Environmental Safety Case

An environmental safety case (ESC) is a key submission to safety and environmental regulators that sets out a range of arguments demonstrating optimisation of disposal facility design and operations, and showing that the facility will be safe both in terms of operational and post-closure impacts on humans and the environment.

Typically, depending upon the relevant national approach to regulation, review of an ESC by regulators is a key process towards authorisation or re-authorisation of disposals to a facility. In the UK, acceptance of an ESC by the relevant environment agency is an essential pre-cursor to a Permit Application which, when granted, will permit disposals at a facility.

Quintessa has supported ESC development for a range of surface and near-surface facilities in the UK and overseas for many years, from legacy disposal facilities, through to operational waste repositories, and indeed ESCs for facilities that are yet to be built. We have either led or provided a key supporting role to a number of such programmes. Clarity of arguments and lines of reasoning, demonstration of optimisation, and robust approaches to assessments have underpinned all of our contributions to ESC submissions.

We recently provided a significant level of support to the 2011 ESC for the UK’s low-level waste repository, for example providing support to the demonstration of optimisation, the assessment of impacts associated with key release pathways, and authorship of ESC documents.

In addition, Quintessa developed and subsequently updated the Post-Closure Environmental Safety Case for the D1225 "Shaft" at Dounreay, Scotland. The safety case included detailed analysis and modelling of the geological environment, and assessment of human health and environmental impacts. The finalised document, which runs to over 800 pages, presents a thorough evaluation of long-term effects of the contamination around the Shaft following retrieval of the waste, leading to robust conclusions about its safety.