21 May 2018
In July 2014, Natural Resources Wales issued a marine licence to NNB Genco, a wholly owned subsidiary of EDF Energy. The licence relates to the disposal of sediment being dredged as part of the construction of a cooling water system for the new Hinkley Point C nuclear power station in Somerset. EDF is building two new nuclear reactors at the site, capable of generating a total of up to 3,260MW of electricity.
As part of the construction of the site, EDF plans to dredge sediment from the seabed in the estuary before drilling of six vertical shafts for the cooling water system. In order to do this, the company will need to dredge the immediate area where the shafts will be installed. The dredged material, estimated to be approximately 200,000m3, will be placed into barges and transported to the Cardiff Grounds disposal site to be deposited. The Cardiff Grounds site is an established disposal site for marine dredged materials off the coast of south Wales.
The proposals have been the subject of much controversy, and since November 2017 the Petitions Committee has given detailed consideration to a petition relating to the licence. The petition collected 7,171 signatures. The Petitioner’s concerns, expressed widely in the media, primarily centre upon the contents of the material to be dredged and disposed of. The petition was driven by concern that the sediment had not undergone sufficient testing and that it may be radioactive following 50 years of operations at the existing Hinkley sites.
Much of the discourse and debate during the Committee’s consideration of the petition related to the sampling, testing and analysis of the sediment. EDF described the process as following a highly conservative, internationally recognised (International Atomic Energy Agency) assessment methodology. It stated that:
Taking account of the natural and artificial radioactivity together, the dose received would be equivalent to:
- Eating 20 bananas each year (bananas contain potassium -40, a naturally occurring radionuclide);
- 10,000 times less than an airline pilot’s annual dose; or
- 750 times less than the average dose received by a resident of Pembrokeshire (due to Radon).
The Petitioner challenged the testing on a number of grounds, amounting to a conclusion that the testing has:
[…] failed to provide sufficient, coherent, conclusive and precise scientific data for the assessment of radiological impacts to the inhabitants and users/stakeholders of the south Wales inshore waters and coastal zone.
In evidence to the Petitions Committee, EDF sought to refute the Petitioner’s concerns, saying:
It has been referred to, inaccurately, as radioactive, nuclear and toxic waste, and that there may be risks to human health or the environment. The petition also claims that the testing is insufficient.
I want to be completely clear today: all these claims are wrong, alarmist, and go against all internationally accepted scientific evidence. It is not radioactive and poses no threat to human health or the environment. We know this because we have tested it independently three times using world-leading equipment to highly conservative standards. These standards are supported by Natural Resources Wales, Public Health Wales, the Environment Agency, the Centre for Environment, Fisheries and Aquaculture Science (Cefas), the UK Government and the United Nations.
A further issue raised during the Committee’s consideration was a perceived lack of sampling of the material at depth. In the early stages of the petition’s consideration, the Petitioner said that the evidence implied that only surface samples (0-5cm deep) of sediment had been analysed, and expressed concern that at depths below 5cms, radioactivity concentrations may be significantly higher. However, the Committee heard that samples were taken and tested in 2009, 2013 and 2017, with the 2009 samples taken to a depth of 4.8m. NRW told the Committee that it was satisfied no further analysis of samples from beneath the surface was necessary. In light of the Petitioner’s concerns, the Committee wrote to NRW in January 2018, to recommend that NRW consider requesting that the licence holder arrange further samples to be taken at depth and analysed. EDF rejected the idea of additional voluntary sampling, and NRW reiterated its view that further testing was unnecessary. It also stated that this was not something it could re-visit through the licence or its conditions.
The petition also called for a full Environmental Impact Assessment (EIA) to be conducted. NRW told the Committee that an EIA had been conducted on the development of the Hinkley Point C site overall, but not specifically on the dredging proposal. It explained that this decision was taken by the Welsh Government’s Marine Consents Unit, which was responsible for administering the marine licensing system at the time the application was received.
NRW wrote to the Committee on 27 March, providing an update on its consideration of the licence:
We have also completed our assessment of the suite of samples that were submitted to us in November 2017. The report and conclusions were produced by Cefas and we also conducted a technical consultation with Public Health Wales and NRW’s experts using the same international guidelines as for previous samples. The chemical and radiological results were within acceptable limits and we are satisfied that there is no risk to human health or the environment. […] We have therefore formally discharged condition 9.5 of the marine licence [which required further testing for any material to be deposited after March 2016]. However, there is a further condition regarding site monitoring that the licence holder needs to discharge before NRW will provide written approval before the disposal activity can commence.
This suggests that the dredging and disposal activity could be set to proceed from summer 2018 as outlined by EDF in December 2017.
The Assembly is set to debate the Petitions Committee report on 23 May.
Article by Chloe Corbyn, National Assembly for Wales Research Service