IEC 62385:2007

INTERNATIONAL IEC
STANDARD
CEI
NORME
First edition
INTERNATIONALE
Première édition
2007-06
Nuclear power plants –
Instrumentation and control important to safety –
Methods for assessing the performance of
safety system instrument channels

Centrales nucléaires de puissance –
Instrumentation et contrôle-commande
importants pour la sûreté –
Méthodes d’évaluation des performances
des chaînes d’instrumentation
des systèmes de sûreté
Reference number
Numéro de référence
IEC/CEI 62385:2007
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INTERNATIONAL IEC
STANDARD
CEI
NORME
First edition
INTERNATIONALE
Première édition
2007-06
Nuclear power plants –
Instrumentation and control important to safety –
Methods for assessing the performance of
safety system instrument channels

Centrales nucléaires de puissance –
Instrumentation et contrôle-commande
importants pour la sûreté –
Méthodes d’évaluation des performances
des chaînes d’instrumentation
des systèmes de sûreté
PRICE CODE
W
CODE PRIX
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
Pour prix, voir catalogue en vigueur

– 2 – 62385 © IEC:2007
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.8
2 Normative references .8
3 Terms and definitions .8
4 Requirements for performance verification of process instruments .11
4.1 Background .11
4.2 General requirements.11
4.3 Testing environment.11
4.4 Test interval .12
4.5 Test location .12
4.6 Calibration of measurement and test equipment .12
4.7 Test results .12
4.8 Validation of test methods .12
4.9 Qualifications of test personnel .13
5 Acceptable means for instrument performance verification .13
5.1 Introduction .13
5.2 Calibration.13
5.3 Channel checks.14
5.4 Functional test.14
5.5 Response time testing .14
6 Methods to verify instrument calibration.14
6.1 General considerations.14
6.2 Cross-calibration (cross-validation) method .15
6.3 On-line calibration monitoring.16
6.3.1 Introduction .16
6.3.2 Principle of on-line calibration monitoring .16
6.3.3 Data acquisition requirements .16
6.3.4 Data qualification and data analysis requirements .17
6.3.5 Accounting for common mode drift.17
6.3.6 Data collection frequency .17
7 Methods for response time testing .17
7.1 Response time testing of pressure transmitters .17
7.1.1 Ramp test.18
7.1.2 Noise analysis technique .18
7.1.3 Power interrupt (PI) test .19
7.2 Response time testing of temperature sensors .19
7.2.1 Plunge test .19
7.2.2 LCSR test.20
7.2.3 Self-heating test .21
7.2.4 Noise analysis .21
8 On-line detection of blockages and voids in pressure sensing lines .21
9 Verifying the performance of neutron detectors .22

62385 © IEC:2007 – 3 –
Annex A (informative) RTD cross-calibration/cross-validation .23
Annex B (informative) On-line calibration monitoring.28
Annex C (informative) Response time testing techniques for pressure transmitters and
neutron detectors.30
Annex D (informative) Response time testing techniques for RTDs .33

Bibliography.37

– 4 – 62385 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL IMPORTANT TO SAFETY –
METHODS FOR ASSESSING THE PERFORMANCE
OF SAFETY SYSTEM INSTRUMENT CHANNELS

FOREWORD
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International Standard IEC 62385 has been prepared by subcommittee 45A: Instrumentation
and control of nuclear facilities, of IEC technical committee 45: Nuclear instrumentation.
The text of this standard is based on the following documents:
FDIS Report on voting
45A/653/FDIS 45A/661/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 Dire
...