FRENDY

Last Update: 2019/08/20

A nuclear data processing code
 Nuclear data processing Development of FRENDY
Japan Atomic Energy Agency (JAEA)
developed the new nuclear data processing
code FRENDY1, 2) (FRom Evaluated Nuclear
Data librarY to any application) to processevaluated nuclear data files. Features ofFRENDY are as follows: Simple input format
 Extensible & Modular
 Open source software under the2-clause BSD license
FRENDY will help users who want togenerate cross section libraries, processevaluated nuclear data files for their own code,or modify evaluated nuclear data files or crosssection libraries.

Evaluated Nuclear Data(JENDL, ENDF, JEFF)

Cross Section (b)Nuclear data processing is an importantinterface between an evaluated nuclear dataand nuclear transport calculation codes asshown in Fig. 1. The transport codes require across section library which is generated by anuclear data processing code.
The nuclear data processing code is not just aconverter. It performs many processes, e.g.,linearization, reconstruction of the resonanceregion, Doppler broadening, etc.

Nuclear Data Processing
105
Total XS of 235U (293.6 K)
104
103
102
101
100 10-4 10-2 100 102 104 106
Incident Neutron Energy (eV)

Nuclear Calculation
Cross Section
LibraryTransport Codes

Fig. 1 Calculation flow from
evaluated nuclear data tonuclear calculation

 How to get FRENDY?
Everyone can download FRENDY from the following website:

https://rpg.jaea.go.jp/main/en/program_frendy/
Some introduction articles are also found in the above website.
Input instructions and overview of FRENDY are written in Ref. 2.

 References1)2)3)K. Tada, et al., “Development and verification of a new nuclear data processing system FRENDY,” J.
Nucl. Sci. Technol., 54 [7], pp.806-817 (2017).
K. Tada, et al., “Nuclear Data Processing Code FRENDY Version 1,” JAEA-Data/Code 2018-014 (2019).
(https://doi.org/10.11484/jaea-data-code-2018-014)
R. Kondo, et al., “Implementation of random sampling for ACE-format cross sections using FRENDY
and application to uncertainty reduction,” Proc. M&C2019, Aug. 25-29, (2019).

Features of FRENDY
 Simple input format
FRENDY does not require the expertise ofthe nuclear data processing as shown in Fig.
2. The other input parameters areautomatically set from the evaluated nuclear
data file. User can also specify theparameters in the input file if they want tochange them.
FRENDY has an alternative capability ofreading ordinary NJOY inputs without any
modifications.

ace_fast_mode // Processing mode
nucl_file_name U235.dat
ace_file_name U235.ace
temp
296.0 //[K]Fig. 2 Sample input of FRENDY Extensible & ModularFRENDY is developed not only toprocess evaluated nuclear data files but
also to apply the modules to other codes.
FRENDY is written in C++ and all themodules are encapsulated. Users caneasily reuse many modules shown in Fig.
3 into their own codes. For example, aprogram for random sampling from
ACE files is realized by using thesemodules.3) This program is applied tothe uncertainty quantification using acontinuous energy Monte Carlo codeand now included in FRENDY.
There is no restriction to introduce theFRENDY modules into other codes
since this code is an open source
software under the 2-clause BSD license.

 Future plan

ENDF-6format

GNDSformat

Endf6Parser/
Writer/Converter

GndsParser/
Writer/Converter

Resonance
Reconstructor
Doppler
Broader
GasProduction
CrossSection
Calculator
Covariance
DataProcessor

NuclearData
ObjectAceData
Generator
AceDataObjectAceDataParser/Writer
ACE
format

ThermalScattering
DataProcessor
Unresolved
Resonance
DataProcessor
HeatProduction
CrossSection
Calculator

Implemented
Future plan

Fig. 3 System structure of FRENDY

FRENDY version 1 generates the ACE files which are used for continuous energy Monte Carlocodes such as PHITS, MCNP, Serpent, and Open MC. JAEA is now developing a multi-group crosssection generation module. As shown in Fig. 3, the covariance data processing module (CovarianceDataProcessor), the heating production cross-section calculation module (HeatProductionCrossSectionCalculator), and the treatment of GNDS format (GndsParser/Writer/Converter) will be also
implemented. We will release FRENDY version 2 including these modules by 2021.

 Contact information
Dr. Kenichi Tada (tada.kenichi@jaea.go.jp)
Copyright 2019 Japan Atomic Energy Agency. All Rights Reserved.