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During the second long shutdown (LS2) of the accelerator complex at CERN, the access system of the Super Proton Synchrotron (SPS) was completely renovated. This complex project was motivated by the technical obsolescence and lack of sufficient redundancy in the existing system, as well as by the need for homogenisation of technologies and practices across the different machines at CERN. The new Personnel Protection System includes 16 state-of-the-art access points making sure that only fully identified, trained and authorised personnel can enter the facility and an interlock system with a rationalized number of safety chains designed to meet the current safety standards. The control part is based on Siemens 1500 series of programmable logic controllers, complemented by a technologically diverse relay logic loop for the critical safety functions. This paper presents the new system and the design choices made to permit fast installation in a period where the access system itself was heavily used to allow vast upgrades of the SPS accelerator and its infrastructure. It also covers the verification and validation methodology and lessons learned during the commissioning phase., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

Until 2018, the limited firefighting means in the SPS complex largely exposed it to the consequences of self-ignition or accidental fire. In 2015 the SPS Fire Safety project was launched with the objective of improving life safety and property protection by deploying a whole set of automatic actions to protect SPS in case of fire outbreak. If nothing was done, an unmanaged fire could be a threat to lives of those working underground and could mean losing a vast majority of the SPS machine and its equipment. In 2020, CERN has completed the consolidation of its SPS fire safety systems. Among these, a water based sprinkler system, following principles of standard industrial design but customized and tailor-made for SPS and its irradiated areas, is ready to operate. The system must take into account limitations related to the presence of fragile accelerator equipment, radioactive zones, integration constraints and comply with European norms, in particular EN12845. This paper presents the risk assessment, our experience from the planning and installation phase while discussing the custom-chosen and radiation tested equipment to end up with the lessons learned and outlook for the future., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The accelerator facilities at CERN span large areas and the personnel protection systems consist of hundreds of interlocked doors delimiting the accelerator zones. Entrance into the interlocked zones from the outside is allowed only via a small number of access points. These are no longer made of doors which have left their place to turnstiles and then to mantraps or Personnel Access Devices (PAD). Originally meant for high security zones, the commercially available PADs have a number of CERN-specific additions. This paper presents in detail the purpose and characteristics of each piece of equipment constituting the access devices and its integration within the personnel protection system. Key concepts related to personnel safety (e.g. interlocked safety tokens, patrols) and to access control (e.g. access authorisation, biometric identity verification, equipment checks) are introduced and solutions discussed. Three generations of access devices are presented, starting from the LHC model put in service in 2008, continuing with the PS devices operational since 2014 and finally introducing the latest model under development for the refurbishment of the SPS Personnel Protection System., Proceedings of the 16th Int. Conf. on Accelerator and Large Experimental Control Systems, ICALEPCS2017, Barcelona, Spain

In addition to the large LHC experiments, CERN hosts a number of other experimental areas with a rich research program ranging from fundamental physics to medical applications. The risk assessments have shown a large palette of potential hazards (radiological, electrical, chemical, laser, etc.) that need to be properly mitigated in order to ensure the safety of personnel working inside these areas. A Personnel Protection System, typically, accomplishes this goal by implementing a certain number of heterogeneous functionalities as interlocks of critical elements, management of a local HMI, data monitoring and interfacing with RFID badge readers. Given those requirements, reducing system complexity and costs are key parameters to be optimized in the solution. This paper is aimed at summarizing the findings, in terms of costs, complexity and maintenance reduction, offered by a technology from National Instruments® based on cRIO controllers and a new series of SIL-2 certified safety I/O modules. A use case based on a service for the protection of Class 4 laser laboratories will be described in detail., Proceedings of the 16th Int. Conf. on Accelerator and Large Experimental Control Systems, ICALEPCS2017, Barcelona, Spain

Interlocks are an important feature of both personnel and machine protection systems for mitigating risks inherent in operation of dangerous equipment. The purpose of an interlock is to secure specific equipment or entire systems under well defined conditions in order to prevent accidents from happening. Depending on specific requirements for the level of reliability, availability, speed, and cost of the interlock, various technologies are available. Different approaches are discussed, in particular in the context of personnel safety systems, which have been built or tested at CERN during the last few years. Technologies discussed include examples of programmable devices, PLCs and FPGAs, as well as wired logic based on relays and special logic cards., Proceedings of the 15th Int. Conf. on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2015, Melbourne, Australia

Engineering of Personnel Protection Systems (PPS) in large research facilities, such CERN, represents nowadays a major challenge in terms of requirements for safety and access control functionalities. PPS are usually conceived as two separate independent entities: a Safety System dealing with machine interlocks and subject to rigid safe-ty standards (e.g. IEC-61508); and a conventional Access Control System made by integration of different COTS technologies. The latter provides a large palette of func-tionalities and tools intended either to assist users access-ing the controlled areas, either to automate a certain number of control room operator's tasks. In this paper we analyse the benefits in terms of performance, cost and system maintainability of adopting the new generation of NI multipurpose CRIO 903x controllers. These new de-vices allows an optimal integration of a large set of access control functionalities, namely: automatic control of mo-torized devices, identification/count of users in zone, im-plementation of dedicated anti-intrusion algorithms, graphical display of relevant information for local users, and remote control/monitoring for control room opera-tors., Proceedings of the 15th Int. Conf. on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2015, Melbourne, Australia

Access and safety systems are traditionally considered critical in organizations and they are therefore usually well isolated from the rest of the network. However, recent years have seen a number of cases, where such systems have been compromised even when in principle well protected. The tendency has also been to increase information exchange between these systems and the rest of the world to facilitate operation and maintenance, which further serves to make these systems vulnerable. In order to gain insight on the overall level of information security of CERN access and safety systems, a security assessment was carried out. This process consisted not only of a logical evaluation of the architecture and implementation, but also of active probing for various types of vulnerabilities on test bench installations., Proceedings of the 15th Int. Conf. on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2015, Melbourne, Australia