IR 05000483/2019003
| ML19310E924 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 11/05/2019 |
| From: | O'Keefe N NRC/RGN-IV/DRP/RPB-B |
| To: | Diya F Ameren Missouri |
| References | |
| EPID I-2019-003-0006 IR 2019003 | |
| Preceding documents: |
|
| Download: ML19310E924 (36) | |
Text
November 5, 2019
SUBJECT:
CALLAWAY PLANT - INTEGRATED INSPECTION REPORT 05000483/2019003
Dear Mr. Diya:
On September 30, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Callaway Plant. On October 2, 2019, the NRC inspectors discussed the results of this inspection with Mr. T. Herrmann, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Four findings of very low safety significance (Green) are documented in this report. All of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or significance or severity of the violations 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 the Callaway Plant.
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 Callaway. 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/
Neil F. O'Keefe, Chief Reactor Projects Branch B Division of Reactor Projects
Docket No. 05000483 License No. NPF-30
Enclosure:
As stated
Inspection Report
Docket Number:
05000483
License Number:
Report Number:
Enterprise Identifier: I-2019-003-0006
Licensee:
Union Electric Company
Facility:
Callaway Plant
Location:
Steedman, MO 65077
Inspection Dates:
July 1 to September 30, 2019
Inspectors:
D. Bradley, Senior Resident Inspector
S. Janicki, Resident Inspector
J. Drake, Senior Reactor Inspector
P. Elkmann, Senior Emergency Preparedness Inspector
S. Hedger, Emergency Preparedness Inspector
N. Hernandez, Operations Engineer
J. Kirkland, Senior Operations Engineer
G. Pick, Senior Reactor Inspector
E. Schrader, Emergency Preparedness Specialist
Approved By:
Neil F. O'Keefe, Chief
Reactor Projects Branch B
Division of Reactor Projects
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at the Callaway Plant in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information. Self-revealed findings, violations, and additional items are summarized in the table below. A licensee-identified non-cited violation is documented in report section 7115
List of Findings and Violations
Failure to Promptly Identify and Correct Butterfly Valve Issues Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000483/2019003-01 Open/Closed
[P.5] -
Operating Experience 71152 The inspectors reviewed a self-revealed, Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, for the licensees failure to promptly identify and correct a condition adverse to quality, identified several times between 1990 and 2019, to assure that safety-related butterfly valves in the essential service water system would not experience failures. Specifically, essential service water valve EFHV0066 became both decoupled from the motor operator and lost two of three pins holding the valve disc to the valve stem. These failures rendered EFHV0066, the train B ultimate heat sink cooling tower bypass valve, and train B of essential service water to be declared inoperable.
Inadequate Turbine Startup Procedure Caused Elevated Main Generator Vibration Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000483/2019003-02 Open/Closed Not Present Performance 71152 The inspectors reviewed a self-revealed, Green, non-cited violation of Technical Specification 5.4.1.a, Procedures, for the licensees failure to establish, implement, and maintain a procedure for turbine startup and synchronization of the generator. Specifically, the general plant operating procedure for turbine startup and synchronization of the generator failed to include limits for high-pressure and low-pressure turbine differential expansion, resulting in elevated turbine vibrations and a manual trip of the main turbine.
Failure to Establish Maintenance Procedures for Switchyard Maintenance and Modifications Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000483/2019003-03 Open/Closed
[H.12] - Avoid Complacency 71153 The inspectors reviewed a self-revealed, Green, non-cited violation of Technical Specification 5.4.1.a, Procedures, for the licensees failure to establish, implement, and maintain procedures for switchyard maintenance and modifications. Specifically, an incorrect ground wire was installed on circuit breaker MDV55 which led to a switchyard transient and a loss of power to the vital 4160 V bus NB01. As a result, the associated emergency diesel generator automatically started to repower the vital loads including the train of spent fuel pool cooling in service at the time of the event.
Failure to Implement Reactor Startup Procedures Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000483/2019003-04 Open/Closed
[H.2] - Field Presence 71153 The inspectors reviewed a self-revealed, Green, non-cited violation of Technical Specification 5.4.1.a, Procedures, for the licensees failure to monitor all critical parameters during a reactor startup. Specifically, licensed operators failed to bypass the source range high flux trip when required by procedure. Further, senior licensed operators failed to focus on reactivity in their supervisory role. As a result, the reactor automatically tripped.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000483/2019-001-00 Unplanned Loss of Switchyard Bus B Results in System Actuation 71153 Closed LER 05000483/2019-002-00 Mode 4 Entry with Inoperable Auxiliary Building Pressure Boundary 71153 Closed LER 05000483/2019-003-00 Reactor Trip Due to Source Range Hi-Flux 71153 Closed URI 05000483/2018003-01 Failure to Perform 10 CFR 50.59 Evaluation for Compensatory Measures Associated with Stagnant,
Inactive Loop 92701 Closed
PLANT STATUS
Callaway operated at or near rated thermal power for the entire 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 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.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
External Flooding Sample (IP Section 03.04) (1 Sample)
- (1) The inspectors evaluated readiness to cope with external flooding for the condensate storage tank valve house and tunnel including credited operator actions on August 30, 2019
71111.04Q - 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) Vital battery charger NK25 on July 3, 2019
- (2) Safety-related fans including FKG02B, SGN01A, and SGN01B on August 15, 2019
- (3) Emergency diesel generator A on September 5, 2019
- (4) Centrifugal charging pump A on September 24, 2019
71111.04S - Equipment Alignment
Complete Walkdown Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated system configuration during a complete walkdown of the train A control room air conditioning system on July 31, 2019
71111.05A - Fire Protection (Annual)
Annual Inspection (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated fire brigade performance on July 1, 2019
71111.05Q - Fire Protection
Quarterly Inspection (IP Section 03.01) (4 Samples)
The inspectors evaluated fire protection program implementation in the following selected areas:
- (1) Diesel generator building including diesel generator B room, fire area D-2, on July 29, 2019
- (2) Control building and communication corridor, lower cable spreading room, fire area C-21, on August 12, 2019
- (3) Control building, air conditioning room and upper cable spreading room, fire areas C-13 and C-22, on September 14, 2019
- (4) Switchyard including the control building, fire area S-15, on September 26, 2019
71111.06 - Flood Protection Measures
Inspection Activities - Underground Cables (IP Section 02.02c.) (1 Sample)
- (1) The inspectors evaluated cable submergence protection in safety-related cable vaults MH01A and MH01B on September 5, 2019
71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Requalification Program (IP Section 03.04) (1 Sample)
Biennial Requalification Written Examinations The inspectors evaluated the quality of the licensed operator biennial requalification written examination administered on August 1, 2019.
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.
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 10 CFR 55.46.
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) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during:
- Emergency diesel generator A single train air fast start and 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> loaded run on September 4, 2019
- Shift turnover and post-maintenance testing of safety injection pump B on September 11, 2019
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator continuing training in the simulator on September 9, 2019
71111.12 - Maintenance Effectiveness
Routine Maintenance Effectiveness Inspection (IP Section 02.01) (2 Samples)
The inspectors evaluated the effectiveness of routine maintenance activities associated with the following equipment and/or safety significant functions:
- (1) Control room air conditioning system on July 22, 2019
- (2) Vital batteries on September 13, 2019
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the risk assessments for the following planned and emergent work activities:
- (1) Emergent work risk management action due to degraded seals on auxiliary building doors during containment cooler maintenance on July 29, 2019
- (2) Emergent work risk management actions due to an unexpected engineered safety feature actuation system alarm and loss of indication on containment cooler A fan hand switch on August 8, 2019
- (3) Emergent work risk management actions during startup transformer cooling fan replacement on August 15, 2019
- (4) Emergent work risk management actions due to stator cooling water train A pump issues including spurious alarms on September 2, 2019
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 02.02) (4 Samples)
The inspectors evaluated the following operability determinations and functionality assessments:
- (1) Containment cooler standpipe level control valve automatic closure issues, Condition Report 201904963, on July 29, 2019
- (2) Auxiliary building control room air conditioning door DSK15131, degraded seal, Condition Report 201903297, on August 2, 2019
- (3) Startup transformer XMR01, cooling fan motor failures, Condition Report 201905344, on August 8, 2019
- (4) Pressurizer power operated relief valve (PORV), block valve closure and operator burdens, Condition Report 201905928, on September 10, 2019
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 modification:
- (1) Emergency diesel generator train B lubrication oil heaters after temperature switch modification on July 17, 2019
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (5 Samples)
The inspectors evaluated the following post-maintenance tests:
- (1) Service water to essential service water crosstie valves EFHV0025 and EFHV0039, on July 29, 2019
- (2) Battery charger NK25, for 125 Vdc groups 1 and 3 on August 1, 2019
- (3) Solid state protection system train B bypass switch S604 on August 23, 2019
- (4) Safety injection pump PEM01B, train B, after equipment outage on September 12, 2019
- (5) Emergency diesel generator and essential service water, train B, after equipment outage on September 21, 2019
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) Supplemental cooling fans surveillance test on July 15, 2019
- (2) Containment spray pump B surveillance test on September 20, 2019
Inservice Testing (IP Section 03.01) (2 Samples)
- (1) Containment spray pump train A and valve inservice testing on August 27, 2019
- (2) Component cooling water train B inservice test on August 14, 2019
Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)
- (1) Steam generator sample line isolation valve inservice test on August 19, 2019
FLEX Testing (IP Section 03.02) (1 Sample)
- (1) Emergency boration pumps, FLEX-Boron-1 and FLEX-Boron-2, on August 7, 2019
71114.01 - Exercise Evaluation
Inspection Review (IP Section 02.01-02.11) (1 Sample)
- (1) The inspectors evaluated the biennial emergency plan exercise conducted on August 13, 2019. The exercise scenario simulated leaking fuel pins, a failure of the reactor to trip on an automatic signal, a degraded core cooling safety function, and an escalating loss of coolant accident with a containment penetration seal failure.
71114.06 - Drill Evaluation
Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)
The inspectors evaluated:
- (1) Emergency response organization drill, team 4, on September 19, 2019
71114.08 - Exercise Evaluation Scenario Review
Inspection Review (IP Section 02.01 - 02.04) (1 Sample)
- (1) The inspectors reviewed and evaluated the proposed scenario for the biennial emergency plan exercise conducted on August 13,
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)===
- (1) July 1, 2018, through June 30, 2019
IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (1 Sample)
- (1) July 1, 2018, through June 30, 2019
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (1 Sample)
- (1) July 1, 2018, through June 30, 2019
EP01: Drill/Exercise Performance (IP Section 02.12) (1 Sample)
- (1) April 1, 2018, through June 30, 2019
EP02: ERO Drill Participation (IP Section 02.13) (1 Sample)
- (1) April 1, 2018, through June 30, 2019
EP03: Alert & Notification System Reliability (IP Section 02.14) (1 Sample)
- (1) April 1, 2018 through June 30, 2019
71152 - Problem Identification and Resolution
Annual Follow-up of Selected Issues (IP Section 02.03) (3 Samples)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (1) Essential service water valve EFHV0066 cause evaluation for coupling failure on July 9, 2019
- (2) Reactor seal table seismic restraint bolting on August 3, 2019
- (3) Cause evaluation for the May 18, 2019 turbine trip on September 9, 2019
71153 - Follow-up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)
The inspectors evaluated the following licensee event reports (LERs):
- (1) LER 05000483/2019-001-00, Unplanned Loss of Switchyard Bus B Results in System Actuation (ADAMS Accession: ML19157A296), on April 17, 2019. The circumstances surrounding this LER are documented in the Inspection Results section of this report.
- (2) LER 05000483/2019-002-00, Mode 4 Entry with Inoperable Auxiliary Building Pressure Boundary (ADAMS Accession: ML19191A232), on May 11, 2019. The circumstances surrounding this LER are documented in the Inspection Results section of this report.
- (3) LER 05000483/2019-003-00, Reactor Trip due to Source Range Hi-Flux (ADAMS Accession: ML19196A093), on May 17, 2019. The circumstances surrounding this LER are documented in the Inspection Results section of this report.
INSPECTION RESULTS
Failure to Promptly Identify and Correct Butterfly Valve Issues Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000483/2019003-01 Open/Closed
[P.5] -
Operating Experience 71152 The inspectors reviewed a self-revealed, Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, for the licensees failure to promptly identify and correct a condition adverse to quality, identified several times between 1990 and 2019, to assure that safety-related butterfly valves in the essential service water system would not experience failures. Specifically, essential service water valve EFHV0066 became both decoupled from the motor operator and lost two of three pins holding the valve disc to the valve stem. These failures rendered EFHV0066, the train B ultimate heat sink cooling tower bypass valve, and train B of essential service water to be declared inoperable.
Description:
On March 31, 2019, while the reactor was in Mode 1 and with a planned refueling outage starting the following day, operations personnel noted that essential service water was unexpectedly discharging over the ultimate heat sink cooling tower fill material.
Licensee troubleshooting revealed that the ultimate heat sink cooling tower bypass butterfly valve for train B, EFHV0066, was partially closed although the valve indicated fully open in the control room. The licensee then identified that the valve itself was decoupled from the motor operator and declared train B of essential service water inoperable. After evaluating plant risk, including impact to the shutdown safety plan, the licensee proceeded with the planned reactor shutdown and plant cooldown to Mode 5. Due to reaching Mode 5 on April 2, 2019, the essential service water Technical Specification 3.7.8 was no longer applicable.
During this time, the licensee discovered a second issue where two of the three pins that hold the valve disc to the valve stem were missing. The licensee effected repairs to recouple and re-pin EFHV0066 on April 3, 2019, and proceeded with the planned refueling outage. The licensee later replaced EFHV0066 with a new valve to allow forensic analysis of the failed component. The licensee initiated Condition Report 201901943 to document the failures of valve EFHV0066. This valve is a 30-inch Anchor Darling butterfly valve.
The licensee reviewed computer data and identified that valve EFHV0066 had failed on March 30, 2019, based upon flow indication. The licensee formed a cause evaluation team and reviewed the possible causes for both disc pin and valve coupling failures. Ultimately, the licensee determined that vibrations from the flow of essential service water past the open butterfly valve caused both the pins and valve coupling to loosen to the point of failure.
Specifically, the orientation of the butterfly valve, when open in the flow stream, can cause valve fluttering if set incorrectly and yield failures.
The inspectors, in parallel and independent of the licensees review, performed a review of condition reports associated with EFHV0066 and associated operating experience. These reviews revealed several previous examples of internal operating experience where essential service water butterfly valves failed. Additionally, the licensee had several precursor issues that may have indicated a problem with excessive vibrations of the butterfly valve. A summary of these issues is included in the table below.
Date Vibrations Coupling Issue Summary of essential service water butterfly valve issues Condition Report Numbers 8/9/1990
X EFHV0037 excessive valve leakage, coupling found slipped off.
Corrective action to revise 18-month preventative maintenance (PM) to check coupling bolts was not completed.
199001400 10/25/1993
X EFHV0026 found decoupled from motor operator during packing replacement.
199301554 4/5/2013 X
X EFHV0024 excessive valve leakage, coupling bolts found loose.
Corrective action to check coupling bolt torque in next six year PM for similar essential service water butterfly valves including EFHV0066.
Condition report notes failure in 1990 to take corrective action.
201302358 201302424 4/9/2015
X EFHV0025 gap identified between valve shaft to motor operator where coupling connects. Remained coupled.
201502077 12/16/2016
EFHV0066 valve position indication question by NRC on differences in open position compared to EFHV0065.
201609281 11/11/2017 X
EFHV0066 valve fluttering/rattle observed.
201706617 5/2/2018
EFHV0066 packing gland nuts found loose.
201802212 6/28/2018
EFHV0066 packing gland nut found loose again.
201803252 3/31/2019 X
X EFHV0066 failure due to decoupling.
Six year PM for coupling bolt torque checks was due later this year (2019), but not yet completed at the time of failure.
201901943
Further, the licensee had not yet incorporated industry guidance, published in 2003, on how to throttle butterfly valves to minimize flow induced disc vibration per EPRI TR 1007908, Large Butterfly Valve Maintenance Guide.
The inspectors reviewed the licensees guidance for corrective action timeliness. In corrective action Procedure APA-ZZ-00500, Appendix 14, Adverse Condition - ADCN 3, step 4.5 defines timely:
Timely - Corrective action completion time is prompt. Interim measures needed until final Corrective Actions are complete. Due dates should be based on resources available, remedial actions taken to date, assessment of impact on plant operations, likelihood or risk of recurrence, and significance of recurrence.
The inspectors noted that the coupling bolt torque checks could have identified loose couplings and flow induced vibrations prior to the 2019 failure. In the case of EFHV0066, coupling bolt torque checks were not performed prior to failure although the first example of a coupling failure occurred 29 years earlier. Instead of taking positive action following the 2013 failure to assign a corrective action to inspect and torque the couplings of all affected valves, the licensee chose to modify the preventive maintenance (PM) procedure to check the coupling torque. In doing so, the licensee did not control the timeliness of the action, since the timing of completing the torqueing was based on the existing PM schedule.
The inspectors concluded the licensee failed to promptly identify and correct a condition adverse to quality, identified several times between 1990 and 2019, to assure that safety-related butterfly valves in the essential service water system would not experience failures. Specifically, essential service water valve EFHV0066 became both decoupled from the motor operator and lost two of three pins holding the valve disc to the valve stem. These failures rendered EFHV0066, the train B ultimate heat sink cooling tower bypass valve, unable to be operated from the control room. As a result, the valve failure caused train B of essential service water to be declared inoperable, involved an unplanned equipment outage of 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> for repairs, and required accident analysis calculations to be reperformed with as-found conditions to assure the requirements were met for ultimate heat sink performance.
Corrective Actions: The licensee repaired EFHV0066 for the planned refueling outage, replaced the valve later in the refueling outage, performed an extent of condition review of similar butterfly valves, and entered issues into the corrective action program.
Corrective Action References: Condition Report 20190194.
Performance Assessment:
Performance Deficiency: The failure to promptly identify and correct a condition adverse to quality, identified several times between 1990 and 2019, to assure that safety-related butterfly valves in the essential service water system would not experience failures was a performance deficiency. Specifically, the licensee failed to check for loss of torque on coupling bolts for safety-related butterfly valves.
Screening: The inspectors determined the performance deficiency was more than minor, and therefore a finding, because it adversely affected the equipment performance attribute of the Mitigating Systems Cornerstone and its objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences.
Specifically, essential service water valve EFHV0066 became both decoupled from the motor operator and lost two of three pins holding the valve disc to the valve stem. These failures rendered EFHV0066, the train B ultimate heat sink cooling tower bypass valve, unable to be operated from the control room. As a result, the valve failure caused train B of essential service water to be declared inoperable, involved an unplanned equipment outage of 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> for repairs, and required accident analysis calculations to be reperformed with as-found conditions to assure the requirements were met for ultimate heat sink performance.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 2, Mitigating Systems Screening Questions, dated June 19, 2012. The inspectors determined that the finding was of very low safety significance (Green) because
- (1) the finding was not a deficiency affecting the design or qualification of a mitigating system;
- (2) the finding did not represent a loss of system and/or function;
- (3) the finding did not represent an actual loss of function of a single train for greater than its technical specification allowed outage time; and
- (4) the finding does not represent an actual loss of function of one or more non-technical specification trains of equipment designated as high safety-significant in accordance with the licensees maintenance rule program for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Specifically, the time of valve failure is known based upon flow instrumentation and documented examples of previous successful operation. At the time of discovery, the licensee was preparing to shut down for a planned refueling outage and exited the Mode of applicability for Technical Specification 3.7.8 after 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> of inoperability. After identifying the time of failure in past operability reviews, the total duration of the equipment being out of service was 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> which is less than the associated technical specification allowed outage time. Further, the licensee performed engineering analysis of the as-found conditions, including environmental factors at the time of failure, and determined the ultimate heat sink thermal performance would have been met.
Cross-Cutting Aspect: The finding had a cross-cutting aspect in the area of problem identification and resolution associated with operating experience because the licensee failed to systematically and effectively collect, evaluate, and implement relevant internal and external operating experience in a timely manner [P.5]. Specifically, the licensee had internal operating experience that discussed the decoupling failure mechanism and did not incorporate that knowledge into their 2017 evaluation of vibration on EFHV0066 or the 2018 evaluation of loose packing nuts on EFHV0066.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected.
Contrary to the above, from November 11, 2017, to March 31, 2019, the licensee failed to promptly identify and correct a condition adverse to quality to assure that safety-related butterfly valves in the essential service water system remained operable. Specifically, untimely corrective actions for essential service water valve EFHV0066 allowed the valve to become decoupled from the motor operator. These failures rendered EFHV0066, the train B ultimate heat sink cooling tower bypass valve, unable to be operated from the control room.
As a result, the valve failure caused train B of essential service water to be declared inoperable, involved an unplanned equipment outage of 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> for repairs, and required accident analysis calculations to be reperformed with as-found conditions to assure the requirements were met for ultimate heat sink performance.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Inadequate Turbine Startup Procedure Caused Elevated Main Generator Vibration Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events
Green NCV 05000483/2019003-02 Open/Closed Not Present Performance 71152 The inspectors reviewed a self-revealed, Green, non-cited violation of Technical Specification 5.4.1.a, Procedures, for the licensees failure to establish, implement, and maintain a procedure for turbine startup and synchronization of the generator. Specifically, the general plant operating procedure for turbine startup and synchronization of the generator failed to include limits for high-pressure and low-pressure turbine differential expansion, resulting in elevated turbine vibrations and a manual trip of the main turbine.
Description:
On May 18, 2019, while performing the first startup of the turbine generator following replacement of the turbine control system in accordance with Procedure OTN-AC-0001, Main Turbine and Generator Systems, the licensee noted elevated vibrations from the main turbine following synchronization of the main generator with the grid. The licensee entered Procedure OTO-AC-00002, Revision 28, Turbine Vibration, and reduced turbine load in an attempt to lower the turbine vibrations. The licensee then manually tripped the turbine and transitioned to Procedure OTO-AC-00001, Revision 25, Turbine Trip Below P-9, when the turbine vibrations continued to rise following the turbine load reduction.
The manual turbine trip was initiated from 19 percent reactor power and did not cause a reactor trip, by design, since reactor power was below the setpoint for the turbine trip - reactor trip interlock (P-9). This allows the unit to withstand a turbine trip without a direct reactor trip if it is operating below 50 percent power since rod control in conjunction with steam dumps can accommodate the transient. Following the turbine trip, all four atmospheric steam dumps opened as expected and reactor power stabilized at approximately 10 percent power. The licensee commenced plant stabilization and recovery which included performing a Procedure APA-ZZ-00542, Revision 21, Event Review and Post Transient Evaluation.
During the event review, the licensee noted that the new automatic main turbine warmup was completed in less time than when previously performed manually, but differential expansion was also significantly lower than previous turbine startups. During a turbine startup, the turbine components will initially expand as the steam is admitted through the steam chest.
Once the steam begins to roll the turbine, the cooling action of the steam will then result in the turbine train contracting. This expansion and contraction is measured with differential expansion probes that provide an indication in mils. As the turbine expands and contracts, the various turbine components can experience thermally-induced rubbing which will lead to elevated vibration levels.
During the subsequent startup, the licensee monitored turbine differential expansion as steam was admitted to the turbine. The licensee utilized exhaust hood spray, throttling flow to the exhaust hood to maintain turbine differential expansion to a range seen on previous startups.
The turbine startup was able to continue without any further issues after the expected turbine expansion levels were established.
The inspectors review of the elevated vibration and manual turbine trip determined that Procedure OTN-AC-00001, Main Turbine and Generator Systems, utilized for turbine startup was inadequate. Specifically, the turbine startup procedure failed to identify an acceptance band for turbine differential expansion required to roll the main turbine with steam or direct action to control the turbine differential expansion in band by throttling the exhaust hood spray.
Corrective Actions: The licensee stabilized the plant, performed a post-event review and entered the issue into the corrective action program.
Corrective Action References: Condition Report 201903832.
Performance Assessment:
Performance Deficiency: The failure to establish, implement, and maintain a procedure for turbine startup and synchronization of the generator was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor, and therefore a finding, because it adversely affected the procedure quality attribute of the Initiating Events Cornerstone and its objective of limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the inadequate turbine startup procedure resulted in elevated turbine vibrations, a manual trip of the main turbine, and actuation of atmospheric steam dumps.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter (IMC) 0609, Attachment 4, Initial Characterization of Findings, dated October 7, 2016, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 1, Initiating Events Screening Questions, dated June 19, 2012.
The inspectors determined that the finding was of very low safety significance (Green) since the finding did not cause a reactor trip and did not cause the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition.
Cross-Cutting Aspect: None. The inspectors determined there was no cross-cutting aspect because the last significant procedure review occurred in 2014, more than three years before the event, and does not reflect present licensee performance.
Enforcement:
Violation: Technical Specification 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. Regulatory Guide 1.33, Appendix A, Section 2.e, requires that turbine startup and synchronization of the generator be covered by written procedures.
Contrary to the above, prior to May 18, 2019, the licensee failed to establish, implement and maintain the procedure for turbine startup and synchronization of the generator. Specifically, the turbine startup and synchronization of the generator procedure failed to identify turbine differential expansion limits for rolling the turbine with steam and the use of turbine exhaust hood spray to maintain the turbine differential expansion in the required band.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Establish Maintenance Procedures for Switchyard Maintenance and Modifications Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events Green NCV 05000483/2019003-03 Open/Closed
[H.12] - Avoid Complacency 71153 The inspectors reviewed a self-revealed, Green, non-cited violation of Technical Specification 5.4.1.a, Procedures, for the licensees failure to establish, implement, and maintain procedures for switchyard maintenance and modifications. Specifically, an incorrect ground wire was installed on circuit breaker MDV55 which led to a switchyard transient and a loss of power to the vital 4160 V bus NB01. As a result, the associated emergency diesel generator automatically started to repower the vital loads including the train of spent fuel pool cooling in service at the time of the event.
Description:
On April 17, 2019, while the reactor was defueled (in no Mode) with no irradiated fuel movements in progress, the licensee experienced a switchyard transient that resulted in the loss of power to the vital 4160 V bus NB01. Specifically, all core fuel assemblies had been moved to the fuel pool earlier in the refueling outage.
At the time of the event, the licensee was aligning the switchyard for main transformer backfeed to support maintenance. When switchyard circuit breaker MDV53 was shut, a fault was detected on current transformers that resulted in the de-energization of the train B 365 kV switchyard bus. Due to the switchyard alignment at the time of the event, the transformer providing offsite power to vital 4160 kV bus NB01 was also lost. By design, the loss of voltage to vital bus NB01 was detected, the associated train A emergency diesel generator automatically started, and safety-related shutdown loads were automatically sequenced on to repowered bus NB01. These loads included the spent fuel pool cooling pump, one essential service water pumps, and one component cooling water pumps.
The licensee responded to the event with off-normal Procedure OTO-NB-00001, Loss of Power to NB01, and previously running loads were restored within 12 minutes. In this period, the spent fuel pool increased in temperature by 1°F. The licensee restored offsite power to bus NB01 within two hours and reported the actuation of the diesel generator to the NRC under event notification EN 54005. This event was also reported as Licensee Event Report (LER) 05000483/2019-001-00 (ADAMS ML19157A296). The licensee initiated Condition Report 201902606 to document the transient and pursue corrective actions.
During the event review, the licensee determined there was an incorrect ground wire on circuit breaker MDV55 installed during the fall of 2017. The cause of this incorrect ground wire was ineffective management of a scope change for protective relays. Specifically, the requirement for protective relays changed during the design process and the ground jumper was not removed from the schematic although its associated relay was removed from the drawing. As a result, the ground wire was installed per the incorrect drawing.
Since this latent design error was installed, the licensee had not placed the switchyard circuit breakers in a configuration that would have challenged the fault relaying system. Due to the unique power alignment of the switchyard during main transformer backfeed, this additional ground wire now provided a current flow path to the protective relays that detect significant electrical faults. When the neighboring circuit breaker MDV53 was shut during the main transformer backfeed attempt, the electrical flow path through the current transformer activated the protective relays to clear all loads on the train B 365 kV switchyard bus due to a falsely detected flashover event.
The inspectors independently reviewed the cause evaluation, the design, and condition report history for the switchyard circuit breakers. The inspectors noted that circuit breaker design, modifications, and maintenance in the non-safety switchyard is performed by off-site personnel from Ameren Transmission. The licensee, however, is required to review and approve the design, modifications, and maintenance of these circuit breakers per Procedure APA-ZZ-00323, Configuration Management Process. Specifically, section 3 of Procedure APA-ZZ-00323 states staff, identifies configuration discrepancies through established processesensures administrative controls are in place and followed to satisfy plant design and licensing basis requirements concerning physical plant and configuration documentation.
The inspectors concluded the licensee failed to establish, implement, and maintain procedures for switchyard maintenance and modifications. Specifically, the licensee failed to identify that an incorrect ground wire was installed on circuit breaker MDV55 which led to a switchyard transient and a loss of power to the vital 4160 kV bus NB01. As a result, the associated emergency diesel generator automatically started to repower the vital loads including the train of spent fuel pool cooling in service at the time of the event.
Corrective Actions: The licensee restored vital loads to NB01 via offsite power, performed a walk-down of switchyard circuit breakers, reviewed design drawings for switchyard circuit breakers, and entered issues into the corrective action program.
Corrective Action References: Condition Report 201902606.
Performance Assessment:
Performance Deficiency: The failure to establish, implement, and maintain procedures for switchyard maintenance and modifications was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor, and therefore a finding, because it adversely affected the design control attribute of the Initiating Events Cornerstone and its objective to limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations.
Specifically, an incorrect ground wire was installed on circuit breaker MDV55 which led to a switchyard transient and a loss of power to the vital 4160 kV bus NB01.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter (IMC) 0609, Attachment 4, Initial Characterization of Findings, dated October 7, 2016, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 1, Initiating Events Screening Questions, dated June 19, 2012.
The inspectors determined that the finding was of very low safety significance (Green) since the finding involved the partial loss of a support system that contributed to the likelihood of, or caused, an initiating event, but did not affect mitigation equipment. Specifically, with the reactor defueled and in no Mode, shutdown cooling was not required and IMC 0609 Appendix G, Shutdown Operations Significance Determination Process, is not applicable.
Although the switchyard transient did lead to a loss of power to the vital 4160 kV bus NB01, mitigating equipment remained available since the emergency diesel generator automatically restored power to vital loads.
Cross-Cutting Aspect: Individuals implement appropriate error reduction tools. The finding had a cross-cutting aspect in the area of human performance associated with avoiding complacency because the licensee failed to recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes including implementing appropriate error reduction tools [H.12]. Specifically, the licensees review of the off-site design was not thorough enough to recognize the latent issue in the switchyard controls.
Enforcement:
Violation: Technical Specification 5.4.1.a requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Appendix A of Regulatory Guide 1.33, Revision 2. Section 9.a of Appendix A to Regulatory Guide 1.33, Revision 2, requires maintenance that can affect the performance of safety-related equipment should be properly preplanned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances.
The licensee established Procedure APA-ZZ-00323, Configuration Management Process, in part, to meet the regulatory requirement.
Contrary to the above, from fall of 2017 until April 17, 2019, the licensee failed to establish, implement, and maintain procedures for preventative maintenance that can affect the performance of safety-related equipment. As a result, an incorrect ground wire was installed on circuit breaker MDV55 which led to a switchyard transient, a loss of power to the vital 4160 kV bus NB01, and required the emergency diesel generator to automatically restore power to the bus.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Implement Reactor Startup Procedures Cornerstone Significance Cross-Cutting Aspect Report Section Initiating Events
Green NCV 05000483/2019003-04 Open/Closed
[H.2] - Field Presence 71153 The inspectors reviewed a self-revealed, Green, non-cited violation of Technical Specification 5.4.1.a, Procedures, for the licensees failure to monitor all critical parameters during a reactor startup. Specifically, licensed operators failed to bypass the source range high flux trip when required by procedure. Further, senior licensed operators failed to focus on reactivity in their supervisory role. As a result, the reactor automatically tripped.
Description:
On May 16, 2019, while the reactor was in Mode 2 during startup, the licensee experienced an automatic reactor trip due to source range high flux.
At the time of the event, the licensee was monitoring the overlap of indicated reactor power from the source range into the intermediate range per Procedure OTG-ZZ-00002, Reactor Startup - IPTE. The team consisted of two reactor operators, two senior reactor operators, a shift manager, and management oversight for the infrequently performed test or evolution (IPTE). The next required steps, per Procedure OTG-ZZ-00002, involved monitoring for adequate overlap of nuclear instrumentation and blocking of the source range high flux trip once the P-6 permissive lights were in. This permissive allows the intentional blocking of source range scram signals during a planned reactor startup once indication exists in the intermediate range.
The licensed reactor operators were withdrawing control rods and monitoring the trend of the source range and intermediate range including startup rate. The licensed senior reactor operator, serving as control room supervisor, shifted his focus from reactivity management to an unrelated alarm associated with the boron dilution monitoring system (BDMS) that came in during this time. The additional senior reactor operator was not utilized to resolve the BDMS alarm. After the senior reactor operator discussed the BDMS issue with the shift manager, the IPTE manager communicated the proximity to the source range high flux trip to the shift manager. The control room supervisor directed the reactor operator to bypass the source range high flux trip but was they were unable to complete all actions prior to the automatic reactor trip occurring.
The licensee responded to the scram with Procedure E-0, Reactor Trip or Safety Injection, and stabilized the plant in Mode 3. The licensee reported the valid actuation of the reactor protection system to the NRC under Event Notification EN 54069 and Licensee Event Report 05000483/2019-003-00 (ADAMS ML19196A093). The licensee initiated Condition Report 201903787 to document the reactor trip and pursue corrective actions.
During the event review, the licensee determined the licensed operators did not adequately monitor reactivity. Specifically, the reactor operators were overly focused on trends instead of the absolute value of reactor power and believed they had additional time to complete the process of bypassing the source range high flux trip. The control room supervisor and shift manager improperly shifted their focus to a non-urgent alarm on BDMS and did not provide adequate oversight of reactivity.
The inspectors were present in the control room during the trip and independently reviewed the immediate post-trip actions. Later, the inspectors independently reviewed the key parameters of the event, the human performance aspects, and the condition reports for the reactor trip.
The inspectors reviewed reactor startup Procedure OTG-ZZ-00002 and noted Attachment 2 states, Prior to source range count exceeding 5x104 cps, block the source range high flux reactor trip. Procedure OTG-ZZ-00002, step 3.1.9 states, designate a reactivity management [senior reactor operator] to maintain oversight of reactor operations. This role is further defined in Procedure ODP-ZZ-00001, Operations Department Code of Conduct, in step 3.6 which states, during periods of reactivity management or significant plant evolutions, the [reactivity management senior reactor operator] focus must be on reactivityrefrain from conducting concurrent tasks.
The inspectors concluded the licensee failed to implement procedures for reactor startup.
Specifically, licensed operators failed to bypass the source range high flux trip when required by procedure. Further, senior licensed operators failed to focus on reactivity in their supervisory role. As a result, the reactor automatically tripped due to a human performance error.
Corrective Actions: The licensee stabilized the plant in Mode 3, relieved the on-watch operators to perform an event review, and entered these issues into the corrective action program.
Corrective Action References: Condition Report 201903787.
Performance Assessment:
Performance Deficiency: The failure to monitor all critical parameters during a reactor startup was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor, and therefore a finding, because it adversely affected the human performance attribute of the Initiating Events Cornerstone and its objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations.
Specifically, licensed operators failed to bypass the source range high flux trip when required by procedure. Further, licensed operators failed to focus on reactivity in their supervisory role. As a result, the reactor automatically tripped due to a human performance error.
Significance: The inspectors assessed the significance of the finding using Inspection Manual Chapter (IMC) 0609, Attachment 4, Initial Characterization of Findings, dated October 7, 2016, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 1, Initiating Events Screening Questions, dated June 19, 2012.
The inspectors determined that the finding was of very low safety significance (Green) since the finding caused a reactor trip but not the loss of mitigation equipment relied upon to transition the plant from the onset of the trip to a stable shutdown condition.
Cross-Cutting Aspect: H.2 - Field Presence: Leaders are commonly seen in the work areas of the plant observing, coaching, and reinforcing standards and expectations. Deviations from standards and expectations are corrected promptly. Senior managers ensure supervisory and management oversight of work activities, including contractors and supplemental personnel. The finding had a cross-cutting aspect in the area of human performance associated with field presence because licensee leaders failed to promptly correct deviations from standards and expectations including ensuring supervisory and management oversight of work activities [H.2]. Specifically, the senior reactor operators and management did not promptly correct the team and focus on reactivity management during reactor startup.
Enforcement:
Violation: Technical Specification 5.4.1.a requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Appendix A of Regulatory Guide 1.33, Revision 2. Section 2.b of Appendix A to Regulatory Guide 1.33, Revision 2, requires general plant operating procedures for hot standby to minimum load (nuclear start-up). The licensee established Procedure OTG-ZZ-00002, Reactor Startup - IPTE, in part, to meet the regulatory requirement. Steps 5.1.17 and 5.1.31 of OTG-ZZ-00002 require monitoring nuclear instruments and blocking the source range high flux reactor trip above the P-6 permissive.
Contrary to the above, on May 16, 2019, the licensee failed to implement procedures for reactor startup. Specifically, licensed operators failed to monitor all critical parameters (i.e., nuclear instruments) during a reactor startup and failed to bypass the source range high flux trip when required by procedure. Further, senior licensed operators failed to focus on reactivity in their supervisory role. As a result, the reactor automatically tripped.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Licensee-Identified Non-Cited Violation - Auxiliary Building Door Open During Mode Change 71153 This violation of very low safety significance was identified by the licensee and has been entered into the licensee corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Violation: Technical Specification 3.7.13, Emergency Exhaust System (EES), which requires two emergency exhaust system trains to be operable and an operable auxiliary building boundary, is applicable in Modes 1, 2, 3, and 4. Technical Specification 3.0.4, Limiting Condition for Operation Applicability, requires, in part, that when an LCO is not met, entry into a mode or other specified condition in the applicability shall only be made when the associated actions to be entered permit continued operation in the mode for an unlimited period of time or after the performance of a risk assessment.
Contrary to the above, from May 11-12, 2019, with LCO 3.7.13 not met, the licensee entered Mode 4 from Mode 5. Specifically, Door DSK 15041, serving as part of the auxiliary building ventilation boundary for the emergency exhaust system, was left open during mode ascension for 12.9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />. This non-cited violation is associated with Licensee Event Report (LER) 05000483/2019-002-00 (ADAMS ML19191A232).
Significance/Severity Level: The failure to comply with Technical Specification 3.0.4 prior to entering the mode of applicability for the emergency exhaust system was a performance deficiency. The inspectors determined the performance deficiency was more than minor, and therefore a finding, because it adversely affected the SSC and barrier performance attribute of the Barrier Integrity Cornerstone and its objective to provide reasonable assurance that physical design barriers (fuel cladding, reactor coolant system, and containment) protect the public from radionuclide releases caused by accidents or events. Specifically, Door DSK 15041 was left open between the auxiliary building and the radioactive material storage building during mode ascension to Mode 4 where the emergency exhaust system is required to be operable. This door served as part of the auxiliary building ventilation boundary for the emergency exhaust system and is assumed to be shut for accident analysis calculations. As a result, the station did not have an operable auxiliary building boundary, had not performed a risk assessment, and required as-found testing and calculations to demonstrate requirements were met to limit the spread of radioactive materials in a postulated event. Using Inspection Manual Chapter 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 3, Barrier Integrity Screening Questions, dated June 19, 2012, the inspectors determined that the finding was of very low safety significance (Green) because the finding only represented a degradation of the radiological barrier function provided for the control room, auxiliary building, or spent fuel pool.
Specifically, leaving Door DSK 15041 open only affected the radiological barrier function for the auxiliary building.
Corrective Action References: Condition Report 201903596.
Unresolved Item (Closed)
Failure to Perform 10 CFR 50.59 Evaluation for Compensatory Measures Associated with Stagnant, Inactive Loop URI 05000483/2018003-01 92701
Description:
The inspectors identified an unresolved issue related to implementation of 10 CFR 50.59, Changes, Tests, and Experiments, for the licensees failure to perform an adequate evaluation for compensatory measures for a stagnant, inactive loop. As part of the compensatory measures to support atmospheric dump vale/turbine-driven auxiliary feed pump operability due to an issue identified for natural circulation cooldown with a faulted steam generator (i.e., inactive loop), a reduction in the Technical Specification 3.4.16 dose equivalent iodine (DEI) limit (from 1µCi/gm to 0.4µCi/gm) was imposed without a 10 CFR 50.59 evaluation and/or license amendment. Specifically, the licensee did not consider the compensatory measure of reducing Technical Specification 3.4.16 limits on DEI-131 as a change to technical specifications.
It was determined that the issue was not related to 10 CFR 50.59, because it would screen out and direct the licensee to 10 CFR 50.90, since the compensatory measures resulted in a nonconservative technical specification. NRC Administrative Letter 98-10, dated December 29, 1998, "Dispositioning of Technical Specifications that are Insufficient to Assure Plant Safety," states, in part, "Title 10 of the Code of Federal Regulations, Section 50.36, "Technical Specifications," requires that each technical specification limiting condition for operation (LCO) specify, at a minimum, the lowest functional capability or performance level of equipment required for the safe operation of the facility.
Generic Letter (GL) 91-18, Revision 1, "Information to Licensees Regarding NRC Inspection Manual Section on Resolution of Degraded and Nonconforming Conditions," provides guidance to licensees on the type and time frame of any required corrective action. As stated in the GL, whenever degraded or nonconforming conditions are discovered, 10 CFR Part 50, Appendix B, requires prompt corrective action to correct or resolve the condition. In the case of a deficient technical specification, this includes the evaluation of compensatory measures, such as administrative controls, in accordance with 10 CFR 50.59 and prompt actions to correct the technical specification. If the licensee does not resolve the degraded or nonconforming condition, the staff would conclude that corrective action has been inadequate and would consider taking enforcement action. In summary, the discovery of an improper or inadequate technical specification value or required action is considered a degraded or nonconforming condition as defined in GL 91-18. Imposing administrative controls in response to an improper or inadequate technical specification is considered an acceptable short-term corrective action. The staff expects that, following the imposition of administrative controls, an amendment to the technical specification, with appropriate justification and schedule, will be submitted in a timely fashion. Once any amendment correcting the technical specification is approved, the licensee must update the final safety analysis report, as necessary, to comply with 10 CFR 50.71(e). The compensatory measures implemented by the licensee were short term corrective actions and the licensee upgraded the power operated relief valves and modified procedures to allow their use to depressurize the plant in the event of natural circulation cooldown with a faulted steam generator. These actions allowed the licensee to restore Technical Specification 3.4.16 DEI limit back to the 1µCi/gm limit. This issue was closed with no performance deficiency.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On July 15, 2019, the inspectors presented the Emergency Preparedness Scenario Discussion inspection results to G. Rausch, Manager, Emergency Preparedness and other members of the licensee staff.
- On September 12, 2019, the inspectors presented the 71111.11 Biennial Requalification inspection results to D. Farnsworth, Director, Nuclear Operations and other members of the licensee staff.
- On September 19, 2019, the inspectors presented the Emergency Preparedness Exercise inspection results to F. Diya, Senior Vice President and Chief Nuclear Officer, and other members of the licensee staff.
- On October 2, 2019, the inspectors presented the Resident Inspector inspection results to T. Herrmann, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
Condition Reports
201704807, 201805233, 201805781, 201806234,
201902640, 201903877, 201904608
Miscellaneous
E-23AP02
Condensate Transfer and Storage - Alarms and
Instrumentation Schematic
Miscellaneous
M-22AP01
Piping and Instrumentation Diagram - Condensate Storage
and Transfer System - FSAR Figure 9.2-12
Procedures
ITL-AP-000L4
Loop Level, Condensate Storage Tank Level
71111.04Q Corrective Action
Documents
Condition Reports
200303221, 200803108, 200901896, 201602989,
201607971, 201701159, 201706923, 201706998,
201707612, 201800235, 201800442, 201805430,
201904669
71111.04Q Drawings
M-11GN01
Piping and Instrumentation Diagram - Containment Cooling
System - FSAR Figure 9.4-6, Sheet 1
71111.04Q Miscellaneous
JE-13
Emergency Fuel Oil Storage and Day Tank Volume
Requirements
71111.04Q Miscellaneous
M-EF-51
Minimum Essential Service Water Flow to the Containment
Coolers Determine the Minimum Essential Service Water
Flow Through the Containment Coolers Required to Remove
the Design
71111.04Q Miscellaneous
ZZ-179
Plant AC Bus Load List
71111.04Q Procedures
APA-ZZ-00304
Control of Callaway Equipment List
71111.04Q Procedures
EDP-ZZ-07001
Cable Management Program
71111.04Q Procedures
OTN-GN-00001
Containment Cooling and RDM Cooling
71111.04Q Procedures
OTN-NK-00001,
Addendum 1
25 Vdc Bus NK01 and Distribution System
Corrective Action
Documents
Condition Reports
201803896, 291803913, 20185142
Drawings
M-22EF02
Piping and Instrumentation Diagram - Essential Service
Water System - FSAR Figure 9.2-2, Sheet 2
Miscellaneous
Job 18000062
Implement MP 17-0006 Essential Service Water Hammer
Mitigation at SGK04A
Procedures
APA-ZZ-00304
Control of Callaway Equipment List
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
OTO-SA-00001
Engineered Safety Features Actuation Signal Verification
and Restoration
71111.05Q Corrective Action
Documents
Condition Reports
201904602
71111.05Q Miscellaneous
Fire Pre-plan Manual
71111.05Q Miscellaneous
T66.1000S
Fire Drill
71111.05Q Procedures
APA-ZZ-00700
256
71111.05Q Procedures
EIP-ZZ-00226
Fire Response Procedure for Callaway Plant
71111.05Q Procedures
ODP-ZZ-00002,
Appendix 3
Risk Management Actions for Fire Risk Systems and
Components
Corrective Action
Documents
Condition Reports
201804913, 201806566, 201900768
Miscellaneous
Preventative
Maintenance
1005833, 1005834
Work Orders
16503071, 16502102, 16506165, 17513066
Corrective Action
Documents
Condition Reports
201705360, 201705784, 201706686, 201707562,
201800507, 201801750, 201806934, 201900788,
201900798, 201902095, 201902913, 201903787,
201904579
Miscellaneous
Reactivation Packages 2018-2019
Miscellaneous
Cycle 23 Simulator Test Package
Miscellaneous
Simulator Discrepancy Report
7/10/2019
Miscellaneous
List of Simulator Modifications Completed
7/10/2019
Miscellaneous
Cycle 24 Transient test 2, Simultaneous trip of all feedwater
pumps
7/15/2019
Miscellaneous
Cycle 24 Transient test 3, Simultaneous closure of all main
steam isolation valves
7/15/2019
Miscellaneous
Cycle Transient test 11, Maximum design load rejection
7/15/2019
Miscellaneous
Cycle 24 Steady State tests for medium power test
7/15/2019
Miscellaneous
Licensee Watch Hours as RO 7/1/18 - 7/31/18
Miscellaneous
Licensee Watch Hours as BOP 7/1/18 - 7/31/18
Miscellaneous
Licensee Watch Hours as SM 7/1/18 - 7/31/18
Miscellaneous
Licensee Watch Hours as CRS 7/1/18 - 7/31/18
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
Miscellaneous
Miscellaneous
List of Licensed Operators by Crew
07/01/2019
Miscellaneous
List of LOR Qualified Evaluators
07/01/2019
Miscellaneous
List of OE Incorporated into the LOR Program
07/10/2019
Miscellaneous
List of LOCT Training Based on Operator Performance
07/01/2019
Miscellaneous
Simulator Expert Review Group Meeting Minutes
9/27/2018
Miscellaneous
Simulator Expert Review Group Meeting Minutes
9/27/2017
Miscellaneous
Simulator Expert Review Group Meeting Minutes
6/28/2018
Miscellaneous
Simulator Oversight Group Meeting Minutes
9/28/2017
Miscellaneous
Simulator Operating Group Meeting Minutes
9/26/2018
Miscellaneous
Simulator Operating Group Meeting Minutes
6/29/2018
Miscellaneous
Simulator Operating Group Meeting Minutes
11/28/2018
Miscellaneous
AC-RO-S-004
4/22/19
Miscellaneous
AC-RO-S-005
4/22/19
Miscellaneous
Admin1-RO-S&O-
005
4/25/19
Miscellaneous
Admin4-SRO-
S&O-015(TC)
3/28/19
Miscellaneous
AUCA 20190004
Root Cause Analysis for CR 201903787 - Reactor Trip due
to Source Range Hi-Flux
6/19/19
Miscellaneous
DS-04
Dynamic Simulator Exam Scenario
20190429
Miscellaneous
DS-06
Dynamic Simulator Exam Scenario
20190501
Miscellaneous
DS-21
Dynamic Simulator Exam Scenario
20190503
Miscellaneous
DS-22
Dynamic Simulator Exam Scenario
20190430
Miscellaneous
EOP-NLO-P-
007(A
3/25/19
Miscellaneous
EOP-RO-S-
014(A)
4/3/19
Miscellaneous
EOP-RO-S-
23(A)
4/24/19
Miscellaneous
EOP-RO-S-
23(A)
4/24/19
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
EP-NLO-R-001
3/22/19
Miscellaneous
EP-NLO-R-002
4/1/19
Miscellaneous
NE-NLO-P-
001(A)
4/1/19
Miscellaneous
T210.0006
Miscellaneous Licensed Operator Continuing Training
Evaluation Summary Reports
Procedures
APA-ZZ-00912
Callaway Energy Center Medical Certification Program
Procedures
APA-ZZ-00912,
Appendix A
Medical Certification Fire Brigade & Licensed Operators
Exam Elements and Scheduling Frequency
Procedures
CTM-EXAM
Examination Control and Security
Procedures
CTM-OPS
Operations Training Programs
Procedures
CTM-OPS,
Addendum 9
Exam Information
Procedures
CTM-SAT
Systematic Approach to Training
Procedures
CTM-SAT,
Addendum M
Evaluations
Procedures
CTM-SAT,
Addendum O
Just-in-Time-Training
Procedures
CTM-SAT,
Addendum K
Remediation
Procedures
CTM-SAT,
Addendum P
Rescinding and Restoring Qualifications
Procedures
TDP-IS-00001
Simulator Operation and Maintenance
Procedures
TDP-ZZ-00019
NRC License Examination Security and Integrity
Procedures
TDP-ZZ-00019,
Appendix Z
Simulator Security Guidelines
71111.11Q Corrective Action
Documents
Condition Reports
201104071, 201407121, 201802218
71111.11Q Miscellaneous
T61.0810 8
LOCT Guide
Various
71111.11Q Miscellaneous
T61.08108
LOCT Training Guide
71111.11Q Procedures
ODP-ZZ-00001
Operations Department - Code of Conduct
106
71111.11Q Procedures
ODP-ZZ-00001
Operations Department - Code of Conduct
104
71111.11Q Procedures
Safety Injection Train B Inservice Test - Group B
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.11Q Procedures
Standby Diesel Generator B 24 Hour Run and Hot Restart
Test
71111.11Q Work Orders
237782
Corrective Action
Documents
Condition Reports
201009936, 201501242, 201601339, 201607870,
201801292, 201804823, 201902047, 201903004,
201904821, 201904950, 201905435
Drawings
M-22KA01
Compressed Air System
Miscellaneous
Oil Analysis Results
Various
Miscellaneous
E190.0074
Inservice Testing Program
Miscellaneous
RFR 160853
Mobil 1 10w30 Synthetic Formula Change
2/06/2016
Procedures
APA-ZZ-00320
Work Execution
Procedures
APA-ZZ-00356
Pump and Valve Inservice Test Program
Procedures
APA-ZZ-00395
Significant Operator Response Timing
Procedures
EDP-ZZ-01128
Procedures
EDP-ZZ-01131
Plant Health and Performance Monitoring Program
Procedures
EDP-ZZ-01131,
Appendix 0
Dingle Point Vulnerabilities
Procedures
MDP-ZZ-L0001
Lubrication Program
Work Orders
15503300, 18506414
Procedures
APA-ZZ-00322,
Appendix F
Online Work Integrated Risk Management
Corrective Action
Documents
Condition Reports
201605184
Miscellaneous
M-724---634
IM Power Operated Relief Valve
Procedures
RCS Valve Inservice Test
Corrective Action
Documents
Condition Reports
201904750
Miscellaneous
RFR 180001
Approve a More Robust Temperature Switch for the EDGs
Work Orders
19002862
Corrective Action
Documents
Condition Reports
201805241, 201900360, 201904287, 201905831,
201905990, 201906020
Procedures
APA-ZZ-00322,
Appendix E
Post Maintenance Test Program
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
OSP-NE-00001A
Standby Diesel Generator A Periodic Tests
Procedures
Technical Specifications Actions - A.C. Sources
Corrective Action
Documents
Condition Reports
201406773, 201408096, 201604473, 201704959,
201804199, 201805560, 201805563, 201904821
Procedures
FLEX-Boron
Injection
FLEX Boron High Pressure RCS Injection Pump
Background Information Document
Procedures
ODP-ZZ-00002
Equipment Status Control
Procedures
ODP-ZZ-00004
Locked Component Control
Procedures
Train B Containment Spray Pump Inservice Test
Procedures
B Train Supplemental Fan Tests
Work Orders
18003285, 18507920, 18508476, 19508478, SIR 719677
Corrective Action
Documents
Condition Reports
201702329, 201703137, 201703460, 201703570,
201703778, 201704088, 201704334, 201704382,
201706622, 201800600, 201800875, 201800888,
201801238, 201802128, 201802690, 201802722,
201803906, 201804072, 201804073, 201805129,
201805635, 201806927, 201806943, 201806954,
201904165, 201904169, 201904176, 201904738,
201904740, 201905459
Corrective Action
Documents
Resulting from
Inspection
Condition Reports
201905434, 201905438, 201905453, 201905455,
201905459, 201905460, 201905463, 201905478,
201905482, 20195500, 201905501, 201905508,
201905515, 201905554, 201905849
Miscellaneous
Callaway Plant Radiological Emergency Response Plan,
R51
9/26/2018
Miscellaneous
SDP-PI-RERPO RERP
Miscellaneous
After-Action Evaluation Report for the June 29, 2017, Team
Turnover Exercise
8/23/2017
Miscellaneous
After-Action Evaluation Report for the Annual ERO
Exercises, July 20 through August 24, 2017
10/5/2017
Miscellaneous
After-Action Evaluation Report for the Health Physics Drill
conducted August 2, 2017
Miscellaneous
After-Action Evaluation Report for the Training Drills,
January 18 through February 15, 2018
4/10/2018
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
After-Action Evaluation Report for the Team 4 Exercise
conducted March 8, 2018
4/11/2018
Miscellaneous
After-Action Evaluation Report for the Health Physics Drill
conducted March 8, 2018
Miscellaneous
After-Action Evaluation Report for the Environmental Team
Drill conducted May 24, 2018
Miscellaneous
After-Action Evaluation Report for the Third Quarter 2018
Muster Meetings
7/30/2018
Miscellaneous
After-Action Evaluation Report for the Fourth Quarter 2018
Muster Meetings
11/2/2018
Miscellaneous
After-Action Evaluation Report for the Annual ERO
Exercises, November 15 through December 13, 2018
2/13/2019
Miscellaneous
After-Action Evaluation Report for the First Quarter 2019
Muster Meetings
3/26/2019
Miscellaneous
After-Action Evaluation Report for the Training Drills,
January 24 through February 28, 2019
6/4/2019
Miscellaneous
After-Action Evaluation Report for the Health Physics Drill
conducted June 6, 2019
Miscellaneous
After-Action Evaluation Report for the Environmental Team
Drill conducted July 9, 2019
Miscellaneous
After-Action Evaluation Report for the Team 5 Exercise
conducted May 24, 2018
7/16/2018
Miscellaneous
After-Action Evaluation Report for the June 6, 2019,
Exercise
7/17/2019
Miscellaneous
CA2684
Respiratory Protection/TEDE ALARA Evaluation Worksheet
Miscellaneous
CA2783
Emergency Response Facility Functionality Evaluation
Miscellaneous
CA2831
Precautions in the Administration of Potassium Iodide (KI)
Miscellaneous
Course:
T61.08108,
Session:
20180284
Licensed Operator Continuing Training Evaluation Summary
Report
08/09/2018
Miscellaneous
HPCI-08-05
Airborne Exposure Decision Matrix for KI Issuance, Dose
Extensions, and SCBA Issuance
Miscellaneous
Scenario # DS-31
Dynamic Simulator Exam Scenario
7/31/2018
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
Scenario # DS-45
Dynamic Simulator Exam Scenario
6/11/2018
Miscellaneous
Scenario # S-2
Cycle 18-4
DEP Scenarios 1
7/16/2018
Miscellaneous
Scenario # S-5
Cycle 18-4
DEP Scenarios 2
7/16/2018
Miscellaneous
Training
Requests
TR201900150, TR201900151, TR20190152, TR201900158
Procedures
APA-ZZ-01000
Callaway Energy Center Radiation Protection Program
Procedures
APA-ZZ000500
Corrective Action Program
Procedures
EIP-ZZ-00101
Classification of Emergencies, R55
7/11/2018
Procedures
EIP-ZZ-00101,
Addendum 2
Emergency Action Levels Basis Document, R16
4/1/2019
Procedures
EIP-ZZ-00102
Emergency Implementing Actions, R65
6/4/2019
Procedures
EIP-ZZ-00200
Augmentation of the Emergency Response Organization,
R21
4/11/2016
Procedures
EIP-ZZ-00201
Notifications, R51
2/14/2017
Procedures
EIP-ZZ-00201,
Addendum B
TSC (ENS) Communicator Package
Procedures
EIP-ZZ-00201,
Addendum A
Control Room Notification Flowchart, R31
6/27/2019
Procedures
EIP-ZZ-00201,
Addendum C
EOF Notification Package, R32
6/27/2019
Procedures
EIP-ZZ-00211
Field Monitoring, R39
7/31/2019
Procedures
EIP-ZZ-00212
Protective Action Recommendations, R30
3/29/2018
Procedures
EIP-ZZ-00219
Emergency Dispatching of Operations Personnel
Procedures
EIP-ZZ-00220
Emergency Team Formation, R25
11/10/2016
Procedures
EIP-ZZ-00230
Accountability, R35
9/18/2017
Procedures
EIP-ZZ-00240
Technical Support Center Operations, R43
4/20/2018
Procedures
EIP-ZZ-00240,
Addendum B
Technical Assessment Coordinator (TAC) Checklist
Procedures
EIP-ZZ-00240,
Addendum C
Operations Support Coordinator (OSC) Checklist
Procedures
EIP-ZZ-00240,
Addendum D
Administrative (ADMIN) Coordinator Checklist
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
EIP-ZZ-00240,
Addendum G
Chemistry Coordinator Checklist
Procedures
EIP-ZZ-00240,
Addendum H
Security Coordinator Checklist
Procedures
EIP-ZZ-00240,
Addendum A
Emergency Coordinator Checklist, R7
4/20/2018
Procedures
EIP-ZZ-00240,
Addendum E
Health Physics Coordinator Checklist
Procedures
EIP-ZZ-01211
Accident Dose Assessment, R38
4/1/2019
Procedures
EIP-ZZ-A0001
Emergency Response Organization, R20
7/11/2018
Procedures
EIP-ZZ-C0010
Emergency Operations Facility Operations, R40
9/12/2016
Procedures
HDP-Z-01100
ALARA Planning and Review
Procedures
HDP-ZZ-01200
Radiation Work Permits
Procedures
HDP-ZZ-01300
Internal Dosimetry Program
Procedures
HDP-ZZ-01450
Authorization to Exceed Federal Occupational Dose
Procedures
HDP-ZZ-08000
Respiratory Protection Program
Procedures
HTP-ZZ-08002
Respiratory Protection Issue and Use
Procedures
KDP-ZZ-00013
Emergency Response Facility and Equipment Evaluation
Procedures
KDP-ZZ-02001
Drill and Exercise Program, R26
6/17/2019
Self-Assessments Benchmark
201820044-001
Observation of Diablo Canyon's Quality Verification Audit
4/4/2018
Self-Assessments Benchmark
201820044-010
EP Department Staff Improvement
10/15/2018
Self-Assessments Formal Self-
Assessment
201900029-044
Exercise Readiness and Modified Program Inspection
3/26/2019
Self-Assessments SSA 201600059-
051
Pre-NRC Program Inspection
3/13/2017
Self-Assessments SSA 201720030-
009
Implementation of ACAD 15-010, Guidelines for the Training
and Qualifications of Emergency Response Personnel
8/24/2018
71151
Corrective Action
Documents
Condition Reports
201802310, 201803070, 201803485, 201803516,
201803944, 201804523, 201804760, 201805003,
201805129, 201806927, 201806954, 201901978,
201904357, 201904376, 201904701, 201904736
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71151
Procedures
KDP-ZZ-02000
NRC Performance Indicator Data Collection, R19
6/26/2018
71151
Procedures
KSP-ZZ-00110
Siren Alerting System Testing
71151
Procedures
NRC Performance Indicator Transmittal Report
Various
Corrective Action
Documents
Condition Reports
201901943, 201902794
Miscellaneous
CR 201805611
Receipt of Response to TIA 201410, Emergency Diesel
Generator Mission Time for Operability Evaluations at
Callaway Plant
10/25/2018
Miscellaneous
RFR 180048
Evaluate Non-Safety Accessories in Safety HVAC Systems
Miscellaneous
Response to Task Interface Agreement 201410 Related to
the Regulatory Position on Emergency Diesel Generator
Mission Time for Inoperability Evaluations at Callaway Plant
Unit No. 1 (CAC No. MF5099, EPID L2015LRA0001)
10/19/2018
Miscellaneous
ZZ-452
Post-Accident Filter Loading
Procedures
APA-ZZ-00323
Configuration Management Process
Procedures
ODP-ZZ-00002
Equipment Status Control
91