JAEA-Conf 2011-002 - 日本原子力研究開発機構

analysis of integral experiments [6]. Under this background, the present study was performed
to evaluate the effect of the new data of 157Gd on burnup characteristics of high burnup BWR
UO2 and MOX assemblies.
2 Comparison of Capture Cross Section of 157Gd
Thermal capture cross sections of 157Gd measured in experiments and adopted in
recent nuclear data libraries are shown in Table 1, which were provided by K.Shibata[7] and
the cross section adopted in nuclear data libraries were evaluated at 300K. In the evaluation
of cross sections of JENDL-4.0, the data of Leinweber et al. were used. However, the
background cross sections of 157Gd below 0.1eV were determined through the sensitivity study
using ICSBEP critical benchmark data [8].
Table 1 Comparison of thermal capture cross section of 157Gd
Author Energy (eV) *** Capture Cross Section (barns)
Pattenden ‘58 0.0253 264000±4500
Tattersall ‘60
Groshev ‘62
Maxwell
213000±2000
240000±12000
Leinweber ‘06* 226000
Mughabghab ‘06** 254000±815
JENDL-3.3 253681
JENDL-4.0 0.0253
253251
ENDF/B-6.8 253747
ENDF/B-7.0 253747
JEF-2.2 253272
JEFF-3.1.1
JAEA-Conf 2011-002
*Calculated value based Leinweber et al. [1]
**Evaluation
***Energy installed in EXFOR
253272
3 Preparation of modified 157Gd cross section
New point-wise cross sections of 157Gd corresponding to the measurement of
Leinweber et.al,.were prepared for a MVP library [6]. Comparisons of the new and old cross
sections of 157Gd were performed using MVP for a Gd2O3UO2 cell in high burnup BWR UO2
and MOX assemblies shown in Figure 1. A new SRAC cross section library was prepared
based on the above comparative results.