Identifying Needed Fire Input Data to Reduce Modeling Uncertainty
Funding source: NEUP/DOE
Collaborators: Prof. Brian Lattimer (VT), Dr. Jun Wang and Prof. Michael Corradidni (University of Wisconsin-Madison), and Dr. Kelly Senecal (Covergent Science)
The research effort will identify the fire parameters that have the largest impact on fire conditions, quantify those parameters contributing to uncertainties in the fire data through Monte Carlo simulation results, and use statistical analysis and machine learning models from simulation results to assess existing data and recommend appropriate new fire tests to reduce uncertainties that are important to risk. Based on this research, we will develop a framework capable of determining the significant contributors to uncertainty in other physical events that are relevant to the risk assessment.
Ignis Database (fire experimental database under construction)
Non-dimensional Analysis of Density-Wave Instabilities and Dryout-Rewet Cycles during an ATWS
Funding source: U.S. NRC
Collaborators: Prof. Tomasz Kozlowski (UIUC) and Prof. Michael Corradini (University of Wisconsin-Madison)
We will analyze the recent data collected in the Karlstein Thermal Hydraulic Test Facility (KATHY), in Germany, in order to develop a non-dimensional analysis that will be able to demonstrate the general applicability of these test data in the analysis of Boiling Water Reactor Instabilities. The data were collected under conditions representative of an anticipated transient without scram (ATWS) at the Maximum Extended Load Line Limit Analysis Plus (MELLLA+). The analysis will include the development of criteria for the two-phase instability and for the failure to rewet events that can be applicable to future system analysis under similar operating conditions. We also propose to investigate the transition boiling heat transfer coefficient from the available data, and to assess TRACE/PARCS capability to simulate these instabilities. Finally, we will propose a scaling analysis based on a non-dimensional similarity group that can be used to design an experimental setup and verify the conclusions of this work. The results of this proposed work will address important gaps in the understanding of the two-phase flow instabilities that lead to dryout/rewet cycles and eventually to a fuel temperature excursion, which could damage the fuel rods.
high-Pressure HIgh Temperature annuLUS flow Facility
Supported by U.S. NRC and Virginia Tech
We are currently building a high-pressure (up to 18 MPa) facility to investigate the post-critical heat flux heat transfer and void fraction. The facility consists of annular channel test section, a Zircaloy fuel rod simulator instrumented with fiber optic temperature sensors, a pressure control system, a heat exchanger, a high-pressure pump, and up to 100 kW power.
Fiber-Optic Distributed Temperature Sensor Application to Quenching Experiments
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Investigation of Spent Nuclear Fuel (SNF) Dry Cask System for Long-Term Storage
Funding source: VT IIHCC DA
Collaborators: Prof. Rebecca Cai (MSE) and Prof. Snoja Schmid (STS)
The development of a human-centered society must include a reliable source of energy capable of delivering clean energy in a sustainable and safe manner. Nuclear power is considered a zero-emission energy source that is crucial to meet the global demand to reduce greenhouse gas emissions. To contribute to the nuclear energy development in the area of waste management, we are investigating the chloride-induced stress corrosion cracking (CISCC) under conditions consistently encountered in storage sites using accelerated laboratory experiments to simulate marine environments. Our future goals are combining experimental data and stochastic modeling methods to help us make smart technological and equitable policy decisions in the near future.