ML20137P350

Summary of 970327 Meeting W/Tva in Rockville,Md Re ECCS Suction Strainers Mod for Plant,Units 1,2 & 3.List of Attendees & Handouts Encl

ML20137P350
Person / Time
Site:	Browns Ferry
Issue date:	04/07/1997
From:	Williams J NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
IEB-96-003, IEB-96-3, NUDOCS 9704090235
Download: ML20137P350 (16)

Text

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UNITED STATES l g - NUCLEAR REGULATORY COMMISSION-

, WASHINGTON. D.C. 3000H001 April 7, 1997 gp.yyy '

p - ****  ;

4 4

LICENSEE

Tennessee Valley Authority i

FACILITY: Browns Ferry Nuclear Plant, Units 1, 2, and 3

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SUBJECT:

SupMARY '- MARCH 27, 1997 MEETING WITH TVA ON EMERGENCY CORE COOLING-

SUCTION STRAINER MODIFICATIONS l On March 27,-1997, representatives of the Tennessee Valley Authority (TVA) met

.with members of the NRC staff in Rockville, Maryland. TVA had requested this

' meeting to brief the staff on modifications to the Browns Ferry Nuclear Plant

-(BFN) emergency core cooling system (ECCS) suction strainers. These modifications are being made to respond to Bulletin (B) 96-03, " Potential

' Plugging of ECCS Suction Strainers by Debris." A list of attendees is provided in Enclosure 1. A copy of the handout provided by TVA .is given in

' Enclosure.2.  :

i- 3

TVA had requested this meeting to provide an update to the NRC staff on its. l l plans to address B96-03. TVA's November 4,1996 response to this bulletin had  !

< indicated that it would provide additional information to the staff regarding- l plans for suction strainer modifications within 90 days of staff approval of the Utility Resolution Guidelines (URG). Because of delays in submittal and i review of the URG, TVA has proceeded at risk to design and procure an upgraded

' strainer for installation in BFN Unit 2 during its upccming refueling outage.

TVA plans to submit a description of the strainer upgrade to fulfill the

, commitment of the November 4,1996 letter, but wanted to brief the staff in

[ advance to ensure it submits information. addressing staff concerns.

[ Key BFN design features are outlined in TVA's handout. Of particular interest is the use of reflective metal insulation on reactor coolant system components, with fibrous insulation found only within some containment

penetrations.

- TVA is using the URG for the BFN strainer design. The largest strainer

supportable by the existing nozzle is being ordered. TVA's design objectives are to maximize debris loading margin for pump net positive suction head with no credit being taken for containment pressurization; that is, the new

' strainer'is larger than would be required if it were sized merely to accommodate known sources of debris.

j

~During discussion of the debris sources, the staff noted that a generic

communication is being considered to address containment coating issues.

Recently, the staff has becomo aware of problems with tracking of unqualified coatings, and the coating integrity which appears to be sound during routine

)

F visual inspections. l 9704090235 970407 >

PDR P

ADOCK 05000259 PDR 3g h J 1

, TVA plans to submit its supplemental resp:nsi to B96-03 in late May 1997. The modifications will be performed under the provisions of 10 CFR 50.59, so prior staff approval would not be required. The staff noted that priority will be given to reviews for facilities unable to make the modification: under 10 CFR 50.59, with plant-specific (such as Browns Ferry) and generic reviews having lower priority. The staff stated that, while it expects to complete a safety evaluation of TVA's modification, that action would not be a prerequisite for BFN Unit 2 restart-at the end of its refueling outage.

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

Enclosures:

1. Attendance List

2. TVA Handout cc w/ enclosures: See next page Distribution MARD COPY w/ Enclosures 1 and_2 Docket. File-PUBLIC BFN Reading OGC ACRS J. Williams E-MAIL w/ Enclosure I l S. Collins /F. Miraglia (SJC1,FJM)

R. Zimmerman.(RPZ)

S. Varga (SAV)

J. Zwolinski (JAZ) l D. Ross (e-mail to SAM) >p G. Tracy (GMT)

R. Elliott (RBE) '

K. Kavanagh (KAK)

M. Marshall (MXM2)

A. Serkiz (AWS) / l R. Capra (RAC1) i M. Lynch (MDL)

J.. Johnson, RII

, . DOCUMENT NAME: G:\BFN\M96135.MTG 4 n u e . , .e w. 4 we. . w m. wu c co,y wiinooi .ti.cs oii.ncio. . co ,, with .ti.cn ntioncio.u,. = - no ., ,

0FFICE Poll 3/PM j ,, l Poll 3/LA l PDil 3/D , I [t l  !

MAME JWittfans- M RClayton A,/IN FHebdon S W DATE 04/ / /97 / 7 04/ T /97 04/ ~7 /97 0FFICIAL RECORD COPY

BROWNS FERRY NUCLEAR PLANT cc:-

Mr. Oliver D. Kingsley, Jr. Mr. Timothy E. Abney, Manager President, TVA Nuclear and Licensing and Industry Affairs Chief Nuclear Officer Browns Ferry Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place P.O. Box 2000 1101 Market Street Decatur, AL 35609 Chattanooga, Tennessee 37402-2801 Regional Administrator Mr. O. J. Zeringue, Sr. Vice President U.S. Nuclear Regulatory Commission Nuclear Operations Region II i Tennessee Valley Authority 101 Marietta Street, NW., Suite 2900 Atlanta, GA 30323

~

6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Leonard D. Wert Senior Resident Inspector Mr. Jack A. Bailey, Vice President Browns Ferry Nuclear Plant Engineering & Technical Services U.S. Nuclear Regulatory Commission Tennessee Valley Authority 10833 Shaw Road 6A Lookout Place Athens, AL 35611 1101 Market Street Chattanooga, TN 37402-2801 Chairman Limestone County Commission Mr. C. M. Crane, Site Vice President 310 West Washington Street Browns Ferry Nuclear Plant Athens, AL 35611 Tennessee Valley Authority P.O. Box 2000 State Health Officer Decatur, AL. 35609 Alabama Department of Public Health

> 434 Monroe Street General Counsel Montgomery, AL 36130-1701 Tennessee Valley Authority ET 10H 400 West Summit Hill Drive Knoxville, TN 37902 Mr. Raul R. Baron, General Manager Nuclear Assurance and Licensing Tennessee Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Masoud Bajestani, 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

. TVA plans to submit its supplemental response to B96-03 in late May 1997. The modifications will be performed under the provisions of 10 CFR 50.59, so prior staff approval would not be required. The staff noted that priority will be given to reviews for facilities unable to make the modifications under 10 CFR 50.59, with plant-specific (such as Browns Ferry) and generic reviews having lower priority. The staff stated that, while it expects to complete a safety evaluation of TVA's modification, that action would not be a prerequisite for BFN Unit-2 restart at the end of its refueling outage.

l ~ ?- y Joseph F. Williams, Project Manager Project Directorate 11-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation a

> Docket Nos. 50-259, 50-260 and 50-296

Enclosures:

1. Attendance List 4

2. TVA Handout cc w/ enclosures: See next page I

1 l

I l

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ATTENDEES NRC/TVA_, MEETING ON BROWNS FERRY ECCS SUCTION STRAINERS

MARCH 27. 1997 HAmg Oraanization Joe Williams NRC/NRR/DRPE/PD II-3 i

Donald Chung NUS LIS

, Steve Kane TVA - Browns Ferry Licensing Mike Oliver TVA - Browns Ferry Plant Engineering 4

J. D. Wolcott TVA - Browns Ferry Plant Engineering Rob Elliot NRC/NRR/DSSA/SCSB Kerri Kavanagh NRC/NRR/DSSA/SRXB

Mike Narshall NRC/RES Al Serkiz NRC/RES i

h ENCLOSURE 1

AGENDA 1.0 Intro 6w. tion and Meeting Objectives S.M.Kane 2.0 BFN Plant Configuration J. D. Wolcott -

1' 3.0 Approach for Resolving Bulletin 96-03 J. D. Wolcott 4.0 Debris Source Term J. D. Wolcott 5.0 ECCS Pump NPSH Evaluation J. D. Wolcott 6.0 implementation Timeline S.M.Kane i

7.0 Summary and Open Discussion S.M.Kane i

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1 ENCLOSURE 2

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1.0 INTRODUCTION

S AND MEETING OBJECTIVES l

L e Outline 'Apracia Used for Resolving Bulletin 96-03, Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors

-e Review Timeline for Material Fabrication, Delivery and Installation i

e Identify Any Staff Concems t

1 l

i f

S. M. Kane 1

2.0 BFN PLANT CONFIGURATION i

e Mark i Containment

.e Common Emergency Core Cooling System (ECCS) Suction Ring Header e Ring Header Provides Normal Supply to Four Residual Heat Removal and Four Core l Spray Pumps t

e Four Strainers (40 Square Feet) Distributed Along the ECCS Ring Header e Primarily Reflective Metal Pipe Insulation inside Drywell

• i e Fibrous insulation in Some Containment Penetrations '

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J. D. Wolcott 2- "

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3.0 APPROACH FOR RESOLVING BULLETIN 96-03 e Will Utilize Boiling Water Reactor Owners' Group (BWROG) Utility Resolution Guidelines (URG) 1

• Strainer Sizing Strainers Sized and Ordered "At Risk", Prior to Design Completion ,

t Ordered Largest Physical Size:

• ' Supportable By Existing Nozzle i

• No Change in Mark i Long Term Torus Integrity Program Analysis .l Methodology i

• No Structural Modifications to Torus Required e Objectives l -

Maximize Debris Loading Margin Provide Adequate Net Positive Suction Head (NPSH) With No Credit For' j Containment Pressurization s

J. D. Wolcott 3 t

4.0 DEBRIS SOURCE TERM >

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• Pipe Insulation Debris Generation and Modeling Majority of Insulation inside Drywell is Reflective Metallic Insulation (RMil

• Strainers Designed for Saturation RMI Loading Limited Fibrous Insulation in Containment Sleeves

• Completely Recessed Within the Sleeves

• Would Be Dislodged Only By Pipe Break Within the Sleeve .

• Assume Most Limiting Penetration Fibrous Debris

. e 100 Percent Transport to Strainers e Maximum Strainer Design Loading Based on Either Saturation RMI or Most Limiting Penetration Fibrous Debris i

t J. D. Wolcott 4 i i

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4.0 DEBRIS SOURCE TERM (CONT.) -

l.

e Other Modeling Considerations

- Sludge Assumptions I l

l Dirt / Dust Values -

- Qualified Coatings c

Unqualified Coatings

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Rust 1

- Foreign Material Exclusion (FME) Programs i

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4 J. D. Wolcott 5

5.0 ECCS PUMP NPSH EVALUATION U"8 URG 3 23 2 Drywell Debris and r-32A2. , , ,

ksent#y msulaban identry m r , Transport matrs, mart amat separahon #Y charactenstes- at eacit break 9'*h"9 '

locahons and quantty locahon (d req'd) (W Wd)

Y21.2.2 k g 3 g_3 l RG 2.3 2.1 f l URG 3 212 sq Determme Z01 for each material and p9e break of mterest. >URG3232 URG321.1 +

Apply the appropriate w Determee volume of 201 above/below c b ed deb Y A. lowest grahng (# req'd). p

+ 8"PP'***'0" M to matenalin ZOt i M 2.3 f.f Determine amount of debris for each RG 23 f.5 mat'l in the Z08. Determme amount abovebelow grahng (i req'd) 1 EI RG 231.2 JRG 3 2 f 2 3 f Identdy total amount of matenal of interest m the O3g bn P

W Assume a au becomes debns and is transported to the suppressson pool.

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for the g

URG 3 2 2 21 JRG1???? JRG 319 3 JRG 3 2 3 3 valuate dryweH Evaluate drywell Evaluate drywell 8

quantity of fixed, non- quantity of latent Evaiuate Other drywet 4

h @isutahon debns (e g', d e b ris (e.g , cansport of these debne m the Page 2 qualified coatings, unqualified coating, debns speces suppression pool etc ) etc) l RG 23 f.3 RG 231.4 RG 2321 RG 231.3 pg g3 g_4 RG 231.4 Thrs Figure shows the mator steps in the evaluabon of ECCS pump ******Y"**#***'* * "

NPSH as descr bed in the URG. It is not a replacement for the the evaluation f NPSH. The BWROG recommends that NRC review and approve gudance m the URG Reference is made to appbcable sections of a e are at vanance 2 h m h N p to h p h mA h the URC, and Reg Guide 182. Rev. 2 as an med to the user. the sizing of passive strainers used to assure compliance with the requirements of 10CFR50 46.

J. D. Wolcott 6

7 5.0 ECCS PUMP NPSH EVALUATION (CONT.) .

Suppression Pool ,

Debris and Transport t

l l .

t W hsulation 's

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__>: d. tin in the ,

Fmm i sep=esen poos !

Page1 '. .

\....

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t l  !

l 1RG 124 2 # ## IRG3243 1 V URG 3 2 5 Evaeuate quantay of Evaluate quantty suppressen pool Evaluate Evaluate quantdy of of dwt/ dust atm ,

debns other than Total detms in the suppression Total m the suppressen sludge (e g.. rust frorn sgpression pool Page 3

, pooltransport debris loading

! pool unpainted surfaces and setthng etc)

RG 2.11.6 pg 73,_g RG 2 31.7 )l k RG 2322 RG2323 RG 23 24  ;

RG 23 25 i

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Other drywell ,

_ _ _ _ - _ , . d t,ns mine . .

Frtyn k suppression pool /

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• f Page 1 *

+

J. D. Wolcott 7 '

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I 5.0 ECCS PUMP NPSH EVALUATION (CONT.) -

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NPSH Evaluation i

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, URG 3 2.6.2. f -

URG 3 2 6 2.1 g% URG3263 strasner flow

** " Desagn basis pump rate (s)

Ch*'" NPSH requrements RG 2.1 f.t RG2234 *

URG 12g,2'- oon, URG 32623 ung 3_g g 3 }

Is NPSH URG1263 i Total straener Calculate strasner head ' Calculate available available >

p  : debns loading loss

• 7 ECCS pump NPSH 90PSH Page 2 '. l , RG 2.1.1.1

'._'......~,s' RG 2.3 31 RG2334 RG 2332 RG 2.323 RG 23.3.3 As appropnete eso RG2335 yng3gggg RG 2.33 6

. ReAne a@ of '

debns source term (s)

Evaluate temperature eflect on strainer head . Reduce dobrte loss and NPSH source term (s)

URG 3 26.24 RG 2.334 -L i..- .-

Q .

Containment pressure consadorabons - Revine licenoeg basis to improve '

NPSH RG2334

- Other resokstion option

- Combensbon of above

,

• Assure that the URG head loss correlations for the debns of interest are apphcable to the strainer I design evaluated. If not, those head loss correlations which are applicable to the strainer being a

evaluated should be used, and their basis appropnately jushfied J. D. Wolcott 8

__ _ ______ - _ _ _ .- _ _ _ - _ _ _ O

6.0 IMPLEMENTATION TIMELINE TVA / NRC CORRESPONDENCE

^ ^

^

- - V W^

NRC Letter, deemd 54666 TVA Laesr. dated 1104/96, TVA Laner, suppiamonesi P5tC h and W Bunstm 9643- Potenbei Response to Buseen 9643 Response b Bubstm 9643 [As Required]

Pkwne of EGS Sucean ECCS Pump NPSH Ewouston sinuners Anecomend by 5t2257

• Unit 2 Cycle 9 outae*

9(2187 -10(19M7 DESIGN / FABRICATION / DELIVERY C C w r- -  % ., -

3/17S7 Anacsposed try 8f2547 l

C O e.sm % we* %ce 3/1787 Aneces!.d by F/22s7 S. M. Kane 9

O O , g D #

^

7.0

SUMMARY

AND OPEN DISCUSSION .

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{

S. M. Kane 10

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