ML092230343
| ML092230343 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 07/30/2009 |
| From: | Pitesa J Duke Energy Carolinas, Duke Energy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML092230343 (6) | |
Text
PDuke EEnergy MCGUIRE NUCLEAR STATION Duke Energy Corporation 12700 Hagers Ferry Rd.
Huntersville, NC 28078 704 875 4000 July 30, 2009 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001
Subject:
Duke Energy Carolinas, LLC (Duke)
McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-370 Response to Request for Additional Information Regarding Amendment to Technical Specification 3.8.1, "AC Sources-Operating," Revised Surveillance Requirements By letter dated December 1, 2008, Duke submitted a license amendment request (LAR) to correct a non-conservative situation by revising McGuire Technical Specification Surveillance Requirement 3.8.1.4 to increase the minimum required amount of fuel oil for the Emergency Diesel Generators (EDG) fuel oil day tank from 120 gallons to 39 inches of fuel oil (approximately 160 gallons) as read on the local gauge used to perform the surveillance.
By email dated June 10, 2009, the NRC requested additional information to complete the review of this LAR. The attachment to this letter provides the requested additional information.
Please direct any questions, you may have in this matter to P. T. Vu at (980) 875-4302.
Very truly yours, J. W. Pitesa Vice President - Nuclear Support AcI¢ www. duke-energy. corn
U.S. Nuclear Regulatory Commission July 30, 2009 Page 2 xc w/
Attachment:
L. A. Reyes Administrator, Region II U.S. Nuclear Regulatory Commission Atlanta Federal Center 61 Forsyth Street, Suite 23T85 Atlanta, GA 30303 J. B. Brady NRC Senior Resident Inspector McGuire Nuclear Station J. H. Thompson (addressee only)
NRC Project Manager (MNS and CNS)
U.S. Nuclear Regulatory Commission Mail Stop 0-8 G9A Washington, DC 20555-0001 B. 0. Hall, Senior Chief Division of Radiation Section
-1645 Mail Service Center Raleigh, NC 27699-1645
U.S. Nuclear Regulatory Commission July 30, 2009 Page 3 John W. Pitesa affirms that he is the person who subscribed his name to the foregoing statement, and that all the matters and facts set forth herein are true and correct to the best of his knowledge.
John W Pitesa, Vice President, Nuclear Support Subscribed and sworn to me:
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Attachment Response to Request for Additional Information
U.S. Nuclear Regulatory Commission Attachment July 30, 2009 Page 1 of 2 Request for Additional information (RAI)
Intro Discussion:
McGuire licensing basis and Technical Specification (TS) Surveillance Requirement (SR) 3.8.1.4 requires adequate supply of fuel in the day tank to provide at least 30 minutes of run time for the EDG at 100 percent load. This is significantly less than the 60 minute fuel oil storage requirement recommended in American National Standards Institute N195-1976 which is endorsed by Regulatory Guide 1.137. In view of the marginal storage capacity, the NRC staff requests the following additional information to complete the review of the proposed amendment.
RAI Question #1:
The fuel oil volume in the day tank will vary according to the ambient temperature. Hence, the calorific value (BTU/per gallon) will vary according to temperature. Provide details for establishing fuel oil volume in the day tank that envelope worst case design basis temperature.
Response
Fuel oil day tank setpoint calculations are based on a minimum fuel oil specific gravity that accounts for maximum EDG room design basis temperature.
RAI Question #2:
The low level alarm is set at 40 inches which corresponds to 165 gallons. Provide details of instrument uncertainty calculation that demonstrates that the low level alarm setpoint and the proposed day tank level setpoint (39 inches) for TS compliance do not have overlap regions.
Response
Instrument loop uncertainty could result in day tank low level alarm receipt below the proposed SR 3.8.1.4 setpoint. However, this alarm is not used or required to verify the surveillance requirement. The low level alarm allows ample time to allow an orderly shutdown of the EDG from full load operation, assuming the occurrence of a fuel oil transfer pump failure. This function is not impacted by the proposed change to the day tank level setpoint.
RAI Question #3:
EDG fuel oil consumption rates can vary depending on maintenance practices and engine efficiencies. Describe whether site specific tested fuel oil consumption rates were used in calculating the fuel oil storage requirements.
Response
The McGuire EDGs were initially installed at the Dan River Steam Station for type-testing and qualification for nuclear service. During this time, the engine manufacturer, Nordberg, remained involved with the installation maintenance and testing of the engines. At the end of the time these engines were at this facility and after this testing, Nordberg provided Duke a consumption rate of 0.508 pounds-mass per kilowatt hour when the engine is operating at 100% design load
U.S. Nuclear Regulatory Commission Attachment July 30, 2009 Page 2 of 2 and consuming #2 diesel fuel. Duke validated the Nordberg supplied information with on site, pre-startup fuel consumption testing. The Duke calculations which determine the fuel oil storage requirements were derived using this fuel consumption value provided by the engine manufacturer. Duke recognized that diesel fuel properties may fall within a range allowed by Technical Specifications and therefore used this input parameter to size fuel tanks while assuming the lowest allowed specific gravity permitted by Technical Specifications. Specific gravity is the parameter which defines the density and therefore heating value of the fuel and Technical Specifications allow the specific gravity to vary from 0.83 to 0.89. The Duke calculations for fuel storage assume all of the fuel in the storage tank is at a specific gravity of 0.83.