Connection for protection of removable part of closed circuit of power installations

Protection is provided by connecting the part to be protected with a by-pass pipe to a circuit whose protection is superior, such as a pressurizer system with safety valves and a vacuum bubble tank. The by-pass pipe connects the suction side of the primary circuit circulating pump; with the delivery side of the second closing valve. Looping thus eliminates the possible contamination of the steam generator box from the safety valve. An example of the connection is shown by the block diagram of one circulation loop of the main circulation circuit of a nuclear reactor with the pressurizer system connected. (J.B.). 1 fig