The regulatory requirement to develop an upgraded safety basis for a DOE nuclear facility was realized in January 2001 by issuance of a revision to Title 10 of the Code of Federal Regulations Section 830 (10 CFR 830).1 Subpart B of 10 CFR 830, "Safety Basis Requirements," requires acontractor responsible for a DOE Hazard Category 1, 2, or 3 nuclear facility to either submit by April 9, 2001 the existing safety basis which already meets the requirements of Subpart B, or to submit by April 10, 2003 an upgraded facility safety basis that meets the revised requirements.110 CFR 830 identifies Nuclear Regulatory Commission (NRC) Regulatory Guide 1.70, "Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants"2 as a safe harbor methodology for preparation of a DOE reactor documented safety analysis (DSA). The regulation also allows for use of a graded approach. This report presents the methodology thatwas developed for preparing the reactor accident analysis portion of the Advanced Test Reactor Critical Facility (ATRC) upgraded DSA. The methodology was approved by DOE for developing the ATRC safety basis as an appropriate application of a graded approach to the requirements of 10 CFR 830.

This book captures the principles of safety evaluation as practiced in the regulated light-water reactor nuclear industry, as established and stabilized over the last 30 years. It is expected to serve both the current industry and those planning for the future. The work's coverage of the subject matter is the broadest to date, including not only the common topics of modeling and simulation, but also methods supporting the basis for the underlying assumptions, the extension to radiological safety, what to expect in a licensing review, historical perspectives and the implication for new designs.This text is an essential resource for practitioners and students, on the current best-practices in nuclear power plant safety and their basis. Contributors of this work are subject matter experts in their specialties, much of which was nurtured and inspired by Prof. Larry Hochreiter, a prominent nuclear safety pioneer.Related Link(s)

This publication complements Safety Report No. 23, Accident Analysis for Nuclear Power Plants, and presents additional guidance for specific application of advanced computer codes in accident analysis needed for the safety analysis reports. It provides an overview of presently available advanced computer codes for various technical disciplines relevant to reactor accidents and discusses the applciation of such codes for various categories of accidents.

This Safety Guide provides recommendations on the safety assessment for research reactors in the authorization process, and on performance of safety analysis and preparation of the safety analysis report. It also incorporates the relevant lessons learned from the accident at the Fukushima Daiichi nuclear power plant and elaborates guidance on interfaces between nuclear safety and nuclear security. The recommendations in this Safety Guide are intended for operating organizations of research reactors; it can also be used by designers performing a safety assessment for a research reactor. Furthermore, this guide provides useful guidance for regulatory bodies performing a review and assessment of submitted safety analysis reports as an important document within authorization process. This Safety Guide is a revision of IAEA Safety Standards Series No. SSG-20, which it supersedes.

The Advanced Test Reactor (ATR), located at the Idaho National Engineering and Environmental Laboratory (INEEL), was specifically designed to provide a high neutron flux test environment for conducting a variety of experiments. This paper addresses the safety assurance process for two general types of experiments conducted in the ATR facility and how the safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore, this type of experiment is addressed in more detail in the ATR safety basis. This allows the individual safety analysis for this type of experiment to be more standardized. The second type of experiment is defined in more general terms in the ATR safety basis and is permitted under more general controls. Therefore, the individual safety analysis for the second type of experiment tends to be more unique and is tailored to each experiment.