ML19246A975

Submits Addl Response to IE Bulletin 79-04.Util Has Determined Existing Design of Piping Containing 12 3-inch Valves Is Acceptable

ML19246A975
Person / Time
Site:	North Anna
Issue date:	05/23/1979
From:	Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 7907100131
Download: ML19246A975 (2)

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VIRGINIA ELucrusc ann Powen COMI%NY RIcnwonn, VIRGINIA 20261 May 23, 1979 -

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'[/h 5 ,0 PE R h E 25

-40 Mr. James P. O'Reilly, Director Serial No. 221C g '

Office of Inspection and Enforcement P0/DLB:baw f .;

' T, U. S. Nuclear Regulatory Commission Docket No.(50-338/ 9

Region II License No. NP'F~4 ,

101 Marietta Street, Suite 3100 .. 7 Atlanta, Georgia 30303 cy,

SUBJECT:

IE BULLETIN 79-04 NORTH ANNA POWER STATIO.5 UNIT NO. 1 ,

Dear Mr. O'Reilly:

This is in response to IE Bulletin 79-04, " Incorrect Weights for Swing Check Valves Manufactured by Velan Engineering Co pany", and is a supplement to our initial response of May 3, 1979.

As stated in Attachment 2 to our May 3, 1979 response, there are twelve (12) of the subject 3" check valves installed in Nocth Anna Unit No. 1. It has now been determined that the existing design of all piping containing the subject valves is acceptable.

The analytical techniques used fall into three categories as follows:

1) Feur valves in the safety injection lines were reanalyzed by Stone and Webster Engineering Corporation using the PSTRESS/ SHOCK III 03/03 compute codes. All pipe and pipe support stresses were acceptable.

2) Four valves in charging system lines (Cless 1) were reanalyzed by Te'.edyne Engineering Services using the TMR-SAP computer code.

A1.1 pipe and support stresses were acceptable.

3) The four remaining Velan 3 inch C58 velves are located in Class 2 and 3 portions of the charging system which were analyzed by Stone and Webster. These valves were considered separately 1, r="=a **ese

. small, relatively cool lines were analyzed using 7 9 0710 01st 313 345

[fO Y b OFFICIAL C '>Y

James P. O'Relly 2 Vi soix A ELEcTEIC AMD POWER Cow =ANY TO the simplified method described in FSAR Cection 3.7.3.1.3.7.

Seismic qualification of these lines is asaured by conservative support spacing and by conservatively high standard suprort design loads. These standards allow for various in-line components such as valves, flanges, flow restrictors, etc. The exact weight of a specific cotponent is not required.

Very truly yours,

~0 .h. l5lc 0 C. M. Stallings Vice President-Power Supply and Production Operations cc: FRC Office of Inspection and Enfarcement Division of Reactor Operations Inspection Washington, D, C. 20555

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