Radioactive materials are now part of modern life in industry, research laboratories, nuclear fuel processors, power stations, and hospitals. While their benefits are well established, their monitoring and control present special problems. One of these is the difficulty in training staff to detect and control contamination, because in order to achieve this, both trainers and trainees are necessarily exposed to it. This is a clear conflict with generally recognised safety principles, including ALARA. To overcome this, Safe Training Systems (STS) have developed a realistic simulation system, the STS 800 series of Ionizing Radiation Simulators.

STS simulators make possible realistic training without the use of radioactive sources.  The system uses simulated radioactive sources which are in powder or liquid form.  The source releases a gas which is of low toxicity, is non-flammable and is environmentally safe.  A probe, outwardly indistinguishable from a radiation monitoring probe, houses a gas sensor, specific for the gas released from the simulated source.  The probe is connected to either an imitation ratemeter, or to a real ratemeter via an electronic interface mounted underneath the ratemeter case.

In operation, the gas sensor detects the gas from the simulants, the interface allows this signal to be accepted by the ratemeter, and hence, the trainee experiences realistic monitoring.  More detailed descriptions of the uses of this system are given further down the page.

Instrument types

STS manufactures simulated instruments and also modifies real instruments by adding an electronic interface.  Models are available to simulate Eberine, NE Technology, Ludlum, Mini Instruments and others. 

A series of simulated probes for the most popular models are available.  These include the 44A, HP260 and 210, DP2, DP6, BP4, AP3, and SPA6 models.  These probes have their own 5 pin connectors, so that they cannot be connected place of real probes.

Applications

The STS 8000 series of Ionizing Radiation Simulators may be used in many ways to aid the training of staff, including instruction in ratemeter and probe use and manipulation; in the control of spread of contamination; in decontamination exercises and in the staging or exercises to demonstrate the ability of staff to handle an incident.

The use of ratemeters is usually very straightforward, but the correct manipulation of probes is much more complex.  The relative position of the probe to the surface to be monitored is critical, in that too large a distance will result in no radioactivity being found, while too short a distance may lead to probe contamination - an equally undesirable situation.

Thorough training is therefore necessary, and the STS 800 series permits staff to gain confidence in these skills without exposure to real sources.

Control of spread of contamination

The spread of contamination is a particularly significant consideration when process workers, engineers, firefighters and other non-scientific staff are being trained.  To aid this training, the STS liquid source material is particularly useful.  This is a viscous liquid, which transfers easily from surface to surface - for instance from equipment to glove to overall - allowing this particular hazard to be convincingly demonstrated.  

Decontamination exercises

Instruction in decontamination is easily achieved with the STS 800 system.  Either powder or liquid sources may be used, and decontamination can be demonstrated by washing, swabbing, sweeping or other processes.  In the case of the liquid simulators, even vigorous swabbing does not totally remove the contamination from smooth surfaces, while fabrics and rougher surfaces respond even less well, as is the case with actual radioactive contamination.  The use of aerosol foam decontamination materials does, however, result in complete removal.

Materials used in decontamination, in particular swabs, become contaminated, and this can be demonstrated by monitoring with the STS probe.

Incident Exercises 

Exercises to ensure that the various emergency teams - health physicists, firefighters, medical staff and emergency planners - can operate as an integrated organisation requires excellent simulation if realism is to be achieved.

An exercise based on the use of an STS 800 system and including the liquid source material with its ability to realistically spread and contaminate  those involved, has considerable benefits.

Scenarios can be designed which could not be contemplated without the use of this system, and which will lead to a greater understanding of the hazards present, and the need for concerted action to control the situation.

Both the liquid and solid source simulants are based on materials of low toxicity that are non-flammable and are environmentally safe.  Safety data sheets are available.

Patent protection

United Kingdom and Overseas patents have been applied for in respect of this technology.