1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58safety Resistance temperature detectorsICS 27.120.20,Nuclear power plants Instrumentation and contr
2、ol important to BRITISH STANDARDBS IEC 62397:2007BS IEC 62397:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 June 2007 BSI 2007ISBN 978 0 580 52907 8Amendments issued since publicationAmd. No. Date Commentscontract. Users are responsi
3、ble for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of IEC 62397:2007. The UK participation in its preparation was entrusted to Technical Committee NC
4、E/8, Reactor instrumentation.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a INTERNATIONAL STANDARD IEC62397First edition2007-05Nuclear power plants Instrumentation and co
5、ntrol important to safety Resistance temperature detectors Reference number IEC/CEI 62397:2007 BS IEC 62397:2007CONTENTS INTRODUCTION.4 1 Scope.62 Normative references .63 Terms and definitions .64 Design and construction requirements8 4.1 General .8 4.2 Reliability 8 4.3 Materials .8 4.3.1 Radiatio
6、n dose to materials .8 4.3.2 Resistance element material9 4.3.3 Seals and adhesives9 4.4 Connections 11 4.4.1 Electrical connection .11 4.4.2 Mechanical connection 12 4.5 Workmanship 12 4.6 Ambient conditions (normal and accident operations) 13 4.7 RTD performance 13 4.7.1 Accuracy .13 4.7.2 Resista
7、nce temperature calibration14 4.7.3 Self-heating error 14 4.7.4 Thermal response time 14 4.7.5 Interchangeability 15 4.7.6 Electrical insulation resistance 15 4.7.7 Repeatability (thermal shock) 15 4.7.8 Vibration16 4.7.9 Steam test.16 4.7.10 Insulation resistance after storage.16 4.7.11 In situ res
8、ponse time testing17 4.8 Identification17 4.9 Failure mode and effects analysis .17 5 Inspection and tests .18 5.1 General .18 5.2 Inspection and test failure .18 5.3 Inspection and test reports 18 5.4 Qualification tests18 5.4.1 Calibration procedure 20 5.4.2 Thermal cycling .20 5.4.3 Insulation br
9、eakdown test 20 5.4.4 Examination 20 5.5 Production tests 20 6 Technical information required .21 Bibliography22 BS IEC 62397:2007 2 Figure 1 Form and dimensions of an RTD 10 Figure 2 Installation of a rigid RTD (Type I)10Figure 3 Installation of a rigid RTD (Type II) long insertion.11 Figure 4 Inst
10、allation of a rigid RTD (Type II) short insertion .11 BS IEC 62397:2007 3 INTRODUCTION a) Technical background, main issues and organisation of the standard This standard describes the requirements for the design, material selection, procurement, construction, and testing of resistance temperature d
11、etectors (RTDs) being used in nuclear power plants (NPPs). These RTDs may be used in both the nuclear safety I however, this standard does not exclude any other design of RTD which may be required for certain special applications in various types of reactors. RTDs can be supplied in different intern
12、al constructions, which depend on the manufacture, qualifications, and applications. For RTD being used in an NPP, the design and structure of the RTD should consider the environmental conditions in which the detector is being used under normal operating and under design basis accident conditions, a
13、s well as the qualification tests specified by the user1. The use of a flexible mineral-insulated (MI) cable between the RTD and the connector is commonly adopted, and the user may also adopt any other construction. A variation of this design may include a rigid exterior sheath over the MI cable bet
14、ween the RTD and the connector, these being welded to each other. The scope of this standard does not cover the design, material selection, and construction of the thermowell, the guide tube, the extension cable, and the temperature transmitter or bridge which may be associated with the RTD. 2 Norma
15、tive references 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. IEC 60780:1998, Nuclear power pla
16、nts Electrical equipment of the safety system Qualification IEC 60980:1989, Recommended practices for seismic qualification of electrical equipment of the safety system for nuclear generating stations IEC 61224, Nuclear reactors Response time in resistance temperature detectors (RTD) In situ measure
17、ments 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 1The user corresponds to the party or the company that uses the RTD in a NPP for measuring the temperature in a safety or a non-safety system. The term user may also refer to the purchaser or
18、the buyer, or the operator of the RTD. BS IEC 62397:2007 6 3.1 accuracy of measurement closeness of the agreement between the result of a measurement and the conventional true value of the measurand IEV 394-40-35 3.2 calibration set of operations that establish, under specified conditions, the relat
19、ionship between values of quantities indicated by measuring instrument or measuring system, or values represented by material measure or a reference material, and the corresponding values realized by standards IEV 394-40-43 3.3 drift variation in sensor or instrument channel output that may occur be
20、tween calibrations that cannot be related to changes in the process variable or environmental conditions IEC 62385, definition 3.6 3.4 performance monitoring process of demonstrating that an installed instrument channel continues to perform its intended function of monitoring the process variable wi
21、th the expected accuracy, response time, and stability IEC 62385, definition 3.14 3.5 resistance temperature detector (RTD) detector generally made up of a stainless steel cylindrical barrel protecting a platinum resistor whose resistance varies with temperature. This detector is placed in the pipin
22、g containing the fluid whose temperature is measured in this way. It can be directly immersed in the fluid or protected by an intermediate casing called the thermowell NOTE 1 Mounting means or connection heads may be included. The temperature-sensing resistor can be made of platinum, nickel tungsten
23、, copper, or other metals. However, a platinum sensor is commonly used in the RTD in an NPP; therefore, a platinum resistance thermometer is referred to in this standard. NOTE 2 In this standard, the term “sensor” describes the RTD unit with all its associated protection, for example, barrel or ther
24、mowell. For most applications of measuring process fluid temperature in an NPP, the platinum resistor sensor is installed inside a stainless steel thermowell. For air temperature measurement, a direct sensor may be used. 3.6 response time the time required for the output signal of a component to rea
25、ch a specified fraction (generally 90 %) of its final variation after a step change of its input signal 3.7 self-heating error rise in the indicated temperature due to the power dissipated in the sensor BS IEC 62397:2007 7 3.8 thermowell protective jacket for RTDs, thermocouples, and other temperatu
26、re sensors. The thermowell is also used to facilitate replacement of the temperature sensor IEC 62385, definition 3.21 3.9 time constant in the case of a first order system, the time required for the output signal of a system to reach 63,2 % of its final variation after a step change of its input si
27、gnal. If the system is not first order system, the term “time constant” is not appropriate. For a system of a higher order, the term “response time” should be used. 4 Design and construction requirements 4.1 General The RTD and its associated devices shall meet the requirements described in this sta
28、ndard but shall not necessarily be limited to these requirements. 4.2 Reliability The design philosophy for RTDs in an NPP requires a device which is capable of continuous successful operation at rated service conditions throughout the design life of the plant. The equipment should have a failure ra
29、te less than 5 103failures per year. RTDs operated in safety systems should have their design lives defined. For RTD whose design life is less than the design life of the NPP or the safety system, then arrangement shall be made for the RTD to be replaced or re-assessed before its design life is reac
30、hed. 4.3 Materials Materials, processes and standard parts which are not specifically designated herein and which are necessary for the manufacturing and installation of the RTD shall be of high quality and in accordance with the highest calibration practice pertinent to the manufacture and applicat
31、ion of instrumentation equipment. All equipment, material, and articles incorporated in the products covered by this standard shall be new but may be fabricated using components produced from recycled materials to the maximum extent practicable without jeopardizing the intended use. 4.3.1 Radiation
32、dose to materials The maximum radiation dose may be about 900 kGy (90 Mrad) depending on the application and the mission time after a design basis accident. Some devices may be exposed to neutron fluxes. The user shall review and approve the use of the materials, which may be subject to activation.
33、BS IEC 62397:2007 8 4.3.2 Resistance element material Platinum is used extensively for resistance thermometers in an NPP for both safety- and non-safety-related instrument applications. Platinum is a noble metal, relatively stable and unaffected by its surrounding environment. It resists corrosion,
34、oxidation, and other forms of chemical attack. It is easily workable and can be drawn into fine wires. Platinum has a high melting- point, which shows little volatilization below 1 000 C. Platinum can be obtained to a high degree of purity, which has a reproducible electrical and chemical characteri
35、stic over a wide range of temperatures. All this is evidenced by a simple linear and stable resistance temperature relationship that characterizes the platinum sensor. However, the electrical resistance of platinum wire is extremely sensitive to minute quantities of contaminating impurities and to s
36、trains; both of these characteristics may alter the simple resistance-temperature relationship. Other metals may also be used for resistance thermometers provided their accuracy, repeatability, response time, and reliability comply with the requirements of the applications. The sensing wire shall be
37、 mounted so as to be almost free of strains to avoid the strain gauge effect from causing extraneous changes in resistance. Furthermore, the thermometer shall be manufactured with the resistance element free of contaminants. 4.3.3 Seals and adhesives The RTD shall be hermetically sealed. The connect
38、or may or may not be an integral part of the RTD assembly. RTD used in a harsh environment, such as under high-temperature and/or radiation areas, shall be designed without organic material. The use of ceramic material is recommended. The tightness of the insulating termination shall be tested accor
39、ding to an adequate and proven procedure. Commonly suggested seals of the connector are glass-to-metal or ceramic-to-metal, which should have less than 108cm3/s leak rate when tested with helium at an atmospheric differential pressure. All cements, adhesives, or seals used internally in the device s
40、hall be capable of withstanding the service conditions without functional deterioration and without emitting gases. All non-metallic materials, when used for seals, protective finishes, and so forth, shall be moisture- and flame-resistant. These non-metallic materials shall not support fungus growth
41、 and shall not be adversely affected by the ambient environments specified in the performance requirements of this standard. 4.4 Connections 4.4.1 Electrical connection RTDs shall have lead wires terminated through a qualified hermetic seal. There are two common types of electrical connections used
42、in an NPP. Figure 1 provides the general form and dimensions of an RTD without any thermowell. Figure 2 is a rigid RTD without a quick disconnect and is referred to as Type I (standard). Figures 3 and 4 are rigid RTDs with quick disconnectors, and are referred to as Type II with long insertion and s
43、hort insertion, respectively. A user may specify any other form of RTD and construction, depending on its particular applications. BS IEC 62397:2007 9 Type I (standard): The electrical connection is made within a metallic housing (connection head) and is achieved by screw-type terminals. The housing
44、 shall be waterproof when closed and shall permit ready withdrawal of the RTD when open. The removable cap shall be joined to the body by a corrosion-resistant chain. The nipple and the extension may be specified as part of the application or recommended by the temperature-sensor manufacturer2. Type
45、 II (quick disconnect): The electrical connection is achieved by using a multi-pin connector. The connector need not be a hermetic type, but it shall be splash-proof when mated and shall meet the insulation resistance requirements in 4.7.6. In addition, the contact resistance across a mated connecto
46、r shall not exceed 0,25 . For high-accuracy application, the user may consider gold or silver plating for the pins and sockets of the connector. Overall length 406 mm Installed length (spring compressed) 195 mm min. Spring Slot for bayonet pin Spring gap Connection head or connector 6,35 0,127 mmIEC
47、 620/07 NOTE Spring may be enclosed inside connection head.Figure 1 Form and dimensions of an RTD Connector Bayonet pin RTD spring Extension tube RTD ThermowellHex. nut Adaptor IEC 621/07 Figure 2 Installation of a rigid RTD (Type I) 2The manufacturer corresponds to the party or the company that man
48、ufactures the RTD. The term manufacturer may also refer to the supplier or the vendor of the RTD. BS IEC 62397:2007 10 Ceramic terminal block S.S. nipple Thermowell RTD Connection head Coupling IEC 622/07 Figure 3 Installation of a rigid RTD (Type II) long insertion Ceramic terminal block Short inse
49、rtionThermowellRTDConnection head Coupling IEC 623/07 Figure 4 Installation of a rigid RTD (Type II) short insertion The temperature rating of the connector shall be at least 150 C or the accident temperature specified by the user. Unless otherwise specified, the manufacturer shall supply the mating connector half with the RTD. The adapter and the extension tube shall be supplied by the manufacturer. Electrical continuity All circuits shall maintain electrical continuity
