JEFF library releases

The JEFF suite of nuclear data libraries contains a number of different data types, including neutron and proton interaction data, radioactive decay data, fission yields data, and thermal scattering law data.

JEFF-3.3 : Released in November 2017

The JEFF-3.3 nuclear data library has been officially released in November 2017. It includes a thorough update to its neutron, decay data and fission yields library and adopts other sub-libraries (incident proton, alpha, gamma, triton, He-3 and deuteron) from TENDL-2017. Access the JEFF-3.3 release.

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JEFF collaboration

The JEFF project meets twice a year, in spring and fall, during the NEA Nuclear Data Week in a 4 to 5 day technical programme, with the aim to promote co-operation between experimentalists, evaluators and end-users of nuclear data involved in both projects.


For more information on JEFF activities please contact Franco Michel-Sendis at NEA.

The Joint Evaluated Fission and Fusion File (JEFF) is an evaluated library produced via an international collaboration of NEA Data Bank participating countries.

JEFF-3.3 is a thorough update of the neutron, decay data, fission yields, dpa and neutron activation libraries in the EAF format, with neutron thermal scattering files for 20 compounds. Special sub-libraries for incident alphas, deuterons, gammas, helium-3, protons and tritons have been contributed by the TENDL-2017 library and adopted as part of the JEFF-3.3 release. JEFF-3.3 was officially released on November 20, 2017.

Recent updates

  • [December, 2019]: JEFF-3.3.1 Activation file The update labeled JEFF-3.3.1 version of the activation data library in EAF format is now fully consistent with TENDL-2017. All cross-sections included in the activation data library were extracted and processed from TENDL-2017 and successfully benchmarked with CCFE’s V&V suite. They are released in the two EAF energy group structures : 2011 and 709 groups, for all isotopes available in the TENDL library. The previous JEFF-3.3 (pointwise) version, included cross-sections from pure TALYS calculations for the following nuclides: 1,2,3H1,2,3H3,4He3,4He6,7Li6,7Li10,11B10,11B9Be9Be12,13C12,13C14,15N14,15N16,17O16,17O19F19F232Th232Th233,235,238U233,235,238U and 239Pu239Pu.







Release Format Type Content Modified Size Download
Evaluated files
JEFF-3.3 ENDF-6 Neutron 562 incident neutron isotopic evaluations 2018-01-09 15:39 448M  
JEFF-3.3 ENDF-6 Neutron TSL 20 evaluations for 20 compounds
More info...
2017-12-18 15:30 34M  
Processed files
JEFF-3.3 ACE Neutron CE, 293K 2018-12-10 14:52 1.2G  
JEFF-3.3 ACE Neutron CE, 600K 2018-12-10 15:05 1.2G  
JEFF-3.3 ACE Neutron CE, 900K 2018-12-10 15:11 1.1G  
JEFF-3.3 ACE Neutron CE, 1200K 2018-12-12 12:08 1.1G  
JEFF-3.3 ACE Neutron CE, 1500K 2018-12-10 15:42 1.1G  
JEFF-3.3 ACE Neutron CE,1800K 2018-12-10 16:07 1.1G  
JEFF-3.3 ACE Neutron TSL CE, All Temperatures available
More info...
2018-12-10 14:30 884M  
XSDIR files
JEFF-3.3 XSDIR XSDIR file For all temperatures above and TSLs 2019-02-15 14:19 262K  
Neutron activation files
JEFF-3.3 EAF Neutron activation 2797 files 2018-3-26 16:58 275M  
JEFF-3.3 EAF Neutron activation covariance Files 2797 files 2018-3-26 16:57 9.8M  
JEFF-3.3.1 EAF Neutron activation 211g, All TENDL isotopes 2019-12-11 11:40 55M  
JEFF-3.3.1 EAF Neutron activation 211g, Subset of EAF isotopes only 2019-12-11 11:40 13M  
JEFF-3.3.1 EAF Neutron activation 709g, All TENDL isotopes 2019-12-11 11:40 85M  
JEFF-3.3.1 EAF Neutron activation 709g, Subset of EAF isotopes only 2019-12-11 11:40 20M  




Decay Data



Fission Yields





















NDEC analysis

NDEC is the Data Bank’s Nuclear Data Service platform for the automated verification, processing and content analysis of evaluated nuclear data files and libraries.


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