The Home of American Intellectual Conservatism — First Principles

December 18, 2017

Nuclear Power and the Energy Crisis
P. E. Hodgson - 10/22/08

This article is featured in the current Modern Age (50:03, Summer 2008).

nuclear power plant at sunset

The previous article in this series drew attention to the energy crisis that faces the world today. Energy is essential to maintain and increase our standards of living. The demand for it is also increasing due to the world’s rising population. At the same time the available sources of energy are proving inadequate to satisfy the demand: oil production will soon peak and then start to fall; coal and the other fossil fuels are serious polluters; hydroelectric power is limited by geography, and wind, solar, and the other renewable sources are unable to deliver energy in the huge quantities required. This combination of rising demand and falling supply is the basis of the energy crisis. If that were all that could be said, there would be no possibility of resolving the crisis. There is, however, another source—the nucleus of the atom.

In 1939 it was found that when the nuclei of certain heavy elements such as uranium are irradiated by neutrons they became unstable and split into two pieces, a process known as fission. The fission fragments fly apart with great energy and also emit more neutrons. These neutrons can enter nearby uranium nuclei and cause them to fission, resulting in a chain reaction and a large release of energy. This energy release can be controlled and used to drive a turbine to generate electricity. [1]

Many nuclear reactors have now been built, and are making a growing contribution to world energy supplies. They have, however, encountered bitter opposition for a variety of reasons that will be discussed below. The question we have to face is whether nuclear power can provide the solution to the energy crisis, or whether nuclear reactors pose such a threat that they should be phased out as soon as possible. This question can be tackled by applying the same criteria as those already used to evaluate the other energy sources, namely capacity, reliability, cost, safety and effects on the environment.

The Capacity of Nuclear Power

Nuclear power reactors each have an output similar to coal power stations, namely around 1000 MW. There are now about 440 nuclear reactors worldwide delivering about 2,500 TWh per year, around a fifth of world electricity consumption. The numbers of nuclear power stations built in each country depends on its natural resources, principally coal and oil. France, which lacks these resources and is unwilling to become dependent on imports, generates about eighty percent of its electricity from nuclear reactors. It is unlikely to rise higher than this because nuclear reactors take time to get started and therefore cannot react quickly when there is a sudden demand. They are best suited to supply the base load, supplemented by other methods of generation (such as gas power stations) to handle the fluctuations in demand.

Many other countries generate around fifty percent of their electricity from nuclear power, and now nuclear has outstripped coal in Western Europe. There is thus no doubt that nuclear power stations are able to provide a large contribution to the world’s energy needs.

It has been objected that this program, while possible in principle, is unable to solve the energy crisis because of the limited supplies of uranium. At present the rate of uranium use is seventy thousand tonnes per year [a metric ton is about 2,205 lbs], whereas the known economically recoverable sources of uranium amount to over three million tonnes, sufficient for about forty-five years. In addition, there are about twelve million tonnes of highly probable deposits. If eventually there is a uranium shortage the price will rise, increasing the number of economically-recoverable deposits. Since the cost of fuel is a small part of the overall costs of reactors, this will have very little effect on the price of the electricity generated.

The present reactors are thermal reactors that burn uranium-235, which constitutes only 0.7 percent of natural uranium. The remaining 99.3 percent consists of uranium-238 that can be burnt in fast reactors. Prototypes have shown that these reactors can be built, although at present they are uneconomic. If the uranium price rises to the level that they become economical, they can take over, increasing the amount of energy obtainable from uranium by a factor of about sixty. Since it is also possible to use the fissile element thorium, which is even more abundant than uranium, there is thus no danger that nuclear reactors will ever suffer from shortage of fuel.

Reliability

Nuclear reactors are unaffected by the weather and rarely suffer breakdowns. The best reactors operate for over 90 percent of the time and nearly all the remainder is for planned maintenance, which is arranged for periods of low demand. Nuclear reactors are thus highly reliable.

Cost

Nuclear power stations are more costly to build but cheaper to run than other power stations, and therefore the cost of the electricity produced depends strongly on the rate of interest required on the initial capital expenditure. The cost is also affected by the lifetime of the reactor, which may be around fifty years, and in that period the effects of inflation may be very large. This makes it difficult to give a precise figure for the cost of nuclear power.

Some estimates of the cost of nuclear power compared with those of other energy sources were given in the previous article. Such comparisons are affected by many factors, but on the whole, they show that nuclear costs are similar, or perhaps rather less, than those of coal. This comparison takes no account of the huge and unquantifiable costs of global warming and climate change due to the carbon dioxide emitted from coal power stations. The carbon dioxide emissions from nuclear power stations are less than one percent of those from coal power stations.

The decommissioning of nuclear reactors after they have reached the end of their useful life has to be carried out with great care due to the large amounts of radioactivity they contain. The fuel rods are easy to remove, and much of the building and parts of the reactor are not radioactive and can also be removed easily. This leaves the highly radioactive reactor core which can either be allowed to decay for many decades before dismantling or could be sealed and buried under a mound of earth. Dismantling the core greatly increases the cost, since it must be carried out by remote control. This cost can easily be covered by setting aside a small fraction of the profits during each year of the reactor’s life. As a reactor can operate for fifty years or more this accumulates sufficiently to cover the cost of decommissioning. It has been estimated that the cost of decommissioning is about 0.05 p/kWh for pressurized water reactors.

Safety

The safety of nuclear reactors can be quantified in the same way as the other sources as one death per thousand megawatt-years. The deaths are attributable to normal causes, such as those incurred in building, and are unrelated to specifically nuclear causes. This is less than all other sources except for natural gas. Negative public perception of safety is more influenced by rare and spectacular accidents rather than by such statistics. Thus in the years from 1969 to 1986 there have been one hundred eighty-seven mining disasters, three hundred thirty-four oil well fires, nine dam bursts, and one severe nuclear accident at Chernobyl, which is discussed below.

Environmental Effects

Nuclear reactors have four principal effects on the environment, first by emitting carbon dioxide, second by taking up valuable land, third by producing waste, and fourth by emitting radioactivity.

The amounts of carbon dioxide emitted by various power sources in grams per kWh are nuclear: 4, wind: 8, hydro: 8, geothermal: 79, gas: 430, oil: 828, and coal: 955. Other estimates give similar figures. These show that the fossil fuels—gas, oil, and coal—are the greatest emitters, and the other sources—nuclear, wind, and hydroelectric—emit less than about one percent of their amounts.

The land areas occupied by the various types of power stations in square meters per megawatt are nuclear: 630, oil: 870, gas: 1500, coal: 2400, solar: 100,000, hydro: 265,000 and wind: 1,700,000.

The radioactivity emitted by various power sources in man-sieverts per gigawatt-year are coal: 4.0, nuclear: 2.5, geothermal: 2, peat: 2, oil: 0.5 and gas: 0.03. These are all extremely small amounts, and it is noteworthy that coal power stations emit more radioactivity than nuclear power stations. This is because coal contains small but significant amounts of uranium, and a small fraction of this is emitted into the atmosphere. The amounts of uranium vary with the type of coal, and the above figure is a world average obtained by the International Atomic Energy Agency.

Every year, a nuclear power reactor produces about four cubic meters (m3) of high level radioactive waste, 100 m3 of intermediate-level waste, and 530 m3 of low-level waste. The total amount of high-level waste produced in Britain from 1956 to 1986 was about 2000 m3, about the same volume as an average house. This is very small compared with the vast amounts of poisonous chemical waste produced by the manufacturing industries, much of which is buried in the sea or emitted into the atmosphere.

The low- and intermediate-level nuclear waste can safely be buried in deep trenches, but the high-level waste requires special attention. As the uranium or plutonium is burnt in the nuclear reactor, the products of fission accumulate in the fuel rods until they absorb so many neutrons that they prevent the reactor from working. To avoid this, spent fuel rods are continually removed from the reactor and replaced by new ones. The spent fuel rods are taken to the reprocessing plant where the uranium and plutonium are separated and used to make new fuel rods. The remaining portion contains the highly radioactive fission fragments. The first step in the disposal of this high-level waste is to store it in tanks above ground for a few decades so that most of the radioactivity from the short-lived nuclei decays. Then the remainder is concentrated and fused to form a glassy or ceramic substance. For extra safety this is placed in stainless steel containers and then buried far below the surface in a stable geological formation. There is then no chance that the fission products will escape and cause harm. This has been checked by a detailed study sponsored by the European Union. Eventually, over the years, the radioactivity of the fission fragments will decay until it is similar to that of the surrounding rocks.

It has been suggested that the radiation emitted from nuclear power stations increases the number of cases of leukaemia in the area. It has also been suggested that this radiation is responsible for long-tem genetic effects. These possibilities are discussed below.

Nuclear Radiations

One of the main differences between nuclear and other power stations is the presence of nuclear radiation. The fission fragments produced when the uranium nuclei split are highly radioactive and emit alpha-particles and beta and gamma rays until finally a stable nucleus is formed. There are many different nuclei among the fission fragments, and the rates of emission vary from a small faction of a second to many thousands of years. These decay rates are characterized by a half-life, which is the time taken by the radioactivity of a sample of a particular type of nucleus to decay to half its initial value.

When it passes through the human body, nuclear radiation can break up the complicated molecules inside the cells, releasing reactive radicals that can cause more damage. If the level of radiation is small, few cells are affected; they are soon replaced and no harm is done. If, however, the radiation level is high, serious damage will be caused, and cancers may develop during the following years. In the case of massive whole-body irradiation, death can also take place. It is vital, of course, to specify just what we mean by low and high levels of irradiation, and this will be done later.

The three types of nuclear radiation have different effects on the human body. Alpha-particles are helium nuclei and, since they are doubly charged, they lose energy rapidly and ionize strongly and are very destructive. Their short range means that they are harmful only if the radioactive material is inside the body. The beta rays are energetic electrons, and the gamma rays are short-wavelength electromagnetic radiation. They can both penetrate far inside the human body.

Nuclear radiation can easily be detected by very sensitive instruments that can record the passage of a single particle, so it is possible to detect the presence of extremely small amounts of radioactive substances. This enables us to learn how they move through the atmosphere, the oceans, and our own bodies. This property has proved to be extremely useful in medical research.

When considering the effects of nuclear radiation on people, it is necessary to take account of the different sensitivities of the different organs of the body. This is done by defining the rem, which is the dose given by gamma radiation that transfers a hundred ergs of energy to each gram of biological tissue, and for other types of radiation it is the amount that does the same biological damage. A new unit, the Sievert, has now been defined as 100 rem.

Nuclear radiation is often feared because it is unfamiliar and can cause great damage to living organisms without our being aware that anything untoward is happening. The damage only appears afterwards, sometimes very long afterwards, when it is too late to do anything about it. Our senses warn us of many dangers, such as excessive heat and some poisonous gases, and we can take avoiding action. Nuclear radiation is not alone in being invisible; many poisonous gases such as carbon monoxide have no smell, and we don’t know that a wire is live until we touch it and receive an electric shock.

When nuclear radiation was first discovered, it was welcomed with enthusiasm, and to some extent this was justified. In the form of X-rays it improved medical diagnosis and treatment, and bottles of health-giving mineral waters were advertised as radioactive. It was only much later, when pictures were released of the radiation damage to the victims of Hiroshima and Nagasaki, that the public image of nuclear radiation switched to one of fear.

Undoubtedly this reaction has gone too far. Nuclear radiation is indeed dangerous in large amounts, but so are fire and electricity. Properly used, nuclear radiation has numerous beneficial applications in medicine, agriculture, and industry. Like so many of God’s gifts, it can be used for good or evil.

Nuclear radiation is not new; it did not first enter the world with the experiments of Henri Becquerel or Madame Curie. It has been on the earth since the very beginning. Many rocks and minerals, such as the pitchblende refined by Madame Curie to produce the first samples of radium, are naturally radioactive and emit radiation all the time. The nuclei formed by such radioactivity include radon, a gas that seeps up through the soil and enters our homes. The natural radioactivity of the earth varies greatly from one place to another, depending on the concentration of rocks containing uranium. In addition, the earth is bathed in the cosmic radiations from outer space, and they are passing through our bodies all the time. Cosmic rays are attenuated as they pass through the atmosphere and so they are more intense at the top of a mountain than at sea level. There are radioactive materials in our own bodies, such as a rare isotope of potassium. Thus the human species has evolved through millions of years immersed in nuclear radiation. This natural radioactivity is important for estimating the hazards of nuclear radiation in general, since if the additional source emits radiation at a level far below that of the natural radiation it is unlikely to be injurious to health.

In addition to this natural radiation, we are exposed to radiation from medical diagnosis using X-rays, medical treatment, atomic bomb tests, and the nuclear industry. Estimates of the radiation exposure in the United Kingdom due to all these sources (in millirem per year) are 186 mrem for natural radiations, including 50 mrem for radon, and 53 mrem for man-made irradiation, nearly all due to medical treatment and diagnosis. That for medical purposes is quite high, but in the long term what is important is the average exposure over a long time weighted by the age distribution of those exposed. This is because the effects of radiation at levels typical of medical uses do not appear for many years so that the irradiation of young people before the end of their reproductive age is more serious than that given to older people. Since the larger part of the medical irradiation is received during the treatment of cancers, which more often afflict older than younger people, the dangers to health due to medical irradiation are not so great as might appear.

Nearly half the radiation exposure due to the natural background is attributable to radon. This is a radioactive gas formed by the radioactive decay of uranium. In regions where the soil contains uranium the radon seeps upwards into the atmosphere or into our homes where it collects unless the house is well-ventilated. Radon decays with the emission of alpha-particles and when breathed in can irradiate the inside of the lung, causing lung cancer. According to the National Radiation Protection Board a radon gas concentration level of 200 Becquerels/m3, equivalent to an effective dose of 10 mSv per year, is the level at which action should be taken to reduce the level. This involves creating a cavity under the floors and pumping out the radon at a cost of up to £1000. Many local authorities are now recommending that such action be taken.

Before doing this, however, it is necessary to establish the relation between the level of exposure and the probability of lung cancer. Many studies worldwide, in Canada, China, Finland, France, Germany, Japan, Sweden, and the USA have failed to establish any positive correlation and, indeed, in three of these studies, there was an inverse relationship. Other studies [2] find that the increased risk of lung cancer due to a lifetime dose of 100 Becquerels/m3 is about 0.1 percent and twenty-five times greater for smokers. The data used in this study were consistent with a linear dose relationship but do not exclude different behavior at very low exposures. The validity of this assumption is discussed in more detail below. It thus seems that, particularly for non-smokers, the level of irradiation due to radon is so low that when compared with other much greater hazards it is difficult to justify such expensive precautions.

Radioactive isotopes have many medical applications. If, for example, we want to know how salt is taken up by the body, we can feed a patient with some salt that contains a very small amount of a radioactive isotope of sodium. This emits radiation that can be detected by a counter outside the body, and so we can follow the progress of the sodium as it is absorbed. The amount of radiosodium needed is so small that it does no harm to the patient. In this way radioisotopes provide a valuable diagnostic tool. Radioisotopes can also be used for treatment. For example, it is known that iodine tends to concentrate in the thyroid gland. If therefore we want to treat cancer of the thyroid we can feed the patient with radioiodine, and it will go to the thyroid gland and irradiate the tumor, without appreciably affecting the rest of the body.

The powerful nuclear accelerators that are used to explore the structure of the nucleus and to produce new unstable particles can also be used to irradiate tumors. The radiation emitted by radium and other natural sources has the disadvantage that it is relatively low in energy and so can penetrate only a small distance into the body. In addition, the radiation comes out in all directions equally. If we want to treat a tumor deep inside the body we need a way of irradiating the tumor that minimizes the irradiation of the surrounding healthy tissue. The only way to do this is to have a collimated beam of radiation of sufficient energy to penetrate the body, and such beams are produced by accelerators. During the treatment, the patient is rotated so that the beam always passes through the tumor but irradiates a particular part of the surrounding healthy tissue for only a small part of the time. This is a difficult technique, but with great care it can be used successfully. Many nuclear accelerators such as that at Faure in South Africa are used partly for medical treatment and partly for nuclear research.

Sometimes it is difficult to know whether the benefits of radiation outweigh the hazards. Thus X-rays can detect cancers early enough for effective treatment, and yet they can also themselves cause cancers. A detailed study of stomach tumors showed that for young people the dangers outweigh the benefits, whereas for older people the opposite is the case.

There is widespread public anxiety about the effects of nuclear radiation, particularly concerning the genetic effects and the cases of leukemia in children near nuclear installations. The children of the survivors of the atomic bombing of Hiroshima and Nagasaki, who all received massive doses of radiation, have been studied in detail by Professor S. Kondo, who personally visited Nagasaki soon after the bombing and saw the devastation. He has studied the effects of the bombing for forty years and has recorded the indicators of genetic damage for 20,000 children of atomic bomb survivors exposed to an average dose of 400 mS. The numbers of the genetic indicators such as chromosome abnormalities, mutations of blood proteins, childhood leukemia, congenital defects, stillbirths, and childhood deaths showed no differences between the children of the atomic bomb survivors and a control group. There is thus no evidence of genetic damage due to the atomic bombs.

To estimate the biological damage due to a particular dose of radiation we must know the relation between the two quantities. The difficulty is that the doses that cause measurable damage are hundreds of thousands of times larger than the extra doses received by people living around nuclear installations. It is often assumed that there is a linear relation between the two, so that the probability of contracting cancer is proportional to the dose. As it seems the safest assumption to make, it is widely adopted in setting safety standards. There is, however, no direct evidence for this, and indeed there is much contrary evidence. [3] This is not unreasonable, since the body has an innate capacity to repair damage, and it is only when the defenses of the body are overwhelmed by a massive dose that harm occurs. Thus a dose received over a long period is less harmful than if it were received all at once.

A direct result of the linear dose assumption is the setting of unreasonably strict limits on permitted radiation exposure in many industries, thus greatly increasing costs. This leads to reluctance to accept vital radiodiagnostic and radiotherapeutic irradiations, and restricts the use of radiation in industry and research. Adherence to these exposure limits led to large-scale evacuation from the region around Chernobyl, causing much unnecessary distress and suffering.

It is also possible that small doses stimulate the body’s repair mechanisms, so that small doses are beneficial. This is supported by an extensive study made by Frigerio et al at the Argonne National Laboratory in 1973. [4] They compared the cancer statistics for the USA from 1950 to 1967 with the average natural background for each State, and found that the seven States with the highest natural background had the lowest cancer rates. Unless there is some other explanation for this result, it implies that the chance of contracting cancer is reduced by 0.2 percent per rem. Further evidence is provided by “the higher life expectancy among survivors of the Hiroshima and Nagasaki bombs; many times lower incidence of thyroid cancer among children under fifteen exposed to fallout from Chernobyl than the normal incidence among Finnish children; and a 68 percent below-average death rate from leukemia among Canadian nuclear energy workers.” [5] Many studies on animals have given similar results.

Furthermore, it is found that people living in areas of high background radiation show no evidence of detrimental effects; thus in Kerala the life expectancy is seventy-four years compared with fifty-four years for India as a whole. Aircrews are exposed to higher doses of cosmic radiation, and their union asked for compensation. Studies of the mortality rates of 19,184 pilots in the period from 1960 to 1996 showed, however, that they actually decreased with increasing dose. The skin cancer rate was, on the other hand, higher because of the time they spent lying in the sun on tropical beaches. Such evidence has been widely discounted because it seems counter-intuitive.

In favor of the idea of a threshold dose, it can be argued that the passage of a single nuclear particle through a cell, the lowest possible dose, can cause DNA double strand lesions. Such lesions occur naturally at the rate of about ten thousand per cell per day, whereas exposure to radiation at the current population exposure limit would cause only two lesions per cell per day. Thus radiation-induced lesions are insignificant compared with those occurring naturally.

A new technique for evaluating the effects of small doses of radiation has been developed by Professor Feinendegen. [6] His results show conclusively that the linear dose assumption is incorrect: at low doses there is an additional quadratic term. Furthermore, a Joint Report of the Academie des Sciences (Paris) and of the Academie National de Medicine concludes that estimates of the carcinogenic effects of low doses of ionizing radiations obtained using the linear assumption could greatly overestimate those risks. [7]

The concern about nuclear radiation has diverted attention from other threats to our health. Radiation is responsible for only about 1 percent of diseases worldwide, and most of this comes from the natural background and from medical uses. The nuclear industry is responsible for less than 0.01 percent. The vast sums spent to reduce this still further could be spent far more effectively on simple disease prevention. It is greatly in the public interest that these matters should be treated as objectively as possible, taking full account of the scientific evidence. This would avoid much unnecessary anxiety and enable the best decisions to be taken concerning our future energy supplies.

Reactor Accidents

The two reactor accidents that have received wide publicity are that at Three Mile Island in 1979 and the much more serious one at Chernobyl in 1986. The accident at Three Mile Island was initially due to the breakdown of the pumps circulating water in the secondary cooling system. The standby cooling systems failed to come into action, and the reactor temperature rose. The automatic safety system then shut down the reactor, but the radioactive core still emitted heat. The operators at first misinterpreted a dial reading but eventually they brought the reactor under control. A small amount of radioactivity was emitted giving people nearby a dose of about one millirem, which is what they receive every day from natural sources. During the incident several alarming announcements were made to the public, which naturally caused much distress. It was a major financial disaster, and it took more than ten years to remove the damaged reactor at a cost of nearly a billion dollars.

The disaster at Chernobyl was immeasurably worse. It happened by a combination of bad design and operator irresponsibility. The reactor was designed to produce weapons-grade plutonium as well as electrical power. It was thermally unstable at low power, so that overheating would cause further overheating, with catastrophic consequences. The operators were therefore instructed to raise the power rapidly through this dangerous region to ensure stable operation. Such a design would never be accepted in the West. On the fatal night the operators wanted to find out what happened at low power. Fearing that the safety circuits could shut the reactor down before they finished their experiment they switched them off. The power rose rapidly, the graphite caught fire, the cover was blown off, and radioactive materials were discharged into the atmosphere and deposited over much of Europe. Firemen fought the blaze heroically; many received lethal doses of radiation, and fifty-six of them died.

There was, nonetheless, no evidence of excess cases of leukemia or other types of cancer among the hundreds of thousands of workers employed in the clean-up after the accident. Using the discredited linear dose assumption a large increase in cancer victims all over Europe due to the radioactivity released into the atmosphere was predicted, causing much public anxiety. For the same reason large numbers of people were needlessly evacuated from the region around the reactor, causing much distress. Many countries immediately lost faith in nuclear power and opposed the construction of new nuclear power stations. Since that time, more realistic appraisals, especially by industrialists, have convinced them of the necessity of nuclear power, and many new power reactors are being built or are planned. [8] The reactors now in operation are so designed that such accidents can never happen again.

Notes

  1. P. E. Hodgson, Nuclear Power, Energy and the Environment. (London: Imperial College Press, 1999). This book contains many references to the topics discussed in this article.
  2. Sir Richard Doll, H. J. Evans, and S. C. Darby, Nature 367.678.1994.
  3. B. L. Cohen, “Validity of the Linear No-Threshold Theory of Radiation Carcinogenesis at Low Doses,” Nuclear Energy 38.157.1999.
  4. See also J. A. Simmons and D. E. Watt, Radiation Protection Dosimetry—A Radical Reappraisal. (Wisconsin: Medical Physics Publishing, 1999).
  5. Lord Taverne, Speech in the House of Lords. SONE Newsletter No. 71.
  6. Ludwig E. Feinendegen, lecture at the Conference on Nuclear Radiations and their Effects, Nagasaki, August 2004.
  7. M. Tubiana and A. Aurengo, Nuclear Issues (October 2005), 3.
  8. See Ref. 1, pp 81–94 for discussion of Chernobyl. Further details in Nuclear Issues (October 2005).
Intercollegiate Studies Institute • 3901 Centerville Rd. • Wilmington, Delaware 19807 • www.isi.org
Please direct all inquiries regarding First Principles to [email protected].