Carbon-14 Project Phase 2 - Formation of a Gas Phase and its Migration.

Carbon-14 is a key radionuclide in the assessment of the safety of a geological disposal
facility (GDF) for radioactive waste, because of the potential radiological impact of gaseous
carbon-14 bearing species. RWM has established a project team, in which the partners work
together to develop an holistic approach to carbon-14 management in a geological disposal
system. This report is part one a suite of reports produced as part of the project.
This report is concerned with work to understand the likely formation of a gas phase, and its
subsequent migration through the near and far field. In the absence of (i) a site for geological
disposal of radioactive wastes and (ii) detailed information on the GDF design, it is not possible to
develop a single conceptual model for how carbon-14 bearing gases might migrate from a GDF to
the biosphere. Rather, at this generic stage, it is appropriate to consider a range of behaviours. A
set of illustrative, post-closure cases is defined, which can be used to link the generation rates of
carbon-14 bearing gases to radiological risk