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This guideline presents a modern, technology-inclusive, risk-informed, and performance-based (TI-RIPB) process for selection of Licensing Basis Events (LBEs); safety classification of structures, systems, and components (SSCs) and associated risk-informed special treatments; and determination of defense-indepth (DID) adequacy for non-LWRs. This guidance document provides one acceptable means for addressing the aforementioned topics as part of demonstrating a specific design provides reasonable assurance of adequate radiological protection.

The promise of new nuclear technology and the future of commercial power in the United States (U.S.) are linked to the existence of an efficient and safetyfocused regulatory review and licensing process. With an appropriate regulatory framework, reactor suppliers and regulators can design, license, and build advanced reactor units more efficiently and thereby help meet the growing need for clean and reliable energy.To help address the challenge of maintaining compatibility between the regulatory environment and new commercial nuclear plant designs, the U.S. Department of Energy (DOE) is supporting an industry-led effort called the Licensing Modernization Project (LMP). This cost-shared initiative, started in 2016 and scheduled to complete in 2019, targets amendment to key elements of the U.S. nuclear power reactor regulatory framework to specifically address licensing barriers in advanced reactor concepts. The project focused on updating guidance for certain technical licensing requirements that are largely incompatible with non-light-water reactors (non-LWR) and establish a new pathway for design-safety evaluations and license-application development. Upon completion, the project will have created a new pathway, founded on modern probabilistic assessment techniques, that offers developers, suppliers, regulators, and owner-operators greater clarity and assurance in design and licensing decisions.The LMP employs a team of advanced reactor technology and licensing subject matter experts working closely with U.S. regulators, affected industries, and interested members of the public.

quality rigor that can be associated with these historic data, and a configuration management system established to ensure data integrity is not compromised going forward. Recommendation 2: Planning to address SFR fuel knowledge gaps identified in Recommendation 1 is identified as a licensing priority and should be coordinated with the SFR design community. Fuel tests involving irradiations are often long-lead, yet essential, activities in reactor development. Testing in a fast neutron environment will be challenging because no suitable irradiation capability exists within the U.S. and foreign capabilities are limited. Recommendation 3: Complete activities described in the Very High Temperature Reactor (VHTR) Advanced Gas Reactor (AGR) Test Plan (PLN-3636) and the Graphite Technology Development Plan (PLN-2497). These plans focus on developing the fuels and nuclear graphite-related information profiles necessary to license a prismatic-block core modular HTGR plant. Recommendation 4: Complete development of VHTR-compatible safety analysis methods and codes that is already underway. No safety analysis computer codes suited to modern gas-cooled reactor applications have yet been endorsed by NRC for regulatory use. Efforts are now underway within ART to help address this shortcoming and should continue to the planned conclusion. Recommendation 5: Develop a plan whereby liquid metal fast reactor-compatible safety analysis methods and codes are systematically developed and presented to NRC staff for review. There are no NRC-endorsed safety analysis computer codes currently available that are optimized to the unique elements of SFR technology. Research codes do exist that could be updated and submitted for regulatory acceptance. Efforts required to address this issue are not well understood, however. Recommendation 6: Test facilities have been established at Oregon State University (i.e., the High Temperature Test Facility, HTTF) and at Argonne National Laboratory (i.e., the Natural Convection Shutdown Heat Removal Test Facility, NSTF) to address HTGR core heat removal. Continuing these (already planned and underway) test programs will produce information essential to support the regulatory safety evaluation process. Recommendation 7: Form an advanced reactor Industry Advisory Group (IAG) with representatives of the non-light water reactor (non-LWR) design community. Membership would be voluntary and based on interest in ART research. The IAG would be convened by ART project leadership as necessary to provide non-proprietary technical exchange and licensing guidance to ART personnel. Recommendation 8: Establish a set of fundamental instrumentation and control (I&C) system requirements for advance reactor designs. Creating these requirements will provide guidance to researcher when establishing equipment design/fabrication specifications and testing requirements. Section 5 identifies additional topics that are expected to emerge as important licensing priorities at a future time. Resolving these issues may require the su...

This paper describes key aspects of the risk-informed, performance-based licensing methodology as developed by the Department of Energy (DOE) for the Next Generation Nuclear Plant (NGNP) project. The discussion focuses on an event selection process using modular high temperature gas-cooled reactor (HTGR) design attributes and identifies how top-level regulatory criteria can be placed on a frequency-consequence curve. Preliminary Nuclear Regulatory Commission (NRC) staff evaluations concluded that the proposed approach is generally reasonable and responsive to the Commission’s Policy Statement on advanced reactors. However, the NRC deferred issuing any final assessments of the proposed approach due to other agency actions that were under consideration in response to the accident at Fukushima-Daiichi. In addition, important lessons learned during the NGNP prelicensing effort and their potential applications to alternative advanced reactor designs are presented.