Reducing the Energy Carbon Content - Energy and Climate: How to Achieve a Successful Energy Transition - page 71

power stations (first generation), the current series of pressurised water
reactors (PWRs; second generation), such as those implemented in France,
have been successfully operated for nearly 50 years. With PWRs, the heat
produced in the nuclear reactor core is sent to a primary coolant loop and
then used to generate steam by heating a secondary water loop in a steam
generator. With boiling water reactors, steam is generated directly in the
reactor core. Although this avoids the need for an additional loop, the core
volume is larger. Most of the 440 nuclear reactors currently operating in
the world (including 58 PWRs in France) are one of these two types. A
nuclear power station consists of one or more 'generating units', with each
generating unit having a reactor. For the large current power stations, the
power produced by a generating unit varies between 1300MW (1.3GW)
for the present reactors and 1600MW (1.6GW) for the future European
Pressurised Reactor (EPR).
A PWR type power station operates with enriched uranium containing
about 4% 235 U. The uraniumis enriched by gaseous diffusion or,more and
more frequently, by ultracentrifugation.
Development of a new generation (third generation) of PWRs with
improved safety should facilitate the revival of nuclear energy. The
commissioning of a reactor of this type in Finland, and another at
Flamanville in France, will represent the first industrial references of this
process.
New power station projects are planned in the USA and China. Great
Britain has also decided to reconsider this option.
This revival will involve the development of newprocesses, whichmake
better use of uranium resources. At the current rate, the world uranium
resources identified to date (4.75Mt of natural uranium) can supply the
450 reactors currently in service for more than 70 years. If nuclear
electricity production develops rapidly, it will create significant tension
over uranium supplies. The price of uranium is already rising sharply: in
current monetary terms, from the start of 2001 to the end of 2006, it has
escalated by 1000%.
If production increases rapidly, this tension over uranium is likely to
increase. In particular, the uranium resources identified would not be
sufficient to cover the demand from 2020 under the World Nuclear

Association 'high' scenario and resources not yet discovered would be

required [54].
The current electricity-generating reactors which use energy from the
fission induced by thermal neutrons and consume mainly uranium 235,
harness only about 0.6%of the energy potentially contained in the natural
uranium.