Euradwaste '08 - EU Bookshop - Europa

Impact of Advanced Fuel Cycle Scenarios on Geological Disposal
Summary
Jan Marivoet 1 , Miguel Cuñado 2 , Simon Norris 3 , Eef Weetjens 1
1 SCK·CEN, Mol, Belgium
2 Enresa, Madrid, Spain
3 NDA RWMD, Harwell, United Kingdom
The impact of advanced nuclear fuel cycles on radioactive waste management and geological
disposal has been evaluated within the Red-Impact project. Five representative fuel cycles,
which were considered in equilibrium, were identified and the resulting waste volumes and
compositions were estimated. Repository designs for disposal in hard rock and clay formations,
developed by national radioactive waste management agencies for today's waste types,
were used as reference concepts. After a 50 years cooling time, the heat generated in the highlevel
radioactive waste arising from advanced fuel cycles is significantly lower than that in
spent fuel from the present "once through" fuel cycle. This would allow the dimensions of a
geological repository to be comparatively reduced. The impact of advanced fuel cycles on the
radiological consequences in the case of the expected evolution or reference scenario is rather
limited. This is because the maximum dose in this scenario, which is calculated to occur a few
tens of thousands of years after the disposal of the waste and is associated with radionuclide
transport in groundwater, is essentially due to mobile fission and activation products; as geological
disposal systems are very effective at retarding the migration of actinides, the contribution
of the actinides to the effective dose is limited. The associated intermediate-level waste
contains considerable amounts of mobile activation products; these species persist in giving
relatively high post-closure doses. On the other hand, for the variant human intrusion scenario,
calculated doses to a geotechnical worker resulting from inadvertent intrusion into a
high-level waste repository are significantly reduced in the case of advanced fuel cycles, because
of the much lower actinide content of the waste. However, it should be noted that the
realism of human intrusion scenarios, and the weight that could be placed on the associated
outcome, is strongly debatable.
1. Introduction
During the last 15 years, various studies investigating the role and feasibility of partitioning and
transmutation (P&T) within nuclear fuel cycles have been carried out. The European Commission
(EC) has initiated several research projects within its various framework programmes on the possibilities
of applying P&T techniques to reduce the inventories of long-lived isotopes in radioactive
waste [1,2]. The final objective of these EC-funded research projects is to lay the groundwork for
future sustainable nuclear fuel cycle strategies involving transmutation in a dedicated waste-burning
accelerator driven system (ADS) or in future Generation IV fast neutron reactors (FR). The Nuclear
Energy Agency (NEA) has conducted a series of studies on P&T systems [3-5], which focused on a
review of the progress in the separation of long-lived actinides and fission products, the options for
their transmutation, and the possible benefit for the management of the radioactive waste. The International
Atomic Energy Agency (IAEA) has published reports on the implications of P&T on
nuclear fuel cycles and waste management [6,7]. Within the Generation IV International Forum [8],
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