Fuel decontaminating device

Purpose: To remove metal oxides deposited on the surface of fuel rod by using reducing agent without dismantling a fuel assembly. Constitution: A decontaminating liquid supply tool and a liquid removal tool are mounted to one and the other ends of a metal cylinder containing a nuclear fuel assembly in order to flow the decontaminating liquid for chemically dissolving metal oxides. The metal oxides on the surface of the fuels are removed while being dissolved in a chemical reduction manner. In order to increase the dissolving power of the decontaminating liquid, electrolytes reduced by the cathodic electrolysis are used. In this method, decontamination can be carried out even to the gaps or the portions behind the obstacles which can not be cleaned by the mechanical shocks in conventional mechanical elimination method. Further, it is no more necessary to dismantle the fuel assembly thus causing no surrounding contamination. Further, the device is simple and the worker's exposure can be decreased. (Moriyama, K.)