Additional Dounreay particles work recommended
Additional sampling has been recommended of beaches near the Dounreay nuclear power site to help in the detection of radioactive particles.
Sand-sized fragments of irradiated nuclear fuel were flushed into the sea from the site in the 1960s and 1970s.
Work to clean up the particles began in the 1980s, after fragments were found washed up on the foreshore at Dounreay.
The continuation of this work, with additional sampling, has been recommended in a new report.
The report by Scottish Environment Protection Agency (Sepa) said monitoring for particles on the foreshore and also at Sandside Beach, which has been done for many years, should continue for the foreseeable future.
But Sepa said equipment used to detect the fragments should be upgraded to improve detection rates, and also to better find more deeply buried particles.
The agency has further recommended the taking of more samples than taken previously and that monitoring be done in May and again six months later at Strathy Point and Murkle Beach.
In the report, Sepa said work done since the 1990s to 2012 to recover particles from the seabed appeared to have successfully reduced "depleted" the number of particles that came to rest there.
Sepa said the monitoring of the beaches would help to confirm if that was the case.
Dounreay, near Thurso, is in the process of being decommissioned.