A nuclear battery4 July 2017
A micro-modular reactor that can “put power where the demand is” is targeting industrial and off-grid power markets worldwide, Caroline Peachey reports.
Over recent years we have seen dramatic growth in the number of distributed generators and more recognition of the benefits of localised power production. Is there an opportunity for nuclear to get into the mix? What are the options for nuclear on a several megawatt scale?
One innovative proposal comes from a consortium of Amec Foster Wheeler, Cammell Laird, Laing O’Rourke and Urenco, which is aiming to develop what it calls the U-Battery micro-modular reactor. U-Battery is a 10MWt (4MWe) gas-cooled reactor that can provide heat at 710°C.
“All of the large reactors and most of the other SMRs are aimed at providing electricity for the grid,” says U-Battery General Manager Steve Threlfall. “U-Battery is aimed at providing heat and power for remote communities and industrial sites – putting power where the demand is.”
The U-Battery reactor is well suited to remote locations as it can be delivered to site in just five truckloads, and operates for five years on a single fuel cartridge. It will run on high-integrity, ceramic fuel and does not require any cooling water, which eliminates the need for multiple back-up safety systems.
TRISO (TRistructural ISOtropic) fuel is constructed by triple coating spherical particles of uranium fuel. A uranium centre is coated in a layer of carbon, which in turn is coated in silicon carbide, with a further outer layer of carbon. The attraction of TRISO is that its structure, use of ceramic coatings and spherical shape enable it to maintain integrity under extreme conditions. This eliminates the need for diverse engineered back-up safety systems, which are expensive, add complexity and require their own safety cases.
The reactor is also simple to operate. After the first few units Threlfall says the plan is to move to a centralised control room, such as those used for Urenco’s uranium enrichment plants. “We have discussed this proposal with the Canadian Nuclear Safety Commission (CNSC) and we have asked UK Office for Nuclear Regulation (ONR) at conferences...[and they seem] open to the idea,” Threlfall says.
Development of U-Battery begun in 2008, after a challenge set by Urenco CEO Helmut Engelbrecht, which aimed to design an economically viable, modular nuclear power generation system that is intrinsically safe.
The initial conceptual feasibility study for U-Battery, carried out by the University of Manchester and the Technical University of Delft, was completed in 2011. It concluded that there were potential opportunities for micro reactors in the provision of heat and power for large industrial complexes and small towns, with the opportunities arising from modularity and standardisation, simple design, serial fabrication of components and the building of multiple units at one site. The development consortium was formed in 2013, with the objective of making the concept a commercial reality. In 2016 the consortium completed the review of the U-Battery conceptual design and cost estimates.
The next phase, to convert the conceptual design to a basic design is getting underway, with the set up of a dedicated design and licensing team. Phase I will last around two years and cost about £12 million, with funding to include cash from Urenco and “sweat equity” (payment in kind) from the consortium members.
While the design is still in the early stages, many of the components are based on existing technologies, and it is just a case of getting the design work done, according to Threlfall. An early study has shown that in principle the UK has the capability and capacity to deliver the entire reactor. “It can all be done in the UK – the question is should it all be done here?” he says.
The work done over the coming months will form the basis of initial submissions to regulatory authorities as the design moves into licensing. Phase II, beginning around 2019, will involve development of the detailed design, requiring approximately £18 million in funding.
Threlfall says the target is to have a demonstration reactor operating by 2025. For the first unit, 30% of the capital cost will
be for design with 70% for construction. The consortium estimates that by the 4th-of-a-kind unit, capital costs will have reduced to between £40 and £70 million ($49 and $86 million).
Three key markets
U-Battery is initially targeting three markets: Canada, Poland and the UK.
In March, the U-Battery consortium submitted its micro-modular reactor technology for a pre-licensing vendor design review with the Canadian Nuclear Safety Commission (CNSC). Threlfall told NEI in March that the review, which requires submissions on 19 individual topics “could easily run over a two-year period,” but that the schedule was not yet set.
According to CNSC the objective of a pre- licensing review is to verify, at a high level, the acceptability of a nuclear power plant design with respect to Canadian nuclear regulatory requirements and expectations, as well as Canadian codes and standards. The review can also identify fundamental barriers to licensing a new design in Canada and assure that a resolution path exists for any design issues identified. CNSC is currently carrying out pre-licensing reviews for other innovative designs, including LeadCold Reactor Inc.’s SEALER, Ultra Safe Nuclear Corporation’s Micro-Modular Reactor and Terrestrial Energy’s integral molten salt reactor.
Canada is an attractive market for innovative reactor designs. “There is huge potential in Canada with over 300 remote sites currently running on unreliable and expensive diesels,” Threlfall says. There are also lots of potential mining sites. The consortium expects to sell U-Battery reactors to owners or operators in Canada.
The licensing framework in Canada is also favourable for small reactor developers.
“One of the important things in a very small reactor is the cost of licensing,” notes Threlfall. “In the Canada, Poland and the
UK they have goal-based or target-based licensing. Essentially it is up to the applicant to prove that [the reactor] is safe.”
“In the USA they have prescriptive licensing, which was designed for large light-water reactors. They are starting the process of changing that, but it will be ten years or more before it is resolved. We are encouraging this process along with other vendors,” Threlfall says. But he notes that the U-Battery consortium has no plans for the US market “at the moment” due principally to low energy prices.
U-Battery also intends to proceed with licensing in the UK, “as and when it can,” according to Threlfall. In the UK, a reactor design must get permission from the Department for Business, Energy and Industrial Strategy (BEIS) to enter the generic design assessment (GDA) process.
The SMR competition, launched in 2016, was expected to result in one or a small number of reactor vendors being put forward for the GDA process. But that process is stalled, with the industry seeking clarity on what will happen next. Government support is also important for technology at this early state of development.
In the UK the target market will be industry – primarily intensive energy users, such as ceramics or petrochemical companies.
The initial ambition was for a twin-unit demonstration plant at Urenco’s UK site, but the company is not talking about that location today. “The ideal deployment will be as a co-generation unit,” Threlfall says. “We will start the first units at existing nuclear licensed sites, but we hope that industrial sites will be next.” Potential sites have yet to be identified. In terms of operating model, one option is for an organisation to build, own and operate U-Battery units in the UK.
“We certainly imagine that an industrial site may not want to operate the reactor itself and it certainly won’t want to own it,” Threlfall says. “We might have an organisation in the UK that would own and operate. We may be a part of it, but it would make life easier if there is a nuclear generator involved.”
In Poland, U-Battery is being considered for construction adjacent to the country’s MARIA research reactor, and it is hoped that a high-temperature gas reactor programme will run in parallel to Poland’s planned light water reactor deployment. In May 2016, U-Battery signed an agreement with Poland’s National Centre for Nuclear Research (NCBJ) to cooperate on the deployment of U-Battery in Poland. Recently both companies agreed to cooperate with the Japan Atomic Energy Agency (JAEA) on HTGR design. Threlfall says: “Poland is a very important step for the eastern European market.”