BS IEC 60951-4 pdf download

BS IEC 60951-4 pdf download NUCLEAR POWER PLANTS – INSTRUMENTATION IMPORTANT TO SAFETY – RADIATION MONITORING FOR ACCIDENT AND POST-ACCIDENT CONDITIONS – Part 4: Equipment for continuous in-line or on-line monitoring of radioactivity in process streams
1 Scope
This part of IEC 60951 provides general guidance on the design principles and performance criteria for equipment for continuous in-line or on-line monitoring of radioactivity in process stream in nuclear power plants for accident and post-accident conditions. General requirements for technical characteristics, test procedures, radiation characteristics, electrical, mechanical, and environmental characteristics are given in IEC 60951 -1 .
These requirements are applicable in this part unless otherwise stated. IEC 60951 -4 is only applicable to continuous in-line or on-line measurement, i.e. monitors for which the detector measures radioactivity by being positioned in the process stream (i.e. immerged in) or adjacent to the process stream (i.e. viewing straight through a pipe or tank).
It does not apply to monitors for which the detector measures a representative proportion of the stream at some remote location (sampling assembly), which are within the scope of IEC 60951 -2. IEC 60951 -4 is only applicable to monitors for accident and post-accident conditions. Process stream radiation monitoring equipment for normal and incident conditions are within the scope of IEC 60768.
2 Normative 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 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic (12 h + 12 h cycle)
IEC 60068-2-78:2001 , Environmental testing – Part 2-78: Tests – Test Cab: Damp heat,steady state
IEC 60951 -1 :2009, Nuclear power plants – Instrumentation important to safety – Radiation monitoring for accident and post-accident conditions – Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60951 -1 apply.
4 Design principles
4.1 General Except where otherwise specified, all the requirements specified in Clause 4 of IEC 60951 -1 shall be carried out, unless otherwise stated.
4.2 Basic requirements related to functions The main purpose of equipment for continuous in-line or on-line monitoring of radioactivity in process streams is to continuously measure radiation levels in appropriate pipes or tanks, either by being positioned in them (i.e. immerged in the process stream) or adjacent to them (i.e. viewing straight through the process stream). These radiation measurements are displayed locally and/or in control rooms to keep plant operators aware of current radiological conditions. This information is used for control purposes and/or initiation of protective actions. Therefore, the equipment concerned by this standard is capable of actuating alarms and providing inputs to other plant systems and processes in order to isolate processes at abnormal radiation levels.