Missing pellet surface (MPS) defects are local geometric defects in nuclear fuel pellets that result from pellet mishandling or manufacturing. The presence of MPS defects can cause clad stress concentrations that are substantial enough to produce through-wall cladding failure for certain combinations of fuel burnup, and reactor power level or power change. Consequently, the impact of potential ...

The thermophysical performance and solid mechanics behavior of UO2-36.4vol % BeO fuel pellets cladded with Zircaloy, SiC, and FeCrAl, and Zircaloy cladding materials coated with SiC and FeCrAl, are investigated based on simulation results obtained by the CAMPUS code. In addition, the effect of coating thickness (0.5, 1 and 1.5 mm) on fuel performance and mechanical interaction is discussed. The...

At the completion of the fuel drying process, used fuel Zry4 cladding typically exhibits a significant population of d-hydride inclusions. These inclusions are in the form of small platelets that are generally oriented both circumferentially and radially within the cladding material. There is concern that radiallyoriented hydride inclusions may weaken the cladding material and lead to issues du...

To increase the power density and maximum allowable fuel burnup in light water reactors, new fuel rod designs are investigated. Such fuel is desirable for improving the economic performance light water reactors loaded with transuranic-bearing fuel for transmutation, as well as those using UO2 fuel. A proposal for using silicon carbide duplex as fuel cladding is investigated. The cladding consis...

Current standardized testing on air-permeable multilayer cladding is inaccurate since one of the primary parameters for setting the peak net wind loads across the cladding is the external pressure gradient, which is removed from all standardized testing. After implementing a latex-barrier system and examining the control strategy for the pressure loading actuators, a multichamber airbox system ...

We present a full-vectorial modal analysis of a segmented cladding fiber (SCF). The analysis is based on the H-field vectorial finite element method (VFEM) employing polar mesh geometry. Using this method, we have analyzed the circular SCF and the elliptical SCF. We have found that the birefringence of the circular SCF is very small (1.0×10(-8)). Birefringence of a highly elliptical SCF can be ...

A systematic experimental and numerical study of the device performance of waveguide-coupled SiON microresonators with air and polymer cladding is presented. Values of device parameters like propagation losses of the microresonator modes, the off-resonance insertion losses, and the straight waveguide to microresonator coupling are determined by applying a detailed fitting procedure to the exper...

Cladded multimode fiber optic tapers are proposed as chemical sensors using evanescent wave absorption. There is no need to strip the cladding; therefore, fabrication is easy and the taper is mechanically stronger than the taper without cladding. The transmission property and evanescent wave absorption are modeled using ray theory and wave theory, respectively. Effects of some parameters on the...

This paper describes a multi-scale modeling approach to compute the large-strain deformation of zirconium alloy cladding, which is of interest to the study of fuel rod behaviors in transient and accident conditions. A Visco-Plastic Self-Consistent (VPSC) polycrystal plasticity model representing polycrystals by weighted orientations of single crystals has been implemented as the constitutive la...

An edge-emitting laser diode is described in which the epitaxial upper cladding layer is replaced with a metal contact selected for its optical as well as electrical properties. The structure is demonstrated with an In0.1Ga0.9N multiple-quantum-well laser diode operating at 412 nm with silver rather than the typical p-type AlGaN for the upper cladding. Silver is effective as a cladding layer be...