If one must use a conversion from tonnes (metric tonnes) of uranium to oil equivalent, the OECD NEA / IAEA Red Book number conversion of 1 tonne of uranium in a light water reactor (LWR) equaling 10,000 to 16,000 TOE (tonnes of oil equivalent) is as good as any. This is the only conversion rate in the Red Book that is a range because there is enough variability in LWR to make a single value inappropriate. Enrichment levels and reactor designs vary. By far more important is that the conversion rate (uranium to energy value) above is for an "open cycle" nuclear power system. That is, no reprocessing takes place and therefore only about 4% of the fissionable nucleii are fissioned. With reprocessing, the eventual energy obtained from a metric ton of nuclear fuel may be several to many times the above figure.

The traditional method of conversion of nuclear power to energy equivalent is to determine how much electricity is produced (net) using nuclear power and applying a net thermal efficiency rate to convert the nuclear electricity to its energy equivalent.

Some use 10,623 Btu/kWh for nuclear power. Because 1 kWh equals 3,412 Btu by definition, this gives a thermal efficiency for nuclear of 32.1 percent (3412 divided by 10623). British Petroleum has used 33 percent efficiency since at least 1992. We have also found other sources using 33 to 33.2 percent for existing and advanced designs. This conversion rate is good for the U.S. where all reactors are light water reactors. Gas-cooled and heavy water reactors (not in US) might require different conversion factors. Some advanced or alternative designs might also require alternative conversion rates, because some new designs will have greater thermal efficiencies.

The International Energy Agency (IEA) in the book Nuclear Power in the OECD (2001) notes (on pages 40 to 41) "Nuclear power is the only large-scale source of electrical energy that is not dependent on fossil fuels or site specific renewable energy resources. It offers a source of electricity that many governments consider quasi-domestic once the plant is built. Since the 1970's, energy security has been a fundamental reason for government support of nuclear power in some countries. Some countries without domestic fossil energy resources, particularly Belgium, France, Japan, and Korea, have strongly supported the development of nuclear power because of its contribution to energy security." We would add Brazil, China, India, Pakistan, Taiwan, and perhaps others to the list.