Detecting position of defects within tubes - in a liquid metal-to-water type heat exchanger used esp. in sodium cooled nuclear reactor

摘要

Subsequent to draining of the heat exchanger a solid reaction prod. of the liquid metal and water forms at a leak location. Introducing an inert gas to the exterior of the tube where the interior pressure is less than the exterior pressure, and heating the tube, provide dissociation and isolation of the reaction product, which, when analysed for chemical content, indicates which tube or tubes is defective. A heat probe appts. which traverses the interior of the tubes may be used in the heating step, which, as a result of the speed of the dissociation process at high temps. provides a means for detecting the specific leak location within the tube. A heat appts. which traverses the exterior of bayonet type tubes may also be used.