The plant and SSC design strategic element includes the design of advanced reactors and SSCs. Because a significant amount of time has passed since the current operating fleet of LWRs and CANDU reactors was designed, and due to the different features of advanced reactors in terms of coolant, size, and type of fuel, design of advanced reactors will present unique challenges.
Key Issue: Materials Behavior
A complete understanding of the behavior of materials selected during the design under relevant conditions might not be available during the design phase. Because some advanced reactor designs are intended to operate at much higher temperatures than the currently operating LWRs, design practices need to account for the time-dependent behavior of materials in various coolants for safety and lifecycle analyses.
ACTION:
Priority
Status
Capture material data and close data gaps necessary for deployment of advanced reactors: Identify the materials needed for advanced reactor designers in both the near- and mid-term and ensure that materials testing is performed for on-time qualification and licensing. The materials roadmap developed by EPRI should be updated, vendors’ needs should be collected and prioritized, and the needed testing capabilities should be developed. The tests should be performed with a timeline that meets advanced reactor designers’ needs. In addition, Canada should ensure sufficient laboratory facilities are available for Canadian testing and data development requirement.
Action Owner: EPRI, DOE, CNA, advanced reactor vendors
Need Date:
- 2028 for first mover
- 2030 – 2035 for mid-term needs
Priority
Status
Develop surveillance, inspection, and monitoring requirements: Materials data for safety-related SSCs for the entire lifetime of reactor operation may not need to be collected in advance. Surveillance specimens and other inspection and monitoring techniques, potentially coupled with modeling, may be used instead. However, testing and modeling methodologies for both initial licensing applications and ongoing surveillance may not be sufficiently advanced to address the envisioned data needs, necessitating the development of new testing capabilities and/or the ability to substitute the results of available testing capabilities combined with modeling predictions and uncertainty bounds as necessary to support meeting the safety-related functions.
Action Owner: EPRI, DOE, CNA, advanced reactor vendors
Need Date:
- 2028 for first mover
- 2030 – 2035 for mid-term needs
Progress to Date on Addressing Key Issue: EPRI formed the Advanced Reactor Materials Initiative (ARMI) Technical Advisory Group to identify and prioritize material testing and qualification for advanced reactor deployments in the near- and mid-term. The group collaborates with the DOE Advanced Materials and Manufacturing Technologies (AMMT) office to align industry efforts. EPRI issued a report20 that provides approaches to accelerate advanced reactor materials code qualification, with the next phase piloting these approaches in 2025. The ARMI Technical Advisory Group will continue developing work scopes in 2025 to collaboratively address materials gaps.
20Accelerating the Qualification of Structural Materials for Advanced Reactors, Palo Alto, CA: EPRI. 3002029265
Key Issue: Insufficient Data and Analytical Tools
Computer codes and risk assessment tools are needed during design, licensing, and operation to predict the behavior of systems and components. To qualify the analytical tools needed for design, licensing, and operation, the experimental data needed and the analytical tools that require verification and validation (V&V) should be identified, and V&V qualification for the required analytical tools should be completed.
ACTION:
Priority
Status
Develop data and qualify analytical tools for advanced reactor design: Survey advanced reactor vendors to identify analytical tools needed for optimal design, licensing and operation. Conduct gap assessment of engineering analytical tools for advanced reactor design, including coordination with industry stakeholders. Create an action plan to develop and/or qualify tools as needed.
Action Owner: EPRI/advanced reactor vendors
Need Date: 2024 for gap analysis (complete)
Priority
Status
Close gaps on engineering tools readiness: Coordinate technical efforts to close gaps identified in previous action and update engineering tools. Ensure industry alignment on these tools, and work on documenting the tools’ qualifications, validation, and verification efforts.
Action Owner: EPRI/advanced reactor vendors
Need Date: 2027
Progress to Date on Addressing Key Issue: Gap analysis has been performed on engineering tools needs. The general gaps identified include:
- The lack of availability of quality experimental datasets to validate analysis tools
- Difficulties in data transfer between computer codes
- Inefficient workflow handoff procedures and difficulty in communicating conservatism between disciplines
- Aggregation of PRA Data and PRA Software Tool Updates
- Software Qualification and Applicability Issues
- High Performance Computing Access
Key Issue: Reliance on Legacy Designs
New reactor designers often rely on the idea that many types of reactor technology have already been tried in the past and use this as a basis that proven designs exist. However, design drawings and manufacturing details are often not available, so past experience might not be readily available. Also, the subsequent problems found during operation might not be captured and/or understood.
Furthermore, the modes and mechanisms of operation from the historical technology experience might not be the same as those planned for advanced reactors. These different operational challenges may not be understood through historical precedent. To fill this gap, a guide on how to use past designs should be developed, including the identification of past designs that can be useful for advanced reactors. In addition, the industry must coordinate to collect and share operating experience from demonstrations, test beds, and early reactor operating experience to support design and licensing needs for a fleet of new reactor types.
ACTION:
Priority
Status
Develop guide on leveraging legacy reactor experience: Identify best practice uses of legacy advanced reactor demonstration experience and data, while providing guardrails based on their shortcomings.
Action Owner: EPRI, INPO
Need Date: 2025
Priority
Status
Develop or update a database to collect reactor experience from demonstrations, tests, and new reactors: Coordinate between DOE, NEI, advanced reactor developers, EPRI, and INPO to collect new experience from demonstrations, tests, and new reactors. Consider NRC coordination and endorsement.
Action Owner: EPRI, INPO, DOE, advanced reactor developers, NEI, and NRC
Need Date: 2027
Progress to Date on Addressing Key Issue: The DOE Gateway for Accelerated Innovation in Nuclear has a created a website for legacy documents. This resource has 12,000 reports, images, drawings, data files, etc. from the U.S. nuclear research efforts.
INPO has created a website with a collection of reports on lessons learned from deploying various types of reactors.
Key Issue: SSC and Related Function Classification
New reactor designers are using enhanced safety features to reduce the number of safety-related components. Components that have traditionally been safety-related (such as the primary coolant loops, reactor control systems, and electric power systems) may not be safety-related for some of these advanced designs. This issue is closely related to Key Issue: RIPB Design Approach under Technology Readiness, Codes and Standards (C&S). This issue would focus on SSC classification, including definition of safety-related and safety- significant functions, whereas the C&S action focuses on treatment of the components once classified.
ACTION:
Priority
Status
Develop classification guidance to support licensing of microreactors and designs that choose a licensing approach other than traditional (including 50.69) and Licensing Modernization Project (LMP) or NEI 18-04: Coordinate between DOE, NEI, advanced reactor developers, EPRI, and INPO to collect new experience from demonstrations, tests, and new reactors. Consider NRC coordination and endorsement.
Action Owner: EPRI, DOE, advanced reactor developers, NEI, and NRC
Need Date: 2026