Professors Robin Grimes, Centre for Nuclear Engineering, department of Materials, Imperial College, London and William Nuttall, Cambridge Judge Business School and Engineering department, Cambridge University suggest a two-stage plan in their review Science paper that could see countries with existing nuclear infrastructure replacing or extending the life of nuclear power stations, followed by a second phase of global expansion in the industry by the year 2030.

The team say their roadmap would fill an energy gap as old nuclear, gas and coal fired plants around the world are decommissioned, while helping to reduce the planet’s dependency on fossil fuels.

Professor Robin Grimes (right) says:  “Our study explores the exciting opportunities that a renaissance in nuclear energy could bring to the world. Imagine portable nuclear power plants at the end of their working lives that can be safely shipped back by to the manufacturer for recycling, eliminating the need for countries to deal with radioactive waste.

"With the right investment, new technologies could be feasible. Concerns about climate change, energy security and depleting fossil fuel reserves have spurred a revival of interest in nuclear power generation and our research sets out a strategy for growing the industry long-term, while processing and transporting nuclear waste in a safe and responsible way.”

The study suggest that based on how technologies are developing, new types of reactors could come online that are much more efficient than current reactors by 2030. Currently, most countries have light water reactors, which inefficiently only use a small percentage of the uranium for energy.

The team suggests that new ‘fast reactors’ (FBR) could be developed that could use uranium approximately 15 times more efficiently, which would mean that uranium supplies could last longer, ensuring energy security for countries.

Integral fast reactors and liquid fluoride thorium reactors have so far operated successfully only as demonstration plants  and experimental reactors. Nevertheless, a 500MW (0.5GW) fast reactor is to become operational in India at Kalpakkam (right).

China's Experimental Fast Reactor (CEFR) a 65MWt and a 20MWe sodium cooled, pool-type fast reactor achieved first criticality on 21 July 2010, the key  to China’s nuclear plans, of up to 250GWinstalled capacity by 2050, predominantly from FBRs.


Mix and match approach

Another idea is to develop reactors with replaceable parts so that they can last in excess of 70 years, compared to 40 or 50 years that plants can currently operate at. Reactors are subjected to harsh conditions including extreme radiation and temperatures, meaning that parts degrade over time, affecting the life of the reactor. Making replaceable parts for reactors would make them more cost effective and safe to run over longer periods of time.

Flexible nuclear technologies could be an option for countries that do not have an established nuclear industry, suggest the scientists. One idea involves ship-borne civil power plants that could be moored offshore, generating electricity for nearby towns and cities. This could reduce countries' needs to build large electricity grid infrastructures, making it more cost effective for governments to introduce a nuclear industry from scratch.

The researchers also suggest building small, modular reactors that never require refuelling. These could be delivered as sealed units, generating power for approximately 40 years. At the end of life, the reactor would be returned for the maker's  decommissioning/disposal.

Because fuel handling is avoided at the point of electricity generation, the team say radiation doses to workers would be reduced, meaning that the plants would be safer to operate.

The scientists believe roll out of flexible technologies that could be returned to the manufacturer at their end of their shelf life could also play an important role preventing proliferation of nuclear armaments, because only the country of origin would have access to spent fuel, meaning that other countries could not reprocess the fuel for use in weapons.

In the immediate future, researchers suggest the first stage renaissance will see countries with existing nuclear energy infrastructure extending the life of current nuclear power plants made possible by developing technologies for monitoring reactors, enabling them to last longer as engineers can continually assess power plant safety and performance.

New global strategies for  spent fuel and radioactive components will have to be devised. Until now, countries have singularily failed to develop coordinated strategy for dealing with waste (right). One suggestion is to develop regional centres, where countries can send their waste for reprocessing, creating new industries in the process.

Professor Grimes adds: “In the past, there has been the perception in the community that nuclear technology has not been safe. However, what most people don’t appreciate is just how much emphasis the nuclear industry places on safety. In fact, safety is at the very core of the industry. With continual improvements to reactor design, nuclear energy will further cement its position as an important part of our energy supply in the future.”

However, the authors caution that governments around the world need to invest more in training the next generation of nuclear engineers. Without the qualified skills the nuclear industry may not have enough qualified personnel to make this potential renaissance a reality.

Dr William Nuttall, concludes: “The second phase of the ‘Two-Stage Nuclear Renaissance’ is not inevitable, but we would be foolish if we did not provide such an option for those that must make key energy technology decisions in the decades ahead.

Too often, decisions shaping the direction of R&D in the nuclear sector are made as part of a strategy for eventual deployment.As such small research capacities can become confused with multi-billion dollar plans and stall as a result.

Relatively modest R&D can, however, provide us with important options for the future. Such R&D capacities need to be developed now if they are to be ready when needed. While some good measures are already underway, the possible challenge ahead motivates even greater efforts.”