The role of nuclear power in global decarbonisation

OPINION: Written as part of a Sciences Po assignment on decarbonisation pathways.

The world is aiming to limit anthropogenic global warming thereby reducing its worst effects—net greenhouse gas emissions must therefore reach net-zero by 2050¹. Electricity generation is the single largest carbon dioxide source (~40% of total)—consequently, the sector must decarbonise rapidly². Nuclear energy is a proven low-carbon energy source, though it has many drawbacks including environmental issues; technological constraints; high capital costs; and negative public perceptions³. Accordingly, given these issues and the short ~30-year time frame, the role of nuclear in decarbonising the electricity sector must be considered.

Doel Nuclear Power Station in Belgium (Credit: @fredography, Unsplash)

Existing nuclear power facilities have a role in decarbonisation, but major investment in nuclear and the construction of new plants should not be pursued. There are four major reasons for this: the significant capital costs of new plants, the excessively long construction timeframes, the lack of a permanent solution for radioactive waste, and the political impact of public perceptions.

Recent construction issues faced by new plants in the European Union (EU) and the United States of America (USA) clearly demonstrate the continued decline of the nuclear industry. In western Europe only three nuclear reactors are under construction and all have been subject to significant cost blowouts and delays, due to management and quality control issues. For example, France’s Flamanville project is costing €12.4b (a 375% increase) with a timeframe of 15+ years (a 300% increase)⁴. Investment in nuclear is at its lowest level in five years and many major reactor manufacturers have run into major financial difficulties or have quit the industry altogether^{4 5}.

From a health and environmental standpoint, the permanent storage of highly-radioactive nuclear waste is an outstanding problem that has not yet been solved anywhere—only Finland, is close to establishing a suitable facility⁶. With over 250000t stockpiled across the globe, expanding nuclear programmes would be highly irresponsible without solving this key problem—it would simply be pushing costs down the road^{3 7}.

Public perception also has a significant influence on the use of nuclear power, especially following the 2011 Fukushima incident⁸. Nuclear power requires government support—its existence is inherently political⁹. For example, Germany has opted to close all nuclear plants by 2022, despite many having potential to operate into the 2040s⁴. Political opposition can also lead to construction delays and/or the cancellation of projects⁴. These politics contribute to uncertainty in the sector, further impacting on any private-sector interest.

However, nuclear power does have some favourable aspects. There are zero direct carbon dioxide emissions, which is a strong positive point—nuclear power is estimated to have avoided 55 Gt of carbon dioxide emissions in the last 50 years^{3 9}. In addition, operating costs can be competitive with other technologies especially if an appropriately-levied carbon tax is widely introduced and/or financial value is placed on nuclear’s dispatchability and flexibility⁹.

Furthermore, there are some promising new technologies under development, such as ‘small modular reactors’, that improve safety, efficiency and sustainability, while also reducing costs and reactor size^{9 10}. Nuclear fusion is similarly promising but significant unresolved technical issues mean that this cannot presently be considered, though it might be an option mid-century¹¹.

Nuclear power’s low-carbon status cannot be disputed—so instead the question is whether it is the most effective decarbonisation tool to invest in. The evidence would suggest that this is not the case. Investment continues to decrease year-on-year and whilst billions of dollars have been spent producing new, regulatory-approved reactor designs, few designs have been constructed^{4 12}. Across all major renewable energy sources (RES) and fossil fuel sources, nuclear represents the smallest amount of new capacity under construction to 2020⁵. New nuclear reactor additions have stagnated in the last two decades⁴, and recent new nuclear technology trials have faced significant difficulties or even been cancelled^{13 14}.

However, maintaining existing reactors and extending their operating life is proving to be cost-effective, therefore enabling the continuation of power production without direct emissions⁵. Investment on lifetime extensions is increasing as the $/kWh cost of resultant power in the USA and EU presently remains cheaper than the cost for RESs⁹.

Nonetheless, lifetime extensions do not add new capacity to the grid, therefore it is also important to invest in RESs. RESs are sensible candidates for investment, especially considering the political risks of nuclear. Investment in RESs is growing significantly year-on-year, with corresponding capital and operating cost decreases⁵. Additionally, by their nature RESs require no conventional fuel, whereas nuclear still results in environmental disturbance from fuel mining and refinement³. Whilst the International Energy Agency still predicts that additions of new nuclear power are still necessary, they have historically significantly underestimated the growth of renewables in their reports^{9 15}.

The only highly-specific circumstances in which new nuclear construction could succeed would be in the developing world, with its significant growth rate in energy demand⁵. A massive government-backed rollout of standardised designs would be required to bring down the overall cost of construction (and financing), as well as establishing the supply chains and expertise necessary to sustain the programme^{3 9}. However, while this may address the issue of high capital costs—and potentially construction timeframes—the issues of waste and public perception remain outstanding.

To conclude, it is clear that although nuclear power is a low-carbon technology, its many drawbacks mean it should not be relied upon as a key method to decarbonise the electricity sector by 2050. However, the low-carbon nature of current nuclear installations mean they must be maintained for as long as possible, with suitably strong continued regulation to maintain public confidence. The closure of nuclear plants with long potential operating lives should be avoided where possible, which can be made more competitive by a carbon tax. New investment in energy should be made in rapidly growing RESs with proven potential, but some investment in nuclear research should be maintained as there are promising technologies which could be realised later this century. In any case, all energy decisions going forward must be considered through the lens of decarbonisation given the urgent need to avoid the worst effects of global warming.

Addendum: Regarding Aotearoa/New Zealand’s nuclear policy, I wholeheartedly support the maintenance of the ‘nuclear-free’ zone, and do not think that fission-based nuclear power has any valid role in our country.