FY 2016 Status Report: CIRFT Testing on Spent Nuclear Fuels and Hydride Reorientation Study
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
This report provides a detailed description of the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) testing conducted on spent nuclear fuel (SNF) rods in FY 2016, including hydride reorientation test results. Contact-based measurement, or three-LVDT-based curvature measurement, of SNF rods has proven to be quite reliable in CIRFT testing. However, how the linear variable differential transformer (LVDT) head contacts the SNF rod may have a significant effect on the curvature measurement, depending on the magnitude and direction of rod curvature. To correct such contact/curvature issues, sensor spacing, defined as the amount of separation between the three LVDT probes, is a critical measurement that can be used to calculate rod curvature once the deflections are obtained. Recently developed CIRFT data analyses procedures were integrated into FY 2016 CIRFT testing results for the curvature measurements. The variations in fatigue life are provided in terms of moment, equivalent stress, curvature, and equivalent strain for the tested SNFs. The equivalent stress plot collapsed the data points from all of the SNFs into a single zone. A detailed examination revealed that, at same stress level, fatigue lives display a descending order as follows: H. B. Robinson Nuclear Power Station (HBR), Limerick Nuclear Power Station (LMK), mixed uranium-plutonium oxide (MOX). If looking at the strain, then LMK fuel has a slightly longer fatigue life than HBR fuel, but the difference is subtle. The knee point of endurance limit in the curve of moment and curvature or equivalent quantities is more clearly defined for LMK and HBR fuels. The treatment affects the fatigue life of specimens. Both a drop of 12 in. and radial hydride treatment (RHT) have a negative impact on fatigue life. The effect of thermal annealing on MOX fuel rods was relatively small at higher amplitude but became significant at low amplitude of moment. Thermal annealing tended to extend the fatigue life of MOX fuel rod specimens. However, for HR4 testing, the thermal annealing treatment showed a negative impact on the fatigue life of the HBR rod.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE), Fuel Cycle Technologies (NE-5). Used Fuel Disposition Campaign
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1325477
- Report Number(s):
- ORNL/SPR-2016/329; AF5865010; NEAF346; ORNL/TM-2016/329; TRN: US1700078
- Country of Publication:
- United States
- Language:
- English
Similar Records
FY 2016 Status Report: CIRFT Testing Data Analyses and Updated Curvature Measurements
ORNL Interim Progress Report on Hydride Reorientation CIRFT Tests
Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
MIXED OXIDE FUELS
SPENT FUELS
FATIGUE
HYDRIDES
FUEL RODS
ANNEALING
TESTING
URANIUM OXIDES
DATA ANALYSIS
PLUTONIUM OXIDES
STRESSES
BENDING
DIAGRAMS
STRAINS
SERVICE LIFE
VARIATIONS
LIMERICK-1 REACTOR
ROBINSON-2 REACTOR
SNF
CIRFT testing
SNF vibration fatigue
hydride reorientation