Why Simulate?

Why Use Simulation for Radiation and Contamination Monitoring?

Simulators are essential in many training situations, for instance training aircraft pilots, firearms training and in medical procedures, so the principle is very well established. The reasons for their use are complex – sometimes because of cost, sometimes where there is technological difficulty in providing training without a simulator, sometimes to reduce strain on the trainee.

In the case of ionising radiation simulators, there is a very specific reason – the environment that the trainee is ultimately going to work in is fundamentally hazardous and international regulations IRR 1999 forbid any unnecessary exposure of staff – even during training. Simulators are able to replicate the appearance and characteristics of contamination from radioactive sources and replicate cross contamination where clothing contamination or skin contamination may occur. This is not possible to duplicate with a real source scenario without undue and prolonged exposure.

A second consideration is 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.

A further difficulty in detection training with real radiation sources is the amount of paperwork required to move sources, even very small ones, from very secure areas to “open field” exercise areas. This consumes a great deal of time which could be more productively used. Radiation 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.

The requirements for the form and performance of the simulators is worthy of consideration and should be considered in two aspects. Firstly, the technology used should produce a realistic response, so that the trainee experiences a very similar performance from his simulator as he would from a real instrument.

In particular, aspects such as the Inverse Square Law, materials shielding and response speed are vital, as are the function of the major controls on the simulator.

Of great importance is the physical form of the simulator and because there is no substitute for the real thing, simulators need to be as close to the real instrument manufacturers (such as Thermo, Ludlum, Rotem, Automess, Saphymo) as possible. It is essential that the trainee is instructed in the use of the particular instrument that they will go on to use in a real life situation be that an Electra a RO20, a Ram Gene, an SPA6 or an AD6150 etc.

It is the very fact that the simulation situation is true to life that makes the training such a valuable exercise and an instrument that does not react in a realistic fashion – for example by being shielded by paper or plastic will not educate the trainee, and may place them in a potentially hazardous situation.

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

Ultimately trainees will need to make measurements with real instruments and sources, under supervision, but their performance here will be much more confident if they have progressed to that point via good simulation