ML18100A688
| ML18100A688 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 10/29/1993 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLR-N93173, NUDOCS 9311050232 | |
| Download: ML18100A688 (4) | |
Text
- Public Service Electric and Gas Company I
Stanley LaBruna Public Service Electric and Gas-'company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1700 Vice President - Nuclear Engineering OCT 29 1993 NLR-N93173 U.S. Nuclear Regulatory commission Document Control Desk Washington, DC 20555 Gentlemen:
SIGNIFICANT PEAK FUEL CLAD TEMPERATURE CHANGES SALEM GENERATING STATION UNITS 1 & 2 DOCKET NOS. 50-272 AND 50-311 Pursuant to the requirements of 10CFR50.46(a) (3) (ii), Public Service Electric and Gas (PSE&G) hereby submits changes of more than fifty degrees to the calculated peak cladding temperature (PCT) for Salem Units 1 and 2 Small Break Loss of Coolant Accident (SBLOCA) analyses.
These two offsetting changes are a result of a modeling error in the NOTRUMP code used for the SBLOCA analysis and also an improvement to the model for condensation of steam in the intact loops.
The change to the NOTRUMP model resulted from the discovery that the historic assumption of no safety injection into the broken loop was non-conservative rather than conservative, such that explicitly modeling the safety injection into the broken loop was a significant PCT penalty (+150°F).
However, a model improvement for the condensation of steam in the intact Reactor Coolant System loops has added sufficient margin (-150°F) to offset the broken loop effect.
Therefore, the total PCT penalty to the SBLOCA analyses is zero.
Details of the above changes were previously transmitted to the Document Control Desk by Westinghouse (Ref. ET-NRC-93-3971).
PSE&G, in conjunction with the Westinghouse Owners Group, is reviewing the need for further analyses or code changes as a result of this issue and the possible development of a generic program for resolution.
It is anticipated that by 1/31/94, a schedule for completion of this issue will be determined.
Also, discontinuities were discovered in NOTRUMP relative to conditions in the vertical flow regime map.
Westinghouse corrected these errors which resulted a PCT benefit ranging from
-13 to -55 degrees based upon representative plants.
For the purposes of tracking PCT, the minimum benefit of -13 degrees has been conservatively assigned to these changes.
However, since it
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Document Control Desk NLR-N93173 2 -
OCT 29 1993 has been demonstrated that the effect of these changes may exceed a benefit of 50°F and could potentially be considered significant per 10CFR50.46, this PCT change is included in this report.
No additional analyses to determine the absolute benefit is scheduled at ~his time; however, should the SBLOCA analyses be updated for other reasons, a Salem specific value for this issue will be obtained.
Therefore, as stated previously, PSE&G will credit only the minimum PCT benefit for conservatism.
A summary of the current Salem SBLOCA peak clad temperature margin utilization is included in Attachment 1 to this report.
Should you have any questions concerning this transmittal, please contact us.
Sincerely,
.~~~
C Mr. T. T. Martin, Administrator - Region I U. s. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. J. c. Stone, Licensing Project Manager
- u. s. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville,.MD 20852 Mr. c. s. Marschall (S09)
USNRC Senior~Resident Inspector Mr. K. Tosch, Manager, IV NJ Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625
NLR-N93173 I.
ATTACHMENT 1 SMALL BREAK LOCA ANALYSIS -
SUMMARY
(Oct, 1993)
SB LOCA NOTRUMP Based Analysis Result, WCAP 13657
= 1580°F II.
Subsequent permanent PCT margin allocation:
Description of *Issue PCT Change
- 1)
Effect of Safety Injection.in Broken Loop 150°F
- 2)
Effect of' Improved Condensation Model
-150°F
- 3)
Drift Flux Flow Regime Errors*.*.
-l3°F Total Permanent Allocations
= -l3°F NET PERMANENT SB LOCA PCT (1580 - 13)°F = 1567°F SB LOCA PCT LIMIT = 2200°F PCT value of record at the time of NOTRUMP approval by the NRC August 25, 1993.
REF:
NLR-N93173 STATE OF NEW JERSEY SS.
COUNTY OF SALEM
- s. LaBruna, being duly sworn according to law deposes and says:
I am Vice President - Nuclear Engineering of Public Service Electric and Gas Company, and as such, I find the matters set forth in the above referenced letter, concerning the Salem Unit Nos. 1 and 2 Generating Stations, are true to the best of my knowledge, information and belief.
. Subscribed and Sworn t~()before me
_:*this ff1 t)L_
day of (Y@+/-p~, 1993 My Commission expires on KIMBERLY JO BROWN NOT ARY PUBLIC: OF NEW JERSEY My Commission Expires April 2 J, 19!18