ML20027C352

Application for one-time Change to Tech Spec 3/4.4.7.2, Modifying Leak Test Acceptance Criteria.Change Necessary to Preclude Potential for Delay in Return to Power from Refueling Outage

ML20027C352
Person / Time
Site:	Farley
Issue date:	10/11/1982
From:	Clayton F ALABAMA POWER CO.
To:	Varga S Office of Nuclear Reactor Regulation
Shared Package
ML20027C353	List: ML20027C352 ML20027C356
References
NUDOCS 8210150338
Download: ML20027C352 (5)

Text

. M.lling Address

. '. Atabimi Pow:r Company ,n , m 3

600 North 18th Street hJ,s-Post Office Box 2641 Birmingham. Alabama 35291 Telephor's 205 783-6081 F. L Clayton, Jr.

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o AlabamaPower the Southern e!acitC system October 11, 1982 Docket No. 50-364 Director, Nuclear Regulatory Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Mr. S. A. Varga Joseph M. Farley Nuclear Plant - Unit 2 Pressure Isolation Valve Technical Specification Change Request Gentlemen:

In letter dated August 10, 1982, Alabama Power Company requested a permanent change to Unit 2 Technical Specification 3/4.4.7.2, which addresses the performance of leak tests on all reactor coolant system pressure isolation valves. That change request would have permanently incorporated the acceptance criteria for Unit 1 Technical sSpecification 3/4.4.7.3 of 1 to 5 gpm (with certain limitations) into Unit 2 Technical Specification 3/4.4.7.2. Subsequent discussions with the NRC Staff indicate that additional information will be necessary to complete the regulatory review before approval of this permanent change request could be granted. The NRC Staf f stated that this regulatory review may consider the results of an ongofng study, undertaken in recognition that" the 1-gpm limit of the present technical specification may be overly conservative, in order to determine a more reasonable leakage rate. To preclude the potential delay in the return to power attributed to the stringent 1-gpm acceptance criteria, Alabama Power Company hereby bC) ) requests a one-time change of Unit 2 Technical Specification 3/4.4.7.2 i L, to modify the acceptance criteria to 1 gpm for reactor coolant i so,la ti o n

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• valves with a nominal diameter of two inches and 1 to 5 gpm (with ,

VV certain limi-tiatons) for reactor coolant isolation vchves with a' nominal diameter of greater than two inches. . <

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It is imperative that the leakage acceptance criteria be established hrlor to shutdown in order that this critical path not be impacted due to the , regulatory uncertainty. The initial valve testing is performed on the critical path of the unit outage in order to

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Mr. S. A. Varga October 11, 1982 U. S. Nuclear Reguatory Commission Page 2 identify valves requiring repair during the outage. Af ter valve repair and re-installation, the valves are then retested for leakage as a part of the critical path of the return to power. If the results of the leak retesting do not satisfy the stringent 1-gpm acceptance criteria, the critical path of the outage may be further impacted due to valve rework, re-installation, retest and the draindown of the reactor coolant system required to repair several of these valves. Therefore, as stated in letter of August 10, 1982, Alabama Power Company requests the proposed technical specification change prior to the Unit 2 first refueling outage se heduled for October 22, 1982.

The dif ference in acceptance criteria f rom 1 ppm to 3 or 5 gpm requires a variance in leakage configuration that is negligible, inconsequential, and beyond that which can be affected by reasonable maintenance activities. As an example, the disk of a six-inch check valve 'would only be elevated from its seat by approximately 0.00004 in, to produce a leak rate of 1 gpm and by approximately 0.00020 in, to -

produce a leak rate of 5 gpm. To correct small irregularities that produce leak rates between 1 gpm and 3 or 5 gpm, several maintenance and retesting ' iterations may be necessary. This activity subjects plant personnel to greater radiation exposures, potentially requires draining the reactor coolant system to retest the reworked valve and extends the time before the unit is returned to power. To illustrate this point, in one instance valve maintenance activities required to provide a leakage rate consistent *with the stringent 1 gpm acceptance criteria added three days to the critical path of the outage. The valve was repaired on two consecutive occasions in order to resolve a leak that, initially, only s

slightly exceeded the 1-gpm criteria. One repair actually resulted in a small increase in leakage due to the minute variations of configurations i nvol ve d. .This multiple repair, draindown, and.repressurizatio'n process

% 'to resolve a leak that significantly delayed -the return to power was not justified, id Alabama Power Company's judgement, and in additiod '

resulted in personnel exposure exceeding 25 ma,n-rem. -

Consequently, Alabama Power Company requests a one-time change of '

Technical Specification 3/4.4.7.2 to modify the leak test acceptance '

criteria to 1 tp 5 gpm (with certain limitations) for valves with a nomThal diameter greater than two inches and to 3 gpm for valves with a nominal- d~1ameter of two , inches. ' This one-time change is necessary to

- preclude the potential for the delay in the return to power from the Unit f first ref ueling outage.  ?

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Mr. S. A. Varga October 11, 1982 l

U. S. Nuclear Regulatory Commission Page 3 The Unit I leak test acceptance criteria of 1 to 5 gpm (under certain limitations), have been proven to be adequate in establishing the pressure retaining capability of the valves. As shown by testing experience at Farley Nuclear Plant - Unit 1, valves that did not satisfy either the acceptance criteria of 1 gpm or 1 to 5 gpm were found to contain the same minor valve seating irregularities causing the valves not to seat completely under low test pressures, and no evidence of impending valve failure has been found using either acceptance c ri teri a.

For valves with a nominal diameter of two inches, the acceptance criteria of 3 gpm is requested based on review of past leak rate data for two-inch valves. This data showed that such valves did not produce leak rates greater than 3 gpm. The 3-gpm acceptance criteria was selected for smaller valves since repair is easier, actual leakage rates have been small, and the ability to meet and maintain lower leakage rates is facilitated. Additionally, acceptance criteria of 3 gpm is below the 5 gpm criteria that has been proven to establish the pressure retaining capability of the valves.

In conclusion, this proposed one-time change to Unit 2 Technical Specification 3/4.4.7.2 ( Attachment 1) provides for a high assurance of reactor coolant system integrity through surveillance and testing requirements without unwarranted compromise to the health and safety of the public and needless jeopardizing of the timely return of the unit to power operation. The Plant Operations Review Committee of Alabama Power Company, has reviewed this proposed change to the techncial specification and has determined that the change does not involve an unreviewed safety

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question as shown in the attached safety eva1uation (Attachm'ent 2).' The Nuclear Operations Review Board is scheduled to review these ghange at the next meeting.

Your response toIthis proposed one-time technical speci fication e change is requested by October 20, 1982 in order to provide for its incorporation idto the plant procedures prjor && the unit outage. To -

facilitate the NRC Staff's evaluation ~ of the reasonable leakage rate for reactor coolant sys;em isolation valves, Alabama Power Company will

. submit the initial outage test dapa on valve leakage at Unit 2 one' week '

following the start of the outage (app.roximately October 30,1982).

T Th'is proposed amendment is desfgnated as Class III for Unit 2 in accordance with 10 CFR 170.22 requirements. Enclosed is a check for

$4,000.00 to cover the total amount of fees required.

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Mr. S. A. Varga October 11, 1982 U. S. Nuclear Regulatory Commission Page 4 In accordance with 10 CFR 50.30(c)(1)(i), three signed originals and forty (40) additional copies of the proposed change are enclosed. i Yours truly, F. . Clayton Jr.

FLCJ r/M AL : 1 s h-09 Attachments cc: Mr. R. A. Thomas SWORN TO AND SUBSCRI3 fEFOREME l

Mr. G. F. Trowbridge THIS ll A DAY OFL A 1982 Mr. J. P. O'Reilly '

Mr. E. A. Reeves Mr. W. H. Bradf ord O Notary Public My Commission Expires: s i ll-29-W .

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, ATTACHMENT 1 c-Proposed Unit 2 Technical Specification 3/4.4.7.2 New Page 3/4 4-17 New Page 3/4 4-19 Revised Unit 2 Technical Specification 3/4.4.7.2 Revised Page 3/4 4-17 Revised Page 3/4 4-19 M

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