ASME SMR ROADMAP (STP-NU-072) Presented at: Nuclear Energy Standards Steering Collaborative November 3, 2014 Richard Black AdSTM
SMR ROADMAP BACKGROUND AND PURPOSE Respond to near-term SMR licensing schedules (Design Certification Applications to NRC 2015-16) to ensure effective licensing Interact with vendors, ASME and NRC to determine Code/standard issues Identify issues that may present barriers or challenges to effective licensing Provide recommendations and strategies to address potential ASME issues Provide a framework to address other nuclear standard issues for SMRs
ROADMAP SCOPE U.S. SMR designs scheduled for near-term licensing reviews (Submittals: 2015-2016) and commercial deployment (2022-2025) Only U.S. LWR SMR designs Non-LWR SMR designs considered either not ready for licensing or ready for commercial market Roadmap was limited to currently proposed U.S. LWR designs Roadmap might be revised in the future to address Code/Standard issues for other designs
NRC and other stakeholders Roadmap Interactions Domestic SMR vendors ASME Code Committees NRC and other stakeholders NRC Public Meeting and Conference Call: 2/8/14
ASME Nuclear Code Considerations 10 CFR 50.55(a) Requirements: “Reactor Coolant Pressure Boundary” for Class 1 components of Section III, “Rules for Construction of Nuclear Power Plant Components,” of the ASME Boiler and Pressure Vessel Code, Subsection NB “Quality Group B ” for Class 2 components Section III, Subsection NC “Quality Group C” for Class 3 components Section III, Subsection ND “Inservice Testing Requirements” for Class 1, 2, and 3 components of the ASME Code for Operation and Maintenance of Nuclear Power Plants (OM Code) “Inservice Inspection Requirements” for Class 1, 2, 3, MC (metal containment), and CC (concrete containment) components Section XI, “Rules for Inservice Inspection of Nuclear Power Plant Components”
ASME NUCLEAR CODE CASES NRC Regulatory Guides for 10 CFR 50.55(a): Regulatory Guide 1.84, “Design, Fabrication, and Materials Code Case Acceptability, ASME Section III” Regulatory Guide 1.147, “Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1” Regulatory Guide 1.192, “Operation and Maintenance Code Case Acceptability, ASME OM Code”
ROADMAP FINDINGS – CODE SECTION III Vendors have initiated discussions with Code Committees and NRC regarding potential issues Section III: Vendors believe SMR designs comply with requirements NRC could decide that certain Section III Code exceptions based on small size are not acceptable for certain unique aspects and safety functions of SMR designs, e.g.: Exemption for impact testing of small pipes and fittings Exemption for reactor coolant pressure boundary components whose break results in leakage within the capacity of the normal makeup system from meeting the requirements of Subsection NB (Class 1)
ROADMAP FINDINGS – SECTION XI (InService Inspection (ISI)) Potential Issues ISI exemptions for certain Class 1 small components ISI accessibility of NuScale reactor vessel with compact design IWE requirements for NuScale stainless clad steel containment not applicable – visual vs. ultrasound examinations Interior examination of reactor vessels and containment in iPWR design ISI interval requirements based on a 4-year fuel cycle (Code Cases initiated will resolve this issue)
ROADMAP FINDINGS – OM CODE Periodic testing requirements of NuScale ECCS valves that open to establish a natural circulation path to provide core cooling may require consideration by OM Committee
ROADMAP FINDINGS FOR SDOs SMRs are a global enterprise with potential for world-wide fleet deployment Effective licensing and deployment will benefit from international nuclear standards World-wide standards can be adopted by vendor and country of licensing origin and by country of deployment International collaboration on nuclear standards is an important safety and economic function