Activation analysis of impurities was performed on a test specimen of the reference low-activation vanadium alloy NIFS-HEAT-2 (V-4Cr-4Ti) which has been irradiated in Japan Materials Testing Reactor (JMTR) ~16 years before. Since the radioactive nuclides from V, Cr and Ti are produced with short half-lives, intense peaks of ⁶⁰Co (T_1/2 = 5.27 years) were dominant in the measured gamma-ray energy spectra and peaks of ⁹⁴Nb (2.03 × 10⁴ years) were also observed. The concentrations were evaluated to be 0.41 wppm and 0.71 wppm respectively from comparison with results of radioactivity calculation using the FISPACT-2005 code. In the analysis, detection of ^108mAg (418 years), which would have a considerable influence on the material recycling after the usage in a fusion reactor, was intense motivation. Although the peaks of ^108mAg has not been detected, the concentration of Ag was estimated to be <0.034 wppm from analysis of detection limit in gamma-ray peak count. Gamma-ray peaks originated from other impurity elements were not observed in the spectra, and the present analysis are supporting the superior low activation properties of NIFS-HEAT-2.

对参比低活化钒合金NIFS-HEAT-2（V-4Cr-4Ti）的试样进行了杂质活化分析，该试样已在日本材料试验反应堆（JMTR）辐照了约16年。由于来自V，Cr和Ti的放射性核素的半衰期很短， 因此在所测得的伽马射线能谱中，⁶⁰ Co（T _1/2 = 5.27年）的强峰占主导地位，⁹⁴ Nb（2.03×也观察到10 ⁴年。通过与使用FISPACT-2005代码进行的放射性计算结果进行比较，得出浓度分别为0.41 wppm和0.71 wppm。经分析，检测^108mAg（418年）是一个强烈的动机，Ag在聚变反应堆中使用后会对材料的回收产生重大影响。尽管未检测到^108m Ag的峰，但根据对伽马射线峰数的检测极限的分析，估计Ag的浓度＜0.034 wppm。在光谱中未观察到源自其他杂质元素的伽马射线峰，目前的分析支持了NIFS-HEAT-2优异的低活化性能。