Facing new safety-challenges in a large particle accelerator experiment at CERN

An upgraded safety concept for CMS has been adapted to the size of the project and its organisational challenges under today's budgetary constraints, as well as to the increasing levels of risk. Strong magnetic fields and high radiation levels, including neutrons, pose additional hazards to materials, to operators, to maintenance and to ultimate deposit of activated materials. CMS also fits the insurer's risk-description for modern facilities, i.e. characterised by "higher energy density, more combustible materials and unattended operation". The regulatory environment, consisting essentially of CERN's autonomous regulations as well as of those of its host countries, also need to be satisfied with much attention. To face this challenge, seven distinct safety management tools have been identified, which are described in some detail, namely clear safety objectives, documented safety requirements, open items list, safety ( and design)reviews, safety risk analysis, enforcement of compliance and quality management. In implementing and improving these tools the Group Leader in Matters of Safety ( GLIMOS) plays an important role in communication and control. Within the proven-out roles in safety management at CERN, the GLIMOS introduces and uses the improved tools throughout the CMS collaboration.