ML20134C289

Submits Response to NRC Bulletin 96-03, Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling-Water Reactors,

ML20134C289
Person / Time
Site:	Browns Ferry
Issue date:	01/29/1997
From:	Williams J NRC (Affiliation Not Assigned)
To:	Kingsley O TENNESSEE VALLEY AUTHORITY
References
IEB-96-003, IEB-96-3, TAC-M96135, TAC-M96136, TAC-M96137, NUDOCS 9701310322
Download: ML20134C289 (4)

Text

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""% S O O S c, g ly

& UNITED STATES I

l j NUCLEAR RE2ULATORY COMMISSION M2 l o WASHINGTON, D.C. 2008H001

\ .,g January 29, 1997 i

Mr. Oliver D. Kingsley, Jr.

President, TVA Nuclear and Chief Nuclear Officer i Tennessee Valley Authority -

l 6A Lookout Place

1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT UNITS 1, 2, AND 3 - RESPON5? TO BULLETIN 96-03 (TAC NOS. M96135, M96136, AND M96137) l

Dear Mr. Kingsley:

l By letter dated November 4, 1996, Tennessee Valley Authority (TVA), licensee

) for the Browns Ferry Nuclear Plant (BFN) Units 1, 2, and 3, submitted its 1 response to NRC Bulletin (B) 96-03 " Potential Plugging of Emergency Core ,

Cooling Suction Strainers by Debris in Boiling-Water Reactors," dated May 6, i i 1996. In its response, TVA notified the NRC that implementation of the final  ;

resolution of B 96-03 for BFN Unit 3 is not achievable on the schedule called l i for in that bulletin. The staff has reviewed this letter, and has concluded l

! that a deferral of the bulletin's requested actions is acceptable for BFN j

! Unit 3 if the compensatory actions described below are implemented. The staff i expects that the B 96-03 requested actions will be completed for BFN Unit 2

. during its refueling outage scheduled for the fall of 1997, and for BFN Unit 1 l prior to restart.

BACKGROUND

'he NRC staff has issued several other generic communications related to boiling water reactor (BWR) emergency core cooling system (ECCS) strainer

blockage. Bulletin 93-02 " Debris Plugging of Emergency Core Cooling Suction Strainers," dated May 11, 1993, requested licensees to ensure that there were no sources of fibrous material in containment not capable of withstanding a loss of coolant accident. TVA responded to B 93-02 on May 23, 1993, stating l that there were no such sources of fibrous material in containment for BFN

Unit 2 and that BfN Units 1 and 3 would be inspected prior to startup. A February 8,1996 licensee letter to the NRC documented the results of an inspection of BFN Unit 3, stating that " Unit 3 had been inspected and temporary fibrous air filters or other sources of fibrous material have beer removed from the drywell." BFN Unit I remains shutdown, with no restart

schedule establishad.

j B 93-02, Supplement 1 " Debris Plugging of Emergency Core Cooling Suction Strainers," dated February 18, 1994, requested licensees provide training and i emergency operating procedures for plant operators and to specify alternative 4

water sources which may be used to mitigate a strainer blockage event. TVA responded to this bulletin on April 18, 1994, describing the planned resolution of the B 93-02, Supplement 1 issues, stating that implementation }

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PDR ADOCK 05000259

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Mr. O. D. Kingsley .

would be completed by June 30, 1994. The staff concluded on July 19, 1994 that TVA's response adequately addressed the requested actions of B 93-02. On July 29,1994, TVA notified NRC that all commitments related to B 93-02, Supplement I had been completed.

B 95-02, " Unexpected Clogging of a Residual Heat Removal (RHR) Pump Strainer While Operating in Suppression Pool Cooling Mode," dated October 17, 199S, requested licensees to take actions necessary to assure operability of the ECCS with respect to suppression pool cleanliness and foreign material 1

exclusion programs. TVA responded to this bulletin by letters dated November 15, 1995 and March 5, 1996. The staff found TVA's response to be

< acceptable in safety evaluation issued on March 14, 1996.

RESPONSE TO BULLETIN 96-03 TVA's November 4, 1996 response to B 96-03 stated that TVA currently performs

a visual inspection of the ECCS strainers during refueling outages, including an examination of the suppression pool for sludge and debris that could potentially lead to ECCS strainer clogging. The suppression pool is desludged if the inspection results indicate it is necessary. Prior to restart of BFN Unit ; from its extended recovery outage in 1995, TVA drained, cleaned and recoated the suppression chamber surfaces. The suppression pool was refilled with condensate water in April 1995.

TVA also stated that it was participating in the BWR Owners Group Suction Strainer Committee, supporting formulation of Utility Resolution Guidelines (URG) which are intended to be used for resolution of strainer issues. TVA requested that the staff accept a delay of implementation of the B 96-03 requested actions to install an improved ECCS strainer for BFN Unit 3. Based on the schedule for URG development and approval at the time of its B 96-03 response, TVA stated the earliest opportunity to evaluate plant-specific conditions and implement any modifications would be the BFN Unit 2 outage in the fall of 1997. TVA committed to submit its planned actions and schedule within 90 days of NRC staff approval of the URG.

For BFN Unit 3, the staff requests that TVA, as a condition for granting the deferral of the actions of B 96-03, to desludge the suppression pool regardless of inspection results to minimize any accumulation of sludge in the pool prior to startup from refueling outages, in order to minimize the potential burden on the existing strainers. Staff calculations show that the speed and severity of strainer blockage is sensitive to the amount of sludge or rust particles in the suppression pool at the initiation of a loss of coolant accident. Therefore, it is prudent, until the licensee installs the larger strainers, to minimize sludge in the suppression pool.

In addition to desludging the' suppression pool, the staff requests that TVA, as a condition of the BFN Unit 3 deferral, to take the following additional actions during the upcoming refueling outage:

1. Perform an inspection in the drywell to verify that the insulation is not damaged and is properly installed. Repair or replace any insulation that is damaged or not properly installed.

Mr,.OlJverD.Kingsley,Jr. BROWNS FERRY NUCLEAR PLANT Tennessde Valley Authority f

cc:

Mr. O. J. Zeringue, Sr. Vice President Regional Administrator Nuclear Operations U.S. Nuclear Regulatory Commission Tennessee Valley Authority Region II 6A Lookout Place 101 Marietta Street, NW., Suite 2900 1101 Market Street Atlanta, GA 30323 Chattanooga, TN 37402-2801 Mr. Michael J. Morgan Mr. Mark 0. Medford, Vice President Senior Resident Inspector Engineering & Technical Services Browns Ferry Nuclear Plant Tennessee Valley Authority U.S. Nuclear Regulatory Commission .

6A Lookout Place 10833 Shaw Road 1101 Market Street Athens, AL 35611 Chattanooga, TN 37402-2801 Chairman Mr. R. D. Machon, Site Vice President Limestone County Commission Browns Ferry Nuclear Plant 310 West Washington Street Tennessee Valley Authority Athens, AL 35611

P.O. Box 2000 Decatur, AL 35609 State Health Officer Alabama Department of Public Health General Counsel 434 Monroe Street Tennessee Valley Authority Montgomery, AL 36130-1701 ET 10H

400 West Summit Hill Drive Knoxville, TN 37902 Mr. Raul R. Baron, General Manager Nuclear Assurance and Licensing Tennes,see Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 '

Mr. Eugene Preston, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 Mr. Pedro Salas, Manager Licensing and Industry Affairs Tennessee Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Timothy E. Abney, Manager Licensing and Industry Affairs Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609

O Mr,. Oljver D. Kingsley, Jr. BROWNS FERRY NUCLEAR PLANT Tennes'sse Valley Authority f

cc:

Mr. O. J. Zeringue, Sr. Vice President Regional Administrator Nuclear Operations U.S. Nuclear Regulatory Comission Tennessee Valley Authority Region II 6A Lookout Place 101 Marietta Street, NW., Suite 2900 1101 Market Street Atlanta, GA 30323 Chattanooga, TN 37402-2801 Mr. Michael J. Morgan Mr. Mark 0. Medford, Vice President Senior Resident Inspector Engineering & Technical Services Browns Ferry Nuclear Plant Tennessee Valley Authority U.S. Nuclear Regulatory Comission .

6A Lookout Place 10833 Shaw Road 1101 Market Street Athens, AL 35611 Chattanooga, TN 37402-2801 Chairman Mr. R. D. Machon, Site Vice President Limestone County Comission Browns Ferry Nuclear Plant 310 West Washington Street i Tennessee Valley Authority Athens, AL 35611 P.O. Box 2000 Decatur, AL 35609 State Health Officer Alabama Department of Public Health General Counsel 434 Monroe Street Tennessee Valley Authority Montgomery, AL 36130-1701 ET 10h 400 West Sumit Hill Drive Knoxville, TN 37902 Mr. Raul R. Baron, General Manager Nuclear Assurance and Licensing Tennessee Valley Authority .

4J Blue Ridge l 1101 Market Street l Chattanooga, TN 37402-2801 Mr. Eugene Preston, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 Mr. Pedro Salas, Manager Licensing and Industry Affairs Tennessee Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 i

Mr. Timothy E. Abney, Manager Licensing and Indu;try Affairs Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 J

a .

Mr. O. D. Kingsley 2. Perform a thorough drywell and suppression pool inspection, including the vents, downcomers, and ring header, to verify that all foreign material, such as maintenance tools, equipment, construction materials and miscellaneous debris, has been removed.

The staff concludes that these compensatory actions provide confidence of continued safe operation of BFN Unit 3 with the existing strainers when combined with TVA's existing commitments to B 93-02, B 93-02, Supplement 1, and B 95-02.

The staff requests that TVA, as a condition for the approval of the deferral of actions requested by B 96-03 for BFN Unit 3, install and make operational passive suction strainers on or before December 31, 1998. If this schedule is not acceptable, please notify the staff within 90 days of receipt of this letter.

The staff continues to expect that TVA will implement the requested actions of B 96-03 for BFN Unit 2 during the refueling outage scheduled for the fall of 1997, and prior to restart of BFN Unit 1. The staff accepts TVA's commitment to describe its planned actions and :,chedule within 90 days of approval of the URG.

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

Sincerely, Original signed by Joseph F. Williams, Project Manager Project Directorate II-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296 cc: See next page i

Distribution Docket File. PUBLIC BFN Rdg. MLynch .

SVarga JZwolinski OGC I ACRS EMerschoff, RII RLobel l DOCUMENT NAME: G:\BFN\M96135.LTR *See previous concurrence 73 receive a copy of this doctment, Indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with ettechnent/ enclosure "u" = No copy 0FFICE PDil-3/PM ///2 / l PDil-3/LA  ; l SCSB* l PDII-3/D #) l C. i NAME JWilliams g/M BClayton /? A f/ CBerlinger FHebdon 'N -

01/j9 /97// J' 01/23/97 01/ad/97 DATE 01/4G/97 OFFICIAL RECORD COPY