Abstract: A method for remotely monitoring manual valves of fluid systems in the nuclear island of a power station, in which method the manual valves are provided with detectors for detecting their open or closed position and first communication device for wireless communication of the signals relating to the position of each valve, second communication device for communication of the signals are arranged at the locations of the valves, there are arranged local cable networks which allow the signals received to pass through thick walls, and there are arranged, at a monitoring location, processor for receiving and processing the signals after they have passed through the walls. A device used for all fluid systems which includes manual valves whose positions must be monitored remotely.

Abstract: The method according to the invention consists of sampling, at successive times separated by constant or non-constant time intervals, signals supplied by redundant channels measuring or calculating the parameter and validating a value of said parameter, as a function of a sample of N values of each channel, in which N.gtoreq.2. In a preferred manner, each sample of N values is modeled by a straight line using the method of least squares and the validated value of the parameter is worked out as a function of the inter-coherent models.

Abstract: The invention relates to a process for monitoring leaks in the primary circuit of a pressurized water nuclear reactor.The primary circuit consists of the vessel (1), the primary part of the steam generators (6), pipework (3, 4), the pressurizer (10) and various stocktanks (20). Connected to the primary circuit is at least one auxiliary circuit such as the circuit for volumetric and chemical monitoring comprising a stocktank (17). A sectioning of the primary circuit and of the circuit for volumetric and chemical monitoring into volume elements, excluding the stocktanks (20, 17) is determined. At regular time intervals, or steps, the mass of water in each of the volume elements and in each of the stocktanks is determined from measurements of pressure, temperature and levels and then, by addition, of the total mass of water.

Abstract: Method of monitoring a nuclear power station by gathering information, called parameters, relating to the operation and state of the power station and its auxiliary equipment, comparing these parameters with reference data corresponding to normal operation, and signaling the differences, in order to permit an operator to evaluate the state of the power station very quickly, and to undertake any needed steps promptly.