Performance of fuel rods having 97 percent theoretical density UO/sub 2/ pellets sheathed in Zircaloy-4 and irradiated at low thermal ratings (LWBR Development Program)

Technical Report · Mon Jul 01 04:00:00 EDT 1968

OSTI ID:7010743

Engel, J T; Meieran, H B

Two fuel rods in which solid, 97% theoretical density UO/sub 2/ pellets were sheathed in Zircaloy-4 were irradiated in the MTR reactor pressurized water B-4 loop to study the irradiation swelling characteristics of UO/sub 2/ fuel rods. These rods were designed with a minimum void volume so that fuel swelling could manifest itself as measurable external dimensional changes, allowing a comparison with the irradiation swelling characteristics previously observed in UO/sub 2/ fuel plates irradiated to burnups in excess of 30 x 10/sup 20/ fissions/cc. The observed fuel swelling rate for both rods did not contradict those found in the reference UO/sub 2/ plates (0.7% ..delta..V/10/sup 20/ fissions/cc). It should be noted that fuel swelling is now considered to be highly temperature-dependent, and volume increases will be greater than 0.7% ..delta..V/10/sup 20/ fissions/cc at temperatures greater than approximately 2500/sup 0/F. The stress and strain patterns in the two rods were calculated by an analysis incorporated in the computer program CYGRO-2. The calculated strains were greater than the measured strains; however, failure of the cladding from excessive strain caused by the fuel growth was calculated within the range of uncertainty of the strain failure criteria. (NSA 22: 49858)

• Research Organization: Bettis Atomic Power Lab., Pittsburgh, PA (USA)
• DOE Contract Number: AT(11-1)-GEN-14
• OSTI ID: 7010743
• Report Number(s): WAPD-TM-631
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210500* -- Power Reactors
Breeding
ACTINIDE COMPOUNDS
ALLOYS
BREEDER REACTORS
CHALCOGENIDES
FUEL ELEMENTS
FUEL RODS
LWBR TYPE REACTORS
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
REACTOR COMPONENTS
REACTORS
SWELLING
THERMAL REACTORS
TIN ALLOYS
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCALOY
ZIRCALOY 4
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS