EN IEC 61226:2021
(Main)Nuclear power plants - Instrumentation, control and electrical power systems important to safety - Categorization of functions and classification of systems
Nuclear power plants - Instrumentation, control and electrical power systems important to safety - Categorization of functions and classification of systems
This document establishes, for nuclear power plants2, 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 document is applicable to: - the functions important to safety that are performed by I&C systems and supported by electrical power systems (categorization of I&C functions), - the I&C systems that enable those functions to be implemented (classification of I&C systems), - the electrical power systems that support those functions (classification of electrical power systems). The systems under consideration provide automated protection, closed or open loop control, information to the operating staff, and electrical power supply to systems. These systems keep the NPP conditions inside the safe operating envelope and provide automatic actions, or enable manual actions, that prevent or mitigate accidents, or that prevent or minimize radioactive releases to the site or wider environment. The I&C and electrical power systems that fulfil these roles safeguard the health and safety of the NPP operators and the public. This document follows the general principles given in IAEA Safety Requirement SSR-2/1 and Safety Guides SSG-30, SSG-34 and SSG-39, and it defines a structured method of applying the guidance contained in those codes and standards to the I&C and electrical power systems that perform functions important to safety in a NPP. This document is read in association with the IAEA guides together with IEC 61513 and IEC 63046 in implementing the requirements of the IEC 61508 series. The overall classification scheme of structures, systems and components for NPPs can be summarized as follows by Figure 1.
Kernkraftwerke - Leittechnische Systeme und elektrische Energieversorgungssysteme mit sicherheitstechnischer Bedeutung - Kategorisierung von Funktionen und Klassifizierung von Systemen
Centrales nucléaires de puissance – Systèmes d'instrumentation, de contrôle-commande et d'alimentation électrique importants pour la sûreté – Catégorisation des fonctions et classement des systèmes
l'IEC 61226:2020 établit, pour les centrales nucléaires de puissance , une méthode d'affectation en catégories des fonctions spécifiées pour la centrale, sur la base de leur importance pour la sûreté. Le classement, sur la base de la catégorie attribuée, des systèmes d'I&C et d'alimentation électrique assurant ou contribuant à la réalisation de ces fonctions détermine alors les critères de conception appropriés. Les critères de conception, dès lors qu'ils sont appliqués, garantissent que chaque fonction est réalisée selon son importance pour la sûreté. Les critères retenus dans le présent document concernent la fonctionnalité, la fiabilité, les performances, la qualification aux conditions environnementales (par exemple, la qualification sismique) et l'assurance qualité (AQ). Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: - l'alignement sur les exigences, les recommandations et la terminologie de l'AIEA, surtout la prise en compte du document SSR 2/1 (ayant remplacé le NS-R-1) et du guide SSG 30; - l'extension du domaine d'application aux systèmes d'alimentation électrique; - le déplacement des exigences détaillées applicables aux fonctions et aux systèmes d'I&C dans une annexe normative, qui sera supprimée à l'issue de la mise à jour de l'IEC 61513.
Jedrske elektrarne - Merilna, nadzorna in elektroenergetska oprema za zagotavljanje varnosti - Kategorizacija funkcij in klasifikacija sistemov (IEC 61226:2020)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2021
Nadomešča:
SIST EN 61226:2010
Jedrske elektrarne - Merilna, nadzorna in elektroenergetska oprema za
zagotavljanje varnosti - Kategorizacija funkcij in klasifikacija sistemov (IEC
61226:2020)
Nuclear power plants - Instrumentation, control and electrical power systems important
to safety - Categorization of functions and classification of systems (IEC 61226:2020)
Kernkraftwerke - Leittechnische Systeme und elektrische Energiesysteme mit
sicherheitstechnischer Bedeutung - Kategorisierung von Funktionen und Klassifizierung
von Systemen (IEC 61226:2020)
Centrales nucléaires de puissance - Systèmes d'instrumentation, de contrôle-commande
et d'alimentation électrique importants pour la sûreté - Catégorisation des fonctions et
classement des systèmes (IEC 61226:2020)
Ta slovenski standard je istoveten z: EN IEC 61226:2021
ICS:
27.120.20 Jedrske elektrarne. Varnost Nuclear power plants. Safety
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 61226
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2021
ICS 27.120.20 Supersedes EN 61226:2010 and all of its amendments
and corrigenda (if any)
English Version
Nuclear power plants - Instrumentation, control and electrical
power systems important to safety - Categorization of functions
and classification of systems
(IEC 61226:2020)
Centrales nucléaires de puissance - Systèmes Kernkraftwerke - Leittechnische Systeme und elektrische
d'instrumentation, de contrôle-commande et d'alimentation Energiesysteme mit sicherheitstechnischer Bedeutung -
électrique importants pour la sûreté - Catégorisation des Kategorisierung von Funktionen und Klassifizierung von
fonctions et classement des systèmes Systemen
(IEC 61226:2020) (IEC 61226:2020)
This European Standard was approved by CENELEC on 2021-07-05. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61226:2021 E
European foreword
This document (EN IEC 61226:2021) consists of the text of IEC 61226:2020 prepared by IEC/TC 45
"Nuclear instrumentation".
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-07-05
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-07-05
document have to be withdrawn
This document supersedes EN 61226:2010 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
As stated in the nuclear safety directive 2009/71/EURATOM, Chapter 1, Article 2, item 2, Member
States are not prevented from taking more stringent safety measures in the subject-matter covered by
the Directive, in compliance with Community law.
In a similar manner, this European standard does not prevent Member States from taking more
stringent nuclear safety and/or security measures in the subject-matter covered by this standard.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN and CENELEC
websites.
Endorsement notice
The text of the International Standard IEC 61226:2020 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60671:2007 NOTE Harmonized as EN 60671:2011 (not modified)
IEC 61508-1 NOTE Harmonized as EN 61508-1
IEC 61508-2 NOTE Harmonized as EN 61508-2
IEC 61508-3 NOTE Harmonized as EN 61508-3
IEC 61508-4 NOTE Harmonized as EN 61508-4
ISO/IEC 27001 NOTE Harmonized as EN ISO/IEC 27001
ISO/IEC 27002 NOTE Harmonized as EN ISO/IEC 27002
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60709 - Nuclear power plants - Instrumentation, EN IEC 60709 -
control and electrical power systems
important to safety - Separation
IEC 60812 - Failure modes and effects analysis (FMEA EN IEC 60812 -
and FMECA)
IEC 60880 - Nuclear power plants - Instrumentation and EN 60880 -
control systems important to safety -
Software aspects for computer-based
systems performing category A functions
IEC 60964 - Nuclear power plants - Control rooms - EN IEC 60964 -
Design
+EN IEC
60964:2019/AC:201
9-08
IEC 60965 - Nuclear power plants - Control rooms - EN 60965 -
Supplementary control room for reactor
shutdown without access to the main
control room
IEC/IEEE 60980-- Nuclear facilities - Equipment important to EN IEC/IEEE -
344 safety - Seismic qualification 60980-344
IEC 60987 - Nuclear power plants - Instrumentation and prEN IEC 60987 -
control important to safety - Hardware
requirements
IEC 61000-4 series Electromagnetic compatibility (EMC) -- PartE N 61000-4 series
4-1: Testing and measurement techniques
- Overview of IEC 61000-4 series
IEC 61500 - Nuclear power plants - Instrumentation and EN IEC 61500 -
control systems important to safety - Data
communication in systems performing
category A functions
Publication Year Title EN/HD Year
IEC 61513 2011 Nuclear power plants - Instrumentation and EN 61513 2013
control important to safety - General
requirements for systems
IEC 61771 - Nuclear power plants - Main control-room - - -
Verification and validation of design
IEC 61772 - Nuclear power plants - Control rooms - EN 61772 -
Application of visual display units (VDUs)
IEC 61839 - Nuclear power plants - Design of control EN 61839 -
rooms - Functional analysis and
assignment
IEC 62003 - Nuclear power plants - Instrumentation, EN IEC 62003 -
control and electrical power systems -
Requirements for electromagnetic
compatibility testing
IEC 62138 - Nuclear power plants - Instrumentation and EN IEC 62138 -
control systems important to safety -
Software aspects for computer-based
systems performing category B or C
functions
IEC 62566 - Nuclear power plants - Instrumentation and EN 62566 -
control important to safety - Development
of HDL-programmed integrated circuits for
systems performing category A functions
IEC 62645 - Nuclear power plants - Instrumentation, EN IEC 62645 -
control and electrical power systems -
Cybersecurity requirements
IEC 62671 - Nuclear power plants - Instrumentation and - -
control important to safety - Selection and
use of industrial digital devices of limited
functionality
IEC 62859 - Nuclear power plants - Instrumentation and EN IEC 62859 -
control systems - Requirements for
coordinating safety and cybersecurity
IEC 63046 - Nuclear power plants - Electrical power EN IEC 63046 -
system - General requirements
IAEA GSR Part 2 2016 Leadership and Management for Safety - -
IAEA SSG-30 2014 Safety Classification of Structures, - -
Systems and Components in Nuclear
Power Plants
IAEA SSR-2/12016 Safety of nuclear power plants: Design - -
(Rev.1)
IEC/IEEE 60780-- Nuclear facilities - Electrical equipment EN 60780-323 -
323 important to safety - Qualification
IEC 61226 ®
Edition 4.0 2020-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Nuclear power plants – Instrumentation, control and electrical power systems
important to safety – Categorization of functions and classification of systems
Centrales nucléaires de puissance – Systèmes d'instrumentation, de contrôle-
commande et d'alimentation électrique importants pour la sûreté –
Catégorisation des fonctions et classement des systèmes
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.120.20 ISBN 978-2-8322-7973-1
– 2 – IEC 61226:2020 IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 10
4 Abbreviated terms . 16
5 Categorization scheme . 16
5.1 General . 16
5.2 Background . 17
5.3 Description of categories . 17
5.3.1 General . 17
5.3.2 Category A . 19
5.3.3 Category B . 19
5.3.4 Category C . 19
5.4 Assignment criteria . 19
5.4.1 General . 19
5.4.2 Category A . 20
5.4.3 Category B . 20
5.4.4 Category C . 20
6 Categorization/classification procedure . 21
6.1 General . 21
6.2 Identification of anticipated operational occurrences (AOO), design basis
accidents (DBA) and design extension conditions (DEC) . 22
6.3 Identification and categorization of functions . 23
6.4 Classification of systems . 23
6.4.1 Classification of I&C systems . 23
6.4.2 Classification of electrical power systems . 25
7 Assignment of technical requirements to categories and classes . 25
Annex A (normative) Assignment of technical requirements to I&C systems . 28
A.1 General . 28
A.2 Requirements related to functions . 28
A.2.1 Basic requirements
...
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