Experience of monitoring beaches for radioactive particles

This paper discusses some of the theoretical and practical problems that are encountered in monitoring beaches for hot particles. The experience is from operating a near-continuous monitoring program, for a period of eight years, on beaches near the Dounreay site. The reliability and failure mechanisms of the monitoring systems used will be discussed, together with remedial actions employed. The viability and performance of several types and configurations of radiation detectors will be described, along with methods by which particles might be detected, given their response to buried particles. When large areas are being monitored at high spatial resolution, which is required for efficient particle detection, the volume of data recorded for audit purposes can be very large. The use and abuse of Geographical Information Systems for this work is described. Other practical aspects of performing surveys are also discussed, including understanding health-and-safety requirements; constraints imposed by weather, tides and tidal speed; the logistics of making vehicles available to perform the work; and how a particle should be recovered once detected.