Over the past four years, Quintessa has been providing biosphere assessment support to the Nuclear Decommissioning Authority (NDA) Radioactive Waste Management Directorate (RWMD) safety case programme relating to geological disposal of the United Kingdom's higher activity radioactive wastes.
The work has produced a substantial number published reports that are available via the NDA RWMD bibliography, covering topics including:
- Context and approach to future biosphere calculations;
- Biosphere calculations for different geological contexts;
- Representation of climate states and climate state transitions taking key FEPs into account;
- Geosphere-biosphere interface zone issues, catchment-scale modelling and distributed biosphere modelling;
- Representation of redox variations in the soil zone in the context of assessment modelling;
- Catchment modelling in support of post-closure performance assessment;
- Radiological screening;
- Identification of key radionuclides;
- The biosphere transport, distribution and radiological impact of Cl-36, Tc-99 and I-129 released from a geological disposal facility;
- The biosphere transport, distribution and radiological impact of Se-79 released from a geological disposal facility; and
- The biosphere transport, distribution and radiological impact of C-14 released from a geological disposal facility.
The work has been drawn together with more than 25 years' experience of biosphere studies in support of geological disposal in a recent Biosphere Status Report in support of the NDA RWMD's generic Disposal System Safety Case (DSSC). Further reports are in the process of being finalised, covering:
- Approaches to biosphere site characterisation;
- The biosphere transport, distribution and radiological impact of uranium series radionuclides from a geological disposal facility; and
- Biosphere assessment model enhancement.