Patent Number: 054147425
Section: abstract

Leak-detection system and method for detecting a leaking container. The system includes an enclosure defining a cavity therein surrounding the container, which container may be a nuclear fuel rod having fission products leaking through a breach in the exterior surface of the fuel rod. The fission products are capable of adhering to the exterior surface of the fuel rod as the fission products leak through the breach in the fuel rod. A radiation detector is in communication with the cavity for detecting the fission products leaking through the breach. Moreover, a gas injector is in communication with the cavity for injecting a multiplicity of carrier gas bubbles into the cavity to remove any fission products adhering to the exterior surface of the fuel rod and to carry the fission products removed thereby to the radiation detector. In this manner, the detector detects the leaking fission products even though they may tend to adhere to the exterior surface of the fuel rod. In addition, an elevator is connected to the fuel assembly for elevating the fuel assembly in the cavity, so that the external pressure acting against the exterior surface of the fuel rods is reduced in order to relieve the internal pressure in the fuel rods. As the fuel assembly is elevated, any fission products tending to "hide-out" in the fuel rods expand and migrate through the breach. As the fission products migrate through the breach, they are carried by the carrier gas bubbles to the radiation detector where they are detected by the radiation detector. In this manner, otherwise undetectable leaking fuel rods become detectable.