washington

US Vice-President Al Gore announced last week that the Clinton administration will include $157 million in its budget request to Congress for the 1999 fiscal year (which begins on 1 October 1998) to begin building a new spallation source for neutrons at the Oak Ridge National Laboratory in Tennessee.

The Department of Energy (DOE), which operates Oak Ridge, has been planning to build the $1.3 billion facility for some time, but the project has until now received funding only for the planning stages. When completed in 2005, it will be the most powerful source of pulsed neutrons in the world, and will help scientists to refine their characterizations of materials and biological structures.

Gore, a former senator and congressman from Tennessee, said the new facility “will help us to reclaim America's position as the world leader in a technology we invented”. At present, world leadership in spallation neutron production is filled by Britain's ISIS, and France is home to the most productive reactor source of neutrons for research.

The spallation project was conceived as a form of consolation prize for Oak Ridge, which three years ago lost its Advanced Neutron Source, a proposed $3 billion research reactor to have been fuelled by highly enriched uranium, because of tight budgets and concern about nuclear proliferation (see Nature 383, 207; 1996).

Unlike reactors, which produce neutrons through the fission process, spallation sources literally knock neutrons loose from heavy elements such as tungsten, using a stream of high-energy protons from an accelerator. They are largely free from the nuclear waste and other environmental concerns associated with reactors.

Materials researchers, structural biologists and other scientists from universities, national laboratories and industry are lining up to use the DOE's three other neutron sources: Oak Ridge's High Flux Isotope Reactor, the Intense Pulsed Neutron Source at Argonne National Laboratory, and Los Alamos National Laboratory's Neutron Science Center. The Energy Secretary, Federico Peña, told the Oak Ridge audience that about 800 researchers use these neutron sources each year, but many more would like to.

The DOE's other major neutron source, the High Flux Beam Reactor at Brookhaven National Laboratory, has sat idle since the discovery of a tritium leak from the reactor's spent fuel basin more than a year ago (see Nature 388, 503; 1997). Peña recently announced that he had delayed a decision on whether to restart the Brookhaven facility until after the congressional elections next November. Two Republicans from New York, Senator Alfonse D'Amato and Michael Forbes, have announced their opposition to reopening the reactor.