In the context of the battle against climate change, nuclear power offers a large-scale low-carbon source of base-load electricity, but what is the prospect for nuclear power on this island? Tom O'Flaherty reports
Elec

Nuclear power has made a substantial contribution to the world’s energy needs over the past sixty years, but it cannot be denied that it has had something of a chequered history during that time. The events at Three Mile Island, Chernobyl and Fukushima represent the major blots on its performance record.

A quarter of a century passed between Chernobyl in 1986 and Fukushima in March 2011, with no significant nuclear incident having occurred in the interim. It was recognised that Chernobyl involved a Soviet-designed reactor lacking in key safety features, which made it fundamentally different from reactors used in western countries. It was gradually being felt that nuclear power, using western-type reactors, could continue to be a valuable and safe source of low-carbon electricity, and that its use should be progressively expanded.

It is clear now that Fukushima radically changed this perception. The event, as is well known, was caused by a phenomenon external to the nuclear power plant – a catastrophic tsunami, triggered by a major earthquake.

The tsunami itself caused the loss of thousands of lives. The damage to the power plant caused no loss of life directly. Yet the nuclear dimension of the disaster remains in the public consciousness worldwide in a way the natural disaster on its own would arguably never have done (as witness the devastating Asian tsunami of 2004, which has largely faded from public memory).

There can be little doubt that Fukushima has been the key catalyst for a critical downturn in the global perception of nuclear power as a potential contributor to the world’s need for low-carbon sources of electrical generation.

The burgeoning climate of acceptance of nuclear power, which existed pre-Fukushima, was not robust enough to withstand any significant adverse publicity. Such confidence as was emerging in nuclear technology was a delicate growth, and any unfavourable development inevitably triggered a cascade of negative sentiment.

It mattered little that the travails of the plant at Fukushima resulted from an external event unique to earthquake-prone regions, and had no direct relevance to the safety of installations in geologically stable parts of the world. What impacted on the public consciousness was the stark fact that something had gone wrong at a nuclear plant, resulting in serious disruption of people’s lives in a large surrounding area.

Response to Fukushima – reactor design


The response to Fukushima around the world has varied from country to country. In Europe, Germany made a very early decision to phase out nuclear power by 2022. Switzerland, in a parliamentary vote in 2011 (confirmed by a referendum in 2017), decided not to build any new nuclear plants. Belgium’s present policy is to close its existing reactors by 2025, while France plans to scale back from obtaining some 75 per cent of its electricity from nuclear at present to 50 per cent in 2025.

On the other hand, Sweden and Finland are continuing their nuclear programmes. In Asia, China is continuing a major expansion programme, and India is building new plants. South Korea continued its development of nuclear power, and its manufacture of reactors, after Fukushima, but a new government which has come into office in 2017 has announced that it will reverse the country’s policy on nuclear power and build no further new plants.

Against this background, something of a watershed has been reached in reactor design, which has evolved in two contrasting directions. One is towards ever-larger reactors, incorporating increasingly sophisticated safety features and relying on economies of scale for hoped-for improvement in economic performance.

This trend culminated in the development of the French-designed European Pressurised Reactor (EPR), a mammoth unit delivering around 1.6 GW of electric power. The first two of these reactors have been for some years under installation in Finland and in France.

Due to their design complexity, and other reasons associated with first-of-a-kind installations, they are both seriously behind schedule and over budget. Despite this experience, the next nuclear plant to be built in the UK, at Hinkley Point in Somerset, is to be of this type, no doubt in the expectation that lessons learnt from its predecessor plants will result in a more satisfactory construction outcome.

A significant obstacle to the adoption of very large units is the daunting upfront financial commitment required. This problem is lessened by the contrasting design trend, which is in the direction of smaller, simpler reactors, described generically as Small Modular Reactors (SMRs).

Like the larger reactors, these also incorporate enhanced safety features, but in a design of less complexity, and offer economies of capital cost through being to some degree amenable to mass production. Several different reactor designs coming under this heading are at varying stages of development in the US, UK and some other countries. It would be anticipated that by about the mid-2020s, at least some of these will be licensed and commercially available.

The future of nuclear power


So, what then of the future? Clearly, there is a significant downturn in interest in nuclear power in western countries. But there are grounds for believing that the pendulum, which just now has swung very much in the anti-nuclear direction, could in due course swing back. This is because of the fundamental advantage, in the context of the battle against climate change, of a large-scale low-carbon source of base-load electricity.

This is underlined by the clear trend towards more and more of society’s energy requirements being met from electricity. Land transportation in the near future will predominantly be by a combination of electrified rail and electric road vehicles. Space heating will use solar energy, heat pumps and direct electric heating, with possibly also some biomass combustion.

Even allowing that conservation measures and enhanced efficiencies will limit growth in primary energy demand to some degree, there can be little doubt that the transition from fossil fuels to electricity for heating and transport will result in a substantial increase in the demand for electricity, which will have to be generated almost entirely from low-carbon sources.

These sources will be a selection from intermittent renewables (wind, solar, tidal, wave, etc) in conjunction with a variety of energy storage technologies, hydro (at the limited sites where it is available), fossil fuels with carbon capture and storage, biomass and nuclear power. None of these options is a panacea, with all of them having significant technical and/or economic limitations.

The challenges nuclear power has to meet are principally economic viability, adequate assurance of safety, and acceptance of deep geological disposal as a means of dealing with long-lived radioactive waste. For the foreseeable future, national policies in different countries will inevitably take differing standpoints on these issues.

If, over some years, the experience of countries which persevere with nuclear power is positive and free of significant adverse incidents, then it can be expected that other countries will gradually be encouraged to follow in the same path, and adopt a segment of nuclear power as a complement to generation from intermittent renewable sources.

Needless to say, any further bad experiences anywhere will have a correspondingly negative effect.

Fusion power and nuclear technology


It must also, of course, be noted that over the next few decades, nuclear technology itself may have evolved considerably. It would be expected that fast neutron reactors, being developed within the framework of the international ‘Generation IV’ reactor programme, will have achieved commerciality. These reactors will enhance the efficiency of utilisation of uranium by some fifty times, thus extending the life of the world’s uranium resources from decades to centuries (1).

More uncertain, but very possible, is the commercial realisation of nuclear fusion power, which is the subject of a major multinational research and development programme centred on the International Thermonuclear Experimental Reactor (ITER) installation at Cadarache in France.

This technology, if successfully developed, will offer an intrinsically safe source of power using a virtually inexhaustible fuel resource and without creating long-lived radioactive waste.

However, fusion power is clearly at least some decades away. In the interim, nuclear power will be provided by fission reactors, which for several decades have been supplying some 15 per cent of the world’s electricity without contributing significantly to carbon emissions. To abandon this substantial contribution to the world’s need for low-carbon electricity would manifestly be a massive step backwards in the campaign to limit climate change.

Unpalatable though the idea may be to some, the nuclear component of electricity generation surely has to be maintained at least at its current global level, side-by-side with the development of renewables.

What about Ireland?


Whatever may happen globally in the short-to-medium term, it seems clear that any prospect of the use of nuclear power on the island of Ireland is some distance in the future. What is not yet decided about Ireland’s energy policy is what will substitute for the coal burning, base-load-generating plant at Moneypoint when it has to be replaced by a low-carbon source of generation, almost certainly before 2030.

Theoretically, this could be a nuclear plant. To suit our relatively small island system, this would have to be one of the SMR plants currently under development, but it seems clear now that none of these will be available early enough to meet our required timetable.

So, the chief options for replacing Moneypoint are probably a biomass-burning plant, a new fossil-fuel-burning plant in conjunction with carbon-capture-and-storage technology, or some still-to-be-proven form of large-scale energy storage to complement intermittent renewable sources.

Increased interconnection with Britain, and probably with France, will have a part to play, but to rely entirely on interconnection for base-load supply would not seem to be a prudent policy. Any of these options is potentially feasible but, as indicated above, none of them is without problems.

So, even if we were avid enthusiasts for nuclear power, we would have to await the proven commerciality of SMRs before we could adopt nuclear technology. Whether we may do so at some point in the future, perhaps in the 2040s, will depend on a number of factors:

  • Whether the base-load technology we adopt in the interim has proved reliable and cost-effective;
  • Whether SMRs have by then established a proven record of safety, reliability and economic effectiveness; and, above all,
  • Whether our national apprehension about nuclear power has been assuaged by the passage of time and positive performance of nuclear power worldwide over the intervening period.

Reference:
(1) Tom O’Flaherty, ‘If use of nuclear power continues, will there be enough uranium?’ The Engineers Journal, 65(3), May/June 2011, 191-193.

Author:
Tom O’Flaherty BE PhD FIEI FIET Chartered Engineer is a former CEO of the Radiological Protection Institute of Ireland (subsequently merged with the Environmental Protection Agency).

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Nuclear power has made a substantial contribution to the world’s energy needs over the past sixty years, but it cannot be denied that it has had something of a chequered history during that time. The events at Three Mile Island, Chernobyl and Fukushima represent the major blots on its...