ML20217E530

Forwards SE Re Licensee 970307 Submittal of Evaluation of Core Spray Piping Flaws Identified During Insps Performed During Plant,Unit 3 Refueling Outage

ML20217E530
Person / Time
Site:	Browns Ferry
Issue date:	09/22/1997
From:	Williams J NRC (Affiliation Not Assigned)
To:	Kingsley O TENNESSEE VALLEY AUTHORITY
Shared Package
ML20217E534	List: ML20217E530 ML20217E543
References
TAC-M98059, NUDOCS 9710070074
Download: ML20217E530 (4)

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t NUCLEAR REGULATORY. COMMISSION WASHINGTON. D.C. 2004H001

,\ ,,,,* September N , 1997 Mr. Oliver D. Kingsley, Jr.

President, TVA Nuclear and Chief-Nuclear Officer Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT UNIT 3 - SAFETY EVALUATION PIPING WELD FLAW INSPECTION RESULTS (TAC N0. M980S9)

Dear Mr. Kingsley:

On March 7, 1997,. the Tennessee Valley Authority (TVA) submitted its evaluation of core spray piping flaws identified during inspections performed during a Browns Ferry Nuclear Plant (BFN) Unit 0 refueling outage. TVA had identified crack-like downcomet piping. indications at two locations in the core spray internal (P8b) and the pipe to elbow weld (P4d).The two flawed locations are on the collar-t On March 9, 1997. TVA provided supplemental information regarding its core spray piping inspections and evaluations.

By letter dated March 10, 1997. TVA committed to work with the l Boiling Water Reactors Vessel and Internals Project (BWRVIP) to develop inspection methods and repair criteria for future inspection of the P4d weld, and to submit an inspection plan to the Nuclear Regulatory Commission (NRC) 120 days October prior to the start of the BFN Unit 3 refueling outage scheduled for 1998, In a letter dated March 11, 1997, the NRC staff stated that, based on its initial review of the information provided by TVA, no technical issues had been identified which would prevent BFN Unit 3 restart from the refueling outage, with a detailed evaluation to be provided at a later date. The staff noted that TVA's commitments for future inspections appeared to be acce) table if the methods developed provide an adequate means to characterize the 34d weld flaw indications.

method, then the staff stated that an appropriate rIf TVA is unable to develop an lir should be performed to ensure piping structural integrity. TVA was askeu to confirm whether the criteria in TVA'sdiscussed letter of March in this10, letter were consistent with the commitments given 1997.

In response to this request, on April 7. 1997. TVA provided additional discussion of the commitments discussed above. TVA discussed several approaches to characterize effects of the P4d weld flaw, including its commitmet to work with the BWRVIP to develop ultrasonic methods and repair criteria for the P4d weld, to perform other efforts to demonstrate that the observed indications at the weld P4d originate at the outside diameter surface, of the P4d and/or weld. to evaluate core spray system operability assuming the absence i

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Mr. O. D. Kingsley As part of its continuing review, on May 28, 1997. the NRC staff identified a concern regarding the structural integrity of weld P9. Additional information regarding the structural integrity of this weld was requested in order to assess the effect of failure of welds P9 and P8 which could result in degraded core spray system function. including an assessment of core damage risk effects. TVA provided the information requested on June 10, 1997. On June 24, 1997 TVA submitted additional information to clarify the methodology used for calculation of peak cladding temperature for loss of coolant accidents.

As documented in the enclosed safet) ? valuation, the NRC staff has found BFN Unit 3 operation to be acceptable foe the current fuel cycle. The staff notes that a re> air or replacement of the we',1 '8b or a volumetric inspection of the weld P9 w1ose results could be evaluate; to demonstrate its structural integrity should be planned for the next refueling outage. The staff requests that the licensee submit to NRC its plan for inspection and repair, as appropriate, of the welds, P4d, P8b, P9 ud other similar welds in the core saray system 120 days prior to their next 1rispection outage. The staff's a)ility to conclude that BFN Unit 3 can be operated beyond the present fuel cycle will depend on the satisfactory evaluation of the inspection results and any repair implemented during the next refueling outage. In order to avoid any potential impact on plant restart from the next outage the staff believes that TVA should give strong consideration to having a contingency plan developed, such as pipe repair by clamping.

Please call me at (301)415-1470 if you have any questions regarding this topic.

l Sincerely.

l .

f / ^ M~r Joseph F. Williams, Project Manager Project Directorate 11-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-296

Enclosure:

Safety Evaluation cc w/ encl: See next page a

4 Mr. O. D. Kingsley i As part of its continuing review, on May 28. 1997, the NRC staff identified a '

concern regarding the structural integrity of weld P9. Additional information regarding the structural integrity of this weld was requested in order to assess the effect of failure of welds P9 and P8. which could result in degraded core spray system function, including an assessment of core damage  !

risk effects. TVA provided the information requested on June 10. 1997. On 1 June 24. 1997. TVA submitted additional information to clarify the methodology used for calculation of peak cladding temperature for loss of coolant accidents.

As documented in the enclosed safety evaluation, the NRC staff has found BFN Unit 3 operation to be acceptable for the current fuel cycle. The staff notes that a re) air or replacement of the weld P8b or a volumetric inspection of the weld P9 w1ose results could be evaluated to demonstrate its structural integrity should be )lanned for the next refueling outage. The staff requests that the licensee su)mit to NRC its plan for inspection and repair, as appropriate, of the welds. P4d, P8b. P9 and other similar welds in the core saray system 120 days prior to their next inspection outage. The staff's a)ility to conclude that BFN Unit 3 can be operated beyond the present fuel

, cycle will depend on the satisfactory evaluation of the inspection results and l any repair implemented during the next refueling outage. In order to avoid any potential impact on plant restart from the next outage. the staff believes that TVA should give strong consideration to having a contingency plan l developed, such as pipe repair by clamping.

Please call me at (301)415-1470 if you have any questions regarding this topic.

Sincerely.

/S/

Joseph F. Williams. Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket No. 50-296

Enclosure:

Safety Evaluatio-cc w/ encl: See next page DISTRIBUTION:

Docket File FHebdon 0GC JRajan PUBLIC BClayton ACRS KKavanagh BFN Reading 'JWilliams JJohnson, RII CECarpenter BBoger THarris (e-mail TLH3) WKoo DOCUMENT NAME: G:\BFN\M98059.LTR To receive a copy of this document, indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy OFFICE PDil-3/PM PDIl 3/LA l l PDil-3/D i}

fg l g/ lEl l l NAME JWilliamstmw /@ BClayton 4fP FHebden Nf i DATE 09/Ja/97 // 09/- ./97 09/a t/97 09/ /97 I OFF1C1AL R' CORD COPY

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Mr. Oliver D. Kingsley, Jr.

Tennessee Valley Authority BROWNS FERRY NUCLEAR PLANT cc:

Mr. O. J. Zeringue, Sr. Vice President Mr. Mark J. Burzynski, Managar Nuclear Operations .

Nuclear Licensing Tennessee Valley Authority Tennessee Valley Authcrity 6A Lookout Place 4J Blue Ridge 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801 Mr. Jack A. Bailey, Vice President Mr. Timothy E. Abney, Manager Engineering & Technical Services Licensing and Industry Affairs Tennessee Valley Authority Browns Ferry Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Decatur, AL 37402-2801 Mr. C. M. Crane, Site Vice President Regional Administrator, Region II Browns Ferry Nuclear Plant U.S. Nuclear Regulatory Commission Tennessee Valley Authority 61 Forsyth Street, SW., Suite 23T85 l P.O. Box 2000 Atlanta, GA 30303-3415 l Decatur, AL 35609 General Counsel Mr. Leonard D. Wert Senior Resident Inspector Tennessee Valley Authority U.S. Nuclear Regulatory Commission ET 10H Browns Ferry Nuclear Plant 400 West Summit Hill Drive 10833 Shaw Road Knoxville, TN 37902 Athens, AL 35611 Mr. Raul R. Baron, General Manager State Health Officer Nuclear Assurance Alabama Dept. of Public Health Tennessee Valley Authority 434 Monroe Street 4J Blue Ridge Montgomery, AL 35130-1701 1101 Market Street Chattanooga, TN 37402-2801 Chairman Limestone County Commission Mr. Karl W. Singer, Plant Manager 310 West Washington Street Browns Ferry Nuclear Plant Athens, AL 35611 Tennessee Valley Authority P.O. Box 2000 Decatur, At 35609

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