ND-23-0552, Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Unit 4, ITAAC Closure Notification on Completion of ITAAC Item 2.6.04.02c (Index Number 624)

Southern Nuclear Operating Company, Vogtle Electric Generating Plant, Unit 4, ITAAC Closure Notification on Completion of ITAAC Item 2.6.04.02c (Index Number 624)

ML23199A228
Person / Time
Site:	Vogtle
Issue date:	07/18/2023
From:	Coleman J Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
ND-23-0552, ITAAC 2.6.04.02c
Download: ML23199A228 (1)

Text

Jamie M. Coleman 7825 River Road Regulatory Affairs Director Waynesboro, GA 30830 Vogtle 3 & 4 706-848-6926 tel July 18, 2023 Docket No.: 52-026 ND-23-0552 10 CFR 52.99(c)(1)

U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001 Southern Nuclear Operating Company Vogtle Electric Generating Plant Unit 4 ITAAC Closure Notification on Completion of ITAAC Item 2.6.04.02c [Index Number 624]

Ladies and Gentlemen:

In accordance with 10 CFR 52.99(c)(1), the purpose of this letter is to notify the Nuclear Regulatory Commission (NRC) of the completion of Vogtle Electric Generating Plant (VEGP)

Unit 4 Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) Item 2.6.04.02c [Index Number 624]. This ITAAC confirms that the load sequencer associated with each standby diesel generator initiates a closure signal within +/-5 seconds of the set intervals to connect the loads. The closure process for this ITAAC is based on guidance in Nuclear Energy Institute (NEI) 08-01, "Industry Guideline for the ITAAC Closure Process under 10 CFR Part 52," which was endorsed by the NRC in Regulatory Guide 1.215.

This letter contains no new NRC regulatory commitments. Southern Nuclear Operating Company (SNC) request NRC staff confirmation of this determination and publication of the required notice in the Federal Register per 10 CFR 52.99.

If there are any questions, please contact Kelli Roberts at 706-848-6991.

Respectfully submitted, Jamie M. Coleman Regulatory Affairs Director Vogtle 3 & 4

Enclosure:

Vogtle Electric Generating Plant (VEGP) Unit 4 Completion of ITAAC 2.6.04.02c [Index Number 624]

JMC/CSS/sfr

U.S. Nuclear Regulatory Commission ND-23-0552 Page 2 of 2 cc: Regional Administrator, Region ll Director, Office of Nuclear Reactor Regulation (NRR)

Director, Vogtle Project Office NRR Senior Resident Inspector - Vogtle 3 & 4

U.S. Nuclear Regulatory Commission ND-23-0552 Enclosure Page 1 of 3 Southern Nuclear Operating Company ND-23-0552 Enclosure Vogtle Electric Generating Plant (VEGP) Unit 4 Completion of ITAAC 2.6.04.02c [Index Number 624]

U.S. Nuclear Regulatory Commission ND-23-0552 Enclosure Page 2 of 3 ITAAC Statement Design Commitment 2.c) Automatic-sequence loads are sequentially loaded on the associated buses.

Inspections, Tests, Analyses An actual or simulated signal is initiated to start the load sequencer operation. Output signals will be monitored to determine the operability of the load sequencer. Time measurements are taken to determine the load stepping intervals.

Acceptance Criteria The load sequencer initiates a closure signal within +/-5 seconds of the set intervals to connect the loads.

ITAAC Determination Basis Pre-operational testing of the onsite standby power system (ZOS) was performed to demonstrate the automatic-sequence loads were sequentially loaded on the associated buses of each standby diesel generator within the specified time intervals. The operation of the load sequencer for each generator was tested in accordance with test procedure listed in Reference 1.

The A and B train load sequencers were tested independently. The Data Display and Processing System (DDS) was utilized to monitor and record the inputs and outputs of the load sequencer to determine operability during the test. A test signal which simulated a loss of voltage on the associated 6900V bus was initiated to start the operation of the load sequencer.

The start time of the sequencer and the time of the closure signals of each load step was recorded by the DDS. The DDS event log was evaluated to determine the load stepping intervals for each group of loads, and to verify each automatic-sequence load received the closure signal. The test results are included in Reference 1 and confirm that the load sequencer initiated a closure signal within +/-5 seconds of the set intervals to connect the loads.

Reference 1 is available for NRC inspection as part of Unit 4 ITAAC Completion Package (Reference 2).

ITAAC Finding Review In accordance with plant procedures for ITAAC completion, Southern Nuclear Operating Company (SNC) performed a review of findings pertaining to the subject ITAAC and associated corrective actions. This review found there are no relevant ITAAC findings associated with this ITAAC. The review is documented in the ITAAC Completion Package (Reference 2) and is available for NRC review.

ITAAC Completion Statement Based on the above information, SNC hereby notifies the NRC that ITAAC 2.6.04.02c was performed for VEGP Unit 4 and that the prescribed acceptance criteria are met.

Systems, structures, and components verified as part of this ITAAC are being maintained in their as-designed, ITAAC compliant condition in accordance with approved plant programs and procedures.

U.S. Nuclear Regulatory Commission ND-23-0552 Enclosure Page 3 of 3 References (available for NRC inspection)

1. SV4-ZOS-ITR-800624, Rev 0, Unit 4 Recorded Results of Onsite Standby Power System (ZOS) Sequencer Testing: ITAAC 2.6.04.02c, NRC Index Number: 624

2. 2.6.04.02c-U4-CP-Rev0, ITAAC Completion Package