L-93-127, Application for Amend to License NPF-16,requesting Approval of Improved Methodology, Extended Statistical Combination of Uncertainties (Escu). Proprietary Rept CEN-371(F)-P Encl.Rept Withheld (Ref 10CFR2.790(a)(4))
| ML17228A269 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 08/27/1993 |
| From: | Sager D Florida Power & Light Co |
| To: | NRC/IRM |
| Shared Package | |
| ML17228A270 | List: |
| References | |
| L-93-127, NUDOCS 9309020208 | |
| Download: ML17228A269 (7) | |
Text
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REGUL~RY INFORMATION DISTRIBUT~ SYSTEM (RIDS)
I ACCESSION NBR:9309020208 DOC.DATE: 93/08/27 NOTARIZED: YES FACIL:50-389 St. Lucie Plant, Unit 2, Florida Power 6 Light Co.
AUTH.NAME AUTHOR AFFILIATION SAGER,D.A.
Florida Power !'ight Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
DOCKET 05000389
SUBJECT:
Application for amend to License NPF-16,requesting approval of improved methodology, "Extended Statistical Combination of Uncertainties (ESCU)." Proprietary rept CEN-371(F)-P encl. Rept withheld (ref 10CFR2.790(a)(4)).
DISTRIBUTION CODE:
AP01D COPIES RECEIVED:LTR ENCL t
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TITLE: Proprietary Review Distribution Pre Operating License a Opera ing R
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1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE V/ASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO EL!MIHATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DOH'T HEED!
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LTTR 15 ENCL 13
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August 27 r 1993 P.O. Box 12$, Ft. Pierce, FL 34954-0128 L-93-217 U.
S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.
C.
20555 Re:
St. Lucie Unit 2 Docket No. 50-389 1.
NRC Letter November 9,
- 1984, Docket 50-389: J.R.
Miller to J.W. Williams, Enclosure 2:
SAFETY EVALUATION SUPPORTING AMENDMENT No.
8 TO FACILITY OPERATING LICENSE NPF-16.
2.
NRC Letter October 21,
- 1987, Docket No. 50-317 and 50-318: Scott Alexander McNeil to J.A. Tiernan,
Subject:
SAFETY EVALUATION OF TOPICAL REPORT CEN-348(B)-P, "EXTENDED STATISTICAL COMBINATION OF UNCERTAINTIES" (TACS 64985 Ec 64986).
ENCLOSURE (1)
TO THIS LETTER CONTAINS PROPRIETARY INFORMATION PURSUANT TO 10 CFR 2.790(a)(4).
Florida Power and Light Company (FPL) hereby requests approval of an improved methodology, "Extended Statistical Combination of Uncertainties (ESCU)",
for the applications described in the proprietary report CEN-371(F) -P dated July, 1989 (Enclosure
- 1).
The report describes the application of ESCU to the calculation of aggregate analytical uncertainties associated with Departure from Nucleate Boiling (DNB) related analog protection and monitoring system setpoints for St. Lucie Unit 2.
Approval of this improved methodology is requested by February 28, 1994.
ESCU is a modification that upgrades the methodology currently approved for use at St.
Lucie Unit 2
(Reference 1) to combine calculational and measurement uncertainties associated with the calculated Thermal Margin/Low Pressure (TM/LP) Limiting Safety System Setting (LSSS) and DNB Limiting Condition for Operation (LCO).
This same ESCU methodology was previously approved by the NRC on October 21, 1987 (Reference
- 2) for specific application to a
Combustion Engineering (C-E) plant using C-E 14 x
14 fuel assemblies and analog protection and monitoring systems.
The enclosed report is the same as Reference 2 except that it addresses the plant specific differences in design between St. Lucie Unit 2 (e.g.,
C-E 16 x 16 fuel assemblies) and Reference 2.
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L-93-217 The individual measurement and calculational uncertainties described in CEN-371(F) -P are unchanged from those previously approved by the NRC for use in St.
Lucie Unit 2
core reload analyses.
The statistical procedure used to combine these uncertainties (ESCU) is unchanged from the methodology described in the Topical Report that was approved by the NRC in Reference 2.
The resultant penalties imposed on the St.
Lucie Unit 2
TM/LP-LSSS and DNB-LCO setpoint calculations will continue to incorporate all uncertainties at the 95/95 probability/confidence level.
A revised numerical value of the minimum DNB Ratio (MDNBR) limit for St. Lucie Unit 2 using C-E 16 x 16 fuel assemblies is derived in CEN-371(F)-P.
When used in conjunction with ESCU, this MDNBR limit (1.20) provides assurance that there is at least a 95: probability at a 95~ confidence level that the hot fuel rod in the reactor core does not experience DNB during normal operation or design basis Anticipated Operational Occurrences (AOO).
For these
- reasons, the existing minimum acceptable margin of safety associated with the St. Lucie Unit 2
Specified Acceptable Fuel Design Limits on DNB willremain unchanged by application of the ESCU methodology.
Facility Technical Specifications (TS) Bases pages that willrequire revision due to the change in methodology are provided in Attachment 1.
These pages are marked-up to show the proposed bases changes which will become effective following implementation of ESCU.
Enclosure 1 to this letter contains proprietary information, the disclosure of which would compromise a trade secret and commercial information considered by Combustion Engineering, Inc. as privileged or confidential.
Pursuant to 10 CFR 2.790(a)(4)
FPL requests that the enclosed report CEN-371(F) -P be withheld from public disclosure.
Very truly yours, A. Sa Vice Pre St. Luc'e dent Plant DAS/RLD/kw DAS/PSL N975-93 Attachments:
(1) St. Lucie Unit 2 TS Bases Pages B 2-1, B 2-4, and.
B 3/4 2-2.
(2) Affidavit pursuant to 10 CFR 2.790.
4 j
I C
Enclosure:
(1) CEN-371(F)-P, Extended Statistical Combination of Uncertainties: Combustion Engineering; July, 1989; Copy No.
000001 Stewart D. Ebneter, Regional Administrator, Region II, USNRC (w/ Enclosure 1,
Copy No.
000036)
Senior Resident Inspector, USNRC, St. Lucie Plant (w/ Enclosure 1,
Copy No.
000037)
J.
M.
Betancourt, Project
- Manager, Nuclear
- Fuel, Asea Brown Boveri/Combustion Engineering, Inc.
(w/o enclosure)