Posted: 27 November 2007

Nuclear power is not a renewable energy source. It can provide energy without emitting conventional air pollutants and greenhouse gases, although the nuclear fuel cycle does release CO2 during mining, fuel enrichment and plant construction. But although nuclear energy dominates electricity generation in some countries (78 per cent in France) and accounts for 16 per cent of electricity world-wide, its initial promise has not been realised. It is more costly than originally projected, competition from alternative technologies is increasing, and there are concerns related to safety, radioactive waste management, and potential nuclear weapons proliferation.

  • Most analysts project that nuclear energy's contribution to global energy will not grow - and will probably decline in the coming decades.
  • Light Water Reactors (LWRs) which dominate nuclear power globally have a good safety record (unlike the Chernobyl-type reactors), and future LWRs would have improved safety features. But reduced access to low-cost uranium could constrain wider use of LWRs.
  • Newer advanced ('3rd generation') reactors already in service in Japan have simpler designs which reduce capital cost. They are more fuel-efficient and are inherently safer.
  • One possible evolution is the pebble bed modular reactor ('4th generation'), which offers the potential for a high degree of inherent safety without the need for complicated and expensive safety controls. It could also be operated on a proliferation-resistant fuel cycle of denatured uranium or thorium.
  • Other long-term options are alternative breeder concepts - including particle-accelerator-driven reactors - uranium from seawater, and thermonuclear fusion.
  • Nuclear fusion could provide an almost inexhaustible energy supply, but it will probably not be commercially available before 2050 - if then.