Some things to think about
Energy efficiency has a limit. As population rises and the economy grows energy consumption has to increase. While policies to dramatically increase energy efficiency could work to decrease our energy consumption in the short term, they will also defer new investment in energy generation technology. However, eventually such investments need to be made in order to cope with the growing demand for energy due to population increase.
Of course it is also possible to combine energy efficiency with renewable technology. In this case it may be possible to keep C02 levels low enough and be able to supply society with enough energy until renewable energy technology or completely new energy sources become advanced enough such that they can be the main energy source. In fact this is what is proposed in the Federal Goverment's white paper on Energy Reform .For the purpose of studying small communities which will rely heavily on solar power for their energy use. This energy efficiency/renewable energy plan is to encourage research into storage methods for renewables such as solar and wind by providing grants, offer incentives for energy efficiency such as a star system for appliances and subsidise energy efficient devices, force new buildings and large energy users to comply with energy efficiency standards. This situation should be studied thoroughly. The study should include an analysis of the cost to the consumer and ensure that C02 levels can be kept at the required minimum.
In the longer term we will need to develop alternatives to fossil fuels used for transport, to both limit global warming and because of resource exhaustion. Presently Hydrogen appears to be the logical choice for this role. Developing the technology and infrastructure to generate and distribute Hydrogen will require billions of dollars, nevertheless these costs are comparable to those of typical fossil fuel projects.
Humans are exposed to low level radioactivity constantly from naturally occuring radioactive isotopes and cosmic rays from outer space. However, in large doses, radiation has many harmful effects. Therefore it necessary for Nuclear Power plants to in-build many safety mechanisms in order to keep the population safe. This includes the workers as well as humans living around the nuclear power plant. It is also necessary for independant parties to monitor Nuclear Power plants. This ensures that plants adhere to world safery standards and to make sure none of the waste plutonium is diverted for use in nuclear weapons. The International Atomic Energy Agency (IAEA) have developed programs to detect such activity. Nuclear Power Plants in France, Sweden, Canada and Finland have shown that it is possible for the generation of electricty through nuclear power to be extremely safe. Although other nuclear power plants such as Three Mile Island and Chernobyl have had disastrous accidents, it is important to put them into context. The Three Mile Island accident, which destroyed the economic value of the plant, was caused by design flaws and poor operator training. Nevertheless most of the radioactivity was contained at the site. The Chernobyl accident was caused by numerous inherent design flaws, poor operator training and a total disregard for safety.
Another challange for nucear power is dealing with the left over, highly radioactive and long lived nuclear waste. It is necessary to isolate the waste from humans and evironment for about 100,000 years before it decays to safe levels. The consensus amongst the Nuclear Power industry is that radioactive waste should be isolated by multiple barriers and placed deep underground. However other strategies involving waste transmutation are being investigated.
Of course it is also possible to combine energy efficiency with renewable technology. In this case it may be possible to keep C02 levels low enough and be able to supply society with enough energy until renewable energy technology or completely new energy sources become advanced enough such that they can be the main energy source. In fact this is what is proposed in the Federal Goverment's white paper on Energy Reform .For the purpose of studying small communities which will rely heavily on solar power for their energy use. This energy efficiency/renewable energy plan is to encourage research into storage methods for renewables such as solar and wind by providing grants, offer incentives for energy efficiency such as a star system for appliances and subsidise energy efficient devices, force new buildings and large energy users to comply with energy efficiency standards. This situation should be studied thoroughly. The study should include an analysis of the cost to the consumer and ensure that C02 levels can be kept at the required minimum.
In the longer term we will need to develop alternatives to fossil fuels used for transport, to both limit global warming and because of resource exhaustion. Presently Hydrogen appears to be the logical choice for this role. Developing the technology and infrastructure to generate and distribute Hydrogen will require billions of dollars, nevertheless these costs are comparable to those of typical fossil fuel projects.
Energy Requirements and Issues
Electrical Power is a fundamental requirement of a modern technology society. Australia has enjoyed cheap and reliable electrical power for many years. However our energy needs are forecast to grow by 2% per year for the next 15 years to 2020. Meeting this demand requires building 1 GW of new generating plants every year until 2020. If Australia does not build this capacity we will suffer large scale blackouts if demand grows as it has historically. Our previous strategy of employing coal-fired Power Stations will increase our Greenhouse Gas emissions which contribute to global warming. Substantial investments in energy efficiency can mitigate this energy growth but it will require aggressive intervention on the part of the Australian Government. The cost of investing in this energy efficiency is comparible to the cost of building state-of-the-art Nuclear Power plants. Nuclear Power is the cheapest form of non-Greenhouse Gas emitting electrical power production and when used at the world's Best Practice, supplies safe, cheap and environmentally clean energy.
The Challenges of Nuclear Power
Nuclear Power plants generate large quantities of highly radioactive material. This is due to the left over isoptopes (atoms) from the splitting of the atom and the creation of heavier atoms, like plutonium, which the Nuclear Power plant does not utilise. It is called nuclear waste. The actual quantity of waste output is some 100,000 times less than a Fossil Fuel plant but it is much more radioactive.
Humans are exposed to low level radioactivity constantly from naturally occuring radioactive isotopes and cosmic rays from outer space. However, in large doses, radiation has many harmful effects. Therefore it necessary for Nuclear Power plants to in-build many safety mechanisms in order to keep the population safe. This includes the workers as well as humans living around the nuclear power plant. It is also necessary for independant parties to monitor Nuclear Power plants. This ensures that plants adhere to world safery standards and to make sure none of the waste plutonium is diverted for use in nuclear weapons. The International Atomic Energy Agency (IAEA) have developed programs to detect such activity. Nuclear Power Plants in France, Sweden, Canada and Finland have shown that it is possible for the generation of electricty through nuclear power to be extremely safe. Although other nuclear power plants such as Three Mile Island and Chernobyl have had disastrous accidents, it is important to put them into context. The Three Mile Island accident, which destroyed the economic value of the plant, was caused by design flaws and poor operator training. Nevertheless most of the radioactivity was contained at the site. The Chernobyl accident was caused by numerous inherent design flaws, poor operator training and a total disregard for safety.
Another challange for nucear power is dealing with the left over, highly radioactive and long lived nuclear waste. It is necessary to isolate the waste from humans and evironment for about 100,000 years before it decays to safe levels. The consensus amongst the Nuclear Power industry is that radioactive waste should be isolated by multiple barriers and placed deep underground. However other strategies involving waste transmutation are being investigated.
Biological Effects of Radiation.
Thus we can see that during our normal daily activities we are continually exposed to ionising radiation both from natural and human-made sources. The passage of ionising radiation through the body may produce adverse biological effects. The effects of concern are primarily, although not solely, due to damage to the genetic material inside the cell; the DNA or `double-helix' molecule that carries genetic information. The current scientific data suggests that there is no safe minimum, or threshold, for adverse radiation effects on the DNA of biological systems and that even small doses can produce consequences for the organism. The low-dose response of biological systems it believed to be linear - that is, smaller doses of radiation produce a proportionately smaller risk of adverse effects
Cell Death or Apoptosis
- biological systems are composed of many individual tiny cells; each with its own DNA (only red blood cells don't have any DNA - they lose it during development). If there is catastrophic damage to vital cell function by radiation energy absorption the cell may cease to function and `die'.
Cancer Induction
- in this case the DNA is damaged or altered but the alteration is not lethal to the cell. If the normal regulator genes which control the rate at which cells divide and die are rendered malfunctioned the cell may become `immortal' and multiply at an abnormal rate producing an out-of-control growth of a line of abnormal cells. This is a cancer. Most tissues can produce cancers with enough radiation damage but rapidly dividing tissue lines, such as blood-forming `haemopoietic' lines which may produce leukemias, are particularly vulnerable. The risk for cancer production in the general population is estimated to be approximately 0.06 cases per million Micro-Sieverts of absorbed dose.
Genetic Damage to Future Generations
- this can arise because mutations, or changes in the pattern of bases in the DNA, can occur in the DNA that ends up in sperm or eggs and becomes a permanent feature of any resulting babies. Most often, radiation induced damage to such egg or sperm DNA is incompatible with the life of the fetus in utero but there is a finite chance of a live baby being born with defects. This is of particular concern because the damage to the genetic material can then be passed on to all future generations and become a permanent feature of the gene-pool; damaging many individuals. Of course, such mutations are also a natural part of life and the evolution of biological systems. The concern is that we do not want to increase the mutation rate above the natural background rate. The estimated risk of permanent damage to a second generation (grandchild) individual is 0.02 cases per million Micro-Sievert of exposure.
Dose-Response Tissue Reactions
- or `radiation burns'. These are the sorts of effects seen immediately after the bombing of Hiroshima; but lesser effects can occur with smaller doses. However, there does seem to be a `threshold' for this kind of effect with very small doses encountered in normal life (apart from sun-burn!) not producing detectable damage.
A Study on Childhood Cancers in Great Britain
A study on the incidence of childhood cancer around nuclear power plants in Great Britain by the Health Protection Agency for the committee on Medical Aspects of Radiation in the environment concluded that there have been no increase in childhood cancers for children living less than 25km from a nuclear power plant. The report was published in 2005.
Waste Disposal
In the USA, Nuclear Power operators are charged 0.1 cents per KW-Hr for the disposal of Nuclear Waste. In Sweden this cost is 0.13 US cents per KW-Hr. These Countries have utilized these funds to pursue research into Geologic disposal of waste and both now have mature proposals for the task. In France the cost of waste disposal and decommissioning is estimated to be 10% of the construction cost. So far provisions of 71 billion Euros have been acquired for this from the sale of electricity.Current Programs for final disposal of nuclear waste
Currently, no country has a complete system for storing high level waste permanently but many have plans to do so in the next 10 years. There are a number of well-developed proposals from the USA, Sweden, Finland and France for the disposal of long-lived radio-active waste.
All the proposed disposal techniques employ multiple barriers, as discussed above, to isolate the waste from the biosphere for at least 100,000 years. Nevertheless every one of the proposed disposal methods faces strong opposition from environmental groups and it is true that humans have never attempted to do anything on this sort of timescale. However nature has plenty of examples of systems that are stable for much longer periods. The most spectacular being the trans-uranic products of the Oklo natural nuclear reactors, which are discussed below, which have not appreciably moved in over 1.7 billion years.
The World Nuclear Industry appears to have reached a consensus to pursue Geologic disposal as final phase of Nuclear waste management. The US National Academies of Science, Engineering and Medicine also conclude that deep Geologic Disposal can provide a safe means of disposing high level waste.
There are a number of programs that have seriously mishandled the issue of waste from Nuclear Power. The British decision to reprocess spent-fuel appears to have been both an environmental and financial mistake. The Nuclear Weapons program at the Hanford site in Eastern Washington State, U.S.A, created an enormous environmental impact that has so far cost 5.7 billion dollars to clean up.
Currently waste from Nuclear Power plants is being held in temporary storage facilities until such time as long-term disposal is decided. This is a feasible option because of the relatively small amount of material used to generate Nuclear Power.
All the proposed disposal techniques employ multiple barriers, as discussed above, to isolate the waste from the biosphere for at least 100,000 years. Nevertheless every one of the proposed disposal methods faces strong opposition from environmental groups and it is true that humans have never attempted to do anything on this sort of timescale. However nature has plenty of examples of systems that are stable for much longer periods. The most spectacular being the trans-uranic products of the Oklo natural nuclear reactors, which are discussed below, which have not appreciably moved in over 1.7 billion years.
The World Nuclear Industry appears to have reached a consensus to pursue Geologic disposal as final phase of Nuclear waste management. The US National Academies of Science, Engineering and Medicine also conclude that deep Geologic Disposal can provide a safe means of disposing high level waste.
There are a number of programs that have seriously mishandled the issue of waste from Nuclear Power. The British decision to reprocess spent-fuel appears to have been both an environmental and financial mistake. The Nuclear Weapons program at the Hanford site in Eastern Washington State, U.S.A, created an enormous environmental impact that has so far cost 5.7 billion dollars to clean up.
Currently waste from Nuclear Power plants is being held in temporary storage facilities until such time as long-term disposal is decided. This is a feasible option because of the relatively small amount of material used to generate Nuclear Power.
New Technologies for Waste Disposal
Another option for disposal of long-lived (trans-Uranic) waste is to burn it via either Accelerator Driven Systems or within Fourth Generation reactors. However these technologies are not yet mature. Since the waste is stored in large tanks of water for 20-40 years first, it may be that by this time these new technologies will be sufficiently developed so that waste can be destroyed using these new methods.
There are also proposals to use a Fusion-Fission Hybrid for waste-disposal. These devices use the powerful neutrons from a Deuterium-Tritium plasma to drive nuclear transmutation. In some respects this technology is similar to Accelerator driven waste transmutation and the proponents believe that a fleet of 6 Fusion-Fission hybrids, when used in conjunction with a reprocessing waste cycle, would be sufficient to destroy the remaining long-lived nuclear waste from a fleet of 100 commercial power-reactors.
Finally there are experiments with Deep-Burn where fuels originating from reprocessed nuclear-waste would be used to power Very High Temperature Reactors (VHTR). The result would be that a single fuel loading derived from 4 years of operation of a light-water reactor could be used to deliver all the energy needed over the 60-year life of a VHTR. This technology would not only destroy most of the long-lived waste, it would make the existing stockpiles a very valuable source of energy, since it could be used to deliver ten times the energy of the original fuel.
There are also proposals to use a Fusion-Fission Hybrid for waste-disposal. These devices use the powerful neutrons from a Deuterium-Tritium plasma to drive nuclear transmutation. In some respects this technology is similar to Accelerator driven waste transmutation and the proponents believe that a fleet of 6 Fusion-Fission hybrids, when used in conjunction with a reprocessing waste cycle, would be sufficient to destroy the remaining long-lived nuclear waste from a fleet of 100 commercial power-reactors.
Finally there are experiments with Deep-Burn where fuels originating from reprocessed nuclear-waste would be used to power Very High Temperature Reactors (VHTR). The result would be that a single fuel loading derived from 4 years of operation of a light-water reactor could be used to deliver all the energy needed over the 60-year life of a VHTR. This technology would not only destroy most of the long-lived waste, it would make the existing stockpiles a very valuable source of energy, since it could be used to deliver ten times the energy of the original fuel.
How much high level nuclear waste is produced in a nuclear reactor?
According to the International Atomic Energy Agency a nuclear reactor which would supply the needs of a city the size of Amsterdam – a 1000MW(e) nuclear power station – produces approximately 30 tonnes of high level solid packed waster per year if the spent fuel is not reprocessed. In comparison, a 1000MW(e) coal plant produces 300,000 tonnes of ash per year.
Currently, worldwide, nuclear power generation produces 10,000m3 of high-level waste per year.
Currently, worldwide, nuclear power generation produces 10,000m3 of high-level waste per year.
Who is responsible for the nuclear waste?
In most countries it is the responsibility of the power companies to take care of the waste. They are responsible for all the cost of nuclear waste management. In fact most countries are obliged to set aside a certain amount of money each year for waste management. Furthermore there are strict guidelines imposed by governments and other bodies for safe and responsible nuclear waste management. For example the International Atomic Energy Agency runs frequent conferences on the science of nuclear waste disposal, setting and enforcing safety standards, monitoring safety and security of nuclear waste.
Safety of Nuclear Power Plants
Safety is taken very seriously by those working in nuclear power plants. The main safety concern is the emission of uncontrolled radiation into the environment which could cause harm to humans both at the reactor site and off-site.These provide an interesting perspective on the importance both of a vigilent safety culture and a pro-active regulatory oversight.
Management of Nuclear Plant Operations
It's clear from both the French and US experience that pro-active Industry organisations are vital in obtaining efficient plant utilisation and in minimising running costs. In the US in the late 1980's and early 1990's there was little pooling of knowledge and experience amongst Nuclear Power Operators. This was caused by a combination of industry inexperience, the lack of standardised designs and the fragmentation of the industry. Once again this was in contrast to the French experience where the uniform design and the single state-owned organisation allowed knowledge to be more easily shared.
The US industry has has since gone through several cycles of consolidation and the operation of the USA's fleet of Nuclear Reactors has mostly been taken over by specialist companies that specialize in this activity. In addition the industry has learned the benefits of pooling knowledge.
Safety is also important for the workers of nuclear power plants. Radiation doses are controlled via the following procedures,
The US industry has has since gone through several cycles of consolidation and the operation of the USA's fleet of Nuclear Reactors has mostly been taken over by specialist companies that specialize in this activity. In addition the industry has learned the benefits of pooling knowledge.
Safety is also important for the workers of nuclear power plants. Radiation doses are controlled via the following procedures,
- The handling of equipment via remote in the core of the reactor
- Physical shielding
- Limit on the time a worker spends in areas with significant radiation levels
- Monitoring of individual doses and of the work environment
