ML20135F872

Summary of 850805 Meeting W/Util & B&W in Bethesda,Md Re Proposed Exemption to GDC 4 for Reactor Coolant Pump Supports.Viewgraphs Encl

ML20135F872
Person / Time
Site:	Crystal River
Issue date:	09/03/1985
From:	Mozafari B Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 8509170458
Download: ML20135F872 (19)

Text

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, 3 1985 Docket No. 50-302 LICENSEE: Florida Power Corporation

FACILITY

Crystal River, Unit 3

SUBJECT:

SUteARY OF MEETING TO DISCUSS REQUEST FOR EXEMPTION FROM GENERAL DESIGN CRITERIA 4 0F 10 CFR 50, APPENDIX A

Introduction j 1985, the NRC staff met with representatives of Florida Power On Corporation August 5,(the licensee) and Babcock & Wilcox in Bethesda, Maryland to discuss the licensees proposed exemption to GDC-4 for Reactor Coolant Pump (RCP) supports. The list of participants is included as Enclosure 1. ,

Discussion The licensee requested a meeting among NRC staff, Babcock & Wilcox, and FPC .

representatives to clearly define NRC staff needs for information to support  !

l the approval of the proposed exemption request. Presentations were made by FPC and B&W, sumarizing the history of the leak-before-break analysis at Crystal River, and the proposed schedule for completing the removal and/or ,

replacement of the subject hydraulic snubbers. A sumary of the licensee's  !

] description of the history and justification for the request is included as Enclosure 2. In addition, a B&W report (BAW 1847) presents conclusions (see Enclosure 2) which support the modification concept.

The licensee's proposed exemption request is based in part on Generic Letter 84-04 in which the staff accepted the use of the leak-before-break concept on j j certain dockets for certain piping support system analyses. The licensee -

j intends to use similar methodology to justify excluding dynamic LOCA loads ,

from RCS piping and thereby reduce the number of large bore hydraulic  !

snubbers on the reactor coolant pumps. Resultant benefits include reduced

! occupational exposure, improved thermal flexibility, and reduced outage time.

The licensee asked for NRC support in providing timely reviews to meet the  !

, tight submittal schedule shown in Enclosure 2. Specifically, early  ;

l indication of acceptability in principal would be helpful to the licensee in '

initiating its procurement activities.

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! NRC representatives suggested that the licensee's submittal include the  ?

following

i 1. A discussion of the effect of the proposed changes on all safety l margins, including component supports as well as piping.

l 2. The effect on overall system reliability.

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! 3. InputonCodeCaseN-411(TypicalNRCquestionsonN-411were i transmitted separately to the licensee. ,

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4 8509170458 850903

• PDR ADOCK 05000302 '

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The NRC legal representative expressed reservations about the timely approval of an exemption request. FPC should alternately consider providing a comparison to the interim rule expected to be issued by the Comission later this year.

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Brenda Mozafari, Project Manager Operating Reactors Branch #4, DL

Enclosure:

1. List of Attendees

2. FPC Presentation Sumary B#4:DL 0 L BMozafari;cf lisilver 9/3 /85 9/y85 i

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.' MEETING

SUMMARY

DISTRIBUTION '

Licensee: Florida Power Corporation j

• Copies also sent to those people on service (cc) list for subject plant (s).

/ DocketJ.ild

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MDR L POR i ORB #4 Rdg ,

l Project Manager - BMozafari i JStolz j 8 Grimes (Emerg.Preparednessonly)

OELD l EJordan, IE

! ACRS-10 PMorriette i NRC Meeting

Participants:

H511ver i GVissing .

RKlecker l

. BShields, OELD i BBosnak i KWichman J0'Brien

! CYCheng i

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Enclosure 1 FLORIDA POWER CORPORATION - NRC MEETING CRYSTAL RIVER 3 - REQUEST FOR EXEMPTION FROM GDC 8 i

! Attendees Affiliation Harley Silver NRC/DL

! Gary Becker FPC Brenda Mozafari NRC/DL

Guy Vissing NRC/DL

! Randy Schaefer B&W

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J. Frank Walters B&W Joe Maseda FPC R. Klecker NRC/DE Bill Shields NRC/0 ELD i Bob Bosnak NRC/DE i

Keith Wichman NRC/DE John Stolz NRC/DL i Bert Simpson FPC L. Watson Bechtel-SGRCH i

! John O'Brien NRC/RES l

C. Y. Cheng NRC/DE l Lynn Connor Doc-Search Associates /The NRC Calendar

E. H. Davidson FPC K. R. Wilson FPC i

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Enclosure 2 l WEETING TO DISCUSS t

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REQUEST FOR EXEMPTION 4

GENERAL DESIGN CRITERIA 4 i

! PRESENTATION BY FLORIDA POWER CORPORATION t'fPC) i 1

' PHILLIPS BUILDING l

BETHESDA, MD.

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' i AUGUST 5,1985

AGENDA MEETING TO DISCUSS REQUEST FOR EXEMPTION GENERAL DESIGN CRITERIA 4 MRIPS BuluMNG, BETHESDA, MD.

AUGUST 5.1985 1:00 1. INTRODUCTION E. C. SIMPSON j A) FPC ATTENDEES B) PURPOSES OF MEETING l C) DISCUSSION OF AGENDA 1:05 11. BACKGROUND K. R. WILSON A) NRC PIPING REVIEW COMMITTEE B) B&W GENERIC SUBMITTAL OF OCT. 7,1984 l C) LBB METHODOLOGY AS APPLIED TO CR-3 i

D) FPC 12.1it:.M OF FEB.1,1985 1:20 111. CURRENT Pl.ANS OF FPC J. R. MASEDA

, A) PROJECT SCHEDULE TO SUPPORT REFUEL 6 j B) OPTIMlZATION ANALYSIS

- RECENT DAMPlNG VALUES

- RE1ENT10N OF STRESS MARGIN C) REVISED SCHEDULE OF SUBMITTALS 1:45 IV. INPUT FROM NRC A) COMMENTS ON FPC LETTER OF FEB.1,1985 B) COMMENTS ON CURRENT Pl.AN OF FPC C) SCOPE AND FORMAT OF FUTURE FPC SUBMITTALS D) SCHEDULE FOR NRC REVIEW .

2:00 V. CONCLUSIONS E. C. SIMPSON mee ena de =-- _ ce- -MrL due CM a NmN m m ag-

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i i II A NRC PIPING REVIEW COMMITTEE l KEY ACTIONS BY NRC i i l l

ITEM DATE l l

EDO REQUEST TO NRR, RES FOR REVIEW 0F PIPING 5/31/83 l l

EDO APPROVAL OF NRR, RES J0lNT PLAN FOR

• PIPE BREAK TASK GROUP 8/1/83 l l

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GL-84-04 FEB.1984

i PUBUCATION OF NUREG-1061, VOL 3 t

i EVALUATION OF POTENTIAL FOR PIPE BREAKS NOV.1984 i I

PUBUCATION OF NUREG-1061 VOL 5

SUMMARY

, PIPING REVIEW COMMITTEE CONCLUSIONS l AND RECOMMENDATIONS APRIL 1985 q

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KEY RECOMMENDATIONS FROM NUREG-1061 i >

RELEVANT TO FLORIDA POWER CORPORATION VOLUME / RECOMMENDATION DOCUMENT 3 USE WB, RATHER THAN DEGB 10 CFR 50, EXCLUDE DYNAMIC LOADS APPENDIX A, l PIPE WHIP, JET IMPINGEMENT, ET AL GDC-4, ET AL

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2 MODIFY SEISMIC DAMPlNG VALUES R. G. 1.61, t 4  :

USED IN SEISMIC DESIGN SRP 3.9.2 I

l 4 DECOUP2 SEISMIC & LOCA EVENTS  !

WHERE WB IS APPUCABLE SRP 3.9.3 1, 3 VERIFY LEAK DETENTION CAPABluTY TECH SPECS, R.G. 1.45 l

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11 B l B&W GENERIC SUBMITTAL OF OCT. 7,1984 l

BAW-1847  ;

77--1153295-00 SEPTEMBER 1984 .

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THE B&W OWNERS GROUP Leak-Before Break l

Evaluation of Margins Against Full Break for RCS Primary Piping of B&W-Designed NSS -

i Prepared for the

! Babcock & Wilcox Owners Group BABCOCK & WILCOX  :

Utility Power Generation Division

P.O. Box 1260 Lynchburg, Virginia l

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PRINCIPAL CONCLUSIONS OF BAW 1847 i

e DEGB 0F GDC-4 IMPLAUSERE 1

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• DETECTABLE IIAK RATES RESULT IN NO UNSTABli FUM GROWTH.

e POSTULATED LIAKAGE Fl.AW SIZES MUCH SMALLER THAN CRITICAL FLAW SIZE WHICH WlGHT LEAD TO PIPE FAILURE.

e CON 1R011ED REACTOR SHUTDOWN CAN OCCUR BEFORE PIPE WOULD FAIL IN A CATASTROPHIC MANNER.

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~ CRYSTAL RIVER VERSUS GENERIC EVALUATION:

l PIPE SIZE GENERIC MAXIMUM MOMENT FPC MAXIMUM MOMENT

( FT-KIPS ) ( FT-KIPS )

l 28" 1.D.  !

STRAIGHT 3098.0 AT JL 12 2004.4 AT JL 21.5 -

El. BOW 2822.8 AT Jt 24 1617.0 AT Jt. 27.5 l

36" 1.D. -

STRAIGHT 2376.5 AT Jt. 9 2230.1 AT Jt. 9 ELBOW 2376.5 AT Jt. 9 2230.1 AT Jt. 9 9

PIPE SIZE GENERIC MINIMUM MOMENT FPC MINIMUM MOMENT

, ( FT-KIPS ) ( FT-KIPS )

28" 1.D. -

STRAIGHT 560 AT Jt.12 1556.1 AT Jt. 21.5 ELBOW 1246 AT Jt. 24 1294.3 AT Jt. 27.5 36" 1.D. .

STRAIGHT 1010 AT Jt. 9 1738.0 AT Jt. 9 ELBOW 1010 AT Jt. 9 1738.0 AT Jt. 9

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• ,.S.- PP* - g e. me eW -. ewe. pp, e _ mo amme ** a__y =

11 D FPC 12.1itM OF FEB.1,1985 SCOPE OF REQUEST:

APPROVAL OF THIS EXEMPTION WILL ALLOW FPC TO REDESIGN THE RCS PUMP RESTRAINT SYSTEM IN ORDER TO: .

• REMOVE SEVERAL LARGE BORE HYDRAULIC SNUBBERS CURRENTLY RESTRAINING THE REACTOR C001. ANT PUMPS (UP TO 20 OUT OF A TOTAL OF 32).

l 8 REPLACE OTHER REACTOR COOLANT PUMP 1.ARGE BORE SNUBBERS WITH RIGID RESTRAINTS (4 RESTRAINTS).

I e REPLACE REMAINING REACTOR COOLANT PUMP LARGE BORE SNUBBERS WITH SMALLER SNUBBERS (8 SMAL1.ER SNUBBERS).

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OPTIMIZATION ANALYSIS Developed primary loop math model for study purposes.

32 large bore snubber (1000-2000 kips) can be replaced by 8 sneller snubbers (400 kip) and 4 rigid struts. .

A refined primary loop math model was developed for seismic and thermal analysis application.

Performed deadweight, thermal and OBE seismic analysis for the revised support config.uration.

Loading developed for the piping, pumps, motor, RV nozzles and OTSG nozzles.

Evaluated design piping loads with respect to generic LBB enveloping loads.

Preparing revised stress calculations for supplement to original RCS stress report.

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. DAMPING J

Original damping for vital piping systems is 0.5% of critical damping (as listed in FSAR & Reg. Guide 1.61).

RCS analysis for optimized support configuration utilizes variable damping from 2-5% of critical damping for piping' per ASME code case N-411 Provides adequate safety margins for seismic events, while improving the overall thermal flexibility of the system for normal operating conditions.

Code case N-411 approved by ASME in September 1984 and published in 1985 l

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RCS PRIMARY PIPING DESIGN PRIMARY STRESS MARGINS 4

New Support Configuration Old Support Configuration HOT LEG RV Outlet 53% 60%

OTSG Inlet 61% 56%

Minimum Margin 34% 24%~

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UPPER COLD LEG RV Inlet 51% 49%

Pump Discharge 59% 57%

l Minimum Margin 26% 26%

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LOWER COLD LEG OTSG Outlet 41% 34%

Pump Intake 57% 54%

Minimum Margin 3% 0%

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PROJECT SCilEDULE 1

Detailed design MAR 85 Jan 86 actiwilies ----( l Snubber manufacture NOV 85 Nov 86

. and delivery ---------------l l L ink bar manufacture FEl3 86 OCT 86 and delivery --------------------

l NRC/fPC planning and AUG 85 scheduling meeting NRC approval of SEPT 85 LB8 generic analysis NRC/fPC technical I 85 nesting -- ---------

NRC preliminary NOV 85 approval of G00-4 - - - - - - - - - - - - - -

partial exemption NRC formal approval of _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

E8 86 GDC-4 partial exemptiol MAR 87 JUNE 87 Refuel VI --------------------------------[ I

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f  ; i JAN JAN JAN MARCll 1987 1985 1986

SUBMITTAL SCHEDULE Crystal River Unit 3 Leak-Before-Break Evaluation of August,1985 RCS piping loads Crystal River Unit 3 " Safety Balance /Value Impact September,1985 Statement" l

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• October 30, 1985 RCS leakage detection system capability ovaluation I

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BENEFITS OF OPTIMIZATION Reduced radiation exposure to personnel of 2400 Man-Rem 1

over remaining plant life.

Savings of $15 million in labor, material, and equipment costs.

Improved accessibility to other equipment for maintenance and inspection.

Improved thermal flexibility of system

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