Patent Number: 046506357
Section: 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. The means values of the masses of water are calculated over periods of time corresponding to a multiple of the steps and offset in time by at least one step, together with the difference of the mean values corresponding to two successive periods of time, the difference representing the leakage flow in the primary circuit.. The invention applies in particular to nuclear reactors with three or four loops.