1. Install NECP-X
To install NECP-X:
· Uninstall previous installation.
· Download the Linux installer:
| Installer |
Operating system |
NECP-X_0.8.3_Linux |
CentOS 7, Suse, Ubuntu 14.04/16.04, with OpenMPI |
· Execute the script in terminal and install NECP-X. Then modify ~/.bashrc fileas ouput information on screen. The path of NECP-X will be prepended to PATH variable and a new variable NECP_X_ROOT will be created. Once installed, you can run NECP-X from terminal anywhere.
To install NECP-X:
sudo NECP-X-0.8.3-Linux.sh
NECP-X will be installed to the default path /usr/local/necp-x/NECP-X-0.8.3-Linux:
Modify ~/.bashrc file as output information on screen. For example:
Screen output information
2. Run NECP-X
NECP-X can be run in neutronics calculation mode or plot mode.
2.1. Plot mode
· Run NECP-X in plot mode to get 2D and 3D figure.
· Use Paraview to open vtk file generated by NECP-X and plot.
· Use PhotoShop to open ppm file generated by NECP-X and plot.
necp-x input_file -p ! 2D plot to VTK
necp-x input_file -p3 ! 3D plot to VTK
necp-x input_file -ppm ! 2D plot to PPM
2.2. Neutronics calculation mode
· Run NECP-X in neutronics calculation mode.
/openmpi/bin/mpirun -np nprocessors necp-x input_file
3. Options
NECP-X can be run in stady-state, Neutron-Thermal coupling and Multi-Cycle mode. Some option values are introduced here. All characters following an exclamation mark ! are commentary and are ignored by NECP-X.
3.1. Stedy-State mode
· Run NECP-X with serial
In principle, users don’t need any options. If you enconter some problems that you can not solve from this document, please read the full user’s guide.
· Run NECP-X with parallel
Users need to enter n_axial and n_radial in parallel option.
nprocessors = n_axial x n_radial.
/openmpi/bin/mpirun -np nprocessors necp-x input_file
3.2. Neutron-Thermal coupling mode
Users need to enter the is_enable_th in th_coupling option.
Users need to enter the power, t_inlet, rho_inlet, pressure, flow and boron in state option. like:
th_coupling
is_enable_th = yes
/th_coupling
state
power = <power> !unit: KW
t_inlet = <t_inlet> !unit: K
pressure = <pressure> !unit: bar
flow = <flow> !unit: kg/s
boron = <boron> !unit: ppm
/state
3.3. Multi-Cycle mode
Users need to enter the is_enable_dep, power_density and burn_step in depletion option. like:
depletion
is_enable_dep = yes
power_density = <power density> !unit: MW/tU
power_history = <power levels> !percentage of full power
burn_step=
dep = <istep>
unit = <gwd/tu | efpd>
/burn_step
/depletion
If users want to couple with thermal, the options in Neutron-Thermal coupling mode is also needed. like:
th_coupling
is_enable_th = yes
/th_coupling
state
power = <power> !unit: KW
t_inlet = <t_inlet> !unit: K
pressure = <pressure> !unit: bar
flow = <flow> !unit: kg/s
boron = <boron> !unit: ppm
/state
depletion
is_enable_dep = yes
power_density = <power density> !unit: MW/tU
power_history = <power levels> !percentage of full power
burn_step=
dep = <istep>
unit = <gwd/tu | efpd>
/burn_step
/depletion
If users need to enter the equilibrium xenon and equilibrium samarium, please read full uers’s guide.
If users need to search critical boron concentration, please read full uers’s guide.
4. Troubleshooting
4.1. necp-x: command not found
When running necp-x in terminal for the first time, the error necp-x: command not found may occur. This is because the system doesn’t know the change of environment variable yet. To fix this problem, just open a new terminal and re-run necp-x.
4.2. Accuracy problem
If the sudden convergence occurs in eigenvalue convergence, it is possible to set more stringent condition for eigenvalue and fission source. like:
iteration
k_critreria = 5.0e-06
fis_critreria = 1.0e-05
/iteration
4.3. Efficient problem
If the transport calculation takes too much time, users can use the following option. (1) The two-level CMFD method can be used. (2) More one-dimension calculation. like:
cmfd
is_cmfd_fg = yes
/cmfd
4.4. Unstable problem
If the transport calculation is divergence. More two-dimension calcualtion can remit this problem. like:
iteration
n_inner = 3 ! maybe more
/iteration
5. Examples
A single assembly example is given as follows:
· 5.1. VERA problem #3 benchmark