ML113530190

Request for Additional Information Related to License Amendment Request to Modify Technical Specifications Sections 3.8.1, AC Sources - Operating.

ML113530190
Person / Time
Site:	Clinton
Issue date:	01/12/2012
From:	Joel Wiebe Plant Licensing Branch III
To:	Pacilio M Exelon Generation Co
Wiebe, Joel NRR/DORL/LPL3-2, 415-6606
References
TAC ME6876
Download: ML113530190 (3)

Text

",-I'll REGlil UNITED STATES

~'~"... "'I"0 NUCLEAR REGULATORY COMMISSION t!'" ~~(> WASHINGTON, D.C. 20555-0001

<C 0

h  : January 12, 2012

~ ,;;

.t'

"'I)

>(',.,.

...0

• • • • 1<

Mr. Michael J, Pacilio President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

CLINTON POWER STATION, UNIT NO.1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO MODIFY TECHNICAL SPECIFICATIONS SECTIONS 3.8.1, "AC SOURCES OPERATING" (TAC NO. ME6876)

Dear Mr. Pacilio:

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated August 15, 2011 Agencywide Documents Access and Management System (ADAMS) Accession No. ML112280256, Exelon Generation Company, LLC submitted a request to revise the Limiting Condition for Operation 3.8.1, "AC Sources - Operating," through a reduction to the maximum steady state voltage criteria for safety-related 4.16kV buses for the Clinton Power Station, Unit NO.1.

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. During a discussion with your staff on December 14, 2011, it was agreed that you would provide a response within 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) 415-6606.

Sincerely, oJ-av'J oel S. Wiebe, Senior Project Manager lant licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION CLINTON POWER STATION. UNIT NO.1 DOCKET NO. 50-461 In reviewing the Exelon Generation Company's (Exelon's) submittal dated August 15, 2011, related to the request to revise the Limiting Condition for Operation 3.8.1, "AC Sources Operating," for the Clinton Power Station, Unit No.1 (Clinton), the NRC staff has determined that the following information is needed in order to complete its review:

1. Provide a summary of the engineering evaluation which determined that the current maximum steady state voltage limit of 4580 volts (V) for emergency diesel generators (EDGs) specified in Technical Specifications TS 3.8.1, "Surveillance Requirements," is non-conservative with respect to existing design basis analysis for certain 120 VAC [Volt Alternating Current] safety-related components.

2. In the submittal, the licensee stated that the voltage regulation and automatic voltage reset (Le., on startup and the initiation of a loss-of-coolant accident signal), ensure the EDG output voltages are maintained to account for instrument uncertainties during normal conditions and during recovery from transient conditions.

Please provide:

a. Maximum instrument voltage uncertainty.

b. The voltage profiles(s) at 4160 V safety-related buses when powered by EDGs, during the sequencing of large safety-related loads for a loss of coolant accident signal, based on analysis or test.

3. In the submittal, the licensee stated that analyses in Calculations 19-AK-13, 19-AK-06 and 19-AJ-74, specify that the maximum acceptable voltage on the 4160 V safety-related buses is 4454 V for 30 minutes and 4300 V for continuous operation.

Please provide:

a. The basis of the maximum acceptable voltage limits, 4454 V for 30 minutes, and 4300 V for continuous operation as described in Calculations 19-AK-13, 19-AK 06, and 19-AJ-74.

b. A summary of the analysis which confirms that while powered from an offsite power source, the maximum voltage at the safety-related buses can be 4454 V for a maximum of 30 minutes before the voltage is returned to less than 4300 V for continuous operation.

Enclosure

January 12,2012 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

CLINTON POWER STATION, UNIT NO.1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO MODIFY TECHNICAL SPECIFICATIONS SECTIONS 3.8.1, "AC SOURCES OPERATING" (TAC NO. ME6876)

Dear Mr. Pacilio:

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated August 15, 2011 Agencywide Documents Access and Management System (ADAMS) Accession No. ML112280256, Exelon Generation Company, LLC submitted a request to revise the Limiting Condition for Operation 3.8.1, "AC Sources - Operating," through a reduction to the maximum steady state voltage criteria for safety-related 4.16kV buses for the Clinton Power Station, Unit NO.1.

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. During a discussion with your staff on December 14,2011, it was agreed that you would provide a response within 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) 415-6606.

Sincerely, IRA!

Joel S. Wiebe, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC LPL3-2 RtF RidsNrrDorlLpl3-2 Resource RidsNrrPMClinton Resource RidsNrrLASRohrer Resource RidsOgcRp Resource RidsRgn3MailCenter Resource RidsNrrDorlDpr Resource RidsAcrsAcnw_MailCenter Resource ADAMS Accession No'.. ML113530190 NRR-088 LPL3-2/PM LPL3-2/PM LPL3-2/LA LPL3-2/PM OFFICE LPL3-2/BC PHernandez JWiebe NAME JWiebe SRohrer JZimmerman 1110/12 1/10/12 1/10/12 1 111112 1 112/12 DATE OFFICIAL RECORD COpy