This paper deals with the cryogenic risk arising from nitrogen spillage in a box located in Hall A of the underground laboratories of the Gran Sasso National Laboratory, Assergi (L'Aquila). This box will be used as a storage area for some sensitive material (crystals) which will be used for an experiment called "CUORE". Starting from the Fault Tree Analysis (FTA), in order to estimate the global risk for human activities, a consequence analysis has been performed, using EFFECTS software models. The gap between the latest and the real scenario has been covered by a real test during which a "monitored, measured and controlled" gas nitrogen flow has been spilled into the box. Furthermore, a description of a reliable base for computational fluid dynamics (CFD) analysis is treated.

The Gran Sasso National Laboratories (

The aim of this work is the application of a performance-based approach in the field of the Fire Safety Engineering within the Gran Sasso National Laboratories (LNGS), one of the structures owned and managed by the National Institute for Nuclear Physics (INFN). CFD (Computational Fluid Dynamics) models provide a solid foundation on which a complete assessment of the different choices and procedures of evacuation management might be performed. These choices take into account, not only the characteristics of the surrounding environment and the accident scenario, but also the psychological and human aspects induced in people involved in an emergency event. The analysis has been implemented through the development of fire simulation models FDS (Fire Dynamic Simulator of the NIST) applied to new experimental installations, facilities and utilities in one of the LNGS underground areas. The object of the study has been the definition and simulation of a fire caused by an electrical cabinet devoted to the new experimental apparatus named "LUNA-MV" located inside the interferometer tunnel of the LNGS. The analysis addressed the choices in the preliminary design of the safety systems and in the optimization of the technical, economic and design parameters taken into account for each hypothesized event scenario. The work allowed also identifying the crucial factors for reviewing and optimizing the LNGS Emergency Plan, thus providing useful elements to support the LNGS users' training.

No abstract

The aim of this work is to refine the emergency and evacuation management by the application of FDS+Evac (by NIST and VTT) models within the Gran Sasso National Laboratories (LNGS); one of the structures owned and managed by the Italian National Institute for Nuclear Physics (INFN). The application of these models to a peculiar site, such as the LNGS one, has the fundamental role to evaluate the correct definition of the emergency procedures proposed and adopted inside the plant. Thus ensuring, by an agent-based dynamic simulation, a preliminary evaluation of the behaviour of users and emergency teams in case of emergency and, specifically, an assessment of the time of intervention and full evacuation from the site. The analysis has been applied to a new experimental installation in one of the main experimental halls of the LNGS. The object of the study has been the simulation of evacuation after a direct nitrogen release in the service building of the Xenon1T experiment, located in Hall B of the underground laboratories. The implemented models have the great potential to take into account not only the characteristics of the surrounding environment, but also the psychological and human aspects induced in people involved in an emergency. The study aims to provide a first step evaluation of the accuracy of the Internal Emergency Plan (PEI) procedures adopted in the LNGS, highlighting the pros, cons, critical aspects, future progresses and the possibility of