Developments in Sensitivity Methodologies and the Validation of Reactor Physics Calculations

Table 7

Parameter variations and standard deviations obtained by data assimilation.

Parameter	Variation (%)	Init. stand. dev. (%)	Final stand. dev. (%)
Scat. Rad.^a	1.9	4.1	1.7
Γ𝑛 Bou. Lev.^b	−6.4	8.0	6.4
Γn 2.8 Kev^c	0.6	1.9	1.9
Γγ 2.8 Kev^c	10.5	11.8	10.5
Γ𝑛 538 Kev^c	−57.2	65.9	58.4
R. Vol. Rad.^d	−1.8	2.8	1.6
R. Surf. Dif.^e	−0.8	5.0	4.7
R. Vol. Dif.^f	−0.4	2.1	2.1
TOTRED^g	−1.1	3.5	3.2
FUSRED^h	−0.8	5.0	4.0

^aNuclear scattering radius.
^bBound-level resonance.
^cResonance peak energy.
^dOptical model real volume radius for target nucleus.
^eOptical model real surface diffuseness for target nucleus.
^fOptical model real volume diffuseness for target nucleus.
^gOptical model scaling of total cross-sections due to intrinsic model uncertainty.
^hOptical model scaling of absorption cross-sections due to intrinsic model uncertainty.