Nuclear Engineering and Design

DB folder : accident data for simulation cases MODEL folder : machine learning sub-models learned from 10,000 event cases data SIMULATE : python file for running simulation

These files provide the raw data from steady-state and transient thermal hydraulic experiments performed as described in the manuscript titled "Single-Phase, Natural Circulation Annular Flow Measurements for Cartridge Loop Irradiation Experiments" submitted to the Nuclear Engineering and Design journal in August 2020.

The contribution of radiative heat transfer (RHT) to convective heat transfer in a heated vertical pipe with laminar flow and constant wall temperature, for FLiBe molten salt, is investigated computationally. The combined effects of conduction in the fluid, forced convection, buoyancy, temperature-dependent physical properties, and thermal radiation are investigated. The P1 approximation is employed in the discretization of the Radiative Transfer Equation (RTE). The COMSOL Multiphysics software is used to generate the numerical solutions. Theoretical analysis demonstrates that only for intermediate values of the optical thickness, i.e. τ_D~O(1), the participating media effects are expected to be important. This analysis is confirmed computationally, where a value of τ_D≈4 is shown to lead to the highest increase in overall heat transfer behavior. Under forced convection, the Nusselt ratio Nu_total/ Nu_(no-rad) reaches a peak value of 1.76 at τ_D=4 and z/D=200, and is less than 1.1 for τ_D<0.1 and τ_D>60. Under aiding-flow mixed convection, Nu_total/ Nu_(no-rad) reaches a peak of 1.34 at τ_D=4.2 and is less than 1.1 for τ_D<‍0.4 and τ_D>36. Under opposing-flow mixed convection, Nu_total/ Nu_(no-rad) reaches a peak of 1.81 at τ_D=4.2 and is less than 1.1 for τ_D<0.2 and τ_D>50. RHT effects on the overall heat transfer are most pronounced in opposing mixed convection where peak Nu_total/ Nu_(no-rad) is 2.26 observed at z/D=50. The sensitivity to wall emissivity is evaluated; in forced convection, the peak Nu_total/ Nu_(no-rad) is 1.66 at ε=0 (reflective wall) and 2.04 at ε=1 (absorptive wall). The sensitivity to pipe diameter is also discussed. Overall, for a vertical heated tube, radiative heat transfer effects lead to enhancement of heat transfer by as high as a factor of two, and they depend on the optical thickness of the flow, mixed convection environment (Gr\/Re^2 and direction of flow relative to the gravitational force), surface emissivity, and entrance effects.

The properties of boron carbide, hafnium diboride, and hafnium hydride.

Fault trees for 2 failure modes of MSRE freeze valve FV-103 and supporting basic event data

The path for immobilizing low-activity waste (LAW), a mixture of salts, for long-term storage is adding glass-forming and modifying additives and minerals to the solution and vitrifying the resulting slurry in an electric melter. Technetium-99 (99Tc), a long-lived radionuclide present in LAW, is highly volatile at the elevated temperatures in a glass melt. An off-gas system was designed for capturing volatile 99Tc or Re, its nonradioactive surrogate, during continuous charging of a LAW melter feed in a laboratory-scale melter (LSM). The Re retention in the glass was determined via the measured amount of volatilized Re in the off-gas during a time period when the reacting melter feed was at a quasi-steady-state. This study was performed in preparation for the LSM system to be applied for melter feeds containing either a LAW simulant spiked with 99Tc or an actual tank waste.

Experimental data for critical heat flux

Measured data of each sample. CSV files named as 5Kmin, 15Kmin, 05Kmin, and 0125Kmin indicates the samples cooled at 5, 3/2, 1/2, and 1/8 Kmin-1, respectively.

Contains input files (both complete input files as well as templates) along with some output files and CSV-formatted results, along with a few additional figures. Some of the results are not directly used in the corresponding publication, and are either indirectly used, or correspond to cases that were not included in the paper at all; usually those similar to the cases used in the paper, but with different parameters. The Polaris input files are incompatible with the distributed version of SCALE 6.2.

Three dimensional transient analysis of the coupled RCS-containment integral system