The UK Parliament Committees accept Castletown Law’s Evidence to Support Small Modular Reactors in the Transition from Fossil Fuels. (Dec 2023)

Castletown Law

Castletown Law is a UK-based international law firm, focused on energy and infrastructure work with a particular expertise in the nuclear sector. Castletown Law, with others, helped to set up a working group to further the interests of advanced nuclear technologies in the UK. The group was set up on a technology-agnostic basis to further the principal areas of concern (essentially Regulatory and Siting) for advanced nuclear technology developers and vendors. This group has already had meaningful interactions and discussions with DEZNZ and Minister for Nuclear and Networks, Andrew Bowie, and representatives of the group are due to meet shortly with the NDA and ONR to discuss the Regulatory and Siting challenges.

Although the term “Advanced Nuclear Technologies” was coined in the UK to encompass SMR (GEN III small modular reactors) and AMR (GEN IV advanced modular reactors (including both small and micro reactors)), the current evidence is that GBN is focussed solely on SMR technologies. The ongoing consultation process and down-selection for an outcome which is intended to result in two new commitments including one SMR is viewed with some cynicism by the industry with the likelihood that no decision can be reached before the end of 2024, so the government is facing failure in its own managed process unless something changes materially.

The IAEA makes no such distinction between Generation III or Generation IV modular reactors when it refers to SMRs. See in this respect the following extract from the IAEA`S booklet “Advances in Small Modular Reactor Technology Developments”, A Supplement to: IAEA Advanced Reactors Information System (ARIS) 2022 Edition:

“This booklet is reporting the advances in design and technology developments of SMRs of all the major technology lines within the category of SMRs. It covers land-based and marine-based water cooled reactors, high temperature gas-cooled reactors, liquid metal-cooled fast neutron spectrum reactors, molten salt reactors, and a sub-category called microreactors with electrical power typically up to 10MW(e).”

There is a real risk of the UK and other more progressive nuclear jurisdictions moving at different speeds and the UK losing a material and potentially crucial industrial, economic and engineering advantage.

What has prevented SMRs from being established in the UK, given that the technology and fuel sources already exist, and the Government has already financially supported R&D?

The current challenges and obstacles for deployment of SMRs can be summarised as follows:

·       The question identifies a key point namely that the technology exists, the fuel exists and the regulatory and siting conditions for the technology have not changed materially. The preventative factors arise largely from a lack of decision making at the government level, often based on a pretext of the need for an inquiry, a consultation or a competition all of which are obvious political prevarication measures when a difficult decision has to be made.

·        If part of the land available on the current sites put under the responsibility of the newly named Nuclear Restoration Services (NRS) were to be made available, then at least 19 sites could be made available in a very short time. What is required is ministerial willingness and direction that the historic mandate of the NDA should be changed. So a return of the sites to greenfield status is waived and utilising the sites for economic activity including new generation should be included in the NRS mandate and this would transform the decommissioning programme in the UK.

·       The UK Government has announced an ambition of up to 24 GW of new nuclear by 2050.[1]However, there is confusion about the potential role and make-up of the proposed nuclear capacity and greater clarity (including for example a projected roadmap(with timelines)) would assist prospective nuclear technology developers and operators. Language on this has changed subtly over a short period of time and the reference to 24GW of grid-based electricity generation is moving now to just 24GW of electricity.

·       The reference to a roadmap is a key aspect of nuclear sector parlance in new projects. The myriad of stakeholders should be directed and by creating a clear roadmap of the intended delivery sequence and model everyone can join together to support it. The Government`s progress on SMRs has been hampered by failed competitions and consultations which are directly responsible for a lack of investor enthusiasm and commitment to SMR development and deployment in the UK. The absence of a clear roadmap demonstrating the point at which delivery of outputs will be achieved is symptomatic of consultancy-based management when what the sector needs is an industry-based plan to deliver relevant milestone achievements.

·       There is uncertainty around the extent to which deviation from the current regulatory process which was designed to be applied for conventional nuclear power will enable new nuclear technologies to advance at the rate of progress required.  Respecting adherence to recognised international and national standards on security, safeguards and safety, should not be diluted but the standards were written in the absence of the massive advances in digital design, AI, automated manufacturing, fail safe systems designs etc. The objective should be to select applicable requirements and apply them rigorously, rather than apply everything that was applicable to the technology of the 1980’s.

·       Some advanced nuclear technologies may and, on the current evidence, will require testing sites for research and development, including materials testing, potentially criticality testing and simulator application of safety systems. We understand that a Special Development Order was originally put in place to establish the nuclear research establishment at Harwell and we would suggest there would be scope to make use of this if it is still inexistence or to use this approach again. The point being that there is a lack of willingness for government to be innovative in its approach to enabling advanced nuclear technology development despite funding millions of pounds in grants to find innovation in the energy sector. This lack of broad thinking with an entrepreneurial view and innovative ambition is a major reason for a lack of progress.

·       There is currently no siting plan for allocating sites for new nuclear build beyond 2025 and there is no clear indication at present as to how new nuclear technologies (as opposed to conventional large nuclear plants) are to be treated. This is based to some extent alongside the failure to progress the EN1 and EN6/7 amended planning guidance which could open up anew stream of technology development in GEN IV technologies and allow real investment to be considered because of the likely confidence a clear planning policy would bring. These uncertainties (primarily around Siting and Regulation) mean that developers and investors are not able to move forward in the way that they would wish and in practice this means that other jurisdictions (in central and eastern Europe for example) are increasingly being favoured for development.

How realistic are the current targets for SMRs (Final Investment Decision by 2029, deployment mid-2030s)? How should the Government’s targets be revised, if at all?

The FID target date of 2029 with deployment by the mid 2030’s is seen internationally as a sign of a lack of seriousness in the prospects presented. Compare the position internationally with the Baltic countries and Poland, France, USA, Canada, Romania, Turkey etc. The first point to be made is why is it not sooner. If the technology is selected and sites are available, the FID date from an investment point of view looks like a long time away. In our view it would make much more sense to set dates by which the consents will be provided as a timeline to commencing release of the investment funds, in other words a process by which the relevant parties can see what is required of them. Without consenting and siting timelines, setting a FID date in isolation is meaningless.

Having said that the Government will have changed by 2029 and that may be part of the thinking. So while the commitment is to progress two projects before the end of the current parliament that is not a commitment to enable delivery of two projects. So with the FID date of 2029, bearing in mind the change in government likely to happen in 2024and the troubles around Sizewell C there is little confidence in the sector or in the investment side that this is a committed date and as is common when not committed it will move.

SMR developers will have varying project timelines which will need to be tested to determine the extent to which assumptions and readiness levels can be verified. In our view the UK Government needs all forms of clean energy to meet its challenging net zero and decarbonisation challenges and it will need to ensure that it has a ready pipeline of projects for many decades to follow.

Targets are fine in principle but more important are the right policy and regulatory signals. The government should be encouraged (with outside assistance) to develop a roadmap setting out relevant timelines according to when and where energy demand is required.


How should SMRs and larger gigawatt scale reactors be balanced to help the UK meet its net-zero targets and targets to decarbonise the national grid?

The approach to addressing the challenge of net-zero targets and targets to decarbonise the national grid by pitching SMRs versus larger gigawatt-scale reactors is not helpful.

The current new nuclear build does not fully replace the retired nuclear plants. The goal of 24GW nuclear by 2050 is not achievable from large nuclear alone. The best potential delivery rate for large nuclear is likely to be one every ten years- if the supply chain is available- but that is not sufficient to meet the demand and the extent of other countries' demand on the supply chain puts even this delivery rate at risk.

SMR technologies have been recognised and now largely adopted by the IAEA, WNA and IEA as the best solution to keeping the lights on.

A projection of the balance of large nuclear and the advanced nuclear technologies can be understood better through this illustration.

The case for energy production via SMRs has many benefits. Principally this would help to move our current energy system – based on antiquated infrastructure developed over 100 years ago – in to the modern age. SMRs can provide for current needs and make our energy infrastructure secure for generations to come. Some additional benefits are as follows:

1. These advanced nuclear technologies offer passive safety, zero emissions, low carbon output, and a small footprint (including any emergency planning zone requirements) and can be relatively localised and stakeholder communities welcome the availability of low-cost, long-term power generation which has a small waste output and a longevity term which will serve generations.

2. A flexible output in terms of heat, steam and electricity, and the potential to integrate with other forms of power generation as a flexible power source (and not purely load following).

3. SMRs provide low carbon, high output, flexible and consistent power generation at affordable levels.

4. The potential for different applications, such as co-generation, hydrogen production, district heating, desalination plants etc.

What best practice and previous experience, including from other countries, can guide policy, allowing the UK to take advantage of the benefits of SMRs while also making them competitive?

Canadian Case Study:

In Canada, under the Inter-provincial SMR MOU, the provinces of Ontario, New Brunswick and Saskatchewan devised a Strategic Plan in 2022 for the deployment of SMRs (the SMR, unlike the UK categorisation, included the Gen-IV reactors).[2]The strategy opted for the SMR deployment emphasised diversification of the technology types. The plan outlined three separate streams of SMR development covering both on-grid and off-grid applications.

a.     Stream 1 – a grid-scale SMR project of 300 MWe to be constructed at the Darlington site in Ontario by 2028, followed by up to four subsequent units in Saskatchewan between 2034 and 2042.

b.     Stream 2 – two advanced SMR technologies(Advanced Modular Reactor technologies in the UK) being developed in New Brunswick for deployment at the Point Lepreau Nuclear Generating Station site to be operational by the early 2030`s.

c.     Stream 3 – a new class of micro-SMRs designed primarily to replace diesel use in remote communities and mines. For this stream, the first deployment of a 5-MWe gas-cooled demonstration project has been proposed for Chalk River, Ontario, to be in service by 2026.

The Strategic Plan also recognised a more streamlined regulatory and licensing framework with the applicable safety and environmental risks. The CNSC has already established an optional pre-licensing assessment process, referred to as “vendor design review,” which allows prospective project developers to submit project designs to the CNSC for feedback that can assist in developing a formal licence application and which should result in a more efficient and effective licensing process.

The Strategic Plan is a good example of making the best use of available technologies by clearly setting out and identifying the timescale and sites for the type of technologies by diversifying the technology types and building on the country's capacity to export nuclear technologies.

How effective are existing financial models (e.g., Contracts for Difference, Regulated Asset Base) for SMRs? Should new financial models be considered for SMRs?

SMR developers and investors are likely to consider a different range of financial models (including Contracts for Difference and Regulated Asset Base) but also individual power purchase agreements.

In our view the UK government should not be prescriptive as to the financial model that it applies for the deployment of SMRs but should rely on the case presented by the SMR developer. In many cases SMR developers are not seeking any specific financial support from UK Government in any event.  

What is the overall benefit or cost to the public purse from the UK’s adoption of SMR technology in its generating mix?

This is difficult to quantify save to say that the UK Government target of achieving 24GW nuclear capacity by2050 is a challenging one. We are of the view that SMR development and deployment could make a sizeable impact and contribution to this target and at the same time benefit the UK taxpayer.


How does the current SMR technology design competition impact on the delivery of SMRs to commence generating capacity on time and on budget?

The current SMR technology design competition is a start and sends a signal to 6 SMR technology developers about government plans for SMR development. But even then, as stated above, greater clarity is required on the two principal issues of Siting and Regulatory approach. For example, will the ONR have the capacity and resources to process Generic Design Assessment applications for all 6 developers within reasonable timescales?

Importantly the UK government needs to provide more clarity and certainty as to the route available for Generation IV technologies, for example following a similar approach to that adopted by Canada. Without a clear roadmap for deployment, many of these developers will look to move to alternative jurisdictions.

It is notable that the EU have announced a collaborative initiative for SMR developers to work together and without imposing any unnecessary competitive stresses in the development process. There are no doubt lessons the UK could learn from this approach.

What benefits might accrue, and what issues might arise, if the Government were to select more than a single design to commission?

If the Government were to select more than a single design to commission, on the one hand, it would send out a positive signal to the market, encouraging the technology owners and developers to see an opportunity for the development and deployment of their nuclear technologies, resulting in the likelihood of more inward investment. A diversification of different technologies would also ensure more competition which should have a favourable impact on energy prices. However, the selection process has to be more transparent, including fair opportunity and access to market to all types of technologies, whether that be Generation III or Generation IV technologies.

What are the advantages and disadvantages of a prototype SMR being required to be delivered by a winning competitor ahead of installation of the initial SMR?


1. A demonstration of the safety features of the SMR and therefore assisting in robustness of the final Safety Case.

2. A positive signal for investment in the commissioned technology.

3. Robust regulatory assessment.


1.      Imposing such a requirement may have an impact on the costs of the project.

What export opportunities for the UK arise from the winning SMR design or designs?

The winning SMR design or designs will provide strong credibility for other markets. The UK has strong credentials for managing and regulating nuclear power and a winning technology design or designs will have strong credentials for export opportunities.

It is worth noting however that many in the nuclear industry (including potential investors), believe that the time for decisions in the UK is now because there is a real risk of losing a world-leading position. As James Faust suggests: “Some of our important choices have a timeline. If we delay a decision, the opportunity is gone forever. Sometimes, our doubts keep us from making a choice that involves change.  Thus an opportunity may be missed.”

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The UK Parliament Committees accept Castletown Law’s Evidence to Support Small Modular Reactors in the Transition from Fossil Fuels. (Dec 2023)
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