Removal of nuclear element from stain- - less steel sleeve

摘要

Stainless steel covers are removed from elements by bringing the element into a closed space filled with a gaseous mixture of hydrogen fluoride and oxygen, allowing the mixture in the space to react with the cover, and then washing away the residual gaseous mixture from the space. The gaseous mixture of hydrogen fluoride and oxygen is pref. returned to the space at least once after the removal of the residual gaseous mixture. The residual gas mixture is removed in a cold gas stream. The space is filled with the gaseous mixture at a temp. of ca. 600 degrees C, and a pressure of ca. 5 kg/cm2. The gas mixture pref. contains 70-80% vol. of hydrogen fluoride and oxygen. The method is especially suitable for removing stainless steel covers from fissionable elements. The steel is effectively loosened from the element in the form of a very fine structure, which can be easily separated from the element by pneumatic transport. The element does not become swollen or corroded during the treatment.