ML19290E610
| ML19290E610 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 03/06/1980 |
| From: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| TASK-06-07.C1, TASK-6-7.C1, TASK-RR NUDOCS 8003140283 | |
| Download: ML19290E610 (4) | |
Text
'
CONNECTICUT YANKEE ATOMIC POWER COMPANY March 6, 1980 Docket No. 50-213 Director of Huclear Reactor Regulation Attn:
Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Gentlemen:
Haddam Neck Plant SEP Topic VI-7.C.1 Appendix K - Electrical Instrumentation and Control (EIC) Re-reviews In recent verbal requests, Connecticut Yankee Atomic Power Company (CYAPCO) has been asked to provide information regarding possible breaker confleurations which could parallel the two emergency buses at the Haddam Neck Plant. A swanary of the subject connection paths and a discussion of the interlocks /
procedures is provided. Also, a sketch of the auxiliary bus system is attached.
Case 1 This case involves the possible connection of Bus 8 to Bus 9 via the following breakers:
8T2, 2T8, 2T3, 3T9, and 9T3 (Note:
2T3 is normally open).
Resnonse This connection is possible if the offsite supply to either Bus 1-2 or 1-3 is lost, circuit breaker 2T3 will close to supply both divisions from the remaining offsite source.
This allows continued operation c all normally connected loads in each division from one source in exact'_y the same manner as for stations designed with one normal and a seconi (emergency) offsite source.
If the onsite sources are called upon to operate while this paralleling connection is in operation, breakers 2T8, 8T2, 3T9, and 9T3 will open to separate the redundant safety divisions.
An additional interlock on breaker 2T3 will cause it to trip if b.reaker 389T399 is open and breakers 3891 and 3991 are closed. This prevents 2T3 from becoming part of the transmission path between the two 115 KV transmission lines. There are no other constraints on the operation of this breaker.
p 80031 ao 233 Case 2 Is it possible to connect Buses 8 and 9 through the following combination of closed circuit breakers: h850, h851, 5T6, h961, and h960?
Response
Circuit breaker ST6 has been permanently removed from its cubicle in accordance with Haddra Neck Plants Normal Operating Procedure No. 2.16-1, "AC and DC Distribution Normal Configuration".
Therefore, this is not a possible means for paralleling the two divisions.
Case 3 The breakers in Compartments 8A on Bus 1-5 and 12B on Bus 1-6 are alternate supplies for containment air recirculation fan F-17-3 Is it possible for these breakers to parallel divisions A and B?
Response
These two breakers are key interlocked so that only one breaker can supply the fan at any time.
No possibility exists for paralleling of the two divisions.
Case h The breakers in Compartments 8B on Bus 1-5 and llA on Bus 1-6 are alternate supplies for containment air recirculation fan F-lT-2.
Is it possible for these breakers to parallel divisions A and B7 Resnonse These two breakers are key interlocked so that only one breaker can supply the fan at any time.
No possibility exists for paralleling of the two divisions.
Case 5 Is it possible to parallel divisions A and B through the tie breaker between motor control centers 5-5 and 5-67 Resnonse This tie breaker is locked closed.
However, a throwover scheme exists on the supply breakers to MCC 5-5 and MCC 5-6.
These are the breakers in Compart-ments 9C of Bus 1-5 and llc of Bus 1-6.
The throvover scheme assures that there is always a supply for these two MCC's while preventing the MCC's from being supp'.ied by both sources at the same time.
Therefore, no divisional parallel is po sible.
Case 6 Are there any interlocks or procedures preventing the paralleling of divisions A and B through the tie breaker between motor control centers 8-5 and 8-67 Resnonse There are no such interlocks or procedures.
Operation of this breaker is strictly manual.
Case 7 Are there any interlocks or procedures preventing the paralleling of Batteries 1-A and 1-B through the tie breaker between the 125 VDC Buses 1 and 2?
Response
There are no such interlocks or procedures.
This breaker would be manually closed when no battery charger is available on either battery.
We trust this information is responsive to your verbal requests.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER CCMPANY A
./
/
/
//
/[(')l l?
W. G. Cotinsil Vice President Attachment
[exurevicor Ymx,gg_
A us a ouv 'Ro< Sv<vr~
L /20&
t772.
A-INE L.IHf
_a817391 ns' KV
%D UGD 3 89 m m 399 mm 369s 3991
.2.73 Bus 1 -Bas I-3 I
ST9 4970 4840 2.T%
66 EG g
I Dinssa pissst.,
M/$ /cv I
973
~
874.
'2ss 8 l
Bus 9 Eeresener l
Engestact I
4960 4g50 494 497 v
475 i
mm mm mm iv mm I
I i
i ogy; 4g51 1961 4971
- POV l
Bss I-y Bas I-5
~ Basi-4
~8vs I-7 pg
)
)
l
)c
)2D gp 9c l
t/
/
.s=r m
s-c, I
I I
I g-e m
e-o I
I l
DivrStoN b bivising 8 i