New approach to the problems of electrical interference in instrumentation and control systems

In the context of nuclear reactor control and safety, electrical interference can be potentially detrimental, sometimes in subtle ways. The most prolific disturbances are generated by switching mains-powered equipment, the local ground structure constituting a major coupling path via which high-frequency transients can affect electronic systems. When design considerations are outlined, the advantages of using improved screened components, such as superscreened cables, virtually to eliminate interference problems become clear. Procedures for measuring the interference immunity of equipment and of installed systems in situ have been developed. They provide powerful diagnostic, quality control, and commissioning aids. Several case histories are presented to illustrate how the essential principles have been applied successfully in practice and to demonstrate that electrical interference need no longer be a problem