ML15267A683

Second Request for Additional Information Regarding License Amendment Request to Revise Technical Specification 3.8.1

ML15267A683
Person / Time
Site:	Cook
Issue date:	10/05/2015
From:	Dietrich A Plant Licensing Branch III
To:	Weber L Indiana Michigan Power Co
Dietrich A
References
TAC MF5436, TAC MF5437
Download: ML15267A683 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 5, 2015 Mr. Lawrence J. Weber Senior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, Ml 49106

SUBJECT:

DONALD C. COOK NUCLEAR PLANT, UNITS i AND 2 - SECOND REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION 3.8.1 (TAC NOS.

MF5436 AND MF5437)

Dear Mr. Weber:

By letter dated December 17, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14356A022), as supplemented by letter dated July 9, 2015 (ADAMS Accession No. ML15195A434), Indiana Michigan Power Company (l&M, the licensee) requested an amendment to Renewed Facility Operating Licenses DPR-58 and DPR-74 for Donald C. Cook Nuclear Plant, Units 1 and 2. The proposed amendments would revise the Technical Specifications 3.8.1, "AC Sources - Operating," to allow testing of the onsite standby emergency diesel generators (DGs) during modes in which it is currently prohibited.

Specifically, the proposed changes would remove the mode restrictions in the notes of Surveillance Requirements 3.8.1.1 O (DG single largest load rejection test), 3.8.1.11 (DG full load rejection test), and 3.8.1.15 (DG endurance run).

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the subject submittal and supplement, and has determined that additional information is needed to complete the review, as described in the enclosed Second Request for Additional Information (RAI). The draft RAI was sent to l&M via electronic mail on September 23, 2015. The NRC staff clarified the draft RAI in a conference call conducted on October 1, 2015. Based on our discussion, we understand that a response to the RAI will be provided by October 30, 2015.

L. Weber Please feel free to contact me at (301) 415-2846 if you have any additional questions or concerns.

Sincerely,

~f)~

Allison W. Dietrich, Project Manager Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316

Enclosure:

Second Request for Additional Information cc: Distribution via Listserv

SECOND REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS SURVEILLANCE REQUIREMENTS 3.8.1.10. 3.8.1.11 AND 3.8.1.15I DONALD C. COOK NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-315 AND 50-316 TAC NOS. MF5436 and MF5437 The U.S. Nuclear Regulatory Commission staff has determined that the following additional information is needed to complete the review of the Indiana Michigan Power Company license amendment request dated December 17, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14356A022), as supplemented by letter dated July 9, 2015 (ADAMS Accession No. ML15195A434), for the Donald C. Cook Nuclear Plant (CNP), Units 1 and 2.

EEEB-RAl-5 In response to EEEB-RAl-2c, the licensee addressed the emergency diesel generator (EOG) operation during a loss of offsite power (LOOP) with a loss-of-coolant accident (LOCA) while the EOG is operating in parallel with the offsite power. The licensee stated:

When the EOG [emergency diesel generator] is in test mode, the SI [safety injection] or load shed signal will automatically trip the 4 kV [kilovolts] Output Breaker during EOG test mode (these signals are blocked after two seconds, and therefore SI signal is prevented from reopening the breaker if a load shed occurs first, trips the breaker, then the breaker closes to load the EOG and a SI signal is initiated some time later).

a. Please discuss the events or signals that initiate the load shed signal. If an SI signal also initiates a load shed signal, please clarify the sentence in parentheses in the above statement. Also, please explain the EOG operation during degraded grid voltage conditions while the EOG is being tested in parallel with the offsite power source in Mode 1 or 2.

b. Please discuss the EOG operation, including timing of vital load loads sequencing, during a LOOP concurrent with LOCA scenario, while the EOG is being tested in parallel with the offsite power source in Mode 1 or 2. Also, please clarify whether manual action to reset the lockout relay is allowed during a LOOP concurrent with LOCA event in the CNP licensing design basis accident analysis.

Enclosure

c. Please provide the timeline of tripping and closing of the EOG breaker, and discuss the timing of vital load sequencing for the following scenarios, with the EOG initially in test mode and paralleled with the offsite source:

(1) LOOP followed by LOCA (2) LOCA followed by LOOP EEEB-RAl-6 In response to EEEB-RAl-3, the licensee stated that the EOG protective relays for generator overcurrent, generator differential, and generator neutral overcurrent remain active in non-emergency conditions.

a. Please explain the conditions defined as "non-emergency" and "emergency."

b. Please provide a single line diagram showing the connection of the protective relays. Also, please discuss the physical location of the protective relays, including the lockout relay, for the EOG.

EEEB-RAl-7 In response to EEEB-RAl-4, the licensee stated:

The maximum 3 phase fault contribution from the EOG is 4.1 kA [kilo amperes].

The maximum fault at the T Bus is less than 42kA including the EOG contribution. The symmetrical interrupting rating of the 4 kV switchgear and breakers is 46.9 kA adjusted for the 4.16 kV rating. The maximum fault current, 42 kA calculated with the EOG in parallel does not exceed the fault rating of switchgear and breakers. The fault currents are conservatively estimated based on the low circuit impedances and maximum fault contribution from the system and the motors connected to the bus.

a. Section 8.4 of the CNP Updated Final Safety Analysis Report states that one EOG supplies power to two 4.16 KV safety buses (e.g., T11A and T11 Bin Unit 1, Train B). Please clarify whether the EOG is connected to both 4.16 kV safety buses (e.g., T11 A and T11 B) during testing of the EOG paralleled with the offsite power source, and during emergency conditions.

b. Please provide a summary of the short circuit calculations at the T Bus( es) that is( are) connected to the EOG with the EOG in parallel with offsite power.

ML15267A683 *via memorandum OFFICE DORL/LPL3-1 /PM DORL/LPL3-1/LA DE/EEEB/BC* DORL/LPL3-1 /BC DORL/LPL3-1/PM NAME ADietrich MHenderson JZimmerman DPelton ADietrich DATE 9/24/2015 9/25/2015 09/23/2015 10/5/2015 10/5/2015