scholarly journals High-level waste borosilicate glass a compendium of corrosion characteristics. Volume 1

1994 ◽  
Author(s):  
J.C. Cunnane ◽  
J.K. Bates ◽  
C.R. Bradley
Keyword(s):  
Borosilicate Glass ◽  
High Level Waste ◽  
High Level

Performance of Borosilicate Glass High-Level Waste Forms in Disposal Systems

1986 ◽  
Vol 73 (2) ◽  
pp. 139-139
Author(s):  
Edward J. Hennelly ◽  
E. I. Du Pont de Nemours
Keyword(s):  
Borosilicate Glass ◽  
High Level Waste ◽  
Waste Forms ◽  
High Level

Affinity Rate Law Failure to Describe Sodium Borosilicate Glass Alteration Kinetics

2003 ◽  
Vol 807 ◽  
Author(s):  
P. Frugier ◽  
S. Gin ◽  
C. Jégou
Keyword(s):  
Borosilicate Glass ◽  
Chemical System ◽  
High Level Waste ◽  
Critical Examination ◽  
Sodium Borosilicate Glass ◽  
Kinetic Rate ◽  
Rate Law ◽  
Passionate Debate ◽  
Experimental Findings ◽  
High Level

ABSTRACTSimplified glass compositions were chosen to improve our knowledge of the alteration kinetics of complex glasses dedicated to the confinement of high-level waste. Since 1998, the sodium borosilicate glass system is at the center of a passionate debate between an affinity-based kinetic rate law and a protective surface layer theory. All the authors who have investigated ternary 68/14/18 SiO2–B2O3–Na2O glass agree on the fact that the affinity law cannot satisfactorily account for its alteration kinetics. Some authors explained that these discrepancies between classical kinetic rate law and experimental findings could be due to macromolecular amorphous separation in the 68/14/18 sodium borosilicate system and that this simplified glass could be divided into 90% reedmergnerite (NaBSi3O8) and 10% diborate (Na2O–2B2O3). This article provides evidence of the homogeneity of ternary 68/18/14 SiO2–B2O3–Na2O glass at nanometric scale and shows that even phase separation at less than nanometric scale could not explain the inability of hydrated glass-solution affinity laws to describe its alteration. The relative simplicity of the SiO2–B2O3–Na2O chemical system allows a critical examination of the macroscopic alteration laws developed over the last twenty years based only on the hydrated glass-solution chemical affinity without taking into account the formation and reactivity of the gel or its passivating properties.

Volatilization of 137Cs and 106Ru from Borosilicate Glass Containing Actual High-Level Waste

1989 ◽  
Vol 72 (8) ◽  
pp. 1438-1441 ◽  
Author(s):  
Hiroshi Kamizono ◽  
Shizuo Kikkawa ◽  
Yoshihiro Togashi ◽  
Shingo Tashiro
Keyword(s):  
Borosilicate Glass ◽  
High Level Waste ◽  
High Level

Evaluation of Cesium Sujcotitanates as an Alternative Waste Form

1996 ◽  
Vol 465 ◽  
Author(s):  
Yali Su ◽  
M. Lou Balmer ◽  
Bruce C. Bunker
Keyword(s):  
Borosilicate Glass ◽  
Thermal Conversion ◽  
Chemical Durability ◽  
Waste Form ◽  
High Level Waste ◽  
Ion Exchangers ◽  
Heat Treated ◽  
High Level ◽  
Excellent Chemical ◽  
Better Than

ABSTRACTSilicotitanate ion exchangers are potential materials for the removal of radioactive Cs and Sr from tank wastes. In this paper the viability of direct thermal conversion of Cs-loaded silicotitanates to an acceptable high level waste form has been examined. Results show that in aqueous solutions, the Cs leach rates of crystalline silicotitanates (heat treated at 800°C) are 0.04, 0.18, 0.4 g/m2day for Cs loadings of 1, 5, and 20 wt%, respectively. Heating the Cs-loaded (up to 20 wt %) silicotitanates at or above 900 °C for 1 hour further reduces the Cs leach rates to approximately zero (beyond the lppm detection limits). Moreover, Cs volatilization was found to be < 0.8 wt% at temperatures as high as 1000 °C. These results suggest that thermally converted silicotitanate ion exchangers exhibit excellent chemical durability (comparable to or better than borosilicate glass) and thus, have great potential as an alternative waste form.

Interactions of Simulated High Level Waste (HLW) Calcine with Alkali Borosilicate Glass

2003 ◽  
Vol 807 ◽  
Author(s):  
S. Morgan ◽  
R. J. Hand ◽  
N. C. Hyatt ◽  
W. E. Lee
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Borosilicate Glass ◽  
Glass Frit ◽  
High Level Waste ◽  
Second Stage ◽  
Mixed Alkali ◽  
High Level ◽  
Simulated High Level Waste ◽  
Fuel Reprocessing

ABSTRACTThis study looks at the interactions between simulated calcined high level waste from fuel reprocessing and mixed alkali borosilicate glass frit in the early stages of melting, and the possibility of the formation of yellow phase during these stages. Simulant “calcine” from a full scale inactive trial (Magnox: oxide “blend” 25:75) was pre-mixed with alkali borosilicate glass, to achieve a 25wt% waste loading, and melted at 1050°C at various times. It is shown that dissolution occurs in two separate stages; the first involves formation of a low density CsLiMoO4 fluid, which separates and forms a yellow/green layer on the surface of the melt, accompanied by some dissolution of rare- earth elements (Nd, Ce, Gd) and Zr from the waste into the glass matrix. The second stage entails more extensive migration of these rare-earth elements into the glass, and the disappearance of the surface layer on the melt. The glass appears more homogenized at the later stages of melting, but still contains undissolved particles of calcine after 16 minutes.

scholarly journals Radiation resistance of borosilicate glass to beta and gamma radiation evaluated using the accelerated proton method

2021 ◽  
Vol 14 (1) ◽  
pp. 8-18
Author(s):  
A. S. Aloy ◽  
◽  
N. V. Kovalev ◽  
A. M. Prokoshin ◽  
N. F. Karpovich ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Borosilicate Glass ◽  
Chemical Properties ◽  
High Level Waste ◽  
Time Period ◽  
Long Time ◽  
Radiation Induced ◽  
Intermediate Storage ◽  
High Level ◽  
Physical And Chemical

Preservation of the main physical and chemical properties of vitrified high-level waste over a long-time period under the influence of heavy radiation exposure is considered as an essential criterion for its quality assessment used to demonstrate the safety of intermediate storage under controlled conditions and subsequent final disposal of the waste. Earlier calculations covering a time period of up to 104 years allowed to identify the maximum beta- and gamma-radiation induced dose loads for borosilicate glass (BSS) of a basic composition specifically designed to vitrify liquid HLW from ODC MCC [1]. This study evaluates potential feasibility of applying an accelerated proton beam to simulate radiation damage according to the type of beta-gamma effects produced on the BSS and investigates the consequences of such effects on its properties which is seen as a distinctive feature of this research.

The fixation of high-level wastes in glasses

1986 ◽  
Vol 319 (1545) ◽  
pp. 49-62 ◽  
Keyword(s):  
Borosilicate Glass ◽  
High Level Waste ◽  
Geological Repository ◽  
Important Barrier ◽  
Processing Wastes ◽  
Under Construction ◽  
High Level ◽  
Thermal Stability Of ◽  
Selection Of

A plant for the fixation of high-level wastes in borosilicate glass has been operating in France since 1978. A large plant is under construction in the U.S. for the fixation of defence high-level waste and plans for other glass fixation plants are well advanced at several sites around the world. Among the reasons for the selection of borosilicate glass as a fixation medium are the relative ease of processing wastes of variable composition by means of well established technology, and the long-term radiation and thermal stability of the glass. Well formulated glass also has sufficient resistance to the action of groundwater so that it can serve as an important barrier against the spread of radionuclides via groundwater in any forseeable situation. Research is continuing to quantify the reactions of waste glass in site-specific geological repository environments.

Immobilization of high-level waste in ceramic waste forms

1986 ◽  
Vol 319 (1545) ◽  
pp. 63-82 ◽  
Keyword(s):  
Borosilicate Glass ◽  
Nuclear Industry ◽  
Waste Stream ◽  
High Level Waste ◽  
Phase Assemblage ◽  
Crystal Lattices ◽  
Ceramic Waste ◽  
Waste Forms ◽  
Wide Range ◽  
High Level

High-level wastes (HLW) can be incorporated in the crystal lattices of coexisting phases in ceramic waste forms. The properties and performances of ceramic waste forms are largely determined by their phase chemistry, phase assemblage and microstructure. Currently, the best categorized advanced ceramic waste form is SYNROC, a titanate ceramic composed of ‘ hollandite ’ Bat 1(Al,Ti)2^Ti|]*"70 16, zirconolite CaZrTi 2 O 7 , perovskite CaTiO 3 , rutile TiO 2 and minor amounts of metal alloys microencapsulated by the titanate matrix. Two factors contribute to the capacity of synroc to accommodate high (e.g. 20% ) loadings of HLW, together with variations in waste-stream composition. Firstly, the constituent phases can accept, as solid solutions in their crystal lattices, a broad spectrum of cationic species of diverse charge and radius, either singly or by complex substitution mechanisms. Secondly, the phase assemblage itself spontaneously adjusts its modal mineralogy in response to waste stream fluctuations. The presence of both rutile and a source of trivalent titanium (from reaction of rutile with added Ti metal) in the synroc phase assemblage is largely responsible for this flexible and accommodating nature. The titanate minerals in synroc also occur in Nature, where they have survived for many millions of years in a wide range of geological environments. Experimental studies show that synroc is vastly more resistant to leaching by groundwater than borosilicate glass; moreover, its high leach resistance is maintained at elevated temperatures. Experimental and analogue studies indicate that the HLW immobilization properties of synroc are not significantly impaired by radiation damage. These properties show that synroc would provide an effective immobilization barrier for HLW when buried in suitable repositories. They also permit the use of a wider range of geological disposal options than are appropriate for borosilicate glass. In particular, synroc is well suited for disposal in deep drill-holes, both in continental and marine environments. The fact that synroc is composed of minerals that have demonstrated long-term geological stability is important in establishing public confidence in the ability of the nuclear industry to immobilize high-level wastes for the very long periods required.

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