NLS2004019, Response to RAI Regarding Proposed License Amendment Request for Loss-of-Coolant Accident (LOCA) Dose Calculation Methodology and Resolution of Remaining License Condition 2.C0(6) Issues

Response to RAI Regarding Proposed License Amendment Request for Loss-of-Coolant Accident (LOCA) Dose Calculation Methodology and Resolution of Remaining License Condition 2.C0(6) Issues

ML040720324
Person / Time
Site:	Cooper
Issue date:	03/08/2004
From:	Edington R Nebraska Public Power District (NPPD)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NLS2004019, TAC MC1572
Download: ML040720324 (4)

Text

Nebraska Public Power District Always there when you need us NLS2004019 March 8, 2004 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Response to Request for Additional Information Regarding Proposed License Amendment Request for Loss-of-Coolant Accident (LOCA) Dose Calculation Methodology and Resolution of Remaining License Condition 2.C.(6) Issues Cooper Nuclear Station, NRC Docket No. 50-298, DPR-46

Reference:

1. Letter to R. Edington (Nebraska Public Power District) from U.S. Nuclear Regulatory Commission dated February 5, 2004, "Request for Additional Information Regarding Proposed License Amendment Request for Loss-of-Coolant Accident (LOCA) Dose Calculation Methodology and Resolution of Remaining License Condition 2.C.(6) Issues (TAC No. MCI 572)."

2. Letter to U. S. Nuclear Regulatory Commission from R. Edington (Nebraska Public Power District) dated December 9, 2003, "License Amendment Request for LOCA Dose Calculation Methodology and Resolution of Remaining License Condition 2.C.(6) Issues" (NLS2003105).

The purpose of this letter is to respond to the Request for Additional Information provided in Reference I regarding the previously submitted License Amendment Request of Reference 2.

These responses summarize information provided during a teleconference held on January 12, 2004 between Nebraska Public Power District (NPPD) personnel and members of the Nuclear Regulatory Commission staff.

Question I - Regardingthe installation of the new boundary valves, what sort of considerations wvere made in the sizing calculationsforthe handwh eel actuators? The specific concern is that the Operatorwill be able to close the valves without assistance under the process conditions that will exist.

Response - The new boundary valves are in the open position during normal plant operation.

They are standard ANSI rated valves with standard operators to meet normal and design operating conditions.

During the design basis accident, the valves would be manually positioned to establish the post-LOCA Main Steam Isolation Valve (MSIV) leakage pathway boundary. Because the valves are located downstream of the MSIVs and the MSIVs are closed, the only flow downstream is the very low leakage flow past the MSIVs. Additionally, since the MSIV COOPERNUCLEARSTATAON P.O. Box 98 / arownOille, NE 68321-0098 Telephone: (402) 825-3811/ F.vX: (402) 825-5211 www.nppd.com

NLS2004019 Page 2 of 4 leakage pathway to the Main Condenser will be open with condenser vacuum lost, the piping downstream of the MSIVs will be depressurized. Accordingly, operators will manipulate these valves at nearly zero differential pressure. Once positioned, the valves will not be re-positioned. Thus, there is no concern of thermal or pressure binding preventing subsequent valve operation. Moreover, each of the valves was manually operated after installation to assure they could be opened and closed.

Question 2 - Regarding the decision not to include the manual valves in the ISTProgram.

how will thefunctionaltesting beperformed,and how will the testing monitor/address degradingperformance?

Response - The Updated Safety Analysis Report will be revised to specify cycling of the manually operated valves) once per cycle during an outage. The evolution will be controlled via a Station Surveillance Procedure, and the scheduling and tracking of performance will be controlled under the station's surveillance program.

NPPD believes that inclusion of these valves in the Augmented Inservice Testing (IST)

Program is not necessary and would add minimal value for the level of effort to include them in the program. Other than exercising the valves, there is no IST-related testing that can be applied to trend degradation of manual, non-powered valves. Thus, cycling the valve to assure functionality under the surveillance program is an appropriate alternative to detect potential degradation of the valve's function to be manually repositioned. Deficiencies noted during the surveillance would be entered into the corrective maintenance process, or Corrective Action Program, as required.

Should you have any questions concerning this matter, please contact Mr. Paul Fleming at (402) 825-2774.

Sincerely, Rta dall K. Edington Vice President - Nuclear and Chief Nuclear Officer

/wrv I. The MSIV Leakage Pathway boundary consists of 13 valves that are manually closed, 3 power-operated valves that automatically close, and 2 remotely controlled air-operated valves that fail to the closed position during a design basis LOCA. The principal pathway is opened to the Main Condenser during a design basis LOCA by manually opening 3 motor-operated valves via the handwheel.

NLS2004019 Page 3 of 4 cc: Regional Administrator USNRC - Region IV Senior Project Manager USNRC - NRR Project Directorate IV-1 Senior Resident Inspector USNRC NPG Distribution Records

NLS2004019 Page 4 of 4 STATE OF NEBRASKA)

)

NEMAHA COUNTY )

Randall K. Edington, being first duly sworn, deposes and says that he is an authorized representative of the Nebraska Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly authorized to submit this correspondence on behalf of Nebraska Public Power District; and that the statements contained herein are true to the best of his knowledge and belief.

lRandall K. Edingo Subscribed in my presence and sworn to before me this _ day of Z / 2004.

/1 , GENERAL NO- State of Nebraskal

/__ A WIM M. WERNER NOTARY PUBLIC _Exp._Oct_26,2006