ML20033F294
| ML20033F294 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 02/28/1990 |
| From: | Crocker L Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| IEB-88-011, IEB-88-11, NUDOCS 9003190306 | |
| Download: ML20033F294 (6) | |
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WASHINGTON. D. C. 20555
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February 28, 1990 Docket No.
50-424 LICENSEE:
Georgia Power Company FACILITY:
Vogtle Electric Generating Plant, Unit 1
SUBJECT:
SUMMARY
OF MEETING TO DISCUSS THERMAL STRATIFICATION IN PRESSURIZER SURGE LINE On February 26, 1990, the NRC staff met with representatives of the licensee, Georgia Power Company, to discuss the proposed modifications and supporting calculations to resolve problems regarding thermal stratification in the pressurizer surge line at Vogtle Unit 1.
The agerida f or the meeting is at Enclosure 1 while presents a last of attendees.
Vogtle Units 1 and 2 originally were designed with two fixed supports for the pressurizer surge lines.
The line layouts are mirror images, and are constructed of identical materials.
Vogtle Unit I was licensed and went into initial operation with the two fixed supperts.
On December 20, 1988, NRC Bul1etin 88-01 informed the industry that problems with excessive surge line movement had been observed at some
- plants, believed due to thermal j
stratif ication in the surge lines causing larger than expected oipe l
deflections.
As a result of this bulletin, the support system for i
Vogtle Unit 2 was re-designed to replace one of the two fixed supports with a snubber and spring hanger to allow the line unrestrained movement.
This re-design was accepted by the staff l
and Vogtle Unit 2 was licensed with this modification installed.
The licensee now desires to modify Unit 1 to remove one of the two fixed restraints, replacing it with a snubber and spring hanger, l
and making the Unit I surge line support system identical to the existing Unit 2 surge line support system.
The calculations supporting the Unit 2 surge line modification were presented in WCAP-12218(P). Additional unit specific calculations demonstrating ASME Code _ compliance for Unit 1 are presented in WCAP-12210, i
l Supplement 1(P).
The licensee presented a
series of slides explaining and demonstrating the effects of line slope and flow rate on thermal stratification, the correlation between the calculational methods and observed data, and the structural analyses of the surge line using these data.
The slides used contain proprietary data and are not included with this meeting summary.
However, a non-proprietary version of the slides will be made available.
The_ analysis demonstrating the structural integrity of the surge line over the remaining lifetime of Unit I was performed using leak-before-break criteria.
The licensee desires to rely on these 9003190306 900228
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PDR ADOCK 05000424 0\\
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e o Mr. W. G. Fairston, III l
Georgia Power Company Yogtle I.lectric Cenerating Plant CC*
lir. J. A. Bailey Resident Inspector Manager - Licensing Nuclear Regulatory Connission l
Georgia Power Company P.O. Box 572 P.O. Eox 1295 Waynesboro, Georgia 30830 Birn.ingham, Alabama 35201 James E. Joiner, Esq.
Bruce W. Churchill, Esq.
Troutmen, Sanders, Lockerman, Shaw, Pittman, Potts and Trowbridge
& Ashmore 2300 N Street, N.W.
1400 Candler Building Washington, D.C. 20037 127 Peachtree Street, N.E.
Atlanta, Georgia 30303 Mr. G. Bockhold, Jr.
General Manager, Vogtle Electric Mr. R. P. Mcdonald Generating Plont Executive Vice Prtsident -
P.O. Box 1000 huclear Operations Waynesboro, Georgia 30830 Georgia Power Conpany P.O. Box 1295 Regional Administrator, Region !!
Birmingham, Alabama 35201 U.S. kuclear Regulatory Conaission 101 Marietta Street, N.W., Suite 2900 Mr. J. Leonard Ledbetter, Director Atlanta, Georgia 30323 Environnental Protection Division Department of Natural Resources Office of the County Commissioner 205 Butler Street, S.E., Suite 1252 Burke County Commission Atlanta, Georgia 30334 Waynesboro, Georgia 30830 Office of Planning and Dudget Attorney General Room 615B Law Departnent 270 Washington Street, S.W.
132 Judicial Building Atlanta, Georgia 30334 Atlanta, Georgia 30334 Mr. C. K. McCoy Mr. Alan R. Herdt, Chief Vice Presient - Nuclear, Vogtle Project Project Branch #3 Georgia Power Company U.S. Nuclear Regulatory Commission P.O. Box 1295 101 Marietta Street, NW, Suite 2900 Birmingham, Alabama 35201 Atlanta, Georgia 30323 6
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Enclosure i Vogtle Unit 1 Pressurizer Surge Line Thermal Stratification February 26, 1990 AGENDA 1:00 PM Design Transients (Unit 1 Delta-T) 1:30 PM Flow Profile Assumptions 2:30 PM Stress Analysis 3:00 PM Fatigue Usage Factors 4:00 PM Leak Before Break Analysis
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Vogtle Unit 1 Pressurizer Surge Line Thermal Stratification Meeting February 26, 1990 f
ATTENDANCE LIST Name ReDresentinq Position Larry Crocker NRR/PD 11-3 Backup PM, Vogtle Jim Bailey Georgia Power Company Licensing Mgr, Vogtle Brad Maurer Westinghouse Nuclear Safety Seth Swamy Westinghouse Materials Technology T.H.
Liu Westinghouse Piping Technology Rajni B.
Patel Westinghouse Plant Engineering, Manager-SSAD David H.
Roarty Westinghouse Materials Technology Sarita Brewer NRC/EMEB Engineer Giuliano DeGrassi NRC/BNL Consultant Shou-nien Hou NRC/EMEB Senior Mech. Engineer P.T.
Kuo NRC/EMEB Section Chief E.L.
Crawford Westinghouse Engineer J.C. Williams Georgia Power Cmpany Plant Engr. Supervisor M.F.
Testa Duquesne Light Engineer S. Lee NRC/EMCB Materials Engineer Bill Coslow Westinghouse Materials Technology
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AGENDA NRC AUDIT OF BULLETIN 88-11 ISSUES AT V0GTLE UNIT 1 & 2 1.
Audit Discussion items A.
Surge line inspection results B.
Corrective actions implemented or planned C.
Surge line monitoring program and results from on line monitoring and operating logs D.
Surge line analysis methods and models 1.
Transient definition and basis 6.
Stratification profiles b.
Striping 2.
Piping & support structural analysis 3.
Line defection, thermal gradient and local stresses 4.
Stress concentration by weld attachrents E.
Code evaluation - Stress & fatigue 1.
Load, load combination and code allowables 2.
Verification of code compliance
- 11. Document Review A.
Surge line inspection reports B.
Surge line drawings, including drawing updates to reflect corrective actions C.
Stress reports 1.
Detailed calculation, including design and modification of piping and supports 2.
Computer models used 3.
ASME Code evaluation 4.
Deflection assessments to ensure no adverse interaction with other structures D.
Monitoring Program reports E.
Other relevant licensee or NSSS reports 111. Walkcown (Ifaccessible)
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criteria _ since a complete re-analysis of the piping would be required if the leak-before-break criteria cannot be used.
The support system modifications are intended to be installed during the current Unit i ref ueling/ maintenance outage which is scheduled to be complete by about mid-March. A complete re-analysis probably could not be perf ormed in time to meet the scheduled re-start date, and could possibly result in the need for changes to the pipe whip restraints due to changes in postulated break locations.
The NRC staff plans to visit the Vogtle site on 6-7 March to audit the licensee *s response to the Bulletin 80-11 issues.
An agenda for the staff audit visit is at Enclosure 3.
Assuming that the audit does not reveal any unf oreseen problems, the staf f should be able to prepare a safety evaluation by about the end of March, which can be used to support issuance of a license amendment for the modifications to Unit 1 prior to completion of the refueling outage.
/s/
Lawrence P. Crocker, Project Manager Project Directorate 11-3 Division of Reactor Projects-I/11 Enclosures As stated cc. See attached sheet DISTRIBUTION w/ enclosures:
A DecketT E M LCrocker NRC & Local PDRs gram PDil-3 Rdg. Files JSniezek,12/G/18 EJordan DMatthews NRC Participants ACRS(10)
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