[en] Proposed criteria for the application of stored program, digital computers in commercial nuclear power plants is presented. This report emphasizes recommendations for the design of computer systems and recommends a method for the regulatory review of computer system designs. More restrictive requirements are made for protection systems than control systems or other plant computer systems. In making these recommendations, the study team reviewed current regulations, past Nuclear Regulatory Commission reviews of computer systems, the work done by other government agencies, and the work done by many other countries. Results of this study provide a classification of systems, a recommended design method, and a specification of design issues to be resolved during the design and development of digital computer systems. Also included is a recommendation of subject areas that need further research activity. This report is part of a larger program to research computer system design issues, to develop design criteria (hardware and software) for Safety Parameter Display Systems, to research software quality assurance, to provide a comparative risk assessment of digital technology, and to develop electrical isolation criteria