Appendix A3: 235 U-Fueled and Pb-Zoned ADS Core
283
(a) Fuel assembly “F”
Poly. moderator (p)
(10”)
+
Poly. reflector (PE)
(1/2” 17 + 1/4”)
(8.75”)
Unit cell
(1/4”)
1/8”p
(1/8”)
1/16” EU 2
(1/8”)
Al plate
(20.00 mm)
2”Gr
(2”)
2”Gr + Void (1.713”)
60 times
(15”)
Reflector 21.537”
(Lower)
Fuel 15”
(Unit cell 60 times)
Reflector 23.463”
(Upper)
Poly. moderator (p)
(10”)
+
Poly. reflector (PE)
(1/2” 19 + 1/4”)
(9.75”)
Polyethylene
(10”p+1/2”PE 17
+1/4”PE)
(18.75”)
10 times
(2.5”)
1/8”p (1/8”)
1/16”EU 2
(1/8”)
20 mm Al plate
2”Gr
(2”)
2”Gr + Void (1.713”)
Reflector 21.537”
(Lower)
Fuel 15”
(Unit cell 60 times)
Reflector 23.463”
(Upper)
1/16”EU 2
(1/8”)
1/8”Pb
(1/8”)
40 times
(10”)
10 times
(2.5”)
1/16”EU 2
(1/8”)
1/8”p (1/8”)
Polyethylene
(10”p+1/2”PE 19
+1/4PE)
(19.75”)
(b) Fuel assembly “f”
(c) Polyethylene moderator “p”
(d) Polyethylene reflector
Polyethylene moderator (p)
(10”p 5 + 1/2”PE 8)
(54”)
2” Gr
(2”)
2” Gr
(2”)
Polyethylene reflector (PE)
(19”PE 2 + 1/2”PE 33)
(54”)
2” Gr
(2”)
2” Gr
(2”)
Fig. A3.3 Fall sideway view of fuel and polyethylene rods shown in Figs. A3.1, A3.2 (Ref. [1])