IR 05000289/2018003

Integrated Inspection Report 5000289/2018003

ML18317A312
Person / Time
Site:	Crane
Issue date:	11/08/2018
From:	Matt Young NRC/RGN-I/DRP/PB6
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
References
IR 2018003
Download: ML18317A312 (16)

Text

November 8, 2018

SUBJECT:

THREE MILE ISLAND STATION, UNIT 1 - INTEGRATED INSPECTION REPORT 5000289/2018003

Dear Mr. Hanson:

On September 30, 2018, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Three Mile Island, Unit 1 (TMI). On October 19, 2019, the NRC inspectors discussed the results of this inspection with Joe Dullinger, Plant Manager and other members of your staff. The results of this inspection are documented in the enclosed report.

NRC inspectors documented one finding of very low safety significance (Green) in this report.

This finding involved a violation of NRC requirements. The NRC is treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2.a of the Enforcement Policy.

If you contest the violation or significance of the NCV, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the 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 Three Mile Island.

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 the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations (10 CFR ) Part 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Matthew Young, Chief Reactor Projects Branch 6 Division of Reactor Projects

Docket No.

50-289 License No.

DPR-50

Enclosure:

Inspection Report 05000289/2018003

Inspection Report

Docket Number:

50-289

License Number:

DPR-50

Report Number:

05000289/2018003

Licensee:

Exelon Generation Company

Facility:

Three Mile Island Station, Unit 1

Location:

Middletown, PA 17057

Inspection Dates:

July 01 through September 30, 2018

Inspectors:

Z. Hollcraft, Senior Resident Inspector

B. Lin, Resident Inspector

M. Rossi, Acting Resident Inspector

E. C. Burket, Reactor Inspector

P. Ott, Operations Engineer

R. Rolph, Health Physicist

D. Werkheiser, Senior Reactor Inspector

Approved By:

M. Young, Chief

Reactor Projects Branch 6

Division of Reactor Projects

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring Exelons performance at

Three Mile Island, Unit 1 by conducting the baseline inspections described in this report 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. NRC identified and self-revealing findings, violations, and additional items are summarized in the table below.

List of Findings and Violations

1A Emergency Diesel Generator Lube Oil Leak Inadequate Corrective Actions Cornerstone Significance Cross-Cutting Aspect Inspection Results Section Mitigating System

Green NCV 05000289/2018003-01 Closed None 71111.22 A self-revealed Green non-cited violation of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, Corrective Action, was identified for failure to develop and implement adequate corrective actions to ensure the availability and reliability of the 1A emergency diesel generator.

PLANT STATUS

Unit 1 began the inspection period at 100 percent power and operated at or near 100 percent power for the entire 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.

71111.01 - Adverse Weather Protection

Impending Severe Weather (1 Sample)

The inspectors evaluated readiness for impending adverse weather conditions for entry into the flooding abnormal operating procedure following high rain levels on July 24, 2018.

71111.04 - Equipment Alignment

Partial Walkdown (4 Samples)

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

(1) Station blackout diesel air start system on July 6, 2018.

(2) Backup station air system on July 26, 2018.

(3) Emergency feedwater system on August 22, 2018.

(4) Make-up system on August 28, 2018.

71111.05AQ - Fire Protection Annual/Quarterly

Quarterly Inspection (5 Samples)

The inspectors evaluated fire protection program implementation in the following selected areas:

(1) 322 control building 480V switchgear and battery rooms on July 2, 2018.

(2) 305 general area of the auxiliary building on July 18, 2018.

(3) 281 general area of the auxiliary building on July 18, 2018.

(4) 281 intermediate building emergency feedwater system on August 22, 2018.

(5) 338 control building switchgear and cable spreading areas on August 28, 2018.

71111.11 - Licensed Operator Requalification Program and Licensed Operator Performance

Operator Requalification (1 Sample)

The inspectors observed and evaluated a crew of licensed operators in the plants simulator during licensed operator requalification training on July 31, 2018.

Operator Performance (1 Sample)

The inspectors observed and evaluated a crew of licensed operators controlling the plant in manual during integrated control system maintenance in the control room on July 17, 2018.

===71111.11A Licensed Operator Requalification Program

Operator Requalification Exam Results (Annual)===

The inspectors reviewed and evaluated requalification examination results on March 30, 2018.

71111.12 - Maintenance Effectiveness

Routine Maintenance Effectiveness (2 Samples)

The inspectors evaluated the effectiveness of routine maintenance activities associated with the following equipment and/or safety significant functions:

(1) Auxiliary transformers maintenance program on August 29, 2018.

(2) Appendix R emergency lighting system program on September 6, 2018.

71111.13 - Maintenance Risk Assessments and Emergent Work Control

The inspectors evaluated the risk assessments for the following planned and emergent work activities:

(1) Planned maintenance on the 1B emergency diesel generator on July 12, 2018.

(2) Plant conditions associated with potential flooding during high river levels on July 24, 2018.

(3) B train auxiliary transformer automatic transfer switch failure on August 8, 2018.

(4) Control rod drive mechanism degraded power supply on August 8, 2018.

71111.15 - Operability Determinations and Functionality Assessments

The inspectors evaluated the following operability determinations and functionality assessments:

(1) Operability evaluation of A train reactor building cooling river water strainer differential pressure high reading on July 25, 2018.

(2) Operability evaluation of B train auxiliary transformer automatic transfer switch failure on August 8, 2018.

(3) Operability evaluation of B train emergency diesel lube oil leak on September 5, 2018.

(4) Operability evaluation of sheared seismic restraint on the makeup system piping on September 6, 2018.

71111.18 - Plant Modifications

The inspectors evaluated the following temporary or permanent modifications:

(1) Engineering Change Package 624824 - Secondary closed cooling valve SC-V-23 Close Travel Stop on July 24, 2018.

(2) B Aux transformer replacement circuitry and installation on September 4, 2018.

71111.19 - Post Maintenance Testing

The inspectors evaluated post maintenance testing for the following maintenance/repair activities:

(1) B train spent fuel cooling pump on July 12, 2018.

(2) Integrated control system STAR module replacement on August 2, 2018.

(3) B train emergency diesel generator exhaust manifold repair on August 14, 2018.

(4) Heat sink protection system replacement of failed diode on August 6, 2018.

(5) Control rod drive mechanism degraded power supply replacement on August 9, 2018.

(6) B train auxiliary transformer circuitry replacement on August 30, 2018.

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Routine

(1) A train emergency diesel monthly run on May 31, 2018, the inspectors inspection efforts were completed on July 16, 2018.

(2) Make up system ultrasonic void checks on July 10, 2018.

(3) Portable FLEX diesel generator on July 18, 2018.

(4) 1B EDG monthly run on July 12, 2018.

In-service (1 Sample)

(1) Valve IST of EF-V-30s and EF-V-52s on July 25, 2018.

(2) Valve IST of RR-V-5 and RR-V-6 on August 29, 2018.

71114.06 - Drill Evaluation

Drill/Training Evolution (1 Sample)

The inspectors observed an evaluated simulator training evolution for Unit 1 licensed operators on July 31, 2018.

71124.05Radiation Monitoring Instrumentation Walk Downs and Observations

The inspectors evaluated radiation monitoring instrumentation during plant walkdowns.

Calibration and Testing Program (1 Sample)

The inspectors evaluated the licensees calibration and testing program.

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below for the period from April 1, 2017, through June 30, 2018.===

(1) Unplanned power changes.

The inspectors verified licensee performance indicators submittals listed below for the period from July 1, 2017, through June 30, 2018. (6 Samples)

(1) Safety system functional failures.

(2) Emergency AC Power System Mitigating System Performance Index.

(3) High Pressure Injection System Mitigating System Performance Index.

(4) Heat Removal Systems Mitigating System Performance Index.

(5) Residual Heat Removal Systems Mitigating System Performance Index.

(6) Cooling Water Support Systems Mitigating System Performance Index.

71152 - Problem Identification and Resolution

Annual Follow-up of Selected Issues (2 Samples)

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

1) Leak at High Pressure Connection on Reactor Coolant Pump A Thermal Barrier (Issue Report 3950464).

2) Reactor Building Pre-Staging Non-Compliances (Issue Reports 4064384 and 2578255).

INSPECTION RESULTS

1A Emergency Diesel Generator Lube Oil Leak Inadequate Corrective Actions Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000289/2018003-01 Closed Not Applicable 71111.22 A self-revealed Green non-cited violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, was identified for failure to develop and implement adequate corrective actions to ensure the availability and reliability of the 1A emergency diesel generator.

Description:

On May 30, 2018, after a monthly surveillance test, it was discovered that the lube oil filter housing for the 1A emergency diesel generator (EDG) had leaked oil estimated to be in excess of the 30 drop per minute limit established by the licensee in Enclosure 3 of the, Emergency Power System Operating Procedure, 1303-4.16, Revision 144. The cause was determined to be deficient cork gasket material which undergoes relaxation and creep when placed in service. This cork gasket was installed on April 25, 2018, following routine maintenance.

On March 15, 2002, the 1A EDG experienced a leak from the lube oil filter housing, this combined with previous failures from February 2001 and July 2000 led the licensee to complete an apparent cause evaluation (ACE). It concluded that the gasket material, cork/vegetable fiber, was not appropriate for the application, and recommended discontinuing use in this application. The licensee also contacted the vendor (ARGO), and received agreement that the material was inappropriate for the application, and that the Gore-Tex or Style 330 material is compatible for the lube oil filter housing cover. The corrective action evaluated and authorized use of the replacement material (Gore-Tex or Style 330) for this application, but failed to prohibit the use of cork gaskets in the lube oil filter housing.

Corrective Action: Exelon initially declared the diesel inoperable, replaced the gasket with the approved Gore-Tex style and performed hot re-torque checks of the cover bolts. The licensee also performed an extent of condition to verify the correct gasket was installed on the 1B diesel and revised procedure, 1301-8.2, Diesel Generator Major Inspection, Mechanical, to limit usable replacement gaskets to only those comprised of Gore-Tex or Style 330 materials. Exelon performed a past operability analysis, and determined that at the oil leak rate, the oil loss would not have impacted the diesels mission time or operability and initiated an action to update their procedures.

Corrective Action Reference: 4142791

Performance Assessment:

Performance Deficiency: Exelons, Corrective Action Program Procedure, LS-AA-125, Revision 2, the procedure in effect at the time, specifies that a corrective action is action taken after a condition is identified that restores it to an acceptable condition or capability. In addition, LS-AA-125 also specifies, in part, that it is the responsibility of department managers to identify and complete corrective actions. In March of 2002, the licensee identified that cork gasket materials were not appropriate for use as a seal in the lube oil filter housing, but did not ensure corrective actions prevented the future use of cork gaskets.

Screening: This finding is more than minor because it adversely affects the Equipment Performance attribute of the Mitigating Systems cornerstone and affected the cornerstone objective to ensure the availability of systems that respond to initiating events to prevent undesirable consequences. Specifically, failure to implement adequate corrective actions resulted in a reduction of the availability of the 1A EDG due to additional required, unplanned maintenance.

Significance: The inspectors assessed the significance of the finding using IMC 0609.04, Initial Characterization of Findings, and IMC 0609, Appendix A, Exhibit 2, Mitigating Systems Screening Questions. The inspectors determined that this finding was a deficiency affecting the design or qualification of a mitigating structure, system, or component, where the structure, system, or component maintained its operability or functionality. Therefore, the inspectors determined the finding to be of very low safety significance (Green).

Cross-Cutting Aspect: No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected.

Contrary to the above, from March 15, 2002, until May 31, 2018, Exelon failed to ensure that a condition adverse to quality, inadequate gasket material was corrected. Specifically, corrective actions authorized the use of a new Gore-Tex material but failed to preclude the future use of the cork material.

Disposition: This violation is being treated as a Non-Cited Violation, consistent with Section 2.3.2 of the Enforcement Policy.

Observation 71152 Follow-up of selected issues Leak at High Pressure Connection on Reactor Coolant Pump A Thermal Barrier

The thermal barrier of the reactor coolant pump (RCP) is designed to reduce the rate of heat transfer from the reactor coolant to the pump radial bearing and heat exchanger. The thermal barrier is a pressure boundary for the reactor coolant system. In 2016, during hot pressurized walk downs following a maintenance outage, Exelon staff identified a leak of approximately 0.5 gpm originating from a weld that joined the thermal barrier to a 1.25 pipe. The pipe was formerly used for instrumentation to monitor the differential pressure (dP) across the RCP labyrinth seal. A modification in 2015 removed the instrumentation and installed a blank flange in its place.

Upon identification of the leak, the inspectors noted that the station appropriately entered Technical Specification 3.1.6.4, which requires the reactor to be shut down, and a cooldown to the cold shutdown condition be initiated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Exelon identified the location of the leak as the labyrinth seal dP high pressure tap on the A RCP. The inspectors noted that Exelon performed an extent of condition (EOC) review of the remaining five similar weld locations. Specifically, Exelon performed non-destructive examination (NDE) of the low pressure tap on the A RCP and the high and low pressure taps on the B and D RCPs to evaluate whether a similar defect existed at those locations. The C RCP was not included in the EOC since it was installed in 1999 and did not have labyrinth seal dP taps.

In accordance with their corrective action program procedures, Exelon performed a root cause analysis (RCA) of the leak. The inspectors noted that Exelon determined the most probable cause of the leak was a latent weld defect that reduced the fatigue strength of the joint.

Exelons RCA determined that the weld defect created a stress concentration that allowed vibration fatigue to propagate a flaw. The inspectors noted that the most probable cause was supported by the NDE results of the EOC welds.

Exelon implemented a corrective action to prevent recurrence by removing the susceptible welds and replacing them with a welded plug. The inspectors reviewed the work orders associated with the action to verify the repairs were performed in accordance with ASME Code design requirements. The inspectors determined that the corrective actions were reasonable to address the most probable cause of the leak.

Minor Violation

71152 Follow-up of selected issues This violation of minor significance was identified by the licensee and has been entered the licensee corrective action program and is being treated as a minor violation, consistent with the NRC Enforcement Policy.

Minor Violation: During TMIs 2015 refueling outage (T1R21) NRC and the licensee identified issues regarding reactor building pre-staging of materials were documented in NRC inspection report 05-289/2017008 (ADAMS Accession Number ML17191A697). Exelon evaluated and documented corrective actions in ACE report 2578255 which included an action to conduct an effectiveness review of those corrective actions. On October 18, 2017, after refueling outage T1R22, Exelon completed this effectiveness review. Exelon concluded that the implemented corrective actions were ineffective based on an adverse trend of licensee-identified reactor building pre-staging issues during the T1R22 refueling outage preparations. Exelon documented the results of the effectiveness review under assignment 21 of ACE 2578255 and the adverse trend in issue report 4051608. Primarily, direct oversight by Exelon staff during all phases of pre-staging, as approved by the management review committee, was not implemented and resulted in improper storage of materials in the reactor building during pre-staging activities. The improper storage was identified by Exelon during end-of-day walkdowns, from September 11 thru September 14, 2017, and documented in the corrective action program. All other corrective actions from ACE 2578255 were properly implemented.

Screening: Exelons failure to implement the approved corrective actions is a performance deficiency. The inspector evaluated the significance in accordance with IMC 0612, Appendix B, Issue Screening. The inspector determined that this issue was of minor safety significance because non-compliant material configurations in the reactor building were corrected before being left unattended at the end of shift and that the corrective actions determined by ACE 2578255, except for direct Exelon supervision during pre-staging activities, were adequately implemented.

Enforcement:

Exelon identified this violation and documented the issue in report assignments 2578255-21 and 4051608-02. Exelon has initiated actions to include direct Exelon supervision to the current pre-staging corrective actions (AR 4051608-03) and will conduct an effectiveness review of pre-staging activities after the next outage (AR 2578255-22). This failure to comply with 10 CFR Part 50 Appendix B Criterion XVI constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy.

Observation 71152 Follow-up of selected issues Reactor Building Pre-Staging Non-Compliances

With respect to review of issue reports 4064384 and 2578255, Reactor Building Pre-Staging Non-Compliances, the inspector identified a weakness in when the licensee would initiate actions to oversee reactor building pre-staging. Based on corrective actions approved under ACE 2578255, Exelon relies on the initiation of a High Impact Team (HIT) to sponsor and lead effective implementation of reactor building pre-staging. A HIT was initiated for pre-staging oversight during the most recent outage (T1R22) based on the recent, at the time (i.e., July 2017), issue of NRC inspection report 2017008 which documented violations related to previous reactor building pre-staging issues. However, based on review of outage preparation documents and discussion with outage management, the inspector noted that a reactor building pre-staging HIT is not necessarily included or initiated during pre-outage readiness. Exelon procedure OU-AA-101-1002, High Impact (HIT) and Focus Teams, Section 4.1.1, suggests key areas for HIT initiation (e.g. pre-outage) to be considered in areas of less than acceptable past performance. Exelon documented this issue in their corrective action program (issue report 4166537). This is not a finding or violation as the inspectors did not identify any instance where a HIT was not initiated for pre-staging oversight when needed.

EXIT MEETINGS AND DEBRIEFS

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

• On October 19, 2018, the inspector presented the quarterly resident inspector inspection results to Joe Dullinger, Plant Manager, and other members of the licensee staff

DOCUMENTS REVIEWED

71111.13: Maintenance Risk Assessments and Emergent Work Control

Procedure

OP-TM-108-117-1001, Three Mile Island Protected Equipment Program, Revision 4

71111.15: Operability Determinations and Functionality Assessments

Issue Report

4158200

71111.18: Plant Modifications

Miscellaneous

EC-624824, SC-V-23 Close Travel Stop, July 20, 2018

71111.19: Post-Maintenance Testing

Maintenance Order/Work Order

4773055

71111.22: Surveillance Testing

Procedures

1303-4.16, Emergency Power System Operating Procedure, Revision 144

LS-AA-125, Corrective Action Program, Revision 2

Issue Report

4142791

Maintenance Orders/Work Orders

4795498

4795771

4770722

71124.05 Radiation Monitoring Instrumentation

Procedures

1101-2.1

Radiation Monitoring System Setpoints

RP-AA-700

Controls for Radiation Protection Instrumentation

RP-AA-700-1205

Calibration of the Eberline SAC-4 Alpha Counter

RP-AA-700-1209

Calibration of the Shepherd Box Irradiators

RP-AA-700-1214

Operation and Calibration of the PCM-1B

Personnel Monitor

RP-AA-700-1235

Operation and Calibration of the PM-12 Gamma

Portal Monitor

RP-AA-700-1239

Operation and Calibration of the Model SAM-12

Small Articles Monitor

RP-AA-700-1240

Operation and Calibration of the Canberra

ARGOS-5 Personnel Contamination Monitor

RP-AA-700-1401

Operation and Calibration of Eberline Model PM-7

Personnel Contamination Monitor

RP-AA-700-1501

Operation and Calibration of the Model SAM-9/11

Small Articles Monitor

CY-TM-551-832

Post Accident Atmosphere Sampling (NRC MAPS)

N1830

Post Accident Reactor Coolant System Sampling

N1831

Post Accident Atmospheric Sampling (CATPASS)

Condition Reports

03980917

04010997

04028684

04029755

04067406

04120003

04139572

04157878

Calibration Records

04382997

RMA 8G 1302-3.1A.8

February 1, 2018

04369660

RMA 8 HI 1302-17.1B

August 6, 2017

04376805

RMA 6G 1302-3.1A.6

June 1, 2017

04383376

RMG 18

March 9, 2018

04574556

RMG 20

May 25, 2018

04373409

RMG 22

September 21,

2017

04374941

RMG 24

July 4, 2017

Portable Radiation Protection Instrument Calibrations

Instrument Model

Instrument ID

Calibration Dates

ASP-1/Ludlum Model 12-4

78787

April 21, 2017

July 23, 2018

RAS-1

283

July 31, 2017

July 23, 2018

BZA (Radeco)

2903

October 9, 2016

November 1, 2018

SAM 11

714483

April 14, 2017

April 11, 2018

SAM 12

714542

April 1, 2017

March 28, 2018

PM-7

714533

July 18, 2017

July 17, 2018

PM-12

710614

November 29, 2017

November 29,2017

PCM-1B

710927

May 11, 2017

May 8, 2018

AMS-4

710036

March 21, 2017

March 19, 2018

SAC-4

79840

May 9, 2017

May 1, 2018

Ludlum-2000

710872

January 31, 2017

January 26, 2018

ARGOS 5A/B

710078

January 9, 2018

July 24, 2018

RO-2A

078884

March 18, 2017

Scraped

RO-20

078155

March 30, 2017

January 5, 2018

Ludlum-177

20837

October 5, 2017

RO-20

076461

April 18, 2016

February 17, 2017

RSO 50E

0017335

January 9, 2017

January 24, 2018

Telepole

078421

January 12, 2017

October 23, 2017

BAK 2270

0015665

February 24, 2017

October 29, 2017

Whole Body Counter Calibration Records

Accuscan II Calibration

April 16, 2018

Fastscan Calibration

April 13, 2018

Other

TMI-18-01

Evaluation of the Necessity of

Continuous Air Monitors (CAM)

Revision 0

January 12, 2018

71151: Performance Indicator Verification

Issue Report (*IR based on NRC inspection)

4171759*

71152: Problem Identification and Resolution

Procedures

OU-AA-101-1002, High Impact (HIT) and Focus Teams, Revision 7

PI-AA-125, Corrective Action Program (CAP) Procedure, Revision 4

Issue Reports (*IR based on NRC inspection)

2578255

2608560

4051239

4050882

4051547

4051608

4052043

4060989

4064384

4166537*

Work Order

R2233355