1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Nuclear power plants Instrumentation important to safety Equipment for continuous in-line or on-line monitoring o
2、f radioactivity inprocess streams for normal and incident conditionsBS IEC 60768:2009National forewordThis British Standard is the UK implementation of IEC 60768:2009.The UK participation in its preparation was entrusted to Technical CommitteeNCE/8, Reactor instrumentation.A list of organizations re
3、presented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2009ISBN 978 0 580 67857 8ICS 27.120.20Compliance with a British Standard cannot confe
4、r immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 May 2009Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS IEC 60768:2009IEC 60768Edition 2.0 2009-04INTERNATIONAL STANDARD NORME
5、 INTERNATIONALENuclear power plants Instrumentation important to safety Equipment for continuous in-line or on-line monitoring of radioactivity in process streams for normal and incident conditions Centrales nuclaires de puissance Instrumentation importante pour la sret Matriels pour la surveillance
6、 des rayonnements en continu, interne et externe, au niveau des fluides de procds pour les conditions de fonctionnement normal et incidentel INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE WICS 27.120.20 PRICE CODECODE PRIXISBN 2-8318-1037-5 Registered trademark
7、of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale BS IEC 60768:2009 2 60768 IEC:2009 CONTENTS FOREWORD.4 INTRODUCTION.6 1 Scope.8 2 Normative references .8 3 Terms and definitions .10 4 Design principles10 4.1 Basic requirements related to
8、 functions.10 4.2 Measurement range 11 4.3 Energy response .11 4.4 Minimum detectable activity (or detection limit) .12 4.5 Precision (or repeatability).12 4.6 Accuracy (or relative error)12 4.7 Measurement time.13 4.8 Response time 13 4.9 Overload performance.13 4.10 Ambient background shielding or
9、 compensation devices .13 4.11 Requirements related to incident conditions 14 4.12 Reliability 14 4.13 User interface14 4.13.1 General .14 4.13.2 Display of measured value.15 4.13.3 Alarms.15 4.13.4 Status indication15 4.13.5 Local indications16 4.14 System testing, maintenance facilities and ease o
10、f decontamination .16 4.14.1 System testing.16 4.14.2 Maintenance facilities 16 4.14.3 Ease of decontamination .17 4.15 Electromagnetic interference .17 4.16 Power supplies17 4.17 Interfaces 17 4.18 In-line detectors mechanical features.18 4.18.1 General requirements 18 4.18.2 Pressure-containing pa
11、rts18 4.18.3 Materials .18 4.18.4 Verification of material processing.19 4.19 Quality 19 4.20 Type test report and certificate19 5 Functional testing .20 5.1 General .20 5.2 General test procedures 21 5.2.1 General .21 5.2.2 Tests performed under standard test conditions 21 5.2.3 Tests performed wit
12、h variation of influence quantities21 5.2.4 Calculations and/or numerical simulations .21 5.2.5 Reference sources 22 BS IEC 60768:200960768 IEC:2009 3 5.2.6 Statistical fluctuations22 5.3 Performance characteristics 23 5.3.1 Reference response 23 5.3.2 Accuracy (relative error) 23 5.3.3 Response to
13、other artificial radionuclides 24 5.3.4 Response to background radiation.24 5.3.5 Precision (or repeatability).25 5.3.6 Stability of the indication .25 5.3.7 Response time 25 5.3.8 Overload test.26 5.4 Electrical performance tests 26 5.4.1 Alarm trip range.26 5.4.2 Alarm trip stability27 5.4.3 Fault
14、 alarm 27 5.4.4 Status indication and fault alarm tests .27 5.4.5 Warm-up time Detection and measuring assembly27 5.4.6 Influence of supply variations 28 5.4.7 Short circuit withstand tests.29 5.5 Environmental performance test 29 5.5.1 Stability of performance after storage 29 5.5.2 Mechanical test
15、s30 5.5.3 Stability of performance with variation of ambient and stream conditions31 5.5.4 Electromagnetic compatibility 33 Bibliography39 Table 1 Reference conditions and standard test conditions36 Table 2 Tests performed under standard test conditions 37 Table 3 Tests performed with variation of i
16、nfluence quantities38 BS IEC 60768:2009 4 60768 IEC:2009 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ NUCLEAR POWER PLANTS INSTRUMENTATION IMPORTANT TO SAFETY EQUIPMENT FOR CONTINUOUS IN-LINE OR ON-LINE MONITORING OF RADIOACTIVITY IN PROCESS STREAMS FOR NORMAL AND INCIDENT CONDITIONS FOREWORD 1) The
17、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
18、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 comm
19、ittees; 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 fo
20、r 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
21、 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 acc
22、urate, 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 regio
23、nal 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 conformit
24、y 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 pe
25、rsonal 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 r
26、eferences 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
27、for identifying any or all such patent rights. International Standard IEC 60768 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 19
28、83. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: to clarify the definitions. to up-date the reference to new standards published since the first issue. to update the units of radiation. BS IEC 6
29、0768:200960768 IEC:2009 5 The text of this standard is based on the following documents: FDIS Report on voting 45A/729/FDIS 45A/741/RVDFull 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
30、 in accordance with the ISO/IEC Directives, Part 2. This International Standard is to be read in conjunction with IEC 60951:2009. 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:/webstor
31、e.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. BS IEC 60768:2009 6 60768 IEC:2009 INTRODUCTION a) Technical background, main issues and organisation of this Standard This IEC standard
32、 specifically focuses on process streams radiation monitoring systems used for normal and incident operations. This standard is intended for use by purchasers in developing specifications for their plant-specific radiation monitoring systems and by manufacturers to identify needed product characteri
33、stics when developing systems for normal and incident monitoring conditions. Some specific instrument characteristics such as measurement range, required energy response, and ambient environment requirements will depend upon the specific application. In such cases guidance is provided on determining
34、 the specific requirements, but specific requirements themselves are not stated. b) Situation of this Standard in the structure of the IEC SC 45A standards series IEC 60768 is at the third level in the hierarchy of SC 45A standards. It provides guidance on the design and testing of process streams r
35、adiation monitoring equipment used for normal and incident conditions. Other standards developed by SC 45A and SC 45B provide guidance on instruments used for monitoring radiation as part of normal operations and also for accident and post accident conditions. IEC 60761 series provide requirements f
36、or equipment for continuous off-line monitoring of radioactivity in gaseous effluents in normal conditions. IEC 60861 provides requirements for equipment for continuous off-line monitoring of radioactivity in liquid effluents in normal conditions. IEC 60951 standard series establishes requirements f
37、or equipment for radiation monitoring for accident and post accident conditions. Finally, ISO standard 2889 gives guidance on gas and particulate sampling. The relationship between these various radiation monitoring standards is given in the table below: Developer ISO SC 45A Process and safety monit
38、oring Scope Sampling circuits and methods Accident and post-accident conditions Normal and incident conditions SC 45B Radiation protection and effluents monitoring Gas, Particulate and iodine with sampling (OFF LINE) ISO 2889 IEC 60951-1 and 2 IEC 60761 series and IEC 62302 (noble gases only) Liquid
39、 with sampling (OFF LINE) N/A N/A IEC 60861 Process streams (gaseous effluents, steam or liquid) without sampling (ON or IN-LINE) N/A IEC 60951-1 and 4 IEC 60768 N/A Area monitoring N/A IEC 60951-1 and 3 IEC 60532 Central System N/A IEC 61504 IEC 61559 For more details on the structure of the IEC SC
40、 45A standard series, see the item d) of this introduction. c) Recommendations and limitations regarding the application of this Standard It is important to note that this Standard establishes no additional functional requirements for safety systems. BS IEC 60768:200960768 IEC:2009 7 d) Description
41、of the structure of the IEC SC 45A standard series and relationships with other IEC documents, IAEA and ISO The top-level document of the IEC SC 45A standard series is IEC 61513. It provides general requirements for I it shall be specified by the plant designer. The manufacturer shall specify the mi
42、nimum detectable activity (or detection limit) for nuclides of interest, taking into account the check sources or provisions incorporated to provide an on-scale indication on the monitor, as well as all useful data needed to specify the beginning of the effective range of measurement, even in transi
43、ent operating conditions. The influence quantities, their range of values and the variation they cause on the minimum detectable activity (or detection limit) shall be specified. 4.5 Precision (or repeatability) Precision (or repeatability) is a measure of the dispersion of the estimations around th
44、eir average value. It shall be given by the manufacturer in the effective range of measurement in % of the signal value for a given confidence interval (or probability of error). Assuming that the estimations follow a Gaussian distribution, this probability should be expressed in term of a number of
45、 standard deviations. NOTE For example, the precision could be 20 % of the signal value within a part of the effective range of measurement with a probability of 95 % (meaning that all the estimations are within 2, with the standard deviation), and 30 % within another part of the effective range of
46、measurement with another probability. Precision shall be consistent with incident analysis assumptions, operator needs, and requirements imposed by other systems that use the radiation monitoring signals. Moreover, they shall be characterized for signal values below the beginning of the effective ra
47、nge of measurement. The influence quantities, their range of values and the variation they cause on precision shall be specified by the manufacturer. Typically, the precision should be within 10 % over the entire effective range of measurement, all influence quantities taken into account. 4.6 Accura
48、cy (or relative error) Accuracy (or relative intrinsic error) is a measure of the deviation between the conventionally true value and the average of the estimations. It shall be given by the manufacturer in the effective range of measurement in % of the signal value for a given confidence interval (
49、or probability of error). Assuming that the estimations follow a Gaussian distribution, this probability should be expressed in term of a number of standard deviations. NOTE For example, the accuracy could be 20 % of the signal value within a part of the effective range of measurement with a probability of 95 % (meaning that all the estimations are within 2, with the standard deviation), and 30 % within another part of the effective range of measurement with another proba
