Patent Number: 055464351
Section: claims

1. An arrangement for carrying out leak detection of a fuel assembly for a pressurized-water nuclear reactor, comprising: a substantially vertical hollow mast means, in which said fuel assembly to be examined is housable;  means for drawing said fuel assembly to the inside of said mast means from its lower side;  means for lifting at least the part of said mast means housing said fuel assembly to a position in which said fuel assembly is provided near but below the water surface of water inside said nuclear reactor;  means for sucking water from a position inside said mast means above said fuel assembly;  gas separating means for separating gases present in said water sucked from the inside of said mast means; and  gas analyzing means for analyzing the amount of gaseous fission products in said separated gas.  a substantially vertical hollow mast having an open bottom for receiving said fuel assembly therein;  means associated with the mast for drawing the fuel assembly within the mast through the open bottom;  means for lifting the mast containing the fuel assembly to a position in which said fuel assembly is located near, but below the surface of the water level in the reactor;  means for circulating water from within the mast above said fuel assembly and below said water level;  means coupled to the circulating means for separating gasses in the water circulated from the mast; and  analyzing means for analyzing the separated gas for fission products. 2. An arrangement according to claim 1, wherein said gas analyzing means comprises a gas circuit including a pump functioning to pump any gas present in said circuit and a gas space in said gas separating means around said gas circuit and said gas space, therewith enriching any gaseous fission products present in said water sucked from the inside of said mast means. 3. An arrangement according to claim 1, wherein said water suction device and associated fission product analyzing circuit are constructed to detect gaseous fission products that accompany said pumped water, wherein said suction device is adapted to deliver water from the inside of said mast means to said fission detection circuit, which includes a liquid container having a hose for degassified water, a gas detection circuit coupled to the upper part of said container, wherein said gas detection circuit is connected back to said container for enrichment of the fission gases in said gas detection circuit. 4. An arrangement according to claim 1, wherein said fission-gas detection circuit includes a gas separator which includes a gas space and a water reservoir which are mutually separated by a waterseal; a device for finely-dividing the water delivered to said gas space; a gas circuit connected to said gas space; and a measuring chamber located in said gas circuit and functioning to measure occurrent gaseous fission products. 5. An arrangement according to claim 4, wherein said gas circuit includes a moisture separator, a gas dryer and an iodine trap upstream of said measuring chamber as seen in the gas delivery direction. 6. An arrangement for carrying out leak detection of a fuel assembly below the surface of the water level in a pressurized-water nuclear reactor comprising: