PETITIONS to stop 300,000 tonnes of 'radioactively contaminated' mud from Hinkley C being dumped into Cardiff Bay have gained more than 58,000 signatures.

One petition was created by Tim Deere-Jones, an independent marine pollution expert, who says that the dumped sediment could expose people in South Wales to radioactivity.

The sediment is being dredged off the Somerset coast to help create the water cooling system of the £20 billion new nuclear power station at Hinkley Point.

Mr Deere-Jones argues that believes the soil is potentially more radioactive than reports from the government suggest, and is calling for the licence to dump the mud to be suspended until more research is undertaken.

"The available evidence implies that only surface samples (0 to 5cms deep) of the sediment have been analysed, despite the fact that core sample research from elsewhere in the Irish Sea demonstrates that, at depths below 5cms, radioactivity concentrations may be up to five times higher," Mr Deere-Jones said.

"We note the absence of research on the fate of such radioactivity in South Wales inshore waters. In this context we are concerned that the environmental and human health risks from the proposed disposal have not been adequately researched and that any conclusions based on the current incomplete data, are unreliable."

Mr Deere-Jones is calling on the Welsh Government to direct Natural Resources Wales to suspend the licence it has granted NNB Genco to dump the mud.

The campaigners also want a full environmental impact assessment carried out, complete radiological analysis and core sampling, as well as a public inquiry and public consultation take place before any material is dumped.

However French energy giant EDF say they have taken the right steps to ensure the process 'poses no threat to human health or the environment'.

There are two petitions, one of which has just short of 7,000 signatures, and a second separate one on actions.sumofus.org which has 51,000.

An EDF Energy spokesman said: “We will be dredging sediment from the seabed off the Hinkley Point C site ahead of drilling six vertical shafts for the cooling water system for the new nuclear power station.

“We consulted a number of stakeholders, some for more than 12 months, before making an application to the Welsh Government Marine Consents Unit for a Marine Licence to deposit this material at the Cardiff Grounds licensed disposal site.

“We have undertaken a number of assessments as part of this application which concluded the activities pose no threat to human health or the environment."

EDF say all activities on the Hinkley C site are strictly controlled and regulated by a number of statutory bodies to ensure the environment and public are protected.