ML22026A350
| ML22026A350 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 01/26/2022 |
| From: | Erin Carfang Division of Operating Reactors |
| To: | Rhoades D Exelon Generation Co LLC, Exelon Nuclear |
| Carfang E | |
| References | |
| IR 2021004 | |
| Download: ML22026A350 (22) | |
See also: IR 05000220/2021004
Text
January 26, 2022
Mr. David P. Rhoades
Senior Vice President
Exelon Generation Company, LLC
President and Chief Nuclear Officer
Exelon Nuclear
4300 Winfield Road
Warrenville, IL 60555
SUBJECT:
NINE MILE POINT NUCLEAR STATION, UNITS 1 AND 2 - INTEGRATED
INSPECTION REPORT 05000220/2021004 AND 05000410/2021004
Dear Mr. Rhoades:
On December 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an
inspection at Nine Mile Point Nuclear Station, Units 1 and 2. On January 20, 2022, the NRC
inspectors discussed the results of this inspection with Mr. Adam Schuerman, Plant Manager,
and other members of your staff. The results of this inspection are documented in the enclosed
report.
One finding of very low safety significance (Green) is documented in this report. This finding
involved a violation of NRC requirements. We are treating this violation as a non-cited violation
(NCV) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violation or the significance or severity of the violation documented in this
inspection report, you should provide a response within 30 days of the date of this inspection
report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional
Administrator, Region I; the Director, Office of Enforcement; and the NRC Resident Inspector at
Nine Mile Point Nuclear Station, Units 1 and 2.
D. Rhoades
2
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,
Erin E. Carfang, Chief
Projects Branch 1
Division of Operating Reactor Safety
Docket Nos. 05000220 and 05000410
License Nos. DPR-63 and NPF-69
Enclosure:
As stated
cc w/ encl: Distribution via LISTSERV
Erin E. Carfang
Digitally signed by Erin E.
Carfang
Date: 2022.01.26 13:19:19
-05'00'
x
SUNSI Review
x
Non-Sensitive
Sensitive
x
Publicly Available
Non-Publicly Available
OFFICE RI/DORS
RI/DORS
RI/DORS
NAME
GStock
JHawkins
ECarfang
DATE
1/26/22
1/26/22
1/26/22
Enclosure
U.S. NUCLEAR REGULATORY COMMISSION
Inspection Report
Docket Numbers:
05000220 and 05000410
License Numbers:
Report Numbers:
05000220/2021004 and 05000410/2021004
Enterprise Identifier: I-2021-004-0115
Licensee:
Exelon Generation Company, LLC
Facility:
Nine Mile Point Nuclear Station
Location:
Oswego, NY
Inspection Dates:
October 1, 2021 to December 31, 2021
Inspectors:
G. Stock, Senior Resident Inspector
C. Kline, Resident Inspector
B. Sienel, Resident Inspector
J. Demarshall, Senior Operations Engineer
T. Fish, Senior Operations Engineer
J. Hawkins, Senior Project Engineer
P. Ott, Operations Engineer
Approved By:
Erin E. Carfang, Chief
Projects Branch 1
Division of Operating Reactor Safety
2
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees
performance by conducting an integrated inspection at Nine Mile Point Nuclear Station, 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.
List of Findings and Violations
Failure to Correct a Condition Adverse to Quality with an Uninterruptible Power Supply
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
NCV 05000220,05000410/2021004-01
Open/Closed
None (NPP)
The inspectors documented a self-revealed Green non-cited violation (NCV) of Title 10 of the
Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, Corrective Action,
when Exelon did not ensure that a condition adverse to quality (CAQ) associated with an
identified deviation from the normal operating frequency of an uninterruptible power supply
(UPS) was promptly identified and corrected. Specifically, on August 1, 2016, after performing
maintenance on and placing the UPS-162A in service, Exelon documented an off-normal
condition related to the UPS inverter frequency being lower than normal and oscillating.
Exelon closed this issue report (IR) to trend without properly evaluating and correcting the
condition, resulting in the failure of the reactor protection system (RPS) UPS-162A and
causing the plant to experience a half-scram condition, an isolation of both emergency
condensers, and an isolation of the reactor water cleanup (RWCU) system on September 25,
2021.
Additional Tracking Items
Type
Issue Number
Title
Report Section
Status
LER 2021-001-00, Average
Power Range Monitors
Declared Inoperable Due to
Trip of Reactor Recirculation
Pump 13
Closed
LER 2021-002-00, Isolation
of Both Emergency
Condensers Due to Loss of
UPS-162A
Closed
3
PLANT STATUS
Unit 1 began the inspection period at rated thermal power. On October 2, 2021, reactor power
was reduced to approximately 75 percent for a control rod pattern adjustment, control rod scram
time testing, and turbine valve testing and returned to rated thermal power the same day. On
November 2, 2021, reactor power was reduced to approximately 98 percent to maintain inlet to
discharge differential temperature within state limits due to condenser fouling. On
November 13, 2021, reactor power was reduced to approximately 51 percent to correct the
condenser fouling. On November 13, 2021, Unit 1 was returned to rated thermal power. Unit 1
remained at or near rated thermal power for the remainder of the inspection period.
Unit 2 began the inspection period at rated thermal power. On October 9, November 21, and
December 10, 2021, reactor power was reduced to approximately 75 percent to perform control
rod channel interference testing, control rod scram time testing, and control rod pattern
adjustments. In each instance, Unit 2 was returned to rated thermal power on the same day or
the following day and remained at or near rated thermal power for the remainder of the
inspection period.
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 performed activities described in IMC 2515,
Appendix D, Plant Status, conducted routine reviews using IP 71152, Problem Identification
and Resolution, observed risk significant activities, and completed on-site portions of IPs. 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.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated readiness for seasonal extreme weather conditions prior to
the onset of seasonal cold temperatures for the Unit 1 emergency diesel generators
and the Unit 2 Division I and II diesel generators.
Impending Severe Weather Sample (IP Section 03.02) (1 Sample)
(1)
The inspectors evaluated the adequacy of the overall preparations to protect risk-
significant systems from impending severe weather for high winds on
December 6, 2021.
4
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following
systems/trains:
(1)
Unit 2 control rod drive on November 23, 2021
(2)
Unit 2 Division II residual heat removal on November 23, 2021
(3)
Unit 2 Division II diesel generator on November 29, 2021
(4)
Unit 2 reactor building closed loop cooling water on November 29, 2021
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
(1)
The inspectors evaluated system configurations during a complete walkdown of the
Unit 2 standby gas treatment system on November 4, 2021.
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (8 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a
walkdown and performing a review to verify program compliance, equipment functionality,
material condition, and operational readiness of the following fire areas:
(1)
Unit 2 reactor building 175' and 240', reactor core isolation cooling pump room, fire
area 2, on October 5, 2021
(2)
Unit 2 reactor building 261', standby gas treatment rooms A and B, fire areas 4, 73,
and 74, on November 4, 2021
(3)
Unit 2 Division I switchgear room, fire area 17, on November 22, 2021
(4)
Unit 2 Division II diesel generator control room, fire area 29, on November 23, 2021
(5)
Unit 2 reactor building 328, fire areas 34 and 35, on November 30, 2021
(6)
Unit 2 Division III diesel generator control room 261/274', fire area 30, on
December 13, 2021
(7)
Unit 2 Division I diesel generator control room 261/274', fire area 28, on
December 13, 2021
(8)
Unit 2 control building 288' relay room, fire area 24, on December 14, 2021
71111.06 - Flood Protection Measures
Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)
The inspectors evaluated internal flooding mitigation protections in the:
(1)
Unit 2 Division I and II emergency switchgear rooms, on November 22, 2021
5
71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance
Requalification Examination Results (IP Section 03.03) (2 Samples)
(1)
The inspectors reviewed and evaluated the licensed operator examination failure
rates for the requalification annual operating exam administered
October - November 2021.
(2)
The inspectors reviewed and evaluated the Unit 1 licensed operator annual
requalification results for the annual operating exam on December 6, 2021.
71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Requalification Program (IP Section 03.04) (1 Sample)
(1)
Biennial Requalification Written Examinations
The inspectors evaluated the quality of the licensed operator biennial requalification
written examination administered October - November 2021.
Annual Requalification Operating Tests
The inspectors evaluated the adequacy of the facility licensees annual requalification
operating test.
Administration of an Annual Requalification Operating Test
The inspectors evaluated the effectiveness of the facility licensee in administering
requalification operating tests required by 10 CFR 55.59(a)(2) and that the facility
licensee is effectively evaluating their licensed operators for mastery of training
objectives.
Requalification Examination Security
The inspectors evaluated the ability of the facility licensee to safeguard examination
material, such that the examination is not compromised.
Remedial Training and Re-examinations
The inspectors evaluated the effectiveness of remedial training conducted by the
licensee, and reviewed the adequacy of re-examinations for licensed operators who
did not pass a required requalification examination.
Operator License Conditions
The inspectors evaluated the licensees program for ensuring that licensed operators
meet the conditions of their licenses.
6
Control Room Simulator
The inspectors evaluated the adequacy of the facility licensees control room
simulator in modeling the actual plant, and for meeting the requirements contained in
Problem Identification and Resolution
The inspectors evaluated the licensees ability to identify and resolve problems
associated with licensed operator performance.
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01)
(2 Samples)
(1)
The inspectors observed Unit 1 operations personnel during a planned reactor
downpower to approximately 80 percent for a rod pattern adjustment and control rod
scram time testing on October 1, 2021.
(2)
The inspectors observed Unit 2 operations personnel during a planned reactor
downpower to approximately 97 percent and control rod friction testing on
October 8, 2021.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)
(1)
The inspectors observed a Unit 2 simulator evaluation that included the loss of an
emergency switchgear bus, a trip of a feedwater heater drain pump, a failure to
SCRAM, and a loss of coolant accident inside containment on October 12, 2021.
(2)
The inspectors observed a Unit 1 annual examination that included an unplanned
opening of an electro-matic relief valve, the 12 emergency condenser tube leak, an
instrument air leak, and a steam leak inside containment on October 26, 2021.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following
structures, systems, and components (SSCs) remain capable of performing their intended
function:
(1)
Unit 1 safety-related ventilation control room chiller 11B oil leak
(2)
Unit 2 automatic depressurization system makeup valve stuck open
(3)
Unit 2 service water discharge valve failure to open
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the
following planned and emergent work activities to ensure configuration changes and
appropriate work controls were addressed:
7
(1)
Unit 2 elevated risk during scheduled high pressure core spray maintenance on
October 26, 2021
(2)
Unit 1 elevated risk during scheduled 12 feedwater pump maintenance on
November 3, 2021
(3)
Unit 2 elevated risk during unplanned reactor core isolation cooling maintenance on
November 9, 2021
(4)
Unit 2 elevated risk during scheduled Division I emergency diesel generator 6-year
preventive maintenance on November 17, 2021
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the
following operability determinations and functionality assessments:
(1)
Unit 1 emergency diesel generator 102 due to inaccurate day tank level indication on
October 5, 2021
(2)
Unit 1 11 and 12 emergency cooling systems following isolation during the loss of
reactor protection system 11 on October 15, 2021
(3)
Unit 2 Division III diesel generator due to potential fuel oil lubricity out of specification
on October 18, 2021
(4)
Unit 2 Division II diesel generator following jacket water leak on November 3, 2021
(5)
Unit 2 reactor core isolation cooling due to flow controller failure on
November 8, 2021
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)
(1 Sample)
The inspectors evaluated the following temporary or permanent modifications:
(1)
Permanent Modification: ECP-21-000437, Unit 2 Division II Emergency Diesel
Generator Governor Booster Modification
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the following post-maintenance test activities to verify system
operability and functionality:
(1)
Unit 2 Division II diesel generator governor replacement on November 6, 2021
(2)
Unit 2 Division I control building chiller maintenance on December 2, 2021
(3)
Unit 1 121 core spray pump and booster pump breaker replacements on
December 2, 2021
(4)
Unit 2 reactor core isolation cooling following flow controller maintenance on
November 10, 2021
8
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01) (2 Samples)
(1)
N1-ST-Q8A, Liquid Poison 11 and Check Valve Operability Test, on
October 18, 2021
(2)
N2-ISP-CSL-Q001, Low Pressure Core Spray Pump Discharge Flow - Low (Bypass)
Instrument Channel Functional Test, on December 21, 2021
RCS Leakage Detection Testing (IP Section 03.01) (1 Sample)
(1)
N2-OSP-LOG-S001, Shift Checks - Mode 1, on November 29, 2021
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01)
(1 Sample)
(1)
The inspectors evaluated a Unit 2 simulator evaluation which included a failure to
SCRAM, a loss of coolant accident, and the declaration of an Alert on
October 12, 2021.
OTHER ACTIVITIES - BASELINE
71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)
(1)
Unit 1 - October 1, 2020 through September 30, 2021
(2)
Unit 2 - October 1, 2020 through September 30, 2021
MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)
(1)
Unit 1 - October 1, 2020 through September 30, 2021
(2)
Unit 2 - October 1, 2020 through September 30, 2021
MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)
(1)
Unit 2 - October 1, 2020 through September 30, 2021
(2)
Unit 1 - October 1, 2020 through September 30, 2021
71152 - Problem Identification and Resolution (PI&R)
Semiannual Trend Review (IP Section 02.02) (1 Sample)
(1)
The inspectors reviewed the licensees corrective action program for potential
adverse trends that might be indicative of a more significant safety issue.
9
Annual Follow-up of Selected Issues (IP Section 02.03) (2 Samples)
The inspectors reviewed the licensees implementation of its corrective action program
related to the following issues:
(1)
IR 04448532 - Review of Uninterruptible Power Supply Failure
(2)
IR 04372127 - Review of Trend in Surveillance Test Interval Implementation
71153 - Follow Up of Events and Notices of Enforcement Discretion
Event Report (IP Section 03.02) (2 Samples)
The inspectors evaluated the following licensee event reports (LERs):
(1)
LER 05000220/2021-001-00, Average Power Range Monitors Declared Inoperable
Due to Trip of Reactor Recirculation Pump 13. (ADAMS Accession
No. ML21144A050). The inspectors determined that it was not reasonable to foresee
or correct the cause discussed in the LER, therefore no performance deficiency was
identified. The inspectors did not identify a violation of NRC requirements. This LER
is closed.
(2)
LER 05000220/2021-002-00, Isolation of Both Emergency Condensers Due to Loss
of UPS-162A. (ADAMS Accession No. ML21327A024). The inspection conclusions
associated with this LER are documented in this report under Inspection Results. This
LER is closed.
INSPECTION RESULTS
Failure to Correct a Condition Adverse to Quality with an Uninterruptible Power Supply
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
NCV 05000220,05000410/2021004-01
Open/Closed
None (NPP)
The inspectors documented a self-revealed Green non-cited violation (NCV) of Title 10 of the
Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, Corrective
Action, when Exelon did not ensure that a condition adverse to quality (CAQ) associated with
an identified deviation from the normal operating frequency of an uninterruptible power supply
(UPS) was promptly identified and corrected. Specifically, on August 1, 2016, after performing
maintenance on and placing the UPS-162A in service, Exelon documented an off-normal
condition related to the UPS inverter frequency being lower than normal and oscillating.
Exelon closed this issue report (IR) to trend without properly evaluating and correcting the
condition, resulting in the failure of the reactor protection system (RPS) UPS-162A and
causing the plant to experience a half scram condition, an isolation of both emergency
condensers, and an isolation of the reactor water cleanup (RWCU) system on September 25,
2021.
Description: In 1993, motor generator sets at Unit 1 were replaced with four safety-related
UPSs (UPS-162A and -B, UPS-172A and -B) to supply conditioned 120 VAC power to the
RPS and instrument buses. Preventive maintenance is performed on the Unit 1 internal UPS
circuit cards by replacing them every 10 years.
10
On September 25, 2021, UPS-162A experienced voltage and frequency perturbations
(-5 VAC and 0.2 Hz from the normal values) which resulted in actuation of the RPS bus 11
under frequency protective relaying. This actuation caused a loss and subsequent restoration
of RPS bus 11 on UPS-162A which resulted in a half scram, an isolation of both emergency
condensers, and RWCU isolation. After troubleshooting the equipment and consulting with
the vendor, Exelon determined a capacitor, as well as an oscillator and sync circuit card,
required replacement. Exelon replaced these components, sent them for failure analysis, and
restored the UPS to service.
On October 28, 2021, Exelon completed a corrective action program evaluation (CAPE)
under IR 04448532. This evaluation ruled out the capacitor as a cause of the UPS failure.
Exelon determined that the cause of the failure was a premature failure of the UPS-162A
oscillator and sync circuit card. The evaluation found that the circuit card issue had potentially
existed since the UPS circuit cards were last replaced and placed in service in July 2016.
Exelons CAPE documented that two days after placing the UPS in-service, IR 02699078 was
written for observed UPS-162A frequency oscillations of 0.2 Hz and a lower than expected
voltage. This IR was closed with no additional actions taken to troubleshoot or correct the
abnormal condition. Exelons CAPE determined that the organization failed to adequately
address the documented frequency oscillations and generate a work order to investigate and
repair the condition. Exelon also determined that procedure N1-EPM-UPS-003, UPS
Maintenance PM, was inadequate to address frequency oscillations and that system internal
and external operating experience (OPEX) reviews were inadequate. Exelon received the
vendor failure analysis report (FAR 21-005) on November 15, 2021. This report concluded, in
part, that the failed oscillator and sync boards caused the inverter to phase drift and the UPS
to lose sync within 15 minutes when temperatures exceeded 105 degrees Fahrenheit, as
opposed to the normal temperature rating of 120 degrees Fahrenheit.
The inspectors reviewed Exelons CAPE, failure analysis report, and procedures. Exelons IR
02699078, which documented the observed frequency oscillations in 2016, also documented
Recommended Actions to determine if oscillations can lead to a fault in the UPS (could
lead to a loss of RPS 11). The inspectors found no documented answer to the recommended
action above. The Functional Basis section of the IR states, The fluctuation (0.25 Hz) is
within the acceptance criteria for N1-EPM-UPS-003 (59.7-60.3 Hz). A walkdown was
performed by EMD [electrical maintenance] and they did not identify an immediate concern
with functionality. UPS-162A remains functional. However, Exelons CAPE concluded that
procedure N1-EPM-UPS-003 was inappropriately used to determine the functionality of
UPS-162A, specifically that frequency oscillations, whether in the acceptance criteria band or
not, are an abnormal condition and should not be accepted under any circumstance, as this is
a sign of degradation and potential premature failure. The inspectors also noted that Exelon
procedure PI-AA-120, "Issue Identification and Screening Process," Revision 11, Section
4.4.6, states, in part, to determine if the as-found operability and functionality of any system,
structure, or component is affected by the condition and document the basis of the
determination. Section 4.6.6 states, in part, to determine if any additional actions are
necessary and route the issue to the responsible department to create actions.
Based on the information above, the inspectors determined that Exelon did not ensure that a
CAQ associated with an identified deviation from the normal operating frequency of
UPS-162A was promptly identified and corrected. Specifically, after performing maintenance
and placing the UPS in service, Exelon documented an off-normal condition related to the
UPS inverter frequency being lower than normal and oscillating yet closed this IR without
properly evaluating and correcting the condition.
11
Corrective Actions: Exelon replaced the failed UPS oscillator and sync circuit cards, revised
UPS maintenance procedures, added frequency oscillation observation to the system
walkdown checklist, sent the failed circuit cards out for failure analysis, and generated a crew
learning for timely OPEX reviews.
Corrective Action References: IR 04446321
Performance Assessment:
Performance Deficiency: Exelon's failure to ensure that a CAQ associated with an identified
deviation from the normal operating frequency of UPS-162A was promptly identified and
corrected is a performance deficiency that was within Exelons ability to foresee and correct,
and which should have been prevented.
Screening: The inspectors determined the performance deficiency was more than minor
because it was associated with the Design Control attribute of the Mitigating Systems
cornerstone and adversely affected the cornerstone objective to ensure the availability,
reliability, and capability of systems that respond to initiating events to prevent undesirable
consequences. Specifically, Exelon not ensuring that a CAQ associated with a safety-related
UPS was promptly identified and corrected resulted in reduced UPS reliability, a half-scram
condition, an isolation of both emergency condensers, and an isolation of the RWCU system.
Significance: The inspectors assessed the significance of the finding using Appendix A, The
Significance Determination Process (SDP) for Findings At-Power. Using Exhibit 2 of
Appendix A, the inspectors determined this finding was of very low safety significance
(Green) because Yes was not answered to any of the screening questions.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to
this finding because the inspectors determined the finding did not reflect present licensee
performance.
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, in part,
that measures shall be established to ensure that CAQs, such as deviations and
nonconformances are promptly identified and corrected. Exelons procedure PI-AA-120,
"Issue Identification and Screening Process," states, in part, for CAQ to determine if the as-
found operability and functionality of any system, structure, or component is affected by the
condition and document the basis of the determination. The procedure also states to
determine if any additional actions are necessary and route the issue to the responsible
department to create actions.
Contrary to the above, between August 1, 2016, and September 25, 2021, Exelon did not
ensure that a CAQ associated with an identified deviation from the normal operating
frequency of UPS-162A was promptly identified and corrected. Specifically, on August 1,
2016, after performing maintenance and placing the UPS in service, Exelon documented an
off-normal condition related to the UPS inverter frequency being lower than normal and
oscillating but closed this IR without properly evaluating and correcting the condition resulting
in the failure of the RPS UPS-162A and caused the plant to experience a half-scram
condition, an isolation of both emergency condensers, and an isolation of the RWCU system.
Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2
of the Enforcement Policy.
12
Minor Performance Deficiency
Minor Performance Deficiency: The inspectors reviewed a CAPE completed by Exelon staff,
and their identified corrective actions, following a series of issues in the implementation of the
surveillance frequency control program, including a missed surveillance as a result of an
inadequate evaluation. The missed surveillance was for the calibration of Unit 1 remote
shutdown panel reactor vessel water level indication in accordance with the surveillance
frequency control program. Exelons CAPE included an extent of condition review of all
completed surveillance frequency changes to ensure no other technical flaws
existed. Corrective actions included ensuring future surveillance frequency changes are
routed through regulatory assurance to verify the procedures align with the appropriate
technical specification surveillance requirements. Exelon also established a checklist to be
performed during the development of future surveillance frequency changes that includes the
steps required to avoid missed surveillances.
The inspectors reviewed the evaluation, extent of condition review, and relevant IRs and
interviewed the surveillance frequency control program owner. Based on the documents
reviewed and discussions with personnel, the inspectors determined Exelons evaluation of
the issue was adequate and provided for corrective action commensurate with the safety
significance of the problem. Exelon's failure to perform the missed surveillance discussed
above in the required timeframe is a performance deficiency.
Screening: The inspectors determined the performance deficiency was minor. The inspectors
evaluated the missed surveillance for significance in accordance with the guidance in IMC 0612, Appendix B, "Issue Screening," and Appendix E, "Examples of Minor Issues." The
performance deficiency was minor because it did not adversely affect a cornerstone objective
and following identification an appropriate risk assessment was developed and the
surveillance successfully completed in accordance with Technical Specification Surveillance
Requirement 4.0.3.
Significance: The inspectors assessed the significance of the finding using Appendix A, The
Significance Determination Process (SDP) for Findings At-Power. This performance
deficiency was of minor significance and, therefore, are not subject to enforcement action in
accordance with the NRC's Enforcement Policy.
Minor Performance Deficiency
Minor Performance Deficiency: The inspectors performed a review of a recent UPS failure
that occurred at Unit 1 on September 25, 2021. Exelons CAPE, under IR 04448532,
documented that UPS-162A experienced voltage and frequency perturbations (-5 VAC and
0.2 Hz from the normal values) which resulted in actuation of the RPS bus 11 underfrequency
protective relaying. This actuation caused a loss and subsequent restoration of RPS bus 11
on UPS-162A which resulted in a half SCRAM, an isolation of both emergency condensers,
and RWCU isolation. The inspectors reviewed this CAPE to assess Exelons ability to
adequately identify problems, evaluate the causes of the equipment issues, and resolve the
issues in a timely manner.
During the review, the inspectors noted one more than minor performance deficiency (PD)
which is documented separately as an NCV in this report, and one minor PD, which is
documented below.
13
Minor PD: Exelon procedure PI-AA-115, "Operating Experience Program," Revision 5,
Section 4 for the receipt, screening, and processing of OPEX documents states, in part, to
perform an initial screening to determine the appropriate OPEX evaluation significance,
initiate an IR as applicable in Attachment 1, or if there is potentially new information that
challenges the conservatism of current external event design assumptions, and retain
relevant OPEX information in the ENGAGE Health notebooks in accordance with procedure
ER-AA-2030, "Conduct of Equipment Reliability Manual." Procedure ER-AA-2030, Section
4.3.4 for OPEX and peer lessons learned states, in part, that engineers should read daily
industry OPEX reports, review similar station IRs, and perform periodic OPEX searches on
industry websites. In addition, the procedure discusses that the ENGAGE Health notebooks
is where relevant OPEX should be retained and at a minimum updated semiannually.
Attachment 2 of this procedure goes on to state that the engineer is responsible for initial
OPEX reviews and the generation of IRs for required Level 3 OPEX reviews.
Contrary to these procedures, the inspectors found that Exelons CAPE determined that, The
OPEX reviews documented in Engage Health for this system appear to be inadequate. More
robust OPEX reviews may have allowed the frequency oscillations to be identified as a
potential failure mechanism earlier. This contributed to the failure in this event. The
inspectors noted that the CAPE generated an action to generate a crew learning for timely
OPEX reviews. Based on the external OPEX and the lack reviews and retention of the OPEX
for the UPS system, the inspectors questioned Exelon about whether a "crew learning" was
enough to correct this deficiency. The inspectors determined that the "crew learning" was an
action that could correct the OPEX review and retention issues going forward but that the
potential OPEX gap could remain unless system engineers conducted a "look back" to
ensure previous OPEX was accurately captured. Exelon documented this in IR 04448532.
Significance: The inspectors assessed the significance of the finding using Appendix A, The
Significance Determination Process (SDP) for Findings At-Power.
Observation: Semi-Annual Trend
The inspectors evaluated a sample of issues and events that occurred from July 2021
through December 2021 to determine whether issues were appropriately considered as
emerging or adverse trends. The inspectors verified issues were appropriately evaluated by
Exelon staff for potential trends and addressed within the scope of the corrective action
program or through department review.
The inspectors did not identify any new trends that could indicate a more significant safety
issue. Exelon documented a trend in critical component failures during this evaluation
period. This included the failure of the Unit 1 12 high pressure coolant injection controller,
loss of RPS 11 following the failure of UPS-162A, the Unit 2 'C' service water pump discharge
valve failure to open, and Division II emergency diesel generator jacket water leak. These
issues were captured in trend IR 04459468 which resulted in Exelon personnel performing a
work group evaluation for commonalities between the failures. Exelon also identified several
instances of rework associated with supplemental workforce over a short period of time and
documented a potential trend in IR 04439810. None of these cases resulted in inoperability or
unavailability of safety systems. The inspectors also noted other minor potential adverse
trends identified by Exelon staff in the areas of equipment challenges in both units' instrument
air systems and failures of fire detectors at both units requiring additional walkdowns and
patrols.
14
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On January 20, 2022, the inspectors presented the integrated inspection results to
Mr. Adam Schuerman, Plant Manager, and other members of the licensee staff.
THIRD PARTY REVIEWS
Inspectors reviewed the World Association of Nuclear Operators report that was issued during
the inspection period.
15
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
04198397
04445508
04461612
Procedures
N1-OP-64
Meteorological Monitoring
02100
N2-OP-102
Meteorological Monitoring
02800
Severe Weather and Natural Disaster Guidelines
023
Work Orders
C93760254
C93762635
C93805503
Drawings
PID-11D
Piping and Instrumentation Diagram Service Water System
12
PID-13A
Piping and Instrumentation Diagram Reactor Building
Closed Loop Cooling Water
19
PID-30A
Piping and Instrumentation Diagram Control Rod Drive
Hydraulic System
29
PID-30B
Piping and Instrumentation Diagram Control Rod Drive
Hydraulic System
14
PID-30C
Piping and Instrumentation Diagram Control Rod Drive
Hydraulic System
15
PID-31A
Piping and Instrumentation Diagram Residual Heat
Removal System
27
PID-43G
Piping and Instrumentation Diagram Fire Protection -
Water
28
PID-61B
Piping and Instrumentation Diagram Primary Containment
Purge and Standby Gas Treatment
23
PID-61C
Piping and Instrumentation Diagram Primary Containment
Purge and Standby Gas Treatment
8
Miscellaneous
Green NCV
05000410/2018002-
01
Failure to Ensure Proper Control of the Standby Gas
Treatment System Damper Valve, 2GTS-V2000, Within
Procedures, Materials, and Design Controls
Procedures
N2-OP-13
LINEUPS, Reactor Building Closed Loop Cooling System
004
N2-OP-30
Control Rod Drive
26
N2-OP-31
Residual Heat Removal System
036T1
16
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
N2-OP-61B
Standby Gas Treatment
17
N2-OP-61B-
LINEUPS
Standby Gas Treatment - LINEUPS
0100
PID-31B
Piping and Instrumentation Diagram Residual Heat
Removal System
23
PID-31C
Piping and Instrumentation Diagram Residual Heat
Removal System
17
PID-31E
Piping and Instrumentation Diagram Residual Heat
Removal System
21
Drawings
PID - 43G
Charcoal Bed Deluge System
28
Fire Plans
N2-FPI-PFP-0201
Station Fire Protection Instruction
06
N2-PFP-CB261
Control Building, El 261/274
0
N2-PFP-CB288
Control Building, El 288
0
N2-PFP-RX-328
Reactor Building, El 328
0
Procedures
N2-PRA-012
Nine Mile Point Unit 2 Probabilistic Risk Assessment
Internal Flooding Analysis Notebook
3
71111.11Q Miscellaneous
Reactivity
Maneuver Plan
NM1C25-3
October 2021 Quarterly Load Drop
0
Reactivity
Maneuver Plan
NM2C18-9
October 2021 Sequence Exchange, Scram Time Testing,
and Friction Testing
0
Procedures
N1-ST-R1
Control Rod Scram Insertion Time Test
02600
N2-OSP-RDS-
@002
Channel Interference Testing
00600
Corrective Action
Documents
01986288
02005727
02468122
04389154
04412983
04413060
04446429
Corrective Action
Documents
04464682
17
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Resulting from
Inspection
Miscellaneous
(a)(1) Determination
for Unit 2 Service
Water
Approved
12/3/21
1-CRAC-F02
Maintenance Rule System Basis Document
Unit 2 Maintenance
Rule System Basis
Document
Automatic Depressurization
Unit 2 Maintenance
Rule System Basis
Document
Containment Inerting/N2
Unit 2 Maintenance
Rule System Basis
Document
Instrument Air
Unit 2 Maintenance
Rule System Basis
Document
Procedures
N1-MMP-210-001
Control Room Chiller Maintenance
Work Orders
C91883376
C93774298
C93785657
C93785742
C93786175
Procedures
Protected System Verification IAW
7
OP-NM-108-117
Protected Equipment Program at Nine Mile Point
00500
On-Line Maintenance For Limiting Condition For Operation
of Systems of Components
009
Corrective Action
Documents
02715754
04448532
04449792
04449971
04449971
04453026
18
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
04458203
04459510
Drawings
C-18026-C
Emergency Diesel Generator #102 Starting Air, Cooling
Water Lube Oil and Fuel
28
C-19410-C
Fold Out 10/10A - Elementary Wiring Diagram Diesel
Generators #102 and #103 Control Ckts
47
C-19589-C
Elementary Wiring Diagram Reactor Protection System
(Emergency Cooling Channel #11)
51
C-19845-C
Elementary Wiring Diagram DC Valve Board 12
26
Procedures
N1-ST-M4A
Emergency Diesel Generator 102 and PB 102 Operability
Test
03000
N2-OSP-ICS-
Q@002
RCIC Pump and Valve Operability Test and System
Integrity Test and ASME XI Functional Test and Analysis
01600
Work Orders
C93808212
Drawings
0001040209048
Control Diagram Shutdown System
13
PID-104A
Piping and Instrumentation Diagram Standby Diesel Gen
System
34
Engineering
Changes
ECP-21-000437
EDG Governor Booster
0000
Work Orders
C93809772
Corrective Action
Documents
04380928
044595101
04461978
Procedures
Post Maintenance Testing
26
N1-EPM-GEN-150
01800
N1-ST-Q1B
CS 121 Pump, Valve and SDC Water Seal Check Valve
Operability Test
02300
N2-MSP-HVK-
2Y001
Control Building Chiller Performance Test
00000
N2-OSP-EGS-
M@001
Diesel Generator and Diesel Air Start Valve Operability
Test - Division I and II
024T1
N2-OSP-ICS-
Q@002
RCIC Pump and Valve Operability Test and System
Integrity Test and ASME XI Functional Test and Analysis
01600
Work Orders
C93658634
19
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
C93658635
C93811429
C93812090
C93812875
Drawings
Reactor Liquid Poison System ASME Section XI Boundary
Diagram
17
Procedures
N1-ST-Q4A
Liquid Poison Pump 11 and Check Valve Operability Test
01800
N2-ISP-CSL-Q001
LPCS Pump Discharge Flow - Low (Bypass) Instrument
Channel Functional Test
00700
N2-OSP-LOG-S001
Shift Checks - Mode 1
03800
Work Orders
C93771647
71151
Corrective Action
Documents
04444544
Miscellaneous
N1-MSPI-001
Nine Mile Point 1 MSPI Basis Document
11
N2-MSPI-001
Nine Mile Point 2 MSPI Basis Document
16
Regulatory Assessment Performance Indicator Guideline
7
Corrective Action
Documents
04289904
04368005
04371766
04372127
04433486
04439810
04441194
04442220
04446429
04448532
04458203
04459468
4372131
Procedures
Implementation of Technical Specification Surveillance
Frequency Control Program
004
N1-ISP-036-003
HI/LO Reactor Water Level Instrument Trip Channel
Test/Calibration
01400