Nuclear Engineering Commons^™

Multiphysics Analyses And Experiments For Safety Of Advanced Light Water Reactor Fuels, Soon K. Lee

Doctoral Dissertations

The Fukushima Daiichi nuclear plant accident in 2011 triggered worldwide research and development initiatives to advance Light Water Reactor (LWR) fuel materials with excellent tolerance to high-temperature oxidation and deformation. Accident Tolerant Fuel (ATF) design concepts are expected to improve safety margin and extend coping time during severe accident progression, owing to their enhanced mechanical strength, oxidation, and degradation resistance. These concepts require a series of assessments to be licensed by the United States (US) Nuclear Regulatory Commission (NRC). In addition to enhanced safety from ATF materials, supported by the NRC, the US nuclear industry is seeking opportunities to increase …

Accident Tolerant Fuels Claddings And The Evolution Of Their Surface Characteristics Under Critical Heat Flux, Rajnikant V. Umretiya

Theses and Dissertations

Enhanced Accident Tolerant Fuels (ATFs) systems for light water reactors require higher temperature oxidation resistance in steam environments than the current UO₂ – zirconium fuel system. Investigating the ATF materials’ surface properties is needed as they have evidenced to affect the Critical Heat Flux (CHF), which is an important parameter of the thermal-hydraulic performance required to provide safety margins. In this dissertation, the surface properties of FeCrAl alloys (APMT and C26M), Zircaloy-2, Zircaloy-4, and Cr-coating on Zircaloy-4 substrates produced by Physical Vapor Deposition (PVD) and Cold Spray (CS) were investigated according to their chemistry, topography, and wettability. The static …

Multiphysics Assessment Of Accident Tolerant Fuel, Cladding, And Core Structural Material Concepts, Jacob Preston Gorton

Doctoral Dissertations

The severe accident at the Fukushima-Daiichi nuclear power plant in 2011 ignited a global research and development effort to replace traditionally-used materials in Light Water Reactors (LWRs) with Accident Tolerant Fuel (ATF) materials. These materials are intended to extend the coping time of nuclear power plants during severe accident scenarios, but must undergo thorough safety and performance evaluations before being implemented. Four ATF concepts are analyzed in this dissertation using state-of-the-art computer modeling tools: (1) iron-chromium-aluminum (FeCrAl) fuel rod cladding, (2) silicon carbide (SiC) fiber-reinforced, SiC matrix composite (SiC/SiC) boiling water reactor (BWR) channel boxes, (3) mixed thorium mononitride (ThN) …

Experimental Investigation Of Steady-State And Transient Flow Boiling Critical Heat Flux, Soon Kyu Lee

Nuclear Engineering ETDs

The Critical Heat Flux (CHF) causes a rapid reduction of heat transfer coefficient with a rapid increase of cladding temperature, which may induce physical failure of the heated material. Understanding CHF phenomena and reliable prediction of the boiling behavior are needed to design a heat transfer system including nuclear reactors. Due to the complex nature of CHF, it is still an active research topic of interest. With an increasing interest in Accident Tolerant Fuel (ATF), CHF of ATF is essential topic of study for the detailed design of the fuel – cladding element and for the reactor safety analysis.

In …