RTS – MULTIFUNCTION RADIATION MONITORING STATIONS
RTS Instruments has a long time experience in designing and setting-up radiation monitoring outdoor stations for environmental applications as well as for applications related to nuclear power plant, other nuclear facilities, and border control.
The accurate measurement of the presence of radio-nuclides in the environment requires, as well known, careful investigation of airborne contamination, a matter constituting the ‘core business’ of RTS.
Air contamination monitors were formerly designed to measure the beta/gamma emitting long-lived radio-nuclides that may be released from nuclear facilities. Subsequently, the need to increase measurement sensitivity, and to employ these instruments for the surveillance of wider outdoor areas and workplaces, determined the development of more sensitive and reliable equipment able to provide ‘real-time’ or even ‘quasi-real-time’ evaluation of the radioactive contamination in air, due to alpha and beta emitting aerosols (to be noted that most of the interesting gamma emitters are also beta emitters and in any case the detection of alpha and beta particles is a quite sensitive method for a fast determination of a radioactive leak in a plant or around it) divided into its ‘long lived’ and ‘short lived’ components. If this kind of measurement (alpha/beta in air with dynamic compensation and measurement of radon/thoron presence/progenies and gamma background, this last by an internal probe strictly belonging to the RAM unit) is coupled to an ‘external’ or ‘environmental’ sensitive and independent gamma dose-rate monitoring unit, then a relatively complete information may be obtained regarding the controlled area.
The basic configuration of a sound monitoring station is therefore composed by a RTS RAM Radioactive Aerosol Monitor coupled to an external RTS Gamma Dose-rate Monitor (ENVIRAD or HNQ based on GM tubes, or ENVIPGC based on proportional gas counters, or MAG based on ion chambers, or GAMSI based on solid state detectors, or other probes also using gamma spectrometry if/when useful), installed in a properly designed outdoor shelter with, at least, internal conditioning, security and uninterruptible power distribution systems.
The RAM model may be RAM-01 or RAM-31 (circular filters, manual (01) or automatic (31) filter changing capability) or RAM-TF (tape filter, automatic advancement, autonomy 180 equivalent filters). The RAM units may be equipped with silicon detectors with sensitive area from 450 mm2 to 2400 mm2, depending on the Customers’ need and specifications.
The sampling flow rate range may be selected among three main standard choices, each one based on appropriate design and filter media: in general ‘LV’ 2 to 6 m3/h, ‘HV’ 7 to 15 m3/h and ‘HHV’ 16 to 40 m3/h. However a special flow rate range may be optional provided under Customer’s request. A WTS Weather sub-station may be always added.
These basic/simpler configurations belong to the RTS EMS/AMS Stations series.
Further configurations have been set-up with adding instrumentation and capabilities. This may help the Customers for thei selection of characteristics.
The ERMS Station series also include the gamma emitting aerosol facility provided by the RAM-01/31NA (with NaI(Tl) detector) or the RAM-01/31GE (with electrically cooled HPGe detector) and, eventually, the sampling/monitoring of gaseous/molecular species or in any case aerosols not trapped by the RAM filter (as example I-131, but not only), performed by a RTS RIM unit based on charcoal impregnated filters or TEDA standard cartridges and NaI(Tl) detector (RIM-01 type, single filter/cartridge, manual changing, or RIM-14 type with automatic changing capability).
The MRMAS Station series defined as ‘Multifunction Radiation Monitoring Air Stations’ are more complex, characterized by several measuring functions and features. These stations provide at least a further measuring ‘channel’, usually based on NaI(Tl) detector, of the RWM/UWM type (Water monitoring with Marinelli sampling tank or Underwater monitoring) or RGM type (with Marinelli shaped tank for gaseous radioactive contaminants like, as example, noble gases, but not only). This Marinelli head for air monitoring could also be set for containing GAC (granular activated carbon) to enhance sensitivity.
The MRMAS-01 employs a RAM-01/31NA or RAM-01/31GE, uses standard TEDA cartridges for the units type RIM-01/14C and the third monitor belongs to the RWM/UWM series.
The MRMAS-02 is identical but designed to use as third unit a RGM unit instead of RWM/UWM: RGM-02LIR with Marinelli tank but no GAC.
The MRMAS-03 is identical to the ‘02’ model, but with extended multi-functionality: the RIM unit (RIM-01/18CF) may use both charcoal impregnated filters as well as TEDA cartridges and the RGM unit (RGM-02LIM) may have the Marinelli tank with or without GAC.
It is to be noted that actually (October 2019) RTS has developed and is developing further solutions regarding the RAM family. Among them: RAM-01/31CS and RAM-TFCS (they are RAM-01/31 or RAM-TF with the CS/PIN adding detector for gamma emitting aerosols), then RAM-TFD (a RAM-TF with a second, delayed, measuring head) and RAM-CS (a RAM-TF for only gamma, equipped with a CS/PIN detector as basic, with (D) or without the alpha/beta delayed head).
For all the outdoor stations listed above, RTS has standardized the appropriate shelter, which, for most applications, conforms to the ISO standards for transportable containers (in order to make easy the transportation to the installation site) and provides enough internal space for the operators, the auxiliary services/devices and maintenance.
Conditioning system, UPS, security and safety systems, emergency lights, surges and lightning protection, internal climate sensors, etc., are standard.
Redundant data transfer and communication may be provided in several ways.
It is to be noted that these applications are based on standard instrumentation and solutions, and RTS has made efforts to standardize some configurational solutions in order to help the Customers during their choice, but, usually, the final set-up should also be tailored for the effective Costumers’ requirements. And this is a well-know capability of RTS, thanks to its remarkable experience, enriched over the years. The above considerations are the reasons why any reference shall be only considered related to ‘similar systems’, as the case of ‘identical systems’ usually apply exclusively to the same Customer.
