M. Kawai1, T. Watanabe2, T. Nakegawa3, S. Iijima1, H. Matsunobu4, T. Nishigori5, M. Sasaki6, T. Sugi3 and A. Zukeran7

JNDC Fission Product Nuclear Data Sub-Working Group,
Japan Atomic Energy Research Institute
Tokai-mura, Naka-gun, Ibaraki-ken, 319-11, Japan

1) NAIG, 2) KHI, 3) JAERI, 4) SAEI, 5) Osaka Univ., 6) MAPI, 7) Hitachi

Neutron cross sections of 172 nuclides in fission product mass region from As to Tb in the energy range between 0.01 meV and 20 MeV were evaluated for JENDL-3. Compared to JENDL-2 which contains 100 nuclides, the isotopes of As, Se, Br, Sn and Te and several short lived nuclides were added. Threshold reaction cross sections were newly entried. Recent experimental data of resonance parameters and cross sections up to 1987 were utilized. Above unresolved resonance region, cross sections were calculated with spherical optical model, the preequilibrium and statistical theory. The systematics of nuclear model parameters was investigated. Integral test of JENDL-2 FP data was performed using the integral data measured at EBR-II, CFRMF and STEK. For nuclides such as Xe-132, -134, Eu-152, and Eu-154 whose differential data are not available, the capture cross sections were adjusted with integral data.

KEYWORDS: neutron cross sections, nuclear model parameter, fission product nuclides, evaluation, integral test, JENDL-3