Environmental Engineering Reference
In-Depth Information
Table 4.1
Design parameters in water cooled reactors
Parameter
Western type
PWR
VVER
(440/1000)
MW
BWR
RBMK
1.
Coolant
Pressurized H
2
O
Pressurized H
2
O
Boiling H
2
O
Boiling H
2
O
2.
Fuel assembly
materials
(pressure
tube materials)
Zr-4, ZIRLO,
DUPLEX, M5,
MDA
,
NDA
,
Inconel, SS
E110, E635
Zry-2,
Zry-4,
Inconel,
SS
E110, E635
(Zr-2.5Nb)
3. Average power
rating, (kW/l)
80-125
83-108
40-57
5
4.
Fast neutron fl ux,
average, n/cm
2.
s
6-9E13
5-E13
4-7E13
1-2E13
5.
Temperature,
°
C
Average coolant
inlet
Average coolant
outlet
Max cladding
O.D.
Steam mass
content, %
279
-
294
267-290
272
-
278
270
313
-
329
298-320
280
-
300
284
320
-
350
335-352
285
-
305
7
-
14
290
14
6.
System pressure,
bar
155
-
158
125-165
70
67
7.
Coolant fl ow, m/s
3
-
6*
3.5-6
2
-
5*
3.7
8.
Coolant chemistry
Oxygen, ppb
Hydrogen (D
2
),
ppm
cc/kg
Boron (as boric
acid), ppm
Li (as LiOH), ppm
K (as KOH), ppm
NH
3
, ppm
NaOH, ppm
<0.05
2
-
4
25
-
50
0
-
2200
0.5
-
3.5
-
<0.1
30
-
60
0
-
1400
0.05
-
0.6
200
-
400
-
-
-
<20
-
-
-
-
5
-
20
6
-
30
0.03
-
0.35
* Variation from lower to upper part of the core and from plant to plant.
Source: A.N.T. International (2011) and
Cox
et al
. (2006).
are either of 9 × 9 or 10 × 10 square confi guration design (Cox
et al
., 2006 ).
The driving force for this trend was to reduce the linear heat generation rate
(LHGR), which resulted in a number of fuel performance benefi ts such as
lower fi ssion gas release (FGR) and increased pellet clad interaction (PCI)
margins. However, to increase utility competitiveness, the LHGRs of 9 × 9
and 10 × 10 FA have successively been increased, and peak LHGRs are
today almost comparable to those of the older 7 × 7 and 8 × 8 designs.
Also for PWRs there has been a trend to greater subdivision of fuel rods,
for example from the Westinghouse 15 × 15 to 17 × 17 design (Cox
et al
.,
2006). However, since PWRs do not have the same fl exibility with core
internals and control rods as BWRs, to accomplish this requires modifi ca-
tion of the reactor internals. There is, however, one exception, namely DC
Search WWH ::
Custom Search