IEC 60951-1:2022

IEC 60951-1 ®
Edition 3.0 2022-11
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Nuclear power plants facilities – Instrumentation systems important to safety –
Radiation monitoring for accident and post-accident conditions –
Part 1: General requirements
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IEC 60951-1 ®
Edition 3.0 2022-11
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Nuclear power plants facilities – Instrumentation systems important to safety –
Radiation monitoring for accident and post-accident conditions –
Part 1: General requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.120.20 ISBN 978-2-8322-6146-0
– 2 – IEC 60951-1:2022 RLV  IEC 2022
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 13
4 Design principles . 18
4.1 General . 18
4.2 Basic requirements related to functions . 19
4.3 Measurement range . 21
4.4 Energy response . 21
4.5 Minimum detectable activity (or limit of detection) . 21
4.6 Precision (or repeatability) . 21
4.7 Accuracy (or relative error) Linearity . 21
4.8 Measurement time . 22
4.9 Response time . 22
4.10 Overload performance . 22
4.11 Ambient background shielding or compensation devices . 22
4.12 Requirements related to accident conditions . 23
4.13 Reliability . 23
4.14 User interface . 24
4.14.1 General . 24
4.14.2 Display of measured value . 24
4.14.3 Alarms . 24
4.14.4 Status indication . 25
4.14.5 Local indications . 25
4.15 System testing, maintenance facilities and ease of decontamination . 25
4.15.1 System testing . 25
4.15.2 Maintenance facilities . 26
4.15.3 Ease of decontamination . 26
4.16 Electromagnetic interference. 26
4.17 Power supplies . 26
4.18 Interfaces . 27
4.19 Sampling assembly . 27
4.20 Quality . 28
4.21 Type test report and certificate. 28
5 Functional testing . 29
5.1 General . 29
5.2 General test procedures . 30
5.2.1 General . 30
5.2.2 Tests performed under standard test conditions . 30
5.2.3 Tests performed with variation of influence quantities . 30
5.2.4 Calculations and/or numerical simulations . 33
5.2.5 Reference sources . 34
5.2.6 Statistical fluctuations . 35
5.3 Performance Radiation characteristics . 35
5.3.1 Reference response . 35

5.3.2 Sensitivity and relative response for solid sources . 35
5.3.3 Accuracy (relative error) Linearity . 36
5.3.4 Response to other artificial radionuclides . 37
5.3.5 Response to background radiation . 37
5.3.6 Precision (or repeatability) . 38
5.3.7 Stability of the indication . 38
5.3.8 Response time . 39
5.3.9 Overload test characteristics . 39
5.4 Electrical performance tests characteristics . 40
5.4.1 Alarm trip range . 40
5.4.2 Alarm trip stability . 40
5.4.3 Fault alarm . 41
5.4.4 Status indication and fault alarm tests . 41
5.4.5 Warm-up time — Detection and measuring assembly . 41
5.4.6 Influence of supply variations . 41
5.4.7 Short circuit withstand tests . 42
5.5 Environmental performance test characteristics . 43
5.5.1 Stability of performance after storage . 43
5.5.2 Mechanical tests characteristics . 43
5.5.3 Stability of performance with variation of temperature and humidity . 45
5.5.4 Electromagnetic compatibility . 46
Bibliography . 49

Table 1 – Overview of the standards covering the domain of radiation monitoring in
nuclear facilities . 7
Table 2 – Reference conditions and standard test conditions . 31
Table 3 – Tests performed under standard test conditions . 32
Table 4 – Tests performed with variation of influence quantities . 33

– 4 – IEC 60951-1:2022 RLV  IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NUCLEAR POWER PLANTS FACILITIES – INSTRUMENTATION SYSTEMS
IMPORTANT TO SAFETY – RADIATION MONITORING FOR
ACCIDENT AND POST-ACCIDENT CONDITIONS –

Part 1: General requirements
FOREWORD
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