IR 05000416/2019011
| ML19036A958 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf, 05000418 |
| Issue date: | 02/04/2019 |
| From: | Ramirez F NRC/RGN-IV/DRS/EB-2 |
| To: | Emily Larson Entergy Operations |
| Ramirez F | |
| References | |
| IR 2019011 | |
| Download: ML19036A958 (13) | |
Text
ary 4, 2019
SUBJECT:
GRAND GULF NUCLEAR STATION, UNIT 1 - NRC INSPECTION OF TEMPORARY INSTRUCTION 2515/194, INSPECTION REPORT 05000416/2019011
Dear Mr. Larson:
On January 10, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Grand Gulf Nuclear Station. On January 10, 2019, the NRC inspector discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.
The NRC inspector did not identify any finding or violation of more than minor significance.
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 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
Frances C. Ramírez, Acting Chief Engineering Branch 2 Division of Reactor Safety Docket: 50-416 License: NPF-29 Enclosure: Inspection Report 5000416/2019011 w/ Attachment: TI 2515/194 Inspection Documentation Request
U.S. NUCLEAR REGULATORY COMMISSION
Inspection Report
Docket Number: 05000416 License Number: NPF-29 Report Number: 05000416/2019011 Enterprise Identifier: I-2019-011-0020 Licensee: Entergy Operations, Inc.
Facility: Grand Gulf Nuclear Station Location: Port Gibson, Mississippi Inspection Dates: January 8, 2019, to January 10, 2019 Inspector: S. Graves, Senior Reactor Inspector Approved By: Frances C. Ramírez Acting Chief, Engineering Branch 2 Division of Reactor Safety Enclosure
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting 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 Grand Gulf Nuclear Station 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 were identified.
Additional Tracking Items None.
INSPECTION SCOPE
This inspection was conducted using Temporary Instruction 2515/194 (ADAMS Accession No. ML17137A416), effective November 1, 2017. The inspector reviewed the licensees implementation of Nuclear Energy Institutes voluntary industry initiative in compliance with Commission guidance. The inspector discussed the licensees open phase condition system design and ongoing implementation plans with plant staff. The inspector reviewed licensee and vendor documentation, and performed system walkdowns to verify that the installed equipment was supported by the design documentation. The licensee had recently completed the physical installation and the equipment was being operated in a monitoring mode with the trip functions disabled.
OTHER ACTIVITIES
- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 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 is to verify that licensees have appropriately implemented the Nuclear Energy Institute Voluntary Industry Initiative (ADAMS Accession No. ML15075A454) dated March 16, 2015, including updating their licensing basis to reflect the need to protect against open phase conditions.
Temporary Instruction 2515/194-03.01 - Voluntary Industry Initiative (Part 1)
Entergy Operations Inc. selected the open phase detection system designed and manufactured by PCS2000 Solutions, LLC, as the design vendor for the open phase condition system at Grand Gulf Nuclear Station.
At Grand Gulf Nuclear Station, Service Transformer 11 (1R15S111) and Service Transformer 21 (2R15S121) provide power to normal plant loads and provide the preferred offsite power supply to the engineered safety features (ESF) busses. Engineered Safety Feature Transformer 12 (SR11S012) provides an alternate offsite power supply to the engineered safety features busses only. The open phase condition equipment was installed on both service transformers and the engineered safety features transformer 12. The equipment installation was completed in October 2018.
At the end of this inspection the PCS2000 system was in the monitoring mode of operation to facilitate continued data gathering of local bulk power system performance for evaluation and establishing alarm and trip setpoints. The licensee had originally scheduled transitioning the PCS2000 system to full implementation (tripping functions enabled) in December 2018, however the licensee submitted letter CNRO2018-00053 notifying the NRC of a schedule change to the open phase condition detection implementation. The revised implementation date, December 2019, is as described in the September 20, 2018 letter from the Nuclear Energy Institute to the NRC (ML18268A114) which, in part, allows for a period of up to 24 months for local bulk power system performance review prior to engaging the tripping function.
INSPECTION RESULTS
- OBSERVATIONS/ASSESSMENT Based on discussions with licensee staff, review of design and testing documentation, and walkdowns of installed equipment, the inspector had reasonable assurance the licensee is appropriately implementing, with noted exceptions discussed below, the voluntary industry initiative.
The inspector determined by design document review, walkdowns, staff discussions, and observation that:
Detection, Alarms and General Criteria TI 2515/194-03.01 - Voluntary Industry Initiative (Part 1)
- (1) Open phase conditions will be detected and alarmed in the control room.
- (2) Detection circuits will be sensitive enough to identify an open phase condition for all credited loading conditions.
- (3) No Class-1E circuits were being replaced with non-Class 1E circuits in the design.
Protective Actions Criteria TI 2515/194-03.01 - Voluntary Industry Initiative (Part 1)
- (1) The identified transformers were susceptible to an open phase condition and the licensee was implementing design changes to mitigate the effects.
- (2) With an open phase condition present and no accident condition signal, the PCS2000 system would not adversely affect the function of important-to-safety systems, structures, or components. The licensees open phase condition design solution added a set of additional tripping inputs in parallel with existing transformer isolation controls. This addition added a new tripping condition (open phase) to the previously analyzed electrical faults which result in isolation of the transformers. The credited plant response was unaffected and would be the same regardless of the conditions that generated the isolation of the transformer.
No findings were identified.
The inspector identified the following exceptions to the Temporary Instruction criteria resulting from the incomplete design modifications:
Detection, Alarms and General Criteria Exceptions TI 2515/194-03.01 - Voluntary Industry Initiative (Part 1)
- (1) The licensees design installation was essentially complete on the three transformers, and the licensee had begun to gather data in a monitoring mode of operation to ensure the open phase condition design and protective schemes would minimize misoperation or spurious actions in the range of voltage unbalance normally expected in the local bulk power transmission system. As part of the system setpoint tuning process, open phase system alarms from the PCS2000 system were bypassed to limit control room operator burden due to frequent spurious alarms. Discussions with the licensee identified that all other transformer alarms were active. The licensee planned to engage the PCS2000 system alarms once appropriate setpoints were determined.
Because actual demonstration of this criterion requires the system to be in operation with final trip setpoints established, the inspector was not able to fully verify this criterion. After discussions with licensee staff, walkdown of control room panels where the open phase condition alarm had been connected, review of alarm response instructions, and review of design documentation the inspector had reasonable assurance that the actuation circuit design would not result in lower overall plant operation reliability. The inspector did not identify any issues of concern.
- (2) The Updated Final Safety Analysis Report (UFSAR) had not been updated to include information related to open phase conditions at the conclusion of the onsite inspection. The licensee provided a copy of Condition Report CR-GGN-2019-00133, written to change the Updated Final Safety Analysis Report to reflect a credible design vulnerability in the electric power system presented by an open phase condition. The licensee expected to update their Updated Final Safety Analysis Report after completion of the final modifications to initiate the tripping function. The inspector did not identify any issues of concern.
Protective Actions Criteria Exceptions TI 2515/194-03.01 - Voluntary Industry Initiative (Part 1)
- (1) With an open phase condition present and accident condition signal present, the PCS2000 system would not adversely affect the function of the Load Shedding and Sequencing (LSS) System to provide a means of automatically disconnecting and sequencing on loads on the Division I and II safety-related busses; only a new tripping condition (open phase) was being added to the electrical faults which result in isolation of the preferred or alternated offsite sources of power. A loss of voltage caused by isolation of either preferred offsite source or the alternated offsite source due to an open phase condition does not have an adverse effect on the availability of the other two offsite sources, or to the onsite emergency power source. While no changes to this configuration were planned due to the inclusion of the PCS2000 system, actual demonstration of this criterion requires the system to be in full operation. The inspector did not identify any issues of concern.
- (2) At the time of this inspection, the licensee had not finalized documentation for periodic tests, calibrations, setpoint verifications, or inspection procedures for open phase protection system equipment. The inspector held discussions with licensee staff and identified that the vendor guidance, including periodic tests, setpoint verification, and equipment maintenance and inspection would be integrated into plant procedures and processes. The licensee had entered this issue into their corrective action program as Condition Report CR-GGN-2019-00135, to ensure recommended preventative maintenance tasks transition into model work orders, and ensure equipment is part of Maintenance Rule. The new equipment is also subject to the requirements of the North American Electric Reliability Corporation (NERC) protection and control standards for transmission and generation protection system maintenance and testing.
The licensee also captured inspector observations and questions related to inspection criteria for the transformer bushing current transformers to PCS2000 cabinet connection boxes and cables, conduits and seals. These issues were entered into the corrective action program as Condition Reports CR-GGN-2019-00195, -00197, and -00198. The inspector did not identify any issues of concern.
EXIT MEETINGS AND DEBRIEFS
On January 10, 2019, the inspector presented the Temporary Instruction 2515/194 inspection results to Mr. E. Larson, Site Vice President, and other members of the licensee staff. The inspector verified no proprietary information was retained or documented in this report.
DOCUMENTS REVIEWED
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)
Condition Reports (CR-GGN-)
2019-00131
2019-00133
2019-00134
2019-00135
2019-00163
2019-00164
Drawings
Number Title Revision
E-0001 Main One Line Diagram 54
E-0105-002 R11 ESF XFMR Protection & Control ESF 8
Transformer 12, Units 1 & 2
E-0105-007 R11 ESF XFMR Protection & Control ESF XFMR 12 8
Local & Cont. Rm. Computer & Annunciator, Units 1
&2
E-0107-007 R27 Control Room Interface MOAB J3885, 8
Units 1 & 2
E-0110-03 R21 4.16KV BOP System Incoming 7
Breaker 152-1903, Units 1 & 2
E-0110-04 R21 4.16KV BOP System Incoming 7
Breaker 152-1904, Units 1 & 2
E-0110-05 R21 4.16KV BOP System Incoming 7
Breaker 152-1905, Units 1 & 2
E-1102-003 R15 Service Transformer Protection & Control 3
Computer & Annunciator, Unit 1
E-2012-003 R15 Service XFMR 21 Protection & Control 4
Annunciator & Computer, Unit 2
M3460146 Service Transformer ST-11 Backup Differential 5
Lockout Relay
M3470D37 ST-21 Backup Differential DC Schematic Diagram 1
Design Documents
Number Title Revision
EC 52500 Install Open Phase Detection Capability on Service 0
Transformers 11 & 21 and Engineered Safety
Features Transformer 12
EC 56728 Install Open Phase Detection on ST21 0
EC 56730 Service Transformer 11 Open Phase Detection 0
System Installation
EC 56731 ESF Transformer 12 Full Open Phase Detection 0
System Installation
EC-Q1111-15001 Open Phase Analysis 0
Miscellaneous
Documents
Number Title Revision
LBDCR 2018-106 Licensing Basis Document for UFSAR update
SDC-16 System Design Criteria - Load Shedding and 0
Sequencing System (R21-1)
Procedures
Number Title Revision
04-S-02-SH13-P807 Alarm Response Instruction Panel No: SH13-P807 35
Vendor Documents
Number Title Date
460004462 PCS2000 Open Phase Detection System User May 20, 2015
Manual
460004466 PCS2000 Open Phase Detection System Hardware June 30, 2014
Requirements Specification
TI 2515/194 Inspection Documentation Request
Please provide the following documentation (Items 1 - 8) to the lead inspector prior to the onsite
inspection date, preferably no later than December 17, 2018. Whenever practical, please
provide copies electronically. Please provide an index of the requested documents which
includes a brief description of the document and the numerical heading associated with the
request (i.e., where it can be found in the list of documents requested).
Sam Graves, Senior Inspector
RIV/DRS/EB2
1600 E. Lamar Blvd.
Arlington, TX 76011
817-200-1102
Samuel.graves@nrc.gov
1. Copies of any calculations, analyses, and/or test reports performed to support the
implementation of your open phase condition (OPC) solution. If, in your implementation,
OPCs are not detected and alarmed in the control room please include documentation that:
a. Demonstrates the OPC will not prevent functioning of important-to-safety SSCs; AND
b. Detection of an OPC will occur within a short period of time (e.g., 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />).
2. Copies of any modification packages, including 10 CFR 50.59 evaluations if performed,
used for or planned for the implementation of your OPC solution.
3. Copies of periodic maintenance, surveillance, setpoint calibration, and/or test procedures
implemented or planned, for your OPC solution.
4. Copies of your licensing basis changes to Updated Final Safety Analysis Report (UFSAR)
and/or Technical Specifications (TS), or equivalent, as applicable, which discuss the design
features and analyses related to the effects of, and protection for, any open phase condition
design vulnerability. If these documents have not been updated, provide documentation of
your plans to do so.
5. Copies of any procurement specifications and acceptance testing documents related to the
installation of your OPC solution.
6. Copies of any site training the inspector will need to accomplish to gain access to areas
with, or planned, major electrical equipment used in your OPC solution (i.e. switchyard).
7. Provide documentation showing that with an OPC occurrence and no accident condition
signal present, either:
a. An OPC does not adversely affect the function of important-to-safety SSCs, OR
b. TS LCOs are maintained or the TS actions are met without entry into TS LCO 3.0.3
AND
i. Important-to-safety equipment is not damaged by the OPC, AND
ii. Shutdown safety is not compromised
8. With OPC occurrence and an accident condition signal present:
a. Provide documentation showing that automatic detection and actuation will transfer
loads required to mitigate postulated accidents to an alternate source and ensure
that safety functions are preserved, as required by the current licensing bases, OR
b. Provide documentation showing that all design basis accident acceptance criteria are
met with the OPC, given other plant design features. Accident assumptions must
include licensing provisions associated with single failures. Typically, licensing bases
will not permit consideration of the OPC as the single failure since this failure is a
non-safety system.
Please provide the following documentation to the inspector when onsite. Whenever practical,
please provide copies electronically, except for drawings. Drawings should be provided as
paper copies of sufficient size (ANSI C or D) such that all details are legible.
9. A brief presentation describing your electric power system design and typical electrical
transmission and distribution system alignments; OPC design schemes installed to detect,
alarm and actuate; bus transfer schemes; and maintenance and surveillance requirements.
This presentation should be a general overview of your system. Please schedule the
overview shortly after the entrance meeting.
10. Plant layout and equipment drawings for areas that identify: (a) the physical plant locations
of major electrical equipment used in your open phase condition solution; (b) the locations of
detection and indication equipment used in the open phase condition sensing circuits.
11. If OPC actuation circuits are required, provide documentation that demonstrates continued
coordination with the other protective devices in both the offsite electrical system (within
Grand Gulfs area of responsibility) and the onsite electrical systems.
2. Access to locations in which open phase condition equipment is installed or planned (i.e.
switchyard, etc.)
13. Copies of documentation or testing that demonstrates your OPC solution minimizes spurious
actuation or misoperation in the range of voltage imbalance normally expected in the
transmission system that could cause undesired separation from an operable off-site power
source.
This document does not contain new or amended information collection requirements
subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). Existing
information collection requirements were approved by the Office of Management and
Budget, Control Number 31500011. The NRC may not conduct or sponsor, and a person
is not required to respond to, a request for information or an information collection
requirement unless the requesting document displays a currently valid Office of
Management and Budget control number.
This document 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 10 CFR 2.390, Public Inspections, Exemptions, Requests for
Withholding.
SUNSI Review: ADAMS: Non-Publicly Available Non-Sensitive Keyword: NRC-002
By: STG Yes No Publicly Available Sensitive
OFFICE SRI:EB2 AC:EB2 C:PBC AC:EB2
NAME SGraves FRamirez JKozal FRamirez
SIGNATURE /RA/ /RA/ /RA/ /RA/
DATE 02/01/2019 02/01/2019 02/01/2019 02/04/2019