BS IEC 60737 pdf download – Nuclear power plants – Instrumentation important to safety – Temperature sensors (in-core and primary coolant circuit) – Characteristics and test methods
Scope
This International Standard is applicable to general aspects of system and component design,manufacturing and test methods for temperature sensors used in-core and for the primarycoolant circuit in nuclear power reactors.
These sensors include thermocouples and RTDs(Resistance Temperature Detector-RTD).Emphasis is placed on the features specific to the nuclear application and recommendationsconcerning components and sensors are made only when they relate to the containment ofsuch components within the reactor primary envelope and/or in high radiation fields.
The conditions imposed by reactor use are often different from those which occur in non-nuclear applications. Parts of the in-core system may be located in very severe environments.
Exposure to high neutron and gamma radiations is liable to cause error due to nucleartransformations, heating and structural changes, and to affect the mechanical and electricalproperties of the equipment so that extra care has to be taken in the standards adopted forinstallations and in the choice of materials.
Furthermore,design consideration needs to be given to the effects of high environmentalpressure, high temperature，temperature gradients and temperature cycling as well as to theway in which the temperature measuring system could influence the safety or economicperformance of the reactor.
The consequences of nuclear conditions for temperature sensors lead to strong requirementsregarding qualification.
This standard deals with specific requirements for nuclear applications of temperaturesensors. It has two purposes:”
a) to provide a guide which will help to ensure that the reactor conditions do not damage thetemperature sensors;
b) to ensure that the in-core temperature measuring system and the sensor installation do
not prejudice the safe operation and the availabilify of the reactor.
Statements of general applicability are made but detailed consideration is restricted tothermocouples and RTDs.
2Normative 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 editionof the referenced document (including any amendments) applies.
lEC 60584-1，Thermocouples – Part 1: Reference tables
IEC 60584-2，Thermocouples – Part 2: Tolerances
IEC 60584-3, Thermocouples – Part 3: Extension and compensating cables – Tolerances and identfication system
IEC 60709, Nuclear power plants – Instrumenation and control systems important 10 safety – Separation
IEC 60751, Industrial platinum resistance thrmometers and platinum temperature sensors
IEC 60780, Nuclear power plants – Electrical equipment of the safety system – Qulification
IEC 60980, Recommended practices for seismic qulfication of electrical equipment o1 the safety system for nuclear generating stations
IEC 61226, Nuclear power plants – Instrumentation and control important to safety – Classilication of instrumentation and control functions
IEC 61513, Nuclear power plants – Instrumentation and control for systems important to salely – General requirements for systems
IEC 61515, Mineral insulated thermocouple cables and thermocouples
IEC 62342, Nuclear power plants – Instrumentation and control systems important to safety – Management of ageing
IEC 62385, Nuclear power plants – Instrumentation and control important to safety – Methods for assessing the performance of salely system instrument channels
IEC 62397，Nuclear power plants – Instrumentation and control important to safety – Resistance temperature detectors
IEC 62460, Temperature – Electromotive force (EMF) tables for pure- element thermocouple combinations
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IAEA Safety Glossary edition 2007, IEC 60050-393 and IEC 60050-394 apply as well as the following:
3.1
accuracy of measurement
closeness of the agreement between the result of a measurement and the conventionally true value of the measurand
[IEV 394-40-35]
NOTE 1 “Accuracy’ is a qulitative concept.
NOTE2 The term “precision” should not be usod for “accuracy”.
3.2
electrical shunting
effect of the shunting of the source impedance of the sensing device by the input impedance of the measuring device and the earth leakage impedance of the sensor
BS IEC 60737 pdf download – Nuclear power plants – Instrumentation important to safety – Temperature sensors (in-core and primary coolant circuit) – Characteristics and test methods
