Stephen Wickham

Stephen Wickham

Consultant

Dr. Stephen M. Wickham has degrees in Earth Sciences from Oxford University (BA Hons) and Cambridge University (PhD), and has over 20 years research experience in the earth and environmental sciences. He has held academic appointments at the University of Cambridge, the California Institute of Technology, and the University of Chicago. He has contributed to nuclear decommissioning and repository safety assessment programmes in Belgium, France, Sweden, the UK, and the US.

Since 1995 Stephen has worked as a consultant on many issues connected with radioactive waste management, including solid waste treatment, conditioning, packaging and storage, effluent management, repository sealing and backfilling, evolution of repository near-field engineered barriers, and radionuclide transport processes. On behalf of UKAEA Dounreay, he has conducted work on risk assessment for disposal and storage, waste treatment and packaging, historic discharges, disposal and management costs, and risk assessment of long-term radioactive waste storage. He led reviews of scenario development methodologies, and of repository sealing and backfilling concepts and methodologies on behalf of ANDRA (France). He led reviews of radionuclide transport processes by groundwater colloids for EPRI (US) and for SKI (Sweden). He has also managed and contributed to several EC research projects, including a project studying the injection of liquid radionuclides at sites in Russia, a project studying the naturally occurring fission reactors at Oklo, Gabon, a project studying fault hydrogeology and a project studying heavy metal contamination of groundwater.

Since 2002 Stephen has carried out a wide range of work for ONDRAF/NIRAS in support of the Belgian radioactive waste management programmes for Category A (LLW and short-lived ILW), Category B (long-lived ILW) and Category C wastes (vitrified HLW and spent fuel). He has carried out a review of the rationale for buffer design and material selection in HLW/spent fuel disposal programmes worldwide and also implemented a multi-attribute decision analysis (MADA) of the selection of materials for the buffer in the Belgian national concept for deep disposal of HLW and spent fuel (Category B and C wastes). He subsequently managed a series of projects supporting the development of the engineered barrier design in the Belgian disposal concept for Category B and C wastes , and managed a project to develop a FEP list for the engineered barrier system (EBS). He has recently developed and edited reports describing the expected evolution of the EBS in both the Category B and Category C disposal concepts.

Stephen has also supported the ONDRAF/NIRAS disposal programme for Category A wastes. He carried out a review of the role and treatment of concrete barriers in safety assessments of LLW repositories in various countries worldwide, and managed a project to document and justify a state-of-the-art scenario development methodology based on safety functions. This work subsequently led to a further project to undertake methodology development and to support its application to the development and description of scenarios to be used in the safety case for the Category A disposal facility.

Since 1998 Stephen has led a substantial amount of work on storage of radioactive wastes on behalf of UKAEA, NII, Magnox Electric, BNFL, Nirex and overseas clients. On behalf of Magnox Electric, he carried out an analysis of ILW storage options, and participated in a series of workshops aimed at developing a generic Magnox ILW store design. On behalf of UKAEA Dounreay, he has undertaken studies of corrosion and degradation processes in various types of conditioned waste packages. He has undertaken a range of studies for the NII, Nirex and UKAEA focusing on ageing of waste packages, monitoring of environmental conditions in stores, and consideration of “passive safety”. He has also conducted a study for the NII on establishment of delicensing criteria. On behalf of NII he is currently leading a review of ILW storage and monitoring practices at Sellafield.

Stephen has led evaluations for Magnox South (formerly British Nuclear Group) of LLW and Active Waste Water management strategies at various Magnox power stations, to support revision of the RSA93 authorisation at Hinkley Point A. This work has included quantification of the inventory arising from the decommissioning of a Magnox power station, and its subsequent management. He also carried out reviews of effluent management and of effluent plant capability at Hinkley Point A and has also contributed to the development of an electronic database of environmental information relevant to Hinkley Point A decommissioning.

Since 2004 Stephen has been involved in a range of optioneering studies for nuclear waste management and decommissioning, and has facilitated many stakeholder workshops and advised on stakeholder engagement. For example, he played a leading role in the development of a methodology for the conduct of the Windscale Integrated Waste Strategy (IWS) BPEO project, facilitated stakeholder workshops, and was the lead author of the main project report. He has also worked with Sellafield Ltd (formerly British Nuclear Group Sellafield Limited (BNGSL)) on a series of BPEO studies connected with remediation of the Legacy Ponds and Legacy Silos (LP&LS) facilities. This work has included development of optioneering methodologies, facilitation and reporting of stakeholder workshops, and advice on stakeholder interactions. The studies have included a BPEO study on the treatment of wastes from the Magnox Wet Silo, a BPEO study on the treatment of Sellafield Legacy Pond Solids, a BPEO study on the retrieval of wastes and materials from the First Generation Magnox Storage Pond, and a BPEO study for development of an IWS for the Sellafield site. Stephen has recently completed a BPEO study for British Energy on the management of spent ion exchange resins at the Sizewell B power station, including facilitation of stakeholder workshops, and has also undertaken a multi-criteria options study for Magnox North (formerly British Nuclear Group) on the complete removal and management of the boilers at the Trawsfynydd Decommissioning Site in which he helped to develop the optioneering methodology.