IEC TR 61838:2001 Nuclear power plants - Instrumentation and control functions important for safety - Use of probabilistic safety assessment for the classification
This Technical Report provides a survey of some of the methods by which probabilistic risk assessment results can be used to establish "risk based" classification criteria, so as to allow FSEs to be placed within the four categories established within IEC 61226.
The application of risk based techniques, in conjunction with the consequence based classification approach given in IEC 61226, is currently decided by the utility and/or regulator within member Nations. In the absence of an internationally agreed approach, this should continue, but this Technical Report is intended to stimulate debate on this subject and encourage the convergence of views so that an IEC International Standard can be agreed.
The safety principles and the usefulness of a risk-based approach to classification are discussed and a description of four different approaches is presented.
In other respects, references are given in this report to IEC and IAEA documents which relate directly to the topic.
This report also discusses the limitations associated with the use of probabilistic safety assessment (PSA) techniques.
Guidance is given in annex A on modelling instrumentation and control functions for probabilistic risk assessment.
IEC TR 61838:2001 history
2009IEC TR 61838:2009 Centrales nucléaires de puissance – Instrumentation et contr?le-commande importants pour la s?reté – Utilisation des évaluations probabilistes de s?reté pour le classement des fonctions (Edition 2.0)
2001IEC TR 61838:2001 Nuclear power plants - Instrumentation and control functions important for safety - Use of probabilistic safety assessment for the classification