One-Year Leaching of Three SRL Glasses in Granite

1984 ◽  
Vol 44 ◽  
Author(s):  
Bing-Fu Zhu ◽  
D. E. Clark ◽  
L. L. Hench ◽  
G. G. Wicks ◽  
Lars Werme
Keyword(s):  
Stainless Steel ◽  
Nuclear Waste ◽  
Savannah River ◽  
Waste Package ◽  
One Year ◽  
Glass Leaching

AbstractThree Savannah River Laboratory (SRL) simulated nuclear waste glasses were buried in granite boreholes 345 meters deep. Included in the same boreholes were other potential waste package components including stainless steel and bentonite. Samples were maintained at either ambient mine temperature (8–10°C) or 90°C. Differences in glass leaching performances were observed among the three compositions, with SRL 165 being more durable than SRL 131, both with 29.8% TDS waste. Likewise, the presence of some package components affected the leaching performances. Bentonite resulted in accelerated attack on the glass while the presence of stainless steel did not appear to have much effect. Results obtained through one year of burial are presented in this paper.

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.

Effects of Metals and Metal Oxides on the Leaching of Nuclear Waste Glasses

1983 ◽  
Vol 26 ◽  
Author(s):  
Aaron Barkatt ◽  
William Sousanpour ◽  
Alisa Barkatt ◽  
Morad A. Boroomand
Keyword(s):  
Stainless Steel ◽  
Metal Oxides ◽  
Nuclear Waste ◽  
Waste Glass ◽  
Flow Conditions ◽  
Dissolved Silica ◽  
Waste Package ◽  
Beneficial Role ◽  
Rapid Flow

ABSTRACTThe effects of the presence of various metals and metal oxides on the leaching of nuclear waste glasses in water can be considerable even under rapid flow conditions. The systems studied here include SRL TDS-131 glass in the presence of lead and stainless steel, and PNL 76-68 glass in the presence of aluminum, alumina and their mixtures. Lead specifically suppresses dissolved silica, but does not inhibit dissolution of defense waste glass as a whole. Stainless steel specifically reduces the levels of dissolved Ca and Sr. Al and Al2 O3 exercise a general reducing effect on the rates of dissolution of commercial waste glass and the presence of alumina may have a beneficial role in enhancing waste package durability.

scholarly journals Leaching Savannah River Plant Nuclear Waste Glass in a Saturated Tuff Environment

1984 ◽  
Vol 44 ◽  
Author(s):  
N. E. Bibler ◽  
G. G. Wicks ◽  
V. M. Oversby
Keyword(s):  
Stainless Steel ◽  
Radioactive Waste ◽  
Nuclear Waste ◽  
304L Stainless Steel ◽  
Savannah River ◽  
Mass Losses ◽  
Savannah River Plant ◽  
Simulated Waste ◽  
Nuclear Waste Glass ◽  
Time Periods

AbstractSamples of SRP glass containing either simulated or actual radioactive waste were leached at 90°C under conditions simulating a saturated tuff repository environment. The leach vessels were fabricated of tuff and actual tuff groundwater was used. Thus, the glass was leached only in the presence of those materials (including the Type 304L stainless steel canister material) that would be in the actual repository. Tests were performed for time periods up to 6 months at a SA/V ratio of 100 m−1. Results with glass containing simulated waste indicated that stainless steel canister material around the glass did not significantly affect the leaching. Based on Li and B (elements not in significant concentrations in the tuff or tuff groundwater), glass containing simulated waste leached identically to glass containing actual radioactive waste. The tuff buffered the pH so that only a slight increase was observed as a result of leaching. Results with glass containing actual radioactive waste indicated that tuff reduced the concentrations of Cs-137, Sr-90, and Pu-238 in the free groundwater in the simulated repository by 10–100X. Also, radiolysis of the groundwater by the glass (approximately 1000 rad/hr) did not significantly affect the pH in the presence of tuff. Measured normalized mass losses in the presence of tuff for the glass based on Cs-137, Sr-90, and Pu-238 in the free groundwater were extremely low, nominally 0.02, 0.02, and 0.005 g/m2, respectively, indicating that the glass-tuff system retained radionuclides well.

Evaluation of Mandibular Arch Width Changes following Fixed Retention in Post Orthodontic Patients - a Randomized Clinical Trial

2020 ◽  
Author(s):  
Nasreen Iqbal Nagani
Keyword(s):  
Stainless Steel ◽  
Steel Wire ◽  
P Value ◽  
Chi Square ◽  
Mandibular Arch ◽  
Arch Width ◽  
Orthodontic Patients ◽  
Mean Differences ◽  
One Year ◽  
The Stability

Background: Retention is an integral phase in which teeth are maintained in their newly adapted position for which retainers are inserted. Retainers are generally of two types: removable and fixed. Fixed retainers are indicated in the mandibular arch for an indefinite period specifically in the non-extraction cases. Changes in intercanine and intermolar widths are valuable parameters to evaluate the stability. The objectives of this study were to assess and compare the mandibular intercanine and intermolar width changes following orthodontic treatment after insertion of two types of fixed lingual retainers for one year. Methods: Total 54 subjects were recruited in which two types of fixed lingual retainers were inserted in the mandibular arch randomly. Intercanine and intermolar arch widths were measured by digital caliper of 0.01 mm accuracy. Data was analyzed by using Statistical Package of Social Sciences (SPSS V-21). Chi-square and independent t tests were used to compare baseline characteristics. Intercanine and intermolar widths were assessed and compared using independent t test, p-value ≤ 0.05 is considered as statistically significant. Results: Intercanine width increased from baseline to T4 in both retainers. When mean differences of intercanine width were compared between two retainers significant differences were observed at T1, T2, T3 and T4 with significant p-values (< 0.05) and increased intercanine width with multistranded stainless steel wire (MSW) retainers. Conclusion: Mandibular intercanine width increases significantly in post retention phase with multistranded stainless steel retainers. Thus, fiber reinforced composite retainers are more effective in preserving the arch width changes.

scholarly journals Efficiency and safety of using a peritoneal dialysis catheter weighted with a stainless steel ballast : the Limousin experience

2019 ◽  
Vol 2 (4) ◽  
pp. 193-200
Author(s):  
Bénédicte Larivière-Durgueil ◽  
Rémi Boudet ◽  
Marie Essig ◽  
Stéphane Bouvier ◽  
Ali Abdeh ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Peritoneal Dialysis ◽  
Infectious Complications ◽  
Control Group ◽  
Peritoneal Dialysis Catheter ◽  
Causal Factors ◽  
Catheter Migration ◽  
Mechanical Complications ◽  
Increased Risk ◽  
One Year

Objective: To assess the recurrence of PD catheter migration after the introduction of a walnut ballast. Materials and Methods: Retrospective study from 1999 to 2014 of PD patients followed in Limousin. Were compared two groups: ballast group (patients who benefited from the establishment of stainless steel ballast at the intraperitoneal catheter extremity) with 26 patients and control group with 204 patients. The primary endpoint was the occurrence of an episode catheter’s migration after ballast’s establishment. Secondary objectives were (i) to determine the causal factors leading to the catheter weighting, (ii) to ensure the safety of the procedure on the following criteria: infectious complications, mechanicals complications, epurations criteria, and catheter’s survival. Results: More than one year after the implementation of the ballast, no recurrent migration was observed in 86.6% of cases. It wasn’t found an increased risk of infections (OR = 0.5, 95% CI [0.22, 1.13]) or mechanical complications (OR = 1.77- 95% CI [0.77, 4.05]) between the two groups. The adequation criteria were similar: KT / V total : 2.37 in the control group and 2.28 in the ballast group (p = 0.63). The survival of the ballast catheter was comparable among the two groups (p = 0.983). Three causal factors that led to the ballast were identified: automated peritoneal dialysis (APD) (OR = 0.38, 95% CI [0.16, 0.9]), the failure from the first use of the catheter (OR = 19.48, CI 95 % [7.67, 49.48]) and the incarceration of the omentum (OR = 15.84, 95% CI [5.81, 43.21]). Conclusion: The ballast used in these study appears to prevent recurrence of migration, without any impact in terms of infectious or mechanical complications, or on the dialysis criteria or on catheter’s survival. However this catheter does currently not have an EC authorization

Evaluation of the Ewesplint Method for Treating Broken Mouth in Sheep

1984 ◽  
Vol 1984 ◽  
pp. 144-144
Author(s):  
J. E. Vipond
Keyword(s):  
Stainless Steel ◽  
Tooth Loss ◽  
Acrylic Resin ◽  
Dental Cement ◽  
One Year

The ewesplint method of treating broken mouth in sheep was evaluated on five farms in Caithness and Sutherland. The ewesplint is a commercially available technique for splinting together the eight incisor teeth of sheep using a stainless steel brace and acrylic resin. The technique of splinting proved to require considerable skill and practice and is likely to remain a contractor's operation rather than a farm skill. Three lowland Caithness farms which had park-type North Country Cheviot sheep co-operated in the trial. On these farms the sheeps’ teeth were short and broad (“good teeth“) and tooth loss was not a major problem. Two Sutherland farms, one of which was Achany, with hill Cheviots and Blackface X Cheviot sheep co-operated. On these farms incisors were long and rat-like (“bad teeth“) and tooth loss was a major problem. Results on the effectiveness of splinting are shown in Table 1. Most of the sheep on the Caithness farms were unsuitable for splinting because the teeth were too short to carry a splint. Of those that were splinted most lost their splints (62 %) after one year because of inadequate amounts of cement penetrating between the teeth. A more brittle dental cement was used in the Caithness farms which may also have contributed to the higher rate of splint loss.

Materials Interactions Relating to Long-Term Geologic Disposal of Nuclear Waste Glass

1986 ◽  
Vol 84 ◽  
Author(s):  
Ned E. Bibler ◽  
Carol M. Jantzen
Keyword(s):  
Nuclear Waste ◽  
Review Paper ◽  
Waste Glass ◽  
Waste Form ◽  
Glass Waste ◽  
Waste Package ◽  
Geologic Disposal ◽  
Nuclear Waste Glass ◽  
Backfill Materials

AbstractIn the geologic disposal of nuclear waste glass, the glass will eventually interact with groundwater in the repository system. Interactions can also occur between the glass and other waste package materials that are present. These include the steel canister that holds the glass, the metal overpack over the canister, backfill materials that may be used, and the repository host rock. This review paper systematizes the additional interactions that materials in the waste package will impose on the borosilicate glass waste form-groundwater interactions. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g. oxic vs. anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interactions is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. It is noted when further tests of repository interactions are needed before long-term predictions can be made.

Design by Analysis of Waste Packages at Yucca Mountain for Impact Loads

2009 ◽  
Author(s):  
Randy J. James ◽  
Kenneth Jaquay ◽  
Michael J. Anderson
Keyword(s):  
Nuclear Waste ◽  
Impact Loading ◽  
Structural Integrity ◽  
Structural Response ◽  
Yucca Mountain ◽  
Impact Loads ◽  
Geologic Repository ◽  
Dynamic Simulations ◽  
Nuclear Waste Storage ◽  
Waste Package

The proposed geologic repository under development at Yucca Mountain, Nevada, will employ multiple shell metallic containers (waste packages) for the disposal of nuclear waste. The waste packages represent a primary engineered barrier for protection and containment of the radioactive waste, and the design of these containers must consider a variety of structural conditions to insure structural integrity. Some of the more challenging conditions for structural integrity involve severe impact loading due to hypothesized event sequences, such as drops or collisions during transport and placement. Due to interactions between the various components leading to complex structural response during an impact sequence, nonlinear explicit dynamic simulations and highly refined models are employed to qualify the design for these severe impact loads. This paper summarizes the Design by Analysis methodologies employed for qualification of waste package design under impact loading and provides several illustrative examples using these methods. Example evaluations include a collision of a waste package by the Transport and Emplacement Vehicle (TEV) and two scenarios due to seismic events, including WP impact within the TEV and impact by falling rock. The examples are intended to illustrate the stringent Design by Analysis methods employed and also highlight the scope of structural conditions included in the design basis for waste packages to be used for proposed nuclear waste storage at Yucca Mountain.

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