ML20137C268

Responds to GL 95-07, Pressure Locking & Thermal Binding of SR Power Operated Gate Valves

ML20137C268
Person / Time
Site:	Comanche Peak
Issue date:	03/14/1997
From:	Terry C, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-95-07, GL-95-7, TXX-97056, NUDOCS 9703240202
Download: ML20137C268 (3)

Text

. . . . . ._ . . - , - _ . . - --

)

a M" Log # TXX-97056 F9 File # 10035 Ref. # 10CFR50.54(f)

GL 95-07 1UELECTRIC" ,

March 14, 1997 C. Lance Terry ,

Gnap We Presulent U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, D.C. 20555-0001

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) UNITS 1 AND 2 DOCKET NUMBERS 50-445 AND 50-446 RESPONSE TO GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING 0F SAFETY RELATED POWER OPERATED GATE VALVES" REF: 1. Generic Letter 95-07. " Pressure Locking and Thermal Binding of Safety Related Power Operated Gate Valves," dated August 17, 1995

2. TU Electric letter logged TXX-95263 from Mr. C. L. Terry to NRC dated October 16, 1995

3. TV Electric letter logged TXX-95278 froni Mr. C. L. Terry to NRC '

dated November 6, 1995 l

4. TU Electric letter legged TXX-96046 from Mr. C. L. Terry to NRC dated February 13, 1996 1

, On August 17, 1995, the NRC issued Generic Letter 95-07, " Pressure Locking and Thermal Binding of Safety Related Power Operated Gate Valves" (Reference 1).

Pursuant to Section 182a of the Atomic Energy Act of 1954, as amended, and 10 CFR 50.54(f). TU Electric committed to implement the requested actions in Generic  ;

Letter 95-07. Via Reference 3 TU Electric provided clarification to Reference 2.  !

as requested by the NRC.

l In Reference 4 TV Electric stated that. "[I]t is our intention to implement the planned corrective actions for both CPSES Units by the end of the sixth refueling outage for CPSES Unit 1 (1RF06), which is scheduled to start during the first quarter of 1998. However, should the ongoing industry test verification efforts

demonstrate the analytical methods used at CPSES to be adequate. TV Electric will rely on these methods to justify long-term operability without physical / ,

modification of the valves." I i

9703240202 970314 DR ADOCK 0500 5 R5555p5,5555 U l J E40023 P. O. Box 1002 Glen Rose Texas 7600

1 l

I

' TXX'96056 Page 2 of 2 Based on recent industry test verification results. TU Electric has concluded that Commonwealth Edison's analytical method used to calculate the additional stem thrust requirement above that anticipated by the typical design calculations is conservative. TV Electric has applied this method to predict stem thrust to overcome pressure locking on several susceptible valves. This additional thrust combined with the pullout thrust, when compared with the available motor capability, both from the GL 89-10 program, demonstrated adequate margin and valve operability. Therefore, TU Electric has concluded that valve modification plans stated in Reference 4. are not warranted.

If you have any questions, please contact Obaid Bhatty at (817) 897-5839.

Sincerely.

0$

C. L. Terry By: M '

4 Roger'O. Walker Regulatory Affairs Manager OB/ob Attachment I

cc: Mr. J. E. Dyer Region IV Mr. J. I. Tapia, Region IV Mr. T. J. Polich, NRR Resident Inspectors, CPSES 4

1

.*i 6

l Atta'chment 1 to TXX-96056 Page 1 of 1  ;

i UNITED STATES OF AMERICA j NUCLEAR REGULATORY COMMISSION -

In the Matter of )

) .

Texas Utilities Electric Company ) Docket Nos. 50-445

) and 50-446 3 (Comanche Peak Steam Electric )

Station. Units 1 & 2) )

AFFIDAVll Roger D. Walker being duly sworn, hereby deposes and says that he is the Regulatory Affairs Manager of TV Electric, the licensee herein: that he is duly authorized to

, sign and file with the Nuclear Regulatory Commission this Response to Generic

• 1 Letter 95-07, " Pressure Locking and Thermal Binding of Safety.Related Power Operated Gate Valves": that he is familiar with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledge, .l information and belief.

J

~

nGO4 h- '

Roger D M alker Regulatory Affairs Manager i STATE OF TEXAS )

)

COUNTY OF dreditand )

1. 5 Subscribed and sworn to before me, on this /M day of W21Lc/v , 1997.

l j- - -

[ CAROLYflL COSEf#iN0 /' M

'yISNNIMh'lg f Notary Put/lic 4

l ,

-v nv v . , ,_ , , 5

.