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Title: ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES

Abstract

The effect of the important chemical constituents in the Hanford nuclear waste simulant on the anodic behavior of carbon steel was studied. Specifically, the effect of pH, nitrite concentration, nitrite/nitrate concentration ratios, total organic carbon and the chloride concentration on the open circuit potential, pitting potential and repassivation potential was evaluated. It was found that pH adjusting, although capable of returning the tank chemistry back to specification, did not significantly reduce the corrosivity of the stimulant compared to the present condition. Nitrite was found to be a potent inhibitor for carbon steel. A critical concentration of approximately 1.2M appeared to be beneficial to increase the difference of repassivation potential and open circuit potential considerably and thus prevent pitting corrosion from occurring. No further benefit was gained when increasing nitrite concentration to a higher level. The organic compounds were found to be weak inhibitors in the absence of nitrite and the change of chloride from 0.05M to 0.2M did not alter the anodic behavior dramatically.

Authors:
Publication Date:
Research Org.:
Hanford Site (HNF), Richland, WA
Sponsoring Org.:
USDOE - Office of Environmental Management (EM)
OSTI Identifier:
899767
Report Number(s):
CH2M-32543-FP Rev 0
TRN: US0702049
DOE Contract Number:
DE-AC27-99RL14047
Resource Type:
Conference
Resource Relation:
Conference: NATIONAL ASSOCIATION OF CORROSION ENGINEERS (NACE) 2007 CONFERENCE & EXHIBITION 03/11/2007 THRU 03/15/2007 NASHVILLE TN
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 36 MATERIALS SCIENCE; CARBON; CARBON STEELS; CHEMISTRY; CHLORIDES; CONCENTRATION RATIO; CORROSION; ENGINEERS; NITRITES; ORGANIC COMPOUNDS; PITTING CORROSION; POLARIZATION; RADIOACTIVE WASTES; TANKS

Citation Formats

BOOMER, K.D. ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES. United States: N. p., 2007. Web.
BOOMER, K.D. ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES. United States.
BOOMER, K.D. Wed . "ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES". United States. doi:. https://www.osti.gov/servlets/purl/899767.
@article{osti_899767,
title = {ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES},
author = {BOOMER, K.D.},
abstractNote = {The effect of the important chemical constituents in the Hanford nuclear waste simulant on the anodic behavior of carbon steel was studied. Specifically, the effect of pH, nitrite concentration, nitrite/nitrate concentration ratios, total organic carbon and the chloride concentration on the open circuit potential, pitting potential and repassivation potential was evaluated. It was found that pH adjusting, although capable of returning the tank chemistry back to specification, did not significantly reduce the corrosivity of the stimulant compared to the present condition. Nitrite was found to be a potent inhibitor for carbon steel. A critical concentration of approximately 1.2M appeared to be beneficial to increase the difference of repassivation potential and open circuit potential considerably and thus prevent pitting corrosion from occurring. No further benefit was gained when increasing nitrite concentration to a higher level. The organic compounds were found to be weak inhibitors in the absence of nitrite and the change of chloride from 0.05M to 0.2M did not alter the anodic behavior dramatically.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 31 00:00:00 EST 2007},
month = {Wed Jan 31 00:00:00 EST 2007}
}

Conference:
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  • Corrosion in the vapor space and at the liquid/air interface of the Department of Energy (DOE) high level waste (HLW) tanks have emerged as potentially active corrosion mechanisms. Controls on the solution chemistry are in place to preclude the initiation and propagation of further nitrate induced pitting and stress corrosion cracking. However, recent experience has shown that steel not in contact with the bulk waste solution but exposed to the vapor space above the bulk waste and the liquid/air interface may be vulnerable to pitting or stress corrosion cracking. Experimentation was performed to determine the cyclic polarization behavior of ASTMmore » A537 low carbon steel, the materials of construction of the tanks, in the vapor space above simulated waste solution. The results suggest steel in the vapor space is protected provided the bulk solution issufficiently inhibited.« less
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