Evaluation of “Safety Related” and “Important to Safety” terminology for safety classification of nuclear installation items in Brazil
DOI:
https://doi.org/10.15392/2319-0612.2022.1960Keywords:
Safety Related, Important to Safety, Nuclear Safety ClassificationAbstract
In general terms, safety demonstration of nuclear installations is carried out through an assessment of compliance with design criteria and safety requirements established in national and international codes and standards applicable to each type of installation. In addition, a safety analysis consisting of installation behavior study during its useful lifetime, shall be developed considering normal operating conditions, transients, and postulated accidents, to determine safety margins and verify the adequacy of items designed to prevent accidents or mitigate their consequences. Also, design requirements applicable to each installation item depend on its classification with respect to safety. Thus, safety classification of structures, systems, and components (SSCs) must be performed based on adequate methods and clear and consistent criteria to ensure that an overall safety level expected for the installation is achieved. It is worth emphasizing the importance of the terminology adopted and the understanding of concepts definitions used in a safety classification process. The objective of this paper is to present a review of the application of “safety related item” and “item important to safety” terminology, evaluating definitions and interpretations given by the International Atomic Energy Agency (IAEA), the United States Nuclear Regulatory Commission (U.S.NRC) and the National Nuclear Energy Commission (CNEN) of Brazil. In this work, this subject is raised to demonstrate that divergent definitions and misinterpretations of concepts may result in inconsistencies in SSCs safety classification.
- Views: 205
- PDF Downloads: 144
Downloads
References
UNITED STATES NUCLEAR REGULATORY COMMISSION. 10 CFR 50.69 - Risk Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors. Available on: <https://www.nrc.gov/docs/ML0414/ML041470460.pdf>. Accessed on June 15, 2021.
INTERNATIONAL ATOMIC ENERGY AGENCY. Safety Glossary: 2018 Edition. Viena: IAEA, 2018.
COMISSÃO NACIONAL DE ENERGIA NUCLEAR. Glossário do Setor Nuclear e Radiológico Brasileiro. Rio de Janeiro: CNEN, 2021.
COMISSÃO NACIONAL DE ENERGIA NUCLEAR. Modelo Padrão para Relatório de Análise de Segurança de Usinas de Produção de Hexafluoreto de Urânio Natural. Rio de Janeiro: CNEN, 2012 (CNEN NE 1.11 / Resolução CNEN 178/14).
COMISSÃO NACIONAL DE ENERGIA NUCLEAR. Modelo Padrão para Relatório de Análise de Segurança de Usinas de Reprocessamento de Combustíveis Nucleares. Rio de Janeiro: CNEN, 1980 (CNEN NE 1.08 / Resolução CNEN 16/79).
COMISSÃO NACIONAL DE ENERGIA NUCLEAR. Modelo Padrão para Relatório de Análise de Segurança de Fábrica de Elementos Combustíveis. Rio de Janeiro: CNEN, 1980 (CNEN NE 1.09 /Resolução CNEN 06/80)
UNITED STATES NUCLEAR REGULATORY COMMISSION. 10 CFR 50.2 – Definitions. Washington DC: U.S.NRC, 2021.
UNITED STATES NUCLEAR REGULATORY COMMISSION. Appendix A to Part 50 – General Design Criteria for Nuclear Power Plants. Washington DC: U.S.NRC, 2021.
UNITED STATES NUCLEAR REGULATORY COMMISSION. Generic Letter 1984-001 – NRC Use of Terms “Important to Safety” and “Safety Related”. Available on: <https://www.nrc.gov/docs/ML0311/ML031150515.pdf>. Accessed on June 15, 2021.
Richard W. McNally. Special Treatment For Important To Safety Structures, Systems And Components (SSCs) In The Licensing Of Light Water Reactors. Proceedings of ICAPP, paper 8325, 2008.
UNITED STATES NUCLEAR REGULATORY COMMISSION. SECY-86-164 – Proposed Rule on the Important to Safety Issue. Available on: <https://www.nrc.gov/docs/ML1532/ML15322A005.pdf >. Accessed on June 15, 2021.
World Nuclear Association. Safety Classification for I&C Systems in NPP – Current Status & Difficulties (Report nº 2015/008). Londres: WNA, 2015.
Stanislav Rudakov, Charles E. Dickerson. Harmonization of IEEE 1012 and IEC 60880 standards regarding verification and validation of nuclear power plant safety systems software using model-based methodology. Progress in Nuclear Energy, vol. 99, p. 86-95, 2017. DOI: https://doi.org/10.1016/j.pnucene.2017.04.003
Suqiang Xu, Andrei Blahoianu, and Gerry Frappier. A Comparison of Safety Classification Terminology for Nuclear Power Plants. The 19th Pacific Basin Nuclear Conference, p. 24-28, 2014.
UNITED STATES NUCLEAR REGULATORY COMMISSION. Request for Rulemaking – Defining “Important to Safety”. Available on: <https://www.nrc.gov/docs/ML1521/ML15210A776.pdf>. Accessed on June 15, 2021.
ELECTRIC POWER RESEARCH INSTITUTE. Guidelines for the Safety Classification of Systems, Components, and Parts Used in Nuclear Power Plant Applications (NCIG-17). Chicago: EPRI, 1991 (NP-6895).
COMISSÃO NACIONAL DE ENERGIA NUCLEAR. Licenciamento de Instalações Nucleares. Rio de Janeiro: CNEN, 2002 (CNEN NE 1.04 / Resolução CNEN 15/02).
Published
How to Cite
Issue
Section
License
Copyright (c) 2022 Brazilian Journal of Radiation Sciences
This work is licensed under a Creative Commons Attribution 4.0 International License.
Licensing: The BJRS articles are licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
