While nuclear power has never reached the promise it held for those growing up in the atomic age of the 1950s and 1960s, it remains a vital and growing part of our energy mix. It accounts for
around 10%of electricity generation globally – a figure that doubles in advanced economies, according to the International Energy Agency (IEA). In outlier countries like France, nearly
two-thirds of electricity comes from nuclear.
“Nuclear as a source of energy has been a broadly consensus issue since it was first introduced to the energy mechanism in the post war period,” says Steven Daniels, lecturer at Edge Hill University. “Its share of the energy mix has largely remained consistent.” Daniels says that nuclear has become a key part of governments’ decision-making processes when it comes to finding new energy sources because of the opportunities it provides.
We’re at an inflection point for nuclear, the IEA reckons. “The market, technology and policy foundations are in place for a new era of growth in nuclear energy over the coming decades,” the organisation says. The 420 reactors around the world are set to produce record-high levels of nuclear power this year.
Interest from governments and the private sector is helping make an already efficient technology – nuclear fission is nearly 8,000 times more efficient at producing energy than fossil fuels are – even more so. It’s a topic we’ll be discussing at IMechE’s upcoming Steam Turbine and Generator User Group 2025 – tickets for which are still available.
Gaining efficiency
Innovations around the world are eking out more efficiency from nuclear generators. One of the key developments is the rise of small modular reactors (SMRs), favoured by AI and tech companies looking to develop their own proprietary power sources for their technologies.
The power of AI, or optimisation algorithms, has already shown the ability to improve nuclear efficiency. In one lab-based study, researchers demonstrated that advanced algorithms could increase a turbine’s mechanical power output within a nuclear from 996 MW to more than 1,022 MW, boosting efficiency compared to the conventional way systems operated. The gain might seem modest at first, but when scaled to the level of entire power plants, it becomes more significant.
Other breakthroughs are coming from reactor designs that operate at higher temperatures, in turn allowing turbines to operate within better thermodynamic cycles. Supercritical water reactors (SCWRs) push steam required to power a plant into the supercritical region – meaning beyond 374°C – enabling turbine cycles to become around 10 percentage points more efficient than traditional light-water reactors. Operating a reactor at such a high temperature not only increases energy conversion, but also reduces the volume of waste heat needing management.
While there are no SCWRs currently in operation around the world, it’s a technology on the cusp of adoption – and one that could change operations significantly.
Small changes, big impacts
Turbines are ripe for innovation – meaning there are likely more significant changes that can soon come down the pipeline to make nuclear power generation even more efficient. As the World Nuclear Association points out, “reactors derived from designs originally developed for propelling submarines and large naval ships generate about 85% of the world's nuclear electricity” – suggesting that they’re not operating at peak efficiency.
The raft of SMRs currently being developed, financed by investment from large tech companies and institutional investors, are purpose-built in order to try and meet the needs of maximum efficiency, rather than adapting pre-existing technology to a new purpose.
SMRs’ compact, high-temperature cores, such as designs like Integral Molten Salt Reactors (IMSR), which use molten salt as a fuel and a coolant and TerraPower’s Natrium concept, can help provide the steady thermal energy that next-gen turbines can convert with better efficiency into power. What’s more, work is being done to ensure reactors can operate at temperatures high enough to harness this new turbine technology, reducing costs and accelerating their deployment.
While many of the innovations are so far at a lab level or in the early stages of development and rollout, there are plenty of innovative new ideas bubbling under the surface that could propel nuclear power into a new era of adoption.
Steam Turbine and Generator User Group 2025 takes place from 12-13 March 2025 at Emirates Old Trafford Cricket Ground in Manchester. Whether you are involved in the operation, design, maintenance, service or upgrading of steam turbine or generator assets, the User Group is THE forum for engineers and professionals to meet, network and learn from the shared experience of the Steam Turbine and Generator community. Find out more.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.