ML20135F151

Application for Amend to License NPF-35,revising Tech Specs Re ESFAS Instrumentation Trip Setpoints.Fee Paid

ML20135F151
Person / Time
Site:	Catawba
Issue date:	09/10/1985
From:	Owen W DUKE POWER CO.
To:	Adensam E, Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML20135F155	List: ML20135F151 ML20135F160
References
NUDOCS 8509170173
Download: ML20135F151 (5)

Text

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DUKE POWER GOMPAAT Pownn BmLmxo. Box 00180. CHARLOTrm. N. G. asa4a W.M.QWEN RESCW w=Cs ES+0Eu?

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• • '""** "*" " "** September 10, 1985 Mr. Harold R. Denton. Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Ms. E. G. Adensam. Chief Licensing Branch No. 4 Re: Catawba Nuclear Station Docket No. 50-413 Technical Specification Amendment

Dear Mr. Denton:

This letter contains proposed amendments to the Technical Specification for Facility Operating License No. N?F-35 for Catawba Unit 1. The attachment contains the proposed changes and a discussion of the justification and safety analysis. The analysis is included pursuant to 10 CFR 50.91 and it has been concluded that the proposed amendments do not involve significant hazards considerations. It is also requested that these changes be incor-porated into the proposed Catawba Units 1 and 2 combined Technical Specifi-cations which were transmitted by my letter of March 15. 1985.

This request involves one amendment request to Catawba's Technical Specifi-cations. Accordingly, pursuant to 10 CFR 170.21 a check for $150.00 is enclosed.

Pursuant to 10 CFR 50.91 (b) (1) the appropriate South Carolina State Official is being provided a copy of this amendment request.

Very truly yours.

W. H. Owen ROS: sib Attachment 1{O h 3 90 P

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Nk Harold R. Denton, Dircctor September 10, 1985 Page Two ec: Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. P. H. Skinner NRC Resident Inspector Catawba Nuclear Station Mr. Heyward G. Shealy, Chief Bureau of Radiological Health S. C. Department of Health & Environmental Control 2600 Bull Street Columbus, South Carolina 29201 Mr. Jesse L. Riley Carolina Environmental Study Group 854 Henley Place  ;

Charlotte, North Carolina 28207 Palmetto Alliance 2135 Devine Street Columbia, South Carolina 29205 Robert Guild Esq.

P. O. Box 12097 l Charleston, South Carolina 29412 INPO Records Center Suite 1500 1100 circle 75 Parkway Atlanta, Georgia 30339 American Nuclear Insurers c/o Dottie Sherman, ANI Library The Exchange, Suite 245 270 Farmington Avenue Farmington, CT 06032 M&M Nuclear Consultants 1221 Avenue of the Americas.

New York, New York 10020 a

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Mr. Harold R. Denton, Director 1 September 10, 1985 Page Three W. H. Owen, being duly sworn, states that he is Executive Vice President of Duke Power Company; that he is authorized on the part of said Company

to sign and file with the Nuclear Regulatory Commission this revision to the Catawba Nuclear Station Techncial Specificaitions. Appendix A to License No. NPF-35; and that all statements and matters set forth therein are true and correct to the best of his knowledge.

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a W. H. Owen, Executive Vice President j

Subscribed and sworn to before me this 10th day of September,1985.

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Notary Public i

My Commission Expires:

September 20, 1989 I

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JUSTIFICATION AND ANALYSIS'0F NO SIGNIFICANT HAZARDS CONSIDERATION The steam genefator low-low water level trip function protects the reactor from a loss of heat sink in the event of a sustained steam /feedwater flew mismatch. Analyses were performed to justify lowering the programmed steam generator low-low level setpoint for Catawba Unit 1. This setpoint change, along with the addition of a filter to the channel circuitry, will help pre-vent unnecessary reactor trips as a result of load rejections. This change will also prevent unnecessary actuation of the turbine-driven auxiliary feedwater pump due to spurious steam generator low-low level indications which result from " ringing" in the level transmitters. This benefit has been verified by observation of McGuire reactor trips since implementation of this setpoint modification.

To verify the acceptability of the proposed changes, Westinghouse has re-analyzed the Loss of Normal Feedwater, Loss of AC Power, and Feedwater System Pipe Break transients, which rely on the steam generator low-low level reactor trip for protection. The responses of various system param-eters to the above analyzed accidents are given in the attached figures.

Results of these analyses indicate that all applicable safety criteria are met using the revised setpoint and the increased instrument delay time.

For the Loss of Normal Feedwater and Loss of AC Power analyses, it was necessary to revise the original FSAR assumption from one auxiliary feed-water pump feeding two steam generators to two auxiliary feedwater pumps feeding three steam generators in order to compensate for the lower low-low level setpoint. Allowing for the most limiting single failure, a conservatively low flow rate of 600 gpm provided by the two pumps was assumed. The Feedline Break assumption of one auxiliary feedwater pump feeding two steam generators with a flow rate of 492 gpm remains un-changed. The FSAR will be revised to reflect the new assumptions.

The Feedwater Malfunction accident is the only other accident analyzed in the FSAR which takes credit for a reactor trip on steam generator low-low level. During this accident a malfunction is postulated which causes an increase in feedwater flow. When the steam generator level in the faulted loop reaches the high-high level setpoint, all feedwater isolation valves , ,

and feedwater pump discharge valves are automatically closed and the main feedwater pumps are tripped. This prevents a continuous addition of feed-water and initiates a turbine trip. The analysis does not take credit for a reactor trip on turbine trip. Consequently following the turbine trip, core power stabilizes at a reduced level consistent with the reactivity parameters assumed to maximize the initial increase in power. The reactor is tripped on steam generator low-low level if no action is taken by the operator to terminate the reduced power operation. The revised steam generator low-low level setpoint will only delay the time of reactor trip at the reduced power level. Even assuming a delayed reactor trip, the DNBR limit is not exceeded at any time during the accident.

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This evaluation has examined the impact of the proposed steam generator low-low level setpoint on the accident analyses performed in the FSAR. All accidents which take credit for a reactor trip on steam generator low-low level were analyzed. The results of these analyses indicate that all safety criteria are met using the revised setpoint.

10 CFR 50.92 states that a proposed amendment involves no significant hazards considerations if operation in accordance with the proposed amendment would not:

(1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or 4

l (3) Involve a significant reduction in a margin of safety.

The proposed amendment does not involve an increase in the probability or consequences of any previously evaluated accident. The accident analyses have been reviewed and all acceptance criteria has been satisfied.

The proposed amendment does not create the possibility of a new or different.

kind of accident than any previously evaluated since there will be no physical changes made to any plant system other than the reduction of the trip setpoint.

, The proposed amendment does not involve a significant reduction in a margin of safety. All applicable safety analyses have been reviewed and all accept-ance criteria will be met with the revised setpoint.

The Commission has provided guidance concerning the application of standards of no significant hazards determination by providing certain examples (48 FR 14870). This change is similar to example (vi).

For the reasons stated above, it is concluded that the proposed amendment does not involve significant hazards considerations.

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