ML17229A120
| ML17229A120 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 11/04/1996 |
| From: | Wiens L NRC (Affiliation Not Assigned) |
| To: | Plunkett T FLORIDA POWER & LIGHT CO. |
| References | |
| TAC-M74473, TAC-M74474, NUDOCS 9611070096 | |
| Download: ML17229A120 (5) | |
Text
November 4, 1996 Mr. Thomas F. Plunkett President, Nuclear Division Florida Power and Light Company Post Office Box 14000 Juno
- Beach, Florida 33408-0420 Distribution
-Docket...Fi.l e-i PUBLIC
- SVarga, St. Lucie Rdg."
Dear Mr. Plunkett:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) CONCERNING ST.
LUCIE PLANT, UNITS 1
AND 2, INDIVIDUAL PLANT EXAMINATION (IPE)
SUBMITTAL (TAC NOS.
M74473 AND M74474) ii J
"J l ii JJ Based on the continuing review of the St.
Lucie Units 1 and 2 IPE submittal, the NRC staff has determined that additional'information is needed J
to complete our review.
The information needed
'is specified in the enclosure to this letter and was discussed with members of your staff 'during,a telephone J
i call on September 13, 1996.
A response to this RAI is requested within 60 J
fi Ji J
days of receipt.
If you have questions concerning this request, please contact me at (301) 415-1495.
Sincerely, Original signed by Leonard A. Wiens, Senior Project Manager Project Directorate II-3 Division of Reactor Projects-I/II Office of Nuclear Reactor Regulation Docket No. 50-335 and 50-389
Enclosure:
Request for Additional Information cc:
See next page DOCUMENT NAME:
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St. Lucie Nuclear Power Plant, Units I 3
2 IPE Review Supplemental Request for Additional Information BACK-END 1.
The probability of in-vessel recovery (core melt terminated) is high for most PDSs.
This is apparently due to the high probability of RCS depressurization, core coolant injection recovery, and core debris in a eoolable formation in the IPE.
In-vessel recovery eliminates challenges to early containment failure due to HPME and reduces challenges to late containment failure associated with core-concrete interaction, The effects of the assumptions related to in-vessel recovery on the overall containment failure probabilities for St. Lucie are not evaluated and discussed in the IPE submittal.
Please discuss the basis and uncertainties associated with these parameters and discuss the results of your available sensitivity studies covering the CET quantifications.
2.
The statement made in the "Summary and Conclusions" section of the IPE submittal (Sect.
4.8) that "the major contributors to early containment failure for St.
Lucie include containment threats due to HPME loads from high RCS pressure core damage accidents, steam explosion events for low pressure sequences, and isolation failures" is not consistent with the CET quantification results provided in Attachment 12 of the RAI responses.
According to the results presented in RAI responses early containment failure for St. Lucie is dominated by two CET end states for a high pressure PDS.
These two CET end states are associated with successful RCS depressurization (thus no HPME) and the major contributor to containment failure is from overpressurization (with a conditional probability of 0. I), not from steam explosion (with a conditional probability of 0.008).
HPME is not a major contributor because of high probability of successful RCS depressurization.
Similarly, the statement on late containment failure that "the major contributor to late containment failure is steam overpressure in the long term is not consistent with the results presented in the IPE RAI response.
It fails to mention that the major contributors to late containment failure are CET end states associated with core-concrete interaction (or eoolable debris not formed ex-vessel).
According to the data presented in the IPE, the probability of containment failure due to steam pressure alone (without CCI) is, in general, much less than that with CCI.
Please clarify these apparent discrepancies by differentiating in your discussion between the actual CET results obtained for your plant and the hypothetical MAAP code results.
HUMAN RELIABILITYANALYSIS 1.
For all the human failure events denoted as slips, please provide:
the total time available for the operator to take action, the estimated response times required to mitigate the condition, and a listing of the relevant ques the operator would rely on to indicate to him the need to take action.
ENCLOSURE
FRONT-END 1.
Provide the failure rate of the auto-trip function and the operator failure probability for manual scram following failure of auto-trip.
2.
Please discuss why there appears to be no plant-specific failure rate data (FTS or FTR) incorporated into the IPE for the turbine driven AFW pump considering that many tests have been made?
Discuss the basis for combining pump failure data at St. Lucie for pumps with different vendors, sources of power, inservice testing requirements, and service lives.
3.
Please explain how the cutset cutoffs were used for different initiators.
For instance, how did you assure yourselves that the residual was adequately small.
4.
Please provide your work papers covering the loss-of-offsite power derivation, including the power non-recovery assumptions and the breakdown for LOOP causes (weather, grid, plant-centered).
Mr. T. F. Plunkett Florida Power and Light Company St. Lucie Plant CC:
Jack Shreve, Public Counsel Office of the Public Counsel c/o The Florida Legislature 111 West Madison Avenue, Room 812 Tallahassee, Florida 32399-1400 Senior Resident Inspector St.
Lucie Plant U.S. Nuclear Regulatory Commission 7585 S.
Hwy AIA Jensen
- Beach, Florida 34957 Joe Myers, Director Division of Emergency Preparedness Department of Community Affairs 2740 Centerview Drive Tallahassee, Florida 32399-2100 J.
R.
Newman
- Morgan, Lewis 8 Bockius 1800 M Street,'.W.
Washington, DC 20036 John T. Butler, Esquire
- Steel, Hector and Davis 4000 Southeast Financial Center Miami, Florida 33131-2398 Mr. Thomas R.L. Kindred County Administrator St. Lucie County 2300 Virginia Avenue Fort Pierce, Florida 34982 Mr. Charles
- Brinkman, Manager Washington Nuclear Operations ABB Combustion Engineering, Nuclear Power 12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 Mr. Bill Passetti Office of Radiation Control Department of Health and Rehabilitative Services 1317 Winewood Blvd.
Tallahassee, Florida 32399-0700 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street, N.W. Suite 2900 Atlanta, Georgia 30323 H. N. Paduano, Manager Licensing 5 Special Programs Florida Power and Light Company P.O.
Box 14000 Juno
- Beach, Florida 33408-0420 J.
A. Stall, Site Vice President St. Lucie Nuclear Plant P. 0.
Box 128 Ft. Pierce, Florida 34954-0128 J. Scarola Plant General Manager St.
Lucie Nuclear Plant P.O.
Box 128 Ft. Pierce, Florida 34954-0128 Mr. Kerry Landis U.S. Nuclear Regulatory Commission 101 Marietta Street, N.W. Suite 2900 Atlanta, Georgia 30323-0199 E. J.
Weinkam Licensing Manager St.
Lucie Nuclear Plant P.O.
Box 128 Fort Pierce, Florida 34954-0128