ML112690284

Stations, Unit Nos. 1 and 2 - Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications with Bypass Test Capability

ML112690284
Person / Time
Site:	Byron, Braidwood
Issue date:	11/08/2011
From:	Nicholas Difrancesco Plant Licensing Branch III
To:	Pacilio M Exelon Nuclear, Exelon Generation Co
DiFrancesco N, NRR/DORL/LPL3-2, 415-1115
References
TAC ME5836, TAC ME5837, TAC ME5838, TAC ME5839
Download: ML112690284 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 8, 2011 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 SUB~IECT: BRAIDWOOD STATION, UNITS 1 AND 2, BYRON STATIONS, UNIT NOS. 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS WITH BYPASS TEST CAPABILITY (TAC NOS. ME5836, ME5837, ME5838, AND ME5839)

Dear Mr. Pacilio:

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated March 14, 2011 and September 2, 2011 (Agencywide Documents Access and Management System (ADAMS)

Accession Nos. ML110760088 and ML11256A132, respectively), Exelon Generation Company, LLC (EGC, the licensee) requested NRC approval of an amendment to the Facility Operating Licenses for Braidwood Station (Braidwood), Units 1 and 2, and Byron Station (Byron), Unit Nos. 1 and 2. The proposed amendment would revise certain Required Action Notes in the Braidwood and Byron Technical Specifications (TS) 3.3.1, "Reactor Trip System Instrumentation" and TS 3.3.2, "Engineered Safety Features Actuation System Instrumentation,"

to reflect the planned installation of the bypass test capability.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete its review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on October 19, 2011, it was agreed that you would provide a response by November 18, 2011.

Please note that if you do not respond to this letter by the agreed-upon date or provide an acceptable alternate date in writing, we may reject your request for approval under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of NRC staff resources.

M. Pacilio -2 If you have questions concerning this request, please contact me at (301) 415-1115 or Nicholas. DiFrancesco@nrc.gov.

Sincerely,

~9-~~

Nicholas J. DiFrancesco, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-456, STN 50-457, STN 50-454 and STN 50-455

Enclosure:

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

REQUEST FOR ADDITIONAL INFORMATION BRAIDWOOD STATION, UNITS 1 AND 2 AND BYRON STATION, UNIT NOS. 1 AND 2 LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS WITH BYPASS TEST CAPABILITY DOCKET NOS. STN 50-454, STN 50-455, STN 50-456, AND STN 50-457 TAC NOS. ME5836, ME5837, ME5838, AND ME5839 By letters dated March 14, 2011 and September 2,2011 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML110760088 and ML11256A132, respectively), Exelon Generation Company, LLC (EGC, the licensee) requested NRC approval of an amendment to the Facility Operating Licenses for Braidwood Station (Braidwood), Units 1 and 2, and Byron Station (Byron), Unit Nos. 1 and 2. The proposed amendment would revise certain Required Action Notes in the Braidwood and Byron Technical Specifications (TSs) 3.3.1, "Reactor Trip System Instrumentation" and TS 3.3.2, "Engineered Safety Features Actuation System [ESFAS] Instrumentation," to reflect the planned installation of the bypass test capability.

To complete the review, the NRC staff requests the following additional information supporting the licensee's request.

1. Please discuss the interfaces between the Bypass Test Instrumentation (BTl) and the main control room (MCR) indications which enable the operators to recognize which loops are in bypass at anyone time so as to avoid potential technical specification violations regarding minimum channel requirements. Each type of BTl (Le., 7300 card) and nuclear instrumentation system (NIS) provides a description of the following:

a. Describe local light emitting diode indications, MCR alarms, and safety evaluation report indications that occur when a channel is placed into "Test" or "Bypass Enable" and when a loop is placed into "Bypass."

b. Describe any additional controls in place. beyond those provided in WCAP 17349-P, Section 3.5, which prevent inadvertent placement of two loops in different channels from being placed into bypass simultaneously.

2. Technical specification Table 3.3.1-1, indicates the number of required channels is four for each of the following reactor trip systems (RTS) functions:

FUNCTION:

2. Power Range Neutron Flux

a. High

b. Low

3. Power Range Neutron Flux - High Positive Rate Enclosure

-2 However, page 5 of the licensee amendment request (LAR), dated March 14,2011, indicate the NIS functions use 1-out-of-210gic stated below:

"In general, the RTS and ESFAS utilize two-out-of-three and two-out-of-four coincidence logic from redundant channels to initiate protective actions. Within these systems, analog channel comparators, with the exceptions of the NIS one out-of-two functions and the ESFAS containment spray function, are currently placed in the tripped state for channel testing or in response to a channel being out of service."

Please explain the statement of "NIS one-out-of-two functions," while the TS required channels is four, and list the NIS functions which use one-out-of-two logic.

3. Drawings 6065099, sheets 4 and 5, show that the signals of following functions are wired to the BTl panel:

• Power above permissive P-10

• Overpower rod stop

• Power above permissive P-9

• Overpower trip low range

• Overpower trip high range

• Positive rate trip

• Power above permissive P-8 But the LAR only mentioned the following three:

• Overpower trip low range

• .Overpower trip high range

• Positive rate trip Describe how this BTl installation affects all the other functions, and provide regulatory compliance for those functions.

M. Pacilio - 2 If you have questions concerning this request, please contact me at (301) 415-1115 or Nicholas.DiFrancesco@nrc.gov.

Sincerely, IRA!

Nicholas J. DiFrancesco, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-456, STN 50-457, STN 50-454 and STN 50-455

Enclosure:

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

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DATE 11/03/11 11 102/11 09126/11 11 108/11 11 108/11 OFFICIAL RECORD COPY