RD&D-Programme 2004 - SKB

A mixer-settler battery has been put into operation and modified for process studies of ligands
developed in the Partnew project. First process parameters were determined for an analogue
system, after which the results were used to design a partitioning process for the desired
substances. However, due to the cost of the specially formulated reagent, this process could not
be test-run. Hopefully it will be able to be tried in the Europart project by use of a new microseparation
technique.
Predictions of the distribution of metal between organic phase and aqueous phase can be done
with models using the theory of solubility parameters. It has been shown that distribution
coefficients for solvent mixtures can be simulated with good accuracy. The improved theory
has been published.
The emphasis in research on transmutation at the Department of Nuclear and Reactor Physics
at KTH is on safety aspects of accelerator-driven systems. A computer code based on the Monte
Carlo method for simulating burn-up in a subcritical reactor connected to an accelerator-driven
source has been developed at the department. The program uses extensive data libraries with
continuous energy-dependent reaction cross-sections, decay schemes, isomeric states, exchanges
of fission products from various nuclides, etc. The program can simulate neutron transport,
material density and burn-up in three dimensions.
In recent years, the research at KTH has been tied to projects within the EU’s framework
programmes, in which the department actively participates. The following examples can be
mentioned:
• Studies of core design in subcritical reactors for ADS optimized for high transmutation
rates and good safety features. Both lead-bismuth-cooled and gas-cooled systems have
been analyzed as a part of the EU project PDS-XADS.
• Analyses of ADS dynamics and assessment of major reactivity feedbacks.
• Emergency heat removal from ADS.
• Participation in subcritical experiments in Cadarache (EU project Muse – fast neutrons)
and in Minsk (ISTC project Yalina – thermal neutrons).
• Participation in design of subcritical experiment in Dubna (ISTC project SAD – fast
neutrons).
• Sensitivity analyses for nuclear data in association with PDS-XADS.
The department is also participating in studies of the potential of transmutation in hightemperature
gas-cooled reactors (HTGR).
Within the EU’s Sixth Framework Programme, the KTH group is coordinator for the project
RedImpact, whose purpose is to determine what waste streams arise in conjunction with
partitioning and transmutation and how they affect waste management compared with currently
applied methods for disposal of spent nuclear fuel. SKB also has a small part of this project.
Transmutation requires advanced fuel types. Different alternative fuel materials are being
studied in the EU programme. The KTH group is coordinator of the project Confirm, which is
investigating nitride fuels with plutonium and americium, in part by irradiation of PuN rods in
the R2 reactor in Studsvik.
Activities within the Department of Neutron Research (INF) at Uppsala University are focused
on experimental studies of nuclear reaction probabilities for different application areas, such as
transmutation of nuclear waste, biomedical effects and electronics reliability. The experimental
activities are primarily being conducted at The Svedberg Laboratory (TSL) in Uppsala, where
the group has previously developed two unique instruments: Medley and Scandal. Together
with SKI and the power utilities, SKB is funding the project Natt, Neutron data for Acceleratordriven
Transmutation Technology.
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