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The radioactive dump proposal                       


In July 2017 I discovered that the Welsh Government had granted EDF permission to dispose of a maximum of 300,000 tonnes of radioactively contaminated, marine mud to be dredged from the near shore (sub and intertidal zone) of the Hinkley nuclear site. The Welsh Government had granted EDF a licence to dump this material into the Cardiff Grounds marine disposal/dispersal  site, about a mile offshore from Cardiff Bay. The mud is to be dredged in order to allow EDF contractors to construct the coolinAg water Intake and the waste water/liquid radioactive effluent  OUTfalls for the proposed Hinkley C nuclear power station.  

Given that the mud in question has been the receiving environment for 50 years of liquid radioactive effluents from the pre-existing Hinkley A (Magnox) and Hinkley B (AGR) reactors I undertook further investigation of the proposal and discovered that the mud proposed for dredging had been subjected to radio-analysis for only 3 man made radio-nuclides (Americium 241, Cobalt 60 and Caesium 137).  

This rang immediate alarm bells since it is well known that Hinkley A and B discharges of radioactive effluent contained 50+ radio nuclides and it seemed highly likely that dose estimates “modelled” from the results for only 3 radio nuclides would not be truly representative of the real time radiological doses from 50+ nuclides discharged over such a long time period.. 

Further investigation revealed that, despite the size of the project and its potential impacts, the WG, and it’s environmental regulator the NRW, had not required an Environmental Impact Assessment for the proposed dump and thus a number of highly relevant pieces of environmental and public health information had not had not been gathered. 

Major data gaps. As a result of the Welsh Government’s decision the proposal was licensed in the absence of the following information:         


A: The Cardiff Grounds site is a dispersal site i.e.  it is NOT expected that the dumped material will remain there but will be “dispersed” into the Bristol Channel marine environment. 

 It is well understood by marine experts that such marine fine muds will be suspended in the water column, and transported by the dynamic Bristol Channel tidal and current regime until they reach low energy , estuary environments where they can deposit out in mud flats and salt marshes. WANA members will be well aware of the enormous stretches of intertidal mud flat exposed at low tide in the upper reaches of the Bristol Channel, Gwent levels coast and in the major estuaries of the south Wales rivers (Wye, Usk et al’). Studies from elsewhere indicate that these are the most likely final deposition environments for such material. 

However, it quickly emerged that neither the Welsh Government, the NRW, EDF or any other official body had bothered to carry out any studies to identify precisely where along the south Wales coast the dumped radioactive mud might be finally deposited. 

B:The Sea to Land transfer of radioactivity, entrained in sea spray and marine aerosols blowing across the shoreline in onshore winds or coming ashore during coastal inundations (storm surges/super tides),  has been clearly demonstrated by three investigations  along the Welsh coast. These investigations have shown that Americium 241, closely associated Plutonium nuclides and Caesium 137 transfer readily from the sea to the land and contaminate coastal food produce (dairy, arable, horticultural and meat produce) generating dietary doses of MARINE radioactivity from the consumption of TERRESTRIAL produce. (Studies elsewhere have clearly shown that Cobalt 60 also behaves in the same way). In that context, and given that the greatest degree of “inland penetration” of marine radioactivity so far recorded is 10 miles inland it appears inevitable (but so far un-investigated) that Welsh coastal zone populations must also be receiving  inhalation doses. 

South Wales coastal zone populations have also received historical and  ongoing doses of residual weapons test fallout, Chernobyl residues, stack/chimney discharges from the Bristol Channel nuclear power stations (Hinkley, Oldbury and Berkely) and from the Cardiff radio-diagnostics manufacturers (GE Healthcare/Maynard centre) and from the ex weapons factory at Llanishen. 

However,  further investigations of the WG Dump proposal revealed that there had been no attempt to calculate or quantify the radioactivity doses CURRENTLY received by south Wales coastal populations. This is a matter of major importance as the Welsh Government/EDF proposal presents the inadequate data from its radiological analysis of Hinkley muds as if those are the ONLY dose of radioactivity to be received by south Wales coastal populations.  

Since no attempt has been made to calculate pre dump doses there can be no assessment of total (ie pre dump + post dump) doses. 

C:The third major issue is that of the radiological analyses of the Hinkley muds to be dredged. Three surveys have been commissioned by EDF and carried out by CEFAS the UK Government’s analytical laboratory (2009, 2013, 2017). Each survey has used different methodologies, taking samples from widely disparate depths (“0 to 100 cms, 0 to 5 cms, 0 to 2cms), taking widely disparate sample numbers (5, 17, 12) and reported widely different outcomes as follows: 

35% difference between max and min concentrations of man made radioactivity and 

35% difference between total aggregated radioactivity per 300,000 tonnes 

Estimated/calculated doses are also disparate with a 15% difference across the 2 surveys where such results were given. Given such large disparities and differences, the Campaign has no confidence in  the analytical surveys and the dose estimates derived from them. 

D:The Campaign proposes that the WG policy on this is in breach of the UN’s Rio                        Declaration (1992) Human Rights Agenda 21, on the Protection of the Oceans which stipulates that coastal and marine populations should be afforded 

1:the right to a precautionary and anticipatory approach to marine environmental protection         2:the right of access for concerned individuals, groups and organisations to relevant information:  

3:the right to public education, awareness and information on issues arising from the discharge of liquid radioactive wastes to UK  


Campaign Action                        

In the absence of any information about the concentrations of the large number of un-analysed for radio-nuclides in the mud,  and the disparate outcomes of the three official surveys + the data gaps referenced in A and B above,  I initiated the Campaign in August 2017 with the aim of postponing the dump until such data had been gathered and decision making could be reviewed in the light of a full suite of appropriate and relevant data and circulated my concerns to various individuals and organisations in s Wales.  

In September the Campaign initiated a Petition to the Welsh Assembly requesting a postponement of the dump until further data had been gathered. That Petition proved to be one of the fastest growing petitions submitted to the Assembly, gathering over 7,000 signatures in a month, with approximately 95% of signatories coming from Welsh Assembly constituencies and ALL Welsh Assembly constituencies being represented.  

Subsequently, “Sum-of-Us” and Greenpeace also launched broadly similar petitions and gaining signatures from across the globe but with UK, Ireland and Atlantic Europe most strongly represented. Total signatures to date (including the Petition to the Assembly) now stand at over 170,000. 

Following the success of the Petition to the Welsh Assembly, the Campaign has been able to take the case to the Assembly Petitions Committee, which has now held a number of hearings in an attempt to clarify the data issues. However, despite several hearings of evidence from the Campaign and from NRW, EDF and CEFAS, the answers to the Campaign’s concerns have NOT BEEN PROVIDED and there is still a massive black hole as far as information is concerned. 

The Campaign has produced numerous Technical Briefings to the Senedd Petitions Committee and, after some delay has accessed some of the original CEFAS analytical data and engaged an independent laboratory to provide a full review of the radiological information and, hopefully, fill in some of the data yawning data gaps! 

The Campaign wishes to thank  all of those who signed the various petitions, especially those who supported the original petition to the Welsh Assembly, without whose support the inquiries of the Senedd Petitions Committee would not have been initiated. 

The Campaign also wishes to thank  Brian Jones and CND CYMRU, WANA, Stop Hinkley and Neil McEvoy AM who have been strong and active supporters of, and contributors to, the Petitions aims. 

The Campaign is also grateful to Richard Bramhall and Chris Busby who have submitted epidemiological and radiological evidence to the Petition’s Committee in support of the Campaign’s case. 


Tim Deere-Jones (Marine Radioactivity Research & Consultancy)  


Petition text: 

We call on the National Assembly for Wales to urge the Welsh Government to direct Natural Resources Wales to suspend the licence it has granted to NNB Genco, which permits up to 300,000 tonnes of radioactively contaminated material, dredged from the seabed at the Hinkley Point Nuclear power station site, to be dumped into Welsh inshore waters. 


We further request that the suspension of the licence is used to ensure that a full Environmental Impact Assessment, complete radiological analysis and core sampling are carried out under the auspices of Natural Resources Wales, and that a Public Inquiry, a full hearing of independent evidence and a Public Consultation take place before any dump of the Hinkley sediments is permitted. 


Additional information: 

Marine Licence 12/45/ML, granted by the Welsh Government, permits the disposal of up to 300,000 tonnes of radioactively contaminated marine sediment, dredged from the seabed at the Hinkley Point nuclear site, into the Cardiff Grounds marine dump site close to the South Wales coast. This will allow work to begin on the 2 new Hinkley C nuclear reactor pipelines. 


The sediments to be dredged are adjacent to the waste pipes used for the discharges from Hinkley’s 4 existing reactors. Analysis, commissioned by UK Government agencies, shows that the sediment is contaminated by radioactive waste discharged to sea over 50+ years of operations at the Hinkley site. Calculations derived from the official data indicate that the proposed dredge sediments may hold at least 7 billion Bqs of aggregated radioactivity, yet reports state that doses to humans would be very low. 


Hinkley’s radioactive discharges to sea contain over 50 radio-nuclides, but the analysis has only investigated 3 of them. Thus, the actual aggregated radioactivity content of the sediments will be much higher than indicated by the available analysis.  The available evidence also 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 5 times higher. 


While sedimentary radioactive material is initially likely to disperse, studies prove that it later re-concentrates in coastal and estuarine mudflats and saltmarshes, and is also available for sea-to-land transfer during onshore winds and coastal flooding. 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 (dose) risks from the proposed disposal have not been adequately researched and that any conclusions based on the current incomplete data, are unreliable. 


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