IR 05000483/2019004
| ML20031E697 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 01/30/2020 |
| From: | O'Keefe N NRC/RGN-IV/DRP/RPB-B |
| To: | Diya F Ameren Missouri |
| References | |
| IR 2019004 | |
| Download: ML20031E697 (24) | |
Text
January 30, 2020
SUBJECT:
CALLAWAY PLANT, UNIT 1 - INTEGRATED INSPECTION REPORT 05000483/2019004
Dear Mr. Diya:
On December 31, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Callaway Plant, Unit 1. On January 6, 2020, the NRC inspectors discussed the results of this inspection with Mr. B. Cox, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Two findings of very low safety significance (Green) are documented in this report. Both 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.
A licensee-identified violation which was determined to be of very low safety significance is documented in this report. We are treating this violation as an NCV consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the 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 Callaway Plant, Unit 1.
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 Plant, Unit 1. 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,
/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-2019-004-0006
Licensee:
Union Electric Company
Facility:
Callaway Plant, Unit 1
Location:
Steedman, MO 65077
Inspection Dates:
October 1 to December 31, 2019
Inspectors:
D. Bradley, Senior Resident Inspector
S. Janicki, Resident Inspector
P. Elkmann, Senior Emergency Preparedness Inspector
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 Callaway Plant, Unit 1, 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. A licensee-identified non-cited violation is documented in report section 71111.1
List of Findings and Violations
Failure to Incorporate Acceptance Limits into Test Procedures Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000483/2019004-01 Open/Closed None (Not Present Performance)71153 The inspectors reviewed a self-revealed, Green, non-cited violation of 10 CFR Part 50,
Appendix B, Criterion XI, Test Control, for the licensees failure to assure that testing required to demonstrate that the solid state protection system will perform satisfactorily in service is identified and performed. Specifically, the solid state protection system surveillance test procedures failed to incorporate continuity requirements and acceptance limits for the flux doubling bypass switch. As a result, the boron dilution mitigation system was inoperable when an associated switch failed to make electrical contact and that failure went undetected for 3 months.
Failure to Verify or Check the Adequacy of Design for the Control Room Filtration Fan Cornerstone Significance Cross-Cutting Aspect Report Section Barrier Integrity Green NCV 05000483/2019004-02 Open/Closed
[H.7] -
Documentation 71153 The inspectors reviewed a self-revealed, Green, non-cited violation of 10 CFR Part 50,
Appendix B, Criterion III, Design Control, for the licensees failure to assure that design changes were subject to design control measures commensurate with those applied to the original design for the control room filtration fan. Specifically, the replacement thermal overload protection for a control room filtration fan utilized a non-conservative value for brake horsepower which was identified when the fan spuriously tripped. As a result, the undersized thermal overload challenged the fans ability to operate both during normal operation and when responding to design basis events.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000483/2019-006-00 Unrecognized Inoperability of Boron Dilution Mitigation System (BDMS) Train 'B'
71153 Closed LER 05000483/2019-005-00 Inoperability of CREVS B Train 71153 Closed
LER 05000483/2019-001-01 Unplanned Loss of Switchyard Bus B Results in System Actuation 71153 Closed
PLANT STATUS
Callaway Plant, Unit 1, 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
Seasonal Extreme Weather Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures from October 21 to October 28, 2019, for the following systems:
- Intake structure and water treatment plant
- Essential service water
- Fire protection
71111.04Q - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Class 1E air conditioner SGK05A on October 30, 2019
- (2) Train A and B reactor protection system in the control room equipment cabinet area on November 4, 2019
- (3) Rod drive motor generators and reactor trip breakers on November 4, 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) Auxiliary feedwater pipe chase, fire area A-1, on October 24, 2019
- (2) Main steam isolation valve room, fire area A-23, on November 1, 2019
- (3) Control building and communication coordinator equipment cabinet area, fire area C-27, on December 6, 2019
- (4) Electrical penetration rooms, fire area A-17, on December 9, 2019
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:
- Train B class 1E air conditioner unit maintenance on October 10, 2019
- Train A essential service water and emergency diesel generator maintenance on October 29, 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 October 1, 2019
- Licensed operator continuing training in the simulator on December 2, 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) Reactor protection system on November 13, 2019
- (2) Load shedding and emergency load sequencing system on November 19, 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) Planned risk management actions during work on train B components including class 1E air conditioning, spent fuel pool cooling, and an intake pump on October 8, 2019
- (2) Emergent risk management actions for intake structure west power line grounds and cable replacement on October 17, 2019
- (3) Planned risk management actions during maintenance on train A emergency diesel generator and essential service water systems on October 28, 2019
- (4) Planned risk management actions for surveillance testing on train B load shedding and emergency load sequencing system on November 7, 2019
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 02.02) (2 Samples)
The inspectors evaluated the following operability determinations and functionality assessments:
- (1) Load shedding and emergency load sequencing input buffer cards outside required technical specification surveillance frequency, Condition Report 201906720, on October 29, 2019
- (2) Train A control room air conditioning unit SGK04A failure, Condition Report 201907363, on November 19, 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 permanent modification:
- (1) Replace obsolete safety-related 480 Vac motor control center buckets (MP 18-0003)on October 30, 2019
71111.19 - Post-Maintenance Testing
Post-Maintenance Test Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the following post-maintenance tests:
- (1) Train B emergency diesel generator following planned maintenance on October 16, 2019
- (2) Steam generator pressure channel calibration and channel operational test following replacement of steam generator D main steam outlet channel 4 pressure transmitter ABPT0546 on November 1, 2019
- (3) Nitrogen accumulator inservice leakage test following replacement of steam generator auxiliary feedwater/main steam relief valve nitrogen supply accumulator pressure relief valve KAV0705 on November 12, 2019
- (4) Containment spray pump A following planned maintenance on November 20, 2019
71111.22 - Surveillance Testing
The inspectors evaluated the following surveillance tests:
Surveillance Tests (other) (IP Section 03.01)
- (1) Steam generator A, B, C, D narrow range level protection on October 10, 2019
- (2) Fire suppression water system functional test in safety-related areas on October 11, 2019
- (3) Load shedding and emergency load sequencing actuation logic including NF039B relay driver test on November 7, 2019
- (4) Train B emergency diesel generator surveillance test on November 13, 2019
71114.04 - Emergency Action Level and Emergency Plan Changes
Inspection Review (IP Section 02.01-02.03) (1 Sample)
- (1) The inspectors performed an in-office evaluation on December 11, 2019, of Revision 10 to Procedure EIP-ZZ-00101, Addendum 1, Emergency Action Level Classification Matrix, and Revision 17 to Procedure EIP-ZZ-00101, Addendum 2, Emergency Action Level Technical Bases Document. These revisions implemented NRC License Amendment 220, dated July 30, 2019, and other changes made by the licensee that were determined to not reduce the effectiveness of the emergency plan. The licensee implemented Procedure EIP-ZZ-00101, Addendum 1 and Addendum 2 on October 24, 2019. This evaluation does not constitute NRC approval.
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below.
MS07: High Pressure Injection Systems (IP Section 02.06)===
- (1) October 1, 2018, through September 30, 2019
MS09: Residual Heat Removal Systems (IP Section 02.08) (1 Sample)
- (1) October 1, 2018, through September 30, 2019
71152 - Problem Identification and Resolution
Semiannual Trend Review (IP Section 02.02) (1 Sample)
- (1) The inspectors reviewed the licensees corrective action program for potential adverse trends in surveillance testing issues on December 16, 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 05000483/2019-005-00, Inoperability of Control Room Emergency Ventilation System (CREVS) B Train (ADAMS Accession: ML19255H875), on October 15, 2019. The circumstances surrounding this LER are documented in the Inspection Results section of this report. This licensee event report is closed.
- (2) LER 05000483/2019-006-00, Unrecognized Inoperability of Boron Dilution Mitigation System (BDMS) Train B (ADAMS Accession: ML19295D510), on November 20, 2019. The circumstances surrounding this LER are documented in the Inspection Results section of this report. This licensee event report is closed.
- (3) LER 05000483/2019-001-01, Unplanned Loss of Switchyard Bus B Results in System Actuation (ADAMS Accession: ML19312B669), on November 20, 2019. The inspectors reviewed the updated LER submittal. The previous LER submittal was reviewed in Inspection Report 05000483/2019003 and the circumstances surrounding this LER were previously documented in the Inspection Results section of that report.
This licensee event report is closed.
INSPECTION RESULTS
Licensee-Identified Non-Cited Violation 71111.12 This violation of very low safety significance was identified by the licensee and has been entered into the licensees corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Violation: Title 10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires, in part, that a test program shall be established to assure that all testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents.
Contrary to the above, from May 12 to August 20, 2019, the licensee failed to establish a test program to assure that testing required to demonstrate that structures, systems, and components will perform satisfactorily in service was identified and performed in accordance with written test procedures for the engineered safety feature actuation system (ESFAS)under Surveillance Requirement 3.3.2.3.
Contrary to the above, from May 9, 2019, to October 17, 2019, the licensee failed to establish a test program to assure that testing required to demonstrate that structures, systems, and components will perform satisfactorily in service was identified and performed in accordance with written test procedures for the load shedding and emergency load sequencing (LSELS)system under Surveillance Requirement 3.8.1.21.
Specifically, the licensee identified two cases where technical specification surveillance requirements were not being performed at the correct periodicity. First, the licensee incorrectly scheduled a portion of ESFAS testing for steam line and feedwater isolation relays beyond the 31 day required frequency after the 2019 refueling outage. Second, the licensee identified the input buffer cards in the LSELS system were not being tested within the 31 day required frequency for surveillance tests performed since the 2019 refueling outage.
Significance/Severity: Green. The failure to perform required technical specification surveillance testing within the required frequencies was a performance deficiency.
Specifically, the lack of testing adversely affected the Mitigating Systems Cornerstones objective because the licensee was not periodically demonstrating the capability of ESFAS and LSELS to perform their functions in the event of a postulated accident. Since the lack of testing extended beyond one system, the inspectors determined it was a programmatic concern.
The inspectors determined the finding to be of very low safety significance (Green) because the systems maintained their operability. Specifically, the licensee performed subsequent surveillance tests that successfully demonstrated the capabilities and past functionality of ESFAS and LSELS including steam line isolation relays, feedwater isolation relays, and input buffer cards.
Corrective Action References: Condition Reports 2019035843 and 201906720.
Observation: Semi-Annual Trend Review 71152 The inspectors reviewed the licensees corrective action program, performance indicators, system health reports, and other documentation to identify trends that might indicate the existence of a more significant safety issue for surveillance testing.
The following examples were reviewed by the inspectors for potential trends in issues related to surveillance testing:
- (1) Condition Report 201905676: Surveillance testing did not identify that the boron dilution mitigation system was inoperable when an associated switch failed to make electrical contact.
- (2) Condition Report 201905843: Surveillance testing was incorrectly scheduled, resulting in ESFAS testing for steam line and feedwater isolation relays exceeding the monthly testing periodicity.
- (3) Condition Report 201906016: Surveillance testing was not closed appropriately in the work management software, resulting in the non-safety battery inspection for a diesel-driven fire pump exceeding the monthly testing periodicity.
- (4) Condition Report 201906720: Surveillance testing procedures did not include the input buffer cards as a required portion of the LSELS surveillances.
- (5) Condition Report 201907567: Surveillance testing was performed on the incorrect non-safety fire/smoke detector resulting in the inadvertent starting of an electric fire pump.
The inspectors noted that these examples could be placed in several different categories.
Examples
- (1) and
- (4) represent test control inadequacies that did not meet requirements contained in design documents. Examples
- (2) and
- (3) represent human performance errors in managing recurring surveillance tests. Example
- (5) represents a human performance error during the performance of a surveillance test and is the only case where the issue was self-revealed.
The majority of the examples were identified by the licensee through routine daily reviews of planned work and a focused self-assessment of technical specification surveillance testing.
This involved substantial effort by the licensee and is considered a good practice. The inspectors independently evaluated the assigned actions under each condition report noting that the licensee performed appropriate extent of condition reviews, completed human performance evaluations when required, and communicated the lessons-learned to applicable staff.
Given the number of examples affecting several aspects of surveillance testing, the inspectors determined that this may be an emerging trend worthy of additional inspection.
Overall, the inspectors concluded that the licensee demonstrated a low threshold for issue identification and documentation in the corrective action program. The licensee applied a risk-based approach to ensure corrective actions are completed commensurate with an issues safety significance. The inspectors did not identify any additional trends or concerns that might be indicative of a more significant issue with surveillance testing.
Failure to Incorporate Acceptance Limits into Test Procedures Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000483/2019004-01 Open/Closed
None (Not Present Performance)71153 The inspectors reviewed a self-revealed, Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion XI, Test Control, for the licensees failure to assure that testing required to demonstrate that the solid state protection system will perform satisfactorily in service is identified and performed. Specifically, the solid state protection system surveillance test procedures failed to incorporate continuity requirements and acceptance limits for the flux doubling bypass switch. As a result, the boron dilution mitigation system was inoperable when an associated switch failed to make electrical contact and that failure went undetected for 3 months.
Description:
On August 23, 2019, while performing Surveillance Procedure ISF-SB-00A32, Train B Solid State Protection System (SSPS) Slave Relay Testing, the SSPS status lamp failed to illuminate while testing the actuation logic and relays associated with the boron dilution mitigation system (BDMS). The status light provides an indication that the SSPS actuation logic and master/slave relays (K503/K648) have actuated and are functioning properly.
The purpose of the BDMS is to respond to inadvertent dilution of the reactor coolant system that affects reactivity in lower modes. Specifically, the system monitors source range nuclear instrumentation for increases in counts, shuts valves to isolate potential sources of dilution, and opens valves for highly borated water sources such as the refueling water storage tank to supply injection sources.
When the SSPS status lamp failed to indicate the expected response during the test, operators declared BDMS train B inoperable and entered the ESFAS instrumentation Technical Specification 3.3.2, Condition R, a 24-hour shutdown action statement.
The licensees troubleshooting revealed that the flux doubling bypass switch did not have continuity associated with the BDMS actuation logic. The licensee performed multiple cycles of the flux doubling bypass switch to exercise the switch and clean the contacts. Voltage at K648 was restored following the switch manipulations.
With voltage restored, the licensee successfully reperformed the applicable portions of Surveillance Procedure ISF-SB-00A32 and declared BDMS train B operable.
Callaway Plant, Unit 1, performed a past operability review which concluded that the lack of continuity identified on August 23, 2019, had existed since the last operation of the flux doubling bypass switch S604 on May 10, 2019. Between May 10 and August 23, 2019, the lack of continuity in the flux doubling bypass switch could have prevented SSPS train B from initiating a valid actuation of the BDMS. The inspectors noted that the BDMS is required to be operable in Modes 5, 4, 3, and 2 (below the P-6 intermediate range neutron flux interlock)per Technical Specification 3.3.9, Boron Dilution Mitigation System. As a result, the time periods of concern were from the last operation of the flux doubling bypass switch during the refueling outage through Mode ascension.
During this period, the licensee performed the following mode changes:
Date Mode Changes May 10, 2019 Last operation of S604 relay (Mode 5)
May 11, 2019 Mode Change (Mode 5 to Mode 4)
May 14, 2019 Mode Change (Mode 4 to Mode 3)
May 16, 2019 Mode Change (Mode 3 to Mode 2)
May 16, 2019 Exited Mode of Applicability (Reactor Start Up)
May 16, 2019 Reentered the Mode of Applicability in Mode 3 (Following a high source range neutron flux Trip during reactor startup)
May 17, 2019 Exited Mode of Applicability (Mode 3 to Mode 2 and Reactor Start Up)
The licensee exited the modes of applicability for the BDMS on May 17, 2019, when power increased into Mode 1 and above the P-6 Interlock.
The licensees cause determination identified either mechanical binding or stack misalignment as the most likely cause for the flux doubling bypass switchs lack of conductivity.
Corrective Actions: The licensee documented the issue in a condition report and submitted a licensee event report for the BDMS being inoperable for greater than its technical specification allowed outage time. Additionally, the licensee updated the SSPS testing procedures to include a continuity check after operating the flux doubling bypass switch prior to restoring the SSPS to service.
Corrective Action References: Condition Report 201905676.
Performance Assessment:
Performance Deficiency: The failure to verify that an actuation signal from the BDMS would result in an SSPS actuation as part of acceptance limits in surveillance procedures was a performance deficiency.
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 objective of ensuring the availability, reliability, and capability of reactivity control systems that respond to initiating events to prevent undesirable consequences. As a result, the boron dilution mitigation system was inoperable when an associated switch failed to make electrical contact and that failure went undetected for 3 months.
Significance: The inspectors screened this finding utilizing Inspection Manual Chapter 0609, 4, Initial Characterization of Findings, dated October 7, 2016, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 2, Mitigating Systems Screening Questions, dated June 19, 2012. A senior reactor analyst reviewed the use of the at-power SDP and noted the modes of concern for reactivity issues were associated with reactor startup. Using the questions for reactivity control system issues, the inspectors determined that the finding screened to Green because
- (1) the finding did not affect both a single reactor protection system (RPS) trip signal to initiate a reactor scram and the function of other redundant trips or diverse methods of reactor shutdown;
- (2) the finding did not involve control manipulations that unintentionally added positive reactivity; and
- (3) the finding did not result in a mismanagement of reactivity by operators. Specifically, there was no actual reactivity transient while the BDMS was not available to respond to an event.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. The inspectors determined there was no cross-cutting aspect because the last significant opportunity to identify this vulnerability, including operating experience reviews and modifications to the system, occurred more than 3 years before the event.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires, in part, that testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in applicable design documents. The licensee established Surveillance Procedure ISF-SB-00A32, Train B Solid State Protection System (SSPS) Slave Relay Testing, in part, to meet this regulatory requirement.
Contrary to the above, from May 10 to August 23, 2019, the licensee failed to assure that SSPS testing required to demonstrate that structures, systems, and components will perform satisfactorily in service included acceptance limits contained in applicable design documents to assure that the SSPS system would perform satisfactorily in service. Specifically, the solid state protection system surveillance test procedures failed to incorporate acceptance limits to ensure the BDMS actuation signal passed through the flux doubling bypass switch and would cause an SSPS actuation. As a result, the boron dilution mitigation system was inoperable when an associated switch failed to make electrical contact and that failure went undetected for 3 months.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Verify or Check the Adequacy of Design for the Control Room Filtration Fan Cornerstone Significance Cross-Cutting Aspect Report Section Barrier Integrity Green NCV 05000483/2019004-02 Open/Closed
[H.7] -
Documentation 71153 The inspectors reviewed a self-revealed, Green, non-cited violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, for the licensees failure to ensure design changes were subject to design control measures commensurate with those applied to the original design for the control room filtration fan. Specifically, the replacement thermal overload protection for a control room filtration fan utilized a non-conservative value for brake horsepower which was identified when the fan spuriously tripped. As a result, the undersized thermal overload challenged the fans ability to operate both during normal operation and when responding to design basis events.
Description:
On July 17, 2019, following the performance of Surveillance Procedure MSE-GK-0G003, Control Building Emergency Ventilation B Flow Rate Determination, the control room filtration fan B tripped on thermal overload after running for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and 48 minutes, rendering control room emergency ventilation system train B inoperable.
The control room filtration fan train B feeder breaker had recently been replaced as part of a design change, MP 18-0003, Replace Safety Related 480 VAC MCC buckets. This design change involved replacing obsolete safety-related motor control centers (MCC) with a new MCC design including all the associated breakers, fuses, thermal overload relays, auxiliary contacts, control power transformers, and wiring. As part of MP 18-0003, Calculation NG-23, Revision 0, Addendum 2, MCC Set Point Calculation for MP 18-0003, was performed on October 1, 2014, to establish new thermal overload relay settings, on an individual load basis, to protect the equipment required during a design basis accident without causing false or spurious trips during normal operation.
Follow-up testing determined that the breaker and thermal overloads functioned as designed and were set according to the applicable design documents. However, the licensee identified design inconsistencies for the fan motors brake horsepower. Two drawings, M-619.2-00102, Control Room Filtration System Fans, and M-619.2-00043, Control Room Filtration System Fan Data Sheet, identified the fans actual brake horsepower as 4.10 and 4.08 respectively, while the control room filtration system fan performance curve, M-619.2-00126, indicated a brake horsepower value of 3.15.
The fan's thermal overload settings, determined by calculation NG-23, were based on the 3.15 brake horsepower value from the fan's performance curve (M-619.2-00126). This brake horsepower value resulted in the selection of a thermal overload setting close to the fan's normal operating parameters without sufficient margin to prevent spurious tripping during normal operations. The variations in brake horsepower values were a result of design documentation not being updated to reflect the most recent testing performed by the fan's manufacturer.
Corrective Actions: The licensee replaced the thermal overload with one using the correct setpoints, updated the control room filtration fan performance data sheets, performed an extent of condition review, and documented the issue in a condition report.
Corrective Action References: Condition Report 201904906.
Performance Assessment:
Performance Deficiency: The inspectors determined that the licensees failure to apply adequate design control measures to the replacement control room filtration fan supply breaker 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 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, the control room filtration fan spuriously tripped, was declared inoperable, and was unable to perform its function of protecting control room staff from radionuclide releases caused by accidents or events.
Significance: The inspectors screened the significance of the finding using Inspection Manual Chapter 0609, Attachment 4. "Initial Characterization of Findings," dated October 7, 2016, and Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 3, Barrier Integrity Screening Questions, dated June 19, 2012. Using the questions for control room degradation, 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 and did not represent a degradation of the barrier function of the control room against smoke or a toxic atmosphere. Specifically, the failure of the fan to start prevented that train of control room filtration from operating, but did not represent an opening in the system or the control room ventilation boundary.
Cross-Cutting Aspect: H.7 - Documentation: The organization creates and maintains complete, accurate, and up-to-date documentation. The finding had a cross-cutting aspect in the area of human performance associated with documentation because the licensee failed to create and maintain complete, accurate, and up to-date documentation. Specifically, the licensee failed to maintain their design documents with updated vendor testing data for the control room filtration fans. As a result, the associated design documentation, procedures, and work packages were not accurate and current.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, that design changes, including field changes, shall be subject to design control measures commensurate with those applied to the original design and be approved by the organization that performed the original design unless the applicant designates another responsible organization. The licensee established design change modification package MP 18-0003, Replace Safety Related 480 VAC MCC buckets, in part, to meet the regulatory requirement.
Contrary to the above, from October 1, 2014, to July 17, 2019, the licensee failed to ensure design changes, including field changes, were subject to design control measures commensurate with those applied to the original design and be approved by the organization that performed the original design unless the applicant designates another responsible organization. Specifically, the licensee did not ensure the design change measures to replace thermal overload protection for a control room filtration fan were commensurate with those applied to the original design, including using correct values and conservative interpretations of performance curves. The cumulative effect of these design control errors reduced the design margin for the fan spuriously tripping during normal operating conditions and these errors were not identified during the design change process. As a result, the undersized thermal overload self-revealed during surveillance testing and challenged the fans ability to operate both during normal operation and when responding to design basis events.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On December 11, 2019, the emergency preparedness inspectors presented the results for review of EAL changes to G. Rausch, Manager, Emergency Preparedness, and other members of the licensee staff.
- On January 6, 2020, the resident inspectors presented the integrated inspection results to B. Cox, 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 201609239, 201800054, 201800072, 201800076,
201906468, 201907234
Miscellaneous
OE 429980
Trash Racks and Outer Screens Clogged by River Ice
OE 450625
Frazil Ice Formation Impacts Intake Structure
OE 450786
Extremely Low Temperature Switchyard Breaker Trip
OE 452091
Reactor Down Power in Response to Frazil Ice Conditions
OE 452253
Flex Air Compressor Unable to Supply Nominal Service Air
Pressure
OE 07-02
Intake Cooling Water Blockage
Procedures
OE 450710
Loss of Offsite 345 KV Source due to Severe Weather
Conditions
OTN-DE-00001
Intake Water System
OTN-QJ-00003
Plant Freeze protection Heat Tracing
OTO-ZZ-00012
Severe Weather
OTS-ZZ-00007
Plant Cold Weather
71111.04Q Corrective Action
Documents
Condition Reports 200810481, 201008918, 201005432, 201105051,
201109098, 201900478, 201901724, 201903196,
201904821
Miscellaneous
M-22LE02
Control and Diesel Gen. Bldg. Oily Waste System
MP 10-0053
SSPS Printed Circuit Board Power Supply & Master Test
Relay Requirements
Train A Diesel Generator & Sequencer Testing
13-07
Solid State Protection System New Design Universal Logic
Board & Safeguards Driver Board 48VDC Input
2/10/2013
Procedures
Unblocked Actuation Slave Relay K626 - Train A
ITM-SB-0001
SSPS Power Supply Predictive Maintenance
MPM-SK-QW001
Service and Inspection of Plant Doors
MSE-SB-QS001
Reactor Trip Switchgear Surveillance
ODP-ZZ-00006
Operations Department Narrative Logs
OTS-SB-0002A
Placing SSPS Train A in Test in Modes 5, 6 & No Mode
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Work Orders
16506089
71111.05Q Corrective Action
Documents
Condition Reports 201200573, 201404263, 201707147, 201801536,
201900801, 201904077, 201904398, 201901458,
201904809, 201905012, 201906037, 201906460,
201906713, 201907260, 201907482, 201907567,
201907917
Miscellaneous
Fire Pre-Plan
95599-M-001
Design Basis Flood Calculation Updates
Procedures
APA-ZZ-00701
Control of Fire Protection Impairments
APA-ZZ-00741
Control of Combustible Materials
APA-ZZ-00750
Hazard Barrier Program
Site Wide Fire Protection Inspection Procedure 71111.11Q Corrective Action
Documents
Condition Reports 201802284, 201903646, 201905508, 201907056,
201907717, 201907925
Miscellaneous
T61.0110.6
Operations Department - Code of Conduct
T61.016A.6
Control Room Communications
Procedures
APA-ZZ-00300
Component Labeling and Sign Program
ODP-ZZ-00001
Operations Department - Code of Conduct
106
ODP-ZZ-00001,
Addendum 13
Shift Manager Communications
ODP-ZZ-00001,
Addendum 14
Operations Management Expectations
ODP-ZZ-00003
Shift Relief and Turnover
Corrective Action
Documents
Condition Reports 199300312, 201508296, 201509128, 201604450,
201704838, 20183067, 201804220, 201901198, 201902336,
201906720, 201907199
Miscellaneous
ESF Actuation System - LSELS ATI Sub-System Diagram
J-10400166
ESF Actuation System - ATI Signals
J-10400221
ESF Actuation Logic - Subsystem Reliability Analysis
PM1001961
Overhaul Westinghouse DS416 Circuit Breaker
PMID0903683
PRAER 19-426
Evaluation for Missed Sequencer and Load Shedder Testing
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
PRAER 19-427
Risk Evaluation for Loose Creek Offsite Power Line Outage
Greater than 7 Days
RFR 10560A
Undervoltage Trip Protection
Procedures
Loop - Misc; NF039A Relay Driver Test
Loop - Misc; NF039B Relay Driver Test
ITM-SB-0003A
P4 Resistance Test
MSE-SB-QS003
Manual Reactor Trip Switch TADOT
OOA-SB-00002
Operator Aid for Closing Reactor Trip Breakers
Reactor Trip Breaker A Trip Actuating Device Operational
Test
Reactor Trip Breaker P-4 Verification
Work Orders
07513743, 16002500, 17513308, 18513135, 19507645
Corrective Action
Documents
Condition Reports 2011804086, 201804109, 201807147, 201906521,
201906812, 201907085
Corrective Action
Requests
201704094, 201900959, 201901716, 201902063,
201902112, 201902913, 201907006
Miscellaneous
Job 17505328
Power Factor Testing & Oil Analysis XPB117
Industry Guidelines for Monitoring the Effectiveness of
maintenance at Nuclear Power Plants
Procedures
APA-ZZ-00322,
Appendix F
Online Work Integrated Risk Management
APA-ZZ-01250
Operational Decision Making
EDP-ZZ-01128,
Appendix 1
SSCs in the Scope of the Maintenance Rule at Callaway
EDP-ZZ-01129
Callaway Energy Center Risk Assessment
ODP-ZZ-00002,
Appendix 2
Risk Management Actions for Planned Risk Significant
Activities
ODP-ZZ-0002,
Appendix 2
Risk management Actions for Planned Risk Significant
Activities
Corrective Action
Documents
Condition Reports 201007822, 201302004, 201502868, 201504294,
201600029
Miscellaneous
EF-45
Acceptance Criteria used in Essential Service Water Flow
Balance Procedures
8A
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NG-23,
Addendum 2
MCC Set Point Calculation for MP 18-0003
Procedures
APA-ZZ-00500,
Appendix 1
MPE-GK-QC001
Control Room and Class 1E Air Conditioning Unit Charging
MPE-GK-QG002
Control Room Emergency Ventilation System Train B Flow
Verification
ODP-ZZ-00001,
Addendum 15
OTN-GK-00001
Control Building HVAC System
Corrective Action
Documents
Condition Reports 201904906, 201905348, 20195361
Miscellaneous
E-1041A-05002
Qualification Report for NLI Motor Control Center Cubicles
MP 18-0003
Replace 480 VAC MCC Buckets
NG-23,
Addendum 2
MCC Set Point Calculation for MP 18-0003
RFR 180006
Replace 480 VAC MCC Buckets
Emergency Ventilation System Train B Inoperability
Corrective Action
Documents
Condition Reports 201700641, 201703337, 201704362, 201706877,
2018002626, 201902982, 201906703, 201907035
Condition Reports 201900060, 201900666, 201901963, 201905178,
201905362, 201907178
Miscellaneous
EQTR E01AP01
Pressure Transmitter (EQ Report)
M-018-00309
IM Emergency Diesel Generator System
146
MP 19-0116
Evaluate & Approve EMC Improvements for New EGS
Connectors/Connections
Procedures
4KV Bus Undervoltage Time Response Testing
ITP-KJ-00002
Emergency D/G B Trip Checks
MSM-KJ-QK001
Emergency Diesel Generator Inspection
Work Orders
18503885
Corrective Action
Documents
Condition Reports 200809193, 201206716, 201801697, 201906527
Condition Reports 201902336, 201902734, 201906720, 201907557
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
AE-107,
Addendum 1
SG NR Level Loop Tolerance Calculation
IM Installation, Operation and Maintenance for Fire
Protection System Upgrade for Callaway Plant
MP 03-1002
SG NR Level Loop Tolerance Calculation
Procedures
ISL-AE-0LPS2
S/G A, B, C, D NR Level Protection Set 2 Calibration
Loop Misc NF039B Relay Driver Test
ODOP-ZZ-00002,
Appendix 2
Risk Management Actions for Planned Risk Significant
Activities
Fire Suppression Water System Functional Test - SR Areas
OTS-NF-00002
Power Down and Power Up of Load Shed and Emergency
Load Sequencer LSELS
Work Orders
19512281
71151
Miscellaneous
Control Room Logs
MSPI Derivation Reports
Various
Procedures
MSPI Basis Document
APA-ZZ-01111
Mitigating Systems Performance Index (MSPI) Program
Administration
Corrective Action
Documents
Condition Reports 200711385, 201004599, 201103005, 201905260
Condition Reports 201904254, 201906456
Miscellaneous
E-018-00190
IM Motor Control Center
Job 19004321
through
19004326
Extent of Condition Review for CR 201905260
MP 16-0024
Voltage Drop in Circuits Fed from MCC Class 1E Distribution
Panels
ULDBD-NG-001
Low Voltage (480V) - Class 1E
Procedures
MSM-ZZ-QS004
Month Selection of Molded Case 480V Containment
Overcurrent Protective Devices
Corrective Action
Documents
Condition Reports 20190007, 201905676
Miscellaneous
AUCA 20190007
Root Cause Analysis for CR 201905676, Failure of Relay
K503 to Actuation During ISF-SB-00A32
Job 18500461
Control Room Filter Absorber Unit B Flow Test
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
SSPS Train B Functional Test
MSG-GK-QG003
Control Building Emergency Ventilation Train B Flow Rates
16