IEC 61226:2009

Nuclear power plants - Instrumentation and control important to safety - Classification of instrumentation and control functions

IEC 61226:2009 establishes a method of classification of the information and command functions for nuclear power plants, and the instrumentation and control systems and equipment that provide those functions, into categories that designate the importance to safety of the function. The resulting classification then determines relevant design criteria. Is applicable to all the information and command functions and the instrumentation and control systems and equipment that provide those functions. The main changes with respect to the previous edition are listed below:
- to introduce a definition for "non-hazardous stable state";
- to clarify limits of categories;
- to clarify requirements related to equipment used for beyond design events.

Centrales nucléaires de puissance - Instrumentation et contrôle-commande importants pour la sûreté - Classement des fonctions d'instrumentation et de contrôle-commande

La CEI 61226:2009 établit une méthode de classement des fonctions d'information et de commande des centrales nucléaires de puissance et des systèmes d'instrumentation et de contrôle-commande (I&C) et matériels qui assurent ces fonctions en catégories indiquant l'importance pour la sûreté de la fonction. Le classement qui en résulte permet alors de déterminer les critères de conception appropriés. Est applicable à toutes les fonctions d'information et de commande, à tous les systèmes d'I&C et les matériels supports de ces fonctions. Les modifications techniques majeures par rapport à l'édition précédente sont les suivantes:
- introduction d'une définition pour "état contrôlé";
- clarification des limites des catégories;
- clarification des exigences portant sur les matériels utilisés hors dimensionnement.

General Information

• Status: Published
• Publication Date: 07-Jul-2009
• ICS: 27.120.20 - Nuclear power plants. Safety
• Technical Committee: SC 45A - Instrumentation, control and electrical power systems of nuclear facilities
• Drafting Committee: WG 7 - TC 45/SC 45A/WG 7
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 29-Apr-2020

Relations

• Revises: IEC 61226:2005 - Nuclear power plants - Instrumentation and control systems important to safety - Classification of instrumentation and control functions
• Effective Date: 05-Sep-2023
• Revised: IEC 61226:2020 - Nuclear power plants - Instrumentation, control and electrical power systems important to safety - Categorization of functions and classification of systems
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61226 ®
Edition 3.0 2009-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety –
Classification of instrumentation and control functions

Centrales nucléaires de puissance – Instrumentation et contrôle-commande
importants pour la sûreté – Classement des fonctions d’instrumentation et de
contrôle-commande
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IEC 61226 ®
Edition 3.0 2009-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety –
Classification of instrumentation and control functions

Centrales nucléaires de puissance – Instrumentation et contrôle-commande
importants pour la sûreté – Classement des fonctions d’instrumentation et de
contrôle-commande
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
V
CODE PRIX
ICS 27.120.20 ISBN 978-2-88910-448-2
– 2 – 61226 © IEC:2009
CONTENTS
FOREWORD.3

INTRODUCTION.5

1 Scope.8

2 Normative references .8

3 Terms and definitions .9

4 Abbreviations .13

5 Classification scheme.13

5.1 General .13
5.2 Background .14
5.3 Description of categories.14
5.3.1 General .14
5.3.2 Category A .15
5.3.3 Category B .15
5.3.4 Category C .15
5.4 Assignment criteria.16
5.4.1 General .16
5.4.2 Category A .16
5.4.3 Category B .16
5.4.4 Category C .17
6 Classification procedure .17
6.1 General .17
6.2 Identification of design basis .18
6.3 Identification and classification of functions.18
7 Assignment of technical requirements to categories .21
7.1 General requirements.21
7.2 Requirements related to functions .21
7.2.1 Basic requirements.21
7.2.2 Specific requirements .22
7.3 Requirements related to I&C systems.22
7.3.1 Basic requirements.22
7.3.2 Specific requirements .23
7.4 Requirements related to equipment .25

7.4.1 Basic requirements.25
7.4.2 Specific requirements .25
7.5 Requirements related to quality aspects .26
7.5.1 Basic requirements.26
7.5.2 Specific requirements .26
Annex A (informative) Examples of categories .30
Bibliography.32

Figure 1 – Method of classification.20

Table 1 – Tabular correlation between categories and other IEC standards .29

61226 © IEC:2009 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL IMPORTANT TO SAFETY –

CLASSIFICATION OF INSTRUMENTATION AND CONTROL FUNCTIONS

FOREWORD
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International Standard IEC 61226 has been prepared by subcommittee 45A: Instrumentation
and control of nuclear facilities, of IEC technical committee 45: Nuclear instrumentation.

This third edition cancels and replaces the second edition published in 2005 and constitutes a
technical revision. The main changes with respect to the previous edition are listed below:
• to introduce a definition for “non-hazardous stable state”;
• to clarify limits of categories;
• to clarify requirements related to equipment used for beyond design events.

– 4 – 61226 © IEC:2009
The text of this standard is based on the following documents:

FDIS Report on voting
45A/745/FDIS 45A/767/RVD
Full information on the voting for the approval of this standard
...