BIOPROTA is an international collaborative forum designed to support resolution of key issues in biosphere aspects of assessments of the long-term impact of contaminant releases associated with radioactive waste management. It is understood that there are radioecological and other data and information issues that are common to specific assessments required in many countries. Collaboration through projects focused on mutual research needs is intended to make efficient use of skills and resources, and provide a common, transparent and traceable basis for the choices of modelling approaches and parameter values, as well as for the wider interpretation of information used in assessments.

Several collaborative activities concerned with long-term dose assessment for C-14 have been organised through the BIOPROTA forum. These activities have contributed to greater confidence and reduced uncertainties in assessments made for disposal of radioactive waste containing C-14. The latest ongoing project is centred on model-data and model-model comparisons based on three experimental/observational data sets.

• A data set offered by IRSN relating to deposition of C-14 released to the atmosphere from the La Hague site in north-western France to pasture.
• A data set offered by RWM based on a three-year research project at the University of Nottingham in the UK whereby C-13 and C-14 labelled methane was released to the subsoil.
• A data set based on observed C-14 contamination from historical solid waste disposal at the Chalk River site in Canada.

A project workshop was held 22-23 November 2016, hosted by EdF in Paris, France. The objective of the workshop was to share information on the data sets, describe initial model-data comparisons, discuss lessons learned and agree how to complete the current phase of work. The workshop was attended by 14 participants from 7 countries, representing a range of operators, regulators, researchers and technical support organisations.

Financial support for the current project is provided by Andra (France), EdF (France), KORAD (Republic of Korea), Nagra (Switzerland), NUMO (Japan), NWMO (Canada), Posiva (Finland), RWM (United Kingdom), SKB (Sweden) and SSM (Sweden). The technical and financial support of participants and sponsoring organisations is gratefully acknowledged. The project technical support team comprises Quintessa, Mike Thorne and Associated Limited, GMS Abingdon Limited and RadEcol Consulting Limited.