scholarly journals The Reaction of SRL 202 Glass in J-13 and DIW

1992 ◽  
Vol 294 ◽  
Author(s):  
W. L. Ebert ◽  
J. K. Bates ◽  
E. C. Buck
Keyword(s):  
Stainless Steel ◽  
Reaction Rates ◽  
Deionized Water ◽  
High Level Waste ◽  
Similar Reaction ◽  
304L Stainless Steel ◽  
Ph Values ◽  
Stainless Steel Vessel ◽  
J 13 ◽  
High Level

ABSTRACTStatic leach tests were performed in both 304L stainless steel and Teflon vessels using a synthetic high-level waste glass with either deionized water (DIW) or a tuff groundwater solution as the leachant to assess the effects of the vessel and the initial leachant composition on the extent and nature of the glass reaction. The tests were performed using monolith samples at 340 m−1 and crushed samples at 2000 m−1 for times up to 1 year. The results show less silicon is released from the glass into the groundwater solution than into DIW at both high and low glass surface area/leachant volume ratios (SA/V), but the alkali metal and boron releases are not affected by the leachant used. Tests performed in a stainless steel vessel resulted in slightly lower leachate pH values, but similar reaction rates to those performed in a Teflon vessel, as measured by the boron release. Blank tests with DIW or EJ-13 in the vessels showed the Teflon vessels to release small amounts of fluoride (1 to 2 ppm) and to acidify the DIW slightly (4.0 < pH < 5.6). The pH values of blank tests with EJ-13 increased from 8.2 to about 8.6 in steel and to about 9.2 in Teflon vessels. The slightly higher pH values attained in Teflon vessels are attributed to outgassing of CO2 during the test.

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.

Understanding the Behavior and Stability of Some Uranium Mineral Colloids

2002 ◽  
Vol 757 ◽  
Author(s):  
Carol J. Mertz ◽  
Jeff A. Fortner ◽  
Yifen Tsai
Keyword(s):  
Uranyl Nitrate ◽  
Nitrate Solution ◽  
Colloidal Suspensions ◽  
Bimodal Distribution ◽  
Yucca Mountain ◽  
Dominant Mode ◽  
High Level Waste ◽  
Ph Values ◽  
J 13 ◽  
High Level

ABSTRACTColloids are believed to be a dominant mode of transport for radionuclides in the unsaturated zone and thus the characterization of the attributes of the colloids is important for understanding and predicting subsurface transport. As uranium-based spent nuclear fuels will be prevalent at the high-level waste repository at Yucca Mountain, we have examined the colloidal properties of a mixture of two uranium minerals. This paper presents results of analyses on colloidal suspensions of meta-schoepite, (UO2)4)(OH)6·5H2O, and UO2+x, in 10 mM uranyl nitrate or J-13 groundwater (from Yucca Mountain, NV). A suite of techniques was used to characterize the colloids. The colloids detected by dynamic light scattering in the 10 mM uranyl nitrate solution exhibited a mean size of ∼200 nm and a colloid concentration on the order of 1012 particles/L. Likewise, large 200 nm colloids of meta-schoepite and UO2+x were dominant in the transmission electron microscopy analyses. The colloids detected in the J-13 groundwater exhibited a bimodal distribution; large globular 100–200 nm UO2+x colloids and needle-like colloids of meta-schoepite were observed (with extremely fine microstructure exhibited for the meta-schoepite colloids). Electrophoretic mobility measurements of the meta-schoepite and UO2+x suspension in 10 mM uranyl nitrate indicated that the colloids are not stable at pH values less than or equal to five. While at pH values ≥ 5.5, the colloids of meta-schoepite and UO2+x in 10 mM uranyl nitrate are stable, exhibiting zeta potentials of -30 to -60 mV. The results in this paper show that stable colloidal suspensions of uranium substrate colloids are possible under aqueous, oxidizing conditions.

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.

scholarly journals Accelerated Leach Tests of SRL-165 High-Level Waste Glass in Deionized Water

1989 ◽  
Vol 26 (4) ◽  
pp. 441-448 ◽  
Author(s):  
Hiroshi KAMIZONO ◽  
David E. CLARK ◽  
Alexander R. LODDING
Keyword(s):  
Deionized Water ◽  
Waste Glass ◽  
High Level Waste ◽  
High Level

Durability of High-Level Waste Glass in Flowing Groundwater Under Gamma-Irradiation

1994 ◽  
Vol 353 ◽  
Author(s):  
Hiroshi Kamizono ◽  
Masa-Aki Hashimoto ◽  
Yukito Tamura ◽  
Tamio Sagawa ◽  
Sei-Ichiro Matsumoto
Keyword(s):  
Gamma Irradiation ◽  
Waste Glass ◽  
High Level Waste ◽  
Present System ◽  
J 13 ◽  
High Level ◽  
Simulated High Level Waste

AbstractDurability of simulated high-level waste glass in continuously-flowing J-13 tuff groundwater has been examined at 90°C under gamma-irradiation. The results obtained are compared with those without gamma-irradiation. The effects of groundwater radiolysis on the glass durability are discussed based on the Eh-pH excursion obtained in the present system. It is found that the groundwater tends to be reduced under gamma-irradiat ion, however, this may not influence the solubility of multivalent cations leached from the glass.

scholarly journals Parametric Testing of A DWPF Borosilicate Glass

1984 ◽  
Vol 44 ◽  
Author(s):  
F. Bazan ◽  
J. Rego
Keyword(s):  
Stainless Steel ◽  
Borosilicate Glass ◽  
Glass Sample ◽  
Deionized Water ◽  
Savannah River ◽  
Waste Package ◽  
Steel Material ◽  
Stainless Steel Material ◽  
J 13 ◽  
Parametric Testing

AbstractA series of tests have been performed to characterize the chemical stability of a DWPF borosilicate glass sample as part of the Waste Package Task of the NNWSI Project. This material was prepared at the Savannah River Laboratory for the purpose of testing the 165-frit matrix doped with a simulated non-radioactive waste. All tests were conducted at 90°C using deionized water and J-13 water (a tuffaceous formation groundwater). In the deionized water tests, both monoliths and crushed glass were tested at various ratios of surface area of the sample to volume of water in order to compare leach rates for different sample geometries or leaching times. Effects on the leach rates due to the presence of crushed tuff and stainless steel material were also investigated in the tests with J-13 water.

Effect of pH on Plutonium Migration Behavior in Compacted Bentonite

MRS Advances ◽  
2016 ◽  
Vol 1 (61) ◽  
pp. 4011-4017
Author(s):  
Ryo Hamada ◽  
Noriyuki Maeda ◽  
Kazuya Idemitsu ◽  
Yaohiro Inagaki ◽  
Tatsumi Arima ◽  
...  
Keyword(s):  
Pore Water ◽  
Diffusion Coefficients ◽  
High Level Waste ◽  
Migration Behavior ◽  
Effect Of Ph ◽  
Apparent Diffusion Coefficients ◽  
Compacted Bentonite ◽  
Ph Values ◽  
Apparent Diffusion ◽  
High Level

ABSTRACTIn disposing of high-level radioactive waste, the drop in pH in the repository as the iron overpack corrodes must be considered. Plutonium migration behavior may be affected by the pH of pore water in compacted bentonite barriers in high-level waste repositories. To examine the effect of pH on migration behavior, H-bentonite was prepared by treating Japanese Na-bentonite, Kunipia-F, with hydrochloric acid. Diffusion experiments were performed with mixtures of Na- and H-bentonites. The pH value in the pore water of the water-saturated bentonite mixtures decreased from 8 to 3 as the mixing ratio of H-bentonite increased. Diffusion experiments were carried out by using238Pu then apparent diffusion coefficients were determined from the plutonium distribution in the specimens. The apparent diffusion coefficients were on the order of 10-13to 10-12m2/s at pH values lower than 4, whereas they were less than 10-14m2/s at pH values higher than 6.5. These results indicate that plutonium diffused faster as Pu3+or PuO22+due to disproportionation at lower pH while plutonium could be retarded as Pu(OH)40by sorption on bentonite at higher pH.

Electrochemical noise assessment of effect of sol parameters on the performance of an eco-friendly silane sol-gel coating on 304L stainless steel

2018 ◽  
Vol 47 (5) ◽  
pp. 444-452
Author(s):  
Fahimeh Ansari ◽  
Reza Naderi ◽  
Fahimeh Rafiaei
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Electrochemical Noise ◽  
Sol Gel ◽  
304L Stainless Steel ◽  
Nacl Solution ◽  
Noise Resistance ◽  
Content Type ◽  
Ph Values ◽  
Silane Solution

Propose This paper aims to access the protective function of hybrid sol-gel coatings deposited on 304L stainless steel substrate in silane solutions containing a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane with different pH values during various immersion periods. Design/methodology/approach The 304L stainless steels coated through 10 and 30 s of immersion in the silane solutions with pH values of 2.1 and 2.8 were exposed to NaCl solution. The corrosion resistance of the coated substrates was studied through taking advantage of electrochemical noise method as well as atomic force microscopy (AFM), water contact angle and field emission-type scanning electron microscopy (FESEM) surface analysis. Findings The electrochemical current noise, PSD (I) plot, noise resistance and characteristic charge as parameters extracted from electrochemical noise method indicated the superiority of eco-friendly silane coating deposited on the substrate surface during 10 s exposure to the solution, due to the film uniformity and homogeneity as confirmed by FESEM and AFM. Moreover, immersion of the stainless steel in the silane solution with pH 2.1, characterized by higher hydrolysis ratio, led to more effective corrosion control in the NaCl electrolyte according to the results of electrochemical noise and FTIR measurements. Research limitations/implications The noise resistance and characteristic charge as electrochemical noise parameters were only used in this research to evaluate the protective behavior of the water-based silane sol-gel coatings. Future studies should examine the correlation between electrochemical noise data and the parameters extracted from other electrochemical methods, e.g. electrochemical impedance spectroscopy. Practical implications The data obtained in this research may provide an effective approach based on electrochemical noise method to screen the silane sol-gel coatings for protection of metallic substrates against corrosion. Originality/value According to the literature, no report can be found studying the effect of immersion time on a silane solution, including glycidyloxypropyltrimethoxysilane, tetraethoxysilane and methyltriethoxysilane, as well as the silane solution pH on the corrosion resistance of 304L stainless steel in NaCl solution through electrochemical noise method.

scholarly journals Leaching of Actinide-Doped Nuclear Waste Glass in a Tuff-Dominated System

1986 ◽  
Vol 84 ◽  
Author(s):  
Fernando Bazan ◽  
J. Rego ◽  
R. D. Aines
Keyword(s):  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
304L Stainless Steel ◽  
J 13 ◽  
High Level Nuclear Waste ◽  
Low Levels ◽  
And Migration ◽  
High Level ◽  
A Site ◽  
Elemental Mass

AbstractA laboratory leaching test has been performed as part of a project to evaluate the suitability of tuff rocks at Yucca Mountain, Nevada, as a site for a high-level nuclear waste repository. Glass samples were placed in water inside tuff vessels, and then the tuff vessels were placed in water inside Teflon containers. Glass-component leach rates and migration through the tuff were measured for samples of the ATM- 9actinide glass, which is a PNL 76-68 based glass doped with low levels of 99Tc, 237Np, 238U and 239Pu to simulate wastes. Disc samples of this glass were leached at 90°C for 30, 90, and 183 days inside tuff vessels using a natural groundwater (J-13 well-water) as the leachant. Some samples were held by 304L stainless steel supports to evaluate the effect of this metal on the release rate of glass constituents. At the end of each leaching interval, the J-13 water present inside and outside the rock vessel was analyzed for glass components in solution.On the basis of these analyses, boron, molybdenum, and technetium appear to migrate through the rock at rates that depend on the porosity of each vessel and the time of reaction. The actinide elements (uranium, neptunium, and plutonium) were found only in the inner leachate. Sodium, silicon, and strontium are present in the rock as well as in the J-13 water, and the addition of these elements from the glass could not be determined. Normalized elemental mass loss values for boron, molybdenum, and technetium were calculated using the combined concentrations of the inner and outer leachates and assuming a negligible retention on the rock. The maximum normalized release was 2.3 g/m for technetium. Boron, molybdenum, technetium, and neptunium were released linearly with respect to each other, with boron and molybdenum released at about 85% of the technetium rate, and neptunium at 5-10% of the technetium rate. Plutonium was found at low levels in the inner leachate but was strongly sorbed on the steel and Teflon supports. Neptunium was sorbed to a lesser extent. Future analysis of the tuff vessels will determine whether the actinides were strongly sorbed on the surface of the tuff rock.

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