ML19260B146

Requests Amend to License NPF-4 & Forwards Tech Spec Change 25,adding & Deleting safety-related Hydraulic Snubbers Listed in Table 3.7-4

ML19260B146
Person / Time
Site:	North Anna
Issue date:	12/06/1979
From:	Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML19260B147	List: ML19260B146 ML19260B148
References
985, NUDOCS 7912070325
Download: ML19260B146 (3)

Text

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VIHOINIA ELECTRIC ANI) POWER COMmNY IIICHMOND, VIRGINIA 20261 December 6, 1979 Mr. Harold.R. Denton, Director Serial No. 985 Office of Nuclear Reactor Regulation LQA/WRM:shs Attn: Mr. A. Schwencer Chief Operating Reactors Branch No. 1 Docket No. 50-338 Division of Operating Reactors U. S. Nuclear Regulatory Commission License No. NPF-4 Washington, DC 20555

Dear Mr. Denton:

AMEND}ENT TO OPERATING LICENSE NPF-4 NORTH ANNA POWER STATION UNIT NO. 1 PROPOSED TECHNICAL SPECIFICATION CHANGE NO. 25 Pursuant to 10CFR50.90, the Virginia Electric and Power Company hereby requests an amendment, in the form of changes to the Technical Specifications, to Operating License NPF-4 for the North Anna Power Station, Unit No. 1. The proposed changes are enclosed and have been designated as Change No. 25.

The proposed Technical Specification Change No. 25 is a result of the Main Steam Valve House Pipe Support Modificatien. The Technical Specification changes required are the addition and deletion of safety-related hydraulic snubbers listed in Technical Specification Table 3.7-4. This change does not otherwise change Technical Specifications or their basis.

The main steam lines in the vicinity of the main steam containment penetra-tion on the exterior side of containment are supported by gapped restraint / stops.

These gapped stops allew for thermal growth and prevent excessive downward move-ment of the main steam piping resulting from lif ting of the main steam safety valves. Excessive downward movement caused by too large a gap could cause over-stressing of the containment penetration.

During normal heatup, contact of the main steam piping with the stop due to too small a clearance could result in a restrained condition which is not accounted for by the existing stress analysis. The required gap of 0.030 inches at 100% power and 0.010 inches at Hot Standby is difficult to assure under all normal operating conditionc, The proposed solution substitutes a non-gapped restraint for the existing gapped restraint /stop. The modification will redistribute loads in the piping system to keep stress levels within the allowances of the original design basis.

Installation of hydraulic snubbers as main steam pipe supports will not change the level of integrity of the main steam piping or the desi n basis for, the pipe supports.

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VinotNIA Ex.rcTaic AND POWER COMPANY TO Mr. Harold R. Denton 2 The Main Steam Valve House Pipe Support Modification will not affect station operation or the operation of safety-related equipment. The margin of safety, as defined in the basis for any Technical Specification, is not reduced since the original design basis of the system and its supports is not changed. This proposed change has been reviewed and approved by the Station Nuclear Safety and Operating Committee and the System Nuclear Safety and Operating Committee. It has been determined that this request does not involve an unre-viewed safety question as defined in 10CF150.59. This request has been evaluated in accordance with the criteria in 10CFR170. 22. It has been determined that this reques t is administrative in nature and has no safety or environmental significance; therefore, this request requires at Class II license amendment fee. Accordingly, you will find enclosed a voucher check in the amount of $1,200.00 in payment of the amendment fee. Very truly yours, ft L. 28h! W C. M. Stallings Vice President-Power Supply and Production Operations Attachments:

1. Proposed Technical Specification Change No. 25

2. Voucher Check No. 46659 for $1,200.00 cc: Mr. James P. O'Reilly Director Office of Inspection and Enforcement Region II 1511 ?97

COMMONWEALTH OF V IRGINI A )

                            )   s. s.

CITY OF RICHMOND ) Before me, a Notary Public, in and for the City and Common-wealth aforesaid, today personally appeared C. M. stallings, who being duly sworn, made oath and said (1) that he is Vice President-Power Supply and Production Operations, of the Virginia Electric and Power Company, (2) that he is duly authorized to execute and file the fore-going Amendment in behalf of that Company, and (3) that the statements in tSe Amendment are true to the best of his knowledge and belief. Given under my hand and notarial seal this /fh day of Deres:1}w( ,)179 My Commission expires ,) m pf -7 v 2 # , Jf g/ .

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