Method for the oxidation treatment of decaborane gas

A method for oxidation treatment of decaborane gas exhausted from a boron coating of the inner surfaces of vacuum vessels in nuclear fusion reactors comprising passing decaborane gas through a metal tube packed with granules of an alkaline oxidizing agent and granules of a monitoring agent, thereby oxidizing said decaborane gas to stable substances consisting essentially of manganese oxide, potassium borate, water and hydrogen;

• wherein the alkaline oxidizing agent comprises potassium permanganate and potassium hydroxide, and the monitoring agent comprises copper sulfate;
• wherein the metal tube is packed in three layers in the order of a first layer comprising the granules of the oxidizing agent, a second layer comprising the granules of the monitoring agent, and a third layer comprising the granules of the oxidizing agent, whereby the second layer is partitioned from the first layer and from the third layer by means of stainless steel screens;
• wherein the decaborane gas is passed through the layers in order from the first layer to the third layer;
• and
• wherein an inspection window is provided in the metal tube positioned next to the second layer in order to monitor the progress of the oxidative reaction of the decaborane gas by watching the color change of the monitoring agent.