Integral test of JENDL activation library for fusion applications

To meet urgent requirements for the data validation, an experimental analysis has been carried out for isotopic radioactivities induced by D-T neutron irradiation in structural materials. The primary objective is to examine the adequacy of the activation cross sections implemented in the current activation calculation codes considered for use in fusion reactor nuclear design. The JENDL activation file has been evaluated and now in under integral testing with valuable experimental data. This presentation deals with the present status of results of the test concerning fusion applications. Three other activation cross section libraries along with the JENDL activation file, namely, LIB90, REAC63 and REAC175, were investigated in this present analysis. The isotopic induced radioactivity calculations using these four libraries are compared with experimental values obtained in the JAERI/USDOE collaborative program on fusion blanket neutronics. Nine materials subjected are Al, Si, Ti, V, Cr MnCu alloy, Fe, Ni, Nb and SS316. The adequacy of cross sections is investigated through the C/E analysis. As a result, most of discrepancies in the calculations from experiments can be explained by inadequate activation cross sections. In addition, uncertainties due to neutron energy groups, neutron transport calculation are discussed. JENDL gives the best agreements with experiments as a whole, followed by REAC175, LIB90 and REAC63 in this order. In conclusion, activation cross sections predominantly impact on the prediction accuracy in the radioactivity calculation. (author)