Where to put all the rubbish

Jane Marshall concludes our focus on France with reports on energy management.

The energy commission's search for a clean nuclear reactor is like hunting for holy grail

Clean" and "non-polluting" are watchwords for French energy research, with government priorities including the development of renewable energies and a relaunch of long-term studies into a nuclear reactor that would destroy its own long-life waste.

Relative to population, France is one of the world's biggest producers and consumers of nuclear energy, which accounts for three-quarters of electricity generated. As well as meeting national needs, some is exported.

The country's atomic energy authority, the Commissariat a l'Energie Atomique, is the state employer of 16,000 researchers, engineers, technicians and others concerned with research and development of the atom and its use in the fields of energy, industry, health and defence.

The CEA often works jointly with other public research establishments and with industry. Its research touches other areas, such as biology, where it is concerned with the effects of radiation on living organisms for such purposes as food preservation, medical applications such as brain scanning, and imaging on DNA, or on BSE.

The CEA's brief also covers non-fossil alternative energies. Under the government's priorities it will "significantly" increase its research effort into such sources as fuel cells, photovoltaic cells, wind and biomass, with the aim of reducing greenhouse gases, especially in transport. But the government has also confirmed its commitment to nuclear power, undertaking to resume priority for developing "reactors of the future capable of reducing, even eliminating, production of long-term radioactive waste".

The search for the clean reactor is "like hunting for the holy grail - there are many technological problems; it is a mixture of physics and technical options," says Jean-Baptiste Thomas, CEA's hybrid systems programme director, who quotes facts, figures and equations involving heavy water, molten salts, sodium, fluoride and chloride, high temperatures, thermal hydraulics and the right kind of uranium.

"The research and development concerned is like being in a maze where we have to find the right combination of complex techniques," Thomas says.

Nuclear reactors are built to last for up to 40 or 50 years, so it can take a long time for improvements to be incorporated into a new generation. Sometimes experiments tried and rejected decades ago might be valid later following technological advances.

"The clean reactor minimises production of long-term radioactive waste," Thomas says. "There is a political and scientific consensus to work on future reactors so in 30 to 40 years they will have better features than those of today, especially as regards cleanness."