Fission Product Yields

For experimental fission-product yield data see EXFOR; this now includes most of the data compiled earlier in separate files by Crouch and Meek/Rider.

There are three major files for evaluated fission-product yield data for a large number of "fissioning systems", i.e. actinides fissioning by thermal neutrons, fast neutrons, 14 MeV neutrons, or spontaneous fission.

The neutron-induced fission yield data of these files are accessible online from our ENDF page or through our Nuclear Data Information System. Note:To retrieve fission product yields from either system, "N/FPY" has to be entered in the projectile field.

Compilation and evaluation of fission yield nuclear data

Handbook IAEA-TECDOC-1168 (December 2000). Final report of a Co-ordinated Research Project 1991-1996. The appendices contain voluminous tables and also a computer program YCALC for calculating fission yields and are enclosed as a CD-ROM. Limited number of copies available cost-free to scientists from developing countries upon request.

ENDF/B-6 fission-product yield data

This is a separate ENDF/B-6 sublibrary which was released in September 1991 and updated in June 1993 and May 1995. It has two parts: one part for neutron induced fission, another part for spontaneous fission.
Summary see document IAEA-NDS-106 Rev. 3.

JEF-2/FPY

the JEF-2 fission-product yield data library by the NEA Data Bank, in ENDF-6 format. The evaluated data have been taken over from UKFY2, the UK fission-product yield data library by M. James and R. Mills. Brief summary: IAEA-NDS-123 Rev. 1.
Size: 46 000 records, available on tape. - The original UKFY2 file (see below) contains supplementary information such as chain yields, fractional independent yields, and bibliographic references: available on tape.

JENDL-3.2/FPY

the JENDL fission-product yield data library, has been compiled by T. Nakagawa in ENDF-6 format. The evaluated data have been taken over from JNDC-FP2, a special format data library (see below) documented in the reports JAERI-M-89-204 (1989) and JAERI-1320 (1990). Available on tape.

The ENDF/B-6 fission-product yield data are largely based on the following:

"BRADY"

Fission-product yields and fission-neutron data for minor actinides, by M.C. Brady, R.Q. Wright, T.R. England, 1991. A set of two PC diskettes.

The JEF-2 fission-product yield data are largely based on the following:

UKFY2

the UK Fission-Product Yield Library, version 2, 1991. Summary see document IAEA-NDS-124.

For some fissioning systems that are not included in above data libraries the following file should be used which has been obtained from a theoretical thermodynamical model:

ASIYAD

Fission-product yield library by A.F. Grashin reported at the 1988 Mito Nuclear Data Conference, and converted to ENDF-6 format by the Russian Nuclear Data Center, Obninsk.
Summary see document IAEA-NDS-133.

Additional files which may still be in use and which may continue to be of interest for comparison purposes:

JNDC-FP2: The JNDC Nuclear Data Library of Fission-Products, version 2, including fission-yield data for 20 fissioning systems. For further information see under Fission Product Cross Section and Decay Data . Summary document IAEA-NDS-51 Rev. 3.

Chinese evaluated fission product yield library by Wang Dao et al.,1987. Summary see document IAEA-NDS-91.

ENDF/B-5 Fission-Product Yield data for 11 fissioning nuclides; latest version received in 1985.
Summary documentation: IAEA-NDS-62.

Additional specialized compilations:

Delayed fission-neutron yield data: see report NEACRP-L-323 (Dec. 1990) J. Blachot, M.C. Brady, A. Filip, R.W. Mills, D.R. Weaver, Status of delayed neutron data 1990. Data file not available on tape.

Review of fission product yields and delayed neutron data for selected actinides. Report NEANDC-300 by R.W. Mills. July 1990.

Importance of delayed neutrons in nuclear research, by S. Das. Report BARC/1993/E-003 (1993) and journal Progress in Nuclear Energy vol. 28 No. 3 (1994) p. 209-264.