After the catastrophe of TMI, EDF and Nuclear Security (ASN : Ministry of Industry) decided to increase the level of security of Nuclear Power Plants and to multiply by 3 the number of digital and analogue Information provided by sensors, actuators and measures. To be able to acquire and analyse 100.000 logic and 20.000 analogue information in 50ms, a special industrial information system is built. It is based on a very ambitious, Inmos designed, serial/parallel system composed of Transputers. A Bus, FIP based network is also developed. The Specification of process and security provided by engineers from the Nuclear Security is analysed by a natural language analyser, then a model of the process, based on objects and rules declared in the spec, is built. From this model is generated the source code for logic controllers and process computers, as well as the software for the process simulator. The security and process spec is then tested and validated before to be applied to the real..