ML20028C338
| ML20028C338 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 12/30/1982 |
| From: | Adensam E Office of Nuclear Reactor Regulation |
| To: | Tucker H DUKE POWER CO. |
| References | |
| NUDOCS 8301070360 | |
| Download: ML20028C338 (5) | |
Text
I gy 3g DISTRIBUTION Docket Nos:
50-413/414 NRC PDR PRC System LB #4 R/F EAdensam Docket Hos:
50-413 KJabbour and 50-414 MDuncan DEisenhut/RPurple INovak tRosa Mr. H. B. Tucker, Vice President TDunning fluclear Production Department
~
Duke Power Company 422 South Church Street Charlotte,florth Carolina 28242
Dear Mr. Tucker:
Subject:
Request for Additional Information - Catawba fluclear Station In the performance of the Catawba Station licensing review, the llRC staff has identified the need for additional information in the Instru-mentation and Control Systems area (Enclosure). This request for additional infonnation pertains to concerns that were previously dis-cussed with your staff at several meetings. We request that you provide the information herein requested no later than January 17, 1983.
If you require any clarification of this matter, please contact the pro-ject manager, Kahtan Jabbour, at (301) 492-7821.
The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.
Sincerely,
//
/ Elinor G. Adensam, Chief Licensing Branch flo. 4 Division of Licensing
Enclosure:
As stated cc: See next page 8301070360 821230 PDR ADOCK 05000413 A
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CATAWBA Mr. H. B. Tucker, Vice President Nuclear Production Dept.
Duke Power Company 422 South Church Street Charlotte, North Carolina 28242 e
cc: William L. Porter Esq.
North Carolina Electric Membership Duke Power Company Corp.
P.O. Box 33189 3333 North Boulevard Charlotte, North Carolina 28242 P.O. Box 27306 Raleigh, North Carolina 27611 J. Michael McGarry, III, Esq.
Debevoise & Libenian Saluda River Electric Cooperative, 1200 Seventeenth Street, N.W.
Inc.
Washington, D. C.
20036 207 Sherwood Drive Laurens, South Carolina 29360 North Carolina MPA-1 P.O. Box 95162 Mr. Peter K. VanDoorn Raleigh, North Carolina 27625 Route 2, Box 179N York, South Carolina 29745 Mr. F. J. Twogood Power Systems Division James P. O'Reilly, Regional Administrator Westinghouse Electric Corp.
U.S. Nuclear Regulatory Commission, P.O. Box 355 Region II Pittsburgh, Pennsylvania 15230 101 Marietta Street, Suite 3100 Atlanta, Georgia' 30303 Mr. J. C. Plunkett, Jr.
NUS Corporation Robert Guild, Esq.
2536 Countryside Boulevard P.O. Box 12097 Clearwater, Florida 33515 Charleston, South Carolina 29412 Mr. Jesse L. Riley, President Palmetto Alliance Carolina Environmental Study Group 2135 1/2 Devine Street.
l 854 Henley Place Columbia, South Carolina 29205 Charlotte, North Carolina 28208 Richard P. Wilson, Esq.
Assistant Attorney General S.C. Attorney General's Office P.O. Box 11549 Columbia, South Carolina 29211 Mr. Henry Presler, Chairman Charlotte s Pecklenburg Environmental Coalition 943 Henly Place i
Charlotte, North Carolina 28207 l
ENCLOSURE
['
REQUEST FOR ADDTTIONAL fNFORf4ATION INSTRUMENTATION AND CONTROL CONCERNS FOR CATAWBA 1.
In our latest discussions with the applicant, it was indicated that the mini-flow valves (ND 25A and 59B) for the RHR pumps have uniquely configured control' switches. Both switches have a momentary "0 PEN" position which, when pressed, open the corresponding valve.
Thh switch 6s, wh'en in their maintained "AUT0" positions, permit the individual valves to close on either a high pump dis-l l
charge flow or a RHR pump not running signal from their associated pumps, i
Additionally, in the "AUT0" position, the individual valves open on a low t
pump discharge flow and pump running signal from their associated pumps.
The unique feature of these switches is the release bar which, when pressed, takes the switch out of "AUT0" but does not place the switch in "0 PEN".
In this I
neutral position, the miniflow valves cannot change positions until their i
switch is placed either in the "AUT0" or "0 PEN" position.
CONCERN:
The staff is concerned that if the control switches are left in the neutral-position, the miniflow valves will not respond to an automatic open signal l
required for RHR pump protection.
This would appear to be a means by which l
both pumps could be damaged on a SI, if the minimum flow protection is not in the automatic mode.
Provide a discussion on how this issue will be resolved for Catawba.
l l
l l
2.
In recent discussions with the applicant, it was indicated that if the safety injection reset timer or the diesel sequencer fail, manual reset of the sequen-l cer may be prevented or the sequence may not be completed. Under these conditions 1
L
the operator is prevented from possibly manually initiating ESF loads or manually tripping ESF loads unles's he removes power from the sequencer in order to regain manual control or takes action to control individual loads at the switchgear.
CONCERN:
i
?
The staff is concerned that under accident conditions, as well as inadvertent initiation of load sequence programs, the inability of the operator to exercise manual control could lead to consequential damage of safety related equipment.
or prevent initiation of protection systems. As an example, the RHR pumps are protected by miniflow bypass valves which open following a pump start.
If one of these valves fails to open, the operator cannot turn the associated pump off in the event of a sequencer failure without opening breakers or re-moving fuses.
Similarly, the same situation can occur for the NSW pumps which are protected from loss of suction by transfer of intak'e from Lake Wylie to the-SNSWP. While it.is recognized that conditions which could lead to equip-ment damage would require more than a single failure, the types of multiple failures required are not limited to those associated with independent, redun-dant trains of protection equipment.
Thus, it is concluded that' the fault tolerance of the system design and specifically the potential for the operator to be incapable of exercising manual control introduces a safety significant issue.
Therefore,' provide your rationale that the design is acceptable in light of these concerns and/or any specific actions which will be taken to address these concerns.
l 2
3.
One of our previous concerns pertained to the loss of both trains of RHR due to a single instrument bus failure.
In our past discussions, the applicant has stated that the operator is informed that he has lost RHR by low flow alanns, that there is enough time to manually re-establish RHR, and that the operator knows what action to take under these circum-I stances. Additionally, miniflow valves are provided to prevent pump damage.
CONCERN:
The staff is still concerned that the loss of both trains of RHR during decay heat removal is a safety significant issue.
Therefore, a written response should be provided to document the applicant's position that this is not a safety problem, to discuss the importance of time in re-establishing RHR, and to discuss what (training, procedures, etc.)
specifically tells the operator how to respond to this situation.
4.
Logic diagrams for the auxil.iary feedwater pump suction alignment to the NSW system are shown in FSAR Figures 7.4.1.1 and 7.4.1.2.
The logic is complex, containing multiple coincidence logic and several time delays.
CONCERN:
The staff is concerned about the testability of the alignment logic during power operation.
Provide a discussion describing how this circuitry will be tested at power.
1,
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