IEC 62484:2020 pdf free download – Radiation protection instrumentation-Spectrometric radiation portal monitors(SRPMs)used for the detection and identification of illicit trafficking of radioactive material
4.1.1overview
The equipment addressed by this document shall detect the presence of gamma-ray emittingsources, identify gamma-emitting radionuclide(s), and may detect neutron sources.
An indication shall be provided when the measurement results from the detection systemexceed an alarm criterion or pre-set condition(user selectable for radiation level oridentification result).Measurement occurs when the object passes through the detection zone(transient mode) or with the object static within the detection zone where the user performscontrolled analyses of the object (i.e., enters collection time and/or activates the count toobtain a spectrum).
Passage speeds for transient mode testing are stated in each applicable clause andsummarized in Table 2.Testing at different speeds may be performed as a special test uponagreement between the manufacturer and user.
Monitors shall be capable of operating independently of any peripheral device or remotestation and shall be unaffected by any malfunction of a peripheral device.
The detection zone is the area located adjacent to a single-sided detection assembly orbetween two or more detection assemblies where the measurement of radiation takes place(Figure 1).The size of the detection zone is based on the classification of use. If a monitor isused in two or more classifications，its detection zone shall be appropriate for eachclassification.The detection zone shall be of a size that ensures that all objects which couldmove through the detection zone are monitored. The manufacturer shall state the SRPMclassification(s) for which the requirements stated in this document are met.
Operational conditions such as separation distance (distance between opposing detectionassemblies), object speed， and background radiation’should be considered when installingthe monitor.
lt is important to be able to identify the object that caused an alarm. The alarm should begenerated within a period of time to ensure that the object that caused an alarm can beidentified.This is important if complex algorithms are in place that need a finite process time.lt becomes more important if a constant stream of traffic is being monitored (e.g.,pedestrians).
4.1.2Pedestrian monitor
Pedestrian SRPMs shall provide a detection zone to ensure that people are monitored.Pedestrian SRPMs may use a single detection assembly (single-sided) or multiple directlyopposing detection assemblies (two-sided). If the height is restricted by the SRPM frame, thetop testing height of 2 m may be adjusted to allow test sources to pass through the detectionzone.
4.1.3Road vehicle monitor
Road vehicle monitors are divided into two types, large and small.Small road vehicle SRPMstypically monitor vehicles that are s 2,5 m high.Large road vehicle SRPMs typically monitorvehicles that are typically > 2,5 m high.Both types shall be two-sided.
4.1.5ackage (or conveyor) monitor
Package or conveyor SRPMs shall provide a detection zone to ensure that items movingthrough the detection zone are monitored.Package or conveyor SRPMs may use a singledetection assembly or multiple detection assemblies with detectors across the top, bottom,and/or side(s) of the detection zone. The detection zone is located adjacent to a detectionassembly for single sided conveyor SRPMs. For multiple detector conveyor SRPMs, thedetection zone is located between the detection assemblies.
4.2Physical configuration
SRPMs may be designed for use in weather controlled or non-controlled environments.Thedetection assemblies for road and rail vehicle monitoring may be subjected to vibration fromthe passing of heavy vehicles. Mounting techniques (i.e., concrete pads) that are notaddressed by this document shall be designed to minimize the transfer of vibration and shockconditions to the detection assemblies.