JAEA-Conf 2011-002 - 日本原子力研究開発機構
JAEA-Conf 2011-002 - 日本原子力研究開発機構
JAEA-Conf 2011-002 - 日本原子力研究開発機構
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
fuel columns, respectively. These libraries underestimate the loaded number of the fuel columns<br />
by one or two columns, which are caused by the overestimation of the keff value.<br />
The discrepancy of the loaded number of the fuel columns achieving the first criticality<br />
between the experiment and the calculations was resolved by replacing the nuclear data<br />
libraries with JENDL-4.0.<br />
3.2 Excess reactivity of fully loaded core<br />
The excess reactivity of the fully loaded core ex, is defined by<br />
keff<br />
1<br />
ex<br />
. (1)<br />
keff<br />
Table 2 shows that JENDL-4.0 yields the excess reactivity of 12.0%k/k, which agrees well with<br />
the experimental result. Meanwhile, JENDL-3.3, ENDF/B-VII.0 and JEFF-3.1 give the excess<br />
reactivity of 12.4, 12.8 and 12.7%k/k, and they overestimates by 0.4-0.8%k/k.<br />
The problem of overestimating the excess reactivity at the fully loaded core was also<br />
resolved by replacing the nuclear data libraries with JENDL-4.0.<br />
Table 2 Comparisons between experimental[10] and calculation results<br />
Number of fuel columns<br />
achieving the first criticality<br />
Excess reactivity of the fully<br />
loaded core (%k/k)<br />
<strong>JAEA</strong>-<strong>Conf</strong> <strong>2011</strong>-<strong>002</strong><br />
Experiment JENDL-4.0 JENDL-3.3 ENDF/B-VII.0 JEFF-3.1<br />
19 19 18 17 17<br />
12.0 12.0 12.4 12.8 12.7<br />
4. Conclusions<br />
The criticality calculations of 12-30 fuel columns loaded core, which were constructed in<br />
the critical approach, were performed with JENDL-4.0, JENDL-3.3, ENDF/B-VII.0, and<br />
JEFF-3.1. As a result, JENDL-4.0 yields keff values which are 0.5-0.9%k smaller than<br />
JENDL-3.3, and 1.0-1.5%k smaller than ENDFL/B-VII.0 or JEFF-3.1. The keff values<br />
calculated with ENDF/B-VII.0 and JEFF-3.1 are the same within 2 for the all core states.<br />
The discrepancies between the experimental and the calculation results on the following<br />
two issues were resolved as expected by replacing the nuclear data libraries with JENDL-4.0.<br />
This fact shows that the applicability of JENDL-4.0 to the HTTR criticality calculations is more<br />
excellent than the other nuclear data libraries.<br />
(a) The loaded number of fuel columns achieving the first criticality.<br />
(b) Excess reactivity of the fully loaded fuel columns core.<br />
JENDL-4.0 promises to improve the accuracy of the HTGR criticality calculations, which<br />
allows the design of the commercial HTGR with lower cost and higher performance.