IEC TR 63400:2025

IEC TR 63400 ®
Edition 2.0 2025-12
TECHNICAL
REPORT
Nuclear facilities - Instrumentation, control and electrical power systems
important to safety - Structure of the IEC SC 45A standards series

ICS 27.120.20  ISBN 978-2-8327-0760-9

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CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Abbreviated terms . 11
5 IEC SC 45A scope . 12
5.1 Technical scope . 12
5.2 Relationship with other standards bodies . 13
5.2.1 General . 13
5.2.2 Internal IEC liaisons . 13
5.2.3 Liaison with IAEA . 13
5.2.4 Liaison with IEEE NPEC . 13
5.3 Criteria for development of SC 45A standards . 14
5.4 IEC SC 45A terminology policy . 14
6 IEC SC 45A standards structure . 15
6.1 Details of the basic structure . 15
6.2 Technical coverage . 15
6.3 Hierarchy of levels . 16
6.3.1 General . 16
6.3.2 Level 1 (L1) . 16
6.3.3 Level 2 (L2) . 16
6.3.4 Level 3 (L3) . 17
6.3.5 Level 4 (L4) . 17
6.4 Broad topic areas . 17
6.4.1 General . 17
6.4.2 I&C architecture and specifics of I&C (Topic 01) . 18
6.4.3 Electrical power system architecture and specifics of electrics
(Topic 02) . 18
6.4.4 Safety fundamentals (Topic 11) . 18
6.4.5 Equipment qualification and system performance (Topic 12) . 18
6.4.6 Human factors engineering (HFE) (Topic 13) . 19
6.4.7 Cybersecurity (Topic 14) . 19
6.4.8 Ageing management (Topic 15) . 19
6.4.9 Control rooms and human machine interfaces (HMI) (Topic 21) . 19
6.4.10 Sensors and measurement techniques (Topic 22) . 20
6.4.11 Special process measurement (Topic 23) . 20
6.4.12 Radiation monitoring (Topic 24) . 20
6.4.13 Plant wide I&C and electrical equipment (Topic 25) . 20
6.5 Entry point documents . 20
6.6 Presentation of the structure of the SC 45A standards in this document . 21
7 Overview of the IEC SC 45A hierarchy . 22
8 Standards corresponding to the SC 45A scope . 22
8.1 Standards related to the SC 45A full scope . 22
8.2 Non-SC 45A documents of particular relevance to the SC 45A scope . 23
8.3 Standards related to SC 45A specific topics . 23
Annex A (informative) List of IEC SC 45A and selected IEC SC 45B standards . 24
A.1 General . 24
A.2 Document list . 24
Annex B (informative) Other documents of particular relevance to the SC 45A
standards . 34
B.1 General . 34
B.2 IAEA documents . 34
B.2.1 All nuclear facilities. 34
B.2.2 Nuclear power plants (NPPs) . 35
B.2.3 Nuclear Fuel Cycle Facilities (NFCFs) . 36
B.2.4 Research Reactors (RRs) . 36
B.3 Other standards bodies documents . 37
B.3.1 Non-SC 45A IEC documents . 37
B.3.2 ISO documents . 37
B.3.3 ISO/IEC documents . 38
B.3.4 IEEE documents . 38
B.3.5 Other documents . 38
Annex C (informative) List of SC 45A and selected SC 45B standards by topic area . 39
C.1 General . 39
C.2 Document lists for each topic area . 39
C.2.1 Topic 01 – I&C architecture and specifics of I&C . 39
C.2.2 Topic 02 – Electrical power system architecture and specifics of
electrics . 43
C.2.3 Topic 11 – Safety fundamentals . 45
C.2.4 Topic 12 – Equipment qualification and system performance . 49
C.2.5 Topic 13 – Human factors engineering (HFE) . 50
C.2.6 Topic 14 – Cybersecurity . 52
C.2.7 Topic 15 – Ageing management . 54
C.2.8 Topic 21 – Control rooms and human machine interfaces (HMI) . 56
C.2.9 Topic 22 – Sensors and measurement techniques . 58
C.2.10 Topic 23 – Special process measurement . 60
C.2.11 Topic 24 – Radiation monitoring . 63
C.2.12 Topic 25 – Plant wide I&C and electrical equipment . 66

Figure 1 – Structure of the IEC SC 45A standards series . 22

Table A.1 – IEC SC 45A and selected IEC SC 45B standards . 25
Table C.1 – I&C architecture and specifics of I&C . 40
Table C.2 – Electrical power system architecture and specifics of electrics . 43
Table C.3 – Safety fundamentals . 45
Table C.4 – Equipment qualification and system performance . 49
Table C.5 – Human-factors engineering (HFE) . 50
Table C.6 – Cybersecurity. 52
Table C.7 – Ageing management . 54
Table C.8 – Control rooms and human machine interfaces (HMI) . 56
Table C.9 – Sensors and measurement techniques. 58
Table C.10 – Special process measurement . 61
Table C.11 – Radiation monitoring . 63
Table C.12 – Plant wide I&C and electrical equipment . 64
Table C.13 – Plant wide I&C and electrical equipment . 66

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Nuclear facilities –
Instrumentation, control and electrical power systems important to safety -
Structure of the IEC SC 45A standards series
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
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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shall not be held responsible for identifying any or all such patent rights.
IEC TR 63400 has been prepared by subcommittee 45A: Instrumentation, control and electrical
power systems of nuclear facilities, of IEC technical committee 45: Nuclear instrumentation. It
is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
45A/1597/DTR 45A/1622/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
This second edition cancels and replaces the first edition published in 2021. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) This edition reflects changes made to the IEC SC45A portfolio of publications between 2021
and 2025, including the publication of revised standards in addition to new publications
including in the field of artificial intelligence applications for nuclear facilities.
The language used for the development of this Technical Report is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
a) Technical background, main issues and organisation of this document
The IEC SC 45A series of standards include the same common description in their Introduction,
item d), outlining the overall structure of the series and its relationship with other standards
bodies and standards (e.g. specific IAEA safety guides and IEC 61508).
The structure of the IEC SC 45A series at the time of drafting this document can be described
as a "pyramid" extending down from two top-level documents (at level 1) to other documents
(at levels 2, 3 and 4).
With the gradual extension of the IEC SC 45A scope to address electrical power systems,
cybersecurity and human factors engineering, and ongoing development of new standards, it
had become apparent that the common description could no longer, on its own, adequately fulfil
this objective without becoming overly extensive.
This document is therefore intended to augment the common description that is included in the
Introduction, item d), of all IEC SC 45A documents.
A revision of this document can be considered after each IEC SC 45A meeting and, if judged
necessary, a revision then undertaken subject to the availability of the appropriate resources.
In this Edition 2, the list of IEC SC 45A published documents and approved projects and the list
of IAEA documents of particular relevance to the IEC SC 45A technical scope have been
updated. However, no significant changes have been made to either the basic objective or
structure of the edition 1.
This document is organized as follows:
– Clause 5 outlines the scope of the IEC SC 45A standards series;
– Clause 6 describes the basic structure of the IEC SC 45A standards series, with particular
reference to a hierarchy of levels and subdivision into a set of broad topic areas;
– Clause 7 presents the structure of the IEC SC 45A standards series in diagrammatic form;
– Clause 8 introduces and points to three annexes that include:
– the full set of IEC SC 45A standards in tabular form and numerical order,
– other (i.e. non-IEC SC 45A) documents of particular relevance to IEC SC 45A, and
– the IEC SC 45A standards in tabular form for each broad topic area.
NOTE 1 In this edition, the documents under the responsibility of IEC SC 45A, as listed in the annexes, and their
status correspond to the situation that applied on 1 May 2025. For documents developed by other committees cited
for their relevance to IEC SC 45A, this document in most cases reflects the status of the situation that applied on
1 May 2024.
b) Situation of this document in the structure of the IEC SC 45A standards series
This document is a fourth level IEC SC 45A document.
Item d) of this Introduction describes the structure of the IEC SC 45A standards series in
general terms.
This document augments that description to enable users of individual IEC SC 45A standards
to obtain a more comprehensive understanding of the overall structure of the series and its
relationship with other standards bodies and standards. The publication of this document and
its subsequent editions should also enable minor changes in the structure to be described
without the need for amending the common description that is included in the Introduction, item
d), of all IEC SC 45A documents.
c) Recommendations and limitations regarding the application of this document
It is important to note that a Technical Report is entirely informative in nature. It gathers data
collected from different origins and it establishes no requirements.
d) Description of the structure of the IEC SC 45A standards series and relationships with
other IEC documents and other bodies documents (IAEA, ISO)
The IEC SC 45A standards series comprises a consistent set of documents organised in a
hierarchy of four levels. The top-level documents of the IEC SC 45A standards series are
IEC 61513 and IEC 63046, covering general requirements for instrumentation and control (I&C)
systems, and general requirements for electrical power systems of NPPs, respectively.
IEC 61513 and IEC 63046 adopt an overall system life-cycle framework and constitute, along
with the relevant second-level standards, the nuclear implementation of the basic safety series
IEC 61508.
IEC 61513 and IEC 63046 refer directly to other IEC SC 45A standards for general requirements
for specific topics, such as categorization of functions and classification of systems,
qualification, separation, defence against common cause failure, control room design,
electromagnetic compatibility, human factors engineering, cybersecurity, programmable digital
item and hardware aspects for programmable digital systems, coordination of safety and
cybersecurity requirements and management of ageing.
At a third level, IEC SC 45A standards not directly referenced by IEC 61513 or by IEC 63046
are standards related to specific requirements for specific equipment, technical methods, or
activities. Usually, these documents refer to second-level documents for general requirements
and can be used on their own.
A fourth level extending the IEC SC 45A standards series, corresponds to the Technical Reports
which are not normative.
The IEC SC 45A standards series consistently implements and details the safety and security
principles and basic aspects provided in the relevant IAEA safety standards and in the relevant
documents of the IAEA nuclear security series (NSS). In particular this includes the IAEA
requirements SSR-2/1, establishing safety requirements related to the design of nuclear power
plants (NPPs), the IAEA safety guide SSG-30 dealing with the safety classification of structures,
systems and components in NPPs, the IAEA safety guide SSG-39 dealing with the design of
instrumentation and control systems for NPPs, the IAEA safety guide SSG-34 dealing with the
design of electrical power systems for NPPs, the IAEA safety guide SSG-51 dealing with human
factors engineering in the design of NPPs, and the implementing guide NSS42-G for computer
security at nuclear facilities. The safety and security terminology and definitions used by the
SC 45A standards are consistent with those used by the IAEA.
IEC 61513 and IEC 63046 refer to ISO 9001 as well as to IAEA GSR part 2 and IAEA GS-G-
3.1 and IAEA GS-G-3.5 for topics related to quality assurance (QA).
At level 2, regarding nuclear security, IEC 62645 is the entry document for the IEC/SC 45A
security standards. It builds upon the valid high-level principles and main concepts of the
generic security standards, in particular ISO/IEC 27001 and ISO/IEC 27002; it adapts them and
completes them to fit the nuclear context and coordinates with the IEC 62443 series. At level 2,
IEC 60964 is the entry document for the IEC/SC 45A control rooms standards, IEC 63351 is the
entry document for the human factors engineering standards and IEC 62342 is the entry
document for the ageing management standards.
NOTE 2 This document provides a more comprehensive description of the overall structure of the IEC SC 45A
standards series and of its relationship with other standards bodies and standards.

1 Scope
The IEC SC 45A series of standards includes a general description in the Introduction, item d)
of each part, outlining the overall structure of the series and its relationship with other standards
bodies and standards (e.g. specific IAEA safety guides and IEC 61508).
This document is intended to augment that description to enable users of individual IEC SC 45A
International Standards to obtain a more comprehensive understanding of the overall structure
of the series and its relationship with other standards bodies and standards.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.1
computer-based item
item that relies on software instructions running on microprocessors or microcontrollers
Note 1 to entry: In this term and its definition, the term item can be replaced by the terms: system, or equipment,
or device.
Note 2 to entry: A computer-based item is a kind of programmable digital item.
Note 3 to entry: This term is equivalent to software-based item.
Note 4 to entry: See also the definition of E/E/PE item and the associated notes.
[SOURCE: IEC 62138:2018, 3.8, modified – Note 4 added.]
3.2
electrical/electronic/programmable electronic item
E/E/PE item
item based on electrical (E) and/or electronic (E) and/or programmable electronic (PE)
technology
Note 1 to entry: In this term and its definitions, the term item can be replaced by the terms: system, or equipment,
or device.
Note 2 to entry: See also the definitions of programmable digital item, of computer-based item, of hardwired item,
of programmable logic item and the associated notes.
Note 3 to entry: The definitions of the terms related to the technology: E/E/PE item, programmable digital item,
computer-based item, hardwired item, programmable logic item are totally consistent and coherent.
[SOURCE: IEC 62138:2018, 3.15, modified – Note 2 and Note 3 added.]
3.3
electrical power system
EPS
system performing electrical power generation, transmission and distribution; performing supply
functions to operate plant equipment (pumps, valves, heaters, etc.) and to I&C systems
Note 1 to entry: The Electrical Power System is composed by several electrical power sub-systems.
Note 2 to entry: An electrical system can integrate E/E/PE items to perform its internal electrical control and
protection.
[SOURCE: IEC 63046:2020, 3.12]
3.4
function
specific purpose or objective to be accomplished, that can be specified or described without
reference to the physical means of achieving it
[SOURCE: IEC 61226:2020, 3.10]
3.5
hardwired item
item that relies on relays, on analogue electronic or on discrete digital logic
Note 1 to entry: In this term and its definition, the term item can be replaced by the terms: system, or equipment,
or device.
Note 2 to entry: This term used by IEC SC 45A is roughly equivalent to electronic item used by IEC 61508. Relays
are electro-mechanical items, not electronic items, but they are included in the term hardwired-based item.
Note 3 to entry: Hardwired item are also usually called conventional items.
Note 4 to entry: The definitions for the following terms: E/E/PE item, Electrical item, I&C systems, Programmable
digital item, Computer-based item, Hardwired item, Programmable Logic Device, HDL Programmed Device (HDL
Hardware Description Language), have to be considered in conjunction and are totally consistent and coherent. They
are totally consistent and coherent with the general requirements established by IEC 61513 and IEC 63046 for
instrumentation, control and electrical systems for nuclear power plants.
[SOURCE: IEC 60987:2021, 3.10]
3.6
HDL-programmed device
HPD
integrated circuit configured (for NPP I&C systems), with Hardware Description Languages and
related software tools
Note 1 to entry: HDLs and related tools (e.g. simulator, synthesizer) are used to implement the requirements in a
proper assembly of pre-developed micro-electronic resources.
Note 2 to entry: The development of HPDs can use Pre-Developed Blocks.
Note 3 to entry: HPDs are typically based on blank FPGAs (Field Programmable Gate Arrays) or similar
programmable integrated circuits.
Note 4 to entry: HPD is a kind of programmable logic item.
Note 5 to entry: See also the definition of E/E/PE item and the associated notes.
[SOURCE: IEC 62566:2012, 3.7, modified – Note 3 modified, Note 4 and Note 5 added.]
3.7
I&C system
system, based on E/E/PE items, performing plant I&C functions as well as service and
monitoring functions related to the operation of the system itself
Note 1 to entry: The term is used as a general term which encompasses all elements of the system, such as internal
power supplies, sensors and other input devices, data highways and other communication paths, interfaces to
actuators and other output devices. The different functions within a system may use dedicated or shared resources.
Note 2 to entry: The elements included in a specific I&C system are defined in the specification of the boundaries
of the system.
Note 3 to entry: See also "electrical power system". The terms "electrical power system" and "I&C system" are
terms related to the main functions the systems perform; respectively "electrical power generation, transmission and
distribution" and "measurement, protection, control and HMI related to the NPP process". They have to be considered
in conjunction and are totally consistent and coherent with the general requirements established by IEC 61513 and
IEC 63046 for instrumentation, control and electrical power systems for nuclear power plants.
Note 4 to entry: See also the definition of E/E/PE item and the associated notes.
Note 5 to entry: According to their typical functionality, IAEA distinguishes between automation / control systems,
HMI systems, interlock systems and protection systems.
[SOURCE: IEC 62138:2018, 3.26, modified – Note 3 added.]
3.8
nuclear facility
facility (including associated buildings and equipment) in which nuclear material is produced,
processed, used, handled, stored or disposed of
[SOURCE: IEC 63272:2024, 3.24]
3.9
nuclear safety
achievement of proper operating conditions, prevention of accidents and mitigation of accident
consequences, resulting in protection of workers, the public and the environment from undue
radiation risks
[SOURCE: IAEA Nuclear Safety and Security Glossary, 2022 (Interim) edition]
3.10
programmable digital item
item that relies on software instructions or programmable logic to accomplish a function
Note 1 to entry: In this term and its definition, the term item can be replaced by the terms: system or equipment or
device.
Note 2 to entry: The main kinds of programmable digital items are computer-based items and programmable logic
items.
Note 3 to entry: This term used by IEC SC 45A is equivalent to programmable electronic item (PE item) defined
according to IEC 61508.
Note 4 to entry: See also the definition of E/E/PE item and the associated notes.
[SOURCE: IEC 62138:2018, 3.34, modified – Note 4 added.]
3.11
programmable logic item
item that relies on logic components with an integrated circuit that consists of logic elements
with an inter-connection pattern, parts of which are user programmable
Note 1 to entry: In this term and its definition, the term item can be replaced by the terms: system or equipment or
device.
Note 2 to entry: A programmable logic item is a kind of programmable digital item.
Note 3 to entry: See also the definition of E/E/PE item and the associated notes.
[SOURCE: IEC 62138:2018, 3.35]
3.12
standard
document, established by consensus and approved by a recognized body, that provides, for
common and repeated use, rules, guidelines or characteristics for activities or their results,
aimed at the achievement of the optimum degree of order in a given context
Note 1 to entry: Standards should be based on the consolidated results of science, technology and experience, and
aimed at the promotion of optimum community benefits.
[SOURCE: ISO/IEC Directives, Part 2:2021, 3.1.2]
3.13
international standard
standard that is adopted by an international standardizing/standards organization and made
available to the public
[SOURCE: ISO/IEC Directives, Part 2:2021, 3.1.3]
3.14
Technical Report
TR
document published by ISO or IEC containing collected data of a different kind from that
normally published as an International Standard or Technical Specification
Note 1 to entry: The content of a Technical Report is not permitted to include requirements, recommendations or
permissions.
[SOURCE: ISO/IEC Directives, Part 2:2021, 3.1.8, modified – original Note 1 and Note 2
removed.]
4 Abbreviated terms
AC Administrative Circular
BWR Boiling water reactor
CCF Common cause failure
CBP Computer-based procedures
EMI Electromagnetic interference
EP Electrical power
EPS Electrical power system
HFE Human factors engineering
HMI Human machine interface
HW Hardware
IAEA International Atomic Energy Agency
IEC International Electrotechnical Commission
IEEE Institute of Electrical and Electronic Engineers
IEV International Electrotechnical Vocabulary
ISO International Organization for Standardization
ITNS Important to nuclear safety
I&C Instrumentation and control
L/C Lifecycle
L1, L2, … Level 1, Level 2, …
NP New work item proposal
NPEC Nuclear Power Engineering Committee (of the IEEE)
NPP Nuclear power plant
NSS Nuclear Security Series (of the IAEA)
PWR Pressurised water reactor
RFI Radio frequency interference
RTD Resistance temperature detector
SC Subcommittee
SW Software
TC Technical committee
TR Technical Report
WG Working group
5 IEC SC 45A scope
5.1 Technical scope
An abridged version of the IEC SC 45A technical scope is as follows.
To prepare standards applicable to the electronic and electrical functions and associated
systems and equipment used in nuclear energy generation facilities (nuclear power plants, fuel
handling and processing plants, interim and final repositories for spent fuel and nuclear waste)
to improve the efficiency, safety and security of nuclear energy generation.
The standards cover the entire lifecycle of these instrumentation, control and electrical power
systems, from conception, through design, manufacture, test, installation, commissioning,
operation, maintenance, ageing management, modernization and decommissioning.
Refer to the IEC website for the IEC SC 45A full technical scope statement. The following two
links can be used to obtain information relating to IEC SC 45A and the list of IEC TCs / SCs,
respectively:
https://www.iec.ch/dyn/www/f?p=103:7:::::FSP_ORG_ID:1358
https://www.iec.ch/technical-committees-and-subcommittees#tclist
NOTE For more information about IEC management and activities, see: https://www.iec.ch/homepage.
5.2 Relationship with other standards bodies
5.2.1 General
Many IEC SC 45A standards make reference to other SC 45A standards and, where applicable,
they also make reference to various non-SC 45A IEC and ISO standards rather than repeating
their requirements.
In addition to the above, IEC SC 45A has established a number of liaisons with other IEC
technical committees/subcommittees and with technical committees of other standards bodies.
For further details of these, refer to the IEC website as below and then select "Liaisons":
https://www.iec.ch/dyn/www/f?p=103:29:8332652503242::::FSP_ORG_ID,FSP_LANG_ID:
1358,25
The relevance of some of these liaisons to the work of IEC SC 45A is outlined in 5.2.2 to 5.2.4.
5.2.2 Internal IEC liaisons
IEC 61513 and IEC 63046 are the IEC SC 45A nuclear sector standards, covering I&C and the
EPS respectively, equivalent to the basic safety publication IEC 61508-1, IEC 61508-2 and
IEC 61508-4, the latter standards series being prepared by IEC SC 65A, system aspects, of
IEC TC 65, industrial-process measurement, control and automation. The IEC SC 45A
standards suite IEC 60880, IEC 62138, IEC 62566 and IEC 62566-2, are similarly equivalent to
IEC 61508-3.
The IEC SC 45A standards (IEC 61513, IEC 60880, etc.) differ from IEC 61508 in that they take
into account the "traditional" nuclear sector deterministic design approach used since the 1950s.
NOTE As a result of the above, systems designed in accordance with the IEC SC 45A standards generally comply
with IEC 61508, but the reverse is not true.
It is also worth noting that IEC SC 45A and IEC SC 45B include radiation monitoring for different
functions. The IEC SC 45B radiation monitoring standards are therefore of interest to the
IEC SC 45A scope.
5.2.3 Liaison with IAEA
The IEC SC 45A standards series consistently implements and details the safety and security
principles and basic aspects provided in the relevant International Atomic Energy Agency (IAEA)
safety standards and in the relevant documents of the IAEA Nuclear Security Series (NSS).
These IAEA documents are introduced in 8.2 and included in Annex B.
In addition, the safety and security terminology and definitions used by IEC SC 45A standards
are consistent with those used by the IAEA as described in 5.4.
5.2.4 Liaison with IEEE NPEC
Recognizing the synergies between the IEC SC 45A and the IEEE NPEC nuclear standards
organizations, a collaborative programme was established to allow the development of joint
IEC/IEEE standards. There are two forms of joint or "dual logo" standards:
– Existing IEEE standards that are adopted by IEC: These receive new IEC identifiers.
– Existing IEC standards that are adopted by IEEE: These receive new IEEE identifiers.
– Standards that are developed jointly: These receive identifiers of the form IEC/IEEE xxxxx.
To enable this, the following agreements were established between IEC SC 45A and the
Nuclear Power Engineering Committee (NPEC) of the Institute of Electrical and Electronic
Engineers (IEEE):
AC/138/2002 – Co-operation and Licence Agreement between IEC and IEEE.
AC/24/2007 – IEC-IEEE dual logo maintenance procedure.
AC/22/2008 – IEC-IEEE joint development agreement.
These agreements have made possible:
– The joint development of dual logo IEC/IEEE standards on an agreed set of specific topics;
– The endorsement and publication of selected existing IEEE standards as IEC standards.
The three Administrative Circulars (ACs) can be accessed via the IEC website by following the
link (below)and entering the relevant document identifiers in the "search" field:
https://www.iec.ch/news-resources/acs#2
A guide on IEC/IEEE collaboration can also be accessed via the IEC website at:
www.iec.ch/resource-centre/guide-iecieee-cooperation
5.3 Criteria for development of SC 45A standards
Generic international standards (e.g. IEC, ISO) have been developed for most types of systems,
equipment and methods that are required by industry.
When there is a generic standard for a topic which cannot be used directly or which needs
adaptation for the nuclear sector, guidelines are developed for its use or "nuclear equivalent"
standards are developed.
In such cases, the IEC SC 45A "application" guidelines and "nuclear equivalent" standards
make reference to, and adhere as closely as possible to, the generic international standard.
5.4 IEC SC 45A terminology policy
The IEC SC 45A terminology policy has the following three broad objectives:
a) to use the IAEA safety and security terminology in the development of the IEC SC 45A
standards and any dual logo IEC/IEEE standards;
b) where this is not possible, to use applicable IEV definitions for generic terms in the
electrotechnical domain and applicable ISO definitions for generic terms in other domains;
c) where the above are not applicable, to develop new definitions.
Links to the IEC Electropedia and ISO Online browsing platform have already been provided in
Clause 3, and the IAEA nuclear safety and security glossary can be found at:
https://doi.org/10.61092/iaea.rrxi-t56z
NOTE 1 IEC and ISO terms are developed separately for each TC and SC and so there can be multiple definitions
for any given term.
Where the definition of a term in the IAEA Nuclear Safety and Security Glossary (see B.2.1) is
judged fully satisfactory, it is included directly into the IEC SC 45A relevant standard.
If an IAEA definition of a term is judged not fully satisfactory for direct use in an IEC SC 45A
standard, the original IAEA definition is integrated and a note is added to give precision or
introduce some nuance.
If an IAEA definition of a term cannot be used in a specific IEC SC 45A standard, a definition is
developed for inclusion in the standard and a note is added indicating that the definition is
different from the IAEA one and explaining the reason for the discrepancy.
NOTE 2 Where it is judged not possible to use an IAEA definition, a suitably justified proposal is made to the IAEA
to evolve their definition so that it can be used in the IEC SC 45A standards series in the future.
6 IEC SC 45A s
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