1、BRITISH STANDARDBS IEC 60568:2006Nuclear power plants Instrumentationimportant to safety In-coreinstrumentation for neutron fluence rate (flux) measurements in power reactorsICS 27.120.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g
2、55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS IEC 60568:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 1 March 2006 BSI 1 March 2006ISBN 0 580 47594 8National forewordThis British Standard repr
3、oduces verbatim IEC 60568:2006 and implements it as the UK national standard. It supersedes BS 5552:1978 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee NCE/8, Reactor instrumentation, which has the responsibility to: A list of organizations represente
4、d on this committee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “
5、Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal
6、 obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary
7、of pagesThis document comprises a front cover, an inside front cover, the IEC title page, pages 2 to 16, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsIECI
8、NTERNATIONALSTANDARD 60568Second edition2006-01Nuclear power plants Instrumentation important to safety In-core instrumentation for neutron fluence rate (flux) measurements in power reactors Reference number CEI/IEC 60568:2006 BS IEC 60568:2006BS IEC 60568:2006 2 CONTENTSFOREWORD.3INTRODUCTION.51 Sc
9、ope and object72 Normative references .73 Terms and definitions .84 General considerations.95 System design: general requirements106 On-line in-core neutron detectors: general requirements127 Mechanical characteristics138 Electrical and nuclear characteristics 149 Range of operating conditions.1510
10、Prototype testing 1511 Production testing.1512 Testing of system before operation .1613 Disposal.16 3 BS IEC 60568:2006INTERNATIONAL ELECTROTECHNICAL COMMISSION _NUCLEAR POWER PLANTS INSTRUMENTATION IMPORTANT TO SAFETY IN-CORE INSTRUMENTATION FOR NEUTRON FLUENCE RATE (FLUX) MEASUREMENTS IN POWER REA
11、CTORS FOREWORD1) 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 i
12、n 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 entrus
13、ted 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 Internat
14、ional 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 eac
15、h 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 IE
16、C 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 the
17、ir 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 declar
18、ed 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
19、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 dra
20、wn 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
21、 be held responsible for identifying any or all such patent rights. International Standard IEC 60568 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 ed
22、ition published in 1977. It constitutes a technical revision. The revision of this standard is intended to accomplish the following: x to up-date the reference to new standards published since the first issue, including IEC 61513 and IEC 61226; x to address the consistency with the new IEC 61468:200
23、0 and its amendment 1:2003; BS IEC 60568:2006 4 x to adapt the definitions; x to update the format to align with the current IEC/ISO directives on style of standards. The text of this standard is based on the following documents: FDIS Report on voting 45A/596/FDIS 45A/603/RVD Full information on the
24、 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. The committee has decided that the contents of this publication will remain unchanged until the maintenanc
25、e 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. 5 BS IEC 60568:2006INTRODUCTIONTechnical background, main issues and org
26、anisation of the standard This International Standard addresses the issues specific to in-core instrumentation systems. A system is understood as a measurement system producing the signals from the detectors. The calculation of power and its distribution are not within the scope of this standard. Th
27、is standard gives the principles of power distribution measurements based on several types of detectors: Self Powered Neutron Detectors (SPND), fission chambers or calorimeters. It is organised into the following major sections providing: x the general requirements for systems, x the general require
28、ments for on-line in-core detectors including mechanical, electrical and nuclear characteristics and the range of operation, x the requirements for testing of detectors (prototype, serial production), x the requirements for testing the system, x recommendations for maintenance of the detectors after
29、 operation. Situation of the current standard in the structure of the IEC SC 45A standard series IEC 60568 is the third level IEC SC 45A document tackling the specific issue of in-core instrumentation for neutron fluence rate measurement in power reactors. For more details on the structure of the IE
30、C SC 45A standard series, see the fourth part of this introduction. Recommendation and limitation regarding the application of this standardThis standard should be considered in combination with IEC 61468:2000 and its amendment 1:2003 which provide clarification regarding the applicability to Self P
31、owered Neutron Detectors (SPND). Description of the structure of the IEC 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 instrumentatio
32、n and control systems and equipment (I&C systems) that are used to perform functions important to safety in Nuclear Power Plants (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 functi
33、ons 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
34、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
35、 topics, can be used on their own. BS IEC 60568:2006 6 A fourth level extending the 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 fra
36、mework 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 this standard will facilitate consistency with the requirements of IEC 61508 as they have been interpre
37、ted 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 for topics related to quality assurance. The IEC SC 45A standards series consistently implements and details the pr
38、inciples and basic safety aspects provided in the IAEA Code on the safety of nuclear power plants and in the IAEA safety series, in particular the Requirements NS-R-1, “Safety of Nuclear Power Plants: Design” and the Safety Guide NS-G-1.3, “Instrumentation and control systems important to safety in
39、Nuclear Power Plants”. The terminology and definitions used by IEC SC 45A standards are consistent with those used by the IAEA. 7 BS IEC 60568:2006NUCLEAR POWER PLANTS INSTRUMENTATION IMPORTANT TO SAFETY IN-CORE INSTRUMENTATION FOR NEUTRON FLUENCE RATE (FLUX) MEASUREMENTS IN POWER REACTORS 1 Scope a
40、nd object This standard applies to on-line in-core neutron detectors, together with associated components and instrumentation, designed for purposes important to reactor safety: protection, information or control. The detector types usually used are direct current ionization chambers, fission ion ch
41、ambers and self-powered neutron detectors. This standard provides guidance for the design of in-core instrumentation for neutron fluence rate measurements in thermal neutron reactors designed for power production. The major emphasis in this standard is on the general design aspects of on-line system
42、s. For the principles of overall system design and for the purpose of neutron flux measurements, reference should be made to IEC 61513. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited appli
43、es. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60880:1986, Software for computers in the safety systems of nuclear power stationsIEC 60987:1989, Programmed digital computers important to safety for nuclear power stationsIEC 61226:200
44、5, Nuclear power plants Instrumentation and control systems important to safety Classification of instrumentation and control systems IEC 61468:2000, In-core instrumentation Characteristics and test methods of self-powered neutron detectors Amendment 1 (2003)IEC 61513:2001, Nuclear power-plants Inst
45、rumentation and control for systems important to safety General requirements for systemsIEC 62138:2004, Nuclear power plants Instrumentation and control important to safety Software aspects for computer-based systems performing category B or C functionsBS IEC 60568:2006 8 3 Terms and definitions For
46、 the purposes of this document, the following terms and definitions apply: 3.1 additional signal additional (background) signals are part of output value not directly related to the measured value (for example, gamma radiation effect for neutron flux detectors or part of signal wire current for SPND
47、, additional error of thermocouple caused by gamma radiation) 3.2 burn-up life neutron detectorestimated fluence of neutrons of a given energy distribution, after which the sensitive material will be consumed to such an extent, that the detector characteristics exceed the specified tolerances for a
48、specified purpose IEC 60050-394:1995, 394-18-3013.3 in-core neutron detector detector, fixed or movable, designed for the measurement of neutron fluence rate (flux) or neutron fluence at a defined point or in a region of a reactor core or primary (vessel) envelope 3.4 limit of output error maximal v
49、alue of possible deviation of output detector signal compared to correct value under normal operational conditions for the whole design operation time 3.5 main signal part of output value caused by the measured value effect (for example neutron flux density for neutron flux detectors) 3.6 off-line neutron detector detector, the output signal of which is not available for readout until the detector has been removed from the measuring position. The part subjected to neutron exposure may be in the form
