Research finds ‘significant concentrations’ of radioactivity in samples taken from across the Somerset and south Wales coast
A new survey has concluded the spread of man-made radioactivity from reactor discharges into the Bristol Channel is far more extensive and widespread than previously reported.
The research has also detected a high concentration of radioactivity in Splott Bay, which could be linked to the controversial dumping of dredged waste off the Cardiff coast in 2018.
The survey was undertaken over the summer by groups from both sides of the Bristol Channel after EDF Energy refused to carry out pre-dumping surveys of the Cardiff Grounds and Portishead sea dump sites where they have disposed of waste from the construction of the Hinkley Point C nuclear power plant.
The survey found that shoreline concentrations of two radio nuclides (Caesium 137 and Americium 241) typical of the effluents from the Hinkley reactors and indicators of the presence of Plutonium 239/240 and 241, do not decline significantly with distance from the Hinkley site as Government and Industry surveys had previously reported
Overall, the study found significant concentrations of Hinkley derived radioactivity in samples from all 11 sites, seven along the Somerset coast and four in south Wales and found unexpectedly high concentrations in sediments from Bristol Docks, the tidal River Avon, the Portishead shoreline, Burnham-on-Sea and Woodspring Bay.
Along the Welsh coast all samples held significant concentrations of Caesium 137 (10Bq/Kg or more) and positive concentrations of Americium 241.
The highest concentration of both radio nuclides was detected at the most westerly of the Welsh sample sites (Splott Bay), which is also the most distant from the Hinkley point effluent outfalls, leading to the conclusion that the degree of concentration has been possibly impacted by the 2018 dumping of dredge wastes at the Cardiff Grounds
The samples also confirmed that some of the sediment to be dredged from Bridgwater Bay and dumped at Portishead and Cardiff Grounds held well over twice as much Caesium 137 as the sediments around the dump sites, thus risking a localised increase in radioactivity concentrations as a result of the dumping of dredge waste.
Grounds for concern
Speaking on behalf of the Somerset based Stop Hinkley and Welsh campaigns against the radioactive mud dump, Marine Radioactivity Researcher Tim Deere-Jones said: “The results of this survey clearly demonstrate that there are serious grounds for concern that the Bristol Channel/Severn estuary coasts and communities had already been subjected to radiological contamination from Hinkley since the 1960s and that EDFs current programme of dumping radioactive wastes at Cardiff Grounds and Portishead should not have been permitted by the Welsh and English Agencies in the absence of the baseline data.”
In August the Marine Management Organisation (MMO) approved EDF’s application to dump mud and sediment from the construction of the Hinkley Point C nuclear power station into a coastal site close to the north Somerset town of Portishead.
EDF had originally applied to National Resources Wales in February 2020 for a licence to dump 800,0000 tonnes of mud dredged as part of building work for the new plant being built on the site of the disused Hinkley Point A facility at the Cardiff Grounds after previously disposing of mud at the site two years earlier.
It claims the Bridgewater Bay sediment is “not radioactive under law”, but campaigning groups point out that the UK Government’s official radioactivity monitoring reports annually confirm the presence of human-made radioactivity, derived largely from over 50 years of discharges to sea from the Hinkley Point reactors, including Plutonium, Caesium 137, Tritium, Technetium 99, Carbon 14 into the Bridgewater Bay sedimentary and marine environment.