United States Nuclear Regulatory Commission - Protecting People and the Environment
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Emergency Preparedness Rulemaking with Regard to Small Modular Reactors and Other New Technologies (RIN: 3150-AJ68; NRC Docket ID: NRC-2015-0225)

The U.S. Nuclear Regulatory Commission (NRC) is developing emergency preparedness (EP) requirements and guidance as they apply to the rulemaking for light-water small modular reactors (SMRs) and other new technologies (ONTs).

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Key Messages

The current EP regulatory framework for large light water reactors (LWR) adequately protects the health and safety of workers, the public, and the environment.

In SRM-SECY-16-0069, the Commission approved the staff's plan and schedule for the rulemaking pertaining to emergency preparedness for SMRs and ONTs such as non-light-water reactors (non-LWRs) and medical isotope production facilities. This rulemaking would develop EP requirements, and associated guidance, for these technologies that would be commensurate with their potential consequences to public health and safety.

The potential new regulations and guidance would do the following:

  • Adopt a consequence-oriented, performance-based, and technology-inclusive approach, to the extent possible,
  • Adopt a scalable plume exposure pathway emergency planning zone (EPZ) approach that will take into account: (1) the dose/distance boundaries to which planning for initiation of predetermined protective actions is warranted, (2) the time-dependent characteristics of potential releases and exposures, and (3) the isotopic characteristics of radioactive materials that can potentially be released off site into the environment,
  • Address advanced and new technologies in reactor plant designs,
  • Include EP for medical isotope production facilities,
  • Provide guidance to facilitate the implementation of the rule, and
  • Maintain adequate protection of the health and safety of workers, the public, and the environment.

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The existing EP regulatory basis and guidance resulted from a study conducted in 1978 by a joint NRC and the U.S. Environmental Protection Agency (EPA) task force. The task force published its report, "Planning Basis for the Development of State and Local Government Radiological Emergency Response Plans in Support of Light Water Nuclear Power Plants," NUREG-0396/EPA 520/1-78-016 (NUREG-0396), in December 1978. NUREG-0396 was based on NUREG-75/014, "Reactor Safety Study: An Assessment of Accident Risks in U.S. Commercial Nuclear Power Plants (WASH-1400)," issued in October 1975. NUREG-0396 considered various accident sequences for a large pressurized-water reactor or boiling-water reactor). The task force recommended, in NUREG-0396, that a plume exposure pathway EPZ of about 10 miles (16 kilometers) and an ingestion exposure pathway EPZ of about 50 miles (80 kilometers) be established to provide dose savings to the population in areas where the projected dose from accidents could be expected to exceed the applicable protective action guidelines (PAGs) (1-5 rem (10-50 millisievert) total effective dose equivalent under unfavorable atmospheric conditions).

In addition to identifying the recommended EPZ sizes for emergency planning, NUREG-0396 stated the following: "Further, the range of possible selections for a planning basis is very large, starting with a zero point of requiring no planning at all because significant offsite radiological accident consequences are unlikely to occur, to planning for the worst physically possible accident regardless of its extremely low likelihood." Both the NRC policy statement of October 23, 1979 (published in the Federal Register (FR), 44FR61123) and EPA's policy statement of January 15, 1980 (45FR2893), endorsed the task force recommendation in NUREG-0396. The NRC codified the plume and ingestion exposure pathway EPZs through the rulemaking process in August 1980 (45FR55402). The 10- and 50-mile (16- and 80 kilometer) EPZ sizes were subsequently incorporated into Title10 of the Code of Federal Regulations (10 CFR) 50.47(c)(2) and Appendix E, "Emergency Planning and Preparedness for Production and Utilization Facilities," to Part 50, "Domestic Licensing of Production and Utilization Facilities." Additionally, 10 CFR 50.47(c)(2) included a provision allowing for a case-by-case determination of the size of appropriate EPZs for reactors with an authorized power level less than 250 megawatts thermal and for gas-cooled reactors. The NRC withdrew the October 23, 1979, policy statement on January 20, 1995 (60 FR 4071) because it was incorporated into the rule.

The underlying objectives of the recommended EPZs in NUREG-0396 were to ensure that pre-planned protective actions would be identified and practiced and to reduce dose in the unlikely event of a large release that would exceed the EPA PAGs off site. The development of EP requirements for currently operating large LWRs, including the 10- and 50 mile (16- and 80 kilometer) EPZs, complemented the prevention and mitigation measures that are part of the agency's defense-in-depth approach to protecting people and the environment against the harm of radiation in the unlikely event of a severe radiological accident resulting in offsite dose.

The staff has previously communicated to the Commission its intention to consider EP issues related to designs that differ from those of the current fleet of large LWRs. In SECY-93-092, the staff suggested that there be no change to existing regulations governing EP for advanced reactors and stated that regulatory direction would be provided at or before the start of the design certification phase in such a way that design implications for EP could be addressed. In the staff requirements memorandum (SRM) for SECY-93-092, the Commission directed that "the staff should submit to the Commission recommendations for proposed technical criteria and methods to use to justify simplification of existing emergency planning requirements."

In SECY-97-020, the staff stated the following: "Because industry has not petitioned for changes to EP requirements for evolutionary and passive advanced LWRs, the staff did not dedicate the resources to fully evaluate these issues. The staff remains receptive to industry petitions for changes to EP requirements for evolutionary and passive advanced LWRs."

In March 2010, the staff noted in SECY-10-0034 that EP is a key technical issue for licensing both SMRs and non-LWRs because of its role in the protection of the public, as well as its relationship to the key technical issue of SMR accident source term. The staff recognizes that EP requirements, particularly those concerning potentially reduced EPZ sizes, are important in decreasing regulatory uncertainty for SMR design certification and combined license applications. Also, industry has indicated that the EPZ issue will be a key factor in the business case for SMR feasibility and development.

Following public meetings with industry stakeholders and review of other SMR issues, the staff developed SECY-11-0152. This information paper discussed "the staff's intent to develop a technology-inclusive, dose-based, consequence-oriented EP framework for SMR sites that takes into account the various designs, modularity and collocation, as well as the size of the EPZ." It also stated that the "staff will work with stakeholders to develop general guidance on calculating the offsite dose, and is anticipating that the industry will develop and implement the detailed calculation method for review and approval by the staff."

The Nuclear Energy Institute (NEI) submitted a white paper to the NRC in December 2013 outlining a high level approach to determining EPZ size. Tennessee Valley Authority submitted an application for an early site permit (ESP) for two or more SMR modules (up to 800 MWe, 2420 MWt) at the Clinch River Nuclear site on May 12, 2016. This application uses the Plant Parameter Envelope approach which means no design has been selected. The staff in SECY-10-0034 stated: "Should it be necessary, the staff will propose changes to existing regulatory requirements and guidance or develop new guidance concerning reduction of offsite emergency preparedness for SMRs in a timeframe consistent with the licensing schedule." The staff believes that key SMR EP issues must be resolved and in SECY-15-0077, "Options for Emergency Preparedness for Small Modular Reactors and Other New Technologies" (ADAMS Accession No. ML15037A176), the staff sought Commission direction to proceed with rulemaking for EP for SMRs and other new technologies. This paper stated that: "The NRC technical staff will rigorously review design and licensing information to ensure that the information applicants provide on the offsite dose consequences is commensurate with the requested EPZ size and that the applicable requirements ensure adequate protection of public health and safety, and the environment." Subsequently, the Commission issued SRM-SECY-15-0077, "Staff requirements - SECY-15-0077 - Options for Emergency Preparedness for Small Modular Reactors and Other New Technologies" directing the staff to proceed with rulemaking and to develop a plan and schedule to undertake the EP rulemaking for SMRs and other new technologies, such as non-LWRs and medical isotope production facilities. In SECY-16-0069, "Rulemaking Plan on Emergency Preparedness for Small Modular Reactors and Other New Technologies" the staff requested Commission approval of the schedule for a rulemaking for emergency preparedness for SMRs and ONTs, such as non-LWRs and medical isotope production facilities. This rulemaking would develop EP requirements for these technologies that would be commensurate with the potential consequences to public health and safety. Subsequently, SRM-SECY-16-0069, "Staff requirements - SECY-16-0069 - Rulemaking Plan on Emergency Preparedness for Small Modular Reactors and Other New Technologies," the Commission approved the staff's plan and schedule to proceed with the rulemaking effort pertaining to emergency preparedness for SMRs and ONTs, which started with the development of a regulatory basis document.

The concept of an EPZ size commensurate with the offsite radiological risk is not new to the NRC. The staff recently reviewed exemption requests from specific EP requirements from certain reactor licensees that have permanently ceased operations (SECY-14-0066 and SECY-14-0118). The staff reviewed these exemption requests against the requirements in 10 CFR 50.47, "Emergency Plans," Appendix E to 10 CFR Part 50, and 10 CFR 72.32, "Emergency Plan." The staff considered the status of permanently shutdown and defueled facilities and the low likelihood of any credible accident resulting in radiological releases requiring offsite protective measures. The staff based its evaluation of the requests for exemptions from EP requirements on site-specific analyses. The staff verified that with the requested exemptions, the licensees' emergency plans continued to provide reasonable assurance that (1) an offsite radiological release would not exceed the EPA PAGs at the site boundary and (2) in the unlikely event of an accident resulting in a loss of all spent fuel pool cooling, there would be sufficient time to initiate appropriate mitigating actions. In SRM-SECY-14-0118, the Commission directed the staff to proceed with rulemaking on decommissioning and address issues raised in SECY-00-0145, such as a graded approach to EP. Preapplication information and SMR design concepts provided by NuScale, mPower™, and Westinghouse indicate that these SMRs could have lower offsite dose consequences in the unlikely event of an accident, although this has not yet been verified.

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Regulatory Basis

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  • Complete regulatory basis - September, 2017
  • Proposed rule and draft guidance due to Commission - October, 2018
  • Final rule and final guidance due to Commission - March, 2020

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Page Last Reviewed/Updated Monday, August 26, 2019