IR 05000341/2021013
| ML21351A345 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 12/17/2021 |
| From: | Richard Skokowski Engineering Branch 3 |
| To: | Peter Dietrich DTE Electric Company |
| References | |
| IR 2021013 | |
| Download: ML21351A345 (11) | |
Text
December 17, 2021 Mr. Peter Dietrich Senior VP and Chief Nuclear Officer DTE Electric Company Fermi 2 - 260 TAC 6400 North Dixie Highway Newport, MI 48166 SUBJECT: FERMI POWER PLANT, UNIT 2 - NRC INSPECTION OF TEMPORARY INSTRUCTION 2515/194, INSPECTION OF THE LICENSEES IMPLEMENTATION OF INDUSTRY INITIATIVE ASSOCIATED WITH THE OPEN PHASE CONDITION DESIGN VULNERABILITIES IN ELECTRIC POWER SYSTEMS (NRC BULLETIN 2012-01) - INSPECTION REPORT 05000341/2021013
Dear Mr. Dietrich:
On November 8, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Fermi Power Plant, Unit 2 and discussed the results of this inspection with Mr. E. Olson, Site Vice President and other members of your staff. The results of this inspection are documented in the enclosed report.
No findings or violations of more than minor significance were identified during this inspection. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Signed by Skokowski, Richard on 12/17/21 Richard A. Skokowski, Chief Engineering Branch 3 Division of Reactor Safety Docket No. 05000341 License No. NPF-43
Enclosure:
As stated
Inspection Report
Docket Number: 05000341 License Number: NPF-43 Report Number: 05000341/2021013 Enterprise Identifier: I-2021-013-0012 Licensee: DTE Electric Company Facility: Fermi Power Plant, Unit 2 Location: Newport, MI Inspection Dates: July 26, 2021 to July 30, 2021 Inspectors: I. Hafeez, Reactor Inspector L. Kozak, Senior Reactor Analyst Approved By: Richard A. Skokowski, Chief Engineering Branch 3 Division of Reactor Safety Enclosure
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an NRC Inspection of Temporary Instruction 2515/194, Inspection of the Licensees Implementation of Industry Initiative Associated with the Open Phase Condition Design Vulnerabilities in Electric Power Systems (NRC Bulletin 2012-01) - Inspection at Fermi Power Plant, Unit 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
No findings or violations of more than minor significance were identified.
Additional Tracking Items
None.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), inspectors were directed to begin telework. In addition, regional baseline inspections were evaluated to determine if all or a portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on site. The inspections documented below met the objectives and requirements for completion of the IP.
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 2515/194 - Inspection of the Licensees Implementation of Industry Initiative Associated With the Open Phase Condition Design Vulnerabilities In Electric Power Systems (NRC Bulletin 2012-01)
This inspection was conducted using Temporary Instruction 2515/194 (ADAMS Accession No. ML20230A328), dated August 18, 2020. The inspectors reviewed the licensees implementation of Nuclear Energy Institute (NEI) voluntary industry initiative (VII) in compliance with Commission guidance. The inspectors discussed the impacts of open phase conditions (OPCs) on the licensees electrical system design, the ability to detect and alarm OPCs on station transformers, and ongoing implementation of training and updates to operating procedures with plant staff. The inspectors reviewed licensee and vendor documentation and performed system walkdowns to verify that the installed equipment was supported by the design documentation. The inspectors verified that the licensee had completed the installation and testing of equipment (with the exception of the tripping functions), installed and tested alarming circuits both local and in the control room, and analyzed potential impacts associated with the design implementation on the current licensing basis. The inspectors also reviewed licensee analysis and calculations, and performed distribution system and switchyard equipment walkdowns.
The objective of Temporary Instruction 2515/194 is to verify that licensees have appropriately implemented the NEI voluntary industry initiative (ADAMS Accession No. ML19163A176), dated June 6, 2019, including updating their licensing basis to reflect the need to protect against OPC.
For sites that are implementing the risk-informed evaluation method to demonstrate that operator manual actions will be sufficient to mitigate the impact of an OPC, in lieu of TI Section 03.01.b (automatic protective actions), TI Section 03.01.c will be performed.
Inspection of the Licensees Implementation of Industry Initiative Associated With the Open Phase Condition Design Vulnerabilities In Electric Power Systems (NRC Bulletin 2012-01)
(1 Sample)
- (1) Temporary Instruction 2515/194-03.01 - Voluntary Industry Initiative DTE Electric Company, selected two separate open phase detection systems for Fermi 2. On Transformer 1 which feeds the Division 1 systems from the 120KV switchyard bus 101 Fermi has installed Alstom open phase detection system which utilizes optical current transformers (OCT) on the primary bushings of Transformer #1 and their connection to the Open Phase Protection System (OPPS) cabinet in which there are three independent relays/relay circuits for measuring, transmitting, and analyzing, with output connected in a two out of three control logic. A reference voltage and frequency is used as input to the control panel to compare the measured values to detect an open phase. In its current configuration upon detection of an open phase event the unit will provide a Transformer 1 trouble alarm to the Main Control Room (MCR). Upon receipt of Transformer 1 trouble alarm the operators will validate if the alarm is due to an OPC by checking for a greater than 20 percent phase current imbalance on the 4160V Bus 64A ammeter. If there is a phase imbalance, then by procedure the reactor will be immediately shutdown and the incoming breakers to the 4160V buses fed from Transformer 1 will be opened actuating the loss of voltage relaying.
On Transformer 64 which feeds the Division 2 systems from the 345KV switchyard bus 301 Fermi selected a system designed and manufactured by Power System Sentinel Technologies, LLC, (PSSTech) for the OPC detection system. The PSSTech equipment was installed on the high voltage side of the transformer installed Neutral Injection and Current Monitoring OPPS cabinets is used to detect an OPC Condition. Upon detection of an open phase event the unit will provide Transformer Trouble alarm to the MCR. Upon receipt of Transformer Trouble alarm the operators will validate if the alarm is due to an OPC by checking for a greater than 20 percent phase current imbalance on the 4160V Bus 65D ammeter and Bus 65G ammeter. If there is a phase imbalance, then by procedure the reactor will be immediately shutdown and the incoming breakers to the 4160V buses fed from Transformer 65 will be opened actuating the loss of voltage relaying.
The Alstom and PSSTechs were in the "Detect" mode of operation. The trip function was bypassed and will remain disabled as Fermi has elected to implement the risk-informed evolution method to isolate an OPC. Both systems were monitoring and would alarm the MCR. The OPC relays monitors/detect an OPC , which is defined as one or two phases, with or without a ground for the OPC or low load conditions is detected or if a relay was non-functional.
INSPECTION RESULTS
Observation: Temporary Instruction 2515/194-03.01 Voluntary Industry Initiative 2515/194 Based on discussions with Fermi staff, review of design and testing documentation, and walkdowns of installed equipment, the inspectors had reasonable assurance that Fermi is appropriately implementing, with noted exceptions discussed below, the voluntary industry initiative at the Fermi Unit 2 Power Plant. The inspectors verified the following criteria:
(1) [03.01(a)(1)] Open phase conditions (OPCs) are detected will be alarmed in the Main Control Room (MCR) common annunciator panel.
(2) [03.01(a)(2)] Detection circuits are sensitive enough to identify an OPC for credited loading conditions (i.e., high and low loading). See next section for inspector identified exceptions.
(3) [03.01(a)(3)] The OPC design and protective schemes minimize misoperation or spurious action in the range of voltage unbalance normally expected in the transmission system that could cause separation from an operable off-site power source. Licensees have demonstrated that the actuation circuit design does not result in lower overall plant operation reliability.
(4) [03.01(a)(4)] No Class-1E circuits were replaced with non-Class-1E circuits in this design.
(5) [03.01(a)(5)] The Updated Final Safety Analysis Report (UFSAR) was updated to discuss the design features and analyses related to the effects of any OPC design vulnerability. See next section for inspector identified exceptions.
(6) [03.01(a)(6)] Identify if Open Phase Isolation System (OPIS) detection and alarm components are maintained in accordance with station procedures or maintenance program, and that periodic tests, calibrations, setpoint verifications, or inspections (as applicable) have been established. See next section for inspector identified exceptions.
Use of Risk-Informed Evaluation Method (1) [03.01(c)(1)] The plant configuration matched the changes made to the probabilistic risk assessment model to address an OPC, and the logic of the probabilistic risk assessment model changes is sound.
(2) [03.01(c)(2)] The procedures which validate that an OPC alarm would identify the proper indication to validate the OPC at all possible locations.
(3) [03.01(c)(3)] Observations associated with procedures and operator actions required to respond to an OPC alarm and potential equipment trip match the Human Reliability Analysis (HRA).
(4) [03.01(c)(4)] [03.01(c)(4)] Sensitivity analyses used in the licensees probabilistic risk analysis (PRA) analysis for using Operator Manual Actions (OMAs) in leu of OPC automatic protective relay actuation did not exceed the thresholds defined in the NEI 19-02 guidance document for delta Core Damage Frequency (CDF) or delta Large Early Release Frequency (LERF).
(5) [03.01(c)(5)] Assumptions, procedures, and operator actions specified in the licensees NEI 19-02 analysis are consistent with the plant-specific design and licensing basis, including:
- (a) Initiating events considered in the analysis.
- (b) Boundary conditions specified in Attachment 1 of the NEI Voluntary Industry Initiative, Revision 3.
- (c) Operating procedures for steps taken to recover equipment assumed tripped, locked out, or damaged due to an OPC.
- (d) Where recovery was assumed in the PRA analysis for tripped electric equipment, restoration of the equipment was based on analyses that demonstrate that automatic isolation trips did not result in equipment damage.
Observation: Inspector Identified Method Exceptions 2515/194
[03.01(a)(2)] - Detection circuits are sensitive enough to identify an open phase condition (OPC) for credited loading conditions (i.e., high and low loading).
Exception - The OPPS utilized at Fermi consists of a hybrid design with protection that detect at the high sides of the Transformer 1 which utilizes the Alstom open phase detection system and Power Systems Sentinel Technologies, LLC (PSSTech) design on Transformer 64 (The pilot inspections performed by NRR include both of these designs). At the 4kV level, OPP is provided by checking for a greater than 20 percent phase current imbalance on the 4160V Bus ammeters. If there is a phase imbalance, then procedure will be entered, and the reactor will be immediately shutdown and the incoming source breaker to the 4KV safeguards buses fed from Transformer 1 and Transformer 65 will be opened actuating the loss of voltage relay which are being relied on to actuate before damage to safety related equipment or tripping of their electrical protective devices would occur.
In addition, the inspectors found the alarm and protection design is consistent with the NEI VII guidance. Additionally, where automatic detection is not reliable, Fermi has established monitoring requirements on a per shift basis to look for evidence of an OPC.
Operator rounds procedures have also been revised to inspect the integrity of electrical connections on both transformers. These actions are intended to identify any OPCs present on transformers 1 and Transformer 65.
[03.01(a)(5)] The Updated Final Safety Analysis Report (UFSAR) was updated to discuss the design features and analyses related to the effects of any OPC design vulnerability.
Exception - Fermi UFSAR has not been updated; however, LCR 15-060-UFS and LCR 17-041-UFS are approved that have been issued to update the UFSAR.
[03.01(a)(6)] - Identify if Open Phase Isolation System (OPIS) detection and alarm components are maintained in accordance with station procedures or maintenance program, and that periodic tests, calibrations, setpoint verifications, or inspections (as applicable) have been established.
Exception - At the time of this inspection, the licensee had not developed adequate testing and calibration for the Bus 64A, Bus 65D and Bus 65G ammeters since there is no Preventative Maintenance (PM) strategy. Consequently, these components need to be re-assessed for a proper PM strategy application. In addition, PM needs to be revised to test the Transformer 1 Open Phase equipment based on the Open Phase SAT Plan and needs to be revised to test the SST65 Open Phase equipment function.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On November 8, 2021, the inspectors presented the NRC Inspection of Temporary Instruction 2515/194, Inspection of the Licensees Implementation of Industry Initiative Associated with the Open Phase Condition Design Vulnerabilities in Electric Power Systems (NRC Bulletin 2012-01) - Inspection results to Mr. E. Olson, Site Vice President and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection Type Designation Description or Title Revision or
Procedure Date
2515/194 Corrective Action 20-29744 TMPE-20-0155 Self-Assessment Deficiency - Critical 08/28/2020
Documents Attribute 5 - Equipment Recovery Analysis for OPC
Drawings 5SD721M-0034 Schematic Diagram System Service Trans #65 Relaying F
61721-2571-01 One Line Synchronizing Diagram 4160V System Service and E
EDG. Breakers
61721-2572-28 Schematic Diagram 4160V ESS. Buses #64B & 64C - Load V
Shedding Strings
61721-2578-05 Relay and Metering Diagram 4160V ESS. Buses #64B U
61721-2581-13 Schematic Diagram S.S. Transformer #65 Temperature K
Control & CT Connections
6SD721-2500-01 One Line Diagram Plant 4160V & 480V System Service CD
6SD721-2500-10 Phasing Diagram 4160V & 480V System Service G
Engineering 1T010RPT001 Fermi 2 Open Phase Condition Risk Analysis 0
Evaluations
Miscellaneous EDP-37425 EDP Continuation Sheet for Transformer 65 A
EDP-37519 EDP Continuation Sheet for Transformer 1 A
Procedures 20.300.120kV Loss of 120KV 19A
20.300.PHASE Loss of Phase 2
ARP 10D60 SS 65 Transformer Trouble 12
ARP 10D60 SS 65 Transformer Trouble 12
ARP 11D44 Transformer 1 Trouble 15
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