Highest International Quality Standards Methods and Results of Qualification of Electrical and I&C Equipment in German Nuclear Power Plants

The electrical and instrumentation and control (I&C) systems in a nuclear power plant comprise approx. 200,000 units made up of roughly 6,000 different types. Above and beyond their qualifications as standard mass products, 2/3 of these units carry additional certificates of quality. Because of the large number of units employed, failure rates can be detected from statistical studies and limited effectively by preventive maintenance. As a consequence of the special design of nuclear power plants (redundant systems existing in more than one piece, diverse systems functioning in accordance with different physics processes), failures of individual units are accommodated reliably without any loss in technical safety.