Nuclear Security Assessment Methodologies (NUSAM): A Medical Facility Using Radioactive Sources

This paper describes the outcomes of a case study undertaken by the UK’s National Nuclear Laboratory (NNL) as part of the International Atomic Energy Agency’s (IAEA) Co-ordinated Research Project (CRP) on Nuclear Security Assessment Methodologies (NUSAM). The aim of NUSAM is to provide guidance on nuclear security assessment, utilising 3 exemplar case studies. Work undertaken by NNL within one of these cases studies sought to explore whether those different methods give comparable output. A case study was undertaken evaluating the security arrangements at a hypothetical medical irradiator facility, referred to hereafter as the University Medical Centre (UMC). The methodologies considered were; a prescriptive analysis against IAEA Nuclear Security Series 111 (NSS11), a qualitative analysis using a regulatory questionnaire, a quantitative analysis using a regulatory simple pathway method and a modelling and simulation analysis using the AVERT© software2. Whilst these methods vary significantly in complexity, they are often used interchangeably by organisations around the world. This paper presents the results from these analyses and compares them to highlight the strengths and weaknesses of each methodology and the landscape of their suitability for purpose.