How the STS Radiation simuation systems work

STS Radiation Simulation Systems

How they work..

Contamination Simulation System

STS specialises in the conversion of standard instruments for training purposes. A range of instruments from the Thermo RadEye & Rotem Ram Gene to the Thermo Electra and Mini 900 are available all designed to replicate the response and characteristics of the real instruments.

STS Simulators are able to replicate the characteristics of contamination from radioactive sources
including cross contamination where clothing, skin or environmental contamination may occur; this is not possible to achieve with a real source scenario without undue exposure to the trainee.

Limiting the exposure of the trainer – if real sources are used, every training session poses an additional cumulative dose to the trainer, while the trainee receives only the dose resulting from the session attended.

Training with real radiation sources requires a considerable amount of paperwork to move sources, even very small ones, from secure areas to “open field” exercise areas taking time which could be more productively used.
STS simulators solve these problems – the trainer has no cumulative exposure from each training session and the trainee can make serious mistakes without any hazard to anyone.

Good simulators allow training to progress from “no knowledge” to a full understanding of instrument controls, the relationship of source position, Instrument position and meter reading.

Ultimately as simulators cannot recreate the 1:1 million dynamic range of modern survey instruments, trainees will need to make measurements with real instruments and sources, under supervision, but their performance will be much more confident if they have progressed to that point via good simulation training.

TechnologyThis simulator uses proprietary gas sensing technology.This technology consists of two parts, simulated contamination and a modified meter or smart probe to detect it. The simulated contamination is a safe liquid - STS LS1 - which can be applied to clothing, equipment, plant and surfaces where it slowly evaporates. Because the gas is very dense, the gas cloud stays near to the surface. OperationThis simulation system is used to train staff in monitoring general radioactive contamination, or, in specific sites, Alpha contamination.The gas cloud stays within about 2 cm of the surface, and within this range, the signal will range from 2000cps at almost contact to background at 2 cm. To force the trainee to develop good monitoring technique, the system is regulated so that if the monitor is passed too quickly over the surface or is too far away, little gas is captured. Hence the trainee learns to monitor with the probe close to the surface and travelling slowly.

The period when the LS1 is generating sufficient gas to enable the simulation to operate is dependant on length of time, temperature and roughness of the surface. For example, on a cold concrete floor, the LS1 may remain for 8 hours, while on a warm, rough cloth sleeve the liquid will be have evaporated in less than 1 hour.

In any case, the source will have completely evaporated in 24 hours, allowing a new session to be undertaken without a ‘hangover’ from the previous training session.

Because the liquid is sticky it is easy to demonstrate transfer of contamination – brushing a hand over a contaminated
surface will result in the hand becoming contaminated and then everything touched is also likely become ontaminated.
Decontamination by wiping or washing will allow clean-up procedures to be undertaken.

For some applications a solid contaminant may be required and STS produce the SS4 powder stimulant for this purpose.

Radiation Field Simulation System

The New STS Safe-Series is the latest development in hand held radiation instrument simulation providing the most realistic experience yet for trainees in the Nuclear Industry, Homeland Security and Emergency Services.

This new system has been developed to as closely as possible mimic a real ionising radiation field and the detection instruments have been designed to replicate the real response an instrument would give.

The simulated field is generated with a Radio Frequency source which utilises a unique antennae design producing a near isotropic field of simulated radioactivity. The field is emitted in all directions out to a distance of approximately 15M depending on the activity level set on the source.

The Safe Series MiniSources are extremely compact measuring just 80x60x40mm and so are ideal for covert training for either emergency planning, source retrieval or CBRN exercises. The sources are available in either a fixed activity level which may be selected individually on ordering or a variable activity from a choice of 10 settings. The flexible software allows for simulated radiation fields of up to 10Sv/hr to be generated and down to 0.5uSV/hr for more subtle applications.

The detectors alarm and background levels can be preset such that they are in line with the real instruments used by the trainees, this applies to both the Safe-Survey meters and Dosimeters. The nuclear training can therefore be truly tailored to the trainees requirements be that Ambulance or HART radiation training, Police radiation response training, Military training, Civilian Nuclear Power or Homeland Security hazmat training.

The real benefit of the new Safe-Series comes when group training is required. Up to 16 units can be fielded at any one time and in any combination. So 6 participants can all have a survey meter operating whilst wearing a Safe-EPD or Dosi-Safe dosimeter and 4 sources of different field strengths can also be fielded- as below. All of the units talk to each other and the effect of having multiple sources means an accumulated field strength is registered on the instrument. Exercises may therefore be conducted to demonstrate the hazards involved where multiple sources are located and a large source may be masking the activity of other weaker sources.

The Safe-Series system requires no trainer input except to set up the background and alarm levels required before commencing a training session. Levels once set are remembered by the system so that next time the units are ready to go without adjustment, on delivery the instruments are set to the customers requested setting before being dispatched.

Both Dosimeters and Survey meters have LED alarm lights which are activated once the alarm threshold is breached and audible buzzers (approx 80DB) which sound on the thresholds of either rate or dose alarms. On the dosimeters the alarm has to be acknowledged in order to stop the unit from sounding, each alarm has a different tone with the final dose alarm being an uninterrupted tone.

The radio frequency system allows the signal to be read though materials such as wood, brick, glass and plasterboard - and the signal received by the instrument is attenuated differently for each material. The system is therefore particularly suited to demonstrating the effects of distance (inverse square law), shielding and time on the trainees received dose.

As new instruments are developed by STS so they will all still work with the existing system - so new instruments can be incorporated into the existing Safe Series framework without needing to replace existing equipment.