IR 05000341/2020010

Confirmatory Action Letter Followup Inspection Report 05000341/2020010 and Closure

ML20310A133
Person / Time
Site:	Fermi
Issue date:	11/05/2020
From:	Jack Giessner NRC/RGN-III
To:	Peter Dietrich DTE Electric Company
References
EA-19-097 IR 2020010
Download: ML20310A133 (15)

Text

November 5, 2020

SUBJECT:

FERMI 2 POWER PLANT - CONFIRMATORY ACTION LETTER FOLLOWUP INSPECTION REPORT 05000341/2020010 AND CLOSURE

Dear Mr. Dietrich:

On September 25, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Fermi 2 Power Plant and discussed the results of this inspection with Mr. E. Olson, Site Vice President and other members of your staff. The results of this inspection are documented in the enclosed report.

No NRC-identified or self-revealing findings were identified during this inspection.

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 a non-cited violation (NCV)

consistent with Section 2.3.2 of the Enforcement Policy.

If you contest the violation or the significance or severity of the violation 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 III; the Director, Office of Enforcement; and the NRC Resident Inspector at Fermi 2 Power Plant. 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/

John B. Giessner, Regional Administrator Docket No. 05000341 License No. NPF-43

Enclosure:

As stated

Inspection Report

Docket Number: 05000341 License Number: NPF-43 Report Number: 05000341/2020010 Enterprise Identifier: I-2020-010-0060 Licensee: DTE Electric Company Facility: Fermi 2 Power Plant Location: Newport, MI Inspection Dates: March 15, 2020 to September 25, 2020 Inspectors: M. Holmberg, Senior Reactor Inspector M. Jones, Reactor Inspector J. Park, Reactor Inspector T. Taylor, Resident Inspector Approved By: Karla K. Stoedter, Chief Engineering Branch 2 Division of Reactor Safety Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a confirmatory action letter followup inspection at Fermi 2 Power Plant, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information. A licensee-identified non-cited violation is documented in report section: 9270

List of Findings and Violations

No findings or violations of more than minor significance were identified.

Additional Tracking Items

Type Issue Number Title Report Section Status CAL EA-19-097 Commitment to Address 92702 Closed Degraded Torus Coatings

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), regional inspectors were directed to begin telework. Regional based inspections were evaluated to determine if all or a portion of the objectives and requirements stated in the IP could be performed remotely. For the inspection documented below portions of the IP were completed remotely as well as on site and all the objectives and requirements for completion of the IP were met.

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 92702 - Followup on Traditional Enforcement Actions Including Violations, Deviations, Confirmatory Action Letters, Confirmatory Orders, And Alternative Dispute Resolution Confirmatory Orders During an NRC design basis assurance inspection (DBAI) performed in May 2019, the inspection team identified concerns regarding the condition of coatings located in the submerged portion of the torus. These concerns were discussed in NRC Inspection Report 05000341/2019012 dated July 29, 2019 (ADAMS Accession No. ML19211B289). The NRC evaluated the torus coating information gathered as part of the DBAI and concluded a special inspection was needed to fully evaluate the torus coating condition and the potential impact the coating could pose to the operation of equipment following a design basis accident. The results of the special inspection are documented in NRC Inspection Report 05000341/2019050 dated January 31, 2020 (ML20031D253).

On September 26, 2019, the licensee submitted a letter to the NRC documenting their commitment to remove and replace the degraded coating in the submerged portion of the torus during the 2020 refueling outage (ML19270E090). The NRC formally documented the licensees commitment in a Confirmatory Action Letter dated October 4, 2019 (ML19280D881).

The licensee notified the NRC of the need to revise their commitment and provided information supporting the commitment revision via letters dated March 13, 2020 and June 19, 2020 (ML20073N414 and ML20171A600, respectively). The NRC independently reviewed this information and revised the Confirmatory Action Letter on March 27, 2020 (ML20087L769) and June 24, 2020 (ML20177A383). The revised commitment, which was the subject of this inspection, read as follows:

• DTE commits to mitigate the degraded coating in the submerged portion of the torus by removing all coating (i.e., to the extent possible) in the submerged portion of the torus and applying a qualified coating capable of withstanding design basis accident conditions. Removal of coating and application of qualified coating will also be performed for torus internals in the submerged portion of the torus with the exception of the internal surfaces of the downcomers and the internal surfaces of process piping.

The internal surfaces of the submerged portion of the downcomers and the coated internal surfaces of the submerged portion of process piping will be inspected and degraded coating, if any, will be removed during the next refueling outage. Torus internals that do not require protective coating to perform their intended function may be left uncoated. Following completion of these activities, unqualified coatings in the submerged portion of the torus will be explicitly addressed for potential impact on ECCS

[emergency core cooling system] strainers in the same manner as other unqualified coatings in primary containment. This DTE commitment will be completed prior to resuming power operation following the next refueling outage. The next refueling outage will begin no later than April 30, 2020.

On July 6, 2020, DTE notified the NRC that the actions needed to satisfy the Confirmatory Action Letter commitment were complete (ML20188A299). Activities completed by DTE included:

• All coating was removed from the torus shell and torus internal components to the extent possible below an elevation of approximately 5582, with the exception of torus downcomer internal surfaces. This elevation is approximately one foot above the normal water level in the torus and includes the Technical Specification (TS) allowable water level range of 557+/-2.

• The coating on the internal surfaces of all 80 downcomers was inspected beginning from the bottom up to a few inches above the torus water level. No blistered coating was identified. A few small areas of mechanical damage and corrosion were identified in several of the downcomers. These minor coating defects were removed as needed.

• A review to verify the presence of internally coated process piping in the torus was completed. Design information associated with process piping in the submerged portion of the torus, and supplemental inspections during RF20, identified no process piping (other than the downcomers) that was internally coated.

• The application of a new, design basis accident (DBA) qualified coating up to the elevation of approximately 5582 was completed. The new coating was applied to the surfaces in this region except for the downcomer internal surfaces and those which were determined to not require a protective coating to perform their intended function, such as stainless steel surfaces.

• A review to document and quantify unqualified coating resulting from the above activities was completed. The quantity of unqualified coating, although small, was added to the unqualified coatings log for evaluation against available margin in ECCS strainer debris loading calculations in the same manner as other unqualified coatings in primary containment.

The inspectors determined the CAL commitment activities reviewed were adequately completed and effective in mitigating the degraded torus coatings. As a result, the Confirmatory Action Letter commitment is closed.

INSPECTION RESULTS

Assessment 92702 From March 15 to September 25, 2020, the inspectors reviewed, observed and evaluated actions taken by the licensee, as discussed above, to mitigate the degraded torus coating and apply a safety-related coating qualified to withstand design basis accident conditions.

Specifically, the inspectors reviewed:

• Work documents and quality assurance/control activities and records associated with the removal of coating and the application of qualified coating on the torus shell and torus internals (with the exception of the downcomer surfaces) in the submerged portion of the torus. The inspectors also confirmed all coating was removed from the torus shell and torus internal components to the extent possible below an elevation of approximately 5582.

• Inspection activities associated with assessing the condition of coating located on the internal surfaces of the submerged portion of the downcomers and the internal surfaces of submerged process piping. The inspectors confirmed the licensee assessed any notable indications and remediated degradation as necessary. The inspectors also reviewed a sample of the inspection records confirming the coating on the internal surfaces of all 80 downcomers was inspected from the bottom up to a few inches above the torus water level. The inspectors verified no blistered coating was identified as indicated by the licensee.

• Design information associated with process piping in the submerged portion of the torus, and supplemental inspections during RF20, to verify no process piping (other than the downcomers) was internally coated.

• Records documenting torus internals not requiring protective coating to perform their intended function were left uncoated. Specific items left uncoated included submerged stainless steel internal components the licensee had previously identified as coated. The inspectors agreed with the licensee's determination that these components did not require a protective coating to perform their intended function.

• Documents addressing unqualified coatings in the submerged portion of the torus.

The inspectors reviewed and sampled the licensees unqualified coatings log and ECCS strainer margin calculation to confirm the amount of unqualified coating remained within the calculation assumptions.

• Problem identification and resolution activities associated with the coating inspection, removal and application activities.

The inspectors also performed on-site activities which included:

• Verification of coatings removal;

• Verification of surface preparation prior to performing the torus recoat; and

• Verification that recoat and repair activities were complete.

While performing a daily review of corrective action documents, the inspectors noted condition reports documenting potentially failed coatings in the vent header. These failed coatings were found during the licensees review of downcomer inspection video. Following these discoveries, the licensee performed a vent header inspection concentrating on the areas where the vent header comes down from the drywell and meets the vent header ring in the torus since water has collected in this area in the past. The inspectors reviewed the circumstances surrounding the discovery of the failed vent header coating to determine any prior opportunities to identify this condition and weaknesses which could have led to this condition going unrecognized.

On August 8, 1982, during plant construction, the licensee documented Design Change No. 6816, "Vent Header Drain in Torus T23-03," Revisions A and B. The purpose of this design change was "to facilitate installation of the vent line bay vent header deflectors."

Specifically, Revision A supported a document change which added pipe caps to the vent header drain lines to maintain the pressure boundary provided in CB&I Drawing 210, Revision 1. Revision B was performed to facilitate installation of the vent header drain line caps.

On April 6, 2003, during refueling outage (RF) 09, the licensee generated condition assessment resolution document (CARD) 03-14450, "Water Accumulation in Torus Downcomers to Vent Header Tee Connections," which indicated, "during inspections it was discovered [the] 8 tee locations were [found] full of water up to the bottom of the vent header." The licensee documented the source of water to be routine outage-related system draining which was routed through the downcomers. The licensee took action to evaluate the condition prior to returning to power operation. These actions included addressing the practice of draining systems into the torus and determining the effect of the water on the Mark I containment hydrodynamic loads. Engineering Functional Analysis (EFA)

T23 -03-006, performed by the licensee shortly after discovering the accumulated water, included information from a General Electric (GE) evaluation titled "Hydrodynamic Loads for Excess Water in the Drywell Vents at Fermi 2 - draft," dated April 23, 2003. The licensees EFA concluded the containment components remained structurally acceptable, and operable, after applying limiting level C Service Limits to the components and factoring in the additional load caused by the standing water present in the vent pipe to vent header intersections. The inspectors noted that neither the licensee, nor GE, identified the potential for the standing water to lead to vent header coating degradation.

On May 2, 2003, GE provided a final report to the licensee titled "Hydrodynamic Loads for Excess Water in the Drywell Vents at Fermi 2 - Final." This report concluded, "...the vent system thrust and pressurization loading is the only hydrodynamic load that is potentially affected by the standing water in the vent header system. No other containment hydrodynamic loads are affected by the standing water in the vent header system." The final report did not contain information regarding potential impacts on the vent header coating.

On June 4, 2003, GE issued 10 CFR Part 21 Communication, SC03-10, Transfer of Information [21.21(b)], Subject: "Impact of Water Accumulation on Containment Vent Thrust Loads." The purpose of this communication was to inform plants with Mark 1 containments that the torus vent header/ring header configuration could result in the significant accumulation of water and potentially impact plant safety due to the additional forces exerted by the water. The inspectors noted the 10 CFR Part 21 reported the accumulation of water in the vent header area had been identified at two facilities including Fermi 2.

On June 24, 2003, the NRC issued Information Notice (IN) 2003-07, "Water in the Vent Header/Vent Line Spherical Junctions" (ML031750146). The purpose of this IN was to inform all holders of operating licenses for boiling water reactors with Mark 1 containments of the unanticipated condition of standing water in the vent header/vent line (VH/VL) which had been identified at several nuclear facilities. The IN noted the standing water in the VH/VL was not included in the generic Mark 1 containment accident analysis because the spherical junctions were assumed to remain dry. The primary concern was that standing water increased the vent system thrust loads experienced during the reactor blowdown phase of a loss-of-coolant accident inside containment beyond design limits. The inspectors noted no mention of potential coating issues from the standing water within the IN.

On October 17, 2019 (RF19), the licensee performed work order (WO) 47505344, Perform 43.000.019 Inside/Outside Torus & Drywell Inspection, which implemented Procedure 43.000.019, Revision 9. The licensee used Procedure 43.000.019 to perform visual examinations of the vent header/vent line general condition every 10 years and to detect evidence of degradation that may affect structural integrity or leak tightness. The inspectors reviewed the completed WO and found the licensee had documented sporadic areas with minor loss of coatings in each of the sixteen

(16) ring header segments as provided in Procedure 43.000.019, Attachment 1, "Coating Examination Data Sheet." Within Procedure 43.000.019, Attachment 2, Surface Area Examination Data Sheet, the licensee noted light rust in the areas of loss." The licensee evaluated these conditions, concluded the areas were "typical in nature and did not give any appearance of wall loss," and "recommended future coatings repairs." The inspectors found that while these issues were documented in the corrective action system for trending and repair as CARD 18-28240, no further assessment of the submerged coatings in the vent header were documented.

During Refueling Outage 20, Fermi-2 initiated the following corrective action documents:

• CARD 20-27443 - Torus Vent Header Inspection

• CARD 20-27585 - Indication Found During Torus Vent Header Inspection

• CARD 20-27792 - RF20 Torus Vent Header Lower Interior Coating (below scum line)

Failed Knife Testing

• CARD 20-27961 - Unanticipated Condition of Torus Ring Header

• CARD 20-27970 - Extensive Pitting in Torus Vent Header Intersection Assemblies 2, 6, 10, and 16 The inspectors determined that due to the licensee's torus recoat effort, the VH/VL were in a dry condition which allowed for the discovery of significant coating degradation below the VH/VL water line and extensive pitting in the torus vent header assemblies. The licensee performed an extensive evaluation of the condition and discovered approximately 170 pounds of degraded coating material that required removal prior to plant restart. The licensee evaluated the potential for the VH/VL degraded coatings and the previously identified torus coatings to clog ECCS pump suction strainers. The licensee determined the coating and debris present in the torus and the vent header did not impact the ability of ECCS systems to perform their safety function prior to entry into RF20. Additionally, following discovery of extensive pitting in the vent header intersection assemblies, the licensee evaluated and repaired several areas that did not meet minimum wall thickness requirements. The licensee evaluated the pitting and determined that no impact to operability occurred prior to entering RF20.

The inspectors toured the VH/VL area to verify the degraded coatings were removed and the remaining coating did not pose a threat to the continued operability of the ECCS systems.

The inspectors also reviewed the licensees vent header intersection examination results and the repair plans and had no concerns. The licensee missed opportunities to previously identify the degraded VH/VL coatings due to deficiencies in Procedure 43.000.019, Revision 9 which was issued on March 21, 2018. Specifically, the procedure contained an enclosure (Enclosure B) which provided special instructions for visual inspections. However, there were no steps in Procedure 43.000.019 which specified when Enclosure B was to be used. Procedure 43.000.019, Enclosure B, Step 3.1.8.5, directed special emphasis be placed on the accessible surfaces of areas in the vent header and vent lines that could accumulate water, but no acceptance criteria existed to determine the continued acceptability of these areas. This issue is dispositioned in the licensee identified violation section of this report.

Licensee-Identified Non-Cited Violation 92702 This violation of very low safety significance was identified by the licensee, entered into the 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 of the Code of Federal Regulations (CFR), Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires, in part, that activities affecting quality be prescribed by documented procedures of a type appropriate to the circumstances and be accomplished in accordance with these procedures.

Contrary to the above, since March 21, 2018, the licensee did not have procedures appropriate to the circumstance for inspecting and assessing the condition of vent header coating (an activity affecting quality). Specifically, Procedure 43.000.019, Revision 9, did not provide instructions to direct when Enclosure B, "Special Instructions for Visual Inspections, was to be used. In addition, Step 3.1.8.5 of Enclosure B directed that special emphasis be placed on the accessible surfaces of areas in the vent header and vent lines that could accumulate water, but no acceptance criteria existed to determine the continued acceptability of these areas. As a result, approximately 170 pounds of degraded coating was not identified or evaluated for acceptability during previous inspections of the vent header areas.

Significance/Severity: Green. The finding was evaluated using the Significance Determination Process in accordance with Inspection Manual Chapter 0609 Appendix A, The Significance Determination Process for Findings At-Power, using Exhibit 2, Mitigating Systems Screening Questions. The finding screened as having very low safety significance (Green) because it did not result in the loss of operability or functionality of the ECCS systems taking suction from the suppression pool. Specifically, the licensee reasonably determined that ECCS net positive suction head margin remained greater than 15 percent assuming the degraded vent header material was able to transport to the strainers.

Corrective Action References:

• CARD 20-27443, Torus Vent Header Inspection

• CARD 20-27585, Indication Found During Torus Vent Header Inspection

• CARD 20-27792, RF20 - Torus Vent Header lower interior coating (below scum line)failed knife testing

• CARD 20-27961, Unanticipated Condition of Torus Ring Header

• CARD 20-27970, Extensive Pitting in Torus Vent Header Intersection Assemblies 2, 6, 10, and

EXIT MEETINGS AND DEBRIEFS

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

• On September 25, 2020, the inspectors presented the confirmatory action letter followup inspection results to Mr. E. Olson, Site Vice President and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

2702 Calculations DC-5979 Estimation of Debris Sources for ECCS Suction Strainers A

DC-6213 Evaluation of Standing Water in the Vent Pipe to Vent Header 0

Intersections

Corrective Action 18-28240 Light Surface Rust Noted Throughout the Interior of the Ring 10/13/2018

Documents Header

19-24218 2019 DBAI: NRC Concern Blistered Torus Coating 06/03/2019

20-22581 Torus Recoat - DBA Testing of New Torus Coating Not 03/09/2020

Performed As Specified

20-26804 Torus Coating Issues 06/12/2020

20-26848 Torus Project - Two Temporary Thermocouples for the 06/18/2020

Forced Cure Reading Lower than Expected

20-26999 Torus Recoat - Update to Unqualified Coatings Log 06/18/2020

20-27008 Error in Density Calculation in DC-2887 for Plasite 7155 06/18/2020

20-27014 Torus Amine Blush Inspection 02/23/2020

20-27164 Torus Project - Coating Thickness Readings Post Forced 06/23/2020

Cure Show One DFT Reading Below Specification

20-27225 Use of Carboguard 6250N Prior to Build Up Test Results 06/23/2020

20-27225 Use of Carboguard 6250N Prior to Build Up Test Results 06/23/2020

20-27285 Post Torus Painting Touch Up Required 06/25/2020

20-27443 Torus Vent Header Inspection 06/29/2020

20-27457 NQA- RF20- UESI QC Hold Point Performed by UESI 06/29/2020

Inspector Prior to Certification Being Accepted by DTE NQA

20-27530 NQA- RF20- Discrepancies Identified While Reviewing Torus 07/01/2020

UESI Coating Surface Preparation

20-27572 Indications Found During Torus Cleaning Activities 07/02/2020

20-27578 Unexpected Material Found During Vent Header Cleanup 07/03/2020

20-27735 Debris-Crud Discovered in Torus After Fill 07/07/2020

20-27792 RF20 - Torus Vent Header Lower Interior Coating (Below 07/08/2020

Scum Line) Failed Knife Testing

20-27961 Unanticipated Condition of Torus Ring Header 07/10/2020

20-27970 Extensive Pitting in Torus Vent Header Intersection 07/10/2020

Inspection Type Designation Description or Title Revision or

Procedure Date

Assemblies 2, 6, 10, and 16

20-28293 NQA 0 RF20 - Unsatisfactory Visual Inspection on 07/16/2020

Excavation/Ground Surfaces Prior to Welding in Bay 10 of

Torus Vent Header

20-28401 Damaged Coatings External to Vent Header in Areas of 07/19/2020

Welds

20-28674 Vent Line Inspection Results WO 57851037 07/27/2020

Corrective Action 20-26620 NRC Identified - Arc Strike Outboard Ring Girder 14/15 06/06/2020

Documents 20-26629 NRC Identified - Indication on Torus Shell Bay #6 06/07/2020

Resulting from 20-27611 NRC Walkdown - Torus Vapor Space Foreign Material 07/04/2020

Inspection Concerns

20-27612 NRC Walkdown - Torus Vapor Space Coating Concerns 07/04/2020

20-27613 NRC Walkdown - Torus Vapor Space Bay 2 Shell Coating 07/04/2020

Concerns

20-27614 NRC Walkdown - Torus Immersion Space Foreign Material 07/04/2020

Concerns

20-27615 NRC Walkdown - Torus Immersion Space Coating Questions 07/04/2020

Engineering 80131 Torus Coating Modification 07/06/2020

Evaluations EFA-T23-20-002 Evaluation of Vent Header RF-20 As-Left Condition on Torus 07/26/2020

Systems

NUC2020124 Coating Adhesion Test Report 05/18/2020

TE-T23-20-008 Unqualified Coating Log A

Miscellaneous QA Record Master Log - SP 10 Surface Profiles - Torus Bays 05/30/2020

Torus Recoat Amine Blush Plan 1

Film Build Test Plan 05/19/2020

Procedures QCP-9-3-0-6250N Coating Application, Inspection, Repair and Curing of 0

Carboguard 6250N

Work Orders 31843129 Perform 43.000.019 Inside Torus/Inside Drywell/Outside DW 04/23/2012

(Offline) Inspection

31843129 Perform 43.000.19 Inside Torus/Inside Drywell/Outside DW 04/25/2012

(Offline) Inspection

47505344 Perform 43.000.019 Inside/Outside Torus & Drywell 09/24/2018

Inspection

Inspection Type Designation Description or Title Revision or

Procedure Date

55151575 Torus - Torus Recoat

56727429 TORUS - Forced Cure (EDP 80131) 03/25/2020

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