2009 Report to Government on National Research and

environment, all with the characteristics and behaviour of humans, other animals
and plants taken <strong>to</strong> be as they are in similar environments <strong>to</strong>day. This is known
as the “reference biosphere” approach (Health Protection Agency, <strong>2009</strong>). Typical
safety case calculations employ several reference biospheres, each for a
different climate state that could occur at the future at a GDF site. The states
differ in aspects such as temperature and rainfall, and, for coastal sites, sea
level.
A.102 The models and data required for the reference biosphere approach largely exist.
The models have been developed over many years using experimental and
observational data (for example, on the movement of radionuclides routinely
discharged <strong>to</strong> air and sea from nuclear facilities). Since the whole ‘calculational’
approach is stylised, it is unnecessary <strong>to</strong> perform uncertainty analyses.
A.103 The adoption of the reference biosphere approach means that there is a limited
requirement for biosphere R&D for geological disposal safety case purposes.
This is not <strong>to</strong> say that such R&D is not needed for other purposes, or that the
knowledge gained in other contexts should not be used for GDF safety cases.
There may also be a need for R&D <strong>to</strong> improve predictions of radionuclide
movement through the geosphere-biosphere interface (for example, movement
from rocks <strong>to</strong> soils and sediments).
CoRWM Document 2543, Oc<strong>to</strong>ber <strong>2009</strong> Page 125 of 151