20.4 Conclusion
This study shows the sensitivity analyses of initial compositions and cross sections
for activation products of in-core structure materials. The results clarified the source
elements and nuclear reactions dominating the generation pathways of the activation products even for the nuclides generated through complicated pathways. The
sensitivity coefficients of initial compositions are beneficial for the evaluation of
the error propagated from the uncertainty of the initial composition of target
materials. The sensitivity coefficients of cross sections are effective in selecting
Table 20.11 Sensitivity coefficient of cross section in SUS304 stainless steel
Target nuclide
Sensitivity coefficient of cross section
First largest
Second largest
Ni-59
Ni-58
(n, γ)
1.00
Ni-63
Ni-62
(n, γ)
1.00
Fe-55
Fe-54
(n, γ)
0.99
Ni-58
(n, α)
0.01
Co-60
Co-59
(n, γ)
0.46
Co-59
(n, γ) m
0.46
Mn-54
Fe-54
(n, p)
1.00
C-14
N-14
(n, p)
1.00
Cl-36
Cl-35
(n, γ)
1.00
Fig. 20.3 Dominant generation pathways of activation products in SUS304 stainless steel
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K. Yamamoto et al.