Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Recent experimental observations on low temperature swelling of irradiated uranium silicide dispersion fuels have indicated that the growth of fission gas bubbles appears to be affected by fission rate. The swelling curve of the material exhibits a distinct knee'' that shifts to higher fission density with increased fission rate due to higher enrichments. Current state-of-the-art models for fission gas behavior do not predict such a dependence. Indirect evidence from various experiments leads the present authors to speculate that a dense network of subgrain boundaries forms at a dose corresponding to the knee'' in the swelling curve, upon which gas bubbles nucleate and then grow at an accelerated rate compared to those in the bulk material. A theoretical formulation is presented wherein the stored energy in the material is concentrated on a network of crystallization'' sites which diminish with dose due to interaction with radiation produced defects (vacancy-impurity pairs). Recrystallization is induced by statistical fluctuations when the energy per site is high enough such that the creation of grain boundary surfaces is offset by the creation of strain free volumes with a resultant net decrease in the free energy of the material. This formulation is shown to provide a reasonable interpretation of the observed phenomena. 11 refs., 7 figs.
Mechanistic Interpretation of an Observed Rate Dependence of Low Temperature Swelling of Irradiated Uranium Silicide Dispersion Fuels
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Recent experimental observations on low temperature swelling of irradiated uranium silicide dispersion fuels have indicated that the growth of fission gas bubbles appears to be affected by fission rate. The swelling curve of the material exhibits a distinct knee'' that shifts to higher fission density with increased fission rate due to higher enrichments. Current state-of-the-art models for fission gas behavior do not predict such a dependence. Indirect evidence from various experiments leads the present authors to speculate that a dense network of subgrain boundaries forms at a dose corresponding to the knee'' in the swelling curve, upon which gas bubbles nucleate and then grow at an accelerated rate compared to those in the bulk material. A theoretical formulation is presented wherein the stored energy in the material is concentrated on a network of crystallization'' sites which diminish with dose due to interaction with radiation produced defects (vacancy-impurity pairs). Recrystallization is induced by statistical fluctuations when the energy per site is high enough such that the creation of grain boundary surfaces is offset by the creation of strain free volumes with a resultant net decrease in the free energy of the material. This formulation is shown to provide a reasonable interpretation of the observed phenomena. 11 refs., 7 figs.
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Recent experimental observations on low temperature swelling of irradiated uranium silicide dispersion fuels have indicated that the growth of fission gas bubbles appears to be affected by fission rate. The swelling curve of the material exhibits a distinct knee'' that shifts to higher fission density with increased fission rate due to higher enrichments. Current state-of-the-art models for fission gas behavior do not predict such a dependence. Indirect evidence from various experiments leads the present authors to speculate that a dense network of subgrain boundaries forms at a dose corresponding to the knee'' in the swelling curve, upon which gas bubbles nucleate and then grow at an accelerated rate compared to those in the bulk material. A theoretical formulation is presented wherein the stored energy in the material is concentrated on a network of crystallization'' sites which diminish with dose due to interaction with radiation produced defects (vacancy-impurity pairs). Recrystallization is induced by statistical fluctuations when the energy per site is high enough such that the creation of grain boundary surfaces is offset by the creation of strain free volumes with a resultant net decrease in the free energy of the material. This formulation is shown to provide a reasonable interpretation of the observed phenomena. 11 refs., 7 figs.
Mechanistic Interpretation of an Observed Fission-Rate Dependence of Low-Temperature Swelling of Irradiated Uranium Silicide Dispersion Fuels
Author: J. Rest
Publisher:
ISBN:
Category : Bubbles
Languages : en
Pages : 13
Book Description
Recent experimental observations on low-temperature swelling of irradiated uranium silicide dispersion fuels have indicated that the growth of fission gas bubbles appears to be affected by fission rate. The swelling curve of the material exhibits a distinct "knee" that shifts to higher fission density with increased fission rate due to higher enrichments. Current state-of-the-art models for fission gas behavior do not predict such a dependence.
Publisher:
ISBN:
Category : Bubbles
Languages : en
Pages : 13
Book Description
Recent experimental observations on low-temperature swelling of irradiated uranium silicide dispersion fuels have indicated that the growth of fission gas bubbles appears to be affected by fission rate. The swelling curve of the material exhibits a distinct "knee" that shifts to higher fission density with increased fission rate due to higher enrichments. Current state-of-the-art models for fission gas behavior do not predict such a dependence.
Energy Research Abstracts
Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 584
Book Description
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 584
Book Description
Effects of Radiation on Materials
Author: Roger E. Stoller
Publisher: ASTM International
ISBN: 080311477X
Category : Materials
Languages : en
Pages : 1315
Book Description
Symposium held in Nashville, Tennessee, June 1990. Almost two-thirds of these 91 papers are authored by researchers outside of the US (including information on research in the former USSR, Japan, and Europe). Topics include: current commercial power reactor systems; microstructural characterization
Publisher: ASTM International
ISBN: 080311477X
Category : Materials
Languages : en
Pages : 1315
Book Description
Symposium held in Nashville, Tennessee, June 1990. Almost two-thirds of these 91 papers are authored by researchers outside of the US (including information on research in the former USSR, Japan, and Europe). Topics include: current commercial power reactor systems; microstructural characterization
Fundamental Aspects of Inert Gases in Solids
Author: S.E. Donnelly
Publisher: Springer
ISBN: 1489936807
Category : Science
Languages : en
Pages : 458
Book Description
The NATO Advanced Research Workshop on Fundamental Aspects of Inert Gases in Solids, held at Bonas, France from 16-22 September 1990, was the fifth in a series of meetings that have been held in this topic area since 1979. The Consultants' Meeting in that year at Harwell on Rare Gas Behaviour in Metals and Ionic Solids was followed in 1982 by the Jiilich Inter national Symposium on Fundamental Aspects of Helium in Metals. Two smaller meetings have followed-a CECAM organised workshop on Helium Bubbles in Metals was held at Orsay, France in 1986 while in February 1989, a Topical Symposium on Noble Gases in Metals was held in Las Vegas as part of the large TMS/AIME Spring Meeting. As is well known, the dominating feature of inert gas atoms in most solids is their high heat of solution, leading in most situations to an essentially zero solubility and gas-atom precipita tion. In organising the workshop, one particular aim was to target the researchers in the field of inert-gas/solid interactions from three different areas--namely metals, tritides and nuclear fuels-in order to encourage and foster the cross-fertilisation of approaches and ideas. In these three material classes, the behaviour of inert gases in metals has probably been most studied, partly from technological considerations-the effects of helium production via (n, a) reac tions during neutron irradiation are of importance, particularly in a fusion reactor environ ment-and partly from a more fundamental viewpoint.
Publisher: Springer
ISBN: 1489936807
Category : Science
Languages : en
Pages : 458
Book Description
The NATO Advanced Research Workshop on Fundamental Aspects of Inert Gases in Solids, held at Bonas, France from 16-22 September 1990, was the fifth in a series of meetings that have been held in this topic area since 1979. The Consultants' Meeting in that year at Harwell on Rare Gas Behaviour in Metals and Ionic Solids was followed in 1982 by the Jiilich Inter national Symposium on Fundamental Aspects of Helium in Metals. Two smaller meetings have followed-a CECAM organised workshop on Helium Bubbles in Metals was held at Orsay, France in 1986 while in February 1989, a Topical Symposium on Noble Gases in Metals was held in Las Vegas as part of the large TMS/AIME Spring Meeting. As is well known, the dominating feature of inert gas atoms in most solids is their high heat of solution, leading in most situations to an essentially zero solubility and gas-atom precipita tion. In organising the workshop, one particular aim was to target the researchers in the field of inert-gas/solid interactions from three different areas--namely metals, tritides and nuclear fuels-in order to encourage and foster the cross-fertilisation of approaches and ideas. In these three material classes, the behaviour of inert gases in metals has probably been most studied, partly from technological considerations-the effects of helium production via (n, a) reac tions during neutron irradiation are of importance, particularly in a fusion reactor environ ment-and partly from a more fundamental viewpoint.
Detailed Analysis of Uranium Silicide Dispersion Fuel Swelling
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Swelling of U3Si and U3Si2 is analyzed. The growth of fission gas bubbles appears to be affected by fission rate, fuel loading, and microstructural change taking place in the fuel compounds during irradiation. Several mechanisms are explored to explain the observations. The present work is aimed at a better understanding of the basic swelling phenomenon in order to accurately model irradiation behavior of uranium silicide disperson fuel. 5 refs., 10 figs.
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Swelling of U3Si and U3Si2 is analyzed. The growth of fission gas bubbles appears to be affected by fission rate, fuel loading, and microstructural change taking place in the fuel compounds during irradiation. Several mechanisms are explored to explain the observations. The present work is aimed at a better understanding of the basic swelling phenomenon in order to accurately model irradiation behavior of uranium silicide disperson fuel. 5 refs., 10 figs.
Proceedings of the 1990 International Meeting on Reduced Enrichment for Research and Test Reactors, Newport, Rhode Island, September 23-27, 1990
Author: Armando Travelli
Publisher:
ISBN:
Category : Engineering test reactors
Languages : en
Pages : 464
Book Description
Publisher:
ISBN:
Category : Engineering test reactors
Languages : en
Pages : 464
Book Description
Engineered Materials Abstracts
Author:
Publisher:
ISBN:
Category : Ceramic materials
Languages : en
Pages : 724
Book Description
Publisher:
ISBN:
Category : Ceramic materials
Languages : en
Pages : 724
Book Description
Government Reports Annual Index
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1656
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1656
Book Description
A New Swelling Model and Its Application to Uranium Silicide Research Reactor Fuel
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
This document discusses a new version of the dispersion fuel behavior model currently being incorporated in DART, which has been generated. The model's description of fuel swelling - more specifically, the evaluation of fission-gas bubble morphology - is significantly improved. Although some of the assumptions underlying the basic model are derived from systems other than U3Si2, it represents a physically realistic interpretation of the observed irradiation behavior of U3Si2 over a wide range of fission densities and fission rates.
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Book Description
This document discusses a new version of the dispersion fuel behavior model currently being incorporated in DART, which has been generated. The model's description of fuel swelling - more specifically, the evaluation of fission-gas bubble morphology - is significantly improved. Although some of the assumptions underlying the basic model are derived from systems other than U3Si2, it represents a physically realistic interpretation of the observed irradiation behavior of U3Si2 over a wide range of fission densities and fission rates.