ML20030B134
| ML20030B134 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 08/04/1981 |
| From: | Colbert W DETROIT EDISON CO. |
| To: | Kintner L Office of Nuclear Reactor Regulation |
| References | |
| EF2-54213, NUDOCS 8108060135 | |
| Download: ML20030B134 (6) | |
Text
_
D Deholt Edison E##in==
August 4, 1981 EF2 - 54213 Mr. L. L. Kintner
,,1 U. S. Nuclear Regulatory Ccmnission
/h /
Q*\\
h1JLi Division of Project Management w
Office of Nuclear Reactor Regulation 67
't Washington, D. C.
20555
- I'U 3 gggj p O
q W.5. ein e'*
Dear Mr. Kintner 9-6 l
Reference:
Enrico Fermi Atomic Power Plant, Unit
(,,"
NRC Docket No. 50-341 l
Subject:
Reheater Steam Flow The attachment to this letter summarizes our understanding of the cal-culations we agreed to perform at the informal July 30, 1981 meeting on reheater bypass flow. As agreed, we plan to submit the results to you by September 1, 1981.
Sincerely, Yf$
W. F. Colbert Technical Director Enrico Fermi 2 hTC/MKD/dk Attachment Bool s
/ /
hD DOC OO 4
l Proposed Scope of Work to Complete Rcheater Bypass Flow Analysis A series of computer runs involving RETRAN models will be performed to help demonstrate the adequacy of bypass flow through the reh*ater during certain overpressure transients in Fermi 2.
These calculations are l
conveniently separated into three groups.
Uncertainties in the conditions on the shell side of the o
reheater will be resolved by performing a calculation that conservatively ramps the heat transfer from the metal tubes to the shell side to zero in 0.2 seconds. The remainder of the model will be that pictured as "RETRAN VERSION 2" in Figure 1.
To resolve staff questions concerning the potential for o
.i i
pressure oscillations adversely interacting with reheater 4
l flow, additional runs with the previous model will be made using more nodes in the main steam line and in the line between the manifold and reheater. A composite run with appropriate nodalization and incorporating the 0.2 see shell side heat transfer decay will be used to confirm that the bypass flow through the reheater during a turbine q
trip is adequately represented by the FSAR curve duplicated I
h=re as Figure 2.
f The final staff concern noted that ODYN lumps the reheater o
flow and flow through the turbine stop valve into a single equivalent junction flow (as shown in Figure 2).
A more i
realistic case would place the reheater junction and stop i
valves at different locations and would use appropriate individual flows (stop valve ramped to zero in 0.2 seconds; i
reheater maintained at 10% for 2 seconds followed by a ramp to zero). These two flow configurations properly nodalized t
J
,,~...-=,,,,,-,-.,,---,,_=-c.m.-,
,-.,,m~,,7,...-,_-..w.-4,-
. -.,,---.-y---,---,,,.m-.w.,
..ry-,,,,--,
3.-
.,rv.,m-e..-
will each be incorporated into a standard NSSS RETRAN turbine trip model (Figure 3) to form two different models for comparison runs.
It is expected that the models will produce comparable results.
EMP:br 8/4/81
TT En E n Tr.n 3Y:Tdn ricotts
~
E 5a* <- +%(Al f/GURE /
.__s OAM l #Us f.it.is Q6 QS (c.....
__f ___
A j
M
' u, pt t Pn (x) a g
g g
%^
\\if-- HTR L
',^l% uie 5 J.//n 7,,,,
4
-)lem A
]
$4:4 I
g g
PLI Vce s,w egs l
m,,9 n,3,)
cy)
'> c,y)
W tiepta t 4 -nan f6s6/
SC+. TAW P-facusar R - P ti>5 Q - iker bsn t
+-
5
<w H ttefe Qadu ' - u.
06 l'eter b
f-4 a.W
' e U, R
g 4
lsul T*GE
}g% g:3 g, lost,:;
Og Mas" lF6-in y
l j'yj g
[nt:c.
Livs6 l
4
-[
d '*
~
l
[ys4 e
1 l
c' s
t I
,, l V' R s. 1
'" c.(0 H,d n
s
'--------+
4.e1 RETRA!/ Vru u !
wRigt4Tf4 4
$C44 T Aalt f.<
. - 6 1 '- ** M
+
s>
Uns(M v f 0.iA
'( G A.'x U4,(M) ld 4L I
l.:ik 1.
UJ,(M)
If.e i =
U t(d "8 'M h h.(4 L
h HTR f UC#
Liut Tatt
- T I
b.c fra l,-c n' His 6 l s-t T'
u s j
ln a l F6.a l
T44
+
mg n
.)
_)
u l i -
8 l
Rent ter
'+ GA) d G.(J)[3#-
f4N f
RETRW VER5 lou
< sr.o
. s,.a g
4 e f.
- -,, < r.mpeg p u - sp - q v-, -
3 c?
g r
-w
- 7.,,
- y w.-
-+-wn.,
w
.-,,c-7
,wr enn r+ ; ~ v n:
B EF-2-FSAR i
1A i
l i
I i
r 3<
E E
e E
i; 4=
D 5
dzg
, -)
=
~
TURBINE STOP V ALVE CLOSURE REHE ATER F LOW Jos -
I I
I v
I J
1 2
3 4
5 TIME (s)
FIGURE 2 ENRICO FERMI ATOMIC POWER PLANT l
UNIT 2 FINAL SAFETY ANALYSIS PEPORT FIGURE 15B.0-3 MAIN STE AM FLOW AFTER TURBINE TRIP, ALLOWING NO FLOW THROUGH BYPASS VALVES AMENDMENT 22 - APRIL 1979 15B.0-21
THREE GROUPS SAFETY /PELIEF VALVES STEAM DCME o
a a
V 10 J30 J31 J32
+
V 18 p
i Jil SEPARATION ZONE V21 MIXTURE V9 J20 LEVEL P
JIO JIOl 1r lJ9 f
V22 ocwn UPPER PLENUM ccts J29 FEED WATER COMLR COyLk Jz]
d-V ll Vil h
a g,f i t
J23 I
V6
'J6
[gg g
)
r J 22 -+
CORE h
J 16 v23 VS
.J5 l1
)
r l
CCRE y
V7 STC" T
V4 J4 T
8 D
V " L'. E D
CORE p
a p
J28 I
U V3 J3 P
U A
V S
l S
w CORE 4
S P
C STE*v C
r V2 h-H J i 9 *-
-+ J 13 H
TO CORE 4
A vg A
TURD NF A
r Vl7 R
IJi IJ7 R
G G
U E
E 1r J24 J'
S VOL1 S
U U
C C
VIG y;3 T
T LOWER PLENUY.
I i
O O
N N
VIS VI2
\\
J21 J20 JI4 JIS
+-V20*
+Vl9 -+
RECIRC RECIRC PUMP PUMP flGURE 3
RETRAN DYNAMIC MODEL FOR FERMI-2 TURBINE TRIP PRESSURE TRANS:ENT STUDIES D
_i
_