JENDL

JENDL
Name	JENDL
Full name	Japanese Evaluated Nuclear Data Library
Organization	Japan Atomic Energy Research Institute, Japan Atomic Energy Agency
Country	Japan
Established	1957
Type	Evaluated nuclear data library
Domain	Nuclear physics, reactor engineering
Formats	ENDF, ACE

JENDL

JENDL is a national evaluated nuclear data library produced in Japan to support reactor design, neutron transport, shielding, and radiological applications. It provides reaction cross sections, decay data, fission yields, and thermal scattering data used by researchers at institutions such as Japan Atomic Energy Research Institute and Japan Atomic Energy Agency. JENDL is disseminated in standard exchange formats interoperable with tools developed at Los Alamos National Laboratory, Brookhaven National Laboratory, and laboratories across Europe, South Korea, and China.

Overview

JENDL compiles evaluated nuclear data for nuclides and isotopes covering neutron-induced reactions, charged-particle interactions, and photonuclear processes, aligning with standards from Nuclear Data Standards committees and international projects like the Nuclear Energy Agency and the International Atomic Energy Agency. The library includes raw experimental datasets digitized from measurements performed at facilities such as Tokai Research Establishment, Kyoto University Research Reactor, and accelerator centers collaborating with CERN and Oak Ridge National Laboratory. Users apply JENDL datasets within transport codes maintained by groups at Argonne National Laboratory, CEA (French Alternative Energies and Atomic Energy Commission), and commercial vendors supporting utilities like Tokyo Electric Power Company.

History and Development

Development began in the postwar period with early efforts at the Japan Atomic Energy Research Institute influenced by international exchanges with United States Atomic Energy Commission laboratories. Major development phases correspond to coordinated evaluation projects involving national laboratories, universities, and industrial partners including Mitsubishi Heavy Industries and Hitachi. Technical direction has been guided by committees involving representatives from Ministry of Education, Culture, Sports, Science and Technology (Japan), research institutes, and international advisory bodies such as the OECD Nuclear Energy Agency Committee on Nuclear Data. Collaborative benchmarks and intercomparisons were conducted with datasets from ENDF/B in the United States, BROND in Russia, and CENDL in China.

Data Contents and Formats

JENDL provides evaluated cross sections, angular distributions, energy spectra, resonance parameters, covariance matrices, activation data, decay schemes, and thermal scattering law (S(α,β)) files. Data are formatted in exchange standards including the Evaluated Nuclear Data File (ENDF), the ACE format used by the Monte Carlo N-Particle Transport Code (MCNP), and interfaces compatible with the Serpent Monte Carlo code and deterministic solvers developed at KAERI and IPPE. Nuclear structure and decay information in JENDL align with compilations at National Nuclear Data Center and incorporate experimental values from measurements reported at conferences such as the International Conference on Nuclear Data for Science and Technology.

Evaluation and Validation

Evaluators combine theoretical models—such as optical model potentials applied at Oak Ridge National Laboratory and Hauser-Feshbach calculations used in collaborations with Los Alamos National Laboratory—with experimental datasets from facilities like Japan Proton Accelerator Research Complex and international beamlines. Uncertainty quantification employs covariance evaluation methods comparable to work by teams at Brookhaven National Laboratory and the NEA Data Bank. Validation leverages benchmark suites including criticality benchmarks from the International Criticality Safety Benchmark Evaluation Project, shielding experiments at Sandia National Laboratories, and integral experiments reported by European Atomic Energy Community projects.

Applications and Use Cases

JENDL underpins reactor physics calculations for light-water reactors operated by utilities such as Chubu Electric Power and research reactors at Kyushu University and Hokkaido University. It supports fusion research programs at ITER partners and material damage assessments in collaboration with Japan Aerospace Exploration Agency facilities. Other applications include medical isotope production modeled with codes developed at National Institute of Radiological Sciences, nuclear forensics studies coordinated with agencies like Interpol and International Atomic Energy Agency, and safeguards assessments used by inspectors from IAEA and national regulatory bodies.

Version Releases and Updates

Major JENDL releases are versioned and published periodically following evaluation campaigns and benchmarking activities. Significant releases have been coordinated around milestones recognized by international communities, with update cycles influenced by experimental campaigns at facilities such as J-PARC and accelerator measurements disseminated through proceedings of the American Nuclear Society. Each release includes revisions to resonance parameters, covariance data, and newly evaluated isotopes in response to demands from reactor designers, fusion researchers, and medical isotope producers.

Comparison with Other Nuclear Data Libraries

JENDL is frequently compared with international evaluated libraries including ENDF/B from the United States, BROND from Russia, CENDL from China, and the European JEFF library. Comparative studies conducted by consortia that include participants from CEA, VTT Technical Research Centre of Finland, and RIKEN examine differences in thermal scattering data, fission product yields, and covariance matrices. These intercomparisons inform users at utilities, research institutions, and regulatory agencies when selecting datasets for sensitivity studies, uncertainty propagation, and licensing calculations.

Category:Nuclear data libraries