ML060390355

Response to Request for Additional Information Pertaining to License Amendment Request to Relocate RBS Flow Instrument from Technical Specifications Technical Specification Change (TSC) Number 2004-01, Supplement 1

ML060390355
Person / Time
Site:	Oconee
Issue date:	01/31/2006
From:	Brandi Hamilton Duke Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML060390355 (4)

Text

BRUCE H HAMILTON

_ Fuke Vice President f-PPowero, Oconee Nuclear Station Duke Power ON01 VP / 7800 Rocherster Highway Seneca, SC 29672 864 885 3487 864 885 4208 fax January 31, 2006 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Document Control Desk

Subject:

Oconee Nuclear Station Docket Numbers 50-269, 270, and 287 Response to Request for Additional Information Pertaining to License Amendment Request to relocate RBS flow instrument from Technical Specifications Technical Specification Change (TSC) Number 2004-01, Supplement 1 In a submittal dated August 20, 2004, Duke Energy Corporation (Duke) proposed to amend Appendix A, Technical Specifications, for Facility Operating Licenses DPR-38, DPR-47 and DPR-55 for Oconee Nuclear Station (ONS), Units 1, 2, and 3. The proposed amendment revises Technical Specification (TS) 3.3.8, "Post Accident Monitoring Instrumentation," to eliminate TS requirements associated with the Reactor Building Spray (RBS) flow instruments commensurate with the importance of their revised post accident function.

The proposed change removes the RBS flow instrument from TS 3.3.8 based on it no longer being a Type A or Category 1 variable. Recent modifications plugged approximately 50% of the reactor building spray nozzles and replaced the flow metering orifice in each RES header. This eliminated the need to manually throttle RBS flow rate within 15 minutes of accident initiation during the injection phase of post-accident operation, and the need to manually throttle RBS flow rate prior to transferring suction to the RBES.

Therefore, the variable is now Category 2, Type D.

During a conference call between Duke (Graham Davenport and Boyd Shingleton) and NRC Staff (Leonard Olshan, John Nakoski, and Joe Burns), the NRC requested Duke to provide a qualitative statement regarding the 50.59 evaluation for the A4g) www. dukepower. corn

January 31, 2006 Page 2 RBS flow modification and two calculations, OSC-7993 and OSC-5280, that support the modification.

The 50.59 safety evaluation for the RBS pump flow rate improvement modifications documents that RBS system operation was evaluated to demonstrate that the proposed change would not have an adverse effect on RBS pump performance, an adverse effect on LBLOCA long-term cooling requirements or have any adverse effect on the net positive suction head for the Low Pressure Injection pumps. The system resistances added by this modification are designed to provide RBS flow rates of 700 -1200 gpm, without requiring throttling. The range of flow rates and system performance within this range were evaluated in OSC-7993, RBS System Hydraulic Analysis for ON-X3105, and found to be adequate for injection and recirculation modes. The new flow rates were also used as input into OSC-5280, "FSAR Section 15.14.5 LBLOCA Long-term Cooling Requirements II," and no adverse effects due to this modification were found.

If there are any additional. questions, please contact Boyd Shingleton at (864) 885-471.6.

Very truly yours, Bruce H. Hamilton, Vice President Oconee Nuclear Site

January 31, 2006 Page 3 cc: Mr. L. N. Olshan, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-14 H25 Washington, D. C. 20555 Mr. W. D. Travers, Regional Administrator U. S. Nuclear Regulatory Commission - Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. M. C. Shannon Senior Resident Inspector Oconee Nuclear Station Mr. Henry Porter, Director Division of Radioactive Waste Management Bureau of Land and Waste Management Department of Health & Environmental Control 2600 Bull Street Columbia, SC 29201

January 31, 2006 Page 4 Bruce H. Hamilton, being duly sworn, states that he is Vice President, Oconee Nuclear Site, Duke Energy Corporation, that he is authorized on the part of said Company to sign and file with the U. S. Nuclear Regulatory Commission this revision to the Renewed Facility Operating License Nos. DPR-38, DPR-47, DPR-55; and that all the statements and matters set forth herein are true and correct. to the best of his knowledge.

Bruce H. Hamilton, Vice President Oconee Nuclear Site scribed and sworn to before me this 3 day of t 2006 ItryPublic My Commission Expires:

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