Small modular reactors (SMRs) have been hailed as a revolution in nuclear technology; however, the real test facing the United Kingdom will not be physics-related. Rather, the greatest challenge that the U.K. faces is executing. Moving from ambition to delivery will require answering a fundamental question regarding the ability to engineer and license nuclear projects in such a way that creates a fleet, rather than a patchwork of individual demonstration projects.
The journey from reactor design to delivery systems
For decades, nuclear development in the U.K. has operated under a “bespoke” model. Each project was viewed as a unique endeavor and was subject to various site-specific engineering decisions, custom-tailored supply chain relationships, and one-time regulatory processes. Although technically viable, this process resulted in long durations of time before start-up, increased risk, and limited opportunity for knowledge sharing between projects.
In contrast, Amentum’s involvement in the U.K.’s developing SMR Program represents a departure from that tradition. In addition to supporting reactor hardware, they provide an integrated engineering framework that views delivery as a system. Design standards, constructability, regulatory compatibility, and lifecycle planning are all being addressed concurrently, rather than sequentially.
While there is little difference in these two approaches in terms of their engineering merits, there is significant importance in the fact that success in nuclear is increasingly dependent upon repeatability, versus novelty.
Using engineering as the means to achieve scale
SMRs promise smaller physical footprints, modular construction, and faster building schedules; however, those benefits will only occur when the engineering method used to develop them supports those characteristics. Amentum’s framework places emphasis on front-end engineering, which takes into account potential constraints that will be encountered during subsequent phases of the project life cycle, including site preparation, integration with the electrical grid, and long-term operational requirements.
By establishing consistency in engineering decision-making up-front, the framework also minimizes uncertainty further along in the project schedule. Components can be designed for manufacture at off-site facilities; interfaces between different components of the system can be made uniform, and construction sequencing can be determined prior to initiating any actual construction activity.
This enables Amentum to apply lessons learned from one deployment to subsequent deployments. Engineering in this manner serves as a bridge between policy-based ambitions and actual physical infrastructure.
The fleet-based vs. prototype-based approach
The U.K. has clearly stated its intent to pursue an SMR-based strategy focused on enabling the creation of a fleet of Deployments. To date, the primary goal of most programs has been to successfully demonstrate a new type of reactor or technology. For Amentum, the strategy is centered around developing common technical baselines and consistent delivery expectations to ensure that any number of deployments can be achieved.
Both regulators and investors benefit from this approach. A standardized engineering framework results in reduced need to debate and approve design decisions for each site, thus reducing the length of time needed to obtain approvals and increasing the predictability of costs. Ultimately, the risk associated with construction activities transitions towards planning activities, where it can be managed more proactively. Therefore, Amentum is creating a path where learning is cumulative rather than episodic.
Integration with national infrastructure goals
SMRs are not independent entities. SMRs must interface appropriately with existing electric grids, industrial regions, and long-term energy plans. Amentum’s systems-level approach to engineering addresses this requirement by analyzing how SMRs interoperate with transmission networks, local supply chains, and future capacity requirements. As opposed to viewing each plant independently as a discrete asset, Amentum’s framework establishes a linkage between nuclear deployment and broad-scale planning for infrastructure.
Enhancing the likelihood that SMRs contribute positively to energy security and decarbonization objectives for regions. Amentum’s role in providing initial SMR feet support for the U.K. demonstrates a less prominent yet important aspect of nuclear strategy evolution. The focus is shifting from demonstrating that reactors can be constructed to demonstrating that reactors can be constructed repetitively, consistently, and economically at scale.
