Possible origin of the gamma-ray discrepancy in the summation calculations of fission product decay heat

Tadashi Yoshida, Takahiro Tachibana, François Storrer, Kazuhiro Oyamatsu, Jun Ichi Katakura

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

In order to identify the origin of the ubiquitous and long-standing discrepancy seen in the γ-ray component of the FP decay heat in the cooling time range 300-3,000 s, a comprehensive analysis of the differences between the summation calculations and the experiments has been carried out. There may be some missing of the β-strength in the high energy region of the FPs in the mass region A=100-110. Especially, 102Tc, 104Tc, 105Tc and 108Rh are potentially responsible for the γ-ray discrepancy seen in the three major fissioning nuclides, 235U, 238U and 239Pu, systematically. The β-strength functions are theoretically calculated in order to validate this possibility. It is proved that the chance for finding the additional β-strength required to solve the discrepancy is not so large but still exists, and the exact β-feed from Tc to the highly excited levels in Rb should be identified experimentally. Finally, the impact of the γ-ray discrepancy on the reactor-core decay heat is evaluated quantitatively for the first time. It may introduce 0.5-1% underestimation of the total FP decay heat from 1 to 2,000 s after reactor shutdown, and the underestimation may reach 3% at the maximum when the γ-ray component of the decay heat is separately taken into consideration.

Original languageEnglish
Pages (from-to)135-142
Number of pages8
JournalJournal of Nuclear Science and Technology
Volume36
Issue number2
Publication statusPublished - 1999 Feb

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fission products
Fission products
Gamma rays
rays
gamma rays
heat
decay
Reactor shutdowns
reactor cores
shutdowns
Reactor cores
nuclides
Isotopes
reactors
Cooling
cooling
Hot Temperature
Experiments
energy

ASJC Scopus subject areas

  • Nuclear Energy and Engineering

Cite this

Possible origin of the gamma-ray discrepancy in the summation calculations of fission product decay heat. / Yoshida, Tadashi; Tachibana, Takahiro; Storrer, François; Oyamatsu, Kazuhiro; Katakura, Jun Ichi.

In: Journal of Nuclear Science and Technology, Vol. 36, No. 2, 02.1999, p. 135-142.

Research output: Contribution to journalArticle

Yoshida, Tadashi ; Tachibana, Takahiro ; Storrer, François ; Oyamatsu, Kazuhiro ; Katakura, Jun Ichi. / Possible origin of the gamma-ray discrepancy in the summation calculations of fission product decay heat. In: Journal of Nuclear Science and Technology. 1999 ; Vol. 36, No. 2. pp. 135-142.
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