IAEA-led efforts to accelerate the deployment of SMRs through standardization are making progress. A new working paper produced by the IAEA’s Nuclear Harmonization and Standardization Initiative (NHSI) explores how integrating non-nuclear codes and standards into small modular reactor (SMR) production and harmonizing these across jurisdictions could significantly reduce both the cost and time required for SMR deployments. The group is meeting in Vienna this week to discuss additional pathways that could support SMR project harmonization.
Nuclear power plants must comply with a range of standards governed by nuclear regulatory bodies to ensure safety in their design and operation. But they are also required to adhere to numerous codes applicable to industrial facilities in general, including exit routes , voltages and environmental regulations such as bans on certain building components. These standards may vary widely across jurisdictions, and adjusting plant designs to meet various national or regional standards increases cost and can lead to potentially significant deployment delays. If SMRs are to be deployed rapidly across the world, a more streamlined approach based on enhanced regional and international cooperation must be pursued.
“For nuclear power to maximally contribute to our net zero goals, it is essential to consider all potential sources of improvements, from design processes to regulatory oversight and approval phases, and to share lessons learned and practical solutions implemented in recent large new build projects,” said Aline des Cloizeaux, Director of the IAEA’s Division of Nuclear Power. “Harmonizing non-nuclear codes both within and between countries is part of this and could allow for much faster deployments of SMRs and other advanced reactors.”
Launched in 2022, NHSI aims to facilitate the deployment of safe and secure SMRs and other advanced reactors. NHSI consists of two tracks, one focused on harmonizing regulatory approaches and the other on supporting the development of more standardized industrial approaches to SMR manufacturing, construction, operations, and management. Industry Track Topic Group 2 (TG2), which published a working paper on how serial component manufacturing could facilitate quicker SMR deployments last year, has identified ways to address the myriad challenges posed by non-nuclear codes and standards in implementing nuclear power projects.
“The group identified several areas in which the code requirements coming from non-nuclear regulators lead to potentially significant redesign,” said Pekka Pyy, an IAEA Senior Expert. “As these often drive the cost of nuclear power projects, the group wishes to raise awareness of this topic and highlight that increased cooperation will be necessary.” TG2 is collecting relevant codes and standards as examples together with trying to identify areas for harmonization, he added.
“Standardization is key to international fleet deployment of SMRs. A standard plant design maximizes the read-across of safety and operational experience and is essential to minimize build schedules and the cost of electricity,” said Tim Gully, an Engineering Capability Manager focused on technology and facilities at Rolls-Royce and member of TG2. “Even minor differences in elements such as fire regulation can have large impacts on plant footprint, require redesigns and ultimately result in on-grid delays for operators and consumers. All reasonable efforts to increase harmonization without impacting safety should be progressed as far as practicable.”
TG2 took a look at several possible approaches to managing different requirements across jurisdictions, including an ‘enveloping’ approach, in which designers develop project specifications according to the most demanding requirements identified across jurisdictions expected to see SMR deployments in the near future. They also consider circumstances where a standard ‘product-as-is’ approach, in which no changes are made to the SMR design, could be possible.
“For new nuclear plant design, it is prohibitively expensive to incorporate all possible requirements into the Standard Plant design. An alternate strategy is to apply a subset of the requirements during the initial development of the Standard Plant design and select that subset to be representative or bounding,” said Michael Arcaro, Principal Engineer for Systems Engineering at GE-Hitachi Nuclear Energy and TG2 member. “For this approach to be successful, it is still important to have a basic understanding of the range of requirements that will be applied in the various applications for the implementation of the NPP. Most requirements that vary from site to site are non-nuclear site-specific requirements associated with systems such as fire protection and balance of plant auxiliary system cooling water systems.”
The group concluded that achieving such harmonization would require project owners and operators to engage with regulators and suppliers in the early stages of a project, and that technology developers must be prepared to show how their design complies with various jurisdictional requirements. Proactive cooperation at national, regional and international levels should be a priority to implement increased harmonization, and standardization methodologies successfully employed in other sectors, with the commercial aircraft industry standing as a prime example, should be looked to for guidance.
TG2 is meeting in Vienna from 10-11 June to consider additional strategies for streamlining SMR project implementation. The group is currently in the process of compiling fire and building codes, including by mapping fire exit regulations in various countries where SMRs may soon be deployed.
