New low enriched uranium (LEU) fuels are being developed for replacement of high enriched uranium (HEU) fuels in high power research reactors. U-Mo LEU plate fuels have been identified as a candidate for replacement of current HEU fuels. However, U-Mo fuels tend to exhibit accelerated swelling typically at fission densities...
The corrosion behaviors of carbon and stainless steels were investigated in supercritical CO₂ (sCO₂ ) containing H₂O and O₂ simulating conditions that exist in direct sCO₂ power cycle heat exchangers. Thermodynamic properties of CO₂-H₂O-O₂ systems related to the corrosion phenomena were determined using NIST software. The exposure tests of the...
Mechanical property degradation due to isothermal ageing is of potential concern for alloys based on the Ni-Cr binary system (e.g., Inconel 690, 625), particularly in nuclear power applications where component lifetimes can exceed 40 years. In the present research, the disorder-order phase transformation, which is the primary mechanism of ageing,...
The corrosion resistances of several alloys were investigated to optimize performance and cost in seawater and supercritical CO2 environments. Many alloys are prone to corrosion in seawater and/or supercritical CO2 containing impurity environments. Exposure and electrochemical experiments were conducted in both environments to evaluate alloys’ corrosion resistance. In seawater corrosion...
High purity niobium metal is used in the construction of superconducting radio frequency (SRF) cavities in superconducting particle accelerators, such as the Large Hadron Collider (LHC) at CERN or the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The usual method for characterizing the impurities in this niobium, the...
This work explores the hypothesis that proton irradiation is a feasible alternative to simulate accelerated thermal aging for Ni2Cr long-range ordered phase formation within NiCr and NiCrFe alloys. In this study, various model alloys and commercial alloys 690 and 690+P (0.01 wt.% P) were subject to 2 MeV proton irradiation...
This work explores the mechanical properties of single-phase niobium alloy C103 from room temperature to 600°C for the purpose of expanding safe uses of the material into new applications. The study utilizes a symmetrically notched triaxial tensile specimens to manipulate the internal stress field in order to observe the changes...
Duplex stainless steels (DSS) are an attractive potential material in nuclear power generation systems due to an excellent combination of corrosion resistance, strength, toughness, and affordability. Thermal embrittlement caused by phase instability in the temperature range of ~300-550°C severely limits the service temperature of DSS. The rate of embrittlement varies...
Directed energy deposition and laser cladding technologies are suitable advanced manufacturing techniques for applying corrosion-resistant claddings to large carbon steel components. In this work, we clad 309L stainless steel wire onto carbon steel substrates and examine the effects of cladding parameters (laser power and travel speed) on metallurgical bonding, composition,...
Variations in heat treatments have significant effects on the microstructure of tool steels. For CPM-M4 tool steel, the changes in microstructure and mechanical properties were observed based off of variations in temperature. Five heat treatments with constant exposure time and variable austenitizing and tempering temperatures were performed on samples of...