Open AccessLaboratory studies of gas generation and potential for tank wall corrosion during blending of high-level wastes at the West Valley Demonstration Project
Author(s) -
W.J. Gray,
R.E. Westerman
Publication year - 1995
Language(s) - English
Resource type - Reports
DOI - 10.2172/70736
Subject(s) - purex , corrosion , mixing (physics) , dilution , nitric acid , waste management , environmental science , chemistry , nuclear reprocessing , spent nuclear fuel , materials science , metallurgy , nuclear chemistry , chromatography , inorganic chemistry , thermodynamics , engineering , physics , quantum mechanics , solvent extraction , extraction (chemistry)
Laboratory experiments were conducted to simulate the transfer of acidic THOREX waste from Tank 8D-4 into the alkaline PUREX waste in Tank 8D-2 at West Valley. The purpose of the experiments was to explore means of minimizing the production of nitric oxide (NO) gas during mixing of the two wastes and to assess the potential for the gas to further react in the vapor space possibly leading to enhanced corrosion of the tank walls. Forty one THOREX/PUREX mixing tests were conducted to explore the effects of stirring rate, pH, THOREX addition rate, THOREX or PUREX dilution, and temperature. The two most important criteria for minimizing NO production were to maintain some degree of agitation and the keep the pH in the PUREX high, preferably >12. Steel corrosion tests were performed in the presence of low partial pressures of NO{sub 2} and liquid water or water vapor. The NO{sub 2} (from oxidation of NO in the vapor space) concentrations were representative of those derived from the THOREX/PUREX mixing tests. It was concluded that no significant corrosion of the tank walls would be expected under the anticipated THOREX/PUREX mixing conditions if the exposure was short (<100 days)