Irradiation induced primary creep (LWBR Development Program). [Zirconium base alloys]

Technical Report · Mon Apr 01 04:00:00 EDT 1974

OSTI ID:7010329

Dollins, C C; Tucker, R P

A model for primary creep of clad materials in an irradiation environment is developed subject to the following assumptions: creep is due to the glide of edge dislocations which encounter irradiation produced depleted zones, as barriers to their motion. The rate controlling step is the climb of the dislocations through the zones. Irradiation affects the creep rate in two opposing ways. The vacancy-rich depleted zones resulting from the irradiation serve as pinning sites for the dislocations thus slowing their glide through the crystal. On the other hand, the radiation-produced interstitials and vacancies cause faster dislocation climb than would be expected out-of-pile. During the early stages of irradiation before the damage due to depleted zones has saturated far more isolated interstitials are produced than isolated vacancies. Consequently, the flux of interstitials to dislocations is substantially greater than that of vacancies causing the dislocations to climb relatively fast. Contributing also to the rapid creep rate in the early stages is the reduced number of obstacles available to pin the dislocations. Once the damage has saturated, it is generally assumed that unassociated vacancies and interstitials are produced in equal numbers; thus, the bias for climb due to an excess of only one type of point defect is substantially reduced. A quantitative model based on these assumptions has been developed and results obtained for zirconium-base alloys. (NSA 30: 24606)

• Research Organization: Bettis Atomic Power Lab., Pittsburgh, PA (USA)
• OSTI ID: 7010329
• Report Number(s): WAPD-TM-1123
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
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36 MATERIALS SCIENCE
360106 -- Metals & Alloys-- Radiation Effects
ALLOYS
BREEDER REACTORS
CREEP
FUEL CANS
LWBR TYPE REACTORS
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
REACTORS
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS