Cross section adjustment method based on random sampling technique

Figures & data

Table 1. Configuration of fuel pin-cell.

Parameter	Value
Fuel pellet material	UO2
Fuel density [g/cm^3]	10.283
Fuel enrichment [wt%]	4.85
Fuel pellet diameter [mm]	9.391
Cladding material	Zircaloy-2
Cladding outside diameter [mm]	10.928
Cladding thickness [mm]	0.673
Unit cell pitch [mm]	14.427

Table 2. Conditions of pin-cell calculation.

Parameter	Value
Fuel temperature [K]	900
Moderator temperature [K]	600
Cladding temperature [K]	636
Boron concentration [ppm]	0

Table 3. k-infinity and their differences from the virtual experimental value.

			After adjustment
			Present
	Virtual experimental value	Before adjustment	5	50	200	500	Convectional
k-infinity	1.28652	1.27703	1.28655	1.28651	1.28652	1.28653	1.28655
Difference	–	−9.5×10^−3	3×10^−5	−1×10^−5	0	1×10^−5	3×10^−5

Note: Difference is defined by (calculation value)–(virtual experimental value). Each of 5, 50, 200, and 500 means the number of random samples in the present method.

Figure 1. Variations of cross sections by the conventional method (normalized by standard deviation of cross section) and sensitivity coefficients.

Figure 2. Differences of adjusted cross sections of the proposed method from those of the conventional method for 5, 50, and 500 samples. The vertical axis is normalized by the standard deviation of cross section.

Figure 3. The average and maximum differences of adjusted cross sections obtained by the present and the conventional methods for various numbers of samples. The vertical axis is normalized by the standard deviation of cross section.

Figure 4. Relationship between differences of adjusted cross sections by the present and the conventional methods and sensitivity coefficients. The vertical axis is normalized by the standard deviation of cross section.