Functional Safety is the part of the overall safety of a technological system based on the correct implementation of Instrumented Safety Functions (SIF) through Instrumented Protection Systems (SIS) made with E/E/EP technologies (Electric, Electronic, Electronic Programmable).
The main international reference is the IEC/EN 61508 standard, based on a risk-based philosophy, which governs the entire life cycle of E/E/EP security systems, including hazard identification and risk assessment activities, allocation of requirements in terms of “Safety Integrity” (SIL), systems designing and engineering, operation and maintenance, modification and dismantling.
Through sector application standards, the general standard extends to several specific domains including Process Industry, Power Nuclear Plants sector, rail transport sector, Industrial Combustion Systems sector, machinery sector, Fire & Gas Detection systems, etc.
The services delivered by RAMS&E within Functional safety are the following:
- Functional Safety studies in accordance with IEC EN 61508 and industry application standards
- SIL Allocation Studies for Safety Instrumented Functions (SIF)
- Support to Engineering and SIL Verification Studies for Safety Instrumented Systems
- Support for the designing and management of the Safety Life Cycle
- Evaluation and Auditing of Functional Safety
Functional Safety study for a test facility created for the study of a system for generating a beam of high-energy neutral particles (1MeV), which will form one of the auxiliary plasma heating systems of the ITER nuclear fusion reactor
GOALS OF THE ACTIVITY
As part of the project, RAMS&E supported the Customer, well-known Italian research center on nuclear fusion and particle physics, for the designing of the central security system (CSS) for two experimental plants under construction at the test facility, called “Megavolt ITER Injector & Concept Advancement” (SPIDER) and “Source for Production of Ion of Deuterium Extracted from Rf plasma” (MITICA).
The first experiment represents the prototype, on a reduced scale, of the negative ion source of H2/D2. The second experiment, instead, is the full-scale realization of the particle injector prototype that will be made at ITER and uses the ion source integrating it with everything needed to create a neutral particle beam (ion acceleration grids; a neutralizer, a residual ion killer, a calorimeter). Everything is placed inside a vacuum chamber, from which it is possible to insert the diagnostic tools, as well as all the connections with the systems that are used to keep the structure under vacuum, the power supply system, the gas injection system needed to make the plasma and the cryogenic cooling system.
The following activities have been developed.
- Support for CSS project of the two experimental systems, with the identification of the technical specifications in the Functional safety field for the activities related to the two experiments.
- Development of analyzes for the identification and definition of the Instrumented Safety Functions (SIFs) that must be provided and implemented by the CSS system, to keep experimental processes and related activities safe, in relation to any specific and foreseeable dangerous event.
- SIL Allocation study, according to IEC/EN 61511 (application standard in the field of process plants), with which the requirements associated with the Instrumented Safety Functions were defined in relation to the defined risk acceptability criteria, through the application of the semi-quantitative LOPA technique (Layer Of Protection Analysis).
- SIL Verification activities to support the engineering of Safety Instrumented Systems (SISs) implemented to CSS
- Functional Safety Assessment activities to support the preparation of the Safety Life Cycle documentation, with particular reference to the following phases:
- Hazard Identification and Risk Assessment;
- SIL allocation of the identified SIFs;
- Designing and Engineering of SIFs and verification of compliance of SISs with the assigned security requirements (both for hardware and software aspects);
- Validation and Test of the implemented SISs;
- Maintenance and Test/Periodic Inspection of SISs.