RS-15-065, Response to Request for Additional Information Regarding License Amendment to Revise Battery Surveillance Requirements
| ML15035A266 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 02/04/2015 |
| From: | Simpson P Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RS-15-065 | |
| Download: ML15035A266 (6) | |
Text
4300 Winfield Road Warrenville. IL 605'.15 Exelon Generation@
630 657 2000 Office RS-15-065 February 4, 2015 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265
Subject:
Additional Information Regarding Request for License Amendment to Revise Battery Surveillance Requirements
References:
- 1. Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. NRC, "Request for License Amendment to Revise Battery Surveillance Requirements," dated June 10, 2013
- 2. Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. NRC, "Additional Information Regarding Request for License Amendment to Revise Battery Surveillance Requirements," dated December 4, 2014 In Reference 1, Exelon Generation Company, LLC (EGC) requested an amendment to Renewed Facility Operating License Nos. DPR-29 and DPR-30 for Quad Cities Nuclear Power Station (QCNPS), Units 1 and 2, respectively. The proposed change revises Technical Specifications (TS) Surveillance Requirements (SR) 3.8.4.2 and SR 3.8.4.5 to add new acceptance criteria for total battery connection resistance.
Additional information was submitted in Reference 2 to support the NRC review. In recent discussions, the NRC requested clarification of some of the information in Reference 2. In response to this request, EGC is providing the attached information.
EGC has reviewed the information supporting a finding of no significant hazards consideration, and the environmental consideration, that were previously provided to the NRC in Attachment 1 of Reference 1. The additional information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. In addition, the additional information provided in this submittal does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.
February 4, 2015 U.S. Nuclear Regulatory Commission Page 2 There are no regulatory commitments contained in this letter. Should you have any questions concerning this letter, please contact Mr. Kenneth M. Nicely at (630) 657-2803.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 4th day of February 2015.
Re~R Patrick R. Simpson Manager - Licensing
Attachment:
Response to Request for Additional Information cc:
NRC Regional Administrator, Region Ill NRC Senior Resident Inspector - Quad Cities Nuclear Power Station Illinois Emergency Management Agency - Division of Nuclear Safety
ATTACHMENT Response to Request for Additional Information Page 1 NRC Request 1 Provide a summary of the calculation which demonstrates that the proposed TS total connection resistance limiting values (i.e., 2.4E-3 ohms and 6.0E-3 ohms) will maintain the required minimum voltages (i.e., 105 VDC for the 125 VDC batteries and 210 VDC for the 250 VDC batteries) at the batteries' terminals under worst-case design basis loading conditions.
Response
125 VDC Batteries As a verification to the results detailed in calculation QDC-8300-E-1587 for the Technical Specifications (TS) acceptance criteria, the following alternate analysis shows that the 105 VDC minimum required voltage at the battery terminals will be maintained under worst-case design conditions.
Figure 1 is a simplified diagram of the Unit 2 125 VDC normal battery. This battery was chosen since it has the highest load current (i.e., 678 amps (A) versus 666 A for Unit 1), lowest voltage margin (i.e., 1.0 VDC versus 1.1 VDC for Unit 1), and the longest jumper cable lengths (i.e.,
18.5 feet versus 3.92 feet for Unit 1), which makes this battery the most limiting 125 VDC battery.
Figure 1: Simplified Diagram of the Unit 2 125 VDC Normal Battery From the latest Unit 2 125 VDC normal battery discharge test, which was conducted on October 22, 2014, the lowest voltage recorded was 108.1 VDC using a maximum current of 678 A. Using Ohm's Law, the voltage drop along the battery string would be:
V = IR = (678 A)(2400 + 162 ) = 1.73 VDC 108.1 VDC - 1.73 VDC = 106.3 VDC Since 106.3 VDC is greater than the 105 VDC minimum required voltage, the battery remains operable. Note that the Unit 2 125 VDC normal battery was chosen since it is the most limiting, as discussed above, along with the lowest recorded voltage.
+
RJumper RTech Spec Where:
RTech Spec = 2400 RJumper = 162 I = 678 A
ATTACHMENT Response to Request for Additional Information Page 2 250 VDC Batteries As a verification to the results detailed in calculation QDC-8300-E-1587 for the TS acceptance criteria, the following alternate analysis shows that the 210 VDC minimum required voltage at the battery terminals will be maintained under worst-case design conditions.
Figure 2 is a simplified diagram of the Unit 2 250 VDC battery. This battery was chosen since it has the highest load current (i.e., 784 A versus 777 A for Unit 1) and the longest jumper cable lengths (i.e., 32.1 feet versus 18.92 feet for Unit 1), which makes this battery the most limiting 250 VDC battery. The calculated voltage margins are 7.1 VDC for both the Unit 1 and Unit 2 250 VDC batteries.
Figure 2: Simplified Diagram of the Unit 2 250 VDC Battery From the latest Unit 2 250 VDC battery discharge test, which was conducted on April 15, 2014, the lowest voltage recorded was 222.0 VDC using a maximum current of 784 A. Using Ohm's Law, the voltage drop along the battery string would be:
V = IR = (784 A)(6000 + 395 ) = 5.00 VDC 222.0 VDC - 5.00 VDC = 217.0 VDC Since 217.0 VDC is greater than the 210 VDC minimum required voltage, the battery remains operable. Note that the Unit 2 250 VDC battery was chosen since it is the most limiting, as discussed above, along with the lowest recorded voltage.
+
RJumper RTech Spec Where:
RTech Spec = 6000 RJumper = 395 I = 784 A
ATTACHMENT Response to Request for Additional Information Page 3 NRC Request 2 Please provide the margins available between the proposed TS total connection resistance values (i.e., 2.4E-3 ohms for the 125 VDC battery and 6.0E-3 ohms for the 250 VDC battery) and the resistances of the 125 VDC and 250 VDC battery units for maintaining the required minimum voltages at the batteries' terminals.
Response
125 VDC Batteries Figure 3 is a simplified diagram of the Unit 2 125 VDC normal battery. The resistance for maintaining the required minimum voltage at the batteries' terminals is 2713, which is taken from the originally submitted calculation QDC-8300-E-1587.
The margin available is 2713 - 2400 = 313 Figure 3: Simplified Diagram of the Unit 2 125 VDC Normal Battery Note that using Ohm's Law and the 108.1 VDC minimum voltage discussed in response to NRC Request 1, the voltage at the battery terminals would be:
V = IR = (678 A)(2713 + 162 ) = 1.95 VDC 108.1 VDC - 1.95 VDC = 106.15 VDC Since 106.15 VDC is greater than the 105 VDC minimum required voltage, the battery remains operable.
+
RTotal-Allow Where:
RTotal-Allow = 2713 RJumper = 162 I = 678 A RJumper
ATTACHMENT Response to Request for Additional Information Page 4 250 VDC Batteries Figure 4 is a simplified diagram of the Unit 2 250 VDC battery. The resistance for maintaining the required minimum voltage at the batteries' terminals is 11,557, which is taken from the originally submitted calculation QDC-8300-E-1587.
The margin available is 11,557 - 6000 = 5557 Figure 4: Simplified Diagram of the Unit 2 250 VDC Battery Note that using Ohm's Law and the 222.0 VDC minimum voltage discussed in response to NRC Request 1, the voltage at the battery terminals would be:
V = IR = (784 A)(11,557 + 395 ) = 9.37 VDC 222.0 VDC - 9.37 VDC = 212.63 VDC Since 212.63 VDC is greater than the 210 VDC minimum required voltage, the battery remains operable.
+
RTotal-Allow Where:
RTotal-Allow = 11,557 RJumper = 395 I = 784 A RJumper