Sizewell under the Sea

Unlike the lack of unanimity about the carbon cost of nuclear, sea level behaviour seems clear. Each time scientists pronounce on it, the expected rise is higher and quicker. EDF Energy acknowledges that new defences are needed at Sizewell according to a ‘reasonably foreseeable climate change up to 2110’, by which time, so they say, the nuclear power stations would have been decommissioned, including Sizewell C. That time scale seems to be unrealistic, bearing in mind that Sizewell C would not be completed until at least 2030 and then expected to last for 60 years. It is hardly likely that the radioactivity would decay within only 20 years!

The Office for Nuclear Regulation has prescribed new defences at a minimum of 10m AOD. So far EDF’s design for these consist of 1:4 and 1:3 slopes from the shingle up to a height of 10.2m along the whole of the frontage of what would be the three nuclear power stations. The ‘recreational corridor’ would run between the two slopes. The defences would be reinforced with rock armouring, which would be covered with more natural material. They would be so devised, that in case of unexpected sea rise and storm surges, the level could be raised to 14m. Behind these would be the artificially engineered platform for Sizewell C, at a height of 7.3m. On this would sit the two reactors and other permanent buildings. It is EDF’s belief that any changes would happen slowly, giving them time to adjust accordingly. This, however, is not borne out by history which has demonstrated over and again that our coastal disasters have been unexpected and fast.

The new access road would have to cross the Leiston Beck, presumably at more or less the same height as the platform and, here again, this would be a very large concrete structure with culverts for the river. In itself, it could act as something of a defence to the marshes behind, but one of our concerns is that the energy of the waves would simply do far worse damage further north, putting Minsmere Bird Reserve and the residents of Eastbridge and Middleton at much greater risk of flooding.

EDF Energy has been carrying out work with Cefas on coastal processes for some years now, but even a Freedom of Information request has failed to secure any of this important information for the public. It is quite wrong that such investigations should be carried out in secret. We do know that the cooling water tunnels would have to extend to around 3km offshore and engineered beneath the Sizewell and Dunwich banks, which at present give some protection from the waves. It is unclear how these banks might be affected as the result of such works.

The carbon cost of such massive works has, needless to say, never been calculated.