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.

scholarly journals Uranium(VI) and neptunium(V) transport through fractured, hydrothermally altered concrete

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
S.L. Matzen ◽  
J.M. Beiriger ◽  
P.C. Torretto ◽  
P. Zhao ◽  
B.E. Viani
Keyword(s):  
Chemical Properties ◽  
High Level Waste ◽  
Physical And Chemical Properties ◽  
Hydrothermal Conditions ◽  
Concrete Core ◽  
The Core ◽  
Waste Repository ◽  
High Level ◽  
Physical And Chemical ◽  
And Chemical Properties

In a high level waste repository in which temperatures are elevated due to waste decay, concrete structures will be subjected to hydrothermal conditions that will alter their physical and chemical properties. Virtually no studies have examined the interaction of hydrothermally altered concrete with radionuclides. We present the results of experiments in which soluble and colloid-associated U and Np, were eluted into a fractured, hydrothermally altered concrete core. Although the fluid residence time in the fracture was estimated to be on the order of 1 minute, U and Np in the effluent from the core were below detection (10

scholarly journals Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Eduardo Sadot Herrera-Sosa ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera-Díaz ◽  
Epifanio Cruz-Zaragoza
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Chemical Properties ◽  
Plain Concrete ◽  
Cement Matrix ◽  
Portland Cement Concrete ◽  
High Concentration ◽  
Good Tool ◽  
Waste Tire ◽  
Physical And Chemical

In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with) irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16%) are compensated with the use of high concentration of waste tire particles (30%), which ensures that the concrete will not significantly increase the cost.

CAREM X INPRO Case Study

2004 ◽  
Author(s):  
Pablo C. Florido ◽  
Dari´o Delmastro ◽  
Daniel Brasnarof ◽  
Osvaldo E. Azpitarte
Keyword(s):  
Nuclear Reactor ◽  
Fuel Cycle ◽  
High Level Waste ◽  
Fuel Cycles ◽  
Surface Intermediate ◽  
Geological Repository ◽  
Enriched Uranium ◽  
Intermediate Storage ◽  
High Level

Argentina is performing CAREM X Nuclear System Case Study based on CAREM nuclear reactor and Once Through Fuel Cycle, using SIGMA for enriched uranium production, and a deep geological repository for final disposal of high level waste after surface intermediate storage in horizontal natural convection silos, to verify INPRO (International Project on Innovative Nuclear Reactors and Fuel Cycles) methodology. Projections show that developing countries could play a crucial role in the deployment of nuclear energy, in the next fifty years. This case study will be highly useful for checking INPRO methodology for this scenario. In this contribution to ICONE 12, the preliminary findings of the Case Study are presented, including proposals to improve the INPRO methodology.

Triclinic boron nanosheets high-efficient electrocatalysts for water splitting

2021 ◽  
Author(s):  
Maoping Xu ◽  
Rui Wang ◽  
Kan Bian ◽  
Chuang Hou ◽  
Yaxing Wu ◽  
...  
Keyword(s):  
Active Sites ◽  
Theoretical Calculations ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Energy Storage And Conversion ◽  
High Efficient ◽  
Long Time ◽  
Time Cycle ◽  
Metal Properties ◽  
Physical And Chemical

Abstract Recently, two-dimensional (2D) boron nanosheets have been predicted to exhibit exceptional physical and chemical properties, which is expected to be widely used in advanced electronics, optoelectronic, energy storage and conversion devices. However, the experimental application of 2D boron nanosheets in hydrogen evolution reactiuon (HER) has not been reported. Here, we have grown ultrathin boron nanosheets on tungsten foils via chemical vapor deposition (CVD). The prepared triclinic boron nanosheets are highly crystalline, which perfectly match the structure in the previous theoretical calculations. Notably, the boron nanosheets show excellent HER performance. The Tafel slope is only 64 mV/dec-1 and the nanosheets can maintain good stability under long-time cycle in acidic solution. The improvement of performance is mainly due to the metal properties and a large number of exposed active sites on the boron nanosheets, which is confirmed by first-principle calculations.

scholarly journals Spent Fuel as a Waste Form - Data Needs to Allow Long Term Performance Assessment Under Repository Disposal Conditions.

1986 ◽  
Vol 84 ◽  
Author(s):  
V. M. Oversby
Keyword(s):  
Performance Assessment ◽  
Waste Form ◽  
High Level Waste ◽  
Detailed Knowledge ◽  
Spent Fuel ◽  
Expected Performance ◽  
High Level ◽  
Term Performance ◽  
Physical And Chemical ◽  
Waste Repositories

AbstractPerformance assessment calculations are required for high level waste repositories for a period of 10,000 years under NRC and EPA regulations. In addition, the Siting Guidelines (IOCFR960) require a comparison of sites following site characterization and prior to final site selection to be made over a 100,000 year period. In order to perform the required calculations, a detailed knowledge of the physical and chemical processes that affect waste form performance will be needed for each site. While bounding calculations might be sufficient to show compliance with the requirements of IOCFR60 and 40CFRI91, the site comparison for 100,000 years will need to be based on expected performance under site specific conditions. The only case where detailed knowledge of waste form characteristics in the repository would not be needed would be where radionuclide travel times to the accessible environment can be shown to exceed 100,000 years. This paper will review the factors that affect the release of radionuclides from spemt fuel under repository conditions, summarize our present state of knowledge, and suggest areas where more work is needed in order to support the performance assessment calculations.

Reliable solubility data in the age of computerized chemistry. Why, how, and when?

2001 ◽  
Vol 73 (5) ◽  
pp. 825-829 ◽  
Author(s):  
John Rumble ◽  
Angela Y. Lee ◽  
Dorothy Blakeslee ◽  
Shari Young
Keyword(s):  
Reference Data ◽  
Driving Forces ◽  
Solubility Data ◽  
International Union ◽  
Time Period ◽  
Property Data ◽  
The World ◽  
Long Time ◽  
Iupac Commission ◽  
Physical And Chemical

Since 1979, the International Union of Pure and Applied Chemistry (IUPAC) Commission V.8 on Solubility Data has published over 70 compilations of evaluated data on the solubility of gases in liquids, liquids in liquids, and solids in liquids. These volumes represent one of the largest collections of chemical property data ever produced and are the result of work of scientists throughout the world. In 1998, IUPAC signed an agreement with the National Institute of Standards and Technology (NIST) to continue the series by replacing the monographs by articles in the Journal of Physical and Chemical Reference Data. Five data compilations have already been published in the Journal, and many more are under way. Recently, IUPAC and NIST have concluded another agreement about computerizing all previously published IUPAC solubility data. In this paper, we describe in detail the computerization of IUPAC solubility data, with some emphasis on harmonizing data published over a long time period. We describe the anticipated query paths that will be supported. We also discuss some of the driving forces for making these and other data resources available over the World Wide Web.

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.

Defect Structure of Ion-Irradiated Amorphous SiO2

1997 ◽  
Vol 30 (5) ◽  
pp. 618-622 ◽  
Author(s):  
Y. Eyal ◽  
R. Evron ◽  
Y. Cohen
Keyword(s):  
Ion Irradiation ◽  
Chemical Properties ◽  
Atomic Displacement ◽  
Amorphous Sio2 ◽  
X Ray Scattering ◽  
Scattering Centers ◽  
Radiation Induced ◽  
Induced Changes ◽  
Physical And Chemical ◽  
And Chemical Properties

Uniformly enhanced small-angle X-ray scattering intensities of amorphous SiO2, measured following irradiation with 320 keV H+ and He+ beams, are shown to be correlated, irrespective of the incident ion, with the O and Si cumulative displacement yields. Damage by both beams originated primarily from nuclear stopping but, under H+-ion irradiation, contributions from ionization processes were significant as well. At low beam fluences, the irradiated structure is compatible with the presence of stable radiation-induced interstitial-like O and Si atoms and complementary O and Si vacancy-like sites. There is no evidence for recovery near room temperature of the modified structure to the pre-irradiated state or for formation of colloidal-size scattering centers, such as gas bubbles or voids. Thus, ion-irradiation-induced changes in physical and chemical properties of silica seem to be due to the effect of the preserved primary atomic displacement damage.

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