7 Neutronics of Lead and Bismuth
179
(a) Normal fuel rod “F” (1/8”p60EUEU) in Fig. 7.1
(b) “40” partial fuel rod (1/8”p40EUEU) in Fig. 7.1
(c) “14” partial fuel rod (1/8”p14EUEU) in Fig. 7.1
Poly. moderator (p)
(10.0”p 2 = 20”)
Unit cell
(1/4”)
1/8”p
(1/8”)
1/16” EU 2
(1/8”)
Al plate
(20.00 mm)
1/8“p 4 (1/2”)
1/8”p 16 (2”) +
Void (1.71”)
60 times
(15”)
Reflector (21.29”)
(Lower)
Fuel (15”)
(Unit cell 60 times)
Reflector (23.71”)
(Upper)
Poly. moderator (p)
(10.0”p 2 = 20”)
Polyethylene
(10.0”p 2)
(20”)
20 mm Al plate
+ 1/8”p 4 (1/2”)
Al cell (10 cells;
(1/16”Al 2+1/8”p) 10 = 2.5”)
1/8”p 16 (2”) +
Void (1.71”)
40 times
(10”)
Reflector (23.79”)
(Lower)
Fuel (10”)
(Unit cell 40 times)
Reflector (26.21”)
(Upper)
Unit cell
(1/4”)
1/16” EU 2
(1/8”)
1/8”p
(1/8”)
Al cell
10
times
Al cell
10
times
Polyethylene
(10.0”p 2)
(20”)
Polyethylene
(10.0”p 2)
(20”)
20 mm Al plate
+ 1/8”p 4 (1/2”)
Al cell (10 cells;
(1/16”Al 2+1/8”p)*23 = 5.75”)
1/8”p 16 (2”) +
Void (1.71”)
14 times
(3.5”)
Reflector (27.04”)
(Lower)
Fuel (3.5”)
(Unit cell 14 times)
Reflector (29.46”)
(Upper)
Unit cell
(1/4”)
1/16” EU 2
(1/8”)
1/8”p
(1/8”)
Al cell
23
times
Al cell
23
times
Polyethylene
(10.0”p 2)
(20”)
10 times
(2.5”)
1/8”p
(1/8”)
1/16” EU 2
(1/8”)
20 mm Al plate
1/8”p 4
(1/2”)
Reflector (21.29”)
(Lower)
Fuel (15”)
(Unit cell 60 times)
Reflector (23.71”)
(Upper)
1/16” EU 2
(1/8”)
1/16” Al 2
(1/8”)
40 times
(10”)
10 times
(2.5”)
1/16” EU 2
(1/8”)
1/8”p
(1/8”)
Polyethylene
(10.0”p 2)
(20”)
Polyethylene
(10.0”p 2)
(20”)
(d) Reference fuel rod “f” containing Al plates (1/8”Al40p20EUEU) in Fig. 7.1
Fig. 7.2 Schematic drawing of fuel assemblies in the KUCA A-core (Fig. 7.1) (Ref. [1])