scholarly journals HEAT-UP AND COOL-DOWN TEMPERATURE-DEPENDENT HYDRIDE REORIENTATION BEHAVIORS IN ZIRCONIUM ALLOY CLADDING TUBES

2014 ◽  
Vol 46 (5) ◽  
pp. 681-688 ◽  
Author(s):  
JU-JIN WON ◽  
MYEONG-SU KIM ◽  
KYU-TAE KIM
Keyword(s):  
Zirconium Alloy ◽  
Temperature Dependent ◽  
Hydride Reorientation

A Probabilistic-Micromechanical Methodology for Assessing Zirconium Alloy Cladding Failure

2006 ◽  
Vol 985 ◽  
Author(s):  
Yi-Ming Pan ◽  
K. S. Chan ◽  
D. S. Riha
Keyword(s):  
Critical Stress ◽  
Zirconium Alloy ◽  
Spent Nuclear Fuel ◽  
Performance Criteria ◽  
Time To Failure ◽  
Fuel Rods ◽  
Model Calculations ◽  
Delayed Hydride Cracking ◽  
Hydride Reorientation ◽  
Hydride Cracking

AbstractCladding failure of fuel rods caused by hydride-induced embrittlement is a reliability concern for spent nuclear fuel after extended burnup. Uncertainties in the cladding temperature, cladding stress, oxide layer thickness, and the critical stress value for hydride reorientation preclude an assessment of the cladding failure risk. A set of micromechanical models for treating oxide cracking, blister cracking, delayed hydride cracking, and cladding fracture was developed and incorporated in a computer model. Results obtained from the model calculations indicate that at temperatures below a critical temperature of 318.5 °C [605.3 °F], the time to failure by delayed hydride cracking in Zr-2.5%Nb decreased with increasing cladding temperature. The overall goal of this project is to develop a probabilistic-micromechanical methodology for assessing the probability of hydride-induced failure in Zircaloy cladding and thereby establish performance criteria.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

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