Author Contributions
Conceptualization, G.K.D., P.R. and A.A.; methodology, G.K.D., P.R., A.A. and K.I.; software, G.K.D., P.R., A.A. and J.H.; validation, P.R., A.A., K.I. and M.A.; formal analysis, K.I., M.A. and J.H.; investigation, G.K.D. and P.R.; resources, K.I., M.A. and J.H.; data curation, G.K.D., P.R. and A.A.; writing—original draft preparation, G.K.D., P.R. and A.A.; writing—review and editing, K.I., M.A. and J.H.; visualization, G.K.D., P.R. and A.A.; supervision, K.I., M.A. and J.H.; project administration, K.I., M.A. and J.H.; funding acquisition, K.I., M.A. and J.H. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Construction of the Polaris inputs from template.
Figure 1.
Construction of the Polaris inputs from template.
Figure 2.
On-the-fly verification of Polaris library generation.
Figure 2.
On-the-fly verification of Polaris library generation.
Figure 3.
General scheme of the MPI driven multi-physics multi-scale general simulation framework developed at NCSU.
Figure 3.
General scheme of the MPI driven multi-physics multi-scale general simulation framework developed at NCSU.
Figure 4.
CTF-PARCS external coupling using a client/server MPI Coupling Interface.
Figure 4.
CTF-PARCS external coupling using a client/server MPI Coupling Interface.
Figure 5.
Coupled code information for (a) feedback parameters and (a) transient temporal scheme.
Figure 5.
Coupled code information for (a) feedback parameters and (a) transient temporal scheme.
Figure 6.
Details of the coupled steady-state convergence.
Figure 6.
Details of the coupled steady-state convergence.
Figure 7.
Scheme of the coupled code convergence during depletion simulations.
Figure 7.
Scheme of the coupled code convergence during depletion simulations.
Figure 8.
Details of the coupled depletion convergence.
Figure 8.
Details of the coupled depletion convergence.
Figure 9.
Uncertainty quantification approach.
Figure 9.
Uncertainty quantification approach.
Figure 10.
Axially averaged 2D burnup distribution at (a) BOC and (b) EOC.
Figure 10.
Axially averaged 2D burnup distribution at (a) BOC and (b) EOC.
Figure 11.
1/4 Assembly layouts modeled in Polaris. (a) Assembly without burnable poisons or rods; (b) Assembly with 4 rods and without burnable poisons; (c) Assembly with 8 rods and without burnable poisons; (d) Assembly with 8 rods and with burnable poisons.
Figure 11.
1/4 Assembly layouts modeled in Polaris. (a) Assembly without burnable poisons or rods; (b) Assembly with 4 rods and without burnable poisons; (c) Assembly with 8 rods and without burnable poisons; (d) Assembly with 8 rods and with burnable poisons.
Figure 12.
Reflector configurations in Polaris, (a) radial reflector, (b) axial reflector.
Figure 12.
Reflector configurations in Polaris, (a) radial reflector, (b) axial reflector.
Figure 13.
Radial (a) and axial (b) nodalization of the CTF-PARCS modeling.
Figure 13.
Radial (a) and axial (b) nodalization of the CTF-PARCS modeling.
Figure 14.
ECDF of (a) , (b) , (c) and (d) .
Figure 14.
ECDF of (a) , (b) , (c) and (d) .
Figure 15.
Statistically significant cross-sections Spearman correlation coefficients for (a) and (b) .
Figure 15.
Statistically significant cross-sections Spearman correlation coefficients for (a) and (b) .
Figure 16.
SCALE 56-group correlation matrix between 238U elastic (MT = 2) and inelastic (MT = 4) scattering.
Figure 16.
SCALE 56-group correlation matrix between 238U elastic (MT = 2) and inelastic (MT = 4) scattering.
Figure 17.
Radial distribution of the maximum Spearman correlation coefficient between the axially maximum linear power and (a) 238U elastic scattering and (b) 238U inelastic scattering.
Figure 17.
Radial distribution of the maximum Spearman correlation coefficient between the axially maximum linear power and (a) 238U elastic scattering and (b) 238U inelastic scattering.
Figure 18.
Axial profile for (a) , (b) , (c) and (d) .
Figure 18.
Axial profile for (a) , (b) , (c) and (d) .
Figure 19.
Radial profile of (a) mean and (b) standard deviation.
Figure 19.
Radial profile of (a) mean and (b) standard deviation.
Figure 20.
Radial profile of (a) mean and (b) standard deviation.
Figure 20.
Radial profile of (a) mean and (b) standard deviation.
Figure 21.
ECDF of (a) , (b) , (c) and (d) .
Figure 21.
ECDF of (a) , (b) , (c) and (d) .
Figure 22.
Statistically significant cross-sections Spearman correlation coefficients for (a) , (b) , (c) and (d) .
Figure 22.
Statistically significant cross-sections Spearman correlation coefficients for (a) , (b) , (c) and (d) .
Figure 23.
SCALE 56-group correlation matrix between 238U (MT = 456) and (MT = 455).
Figure 23.
SCALE 56-group correlation matrix between 238U (MT = 456) and (MT = 455).
Figure 24.
Temporal evolution of the (a) , (b) and (c) .
Figure 24.
Temporal evolution of the (a) , (b) and (c) .
Figure 25.
Radial profile of (a) mean and (b) standard deviation.
Figure 25.
Radial profile of (a) mean and (b) standard deviation.
Figure 26.
Radial profile of (a) mean and (b) standard deviation.
Figure 26.
Radial profile of (a) mean and (b) standard deviation.
Figure 27.
ECDF of (a) , (b) , (c) and (d) .
Figure 27.
ECDF of (a) , (b) , (c) and (d) .
Figure 28.
Statistically significant cross-sections Spearman correlation coefficients for (a) , (b) and (c) .
Figure 28.
Statistically significant cross-sections Spearman correlation coefficients for (a) , (b) and (c) .
Figure 29.
Axial profile for (a) , (b) , (c) and (d) .
Figure 29.
Axial profile for (a) , (b) , (c) and (d) .
Figure 30.
Radial profile of (a) mean and (b) standard deviation.
Figure 30.
Radial profile of (a) mean and (b) standard deviation.
Figure 31.
Radial profile of (a) mean and (b) standard deviation.
Figure 31.
Radial profile of (a) mean and (b) standard deviation.
Figure 32.
ECDF of (a) , (b) , (c) and (d) .
Figure 32.
ECDF of (a) , (b) , (c) and (d) .
Figure 33.
Statistically significant cross-sections Spearman correlation coefficients for (a) , (b) , (c) and (d) .
Figure 33.
Statistically significant cross-sections Spearman correlation coefficients for (a) , (b) , (c) and (d) .
Figure 34.
Temporal evolution of the (a) , (b) and (c) .
Figure 34.
Temporal evolution of the (a) , (b) and (c) .
Figure 35.
Radial profile of (a) mean and (b) standard deviation.
Figure 35.
Radial profile of (a) mean and (b) standard deviation.
Figure 36.
Radial profile of (a) mean and (b) standard deviation.
Figure 36.
Radial profile of (a) mean and (b) standard deviation.
Figure 37.
ECDF of (a) and (b) .
Figure 37.
ECDF of (a) and (b) .
Figure 38.
Statistically significant cross-sections Spearman correlation coefficients for the .
Figure 38.
Statistically significant cross-sections Spearman correlation coefficients for the .
Figure 39.
Evolution over depletion of the (a) (b) and (c) .
Figure 39.
Evolution over depletion of the (a) (b) and (c) .
Figure 40.
Axial profile of the (a) (b) and (c) compared with the benchmark reference.
Figure 40.
Axial profile of the (a) (b) and (c) compared with the benchmark reference.
Figure 41.
Radial profile of (a) mean and (b) standard deviation at the EOC.
Figure 41.
Radial profile of (a) mean and (b) standard deviation at the EOC.
Figure 42.
Average radial burnup discrepancy between the predicted and the benchmark reference.
Figure 42.
Average radial burnup discrepancy between the predicted and the benchmark reference.
Table 1.
Nuclide reactions analyzed in the uncertainty quantification framework.
Table 1.
Nuclide reactions analyzed in the uncertainty quantification framework.
MT | Reaction |
---|
2 | Elastic scattering |
4 | Inelastic scattering |
18 | Fission |
102 | Radiative capture |
455 | : delayed neutrons released per fission |
456 | : prompt neutrons released per fission |
1018 | Fission spectrum |
Table 2.
CTF input uncertainty quantification and boundary conditions with N = Normal (Mean, Standard Deviation) and U = Uniform (Min, Max) determined based on LWR-UAM Phase II [
37] and Phase III [
24] specifications and recommendations.
Table 2.
CTF input uncertainty quantification and boundary conditions with N = Normal (Mean, Standard Deviation) and U = Uniform (Min, Max) determined based on LWR-UAM Phase II [
37] and Phase III [
24] specifications and recommendations.
Input | Variable | Probability Density Function |
---|
Fuel Thermal Conductivity | | N (1.0, 0.00774) |
Cladding Thermal Conductivity | | N (1.0, 0.00559) |
Fuel Specific Heat Capacity | | N (1.0, 0.015) |
Cladding Specific Heat Capacity | | N (1.0, 0.015) |
Gap Conductance | | U (0.75, 1.25) |
Outlet Pressure | | N (1.0, 0.005) |
Inlet Mass Flux | | N (1.0, 0.001) |
Inlet Coolant Temperature | | N (1.0, 0.00267) |
Table 3.
Manufacturing parameters input uncertainty quantification with N = Normal (Mean, Standard Deviation) determined based on LWR-UAM Phase II [
37] and Phase III [
24] specifications and recommendations.
Table 3.
Manufacturing parameters input uncertainty quantification with N = Normal (Mean, Standard Deviation) determined based on LWR-UAM Phase II [
37] and Phase III [
24] specifications and recommendations.
Input | Variable | Units | Probability Density Function |
---|
235U enrichment | | w/o% | N (4.95, 0.000746) |
density | | | N (10.283, 0.0566) |
density | | | N (10.14, 0.0566) |
Fuel outer radius | | cm | N (0.46955, 0.000433) |
Cladding inner radius | | cm | N (0.4791, 0.0008) |
Cladding outer radius | | cm | N (0.5464, 0.00083) |
Instrumentation tube outer radius | | cm | N (0.6261, 0.00083) |
Control rod outer radius | | cm | N (0.6731, 0.00083) |
Guide tube outer radius | | cm | N (0.6731, 0.00083) |
Table 4.
Parameter coverage used for the history and branch modeling in the fuel assemblies.
Table 4.
Parameter coverage used for the history and branch modeling in the fuel assemblies.
Parameter | Variable | Units | Min | Max |
---|
Fuel temperature | | | 560 | 1600 |
Moderator density | | | 0.60811 | 0.76971 |
Boron concentration | | | 0 | 1800 |
Control rod insertion | - | - | 0 | 1 |
Table 5.
Output quantities for steady-state calculations.
Table 5.
Output quantities for steady-state calculations.
Output Quantity | Description | Variable |
---|
Scalar | Maximum linear power in the 3D core | |
Maximum fuel centerline temperature in the 3D core | |
Minimum coolant density in the 3D core | |
Effective multiplication factor | |
Functional 1D | Radially averaged axial linear power | |
Radially averaged axial fuel centerline temperature | |
Radially averaged axial coolant temperature | |
Radially averaged axial coolant density | |
Functional 2D | Axially averaged radial linear power | |
Axially averaged radial fuel centerline temperature | |
Table 6.
Output quantities for transient calculations.
Table 6.
Output quantities for transient calculations.
Output Quantity | Description | Variable |
---|
Scalar | Maximum linear power during the transient | |
Maximum fuel centerline temperature during the transient | |
Maximum fuel enthalpy during the transient | |
Inserted reactivity | |
Functional 1D | Maximum linear power over time | |
Maximum fuel centerline temperature over time | |
Maximum fuel enthalpy over time | |
Functional 2D | Axially averaged radial linear power, end of the transient | |
Axially averaged radial fuel centerline temperature, end of the transient | |
Table 7.
Output quantities for depletion calculations.
Table 7.
Output quantities for depletion calculations.
Output Quantity | Description | Variable |
---|
Scalar | Average burnup at EOC | |
Maximum burnup at EOC | |
1D Functional | Maximum linear power over depletion | |
Maximum fuel centerline temperature over depletion | |
Maximum burnup over depletion | |
Radially averaged axial linear power at BOC | |
Radially averaged axial linear power at EOC | |
Radially averaged axial burnup at EOC | |
2D Functional | Axially averaged radial burnup at EOC | |