Performance & Safety

Quintessa supports developers and regulators of geological disposal facilities in developing Performance Assessments (PAs) and Environmental Safety Cases (ESCs) that provide quantitative and qualitative evidence relating to long-term safety.

Our capabilities and experience is based on our integrative systems assessment services and includes:

  • analysis of key Features Events and Processes (FEPs) and  development of assessment scenarios that underlie a comprehensive safety case;
  • development of conceptual models that reflect the available data and understanding of key processes;
  • development and application of mathematical models for understanding key processes, and also for assessing sub-system and total system performance;
  • near-field evolution and release modelling;
  • flow and transport modelling in porous and/or fractured rocks;
  • consequences of waste-derived gas including coupled modelling of resaturation, gas generation and two-phase gas/water flow;
  • modelling radionuclide transfer and exposure in the biosphere including consideration of non-human biota as receptor species;
  • assessment of the impacts of human actions including human intrusion;
  • analysis of exposure to chemotoxic components of the waste inventory;
  • uncertainty analysis, and assessment of the effects of spatial and temporal variability;
  • use of multiple lines of reasoning, including  natural and historical analogues and supplementary analyses to support system understanding and stakeholder confidence;
  • documenting and presenting assessments for a range of audiences, and identification of future R&D needs; and
  • system specification, optioneering and optimisation studies.