IR 05000313/2019013
| ML19178A249 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/26/2019 |
| From: | Nick Taylor Division of Nuclear Materials Safety IV |
| To: | Richard Anderson Entergy Operations |
| Taylor N | |
| References | |
| IR 2019013 | |
| Download: ML19178A249 (11) | |
Text
June 26, 2019
SUBJECT:
ARKANSAS NUCLEAR ONE, UNITS 1 AND 2 - TEMPORARY INSTRUCTION 2515/194 REPORT 05000313/2019013 AND 05000368/2019013
Dear Mr. Anderson:
On June 6, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Arkansas Nuclear One, Units 1 and 2 and discussed the results of this inspection with Mr. Terry Evans, Coord-Site Vice President, 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/
Nicholas H. Taylor, Chief Engineering Branch 2 Division of Reactor Safety
Docket Nos. 50-313 and 50-368 License Nos. DPR-51 and NPF-6
Enclosure:
Inspection Report 05000313/2019013 and 05000368/2019013
Inspection Report
Docket Numbers:
05000313 and 05000368
License Numbers:
Report Numbers:
05000313/2019013 and 05000368/2019013
Enterprise Identifier: I-2019-013-0000
Licensee:
Entergy Operations, Inc.
Facility:
Arkansas Nuclear One, Units 1 and 2
Location:
Russellville, AR
Inspection Dates:
June 3, 2019, to June 6, 2019
Inspector:
S. Graves, Senior Reactor Inspector
Approved By:
Nicholas H. Taylor, Chief
Engineering Branch 2
Division of Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a Temporary Instruction 2515/194 inspection at Arkansas Nuclear One, Units 1 and 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.
Findings and violations being considered in the NRCs assessment are summarized in the table below.
List of Findings and Violations
No findings were identified.
Additional Tracking Items
None.
INSPECTION SCOPE
Inspections were conducted using the appropriate portions of the Temporary Instruction (TI)inspection in effect at the beginning of the inspection unless otherwise noted. Samples were declared complete when the TI requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspector 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
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) (1 Sample)
This inspection was conducted using Temporary Instruction 2515/194 (ADAMS Accession No. ML17137A416), effective November 1, 2017, 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. The inspector reviewed the licensees implementation of Nuclear Energy Institutes voluntary industry initiative in compliance with Commission guidance. The inspector reviewed and discussed the licensees open phase condition system design, installation, testing and maintenance plans with plant staff, and performed system walkdowns to verify that the installed equipment was supported by the design documentation.
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 Arkansas Nuclear One.
During normal operations, auxiliary power for plant electrical loading is supplied by each units main generator through an associated Unit Auxiliary Transformer. Arkansas Nuclear One has three standby transformers, Startup Transformers 1, 2, and 3, which are credited General Design Criteria, GDC-17, offsite power sources. During normal operation, Startup Transformers 1 and 3 are connected to 22-kV tertiary windings of the switchyard bus tie autotransformer bank. Startup Transformer 2 is connected to the switchyard 161-kV ring bus.
Each Startup Transformer provides a source of power for startup, shutdown, and post-shutdown loads. Startup Transformer 1 serves as a standby source for the plant auxiliaries of Unit 1, Startup Transformer 3 serves as a standby source for the plant auxiliaries of Unit 2. Startup Transformer 2 is common to both units. The system is designed to transfer loads to a Startup Transformer following a turbine generator or reactor trip without a loss of auxiliary load. Each units engineered safety features busses are capable of being supplied from either the unit auxiliary transformer during normal operation, the associated units Startup Transformer, or Startup Transformer 2.
Arkansas Nuclear One installed redundant open phase detection systems on each Startup Transformer and at the end of this inspection the PCS2000 system was operating with all functions enabled for each Startup Transformer.
INSPECTION RESULTS
Observation 2515/194 Based on discussions with licensee staff, review of design, installation and testing documentation, and walkdowns of installed equipment, the inspector had reasonable assurance the licensee is appropriately implementing the voluntary industry initiative.
The inspector determined by design document review, walkdowns, staff discussions, and observation that:
Detection, Alarms, and General Criteria
- (1) Open phase conditions will be detected and alarmed in the control rooms.
- (2) Detection circuits are sensitive enough to identify an open phase condition for all credited loading conditions.
- (3) The PCS2000 system is designed to minimize misoperation or spurious action in the range of voltage unbalance normally expected in the transmission system that could cause separation from an operable offsite power source. The licensee had demonstrated that the actuation circuit design did not result in lower overall plant operation reliability.
- (4) No Class-1E circuits were replaced with non-Class 1E circuits in the design.
- (5) The licensee had updated the Unit 1 and Unit 2 Final Safety Analysis Reports to discuss the design features and analyses related to the effects of, and protection for, any open phase condition vulnerabilities.
Protective Actions Criteria
- (1) Startup Transformers 1, 2, and 3 were identified as susceptible to an open phase condition and the licensee had implemented design changes to mitigate the effects.
- (2) With an open phase condition present and no accident condition signal present, 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 independent of the conditions that generated the isolation of the transformer.
- (3) With an open phase condition present and accident condition signal present, the PCS2000 system would not adversely affect the transfer of 4.16-kV engineered safeguards buses to the onsite emergency diesel generators as required by the current licensing bases; only a new tripping condition (open phase) was added to the electrical faults which result in isolation of the alternate offsite source of power.
The 4.16-kV engineered safeguards buses are normally energized from the main generator through the unit auxiliary transformer and the non-engineered safeguards busses. Upon loss of the normal power source, the engineered safeguards loads are automatically transferred to the selected Startup Transformer. Isolation of the Startup Transformer due to an open phase condition results in the engineered safeguards loads being automatically transferred and energized from the respective emergency diesel generator in the same manner as required by the current licensing bases.
Protective Actions Criteria Exception
At the time of this inspection, the licensee had not finalized development for all periodic tests, calibrations, setpoint verifications, or inspection procedures for open phase protection system equipment. The licensee had developed and implemented work instructions and procedures for the uninterruptible power supplies used to power the open phase protection equipment, had established preventive maintenance identification for the system components, and had established plans for repair or replacement of degraded components. The inspector held discussions with licensee staff and identified that the vendor guidance, including periodic tests, setpoint verification, and equipment maintenance and inspections would be integrated into plant procedures and processes. The licensee had performed a pre-inspection self-assessment, documented in Condition Report LO-ALO-2019-00029 which documented, in part, the licensees pending actions to determine if any of the open phase detection components needed to be included in the Maintenance Rule program and, if so, ensure actions are in place to include the components in the program.
EXIT MEETINGS AND DEBRIEFS
On June 6, 2019, the inspector presented the Temporary Instruction 2515/194 results to Mr. T. Evans, Coord-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
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2515/194
Calculations
CALC-14-E-
2001-01
EMTP Station Open Phase
LOCA Analysis
CALC-15-D-
3001-01
EMTP Transmission Line Open
Phase Analysis
CALC-15-D-
3001-02
EMTP Station Open Phase
Analysis
CALC-17-E-
3001-01
Coordination of Open Phase
Detection Time Delay Trip
Setting
CALC-84-E-
0103-01
General Criteria for Safety
Buses
CALC-ANOC-
EE-18-00001
ANO SU1 & SU3 Open Phase
Detection Monitoring Period
Report June - December 2017
CALC-ANOC-
EE-18-00003
SU2 Open Phase Detection
Monitoring Period Report
October 2018
Corrective
Action
Documents
LO-ALO-
2019-00029
Track the Pre-NRC Inspection
Focused Self-Assessment for
Open Phase Condition Design
Vulnerabilities
2/21/2019
Corrective
Action
Documents
Resulting from
Inspection
CR-ANO-1-
2019-01375
6/04/2019
Drawings
E-1
Station Single Line Diagram
E-112
Schematic Diagram StartUp
XFMR Aux Systems Local
Annunciator Reflash Modules
E-2001
Station Single Line Diagram
E-2094
Schematic Diagram Startup
Transformer #3 Lockout Relay
E-2112
Schematic Diagram Start-Up
Transformer Auxiliary System
E-2812
Transformer Area Grounding &
Underground Ductbank Layout
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
E-2814
Transformer Area Grounding &
Underground Ductbank Layout
E-2816
Transformer Area Isophase
and Non-Segregated Busses
and Overhead Lines
E-2819
Transformer Yard Deluge
System Conduit Layout
E-613
Underground Conduit and
Grounding Transformer Yard
Area
E-614
Transformer Yard Area
Isophase Bus, Structures and
Overhead Lines
E-94
Schematic Diagram Startup
Transformers No 1 & No 2
Lockout Relays
Engineering
Changes
Provide Open Phase Detection
and Protection for Startup
Transformer No. 2
Enable Open Phase Detection
Trip Circuits (Parent EC)
Enable Open Phase Detection
Trip and Alarm Circuits Startup
Transformer 1
(CHILD EC TO EC 73661)
2/21/2017
Enable Open Phase Detection
Trip and Alarm Circuits Startup
Transformer 2
(CHILD EC TO EC 73661)
2/21/2017
Enable Open Phase Detection
Trip and Alarm Circuits Startup
Transformer 3
(CHILD EC TO EC 73661)
2/21/2017
ECT-48708-
Post Modification Testing of
Trip and Alarm Functions for
SU3 Open Phase Detection
4/20/2017
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
(OPD)
ECT-48770-
Post Modification Testing of
Trip and Alarm Functions for
SU2 Open Phase Detection
(OPD)
9/24/2017
ECT-48771-
Post Modification Testing of
Trip and Alarm Functions for
SU1 Open Phase Detection
(OPD)
11/17/2017
Miscellaneous
Arkansas Nuclear One, Unit 1
Safety Analysis Report
Amendment
Arkansas Nuclear One, Unit 2
Safety Analysis Report
Amendment
PCS2000 Open Phase
Detection System Factory
Acceptance Testing for Start
Up Transformers 1, 2, and 3
8/08/2016
PCS2000 Open Phase
Detection System ANO SU1
Site Acceptance Test
11/11/2016
PCS2000 Open Phase
Detection System ANO SU2
Site Acceptance Test
9/24/2017
PCS2000 Open Phase
Detection System ANO SU3
Site Acceptance Test
4/20/2017
Process Applicability
Determination for EC 73661,
Enable Open Phase Detection
Trip Circuits (Parent EC)
11/12/2018
Licensing
Basis
Document
Change
LBDC 17-015
Clarification of Offsite Power
Operability Requirements
3/15/2017
Licensing
Basis
Document
Change
LBDC 17-016
Clarification of Offsite Power
Operability Requirements
3/10/2017
Procedures
1107.001
Electrical System Operations
23
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
203.012B
Annunciator K02 Corrective
Action
048
2107.001
Electrical System Operations
29
203.012A
Annunciator 2K01 Corrective
Action
049
203.054
Abnormal Grid
2
Work Orders
00499121-01
D-71 Battery Charger for SU1
Open Phase Detection,
Perform Monthly Battery
Charger Checks for Voltage
and Current Output, Check and
Reset Alarms and Perform
Alarm Indication Lamp Tests
00506901-01
D-71 Start-up (SU) #1 Open
Phase Detection 125 VDC
Battery Bank Monthly
Monitoring and Inspection
11/07/2018
00506913-01
2D-70 Battery Bank for SU3
Open Phase Detection Monthly
Monitoring and Inspection
10/29/2018
2816135-01
2D-70 Battery Bank for SU3
Open Phase Detection Monthly
Monitoring and Inspection
2/03/2018
2843065
D-71 Battery Charger Monthly
4/24/2019
SUNSI Review: ADAMS: Non-Publicly Available Non-Sensitive Keyword: NRC-002
By: STG Yes No Publicly Available Sensitive
OFFICE
SRI:EB2
C:EB2
C:PBD
C:EB2
NAME
SGraves
NTaylor
JDixon
NTaylor
SIGNATURE
/RA/
/RA/
/RA/
/RA/
DATE
6/25/2019
6/25/2019
6/26/2019
6/26/2019