More than 270 fragments of nuclear fuel have been recovered from the seabed since the latest phase of offshore clean-up got underway at the start of August. Of the 279 recovered to date, 40 fragments have been categorised as a "significant risk" to health, with the remainder falling into lower levels of radioactivity.
The fragments are being detected in an area of 12.5 hectares - equivalent in size to 17 international football pitches - in the vicinity of a disused seabed outfall 600 metres offshore.
A remotely-operated vehicle (ROV) equipped with the Groundhog detection system is criss-crossing the seabed in water up to 30 metres deep, retrieving fragments using a front-mounted auger and suction system.
The operation is controlled by a team of 22 working around the clock on a barge anchored offshore. Twenty-three days have been lost to bad weather. The main contractor is Land and Marine, supported by Nuvia.
The clean-up has cost £1.5 million so far this year. It continues into October.