The FRENDY (FRom Evaluated Nuclear Data librarY to any application) code.
FRENDY is publicly available under BSD 2-Clause "Simplified" License at https://git.oecd-nea.org/frendy/frendy
To submit a request, click below on the link of the version you wish to order. Rules for end-users are available here.
| Program name | Package id | Status | Status date |
|---|---|---|---|
| FRENDY V2 | NEA-1907/03 | Tested | 16-DEC-2025 |
Machines used:
| Package ID | Orig. computer | Test computer |
|---|---|---|
| NEA-1907/03 | Linux-based PC | Gitlab |
FRENDY is publicly available under BSD 2-Clause "Simplified" License at https://git.oecd-nea.org/frendy/frendy
FRENDY (FRom Evaluated Nuclear Data librarY to any application) is a nuclear data processing system to generate a cross-section file from evaluated nuclear data file. FRENDY supports recently evaluated nuclear data libraries (e.g., JENDL-4.0 and JENDL-5 in Japan, ENDF-B/VII.1 and ENDF-B/VIII.0 in the US, JEFF-4.0 in Europe).
The first version of FRENDY, which is called FRENDY Version 1 generates the ACE file which is used for continuous energy Monte Carlo codes such as PHITS, Serpent, and MCNP.
FRENDY Version 2 generates the multi-group neutron cross-section file for multi-group deterministic calculation codes from the ACE file. The available multi-group cross section format is GENDF and MATXS. The other major improvements are as follows: (1) uncertainty quantification for the probability tables of the unresolved resonance cross-sections, (2) perturbation of the ACE file for uncertainty quantification using a continuous Monte Carlo code, and (3) modification of the ENDF-6 formatted nuclear data file.
FRENDY accepts two types of input formats: Simple input format and NJOY compatible format. The simple input format requires only the processing mode and evaluated nuclear data file name at the minimum. This input format does not require the expertise of nuclear data processing. The other input parameters are automatically set from the evaluated nuclear data file. Users can also specify the parameters in the input file if they want to change them.
FRENDY has an alternative capability of reading ordinary NJOY inputs without any modifications. Many users process the evaluated nuclear data file with NJOY. They can easily use FRENDY without changing the input files for NJOY. They can therefore replace NJOY modules with FRENDY ones as they need. In addition, the modules of FRENDY and NJOY can be used in combination. For example, users can generate the multi-group cross-section data library using the GROUPR module of NJOY with the PENDF file generated by FRENDY. Available NJOY modules in FRENDY are RECONR (resonance reconstruction and linearization), BROADR (Doppler broadening), GASPR (calculation of gas production cross-section), PURR (generation of probability table), UNRESR (calculation of Bondarenko-type self-shielded cross-section), THERMR (calculation of thermal scattering cross-section), ACER (generation of ACE file), and MODER (modification of PENDF file).
FRENDY is developed not only to process evaluated nuclear data files but also to apply the modules to other codes. FRENDY is written in C++ and all the modules are encapsulated. Users can easily employ many functions (e.g., read, write, and process an evaluated nuclear data file) in their codes when they implement the classes of FRENDY to their codes. FRENDY prepares utility tools, e.g., the ACE file perturbation tool, in the code package.
FRENDY prepares sample cases to generate ACE files. All 15 sample input files ran in about 15 minutes on Intel Xeon Gold 6154 (3.00 GHz) without parallel computation.
The other sample input files to generate ACE, GENDF, and MATXS files can be found in the manual of FRENDY in the FRENDY package.
FRENDY has the following unusual capabilities:
Generation of the multi-nuclide data, e.g., U-235, U-238, and O-16 in UO2, to explicitly consider the resonance interference effect in a material.
Automatic background cross section set with the minimum number of background cross-sections.
Perturbation of ACE file with perturbation_ace_file.exe.
A random sampling of ACE file with make_perturbation_factor.
Perturbation_ace_file: Program to perturb an ACE file when a user sets the ACE file name, reaction type, energy region, and amount of perturbation.
Make_perturbation_factor: Program for uncertainty analysis using the random sampling method for ACE file.
Read_errorr_data: Program to generate the input file and the CSV file for the make_perturbation_factor tool from the GENDF file generated by the ERRORR module in the NJOY code.
Make_xsdir_list: Program to generate the XSDIR file and copy ACE files to use continuous energy Monte Carlo codes without any modification.
FRENDY runs on the following operation systems: Linux, Windows, and Mac.
The supported C++ compilers are Intel compiler and GNU compiler.
BOOST and LAPACK libraries are required to compile FRENDY.
Matrix calculation library Eigen is required to compile related program make_perturbation_factor.
Keywords: ACE, ENDF, ENDF-B/VII.1, ENDF-B/VIII.0, JEFF, JEFF-3.2, JEFF-3.3, JENDL, JENDL-3.3, JENDL-4.0, cross sections, data library, data processing, evaluated nuclear data, nuclear data, open-source code.
