CORROSION EVALUATION OF EQUIPMENT USED FOR REPROCESSING ZIRCONIUM ALLOY NUCLEAR FUELS

摘要

Corrosion rates for Monel-400 and various stainless steels in process solutions were determined in laboratory studies and in plant service. The plant service period included the first reprocessing of zirconium alloy nuclear fuels using boric acid as a soluble poison during dissolution. Corrosion rates for a Monel-400 dissolver using hydrofluoric-fluoboric acid dissolvent and sulfuric and chromic acids for cleanout ranged between two and eight mils per month. Corrosion rates for stainless steel plates containing boron as a fixed poison in the first cycle product evaporator were very low. The low corrosion rates for this and other process equipment indicate that the system can be used for future reprocessing operations.