Preparing for accidents which involve major airborne releases of materials presents trainers with many difficulties:
• Creating a sense of realism may be impossible
• Supervisory staff may not be available
• Large areas may need to be covered
• Communications may be inadequate
• Staff may be required to act on their own for long periods
To provide a solution to these problems, STS has designed the PLUMES SIMULATION EXERCISE SYSTEM. A simulated survey meter, containing GPS and some real time computing, continuously establishes the operator’s position and calculates the airborne hazard that the operator should experience. This system adds great realism to exercises, and thus enhances the skills of monitoring staff.
The PLUMES System may be used to simulate the releases of radioactivity, chemical and biological warfare agents or toxic industrial gases.
The simulation has three main features - GPS to inform the instrument of its position in the training area; a microprocessor to calculate the position within the simulated plume; and an algorithm which describes the dispersal of the released material using the position data and source terms.
Input Data
The source terms for the release are created on a PC, using STS software.
These terms include:
• Coordinates of the release point
• Wind speed and direction
• Quantity of radioactivity released
• Height of release above ground
• Rate of release
• Time of release
• Elevation
Algorithms
PLUMES uses an algorithm to continuously calculate the concentration of gas or radiation at any position, using both the stored source terms and the GPS position data. Algorithms such as the NRPB R91 work well and others may be used.
Cloud Measurement Exercises
Exercises involving the measurement of a cloud material passing across an area are easily simulated using Plumes.
The simulator may be set for a continuous release scenario, or for a short term release, when an isolated "cloud" of gas appears to travel downwind from the release point.
Deposited Material Exercises
GPS now gives a positional accuracy of better than 2 m and this allows the monitor to achieve realistic repeat readings at the same monitoring point., allowing ground deposition exercises to be staged.
