ML19208A959

Ack Receipt of 790716 Ltr.Provides Info Re Target Rock Safety Relief Valves,Including Current Status,Mods,Maint & Testing

ML19208A959
Person / Time
Site:	Peach Bottom
Issue date:	09/11/1979
From:	Gallagher J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Grimes B Office of Nuclear Reactor Regulation
References
NUDOCS 7909180354
Download: ML19208A959 (3)

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PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 JOSEPH W. G ALLAGHER nactnic Pecouct ou capamvusset (215)841-5003 September 11, 1979 Re: Docket Nos.: 50-277 50-278 Mr. Brian K. Grimes Acting Assistant Director for Systems Engineering Division of Operating Reactors United States Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Grimes:

This is in response to your letter of July 16, 1979, which requested information on Target Rock safety / relief valves. Your questions and our responses for Peach Bott on A t omic Power Station, Units 2 and 3, are treated sequentially.

1. What is the status of each of the Target Rock safety / relief valves at your plant (s); i.e.:

a. Are they in their original design configuration?

Response

All Target Rock safety / relief valves are in their origlua?

design configuration.

b. What is the existing simmer margin?

Resoonse The existing simmer margin of these valves ranges from 109 psi to 134 psi with an average simmer margin of 119 psi. (

3) V

c. What modificetions have you implemented to improve s reliability? 97' ,

360080 @C 35V f 7909180 99 g

Mr. Brian = ~ . . Grimes Page 2

Response

The following modifications have been made to the Target Rock safety / relief valves presently installed:

1. Insulation was modified so as to not enclose any portion of the ait operator.

2. Installation of improved air operator diaphragm (General Electric SIL #196, Supplement 2).

3. Reinstallation of pilot filters in pilot valve ports (General Electric SIL #196).

4. Second stage insert was shortened to preclude stem binding (General Electric SIL #196).

5. Setpoint of valves was increased to increase simmer margin.

d. On naat date were these modifications made?

Mesconse The modifications listed above were completed on the following dates respectively:

1. November 14, 1978

2. December 7, 1973

3. January 29, 1979

4. January 30, 1979

5. August 18, 1977 for Unit 2 May 17, 1978 for Unit 3

2. 'What maintenance and testing do you routinely perform on these valves and how often is it performed?

Response

Technical Specification 4.6.D.1 requires that at least five Target Rock safety / relief valves shall be setpoint tested or replaced once every operating cycle and that all valves be tested every two operating cycles. Technical Specification 4.6.D.2 requires that at least one valve be disassembled and inspected each refueling outage. Presently, all Target Rock safety / relief valves installed at Peach Bottom are setpoint checked and overhauled each refueling outage.

Additionally, all valves are normally operated once each operating cycle in accordance with Technical Specification 4.6.D.4.

360081

'f r . Brian K. Grimes Page 3

3. What additional modifications and/or maintenance do you plan to implement in the future?

Resnonse We expect to replace the original three stage pilot operated actuators with the redesigned two stage pilot operated actuators when the new actuators become commercially available.

4. On what date will the modification (s) and/or maintenance in item 3 be implemented?

Resoonse The actuator replacements will be effected during forthcoming refueling outages.

Should you require additional information, please do not hesitate to contact us.

Very truly yours,

- +: s Q2etd 0G0082