IEC 61226:2020 establishes, for nuclear power plants , a method of assignment of the functions specified for the plant into categories according to their importance to safety. Subsequent classification of the I&C and electrical power systems performing or supporting these functions, based on the assigned category, then determines relevant design criteria. The design criteria, when applied, ensure the achievement of each function in accordance to its importance to safety. In this document, the criteria are those of functionality, reliability, performance, environmental qualification (e.g. seismic) and quality assurance (QA). This edition includes the following significant technical changes with respect to the previous edition: – to align on IAEA requirements, recommendations and terminology, particularly to take into account the replacement of NS-R-1 by SSR 2\/1 and publication of SSG 30; – to extend the scope to electrical power systems; – to move the detailed requirements applying to functions and I&C systems to a normative annex, which will be removed after updating IEC 61513.<\/p>\n
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| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 1 Scope <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 2 Normative references Figure 1 \u2013 Overall classification scheme <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 4 Abbreviated terms 5 Categorization scheme 5.1 General <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 5.2 Background 5.3 Description of categories 5.3.1 General <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5.3.2 Category A 5.3.3 Category B 5.3.4 Category C 5.4 Assignment criteria 5.4.1 General <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.4.2 Category A 5.4.3 Category B 5.4.4 Category C <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 6 Categorization\/classification procedure 6.1 General <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 6.2 Identification of anticipated operational occurrences (AOO), design basis accidents (DBA) and design extension conditions (DEC) Figure 2 \u2013 Method of categorization of functions and classification of I&C systems <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 6.3 Identification and categorization of functions 6.4 Classification of systems 6.4.1 Classification of I&C systems <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Table 1 \u2013 Correlation between classes of systems and categories of functions <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 6.4.2 Classification of electrical power systems 7 Assignment of technical requirements to categories and classes Figure 3 \u2013 Method of classification of electrical power systems <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Table 2 \u2013 Tabular correlation between classes and other IEC standards <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annex A (normative) Assignment of technical requirements to I&C systems A.1 General A.2 Requirements related to functions A.2.1 Basic requirements A.2.2 Specific requirements <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | A.3 Requirements related to systems A.3.1 Basic requirements <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | A.3.2 Specific requirements <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | A.4 Requirements related to equipment qualification A.4.1 Basic requirements A.4.2 Specific requirements <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | A.5 Requirements related to quality aspects A.5.1 Basic requirements <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | A.5.2 Specific requirements <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Annex B (informative) Examples of categories and classes B.1 General B.2 Category A\/Class 1 B.2.1 Typical functions B.2.2 Typical I&C systems B.2.3 Typical electrical power systems B.3 Category B\/Class 2 B.3.1 Typical functions <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | B.3.2 Typical I&C systems B.3.3 Typical electrical power systems B.4 Category C\/Class 3 B.4.1 Typical functions B.4.2 Typical I&C and electrical power systems <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Nuclear power plants. Instrumentation, control and electrical power systems important to safety. Categorization of functions and classification of systems<\/b><\/p>\n |