Process for decontamination of metal surfaces, especially of constituent parts of a pressurised water nuclear reactor, and decontaminating solutions employed in this process

摘要

This process consists in performing at least one decontamination cycle comprising the following stages: a)Bringing the surface to be decontaminated into contact with an oxidising solution containing potassium permanganate and either boric acid or lithia, and b) bringing the surface thus treated into contact with a reducing complexing solution containing ascorbic acid and citric acid and optionally EDTA. Very low percentages of residual contamination with Co-58, Mn-54 and Co-60 can be obtained in 72-80 hours by operating at a temperature of 70 to 95 DEG C, for example 85 DEG C, and with periods of 2 h for each stage. IMAGE