ML20128J555
| ML20128J555 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 05/07/2020 |
| From: | O'Keefe N NRC/RGN-IV/DRP/RPB-B |
| To: | Peters K Vistra Operations Company |
| References | |
| IR 2020001 | |
| Download: ML20128J555 (24) | |
See also: IR 05000445/2020001
Text
May 7, 2020
Mr. Ken Peters
Senior Vice President and Chief Nuclear Officer
VISTRA Operations Company, LLC
P.O. Box 1002
Glen Rose, TX 76043
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT, UNITS 1 AND 2 -
INTEGRATED INSPECTION REPORT 05000445/2020001 AND
Dear Mr. Peters:
On March 31, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection
at Comanche Peak Nuclear Power Plant, Units 1 and 2. On April 2, 2020, the NRC inspectors
discussed the results of this inspection with Mr. T. McCool, Site Vice President, 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 IV; the Director, Office of Enforcement; and the NRC Resident Inspector
at Comanche Peak Nuclear Power Plant, Units 1 and 2.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a
response within 30 days of the date of this inspection report, with the basis for your
disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk,
Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; and the
NRC Resident Inspector at Comanche Peak Nuclear Power Plant, Units 1 and 2.
K. Peters
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,
Neil F. O'Keefe, Chief
Reactor Projects Branch B
Division of Reactor Projects
Docket Nos. 05000445 and 05000446
License Nos. NPF-87 and NPF-89
Enclosure:
As stated
cc w/ encl: Distribution via LISTSERV
Cornelius
F. O'Keefe
Digitally signed by
Cornelius F. O'Keefe
Date: 2020.05.07
14:50:23 -05'00'
SUNSI Review
Non-Sensitive
Sensitive
Publicly Available
Non-Publicly Available
OFFICE SRI:DRP/B
RI:DRP/B
DRS/IPAT
DRS/EB1
NAME
JEllegood
NDay
AAgrawal
VGaddy
DATE
05/01/2020
05/04/2020
05/01/2020
05/04/2020
OFFICE DRS/EB2
DRS/OB
DRS/RCB
DNMS/RxIB
NAME
NTaylor
GWerner
MHaire
GWarnick
DATE
05/04/2020
05/04/2020
05/01/2020
05/04/2020
OFFICE SPE/DRP/B
BC:DRP/B
NAME
DProulx
NOKeefe
DATE
05/04/2020
05/07/2020
Enclosure
U.S. NUCLEAR REGULATORY COMMISSION
Inspection Report
Docket Numbers:
05000445 and 05000446
License Numbers:
Report Numbers:
05000445/2020001 and 05000446/2020001
Enterprise Identifier: I-2020-001-0010
Licensee:
VISTRA Operations Company, LLC
Facility:
Comanche Peak Nuclear Power Plant, Units 1 and 2
Location:
Glen Rose, TX 76043
Inspection Dates:
January 1 to March 31, 2020
Inspectors:
J. Ellegood, Senior Resident Inspector
D. Antonangeli, Health Physicist
B. Baca, Health Physicist
N. Day, Resident Inspector
N. Greene, Senior Health Physicist
J. Melfi, Project Engineer
J. O'Donnell, Senior Health Physicist
Approved By:
Neil F. O'Keefe, Chief
Reactor Projects Branch B
Division of Reactor Projects
2
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees
performance by conducting an integrated inspection at Comanche Peak Nuclear Power Plant,
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
Manual Reactor Trip Due to Loss of both Main Feed Pumps
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Green
Open/Closed
[H.12] - Avoid
Complacency
A self-revealed finding and associated non-cited violation (NCV) of very low safety
significance occurred when the licensee failed to implement procedures for operation of the
feed and condensate system as required by Technical Specification 5.4.1.a. Specifically,
while adjusting flow to the auxiliary condensers for the Unit 2 main feed pumps, the operators
isolated circulating water flow to the condensers, causing a loss of both Unit 2 main feedwater
pumps. Control room operators manually insert a plant trip in response to the loss of
Additional Tracking Items
Type
Issue Number
Title
Report Section
Status
LER 2018-002-01 for
Comanche Peak, Unit 2,
Automatic Actuation of
Auxiliary Feedwater System.
Closed
LER 2019-002-00 for
Comanche Peak Nuclear
Power Plant, Unit 2,
Automatic Actuation of
Auxiliary Feedwater System.
Closed
3
PLANT STATUS
Unit 1 began the inspection period at rated thermal power and remained there throughout the
inspection period.
Unit 2 began the inspection period at rated thermal power. On January 1, 2020, the licensee
inserted a manual trip in response to a loss of both main feed pumps while adjusting circulating
water flow to the auxiliary condensers. The licensee took the reactor critical and synchronized
to the grid on January 3, 2020. The licensee reached 100 percent power on January 4, 2020,
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. From January 1 - March 19, 2020, the inspectors performed
plant status activities described in IMC 2515, Appendix D, Plant Status, and conducted routine
reviews using IP 71152, Problem Identification and Resolution. 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), resident
inspectors were directed to begin telework and to remotely access licensee information using
available technology. During this time the resident inspectors performed periodic site visits
each week and during that time conducted plant status activities as described in IMC 2515,
Appendix D; and observed risk-significant activities when warranted. In addition, resident and
regional baseline inspections were evaluated to determine if all or portions 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 the cases where it was
determined the objectives and requirements could not be performed remotely, management
elected to postpone and reschedule the inspection to a later date.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
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 forecasted thunderstorms on January 10, 2020
4
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (1 Sample)
The inspectors evaluated system configurations during partial walkdowns of the following
systems/trains:
(1)
Unit 2, chemical and volume control system on February 6, 2020
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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 1, turbine building basement on January 17, 2020
(2)
Unit 2, turbine building basement on January 17, 2020
(3)
Unit 2, emergency diesel generator A room on January 23, 2020
(4)
Service water intake structure building on March 26, 2020
Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)
(1)
The inspectors evaluated the onsite fire brigade training and performance during an
unannounced fire drill on March 3, 2020
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1
Sample)
(1)
The inspectors observed and evaluated licensed operator performance in the control
room during turbine start and synchronization to the grid on January 3, 2020
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
(1)
The inspectors observed and evaluated licensed operators for just in time training for
a reactor startup on January 2, 2020
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (1 Sample)
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 2, auxiliary feedwater system on February 25, 2020
5
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;
(1)
Realignment of the Units 1 and 2 circulating water system on January 15, 2020
(2)
Planned yellow risk for Unit 1 auxiliary feedwater valve strokes concurrent with
emergent work to restore the Unit 1 emergency diesel generator A to operable status
on February 14, 2020
(3)
Risk associated with switchyard work and troubleshooting of Unit 2 circulating water
pump on February 7, 2020
(4)
Risk associated with starting the Unit 2 circulating water pump 2 on March 5, 2020
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the
following operability determinations and functionality assessments:
(1)
Unit 1, residual heat removal systems A and B, due to increasing pressures as
described in condition report CR-2019-009779 on January 9, 2020
(2)
Unit 2, emergency diesel generator A, due to a degraded time delay device as
described in condition report CR-2020-001295 on February 24, 2020
(3)
Unit 2, safety chiller 2-06, tripping due to a shorting bulb socket assembly as
described in condition report CR 2020-001502 on March 2, 2020
(4)
Unit 2, control rods from potential thermal sleeve cracking as described in Part 21
report LTR-NRC-19-79, and corrective action document TR 2020-1247
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)
Repair of disconnected wires and replacement of components in the Unit 2 safeguard
sequencer system per Work Order 5840776 on February 20, 2020
(2)
Replacement of cell 22 on battery 1DT4 per Work Order 5848383 on January 31,
2020
(3)
Repair of failed switch on neutron flux power ranch channel N-42 per Work
Order 5866789 on February 28, 2020
(4)
As found testing, calibration, and installation of Unit 2 safeguard sequencer B
undervoltage relays per Work Order 5666818 on March 4, 2020.
6
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01) (4 Samples)
(1) Unit 2, emergency diesel generator monthly load test per Procedure OPT 214B, Diesel
Generator Operability Test, Revision 16, on January 22, 2020
(2) Unit 2, at power end of core life reactivity test per Work Order 5659452 on February 10,
2020
(3) Unit 1, monthly control rod exercise surveillance per Work Order 5829754 on
January 24, 2020
(4) Unit 1, train A slave relay K609 actuation test per Work Order 5656218 on March 11,
2020
71114.06 - Drill Evaluation
Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01)
(1 Sample)
(1)
The blue team emergency preparedness drill on February 19, 2020.
RADIATION SAFETY
71124.05 - Radiation Monitoring Instrumentation
Walk Downs and Observations (IP Section 02.01) (1 Sample)
The inspectors evaluated the following radiation detection instrumentation during plant
walkdowns:
(1)
Portable Survey Instruments
RM-177, HP-1461
RM-177, HP-1113
RM-177, HP-1145
RM-177, HP-2400
RM-177, HP-1464
RM-177, HP-1081
RM-177, HP-1026
AMS-4, HP-2166
3030E, HP-3270
Source Check Demonstration
Rad Eye G, HP-3112
Telepole, HP-1906
Rad Eye GX, HP-4045
Ludlum Model 3000, HP-3166
Area Radiation Monitors and Continuous Air Monitors
2-RE-6253
7
2-RE-6259A
2-RE-6297
X-RE-5896A
X-RE-5895B
1-RE-6256
1-RE-6295
Personnel Contamination Monitors, Portal Monitors and Small Article Monitors
SAM, HP-0063
GEM-5, HP-0075
SAM, HP-0055
GEM-5, HP-0076
Calibration and Testing Program (IP Section 02.02) (1 Sample)
The inspectors evaluated the calibration and testing of the following radiation detection
instruments:
(1)
Alarm Setpoint and Calibration Method Check of Personnel Contamination Monitors,
Portal Monitors and Small Article Monitors
GEM-5, HP-0075
SAM, HP-0063
Failure to Meet Calibration or Source Check Acceptance Criteria
Telepole, HP-1907
ARGOS, HP-0065
RO-20AA, HP-4123
AMS-4, HP-2166
71124.06 - Radioactive Gaseous and Liquid Effluent Treatment
Walk Downs and Observations (IP Section 02.01) (1 Sample)
The inspectors walked down the following gaseous and liquid radioactive effluent monitoring
and filtered ventilation systems to assess the material condition and verify proper alignment
according to plant design:
(1)
Plant Vent Stack Radiation Monitoring System
Liquid Waste Processing Radiation Monitoring System
Turbine Sump Radiation Monitoring System
Station Service Water to Discharge Canal Radiation Monitoring System
Calibration and Testing Program (Process & Effluent Monitors) (IP Section 02.02) (1 Sample)
The inspectors reviewed the following gaseous and liquid effluent monitor instrument
calibrations and tests:
(1)
WO 5360001, X-RE-5567A, South Plant Vent Stack Radiation Monitor
Calibration, 07/30/2018
8
WO 5590739, X-RE-5570B, North Plant Vent Stack WRGM Radiation Monitor
Calibration, 10/01/2019
WO 5585319, X-RE-5253, Liquid Waste Processing Discharge Radiation
Monitor Calibration, 10/28/2019
WO 5556086, 2-RE-5100, Turbine Sump 2-04 Radiation Monitor Calibration,
06/12/2019
WO 5421935, 1-RE-4269, Unit 1 Station Service Water Train A to Discharge
Canal Radiation Monitor Calibration, 10/24/2018
WO 5631300, 1-RE-4270, Unit 1 Station Service Water Train B to Discharge
Canal Radiation Monitor Calibration, 01/14/2020
WO 5576336, 2-RE-4269, Unit 2 Station Service Water Train A to Discharge
Canal Radiation Monitor Calibration, 09/25/2019
WO 5447947, X-FT-5288, LWPS LHMT X-01/X-02 Discharge to VD System
Flow Transmitter Calibration, 09/27/2018
Sampling and Analysis (IP Section 02.03) (1 Sample)
The inspectors reviewed the following:
(1)
Radioactive Effluent Sampling and Analysis Activities
Plant Ventilation Weekly Sampling, 01/27/2020
Containment Ventilation Sampling, 01/30/2020
Effluent Discharge Permits
G2018-034, Unit 1 Containment Vent, 02/27/2018
G2018-208, Plant Vent Stack B, 12/09/2018
G2018-210, Non-Routine Gas Normal, 12/10/2018
G2019-046, Plant Vent Stack B, 03/12/2019
G2019-193, Unit 2 Containment Vent, 11/24/2019
G2019-216, Plant Vent Stack A, 12/31/2019
L2018-023, Plant Effluent Tank 1, 07/05/2018
L2018-040, Plant Effluent Tank 2, 10/24/2018
L2018-051, Low Volume Waste Pond (LVWP), 12/01/2018
L2019-016, Plant Effluent Tank 1, 02/14/2019
L2019-055, Squaw Creek Reservoir, 08/01/2019
L2019-072, Plant Effluent Tank 2, 12/12/2019
Instrumentation and Equipment (IP Section 02.04) (1 Sample)
The inspectors reviewed the following radioactive effluent discharge system surveillance test
results:
(1)
WO 5319196, Primary Plant Ventilation Exhaust Filter Unit X-16 - Carbon
Analysis B Train, 01/13/2018
WO 5377734, Primary Plant Ventilation Exhaust Filter Unit X-01 - ESF Filter
Test A Train, 10/31/2018
WO 5431297, Primary Plant Ventilation Exhaust Filter Unit X-02 - ESF Filter
Test B Train, 11/07/2018
9
WO 5558463, Primary Plant Ventilation Exhaust Filter Unit X-02 - Carbon
Analysis B Train, 09/18/2019
Dose Calculations (IP Section 02.05) (1 Sample)
The inspectors reviewed the following to asses public dose:
(1)
Liquid and Gaseous Discharge Permits
G2018-034, Unit 1 Containment Vent, 02/27/2018
G2018-208, Plant Vent Stack B, 12/09/2018
G2018-210, Non-Routine Gas Normal, 12/10/2018
G2019-046, Plant Vent Stack B, 03/12/2019
G2019-193, Unit 2 Containment Vent, 11/24/2019
G2019-216, Plant Vent Stack A, 12/31/2019
L2018-023, Plant Effluent Tank 1, 07/05/2018
L2018-040, Plant Effluent Tank 2, 10/24/2018
L2018-051, Low Volume Waste Pond (LVWP), 12/01/2018
L2019-016, Plant Effluent Tank 1, 02/14/2019
L2019-055, Squaw Creek Reservoir, 08/01/2019
L2019-072, Plant Effluent Tank 2, 12/12/2019
Annual Radiological Effluent Release Reports
2017 Annual Radioactive Effluent Release Report, 03/12/2018
2018 Annual Radioactive Effluent Release Report, 04/20/2019
Abnormal Gaseous or Liquid Tank Discharges
None were available for review during this inspection
71124.07 - Radiological Environmental Monitoring Program
Site Inspection (IP Section 02.01) (1 Sample)
The inspectors evaluated the radiological environmental monitoring program
implementation.
(1)
The inspectors reviewed the following:
Walkdowns, Calibrations, and Maintenance Record Review
Air sampling stations: A1, A2, A3, A4, A5, A6, A7, A8
Thermoluminescent dosimeter (TLD) monitoring stations: R1, R4, R11, R13,
R22, R25, R27, R29, R30, R36
Calibrations of selected air sample pumps: 2178, 2196B, 2214, and 2224
Environmental Sample Collections and Preparation Observation
Air particulate (A1, A2, A3, A4, A5, A6, A7, A8)
Air charcoal (A1, A2, A3, A4, A5, A6, A7, A8)
Broad leaf (BL1, BL2, BL3)
Surface water (SW1, SW2, SW3, SW4, SW5)
10
Licensee Actions in Response to Missed Sample, Inoperable Sampler, Lost
Thermoluminescent Dosimeter (TLD) or Anomalous Measurement
The inspectors reviewed the licensee's response to 13 missing or anomalous TLD
results. The inspectors reviewed 6 inoperable samplers as noted in corrective action
documents since May 2017 and noted in the 2017 and 2018 Annual Environmental
Operating Reports. The majority of inoperable samplers were attributed to loss of
power due to external events, such as weather and power line work.
Sampling Program for the Potential of Licensed Material Entering Groundwater
Groundwater Monitoring Wells: 9, 10, 11, 12, 14, 15, 16, 19, 25, CP-A, CP-B,
Groundwater Protection Initiative (GPI) Implementation (IP Section 02.02) (1 Sample)
(1)
The inspectors evaluated the licensee's voluntary groundwater protection initiative.
A few observations were as follows:
The general maintenance and material condition of the groundwater
monitoring wells was adequate with the general area around the well was
kept clear of any obstructions.
Most monitoring wells had enough water for samples to be taken.
Monitoring well locations 11 and CP-A had results of 835 and 1700 pCi/L,
respectively, which are both below their lower limit of detection (LLD)
requirements. The remaining well location samples all tested below the
minimum detectable activity.
The licensee implemented additional surface water sampling of the drainage
flow catch basin to track the potential impact of a water treatment filtered
water storage tank leak. The licensee has corrective actions in progress to
address the identified leak.
OTHER ACTIVITIES - BASELINE
71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01) (2 Samples)
(1)
Unit 1 January 1, 2019, to December 31, 2019
(2)
Unit 2 January 1, 2019, to December 31 2019
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02)
(2 Samples)
(1)
Unit 1 January 1, 2019, to December 31, 2019
(2)
Unit 2 January 1, 2019, to December 31, 2019
11
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)
(1)
Unit 1 January 1, 2019, to December 31, 2019
(2)
Unit 2 January 1, 2019, to December 31, 2019
71153 - Follow-up of Events and Notices of Enforcement Discretion
Event Follow-up (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated licensee response to a Unit 2 reactor trip on January 1,
2020.
Event Report (IP Section 03.02) (2 Samples)
The inspectors evaluated the following licensee event reports (LERs):
(1)
LER 05000446/2019-002-00, Automatic Actuation of Auxiliary Feedwater System
(ADAMS Accession No. ML19199A033). 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.
(2)
LER 05000446/2018-002-01, Automatic Actuation of Auxiliary Feedwater System
(ADAMS Accession No. ML 19199A032). 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.
INSPECTION RESULTS
Manual Reactor Trip Due to Loss of both Main Feed Pumps
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Green
Open/Closed
[H.12] - Avoid
Complacency
A self-revealed finding and associated non-cited violation (NCV) of very low safety
significance occurred when the licensee failed to implement procedures for operation of the
feed and condensate system as required by Technical Specification 5.4.1a. Specifically,
while adjusting flow to the auxiliary condensers for the Unit 2 main feed pumps, the licensee
isolated circulating water flow to the condensers, causing a loss of both Unit 2 main
feedwater pumps. Control room operators manually insert a plant trip in response to the loss
of feedwater.
Description: On January 1, 2020, the Comanche Peak on-shift operations crew decided to
secure a running circulating water pump for Unit 2. Although securing the pump was not on
the plan of the day schedule, the shift manager added the activity into the shift's work
activities to support planned work the following week. The inspectors noted that the activity
would use normal circulating water system operating Procedure SOP-310B, Circulating
Water, Revision 18, and the work schedule provided enough time to prepare for and conduct
the evolution. The procedure was structured to secure one circulating water pump, adjust
12
flow as needed to the main condenser, and then to adjust flow to the two main feedwater
pump auxiliary condensers. There are two steam driven main feedwater pumps.
The auxiliary condensers support operation of the two main feedwater pumps by condensing
the steam used by the feedwater pump turbines. Flow was being adjusted to optimize plant
thermal efficiency.
The crew successfully secured the circulating water pump and adjusted main condenser flow.
The crew then proceeded to the auxiliary condensers to adjust circulating water flow. A field
operator was stationed at each of the two auxiliary condenser outlet valves and a third field
operator was communicating with the main control room staff. In addition, a senior reactor
operator provided local oversight of the evolution. The crew intended to adjust the throttle
position of the circulating water with a final position directed by the reactor operator in the
control room. The reactor operator directed the valve operators to slowly close their
respective valves (simultaneously) to his mark while he monitored water box outlet
temperature. The valves were initially in a throttled position at the start and they reached the
fully closed position shortly after starting. Without any flow to the auxiliary condensers, both
main feedwater pumps automatically tripped on low vacuum to protect the pumps. Control
room staff immediately inserted a manual trip from 100 percent power. The control room
operators stabilized the plant in mode 3 using Emergency Procedure E-0, Reactor Trip and
Safety Injection, and normal operating procedures without further issue.
Personnel directly involved in the task failed to recognize that condenser vacuum would
respond quickly to reduced cooling water flow, but there would be delays before condensate
temperature would be reduced as the circulating water was adjusted due to mixing. In
addition, the personnel directly involved in the task did not recognize that the auxiliary
condenser outlet valves were two turns from full closed at the start of the evolution. These
factors led the field operators to erroneously fully close the valves prior to control room
direction to stop throttling the valves. The inspectors noted that the auxiliary condenser outlet
valves had large valve position indicators to provided system configuration information to the
local operators.
Comanche Peak performed a root cause evaluation to understand the event. The review
identified several weaknesses in crew performance that contributed to the event. Weakness
identified as the root cause were an over-reliance on process (i.e., procedures) coupled with
a failure to address gaps in behaviors and standards. This resulted in a lack of critical
thinking by plant staff as well as a failure to understand and address risks associated with the
proposed activities. During this evolution, operators failed to recognize the potential to lose
vacuum for the feed pumps due to a lack in understanding system operation and
fundamentals. The crew considered the throttling of cooling water flow to be a routine activity
and, therefore, the task preparations did not trigger a focused brief to discuss the evolution.
However, changing the circulating water pump configuration only occurs during winter months
to allow for maintenance on the pumps. The operators assigned to the task had a lack of
proficiency as none of the operators directly involved with adjusting flow on the auxiliary
condensers had secured a circulating water pump before. Furthermore, the operations shift
included three operators that had performed this evolution previously, but none were directly
involved in adjusting flow to the auxiliary condensers. The inspectors noted that their direct
involvement could have reduced the likelihood of an error during the evolution. In addition,
periodic throttling of the auxiliary condenser outlet valve flow occurred with regularity;
however, the adjustments were normally made in small increments with time between valve
movements to allow the system to equilibrate.
13
The inspectors performed walkdowns of the evolution after the event, interviewed the
personnel involved, reviewed plant operating procedures, and reviewed the root cause
evaluation. The inspectors noted that although Comanche Peak used the correct procedure
and the procedure had been used successfully previously, weaknesses in preparation for the
activity and oversight led to the loss of the feed pumps. Weaknesses included a failure to
recognize the risks associated with throttling auxiliary condenser circulating water flow,
adjusting flow to two condensers simultaneously, giving a non-standard order (throttle slowly
closed to my mark), not understanding the throttling characteristics of a butterfly valve, not
establishing the initial valve positions and closely monitoring the position as it was adjusted,
not monitoring the most applicable system parameters for the expected changes, and failure
to recognize and compensate for a lack of proficiency of the operators in performing this
evolution.
Corrective Actions: As an immediate corrective action, Comanche Peak operators tripped the
Unit 2 reactor and stabilized the plant in mode 3. Personnel involved were removed from
on-shift duties pending remedial training. Longer term actions included additional oversite of
operations activities. Additional actions are discussed on AR 2020-00008.
Corrective Action References: CR-2020-00008
Performance Assessment:
Performance Deficiency: The failure to adequately supervise component manipulations and
control system parameters within procedure limits while adjusting circulating water flow
through the auxiliary condensers was a performance deficiency. Specifically, operators failed
to adequately prepare for adjusting circulating water flow to the Unit 2 main feedwater pump
auxiliary condenser outlet valves, which caused inappropriate valve manipulation during the
evolution and created a condition that required a Unit 2 reactor trip.
Screening: The inspectors determined the performance deficiency was more than minor
because it was associated with the human performance attribute of the Initiating Events
Cornerstone and adversely affected the cornerstone objective to limit the likelihood of events
that upset plant stability and challenge critical safety functions during shutdown as well as
power operations. Specifically, the failure to adequately supervise component manipulations
and maintain system parameters within procedural limits led to the loss of both running main
feedwater pumps and a plant trip.
Significance: The inspectors assessed the significance of the finding using Appendix A, The
Significance Determination Process (SDP) for Findings At-Power. In accordance with
IMC 0609, Appendix A, Exhibit 1, the inspectors determined that the finding required a
detailed risk evaluation because the loss of feedwater caused operators to manually trip the
reactor and the loss of main feedwater constituted a loss of mitigation equipment used to
transition the plant to a stable shutdown condition.
The senior reactor analyst performed a detailed risk evaluation by treating the finding as an
initiating event and using the conditional core damage probability for a loss of main feedwater
as called for in Section 8.0, Initiating Event Analyses, of the Risk Assessment of Operational
Events Handbook. The analyst used Comanche Peak SPAR model version 8.58, run on
SAPHIRE, software version 8.2.1, for the evaluation.
The model was modified to reflect probabilistic recovery of a main feedwater pump. To
accomplish this, the analyst adjusted Basic Event MFW-XHE-XL-TRIP, Operator Fails to
14
Restart Main Feedwater Flow, used in Fault Tree MFW, Main Feedwater System, from
TRUE to a SPAR-H human reliability model derived value of 4.40E-2. In this human reliability
analysis, the analyst assigned high stress to both diagnosis and action and moderate
complexity to both diagnosis and action for the recovery. All other performance shaping
factors were set to nominal. Also, the analyst credited the use of the licensees diverse and
flexible coping strategies (FLEX) equipment. Performance of the initiating event analysis with
these modifications yielded an estimate of the increase in core damage frequency of 7.8E-7
per year from internal events. Loss of main feedwater events were the dominant sequences
and were mitigated by the auxiliary feedwater system.
The analyst noted that this detailed risk assessment evaluates an actual event in which no
external events occurred. Additionally, the period that the events impacted plant equipment
was small enough that the probability of an external initiator occurring during this time would
be negligible. Therefore, the analyst assumed that the risk from external events, given the
subject performance deficiency, was essentially zero. This resulted a total estimate in the
increase of core damage frequency of 7.8E-7 per year, making the finding of very low safety
significance (Green).
The increase in large early release frequency from this finding was determined to be of very
low safety significance using IMC 0609, Appendix H, Containment Integrity Significance
Determination Process, because loss of main feedwater sequences screen as having low
safety significance in pressurized water reactors with large dry containments.
Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the
possibility of mistakes, latent issues, and inherent risk, even while expecting successful
outcomes. Individuals implement appropriate error reduction tools. The licensee identified in
their root cause analysis that operations did not recognize nor understand the risks
associated with the evolution. The inspectors concluded that as a result, operators did not
plan for the possibility of mistakes or implement appropriate error reduction tools.
Enforcement:
Violation: Technical Specification Section 5.4.1.a requires, in part, that written procedures
shall be established, implemented, and maintained covering the applicable procedures
recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978.
NRC Regulatory Guide 1.33, Revision 2, Appendix A, Section 3, addresses Procedures for
Startup, Operation, and Shutdown or Safety-Related PWR Systems and Section 3.K,
addresses Feedwater System. The licensee established Procedure SOP-310B, Circulating
Water, Revision 18, to address operation of the circulating water system, including adjusting
flow to the auxiliary condensers which support operation of main feedwater system.
Procedure SOP-310B, Revision 18, step 5.3.7, requires operators to slowly adjust the
auxiliary condenser differential pressure to between 1- and 10 feet H2O. Contrary to the
above, on January 1, 2020, the licensee failed to slowly adjust the auxiliary condenser
differential pressure and maintain it between 1- and 10 feet H2O when operators fully closed
the valves, causing a condition (dual feedwater pump trips on low vacuum) that required a
Enforcement Action: This violation is being treated as a non-cited violation, consistent with
Section 2.3.2 of the Enforcement Policy.
15
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
On January 31, 2020, the inspectors presented the radiation safety exit meeting
inspection results to Mr. T. McCool, Site Vice President, and other members of the
licensee staff.
On April 2, 2020, the inspectors presented the integrated inspection results to
Mr. T. McCool and other members of the licensee staff.
16
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
SOP-103B
Chemical and Volume Control System
13
Fire Plans
FPI-105B
U-2, train B Diesel generator and Equipment Elevation, 810'
2
Miscellaneous
Fire Hazard Analysis Report Sections 5.9.7 and 5.6
32
Drill 20-15-01
Fire Drill Scenario for EDG 2-02 810' Fuel Oil Transfer Pit
March 3,
2020
Corrective Action
Documents
TR-YYYY-NNNN
2016-008019
Miscellaneous
Maintence Rule Summary Report for Unit 1 and Unit 2
Auxillary Feedwater
02/18/2020
Auxiliary Feedwater System Status
2nd Quarter
FY19
Drawings
E2-0026
6.9KV Three Line Diagram Normal Buses
13
Miscellaneous
STI-600.01-1
Guarded Equipment Management Posting Log
February 12,
2020
Procedures
SOP-310B
18
Work Orders
5835726
Auxiliary Feedwater Pump Turbine 2-01Govenor Stroke
02/13/2020
Corrective Action
Documents
CR
2019-9530
12/13/2019
2020-1247
February 19,
2020
Drawings
M2-2760
Diesel Engine Start/Stop Logic
15
Operability
Evaluations
FSAR Table 8.3-1, Loading Requirements for Loss of
Coolant Accident Coincident with Loss of Offsite Power
104
CR-
2020-001295
Corrective Action
Documents
CR-YYYY-NNNN
2019-009453
IR-2020-001597
Multiple Relays Out of Tolerance on Unit 2 Train B
Sequencer
Procedures
INC-7393A
CH Cal Neutron Flux Power Range ION Current Gain and
Summing Level Amplifier
6
MSE-S2-0673B
Unit 2 Train B Sequencer Under Voltage Relay Surveillance
5
Work Orders
Perform MSE-S2-0673B, TR B Sequencer UV Relay
Troubleshoot and Repair Sequence Alarm Circuit as
documented in IR-2019-009453
17
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Replace Cell 22 on BT1D4 at Power
Perform CCAL IAW INC-7393A
Troubleshoot test signal going to zero described in CR 2020-
001447
Miscellaneous
BEACON 3D Reactivity Projection for Unit 2 Forced Outage
Startup
01/01/2020
Procedures
ETP-106
Monthly RCCA Repositioning
1
OPT-106A
Control Rod Exercise
12
OPT-467A
Train A Safeguards Slave realy K609 Actuation Test
Revision 5
Work Orders
Solid State Protection System Slave Relay Test
March 11,
2020
Perform NUC 202 AT-Power MTC Measurement
OPT-106A, Control Rod Exercise Test
Monthly RCCA Reposit ETP-106
IR-2020-000542 Troubleshoot 2-01 EDG Volt Reg TRBL
Miscellaneous
ERO team Exercise
February 9,
2020
Calibration
Records
3443188
X-RE-5700 ICI-4998, CCAL FB VNT EXH
06/24/2009
3648653
2-RE-6297, ICI-4961 Channel Calibration
09/30/2010
391556
1-RE-6295 ICI-4961, CCAL
03/16/2009
4373552
1-RE-6295 ICI-4961, CCAL
04/12/2016
4374577
2-RE-6297 ICI-4961, CCAL
05/10/2017
4426655
X-RE-5700 ICI-4998, CCAL FB VNT EXH
01/22/2015
4520934
1-RE-6256 ICI-4959 CCAL HRAM
06/09/2015
5371788
X-RE-5701 INC-4915X, CCAL AB VNT GPRM
07/18/2019
5522342
1-RE-6290A INC-7079, CCAL CNTMT HRRM
05/16/2019
5522458
1-RE-6290B INC-7079, CCAL CNTMT HRRM
05/02/2019
5526341
1-RUK-2326A/2328A INC-4916 CCAL
07/17/2019
ASCAN
WBC System Calibration Data Package
11/20/2019
FSCAN
WBC System Calibration Data Package
09/12/2019
HP-0058
Argos/Sirius Calibration Data Sheet
11/10/2019
HP-0063
NE Technology SAM Calibration Data Sheet
10/22/2018
HP-0075
GEM-5 Calibration Data Sheet
02/04/2019
18
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
HP-1206
Ludlum Model 177 Frisker Calibration Data Sheet
01/27/2020
HP-2166
AMS-4 Calibration Data Sheet
10/04/2019
HP-4124
Thermo RO-20AA Calibration Data Sheet
01/29/2020
HP-5002
Low Volume Air Sampler Calibration Data Sheet
10/12/2018
HP-711812
RDS-31 Calibration Data Sheet
10/07/2019
Corrective Action
Documents
CR-YYYY-NNNN
2011-006222, 2016-001350, 2018-003694, 2018-006522,
2018-006631, 2018-007217, 2019-000184, 2019-001550,
2019-004125, 2019-004570, 2019-005318, 2019-007716,
2019-008045, 2019-008114, 2019-008129
TR-YYYY-NNNN
2018-006999, 2018-007197, 2018-007846, 2019-001511,
2019-003201, 2019-003405, 2019-003992, 2019-004146,
2019-004149, 2019-004221, 2019-005656, 2020-000063
Corrective Action
Documents
Resulting from
Inspection
CR-YYYY-NNNN
2020-000750, 2020-000783, 2020-000814
Miscellaneous
1-RE-6290A
Last Detector Primary Calibration
05/15/2019 19-001 through 19-007
Calibration Well Source Charts
08/08/2019
2Qtr FY19
CPNPP System Status: Radiation Monitoring
T190990
RadCal 2026C and 1800cc, 180cc, and 6cc detectors
05/29/2019
Procedures
CLI-782
APEX Gamma Spectroscopy Counting System
2
ICI-4959
Channel Calibration - High Range Area Radiation Monitors
4
ICI-4961
Channel Calibration - Digital High Range Area Monitors
4
ICI-4998
Channel Calibration - Gas Process Radiation Monitor
4
INC-7079
Channel Calibration -
Containment High Range Radiation Monitor Channels
1-RE-6290A/B and 2-RE-6290A/B
6
RPI-301
Portable Survey Instruments
13
RPI-800
Control of Radiation Protection Equipment
17
RPI-802
Performance of Source Checks
28
RPI-862
Calibration of the Argos/Sirius Personnel Contamination
Monitor and Gem-5 Gamma Exit Monitor
14
STA-619
Administrative Control of Digital Radiation Monitoring System
7
19
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
STA-650
General Health Physics Plan
8
STA-658
Radiation Protection Equipment Calibration Program
12
STA-677
Preventative Maintenance Program
13
STA-700
Surveillance Frequency Control Program
1
STI-677.01
PM Change Processing
2
Self-Assessments EVAL-2018-006
Work Management/Radiation Protection Audit
08/02/2018
EVAL-2019-007
Chemistry Control and Chemistry Measurement & Analysis
11/21/2019
Calibration
Records
X-RE-5567A, South Plant Vent Stack Radiation Monitor
Calibration
07/30/2018
1-RE-4269, Unit 1 Station Service Water Train A to
Discharge Canal Radiation Monitor Calibration
10/24/2018
X-FT-5288, LWPS LHMT X-01/X-02 Discharge to VD System
Flow Transmitter Calibration
09/27/2018
2-RE-5100, Turbine Sump 2-04 Radiation Monitor Calibration 06/12/2019
2-RE-4269, Unit 2 Station Service Water Train A to
Discharge Canal Radiation Monitor Calibration
09/25/2019
X-RE-5253, Liquid Waste Processing Discharge Radiation
Monitor Calibration
10/28/2019
X-RE-5570B, North Plant Vent Stack WRGM Radiation
Monitor Calibration
10/01/2019
1-RE-4270, Unit 1 Station Service Water Train B to
Discharge Canal Radiation Monitor
01/14/2020
Corrective Action
Documents
CR-YYYY-NNNN
2019-008687, 2019-008794
TR-YYYY-NNNN
2017-000757, 2018-003362, 2019-001642, 2019-005866,
2019-006713, 2019-008605
Corrective Action
Documents
Resulting from
Inspection
TR-YYYY-NNNN
2020-000766, 2020-000815, 2020-000817
TR-YYYY-NNNN
2020-000766, 2020-000815, 2020-000817
Miscellaneous
CPSES Offsite Dose Calculation Manual, Unit 1 and Unit 2
34
2017 Annual Radioactive Effluent Release Report
03/12/2018
2018 Annual Radioactive Effluent Release Report
04/20/2019
G2018-034
Gaseous Discharge Permit - Unit 1 Containment Vent
02/27/2018
G2018-208
Gaseous Discharge Permit - Plant Vent Stack B
12/09/2018
20
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
G2018-210
Gaseous Discharge Permit - Non-Routine Gas Normal
12/10/2018
G2019-046
Gaseous Discharge Permit - Plant Vent Stack B
03/12/2019
G2019-193
Gaseous Discharge Permit - Unit 2 Containment Vent
11/24/2019
G2019-216
Gaseous Discharge Permit - Plant Vent Stack A
12/31/2019
L2018-023
Liquid Discharge Permit - Plant Effluent Tank 1
07/05/2018
L2018-040
Liquid Discharge Permit - Plant Effluent Tank 2
10/24/2018
L2018-051
Liquid Discharge Permit - Low Volume Waste Pond (LVWP)
12/01/2018
L2019-016
Liquid Discharge Permit - Plant Effluent Tank 1
02/14/2019
L2019-055
Liquid Discharge Permit - Squaw Creek Reservoir
08/01/2019
L2019-072
Liquid Discharge Permit - Plant Effluent Tank 2
12/12/2019
Procedures
CHM-170
Liquid and Gaseous Effluent Program
4
CHM-230
Guidelines for Sample Collection
3
CLI-744
Radioactive Effluent Pre-Release Permit Processing
2
CLI-745
Radioactive Effluent Post-Release Permit Processing and
Surveillance Tracking
3
STA-603
Control of Station Radioactive Effluents
21
STA-619
Administrative Control of the Digital Radiation Monitoring
System
7
STA-677
Preventive Maintenance Program
13
Self-Assessments EVAL-2019-007
Radioactive Waste, Effluents, Environmental, and Chemistry
Programs
11/21/2019
Work Orders
Primary Plant Ventilation Exhaust Filter Unit X-16
01/31/2018
Primary Plant Ventilation Exhaust Filter Unit X-01
10/03/2018
Primary Plant Ventilation Exhaust Filter Unit X-02
11/17/2018
Primary Plant Ventilation Exhaust Filter Unit X-02
09/18/2019
Corrective Action
Documents
CR-YYYY-NNNN
2018-001574, 2018-001611, 2018-001760, 2018-004523,
2019-002077
TR-YYYY-NNNN
2018-001867, 2018-004228, 2019-001642, 2019-007287
2019-008284, 2019-009052, 2019-009165
Corrective Action
Documents
Resulting from
Inspection
CR-YYYY-NNNN
2020-000748
21
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
2017 Annual Radiological Environmental Operating Report
04/30/2018
2018 Annual Radiological Environmental Operating Report
04/01/2019
NUPIC Audit
23724
GEL Laboratories (JQA-14-097)
05/29/2014
NUPIC Audit
24747
(NOV2019-069)
GEL Laboratories (NOD-19-018)
08/29/2019
Comanche Peak Steam Electric Station Offsite Dose
Calculation Manual Unit 1 and Unit 2
34
RPI-714-1-
20180715
2018 Land Use Census
07/31/2018
RPI-714-1-
20190620
2019 Land Use Census
07/25/2019
Procedures
RPI-538
Process Environmental Badges
9
RPI-710
Radiological Environmental Monitoring, Sampling, and
Analysis Program
22
RPI-713
Collection, Preparation, and Shipment of Radiological
Environmental Samples
19
RPI-714
Land Use Census
6
RPI-888
Calibration of Portable Air Sample Equipment
5
STA-653
Contamination Control Program
20
STA-654
Groundwater Protection Program
9
Self-Assessments EVAL-2019-007
Radioactive Waste, Effluents, Environmental, amd Chemistry
PRgrams
11/21/2019
Work Orders
WO- 4938991, 4965490, 5052258, 5080201, 5490927,
5651858, 5654059, 5654081, 5654093, 5654106,
5654119, 5654136, 5659602, 5659645, 5667801,
5736155, 5736168, 5736197, 5736232, 5736248,
5736282, 5736299, 5741625, 5747140