scholarly journals Development of Integrated Mechanistically-Based Degradation-Mode Models for Performance Assessment of High-Level Waste Containers

1999 ◽  
Vol 556 ◽  
Author(s):  
J. C. Farmer ◽  
R. D. Mccright ◽  
J. C. Estill ◽  
S. R. Gordon
Keyword(s):  
Stainless Steel ◽  
Crevice Corrosion ◽  
Chloride Concentration ◽  
Yucca Mountain ◽  
304 Stainless Steel ◽  
High Level Waste ◽  
Mechanistic Models ◽  
Alloy 22 ◽  
High Level ◽  
Impurity Elements

AbstractAlloy 22 [UNS N06022] is now being considered for construction of high level waste containers to be emplaced at Yucca Mountain and elsewhere. In essence, this alloy is 20.0–22.5% Cr, 12.5–14.5% Mo, 2.0–6.0% Fe, 2.5–3.5% W, with the balance being Ni. Other impurity elements include P, Si, S, Mn, Co and V. Cobalt may be present at a maximum concentration of 2.5%. Detailed mechanistic models have been developed to account for the corrosion of Alloy 22 surfaces in crevices that will inevitably form. Such occluded areas experience substantial decreases in pH, with corresponding elevations in chloride concentration. Experimental work has been undertaken to validate the crevice corrosion model, including parallel studies with 304 stainless steel.

Susceptibility of 304 Stainless Steel to Crevice Corrosion in Electrochemically Active Fluids

CORROSION ◽  
10.5006/3324 ◽  
2020 ◽  
Vol 76 (4) ◽  
pp. 424-435
Author(s):  
Abinaya Kamaraj ◽  
Johann Wilhelm Erning
Keyword(s):  
Stainless Steel ◽  
Crevice Corrosion ◽  
Chloride Concentration ◽  
304 Stainless Steel ◽  
Water Composition ◽  
Polyether Ether Ketone ◽  
Electrochemically Active ◽  
Ether Ketone ◽  
Type 304 ◽  
Type 304 Stainless Steel

The susceptibility of Type 304 stainless steel (SS) to crevice corrosion upon contacting with electrochemically active fluids was investigated using exposure tests and stepwise potentiostatic polarization. Crevice materials made of 304 SS and polyether ether ketone (PEEK) were focused on in this study. The combined influence of oxidant and chloride concentration on crevice corrosion was examined in detail in the two types of crevice combinations (304 SS-to-PEEK and 304 SS-to-304 SS). The 304 SS specimens were strongly susceptible to crevice corrosion when coupled with 304 SS. Even at a low concentration of 5 mg/L free chlorine and 150 mg/L chloride, which is below nominal dilutions in beverage industries, the examined specimens underwent crevice corrosion in both crevices. The effect of water composition on crevice corrosion was also studied, indicating high susceptibility of 304 SS to crevice corrosion in low pH (pH ≤ 5) solutions. The corroded surface morphology was analyzed using scanning electron microscope, energy dispersive x-ray, and confocal microscope.

scholarly journals Parametric Effects of Glass Reaction Under Unsaturated Conditions

1989 ◽  
Vol 176 ◽  
Author(s):  
John K. Bates ◽  
Thomas J. Gerding ◽  
Alan B. Woodland
Keyword(s):  
Stainless Steel ◽  
Yucca Mountain ◽  
Test Method ◽  
High Level Waste ◽  
304L Stainless Steel ◽  
Water Contact ◽  
Mountain Site ◽  
Parametric Effects ◽  
Degree Of Sensitization ◽  
High Level

ABSTRACTEventual liquid water contact of high-level waste glass stored under the unsaturated conditions anticipated at the Yucca Mountain site will be by slow intrusion of water into a breached container/canister assembly. The water flow patterns under these unsaturated conditions will vary, and the Unsaturated Test method has been developed by the YMP to study glass reaction. The results from seven different sets of tests done to investigate the effect of systematically varying parameters such as composition and degree of sensitization of 304L stainless steel, water input volume, and the interval of water contact are discussed. Glass reaction has been monitored over a period of five years, and the parametric effects can result in up to a ten-fold variance in the degree of glass reaction.

scholarly journals High Level Waste (HLW) Vitrification Experience in the US: Application of Glass Product/Process Control to Other HLW and Hazardous Wastes

2008 ◽  
Vol 1107 ◽  
Author(s):  
Carol M. Jantzen ◽  
James C. Marra
Keyword(s):  
Process Control ◽  
High Level Waste ◽  
Glass Product ◽  
Mechanistic Models ◽  
Glass Waste ◽  
Statistical Process ◽  
Feed Composition ◽  
Feed Forward ◽  
Bonding Structure ◽  
High Level

AbstractVitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. At the Savannah River Site (SRS) actual HLW tank waste has successfully been processed to stringent product and process constraints without any rework into a stable borosilicate glass waste since 1996. A unique “feed forward” statistical process control (SPC) has been used rather than statistical quality control (SQC). In SPC, the feed composition to the melter is controlled prior to vitrification. In SQC, the glass product is sampled after it is vitrified. Individual glass property models form the basis for the “feed forward” SPC. The property models transform constraints on the melt and glass properties into constraints on the feed composition. The property models are mechanistic and depend on glass bonding/structure, thermodynamics, quasicrystalline melt species, and/or electron transfers. The mechanistic models have been validated over composition regions well outside of the regions for which they were developed because they are mechanistic. Mechanistic models allow accurate extension to radioactive and hazardous waste melts well outside the composition boundaries for which they were developed.

Effects of Perched Water on Thermally Driven Moisture Flow at the Proposed Yucca Mountain Repository for High-Level Waste

1999 ◽  
Vol 125 (2) ◽  
pp. 235-253 ◽  
Author(s):  
Goodluck I. Ofoegbu ◽  
Amvrossios C. Bagtzoglou ◽  
Ronald T. Green ◽  
Michael A. Muller
Keyword(s):  
Yucca Mountain ◽  
High Level Waste ◽  
Moisture Flow ◽  
Perched Water ◽  
Thermally Driven ◽  
High Level

The pitting and crevice corrosion of 304 stainless steel in phosphate-borate buffer containing sodium chloride

1992 ◽  
Vol 33 (10) ◽  
pp. 1645-1651 ◽  
Author(s):  
J. Morales ◽  
P. Esparza ◽  
R. Salvarezza ◽  
S. Gonzalez
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
Crevice Corrosion ◽  
Borate Buffer ◽  
304 Stainless Steel

Corrosion of Stainless Steel for HLW Containers Under Gamma Irradiation

1992 ◽  
Vol 294 ◽  
Author(s):  
K. Osada ◽  
S. Muraoka
Keyword(s):  
Stainless Steel ◽  
Radioactive Waste ◽  
Gamma Irradiation ◽  
Pitting Corrosion ◽  
Electrochemical Method ◽  
Fission Products ◽  
304 Stainless Steel ◽  
Redox Potentials ◽  
High Level Radioactive Waste ◽  
High Level

ABSTRACTThe corrosion behavior of type 304 stainless steel was studied under gamma irradiation as part of the evaluation for the long-term durability of high-level radioactive waste (HLW) disposal containers. Gamma rays, generated from fission products in high-level radioactive waste, are considered to change the environment around the canisters and overpacks. The redox potentials for NaCl solutions and corrosion potentials of stainless steel were measured to consider the effects of gamma irradiation, by using an electrochemical method. The pitting potentials of stainless steel for NaCl solutions were also measured to examine the pitting corrosion under gamma irradiation. As a result of this experiment, it is concluded that the oxidizing properties as a result of the formation of H2O2 and H2 produced by gamma irradiation depended on the concentration of Cl−, and that the strength of oxidizing properties of 1M (mol·dm−3) NaCl solution was particularly high. and the pitting corrosion was found for 1M NaCI solution under gamma irradiation at the dose rate of 2.6×102 C/kg·h (1.0×106 R/h) at 60°C, by using an electrochemical method.

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