ML112210285
| ML112210285 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 08/15/2011 |
| From: | Billoch-Colon A Plant Licensing Branch III |
| To: | Pacilio M Exelon Nuclear, Exelon Generation Co |
| Billoch-Colon A, NRR/DORL, 301-415-3302 | |
| References | |
| TAC ME6176, TAC ME6177 | |
| Download: ML112210285 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Augus t 15, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT TO TECHNICAL SPECIFICATIONS SECTION 3.7.3, "ULTIMATE HEAT SINK" TAC NOS. ME6176 AND ME6177)
Dear Mr. Pacilio:
By letter to the U.S. Nuclear Regulatory Commission (NRC) dated May 6, 2011, (Agencywide Documents Access and Management System Accession No. ML111290197) Exelon Generation Company, LLC submitted a request to limit the core standby cooling system (CSCS) pond sediment level to less than or equal to 1.0 feet, which will reduce the post-accident heatup in the CSCS pond from 2.0 OF to 1.3 OF, and allow an increase of the technical specification temperature limit of the cooling water supplied to the plant from the CSCS pond to 101.95 OF, for the LaSalle County Station, Units 1 and 2.
The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. A response is requested 30 days from the date of this letter.
The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for NRC staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3302.
Sincerely, Araceli T. Billoch Colon, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374
Enclosure:
Request for Additional Information cc w/encl: Distribution via ListServ
REQUEST FOR ADDITIONAL INFORMATION LASALLE COUNTY STATION, UNITS 1 AND 2 DOCKET NOS. 50-373 AND 50-374 In reviewing the Exelon Generation Company's (Exelon's) submittal dated May 6, 2011, (Agencywide Documents Access and Management System Accession No. ML111290194) related to the request to revise technical specifications (TSs) Section 3.7.3, "Ultimate Heat Sink (UHS)," for the LaSalle County Station (LSCS), Units 1 and 2, the U.S. Nuclear Regulatory Commission staff has determined that the following information is needed in order to complete its review:
Question 1 Exelon's request for amendment to TSs dated May 6, 2011 states:
"High temperatures and humidity during the daytime, in conjunction with minimal cooling at night and little precipitation during the summer months, results in elevated water temperatures in the LSCS UHS. Weather conditions in the future may result in the temperature of the [Core Standby Cooling System] CSCS pond challenging the current TS limit of 101.25 of.
LSCS updated final safety analysis report (UFSAR) Section 9.2.6.3.2, "Ultimate Heat Sink Temperatures and Evaporation Losses During Shutdown Conditions," states:
liThe results of the analysis for the worst-case historical weather effect on the temperature of cooling water supplied to the plant from lake/UHS indicate the peak temperature of cooling water from the lake will be 97.5 of and it occurs late in the afternoon (approximately 6 pm)."
If the analysis shows that the worst case historical weather effect on the cooling water to the plant from the lake/UHS results in a peak temperature of 97.5 of, (a) Why is the CSCS pond temperature exceeding 97.5 OF and approaching the TS limit of 101.25 OF?
(b) With the CSCS pond exceeding the UFSAR peak temperature of 97.5 of and the high temperatures and humidity (as stated above). discuss the validity of the 1.3 of post accident heatup in the CSCS pond and its effect upon the actual peak post-accident UHS temperature of 104 of.
Question 2 Surveillance requirement (SR) 3.7.3.2 verifies sediment level in the intake flume and CSCS pond. The SR has a frequency in accordance with the Surveillance Frequency Control Program. Explain how often the SR is performed now and how often do you plan to perform the SR in the future.
August 15, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT TO TECHNICAL SPECIFICATIONS SECTION 3.7.3, "ULTIMATE HEAT SINK" (TAC NOS. ME6176 AND ME6177)
Dear Mr. Pacilio:
By letter to the U.S. Nuclear Regulatory Commission (NRC) dated May 6, 2011, (Agencywide Documents Access and Management System Accession No. ML111290197) Exelon Generation Company, LLC submitted a request to limit the core standby cooling system (CSCS) pond sediment level to less than or equal to 1.0 feet, which will reduce the post-accident heatup in the CSCS pond from 2.0 OF to 1.3 OF, and allow an increase of the technical specification temperature limit of the cooling water supplied to the plant from the CSCS pond to 101.95 of, for the LaSalle County Station, Units 1 and 2.
The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. A response is requested 30 days from the date of this letter.
The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for NRC staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3302.
Sincerely, IRA!
Araceli T. Billoch Colon, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374
Enclosure:
Request for Additional Information cc w/encl: Distribution via ListServ DISTRIBUTION:
PUBLIC RidsNrrDorlDpr Resource RidsOgcRp Resource LPL 3-2 RtF RidsRgn3MailCenter Resource RidsNrr DorlLpl3-2 Resource RidsNrrPMLaSalle Resource RidsNrrLASRohrer Resource RidsAcrsAcnw _MaiICTR Resource ADAMS Accession No ML112210285 NRR-088 OFFICE U!L3-2/PM LPL3-21LA LPL3-2/BC NAME ABillochColon SRohrer JZimmerman DATE 8/11111 8/11/11 8/15/11 OFFICIAL RECORD COpy