Heysham Nuclear Power Station – Key Facts
The site at Heysham is divided into two individually managed stations, 1 and 2. Heysham 1 and Heysham 2 are both made up of two advanced gas-cooled reactors, which provide enough energy to run 2.5 million homes each, equivalent to around three cities the size of Birmingham, during peak loading hours.
Heysham 1 and Heysham 2 contribute about 22.3% of the UK’s nuclear energy, with a combined capacity of 2370MW (H1 – 1160MW, H2 – 1210MW). Together they provide 3.86% of the UK’s total electricity supply.
Nuclear power can be a huge benefit on the host nation, being able to provide constantly high amounts of energy, while at the same time being emission free (although the resulting nuclear waste is difficult to dispose of). In 2011 the 11% intensification of nuclear energy sources helped reduce greenhouse gas emissions by 7%.
Heysham Nuclear Power Station – Brief History
While Heysham 1 was built and complete in 1983, it did not reach its full potential for commercial operation until 1989. The building process was filled with time-consuming interruptions due to a compacted design, being used in order to cut capital expense, creating construction problems over constrained access.
It seemed that in 2007 Heysham 1’s day would be numbered after the reactor was placed out of service following the discovery of wire corrosion during a routine maintenance check. However EDF’s strategic priority is to maintain and extend the lives of as many nuclear power stations as possible. Therefore repairs were made and it was reopened on a reduced capacity in 2009. In 2010 it was given a further life-line when EDF granted it an additional five years, on top of the original decommissioning date of 2014, when plans were devised to enhance output close to full-potential.
Heysham 2 was completed in 1988 and built by the National Nuclear Corporation, using a larger footprint while at the same time not compromising on potential output. This was due to the lessons that were learnt during the construction of the more compressed Heysham 1. It has a scheduled decommissioning of 2023, however that may change depending on the stance of EDF.
Heysham Nuclear Power Station – Environmental Impact
Throughout the history of Heysham’s nuclear power stations, there have been concerns as to the proximity of the sites to highly populated areas. As a result the Health and Safety Executive advised that an area south of the site of Heysham 2, of around 80 acres, could not exceed the semi-urban criterion. The importance of water also causes problems in many cases, due to nuclear power stations requiring vast quantities in order to pump cooling water through the system, often at a rate of 50m3 per second. However, at Heysham the stations are situated on the coast and so these problems are minimised.
New Power Startion at Heysham?
In 2010, Heysham was admitted onto a shortlist of eight potential sites for a new power station. However, after EDF cancelled an agreement with the National Grid, talks seemed to cool over a third Heysham station, with thoughts turning instead to Hinckley Point and Sizewell.
Background to the French Nuclear Power Industry
In 1974, the French government decided to go ‘nuclear’ as the result of the oil shock and a lack of any real indigenous energy resources, this was known as the Messmer Plan after the then Prime Minister, Pierre Messmer. With nuclear power at the heart of energy strategy, the aim was to make France completely independent of the oil-rich nations. It was initially envisaged that 80 plants were to be built by 1985 with a further 110 plants in operation by 2000, based on electricity demand estimates doubling every 10 years.
Their demand forecasts fortunately did not come to fruition, and so actually there are currently only 58 commercially operated nuclear reactors in France (and one test fast breeder reactor) all operated by EDF, producing approximately 421TWh of electricity every year. These 58 reactors are situated within 20 nuclear power plants and accounted for 78% of the total electricity generated in France during 2011.
One of the major benefits of making the nuclear plants in relatively quick succession was that they were built to similar specification, which resulted in economies of scale during the manufacturing process, in addition to high levels of reliance. The plants are all pressurised water reactors, of which 34 are 3-loop reactors rated at 900MW, 20 are 4-loop P4 reactors rated at 1300MW and the final 4 are 4-loop N4 reactors with a capacity of 1450MW. Despite some of these plants being relatively old (in some cases over 40 years), they have all recently had the operating lifetimes extended through 2020.
In 2006, EDF confirmed it was going to be building another reactor within the Flamanville Nuclear Plant, Normandy. This will be rated at 1650MW, making it the largest reactor in France, and will give the Flamanville nuclear plant a total operating capacity of 4250MW (there are already 2 1300MW reactors in this location). As a result of the Fukushima atomic disaster, the start has been delayed and costs have also increased. It is thought the plant will now come on line in 2016, and will cost approximately £5bn to produce.
Matching Electricity Supply and Demand in France
As discussed elsewhere on TheGreenAge, nuclear power is a very inflexible source of electricity, with plants taking several days to generate electricity from their ’off-line’ mode. As such, nuclear power tends to provide much of the base power to the energy mix, with plants being kept on 24/7 as this is by far the most economical way of running the plants, and there is very little flexibility in their output (when compared to Hydroelectric Power or Gas Power). In France however, they have tried to use nuclear plants in a more flexible way, by attempting to match supply with demand, meaning some plants are not in operation over weekends. This has actually meant that the plants have a relatively low capacity factor (operating capacity as a percentage of full output capacity).
Despite this, matching supply and demand is not easy, and as such France exports much of the electricity it produces from nuclear, and imports electricity to help meet demand when it is especially high. Unfortunately it can only export electricity when demand is low, so the price that France receives for its exported electricity is also low. Conversely, when it suffers peaked demand and needs to import additional electricity it is obviously charged at a higher rate.
This was compounded in the years following the installation of the nuclear power plants, as there was substantial over capacity at this time, because the French government had over-forecast actual electricity demand. As a result, the government pushed the French population to use more electricity to try and increase the base load. The increased base load came from using electricity for heating as opposed to heating gas or oil. Unfortunately using electricity for heating is relatively inefficient, unless insulation is prevalent.
This over reliance on electricity for heating has resulted in sharp increases in electricity demand when the temperature drops, so actually the demand for imported electricity has increased and costs more.
Exporting French Produced Electricity to the UK
As mentioned above, to help regulate supply and demand better, EDF exports some of the electricity it produces in its nuclear power plants to neighbouring countries. In 2010, France exported 2.66TWh of electricity directly to the UK (National Grid), but in total it tends to export between 65-80 TWh / year to it’s neighbours.
Nuclear Energy – Electricity Prices and Environmental Costs
In 2009, EDF estimated that it produced nuclear energy at a cost of EUR 4.6 cents/kWh, while the energy regulator CRE put the figure at 4.1 cents/kWh, which is a relatively cheap source of power, however it does obviously produce nuclear waste that needs to be treated / stored, and there are decommissioning costs associated with nuclear power.
Nuclear waste is limited in France though compared to such countries as the USA, because it is allowed to reprocess old fuel rods, extracting the unused Uranium and Plutonium and making them into new fuel rods. The spent nuclear fuel is all reprocessed at the La Hague site (this site has almost 50% of the world’s reprocessing capacity), which over the years has faced some opposition from organisations such as Greenpeace.
Nuclear Power in the UK
Nuclear power began here in 1956 when the Queen officially opened the first nuclear power plant in Calder Hall, Cumberland. Today there are only a few plants remaining in the UK.
Nuclear Fission – The Science Behind Nuclear Power
When people refer to nuclear power today, they are referring to the process of nuclear fission. There is another process called nuclear fusion, which would be our energy game-changer, providing limitless cheap energy – unfortunately this has yet to become reality.
To understand nuclear fission, first you need a basic understanding of chemistry:
An atom of any material is made up of three simple types of subatomic particle; protons, neutrons and electrons. Protons and neutrons are found in the nucleus of an atom, while the electrons whizz round the nucleus like orbiting moons. These electrons in comparison are incredibly small and carry a negative charge. The protons carry a positive charge and the neutrons are – as the name suggests – neutrally charged.
The number of protons determines what element an atom is, and the number of electrons normally equals the number of protons, to balance the charge across the atom. In the nuclei of lighter elements, the number of protons and neutrons is normally fairly equal too, but as you move down the periodic table the balance begins to change. The heaviest elements have a disproportionately high number of neutrons, and to fuse lighter elements together to create the heavier elements takes an enormous amount of energy (the sort of energy released when stars explode). This means that the chemical bonds in these elements hold an incredible amount of energy, which can be released and harnessed to make electricity.
The heavier the atom, the less stable the nucleus; therefore by firing a neutron at the atom, we can disrupt the delicate balance of the nucleus, causing it to break down into more stable, lighter atoms. This process will release all the energy required to make the atoms in the first place. This is the basis of nuclear energy, and this process is called nuclear fission.
Uranium-235 in Nuclear Fission
A neutron, (a subatomic particle) is fired at a nucleus, which is then absorbed by the nucleus resulting in the creation of an unstable isotope (an isotope simply means the same number of protons, but a different number of neutrons), which in turn splits into lighter nuclei that are different from the parent atom and neutrons. This reaction creates an enormous amount of heat, one that can be used to turn water into steam, which can drive a generator and create electricity. The neutrons produced in the fission reaction can be captured by other atoms so further reactions could take place (known as a chain reaction) with more neutrons produced each time fission takes place, so that the reactions become self-sustaining.
Fissile isotopes are isotopes of an element that can be split through nuclear fission, and only certain isotopes of certain elements are fissile. Uranium is the main element used in nuclear reactors (and atomic bombs), with uranium-235 being the specific isotope used. When a neutron strikes the uranium-235 isotope, it is initially absorbed creating the unstable isotope uranium-236, which then causes the atom to split (fission). The fissioning of this atom can produce over 20 different products. However the resulting product masses when added up, always add up to 236, with the one, extra, additional neutron that drives this chain reaction process.
How we harness Fission today in Nuclear Power Plants
The majority of nuclear power today is produced within light water reactors (LWR), which work in a relatively simple way. Hundreds of long, thin zirconium rods are filled with pellets of uranium oxide, lightly enriched with a 5% concentration of uranium-235, far less than the 90%+ enrichment needed for a weapon. The rods are placed closely together in the reactor core. When a free flying neutron strikes the nucleus of a uranium-235, the binding energy that holds the nucleus together is released as the atom splits (fissions) into two smaller, unstable nuclei, called fission products.
As they fly away, one or more neutrons are ejected as well. Some of them bombard the nuclei of other uranium-235 atoms, causing them to fission, and that’s your basic chain reaction. 80% of the energy released by the reaction is accounted for by the kinetic energy within the fission products, which when hit nearby atoms release a serious amount of heat.
This heat is removed from the rods using fast flowing water, which can be used to drive turbines producing electricity. LWRs operate at about 3200C, which is well above the boiling temperature of water, so a great deal of pressure has to be applied to keep the water liquid, and if the water cooling stops, the fission will stop.
However, in addition to kinetic energy, the fission products also produce decay heat, and this is how meltdowns occur. If the rods aren’t cooled, this decay heat builds up causing the nuclear plants to go into meltdown. A meltdown is when the fuel elements begin to melt, allowing the nuclear fuel to leach into the coolant, potentially allowing long half life radioactive materials to enter the environment. A great deal of work is currently being carried out on nuclear plant safety though, which is concentrated on minimising risks of meltdowns.
Nuclear Power Industry development
Proponents of nuclear energy contend that nuclear energy is a sustainable energy source that reduces carbon emissions and increases energy security by reducing our dependence on energy harnessed from fossil fuels. Nuclear power can also produce the base-load power, unlike many renewable forms such as hydroelectric, wind and solar power plants, which are intermittent.
Opponents believe that nuclear power poses threats to people and the environment including processing, transport and storage on nuclear waste and the threat of serious nuclear accidents. The most important recent event that tipped the tide against more nuclear power was the Fukushima disaster in Japan, 2011. However, due to the potential energy crisis that may hit various parts of the world as supply is outstripped by demand, nuclear power has the potential to prevent this becoming an issue.
To counter this, plant and reactor investment required is still very capital intensive, especially in these economic times where low cost financing is harder to obtain. In summary, if you are a company looking to invest in nuclear power, you must note that there are large financial and regulatory barriers to consider. Financial costs include start-up costs, maintenance costs and decommissioning costs at the end of the plant lifecycle. Regulatory barriers also exist, as the industry is regulated for health and safety above anything else. In the UK this service is performed by the Office for Nuclear Regulation, which is part of the Health and Safety Executive.
Nuclear Power development in the UK
The DECC policy with regards to nuclear power is to support development in the UK, which means supporting new nuclear stations being built and using existing financial resources to subsidise the clean up and decommissioning of existing reactors. According to the Nuclear Decommissioning Authority some £2.3bn per annum is provided by DECC to continue the clean-up process. In terms of scale, this is now calculated as being over 50% of the department’s annual budget.
From this summary you can see that the public is still paying for the true cost of nuclear power and why many commentators are now sceptical whether the private sector has taken all these costs into consideration when looking to invest in new power stations. By 2025, most of the existing nuclear reactors would have been decommissioned and the 20% of electricity currently provided by nuclear will have to be replaced by more nuclear or some other form of generation.
With financial pressures and social uncertainties towards nuclear, we saw in March 2012, E.ON and RWE Npower pulling out of a series of projects to build nuclear reactors capable of generating 16GW of power. This had followed SSE’s announcement in September 2011, which was to promise a complete pull out of the nuclear sector and concentrate its assets on renewables and carbon capture & storage (CCS) technology.
If nuclear power investment doesn’t happen soon or be replaced by another form of renewable energy, we may see as in Germany and Japan (who have taken steps to reduce nuclear), an increase in fossil fuel electricity generation, as renewables like wind and solar power plants are simply not growing fast enough to satisfy the energy gap.
On balance it is difficult to say whether nuclear investment will happen in the UK based on the consideration of cost, risk and future social legacy. Different commentators give different points of view. The Committee on Climate Change found: ’nuclear is potentially the cheapest of all low-carbon options available until 2030’. However, the historical example shows that the current generation may still be paying for a good consumed 20-30 years ago, which then becomes the true cost, and one not quoted previously.