Waste water treatment in the nuclear industry

Abstract

The nuclear fuel cycle comprises all the activities connected with the fuel in the production of electricity from fissile materials, and includes mining and milling of uranium ore, conversion to uranium hexafluoride, enrichment of uranium 235, fabrication of fuel, operation of nuclear power reactors, reprocessing of spent fuel and treatment, storage and/or disposal of radioactive wastes.

The waste water streams which occur in the nuclear industry are very similar to those found in any chemical process industry, except that they are contaminated with radioactivity. Even for high concentrations of radio activity, treatment is concerned with the efficient removal of low concentrations of radioactive chemical contaminants from waste waters ranging from those which are otherwise clean, e.g. cooling waters, to those with high concentrations of dissolved solids. The problems in treating these wastes with their highly diverse chemical and radiochemical content and the high degree of monitoring and control necessary for safe handling, allied to very restrictive legislation on releases, call for more elaborate waste management techniques than have been common in other industries. This experience will be valuable to industries which are becoming subject to more stringent pollution control legislation and to the requirement for onsite treatment of wastes.

This paper reviews only those techniques used to treat wastes containing low levels of radioactivity with the object of re-using or releasing the water. Liquids containing high levels of radioactivity are a major concern in the nuclear industry but the techniques proposed for their treatment are more specialised and of less general interest, and are not discussed further.