On the methodology of the event tree analysis used for safety probabilistic study of Angra-1
- 1. Rio de Janeiro Univ. (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia
Description
In the context of the probabilistic safety analysis for the Angra I nuclear plant, which has resulted from the joint effort by CNEN, Furnas and COPPE/UFRJ, 11 initiating events have been identified for analysis, in order to evaluate the plant core-degradating frequency. As thousands of accident sequences had to be identified and evaluated, a computer code had to be developed so as to furnish all the relevant results in an efficient and quick fashion. The concept employed has been the 'great event trees/small fault trees' one, so that event trees with boundary conditions have been used which were developed from the ideas of support systems (e.g., electric power), front-line systems (e.g., containment fan cooler system) and impact vectors, which assess the impacts induced on the front-line systems by the failure-success combinations of the support systems. The results obtained for the small-break LOCA initiator are presented as an illustrative example. (Author)
Abstract (Portuguese)
No contexto do estudo probabilistico da seguranca de Angra 1, resultante do esforco conjunto da CNEN, Furnas e COPPE/UFRJ, percebeu-se a necessidade de analisar 11 eventos iniciadores para avaliar a frequencia de degradacao do nucleo da central. A identificacao das milhares de sequencias pertinentes levou-nos a tarefa de desenvolver software adequado para obter de maneira rapida e eficiente todos os resultados de interesse. A filosofia empregada para tal foi a de 'grandes arvores de eventos/pequenas arvores de falhas', o que nos conduziu a manipulacao de arvores de eventos com condicoes de contorno para sistemas de suporte (e.g., potencia eletrica), sistemas de linha de frente (e.g., sistema de ventiladores da contencao) e vetores de impacto, que avaliam os impactos provocados nos sistemas de linha de frente pelas varias combinacoes de estados dos sistemas de suporte (falhas e sucessos totais e/ou parciais). Como exemplo ilustrativo, apresentamos os resultados obtidos para a arvore de eventos do iniciador 'pequeno LOCA'. (Autor)Additional details
Additional titles
- Original title (Portuguese)
- Sobre a metodologia de analise de arvores de eventos utilizada no estudo probabilistico da seguranca de Angra 1
Publishing Information
- Imprint Title
- Proceedings of the 1. General Congress of Nuclear Energy. v. 1
- Imprint Pagination
- 430 p.
- Journal Page Range
- v. 1 p. 53-57.
- Report number
- INIS-BR--537(v.1)
Conference
- Title
- 1. General Congress of Nuclear Energy.
- Dates
- 17-20 Mar 1986.
- Place
- Rio de Janeiro, RJ (Brazil).
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 17069462
- Subject category
- S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- ANGRA-1 REACTOR; E CODES; FAULT TREE ANALYSIS; LOSS OF COOLANT; REACTOR SAFETY; RISK ASSESSMENT
- Descriptors DEC
- ACCIDENTS; COMPUTER CODES; ENRICHED URANIUM REACTORS; POWER REACTORS; PWR TYPE REACTORS; REACTOR ACCIDENTS; REACTORS; SAFETY; SYSTEM FAILURE ANALYSIS; SYSTEMS ANALYSIS; THERMAL REACTORS; WATER COOLED REACTORS; WATER MODERATED REACTORS
Optional Information
- Notes
- Imprint:Anais do 1. Congresso Geral de Energia Nuclear. v. 1.