Storm Surge

We refer extensively to British Energy Generation Ltd, Review of medium to long-term coastal, geohazard risks at British Energy sites, September 2007 which hereafter we shall refer to as ‘the Review’.

Estimates of the effects of storm surge have been grossly underestimated. The figures used in the Review consider a 1 in 50 year (1/50 p.a.) surge of 3.00m. We have difficulty in finding any further data on expected frequency of storm surges.

However, the 1953 storm surge has been quoted as a 1/100 p.a. (sometimes 1/250 p.a.) surge of 4m. Even using the frequency of 1/250p.a. this still gives nearly a 38% probability of such an event in the period up to 2130 when we have been told the stored nuclear waste will be removed from the site. We would also like to note at this point that, as yet, no repository for long term disposal of nuclear waste has been decided upon and it is unclear how this would be done safely. Therefore even the 2130 date could be in doubt.
The effects of flooding at a nuclear power station could be very severe and as such the IAEA expect that the probability of such an event should be 1 in 10,000 years (1/10000 p.a.). The HSE apply a safety margin on this of 1.4 so the probability of these should be 1/14,000 p.a.

We would therefore expect to be provided with estimates of the 1/14,000 p.a. storm surge height.

A storm surge in 1978 resulted in surges of between 4.6 and 5.9m O.D. along the North Norfolk coast (The Storm Surge of 11 January 1978 on the East Coast of England, J. A. Steers, D. R. Stoddart, T. P. Bayliss-Smith, T. Spencer and P. M. Durbidge,The Geographical Journal, Vol. 145, No. 2 (Jul., 1979), pp. 192-205 ). Hurricane Katrina caused a reported surge of 8m. Although such surges are not as likely at Sizewell they may well be within the 1/14,000 p.a. probability.
It is necessary to consider such low probability events rather the the 1/50 p.a. probability which has over a 90% chance of happening before 2130.

Effects of Climate Change

The figures for fsea level rises in the Review are taken from IPCC Third Annual Report. As noted in the Review these figures do not reflect any contribution from the melting of the Greenland or Antarctic ice sheets. The Review states:

It is thought that although the Greenland Ice sheet will continue to melt, the increase in sea level this would cause may be offset by increase precipitation over the Earth’s other major ice sheet, Antarctica.

The use of the word ‘may’ in the above quote seems to us to be based on optimism rather than analysis of the worse case scenario. We would like to note that the IPCC Fourth Assessment Report estimates net loss from Antarctica. Although the net mass balance of Antarctica is a matter of debate there seems little or no scientific consensus that it would compensate for the net loss from the Greenland Ice sheet.

More recent studies not only show a net loss from the Antarctic Ice Sheet but also suggest that rapid melting can occur due to changes in ocean currents and other factors (e.g. Steffen K et al., Chap. 2 in Abrupt Climate Change, U.S. Climate Change Science Program, SAP-3.4 2008)

The IPCC Third Annual Report figures used in the Review are therefore not even a minimum let alone a ‘worse case’ scenario.

We note with alarm the recent findings of substantially increased melting of the Greenland Ice Cap (M Tedesco et al 2011 Environ. Res. Lett. 6 014005).
Due to the lack of understanding of possible sea level rises in the future and the evidence that these changes could be rapid it is difficult to suggest what figure should be used. Some have suggested that a 2m rise by the end of the century (Rob Young and Orrin Pilkey, The Rising Sea, 2009). Even if a predicted rise has low probability it should be used if it would impact on the 1/14,000 p.a. flooding risk.

Taking into account the isostatic change of 6.6cm and 2m rise, and adding the 50% factor for regional variation recommended by the IPCC, this would lead to a worse case scenario of a over 3m rather than 1.1m given in the Review.
Since the change is sea level rise is a continuous change, although as noted this change could be relatively rapid (over a decade), it may be wise to consider two values for the probability. One for future viability of the site and another ‘absolute worse case’. For example if sea levels do rise by an amount that posed a significant flood risk would it be possible to safely decommission the plant and remove all radioactive material within a short time scale. We have been unable to find any documents relating to such contingency planning. Without such contingency plans and in light of such sea level rises not being outside the bounds of reasonable probability, this would exclude Sizewell from being a suitable site.

There would need to be less than 1% probability of any sea rise would not resulting in a significant flooding risk by 2130 if IAEA standards are to be met.
We are not alone in having these concerns:

“The Sizewell B nuclear plant has been built on the Suffolk coast, a site that has been earmarked for the construction of several more nuclear plants. However, Sizewell will certainly be affected by rising sea levels. Engineers say they can build concrete walls that will keep out the water throughout the working lives of these new plants. But that is not enough. Nuclear plants may operate for 50 years, but it could take hundreds of years to decommission them. By that time, who knows what sea-level rises and what kinds of inundations the country will be experiencing?”

Dr Colin Brown, director of engineering at the Institution of Mechanical Engineering http://www.guardian.co.uk/science/2009/mar/08/climatechange-flooding

Coastal Erosion

The coastline around Sizewell is very dynamic and there seems to be no predictive model about its future behavior. In Proposed Nuclear Development at Sizewell – Environmental Scoping Report, British Energy 2008 it is stated.

“The Sizewell frontage incorporates a soft shore flood defence. There are two lines of embankment (in general appearance, vegetated dunes) fronting the Sizewell C Site which, properly maintained, comprise the flood defences. The 10m high embankment fronting the B site has an internal structure but the 5m high embankment does not. The design concept is that the 5m structure will collapse into the beach and thus mitigate erosional influences on the 10m structure during extreme storm events.”

The design concept is flawed in that it assumes that only one such extreme storm event takes place during the lifetime of radioactive material being stored at the site. If the 5m structure collapses then it will no longer be there to mitigate future erosional influences on the 10m structure.

It is known that vast volumes of deposits such as those that make up the coast at Sizewell can be moved in a single storm surge. For example it was estimated that 30,000m3 of material was moved at the Scott Head when the dunes were cut back by 20m during the 1978 storm surge (The Storm Surge of 11 January 1978 on the East Coast of England, J.A. Steers, D. R. Stoddart, T. P. Bayliss-Smith, T. Spencer and P. M. Durbidge,The Geographical Journal, Vol. 145, No. 2 (Jul., 1979), pp. 192-205 ).

In mitigating any degradation of the shore defences at Sizewell there has been no data presented to show what affect these would have on the surrounding coastline. Currently the erosion of area to the north of Sizewell provides material which is naturally transported south along the coast to provide protection for both Sizewell and further south to Thorpness. Any disruption to this natural process to provide protection for the power stations would necessarily decrease the protection to the south.

It has been noted by several local residents that the Thorpness area which has been relatively stable recently has undergone increased erosion and increased sea defences have been put in place.

Although it is noted by British Energy that coastal erosion is a problem and that extra sea defences are necessary there are no firm details of how this is to be done or any assessment of the affects (social, economic and environmental) on the local area. These possible affects need to be studied and quantified before any benefits of the power station can be weighed against the possible loss of homes, businesses and agricultural land as well as the natural environment.
We would also like to note that many of these factors also impact on the current Sizewell plants and in light of recent knowledge about the affects of climate change the operation and proposals for waste storage at these sites should be reviewed immediately.

Area of Outstanding Beauty (AONB)

The Sizewell site is totally within an AONB. The decision to site a new nuclear power station within an AONB has been taken due to the lack of alternative sites for nuclear power generation. However, we feel that in considering whether to allow development in the AONB then alternative power sources should be considered that could be sited outside the AONB or have a dramatically reduced affect on the locality. We would like to note that initial work has already began at Sizewell and Hinkley sites without the consultation process being completed or a final decision being made.

The Consultation Process

We are unhappy with the consultation process since it seems that the decision has already been made and the process of consultation is merely a formality. The treatment of previous consultation has not been a full analysis of the data and arguments presented. It seems that for everything that is seen as going against the decision a counter argument is presented.

We would expect that a consultation process would involve making a decision weighed on the balance of evidence presented not just a crude justification process for what has already been decided.

This is not just a matter of making undemocratic decisions but it is highly likely that the wrong decision has been made.

It is evident that the decisions rely a lot on the information presented by nuclear power companies who have also been heavily involved in the consultation process with the public. In fact it transpired at a recent meeting between local residents and the Office for Nuclear Development that many local residents thought that the consultation was run by EdF rather than DECC.
Although much of the data presented by the nuclear power companies has, unsurprisingly, put the nuclear option in a favourable light. This information has often been taken without question.

For example British Energy stated that the CO2 emissions from Nuclear Power were 6g/KWh. However most other studies put the figure about ten times higher (Benjamin K. Sovacool. Valuing the greenhouse gas emissions from nuclear power: A critical survey. Energy Policy, Vol. 36, 2008, p. 2950). However, it was the British Energy figure that the government used.

This also ignores the fact that nuclear power stations take longer to build than alternatives and therefore result in longer emissions from power sources such as coal and gas. This “opportunity cost emissions due to delays” would add 69-106g/KWh (Review of solutions to global warming, air pollution, and energy security, Mark Z. Jacobson, Energy & Environmental Science, Royal Society of Chemistry October 2008).

Despite mentioning CO2 emissions we would like to point out that even with ‘new build’ nuclear would only account for at most 20% of electricity generation which is less than 20% of the UKs energy need. Nuclear would therefore meet less than 4% of our energy needs. What are we doing about the other 96%?

As well as taking part in the consultation we have also contacted our MPs on several issues about nuclear power. However, none of our specific concerns have been addressed.

Despite the Aarhus Convention it still seems that access to information, public participation and access to justice is beyond the scope of even well funded NGOs let alone local individuals and is to only available to corporations.