fz-cristal

A Funz plugin for Cristal (French criticality package).

This plugin enables parametric studies with Cristal (V1 and V2) through the fz framework.

Features

Cristal is a French criticality package available at http://oecd-nea.org/tools/abstract/detail/nea-1903/

This plugin supports:

• Cristal V1.2
• Cristal V2.0, V2.0.2, V2.0.3
• Multiple calculation types: SN KEFF, SN Normes, Pij-MC, and AP2M5 (XML-based)

Installation

This plugin requires the Funz/fz framework.

pip install git+https://github.com/Funz/fz.git

Set up your Cristal installation path:

export CRISTAL_HOME="/opt/CRISTAL_V2"  # Adjust to your installation
export CRISTAL_VERSION="2.0.3"         # Optional: specify version

Supported Models

1. Cristal-SnKeff

For SN KEFF calculations.

Input syntax:

• Variable prefix: $
• Formula prefix: @
• Delimiters: {}
• Comment character: *

Outputs:

• keff: Effective multiplication factor
• kinf: Infinite multiplication factor
• slowing_down: Slowing down area
• M2: Migration area (cm²)
• B2: Buckling

Example:

DEBUT_APOLLO2
*Umetal
nom_mil = 'FISSIL REFLEC0 ' ;
TOPT.'STMIL'.nom_mil = TABLE: ;
TOPT.'STMIL'.nom_mil.'U238    ' = $(U238~2.49865E-03) ;
TOPT.'STMIL'.nom_mil.'U235    ' = $(U235~4.49988E-02) ;
...
FIN_APOLLO2

2. Cristal-SnNormes

For SN Normes calculations with extended outputs.

Additional outputs beyond SnKeff:

• dimension: Reactor dimension
• cx: C(X) concentration parameter
• hx: H/X ratio

3. Cristal-Pij-MC

For Pij Monte Carlo calculations (combined APOLLO + MORET).

Input syntax:

• Variable prefix: $
• Formula prefix: @
• Delimiters: {}
• Comment character: *

Outputs:

• mean_keff: Mean k-effective value
• sigma_keff: Standard deviation of k-effective
• dkeff_pertu: Delta k-effective for perturbation
• sigma_dkeff_pertu: Standard deviation of delta k-effective
• cU: Uranium concentration array
• cPU: Plutonium concentration array
• M2: Migration area array
• B2: Buckling array
• KINF: K-infinite array

Example:

DEBUT_APOLLO2
...
FIN_APOLLO2

DEBUT_MORET
TITRE Installation

ARRE
  ETAP
    ACTI 100
    PASS 3
  KEFF
    SIGM 0.001
FARR

GEOM
MODU 0
TYPE 1 SPHE $(r~8.741)
...
FIN_MORET

4. CRISTAL-AP2M5

For XML-based model definitions.

Input syntax:

• Variable prefix: $
• Formula prefix: @
• Delimiters: {}
• Comment character: #

Same outputs as Cristal-Pij-MC.

Usage

With fz Python API

import fz

# Example: Run calculation with varying parameters
results = fz.fzr(
    input_path="examples/godiva1d.snk",
    input_variables={
        "U235": [4.0e-2, 4.5e-2, 5.0e-2],
        "U238": [2.0e-3, 2.5e-3, 3.0e-3]
    },
    model="Cristal-SnKeff",
    calculators="localhost_Cristal",
    results_dir="my_results"
)

print(results[['U235', 'U238', 'keff', 'kinf']])

Directory Structure

fz-cristal/
├── examples/
│   ├── godiva1d.snk        # SN KEFF example
│   ├── godiva1d.snn        # SN Normes example
│   ├── godiva.mor          # Monte Carlo example
│   └── godiva_model.xml    # XML-based model example
├── .fz/
│   ├── models/
│   │   ├── Cristal-SnKeff.json
│   │   ├── Cristal-SnNormes.json
│   │   ├── Cristal-Pij-MC.json
│   │   └── CRISTAL-AP2M5.json
│   └── calculators/
│       ├── Cristal.sh
│       └── localhost_Cristal.json
├── tests/
│   └── test_plugin.py
└── results/                    # Generated by fz

Configuration

Environment Variables

• CRISTAL_HOME: Path to Cristal installation (required)
• CRISTAL_VERSION: Cristal version to use (1.2, 2.0, 2.0.2, 2.0.3)
  • If not set, auto-detects based on available installation

Calculator Configuration

Edit .fz/calculators/localhost_Cristal.json to customize:

{
    "uri": "sh://",
    "models": {
        "Cristal-SnKeff": "bash .fz/calculators/Cristal.sh",
        ...
    }
}

Examples

See the examples/ directory for example input files organized by model type:

• examples/godiva1d.snk - 1D Godiva sphere (SN KEFF)
• examples/godiva1d.snn - 1D Godiva sphere (SN Normes)
• examples/godiva.mor - Godiva Monte Carlo
• examples/godiva_model.xml - XML-based model

Remote Execution

To run calculations on a remote server:

results = fz.fzr(
    input_path="examples/godiva1d.snk",
    input_variables={"U235": [4.0e-2, 4.5e-2]},
    model="Cristal-SnKeff",
    calculators="ssh://user@server.com/bash /path/to/calculators/Cristal.sh",
    results_dir="remote_results"
)

Running Tests

python tests/test_plugin.py

License

BSD 3-Clause License. See LICENSE file.

Related Links

• Funz/fz - Main framework
• Cristal at NEA - Cristal package information