Kadir C. Sener

Analysis Recommendations for Steel-Composite (SC) Walls of Safety-Related Nuclear Facilities

Steel-plate composite (SC) walls are of significant interest for designing containment internal structures for third generation nuclear power plants. As part of containment internal structures, these walls may be exposed to seismic loading and combined thermal and mechanical loading in the event of a postulated accident scenario. Experimental and analytical evaluations indicate that SC walls subjected to accident thermal loading develop nonlinear temperature gradients through the wall thickness and undergo concrete cracking. This concrete cracking significantly reduces the stiffness of the SC walls, and thus the thermally induced forces and moments. The paper includes recommendations for: (i) estimating the structural stiffness of SC walls subjected to accident thermal loading, (ii) estimating the maximum moments induced due to thermal gradients, and (iii) developing linear elastic finite element (LEFE) models of SC walls for conducting dynamic seismic analysis.

Modeling and Simulation of Used Nuclear Fuel During Transportation with Consideration of Hydride Effects and Cyclic Fatigue

The objective of this work is to understand the integrity of Used Nuclear Fuel (UNF) during transportation. Previous analysis work has been performed to look at the integrity of UNF during transportation but these analyses have neglected to analyze the effect of hydrides and flaws (fracture mechanics models to capture radial cracking in the cladding). In this study, the clad regions of interest are near the pellet-pellet interfaces. These regions can experience more complex stress-states than the rest of the clad during cooling and have a greater possibility to develop radially reoriented hydrides during vacuum drying.

Load-Rating Procedures for Railroad Flatcars Repurposed as Sustainable Highway Bridges

AbstractMany county highway agencies have explored different options for economical replacement of existing deteriorating bridges. Using retired railroad flatcars (RRFCs) as the bridge superstructure is an attractive and sustainable option for some owners with very limited budgets and where traffic volumes are low. Using RRFCs is also environmentally attractive because they are 100% recyclable. Previous research focused on the development of guidelines to address the uncertainty that exists when load rating these types of structures. Those guidelines were based on field testing conducted on existing RRFC bridges. However, questions remain about the response under loads higher than could be easily achieved during the field testing. Further, although most RRFC bridges utilize timber decks or thin plate decks covered in bituminous material, there is evidence suggesting that installing a traditional composite RC deck is actually more economical and greatly improves load distribution. This paper presents the r...