IEC 60880 Ed. 1.0 b:1986

Applies to highly reliable software required for computers to be used in the safety systems of nuclear plants for safety functions (Class 1 functions according to IEC 643). This includes the safety actuation systems, the safety system support features and the protection systems. This standard provides requirements for each stage of software generation, including design, development, qualification and operation as well as the documentation for each stage of the software generation for the purpose of achieving highly reliable software. Additional guidance and information on how to comply with the requirements of the main part of this standard is given in appendices.