Meeting: III Annual Meeting of the Argentinean Group of Calculation and Reactor Analysis.
Date: November 17, 2016.
Location: Central Headquarters of the National Atomic Energy Commission.
Total Duration: 6 hours.
Instructor: Ramiro Vignolo.
DRAGON contains a series of models that enable the simulation of neutron behavior in a nuclear reactor fuel cell or fuel element. This code includes the main features of a cell code: interpolation of microscopic cross-sections obtained from libraries; self-shielding calculations in multidimensional geometries; multigroup and multidimensional neutron flux calculations; homogenization of nuclear properties for core calculations and isotopic depletion. In this workshop, participants will learn to use the DRAGON cell code in its fifth version, covering the different stages that constitute a generic input and performing various examples that reinforce the understanding of each of them. Finally, the use of external tools recommended by the developers as well as by the workshop instructors will be addressed.
- Prerequisites
- Installation
- Workshop Structure
- General Considerations
- File Description
- Directory Description
- Usage Examples
- Technical Background
- Troubleshooting
- Contributing
- License
Before starting this workshop, ensure you have the following software installed:
- DRAGON V5: Nuclear reactor cell calculation code
- Download from Merlin server
- Must be accessible via the
dragoncommand in your terminal
- Bash shell: For running the provided scripts
- C compiler: For compiling custom routines (GCC recommended)
- GhostView: For PostScript file visualization
- Gnuplot: For 2D and 3D plotting
- Pyxplot: Alternative to gnuplot for 2D plots (if available)
- Kate: Text editor with DRAGON syntax highlighting
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Clone this repository:
git clone https://github.com/rvignolo/workshop-dragon.git cd workshop-dragon -
Verify DRAGON installation:
dragon --version
If this command fails, ensure DRAGON is properly installed and added to your PATH.
-
Set up your environment:
# Make all scripts executable find . -name "*.sh" -exec chmod +x {} \;
-
Test the installation:
cd 1.materials/1.macroscopic ./run.sh
The workshop is organized into 5 progressive modules, each building upon the previous knowledge:
workshop-dragon/
├── 1.materials/ # Cross-section definitions and libraries
│ ├── 1.macroscopic/ # Macroscopic cross-sections
│ └── 2.microscopic/ # Microscopic cross-sections
├── 2.geometries-and-tracking/ # Geometry definitions and ray tracing
│ ├── 1.cna2_excelt/ # CANDU-2 EXCELT geometry
│ ├── 2.cna2_nxt/ # CANDU-2 NXT geometry
│ ├── 3.square_ass/ # Square assembly
│ ├── 4.candu_marleau/ # CANDU Marleau geometry
│ └── 5.hexagonal_ass/ # Hexagonal assembly
├── 3.flux-calculation/ # Neutron flux calculations
│ └── 1.flux-dist/ # Flux distribution analysis
├── 4.reference-burnup/ # Reference burnup calculations
└── 5.local-perturbations/ # Local perturbation analysis
└── 1.linear-loop/ # Linear perturbation loop
-
The main directory contains various folders with DRAGON inputs and scripts organized in 5 numbered directories. The numbering respects the order in which the workshop topics will be addressed.
-
It is recommended to have GhostView installed for PostScript visualization and gnuplot for 2D and 3D plotting. However, if you have pyxplot available, 2D plots will be generated using this program instead of gnuplot.
-
As a text editor, the use of Kate is recommended since we have written syntax highlighting for DRAGON.
-
It is necessary to have DRAGON installed globally and accessible via the
dragoncommand. It can be downloaded from the Merlin server. -
In the downloads section, you will find slides that can be used to accompany the workshop reading.
The numbered directories from 1. to 5. contain the complete practical part of the
workshop, including DRAGON inputs and scripts. In the generic case, a directory may contain
the following files:
.x2mfiles: DRAGON input files containing the main calculation parameters.c2mfiles: DRAGON procedure files with reusable code modules
clean.sh: Cleans the information obtained after running an input (note that you can modify this script as needed)run.sh: Properly executes the DRAGON input. Additionally, if the-goption is given, it will display PostScript outputs in GhostViewxs-plot.sh: Generates cross-section plots in gnuplot or pyxplot and in 2D and 3D as appropriatecompile.sh: Compiles C routines using GanLib libraries
After executing the run.sh script in each directory, in the most general case, files of
the following type will be obtained:
.resultfiles: Contain the DRAGON output with calculation results.psfiles: PostScript files with geometry plots showing region distribution, mixtures, or flux.mfiles: MATLAB/Octave files containing ray tracing informationDatabase.dat: File generated by theCOMPO:module of DRAGON and converted to ASCII.datfiles: Cross-section information after processingDatabase.datwith C routines
Each workshop directory will be briefly and individually explained.
This directory contains two subdirectories, 1.macroscopic and 2.microscopic, where the
input format for the MAC: and LIB: modules respectively is specified. Particular
attention should be paid to, for example, the format of scattering cross-sections and the
results of the runs.
Key Learning Objectives:
- Understand macroscopic vs. microscopic cross-section definitions
- Learn proper input formatting for DRAGON modules
- Analyze scattering cross-section matrices
- Interpret calculation results
This directory contains inputs that describe different types of geometries, to which different ray tracing modules can be applied. It is important to analyze each of the geometries and understand both material definitions and boundary conditions. Once each of these cases is understood, propose a geometry and try to implement it.
Key Learning Objectives:
- Master geometry definition in DRAGON
- Understand ray tracing algorithms
- Learn boundary condition specification
- Practice with different fuel assembly types
Flux calculation is proposed in the same geometry but defined in different ways. Compare the
results and understand the use of DRAGON's new tools, such as the G2S: and SALT:
modules.
Key Learning Objectives:
- Compare different flux calculation methods
- Understand the
G2S:andSALT:modules - Analyze flux distribution patterns
- Validate calculation convergence
The reference burnup is, precisely, a run that performs isotopic evolution. The output of this run consists of cross-sections as a function of burnup. The important aspects are understanding both the algorithm used for burning and the tools employed to collect the information.
Key Learning Objectives:
- Understand burnup algorithms
- Learn isotopic evolution tracking
- Master cross-section interpolation
- Analyze burnup-dependent behavior
Local perturbations take the reference burnup and traverse it while locally perturbing some parameter. This allows obtaining cross-sections as a function of burnup and a local perturbation. By post-processing these values, it is possible to obtain, for example, the derivatives of cross-sections with respect to the local parameter as a function of burnup.
Key Learning Objectives:
- Implement local perturbation methods
- Calculate sensitivity coefficients
- Understand uncertainty propagation
- Master post-processing techniques
cd 1.materials/1.macroscopic
./run.shcd 2.geometries-and-tracking/1.cna2_excelt
./run.sh -g./clean.sh
./run.shcd 4.reference-burnup
./compile.sh
./run.shDRAGON (Deterministic Transport Analysis of Reactor Physics) is a deterministic neutron transport code developed at École Polytechnique de Montréal. Version 5 represents a significant advancement in nuclear reactor cell calculations, offering:
- Advanced Geometry Modeling: Support for complex 2D and 3D geometries
- Multiple Transport Methods: Method of characteristics, collision probability, and discrete ordinates
- Comprehensive Cross-section Processing: Self-shielding, resonance treatment, and temperature interpolation
- Burnup Capabilities: Isotopic evolution and depletion calculations
- Sensitivity Analysis: Local and global perturbation methods
MAC:: Macroscopic cross-section definitionLIB:: Microscopic cross-section library processingGEO:: Geometry definition and representationEXCELT:: Method of characteristics ray tracingFLU:: Flux calculationBURN:: Burnup calculationsCOMPO:: Composition tracking
DRAGON command not found:
# Check if DRAGON is in your PATH
which dragon
# If not found, add to your PATH or install DRAGONPermission denied on scripts:
chmod +x *.shPostScript files not displaying:
# Install GhostView
sudo apt-get install gv # Ubuntu/Debian
brew install ghostscript # macOSGnuplot not available:
# Install gnuplot
sudo apt-get install gnuplot # Ubuntu/Debian
brew install gnuplot # macOS- Check the DRAGON user manual
- Review the
.resultfiles for error messages - Ensure all input files are properly formatted
- Verify that all required modules are available
This workshop material is part of the nuclear engineering community. If you find errors or have suggestions for improvements:
- Fork the repository
- Create a feature branch
- Make your changes
- Submit a pull request
Please ensure that:
- All scripts remain executable
- Input files follow DRAGON V5 syntax
- Documentation is updated accordingly
This workshop material is provided for educational purposes. Please respect the original author's work and cite appropriately when using these materials in publications or presentations.
Note: This workshop assumes basic knowledge of nuclear reactor physics and neutron transport theory. For additional background, refer to standard nuclear engineering textbooks and the DRAGON user manual.