ML12128A030
| ML12128A030 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 04/16/2012 |
| From: | Repko R Duke Energy Carolinas, Duke Energy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML12128A030 (8) | |
Text
REGIS T. REPKO 7' 1eDuke Vice President Energy McGuire Nuclear Station Duke Energy MG01 VP.! 12700 Hagers Ferry Rd.
Huntersville, NC 28078 980-875-4111 980-875-4809 fax regis.repko@duke-energy.com April 16, 2012 10 CFR 50.90 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001
Subject:
Duke Energy Carolinas, LLC (Duke Energy)
McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-370 Amendment to Technical Specification 3.8.3, "Diesel Fuel Oil and Starting Air" Response to Request for Additional Information By letter dated September 26, 2011, Duke Energy submitted a License Amendment Request (LAR) for the Renewed Facility Operating License and Technical Specifications for McGuire Nuclear Station Units 1 and 2. The proposed LAR adopted Westinghouse Standard Technical Specification (NUREG-1431) 3.8.3 Condition E regarding Diesel Generator starting air receiver pressure limits.
By letter dated March 15, 2012, the Nuclear Regulatory Commission (NRC) staff requested additional information regarding this LAR. The attachment to this letter provides the response to this request for additional information. There are no regulatory commitments contained in this submittal. The conclusions reached in the original determination that the LAR contains No Significant Hazards Considerations and the basis for the categorical exclusion from performing an Environmental/Impact Statement have not changed as a result of this request for additional information.
Please direct any questions you may have in this matter to P. T. Vu at (980) 875-4302.
Very truly yours, Regis T. Repko Attachment www.duke-energy.com , g "
U. S. Nuclear Regulatory Commission April 16, 2012 Page 2 xc:
V. M. McCree Administrator, Region II U. S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 J. Zeiler NRC Senior Resident Inspector McGuire Nuclear Station J. H. Thompson (addressee only)
NRC Project Manager U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 W. L. Cox, Ill, Section Chief Division of Environmental Health, Radiation Protection Section North Carolina Department of Environmental and Natural Resources 1645 Mail Service Center Raleigh, NC 27699-1645
.U. S. Nuclear Regulatory Commission April 16, 2012 Page 3 Regis T. Repko 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.
Regis T. Rgpko, Vice President, McGuire Nuclear Station Subscribed and sworn to me: ( 14, Aif2rL Date 101%j-Public My commission expires: / 2-0/2--
ATTACHMENT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
U. S. Nuclear Regulatory Commission Attachment April 16, 2012 Page 1 of 4 Question 1-1:
In section 3.0 of the LAR, the licensee states:
McGuire Updated Final Safety Analysis Report [UFSAR] Figure 9-143 provides a summary flow diagram of the VG [Starting Air] system. Note that this figure will be revised to show the cross-connection line between the VG sub-trains upstream of the VG receiver tanks.
Please provide the proposed revised figure referenced in section 3.0 of the LAR so that the proposed cross connection is clearly identified.
Response
The figure is provided below with the cross connection line shown immediately upstream of the VG receiver tanks, as described in the third paragraph of section 3.0 in the LAR submitted September 26, 2011. Revised Figure 9-143 was incorporated into the UFSAR by Revision 16 in 2011.
Figure 9-143 BMR7SRN FILl DRYERA2/R2 RFTERCOORERN AIR AZ/BZ COMPRESSORAZ/R2 NOTES, E..
C UIT
.. *S T-O *ISEL Er.-NS ýAA.D THE-: NGINE.
A ANDA EAVSSREA E[SUEP4iENT TAG N.EDBVRSAREDISL*AYEO.
B. SOLE7.O10 lA *LS 'VOSASI6C/V55 S /511S. HA LOCATDA
.A 116EE ANTE DRICTRW t &A:HEHADR. SEE E&C E40EVO.03
.ETAILSMCI4-(UNITI)A.OfI-49v~* UI )
B. 1241B VALVE IUEB- TYPICAl. FOR UNITS I AND 2 "UIMARY fLOWDýtR BEER-1IA-RE.AE STATEE
((BuITA DIESEL GENERHATrOR INE SM N-J4-!I. ,4*! ST INt
U. S. Nuclear Regulatory Commission Attachment April 16, 2012 Page 2 of 4 Question 1-2:
In Section 3.0 of the LAR, the licensee states:
Empirical test data from VG system testing was used to determine the mass of air required per start during multiple starts from a single air receiver.
Section 9.5.6.1, "Design Bases," of the UFSAR states:
Analysis based on results obtained during testing finds the McGuire diesels are capable of starting 5 times consecutively from the initial conditions of one of the two starting air receivers isolated, the other receiver at the lowest pressure allowed by Technical Specifications and diesel room temperature at the highest allowed by Selected Licensee Commitments. At least the first of these 5 consecutive starts will be a fast start.
Please provide the empirical test results and analysis, including the assumptions.
Response
The analysis of the VG system begins with the empirical testing in which the 1 B diesel was started using 1 of 2 starting air receivers (the other was isolated during the test by closing local valves), and then the diesel was started and shut down repeatedly until it would no longer start.
This table provides the test results from this test:
1B Diesel Start Test Data Start Attempt 11B1 Beginning 11B1 Ending Calculated Change in Time to Receiver Receiver Pressure (Beginning - Speed Pressure Pressure Ending Receiver (seconds)
(psig) (psig) Pressure) (either psig or psia) 1 225 188 37 9.4 2 188 160 28 9.5 3 160 142 18 10.0 4 142 129 13 10.1 5 129 117 12 10.6 6 117 108 9 10.9 7 108 100 8 11.0 8 Will not start, shaft did not rotate Table 1 - Test Results This test served as the basis for the analysis and it suits this application because the engine was challenged to start as many times as a single receiver would allow. The initial conditions of this test were not identical to the conditions which must be analyzed in this calculation but this test serves as the input to determine the mass of air consumed for each successive start. The data obtained was then adjusted using the Ideal Gas Equation to determine the mass of air consumed for the diesel start. This resulted in the following table being developed:
U. S. Nuclear Regulatory Commission Attachment April 16, 2012 Page 3 of 4 Start Number Change in Calculated Mass Receiver of Air for Start Pressure (psia) (Ibm) 1 37 19.31 2 28 14.61 3 18 9.40 4 13 6.79 5 12 6.26 6 9 4.70 7 8 4.18 Table 2 - Calculated Mass of Air for Each Start With the mass of air determined for each start, the initial starting air pressure was reduced to the lowest pressure at which the diesel is considered operable, the room temperature was assumed to be at the highest allowable room temperature (resulting in less mass of air in the receiver at the elevated pressure), and the resulting pressure at the end of each start calculated. Since it would be impractical to heat the room and allow temperature to stabilize at the highest temperature allowed, this analysis accounts for this condition. The results of this analysis are summarized in the following table:
Start Receiver Mass in Mass Consumed Mass in Receiver Attempt Pressure At Receiver At During Start (Ibm) Receiver at Pressure at Beginning of Beginning of End of Start End of Start Start (psig) Start (Ibm) (Ibm) (psig) 1 210.0 103.75 17.00 86.75 173.2 2 173.2 86.75 12.07 74.68 147.0 3 147.0 74.68 8.56 66.12 128.5 4 128.5 66.12 6.08 60.04 115.3 5 115.3 60.04 4.31 55.73 106.0 6 106.0 55.73 3.06 52.67 99.4 Table 3 - Calculated Pressures Following Each Start This table finds the diesel is capable of 5 starts since the starting pressure in the receiver at the beginning of the 5th start attempt is greater than the lowest starting air pressure which successfully started the engine in the empirical testing. The assumptions used in the calculation are summarized below:
- 1. The VG air receiver tank volume is 100 cu. ft. There is piping connected between the tank and engine starting air solenoid valves which is pressurized to the same pressure as the tank and serves as additional volume of stored air for starting the engine. For the analysis of empirical test data, the total volume of pressurized piping will include the 3" piping and the filter housing. Small lines and vent piping will not be accounted for as these are not significant contributors to the total volume.
- 2. Air is the gas analyzed in this calculation and will be treated as an ideal gas.
- 3. This calculation uses empirical test data to determine the receiver pressure drop per start, and then calculates the mass of air consumed from that pressure drop. The temperature of the air or receiver was not recorded during testing. For this testing, it is assumed that the temperature of the air in the receiver was 75 0 F.
U. S. Nuclear Regulatory Commission Attachment April 16, 2012 Page 4 of 4
- 4. The diesel room temperature can vary from 55 0 F to 1250 F without declaring the associated diesel inoperable. This calculation takes a calculated mass of air per start and applies the most limiting room temperature assuming the air in the receivers has equalized with this room temperature.
- 5. The empirical test data used does not list the starting pressures in the tank before each start, only the ending pressure. It is assumed the starting pressure for the next start is equal to the ending pressure of the previous engine start. This approach assumes no leakage from the receiver or VG system between starts.
- 6. This calculation is based on one empirical test performed. It is assumed the test results of this one test may be applied to the other engines and other VG receivers. The VG systems between the 4 emergency diesel generators are similar; the engines are all the same model and are maintained to the same standards.
- 7. Any reduction in receiver volume due to water accumulation is disregarded. Routine blowdown of this water prevents the accumulation of water and therefore this volume would be small and inconsequential to the outcome of this analysis.