Nuclear reactors create large quantities of potentially harmful radioactive nuclides. It is the general concern of reactor technologists to achieve some useful objective from the controlled fission process while at the same time rendering harmless the radioactivity produced. Radioactive species, deposited from the coolant on ion-exchange resins, can cause decross-linking or can cause the release of soluble sulfonates or amines. The removal of borated "shim" from the primary coolant system of land-based nuclear power plants must be carefully controlled. Large quantities of boron, with or without radioactivity, are undesirable contaminants for the environment. Therefore, it has become general practice to treat any and all solutions containing boron for final complete and safe disposal. In high-pressure and supercritical cycles in nuclear systems, problems arising from the transport of volatile solutes will be further complicated by the radioactivity of these volatile solutes.