Nuclear power is a mature technology with 434 nuclear reactors operating in 32 countries in 1999, with a total capacity of around 349GWe generating 2,398 TWh or some 16% of global electricity generation in 1999 (IAEA, 2000b). In general, the majority of current nuclear power plants worldwide are competitive on a marginal cost basis in a deregulated market environment20.
The life cycle GHG emissions per kWh from nuclear power plants are two orders of magnitude lower than those of fossil-fuelled electricity generation and comparable to most renewables (EC, 1995; Krewitt et al., 1999; Brännström-Norberg et al., 1996; Spadaro et al., 2000). Hence it is an effective GHG mitigation option, especially by way of investments in the lifetime extension of existing plants.
Whether or not nuclear power would be accepted in the market place depends on new capacities becoming economically competitive and on its ability to restore public confidence in its safe use.
Where gas supply infrastructures are already in place, new nuclear power plants at US$1700US$3100/kWe (Paffenberger and Bertel, 1998) cannot compete against natural gas-fuelled CCGT technology at current and expected gas prices (OECD, 1998b). Nuclear power can be competitive versus coal and natural gas, especially if coal has to be transported over long distances or natural gas infrastructures are not in place. Discount rates are often critical in tilting the competitive balance between nuclear power and coal. A study (OECD, 1998b) surveyed the costs of nuclear, coal, and natural gas-fuelled electricity generation in 18 countries for plants that would go into operation in 2005. The results, estimated for both 5% and 10% discount rates, showed that nuclear power is the least cost option in seven countries at a 5% discount rate (generating cost range US$0.0250.057/kWh), but only in two countries at a 10% discount rate (generating cost range US$ 0.0390.080/kWh). In fully deregulated markets such as the UKs, rates of return in excess of 14% have been required at which level new nuclear plant construction would not be competitive at current fossil fuel market prices21.
Technological approaches for safe and long-term disposal of high-level radioactive waste have been extensively studied (Posiva Oy, 1999; EC, 1999). One possible solution involves deep geological repositories, however, no country has yet disposed of any spent fuel or high-level waste in such a repository because of public and political opposition (NEA, 1999). Several countries are actively researching this issue. Long-term disposal of radioactive wastes should not be an intractable problem from a technical perspective, because of the small quantities of storage space required (Goldemberg, 2000; Rhodes and Beller, 2000). Radioactive waste storage density limits defined for storing light water reactor (LWR) fuel at Yucca Mountain are about 41 m2/MWe of nuclear generating capacity for a power plant over its expected 30 years of operating life22 (Kadak, 1999). High level waste volumes can be further reduced if spent fuel is reprocessed so that most of the plutonium and unused uranium is extracted for reuse. The remaining high-level waste is compacted and vitrified (melted with other ingredients to make a glassy matrix), and placed into canisters that are appropriate for long-term disposal. However, reprocessing of spent fuel and the separation of plutonium are often viewed as potentially opening the door for nuclear weapons proliferation. For this and economic reasons, several countries therefore prefer once-through fuel cycles and direct disposal of spent reactor fuel.
Because of the low waste volumes, it may be plausible to accumulate high level radioactive wastes in a few sites globally rather than every country seeking national solutions (Goldemberg, 2000) These international repositories would be operated and controlled by an international organization which would also assume the responsibility of safeguarding these sites (McCombie, 1999a; 1999b; McCombie et al., 1999; Miller et al., 1999). For the time being, most governments remain committed to identifying suitable high-level waste disposal or interim storage solutions within their own national territories.
In the longer run, fundamentally new reactor configurations may need to be developed that are based on innovative designs that integrate inherent operating safety features and waste disposal using previously generated radioactive waste as fuel and, by way of transmutation, convert nuclear waste or plutonium to less hazardous and short-lived isotopic substances (Rubbia, 1998).
Present technology can be used to reduce the growth of the plutonium stocks
by use of mixed plutonium/uranium oxide fuels (MOX) in thermal reactors. Belgium,
France, Germany, and Switzerland use MOX fuels in existing reactors. Japan also
has been progressing its MOX utilizing programme.
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