The Development of a Ceramic Waste Form for Immobilisation of Highly Active Wastes from Radical Purex Reprocessing Operations

1996 ◽  
Vol 465 ◽  
Author(s):  
Ewan Maddrell
Keyword(s):  
Fuel Cycle ◽  
Nuclear Fuel Cycle ◽  
Waste Form ◽  
Phase Assemblage ◽  
Waste Streams ◽  
Initial Development ◽  
Ceramic Phase ◽  
Highly Active ◽  
Waste Minimisation ◽  
Optimum Solution

ABSTRACTThe development of novel, Radical Purex, reprocessing technologies, leading to fission product waste streams with high levels of inert constituents, may mean that vitrification is no longer the optimum solution for the immobilisation of highly active wastes at the back end of the nuclear fuel cycle. A ceramic phase assemblage is described which uses the inert constituents of the waste stream as a functional component of the waste form, permitting high waste loadings to be achieved and thus enabling waste minimisation considerations to be satisfied. The initial development of this phase assemblage is presented.

scholarly journals Comparison of Ceramic Waste forms Produced by hot Uniaxial Pressing and by Cold Pressing and Sintering

1994 ◽  
Vol 353 ◽  
Author(s):  
V. M. Oversby ◽  
E.R. Vance
Keyword(s):  
Production Method ◽  
Activity Level ◽  
Waste Form ◽  
Phase Assemblage ◽  
Waste Streams ◽  
Cold Pressing ◽  
N2 Atmosphere ◽  
Precursor Material ◽  
Simulated Waste ◽  
Cold Pressed

AbstractSynroc C waste form specimens prepared using the Australian-developed technology are uniaxially pressed in stainless steel bellows at 1200°C and 20MPa. This produces a material with high chemical and physical durability and with the radioactivity enclosed inside both the waste form and the bellows. An alternative method of producing the ceramic product is to use cold pressing of pellets followed by reactive sintering to provide densification and mineralization. Depending on the scale of waste form preparation required and on the activity level and nature of the waste streams, the cold press and sinter method may have advantages. To evaluate the effects of production method on waste form characteristics, especially resistance to dissolution or leaching of waste elements, we have prepared two simulated waste samples for evaluation. Both samples were prepared from liquid precursor materials (alkoxides, nitrates, and colloidal silica) and then doped with waste elements. The precursor material in each case corresponded to a basic phase assemblage of 60% zirconolite, 15% nepheline, 10% spinel, 10% perovskite, and 5% rutile. One sample was doped with 25% by weight of U; the other with 10% by weight each of U and Gd. Each sample was calcined at 750°C for 1 hr. in a 3.5% H2 in N2 atmosphere. Then one portion of each sample was hot pressed at temperatures ranging from 1120 to 1250°C and 20MPa pressure in steel bellows. A separate portion of each sample was formed into pellets, cold pressed, and sintered in various atmospheres at 1200°C to produce final products about 2/3 cm in diameter. Samples were then examined to determine density of the product, grain sizes of the phases, phase assemblage, and the location of the U and Gd in the final phases. Density data indicate that sintering gives good results provided that the samples are held at 200°C for long enough to allow trapped gases to escape.

scholarly journals Immobilization in Ceramic Waste Forms of the Residues From Treatment of Mixed Wastes

1993 ◽  
Vol 333 ◽  
Author(s):  
V. M. Oversby ◽  
R. A. Van Konynenburg ◽  
W. E. Glassley ◽  
P. G. Curtis
Keyword(s):  
Waste Management ◽  
Treatment Process ◽  
Waste Form ◽  
Phase Assemblage ◽  
Technology Program ◽  
Ceramic Phase ◽  
Waste Forms ◽  
Starting Point ◽  
Treatment Technologies ◽  
Inorganic Waste

ABSTRACTThe Environmental Restoration and Waste Management Applied Technology Program at LLNL is developing a Mixed Waste Management Facility to demonstrate treatment technologies that provide an alternative to incineration. As part of that program, we are developing final waste forms using ceramic processing methods for the immobilization of the treatment process residues. The ceramic phase assemblages are based on using Synroc D as a starting point and varying the phase assemblage to accommodate the differences in chemistry between the treatment process residues and the defense waste for which Synroc D was developed. Two basic formulations are used, one for low ash residues resulting from treatment of organic materials contaminated with RCRA metals, and one for high ash residues generated from the treatment of plastics and paper products. Treatment process residues are mixed with ceramic precursor materials, dried, calcined, formed into pellets at room temperature, and sintered at 1150 to 1200°C to produce the final waste form. This paper discusses the chemical composition of the waste streams and waste forms, the phase assemblages that serve as hosts for inorganic waste elements, and the changes in waste form characteristics as a function of variation in process parameters.

Aluminosilicate-Phosphate Model of Polyphase Matrices for Immobilization of Sr-Cs-fractions of Nuclear Fuel Cycle HLW

2013 ◽  
Vol 7 (3) ◽  
pp. 209-219 ◽  
Author(s):  
R. Bogdanov ◽  
R. Kuznetsov ◽  
V. Epimahov ◽  
A. Titov ◽  
E. Prudnikov
Keyword(s):  
Nuclear Fuel ◽  
Fuel Cycle ◽  
Nuclear Fuel Cycle

A family of uranyl oxide hydrate phases with bivalent cations [MII(H2O)4][(UO2)3O3(OH)2]·H2O (MII – Mn, Co, Ni, Zn): synthesis, characterization and chemical stability in aqueous solutions

2021 ◽  
Author(s):  
Nikolay G. Chernorukov ◽  
Oxana V. Nipruk ◽  
Kseniya A. Klinshova ◽  
Olga N. Tumaeva ◽  
Dmitry V. Sokolov
Keyword(s):  
Aqueous Solutions ◽  
Nuclear Fuel ◽  
Chemical Stability ◽  
Fuel Cycle ◽  
Nuclear Fuel Cycle ◽  
Oxide Hydrate ◽  
Uranium Compounds ◽  
Bivalent Cations

A series of new uranium compounds [MII(H2O)3][(UO2)3O3(OH)2]·2H2O (MII – Mn, Co, Ni, Zn) were synthesized for binding radionuclides in the environment and nuclear fuel cycle.

Comparison of nuclear data uncertainties with other nuclear fuel cycle uncertainty sources

2021 ◽  
Author(s):  
Aris V. Skarbeli ◽  
Rubén Eusebio‐Yebra ◽  
Pablo Romojaro ◽  
Francisco Álvarez‐Velarde ◽  
Daniel Cano‐Ott
Keyword(s):  
Nuclear Fuel ◽  
Fuel Cycle ◽  
Nuclear Data ◽  
Nuclear Fuel Cycle ◽  
Uncertainty Sources

Massimo Salvatores’ seminal ideas and comprehensive views on nuclear fuel cycle studies

2021 ◽  
Vol 157 ◽  
pp. 108223
Author(s):  
Concetta Fazio ◽  
Fabrizio Gabrielli ◽  
Andrei Rineiski ◽  
Barbara Vezzoni
Keyword(s):  
Nuclear Fuel ◽  
Fuel Cycle ◽  
Nuclear Fuel Cycle

scholarly journals Progress in Uranium Chemistry: Driving Advances in Front-End Nuclear Fuel Cycle Forensics

2021 ◽  
Author(s):  
Kevin J. Pastoor ◽  
R. Scott Kemp ◽  
Mark P. Jensen ◽  
Jenifer C. Shafer
Keyword(s):  
Nuclear Fuel ◽  
Fuel Cycle ◽  
Nuclear Fuel Cycle ◽  
Front End
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