IEC 60987:2007+A1:2013 Is applicable to computer-system hardware for systems of Class 1 and 2 (as defined by IEC 61513) in nuclear power plants. This new edition reflects recent developments in computer system hardware design, the use of pre-developed hardware and changes in terminology. This consolidated version consists of the second edition (2007) and its amendment 1 (2012). Therefore, no need to order amendment in addition to this publication.