Pressureless Sintering of Sodalite Waste-forms for the Immobilization of Pyroprocessing Wastes

2015 ◽  
Vol 1744 ◽  
pp. 61-66 ◽  
Author(s):  
M. R. Gilbert
Keyword(s):  
Microstructural Analysis ◽  
Chloride Salt ◽  
Sintering Aid ◽  
Aluminophosphate Glass ◽  
Waste Forms ◽  
Naturally Occurring ◽  
Immobilization Matrix ◽  
Pre Treatment ◽  
Waste Salt ◽  
Pyrochemical Reprocessing

ABSTRACTSodalite (Na8[AlSiO4]6Cl2), a naturally occurring Cl-containing mineral, has long been regarded as a potential immobilization matrix for the chloride salt wastes arising from pyrochemical reprocessing operations, as it allows for the conditioning of the waste salt as a whole without the need for any pre-treatment. Here the consolidation and densification of Sm-doped sodalite (as an analogue for AnCl3) has been investigated with the aim of producing fully dense (i.e. > 95 % t.d.) ceramic monoliths via conventional cold-press-and-sinter techniques at temperatures of < 1000 °C. Microstructural analysis of pressed and sintered sodalite powders under these conditions is shown to produce poorly sintered, porous, inhomogeneous pellets. However, by the addition of a sodium aluminophosphate glass sintering aid, fully dense Sm-sodalite ceramic monoliths can successfully be produced by sintering at temperatures as low as 800 °C.

Different methods to synthesize sodalite, as a matrix for conditioning chloride spent salts from pyroprocesses

2008 ◽  
Vol 96 (4-5) ◽  
Author(s):  
G. De Angelis ◽  
R. Nannicini ◽  
F. Martini ◽  
C. Mazzocchia ◽  
G. Modica
Keyword(s):  
Spent Nuclear Fuel ◽  
Direct Synthesis ◽  
Fission Products ◽  
Sodium Aluminate ◽  
Chloride Salt ◽  
Naturally Occurring ◽  
Zeolite 4A ◽  
Waste Salt ◽  
Pyrometallurgical Processing ◽  
Salt Waste

The pyrometallurgical processing of spent nuclear fuel generates a chloride salt waste containing alkali-metal, alkaline-earth, and some rare-earth fission products. Sodalite, a naturally occurring mineral containing chlorine, has been investigated as an immobilization matrix for this salt waste. To this end different routes for the synthesis of sodalite have been followed: on one hand, direct synthesis from kaolinite, metakaolinite, or from silica and sodium aluminate have been carried out; on the other hand, a synthesis from Zeolite 4A used for preliminary decontamination of the salt by ion-exchange has been performed. The former allows to condition the waste salt as a whole, whenever discarding an entire process salt batch becomes necessary; this is the case when an electrorefiner plant has to be decommissioned, or in the event of a severe process upset; the latter is more suitable for routine operations, which better require the clean-up of the salt and its recycle to the electrorefiner, thus avoiding the production of huge quantities of solidified wastes to be disposed of.

Evaluation effects of Quercetin on streptozotocin-treated RINm5F pancreatic β-cells in vitro

2021 ◽  
Vol 16 ◽  
Author(s):  
Maryam Mazraesefidi ◽  
Maryam Mohammad Sadeghipour ◽  
Hossein Khorramdelazad ◽  
Mahdi Mahmoodi ◽  
Alireza Khoshdel ◽  
...  
Keyword(s):  
Cell Viability ◽  
Insulin Content ◽  
Β Cells ◽  
Simultaneous Treatment ◽  
Beneficial Effects ◽  
Naturally Occurring ◽  
Low Toxicity ◽  
Pre Treatment ◽  
Glucose Stimulated Insulin Secretion

Background and objectives: Quercetin is a naturally occurring phenolic compound abundantly present in plants as a secondary metabolite. The purpose of this study was to investigate the effect of quercetin on improving RINm5F β-insulinemia cell viability, glucose-stimulated insulin secretion (GSIS), and cell insulin content in the presence or absence of streptozotocin (STZ). Methods: This experimental study was conducted on RINm5F β-insulinemia cell line. The cell viability was evaluated by MTT assay. The necrosis was confirmed by flowcytometry and insulin ELISA kit was used to measure the GSIS level and cell insulin content. It should be noted that for testing of cells by 50μM of quercetin, simultaneous treatment and pre-treatment of quercetin were performed in the presence of STZ (20mM). Results: The quercetin was able to improve the viability of RINm5F cells in the presence of STZ and to increase the GSIS level and cell insulin content under STZ and glucotoxic conditions Conclusion: The quercetin seems to have beneficial effects on β-cells, especially the synthesis and secretion of insulin. In addition to the therapeutic effect, given the low toxicity of this flavonoid and the results of this study, the quercetin as a preventive agent may play an important role in maintaining the health of β-cells in people at risk of diabetes.

Aging Studies of Pu-238 and -239 Containing Calcium Phosphate Ceramic Waste-forms

2013 ◽  
Vol 1518 ◽  
pp. 73-78 ◽  
Author(s):  
Shirley K. Fong ◽  
Brian L. Metcalfe ◽  
Randall D. Scheele ◽  
Denis M. Strachan
Keyword(s):  
Calcium Phosphate ◽  
Accelerated Aging ◽  
Waste Form ◽  
Calcium Phosphate Ceramic ◽  
Ceramic Waste ◽  
Waste Forms ◽  
Aging Studies ◽  
Flow Through ◽  
Pyrochemical Reprocessing

ABSTRACTA calcium phosphate ceramic waste-form has been developed at AWE for the immobilisation of chloride containing wastes arising from the pyrochemical reprocessing of plutonium. In order to determine the long term durability of the waste-form, aging trials have been carried out at PNNL. Ceramics were prepared using Pu-239 and -238, these were characterised by PXRD at regular intervals and Single Pass Flow Through (SPFT) tests after approximately 5 yrs.While XRD indicated some loss of crystallinity in the Pu-238 samples after exposure to 2.8 x 1018 α decays, SPFT tests indicated that accelerated aging had not had a detrimental effect on the durability of Pu-238 samples compared to Pu-239 waste-forms.

HRTEM observations on electron irradiation damage in F-apatite

1992 ◽  
Vol 50 (1) ◽  
pp. 378-379
Author(s):  
M. Cameron ◽  
L.M. Wang ◽  
K.D. Crowley ◽  
R.C. Ewing
Keyword(s):  
Nuclear Waste ◽  
Materials Science ◽  
Dental Enamel ◽  
Irradiation Damage ◽  
Apatite Structure ◽  
Waste Forms ◽  
Naturally Occurring ◽  
The Earth ◽  
Hydroxyl Apatite ◽  
Nuclear Waste Forms

Radiation damage in crystalline phases with the apatite structure is of interest in the biomedical, geoscience, and materials science communities. Phases close to hydroxyl apatite [Ca5(PO4)3OH] in composition are volumetrically the most significant in dental enamel and bone. Natural apatites with variable halogen compositions [Ca5(PO4)3(F,OH,Cl)] are used by geoscientists to place constraints on the thermochronologic conditions under which portions of the Earth evolved. Rare-earth-silicate isomorphs of these naturally occurring apatites are also of interest because they may be actinide hosts in ceramic nuclear waste forms.

Salt-Occluded Zeolites as an Immobilization Matrix for Chloride Waste Salt

1993 ◽  
Vol 76 (11) ◽  
pp. 2826-2832 ◽  
Author(s):  
Michele A. Lewis ◽  
Donald F. Fischer ◽  
Londa J. Smith
Keyword(s):  
Immobilization Matrix ◽  
Waste Salt

Candidate waste forms for immobilisation of waste chloride salt from pyroprocessing of spent nuclear fuel

2012 ◽  
Vol 420 (1-3) ◽  
pp. 396-404 ◽  
Author(s):  
E.R. Vance ◽  
J. Davis ◽  
K. Olufson ◽  
I. Chironi ◽  
I. Karatchevtseva ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Chloride Salt ◽  
Waste Forms

A study of alteration phases on glass-bonded zeolite and sodaiate using the vapor hydration test

1999 ◽  
Vol 556 ◽  
Author(s):  
Donglin Sun ◽  
D. J. Wronkiewicz ◽  
L. J. Simpson
Keyword(s):  
Relative Increase ◽  
Sem Analysis ◽  
Aluminum Silicate ◽  
Ceramic Waste ◽  
Waste Forms ◽  
Naturally Occurring ◽  
Salt Crystals ◽  
Major Alteration ◽  
Over Time ◽  
Scanning Electron

AbstractThis paper focuses on the reaction of glass-bonded zeolite and sodalite ceramic waste forms, naturally occurring sodalite, and their respective alteration phases that formed after reaction in a Vapor Hydration Test (VHT). Scanning electron microscope (SEM) analysis of the glass-bonded zeolite and sodalite samples indicate that NaCI is the major alteration phase present, along with KCI, Na-Al-Si, and Na-K-Ca-Al-Si phases. The order of precipitation of salt crystals from ceramic waste form occurred in the sequence NaCl ⇒ KC1 ⇒ CaCl2 and MgCl2. We also found aluminum silicate phases containing Ca, Mg, K-Na-Ca, K-Mg, Na-K-Mg, K-Ca-Na-Mg, as well as CaCO3, SiO2. The ratio of Si/Al in the alteration phases was noted to increase from approximately 1.5 to 5 during the progressive alteration of the samples. This trend indicates a relative increase in the contribution of silicon from the relatively Si-rich glass regions of the samples over time. Phases enriched in Cs, Ba and rare earth elements (RE) were also observed on the altered samples. Alteration phases initially appeared along the micro-fractures during the early stages of alteration. The number of micro-fractures, density of alteration phase cover, and grain size of alteration phases increased with reaction time and temperature.

An Investigation of Metamict And Annealed Natural Pyrochlores by XRAY Absorption Spectroscopy

1984 ◽  
Vol 44 ◽  
Author(s):  
R. B. Greegor ◽  
F. W. Lytle ◽  
B. C. Chakoumakos ◽  
G. R. Lumpkin ◽  
R. C. Ewing
Keyword(s):  
Absorption Spectroscopy ◽  
Radiation Effects ◽  
Full Range ◽  
Pyrochlore Structure ◽  
Structure Type ◽  
Slight Reduction ◽  
Coordination Geometry ◽  
Waste Forms ◽  
Naturally Occurring ◽  
Pyrochlore Group

AbstractThe pyrochlore structure type, A1−2 B2 O6 Y0−1, is a common phase in polycrystalline waste forms. A principal concern has been the effect of alpharecoil events on the longterm stability of these phases. Naturally occurring minerals of the pyrochlore group provide an example of the full range of radiation effects from fully crystalline to xray diffraction amorphous (the metamict state). Xray absorption spectroscopy is used to investigate the coordination geometry of Tisites in metamict and annealed (1,000°C) pyrochlores. The principal effects in the fullydamaged material (∼4026 alpha events/m3) compared to annealed samples include an increase in the asymmetry of the Tisite and a slight reduction in bond length and coordination number.

scholarly journals Bacterial Growth Induced Biocementation Technology, ‘Space-Brick’ - A Proposal for Experiment at Microgravity and Planetary Environments

2020 ◽  
Author(s):  
Aloke Kumar ◽  
Rashmi Dikshit ◽  
Nitin Gupta ◽  
Animesh Jain ◽  
Arjun Dey ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Guar Gum ◽  
Microstructural Analysis ◽  
Fold Increase ◽  
Strength Properties ◽  
Low Earth Orbit ◽  
Calcite Precipitation ◽  
Planetary Environments ◽  
Naturally Occurring ◽  
Lunar Simulant

AbstractWe present results of our investigation of microbial induced calcite precipitation for manufacturing ‘space bricks’ and a proposal for study of this activity in low-earth orbit (LEO). Sporosarcina pasteurii, a urease producing bacterial strain was used to consolidate lunar simulant soil (LSS) in the form of a ‘brick’ with non-trivial strength properties. Potential of a naturally occurring polymer namely, guar gum, as an additive was investigated for enhancement in compressive strength of bio-consolidated samples. Experimental results of bio-brick exhibited an approximate 10-fold increase in compressive strength with guar gum supplementation in soil. We present results of microstructural analysis of the ‘space bricks’ and also propose a payload design for related experiments in LEO.

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