Establishing confidence in nuclear energy: a study of 120 years of evidence and 80 years of myth

Posted by Wade Allison on 20 February 2024 in Articles

Tagged with: COP28, Chernobyl, Fukushima, Louis de Broglie, Radiophobia, Renewables.

Plentiful energy, available anywhere and at all times, is essential to a thriving society. But there are only three types of primary energy source widely available on Earth today: sources commonly called the renewables, fossil fuels, and nuclear. Secondary sources, like hydrogen and electricity, are important but rely on a primary source. The contrast between the three is evident from the weight of fuel—energised material—sufficient for one person in an advanced nation to cover food, heating, transport, and other needs throughout their life. For the three primary energy source types this might be 10 million tonnes of water from a dam 100 metres high, the combustion of a thousand tonnes of coal, or the fission of one kilogramme of uranium-235. (The masses of other energy sources in any given category are similar.) These numbers are based on firm natural science, not speculative technology. But why are they so different? And how are the sources stabilised and controlled?

The recent international agreement at COP28 calls on the world to ‘transition away from fossil fuels in energy systems’ and ‘accelerate technologies including renewables [and] nuclear’. But only nuclear has the energy to fill the gap left by fossil fuels sufficiently to avoid economic collapse. Though many are fearful of nuclear energy as being too powerful, everybody should ask whether this matches experience. Posters exhort rail passengers in the UK today, If you see something that doesn’t look right, report it—See it, Say it, Sorted! But leaving judgement to higher authority, as the tale of the Emperor’s New Clothes illustrates, easily leads to neglect of evidence. Indeed, does the pressure on authority to continue the inherited mantra on nuclear energy involve such blindness?

The misunderstanding of nuclear energy

The Fukushima Daiichi accident in March 2011 was perceived throughout the world as a major disaster. It precipitated near-panic in Japan and worldwide changes in energy policy. However, the released nuclear radiation caused no casualties—no one was hurt at the time or is likely to be in future. The reactions were not justified. The same happened following the accident at Three Mile Island in 1979. At Chernobyl in 1986 there were 28 fatalities from acute radiation syndrome, but no evidence for the thousands of fatalities predicted by experts. And no other radiation accident has recorded a significant loss of life at a nuclear power plant, anywhere in 70 years.

In such accidents, mass evacuation and food restrictions, hurriedly arranged by ill-informed authorities, contribute to public fear and a loss of trust in society. The payment of compensation and misdirected mitigation measures amplify the damage to mental health and add to the bewilderment. Whenever confidence ebbs, lawyers and accountants search for somebody responsible, insurance is reassessed, and cost estimates rise inevitably. Everybody thought that these were exceptional exposures to nuclear energy and its radiation—but that was incorrect.

Ever since life appeared on Earth, it has been bathed in radiation. Although we cannot feel them, some 7,000 radioactive decays occur in our bodies every second, and more radiation from space, nearby rocks, and other materials passes through us, too. Because life evolved in this environment, it learned to cope with it safely long ago; otherwise we would not be here. Fortunately, it devolved the job of replacing cells, repairing DNA, and neutralising the molecular garbage that radiation leaves, to cells and local groups of cells in the body. The central nervous system and the brain are not alerted. So animals, and plants too, are fully protected from the effects of low and medium doses of radiation without knowing it. That is why the flora and fauna in the Chernobyl evacuation zone survive unscathed, and today they are flourishing despite their residual radioactivity. They are fortunate to be spared the exciting accounts of the accident that continue to stimulate human society.

Humans suffer by having made instruments that detect radiation. This then frightens them, and although they cannot feel anything, their imagination urges them to protect themselves—somehow. Such worries attract the services of regulators, insurers, and other authorities, who can often do little. But provided the radiation level is not too high, their services are unnecessary anyway.

In fact, most humans have a friend or relative who has received rather high doses of radiation for their own health, as part of a course of cancer therapy. Such benefits are not new. They are built on the legacy of Marie Curie, who won Nobel prizes in both physics and chemistry before applying the science in medicine more than a century ago. The threshold at which a radiation dose rate becomes possibly dangerous was settled by international agreement in 1934. Whereas many of the biological mechanisms have been elucidated and the data available have vastly increased, there has been no reason to doubt the safety threshold chosen 90 years ago.

The energy of chemical and nuclear fuels

Human supremacy on Earth began with the ability to control fire, perhaps a million years ago. This required study to establish how it worked and the ability to then teach others how to use it safely. Critically, unlike other animals, humans were able calmly to overcome their innate fear. However, the fuel supply was inadequate until the Industrial Revolution. Then fossil fuels became widely available and the technology of engines translated the heat of combustion into mechanical work. At that point the ideal provision of energy seemed to have been found. The population of the world quadrupled and life expectancy doubled. Admittedly, not everybody had access to fossil fuels, and this inequality became a principal driver of economic and political activity.

Beyond naming it “chemistry” and sorting out its pattern of behaviour, the underlying science of combustion remained obscure. A lump of coal has no apparent moving parts or springs—its energy resides internally. All matter is composed of atoms containing electrons, and at the centre of each atom is a nucleus containing protons and neutrons. In 1924 a young French PhD student, Louis de Broglie, provided an amazingly simple universal explanation of the motion (speed v) of these electrons, protons, and neutrons (mass m). His thesis was that they are described by waves of length, h/mv, where h is Planck’s constant. This wavelength of vibration is set by the size of the region, L, like the pitch from a musical instrument. The smaller the region, the higher the pitch. The kinetic energy of an electron in an atom is h2/8mL2, and this well matches the energy scale of chemistry, electronics, batteries, food, and other forms.

But the same calculation can be made for neutrons and protons in any nucleus. There, L is 100,000 times smaller and the particles have mass m 2,000 times larger than an electron. Thus, the kinetic energy is 5 million times greater—that is the scale of nuclear energy relative to fossil fuel energy. A follower who got the message early was Winston Churchill. In 1931 he wrote an article in the Strand Magazine:

The coal a man can get in a day can easily do five hundred times as much work as the man himself. Nuclear energy is at least one million times more powerful still … The discovery and control of such sources of power would cause changes in human affairs incomparably greater than those produced by the steam-engine four generations ago.

He was right. In 1931 nobody knew how to extract this energy, but that was solved in a few years. A greater problem was that human society was culturally ill prepared for a million-fold increase in available energy—and still is today.

The control and safety of nuclear energy

Except at temperatures of millions of degrees, nuclei are prevented from ever reaching one another. This nuclear celibacy is enforced by the intense electric barrier that surrounds each. The uncharged neutron is the only key to penetrating the barrier and releasing the energy within. But neutrons are rapidly absorbed and decay in a few minutes, giving prompt control and ideal security. Exceptionally, a neutron can fission a nucleus, leaving two nuclear fragments, a few more neutrons, and considerable energy. The process is simply halted by absorbing the neutrons.

A secondary process is the radioactive decay of the unstable nuclear fragments with the emission of radiation some time later. Unlike fission, this decay is uncontrollable, and its energy, a few percent of fission, must be dispersed; otherwise, the temperature rises, and materials melt or burn, chemically. However, in such a meltdown, the elevated temperature has no effect whatever on the release of nuclear energy. Some radioactivity may be scattered in the environment by physical or chemical explosion, as happened at Fukushima Daiichi after the cooling failed.

Radiation damages atoms and molecules but does not affect nuclei. Consequently, neither radioactivity nor its radiation can spread by contagion, like an infection, or by ‘catching’, like fire. This is useful to know following an accident, but is seldom stated! Radiation does not make materials or people radioactive. In fact, for an exposure below the 1934 threshold there is nothing for radiological protection authorities to worry about. But they have jobs—and so readily don a hazmat suit as a uniform that signals fearsome danger. This is not reassuring for the public.

This situation is not without precedent. The public have been scared of technological change before. Prior to 1896 the public were alarmed that high-speed steam engines might be permitted on the roads. So the speed was limited to three miles per hour with someone walking in front waving a red flag. When smaller cars appeared, the authorities acknowledged the economic case for change, and the Red Flag Act was repealed. Today, a similar economic uplift is expected with the introduction of small, simpler nuclear reactors, deliverable as a whole or in modules from a factory by road. But first, the restrictive precautionary regulations, like the Red Flag Act, should be replaced by ones based on evidence.

The era of nuclear fear

Every new energy revolution has increased the power to destroy life and property. The chemical energy of gunpowder, dynamite, and TNT increased fear, overtaking the power of archery and the sword to strike an adversary. So in 1945 the arrival of nuclear weapons with their million-fold energy enhancement traumatised society. Talk of widespread mass annihilation provoked a political frenzy as access to nuclear weapons spread to more nations. Large political demonstrations, public marches, and organised petitions were part of public life for three decades and more. The secrecy of weapons development and the threat of large opposing arsenals effectively demonised the image of nuclear energy and radiation. Some countries outlawed nuclear technology completely—except in medicine, notably. More widely, radiation regulations were enacted with safety set some 500 times more cautiously than in 1934, but without supporting evidence. Today we inherit a legacy of inept regulation with a frightened and ill-informed populace. In democracies this obstructs the deployment of the civil nuclear technology that we need.

But what are the dangers to life from radiation? In the early decades of the Cold War it was feared that genetic damage from exposure to radiation might be inherited by later generations. However, thorough studies of all survivors of Hiroshima and Nagasaki and their descendants show no evidence of this. Unfortunately, such ghoulish stories are kept alive in the public imagination by science fiction.

Cancer is not inheritable, but radiation is carcinogenic at high dose rates. Among the Hiroshima and Nagasaki survivors who received doses below 30 times the chronic threshold agreed in 1934, there is no evidence of additional cancer or leukaemia. Published evidence for those with greater doses suggests 573 additional cancer deaths between 1950 and 2000. This is about a third of the 1,600 to 2,000 who died from the inept evacuation at Fukushima Daiichi, suggesting that fear can be more dangerous than radiation, even from nuclear weapons. Contrary to what many have been led to believe, the huge death toll from the bombs dropped on Japan was from the immediate blast and fire, not the delayed effects of radiation such as cancer and leukaemia.

Nuclear versus renewables on sustainability and security

Exorcising this image of nuclear in the public mind may take a generation or two. School teachers should study the evidence, and the syllabus they teach should match the science. Trust should grow as school children explore what radioactive sources do in smoke detectors and what they see on school visits to radiotherapy units and nuclear power plants. Children explaining to their parents what they have learned at school is a potent tool of social education.

Energy security is also a matter of confidence. Nuclear fuel supplies can be stockpiled at power stations, safe for future use whatever the weather. A network of small, relatively local nuclear stations, built close to consumers, would reduce the necessity for a large, expensive grid, vulnerable to sabotage and the extreme weather events that now seem likely. With short supply lines, the losses from megawatt-miles would be minimised. Community confidence grows from local security.

If nuclear capacity is matched reliably to provide peak demand, there is no need for separate base-load and backup supplies. Then off-peak energy is available for desalination, hydrogen production, and heavy industrial use. The thermal heat produced can be used for district heating and intensive horticulture or vertical farming, reducing food-miles too. The high energy density of nuclear means that little fuel is required and little waste is produced. Currently there are some 70 realistic reactor designs in development and enough uranium and thorium fuel for many centuries. There is nothing inherently expensive about these designs, but, as in all human activity, a lack of confidence invariably increases perceived risks and inflates costs.

The technology of renewables requires many minerals of limited availability. Batteries, turbine magnets, and solar panels make hungry demands for lithium, cobalt, rare earth, and other elements. Solar and wind installations last about 20 years, a quarter of the time for nuclear. Their energy production is intermittent, only 20–30 per cent, depending on the weather. The success of the Industrial Revolution relied on energy being available in all weathers. Even hydro suffers when the climate shifts. As sources of energy, renewables fail on every criterion except primitive popular acceptability. Yet for 70 years, the lack of such acceptability has been the only reason to reject nuclear energy—a cultural argument that is evidently flawed. Current regulations and outdated bureaucracy are obstructing the exceptional benefits that Churchill foresaw for nuclear energy nearly a century ago. Reform is overdue.