20.3.3 Results of Sensitivity Analyses
Sensitivity analyses were conducted for several selected nuclides in Zircaloy-2,
SUS304 stainless steel, and INCONEL alloy. Analyses in Zircaloy-4 were skipped
because the sensitivity coefficients were thought to be almost the same as that
in Zircaloy-2 because calculation conditions were similar. For SUS304
stainless steel, activations using the cross-section library of void ratio 0 % were
evaluated because the concentrations in the case of void ratio 0 % were larger
than that of void ratio 70 %.
The sensitivity coefficients of initial compositions are shown in Table 20.7. As
defined in Eq. (20.1), the value shows the relative amount of variation in concentration of the target nuclide when the initial composition of element varies by a unit
amount. Therefore, the source elements leading to the generation of target nuclides
was clarified from the results. For example, Table 20.7a shows that Fe-55 is
generated from both iron and nickel and that the contribution from iron is dominant.
The results can also be useful in the evaluation of the error propagated from the
measurement uncertainty of initial composition.
As defined in Eq. (20.2), a sensitivity coefficient of a cross section shows the
relative amount of variation in the concentration of the target nuclide when the
Table 20.6 (continued)
Nuclide
Concentration of
activation products
(g/t)
Concentration of fission
products (g/t)
Comparison
(%)
Target
nuclide
①Zry-2
②Zry-4
③
③ /(①+③)
(c) INCONEL alloy 718
Nuclide Concentration of activation products (g/t)
Target
nuclide
Ni-59
3.5E + 03
○
Ni-63
6.2E + 02
○
Co-60
2.6E + 02
○
Nb-94
1.6E + 02
○
Mo-93
5.4E + 00
○
Tc-99
5.4E + 00
○
Fe-55
3.4E + 00
○
Zr-93
1.3E-01
○
Mn-54
4.8E-04
○
Be-10
2.8E-04
○
Cl-36
1.7E-04
○
C-14
5.4E-05
○
Zn-65
1.7E-07
○
Sr-90
1.3E-08
○
Si-32
7.9E-09
○
H-3
1.8E-09
○
20 Sensitivity Analyses of Initial Compositions and Cross Sections. . .
241
Sensitivity analyses were conducted for several selected nuclides in Zircaloy-2,
SUS304 stainless steel, and INCONEL alloy. Analyses in Zircaloy-4 were skipped
because the sensitivity coefficients were thought to be almost the same as that
in Zircaloy-2 because calculation conditions were similar. For SUS304
stainless steel, activations using the cross-section library of void ratio 0 % were
evaluated because the concentrations in the case of void ratio 0 % were larger
than that of void ratio 70 %.
The sensitivity coefficients of initial compositions are shown in Table 20.7. As
defined in Eq. (20.1), the value shows the relative amount of variation in concentration of the target nuclide when the initial composition of element varies by a unit
amount. Therefore, the source elements leading to the generation of target nuclides
was clarified from the results. For example, Table 20.7a shows that Fe-55 is
generated from both iron and nickel and that the contribution from iron is dominant.
The results can also be useful in the evaluation of the error propagated from the
measurement uncertainty of initial composition.
As defined in Eq. (20.2), a sensitivity coefficient of a cross section shows the
relative amount of variation in the concentration of the target nuclide when the
Table 20.6 (continued)
Nuclide
Concentration of
activation products
(g/t)
Concentration of fission
products (g/t)
Comparison
(%)
Target
nuclide
①Zry-2
②Zry-4
③
③ /(①+③)
(c) INCONEL alloy 718
Nuclide Concentration of activation products (g/t)
Target
nuclide
Ni-59
3.5E + 03
○
Ni-63
6.2E + 02
○
Co-60
2.6E + 02
○
Nb-94
1.6E + 02
○
Mo-93
5.4E + 00
○
Tc-99
5.4E + 00
○
Fe-55
3.4E + 00
○
Zr-93
1.3E-01
○
Mn-54
4.8E-04
○
Be-10
2.8E-04
○
Cl-36
1.7E-04
○
C-14
5.4E-05
○
Zn-65
1.7E-07
○
Sr-90
1.3E-08
○
Si-32
7.9E-09
○
H-3
1.8E-09
○
20 Sensitivity Analyses of Initial Compositions and Cross Sections. . .
241