ML20066L000

Application for Amends to Licenses NPF-4 & NPF-7,modifying Tech Specs Re Snubber Visual Insp Frequency

ML20066L000
Person / Time
Site:	North Anna
Issue date:	01/31/1991
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20066L005	List: ML20066L000 ML20066L011
References
91-008, 91-8, GL-90-09, GL-90-9, NUDOCS 9102060199
Download: ML20066L000 (7)

Text

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- - Vinoixir P.i.i:cruic axn Pown:n rom xxy Ihrnwown,Vnmina unum January 31,1991 U. S. Nuclear Regulatory Commission Serial No 91 008 Attn: Document Control Desk NL&P/TAH:R4a Washington, D. C. 20555 Docket Nos. 50 338 50 339 License Nos. NPF 4 NPF 7 Gentlemen:

VIRGINIA ELECTRIC AND POWER Q_OMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 AMENDMENT REQUEST TO CHANGE TECHNICAL SPECIFICATIONS S14UBBER VISU AL INSPECTION FREQUENCY Pursuant to 10 CFR 50.90, the Virginia Electric and Power Company reouests amendments, in the form of changes to the Technical Specifications, to Operating License Nos. NPF 4 and NPF 7 for the North Anna Power Station Units 1 and 2, respectively. This proposed changes modify the visual snubber laspection program and is consistent with the guidance of the NRC's Generic Letter 90 09, " Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions," dated December 11,1990.

A discussion of the changes is included in Attachment 1. The proposed changes are included in Attachment 2. The basis for the no significant hazards consideration determination is included in Attachment 3. No MERITS format specifications are enclosed because this specification is being relocated from Technical Specifications to a controlled program in the MERITS Technical Specification improvement process.

The Station Nuclear Safety and Operating Committee and the Management Safety Review Committee have reviewed and approved this request and have determined that the proposed changes do not involve an unroviewed safety question as defined in 10 CFR 50.59 or a significant hazards consideration as defined in 10 CFR 50.92, Very truly yours,

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W. L. Stewart Senior Vice President - Nuclear Attachments

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Docket Nos. 50 338 & 339 Serial No. 91008 cc: U. S. Nuclear Regulatc ry Commission Region 11 101 Marietta Street, N. W.

Suite 2900 Atlanta, Georgia 30323 Mr. M. S. Lesser NRC Senior Resident inspector North Anna Power Station Commissioner Department of Health Room 400 109 Governor Street Richmond, Virginia 23219

COMMONWEALTHOFVIRGINIA )

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COUNTYOF HENRICO )

The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by W. L. Stewart who is Senior Vice President - Nuclear, of Virginia Electric and Power Company. He is duly authorized to execute and file the foregoing document in behalf of that Company, and the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this 3/S day of ordMd. , 19 9/

, 19 My Commission Expires: O,aOY 30 .

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Notary Public (SEAL)

ATTACHMENT ONE DISCUSSION t

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VIRGINIA ELECTRIC AND POWER COMP ANY w - - y -

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l Docket Nos. 50-338 & 339

- Serial No. 91008 QlSCUSSION OF PROPOSED CHANGE in Generic Letter 90 09,

• Alternate Requirements for Snubber Visual Inspection Intervals and Corrective Actions," dated December 11,1990, the NRC identified that the existing Technical Specifications specify a schedule for visual inspections of snubbers that is based on the number of inoperable snubbers found during the previous visual inspection and does not take into consideration the size of the snubber population.

The purpose of the visual inspection is the observation of the condition of installed snubbers to idemify those that are damaged, degraded, or inoperable as caused by physical means, leakge, corrosion or environmental exposure. Functional testing is performed to assure the there is a 95% confidence level that 90% to 100% of the snubbers will operate witLin their specified performance limits. The visual inspection compliments the functior at testing and provides additional confidence in snubber operability.

Performing these inspections at the frequency determined by the existing Technical Specification requires a significant amount of resources and unnecessary radiological exposure. The same level of confidence in reliability can be obtained with a longer inspection interval by a proper grouping and statistical sampling program for the visual inspection of the snubbers.

The NRC has developed an alternate inspection schedule for visual inspections that maintains that confidence level and will generally allow the inspection during plant outages, reduce occupational radiation exposure and is consistent with the Commission's policy statement on Technical Specification Improvements. This new method for determining the snubber visual inspection intervals is based on the number of unacceptable snubbers found during the previous inspection, the total population or category size for each snubber type, and the previous inspection interval.

We are proposing a Technical Specification change to incorporate the guidance and requirements of Generic Letter 90 09 for visualinspection of snubbers The wording of the proposed changes was derived from the Model Technical Specification Changes provided in Enclosure B of the generic letter.

In addition, the generic letter lists three acceptance criteria for visual inspections. They are: (1) the snubber has no visible indications of damage or impaired OPERABILITY, (2) attachments to the foundation or supporting structure are functional, and (3) fasteners for the attachment of the snubber to the component ano to the snubber anchorage are functional. We have chosen to retain an additional fourth acceptance criterion, which currently exists in our Technical Specifications, to require "in those locations where snubber movement can be manually induced without disconnocting the snubber, that the snubber has freedom of movement and is not frozen up."

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Docket Mos. 50 338 T. 339 Sertal No. 91008 North Anna Unit 1 is currently in a refueling outage and snubber visualinspections are underway. Unit 2 completed its most recent recent refueling outage and snubber inspection on November 2,1990. We have discussed the timing of the North Anna outages and snubber inspections with the NRC North Anna Project Manager and the NRC point of contact for Generic Letter 90-09 in light of the recent issuance of the generic letter.

The conclusion reached in those discussions is that a relatively short period of time is expected to have elapsed between the completion of the visual inspections and issuance of a license amendment. Accordingly, when the amendment is issued, it would be permissible to apply the criteria for determining the inspection intervals in the amendment to the Unit 1 and 2 refueling outage inspection results and then rn determine the Inspection intervals at that time.

Therefore we are not adding the phrase " cod the first inspection interval determined using this criteria shall be based upon the pr9vious inspection interval as established by the requirements in effect before amendment (*)" to the proposed Technical Specification Surveillance Requirement 4.7.10.b. " Visual inspections" for North Anna i Units 1 and 2.

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4 ATTACHMENT TWO TECHNICAL SPECIFICATION CHANGES NORTH ANNA POWER STATION UNITS 1 AND 2

- VIRGINIA ELECTRIC AND POWER COMPANY t.