PLANS to dump 300,000 tonnes of mud from the Hinkley Point nuclear power station in Somerset off the coast of south Wales have been met with widespread opposition, with campaigners claiming it could be radioactive.

EDF Energy, which is constructing the new £18 billion power station - which is just 43 miles away from Newport across the Bristol Channel - has been granted a licence by Natural Resources Wales (NRW) to dispose of mud from the site about one mile out to sea off the coast of Cardiff.

But campaigners have said they are concerned the mud from the site, which has been home to a nuclear power station since 1976, could be contaminated with radiation and hazardous to the health of people and wildlife and damaging to the environment, and a protest against the plans will be held outside the Senedd in Cardiff Bay on Bank Holiday Monday.

Although the dumping, which will be monitored by NRW, was due to start this month, it has been delayed and is now expected to begin early next month.

EDF has insisted the mud is "typical of sediment found anywhere in the Bristol Channel" and poses "no threat to human health or the environment".

And an NRW-commissioned study carried out last year concluded the mud "did not have unacceptable levels of chemicals or radiological materials and was suitable for disposal at sea".

But campaigners have continued to express concerns over the plan.

One of the most vocal campaigners has been South Wales Central AM Neil McEvoy, who has called for the dumping licence to be suspended while further investigations are carried out.

Writing for nation.cymru the Independent AM said: "The fact is that only five samples of mud were taken from below 5cm back in 2009.

"The raw data from the testing was also destroyed. Why was that?

"I note also that only one kind of testing was done, whereas officials of the UN environment programme investigating potentially radioactive mud in Kosovo tested samples three ways, using beta spectrometry, alpha spectrometry and plasma mass spectrometry.

"If it is good enough for Kosovo why is it not good enough for Wales?"

He added: "We are talking about the health of an entire nation here. The mud particles will migrate 10 miles in from the Welsh coast that they will be washed all around.

"If I were a decision maker, I would ensure that as much testing as possible was carried out. This is only reasonable."

Plaid Cymru has also objected to the plan. Shadow energy, climate change and rural affairs secretary Llyr Gruffydd said: "We believe that it is completely unacceptable and unprincipled that waste from a nuclear construction site in England should be disposed of in Welsh waters.

"If it disperses or has an effect on the local environment it will be for the Welsh Government to make good any such impact in a protected marine area. Despite this, no payment or compensation has been offered to the Welsh taxpayer.”

Last year a petition against the plans set up by a self-employed marine pollution consultant Tim Deere-Jones was signed by 7,033 people.