In-pile dimensional changes of Zircaloy-4 tubing having low hoop stresses (LWBR Development Program)

Technical Report · Thu Jul 01 04:00:00 EDT 1971

OSTI ID:7010518

Daniel, R C

Diameter and length changes were measured for 0.25 to 0.30 inch O.D. fuel rods having Zircaloy-4 cladding thicknesses from 17 to 22 mils. The external coolant pressure (2000 psi) yielded hoop stresses in the range of 11,000 to 15,000 psi. Short rods (6 to 11 inch) were irradiated in an ETR loop (peak fast flux approximately = 1.5 x 10/sup 14/ nv) while long rods (approximately 10 feet) were irradiated in a NRX loop (2.5 x 10/sup 13/ nv). A method is described for separating components of the diameter and length changes caused by Zircaloy growth, external pressure, and fuel-clad interactions. It is concluded that the diameter shrinkages of the former rods (up to about 1 mil, 0.4%) were caused entirely by the external pressure. However, those of the latter rods (up to approximately 2 mils, 0.8%) were strongly dependent on fuel-clad interactions, with large diameter shrinkages being accompanied by large length increases (up to about 0.7%). A calculational method based on the CYGRO computer program is proposed for simulating such behavior for long rods. 8 references. (NSA 25: 51098)

• Research Organization: Bettis Atomic Power Lab., Pittsburgh, PA (USA)
• DOE Contract Number: AT(11-1)-GEN-14
• OSTI ID: 7010518
• Report Number(s): WAPD-TM-973
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210500* -- Power Reactors
Breeding
ALLOYS
BREEDER REACTORS
FUEL CANS
FUEL ELEMENTS
FUEL RODS
LWBR TYPE REACTORS
REACTOR COMPONENTS
REACTORS
SHRINKAGE
STRESSES
THERMAL REACTORS
TIN ALLOYS
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCALOY
ZIRCALOY 4
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS