| Paper | Title | Page |
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| MOMIB06 | Personnel Protection of the CERN SPS North Hall in Fixed Target Primary Ion Mode | 66 |
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| While CERN's Super Proton Synchrotron (SPS) is able to deliver both secondary proton and primary ion beams to fixed targets in the North Area, the experimental areas (North Hall) are widely accessible during beam. In ion mode all normal safety elements involved in producing secondary beams are removed, so that an accidental extraction of a high-intensity proton beam into the North Hall would expose personnel present there to a radiation hazard. This has required an injector reconfiguration restricting operation to either ions or protons. However, demands for operational flexibility of CERN accelerators have led to a need to mix within the same SPS super-cycle both high-intensity proton cycles for LHC or HiRadMat and ion cycles for the North Area. We present an active interlock designed to mitigate this hazard: Beam Current Transformers are used to measure the level of beam intensity, and if above a set threshold, pulsing of the extraction septa is vetoed. The safety function is implemented by means of two logically equivalent but diverse and separate interlock chains. This interlock is expected to be in place once the SPS resumes operation after the first Long Shutdown in 2014. | ||
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Slides MOMIB06 [0.236 MB] | |
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Poster MOMIB06 [4.250 MB] | |
| MOPPC054 | Application of Virtualization to CERN Access and Safety Systems | 214 |
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| Access and safety systems are by nature heterogeneous: different kinds of hardware and software, commercial and home-grown, are integrated to form a working system. This implies many different application services, for which separate physical servers are allocated to keep the various subsystems isolated. Each such application server requires special expertise to install and manage. Furthermore, physical hardware is relatively expensive and presents a single point of failure to any of the subsystems, unless designed to include often complex redundancy protocols. We present the Virtual Safety System Infrastructure project (VSSI), whose aim is to utilize modern virtualization techniques to abstract application servers from the actual hardware. The virtual servers run on robust and redundant standard hardware, where snapshotting and backing up of virtual machines can be carried out to maximize availability. Uniform maintenance procedures are applicable to all virtual machines on the hypervisor level, which helps to standardize maintenance tasks. This approach has been applied to the servers of CERN PS and LHC access systems as well as to CERN Safety Alarm Monitoring System (CSAM). | ||
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Poster MOPPC054 [1.222 MB] | |
| MOPPC055 | Revisiting CERN Safety System Monitoring (SSM) | 218 |
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| CERN Safety System Monitoring (SSM) is a system for monitoring state-of-health of the various access and personnel safety systems at CERN since more than three years. SSM implements monitoring of different operating systems, network equipment, storage, and special devices like PLCs, front ends, etc. It is based on the monitoring framework Zabbix, which supports alert notifications, issue escalation, reporting, distributed management, and automatic scalability. The emphasis of SSM is on the needs of maintenance and system operation, where timely and reliable feedback directly from the systems themselves is important to quickly pinpoint immediate or creeping problems. A new application of SSM is to anticipate availability problems through predictive trending that allows to visualize and manage upcoming operational issues and infrastructure requirements. Work is underway to extend the scope of SSM to all access and safety systems managed by the access and safety team with upgrades to the monitoring methodology as well as to the visualization of results. | ||
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Poster MOPPC055 [1.537 MB] | |
| MOPPC057 | Data Management and Tools for the Access to the Radiological Areas at CERN | 226 |
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As part of the refurbishment of the PS Personnel Protection system, the radioprotection (RP) buffer zones & equipment have been incorporated into the design of the new access points providing an integrated access concept to the radiation controlled areas of the PS complex. The integration of the RP and access control equipment has been very challenging due to the lack of space in many of the zones. Although successfully carried out, our experience from the commissioning of the first installed access points shows that the integration should also include the software tools and procedures. This paper presents an inventory of all the tools and data bases currently used (*) in order to ensure the access to the CERN radiological areas according to CERN’s safety and radioprotection procedures. We summarize the problems and limitations of each tool as well as the whole process, and propose a number of improvements for the different kinds of users including changes required in each of the tools. The aim is to optimize the access process and the operation & maintenance of the related tools by rationalizing and better integrating them.
(*) Access Distribution and Management, Safety Information Registration, Works Coordination, Access Control, Operational Dosimeter, Traceability of Radioactive Equipment, Safety Information Panel. |
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Poster MOPPC057 [1.955 MB] | |
| MOPPC059 | Refurbishing of the CERN PS Complex Personnel Protection System | 234 |
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| In 2010, the refurbishment of the Personnel Protection System of the CERN Proton Synchrotron complex primary beam areas started. This large scale project was motivated by the obsolescence of the existing system and the objective of rationalizing the personnel protection systems across the CERN accelerators to meet the latest recommendations of the regulatory bodies of the host states. A new generation of access points providing biometric identification, authorization and co-activity clearance, reinforced passage check, and radiation protection related functionalities will allow access to the radiologically classified areas. Using a distributed fail-safe PLC architecture and a diversely redundant logic chain, the cascaded safety system guarantees personnel safety in the 17 machine of the PS complex by acting on the important safety elements of each zone and on the adjacent upstream ones. It covers radiological and activated air hazards from circulating beams as well as laser, and electrical hazards. This paper summarizes the functionalities provided, the new concepts introduced, and, the functional safety methodology followed to deal with the renovation of this 50 year old facility. | ||
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Poster MOPPC059 [2.874 MB] | |
| TUCOCA04 | Formal Methodology for Safety-Critical Systems Engineering at CERN | 918 |
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| A Safety-Critical system is a system whose failure or malfunctioning may lead to an injury or loss of human life or may have serious environmental consequences. The Safety System Engineering section of CERN is responsible for the conception of systems capable of performing, in an extremely safe way, a predefined set of Instrumented Functions preventing any human presence inside areas where a potential hazardous event may occur. This paper describes the formal approach followed for the engineering of the new Personnel Safety System of the PS accelerator complex at CERN. Starting from applying the generic guidelines of the safety standard IEC-61511, we have defined a novel formal approach particularly useful to express the complete set of Safety Functions in a rigorous and unambiguous way. We present the main advantages offered by this formalism and, in particular, we will show how this has been effective in solving the problem of the Safety Functions testing, leading to a major reduction of time for the test pattern generation. | ||
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Slides TUCOCA04 [2.227 MB] | |