Sizewell Emergency Planning

Moving the Goal Posts?

In the late 1950’s and early 1960’s it was policy to base the emergency planning at CEGB nuclear power stations on the basis of the Maximum Credible Accident. That is the worst thing that could happen. In the case of these early “magnox” reactors it was something like this.

The uranium fuel was metallic and sealed in a magnesium/aluminium alloy. I was given the name “Magnox”, (magnesium non-oxidising).  It was chosen because it was stable in CO2 , had good heat transfer properties, and a low neutron capture cross-section. These fuel elements were placed in channels spaced out in a very large block of graphite. The reactor was cooled by blowing CO2, under pressure, through the graphite channels, then through a heat exchanger to raise steam to drive the turbines. The maximum credible accident involved a sudden bursting of the reactor vessel or one of the heat exchanger ducts carrying the CO2. If this happened, for whatever reason, the reactor would shut down and most of the residual heat would be absorbed by the graphite block. It was reckoned that at most in 10 channels of fuel the magnox would melt and the uranium oxidise. It was reckoned that 10% of the radioactive isotopes in this fuel could be released into the atmosphere.

It is acknowledged by the government that an accident at a nuclear power station could result in a significant release of radiation which would cause long lasting damage to health and the environment. In light of this, the Office of Nuclear Regulation (ONR) has a legal responsibility to ensure that a workable emergency plan is in place around all nuclear facilities. The terms of that plan are set out in The Radiation (Emergency Preparedness and Public Information) Regulations 2001, commonly referred to as REPPIR.1

A central part of the emergency plan is to establish a detailed emergency planning zone (DEPZ) around the power station. At Sizewell, plans for the evacuation of people living within this zone have been drawn up and will be used if necessary in the event of a nuclear accident, and potassium iodate tablets have been distributed to people. The potassium iodate tablets fill up the thyroid gland with uncontaminated iodine and therefore prevent a build up of contaminated iodine 131 from the release (though unfortunately nothing can be done about the other dozens of radioactive products which might be present in such a release).

The size of the DEPZ is contentious. Having a radius of only 2.4km means it does not include Leiston. If the catchment area were extended to include the town, many more people would have to be notified about the emergency arrangements, and therefore many more concerns could be expressed from people who hitherto have not seen Sizewell nuclear power station as a threat.

The red spot shows the current evacuation zone of 2.4km set around Sizewell


People living within the DEPZ have been given leaflets with instructions of what to do in the event of a radioactive leak. Suffolk County Council has the overall responsibility to co-ordinate the emergency plan, and a copy of it is held in the Council offices at Leiston for inspection by members of the public.


The diagrams below show the exclusion zones of Fukushima and Chernobyl mapped onto Sizewell

As of October 2012, the Fukushima nuclear
plant may still be leaking radiation.2

Chernobyl - 26 Years on, an area
of this size is still uninhabitable

This information is also available as a leaflet.

Over a period of 3-4 years the fuel from a nuclear reactor is taken out and placed in spent fuel ponds. Therefore after this period there is more spent fuel in the fuel ponds than in the reactor core. Fuel from Sizewell A is sent for processing at Sellafield but for Sizewell B and the proposed Sizewell C&D the fuel will be kept on-site until at least 21301.

About Spent Fuel

'Burning' the fuel in the reactor results in it being over a million times more radioactive than fresh fuel. It is so radioactive that standing next to spent fuel will cause death in minutes. The radioactive decay of the spent fuel also produces a large amount of heat. If the fuel is not effectively cooled it can heat up to a point where the fuel rods can catch fire.

Spent fuel still contains a significant amount of fissile material including plutonium-239 and uranium-235. It is therefore possible for 'renewed criticality' – i.e. the fission process restarts to produce large amounts of heat. To counteract this special care has to be taken when storing fuel with adequate spacing and neutron absorbers placed around the spent fuel. Since these fissile isotopes have long half lives the possibility of 'renewed criticality' does not decrease significantly while in storage.

Amount of Spent Fuel

Over the lifetime of Sizewell B about 1400 tonnes of spent fuel will accumulate while the Sizewell C&D will add a further of 3500 tonnes2. The proposed new reactors will use 'high burnup' fuel which means that more electricity can be generated from the same volume of fuel in the reactor. However, this makes the fuel more radioactive and 'hotter' than the fuel in from Sizewell B.

The actual volume of mass of fuel is not what is important but the radioactivity contained in the fuel. One of the most dangerous isotopes in the spent fuel is Caesium 137 (Cs-137). It is this isotope which is used to determine evacuation areas in the event of a nuclear accident. The International Atomic Energy Agency sets its "operational criteria for evacuation" at 1MBq per square meter3. The amount of Cs-137 that will be stored at Sizewell C&D (1x1019Bq) would be enough to contaminate an area 40 times that of the UK4. It is extremely unlikely that an incident at the spent fuel at Sizewell will release all the Cs-137 and even more unlikely that it will distribute evenly. At Chernobyl only 30% of the 2.8x1017Bq of Cs-137 was released and resulted in an exclusion zone of 2,600Km2. Note that if Sizewell C&D go ahead they will contain over 100 times the Cs-137 released by Chernobyl.

Storing Spent Fuel

Initially the large quantities heat generated by the spent fuel means that it has to be stored under water in spent fuel ponds. The water also provides protection from the intense radiation.

After at least 5 years in the cooling ponds the fuel can be transferred to 'dry cask' storage which are air cooled and do not require a water supply and pumps to operate and are considered to be much safer than storage in ponds. It is planned to start moving fuel from Sizewell B from the spent fuel ponds to dry storage in the near future. However, the fuel from the new reactors would produce too much heat and it is currently planned to keep the fuel in fuel ponds until 2130 at least1.

Unlike the reactor the spent fuel ponds are not protected by a strong 'containment building' in the UK. However, in Germany such containment buildings have been compulsory since the 1970s due to the threat of terrorist attack. The fuel is also moved from the fuel ponds to dry storage after 5 years.

Even if technology is developed to store the new type of fuel in dry storage there is not sufficient space on the current site plans5.

Accidents and Terrorism

If water is lost from the ponds the radiation levels in the building will rise dramatically which can make any remedial work on the fuel pond very difficult. When there is not sufficient water in the fuel pond the fuel can heat up to a point where the fuel rods rupture. At higher temperatures the fuel rods can burn in air or when in contact with water6. When they react with water the fuel rods produce hydrogen gas which is explosive when mixed with air. Such fires could be self sustaining and result in large releases of radioactive material including Cs-137. A 1997 report by the Nuclear Regulatory Commission in the US concluded that the consequences of such a fire involving 400T of spent fuel could included: 54,000–143,000 extra cancer deaths, 2000–7000 Km2 of agricultural land condemned, and economic costs due to evacuation of $117–566 billion7. The fuel ponds at Sizewell C&D would hold nine times this amount of spent fuel.

  • The water could be lost via a leak such as the one that almost lead to disaster at Sizewell A in 20078.

  • If power is lost to the water pumps at the fuel pond the water can heat up to boiling point. Eventually the fuel rods would be exposed and could result in a fire. This almost happened at Fukushima9.

  • A terrorist attack could damage the fuel pond – bunker buster type bombs are not necessarily high technology and in fact the GBU-28 bunker buster is an artillery gun barrel packed with explosives10. More sophisticated weapons have also been sold around the world and could fall into the hands of terrorists.

If Sizewell C&D are built then the risk of an incident at the spent fuel ponds will remain for at least the next 117 years.

1Spent Fuel Management – EDF Energy Perspective,EDF Energy March 2012 (

2 Sizewell B calculated ( EDF give a figure of 3600 tonnes ( which is slightlyy higher than our calculated value of 3500 tonnes (

3IAEA says Fukushima fallout warrants more evacuation, New Scientist, 2011 (

5Sizewell B dry fuel store is to be 110m by 50m ( ). The new station will have to store 2.5 times the amount of fuel and will therefore require a building at least 2.5 times that of the Sizewell B dry cask store.

6See the report by the US National Academies which was commissioned by the US congress (

7Reducing the Hazards from Stored Spent Power-Reactor Fuel in the United States, Alvarez et al, 2003 (

8Sizewell nuclear disaster averted by dirty laundry, says official report, Guardian 2009 (

10Guided Bomb Unit-28 (GBU-28), Federation of American Scientists (


This information is also available as a leaflet.

In times of economic hardship it is difficult to resist the promise of jobs. Edf have claimed that building Sizewell C could create 25,000 jobs. This claim is extremely misleading. EDF expect that the average length of contracts for construction workers would be 1 year, and they calculated the number of jobs based on this.1 The 25,000 jobs are each for 1 year- if everyone worked for 2 years, the 25,000 is halved, 5 years and the figure is 5000 and so on. Using Edfs own figures, if the number of jobs is calculated from a persons normal working life of 45 years the number of jobs is equivalent to only 580 permanent jobs.

As the project moves through the stages of construction, groups of workers will be replaced by others from different trades. The short term nature of the employment (average 1 year) means that it would be unsuitable for young people wishing to develop a career in this industry sector, as training is usually done via apprenticeships which normally take 2-3 years. People will be expected to prepare for jobs which may last for less time than the training takes.

Edf expect that only 20% of the jobs will go to local people (based on the building of Hinkley C power station). According to the 2011 Leiston Town Appraisal only 4% of people responded nuclear when asked the question "if you are working into which category does your job fall? ". Roughly 31 workers. This 4% figure will also include some Sizewell A workers.

Short duration, capital intensive construction projects like that proposed at Sizewell C have been shown to seriously distort the local labour market. Often the bulk of those employed are from outside of the area. After the project is completed many migrant workers remain in the area compounding local employment problems. Even when an effort is made to hire local people the construction project can have a detrimental effect by competing with local firms for a limited number of skilled workers. In some cases where a local firm is already in difficulty, the higher wages offered on a large construction project can be the last straw. Evidence suggests that major construction projects in rural areas prevent the growth of employment in more stable industries, and increase unemployment over the longer term2.

Nuclear Compared With Other Power Generation

Every pound invested in nuclear jobs is a pound not invested in jobs in other sectors. Nuclear power produces fewer jobs per unit energy than any other form of electricity generation. Research shows that for every Tera Watt hour of energy produced from small scale wind energy 1,000 people per year will have been employed; however a Tera Watt hour of nuclear power only employs 75 people per year.3 This is because most of the costs for nuclear build go into the construction materials whereas the costs for wind come primarily from employing people.

If nuclear new build fails to go ahead then other energy sources would have to be found to meet our energy supply. The graphs below show the contrast between employment in nuclear and wind energy

Wind has been used because data for wind energy is readily available and the east coast already has a growing wind industry. We would expect that a large range of renewables and technologies such as combined heat and power (CHP) would be used in place of nuclear power.

This graph shows the expected jobs created by 16GWe of new build nuclear8. The employment peak is in about 2021 at 14,000 jobs with just under 6,000 permanent jobs being created at the end of the build.

Projections for employment in the wind energy show a very different profile with a gradual increase in employment: This in part reflects the large number of smaller units required for wind generation. As can be seen offshore wind alone could produce 23,000MWe of installed capacity and nearly 30,000 jobs by 20214.

The continued success of wind and marine energy is dependent on attracting skilled workers. There were around 10,000 people employed in these industries in 2010, and approximately 88,000 will be needed in wind and marine industries by 2021. This represents a huge opportunity to create UK jobs.

In addition to swallowing up investment that could go into renewable energy, Sizewell C could damage the existing tourist industry which relies on a reputation for a clean environment to attract business. The value of the tourist industry to Suffolk is currently estimated as 1.7billion and rising.

During the construction of Sizewell b the beach was turned into a massive building site. The large influx of workers to build the new reactor had a huge impact on Leiston. As one local campaigner said at a public meeting with DECC “during the construction of Sizewell B. Leiston became like the backend of the docks – people didn’t want to go to shops or pubs”

Quality of Jobs

There are important questions arising about the quality of construction jobs at nuclear sites. There are currently two reactors of the type proposed for Hinkley and Sizewell being built in Europe. One is at Flamanville in France and the other at Olkiluoto in Finland. Both have attracted severe criticism for carelessness over workplace rights and health and safety matters.

The calculations of the cost of new nuclear plants are based on the premise that the first site will cost more than the subsequent ones because lessons will be learned and experience will be gained through construction of the primary plant. A major factor in the delays at the nuclear power stations under construction at Flamanville and Olkiluoto has been due to a shortage of experienced subcontractors. Given this fact, it is highly likely that a considerable proportion of the Sizewell new build will go to specialized subcontractors currently working on these and similar projects.

A 2008 Greenpeace study of the Olkiluoto3 power station revealed that all significant subcontracts have been won by foreign companies and even in Olkiluoto itself, about a third of the workforce is Finnish and two thirds are foreigners. Polish and German workers account for 18 percent of the workforce, while 9 percent are expert welders from Croatia. A maximum of 25% of the investment in the plant stays in Finland.

Olkiluoto has been a complete disappointment for us. There have been fewer than 100 Finnish builders there. It is the view of our experts that huge amounts of cheap labour have been brought here from abroad to work inefficiently”, Said Kyösti Suokas, co-chairman of the Finnish Construction Union.5

In relation to Flamanville, Yannick Rousselet from Greenpeace France said ‘There are 18 different nationalities working there and most of the work is done by sub-contractors. This means there is no job security and the pay is poor. Workers get shipped in and shipped out and have none of the benefits of permanent work.’

He added: ‘People have been flooding into the area because they have heard that work is available but then they find there is nothing. This means that local unemployment has actually increased since construction at Flamanville began.'’6

Nuclear tends to rely on huge investment which has always come from large national programmes using taxpayer’s money. Such investments tend to be intermittent varying with changes in policy or political leadership.

2 French, M “The Impact of a Power Station on Gwynedd”. Gwynedd County Council Planning Office, September 1976. See Hanlon, J “Is Gwynedd a Developing Country?” New Scientist 4th May 1978

3The Case for Renewable Energies, José Goldemberg Instituto de Electronica e Energia Universidade de São Paulo (​renewable.pdf

8Next Generation – Skills for New Build Nuclear,

5Concrete cover ups and others at nuclear construction site, Helsingin Sanomat, February 2010

6Workers at Hinkley C nuclear power plant in for a raw deal, Stop Hinkley



This information is also available in our leaflet.

The map above reproduced from the UK Environment Agency shows the flood risk around the Sizewell plants.

In 2009 scientists warned that rising sea levels, triggered by global warming, pose a far greater danger to the planet than was previously estimated. There is now a major risk that many coastal areas around the world will be inundated by the end of the century because Antarctic and Greenland ice sheets are melting faster than previously estimated.1

According to a report by the Centre for Environmental Policy at the Imperial College London, the rising sea levels could lead to extensive flooding around the coast of East Anglia. Storm surge heights with a 50 year return interval are predicted to reach heights of over 410cm OD by the end of the 21st century, and It is likely that 100 year return period events will occur every 20 years by 2050.2


Coastal Erosion

The coastline around Sizewell is very dynamic and it is difficult to precisely predict its future behaviour. 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.1

According to Dr Colin Brown, director of engineering at the Institution of Mechanical Engineering:

...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?”2

Although it is noted in the Sizewell C stage 1 environmental report that coastal erosion is a problem and that extra sea defences will be necessary, there are no examples of how this might be achieved, or any assessment of the affects (social, economic and environmental) on the local area of Sizewell 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 including Minsmere and the Sizewell AONB 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 adjoining coastline either. Currently the erosion of areas 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. EDF are apparently confident that the calculations for the design for Sizewell C will ensure it is sufficiently robust to withstand storm surge levels, therefore they should perhaps be able to also give some indication of the costs and consequences of various flood mitigation measures, given that they have had several years within which to study the coastline. It is difficult to have a meaningful consultation without first being given any sort of clue what we may be faced with at Sizewell.

In the 2008 Proposed Nuclear Development at Sizewell – Environmental Scoping Report, British Energy flood defences are described as follows

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.”3

It is unclear whether the 5 meter structure, once collapsed would be built up again, or whether it is assumed that only one such extreme storm event will take 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.

The consultation documents published by EDF do not appear to contain any discussion of who might pay for the flood defences. If areas around Sizewell are allowed to be breached in order to lessen the impact of flooding at Sizewell, it is unclear whether homes and businesses will be compensated for their loss by EDF, the government or insurance or whether they will be expected to cover the costs themselves. If EDF have factored in a contingency for flood defences, then they should be able to give an indication of what extent this will cover. If they have not made decisions on what will be paid for, it is difficult to assess how the government and EDF will reach the strike price for nuclear power which is set to be announced imminently.

1 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