An integrated testing programme for a near field radionuclide migration code

The DRINK code is a 2D, biogeochemical transport code developed as a research tool to simulate the long term evolution of near surface LLW disposal sites and to generate gaseous and liquid source terms for far field studies. The code was recently upgraded to provide a more generic modelling tool with wider application to radionuclide migration scenarios. During the
development of this code, the Generalised Repository Model (GRM), an integrated strategy has
been employed to ensure the production of a fully tested, verified and quality assured product.
This strategy is based around a code development protocol with three main components: quality
assurance and documentation, verification and realism testing. Realism testing includes both peer review and model testing, with the latter including: experimental test cases; natural and
anthropogenic analogues; field observations and finally uncertainty and sensitivity analysis. This
paper describes the successful application of the protocol to the development and testing of the
GRM code with specific emphasis upon verification and realism testing.