IEC 60910:2022

Nuclear power plants - Instrumentation important to safety - Containment monitoring for early detection of developing deviations from normal operation in light water reactors

IEC 60910:2022 provides requirements for primary and secondary containment parameter monitoring that enable the operator to identify developing deviations from normal operation. The operator can then take corrective action at an early stage to prevent a minor failure from developing into a serious plant failure or an accident condition. This document is directed towards monitoring the primary and secondary containment under normal conditions only.
This second edition cancels and replaces the first edition, published in 1988. This edition includes the following significant technical changes with respect to the previous edition:
a. Modification of title;
b. Integration of new technology and knowledge;
c. Drafting directed towards monitoring conditions in containment under normal conditions.

Centrales nucléaires de puissance – Systèmes d'instrumentation importants pour la sûreté – Surveillance de l'enceinte de confinement pour une détection rapide des écarts par rapport au fonctionnement normal dans les réacteurs à eau légère

IEC 60910:2022 fournit des exigences relatives à la surveillance des paramètres de confinement primaire et secondaire qui permettent à l'exploitant d'identifier le développement d'écarts par rapport au fonctionnement normal. L'exploitant peut alors entreprendre une action corrective à un stade précoce afin d'empêcher qu'une défaillance mineure n'évolue en grave défaillance de la centrale ou en condition accidentelle. Le présent document traite de la surveillance de l'enceinte de confinement primaire et secondaire en conditions normales uniquement.
Cette deuxième édition annule et remplace la première édition parue en 1988. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a. Modification du titre;
b. Intégration de nouvelles technologies et connaissances;
c. projet centré sur les conditions de surveillance de l'enceinte de confinement en conditions normales de fonctionnement.

General Information

• Status: Published
• Publication Date: 14-Nov-2022
• ICS: 27.120.20 - Nuclear power plants. Safety
• Technical Committee: SC 45A - Instrumentation, control and electrical power systems of nuclear facilities
• Drafting Committee: WG 5 - TC 45/SC 45A/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 25-Nov-2022
• Completion Date: 15-Nov-2022

Standards Content (Sample)

IEC 60910
®

Edition 2.0 2022-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE



Nuclear power plants – Instrumentation important to safety – Containment
monitoring for early detection of developing deviations from normal operation
in light water reactors

Centrales nucléaires de puissance – Systèmes d'instrumentation importants
pour la sûreté – Surveillance de l'enceinte de confinement pour une détection
rapide des écarts par rapport au fonctionnement normal dans les réacteurs à
eau légère

IEC 60910:2022-11(en-fr)

---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60910

®


Edition 2.0 2022-11




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE











Nuclear power plants – Instrumentation important to safety – Containment

monitoring for early detection of developing deviations from normal operation

in light water reactors



Centrales nucléaires de puissance – Systèmes d'instrumentation importants

pour la sûreté – Surveillance de l'enceinte de confinement pour une détection


rapide des écarts par rapport au fonctionnement normal dans les réacteurs à

eau légère












INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.120.20 ISBN 978-2-8322-5926-9




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

---------------------- Page: 3 ----------------------
– 2 – IEC 60910:2022 © IEC 2022
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Physical parameters . 9
4.1 General . 9
4.2 Temperature of containment atmosphere and fluid drains . 9
4.2.1 General . 9
4.2.2 Atmospheric temperature . 9
4.2.3 Drain temperatures . 10
4.3 Pressure in the containment. 10
4.4 Humidity in the containment . 10
4.5 Combustible gas concentration in the containment . 10
4.6 Water level in the drain sumps . 10
4.7 Fluid flow balance . 10
4.8 Radioactivity in the containment atmosphere . 10
4.9 Chemical analysis of water in the drain sumps . 11
4.10 Visible abnormalities . 11
4.11 Noise and vibration . 11
4.12 Fire . 11
4.13 Operability of instrumentation . 11
4.14 Performance requirements . 11
4.15 Documentation of performance criteria . 11
5 Design criteria . 12
5.1 Performance requirements . 12
5.2 Physical independence . 12
5.3 Electrical isolation . 12
5.4 Information ambiguity . 12
5.5 Power supply . 12
5.6 Calibration . 12
5.7 Testability . 12
5.8 Direct measurement . 12
5.9 Control of access . 13
5.10 Measurement and repair . 13
5.11 Supporting features . 13
5.12 Alarm . 13
6 Qualification criteria . 13
6.1 General . 13
6.2 Environmental . 13
6.3 Seismic . 13
6.4 Accident . 13
7 Display criteria . 14
7.1 Human factors . 14
7.2 Display of distributed data . 14
7.3 Trend or rate information . 14

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IEC 60910:2022 © IEC 2022 – 3 –
7.4 Continuous versus on-demand displays . 14
7.5 Display identification . 14
7.6 Display location . 14
8 Quality assurance . 14
Bibliography . 15

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– 4 – IEC 60910:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

NUCLEAR POWER PLANTS –
INSTRUMENTATION IMPORTANT TO SAFETY –
CONTAINMENT MONITORING FOR EARLY DETECTION OF DEVELOPING
DEVIATIONS FROM NORMAL OPERATION IN LIGHT WATER REACTORS

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
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preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
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IEC 60910 has been prepared by subcommittee 45A: Instrumentation, control and electrical
power systems of nuclear facilities, of IEC technical committee 45: Nuclear instrumentation.
It is an International Standard.
This second edition cancels and replaces the first edition, published in 1988. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Modification of title;
b) Integration of new technology and knowledge;
c) Drafting directed towards monitoring conditions in containment under normal conditions.

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IEC 60910:2022 © IEC 2022 – 5 –
The text of this International Standard is based on the following documents:
Draft Report on voting
45A/1443/FDIS 45A/1452/RVD

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard 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/standardsdev/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,
• replaced by a revised edition, or
• amended.

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– 6 – IEC 60910:2022 © IEC 2022
INTRODUCTION
a) Technical background, main issues and organisation of this Standard
IEC 60910 provides recommendations for measurements that allow operator diagnosis of
developing deviations from normal operation. The recommendations located herein are
intended to be general so that they may apply to containment I&C systems for different types
of light water reactors.
The IAEA Safety Glossary defines containment as the methods or physical structures designed
to prevent or control the release and dispersion of radioactive substances. IEC 60910 uses this
definition of containment.
This document is intended to monitor the parameters which, when appropriate action is taken,
will prevent accident scenarios from occurring.
It is intended that this document be used by operators of NPPs (utilities), systems evaluators
and by licensors.
b) Situation of the current Standard in the structure of the IEC SC 45A standard series
IEC 60910 is a third level IEC SC 45A document covering the instrumentation important to
safety in containment as defined in IEC 61513
For more details on the structure of the IEC SC 45A standard series, see item d) of this
introduction.
c) Recommendations and limitations regarding the application of the Standard
To ensure that the document will continue to be relevant in future years, the emphasis has been
placed on issues of principle, rather than specific technologies.
d) Description of the structure of the IEC SC 45A standard series and relationships with
other IEC documents and other bodies documents (IAEA, ISO)
The IEC SC 45A standard series comprises a hierarchy of four levels. The top-level documents
of the IEC SC 45A standard series are IEC 61513 and IEC 63046.
IEC 61513 provides general requirements for instrumentation and control (I&C) systems and
equipment that are used to perform functions important to safety in nuclear power plants (NPPs).
IEC 63046 provides general requirements for electrical power systems of NPPs; it covers power
supply systems including the supply systems of the I&C systems.
IEC 61513 and IEC 63046 are to be considered in conjunction and at the same level. IEC 61513
and IEC 63046 structure the IEC SC 45A standard series and shape a complete framework
establishing general requirements for instrumentation, control and electrical power systems for
nuclear power plants.
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, software and
hardware aspects for programmable digital systems, coordination of safety and security
requirements and management of ageing. The standards referenced directly at this second level
should be considered together with IEC 61513 and IEC 63046 as a consistent document set.

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IEC 60910:2022 © IEC 2022 – 7 –
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, which make reference to second-level documents for
general requirements, can be used on their own.
A fourth level extending the IEC SC 45 standard 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 have adopted a presentation format similar to the basic safety
publication IEC 61508 with an overall life-cycle framework and a system life-cycle framework.
Regarding nuclear safety, IEC 61513 and IEC 63046 provide the interpretation of the general
requirements of IEC 61508-1, IEC 61508-2 and IEC 61508-4, for the nuclear application sector.
In this framework, IEC 60880, IEC 62138 and IEC 62566 correspond to IEC 61508-3 for the
nuclear application sector.
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 1 It is assumed that for the design of I&C systems in NPPs that implement conventional safety functions (e.g.
to address worker safety, asset protection, chemical hazards, process energy hazards) international or national
standards would be applied.
NOTE 2 IEC TR 64000 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.

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– 8 – IEC 60910:2022 © IEC 2022
NUCLEAR POWER PLANTS –
INSTRUMENTATION IMPORTANT TO SAFETY –
CONTAINMENT MONITORING FOR EARLY DETECTION OF DEVELOPING
DEVIATIONS FROM NORMAL OPERATION IN LIGHT WATER REACTORS



1 Scope
This document provides requirements for primary and secondary containment parameter
monitoring that enable the operator to identify developing deviations from normal operation.
The operator can then take corrective action at an early stage to prevent a minor failure from
developing into a serious plant failure or an accident condition. This document is directed
towards monitoring the primary and secondary containment under normal conditions only.
2 Normative references
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.
IEC/IEEE 60780-323, Nuclear facilities – Electrical equipment important to safety –
Qualification
IEC/IEEE 60980-344, Nuclear facilities – Equipment important to safety – Seismic qualification
IEC 61226, Nuclear power plants – Instrumentation, control and electrical power systems
important to safety – Categorization of functions and classification of systems
IEC 61513, Nuclear power plants – Instrumentation and control important to safety – General
requirements for systems
IEC TR 63123, Nuclear power plants – Instrumentation, control, and electrical power systems
– Guidance for the application of IEC 63147:2017/IEEE Std 497™-2016 in the IAEA/IEC
framework
IEC 63147, Criteria for accident monitoring instrumentation for nuclear power generating
stations
IAEA Safety Glossary:2016, Terminology used in nuclear safety and radiation protection,
available at https://www-pub.iaea.org/books/IAEABooks/7897/IAEA-Safety-Glossary
IAEA Safety Standard Series No. SSR-2/1 Rev:1, Safety of Nuclear Power Plant: Design

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IEC 60910:2022 © IEC 2022 – 9 –
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the IAEA Safety Glossary
apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Physical parameters
4.1 General
The physical parameters that should be monitored to detect developing deviations from normal
operation within containment vary with different reactor systems. The measurement sensitivities
required to detect a developing deviation can be estimated by analytical methods appropriate
to the individual plants. Typical conditions that introduce parameter changes are:
• Release or accidental leakage of high-temperature fluid;
• Release or accidental leakage of high-pressure fluid;
• Presence of radioactive gas or liquids;
• Fire;
• Component mechanical or electrical failure.
The following is a list of parameters and conditions which shall be monitored:
• Temperature of the containment atmosphere and of the fluid drains;
• Pressure in the containment building;
• Humidity in the containment building;
• Combustible gas concentrations in the containment building;
• Fluid level in the drains;
• Fluid flows;
• Radiation;
• Chemical analysis of drain fluids;
• Visible abnormalities;
• Noise and vibrations;
• Fire;
• Operability of existing instrumentation.
4.2 Temperature of containment atmosphere and fluid drains
4.2.1 General
The atmospheric and fluid drain temperatures shall be measured.
4.2.2 Atmospheric temperature
A sufficient number of temperature sensors should be installed to measure the atmospheric
temperature distribution throughout the containment building. In addition, measurement of the
fluid temperatures of the containment air coolers should be used to estimate the temperature
of the atmosphere.

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– 10 – IEC 60910:2022 © IEC 2022
The data display shall present the temperature distribution and the local trends in atmospheric
temperatures to the operators.
4.2.3 Drain temperatures
The temperature shall be measured in selected fluid drains (system drains, floor drains). These
temperature measurements should be recorded to show trends. The data display should present
the temperature distribution and the local trends in fluid temperatures to the operators.
4.3 Pressure in the containment
Leakage of gases or fluids such as compressed air, nitrogen, or water may be the cause of
pressure increases. To detect such leaks, measurements of the ambient pressure shall be
provided from the appropriate compartments in the containment building. These measurements
shall not be significantly affected by variations in other parameters such as temperature,
humidity, or ionizing or electromagnetic radiation. These pressure measurements should be
recorded to show trends and shall be displayed to the operators.
4.4 Humidity in the containment
The humidity is a highly significant factor for the detection of anomalies. Parameters which
indicate changes in humidity are:
• Dew point and temperatu
...