DIN 7516:2016-12

Safety-related control systems in nuclear power plants shall be fault-tolerant for the effects of plant/equipment faults and internal and external hazards. DIN EN 60709 (VDE 0491-7):2010-12 contains requirements to achieve independence between redundant sections of safety systems and between safety systems and lower-class systems. Among the techniques available to increase the tolerance of control systems to such effects is the use of isolation devices when establishing connections between redundant sections of safety-related equipment or safety-related equipment and lower-class systems. DIN EN 62808 (VDE 0491-9-3) contains technical requirements and recommendations for the design and qualification of isolation devices required by DIN EN 60709 (VDE 0491-7):2010-12. It addresses the criteria and methods used to demonstrate that the design of isolation devices meets isolation requirements; namely, that assumed faults in connected lower-class systems or redundant channels do not prevent the safety systems from performing requested functions. Isolation devices may be required at power or signal interfaces within the system. The responsible committee is DKE/UK 967.1 "Leittechnik für kerntechnische Anlagen" ("Instrumentation and control of nuclear facilities") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.