RD&D-Programme 2004 - SKB

As mentioned above, fast reactors can be used for transmutation. During the 1990s, fuel
research was focused on combustion of plutonium in sodium-cooled fast reactors. Special types
of fuel were studied in France. In recent years, interest has also been directed towards gascooled
fast reactors. The fast reactor can also be used for transmutation of other transuranics.
However, this requires a special design in order to prevent serious deterioration of the dynamic
and safety-related properties of the reactor. If the fast reactor is designed as a breeder reactor,
very high level of energy recovery can be achieved from the mined uranium as well as an
effective transmutation of all transuranics. Studies by the OECD/NEA indicate that a breeder
reactor can extract up to 100 times more energy per tonne of natural uranium compared with a
light-water reactor with direct disposal (once-through fuel cycle) /23-10/.
The Russians are also interested in civilian applications of fast reactors cooled with liquid
lead-bismuth. Furthermore, some work is being done on ADS with funding mainly through
the so-called ISTC (International Science and Technology Centre) programme.
As already mentioned, systems with a high flux of fast neutrons are of greatest interest when a
virtually complete transmutation of all long-lived transuranics is desired. If one is content with
transmutation of plutonium alone, however, other systems may also be used. French studies
show that with specially designed fuel assemblies, the amount of plutonium generated by a
light-water reactor park can be limited and stabilised. Studies by General Atomics in the USA
and others have shown that a fuel can be developed for gas-cooled high-temperature reactors
that permits a burn-up of up to 700 MWd/kg and combustion of more than 90 percent of the
actinide content, including plutonium-239.
Research in the EU
Current research was dealt with to some extent in the previous section. As noted above,
relatively large research programmes are under way in several countries. The biggest national
programmes are in France, Japan and the USA. In the EU there is also considerable collaboration
between the member states within projects partially funded by the European Commission.
The scope of the EU programme for research on partitioning and transmutation has grown over
the past decade, see Table 23-1.
The EU’s Fifth Framework Programme is coordinated in so-called clusters associated with
the EU’s Adopt network, whose purpose is to ensure coordination and consistency between
the various EU project and the national programmes. Adopt is also trying to identify gaps in
the programmes and is supposed to provide input for future research projects. With regard to
transmutation, the projects are strongly focused on accelerator-driven systems. The biggest
project is a preliminary design study of an accelerator-driven system: PDS-XADS. It is being
led by Framatome in France and has no fewer than 25 participating partners. Fuel studies
concerning plutonium and americium nitrides (Confirm), oxides (Future) and thorium fuels are
included in the cluster Fuetra. A number of technological special studies have been gathered
within Testra. They concern irradiation effects on materials, particularly windows, for spallation
sources (Spire), technology for systems cooled with lead-bismuth (Tecla) and participation in
the Megapie project at PSI involving testing of a spallation source with lead-bismuth. Basic data
are being gathered within the projects included in Bastra. The Muse project involves reactor
physics measurements on subcritical systems with a fast neutron spectrum and is being carried
Table 23-1. Scope of the EU’s programme for research on partitioning and transmutation.
Programme Period when projects EU grants in millions of euro for research and
are approved and started development on partitioning and transmutation
FWP 3 1991–1994 4.8
FWP 4 1994–1998 5.8
FWP 5 1999–2002 28.6
FWP 6 tentative 2003–2006 30–35
RD&D-Programme 2004 313