Design for Experimental Reactor Safety Circuits Involving Numerical Data Processing

The paper gives a brief description of the reactor, followed by an exposition of the principles underlying the design of the safety circuits, stress being laid on problems of redundancy of measurements and of inter-signal coincidences. The data processing computer plays a part in the safety of the reactor. Its role in the safety circuits is defined, together with the extent of its participation in the triggering of corrective action. A brief description is given of the general structure of the safety circuits showing the application of the above principles and the structure of the numerical data processing with the essential features associated with safety. These include in particular the duplication of certain units and the separation of measurement channels. In view of the complexity of the circuits, tests are arranged under load conditions, to check their proper operation. The various test systems are described, including the following: - The fine pulse test, giving a check on the proper operation of the whole safety logic including the safety rod holding magnets. - Tests of data processing. These tests will automatically cause the switch-over to the duplicate units. The paper concludes with a description of the technology underlying the safety circuits; emphasis is placed on matters of reliability of both components and sub-assemblies. (author)