Document: NRC Regulatory Guide
Document ID: 46b2c829-ce4c-4a6a-8a01-908725558ffe
Document Type: regulatory_guide
Title: Volcanic Hazards Assessment for Proposed Nuclear Power Reactor Sites + HISTORY - HISTORY 03/2020 – DG-4028-Proposed New Guide
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML2000/ML20007D621.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.26
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CFR Title: 

Content:
large source terms or design fragilities; potentially significant number of alternative hazard models available; moderate-to-low confidence in the completeness and accuracy of the geologic record; and complex, multi-hazard scenarios considered • Level 4: facility with potentially large source terms or design fragilities; significant number of alternative or potentially contradictory hazard models available; low confidence in the completeness and accuracy of the geologic record; and numerous complex, multi-hazard scenarios considered Harmonization with International Standards IAEA recognizes volcanic hazards as presenting potential challenges for the siting and operation of nuclear installations. As discussed in IAEA Safety Guide NS-G-1.5, “External Events Excluding Earthquakes in the Design of Nuclear Power Plants,” issued 2003, some nuclear installations located in volcanic terranes likely would need to consider volcanic hazards as potential design-basis events if such hazards at the site did not preclude development of the installation (IAEA, 2003). Consideration of volcanic hazards also is a specific site requirement in IAEA Specific Safety Requirement (SSR)-1, “Site Evaluation for Nuclear Installations,” issued 2019, which indicates that a potential site would be unsuitable if volcanic hazards could not be accommodated within a proposed installation’s design basis (IAEA, 2019b). IAEA Specific Safety Guide (SSG)-18, “Meteorological and Hydrological Hazards in site Evaluation for Nuclear Installations,” issued 2011, also recognizes that volcanic activity can initiate land movements that trigger floods, tsunamis, and seiches (IAEA, 2011). Although these IAEA guidance documents recognize the need for the evaluation of potential volcanic hazards, they do not provide specific guidance on the conduct of a volcanic hazards assessment or criteria to evaluate the significance of potential volcanic hazards. IAEA SSG-21, “Volcanic Hazards in Site