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
CFR Part: 
CFR Title: 

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f reviewed detailed analyses on the likelihood of a new volcano forming at the proposed repository site, and the potential consequences of that event on the performance of the proposed waste isolation system. The NRC staff determined that the risk from future volcanic activity was acceptable because (1) the likelihood of future volcanic events was low, (2) the amount of high-level waste that could be entrained and ejected during a volcanic eruption was small, and (3) the combination of natural and engineered barriers was sufficient to limit radionuclide release from damaged waste packages remaining in repository drifts after a volcanic event (NRC 2014c). These reviews demonstrate that a typical volcanic eruption produces a variety of potentially hazardous phenomena, many of which can affect a site simultaneously. Some of these phenomena, such as ash fall, can be mitigated through appropriate design and operational bases. Other phenomena, such as lava flows, present significant design and operational challenges to nuclear facilities. The rare occurrences of volcanic eruptions, and the diverse character of eruptive phenomena, can create significant uncertainties in a volcanic hazards analysis that must be evaluated in regulatory decision-making. The next sections of this guide develop the technical basis for an acceptable analysis of volcanic hazards for a proposed commercial nuclear reactor. Overview of Volcanic Hazards The International Atomic Energy Agency (IAEA) published IAEA-TECDOC-1795, “Volcanic Hazard Assessments for Nuclear Installations: Methods and Examples in Site Evaluation,” issued 2016, which includes a detailed discussion of volcanic phenomena and associated hazards for nuclear installations.1 This document was developed to support IAEA Specific Safety Guide (SSG)-21, “Volcanic Hazards in Site Evaluation for Nuclear Installations.” Although IAEA TECDOC 1795 was developed for the siting of nuclear installations, the NRC staff is focusing on the