ULNRC-03277, Forwards Response to NRC GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves
| ML20093K975 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/10/1995 |
| From: | Schnell D UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-95-07, GL-95-7, ULNRC-03277, ULNRC-3277, NUDOCS 9510250128 | |
| Download: ML20093K975 (5) | |
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1901 Chouteau Avenue Post Ottice Box 149 St. Louis. Mssouri 63166
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314-554-2650 3
DonaldF. Schnell N
senior vice eresieent C
nuseer h'3 October 10, 1995 U.S. Nuclear Regulatory Commission i
ATTN: Document Control Desk Mail Station F1-137 Washington, DC 20555-0001 f
Gentlemen:
ULNRC-03277-CALLAWAY PLANT DOCKET NUMBER 50-483 PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES
Reference:
NRC GENERIC LETTER 95-07 dated August 17, 1995 The attachment to this letter contains Union Electric's response to NRC Generic Letter 95-07.
If you have any questions concerning this information, please contact us.
Ve truly yours,
/
onald F.
Sc nell WEK/jdg Attachment (2 pages)
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9510250128 951010 y
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STATE OF MISSOURI
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Donald F.
Schnell, of lawful age, being first duly sworn upon oath says that he is Senior Vice President-Nuclear and an officer of Union Electric Company; that he has read the foregoing document and knows the content thereof; that he has executed the same for and on behalf of said company with full power and authority to do'so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.
By Donald F.
Schnell Senior Vice President Nuclear I
1 SUBSC IBED and sworn to before me this d
day of ffjt/L4) 1995.
<Ab/A A-.
hU BARBARk J. PFME "
NOTARY PUBLIC-STATE OF MISSOURI My GOMMISSION EXPIRES APRll 22,199Z j
ST, LOUIS COUNTX i
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cc:
T. A.
Baxter, Esq.
Shaw, Pittman, Potts & Trowbridge-2300 N. Street, N.W.
Washington, D.C.
20037 i
M. H. Fletcher Professional Nuclear Consulting, Inc.
'i 19041 Raines Drive Derwood, MD 20855-2432 i
L. Joe Callan Regional Administrator U.S. Nuclear Regulatory Commission Region IV.
611 Ryan Plaza Drive Suite 400 l
Arlington, TX 76011-8064 l
Senior Resident Inspector Callaway Resident Office U.S.
Regulatory Commission RR#1 Steedman, MO 65077 r
L. R. Wharton (2)
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission 1 White Flint, North, Mail Stop 13E21 l
11555 Rockville Pike-l Rockville, MD 20852-2738 Manager, Electric Department Missouri Public Service Commission P.O.
Box 360 l
Jefferson City, MO 65102 l
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UNION ELECTRIC RESPONSE TO NRC GENERIC LETTER 95-07 PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES Introduction j
NRC Generic Letter 95-07, dated August 17, 1995, requires actions be taken by utilities in regard to the susceptibility of power-operated gate valves to pressure locking and thermal binding.
The information contained herein addresses, for Callaway Plant, the 60 day response to Generic Letter 95-07.
Union Electric Assessment Union Electric will implement the actions requested in Generic Letter 95-07.
Within 90 days of the issuance of Generic Letter 95-07 (November 15, 1995), Union Electric will perform a screening evaluation to identify any safety-related power-operated gate valves which may be potentially susceptible to thermal binding or pressure locking.
If any
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valves are identified as susceptible, the basis for operability and continued plant operation will be documented.
Within 180 days of the issuance of generic Letter 95-07 (February 13, 1996), Union Electric will evaluate the operational configurations of valves identified as susceptible to pressure locking or thermal binding.
Additional analyses will be performed as appropriate, and corrective actions will be implemented to ensure all valves identified as susceptible are capable of performing their intended safety functions.
A summary description will be provided for the following:
1.
The susceptibility evaluation and any further analyses performed including the criteria for determining that valves are or are not susceptible to pressure locking or thermal binding.
2.
The results of the susceptibility evaluation and any further analyses, including a liuting of the susceptible valves.
3.
The corrective actions for any valves identified as susceptible to pressure locking or thermal binding.
Union Electric has been aware of the potential for gate valves to pressure lock or thermally bind as early as December 1984 when SOER 84-07 was issued by INPO.
Starting in September 1985, Union Electric has documented reviews of gate valves in service at the Callaway Plant for pressure locking and/or thermal binding in response to SOER 84-07,
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'SER'8-88, NRC Notice 92-26, NUREG-1275 Volume'9, NRC Notices 95-14 & 95-18, and NRC Temporary Instruction 2515/109.
These reviews have been a continuous process, factoring in additional information as.it has become available.
The reviews have not identified any valves at Callaway that, when required to perform their safety function, are susceptible to' pressure locking or thermal binding.
As new issues emerged, our ongoing reviews have included such items as valve design and setup, testing conditions, and procedural sequence of operation for each valve being evaluated.
These exising reviews will be enhanced as appropriate to ensure all requirements of Generic Letter 95-07 are met.
Industry Activities Union Electric is aware of the various industry efforts related to this issue.
We are involved in the Westinghouse Owners Group project which will provide a standardized methodology to identify and address valves susceptible to pressure locking and thermal binding.
We are also monitoring testing activities used by individual utilities.
l The data from these efforts will be evaluated for its applicability to the Callaway Plant and factored into our evaluations as the results become available.
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