자료유형  

 학위논문

Control Number  

0017163653

International Standard Book Number  

9798384455646

Dewey Decimal Classification Number  

539.76

Main Entry-Personal Name  

Nelson, Malachi.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of California, Berkeley., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

142 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-04, Section: B.

General Note  

Advisor: Hosemann, Peter.

Dissertation Note  

Thesis (Ph.D.)--University of California, Berkeley, 2024.

Summary, Etc.  

요약Increases to reactor power cause fuel pellet thermal expansion which can impose strain generating high stresses in the cladding and potentially lead to a breach in the fuel system. This phenomenon is known as a pellet-cladding interaction and the stress accumulation and retention during such an event is highly relevant to the fuel performance. This dissertation investigates the anisotropic deformation mechanisms controlling mechanical behavior of cold-worked stress-relieved Zircaloy-4 under pellet-cladding interaction conditions through mechanical testing, microstructure characterization, and stress analysis. Two loading modes are used to compare the effects of different stress states. These include axial tension which is commonly used to measure the mechanical properties, and internal pressurization loading which better simulates pellet-cladding loading conditions. It is hypothesized that the cladding subjected to internal pressure loaded will display enhanced stress relaxation due to increased stress and defect accumulation during loading and more competitive slip system activity during relaxation. Results confirm these hypotheses and find that the rate-limiting deformation mechanism during relaxation is screw dislocation glide on prismatic planes limited by edge dislocation jog and dipole climbing on basal planes. Differences in stress and defect accumulation are observed and do affect the stress relaxation behavior, but the dissertation finds that the primary reason for enhanced relaxation is because internal pressure loading imposes higher resolved shear stresses on basal slip systems which accelerates the rate-limiting deformation mechanism.

Subject Added Entry-Topical Term  

Nuclear engineering.

Subject Added Entry-Topical Term  

Energy.

Subject Added Entry-Topical Term  

Materials science.

Subject Added Entry-Topical Term  

Engineering.

Index Term-Uncontrolled  

Anisotropy

Index Term-Uncontrolled  

Mechanical testing

Index Term-Uncontrolled  

Microstructure characterization

Index Term-Uncontrolled  

Pellet-cladding interaction

Index Term-Uncontrolled  

Stress relaxation

Index Term-Uncontrolled  

Zircaloy

Added Entry-Corporate Name  

University of California, Berkeley Nuclear Engineering

Host Item Entry  

Dissertations Abstracts International. 86-04B.

Electronic Location and Access  

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Control Number  

joongbu:657872