IEC 61468:2000 pdf free download

IEC 61468:2000 pdf free download Nuclear power plants – In-core instrumentation – Characteristics and test methods of self-powered neutron detectors
1 Scope and object
This International Standard applies to in-core neutron detectors and instrumentation which are designed for purposes important to safety: protection, control and information. It is restricted to characteristics and test methods for self-powered neutron detectors (SPNDs). Self-powered neutron detectors can be used for neutron fluence rate (flux) measurements and spatial power measurements in nuclear reactors.
This standard gives requirements, recommendations and guidance on selection of the type and characteristics of SPNDs for different possible applications of SPNDs. For the principles of overall plant and I&C system design and the purpose of neutron fluence rate measurements, reference should be made to general principles of nuclear reactor instrumentation according to IAEA Codes and Safety Guides and IEC 61 51 3.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60050(394):1 995, International Electrotechnical Vocabulary (IEV) Chapter 394: Nuclear Instrumentation: Instruments
IEC 6051 5:1 975, Radiation detectors for the instrumentation and protection of nuclear reactors; characteristics and test methods
IEC 60568:1 977, In-core instrumentation for neutron fluence rate (flux) measurements in power reactors
IEC 61 226:1 993, Nuclear power plants – Instrumentation and control systems important for safety – Classification
IEC 61 51 3, Nuclear power plants – Instrumentation and control for systems important to safety – General requirements for systems 1 )3 Definitions and abbreviations
3.1 Definitions
For the purpose of this publication, the following definitions apply:
3.1 .1
background or lead-compensation (of a self-powered detector signal)
a method employed to correct the current from a SPND for background contribution. This is usually accomplished by placing an “emitterless” background detector in the in-core assembly, or by using detectors with an internal compensating lead wire (see figure 3)
3.1 .2
beta decay
radioactive decay process in which mass number A remains unchanged but the atomic number Z changes. Processes include electron emission (β – decay), electron capture, and positron emission (β + decay)
3.1 .3
burn-up
depletion or reduction of target atoms when exposed to a thermal neutron fluence rate over time, due to conversion to other radioisotopes