4.3.2 Nuclear energy
In 2005, 2626 TWh of electricity (16% of the world total) was generated by nuclear power, requiring about 65,500 t of natural uranium (WNA, 2006a). As of December 2006, 442 nuclear power plants were in operation with a total installed capacity of about 370 GWe (WNA, 2006a). Six plants were in long-term shutdown and since 2000, the construction of 21 new reactors has begun (IAEA, 2006). The US has the largest number of reactors and France the highest percentage hare of total electricity generation. Many more reactors are either planned or proposed, mostly in China, India, Japan, Korea, Russia, South Africa and the US (WNA, 2006a). Nuclear power capacity forecasts out to 2030 (IAEA, 2005c; WNA, 2005a; Maeda, 2005; Nuclear News, 2005) vary between 279 and 740 GWe when proposed new plants and the decommissioning of old plants are both considered. In Japan 55 nuclear reactors currently provide nearly a third of total national electricity with one to be shut down in 2010. Immediate plans for construction of new reactors have been scaled down due to anticipated reduced power demand due to greater efficiency and population decline (METI, 2005). The Japanese target is now to expand the current installed 50 GWe to 61 GWe by adding 13 new reactors with nine operating by 2015 to provide around 40% of total electricity (JAEC, 2005). In China there are nine reactors in operation, two under construction and proposals for between 28 and 40 new ones by 2020 (WNA, 2006b; IAEA, 2006) giving a total capacity of 41–46 GWe (Dellero & Chessé, 2006). To meet future fuel demand, China has ratified a safeguards agreement (ANSTO, 2006) enabling the future purchase of thousands of tonnes of uranium from Australia, which has 40% of the world’s reserves. In India seven reactors are under construction, with plans for 16 more to give 20 GWe of nuclear capacity installed by 2020 (Mago, 2004).
Improved safety and economics are objectives of new designs of reactors. The worldwide operational performance has improved and the 2003–2005 average unit capacity factor was 83.3% (IAEA, 2006). The average capacity factors in the US increased from less than 60% to 90.9% between 1980 and 2005, while average marginal electricity-production costs (operation, maintenance and fuel costs) declined from 33 US$/MWh in 1988 to 17 US$/MWh in 2005 (NEI, 2006).
The economic competitiveness of nuclear power depends on plant-specific features, number of plants previously built, annual hours of operation and local circumstances. Full life-cycle cost analyses have been used to compare nuclear-generation costs with coal, gas or renewable systems (Section 4.4.2; Figure 4.27) (IEA/NEA, 2005) including:
- investment (around 45–70% of total generation costs for design, construction, refurbishing, decommissioning and expense schedule during the construction period);
- operation and maintenance (around 15–40% for operating and support staff, training, security, and periodic maintenance); and
- fuel cycle (around 10–20% for purchasing, converting and enriching uranium, fuel fabrication, spent fuel conditioning, reprocessing, transport and disposal of the spent fuel).
Decommissioning costs are below 500 US$/kW (undiscounted) for water reactors (OECD, 2003) but around 2500 US$/kW for gas-cooled (e.g. Magnox) reactors due to radioactive waste volumes normalized by power output being about ten times higher. The decommissioning and clean-up of the entire UK Sellafield site, including facilities not related to commercial nuclear power production, has been estimated to cost £31.8 billion or approximately 60 billion US$ (NDA, 2006).
Total life-cycle GHG emissions per unit of electricity produced from nuclear power are below 40 gCO2-eq/kWh (10 gC-eq/kWh), similar to those for renewable energy sources (Figure 4.18). (WEC, 2004a; Vattenfall, 2005). Nuclear power is therefore an effective GHG mitigation option, especially through license extensions of existing plants enabling investments in retro-fitting and upgrading. Nuclear power currently avoids approximately 2.2–2.6 GtCO2/yr if that power were instead produced from coal (WNA, 2003; Rogner, 2003) or 1.5 GtCO2/yr if using the world average CO2 emissions for electricity production in 2000 of 540 gCO2/kWh (WEC, 2001). However, Storm van Leeuwen and Smith (2005) give much higher figures for the GHG emissions from ore processing and construction and decommissioning of nuclear power plants.