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Alternative Energy | SMR make or break

Donald Trump’s election as US president is expected to change the game in economics and politics around the world. Take UK energy policy for instance.

Trump’s decisions could make or break fledgling plans for construction of small modular reactors (SMRs) as an addition or alternative to large nuclear power plants scheduled to provide base load power from the 2030s onwards.

The reason why is a combination of a few things. A successful UK SMR programme would need a whole new British industry, including trained personnel and a robust supply chain producing factory made plant –reactor, integral pipework, wiring and housing.

Nuclear under 300MW

“The idea is to make small reactors of under 300MW competitive by making them simpler and building them in modular fashion in factories where conditions and productivity are much better, to offset the apparent economies of scale of the larger gigawatt-sized plants,” says former managing director of Rolls-Royce Nuclear, Tony Roulstone who teaches on the nuclear energy masters programme at Cambridge University.

“Economies of scale all lie in the vessels, equipment and systems that are factory built, but these savings are more than offset by the complexity of construction and the huge cost of 10 years or more of on-site work for the largest plants.

Economies of scale all lie in the vessels, equipment and systems that are factory built, but these savings are more than offset by the complexity of construction and the huge cost of 10 years or more of on-site work for the largest plants

Tony Roulstone, Cambridge University

“At last, it has been realised that no private utility or reactor vendor can afford to take on the £10bn financial risk of building a single large nuclear station without government support. By reducing the size of investment and its risk, the SMR option could be made affordable and attractive for private sector investment.”

These “small” plants are still pretty big. Roulstone describes them as the “parish churches rather than cathedrals of nuclear energy”. Costs of SMRs have been estimated at around £1bn per unit, compared with the £20bn price of the twin 1.65GW reactors of Hinkley Point C, with all of its complications of state-backed investments from France and China.

But the UK does not require enough SMRs to make this worthwhile, so would rely on creating a new export market to make investment cost effective. And to share the development costs and beef up intellect following the decision 20 years ago to shut down the UK’s nuclear industry, the country would benefit from a partner.

Multiple SMRs on one site

The vision is that multiple SMRs funded by private sector investors could be constructed on existing nuclear sites as alternatives to a single plant. SMRs would most likely be developed in partnership with another country, with the United States ahead of China and South Korea as preferred options.

The US is committed to building at least one SMR, but needs its new president to continue to support the concept. It is already ahead of the UK in developing the SMR concept and two of its firms – Westinghouse and NuScale have expressed interest in the UK market.

“I’d pick the US,” Roulstone says. “All nuclear reactors, including SMRs, are a complex business. American firms know the technology at a deep level. Also, there is a long term trust relationship between the US and the UK. But there is an ‘if” and it’s ‘if Trump likes it’.

Trump and energy policy

“The Americans are going to build at least one SMR unless Trump stops them with his new energy policies. We have a successful record of working with the US – in aerospace and the military. They are 10 years of SMR development ahead. Everything is not so completely sewn up. There are still openings for collaboration.”

There is justification for the UK to push on regardless, but it will require courage and a commitment to the long term.

“SMRs can also operate as combined heat and power plants providing not just electricity but also thermal energy to large scale district heat networks,” says Mott MacDonald energy economist Sam Friggens.

CHP challenges

There are a few challenges here. The amount of infrastructure investment required to make the SMRs work as combined heat and power plants would be colossal. Each city would require many kilometres of tunnels several metres in diameter to distribute hot water around city centres. There are also the issues of security, waste and public acceptability, with the latter arguably the most contentious.

“SMR development needs to become part of the emerging UK industrial strategy because we think SMRs would be a good addition to the ways of addressing climate change and something we could be good at building in the UK and exporting,” says Roulstone. “But we have to make a decision to spend significant public money on development – we’d need an SMR demonstrator by 2027 in order to attract private investment for a series build by about 2030. The timescales of such a project mean that decisions are urgent.

“Whether the current energy market will deliver the investment and whether we will get round to SMRs without a proper UK energy strategy are the two big questions.”

 

The Technologies: Light water and ‘advanced’ reactors

There are two groups of technologies for SMRs. Light Water Reactors (LWR) and “advanced” reactors, which group together a number of different technological approaches.

Most designs coming forward are integral light water pressurised reactors, made of the same four major components that make up a standard LWR or pressurised water reactor  – the reactor, stream generators, pumps and the pressuriser.

In the integral SMR, there is one vessel and all of these four components are either inside or directly part of the SMR vessel, removing all of the complicated pipe work that connects the components within a large nuclear reactor. The problem with these reactors is that they share complexity with the larger LWRs and it now appears unlikely that light water SMRs will be able to significantly reduce the cost of generation compared with larger reactors using the same technology due to no reduction in the required safety control system and site operations.

The “advanced” category groups together a number of technologies including high temperature gas-cooled reactors (see feature p42), sodium-cooled reactors and molten salt reactors, among others. Some believe that this technology is too far away as there are more uncertainties in both the technical and cost aspects of advanced reactors. However, there is the possibility of a true price breakthrough because of the simplicity of design of most of these options. For example, they could have intrinsic safety which would reduce risk and control and operation requirements – but this is not yet proven.

 

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