Impact of Glass Irradiation on Laser-Induced Breakdown Spectroscopy Data Analysis
Increased absorption of optical materials arising from exposure to ionizing radiation must be accounted for to accurately analyze laser-induced breakdown spectroscopy (LIBS) data retrieved from high-radiation environments. We evaluate this effect on two examples that mimic the diagnostics placed within novel nuclear reactor designs. The analysis is performed on LIBS data measured with 1% Xe […]
A review on the sizing and selection of control valves for thermal hydraulics for reactor system applications
This study presents an overview regarding how to model/size, choose, and maintain control valves (CVs) for a reactor system thermal hydraulics experimentation—specifically simulating pipe break(s) and a loss of coolant accident (LOCA) analysis. In a thermal hydraulics test loop, CVs modulate fluid flow according to the control signal generated by the controller to control the […]
Preliminary Pilot-scale Study and Techno-economic Analysis of Chemical Heat Pump with Conventional Nuclear Reactors
The energy economy is continually evolving, particularly in terms of primary energy sources, their conversions to useful forms such as electricity and heat, and their utilization in different sectors, in response to socio-political factors. Because nuclear source is clean and non-carbon-emitting energy source, it is crucial to consider its role in the evolution of the […]
A CONDUCTION-BASED HEAT PIPE MODEL FOR ANALYZING THE ENTIRE PROCESS OF LIQUID-METAL HEAT PIPE STARTUP
The Heat Pipe-cooled Microreactor (HPM) is one of the micro nuclear reactor designs under active study at the U.S. Idaho National Laboratory. Among the major concerns of HPM research is to understand the startup behavior of the heat pipe-cooled system associated with the startup of the liquid-metal heat pipes initialing from frozen state. The startup […]
Large Eddy Simulation of Flow through an Axisymmetric Sudden Expansion
This study aims at investigating the effect of flow condition at the inlet for flow in an axisymmetric sudden expansion flows with an expansion ratio (ER) of 2.0 and study its flow characteristics. A series of large eddy simulations (LES) with WALE model proposed by Nicoud and Ducros1 were conducted for different inlet Reynolds numbers […]
INL Analysis and Recommendations to Framatome FMEA and PIRT for UZr2 Fuel
A fuel design being proposed by Framatome includes an annular fuel rod that consists of a 50 wt.% Zr uranium-zirconium (U-50Zr) alloy enriched to less than 20% U235 with an external zircaloy cladding while maintaining other aspects of the typical LWR fuel rod design. The rods are in a rectangular array supported and positioned by […]
A two-phase three-field modeling framework for heat pipe application in nuclear reactors
Heat pipes and two-phase thermosyphons are highly efficient heat transfer devices utilizing continuous evaporation and condensation of working fluid for two-phase heat transport in closed systems. Because of the nearly isothermal and fully passive phase-change heat transfer mechanism, heat pipes and thermosyphons have found many applications in nuclear engineering, space technologies, and other energy systems. […]
Post-Irradiation Examination of Optical Components for Advanced Fission Reactor Instrumentation
The use of optical instrumentation in advanced nuclear fission systems, such as molten salt reactors, liquid metal-cooled reactors, and high-temperature gas-cooled reactors, has the potential to enhance reactor safety and economic performance through in situ and online measurement of reactor conditions. Selection of suitable optical components, such as optical windows and fibers, is essential for […]
Numerical study to predict the effect of surface roughness on the thermal and hydraulic performance of additively manufactured heat exchangers
Heat exchangers are used in many industries to transfer thermal energy between two or more objects with an associated thermal and hydraulic performance indicated by thermal effectiveness and pressure drop respectively. Many investigations have aimed to enhance the thermal effectiveness of heat exchangers by introducing turbulent flow inducers that increase the heat transfer rate at […]
CODE-TO-CODE BENCHMARK STUDY FOR THERMAL STRESS MODELING AND PRELIMINARY ANALYSIS OF THE HIGH-TEMPERATURE SINGLE HEAT PIPE EXPERIMENT
Microreactors are very small nuclear reactors with typical thermal-energy output of up to 20 MWth. The microreactor concept is gaining more and more attention for safe, robust, and reliable supply of electricity for remote locations and to meet industrial process heat needs. Heat-pipe-cooled microreactor is one of the microreactors being investigated at Idaho National Laboratory. […]