Experience from licensing and installing programmable electronics in the power range monitoring safety system in the Barsebaeck Nuclear Power Plant

The old electronics were replaced because of reduced availability and problems to obtain spare parts. In 1989 we decided to use a standard industrial programmable equipment (ABB Master) as new electronics. To develop and test the equipment, it was slowly introduced in unit 2 by a three step model. The third step was completed in unit 2 in July 1992, by replacing all electronics. During this three years we had a close dialogue with our internal safety department and several information meetings with the authority SKI in order to address all safety issues. The difficulties to quantify the reliability of software and the importance of operating experience made us decide to have an analog diversification for the most critical safety function. (author)