ML19329A579
| ML19329A579 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/02/1971 |
| From: | Knighton G US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001070576 | |
| Download: ML19329A579 (1) | |
Text
m, fr
~
gtSt
'l UNITED STATES 3 f.L ATOMIC ENERGY COMMISSION
[d'I e
WASHINGTON. D.C.
20545 July 12, 1971 R. C. DeYoung, Assistant Director for Pressurized Water ;teactors, DRL TilRU: D. R. Muller, Chief, PWR Projects Branch #1, DRL TWO PUMP OPERATION OF TWO LOOP-4 PUMP REACTORS As part of OL Review for Calvert Cliffs the operation of the reactor coolant loop with 4, 3, and 2 reactor coolant pumps was evaluated.
One step of the review was to compare to other plants, and the second step was to perform in-house simplified calculations.
The results of these steps are as foolows:
I I
i PLANT Reactor Flow Rate (7) of 4 pump 4 pumps 3 pumps
- l-each loop 2-one loop 1 pump Calvert Cliffs (BG6E 100 73 50 47 Calvert Cliffs (DRL) 100 72.5 45.6 27.6 18.5 Palisades (CPC) 100 71 46 46 Oconee (DPC) 100 74 49 42.8 21
\\
i Note that a significant difference was found between the manufacturers and DRL calculated flow with operation of 2 pumps in one loop.
supports the in-house calculated results.
Our judgement i
The in-house calculations used the basic flow resistance as symbolized in Fig. 1.
i i
I 1
N.
i
.i
'I
._w
..w,
.n.
i 6
i y
r I'IG.
._1_
_Calvert Cliffs Plant 2 pumps Operating In One Loop Rsre t Rr - Reactor Rsg - Steam Ger.erator 4
Rp - Pump P - Operating Iump t
Using Combustion engineering Flow vs liaad curve fot the dead pumps, and pressure drop approximations tlrough the reactorback-flow t and steam generators based on FSAR data, the flow through the reactor was determined as 27.6% of 4 pump flow rate.
i In an effort to determine the cause of the dif ferer ce in calculations, FIG. I was revised to FIG. 2 configuration.
This tepresents one possible error in the manufacturers codes.
3 FIG. 2
+
r
-Q'y**,'
--C
=
1
'A Rez Solving this configuration we find the reactor flow at 47.8 compared to the manufacturers value of 47%.
This configuration is physically impossible to achieve.
Since manufacturers find flows almost equal for either two pump operation, their Tech 1
Specs do not differentiate between the two.
O Since our calculations show the one condition flow much greater than the other, it is suggested that the Project Leaders be aware i
of this apparent, anomaly.
situation to their satisfaction.They may want to clarify their particular Careful flow testing in the field will provide conclusive answers required for rea tor safety.
l
}
s G. W.
nigh Project Leader
,j PWR froject raach #1 A
Division cf Reactor Licensing 4
I l
~... -
.