Molten salt reactors and electrochemical reprocessing: synthesis and chemical durability of potential waste forms for metal and salt waste streams

2020 ◽  
pp. 1-25 ◽  
Author(s):  
Krista Carlson ◽  
Levi Gardner ◽  
Jeremy Moon ◽  
Brian Riley ◽  
Jake Amoroso ◽  
...  
Keyword(s):  
Molten Salt ◽  
Chemical Durability ◽  
Waste Streams ◽  
Waste Forms ◽  
Salt Waste

HIPed Tailored Pyrochlore-Rich Glass-Ceramic Waste Forms for the Immobilization of Nuclear Waste

2008 ◽  
Vol 1124 ◽  
Author(s):  
Melody Lyn Carter ◽  
Hui Li ◽  
Yingjie Zhang ◽  
Andrew L Gillen ◽  
Eric R Vance
Keyword(s):  
Nuclear Waste ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Spectroscopic Characterization ◽  
Chemical Durability ◽  
Intermediate Level ◽  
Crystalline Phases ◽  
Waste Forms ◽  
Ceramic Samples

AbstractHot isostatically pressed (HIPed) glass-ceramics for the immobilization of uranium-rich intermediate-level wastes and Hanford K-basin sludges were designed. These were based on pyrochlore-structured Ca(1-x)U(1+y)Ti2O7 in glass, together with minor crystalline phases. Detailed microstructural, diffraction and spectroscopic characterization of selected glass-ceramic samples has been performed, and chemical durability is adequate, as measured by both MCC-1 and PCT-B leach tests.

REE and TRU Incorporation into Monazite Structure Ceramics

2004 ◽  
Vol 824 ◽  
Author(s):  
S. I. Rovnyi ◽  
G. M. Medvedev ◽  
A. S. Aloy ◽  
T. I. Koltsova ◽  
S. E. Samoylov
Keyword(s):  
Thin Film ◽  
Solid Solution ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Chemical Durability ◽  
Spent Fuel ◽  
Waste Streams ◽  
Oxalate Precipitation ◽  
Spent Fuel Reprocessing ◽  
Fuel Reprocessing

AbstractOne of the high levels of actinide, and in particular Cm, waste streams at the Russian radiochemical Production Association (PA) Mayak was generated during spent fuel reprocessing. Using oxalate precipitation, the rare earth elements (REE) and transuranic elements (TRU) settled out in the form of oxalate residues. Due to in high REE contents in this residue, the mineral-like matrix based on (REE)PO4 solid solution, with monlclinic monazite structure have been proposed to use as a suitable ceramics form for final actinide immobilization. For this purpose the synthetic REE oxalates were first transformed into REE orthophosphates in a thin-film evaporator (TFE). Then the (REE)PO4 powder was compacted both by either hot uniaxial pressing (HUP) or cold uniaxial pressing followed by sintering (CUP). This ceramic with the monazite structure has a high density and exhibits chemical durability by leaching.

Characteristics of Preliminary Waste Forms for Icpp Low Activity Waste (Law) Fractions after Radionuclide Separations

1995 ◽  
Vol 412 ◽  
Author(s):  
Krishna Vinjamuri
Keyword(s):  
Structural Parameters ◽  
Chemical Durability ◽  
Liquid Sodium ◽  
Processing Plant ◽  
Chemical Processing ◽  
Waste Streams ◽  
Standard Glass ◽  
Radioactive Sodium ◽  
High Level ◽  
Low Activity

AbstractCurrently, at the Idaho Chemical Processing Plant (ICPP) there are about 6800 m3 of liquid sodium-bearing and liquid high-level wastes (HLW), and 3800 m3 of solid calcined HLW. One of the waste processing options under consideration includes separation of the HLW into high activity and low activity (LAW) wastes, followed by immobilization. Preliminary glasses were synthesized for the sodium-bearing, alumina-bearing, and the zirconia-bearing LAW fractions after radionuclide separations. The glasses were formed by crucible melting of a mixture of reagent chemicals representative of the LAW waste streams and frit additives at 1200 °C for 5 hours, followed by overnight annealing at 550 °C and furnace cooling of the melt. These glasses were characterized for density, elastic property, viscosity, chemical durability, structural parameters, and glass phase separation. The results are compared with that of the Hanford's standard glass ARM-i, Savannah River's benchmark glass EA, and the ICPP's grout waste form prepared using the simulated non-radioactive sodium-bearing waste fraction.

scholarly journals Apatite- and Monazite-Bearing Glass-Crystal Composites for the Immobilization of Low-Level Nuclear and Hazardous Wastes

1995 ◽  
Vol 412 ◽  
Author(s):  
D. J. Wronkiewicz ◽  
S. F. Wolf ◽  
T. S. DiSanto
Keyword(s):  
Transition Metals ◽  
Nuclear Waste ◽  
Toxic Metals ◽  
Hazardous Wastes ◽  
Waste Streams ◽  
Waste Forms ◽  
Glass Crystal ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Crystal Composite

AbstractThis study demonstrates that glass-crystal composite waste forms can be produced from waste streams containing high proportions of phosphorus, transition metals, and/or halides. The crystalline phases produced in crucible-scale melts include apatite, monazite, spinels, and a Zr-Si-Fe-Ti phase. These phases readily incorporated radionuclide and toxic metals into their crystal structures, while corrosion tests have demonstrated that glass-crystal composites can be up to 300-fold more durable than simulated high-level nuclear waste glasses, such as SRL 202U.

scholarly journals Formulation and Analysis of Compliant Grouted Waste Forms for SHINE Waste Streams

2014 ◽  
Author(s):  
William Ebert ◽  
Candido Pereira ◽  
Thad A. Heltemes ◽  
Amanda Youker ◽  
Vakhtang Makarashvili ◽  
...  
Keyword(s):  
Waste Streams ◽  
Waste Forms

scholarly journals Alternative Electrochemical Salt Waste Forms, Summary of FY11-FY12 Results

2014 ◽  
Author(s):  
Brian J. Riley ◽  
John S. Mccloy ◽  
Jarrod V. Crum ◽  
William C. Lepry ◽  
Carmen P. Rodriguez ◽  
...  
Keyword(s):  
Waste Forms ◽  
Salt Waste

Performance Assessment of Zircon as a Waste Form for Excess Weapons Plutonium Under Deep Borehole Burial Conditions

1995 ◽  
Vol 412 ◽  
Author(s):  
W. J. Weber ◽  
R. C. Ewing ◽  
W. Lutze
Keyword(s):  
Performance Assessment ◽  
Radiation Damage ◽  
Alpha Decay ◽  
Chemical Durability ◽  
Waste Form ◽  
Accessory Mineral ◽  
Deep Borehole ◽  
Waste Forms ◽  
Weapons Grade Plutonium ◽  
Precambrian Terranes

AbstractZircon (ZrSiO4) is proposed as a waste form for excess weapons-grade plutonium. Zircon is an extremely durable ceramic that is often found as an accessory mineral in Precambrian terranes with ages up to 4 billion years. The chemical durability of zircon in groundwater far exceeds that of other waste forms, as modeled leach rates may be as low as 10-11g/m2d. At least 10 wt% Pu can substitute for Zr in zircon. Self-radiation damage from alpha decay leads to a crystalline-to-amorphous transformation that is modeled as a function of time and temperature for deep borehole conditions. Based on the results of this assessment, zircon could meet all necessary durability and criticality criteria required for a Pu waste form. The types of data used in this analysis are generally not available for other crystalline ceramics or glasses.

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