Corrosion of steel in simulated nuclear waste solutions

Conference · Wed Dec 01 04:00:00 EST 1993

OSTI ID:10106741

Mickalonis, J I

Processing of inhibited nuclear waste to forms for long-term storage will cause waste tank environments to have dynamic conditions. During processing compositional changes in the waste may produce a corrosive environment for the plain carbon steel tanks. Large concentrations of nitrates which corrode steel are contained in the waste. Nitrite and hydroxides are added to inhibit any corrosion. Concentration changes of nitrate and nitrite were investigated to identify corrosion regimes that may occur during processing. Corrosion testing was performed with cyclic potentiodynamic polarization and linear polarization resistance. Test samples were plain carbon steel which was similar to the material of construction of the waste tanks. The corrosion morphology of test samples was investigated by visual evaluation and scanning electron microscopy. Qualitative chemical analysis was also performed using energy dispersive spectroscopy. The corrosion mechanism changed as a function of the nitrate concentration. As the nitrate concentration was increased the steel transitioned from a passive state to general attack, and finally pitting and crevice corrosion. The nitrate anion appeared to destabilize the surface oxide. Nitrite countered the oxide breakdown, although the exact mechanism was not determined.

• Research Organization: Westinghouse Savannah River Co., Aiken, SC (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC09-89SR18035
• OSTI ID: 10106741
• Report Number(s): WSRC-MS--93-518; CONF-940222--7; ON: DE94003856
• Country of Publication: United States
• Language: English

Related Subjects

052001
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360105
CARBON STEELS
CORROSION
CORROSION AND EROSION
CORROSION PROTECTION
CREVICE CORROSION
HIGH-LEVEL RADIOACTIVE WASTES
NITRATES
NITRITES
NITROGEN COMPOUNDS
PITTING CORROSION
QUALITATIVE CHEMICAL ANALYSIS
RADIOACTIVE WASTE PROCESSING
TANKS
WASTE PROCESSING