TOxic Substances& Chemicals behaviour Assessment (TOSCA)

Objective

Analyse the current knowledge and identify relevant gaps on toxic substances and chemicals regarding their inventories, source term, behaviour in engineered barriers and the geosphere, and interactions with the biosphere, to propose an evidence-based approach for integrating non-radiological 

Description of the WP

Assessing the impact of toxic chemicals is a major topic in the safety assessments for repositories (surface, near surface and deep geological repository), especially considering the risks associated with these substances and their potential persistence. While repositories are primarily designed to protect against radiological hazards, incorporating toxic substances into the safety assessments will further strengthen the case for the overall safety of disposal.
Through a review of current knowledge on the behaviour of toxic chemicals in nuclear waste repositories, TOSCA WP aims to identify the R&D priorities required to address behaviour and potential impacts of toxic chemicals within repository systems, for surface, near surface and deep geological disposal. In the framework of a strategic study, special focus will be given to inventories and source terms of toxic chemicals, their interactions within the biosphere (including human and non-human biota) and their behaviour in engineered barriers and the geosphere.
This work package will address the issue of non-radiological toxicity in the light of evolving environmental regulations, including an increasing focus on persistent (chemical) pollutants, emerging pollutants (e.g., PFAS, BPA) as well as potential future waste streams, such as those arising from Gen IV reactors. 

Outcomes

-    Scientific Insight: A review of current knowledge about toxic chemicals and substances will help to identify the R&D priorities needed to address their behaviour and potential impacts within the repository. The comprehensive review will prioritise toxic substances and recommend those with lacking data on environmental behaviour and impact for further studies.
-    Implementation for safety: Through the identification of potential impacts of toxic chemicals in repositories and the wider abiotic and biotic environment, TOSCA WP will support the development of international best practice to help ensure robust approaches in these areas.
-    Societal Engagement: This work package aims to address the emerging issue of non-radiological toxicity in the light of evolving environmental regulations, including an increasing focus on persistent (chemical) pollutants.  The direct involvement of Civil Society representatives from the TSO college will help to take Civil Society’s considerations and build trust with the stakeholders.