Day 5 of 1415 minutes

Day 5: Nuclear's Role in the Transition

The UK's nuclear legacy and future

Learning Objectives

  • Understand the current state of the UK's nuclear fleet and why most existing stations are nearing retirement.
  • Know the key new nuclear projects — Hinkley Point C, Sizewell C, and Small Modular Reactors — and the debates around their cost, timelines, and role.
  • Appreciate the arguments for and against nuclear power in a net zero energy system.

The UK's Nuclear Legacy

The UK was a nuclear pioneer. It opened the world's first commercial nuclear power station — Calder Hall in Cumbria — in 1956. At its peak in the 1990s, nuclear provided around 25% of UK electricity. Today, that share has fallen to roughly 13–15%, and it's set to decline further as the ageing fleet of reactors reaches the end of its operational life.

As of 2024, the UK has five operating nuclear power stations: Heysham 1 and 2 in Lancashire, Hartlepool in County Durham, Torness in East Lothian, and Sizewell B in Suffolk. All except Sizewell B are Advanced Gas-cooled Reactors (AGRs) operated by EDF Energy, and all are scheduled to close by the end of the 2020s. Sizewell B, a Pressurised Water Reactor, has an operating life extending into the 2030s. When these stations close, the UK will lose the vast majority of its existing nuclear capacity.

This creates a dilemma. Nuclear power provides reliable, low-carbon electricity around the clock — it doesn't depend on the wind blowing or the sun shining. If the UK loses most of its nuclear capacity without replacement, the burden on other low-carbon sources (and on gas backup) increases significantly.

When the UK's current fleet of nuclear reactors closes over the next few years, the country will lose roughly 6 GW of reliable, low-carbon generation capacity.

Hinkley Point C: The Flagship (and Its Difficulties)

The UK's first new nuclear power station in over 20 years, Hinkley Point C in Somerset, is a case study in the challenges of large-scale nuclear construction. The project was given the go-ahead in 2016, with an original target completion date of 2025 and an original cost estimate of £18 billion.

As of 2024, the estimated cost has risen to £31–33 billion, and the first reactor is not expected to generate electricity until 2029–2031 at the earliest. EDF, the developer, has attributed delays to construction complexity, the pandemic, and supply chain difficulties. The project uses the European Pressurised Reactor (EPR) design, which has also experienced significant delays and cost overruns at Flamanville in France and Olkiluoto in Finland.

Hinkley Point C will have a capacity of 3.2 GW — enough to power around six million homes — and its electricity will be bought under a Contract for Difference (CfD) at a strike price of £92.50 per MWh (in 2012 prices, index-linked), guaranteed for 35 years. Critics argue this makes it among the most expensive electricity in the UK system. Supporters counter that it provides firm, low-carbon baseload power with a 60-year design life, and that the cost should be judged against the value of reliability and zero-carbon output, not just against the cheapest variable renewables.

Sizewell C and Great British Nuclear

The government has committed to a second large nuclear project: Sizewell C in Suffolk, a near-replica of Hinkley Point C. In 2024, the government confirmed a substantial equity stake in the project, with a target for a final investment decision. The hope is that Sizewell C will benefit from lessons learned at Hinkley — using the same EPR design but with improved construction processes — and that costs will be lower as a result.

Beyond these large projects, the government established Great British Nuclear (GBN) in 2023 as a new arms-length body to coordinate nuclear development. GBN's first major task has been to run a competition for Small Modular Reactors (SMRs) — smaller, factory-built nuclear reactors that could be deployed faster and more cheaply than giant projects like Hinkley Point C.

SMR designs typically generate 300–470 MW each (compared to 1.6 GW per reactor at Hinkley Point C). Their appeal lies in modular construction: components are manufactured in a factory and assembled on site, potentially reducing construction time and cost. Several companies are competing for UK SMR contracts, including Rolls-Royce SMR (a UK consortium) and international designs from GE Hitachi and Holtec. GBN selected two preferred technologies in late 2024, with deployment possible in the early to mid-2030s.

Small Modular Reactors are designed to be factory-built and deployed faster than traditional nuclear — but none has yet been built and operated commercially in the UK.

The Nuclear Debate: Cost, Waste, and Public Perception

Nuclear power in the UK inspires strong opinions on both sides. It's worth laying out the key arguments honestly, because this is a genuinely contested issue:

The case for nuclear: Nuclear provides dispatchable, low-carbon electricity — it runs whether or not the wind is blowing. The CCC has consistently said that some new nuclear is needed in a cost-effective path to net zero, to complement variable renewables. Nuclear's lifecycle carbon emissions are comparable to wind and significantly lower than gas, even when construction and fuel processing are included. It also provides energy security by reducing dependence on imported gas.

The case against nuclear (or for scepticism): The costs of large nuclear projects in Western democracies have been consistently higher than projected. Hinkley Point C is a prominent example, but it's part of a global pattern. Renewable energy costs have fallen so dramatically that wind and solar are now far cheaper per MWh. Critics argue the money spent on nuclear would achieve greater emissions reductions if invested in renewables and storage. Nuclear waste — while a small volume — remains radioactive for thousands of years and the UK still lacks a permanent geological disposal facility (a site selection process is underway). Public perception is also mixed, with significant opposition in some communities.

The middle ground: Most credible energy modelling for the UK — including the CCC's analysis and National Grid ESO's Future Energy Scenarios — suggests that some new nuclear makes the transition cheaper and more secure, but it is not essential if alternatives (particularly large-scale storage and demand flexibility) can be scaled sufficiently. The practical question may be less about principle and more about execution: can the UK build nuclear at a reasonable cost and speed?

Key Takeaway

Nuclear power offers reliable, low-carbon electricity that complements variable renewables, but the UK's track record on cost and delivery — exemplified by Hinkley Point C — means the case for nuclear rests heavily on whether SMRs and improved construction practices can break the pattern of delays and overruns.

Quick-Fire Recap

  • Nuclear currently provides roughly 13–15% of UK electricity, but most existing reactors will close by the end of the 2020s.
  • Hinkley Point C (3.2 GW) has seen costs rise to £31–33 billion, with first power expected 2029–2031.
  • Sizewell C is planned as a near-replica of Hinkley Point C, with the government taking an equity stake.
  • Great British Nuclear is running an SMR competition, with Rolls-Royce SMR among the leading contenders.
  • The CCC considers some new nuclear part of a cost-effective net zero pathway, though the debate around cost and alternatives is legitimate.

Reflection Prompt

If you were advising a government minister on energy investment, how would you weigh the certainty of nuclear baseload power against its higher cost and long build times, compared to the lower cost but variability of renewables?

Sources & Further Reading

  1. EDF Energy, "Hinkley Point C", EDF, 2024. https://www.edfenergy.com/energy/nuclear-new-build-projects/hinkley-point-c
  2. EDF Energy, "Sizewell C", EDF, 2024. https://www.sizewellc.com/
  3. Great British Nuclear, "SMR Technology Selection", GBN, 2024. https://www.gov.uk/government/organisations/great-british-nuclear
  4. Rolls-Royce SMR, "Small Modular Reactors", Rolls-Royce, 2024. https://www.rolls-royce-smr.com/
  5. Climate Change Committee, "Sixth Carbon Budget – Electricity Generation", CCC, December 2020.
  6. National Grid ESO, "Future Energy Scenarios 2024", National Grid ESO, 2024.
  7. Department for Energy Security and Net Zero, "Civil Nuclear Roadmap", DESNZ, January 2024. https://www.gov.uk/government/publications/civil-nuclear-roadmap-to-2050
  8. Nuclear Decommissioning Authority, "Strategy", NDA, 2024. https://www.gov.uk/government/organisations/nuclear-decommissioning-authority

Through a Product Designer's Lens

Nuclear megaprojects like Hinkley Point C are among the most complex construction endeavours on Earth. They are also, arguably, failures of project management product design. The construction industry — nuclear included — has been slower to adopt digital project management, real-time progress dashboards, and predictive scheduling tools than almost any other sector. There's a significant opportunity for software products that bring better visibility, coordination, and risk management to large infrastructure projects, using digital twins, real-time sensor data, and AI-powered schedule optimisation.

From a service design and systems thinking perspective, the nuclear waste question is an extraordinary long-term design challenge. The UK's planned Geological Disposal Facility must communicate danger to humans who may encounter it thousands of years from now — a challenge studied by semioticians, designers, and anthropologists. How do you design warning systems for a timescale that exceeds the entire history of written language? It's a humbling reminder that design operates on very different scales.

The SMR programme also offers product strategy lessons. Rolls-Royce SMR is essentially applying a consumer product principle to energy infrastructure: standardise, modularise, and move production to a factory to drive down cost and improve quality. The product management challenge is immense — delivering a nuclear reactor as a repeatable product rather than a one-off construction project.

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