By Steven McKenzie
BBS Scotland news website
Highlands and Islands reporter
Experts have run tests on the effectiveness of equipment used to monitor for radioactive particles on a beach near Dounreay.
Vehicles searched for deliberately hidden radioactive sources
The Committee on Medical Aspects of Radiation in the Environment (Comare) checked that kit used on Sandside Beach is up to the task.
It is the first time such trials have been carried out on the vehicles called Groundhog Evolution and Groundhog Mk I.
Test results will not be available for a number of weeks.
Professor Alex Elliott, chairman of Comare, said the Groundhog Mk I had to be rebuilt for the trials because it was taken out of service several years ago.
The equipment, used by UK Atomic Energy Authority contractors, had to detect radioactive sources deliberately buried in the Caithness beach.
For safety reasons the sources were kept in sealed containers and later recovered under the supervision of environment agency Sepa.
Prof Elliott said tests involved checking that the equipment could detect caesium 137 particles from fuel repossessing and cobalt 60 which comes from "activated" steel.
Trials at Sandside were carried out from 8 to 10 April on the recommendation of the Dounreay Working Group.
Sepa observed the trials and confirmed all sources were recovered.
Comare has previously examined childhood cancer rates close to Rosyth Naval Base and nuclear power stations.
Geoffrey Minter, who owns Sandside Beach, welcomed the trials.
He said: "We are pleased that six long years after the radioactive nuclear fuel particles began to be found in number here, at long last, a thorough and serious study of the monitoring is being conducted.
"We shall be provided with the full results.
"There is another kind of radioactive waste particle that could have arrived but that the detection vehicles were not set to find and we have long expressed a view that they should be."
The equipment that has been used to monitor Sandside until now - Ground Hog Mk I and Mark II - was not set to find cobalt particles, which have already been found at Dounreay beach and offshore.
"There is nothing to stop them arriving at Sandside," said Mr Minter.