Rolls Royce has made nuclear reactors for decades, small enough to fit inside nuclear submarines. It’s now adapting that expertise for the grid. Dan Yurman runs through the details of the firm’s plans, including a look at its first-of-a-kind 440MW technology. Regulatory timescales will be kept short by developing the small modular reactors (SMRs) at existing licensed nuclear sites – with Cumbria and Wales its main targets. Importantly, an innovative financing model is being promoted: the Regulated Asset Base (RAB). This will be crucial for keeping costs down as well as securing the first five clients that ensure economies of scale are reached. Financing failures are a main reason why only one new nuclear project has broken ground in the UK this decade despite a need to replace declining yields from North Sea Oil & Gas and to meet decarbonisation goals. It also explains why the UK’s leading business lobby, the CBI, is voicing support for SMRs and the RAB model.

A consortium headed by British engineering giant Rolls Royce announced this month it expects to develop its first-of-a-kind small modular nuclear reactors in Cumbria, northwest England. The firm has made nuclear reactors for decades that fit inside the UK nuclear submarines and is now adapting that expertise to commercial applications.

Alan Woods, director of strategy and business development at Rolls Royce, told delegates at the Global Reach 2019 event in Manchester, UK, that the company is focusing its efforts on developing small modular reactors (SMRs) at existing licensed nuclear sites – with Cumbria and Wales its top targets.

In July the government said it will invest up to £18m ($23m) to support the design of the UK-made SMRs. And this week UK Research and Innovation pledged to provide a further £18m which will be matched by members of the consortium, to progress the project.

First-of-a-kind SMR

The government said in July that the Rolls-Royce consortium had proposed a significant joint investment of more than £500m ($640m) focused on designing a first-of-a-kind SMR.  In fact the consortium could easily add a third zero to the investor led funding goal given the costs of completing the design, testing and qualifying the fuel, getting the design through the UK GDR, a minimum four year process, and building the first-of-a-kind (FOAK) assuming a customer comes onboard on a timely manner.

The consortium is led by Rolls-Royce, which is responsible for the design, construction and support of the small nuclear power plants that power Britain’s atomic submarines. The consortium comprises firms Assystem, Atkins, BAM Nuttall, Laing O’Rourke, National Nuclear Laboratory, Nuclear AMRC, Rolls-Royce, Wood and The Welding Institute.

“The consortium expects to more than match any government funding both by direct investment and by raising funds from third-party organisations,” a statement said. However, the firm did not announce a customer for the units. The Rolls Royce consortium aims to have the first working model up-and-running in the early 2030s.

Mr Woods told the conference that despite being at the design stage, Rolls Royce is already considering sites for SMRs.

Built on existing licensed sites

“They will be built on existing nuclear licensed sites,” he said. “We expect to build them on sites in Wales and particularly in Cumbria. That’s where we’re focusing, that’s where we’ll put our effort.”

“All our focus has been on reducing the capital, absolutely reducing the construction period, and removing risks where we can. It opens the market to much greater potential investors. We have to make them cost competitive.”

400+MW is more “mid-sized” than “small”

The Rolls Royce design is actually larger than what is considered by the IAEA as an SMR. The upper limit by the agency is 300 MW. The Rolls Royce design comes in at 400-450 MW. This makes it more of a mid-size reactor.

It is a three loop, close-coupled, Pressurised Water Reactor (PWR) provides a power output at circa 400-450 MWe from 1200- 1350 MWth using industry standard UO2 fuel.

Coolant is circulated via three centrifugal Reactor Coolant Pumps (RCPs) to three corresponding vertical u-tube Steam Generators (SGs). The design includes multiple active and passive safety systems, each with substantial internal redundancy (see image above).

Target costs

The target cost for each station is £1.8 billion ($2.3 billion) by the time five have been built, with further savings possible, Rolls-Royce said. Each power station will be able to operate for 60 years and provide 440 MWe of electricity.

Estimates of the cost of smaller SMRs, that is with power ratings of less than 300 MWe, are currently in the range of $4,000 to $5,000 / Kw. A 440 MW plant would therefore cost, using these numbers, between $1.76bn and $2.20bn which puts the Rolls Royce number in the neighbourhood of $5,000/kw.

Ready by the 2030s

Next steps for Rolls Royce, once the design is complete, is to enter it in the UK nuclear safety regulatory Generic Design Assessment Process (GDA). At the same time, Rolls Royce said, it will begin to develop the supply chain for what it hopes will be a fleet of these types of units.

The GDA can take four years and construction for the FOAK could easily be a three year journey. Best estimate for the first commercial unit being in revenue service would be by the early 2030s.  While the firm said it would target existing nuclear sites for the plants, it did not specify any commitments from electric utilities to buy one of the units. Such a commitment would be crucial for gaining investor confidence.

According to World Nuclear News, the concept is that the components for the SMRs would be manufactured in sections in factories across the UK. They would then be taken to their construction sites where they would be quickly assembled within weatherproof canopies.

This approach would allow incremental efficiency savings through the use of standardised and streamlined manufacturing methods for the components. It would also reduce costs by preventing weather disrupting the assembly process. The SMRs would be assembled at existing nuclear sites.

Key UK business group pushes for SMRs and innovative financing

The Confederation of Business & Industry (CBI) has weighed in on the need for small modular reactors as a way to replace the UK aging power stations of full size units. The CBI has also demanded progress on using a new way for financing large-scale developments.

At the launch of “The low-carbon 2020s: A decade of delivery” report, CBI director general Carolyn Fairbairn said in a statement that the business organisation believed a Regulated Asset Base (RAB) model “could be the answer” to replacing the UK’s ageing nuclear fleet. And she also called on the Government to identify sites for Small Modular Reactors (SMRs) and put in place regulatory processes to ensure the technology to be deployed by the 2030.

Regulated Asset Base (RAB) financing

Ms Fairbairn said “We believe a RAB approach could be the answer — given its potential to reduce risks and costs for investors as well as deliver better value to consumers and taxpayers.”

Meanwhile, the CBI report also calls for greater momentum behind SMRs, which it says have the “potential to be cost-effective, innovative contributors to the UK’s energy mix”.

A consultation by the Department for Business, Energy and Industrial Strategy on adapting the RAB model to fund new nuclear came to a close last month. The UK government has been considering it as more conventional financing methods haven’t produced agreements with global vendors to deliver multiple nuclear reactors for a fixed price.

Industry leaders in Cumbria think using the RAB method will resurrect the potential for a large-scale development to take place at the Moorside site adjacent to Sellafield, after NuGen’s plans for three reactors collapsed in November 2018. Since then plans for nuclear power stations at Wylfa Newydd, Anglesey and Oldbury, Gloucestershire, have also been shelved due to issues over financing them.

In fact, with the exception of Hinkley Point C, which will provide 3,200 MWe when complete in the mid-2020s, no other new nuclear project has broken ground in the UK this decade despite a need to build out at least 19 GWe of nuclear power to replace declining yields from North Sea Oil & Gas and, of equal importance, to meet decarbonisation / climate change goals.

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Dan Yurman is the author of Neutron Bytes and writes on nuclear matters

This article is published with permission