Studies of MYRRHA using thorium fuel

The problem of long-lived radioactive waste has yet to find an acceptable solution, with
political opposition to geological storage remaining strong. One possible solution which
has often been discussed is to use ADSR systems for its incineration. The advantages of
thorium as a fuel in this process are obvious, but few detailed numerical studies have been
performed. We investigate the potential for using a thorium fuelled subcritical reactor for
the incineration of long-lived minor actinide radioactive waste, based on the welldeveloped
MYRRHA reactor design, operating in sub-critical mode. We examine the
neutron fluxes and spectra in the reactor, particularly in the In-Pile Section (IPS) regions
that would be appropriate for such transmutation, comparing the result from thorium fuel
rods with those of the standard uranium/plutonium fuel. From this we present the burn-up
rates that would be achieved, both initially and in the longer term as 233U is formed