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崩壊熱評価ワーキンググループ1997年第二回サブグループ会合議事録
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Summary Record of the 1997-2nd DHWG Sub-Group Meeting
Tokyo, June 25, 1997, 13:30 - 17:30
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Meeting Room 2, JAERI Head Quaters, Uchisaiwaicho, Tokyo
Participants:
N.Higano (PNC), J.Katakura(JAERI), K.Oyamatsu (Nagoya Univ)
F.Storrer(Guest; PNC-CEA), T.Tachibana(Waseda Univ),
T.Yoshida(Musashi Tech)
1. Remarks to the minutes of the 1997-1st meeting (Tokai, April 28, 1997)
2. Status Review
1) Higano reported the present status of the PNC-Yayoi Decay Heat
Measurement.
- the design of the capsule has a little bit been changed to reinforce the
attachment of the titanium foil and sample to the head of the capsule.
- endurance tests with the new capsule were performed successfully.
- measurement of the beta and gamma background with the new capsule.
- irradiation test of a u235 sample ( for 10 and 100 sec), and measurement
of the gamma spectrum versus cooling time with the NaI(Tl) detector and
than with the Germanium detector to get the number of fission (derived from
the Nb97M activity).
2) Yoshida reported an trial for defining the source of the long-standing
discrepancy in the gamma-ray component of the decay heat according to a
Trieste paper.
3) Oyamatsu reported the activityes at Nagoya University, which aim at
an accurate evaluation of FP properties from the yields to decay heat.
They consist of the uncertainty calculations, the intercomparison of the
decay and yield data libraries and a new method for evaluationg the
consistency among the various DH measuremtns and the calculations.
4) Storrer presented some data libraries (JEF2, NUBASE) and computer
programs implemented on the workstation at OEC/PNC for decay heat
calculation and data analysis.
-nucleus PC program (DOS): to display JEF2 and NUBASE data
"cydre" fortran code: to deal with the decay data in ENDF6 format
"cytare" fortran code: to deal with the fission yields data in ENDF6 format
"cfe" fortran code: to perform decay heat calculation.
"trij" fortran code: to sort the gamma, beta and total fission product
decay heat contribution versus cooling time.
3. Strategy for France-Japan Cooperation
The participants agreed to continue the France-Japan cooperation in this
research field even after the leave of Dr. Storrer back to Cadarache.
A cooperation program was discussed and they agreed to start with the
following steps:
1) As the first step, they concentrate on the gamma-ray discrepancy in the
cooling time range from 100sec to 3000 sec.
2) Storrer and Oyamatsu list up all the nuclide contributing more than 0.5%
to the gamma-ray component in this cooling time range based on JEF2.2 and
JNDC-V2, respectively.
3) The above lists will be distributed all the participants before mid-July.
4) Storrer, Oyamatsu, Tachibana and Yoshida will be allotted several or
decades(?) of nuclides for critical review of their decay schemes. At least
two persons share one nuclide in order to effectuate the spirit of cross-
checking.
5) A criterion of the review is how high the beta strength is given in the
scale of the excitation energy. Eighty or ninety percent of the beta-decay
Q-value?
6) Through the critical review, the nuclides possibly responsible for the
gamma-ray discrepancy will be identified. In this course of this
identification,
process (the Ghost Hunting, so to speak), the Yoshida's Trieste paper may
provide an useful guide-line.
7) The final list of the candidate nuclides will be sent to Claes Nordborg
for the High Priority Request List as a result of our France-Japan joint effort.
8) This joint effort will provide a framework for further cooperation
between us in the near future.
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Tadashi Yoshida
Dept. of Physics, Faculty of Engineering
Musashi Institute of Technology
1-28-1 Tamazutsumi, Setagaya-ku
Tokyo 158, Japan
Tel: +81-3-5707-1168
Fax: +81-3-5707-1168
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