182
C. H. Pyeon
(a) Case 1
(b) Case 2
(c) Case 3
(d) Case 4
10 11 12 13
14 15 16
17 18 19 20
H
p
p
p
p
p
p
p
p
p
p
p
I
p
p
p
p
p
p
p
p
p
p
p
J
p
p
p
p
p
p
p
p
p
p
p
K
p
p
F
F
F
F
F
p
p
L
p
p
p
F
F
f
F
F
p
p
p
M
p
p
p
F
b
b
b
F
p
p
p
O
p
p
p
F
F
f
F
F
p
p
p
Q
p
p
F
F
F
F
F
p
p
R
p
p
p
F
F
F
F
F
p
p
p
T
p
p
F
4 0 1 4 4 0
F
p
p
U
p
p
p
p
p
p
p
p
p
p
p
V
p
p
p
p
p
p
p
p
p
p
p
W
p
p
p
p
p
p
p
p
p
p
p
b
Test fuel (1/8"Pb40p20EUEU or 1/8"Bi40p20EUEU)
C2
S4
C3
S5
C1
S6
10 11 12 13
14 15 16
17 18 19 20
H
p
p
p
p
p
p
p
p
p
p
p
I
p
p
p
p
p
p
p
p
p
p
p
J
p
p
p
p
p
p
p
p
p
p
p
K
p
p
F
F
F
F
F
p
p
L
p
p
p
F
F
b
F
F
p
p
p
M
p
p
p
F
f
b
f
F
p
p
p
O
p
p
p
F
F
b
F
F
p
p
p
Q
p
p
F
F
F
F
F
p
p
R
p
p
p
F
F
F
F
F
p
p
p
T
p
p
F
40 14 40
F
p
p
U
p
p
p
p
p
p
p
p
p
p
p
V
p
p
p
p
p
p
p
p
p
p
p
W
p
p
p
p
p
p
p
p
p
p
p
C2
S4
C3
S5
C1
S6
10 11 12 13
14 15 16
17 18 19 20
H
p
p
p
p
p
p
p
p
p
p
p
I
p
p
p
p
p
p
p
p
p
p
p
J
p
p
p
p
p
p
p
p
p
p
p
K
p
p
F
F
F
F
F
p
p
L
p
p
p
F
F
b
F
F
p
p
p
M
p
p
p
F
b
f
b
F
p
p
p
O
p
p
p
F
F
b
F
F
p
p
p
Q
p
p
F
F
F
F
F
p
p
R
p
p
p
F
F
F
F
F
p
p
p
T
p
p
F
4 0 1 4 4 0
F
p
p
U
p
p
p
p
p
p
p
p
p
p
p
V
p
p
p
p
p
p
p
p
p
p
p
W
p
p
p
p
p
p
p
p
p
p
p
C2
S4
C3
S5
C1
S6
10 11 12 13
14 15 16
17 18 19 20
H
p
p
p
p
p
p
p
p
p
p
p
I
p
p
p
p
p
p
p
p
p
p
p
J
p
p
p
p
p
p
p
p
p
p
p
K
p
p
F
F
F
F
F
p
p
L
p
p
p
F
F
b
F
F
p
p
p
M
p
p
p
F
b
b
b
F
p
p
p
O
p
p
p
F
F
b
F
F
p
p
p
Q
p
p
F
F
F
F
F
p
p
R
p
p
p
F
F
F
F
F
p
p
p
T
p
p
F
40 14 40
F
p
p
U
p
p
p
p
p
p
p
p
p
p
p
V
p
p
p
p
p
p
p
p
p
p
p
W
p
p
p
p
p
p
p
p
p
p
p
C2
S4
C3
S5
C1
S6
Fig. 7.5 Patterns of sample reactivity worth experiments (Refs. [1–3])
excess reactivity was obtained with the combined use of both the reactivity worth of
each control rod evaluated by the rod drop method and its integral calibration curve
obtained by the positive period method.
The estimated experimental error of excess reactivity measurement was less than
5%. In the Al reference and Pb or Bi test cores, the effective delayed neutron fraction
(β eff ) was acquired by MCNP6.1 [5] (2,000 active cycles of 50,000 histories; 2
pcm statistical error) with JENDL-4.0, [6] and the values of 798 and 801 pcm were
applied to these two cores, respectively, when the excess reactivity in dollar units
was converted into that in pcm units.