Nuclear power plants - Electrical power system - General requirements (IEC 63046:2020)

This document:
• provides requirements and recommendations for the overall Electrical Power System. In
particular, it covers interruptible and uninterruptible Electrical Power Systems including
the systems supplying the I&C systems;
• is consistent and coherent with IEC 61513. Like IEC 61513, this document also highlights
the need for complete and precise requirements, derived from the plant safety goals.
Those requirements are prerequisites for generating the comprehensive requirements for
the overall Electrical Power System architecture, and for the electrical power supply subsystems;
• has to be considered in conjunction with and at the same level as IEC 61513. These two
standards provide a complete framework establishing general requirements for
instrumentation, control, and Electrical Power System for Nuclear Power Plants.
This document establishes:
• the high level specification and requirement to implement a suitable Electrical Power
System in a NPP that supports reactor systems important to safety. It also enables
electrical energy production providing the transmission grid with active and reactive power
and electro-mechanical inertia;
• the relationships between:
– the plant safety requirements and the architecture of the overall Electrical Power
System and its sub-systems (see Figure 1) including:
a) the contribution to the plant Defence in Depth;
b) the independency and redundancy provisions;
– the electrical requirements and the architecture of the Electrical Power System and its
sub-systems;
– the functional requirements and the architecture of the Electrical Power System and its
sub-systems;
– the requirements associated with the maintenance strategy and the architecture of the
Electrical Power System and its sub-systems;
• the design of Electrical power sub-systems (e.g. interruptible and uninterruptible);
• the requirements for supporting systems of Electrical Power System (HVAC, I&C, etc.);
• the Electrical Power System life-cycle framework.
This document does not cover the specification of:
• I&C systems;
• the transmission lines connecting to substations outside the NPP;
• electrical equipment requirements already defined in the industrial IEC standards;
• electrical power for security systems (e.g., fences, surveillance systems, entrance
control);
• lighting and socket facility.
This document does not consider power production requirements.

Kernkraftwerke - Elektrische Stromversorgungssysteme - Allgemeine Anforderungen (IEC 63046:2020)

Centrales nucléaires de puissance - Système d'alimentation électrique - Exigences générales (IEC 63046:2020)

l'IEC 63046:2020 fournit des exigences et des recommandations pour l'ensemble du système d'alimentation électrique. Il couvre en particulier les systèmes d'alimentation électrique interruptibles et sans interruption, y compris les systèmes alimentant les systèmes d'I&C. Le présent document est en conformité et cohérence avec l'IEC 61513. Tout comme l'IEC 61513, le présent document souligne également la nécessité de disposer d'exigences complètes et précises, issues des objectifs de sûreté de la centrale. Ces exigences constituent les conditions préalables à l'établissement des exigences relatives à l'architecture d'ensemble du système d'alimentation électrique, puis à l'établissement de celles portant sur les sous-systèmes d'alimentation électrique. Le présent document établit la spécification et les exigences de haut niveau pour la mise en œuvre d'un système d'alimentation électrique approprié dans une CNP, système qui est le support des systèmes importants pour la sûreté des réacteurs. Il permet également la production d'énergie électrique, fournissant la puissance active et réactive et l'inertie électromécanique du réseau de distribution.

Jedrske elektrarne - Elektroenergetski sistemi - Splošne zahteve (IEC 63046:2020)

General Information

Status
Published
Public Enquiry End Date
28-Feb-2021
Publication Date
09-Jun-2021
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
04-Jun-2021
Due Date
09-Aug-2021
Completion Date
10-Jun-2021

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SLOVENSKI STANDARD
SIST EN IEC 63046:2021
01-julij-2021
Jedrske elektrarne - Elektroenergetski sistemi - Splošne zahteve (IEC 63046:2020)
Nuclear power plants - Electrical power system - General requirements (IEC
63046:2020)
Kernkraftwerke - Elektrische Stromversorgungssysteme - Allgemeine Anforderungen
(IEC 63046:2020)
Centrales nucléaires de puissance - Système d'alimentation électrique - Exigences
générales (IEC 63046:2020)
Ta slovenski standard je istoveten z: EN IEC 63046:2021
ICS:
27.120.20 Jedrske elektrarne. Varnost Nuclear power plants. Safety
SIST EN IEC 63046:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 63046:2021

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SIST EN IEC 63046:2021


EUROPEAN STANDARD EN IEC 63046

NORME EUROPÉENNE

EUROPÄISCHE NORM
May 2021
ICS 27.120.20

English Version
Nuclear power plants - Electrical power system - General
requirements
(IEC 63046:2020)
Centrales nucléaires de puissance - Système d'alimentation Kernkraftwerke - Elektrische Stromversorgungssysteme -
électrique - Exigences générales Allgemeine Anforderungen
(IEC 63046:2020) (IEC 63046:2020)
This European Standard was approved by CENELEC on 2021-05-17. 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 63046:2021 E

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SIST EN IEC 63046:2021
EN IEC 63046:2021 (E)
European foreword
The text of document 45A/1348/FDIS, future edition 1 of IEC 63046, prepared by SC 45A
"Instrumentation, control and electrical power systems of nuclear facilities" of IEC/TC 45 "Nuclear
instrumentation" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN IEC 63046:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-02-17
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-05-17
document have to be withdrawn
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.
Endorsement notice
The text of the International Standard IEC 63046:2020 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 60364-5-52 NOTE Harmonized as HD 60364-5-52
IEC 60880 NOTE Harmonized as EN 60880
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
IEC 62003 NOTE Harmonized as EN IEC 62003
IEC 62040-3 NOTE Harmonized as EN 62040-3
IEC 62138 NOTE Harmonized as EN IEC 62138
IEC 62271-200 NOTE Harmonized as EN 62271-200
IEC 62305-1 NOTE Harmonized as EN 62305-1
IEC 62305-3 NOTE Harmonized as EN 62305-3
IEC 62305-4 NOTE Harmonized as EN 62305-4
IEC 62340 NOTE Harmonized as EN 62340
IEC 62566 NOTE Harmonized as EN 62566
IEC 62645 NOTE Harmonized as EN IEC 62645
ISO/IEC 27001 NOTE Harmonized as EN ISO/IEC 27001
ISO/IEC 27002 NOTE Harmonized as EN ISO/IEC 27002
ISO 9000 NOTE Harmonized as EN ISO 9000
2

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SIST EN IEC 63046:2021
EN IEC 63046:2021 (E)
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 60038 (mod) 2009 IEC standard voltages EN 60038 2011
IEC 60671 -  Nuclear power plants - Instrumentation and EN 60671 -
control systems important to safety -
Surveillance testing
IEC 60709 2018 Nuclear power plants - Instrumentation, EN IEC 60709 2019
control and electrical power systems
important to safety - Separation
IEC 60964 2018 Nuclear power plants - Control rooms - EN IEC 60964 2019
Design
  +EN IEC
60964:2019/AC:201
9-08
IEC 61225 -  Nuclear power plants - Instrumentation, EN IEC 61225 -
control and electrical power systems -
Requirements for static uninterruptible DC
and AC power supply systems
IEC 61226 -  Nuclear power plants - Instrumentation and EN 61226 -
control important to safety - Classification
of instrumentation and control functions
IEC 61513 2011 Nuclear power plants - Instrumentation and EN 61513 2013
control important to safety - General
requirements for systems
IEC 62671 -  Nuclear power plants - Instrumentation and - -
control important to safety - Selection and
use of industrial digital devices of limited
functionality
IEC 62808 -  Nuclear power plants - Instrumentation and EN 62808 -
control systems important to safety -
Design and qualification of isolation
devices
IEC 62855 2016 Nuclear power plants - Electrical power prEN IEC 62855 2021
systems - Electrical power systems
analysis
3

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SIST EN IEC 63046:2021
EN IEC 63046:2021 (E)
Publication Year Title EN/HD Year
IEC 62859 -  Nuclear power plants - Instrumentation and EN 62859 -
control systems - Requirements for
coordinating safety and cybersecurity
ISO 9001  Quality management systems - EN ISO 9001 2015
Requirements
IEC/IEEE 60780--  Nuclear facilities - Electrical equipment EN 60780-323 -
323 important to safety - Qualification
IEC/IEEE 60980--  Nuclear facilities - Equipment important to EN IEC/IEEE-
344 safety - Seismic qualification 60980-344

4

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SIST EN IEC 63046:2021




IEC 63046

®


Edition 1.0 2020-10




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Nuclear power plants – Electrical power system – General requirements



Centrales nucléaires de puissance – Système d'alimentation électrique –

Exigences générales

















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.120.20 ISBN 978-2-8322-8817-7




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN IEC 63046:2021
– 2 – IEC 63046:2020 © IEC 2020
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
1.1 General . 9
1.2 Application: new and pre-existing plants . 11
1.3 Framework . 11
1.4 Interaction with level 2 standards . 11
2 Normative references . 13
3 Terms and definitions . 14
4 Abbreviated terms . 23
5 Overall Electrical Power System life cycle . 24
6 Architecture of Electrical Power System: identification of requirements. 25
6.1 Objectives . 25
6.2 Safety requirements applicable to the electrical architecture design . 26
6.2.1 Defence in Depth . 26
6.2.2 Application of Single Failure Criterion . 26
6.2.3 Management of the Common Cause Failure . 26
6.2.4 Loss Of Off-site Power conditions . 26
6.2.5 Station Black Out conditions . 27
6.2.6 Loss of Electrical Power conditions . 27
6.2.7 Application of internal and external Hazards . 27
6.2.8 Nuclear security requirements . 28
6.2.9 Classification requirements . 28
6.2.10 Probabilistic requirements . 28
6.3 Electrical requirements . 28
6.3.1 Requirements coordinated with the electric grid operator . 28
6.3.2 Electrical disturbances . 29
6.4 Functional performance requirements . 29
6.5 Maintenance requirements . 30
7 Design of the electrical architecture . 30
7.1 Objectives . 30
7.2 Safety design provision . 30
7.2.1 Defence in Depth in the Electrical Power System . 30
7.2.2 Single Failure in the Electrical Power System . 31
7.2.3 Common Cause Failure in the Electrical Power System . 31
7.2.4 Provisions for coping with Loss Of Off-site Power . 37
7.2.5 Provisions for coping with Station Black Out . 38
7.2.6 Provisions to avoid or reduce Loss of Electrical Power . 38
7.2.7 Classification consideration . 38
7.2.8 Provisions to achieve the reliability target for the Electrical Power System . 39
7.3 Electrical design provision . 40
7.3.1 General . 40
7.3.2 Coordination with the grid . 40
7.3.3 Design to achieve electrical requirements . 40
7.4 Functional and performance design provisions . 46
7.4.1 General . 46

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SIST EN IEC 63046:2021
IEC 63046:2020 © IEC 2020 – 3 –
7.4.2 Electrical Power System studies . 46
7.4.3 Design of the Interruptible Power Supply System . 49
7.4.4 Design of the Uninterruptible Power Supply System . 49
7.5 Maintenance . 50
7.5.1 Consideration of the maintenance in the electrical design . 50
7.6 Multi-unit shared electrical power systems . 51
7.7 Electrical system layout . 51
7.8 Supporting and associated systems for the Electrical Power System . 51
7.9 Overall quality assurance programs . 52
7.10 Requirements for output documentation . 53
7.10.1 General . 53
7.10.2 Architecture principles . 54
7.10.3 Single line diagrams . 55
8 Sub-system requirements . 55
8.1 Electrical Power System basis requirements . 55
8.1.1 General . 55
8.1.2 System Design . 56
8.1.3 Single line diagram . 56
8.2 Equipment design specification . 56
8.3 Equipment requirements . 56
8.4 AC Interruptible Electrical Power Supply System . 56
8.5 AC/DC Uninterruptible Power Supply System . 57
8.6 Coordination and interaction with power grid . 57
8.7 Earthing . 57
9 Verification of the architecture of the Electrical Power System . 57
9.1 General . 57
9.2 Computerised tools and models verification . 57
9.2.1 Electrical Power System verification . 57
9.2.2 Layout of electrical power systems and equipment verification . 57
9.3 Test requirements . 58
10 Overall integration and commissioning . 59
10.1 General . 59
10.2 Requirements . 59
10.3 Output documentation . 60
11 Overall operation and maintenance . 60
11.1 General . 60
11.2 Requirements . 60
11.3 Output documentation . 60
12 System quality assurance plan . 61
12.1 General . 61
12.2 System verification plan . 61
12.3 System configuration management plan . 62
12.4 Fault resolution procedures . 62
Annex A (informative) Basic safety issues in NPPs . 63
A.1 General . 63
A.2 Plant safety objectives . 63
A.3 Plant safety analysis . 63
A.3.1 General . 63

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SIST EN IEC 63046:2021
– 4 – IEC 63046:2020 © IEC 2020
A.3.2 Analysis of event sequences . 64
A.3.3 Assessment of design basis: deterministic/probabilistic methods . 64
A.4 Defence in Depth . 64
Annex B (informative) AC Interruptible Electrical Power System . 67
B.1 General . 67
B.2 Electrical design provisions . 67
B.2.1 Steady state conditions for Electrical Power System . 67
B.2.2 Electrical disturbances . 68
B.3 Design of the Interruptible power system . 71
B.3.1 Design of the preferred power supply . 71
B.3.2 Design of the off-site power supply . 71
B.3.3 Design of on-site preferred power supply . 72
B.3.4 Design of the AC interruptible power systems important to safety . 72
B.3.5 Design of internal standby sources . 72
B.4 Preferred power supply system (from IAEA SSG 34:2016, chapter 6, clauses

6.1 to 6.44) . 73
B.4.1 General . 73
B.4.2 Operation . 73
B.4.3 Grid interface and agreement with grid operator . 73
B.4.4 Reliability of the preferred power supply . 73
B.4.5 Off-site power supplies . 74
B.4.6 Availability . 75
B.4.7 Independence of off-site circuits . 75
B.4.8 Switchyard . 76
B.5 Safety power supply system supporting DBC . 76
B.5.1 General . 76
B.5.2 Design (from IAEA SSG 34:2016, chapter 7, clauses 7.36 to 7.63) . 77
B.5.3 Testing (from IAEA SSG 34:2016, chapter 7, clauses 7.64 to 7.67). 79
B.5.4 Performance criteria (transient and dynamic) (from IAEA SSG 34:2016,
chapter 7, clauses 7.68 to 7.70) . 79
B.5.5 Relay protection of standby power sources (from IAEA SSG 34:2016,
chapter 7, clauses 7.71 to 7.75) . 79
B.5.6 Support systems for standby AC power sources . 80
B.5.7 Fuel for standby AC power sources . 80
B.6 Power supply system important to safety supporting DEC . 80
B.6.1 General . 80
B.6.2 Design (from IAEA SSG 34:2016, chapter 8, clauses 8.1 to 8.18) . 81
B.7 Mobile sources connections network . 82
B.8 Monitoring and switching of buses . 82
Annex C (informative) Earthing . 84
Annex D (informative) Logic diagram followed for the design of the EPS . 85
Bibliography . 86

Figure 1 – Scope of work of this document. 10
Figure 2 – Architecture of Electrical Power System . 12
Figure 3 – Connections between the overall Electrical Power System life cycle and the
life cycles of the electrical power sub- systems . 25
Figure 4 – Typical voltage design bases (IEC 62855) . 43

Table A.1 – Support of the electrical power supply for the defence in depth of the plant . 66

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SIST EN IEC 63046:2021
IEC 63046:2020 © IEC 2020 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

NUCLEAR POWER PLANTS –
ELECTRICAL POWER SYSTEM –
GENERAL REQUIREMENTS

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 63046 has been prepared by subcommittee 45A: Instrumentation,
control and electrical power systems of nuclear facilities, of IEC technical committee 45:
Nuclear instrumentation.
The text of this International Standard is based on the following documents:
FDIS Report on voting
45A/1348/FDIS 45A/1355/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

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SIST EN IEC 63046:2021
– 6 – IEC 63046:2020 © IEC 2020
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://
...

SLOVENSKI STANDARD
oSIST prEN IEC 63046:2021
01-februar-2021
Jedrske elektrarne - Elektroenergetski sistemi - Splošne zahteve
Nuclear power plants - Electrical power system - General requirements
Kernkraftwerke - Elektrische Stromversorgungssysteme - Allgemeine Anforderungen
Centrales nucléaires de puissance - Système d'alimentation électrique - Exigences
générales
Ta slovenski standard je istoveten z: prEN IEC 63046
ICS:
27.120.20 Jedrske elektrarne. Varnost Nuclear power plants. Safety
oSIST prEN IEC 63046:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 63046:2021

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oSIST prEN IEC 63046:2021


EUROPEAN STANDARD DRAFT
prEN IEC 63046
NORME EUROPÉENNE

EUROPÄISCHE NORM

December 2020
ICS 27.120.20

English Version
Nuclear power plants - Electrical power system - General
requirements
(IEC 63046:2020)
Centrales nucléaires de puissance - Système d'alimentation Kernkraftwerke - Elektrische Stromversorgungssysteme -
électrique - Exigences générales Allgemeine Anforderungen
(IEC 63046:2020) (IEC 63046:2020)
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2021-03-12.

The text of this draft consists of the text of IEC 63046:2020.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CENELEC 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.


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
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 72883 Ref. No. prEN IEC 63046 E

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oSIST prEN IEC 63046:2021
prEN IEC 63046:2020 (E)
European foreword
This document (prEN IEC 63046:2020) consists of the text of IEC 63046:2020 prepared by
IEC/SC 45A "Instrumentation, control and electrical power systems of nuclear facilities", of IEC/TC 45
"Nuclear instrumentation".
This document is currently submitted to the Enquiry.
The following dates are proposed:
• latest date by which the existence of this document (doa) dor + 6 months
has to be announced at national level
• latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication of an
identical national standard or by endorsement
• latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to be withdrawn (to be confirmed or
modified when voting)
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.
2

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oSIST prEN IEC 63046:2021
prEN IEC 63046:2020 (E)
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 60038 (mod) 2009 IEC standard voltages EN 60038 2011
IEC 60671 - Nuclear power plants - Instrumentation and EN 60671 -
control systems important to safety -
Surveillance testing
IEC 60709 2018 Nuclear power plants – Instrumentation, control EN IEC 60709 2019
and electrical power systems important to
safety – Separation
IEC/IEEE 60780-323 - Nuclear facilities – Electrical equipment EN 60780-323 -
important safety – Qualification
IEC 60964 2018 Nuclear power plants - Control rooms - Design EN IEC 60964 2019
- -  AC 2019
IEC/IEEE 60980-344 - Nuclear facilities - Equipment important to - -
safety - Seismic qualification
IEC 61225 - Nuclear power plants - Instrumentation, control EN IEC 61225 -
and electrical power systems - Requirements
for static uninterruptible DC and AC power
supply systems
IEC 61226 2020 Nuclear power plants - Instrumentation and - -
control important to safety - Classification of
instrumentation and control functions
IEC 61513 2011 Nuclear power plants - Instrumentation and EN 61513 2013
control important to safety - General
requirements for systems
IEC 62671 - Nuclear power plants - Instrumentation and - -
control important to safety - Selection and use
of industrial digital devices of limited
functionality
IEC 62808 - Nuclear power plants – Instrumentation and EN 62808 -
control systems important to safety – Design
and qualification of isolation devices
IEC 62855 2016 Nuclear power plants - Electrical power - -
systems - Electrical power systems analysis
3

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prEN IEC 63046:2020 (E)
Publication Year Title EN/HD Year
IEC 62859 - Nuclear power plants – Instrumentation and - -
control systems – Requirements for
coordinating safety and cybersecurity
IEC 63272  Nuclear facilities – Electrical power systems –
AC interruptible power supply systems
ISO 9001 2015 Quality management systems – Requirements EN ISO 9001 2015
IAEA Safety Guide GS-G-3.1 2006 Application of the management System for - -
facilities and activities
IAEA GS-R, Part 2 2016 Leadership and Management for Safety - -
IAEA Safety Guide SSG-34 2016 Design of electrical power systems in Nuclear
Power Plants

4

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oSIST prEN IEC 63046:2021




IEC 63046

®


Edition 1.0 2020-10




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Nuclear power plants – Electrical power system – General requirements



Centrales nucléaires de puissance – Système d'alimentation électrique –

Exigences générales

















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.120.20 ISBN 978-2-8322-8817-7




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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oSIST prEN IEC 63046:2021
– 2 – IEC 63046:2020 © IEC 2020
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
1.1 General . 9
1.2 Application: new and pre-existing plants . 11
1.3 Framework . 11
1.4 Interaction with level 2 standards . 11
2 Normative references . 13
3 Terms and definitions . 14
4 Abbreviated terms . 23
5 Overall Electrical Power System life cycle . 24
6 Architecture of Electrical Power System: identification of requirements. 25
6.1 Objectives . 25
6.2 Safety requirements applicable to the electrical architecture design . 26
6.2.1 Defence in Depth . 26
6.2.2 Application of Single Failure Criterion . 26
6.2.3 Management of the Common Cause Failure . 26
6.2.4 Loss Of Off-site Power conditions . 26
6.2.5 Station Black Out conditions . 27
6.2.6 Loss of Electrical Power conditions . 27
6.2.7 Application of internal and external Hazards . 27
6.2.8 Nuclear security requirements . 28
6.2.9 Classification requirements . 28
6.2.10 Probabilistic requirements . 28
6.3 Electrical requirements . 28
6.3.1 Requirements coordinated with the electric grid operator . 28
6.3.2 Electrical disturbances . 29
6.4 Functional performance requirements . 29
6.5 Maintenance requirements . 30
7 Design of the electrical architecture . 30
7.1 Objectives . 30
7.2 Safety design provision . 30
7.2.1 Defence in Depth in the Electrical Power System . 30
7.2.2 Single Failure in the Electrical Power System . 31
7.2.3 Common Cause Failure in the Electrical Power System . 31
7.2.4 Provisions for coping with Loss Of Off-site Power . 37
7.2.5 Provisions for coping with Station Black Out . 38
7.2.6 Provisions to avoid or reduce Loss of Electrical Power . 38
7.2.7 Classification consideration . 38
7.2.8 Provisions to achieve the reliability target for the Electrical Power System . 39
7.3 Electrical design provision . 40
7.3.1 General . 40
7.3.2 Coordination with the grid . 40
7.3.3 Design to achieve electrical requirements . 40
7.4 Functional and performance design provisions . 46
7.4.1 General . 46

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7.4.2 Electrical Power System studies . 46
7.4.3 Design of the Interruptible Power Supply System . 49
7.4.4 Design of the Uninterruptible Power Supply System . 49
7.5 Maintenance . 50
7.5.1 Consideration of the maintenance in the electrical design . 50
7.6 Multi-unit shared electrical power systems . 51
7.7 Electrical system layout . 51
7.8 Supporting and associated systems for the Electrical Power System . 51
7.9 Overall quality assurance programs . 52
7.10 Requirements for output documentation . 53
7.10.1 General . 53
7.10.2 Architecture principles . 54
7.10.3 Single line diagrams . 55
8 Sub-system requirements . 55
8.1 Electrical Power System basis requirements . 55
8.1.1 General . 55
8.1.2 System Design . 56
8.1.3 Single line diagram . 56
8.2 Equipment design specification . 56
8.3 Equipment requirements . 56
8.4 AC Interruptible Electrical Power Supply System . 56
8.5 AC/DC Uninterruptible Power Supply System . 57
8.6 Coordination and interaction with power grid . 57
8.7 Earthing . 57
9 Verification of the architecture of the Electrical Power System . 57
9.1 General . 57
9.2 Computerised tools and models verification . 57
9.2.1 Electrical Power System verification . 57
9.2.2 Layout of electrical power systems and equipment verification . 57
9.3 Test requirements . 58
10 Overall integration and commissioning . 59
10.1 General . 59
10.2 Requirements . 59
10.3 Output documentation . 60
11 Overall operation and maintenance . 60
11.1 General . 60
11.2 Requirements . 60
11.3 Output documentation . 60
12 System quality assurance plan . 61
12.1 General . 61
12.2 System verification plan . 61
12.3 System configuration management plan . 62
12.4 Fault resolution procedures . 62
Annex A (informative) Basic safety issues in NPPs . 63
A.1 General . 63
A.2 Plant safety objectives . 63
A.3 Plant safety analysis . 63
A.3.1 General . 63

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A.3.2 Analysis of event sequences . 64
A.3.3 Assessment of design basis: deterministic/probabilistic methods . 64
A.4 Defence in Depth . 64
Annex B (informative) AC Interruptible Electrical Power System . 67
B.1 General . 67
B.2 Electrical design provisions . 67
B.2.1 Steady state conditions for Electrical Power System . 67
B.2.2 Electrical disturbances . 68
B.3 Design of the Interruptible power system . 71
B.3.1 Design of the preferred power supply . 71
B.3.2 Design of the off-site power supply . 71
B.3.3 Design of on-site preferred power supply . 72
B.3.4 Design of the AC interruptible power systems important to safety . 72
B.3.5 Design of internal standby sources . 72
B.4 Preferred power supply system (from IAEA SSG 34:2016, chapter 6, clauses

6.1 to 6.44) . 73
B.4.1 General . 73
B.4.2 Operation . 73
B.4.3 Grid interface and agreement with grid operator . 73
B.4.4 Reliability of the preferred power supply . 73
B.4.5 Off-site power supplies . 74
B.4.6 Availability . 75
B.4.7 Independence of off-site circuits . 75
B.4.8 Switchyard . 76
B.5 Safety power supply system supporting DBC . 76
B.5.1 General . 76
B.5.2 Design (from IAEA SSG 34:2016, chapter 7, clauses 7.36 to 7.63) . 77
B.5.3 Testing (from IAEA SSG 34:2016, chapter 7, clauses 7.64 to 7.67). 79
B.5.4 Performance criteria (transient and dynamic) (from IAEA SSG 34:2016,
chapter 7, clauses 7.68 to 7.70) . 79
B.5.5 Relay protection of standby power sources (from IAEA SSG 34:2016,
chapter 7, clauses 7.71 to 7.75) . 79
B.5.6 Support systems for standby AC power sources . 80
B.5.7 Fuel for standby AC power sources . 80
B.6 Power supply system important to safety supporting DEC . 80
B.6.1 General . 80
B.6.2 Design (from IAEA SSG 34:2016, chapter 8, clauses 8.1 to 8.18) . 81
B.7 Mobile sources connections network . 82
B.8 Monitoring and switching of buses . 82
Annex C (informative) Earthing . 84
Annex D (informative) Logic diagram followed for the design of the EPS . 85
Bibliography . 86

Figure 1 – Scope of work of this document. 10
Figure 2 – Architecture of Electrical Power System . 12
Figure 3 – Connections between the overall Electrical Power System life cycle and the
life cycles of the electrical power sub- systems . 25
Figure 4 – Typical voltage design bases (IEC 62855) . 43

Table A.1 – Support of the electrical power supply for the defence in depth of the plant . 66

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IEC 63046:2020 © IEC 2020 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

NUCLEAR POWER PLANTS –
ELECTRICAL POWER SYSTEM –
GENERAL REQUIREMENTS

FOREWORD
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 63046 has been prepared by subcommittee 45A: Instrumentation,
control and electrical power systems of nuclear facilities, of IEC technical committee 45:
Nuclear instrumentation.
The text of this International Standard is based on the following documents:
FDIS Report on voting
45A/1348/FDIS 45A/1355/RVD

Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

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The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.

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oSIST prEN IEC 6304
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