Radiation scans of two north coast beaches near a nuclear plant have not revealed any fresh finds, according to the UK Atomic Energy Authority (UKAEA).
Particles have been found on beaches near the plant
Monitoring teams spent July checking Dunnet and Melvich for signs of historic radioactive leaks from Dounreay in Caithness.
A particle and an unidentified radioactive object were recovered from Dunnet Beach in March 2005.
Last April, a further particle was found at Murkle.
Nearly all off-site contamination has been detected on the seabed off the complex and at Sandside Beach.
Monitoring of Sandside has been suspended since May.
Local estate owner Geoffrey Minter barred access to the beach after losing patience with the UKAEA's efforts to come up with a plan to deal with the contamination.
The monitoring programme covers beaches at Melvich, Sandside, Crosskirk, Brims Ness, Scrabster, Murkle, Peedie and Dunnet.
A total of 95 particles and an unknown radioactive object have previously been recovered from the 4 mile (6km) stretch of sand at Sandside.