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UNITED STATES 5
NUCLEAR REGULATORY COMMISSION k
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WASHINGTON, D.C. 20555-0001 Docket $os.50-335 Jang 4,1994 and 50-389 MEMORANDUM FOR:
Herbert N. Berkow, Director Project Directorate II-2 i
Division of Reactor Projects - I/II FROM:
Jan A. Norris, Sr. Project Manager f
Project Directorate 11-2 Division of Reactor Projects - I/II
SUBJECT:
INDIVIDUAL PLANT EXAMINATION FOR ST. LUCIE UNITS 1 AND 2 l
(TAC NOS. M74473 AND M74474)
By letter dated December 9,1993, Florida Power & Light Company (FPL) has submitted its Individual Plant Examination (IPE) for St. Lucie Units 1 and 2 in accordance with Generic Letter 88-20, " Individual Plant Examination for 4
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Severe Accident Vulnerabilities - 10 CFR 50.54(f)," and NUREG-1335, a
" Individual Plant Examination Guidance." This submittal includes a Level 2 PRA.
Internal Events (Level 1) Findinas The overall core damage frequency due to internally initiated events for St.
Lucie 1 is 2.3E-5/yr and for St. Lucie 2 is 2.6E-5/yr. This is much less than the NRC safety goal of 1.0E-4/yr.
The overall core damage frequency for St. Lucie Units 1 and 2 is within the range of past PRAs performed for PWRs. Thus, the susceptibility to core damage at St. Lucie Units 1 and 2 is not unlike other PWRs.
I The largest contributor to core damage risk is small-small (I/2" - 3") LOCAs, I
31% and 29% for Units 1 and 2, respectively. Total loss of feedwater events are also important accident sequences for core damage risk, 27% and 28% for Units 1 and 2, respectively.
St. Lucie has several means of providing feedwater to the steam generators for decay heat rencval. No vulnerability related to USI A-45, Decay Heat Removal, has been identified.
Containment Performance (Level 2) Findinas The St. Lucie Units 1 and 2 large dry containment design provides adequate capability to mitigate severe accidents., No unusual poor containment performance has been found.
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' o The greatest threat to containment integrity is due to a loss of all containment heat removal during an accident where the RCS is at high pressure.
Steam generation without the ability to remove heat and condensate steam increases the likelihood that high pressure melt ejection at vessel breach can iall the containment.
A key feature of the St. Lucie containment design is that for almost all accident sequences, the reactor cavity is flooded with water.
This decreases the likelihood of reactor vessel failure due to ex-vessel cooling and results in lower releases (due to retention of fission products in the RCS and scrubbing of ex-vessel fission products by the water) compared to vessel failure and core failure on a dry cavity floor.
The St. Lucie PRA has been performed in a manner consistent with the objectives stated in Generic Letter 88-20 and the results show that there are no plant-unique severe accident vulerabilities. Consequently, FPL did not make any modifications to the units.
FPL performed the PRA analyses of their nuclear sites in sequence. Turkey Point Units 3 and 4 preceded St. Lucie Units 1 and 2.
The work on PRA for the Turkey Point units was done by Science Applications International Corporation with FPL engineers perfoming over 50% of the work. With the experience gained during the Turkey Point PRA, FPL developed the St. Lucie PRA with minimal contractor support.
(Original Signed By)
Jan A. Norris, Sr. Project Manager Project Directorate 11-2 Division of Reactor Projects - I/II cc:
See next page Distribution Decket File PDIl-2 RF S. Varga G. Lainas T. Murley/F. Miraglia L. J. Callan 1
W. Russell S. Varga A. Thadani J. Wiggins E. Rossi B. Boger R. Hernan C. Ader J. Flack H. Berkow E. Tana J. Norris OGC ACRS (10)
M. Sinkule, RII PM:PDb 0: PDII-J 0FC LA:PDIl-2 JNorrksNJ HBer h )
NAME ETana J
- i 9g I l/ /93 DATE
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0FFICIA'. RECORD COPY - FILENAME: S:\\PRA.SL j
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Mr. J. H. Goldberg Florida Power and Light Company St. lum : Plant I
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Jack Shreve, Public Counsel Mr. Bill Passetti Office of the Public Counsel Office of Radiation Control c/o The Florida Legislature Department of Health and
'111 West Madison Avenue, Room 812 Rehabilitative Services
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Tallahassee, Florida 32399-1400 1317 Winewood Blvd.
Tallahassee, Florida 32399-0700 Senior Resident Inspector St. Lucie Plant Regional Administrator, RII U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission 7585 S. Hwy A1A 101 Marietta Street N.W., Suite 2900 Jensen Beach, Florida 34957 Atlanta, Georgia 30323 j
Mr. Joe Myers, Director Mr. H. N. Paduano, Manager Div. of Emergency Preparedness Licensing & Special Projects Department of Community Affairs Florida Power and Light Company 2740 Centerview Drive P.O. Box 14000 Tallahassee, Florida 32399-2100 Juno Beach, Florida 33408-0420 Harold F. Reis, Esq.
D. A. Sager, Vice President Newman & Holtzinger St. Lucie Nuclear Plant 1615 L. Street, N.W.
P.O. Box 128 Washington, DC 20036 Ft. Pierce, Florida 34954-0128 John T. Butler, Esq.
C. L. Burton Steel, Hector and Davis Plant General Manager 4000 Southeast Financial Center St. Lucie Nuclear Plant Miami, Florida 33131-2398 P.O. Box 128 Ft. Pierce, Florida 34954-0128 Mr. Thomas R.L. Kindred County Administrator St. Lucie County 2300 Virginia Avenue Fort Pierce, Florida 34982 Mr. Charles B. Brinkman, Manager Washington Nuclear Operations ABB Combustion Engineering, Nuclear Power 12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 9
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