Powder Technological Vitrification of High Level Nuclear Waste by In-Can Hot Pressing Including a Sol-Gel Route

1984 ◽  
Vol 44 ◽  
Author(s):  
A. Caneiro ◽  
G. Ondracek ◽  
Toscano E.H.
Keyword(s):  
Nuclear Waste ◽  
Hot Pressing ◽  
Sol Gel ◽  
Softening Temperature ◽  
Element Distribution ◽  
Powder Technology ◽  
High Level Waste ◽  
Low Viscosity ◽  
High Level Nuclear Waste ◽  
High Level

AbstractPowder technology is used to immobilize high level nuclear waste (HLW) in sintered borosilicate glass. By uniaxial in-can hot pressing(temperature 950 K; pressure 1 MPa; heating rate ∼100 K/h; cooling rate 5 K/h), glass products containing simulated HLW(15 wt.%) have been produced in stackable steel cans (≤ 200 mm diameter). High densities, bulk integrities and homogeneities for the waste element distribution are realized. The advantages of powder technology are for example: (i) no segregation due to solid state vitrification, (ii) low evaporation losses and no compatibility problems due to low densification temperatures (sinter temperature ∼0.6 softening temperature of glass), (iii) production in easily arrangeable and interchangeable stacking units at modest pressures adequate especially for the use in hot cells under remote handling conditions, (iv) choosing units with alternatively HLWo r MLWin prescribed sequences to control the heat production of the package. As demonstrated now, the process is appropriate for high level waste (HLW), medium level waste (MLW) and mixed (HLW/ MLW vitrification, and is insensitive to waste modifications.As the next step the effect of glass modifications was studied. In order to improve the glass leaching resistance and maintain low viscosity, silicon dioxide was doped with titanium dioxide. The mixture (referring to eutectic composition) was produced by a sol gel route and combined finally with 15 w/o HLW-oxides. Hot pressing of the obtained gels at 1273 K and 20 MPa provided highly homogeneous products with high densities.

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.

scholarly journals Transporting and Storing High-Level Nuclear Waste in the U.S.—Insights from a Mathematical Model

2019 ◽  
Vol 9 (12) ◽  
pp. 2437 ◽  
Author(s):  
Sebastian Wegel ◽  
Victoria Czempinski ◽  
Pao-Yu Oei ◽  
Ben Wealer
Keyword(s):  
Nuclear Waste ◽  
The United States ◽  
Nuclear Industry ◽  
High Level Waste ◽  
Geological Repository ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Interim Storage ◽  
Storage Facilities

The nuclear industry in the United States of America has accumulated about 70,000 metric tons of high-level nuclear waste over the past decades; at present, this waste is temporarily stored close to the nuclear power plants. The industry and the Department of Energy are now facing two related challenges: (i) will a permanent geological repository, e.g., Yucca Mountain, become available in the future, and if yes, when?; (ii) should the high-level waste be transported to interim storage facilities in the meantime, which may be safer and more cost economic? This paper presents a mathematical transportation model that evaluates the economic challenges and costs associated with different scenarios regarding the opening of a long-term geological repository. The model results suggest that any further delay in opening a long-term storage increases cost and consolidated interim storage facilities should be built now. We show that Yucca Mountain’s capacity is insufficient and additional storage is necessary. A sensitivity analysis for the reprocessing of high-level waste finds this uneconomic in all cases. This paper thus emphasizes the urgency of dealing with the high-level nuclear waste and informs the debate between the nuclear industry and policymakers on the basis of objective data and quantitative analysis.

Characterization of High-Level Nuclear Waste Glass Using Magnetic Measurements

1993 ◽  
Vol 333 ◽  
Author(s):  
Frank E. Senftle ◽  
Arthur N. Thorpe ◽  
Julius R. Grant ◽  
Aaron Barkatt
Keyword(s):  
Nuclear Waste ◽  
Magnetic Measurements ◽  
Rapid Quenching ◽  
Small Sample ◽  
High Level Waste ◽  
Air Cooling ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Simulated High Level Waste

ABSTRACTMagnetic measurements constitute a promising method for the characterization of nuclear waste glasses in view of their simplicity and small sample weight requirements.Initial studies of simulated high-level waste glasses show that the Curie constant is generally a useful indicator of the Fe2+:Fe3+ ratio. Glasses produced by air-cooling in large vessels show systematic deviations between experimental and calculated values, which are indicative of the presence of small amounts of crystalline iron-containing phases. Most of the iron in these phases becomes dissolved in the glass upon re-heating and more rapid quenching. The studies further show that upon leaching the glass in water some of the iron in the surface regions of the glass is converted to a form which has high temperature-independent magnetic susceptibility.

scholarly journals Radiation Effects in Glasses Used for Immobilization of High-level Waste and Plutonium Disposition

1997 ◽  
Vol 12 (8) ◽  
pp. 1948-1978 ◽  
Author(s):  
William J. Weber ◽  
Rodney C. Ewing ◽  
C. Austen Angell ◽  
George W. Arnold ◽  
Alastair N. Cormack ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Radiation Effects ◽  
Experimental Methods ◽  
Current Status ◽  
High Level Waste ◽  
Microstructure Development ◽  
Comprehensive Review ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Damage Processes

This paper is a comprehensive review of the state-of-knowledge in the field of radiation effects in glasses that are to be used for the immobilization of high-level nuclear waste and plutonium disposition. The current status and issues in the area of radiation damage processes, defect generation, microstructure development, theoretical methods and experimental methods are reviewed. Questions of fundamental and technological interest that offer opportunities for research are identified.

Comparative Study of Synroc-C Ceramics Produced by Hot-Pressing and Inductive Melting

1996 ◽  
Vol 465 ◽  
Author(s):  
I. A. Sobolev ◽  
S. V. Stefanovsky ◽  
B. I. Omelianenko ◽  
S. V. Ioudintsev ◽  
E. R. Vance ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Sol Gel ◽  
High Level Waste ◽  
Elemental Distribution ◽  
Pressing Method ◽  
Cell Parameters ◽  
Alloy Particles ◽  
Mineral Compositions ◽  
High Level ◽  
Simulated High Level Waste

ABSTRACTThree Synroc-C samples, containing simulated high level waste were studied. One was produced by the conventional hot-pressing method at ANSTO, Australia, and the others were obtained using cold crucible technology at Radon, Russia. One of the melted samples was prepared using the Australian sol-gel precursor and the second one was obtained from an oxide-nitrate mixture. It was established that the specimens have closely similar mineral compositions, with major hollandite, perovskite, zirconolite, and rutile. Small amounts of hibonite were also found. Unlike the hot-pressed Synroc containing metallic alloy particles, melted Synrocs contain molybdates. An investigation of mineral compositions and elemental distribution in the samples was carried out. Features of hot-pressed and melted ceramics were compared. Unit cell parameters of the Synroc phases were determined and preliminary results on durability of the melted Synroc are presented.

Development of Ceramic Waste Forms for High-Level Nuclear Waste over the Last 30 years

2006 ◽  
Vol 985 ◽  
Author(s):  
Eric Vance
Keyword(s):  
Nuclear Waste ◽  
Nuclear Power ◽  
Waste Treatment ◽  
Processing Parameters ◽  
Point Of View ◽  
High Level Waste ◽  
Chemical Design ◽  
Important Processing ◽  
High Level Nuclear Waste ◽  
High Level

AbstractMany types of ceramics have been put forward for immobilisation of high-level waste (HLW) from reprocessing of nuclear power plant fuel or weapons production. After describing some historical aspects of waste form research, the essential features of the chemical design and processing of these different ceramic types will be discussed briefly. Given acceptable laboratory and long-term predicted performance based on appropriately rigorous chemical design, the important processing parameters are mostly waste loading, waste throughput, footprint, offgas control/minimisation, and the need for secondary waste treatment. It is concluded that the “problem of high-level nuclear waste” is largely solved from a technical point of view, within the current regulatory framework, and that the main remaining question is which technical disposition method is optimum for a given waste.

Nuclear waste immobilization into structure of zirconolite by Complex Sol Gel Process

2014 ◽  
Vol 1683 ◽  
Author(s):  
Tomasz Smoliński ◽  
Andrzej Deptuła ◽  
W. Lada ◽  
Tadeusz Olczak ◽  
Andrzej G. Chmielewski ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Nuclear Waste ◽  
Thermal Analyses ◽  
Sol Gel ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
High Level Nuclear Waste ◽  
Nuclear Waste Immobilization ◽  
High Level

ABSTRACTZirconolite (CaZrTi2O7) is one of the components of Synroc materials, which are regarded throughout the world nuclear as the second generation of high-level nuclear waste forms. The zirconolite phase was synthesized by a sol-gel method, with one variant of the method making use of ascorbic acid as a strong complexing agent. Into the structure of the zirconolite was incorporated 10 mol% Sr. Undoped and doped samples were examined by thermal analyses and X-ray diffraction. Addition of ascorbic acid to the sols lowered the firing temperature and promoted formation of the zirconolite phase.

scholarly journals Political Mediation in Nuclear Waste Management: a Foucauldian Perspective

2021 ◽  
Author(s):  
Erik Laes ◽  
Gunter Bombaerts
Keyword(s):  
Waste Management ◽  
Nuclear Waste ◽  
Science And Technology Studies ◽  
Management Practices ◽  
High Level Waste ◽  
Practical Implementation ◽  
Technical Mediation ◽  
High Level Nuclear Waste ◽  
Waste Management Practices ◽  
High Level

AbstractThis paper aims to open up high-level waste management practices to a political philosophical questioning, beyond the enclosure implied by the normative ethics approaches that prevail in the literature. Building on previous insights derived from mediation theory (in particular the work of Verbeek and Dorrestijn), Foucault and science and technology studies (in particular Jasanoff’s work on socio-technical imaginaries), mediation theory’s appropriation of Foucauldian insights is shown to be in need of modification and further extension. In particular, we modify Dorrestijn’s figure of “technical determination of power relations” to better take into account the (literal and figurative) aspects of imagination, and complement Dorrestijn’s work with the figures of techno-scientific mediation, and the inherently political figures of socio-technical and state-technical mediation, both based on Foucault’s notion of governmentality. Our analysis implies that the practical implementation of a high-level nuclear waste (HLW) management strategy will require the “stitching together” of these different mediations, which is an inherently political task.

Transmutation of high-level nuclear waste by means of accelerator driven system

2013 ◽  
Vol 3 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Hamid Aït Abderrahim ◽  
Didier De Bruyn ◽  
Gert Van den Eynde ◽  
Sidney Michiels
Keyword(s):  
Nuclear Waste ◽  
Driven System ◽  
High Level Nuclear Waste ◽  
Accelerator Driven System ◽  
High Level
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