Licensing

For small modular reactor (SMR) designs to compete economically with the large plants and with other fuel sources, it is critical that the governing regulations appropriately account for the increased plant simplifications, reduced risk factors, and anticipated increase in safety margins to be incorporated into the designs. Licensing issues and requirements specific to the deployment of SMRs typically result from design philosophies and features that are significantly different from traditional Generation II and III light water-based plants. Items in this area will help to improve the regulatory outlook for the generic class of SMRs.

Title: Technologies for SMR Staffing Optimization

Completion Date: March 2016

Objective: Technical gap analysis of nuclear plant functional areas relevant to SMR designs to identify technologies and insights that can be applied to safely optimize staffing levels needed to operate the plant.

Result: The project identified, evaluated, and documented 25 technologies and/or design details (TDDs) that when implemented would substantially reduce the staffing required for evolving SMR plants. These TDDs embrace work functions from the 10 plant functional areas (numbers in parentheses represent the number of TDDs selected for each given area):

  • Chemistry (3)
  • Radiation Protection (4)
  • Maintenance (5)
  • Engineering (3)
  • Operations (2)
  • Outage Management (0)
  • Training (1)
  • Emergency Preparedness (2)
  • Warehousing and Supply Chain (2)
  • Security (3)

Impact: Owner / operators, SMR designers, engineering procurement and construction contractors, industry regulatory support groups, and related research and development groups can each take specific actions to achieve the benefits of the technologies and / or design details.

Full Report

Title: SMR Source Term Evaluation

Phase 1 - Integrated Pressurized Water Reactor (iPWR) Containment Aerosol Deposition Behavior: Phase 1 - Test Plan Development Completion Date:   September 3, 2014 

Objective: Conduct evaluation of relevant aerosol deposition experimental data and analytical correlations that have been generated since 1993 for relevance to light water-based SMRs, and analyze natural aerosol removal phenomena for applicability to expected geometries, dimensions, and post-accident transient thermal-hydraulic conditions in expected domestic SMR designs. Investigate the impact of SMR containment configurations on post-accident aerosol mitigation and develop recommended testing to extend the understanding of aerosol behavior in iPWR environments.

Result:  Evaluated the basis for a reduction of design basis and beyond-design-basis accident source terms with correspondingly smaller dose to workers and the public.

Phase 1 report - https://www.epri.com/research/products/000000003002004218

Impact: The results provide an informed basis for Nuclear Regulatory Commission (NRC) acceptance of SMR containment aerosol natural deposition correlations that will directly support the industry goal of reducing emergency planning zones (EPZs) required for SMRs with attendant cost reductions and increased ability to site SMRs closer to populated areas.

Phase 2 - Integrated Pressurized Water Reactor Containment Aerosol Deposition Behavior

Phase 2a: Technical Basis and Test Plan for Experimental Testing and Computational Fluid Dynamics Analysis- Integrated Pressurized Water Reactor Containment Aerosol Deposition Behavior:

Phase 2b: Results and Analysis 

Completion Date:  

  • Phase 2a - January 24, 2018
  • Phase 2b - March 28, 2018

Objective: This work builds on the Phase 1 study, with an objective of developing estimates of the decontamination factors associated with the natural deposition mechanisms. Estimation of the decontamination factors is performed by experimentally measuring the aerosol decontamination rates associated with the natural deposition mechanisms along with simulation of these mechanisms with a computational fluid dynamics (CFD) code.

Result: The Phase 2a report provides the details for experimental test planning and preliminary CFD analysis. Phase 2b presents the results of the experiments, providing estimates for the decontamination associated with naturally occurring physical phenomena. Specifically, this report provides decontamination factors associated with the thermal-hydraulic and geometric parameters that characterize iPWRs, based on the experimental work completed. 

Phase 2 reports: 

Impact:  This work supports the nuclear industry by providing improved, quantified analytical correlations to model aerosol decontamination for iPWR-specific, post-accident, thermal-hydraulic environments and design configurations. Improved correlations are expected to result in a more realistic calculation of containment aerosol natural deposition. The results provide a quantified technical basis under which the Nuclear Regulatory Commission can potentially modify regulatory requirements to relieve requirements for SMR emergency planning zones, reducing costs for the deployment of SMRs.