Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
By means of mathematical solutions to the appropriate diffusion equations the kinetics of the thermal diffusion of hydrogen in Zircaloy-2 are described for the various temperatures and concentrations encountered in a heavy water moderated reactor. When the hydrogen concentration is below terminal solid solubility hydrogen is present only in the alpha-phase. Redistributions are then described in terms of the characteristic functions of the diffusion equation. For higher concentrations both the alpha - and delta -phases are present. The two phases were assumed to be always in equilibrium. For moderately small hydrogen concentrations exact solutions of the two-phase equation approached the approximate solutions derived by Sawatzky and for all concentrations the exact solutions exhibit the qualitative features of his result: the two-phase concentration increased with time, everywhere; in the absence of a hydrogen current at the hot end of the sample an alpha-phase region always exists there; the interface of the alpha + delta, alpha-phase boundary moves toward the cold end of the sample and the hydrogen concentration is discontinuous at the interface. Simultaneous solutions of the alpha - and alpha + delta hydrogen distributions and of the concomitant interface motion were obtained and compared to the observations of Sawatzky and Markowitz. The kinetics of the hydrogen diffusion process are shown to lead to an apparent heat of transport of the alpha phase which is lower than the actual value (even for samples with long anneals) thus resolving at least partially the disparity between experimental measurements of this quantity. (auth).
MATHEMATICS OF THE THERMAL DIFFUSION OF HYDROGEN IN ZIRCALOY-2
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
By means of mathematical solutions to the appropriate diffusion equations the kinetics of the thermal diffusion of hydrogen in Zircaloy-2 are described for the various temperatures and concentrations encountered in a heavy water moderated reactor. When the hydrogen concentration is below terminal solid solubility hydrogen is present only in the alpha-phase. Redistributions are then described in terms of the characteristic functions of the diffusion equation. For higher concentrations both the alpha - and delta -phases are present. The two phases were assumed to be always in equilibrium. For moderately small hydrogen concentrations exact solutions of the two-phase equation approached the approximate solutions derived by Sawatzky and for all concentrations the exact solutions exhibit the qualitative features of his result: the two-phase concentration increased with time, everywhere; in the absence of a hydrogen current at the hot end of the sample an alpha-phase region always exists there; the interface of the alpha + delta, alpha-phase boundary moves toward the cold end of the sample and the hydrogen concentration is discontinuous at the interface. Simultaneous solutions of the alpha - and alpha + delta hydrogen distributions and of the concomitant interface motion were obtained and compared to the observations of Sawatzky and Markowitz. The kinetics of the hydrogen diffusion process are shown to lead to an apparent heat of transport of the alpha phase which is lower than the actual value (even for samples with long anneals) thus resolving at least partially the disparity between experimental measurements of this quantity. (auth).
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
By means of mathematical solutions to the appropriate diffusion equations the kinetics of the thermal diffusion of hydrogen in Zircaloy-2 are described for the various temperatures and concentrations encountered in a heavy water moderated reactor. When the hydrogen concentration is below terminal solid solubility hydrogen is present only in the alpha-phase. Redistributions are then described in terms of the characteristic functions of the diffusion equation. For higher concentrations both the alpha - and delta -phases are present. The two phases were assumed to be always in equilibrium. For moderately small hydrogen concentrations exact solutions of the two-phase equation approached the approximate solutions derived by Sawatzky and for all concentrations the exact solutions exhibit the qualitative features of his result: the two-phase concentration increased with time, everywhere; in the absence of a hydrogen current at the hot end of the sample an alpha-phase region always exists there; the interface of the alpha + delta, alpha-phase boundary moves toward the cold end of the sample and the hydrogen concentration is discontinuous at the interface. Simultaneous solutions of the alpha - and alpha + delta hydrogen distributions and of the concomitant interface motion were obtained and compared to the observations of Sawatzky and Markowitz. The kinetics of the hydrogen diffusion process are shown to lead to an apparent heat of transport of the alpha phase which is lower than the actual value (even for samples with long anneals) thus resolving at least partially the disparity between experimental measurements of this quantity. (auth).
Mathematics of the Thermal Diffusion of Hydrogen in Zircaloy-2. A. Sawatzky and E. Vogt
Mathematics of the Thermal Diffusion of Hydrogen in Zircaloy-2
Author: Atomic Energy of Canada Limited
Publisher:
ISBN:
Category :
Languages : en
Pages : 35
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 35
Book Description
Hydriding of Zircaloy-2
Author: Myra S. Feldman
Publisher:
ISBN:
Category : Zircaloy-2
Languages : en
Pages : 156
Book Description
Publisher:
ISBN:
Category : Zircaloy-2
Languages : en
Pages : 156
Book Description
The Thermal Diffusion of Hydrogen in Zircaloy-2
Author: J. M. Markowitz
Publisher:
ISBN:
Category : Hydrogen
Languages : en
Pages : 11
Book Description
Publisher:
ISBN:
Category : Hydrogen
Languages : en
Pages : 11
Book Description
The Time-dependent Solution to Interstitial Diffusion in a Temperature Gradient
Author: Clarence E. Lee
Publisher:
ISBN:
Category : Carbides
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category : Carbides
Languages : en
Pages : 32
Book Description
Hydrogen Redistribution in Zircaloy-2 Under Thermal and Mechanical Stress Gradients
Author: J. M. Markowitz
Publisher:
ISBN:
Category : Zircaloy-2
Languages : en
Pages : 26
Book Description
Publisher:
ISBN:
Category : Zircaloy-2
Languages : en
Pages : 26
Book Description
Zirconium in the Nuclear Industry
Author: George P. Sabol
Publisher: ASTM International
ISBN: 0803124996
Category : Microstructure
Languages : en
Pages : 953
Book Description
Publisher: ASTM International
ISBN: 0803124996
Category : Microstructure
Languages : en
Pages : 953
Book Description
Transactions of the Metallurgical Society of AIME.
Author: Metallurgical Society of AIME.
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 862
Book Description
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 862
Book Description