IR 05000321/2019014
| ML19351E202 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 12/17/2019 |
| From: | Steven Rose NRC/RGN-II |
| To: | Gayheart C Southern Nuclear Operating Co |
| References | |
| IR 2019014 | |
| Download: ML19351E202 (9) | |
Text
December 17, 2019
SUBJECT:
EDWIN I. HATCH NUCLEAR PLANT - 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), REPORT 05000321/2019014 AND 05000366/2019014
Dear Ms. Gayheart:
On November 22, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at EDWIN I. HATCH NUCLEAR PLANT. On November 21, 2019, the NRC inspectors discussed the results of this inspection with Mr. Sonny Dean, 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,
/RA/
Steven D. Rose, Chief Construction Inspection Branch 2 Division of Construction Oversight
Docket Nos. 05000321 and 05000366 License Nos. DPR-57 and NPF-5
Enclosure:
As stated
cc w/ encl: Distribution via LISTSERV
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a 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), at EDWIN I HATCH NUCLEAR PLANT, 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.
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.
ML17137A416), dated October 31, 2017. The inspectors reviewed the licensees implementation of Nuclear Energy Institute voluntary industry initiative (VII) in compliance with Commission guidance. The inspectors discussed the licensees open phase condition (OPC)system design and ongoing implementation plans with plant staff. The inspectors reviewed licensee documentation, vendor documentation, and performed system walkdowns to determine if the installed equipment was supported by the design documentation. These reviews were also made to determine if the licensee had completed the installation and testing of equipment, installed and tested alarming circuits both locally and in the control room, and analyzed potential impacts associated with the design implementation on the current licensing basis.
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 - Inspection of the Licensees Implementation of Industry Initiative Associated With the Open Phase Condition Design Vulnerabilities in Electric Power Systems (NRC Bulletin 2012-01)
The objective of Temporary Instruction 2515/194 was to verify that licensees had appropriately implemented the NEI VII (ADAMS Accession No. ML15075A454), dated March 16, 2015, including updating their licensing basis to reflect the need to protect against OPCs.
Temporary Instruction 2515/194-03.01 - VII (Part 1)
Hatch Nuclear Plant selected the open phase detection system designed and manufactured by Power System Sentinel Technologies, LLC. At the end of this inspection the system remained in the monitoring mode of operation to facilitate continued data gathering of the system for evaluation of alarm and trip setpoints. The equipment was installed on the Start-up Auxiliary Transformers (SAT) 1C, 1D, 2C, 2D, and 2E. Hatch Nuclear Plant will install this equipment on SAT 1E after the installation of that transformer is completed in February 2020. Hatch Nuclear Plant currently is scheduled to transition the open phase detection system to full implementation (tripping functions enabled) by December 31,
INSPECTION RESULTS
Observation: Detection, Alarms, and General Criteria - TI 2515/194-03.01 - VII (Part 1) 2515/194
1. OPCs will be detected and alarmed in the control room on the common annunciator
panel.
2. Detection circuits will be sensitive enough to identify an OPC for all credited loading
conditions for installed equipment.
3. No Class-1E circuits were being replaced with non-Class 1E circuits in the design.
4. The Updated Final Safety Assessment Report (UFSAR) has been updated to discuss
the design features and analyses related to the effects of, and protection for, any OPC design vulnerability.
Observation: Protective Actions Criteria - TI 2515/194-03.01 - VII (Part 1)2515/194
5. Five transformers were susceptible to an OPC as identified in this VII during all modes
of operation. The licensee installed detection and mitigating equipment for these affected transformers. One additional transformer will be installed and connected to the electrical power distribution system and will also have detection and mitigating equipment for OPCs installed.
6. With an OPC present and with or without an accident condition signal, the open phase
design would not adversely affect the function of important-to-safety systems, structures, or components. The licensees OPC design solution added Power System Sentinel Technologies, LLC systems on the Start-up Auxiliary Transformers (SAT) 1C, 1D, 2C, 2D, and 2E. Hatch Nuclear Plant will install this equipment on SAT 1E after the installation of that transformer is completed in February 2020. The tripping function, when enabled, will provide an additional input to the associated transformer lockout relays. The credited plant response is not negatively affected and will be the same regardless of the conditions that generated the lockout of the transformer.
Observation: Detection, Alarms, and General Criteria Exceptions - TI 2515/194-03.01 - VII (Part 1)2515/194
7. The licensees design was operating in the monitoring mode with already established
setpoints and gathering data to verify the OPC design and protective schemes would minimize mis-operation, or spurious actions in the range of voltage unbalance normally experienced in the transmission system. The licensee developed engineering calculations to demonstrate coordination of the OPC detection and tripping setpoints for the actuation circuit that does not result in lower overall plant operation reliability. This calculation was presented in SENH-17-005, HNP Open Phase Detection System PSSTech Setpoints Calculation, Version 1.
8. A draft of the UFSAR was available for the inspectors review that included
information related to OPCs. The licensee provided the inspectors with proposed changes to the licensing basis that discussed the system requirements related to the effects of, and protection for, any OPC design vulnerability.
The inspectors verified the proposed change process was being tracked under Licensing Document Change Request (LDCR) SNC881203, SAT 1C and SAT 1D Open Phase Protection Trip Enable, Version 2.0 and SNC881210, SAT 2C and SAT 2D Open Phase Protection Trip Enable, Version 1.0. The inspectors also determined that the Technical Specification Bases was not affected by this VII as evaluated under these LDCRs as well.
Observation: Protective Actions Criteria Exceptions - TI 2515/194-03.01 - VII (Part 1)2515/194 The licensees OPC design solution uses Power System Sentinel Technologies, LLC to detect, alarm, and provide an input to the associated transformer lockout relays. Upon an initiation of the transformer lockout relays, the associated transformer that is affected is tripped and isolated.
The tripping function input to the transformer lockout relays remained deactivated during the onsite system implementation inspection and was not able to be demonstrated to perform the designed function. The licensee did perform field testing to demonstrate Main Control Room (MCR) annunciator panel illumination and the tripping function signal was present during simulated testing at the Open Phase Protection (OPP) cabinets. The licensee is currently tracking the tripping function initiation under Design Change/Modifications (DCPs)
SNC836321, SNC873725, SNC881203, SNC881210. Once enabled, the OPP system will have the ability to isolate an affected SAT with an OPC detected on the high voltage side of the transformer at any operating condition when the transformers are energized.
Due to the configuration of Hatch Nuclear Plant electrical distribution system a loss of phase on one transformer would not affect power availability to any Essential Bus because the backup SAT would pick-up the affected loads. This configuration would ensure that safety functions are preserved as required by the current licensing bases.
Periodic tests, calibrations, setpoint verifications or inspections (as applicable) have been established for any new protective features. The surveillance requirements have been maintained for the plant Technical Specifications (TSs) in compliance with the provisions of 10 CFR 50.36. Existing plant equipment will continue to be maintained according to the licensees current preventative maintenance program.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On November 21, 2019, the inspectors presented the 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), results to Mr. Sonny Dean, Site Vice President and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2515/194
Calculations
SCNH-16-003,
"Open Phase Protection Cabinet Foundation and Anchorage
Design For Sat 2C and CVR/Circuit Breaker Support"
SENH-17-005
HNP Open Phase Detection System PSSTech Setpoints
Calculation
Drawings
H-13350,
EDWIN I. HATCH NUCLEAR PLANT UNIT No. 1 MASTER
SINGLE LINE DIAGRAM
H-23350
EDWIN I. HATCH NUCLEAR PLANT UNIT No. 2 MASTER
SINGLE LINE DIAGRAM
H-23614
EDWIN I. HATCH NUCLEAR PLANT UNIT No. 2
ELEMENTARY DIAGRAM START-UP TRANSFORMERS
2C & 2D FAULT PRESSURE PROT. SYS. 2R20K & OPP
SYS. 2S11
H-23667
EDWIN I. HATCH NUCLEAR PLANT UNIT No. 2 CONTROL
AND ANNUNCIATOR FOR MAIN POWER TRANSF. & AUX.
TRANS
- F. 2A, 2B, 2C & 2D SYSTEM 2S11 - SHEET 2
S-76895
OPEN PHASE PROTECTION (OPP) SYSTEM,
ELECTRICAL DRAWINGS, CHANNEL 1 & CHANNEL 2 -
SAT 1C
Engineering
Changes
SNC654775
SAT 1C and SAT 1D Open Phase Protection
SNC654779
SAT 2C Open Phase Protection
SNC654780
SAT 2D Open Phase Protection
SNC836321
SAT 2E Open Phase Protection
SNC873725
SAT 1E Open Phase Protection
SNC881203
SAT 1C and SAT 1D Open Phase Protection Trip Enable
and 4
SNC881210
SAT 2C and SAT 2D Open Phase Protection Trip Enable
and 4
Miscellaneous
SNC10133196
Certificate of Conformance - 1/C 4/0 AWG 19/STR
XLPE/CSPE 2000V
07/21/2016
Procedures
ARPS FOR CONTROL PANEL 1H11-P651, ALARM PANEL
27.3
ARPS FOR CONTROL PANEL 2H11-P651, ALARM PANEL
20.2
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
ARPS FOR CONTROL PANEL 2H11-P651, ALARM PANEL
Low Voltage Switchyard Annunciator Functional Test and
Transformer Fault Pressure Annunciator And Open Phase
Protection Trip Functional Test
4.1
Unit 2 Transformers And Open Phase Protection System
Operation
4.1
Work Orders
SNC848540,
F/T TEST FOR OPEN PHASE 1H21-P044 SAT 1C
SNC944287
F/T TEST FOR OPEN PHASE 2H21-P046 ON SAT 2E
SNC968068
U1 START-UP AUXILIARY TRANSFORMER 1C (1S11-
S004) OPP SYSTEM TRIP FUNCTIONAL TEST
09/19/2019