Nuclear energy in a dead end
The history of technology shows that nuclear power for energy supply is a hopelessly outdated technology / Episode 3
The first episodes of this 12-part series dealt with the prehistory of nuclear fission, the development of the civilian use of nuclear energy, its two fundamental problems and the emerging doubts in the 1970s and early 1980s. This episode briefly looks at the current situation of conventional large light-water power plants and then addresses the (vain) hopes that smaller reactors might succeed in restarting nuclear energy.
Continuing decline
Forty years after many nuclear power projects were halted in the wake of persistent cost increases, unresolved problems and the Three Miles Island reactor accident (1979), atomic energy’s record does not look much better. Only a few nuclear power plants were put into operation after 1990, most of them in China. In 2021, 415 reactors (1989: 418) with a total capacity of 369 GWe (1989: 310 GWe) were in operation. While nuclear energy still supplied 17% of global electricity production in 1990, its share had fallen to 10% by 2019. A phase-out model: in 2021, the average age of nuclear power plants in operation was over 30 years.
The breakdown by country is interesting: In the decade 2011–2021, global production of nuclear power increased by only 0.5%. In the OECD, it fell by 1.2%. The only countries where nuclear power production increased by more than one per cent during the last decade were: Iran (41.9%), China (16.7%), Pakistan (14.9%), India (3.1%), Russia (2.5%) and Mexico (1.7%).
While the International Atomic Energy Agency (IAEA), based on financial data, does not foresee a shortage of uranium resources, for the time being, a comprehensive Austrian study on energy balances calculates that, due to the decreasing uranium content of the remaining ores, the energy required for fuel production will increase in such a way that the energy balance of nuclear power with today’s light water technology will become negative between 2050 and 2075, i.e. over the entire life cycle it would consume more energy than it generates.
The nuclear community has become smaller. At the universities, the corresponding study courses have been strongly reduced. Working in the industry has not been chic for a long time — except recently in some of the start-ups described below. But specialists are still needed to operate the existing nuclear power plants and dismantle the decommissioned ones. And for the disposal of the waste.
The research programmes for the former “reactors of the future” have been wound up: High-temperature reactors were shut down in the USA and Germany in the 1980s, and only China continues to develop them. The once highly praised fast breeder reactors were mostly abandoned unfinished: in Germany in 1991 (Kalkar, costs until construction stopped at €3.1 billion), the USA in 1992, Japan in 2016 (Monju, €7.8 billion) and France in 2018 (ASTRID). Only Russia, India and China are still working on this technology with large reactors — and small projects have recently been hoping for a renaissance of the concept with mini-reactors (see below).
But France still holds the nuclear flag high. With nuclear providing around 70% of its electricity production, no country is so dependent on nuclear power. Last autumn, President Macron announced a significant programme to build new large nuclear power plants in France. At present, more than half of France’s 56 nuclear power plants have been at a standstill for months, either because of a lack of cooling water due to climate change or because a dangerous defect in sensitive pipelines has been discovered or is feared.
In Ukraine, which also depended on nuclear power for more than 50% of its energy, the unique dangers of nuclear technology are now becoming visible in the war. Quite differently from other power plants, an attacker can threaten a catastrophe that no one can accept. Only the destruction of a large water reservoir may be remotely comparable to this. Yet the attack on a nuclear power plant does not even have to be physical: also a cyber-attack from afar could have devastating consequences.
Smaller reactors cannot solve problems
The cost development of large nuclear power plants in the USA, France, Finland, England and Japan was such a deterrent that twenty years ago, the shrinking “nuclear community” began to question the pursuit of physical efficiency in large power plants and to focus on much smaller units that could be mass produced. Standardised series production had become the key to cost reductions in many other technology areas. And the increasing societal scepticism towards centralised large-scale technology, briefly mentioned in the last episodes of this series, seemed to suggest that costs could also be reduced in nuclear energy with small units produced in series. The defence industry had experience with small reactors in constructing nuclear submarines and nuclear-powered aircraft carriers. However, this could not easily be transferred to the civilian sector. But many projects for so-called SMRs (small modular reactors) are directly or indirectly of military origin. Mostly with predominantly state support, several start-ups are trying out new concepts that also promise more inherent safety and other advantages through their design. So far, however, no feasibility studies have been carried out, and no prototypes have been built that can run — except for two Russian SMRs, which took twelve years to build, four times longer than initially planned.
The furthest today is probably the company NuScale Power, founded in 2000. The 77 MW modules use conventional light water technology with amodified geometry that does not need emergency cooling. After many delays, NuScale hopes to have the first power plant running with six modules in 2030. However, the planned costs have risen massively even before the start of construction, so the financing is in question. There is a wealth of experience in light water technology after seven decades. Therefore, NuScale can be assessed in terms of safety using primarily established methods and recently, after many changes, received the longed-for “design approval” from the US regulatory authority NRC.
This becomes much more difficult with novel or previously abandoned concepts, for the assessment of which entirely new methods have to be developed. There are now proposals that use other coolants, such as liquid sodium, molten salt or liquid lead, or in which the fuel is sometimes not even present as a separate, solid fuel element but is contained in liquid form directly in the coolant. Instead, non-water-cooled concepts promise more significant advantages, such as better fuel utilisation, which could alleviate the diminishing range of uranium resources, or higher operating temperatures, allowing their use for process heat.
Last year, a comprehensive study for the German Federal Office for the Safety of Nuclear Waste Management listed 136 different concepts and examined 36 in more detail. Like other studies, it concluded that non-water-cooled concepts offer interesting advantages but entail long development times and new risks, especially in fuel development and the reprocessing processes that are often required. Up to 10,000 SMRs would have to be built to replace today’s 400 reactors alone, raising new questions about site safety, transport, dismantling, interim and final storage. Economies of scale that compensate for the increased costs of smaller units are only expected for quantities of around 3000 units produced in series. Just as with conventional reactors, a complex production chain involving several companies that specialised in very different problems would be necessary, whereby new coordination problems and bottlenecks were expected. To assess the new concepts, completely new methods of risk assessment would have to be developed. For even if individual risks of the present light-water reactors could be significantly reduced, the overall context of new risks would have to be assessed — such as risks associated with reprocessing, external impacts with a large number of transports and sites, a smaller number of safety levels, or dangers of misuse due to higher uranium enrichment and high plutonium content. Overall, the study states that according to the current state of knowledge, it cannot be assumed that SMRs are fundamentally safer.
As experience with the first mini-reactors in Russia and with the NuScale reactor concepts has already shown, all these uncertainties could require additional measures which would drive up the costs. Therefore, there are considerable doubts about whether the new small reactors — if realised — would be attractive in terms of costs.
Quite apart from operational safety, SMRs do not solve the problem of nuclear waste. The two fundamentally new issues of nuclear energy identified above remain even with the new concepts — the mass handling of artificially generated radioactive materials, which must be guaranteed for centuries, and the containment of the incomparable destructive potential of nuclear chain reactions.
It is not foreseeable that private investors and insurance companies will be willing to assume all the associated risks, as is usually expected for other energy sources. Therefore, it seems probable that public financiers would not only have to finance the development phase of the propagated new generation of nuclear power plants but also the essential risks of deployment and operation. So far, it is mainly the nuclear weapon states that have been willing to do so.
Even if new, small, mass-produced reactors could reduce some of the problems of the current generation of nuclear power plants, and society was willing to accept the remaining risks until the next major accident — even then, SMRs are far too late for replacing fossil fuels and meeting climate agreements. The former chair of the US Nuclear Regulatory Commission (NRC), Allison Macfarlane, recently said:
“Given how many economic, technical, and logistical hurdles stand in the way of building safer, more efficient, and cost-competitive reactors, nuclear energy will not be able to replace other forms of power generation quickly enough to achieve the levels of emission reduction necessary to prevent the worst effects of climate change.”
Unlike in the seventies, there are alternatives today
Seventy years have passed since the first electricity was generated with a nuclear reactor. The peak of atomic energy use was more than thirty years ago. The basic concepts and problems have remained the same, improvements in safety have led to rising costs. Significant new perspectives are not discernible even with new approaches.
In the 1970s, anyone who still claimed that nuclear fission was an energy of the future because there was no alternative to it — like my father, who supervised Europe’s nuclear facilities for the Nuclear Non-Proliferation Treaty, or the pioneer of climate models Hans Oeschger, with whom I did my physics degree at the time — could still be benevolently described as unimaginative. Anyone who still claims this today has solid interests or should urgently look into the development of science and technology since the discovery of nuclear fission.
After the first steps into the nano-world of molecules, atoms and atomic nuclei, which fundamentally changed our understanding of energy and matter, completely new dimensions, infinite landscapes of new possibilities opened up with new methods. And thus much more advantageous approaches than nuclear fission to provide a humanity of now eight billion with sufficient energy services for a comfortable life. That is the topic of the following episodes in this series.
