IR 05000289/2017004

Integrated Inspection Report 05000289-2017004

ML18026A465
Person / Time
Site:	Three Mile Island
Issue date:	01/25/2018
From:	Silas Kennedy NRC Region 1
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
Shaffer S
References
IR 2017004
Download: ML18026A465 (29)

Text

{{#Wiki_filter:ary 25, 2018

SUBJECT:

THREE MILE ISLAND STATION, UNIT 1 - INTEGRATED INSPECTION REPORT 05000289/2017004

Dear Mr. Hanson:

On December 31, 2017, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Three Mile Island, Unit 1 (TMI). On January 19, 2018, the NRC inspectors discussed the results of this inspection with Mr. Tom Haaf, 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 did not involve a violation of NRC requirements.

If you disagree with the cross-cutting aspect assignment or the finding not associated with a regulatory requirement 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 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 NRCs Public Document Room in accordance with Title 10 of the Code of Federal Regulations (CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, /RA/ Silas R. Kennedy, Chief Reactor Projects Branch 6 Division of Reactor Projects Docket No. 50-289 License No. DPR-50

Enclosure:

Inspection Report 05000289/2017004 w/Attachment: Supplementary Information

REGION I== Docket No: 50-289 License No: DPR-50 Report No: 05000289/2017004 Licensee: Exelon Generation Company Facility: Three Mile Island Station, Unit 1 Location: Middletown, PA 17057 Dates: October 1 through December 31, 2017 Inspectors: Z. Hollcraft, Senior Resident Inspector B. Lin, Resident Inspector J. Furia, Senior Health Physicist J. DeBoer, Emergency Preparedness Inspector Approved by: S. Kennedy, Chief Reactor Projects Branch 6 Division of Reactor Projects Enclosure

SUMMARY

Inspection Report 05000289/2017004, 10/01/2017-12/31/2017; Three Mile Island, Unit 1,

Integrated Inspection Report.

This report covered a three-month period of inspection by resident inspectors and announced inspections performed by regional inspectors. Inspectors identified one finding of very low safety significance (Green). The significance of most findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process (SDP), dated November 15, 2016.

Cross-cutting aspects are determined using IMC 0310, Aspects Within Cross-Cutting Areas, dated December 4, 2014. All violations of Nuclear Regulatory Commission (NRC) requirements are dispositioned in accordance with the NRCs Enforcement Policy, dated November 1, 2016.

The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 6.

Cornerstone: Initiating Events

Green.

The inspectors documented a self-revealing finding involving the failure to follow LS-AA-125, Corrective Action Program, Revision 14. Specifically, the licensee failed to take appropriate corrective actions to correct degraded control rod drive mechanism cable connections identified during a 2010 stuck rod event. This resulted in a rod drop event on October 10, 2017, that caused a turbine runback to 55 percent and required a plant shutdown to repair. As an immediate corrective action, the licensee replaced the Bendix 7-pin electrical connector for the control rod drive mechanism (CRDM) and performed extent of condition visual and resistance checks on the other CRDM cables. The issue was entered into their corrective action program (CAP) as issue report (IR) 04061160.

The performance deficiency is more-than-minor because it was associated with the equipment performance attribute of the Initiating Events cornerstone and adversely affected the objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during power operations. Specifically, a transient resulting from a dropped rod challenged the critical safety function of reactivity control. The inspectors determined that this finding was of very low safety significance (Green) since it did not cause both a reactor trip and the loss of mitigation equipment relied upon to transition the plant to a stable shutdown condition.

This finding has a cross-cutting aspect in the area of Problem Identification and Resolution, Evaluation, because despite indications of degradation during inspections in 2013 and 2015, the site failed to ensure that a resolution addressed the cause commensurate with its safety significance (P.2). (Section 1R12)

REPORT DETAILS

Summary of Plant Status

Unit 1 began the inspection period shutdown in refueling outage (1R22), which started on September 18, 2017. Operators took the reactor critical on October 8 and reached 72 percent power before having to shut the reactor down to perform repairs on the control rod drive system on October 11. Following repairs, operators returned the unit to 100 percent power on October 12. The unit remained at or near 100 percent power for the remainder of the inspection period.

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

1R01 Adverse Weather Protection

.1 Readiness for Seasonal Extreme Weather Conditions

a. Inspection Scope

The inspectors performed a review of Exelons readiness for the onset of seasonal low temperatures on December 11, 2017. The review focused on borated water storage tank heat tracing and industrial coolers. The inspectors reviewed the Updated Final Safety Analysis Report (UFSAR), technical specifications, control room logs, and the CAP to determine what temperatures or other seasonal weather could challenge these systems, and to ensure Exelon personnel had adequately prepared for these challenges.

The inspectors reviewed station procedures, including Exelons seasonal weather preparation procedure and applicable operating procedures. The inspectors performed walkdowns of the selected systems to ensure station personnel identified issues that could challenge the operability of the systems during cold weather conditions.

Documents reviewed for each section of this inspection report are listed in the .

b. Findings

No findings were identified. ==1R04 Equipment Alignment

.1 Partial System Walkdowns

==

a. Inspection Scope

The inspectors performed partial walkdowns of the following systems:

• Protected system lineup on the intermediate closed cooling system on October 7, 2017
• Emergency Feedwater system following the scheduled 1R22 outage on October 20, 2017
• 2 hour backup air supply banks for the Emergency Feedwater System on December 8, 2017 The inspectors selected these systems based on their risk-significance relative to the reactor safety cornerstones at the time they were inspected. The inspectors reviewed applicable operating procedures, system diagrams, the UFSAR, technical specifications, work orders, issue reports, and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted system performance of their intended safety functions. The inspectors also performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and were operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. The inspectors also reviewed whether Exelon staff had properly identified equipment issues and entered them into the corrective action program for resolution with the appropriate significance characterization.

b. Findings

No findings were identified.

.2 Full System Walkdown

a. Inspection Scope

On October 7, the inspectors performed a complete system walkdown of accessible portions of the core flood system to verify the existing equipment lineup was correct prior to the conclusion to the 1R22 outage. The inspectors reviewed operating procedures, surveillance tests, drawings, equipment line-up check-off lists, and the UFSAR to verify the system was aligned to perform its required safety functions. The inspectors also reviewed electrical power availability, component lubrication and equipment cooling, hangar and support functionality, and operability of support systems. The inspectors performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. Additionally, the inspectors reviewed a sample of related issue reports and work orders to ensure Exelon appropriately evaluated and resolved any deficiencies. The inspectors confirmed that systems and components were aligned correctly, free from interference from temporary services or isolation boundaries, environmentally qualified, and protected from external threats. The inspectors also examined the material condition of the components for degradation and observed operating parameters of equipment to verify that there were no deficiencies. For identified degradation the inspectors confirmed the degradation was appropriately managed by the applicable aging management program.

b. Findings

No findings were identified. ==1R05 Fire Protection