scholarly journals Glass Formulation Development in Support of Melter Testing to Demonstrate Enhanced High Level Waste Throughput

2008 ◽  
Vol 1107 ◽  
Author(s):  
James C. Marra ◽  
Kevin M. Fox ◽  
David K. Peeler ◽  
Thomas B. Edwards ◽  
Amanda L. Youchak ◽  
...  
Keyword(s):  
Product Quality ◽  
Department Of Energy ◽  
High Alumina ◽  
High Level Waste ◽  
Alumina Concentration ◽  
Formulation Development ◽  
Technology Innovations ◽  
Glass Formulation ◽  
Waste Loading ◽  
High Level

AbstractThe U.S. Department of Energy (DOE) is currently processing high-level waste (HLW) through a Joule-heated melter (JHM) at the Savannah River Site (SRS) and plans to vitrify HLW and Low activity waste (LAW) at the Hanford Site. Over the past few years at the Defense Waste Processing Facility (DWPF), work has concentrated on increasing waste throughput. These efforts are continuing with an emphasis on high alumina concentration feeds. High alumina feeds have presented specific challenges for the JHM technology regarding the ability to increase waste loading yet still maintain product quality and adequate throughput. Alternatively, vitrification technology innovations are also being investigated as a means to increase waste throughput. The Cold Crucible Induction Melter (CCIM) technology affords the opportunity for higher vitrification process temperatures as compared to the current reference JHM technology. Higher process temperatures may allow for higher waste loading and higher melt rate.Glass formulation testing to support melter demonstration testing was recently completed. This testing was specifically aimed at high alumina concentration wastes. Glass composition/property models developed for DWPF were utilized as a guide for formulation development. Both CCIM and JHM testing will be conducted so glass formulation testing was targeted at both technologies with a goal to significantly increase waste loading and maintain melt rate without compromising product quality.

scholarly journals High Waste Loading Glass Formulations for Hanford High-Aluminum High-Level Waste Streams

2011 ◽  
Author(s):  
Albert A. Kruger
Keyword(s):  
Previous Experience ◽  
High Level Waste ◽  
Waste Streams ◽  
Testing Program ◽  
Glass Formulation ◽  
Waste Loading ◽  
Production Requirement ◽  
High Level ◽  
Glass Compositions ◽  
High Aluminum

The current estimates and glass formulation efforts have been conservative in terms of achievable waste loadings. These formulations have been specified to ensure that the glasses are homogenous, contain essentially no crystalline phases, are processable in joule-heated, ceramic-lined melters and meet WTP Contract terms. The WTP’s overall mission will require the immobilization of tank waste compositions that are dominated by mixtures of aluminum (Al), chromium (Cr), bismuth (Bi), iron (Fe), phosphorous (P), zirconium (Zr), and sulfur (S) compounds as waste-limiting components. Glass compositions for these waste mixtures have been developed based upon previous experience and current glass property models. Recently, DOE has initiated a testing program to develop and characterize HLW glasses with higher waste loadings. Results of this work have demonstrated the feasibility of increases in waste loading from about 25 wt% to 33–50 wt% (based on oxide loading) in the glass depending on the waste stream. It is expected that these higher waste loading glasses will reduce the HLW canister production requirement by about 25% or more.

Materials Interface Interactions Test (MIIT); in-Situ Testing of Simulated Hlw Forms in Salt- Performance of Srs Simulated Waste Glass After up to 5 Years of Burial at the Waste Isolation Pilot Plant (WIPP)

1991 ◽  
Vol 257 ◽  
Author(s):  
G.G. Wicks ◽  
A.R. Lodding ◽  
P.B. Macedo ◽  
D.E. Clark
Keyword(s):  
United States ◽  
Pilot Plant ◽  
Field Tests ◽  
Field Testing ◽  
The United States ◽  
Waste Glass ◽  
Department Of Energy ◽  
High Level Waste ◽  
Waste Isolation Pilot Plant ◽  
High Level

ABSTRACTThe first field tests conducted in the United States involving burial of simulated high-level waste [HLW] forms and package components, were started in July of 1986. The program, called the Materials Interface Interactions Test or MIIT, is the largest cooperative field-testing venture in the international waste management community. Included in the study are over 900 waste form samples comprising 15 different systems supplied by 7 countries. Also included are approximately 300 potential canister or overpack metal samples along with more than 500 geologic and backfill specimens. There are almost 2000 relevant interactions that characterize this effort which is being conducted in the bedded salt site at the Waste Isolation Pilot Plant (WIPP), near Carlsbad, New Mexico. The MIIT program represents a joint endeavor managed by Sandia National Laboratories in Albuquerque, N.M., and Savannah River Laboratory in Aiken, S.C. and sponsored by the U.S. Department of Energy. Also involved in MIIT are participants from various laboratories and universities in France, Germany, Belgium, Canada, Japan, Sweden, the United Kingdom, and the United States. In July of 1991, the experimental portion of the 5-yr. MIIT program was completed. Although only about 5% of all MIIT samples have been assessed thus far, there are already interesting findings that have emerged. The present paper will discuss results obtained for SRS 165/TDS waste glass after burial of 6 mo., 1 yr. and 2 yrs., along with initial analyses of 5 yr. samples.

Improved Third Generation Peristaltic Crawler for Removal of High-Level Waste Plugs in United States Department of Energy Hanford Site Pipelines

2013 ◽  
Author(s):  
Gabriela Vazquez ◽  
Tomas Pribanic
Keyword(s):  
Fatigue Testing ◽  
Experimental Tests ◽  
Department Of Energy ◽  
High Level Waste ◽  
Pipeline System ◽  
United States Department ◽  
Third Generation ◽  
Test Bed ◽  
Hanford Site ◽  
High Level

There are approximately 56 million gallons (212km3) of high level waste (HLW) at the U.S. Department of Energy (DOE) Hanford Site. It is scheduled that by the year 2040, the HLW is to be completely transferred to secure double-shell tanks (DST) from the leaking single-tanks (SST) via transfer pipeline system. Blockages have formed inside the pipes during transport because of the variety in composition and characteristics of the waste. These full and partial plugs delay waste transfers and require manual intervention to repair, therefore are extremely expensive, consuming millions of dollars and further threatening the environment. To successfully continue the transfer of waste through the pipelines, DOE site engineers are in need of a technology that can accurately locate the blockages and unplug the pipelines. In this study, the proposed solution to remediate blockages formed in pipelines is the use of a peristaltic crawler: a pneumatically/hydraulically operated device that propels itself in a worm-like motion through sequential fluctuations of pressure in its air cavities. The crawler is also equipped with a high-pressure water nozzle used to clear blockages inside the pipelines. The crawler is now in its third generation. Previous generations showed limitations in its durability, speed, and maneuverability. Latest improvements include an automation of sequence that prevents kickback, a front-mounted inspection camera for visual feedback, and a thinner wall outer bellow for improved maneuverability. Different experimental tests were conducted to evaluate the improvements of crawler relative to its predecessors using a pipeline test-bed assembly. Anchor force tests, unplugging tests, and fatigue testing for both the bellow and rubber rims have yet to be conducted and thus results are not presented in this research. Experiments tested bellow force and response, cornering maneuverability, and straight line navigational speed. The design concept and experimental test results are reported.

Nepheline Crystallization in High-Alumina High-Level Waste Glass

2015 ◽  
Vol 1744 ◽  
pp. 85-91 ◽  
Author(s):  
José Marcial ◽  
John McCloy ◽  
Owen Neill
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
High Alumina ◽  
High Level Waste ◽  
Interfacial Conditions ◽  
Waste Vitrification ◽  
Cooling Schedules ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Glass Compositions

ABSTRACTThe understanding of the crystallization of aluminosilicate phases in nuclear waste glasses is a major challenge for nuclear waste vitrification. Robust studies on the compositional dependence of nepheline formation have focused on large compositional spaces with hundreds of glass compositions. However, there are clear benefits to obtaining complete descriptions of the conditions under which crystallization occurs for specific glasses, adding to the understanding of nucleation and growth kinetics and interfacial conditions. The focus of this work was the investigation of the microstructure and composition of one simulant high-level nuclear waste glass crystallized under isothermal and continuous cooling schedules. It was observed that conditions of low undercooling, nepheline was the most abundant aluminosilicate phase. Further undercooling led to the formation of additional phases such as calcium phosphate. Nepheline composition was independent of thermal history.

Spinel Settling in HLW Melters

2001 ◽  
Author(s):  
Josef Matyáš ◽  
Jaroslav Kloužek ◽  
Lubomír Němec ◽  
Miroslav Trochta
Keyword(s):  
Liquidus Temperature ◽  
Linear Growth ◽  
Critical Level ◽  
High Level Waste ◽  
Input Concentration ◽  
Average Temperature ◽  
Input Size ◽  
Waste Loading ◽  
High Level ◽  
The Impact

Abstract The efficiency of high-level waste (HLW) melters is limited by spinel settling and accumulation on the melter bottom if the waste loading is increased above a certain limit at which spinel crystallizes from the melt. Spinel accumulation interferes with melter operation and shortens melter lifetime. The mathematical modeling of spinel settling in a HLW melter was applied to define the critical level of spinel deposition during the lifetime of the melter and the corresponding increase in waste loading. In this study, spinel settled on the bottom, slant melter walls, and in the output pipe with a linear growth of spinel-sludge thickness after its concentration stabilized inside the melter. The calculations provided a higher concentration of spinel crystals in the melter regions where the temperature was lower then the liquidus temperature, i.e., T<TL. The effects of the following parameters on sludge-layer thickness were examined: 1) the impact of input concentration of spinel crystals of the same size, 2) the impact of different input size of spinel crystals of the same concentration entering from cold cap (melting batch on the melt surface), and 3) the influence of the average temperature (Tavg) inside of the melting space. The calculations showed that higher a concentration and bigger crystals caused thicker sludge layers in the melter, either because of a higher settling density of crystals or because of their higher settling rate. The nucleation of spinel crystals plays a more important role with decreasing of average temperature inside of the melter, and the thicker layer was formed at lower average temperatures.

U.S. Department of Energy’s High-Level Waste Program: Opportunities and Challenges in Achieving Risk and Cost Reductions

2003 ◽  
Author(s):  
Robin Nazzaro ◽  
William Swick ◽  
Nancy Kintner-Meyer ◽  
Thomas Perry ◽  
Carole Blackwell ◽  
...  
Keyword(s):  
South Carolina ◽  
Program Management ◽  
Department Of Energy ◽  
High Level Waste ◽  
Geologic Repository ◽  
Management Actions ◽  
Technical Challenges ◽  
Treatment And Disposal ◽  
High Level ◽  
The U.S

The U.S. Department of Energy (DOE) oversees one of the largest cleanup programs in history—the treatment and disposal of 356,260 cubic meters of highly radioactive nuclear waste created as a result of the nation’s nuclear weapons program. This waste is currently stored at DOE sites in the states of Washington, Idaho, and South Carolina. In 2002, DOE began an accelerated cleanup initiative to reduce the estimated $105-billion cost and 70-year time frame required for the program. The U.S. General Accounting Office (GAO), an agency of the U.S. Congress, evaluated DOE’s high-level waste program to determine the status of the accelerated cleanup initiative, the legal and technical challenges DOE faces in implementing it, and any further opportunities to improve program management. GAO found that DOE’s initiative for reducing the cost and time required for cleaning up high-level waste is evolving. DOE’s main strategy continues to include concentrating much of the radioactivity into a smaller volume for disposal in a geologic repository. Under the accelerated initiative, DOE sites are evaluating other approaches, such as disposing of more of the waste on site or at other designated locations. DOE’s current savings estimate for these approaches is $29 billion, but the estimate is not based on a complete assessment of costs and benefits and has other computational limitations. For example, the savings estimate does not adequately reflect the timing of when savings will be realized, which distorts the actual amount of savings DOE may realize. DOE faces significant legal and technical challenges to realize these savings. A key legal challenge involves DOE’s authority to decide that some waste with relatively low concentrations of radioactivity can be disposed of on site. A recent court ruling against DOE is a major threat to DOE’s ability to meet its accelerated schedules. A key technical challenge is DOE’s approach for separating waste into high-level and low-activity portions. At the Hanford Site in Washington State, DOE is planning to implement such a method that will not be fully tested until the separations facility is constructed. This approach increases the risk and cost of schedule delays compared to fully testing an integrated pilot-scale facility. However, DOE believes the risks are manageable and that a pilot facility would unnecessarily delay waste treatment and disposal. DOE has opportunities to improve management of the high-level waste program. When it began the initiative to reduce costs and accelerate the high-level waste cleanup schedule, DOE acknowledged it had systematic problems with the way the program was managed. Although DOE has taken steps to improve program management, GAO has continuing concerns about management weaknesses in several areas. These include making key decisions without a sufficiently rigorous supporting analysis, incorporating technology before it is sufficiently tested, and pursuing a “fast-track” approach of simultaneous design and construction of complex nuclear facilities. DOE’s management actions have not fully addressed these weaknesses.

Effects of alumina sources (gibbsite, boehmite, and corundum) on melting behavior of high-level radioactive waste melter feed

MRS Advances ◽  
2016 ◽  
Vol 2 (11) ◽  
pp. 603-608 ◽  
Author(s):  
SeungMin Lee ◽  
Pavel Hrma ◽  
Richard Pokorny ◽  
Jaroslav Klouzek ◽  
Bradley J. VanderVeer ◽  
...  
Keyword(s):  
Glass Production ◽  
Critical Factor ◽  
Melting Behavior ◽  
High Alumina ◽  
High Level Waste ◽  
Reaction Heat ◽  
High Level ◽  
The Relationship ◽  
Foam Thickness ◽  
Floating Layer

ABSTRACTTypes of melter feed materials affect glass production rates. This study focuses on the effects of alumina sources on melting behavior of high-alumina high-level-waste melter feeds containing different alumina sources, namely, gibbsite, boehmite, and corundum. The heat flow from the glass melt to the cold cap, a floating layer of the reacting feed, is partially hindered by a foam layer at the bottom of the cold cap. Volume expansion tests and thermoanalytical methods revealed that a slow-melting feed with corundum foamed extensively, whereas a fast-melting feed with boehmite had a low reaction heat and produced less stable foam. The foam thickness, a critical factor for the rate of melting, estimated using the relationship between the heat conductivity and foam porosity was in reasonable agreement with experimental observation.

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