SIST EN 60671:2011

SLOVENSKI STANDARD
SIST EN 60671:2011
01-oktober-2011
Jedrske elektrarne - Merilna in nadzorna oprema za zagotavljanje varnosti -
Nadzorno preskušanje
Nuclear power plants - Instrumentation and control systems important to safety -
Surveillance testing
Kernkraftwerke - Leittechnik für Systeme mit sicherheitstechnischer Bedeutung -
Prüfungen zur Sicherstellung der Funktionsfähigkeit
Centrales nucléaires de puissance - Systèmes d'instrumentation et de contrôle
commande importants pour la sûreté - Essais de surveillance
Ta slovenski standard je istoveten z: EN 60671:2011
ICS:
27.120.20 Jedrske elektrarne. Varnost Nuclear power plants. Safety
SIST EN 60671:2011 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 60671:2011

---------------------- Page: 2 ----------------------

SIST EN 60671:2011

EUROPEAN STANDARD
EN 60671

NORME EUROPÉENNE
August 2011
EUROPÄISCHE NORM

ICS 27.120.20


English version


Nuclear power plants -
Instrumentation and control systems important to safety -
Surveillance testing
(IEC 60671:2007)


Centrales nucléaires de puissance -  Kernkraftwerke -
Systèmes d'instrumentation et de Leittechnik für Systeme mit
contrôle-commande importants pour la sicherheitstechnischer Bedeutung -
sûreté - Prüfungen zur Sicherstellung der
Essais de surveillance Funktionsfähigkeit
(CEI 60671:2007) (IEC 60671:2007)





This European Standard was approved by CENELEC on 2011-08-08. 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 Central Secretariat 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 Central Secretariat 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, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60671:2011 E

---------------------- Page: 3 ----------------------

SIST EN 60671:2011
EN 60671:2011 - 2 -
Foreword
The text of the International Standard IEC 60671:2007, prepared by SC 45A, Instrumentation and control
of nuclear facilities, of IEC TC 45, Nuclear instrumentation, was submitted to the formal vote and was
approved by CENELEC as EN 60671 on 2011-08-08 without any modification.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2012-08-08
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2014-08-08
with the EN have to be withdrawn
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 measures in the subject-matter covered by this standard.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60671:2007 was approved by CENELEC as a European
Standard without any modification.
__________

---------------------- Page: 4 ----------------------

SIST EN 60671:2011
- 3 - EN 60671:2011
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

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 60987 - Nuclear power plants - Instrumentation and EN 60987 -
control important to safety - Hardware design
requirements for computer-based systems


IEC 61226 - Nuclear power plants - Instrumentation and EN 61226 -
control important to safety - Classification of
instrumentation and control functions


IEC 61513 - Nuclear power plants - Instrumentation and - -
control for systems important to safety -
General requirements for systems


IEC 62138 - Nuclear power plants - Instrumentation and EN 62138 -
control important for safety - Software aspects
for computer-based systems performing
category B or C functions


IAEA Safety guide - Instrumentation and control systems important - -
NS-G-1.3 to safety in nuclear power plants

---------------------- Page: 5 ----------------------

SIST EN 60671:2011

---------------------- Page: 6 ----------------------

SIST EN 60671:2011
INTERNATIONAL IEC
STANDARD
CEI



60671
NORME


Second edition
INTERNATIONALE

Deuxième édition
2007-05


Nuclear power plants – Instrumentation
and control systems important to safety –
Surveillance testing

Centrales nucléaires de puissance –
Systèmes d’instrumentation et de contrôle-
commande importants pour la sûreté –
Essais de surveillance

PRICE CODE
T
CODE PRIX
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
Pour prix, voir catalogue en vigueur

---------------------- Page: 7 ----------------------

SIST EN 60671:2011
– 2 – 60671 © IEC:2007
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.8
2 Normative References .9
3 Terms and definitions .9
4 Basic Principles for Surveillance Testing .11
4.1 General .11
4.2 Gradation of Requirements Based on Category .12
4.3 Extent of Surveillance Testing .12
4.4 Self-supervision in Lieu of Periodic Testing .12
4.5 Continuous Operation in Lieu of Periodic Testing .13
5 General Requirements for Surveillance Testing .13
5.1 Design Requirements .13
5.2 Procedures.14
5.3 Data to be recorded upon detection of a fault .14
5.4 Other data to be recorded .14
5.5 Test intervals .15
5.6 Verification of actuation set-points.15
5.7 Bypass .15
5.8 Response time .15
5.9 Restoration.16
6 Requirements for Testing of Sensors and Signal Processing Devices.16
6.1 General .16
6.2 Non-tested parts.16
6.3 Testing devices .16
6.4 Signals .16
6.5 Variation of signals.17
6.5.1 General .17
6.5.2 Slowly changing signal .17
6.5.3 Rapidly changing signal.17
6.5.4 Large change in signal .17
6.6 Operability.17
6.7 Sensor response time.18
6.8 Testing equipment.18
6.9 Calibration and transfer function.18
6.10 Surveillance .18
7 Requirements for Testing of Electromechanical Equipment.18
7.1 General .18
7.2 Interface.18
7.3 Typical functional tests.19
7.4 Continuous monitoring.19
7.5 Relays and valves .19
8 Requirements for Testing of Logic Assemblies .20
8.1 Scope.20
8.2 General .20

---------------------- Page: 8 ----------------------

SIST EN 60671:2011
60671 © IEC:2007 – 3 –
8.3 Switching of signals.20
8.4 Testing signals .20
8.5 Interface.21
8.6 Data to be displayed.21
8.7 Data to be recorded.21
8.8 Detailed display.21
8.9 Testing equipment.21
8.10 Testing equipment using pulses .22
9 Self-supervision in computer-based I&C systems .22
9.1 Coverage of self supervision .22
9.2 Balance of diagnostic versus functional processing .23
9.3 Watchdog timers .23
9.4 Action taken on detected fault .23
9.5 Categorization of self-supervision software .24

Figure 1 – Extent of I&C Surveillance Testing .9

---------------------- Page: 9 ----------------------

SIST EN 60671:2011
– 4 – 60671 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL
SYSTEMS IMPORTANT TO SAFETY –
SURVEILLANCE TESTING


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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 60671 has been prepared by subcommittee 45A: Instrumentation
and control of nuclear facilities, of IEC technical committee 45: Nuclear instrumentation.
This second edition cancels and replaces the first edition published in 1980 and constitutes a
technical revision.
The main technical changes with respect to the previous edition are as follows:
– Expand scope to cover all systems important to safety, and clarify requirement gradation
for systems and equipment performing category A, B and C functions.
– Align with the new revisions of IAEA documents NS-R-1 and NS-G-1.3 (replacing D3 and
D8).

---------------------- Page: 10 ----------------------

SIST EN 60671:2011
60671 © IEC:2007 – 5 –
– Provide references to relevant normative standards.
– Harmonize terminology with the existing standard hierarchy.
– Strengthen the role of computer self-supervision as an alternative to periodic surveillance
testing.
– Introduce features of digital I&C that present special opportunities or problems to on-line
testing.
– Present design requirements on testing features themselves (categorization, verification,
etc.) that derive from the standards adopted since the first issue of IEC 60671, which will
thus be updated to become consistent with the newer standards.
The text of this standard is based on the following documents:
FDIS Report on voting
45A/648/FDIS 45A/655/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
In the United Kingdom some differences exist:
Introduction, Clauses 1, 2 and 4.2: The classification scheme captured in standard IEC 61226
edition 2 (2005-02) is contrary to the custom, practice, and regulatory expectations as set
down by the United Kingdom Health and Safety Executive's Nuclear Installations Inspectorate
and the understanding in the United Kingdom of IAEA safety guides. Users of this standard
are advised that, in the United Kingdom, this standard should be read in conjunction with the
edition of IEC 61226 published by the BSI, and the Health and Safety Executive's Nuclear
Installations Inspectorate's Safety Assessment Principles to determine the classification of a
function or system.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

---------------------- Page: 11 ----------------------

SIST EN 60671:2011
– 6 – 60671 © IEC:2007
INTRODUCTION
a) Background, main issues and organization of the standard
A fundamental requirement for I&C (instrumentation and control) systems important to safety
in nuclear power plants is that they be capable of being demonstrated to be ready to perform
their safety functions if needed. Surveillance testing may be performed by the execution of
functional tests or by self-supervision within the I&C systems important to safety, and is
augmented by diagnostic functions and by visual inspections of the I&C systems and their
status indicators by the plant operation staff. Depending on the reliability targets and the
testing conditions the demonstration of functional readiness may be performed either while
the plant is on-line or during plant shutdown. This Standard provides technical requirements
and recommendations for the implementation of surveillance testing for I&C systems
important to safety.
The object of this standard is:
– in Clause 4:
to establish the principles for surveillance testing of I&C equipment important to safety.
– in Clauses 5 through 9:
to give requirements to be fulfilled in the design and operation of I&C equipment important
to safety in regards to the surveillance testing.
b) Situation of the current standard in the structure of the SC 45A standard series
IEC 61513 establishes the top level requirements for I&C systems and equipment important to
safety. Among these requirements is the need to demonstrate, on a continuing basis, the
operability of the equipment and its readiness to perform its safety or safety related functions.
IEC 61226 establishes the principles of categorization of I&C functions according to their level
of importance to safety. The reliability required from any function in categories A, B or C
should be determined by either a quantitative probabilistic assessment of the NPP, or by
qualitative engineering judgment, and included in the specification.
IEC 60671 provides the bases and requirements for surveillance testing to demonstrate the
operability, under normal conditions, of these systems and equipment during their operative
life.
IEC 60671 supports the achievement of the target reliability by detecting faults within the
equipment allowing appropriate measures to be initiated (timely repair or any alternative
solutions).
IEC 60671 is the third level SC 45A document tackling the issue of surveillance testing for
I&C systems important to safety
For more details on the structure of the SC 45A standard series see item d) of this
introduction.
c) Recommendations and limitations regarding the application of the Standard
IEC 60671 applies to I&C systems and equipment important to safety. It establishes
requirements for surveillance testing as a means of demonstrating on a continuing basis the
readiness of the systems and equipment to perform their functions important to safety.

---------------------- Page: 12 ----------------------

SIST EN 60671:2011
60671 © IEC:2007 – 7 –
Additional requirements relating to reliability and detailed requirements for redundancy and
diversity are not given in this standard but can be found in other documents of SC 45A.
The attention of the reader is drawn to the fact that in some countries the scope and the
content of periodic testing are defined by regulatory requirements and that these definitions
could differ from the ones used in this standard.
In the case of existing plants it may not be possible to apply all of the requirements of this
standard. Therefore, at the beginning of a modernization project of an I&C system important
to safety the subset of requirements to be applied shall be identified in regards to the overall
scope and consequences of modification of the I&C systems.
d) Description of the structure of the SC 45A standard series and relationships with
other IEC documents and other bodies documents (IAEA, ISO)
The top-level document of the IEC SC 45A standard series is IEC 61513. It provides general
requirements for I&C systems and equipment that are used to perform functions important to
safety in NPPs. IEC 61513 structures the IEC SC 45A standard series.
IEC 61513 refers directly to other IEC SC 45A standards for general topics related to
categorization of functions and classification of systems, qualification, separation of systems,
defence against common cause failure, software aspects of computer-based systems,
hardware aspects of computer-based systems, and control room design. The standards
referenced directly at this second level should be considered together with IEC 61513 as a
consistent document set.
At a third level, IEC SC 45A standards not directly referenced by IEC 61513 are standards
related to specific equipment, technical methods, or specific activities. Usually these
documents, which make reference to second-level documents for general topics, can be used
on their own.
A fourth level extending the IEC SC 45A standard series, corresponds to the Technical
Reports which are not normative.
IEC 61513 has adopted a presentation format similar to the basic safety publication
IEC 61508 with an overall safety life-cycle framework and a system life-cycle framework and
provides an interpretation of the general requirements of IEC 61508-1, IEC 61508-2 and
IEC 61508-4, for the nuclear application sector. Compliance with IEC 61513 will facilitate
consistency with the requirements of IEC 61508 as they have been interpreted for the nuclear
industry. In this framework IEC 60880 and IEC 62138 correspond to IEC 61508-3 for the
nuclear application sector.
IEC 61513 refers to ISO as well as to IAEA 50-C-QA (now replaced by IAEA 50-C/SG-Q) for
topics related to quality assurance (QA).
The IEC SC 45A standards series consistently implements and details the principles and
basic safety aspects provided in the IAEA code on the safety of NPPs and in the IAEA safety
series, in particular the Requirements NS-R-1, establishing safety requirements related to the
design of Nuclear Power Plants, and the Safety Guide NS-G-1.3 dealing with instrumentation
and control systems important to safety in Nuclear Power Plants. The terminology and
definitions used by SC 45A standards are consistent with those used by the IAEA.

---------------------- Page: 13 ----------------------

SIST EN 60671:2011
– 8 – 60671 © IEC:2007
NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL
SYSTEMS IMPORTANT TO SAFETY –
SURVEILLANCE TESTING



1 Scope
Where functional reliability is required by general safety standards, one aspect of
demonstrating this reliability is testing performed on-line during plant operation or during plant
shutdown in preparation for return to power operation.
This standard lays down principles for testing I&C systems performing category A, B and C
functions, per IEC 61226, during normal power operation and shutdown, so as to check the
functional availability especially with regard to the detection of faults that could prevent the
proper operation of the functions important to safety. It covers the possibility of testing at
short intervals or continuous surveillance, as well as periodic testing at longer intervals. It
also establishes basic rules for the design and application of the test equipment and its
interface with the systems important to safety. Further, the effect of any test equipment failure
on the reliability of the I&C systems is considered.
Types of surveillance tests may include:
– self-tests for I&C equipment;
– test of a group of equipment or components to confirm properties that support the safety
function (continuity, power availability, etc.);
– test based on information redundancy or comparison of control signatures (consistency
checking for redundant sensors, CRC-checking, Checksum, etc.);
– periodic testing which is related to the correctness of functional behaviour of an I&C
system.
The dependability targets of any I&C system is reached using an appropriate combination of
tests of the form indicated above.
The extent of the I&C system to be tested is from the interface of the sensors with the process
through to the actuation devices (see Figure 1). It is applicable to the installed I&C systems
as well as to temporary installations which are part of those I&C systems important to safety
(for example, auxiliary equipment for commissioning tests and experiments). This standard
also applies to individual electromechanical equipment, such as relays and solenoid
actuators.
Additional testing and inspections may be performed on I&C equipment for purposes other
than the demonstration of functional capability, such as to optimise preventive maintenance,
etc. Such tests are beyond the scope of this standard; however, they may be combined with
the surveillance testing discussed herein.
For any on-line tests the potential interaction and fault dependencies between the part of the
system under test and the testing part, have to be carefully studied and their influences have
to be fully integrated into the reliability assessment of the functions important to safety (in
accordance with IEC 61513).

---------------------- Page: 14 ----------------------

SIST EN 60671:2011
60671 © IEC:2007 – 9 –
This standard applies to the I&C of new nuclear power plants as well as to I&C upgrading or
...