BS IEC 61031-2020 pdf free download – Nuclear facilities — Instrumentation and control systems — Design, location and application criteria for installed area gamma radiation dose rate monitoring equipment for use during normal operation and anticipated operational occurrences.
Because of their location, area radiation monitors may also be capable of indicating changes inplant parameters which are of interest to the plant operator. Where this is the case，monitoroutput functions shall be available at a remote location, usually the plant control room or anassociated area.
Area radiation monitors may also be used for interlocks and/or for initiating protective actions.In some cases, they may even be considered as inputs to reactor safety systems, although thiswould not normally be regarded as good practice.
Area radiation monitors may also be used under accident conditions if the range ofmeasurement is appropriate to the defined purpose and all sub-assemblies are qualified forthe accident environmental conditions at their locations. This application is covered in moredetail in lEC 60951-1 and lEC 60951-3.
5.2General requirements
5.2.1General characteristics and lifecycle
The design of the area radiation monitor shall meet the requirements of lEC 60532.Furthermore, the additionalspecific requirements given in lEC 61031shall be met.
lf signals from area radiation monitors are used as inputs to interlock systems or plant and/orreactor safety systems，the design of such monitors shall also meet the appropriaterequirements of such systems (for example, in respect to interface requirements, classification,reliability, qualification, etc.).
In the selection of the area radiation monitor，consideration shall be given to the range ofmeasurement,temperature，pressure,humidity,electromagnetic interference,vibration,expected total integrated dose and seismic qualification in the areas where the equipment andin particular the detector will be located. Any requirements to extend the normalenvironmentalspecifications shall be identified (see lEC 60532).
The area radiation monitor performing functions that are important to safety shall comply withthe requirements relating to the characteristics and lifecycle of RMSs defined in lEC 62705 andthe standards referenced in lEC 62705(e.g.IEC 61226).
5.2.2Safety classification and applicable standards
The area radiation monitor shall be classified according to its suitability to implement l&Cfunctions up to a defined category during the system specification phase as shown inIEC61513:2011，6.2.3.
According to the category of the function implemented, the following standards shall be applied:a) System and equipment performing category A functions
Any software in the area radiation monitor performing category A function shall be designedand maintained in accordance with lEC 60880.Any HDL-Programmed Device (HPD) in theequipment of the area radiation monitor performing category A function shall be designedand maintained in accordance with IEC 62566.Any hardware in the area radiation monitorperforming category A function and including software or HPD shall be designed andmaintained in accordance with lEC 60987.
b) System and equipment performing category B or C functions Any software in the area radiation monitor performing category B or C function shall be designed and maintained in accordance with IEC 621 38. Any hardware in the area radiation monitor performing category B function and including software shall be designed and maintained in accordance with IEC 60987. Hardware performing category C function in the area radiation monitor shall be designed, selected and maintained according to the supplier’s requirements.BS IEC 61031 pdf download.