ML20085E053
| ML20085E053 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/11/1991 |
| From: | Schnell D UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| ULNRC-2494, NUDOCS 9110180012 | |
| Download: ML20085E053 (4) | |
Text
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1991 C*no L:A,tn l n t U"wr !
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3'sW 7' Donald L Schocli 7
g g,g, October 11, 1991
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'!3 U.S. Nuclear Regulatory Conunission Doc-nt Control Desh Wat ton, DC 20555 ULNRC-2494 Gentlemen:
ADDITIONAL RESPONSE TO:
INSPECTION REPORT NOS. 50-483/?l013 AND 91014 CALLAWAY PLANT f
Tn reviewing our August 30, 1991 response to the notice of violation contained in the subject inspection reports, we find that concerns expressed in Mr.
A. B.
Davis' transmittal letter dated August 6, 1991 were not fully addressed.
The following is submitted as a supplement to our proposed corrective actions:
In our investigations following detection of unplanned events or circumstances, our first consideration is a prompt determination of the potential impact on the ability of equipment important to safety to perform its intended safety. function.
In some cases, our initial evaluation relics heavily on the engineering judgment and experience of our staff.
This initiul evaluation of safety impact is factored into our assessment of compliance with the provisions of our facility license and Technical Specifications.
It is also used as an input to determine the timeline for reaching a final conclusion on the issue.
In the absence of confirmed or conclusive information, our judgment in determining whether an immediate declaration of inoperability and entry into the associated Technical Specifications action statement is largely based on the initial determination of functional safety impact.
It must be recognized that cach instance is unique and that situations may arise in which differing conclusions may be reached from the same available information.
This is especially true when actions are reassessed after an event.
In the present case, we have thoroughly reviewed and discussed the event timeline and decision-making process with all management personnel involved.
While we continue to believe that our approach 9110180012 911011 4 g 'i PDR ADOCK 05000483 1
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ULNRC-2494 Page 2 October 11, 1991 was appropriato, this event has heightened our sensitivity to t he need for prompt saf ety assescments and techt 4. cal specification compliance determinations.
Concerning the failure of a double verification checkoff to properly establish the position of a safety-related valvo, our response to the NOV addresses action to provent recurrence of this type failure.
We believe the unique configuration of the locking device and the infrequent cycling of ECCS throttic valves contributed significantly to our failure to properly verify position.
The procedural controls and other actions described in our response will assure that double verification prevents recurrence.
Our independent
'r rification process has been effective as evidenced by numerous audits of valvo positioning and operations management overview of plant conditions, but these actions should further strengthen our program.
If you have any questions regarding this additional response, or if further clarification is required, please let me know.
Very truly yours
,m scud \\ i nd '
Donald F.
Schnell DFS/bjp cc:
A. B.
Davis - Regional Administrator, USHRC Region III R. L. Imgue - Chief, Reactor Projects Section 3C, USNRC, Region III M. D. Lynch - USNRC Licensing Project Manager (2 copics)
Manager - Electrical Department, Missouri Public Service Commission B. L. bartlett - USNRC Senior Resident Inspector Shaw, Pt.ttman, Potts & Trowbridge
11Ll4RC-2 494 Pago 3 l
October 11, 1991 bcci A160.0761 (QA Record)
(CA-460)
A170.0103 (91013)
(CA-460)
A170.0103 (91013 - File / Logging) (QAQS CA-460)
Nuclear Date File (S.
L. Dalc)
(470)
E210.0001 D. F. Schnell (Chrono)
G.
L. Randolph J.V.
Laux Licensing and Fuels (A. C. Passwater/D. E.
Shafer) (470)
T. P.
Sharkey NSRB (S. L. Dale)
(470)
P. M. Barrett (100)
IL K. Chernoff (WC110C)
C. E.
Slizewski C.
S.
Petzel D. W.
Notorer W.
E.
Laccfleld
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g-E ii STATE OF MISSOURI-)
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Donald F. Schnell, of lawful age, being first duly sworn uoon oath says thy is Senior Vice President-Nuclear and an of ficcr of Union Ele.:r z '- Companf; that he has read tac foregoing document and
'<s the content thereof; that he has executed the same' for a..r*
on behalf of said company with full power and authority to i so; and that the facts therein stated are true - and correct t =
Lhe best of his knowledge, information and belief.
By hui d d
Donald F.
Schnell Senior /ico President Nuclear
. SUBSCRIBED and sworn to before me this / bat-* [Il_ day of
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