LOWER SIXTH - KGP SCHEDULE, WEEKS 2-9 - ENERGY
MODULE 1 THE DYNAMICS OF CHANGE
10.2 PEOPLE AND THE ENVIRONMENT -POPULATION AND RESOURCES
RENEWABLE ENERGY - HEP
NON-RENEWABLE ENERGY -OIL
   
NUCLEAR ENERGY
Whether the world should develop nuclear power is the single most controversial topic in the field of energy studies. Nuclear power was once hailed as the solution to world's energy problem, yet now it is condemned as the most dangerous and unfitting way to produce energy. Many scientists believe it is the greatest technological breakthrough of the modern age as it can 'bridge' the energy gap by producing unlimited quantities of cheap energy from safe, non polluting sources. Others feel that the linkage with nuclear missiles 'nukes' and the accidents at Three Mile Island in 1979 and most famously Chernobyl in 1986. Both accidents and the nuclear weapon connotations have become landmarks in the development of nuclear policy and political opposition to it.
In 1991 there were some 418 nuclear reactors operating in the world and they contributed roughly 17% percent of the worlds electricity.
The first full-scale commercial nuclear power plant was opened in 1956 at Calder Hall in England. In a power generation kind of system of this kind, much of the energy released by the fission of heavy nuclei (principally those of the radioactive isotope uranium-235) takes the form of heat, which is used to produce steam. This steam drives a turbine, the mechanical energy of which is converted to electricity by a generator. The diagram below highlights the energy processes;
CHEMICAL - HEAT - MECHANICAL - ELECTRICAL
NUCLEAR CYCLE No discussion on nuclear fuel can be complete without a brief exposition of the nuclear fuel cycle. The whole point of a reactor is to cause fission in a nuclear fuel moreover it has turned out that low cost of fuelling is the chief reason for the economic competitiveness of nuclear power. The principal steps of the fuel cycle are uranium mining and extraction from its ore (milling), uranium enrichment, fuel fabrication, loading and irradiation in the reactor, unloading and cooling, reprocessing, waste packaging and waste disposal.
WASTE DISPOSAL The waste disposal method currently being planned by all countries with nuclear power is called geological disposal. This means that all conditioned nuclear wastes are to be deposited in mined cavities deep underground. Shafts are to be sunk into a solid rock stratum, with tunnel corridors extending horizontally from the central shaft region and tunnel 'rooms' laterally from the corridors. The waste would be placed, via the use of robotic devices, into holes drilled into the floors of these rooms, after which the boreholes would be sealed and the rooms and corridors back filled and sealed.
REPROCESSING The burden of nuclear waste is enormously increased by the reprocessing of used up, or 'spent', nuclear fuel at Sellafield. This separates uranium and plutonium from the spent fuel but produces a more than ten fold increase in the amount of radioactive waste. The use of plutonium in as a fuel for the 'fast breeder rector' have not proved to be commercially viable in spite of more than 30 years of costly research, the industry itself has now admitted that reprocessing is not necessary however the practice still continues.
IS NUCLEAR POWER SAFE? This is a very valid question regarding the subject, the industries would have you believe that ever since the 1950's nuclear power is safe, clean cheap and essential source of energy. Nuclear power does not directly produce pollutants like carbon dioxide (main element in climatic change) or sulphur dioxide (causing acid rain) in the way in which coal, oil and gas does. For this reason the nuclear industry claims that nuclear power is 'clean'. However nuclear power produces radioactive pollution. Nuclear waste- as gasses, liquids and solids can remain hazardous for hundreds of thousands of years and needs careful management to ensure that it does not escape into the environment. The industry has no waste management to ensure such long-term protection. The main plan is to bury the waste underground as specified above, however there are many scientific concerns over the safety of this proposal. Furthermore, the UK nuclear industry still has no plans beyond the next fifty years for the long term containment of the most radioactive wastes-'high level' wastes. Other gaseous and liquid wastes are routinely discharged into the air and sea, leading to contamination is not fully monitored, and radiation 'hotspots' resulting from the discharges have been discovered.
IS NUCLEAR POWER CHEAP? In the 1950's promises were made to make nuclear power 'too cheap to meter' however this has clearly not happened. The UK nuclear power industry now admits that nuclear power has always been more expensive than electricity generated by coal, and that massive subsidies have kept the industry afloat. The cost of building nuclear reactors, maintaining the plants and the cost of decommissioning outweighs the money generated by the amount of power produced. The financial loss of UK companies is parallel to those lost in countries such as America which has had to cancel orders of reactors, also in France who had perhaps the most ambitious nuclear power programme has now made the industry 23 billion in debt.
DO WE NEED NUCLEAR POWER? It has been argued that we need nuclear power to reduce the threat of climate change and provide against 'security of supply' against oil prices, these issues are extremely relevant considering the recent climatic problems and oil 'crisis'. However, there are other ways of achieving these aims which are cheaper and which carry less risk.
Nuclear power provides less than 20 per cent of the UK's electricity. By improving the efficiency of the ways we use and generate electricity, we could cut our electricity demand by some 70 per cent-with no loss to standard of living, and at a fraction of the cost of nuclear power stations. There are also other 'cost effective' alternatives. The UK is particularly well endowed with natural, renewable energy sources like wind and wave power. Wind energy alone could support more than 20 per cent of the UK's electricity. By 2025, it is possible that these renewable sources could provide a quarter of our energy- four times than nuclear power does now- with far lower environmental impact.
From the above information it is evident that there is a conflict of views regarding the importance and necessity of nuclear power. Industrialists and many scientists claiming that with the worsening of the environment i.e. via climatic issues and the pending non renewable resources shortages the need for the exploitation of a new source is immense. However many people feel that nuclear power is not economically viable or safe and therefore an alternative source should be found.
RENEWABLE ENERGY - HEP
NON-RENEWABLE ENERGY -OIL