Deep borehole disposal of radioactive waste: challenges and RD&D opportunities

CSIRO is exploring deep borehole disposal as a potential solution for countries with small inventories of long-lived intermediate-level radioactive waste. In Australia, such waste originates mainly from research reactors and radiopharmaceutical production and requires deep geologic disposal. Because of the relatively small volumes, deep borehole disposal would be a cost-effective, and modular, solution. The CSIRO, ANSTO and SANDIA National Laboratories (US) international partnership are planning to execute a full-scale borehole research, development and demonstration (RD&D) project in Australia. The aim of the project is to demonstrate the technical feasibility and the long-term safety of borehole disposal. The execution of this project could also demonstrate options for radioactive waste disposal that would reduce proliferation risks, potentially up to the termination of compliance with international safeguards requirements. The RD&D includes demonstration of surface handling and full-scale field testing of waste/seal emplacement capabilities in a 0.7-m-diameter, approximately 2000-m-deep demonstration borehole, rock characterisation, post-closure safety assessments and safety case development.

 Dr. Dirk Mallants is Senior Principal Research Scientist & Team Leader Environmental Tracers, Water Security Program, CSIRO Land and Water. Dr. Mallants has a background in soil and groundwater hydrology with more than 25 years of experience characterising and modelling water flow and contaminant transport in complex environments - typically variably-saturated soils, aquifers and low-permeable porous media including clay aquitards and man-made materials such as concretes. He specialises in whole-of-system understanding by integrating experimental observations and coupled numerical models. He was previously Project Leader for Low-Level Radioactive Waste Disposal and Environmental Studies and Head of the Performance Assessments Unit at the Belgian Nuclear Research Centre. Dr Mallants graduated as geo-environmental engineer (soil physics) at the Faculty of Agricultural and Applied Biological Sciences of the Catholic University of Leuven (KUL), Belgium. In 1996 he obtained a Doctor of Philosophy (PhD) in soil physics also from the KUL.