different facilities in various countries. In Japan, where land is at a premium, they like to complete all three stages in from five to no more than ten years. At the other extreme, in the United Kingdom, they plan to take more than a century to reach completion of the third stage. Clearly, drawing on Japanese experience, such a long time-scale could be contracted if necessary. France allows a fifty-year period for complete decommissioning. In the United States there are two distinct approaches to decommissioning. In their 'Decon' option they move directly to stage three even though higher levels of radioactivity need to be dealt with. In other cases they reduce this problem through lengthy periods of moth-balling, which is called the 'Safstor' option. Their current regulations allow up to sixty years to reach completion of stage three. The first large reactor to be completely dismantled and have its former site declared fit for unrestricted use was the 60 MWe Shippingport reactor in Pennsylvania, a commercial version of the design employed in the first nuclear-powered submarines. It ran almost faultlessly for a quarter of a century and when it reached its 'use-by' date and became uneconomic by comparison with the larger models coming into service it was retired in 1982. By 1984 the first stage decommissioning was successfully achieved and the whole process completed by 1987 when its site was restored to 'green field' condition. The 'Decon' option was also chosen for the large 330 MWe Fort St Vrain high temperature gas-cooled reactor which was shut down in 1989. Its decommissioning ran to schedule, the site was restored and its nuclear facility licence relinquished in 1997. This was achieved on a fixed price contract which cost consumers less than a cent per kWh despite the short operating lifespan of this unusual design. By way of contrast the more conventional Rancho Seco 900 MWe pressurised water reactor, which was also closed down in 1989, is being decommissioned using the 'Safstor' option. It will remain in stage two mothballing until stage three dismantling is commenced in the year 2008 using funds already committed to it. At multiple-reactor power stations where one reactor is closed down it is most economic to proceed no further than stage two until the remaining reactors cease operation. Then they can all be brought to stage three decommissioning one after another until the

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entire site is restored. At San Onofre unit one, which ceased operation in 1992, is now in 'Safstor' until units two and three are shut down in the year 2013. Likewise the destroyed unit two at Three Mile Island is in 'Safstor' until the operating licence of unit one expires in the year 2014, when both units will be dismantled together to complete the decommissioning of the whole facility. In other countries the story is similar. At Chernobyl the three undamaged RBMK reactors continued in operation supplying essential power until substitute sources were found. The entire Chernobyl station will be decommissioned in stages over several decades, remembering that unit four went a long way toward dismantling itself and is now in stage two of the process. In Great Britain the two 138 MWe Magnox reactors at the Berkely Station were retired in 1989 for economic reasons after operating for 27 years. Stage one decommissioning was completed in March 1992, they will remain at stage two until the year 2022, then maintained at stage three for a further century. France is proceeding a little faster. Three of its gas-cooled reactors have been closed down and partially dismantled to stage two. They do expect to reach stage three of the decommissioning process for another half a century. However they are building at their Marcoule nuclear facility a plant to recycle activated steel from dismantled reactors. Germany has speeded up its decommissioning operations. Their first commercial power reactor, the 250 MWe Gundremmingen-A unit operated from 1966 to 1977. Stage one was commenced in 1983 and dismantling of the highly contaminated parts began in 1990, trialling underwater steel-cutting techniques and recycling much of the material. This experience helped with the 100 MWe Niederraichbach nuclear power station in Bavaria. It has been fully decommissioned and its site was declared fit for unrestricted agricultural use in 1995. The `Decon’ option has also been adopted for the five reactors at the Greifswald power station in the former East Germany. In many countries enough experience has been gained in the techniques and procedures for decommissioning commercial nuclear power reactors for one to confidently assert that it is no longer a problem, if it ever was. The successful reactor decommissionings that have taken place, and the great many others under way, should not be taken to imply that the task is easy. But to assert that it cannot be done is quite false. There are many similar challenges in our high-tech society that have been overcome to the point where we take them for

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granted. Think of the problems in picking up 350 persons and their baggage, whisking them in reasonable comfort at over 800 kilometers an hour to a destination 10,000 kilometers away with greater safety than any alternative means of transportation. This happens thousands of times a day, and even in the rare event of a crash, in which the 350 passengers die, there is little outcry against air travel. So why do the anti-nuclear propagandists pick on the safe decommissioning of nuclear power reactors, with no loss of life, and declare it an insurmountable problem? In concluding his comprehensive analysis of the problems of waste disposal of all kinds, Gerrard (1996) observes that “The anti-nuclear groups (some of which are international, some national, and some local) are similar to the grassroots anti-toxics groups in that they have opposed the siting of any facility. The agenda of many of these groups involves not only the blocking of any new nuclear power plants, but also the closure of all existing nuclear plants and the elimination of the entire nuclear industry. Unlike the anti-toxics groups, the anti-nuclear groups have not focused on the cleanup of existing contaminated sites. They hope that the unavailability of waste disposal sites will increase pressure to eliminate the industry. Thus no siting system of any kind is likely to be acceptable to them, to the extent that it facilitates the survival of the existing nuclear plants .”

TRANSPORT OF RADIOACTIVE MATERIALS This is another target of anti-nuclear scaremongers. In Australia, as in most other countries, there are strict requirements for the confinement and transport of all grades of radioactive materials, including wastes. And especially for protectively casked high-level wastes. I would far rather have ten shipments a day of radioactive nuclear wastes driven past my front door than a single petrol or LPG tanker. Look at the statistics: flaming crashes of petrol tankers occur quite frequently, with alarming pictures of fiercely burning vehicles in newspapers and on television. When was the last time you heard of a civil shipment of radioactive material coming to grief, spilling, and causing life-threatening pollution? Yes, when? I know of none. There is concern that the mere passage of a shipment of low-level waste being trucked past a bystander on the footpath could cause

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harm. In fact the bystander would get about as much radiation dose from eating a banana! A few decades ago the British conducted a spectacular test of the safety of a shipment of high-level radioactive waste. A dummy load was contained in a standard steel transport cask on the back of a large semi-trailer, deliberately stalled on a level crossing. As the cameras whirred, a remotely-controlled obsolete 136 tonne diesel locomotive hauling three retired carriages was made to hurtle onto the cask at more than 160 km/hr. The impact was awesome - far exceeding the spectacle of any Hollywood train crash. When the cloud of dust and debris finally settled the cask was found intact in the middle of the pile of wreckage. Sea transport of nuclear materials never fails to upset the sensitive souls of those folk determined to be upset. In the event of a disaster the shipping casks would sink to the sea-bed where they would, over a timespan of millenia, eventually corrode. Any remaining radioactivity leaking into the sea would be a trifling addition to the amount already there. The world's oceans contain many billions of tonnes of uranium and thorium and much other radioactivity besides.

OTHER NUCLEAR CYCLES Some reactors use heavy water for efficiently slowing down neutrons to fission U-235 and do not require enriched uranium. Most successful is the Canadian CANDU design, now operating in several countries. The ill-fated Soviet RBMK design which operated at Chernobyl at first used natural (unenriched) uranium for its fuel because it employed graphite to slow its neutrons. For both of these designs, stages (2) and (3) in the nuclear cycle (page 5) are quite unnecessary. After the Chernobyl disaster the RBMK reactors were modified to use slightly enriched uranium for more stable and safer performance. In the United States, stages (9), (10) and (11) of the nuclear fuel cycle are by-passed, leading to excessive waste, as mentioned earlier. An exceedingly important cycle is the one for fast breeder reactors. It is able to utilise depleted uranium and recovered plutonium as in stages (4) and (10) but without stage (5). The plutonium fuels the reactor while the uranium forms a blanket around the core. In the blanket the otherwise difficult-to-fission U238 captures neutrons escaping from the core to form additional

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fissionable plutonium to be used as fuel during the next reactor cycle. France, Japan and China are seriously working on breeders to obtain roughly a hundred times more energy from their uranium supplies. India is trying to develop breeder reactors to obtain fissionable U-233 from thorium, because they have on their continent extensive deposits of that fertile element. Over several decades the Russians have been very successful with their BN series of breeder reactors, notably their BN-350 (350 MWe) at Shevchenko by the Caspian Sea. The next larger model, the BN-600, is considered to be the best-performing Russian reactor. Several are operating in the Urals region and more are planned, limited mainly by financial constraints. Their largest model, the BN-800, is at present under advanced development.

ADVANCE AUSTRALIA - MAYBE The nuclear fuel cycle has been a reality for over half a century. Over that time, as in aviation, the industry has matured to the point where the experience obtained can virtually guarantee the success of a new venture that follows best practice. Moreover the nuclear industry has a remarkably good safety record, which should indicate that the litany of fears is without foundation. It would appear that the "What if this.." or "What about that…" voices are simply obstructionist. Despite the construction of over 500 nuclear power reactors (of which 440 are currently operating) and implementation of essential ancilliary stages of the nuclear fuel cycle in several countries, the past half century has seen a vast outpouring of anti-nuclear hostility. At first this was due to an understandable loathing of nuclear weapons. But as there is no nexus with weapons in most of the countries enjoying nuclear electricity, the thrust of anti-nuclear activism has refocussed on waste disposal and safety issues. We have addressed these issues in this essay, but zealous activists are not persuaded by fact or reason. In an age of post-modernist relativism the facts of a matter are irrelevant and reason is of no more worth than unreason (as in unreasonable). In the United States, unreasonable demands and long drawn out litigation by anti-nuclear bodies forced up the cost of nuclear power stations by as much as ten times the original estimates (Cohen 1990). Then along came the Three Mile Island reactor melt-down (causing no loss of life, remember) which dried up investor capital and halted orders for new nuclear stations. Similar legal wrangling

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by activists has delayed for years the opening of the Yucca Mountain radioactive waste repository in Nevada. The construction and commissioning of new nuclear power stations is booming in countries where strong governments put sustainable progress ahead of unsustainable protests. Will Australia join them? At the present time there is little hope that Australia will adopt safe, clean nuclear power, let alone embark on implementing the complete nuclear fuel cycle. For a start there is green-inspired legislation in both New South Wales and Victoria making nuclear facilities illegal - even the act of prospecting for uranium is an offence. Furthermore the Federal Minister for the Environment has publicly pandered to a Greenhouse Conference (February 2003) that the government has "a firm national commitment not to develop nuclear power." Other countries are either pushing ahead with nuclear electricity or rethinking their position. So far in 2003 the Swiss and the Swedes have rejected earlier decisions to phase out nuclear electricity, as did the Germans the previous year. The only European country to buck the trend is Belgium, where they have no idea how they will make up a shortfall of sixty percent of their electricity supply when their existing reactors eventually close down. They may have no alternative but to buy nuclear electricity from their neighbours because the European Union Parliament (in Brussels!) strongly backs nuclear electricity generation in Europe. More than thirty countries in the world have at least one nuclear reactor for electricity generation. They have a head start on Australia. We lost our way back in 1971, when the proposal for a 500 MWe nuclear power station at Jervis Bay was deferred indefinitely. The sorry saga of Australian abandonment of nuclear energy has been well described by Dr Clarence Hardy in his comprehensive history of the Australian Atomic Energy Commission up to the time of its demise in 1987. Then there is finance. Even without legal frustrations the cost of a gigawatt nuclear power station would run to over a billion Australian dollars. But while each of the four major banks continue to post profits of over a billion dollars every year, finance should not be an insurmountable problem. The drive that made a success of the Snowy scheme showed what can be achieved. There are two factors that should force the issue. If greenhouse gas concerns prohibit fossil-fueled power generation, the only alternative is nuclear. Wind, sun and other so-called renewables are

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hopelessly inadequate15. And when there is not enough electricity there will be blackouts with drastic impact on the Australian economy. Across the country views will change. The false promises of the anti-nuclear gurus will be cast aside. Common sense might at last prevail.

BENEFITS FOR AUSTRALIA We may now summarise the benefits to Australia by implementing a complete, closed nuclear fuel cycle for ourselves and other countries. 1. Exporting processed reactor fuel on a leasing basis yields considerably greater economic return than selling uranium yellowcake as a simple commodity. 2. Generating our electricity from nuclear energy can give us cheap and reliable power for home and industry, ensuring future prosperity. 3. Ample electricity will make possible the much-desired "hydrogen economy" yielding fuel for transportation (using fuel cells) when oil supplies run out. Moreover, hydrogen can be used to hydrogenise low-grade crude oil and convert it to jet fuel for aircraft where the weight of hydrogen storage would be prohibitive. 4. One of the most desperately needed projects for our parched continent is large-scale water desalination made possible through use of nuclear electricity from suitably located power reactors. 5. Australia's international ethical standing can only be enhanced by making available our rich uranium resources and extensive disposal potential to meet the needs of other less fortunate countries, subject, of course, to full compliance with existing nuclear non-proliferation treaties. The benefits outlined above are all readily achievable using tried and proven nuclear technology enjoying a well established safety record. The fact that western reactors have clocked up more than ten thousand reactor-years of power production with not a single 15

See the detailed discussion in "Nuclear Electricity Gigawatts", Enlightenment Press.

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radiation fatality makes the nuclear power industry one of the safest undertakings on this planet. By adopting tried and tested reactor types, upgraded to incorporate the latest reliable control systems and passive safety measures, Australia could maintain impeccable standards of performance. Safety first must always be the paramount concern. With a sensible approach, the financial returns will be immense because the world needs abundant energy for industry, transport and domestic use. Ignore fusion power - decades of grappling enormous problems with very limited success make it too much of a long-shot. Forget so-called sustainable alternative energies - wind, solar and others they haven't a hope of supplying our energy needs16. The advocates of these energy sources make fraudulent claims. In the latest issue of their newsletter17 it is claimed that 400 MWe of wind generated electricity is enough to power 200,000 Australian homes. That is 2 kWe per home, which is about right on average. But, and this is a very big but, there is no mention whatever that the wind has to blow strongly enough to provide that amount of electricity continuously 24-hours a day to maintain the average. Under calm conditions the very same wind installation will power exactly zero Australian homes. None at all. That's why some continuous baseload source of power is vital. It is worth noting that a twenty percent contribution of power from intermittent wind or solar sources is about the maximum that a national grid system can accommodate without severe problems, as the Danes and Germans are learning to their cost. What’s more, base load plant must be kept available with turbines spinning ready to take up the load when the wind drops or cloud blocks the sun. As a result the net wind or solar contribution falls to roughly one third of the twenty percent hoped for. Australia at this point in time requires about 40 gigawatts total of electrical generating capacity. The amount needed increases year by year and quite heroic consumption cuts or gigantic efficiency increases will be necessary to stem the demand. Even if some form of energy storage having 100 percent efficiency became available, which is impossible, there would still need to be 8,000 square kilometres of solar panels or 200,000 megawatt-size wind turbines (assuming 20 percent capacity factor) to generate this amount. The ancilliary needs, transmission lines, etc., would be formidable because, unlike nuclear power stations, most wind and solar farms 16 17

See "Nuclear Electricity Gigawatts" (Enlightenment Press) for a full discussion of this point. "Watts News", June 2003.

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are of necessity quite distant from urban areas. (There will always be a few choosing solar panels for household power and live without most of the appliances Australians now take for granted.) Please note that the above figures assumed that perfectly efficient energy storage fortuitously becomes available in the near future to take care of the times when there is no wind or sunshine. So, multiply the number of wind turbines or area of solar panels by a factor that takes into account the actual efficiency shortfall. That factor is unlikely to be lower than two, even if reverse hydro systems, as at the Tumut-5 power station in the Snowy Mountains, are employed (that assumes more similar sites become available, which is hardly likely). The above analysis assumes that there is no other continuous source of electricity present. To be realistic, that would have to be either continued fossil fuel burning, with its pollution and squandering of diminishing petrochemical resources, - or safe, clean nuclear power. Even if we adopt a hydrogen economy, as often advocated, it cannot be stressed often enough that there needs to be some primary source of energy to manufacture the hydrogen. In fact, a hydrogen-based ground transportation regime would consume more electric power for hydrogen production than that consumed by all electricity consumers, industrial and domestic together. Nuclear electricity will, quite literally, give Australia a future.

WHERE AUSTRALIA STANDS – WAKE UP ! A rescue effort, to go nuclear and give Australia a secure energy future, will be a bitter struggle against ideological opposition. It would be naïve to think otherwise. How much time will it take for electricity rationing to really bite and lead to a swing of public opinion in favour of nuclear power? Already, in Queensland, shortages have forced spot prices for electric power up to $4.40 a kilowatt-hour – almost one hundred times normal18. A warning of things to come, maybe? Electric power shortages have massive economic impact. Commerce is so deeply dependent on reliable power. This has been demonstrated several times in the past few years. There was chaos in northeastern America when a solar storm tripped out much of their electricity grid system. Then there was the Californian power crisis which forced the richest State of the Union to purchase power 18

Sydney Morning Hrerald, 26 February 2002

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at prohibitive rates from as far away as Texas. The power cuts they endured at that time and since may be one reason why the State of California has officially gone broke. Closer to home, a couple of years ago in New Zealand, the cable failure that plunged the Auckland central business district into darkness for days caused havoc in company offices, factories, hospitals, hotels and the university. Inner city apartment owners were none too pleased either when they surveyed the mushy contents of their home freezers. It is not possible to say exactly how soon such scenarios will afflict Australians. Apart from the odd catastrophe, the onset of power shortages will be gradual but gathering momentum unless some form of base-load electricity supply is brought online to replace the output of obsolete, clapped out generating stations. A lot depends on how quickly fossil-fuel usage is phased out. Oil supplies are dwindling, natural gas is limited and coal, while relatively plentiful, is far too polluting. Besides, fossil fuels need to be preserved for the future as petrochemical feedstock and as a basis for aviation fuel. Eventually the day must dawn when the average Aussie battler takes a pay cut because of power blackouts and shortages of electricity at the workplace, rides his bicycle home in the chill of winter to an unheated house, is obliged to eat a cold meal by candlelight, without TV, and with little alternative option than going to bed. And spare a thought for commuters and others caught in underground train tunnels, and lifts, when the electricity suddenly cuts out. Events will then, hopefully, take a turn for the better, because trapped, cold, hungry and angry citizens have a vote. A vote bound to bring about an overdue change of fortune for nuclear electricity in Australia. But the Aussie battler will not have his frustrations eased overnight. To cap off this gloomy scenario let us not forget that it will take the better part of a decade to get the first nuclear power station up and running from the word go. Several decades more to get enough power reactors on line to meet even our most basic energy needs. So there is no time to lose. Australia must go for nuclear electricity. It can be done. It must be done if Australia is to have a future in the increasingly nuclear powered Asia-Pacific region. China, India, Japan and South Korea are leading the way with others following. Considering only countries in the southern hemisphere, the four leading economies are Argentina, Australia, Brazil and South Africa. Of these four, Australia is the only country without a nuclear

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power program and a strong ancilliary nuclear industry. Argentina was the successful bidder to build the new Opal replacement research reactor for Lucas Heights, while South Africa is, in collaboration with China, developing the innovative super-safe modular “pebble-bed” power reactor. On the other hand most Australian politicians have been thoroughly spooked by the antinuclear lobby with the result that our country is standing idly by behind the starting gate in nuclear power production. The big question is: how long will it take for the alternative energy fraud to be exposed? Only when that comes about may Australia at long last take the essential steps to guarantee stable nuclear electricity resources that will underpin future prosperity.

AMERICA IS WAKING UP As I write, I learn that the US Senate has passed a bill (247 to 175) supporting nuclear power. I let Senator Pete Domenici, Chairman of the Senate Energy and Natural Resources Committee, have the last word: "We cannot ignore the vast benefits that nuclear energy offers the nation ;" he said. "America must once again start building nuclear power plants using state -of-the-art technology. I predict that we will one day look back and wonder what took us so long to realise the promis e that nuclear energy offers us."

SO WHY IS AUSTRALIA WAITING? STOP PRESS!

The December 2005 issue of the highly respected journal Scientific American contains a major article titled “Smarter use of Nuclear Waste” that supports the general thrust of this book. The article demonstrates how “Fast neutron reactors could extract much more energy from recycled nuclear fuel, minimise the risks of weapons proliferation and markedly reduce the time nuclear waste must be stored”.

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Main Reference Sources Bate, R (ed), "What Risk? Science, Politics and Public Health" ButterworthHeinemann, Oxford 1997. ISBN 0-7506-3810-9. Beckmann, P, “The Non-problem of Nuclear Wastes” Golem Press, Boulder CO, 1979. Also see Beckmann's book "The Health Hazards of NOT Going Nuclear". Cohen, B L, "Nuclear Energy Option", Plenum Press, New York 1990. ISBN 0-306-43567-5. Eisenbud, M, and T Gesell, "Environmental Radioactivity" Fourth edition, Academic Press, San Diego CA 1997. ISBN 0-12-235154-1 Gerrard, M, "Whose Backyard, Whose Risk? Fear and Fairness in Toxic and Nuclear Waste Siting", MIT Press, Cambridge MA 1996. ISBN 0-262-57113-7. Hardy, C, "Enriching Experiences - Uranium Enrichment in Australia 19631996", Glen Haven Publishing, Box 85, Peakhurst, NSW 1996. ISBN 0-64629063-0. Hardy, C. "Atomic Rise and Fall", Glen Haven, 1999. ISBN 0-9586303-0-5. Hayden, H C, "The Solar Fraud - Why Solar Energy won't Run the World", Vales Lake Publishing, Pueblo West CO 2001. ISBN 0-9714845-0-3 Hollister, C D, and S Nadis, “Burial of Radioactive Waste under the Seabed”, Scientific American, Vol 278, No 1, January 1998. Krinov, A, "Nuclear Physics and Nuclear Reactors", Mir Publishers, Moscow 1975. McEwan, A, “Nuclear New Zealand – Sorting Fact from Fiction”, Hazard Press Publishers Ltd, Christchurch, New Zealand 2004. ISBN 1-877270-58-X. Price, M S T, “Transport for the Nuclear Industry”, Nuclear Technology Publishing, Ashford, Kent 1997. Wilson, P D (ed), "The Nuclear Fuel Cycle - From Ore to Waste", Oxford University Press, Oxford 1996. ISBN 0-19-856540-2.

Every effort has been made to ensure the accuracy of the material presented in this book. If an error is detected the author will be pleased for it to be identified and be advised of a more authentic source. Should a correction be needed, the author will be grateful and an amendment incorporated in future printings.

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Nuclear Issues Series Supplement 2007 Colin Keay

The Outrageous Wind Power Swindle It’s time someone nailed the big lie in the current energy debate: that nuclear is too expensive compared with supposedly cheap wind electricity. Wind farms are not an answer to the demands of large-scale electricity generation. It is not simply their intermittency, creating problems of supply, but their huge costs financially, socially, environmentally, aesthetically and not least their global warming contribution. Wind power advocates airily dismiss these concerns and suppress the evidence against them. Let us step by step prove them wrong. A common comparison between wind and nuclear electricity generation is to compare peak powers. One gigawatt (1000 megawatts) is typical for a modern nuclear power reactor. A typical modern wind turbine in a large wind farm (a Vestas V90) is rated at a peak power of two megawatts, requiring 500 of them to match the nuclear reactor’s peak power level. To put this in perspective, in 2006 the total installed power of all of the wind farms in Australia amounted to a little over 800 megawatts – easily within the capability of a single nuclear power reactor. However any meaningful cost comparison must be in terms of energy rather than power, because energy is what we use and pay for. Power is simply the rate of use or generation of energy. In light of that, compare the energy produced by a wind farm with a modern nuclear power reactor that is able to run at its peak rating for a conservative 90 per cent of the time. The reactor will in one year deliver almost 8000 million kilowatt-hours (the kWh is familiar as the unit of energy used for domestic electricity billing). On the other hand the sprawling wind farms of the European Union achieve a load factor of a little under 20 per cent, according to the latest figures presented in a European Commission newsletter. So the 500 wind turbines will in one year deliver just 1750 million kilowatt-hours of energy, less than a quarter of the amount from the nuclear power reactor. Thus the number of twomegawatt wind turbines required to equal the energy production of a onegigawatt nuclear reactor jumps to 2,250, with a corresponding increase in transmission lines. That huge number of wind turbines needed reflects the inherent intermittency of wind as an energy source. But that’s not all. Take the materials used in construction. A single Vestas V90 turbine requires 250 tonnes of steel and, to prevent it toppling over in gale-force winds, a base with about 1000 tonnes of reinforced concrete. The actual amount depends on whether driven piles or rock anchors are employed.

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A 2250-turbine wind farm therefore needs 562,000 tonnes of steel and 2.25 million tonnes of concrete. The amounts for the nuclear equivalent are 35,000 and 200,000 tonnes respectively. In round figures, the wind farm uses 12 times as much material as the nuclear plant. It follows that the wind farm’s contribution to global warming in terms of energy production alone will be 12 times that of a nuclear power reactor. But still there’s more. A wind farm of 2,250 turbines demands huge tracts of land cleared of trees (another contribution to global warming!), high loadbearing road access during construction and maintenance, and an expensive transmission system because of its dispersed extent. By comparison the nuclear station is compact, requiring less than a square kilometer of land overall, including either access to cooling water or the provision of a pair of cooling towers (access to some water is still needed for making up evaporation loss by the towers) and a storage pool for spent fuel. By law in most countries a nuclear power plant must make provision for eventual decommissioning to Greenfield condition, usually after a licensed life of 50 years or so. On the other hand wind turbines have a design life of 20 years and to the best of my knowledge no money is earmarked for removing 2,250 gigantic blocks of reinforced concrete. The cost of electricity from wind comes out at 10 to 13 times that from a modern advanced third generation nuclear reactor – where it is just over four cents (Australian) per kilowatt-hour. A reactor would cost an estimated $1700 million and could be built in 36 months, not including site selection and licensing and other delays. In the US most reactors have fully amortised their capital costs and enjoy performance-based 20-year licence extensions, dropping their electricity prices down to a low of 1.66 US cents per kilowatthour. To those who argue that nuclear power stations take too long to build we might ask how long it would take to construct a mind-boggling 2,250-turbine wind farm. And the environmental degradation due to such a large farm is frightening: simply to make an inefficient substitute for only a single nuclear power plant! In the words of Ari Vatanen, a Finnish member of the European Parliament: “Without nuclear energy our industry cannot be competitive in a merciless global marketplace. I feel sorry for the Germans whose government pays over 120 Euros per megawatt-hour for wind electricity [compared to 15 Euros for Finnish nuclear power], which on average is available one hour out of four and therefore ironically needs parallel fossil fuel back-up for 75 per cent of the time. Common sense has gone with the wind”.

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Enrichment: What They Never Tell You Uranium enrichment is in the news again. But what precisely is it? And why is it necessary? Should Australia be involved? To understand the enrichment process one must take into account the role of a nucleus as the supreme boss of an atom. The number of protons in a nucleus defines the element and hence its chemistry. This figure happens to be 92 for uranium. Atomic nucleii also contain neutrons that do not affect the chemistry of an atom but they lead to profound differences in its nuclear behavior and whether it is stable or not. Atoms of the same element but with differing numbers of nuclear neutrons are called isotopes. Enrichment starts with natural uranium which is composed of two isotopes with very different nuclear properties: their amounts are 0.7 per cent U-235, which is fissile (especially so with slow neutrons), and 99.3 per cent U-238, which is non-fissile (except when exposed to very fast neutrons). Increasing the proportion of U-235 in the mix is what enrichment is all about, but the actual degree of enrichment is rarely mentioned in the media. It is possible to build a reactor fueled by natural (unenriched) uranium, but it needs to be very large, like the gigantic Soviet RBMK (Chernobyl) monsters. However if uranium fuel is enriched to 4 or 5 per cent U-235, ordinary water may then be used in a reactor to slow the neutrons. Such power reactors are not so large , are much safer and are more manageable. Uranium enriched to 4 ot 5 per cent U-235 is therefore closed as reactorgrade fuel. That is far short of the 95 per cent or more U-235 required for a nuclear weapon. Thus weapons-grade uranium requires roughly fifteen times more enrichment than the fuel for power reactors. It is interesting to note that Australia had at one stage developed a successful pilot enrichment plant which was closed down for political reasons in 1983. It could have been expanded to handle all the output from our uranium mines. So instead of exporting yellow-cake, over which we have little control of its end use, we could have leased – not sold – reactor fuel rods on a strict return basis, giving us full control over our indigenous uranium. And as a result of value adding by enrichment we could have earned a very much greater financial return from our uranium. That is yet another instance of Australia’s many lost technical and export opportunities. The uranium enrichment process itself is well worth discussing. It is quite remarkable that it can be done at all. As we said earlier, the isotopes of any given chemical element are chemically identical regardless of their nuclear dissimilarities.

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Therefore chemical methods cannot be used to separate isotopes, especially when the mass difference between the two isotopes of uranium amounts to only three parts in 235. The best technique employs a series of ultra high-speed centrifuges. They require the uranium to be in the form of a gas – a most unusual condition for heavy elements at reasonable temperatures. Neverthe less uranium does happen to have a gaseous form called uranium hexafluoride, thereby making enrichment practical. Moral: Australia might just as well take full advantage of the gifts of uranium deposits and the enrichment means that nature has given us.

A Very Important Principle of Radioactivity There is a simple principle that says that the activity of radioactive elements is inversely proportional to the length of their half-lives. The shorter the half-life the higher the activity and, conversely, the longer the half-life the weaker the activity. Makes good sense when you think about it. So short-lived nuclear wastes are the most to be feared. That is the reason why used reactor fuel rods are stored for a few decades under water that shields and absorbs their intense short-lived radioactive emissions as they rapidly decay. Long-term disposal is then made much easier. Some wastes are quite useful. Many nuclear scientists consider it to be very short-sighted to bury high-level nuclear waste because there is so much in it that is rare and useful. For example, reactor generated Americium finds a valuable use in smoke-detectors. Furthermore the plutonium extracted from exhausted fuel rods is still useful for blending in with fresh reactor fuel, even though it has an isotopic mix rendering it useless for bombmaking. Finally those wastes not worth reprocessing may be “incinerated” in high-flux reactors that are now at an advanced design stage. There are six of these so-called fourth-generation reactors that promise cheaper electricity, inherent safety, operating simplicity and short construction times. Conclusion: It is hardly surprising that nuclear science has advanced a long wayin the past half a century, not least in solving its earlier problems. This supplement shows how thorough investigation is essential to refute only two of the many unsupportable claims made by irresponsible elements of those opposed to safe, clean nuclear electricity production. See the book “Nuclear Energy Fallacies” in my Nuclear Issues series for many examples.

Inside back cover

Nuclear Issues Series by Dr Colin Keay You are reading the fourth booklet in a series designed to provide a better appreciation of the role of peaceful nuclear activities in making the world a better place for its expanding population. The three titles already published are….

Nuclear Energy Fallacies – (2nd edition) Here are the Facts that Refute Them Fortysix anti-nuclear lies and myths are listed and debunked.

Nuclear Radiation Exposed - (2nd edition) A Guide to Better Understanding We live in a sea of nuclear radiation. Contrary to conventional belief. a growing body of evidence proves that it contributes to good health. A chart is included for calculating radiation doses.

Nuclear Electricity Gigawatts Supporting Alternative Energies Alternative energy sources that are intermittent are only useful as supplements to reliable, continuous base-load electricity supplies available to support them at times when they are inactive.

The four booklets of this Nuclear Issues series are no longer on sale. They are now accessible on line in the form of four PDF files that may be copied in full without change or in part subject to normal copyright law.