IR 05000352/2021001

Integrated Inspection Report 05000352/2021001 and 05000353/2021001

ML21120A021
Person / Time
Site:	Limerick
Issue date:	04/30/2021
From:	Jon Greives NRC/RGN-I/DORS
To:	Rhoades D Exelon Generation Co, Exelon Nuclear
Greives J
References
IR 2021001
Download: ML21120A021 (17)

Text

April 30, 2021

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000352/2021001 AND 05000353/2021001

Dear Mr. Rhoades:

On March 31, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Limerick Generating Station, Units 1 and 2. On April 16, 2021, the NRC inspectors discussed the results of this inspection with Mr. Frank Sturniolo, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.

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 I; the Director, Office of Enforcement; and the NRC Resident Inspector at Limerick Generating Station, Units 1 and 2.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; and the NRC Resident Inspector at Limerick Generating Station, Units 1 and 2. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, X /RA/

Signed by: Jonathan E. Greives Jonathan E. Greives, Chief Reactor Projects Branch 4 Division of Operating Reactor Safety Docket Nos. 05000352 and 05000353 License Nos. NPF-39 and NPF-85

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000352 and 05000353 License Numbers: NPF-39 and NPF-85 Report Numbers: 05000352/2021001 and 05000353/2021001 Enterprise Identifier: I-2021-001-0085 Licensee: Exelon Generation Company, LLC Facility: Limerick Generating Station, Units 1 and 2 Location: Sanatoga, PA 19464 Inspection Dates: January 1, 2021 to March 31, 2021 Inspectors: A. Ziedonis, Senior Resident Inspector S. Haney, Resident Inspector G. Walbert, Reactor Engineer H. Anagnostopoulos, Senior Health Physicist M. Henrion, Health Physicist Approved By: Jonathan E. Greives, Chief Reactor Projects Branch 4 Division of Operating Reactor Safety Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Limerick Generating Station, Units 1 and 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors.

Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information. A licensee-identified non-cited violation (NCV) is documented in report section 7115

List of Findings and Violations

Inadequate Maintenance Procedure Result in MSIV Fast Closure and Automatic Scram Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.7] - 71152 NCV 05000352,05000353/2021001-01 Documentation Open/Closed The inspectors determined there was a self-revealing Green NCV of Technical Specification (TS) 6.8, Procedures and Programs, when Exelon did not establish, implement, and maintain procedures to adequately cover maintenance activities that affected the performance of safety-related main steam isolation valves (MSIV). Specifically, on November 13, 2020, primary containment instrument gas (PCIG) supply tubing to the '1B' inboard MSIV experienced a shear failure, which resulted in a valid reactor high pressure condition and automatic scram. Exelon attributed the PCIG supply tubing failure to ambiguous maintenance procedure direction, which resulted in repair and re-use of damaged compression fittings, as opposed to intended replacement, thereby causing overstressed tubing and subsequent shear failure.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000352/2020-001-00 LER 2020-001-00 for 71153 Closed Limerick Generating Station,

Unit 1, Valid Automatic Actuation of Reactor Protection System with Reactor Critical due to Closure of One Main Steam Isolation Valve LER 05000352/2020-001-01 LER 2020-001-01 for 71153 Closed Limerick Generating Station,

Unit 1, Valid Automatic Actuation of the Reactor Protection System with the Reactor Critical Due to Closure of One Main Steam Isolation Valve

PLANT STATUS

Unit 1 began the inspection period at rated thermal power. On March 18, 2021, the unit was down powered to 35 percent and placed in single loop operation for planned '1A' adjustable speed drive hose replacement, main turbine stop valve maintenance, condenser bay steam leak repair, and main turbine valve testing. Following the completion of maintenance and testing, power ascension was placed on hold at approximately 60 percent power due to an unisolable circulating water pipe leak. Following successful leak repair, the unit was returned to rated thermal power on March 24, 2021, and remained at or near rated thermal power for the remainder of the inspection period.

Unit 2 began the inspection period at rated thermal power. Unit 2 entered its end-of cycle coastdown period starting February 23, 2021, and reached 84 percent power at the end of the inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), resident and regional inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time the resident inspectors performed periodic site visits each week, increasing the amount of time on site as local COVID-19 conditions permitted. As part of their onsite activities, resident inspectors conducted plant status activities as described in IMC 2515, Appendix D, observed risk significant activities, and completed on site portions of IPs. In addition, resident and regional baseline inspections were evaluated to determine if all or portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on site. The inspections documented below met the objectives and requirements for completion of the IP.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) Unit 2 high pressure coolant injection (HPCI) system while the reactor core isolation cooling (RCIC) system was out of service for planned maintenance on January 20, 2021

(2) Unit 1 HPCI system following the identification of pump seal leakage on January 23, 2021

(3) Unit 1 'A' residual heat removal system on February 11, 2021

(4) Unit 2 'D22' emergency diesel generator during 'D24' emergency diesel generator testing and inoperability on February 24, 2021

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Fire area 56, Unit 2 RCIC pump room on January 20, 2021

(2) Fire area 31, Unit 1 'B' and 'D' residual heat removal heat exchanger and pump room on February 5, 2021

(3) Fire area 69, Unit 2 control rod drive equipment and neutron monitoring areas on February 5, 2021

(4) Fire area 32, Unit 1 'A' and 'C' residual heat removal heat exchanger and pump room on February 10, 2021

(5) Fire area 87, Unit 1 condensate pump room following report of flooding and receipt of fire alarm on March 23, 2021

71111.06 - Flood Protection Measures

Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)

The inspectors evaluated internal flooding mitigation protections in the:

(1) Unit 1 condenser bay and condensate pump room during 'B' main condenser waterbox circulating water outlet piping leak on March 22, 2021

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) Unit 1 planned load reduction, single loop operation, and power ascension on March 18 through March 22, 2021

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated licensed operator requalification training on January 11, 2021

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (3 Samples)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) Unit common diesel driven fire pump multiple issues on March 18, 2021

(2) Unit common control room fresh air supply system damper failure on March 25, 2021

(3) Unit 1 MSIV (a)(1) evaluation on March 26, 2021

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1) Unit 1 'D13' emergency diesel generator emergent fuel oil leak repair on January 20, 2021

(2) Review of Paragon risk informed completion time non-conservative software error on January 21, 2021

(3) Unit common elevated risk condition during 'B' emergency service water system planned maintenance on January 25, 2021

(4) Unit 1 emergent work in response to main turbine stop valve #2 digital electro-hydraulic control system trouble alarms on February 17, 2021

(5) Unit 1 circulating water leak temporary repair on March 24, 2021

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) Unit 1 emergency service water loop return to service water valve (HV-011-123) long stroke time on January 22, 2021

(2) Unit 1 'D13' emergency diesel generator following identification of water in the fuel oil on January 26, 2021

(3) Unit common foreign material identified in 'A' emergency service water piping on January 27, 2021

(4) Unit common 'A' emergency service water system following the identification of a pipe support gap on February 2, 2021

(5) Unit 1 RCIC system beyond design basis safety functional impact following plant heat-up while isolated from main steam on February 3, 2021

(6) Unit 1 'B' emergency service water through-wall leak in '1A' HPCI pump room cooler piping on March 16, 2021

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)

(1 Sample)

The inspectors evaluated the following permanent modification:

(1) Unit common 'A' emergency service water return to 'B' residual heat removal service water return piping replacement on January 28, 2021

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (5 Samples)

The inspectors evaluated the following post-maintenance test activities to verify system operability and functionality:

(1) Unit 1 'D13' emergency diesel generator lube oil drain valve repair on January 21, 2021

(2) Unit common diesel driven fire pump packing replacement on February 23, 2021

(3) Unit common diesel driven fire pump replacement on March 8, 2021

(4) Unit 1 'A' reactor protection system inverter repair on March 9, 2021

(5) Unit 1 RCIC system relay replacement on March 17, 2021

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)

(1) ST-6-092-313-1, Unit 1 'D13' emergency diesel generator slow start test run on January 20, 2021

(2) ST-6-092-314-2, Unit 2 'D24' emergency diesel generator slow start test run on February 24, 2021

(3) ST-6-022-253-0, Unit common diesel driven fire pump characteristic curve test on

February 24, 2021 Inservice Testing (IP Section 03.01) (1 Sample)

(1) ST-6-051-235-2, Unit 2 'A' residual heat removal pump comprehensive test on

March 16, 2021 FLEX Testing (IP Section 03.02) (1 Sample)

(1) S115.1.B Unit common 0A-G800 FLEX generator maintenance and testing on January 12, 2021

71114.06 - Drill Evaluation

Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) The inspectors evaluated a simulator training evolution on February 8,

71124.05 - Radiation Monitoring Instrumentation

Walkdowns and Observations (IP Section 03.01) (5 Samples)

The inspectors evaluated the following radiation detection instrumentation during plant walkdowns:

(1) Telepole: S/N 334721

(2) AMP-100: S/N 0020791

(3) ASP-1 REM Ball: S/N 334850

(4) RO-20: S/N 079232

(5) Available area radiation monitors in the turbine building and radioactive waste facility

Calibration and Testing Program (IP Section 03.02) (10 Samples)

The inspectors evaluated the calibration and testing of the following radiation detection instruments:

(1) Telepole: S/N 334721

(2) AMP-100: S/N 0020791

(3) ASP-1 REM Ball: S/N 334850

(4) RO-20: S/N 079232

(5) Gamma spectroscopy unit #1

(6) Gamma spectroscopy unit #3

(7) Liquid scintillation counter: S/N SGLO04201243

(8) Personnel contamination monitor: S/N 336001

(9) Portal monitor: S/N 338008

(10) Small article monitor: S/N 335007 Effluent Monitoring Calibration and Testing Program Sample (IP Sample 03.03) (2 Samples)

The inspectors evaluated the calibration and maintenance of the following radioactive effluent monitoring and measurement instrumentation:

(1) RE-026-076-1 Wide Range Accident Monitor - Low Range

(2) RE-026-2N010B Reactor Enclosure Ventilation Exhaust

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below for the period January 1, 2020 through December 31, 2020:

IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 03.02)

=

(1) Unit 1 Unplanned Power Changes per 7000 Critical Hours

(2) Unit 2 Unplanned Power Changes per 7000 Critical Hours

71152 - Problem Identification and Resolution

Annual Follow-up of Selected Issues (IP Section 02.03) (2 Samples)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

(1) Unexpected closure of Unit 1 'B' inboard MSIV (HV-041-1F022B) resulted in automatic high reactor pressure scram root cause report review (IR 4384039)

(2) Unit 1 HPCI and RCIC not aligned for service per procedure root cause report review (IR 4384739)

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 2020-001-00 and LER 2020-001-01, Valid Automatic Actuation of the Reactor Protection System with the Reactor Critical Due to Closure of One Main Steam Isolation Valve (ADAMS Accession No. ML21078A049). The inspection conclusions associated with this LER are documented in this report under the Inspection Results associated with section

INSPECTION RESULTS

Inadequate Maintenance Procedure Result in MSIV Fast Closure and Automatic Scram Cornerstone Significance Cross-Cutting Report Aspect Section Initiating Events Green [H.7] - 71152 NCV 05000352,05000353/2021001-01 Documentation Open/Closed The inspectors determined there was a self-revealing Green NCV of TS 6.8, Procedures and Programs, when Exelon did not establish, implement, and maintain procedures to adequately cover maintenance activities that affected the performance of safety-related MSIV. Specifically, on November 13, 2020, PCIG supply tubing to the '1B' inboard MSIV experienced a shear failure, which resulted in a valid reactor high pressure condition and automatic scram. Exelon attributed the PCIG supply tubing failure to ambiguous maintenance procedure direction, which resulted in repair and re-use of damaged compression fittings, as opposed to intended replacement, thereby causing overstressed tubing and subsequent shear failure.

Description:

On November 13, 2020, Unit 1 experienced an automatic scram from 100 percent power, due to the receipt of a valid high reactor pressure condition. The high reactor pressure condition was caused by a fast closure of the '1B' inboard MSIV. Subsequent investigation identified the PCIG supply manifold tubing had sheared immediately downstream of the compression fitting adapter, on the removable section of the supply tubing.

Exelon performed a root cause evaluation (RCE), under issue report (IR) 4384039, and determined the root cause of the PCIG supply tubing failure was attributed to ambiguous maintenance procedure direction regarding the need for fitting replacement following the identification of damaged threads. Due to this ambiguity, damaged threads were repaired via a die-cutter tool, and subsequently re-used. In addition, the RCE identified that vibration-induced fatigue failure was a contributing cause. Specifically, a laboratory failure analysis concluded the tubing failed by high cycle fatigue that was initiated directly at the tube deformation and notch location created by the back ferrule of the compression fitting.

Although tube notching is anticipated with compression fittings, cracking and subsequent tube failure is not expected. Exelon ultimately determined that repair and re-use of damaged threads resulted in yielding of the fitting body, which introduced localized stress risers on the tubing during installation. Additionally, Exelon stated in the RCE document that if either one of the root or contributing causes was not present, a failure would not have occurred.

Following the automatic scram in 2020, damaged threads were identified on the male threads of the welded-in one-inch PCIG supply coupling adapter at two of the four inboard MSIVs. As part of the RCE, Exelon considered the maintenance history of the PCIG supply tubing to the MSIVs. The removable PCIG supply tubing was determined to have been last replaced in 2016 (as a corrective action from a similar PCIG-to-inboard-MSIV tubing failure in 2015, attributed to the use of an undersized connector; see NCV 2015002-01 in ML15216A194).

The inboard PCIG tubing was also removed and reinstalled in 2018 (not replaced), to support planned maintenance during the refueling outage. Although work order documentation in 2016 and 2018 did not discuss the identification of damaged male threads on the welded-in PCIG coupling adapter, Exelon interviews with maintenance technicians determined that similar conditions, with subsequent repair and re-use, were likely present at the time.

Additionally, the RCE determined that the repaired and re-used male threads on the welded-in one-inch coupling adapter were believed to be from original construction (with the exception of the C inboard male coupling, replaced in 1998). The RCE determined that each time damaged male threads were repaired and re-used on the welded-in coupling adapter, increasing levels of stress risers were likely introduced to the tubing via the yielding of the body on the compression fitting. PCIG tubing replacements were performed at all four inboard MSIVs following the November 13 scram, in an effort to reset the tubing stress and fatigue life of the tubing while the condition could be further evaluated in a RCE.

Exelon procedure MA-AA-716-060, Compression Fittings Inspection, Installation, Remake and Repair, Revision 5, Section 4.2, provided general guidance for the inspection and handling of tubing and fittings, and specified replacement as required, but did not specify under what conditions the tubing and fittings were required to be replaced. The RCE cited multiple industry standard documents (vendor and BWR MSIV template) that specify replacing damaged compression fittings upon identification, as opposed to repair and re-use.

While the intent of replacing damaged fittings was translated to the MA-AA-716-060 maintenance procedure, the procedure steps were not specific enough to clearly indicate that fitting and tubing replacement were required. The RCE determined that maintenance technicians had developed a practice of determining damaged compression fitting thread replacement was not required if the threads could be repaired and re-used.

The inspectors reviewed the RCE, performed walkdowns of the inboard PCIG-to-MSIV supply tubing during the 2020 forced outage, and interviewed Exelon root cause team members and maintenance technicians. The inspectors determined that the RCE was of sufficient evaluation depth, the root and contributing causes were reasonable to the circumstances, and that the assigned corrective actions were adequate to address the causes that were identified.

Corrective Actions: Exelon replaced the PCIG supply tubing on all four inboard MSIVs prior to startup from the November 13, 2020 forced outage. Exelon assigned a corrective action to prevent recurrence of this event, which consisted of revising MA-AA-716-060 to clarify that damaged compression fittings are required to be replaced. In addition, corrective actions were assigned to replace the inboard welded-in PCIG male fittings on Unit 1 and Unit 2; and to optimize the inboard and outboard tubing design to provide additional margin to vibration-induced failures.

Corrective Action References: IR 4384039

Performance Assessment:

Performance Deficiency: The inspectors determined that Exelons inadequate procedure to cover maintenance activities that affected the performance of a safety-related MSIV was a performance deficiency that was reasonably within Exelons ability to foresee and correct, and should have been prevented. Specifically, procedure MA-AA-716-060, Compression Fittings Inspection, Installation, Remake and Repair, Revision 5, Section 4.2, did not provide clear direction regarding the intended replacement of damaged compression fittings, which resulted in repair and re-use. Consequently, localized tubing stress risers were introduced during installation, which resulted in subsequent shear failure of the PCIG supply tubing to the '1B' inboard MSIV during full power operation, and caused '1B' MSIV fast closure and an automatic reactor scram.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Initiating Events cornerstone and adversely affected the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. This finding is also similar to examples 4.b and 5.b, described in IMC 0612, Power Reactor Inspection Reports, Appendix E, Examples of Minor Issues, in that the performance deficiency is more than minor if it results in a reactor trip or scram.

Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power. The inspectors utilized Exhibit 1, Initiating Events Screening Questions, and determined this finding was of very low safety significance (Green), because the finding did not cause a loss of mitigation equipment relied upon to transition the plant to a stable shutdown condition. Specifically, while the finding resulted in a reactor scram and the closure of a single MSIV, the main condenser remained available for its mitigating function.

Cross-Cutting Aspect: H.7 - Documentation: The organization creates and maintains complete, accurate and up-to-date documentation. Specifically, Exelon did not maintain maintenance procedure MA-AA-716-060 complete and accurate with respect to the direction to replace damaged compression fittings, despite recent maintenance opportunities (including 2018) to identify and question ambiguous procedure guidance with respect to industry guidance documents.

Enforcement:

Violation: Limerick Generating Station, Unit 1, TS 6.8, Procedures and Programs, Section 6.8.1a, requires written procedures shall be established, implemented, and maintained covering the activities in Regulatory Guide 1.33, Quality Assurance Program Requirements, Revision 2. Regulatory Guide 1.33, Section 9.a, Procedures for Performing Maintenance, requires maintenance that can affect the performance of safety-related equipment be properly pre-planned and performed in accordance with written procedures.

Contrary to the above, prior to March 12, 2021, Exelon procedure MA-AA-716-060, Compression Fittings Inspection, Installation, Remake and Repair, Revisions 0 through 5, were not established and maintained to cover maintenance that affected the performance of safety-related MSIVs. Specifically, procedure Section 4.2 did not provide clear direction regarding the intended replacement of damaged compression fittings in the PCIG supply to the MSIVs, resulting in repair and re-use. Consequently, localized tubing stress risers were introduced in the PCIG tubing during installation, which resulted in tubing failure to the '1B' MSIV, and a subsequent automatic reactor scram on November 13, 2020.

Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.

Licensee-Identified Non-Cited Violation 71152 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 an NCV, consistent with Section 2.3.2 of the Enforcement Policy.

Violation: Title 10 of the Code of Federal Regulations Part 50 (10 CFR Part 50), Appendix B, Criterion V, "Instructions, Procedures and Drawings," requires, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.

Exelon Procedure GP-2, Normal Plant Startup, Revision 182, Steps 3.4.8 and 3.4.10.8 require RCIC and HPCI to be aligned for automatic operation prior to reaching 150 and 200 psig reactor pressure, respectively.

TS 3.7.3 and 3.5.1 require the RCIC and HPCI systems to be OPERABLE in OPERATING CONDITION 2 with reactor steam dome pressure above 150 and 200 psig, respectively.

TS 3.0.4 requires when a limiting condition for operation is not met, entry into a specified condition in the applicability shall only be made when the associated action requirements permit continued operation for an unlimited period of time, or when an allowance is stated in the specification.

Contrary to the above, on November 16, 2020, Exelon did not accomplish an activity affecting quality in accordance with the procedure. Specifically, while performing plant startup, Exelon staff did not align RCIC and HPCI for automatic operation prior to reaching 150 and 200 psig reactor pressure. With the RCIC and HPCI systems isolated from main steam, these systems were inoperable when reactor steam dome pressure exceeded the specified conditions in the applicability of Section 3.7.3 for RCIC, and Section 3.5.1 for HPCI. The associated action requirements did not permit continued operation for an unlimited period of time, and no such allowance was stated in the specification.

Significance/Severity: Green. The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors utilized Exhibit 2, Mitigating Systems Screening Questions, Section A, "Mitigating SSCs and PRA Functionality." The inspectors determined the finding was of very low safety significance (Green) because the finding was not a deficiency affecting the design or qualification of a mitigating structure, system, or component; did not represent a loss of the probabilistic risk assessment (PRA) function of a single train TS system for greater than its TS allowed outage time; did not represent a loss of the PRA function of one train of a multi-train TS system for greater than its TS allowed outage time; did not represent a loss of the PRA function of two separate TS systems for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; did not represent a loss of a PRA system and/or function; and did not represent a loss of the PRA function of one or more non-TS trains of equipment designated as risk significant in accordance with the licensees maintenance rule program for greater than three days.

Corrective Action References: IR

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On February 19, 2021, the inspectors presented the IP 71124.05 Radiation Protection Instrumentation inspection results to Mr. Frank Sturniolo and other members of the licensee staff.

• On April 16, 2021, the inspectors presented the integrated inspection results to Mr. Frank Sturniolo, Site Vice President, and other members of the licensee staff.

THIRD PARTY REVIEWS Inspectors reviewed Institute of Nuclear Power Operations reports that were issued during the inspection period.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.04 Corrective Action IR 4404502 NRC ID: D22 EDG cylinder #3 weeping fuel oil 2/24/21

Documents

Resulting from

Inspection

71111.06 Corrective Action IR 2651425 2016 U1 CW leak

Documents IR 4410585 Circulating water leak from piping 3/21/21

IR 4410636 Flood alarm not received in condenser area 3/22/21

IR 4415454 No active CC-AA-404 document found for U1 CW leak 4/9/21

IR 4416246 NCAP investigation required for U1 CW leak 4/13/21

Work Orders 1277465

5136680

5141146

71111.12 Corrective Action IR 4396190 HV-078-052B stroke time greater than allowed 1/15/21

Documents

71111.13 Corrective Action IR 202873-02 Historical tech eval for lube oil leakage

Documents IR 4396764 011-1389C found leaking during diesel run 1/19/21

IR 4402656 U1 EHC minor trouble spurious alarm 2/15/21

71111.15 Corrective Action IR 396604 Water in D13 FOST 1/19/21

Documents IR 4396519 Long stroke time for HV-011-123 1/17/21

IR 4396959 Long stroke time for HV-011-123 1/18/21

IR 4398365 Diesel fuel oil semiannual microbiological sampling 1/27/21

IR 4399079 M-0012 sheet 1 rev 93 P&ID needs correction 1/30/21

IR 4399809 'A' ESW pipe support 2/2/21

IR 4408624 Pin hole ESW leak on U1 HPCI unit cooler supply piping 3/12/21

IR 4408926 U1 HPCI unit coolers isolation valve leakby 3/15/21

IR 4408931 U1 HPCI unit coolers isolation valve leakby 3/15/21

IR 498167 FM found inside of ESW 1/26/21

71111.18 Corrective Action IR 4398229 4.0 critique - ESW/RHRSW pipe replacement project drain 1/26/21

Documents plan

Engineering EC 625439 Replace 'A' ESW Return to 'B' RHRSW Return Piping - 0

Changes Online Work (Downstream of HC-011-015A)

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.19 Corrective Action IR 4402503 DDFP packing degraded 2/15/21

Documents IR 4406870 DDFP cooling water strainer clog 3/5/21

IR 4407668 DDFP engine raw water strainer upgrade 3/9/21

IR 4409433 Agastat relay needs replacement 3/16/21

71111.22 Corrective Action IR 4404209 ST-6-022-253-0 UNSAT due to low system discharge 2/23/21

Documents pressure

71152 Corrective Action IR 4057128 2017 RCIC WGE

Documents

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