The Nuclear Industry

Nuclear Power

Nuclear power is a low-cost, low-carbon energy source that has been in commercial use for over 50 years. Rapid growth in demand for electricity, especially over the past 30 years, has paved the way for the development of nuclear power, which has become an established part of global electricity production.

Over the past 20 years, approximately 16 per cent of the world’s electricity supply has come from nuclear power plants.

In 2008, nuclear power supplied electricity to some 31 countries. Of those countries, 17 were dependant on nuclear power for more than 15 per cent of their electricity requirements, while four were reliant on nuclear power for more than 50 per cent of their energy requirements (Belgium 54%, Slovakia 56%, Lithuania 73% and France 76%).

Current renewed interest in nuclear power is being driven by three factors:

1. The scale of the predicted increase in world energy demands, especially from developing nations such as China and India.
2. The political instability of several energy producing countries, which has increased awareness of the importance of energy security.
3. The demand for low-cost ‘clean’ energy, with governments now more conscious of the effect that carbon emissions from burnt fossil fuels are having on global warming.

As of 1 September 2009, there were:

• 436 nuclear reactors operable around the world, producing 372,533 MWe
• 50 new reactors under construction, capable of producing 45,438 MWe (first concrete has been poured or major refurbishment is under way)
• 137 planned reactors, with capacity to produce 151,185 MWe (expected to be in operation within eight years or construction is well advanced, but currently suspended)
• 295 proposed reactors, with capacity to produce 303,405 MWe (expected to be in operation within 15 years).

*Source: WNA, Nuclear share figures 1999-2008

These new reactors will be third generation reactors, the design of which is the result of 50 years of operating experience; they will be state-of-the-art, with better safety systems than previous generation reactors.

The Nuclear Fuel Cycle

Mining: Mine uranium containing crushed ore

Milling: Refining of ore to produce U3O8 (yellowcake)

Conversion: Flurination turns yellowcake into Uranium Hexafloride (UF6), which contains 0.71 per cent fissionable 235U Enrichment: Isotope separation is used to increase the percentage of fissionable 235U in the UF6 to between four and five per cent. Gaseous diffusion and gas centrifuge are the most common methods of isotope separation. Energy required for this separation method is referred to as separative work units (SWU). The volume of SWU used increases with the percentage of 235U required.

Fabrication: Convert the enriched UF6 into Uranium Dioxide (UO2) powder, which is then processed into pellet form. These pellets are fired to create hard ceramic pellets, which are stacked and inserted into tubes of corrosion resistant alloy to create fuel rods. The fuel rods are then bundled to form a nuclear fuel assembly. These assemblies are used to build up the nuclear fuel core of a power reactor.

Spent Fuel Cooling: After three or four years, the fuel assemblies are no longer efficient in producing energy and are removed from the reactor. Spent fuel pellets removed from the assemblies are either reprocessed or placed in a special pool of water contained in a steel-lined concrete basin (spent fuel pool) to cool.

Spent Fuel Storage: After the fuel has cooled significantly it can be moved to dry storage containers made of steel and/or concrete to shield radiation. These storage containers are either placed upright on concrete pads or stored horizontally in metal canisters in concrete bunkers.

*References: WNA, DOE, U.S.NRC

Material balance in the nuclear fuel cycle

The following figures may be regarded as typical for the annual operation of a 1000 MWe nuclear power reactor:

*Source: WNA Website

Useful Links

• World Nuclear Association
• International Atomic Energy Agency
• UxC Weekly Uranium Spot Price
• TradeTech Uranium Info
• Uranium Institute, Swakopmund Namibia