Mr. Alan Mc Donald, a senior officer in the IAEA Department of Nuclear Energy, helped answer these questions.
Do you believe that the positive aspects of nuclear energy outweigh the negatives? Why or why not?
The IAEA has found that the weighing of pros and cons comes out differently for different countries.
The most important determinant will be cost-competitiveness compared to alternatives. Nuclear power plants have a ‘front-loaded’ cost structure, i.e. they are relatively expensive to build but relatively inexpensive to operate. Thus existing well-run operating reactors continue to be a generally competitive profitable source of electricity.
But for new construction, the economic competitiveness of nuclear power depends on several factors.
- First, it depends on the alternatives available. Some countries are rich in alternative energy resources, others less so. Some alternatives that used to be cheap and attractive in the past may be less so in the future – e.g. coal for environmental reasons or natural gas for cost reasons.
- Second, it depends on the overall electricity demand in a country and how fast it is growing.
- Third, it depends on the market structure and investment environment. Other things being equal, nuclear power’s front-loaded cost structure is less attractive to a private investor in a liberalized market that values rapid returns, than to a government that can look longer-term, particularly in a regulated market that assures attractive returns. Private investments in liberalized markets will also depend on the extent to which energy-related external costs and benefits (e.g. pollution, GHG emissions, waste and energy supply security) have been internalized. In contrast, government investors can incorporate such externalities directly into their decisions.
Also important are regulatory risks. Different countries have different approval processes, and political support varies. Some processes are less predictable than others and create greater investment risks. Finally, it depends on national preferences and priorities as expressed in national policies. How countries trade off among considerations including environmental quality, jobs, occupational hazards, energy security and energy costs is at least partly a matter of national preference, and thus an area of legitimate disagreement – even where there is agreement as to the relevant facts.
Is it necessary to replace older nuclear energy stations with those that are more technologically advanced, or would it be more sensible to focus on alternative forms of energy, such as renewable energy?
Focusing on both nuclear power and alternative forms of energy would be advisable at this point in time.
There are good reasons why expectations are currently rising about nuclear power: a good and lengthening track record, increasing energy needs, rising oil and natural gas prices, new environmental constraints, concerns about energy supply security, the nuclear expansion plans of key countries, and the increasingly bullish projections of experts.
But “necessary” is too strong and sweeping a word. Renewables may yet be able to expand at the pace predicted by their strongest advocates, rather than at the more modest rates found in more dispassionate studies. Technological advances may allow cheap coal combustion with carbon sequestration and no GHG emissions. More exotically, nanotechnology may develop solar cells that can be spread on structures like a coat of paint, or genetic engineering might yield microorganisms that use sunlight directly to split water and produce hydrogen.
Most likely, however, the best energy strategies for countries will remain less dramatic. They will vary with national situations, and each will involve a mix of energy sources. New nuclear power plants are most attractive where energy demand growth is rapid, alternative resources are scarce, energy supply security is a priority or reducing air pollution and GHG emissions is mandated. Nuclear expansion currently remains centred in the Far East and South Asia where these factors are most immediate. But the ‘area of immediacy’ appears to be broadening to include particularly Europe and North America. How quickly this happens will depend partly on expectations about market factors, such as the increasing price of natural gas. It will also depend on government policies that encourage long-term thinking, such as those driven by the Kyoto Protocol.
How is spent nuclear fuel managed and what radioactive disposal methods are feasible but have not yet been implemented?
Two different management strategies are used for spent nuclear fuel.
In one, the fuel is reprocessed to extract usable material (uranium and plutonium) for new fuel. In the other, spent fuel is simply considered a waste and is stored pending disposal. If the spent fuel is to be reprocessed, it is shipped to a reprocessing facility where the fuel elements and fuel rods are chopped into pieces, the pieces are chemically dissolved, and the resulting solution is separated into four basic outputs: uranium, plutonium, high level waste (HLW), and various other process wastes. In terms of cooling and shielding, the HLW, which contains fission products and actinides, needs to be handled similarly to spent fuel of the same age. As of today, France, China, India, Japan and the Russian Federation reprocess most of their spent fuel, while Canada, Finland, Sweden and the USA have currently opted for direct disposal. Most countries have not yet decided which strategy to adopt. They are currently storing spent fuel and keeping abreast of developments associated with both alternatives.
However, several countries are also looking at ways to reduce the long-lived radiation burden from HLW. In February 2006, the USA announced a ‘Global Nuclear Energy Partnership’, which includes the development of advanced recycling technologies for use in the USA. France has a three-axis strategy: (1) partitioning and transmutation (P&T) to reduce the long-lived burden, (2) both retrievable and non-retrievable geological repositories, and (3) conditioning and long term storage. Other countries are also doing research on P&T.
If one considers four options (wait-and-see, direct disposal of spent fuel, reprocessing to recycle plutonium eventually in fast reactors, and P&T) here are the basic pros and cons of each of them.
Pros: It is politically and economically the cheapest. Storage is a proven technology with 50 years of experience and success. Extended storage for another 100 or 200 years presents no particularly worrisome obstacles. It allows people and politicians in each country to take as long as they want (centuries if they wish) to work out what their collective preference is for final disposal. It allows the cheapest adjustment to changing circumstances, e.g. if the economics of recycling plutonium change or new technologies are developed. It’s supported by substantial sections of the public where systematic surveys have been made (Canada and France).
Cons: It feels like leaving your garbage for someone else to deal with, i.e. it raises issues of ‘intergenerational equity’ to use the jargon. It creates political obstacles for nuclear power by allowing critics to claim ‘we don’t know how to solve the waste problem’. Accumulations of spent fuel in surface storage may be more attractive targets for proliferation, dirty-bomb or terrorist efforts than deeply buried accumulations.
(2) Direct disposal:
Pros: Currently it’s the second cheapest (only wait-and-see is cheaper). It’s technologically available. It has the political advantage of taking the ‘we don’t know how to solve the waste problem’ argument away from critics. It provides the satisfaction of ‘not leaving our garbage for someone else to deal with’.
Cons: It throws away a lot of usable energy. Recycling in fast reactors could increase the amount of energy extracted from uranium by a factor of 60. This possibility is forgone, or at least made much more difficult, by direct disposal. Direct disposal leaves a potential ‘plutonium mine’ that would be available (although with the difficulty of excavating a very deep site) to future proliferators for thousands of years.
(3) Recycling plutonium for mixed-oxide fuel and fast reactors:
Pros: It extracts 60 times the energy from uranium that a once-through fuel cycle with direct disposal extracts. It leaves no plutonium accumulations that might be proliferation or terrorist risks. It reduces the long-lived radiation burden of the resulting high-level waste.
Cons: It is currently only marginally cost-effective at best. It involves separating plutonium as part of the regular fuel cycle, which adds to proliferation risks.
(4) Partitioning and transmutation:
Pros: The first step in partitioning and transmutation is to separate and recycle plutonium in line with the pros and cons given above. In a second step other long-lived material is separated and destroyed by irradiation. This reduces the long-lived radiation burden and volume of HLW.
Cons: It is still in the research stage and thus currently, and prospectively, the most expensive option.
Is there a likelihood that alternative energy will not be properly implemented until there is no more room on the Earth to store nuclear waste containers?
In terms of geologically suitable sites, running out of space for nuclear waste is not an especially likely scenario. Right now the amount of spent fuel produced annually from all the world’s power reactors would be about two stories high on the area of a basketball court.
Nuclear power may have a longer or shorter run than, say, coal as an important energy source for the world, but eventually it will also be overtaken by something newer and better. That may be the renewables we’re familiar with today like wind and solar, or it might be fusion, or something arising from nanotechnology or genetic engineering, or something that we’re not even doing research on today. As the former Saudi oil minister used to say, “The Stone Age didn’t end because people ran out of stones.” His point was that the oil age will end before the world runs out of oil, and I believe that the nuclear age, to the extent there is one that deserves a label, will end before we run out of uranium or space for waste dumps. Governments should be encouraged to continue research for both nuclear power and renewables, as well as for carbon capture and storage, nanotechnology, genetic engineering and all the rest.
Will the expansion of the nuclear energy market increase the risk of cancer and other health concerns?
It depends on what an expansion of nuclear power would displace.
Radiation is relevant for nuclear, coal, oil, gas and geothermal power plants. These all bring radioactive material in the Earth’s crust to the surface. The US Environmental Protection Agency (EPA) estimates that someone living within 50 miles of a coal fired power plant receives an average dose of 0.3 ?Sv; someone living within 50 miles of a nuclear power plant receives 0.09 ?Sv. Both are more than one thousand times less than the average dose received by people in the USA from X rays and other medical procedures, and more than ten thousand times less than their average dose from natural background radiation.
The figure below presents a worldwide comparison, based on data from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). On a logarithmic scale, it shows that the average radiation dose from nuclear power production is one ten-thousandth of the dose from natural background sources. Background sources include cosmic rays and naturally occurring radioactive substances in the air (mainly radon), in food and water (such as potassium), and in the Earth. Human activities create additional exposure, particularly from medical X-rays (as shown in the figure) and nuclear medical procedures. But living in a brick, stone or concrete building; watching television or using a computer terminal; travelling in a jet airplane; and wearing a luminous wristwatch all add to the dose. The incremental dose from a home smoke detector is comparable to that from living within 50 miles of a nuclear power plant.