Heavy water cooled reactor esp. converter reactor - has off=load fuel changing with substitution of light for heavy water

摘要

A method of operating a heavy water-cooled nuclear reactor in fuel changing consists of replacing the heavy water in the reactor pressure vessel by light water after a specific operating period; this is done by removing heavy water simultaneously with the introduction of light water. At least a quarter of the fuel elements in the core are then changed while the reactor pressure vessel is opened, using the light water as shielding; the reactor pressure vessel is then closed and the light water is replaced progressively by the introduction of heavy water. The outflowing medium is pref. drawn off and stored in different vessels. The exchange of the heavy for light water and vice versa is pref. carried out using their density differences, the heavy water being removed and replaced at the bottom of the vessel and the light water at the top. Used for heavy water-cooled nuclear reactors. partic. high converter reactors.