ML23024A163

Replacement Steam Dryer Visual Inspection Results (U1R14)

ML23024A163
Person / Time
Site:	Browns Ferry
Issue date:	01/24/2023
From:	Sivaraman M Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML23024A163 (1)

Text

Post Office Box 2000, Decatur, Alabama 35609-2000 January 24, 2023 10 CFR 50.4 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 1 Renewed Facility Operating License No. DPR-33 NRC Docket No. 50-259

Subject:

Unit 1 Replacement Steam Dryer Visual Inspection Results (U1R14)

Enclosed is a summary of the results of the visual inspections of the Unit 1 Replacement Steam Dryer that were performed during the recent refueling outage (U1R14). The inspections are required to be performed in accordance with Operating License Condition 2.C(18)(g) during the first two scheduled refueling outages after reaching full Extended Power Uprate conditions which requires that the results of the inspection be submitted in a report within 90 days following startup. This second report for Unit 1 is being submitted pursuant to Operating License Condition 2.C(18)(h) which requires that the results of the inspection be submitted in a report within 90 days following startup.

There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact Christopher L. Vaughn, Nuclear Site Licensing Manager, at (256) 729-2636.

Respectfully, Manu Sivaraman BFN Site Vice President Ma M nu Sivaram

U.S. Nuclear Regulatory Commission Page 2 January 24, 2023

Enclosure:

Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate cc (w/ Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant

ENCLOSURE Browns Ferry Nuclear Plant Unit 1 Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate See Enclosed

Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate 

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Purpose This report provides the results of visual inspections of the Replacement Steam Dryer (RSD) as required by the Browns Ferry Unit 1 Renewed Facility Operating License No. DPR-33, License Condition 2.C.(18).(h). This license condition requires that the results of the visual inspections of the RSD be submitted to the NRC within 90 days following startup from each of the first two respective refueling outages.

Summary The Unit 1 RSD was inspected from October 3 through 15, 2022, during the Fall 2022 refueling outage (Unit 1 Refueling Outage 14: U1R14). This was the second refueling outage following installation of the RSD in October 2018 during Unit 1 Refueling Outage 12 (U1R12) and operation at Extended Power Uprate (EPU) conditions since January 2019. The inspections were performed in accordance with GE Hitachi Nuclear Energy Report No. 003N5663, Revision 2 (Tennessee Valley Authority (TVA) Browns Ferry Nuclear Station (BFNS):

Recommendations for Future Inspections - Replacement Steam Dryer). The RSD design and the materials and fabrication processes utilized are expected to result in significantly improved resistance to stress corrosion cracking. Therefore, the inspection recommendations in the GEH report focus primarily on the locations that may be susceptible to fatigue from flow-induced vibration. The locations identified are those indicated to have relatively significant cyclic loading during the dryers operation, as determined by detailed stress analyses.

Tables 1 (Frequency of Recommended Locations Based on Analysis and 2 (Description of Recommended Inspections Locations) of the GEH Report list locations that are considered the most susceptible for fatigue cracking based on BWR dryer experience and stress analysis. All accessible weld and weld heat-affected zone (HAZ) base metal surfaces of the RSD were visually inspected during U1R14, with a total scope of 646 points. The summary results of the inspections can be found in the table starting on the next page.

The following explanations apply to the table:

NRI:

No Relevant Indication RI:

Relevant Indication The parentheses after each Inspection Location refer to the number of points inspected for each.



Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate 

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Inspection Location Method Inspection

Result

Condition

Report(ifRI)

Disposition

STEAM DRYER ID Divider Plate Welds & HAZs (32)

VT-1-89 NRI Trough Side Plate to Base Plate Weld &

HAZs (6)

VT-1-89 NRI Hood Vertical / Horizontal Welds &

HAZs (12)

VT-1-89 NRI Perforated Plate to Trough Side Plate Weld & HAZs (22)

VT-1-89 NRI Trough Spacer Pin Weld & HAZs (6)

VT-1-89 NRI Skirt to Support Beam Weld & HAZs (8)

VT-1-89 NRI Guide Channel to Tee Weld & HAZs (4)

VT-1-89 NRI Skirt to Tee Weld & HAZs (12)

VT-1-89 NRI Drain Pipe to Trough Base Plate Weld &

HAZs (12)

VT-1-89 NRI Drain Pipe to Elbow Weld & HAZs (21)

VT-1-89 NRI Drain Elbow to Pipe Weld & HAZs (11)

VT-1-89 NRI Drain Elbow to Skirt Weld & HAZs (12)

VT-1-89 NRI Collar to Skirt Weld & HAZs (12)

VT-1-89 NRI Cover Plate to Hood Weld & HAZs (2)

VT-1-89 NRI Trough Base Plate to Hood Weld &

HAZs (4)

VT-1-89 NRI Hood Support Stiffener Assembly, Stiffener to Hood Support Tee Weld &

HAZs, 360-degree weld (16)

VT-1-89 NRI Hood Support Stiffener Assembly, Stiffener to Trough Weld & HAZs, 360 degree weld (16)

VT-1-89 NRI Skirt to Lower Support Ring Weld plus 2 Splice Bars & HAZs (2)

VT-1-89 NRI Skirt to Lower Support Ring Weld &

HAZs (6)

VT-1-89 NRI Splice Bar Attachment Weld and HAZs (4)

VT-1-89 NRI Trans Brace to Upper Support Ring Weld & HAZs (2)

VT-1-89 NRI Trans Brace Coupler Weld & HAZs (1)

VT-1-89 NRI Trans Brace Plate Welds & HAZs (8)

VT-1-89 NRI Trans Brace Support Welds & HAZs (12)

VT-1-89 NRI Base Plate to Upper Support Ring Weld

& HAZs (4)

VT-1-89 NRI Base Plate to Upper Support Ring/Latch Assembly Welds & HAZs (2)

VT-1-89 NRI Base Plate to Upper Support Ring/Lifting Assembly Welds & HAZs (2)

VT-1-89 NRI Cover Plate to Upper Support Ring Weld

& HAZs (2)

VT-1-89 NRI Splice Bar to Upper Support Ring and Trough Welds & HAZs (2)

VT-1-89 NRI USR Segment Weld & HAZs (4)

VT-1-89 NRI

Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate 

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Inspection Location Method Inspection

Result

Condition

Report(ifRI)

Disposition

Skirt to Upper Support Ring Weld &

HAZs (6)

VT-1-89 NRI









STEAM DRYER OD 000 Degree Pad Welds & HAZs (1)

VT-1-89 NRI Steam Dryer Outer Banks Access Panel Welds & HAZs 000 Side (6)

VT-1-89 NRI Steam Dryer Outer Banks Access Panel Welds & HAZs 180 Side (6)

VT-1-89 NRI Both Sides of the Bank to Divider Plate Weld & HAZs (16)

VT-1-89 NRI Both Sides of the Bank to Exhaust Plenum Plate Vertical Weld & HAZs (20)

VT-1-89 NRI Hood to Cover Plate Horizontal Weld &

HAZs (2)

VT-1-89 NRI Hood to Top Cap Horizontal Weld &

HAZs (6)

VT-1-89 NRI Perforated Plate to Bank Top Cap Weld

& HAZs (6)

VT-1-89 NRI Perforated Plate to Trough Side Plate Weld & HAZs (6)

VT-1-89 NRI Trough Side Plate to Base Plate Weld

& HAZs (6)

VT-1-89 NRI Both Sides of the Hood Support to Trough Weld & HAZs (16)

VT-1-89 NRI Perforated Plate to End Plate Weld &

HAZs (4)

VT-1-89 NRI Perforated Plate to Perforated Plate Weld & HAZs (16)

VT-1-89 NRI Perforated Plate to End Plate Weld &

HAZs from Trough Base Plate to Hood Cap (8)

VT-1-89 NRI Trough Spacer Pin Weld & HAZs (6)

VT-1-89 NRI Bank Tie Rod Bolting Welds & HAZs for all 6 locations on the 000 Deg Side (6)

VT-1-89 NRI Bank Tie Rod Bolting Welds & HAZs for all 6 locations on the 180 Deg Side (6)

VT-1-89 NRI Hood to Trough Base Plate Horizontal Weld & HAZs (4)

VT-1-89 NRI Both Sides of the Divider Plate to Inner Plate Welds & HAZs (6)

VT-1-89 NRI Drain Channel to Upper Support Ring Horizontal Weld & HAZs (4)

VT-1-89 NRI Drain Channel to Support Beam Weld &

HAZs (8)

VT-1-89 NRI Drain Channel to Support Ring Tab Welds & HAZs (20)

VT-1-89 NRI Guide Channel to Drain Channel Tee Vertical Weld & HAZs (4)

VT-1-89 NRI

Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate 

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Inspection Location Method Inspection

Result

Condition

Report(ifRI)

Disposition

Drain Channel to Drain Channel Tee Vertical Weld & HAZs (8)

VT-1-89 NRI Skirt to Drain Channel Tee Vertical Weld

& HAZs (4)

VT-1-89 NRI Doubler Plate to Upper Support Ring &

HAZs (8)

VT-1-89 NRI General Overview of the Side Surfaces (4)

VT-1-89 NRI General Overview of the Top Surfaces (1)

VT-1-89 NRI Hood to Inlet End Plate Vertical Weld &

HAZs (18)

VT-1-89 NRI Both Hood to Hood Tee Vertical Welds

& HAZs (4)

VT-1-89 NRI Hood to Hood Tee Vertical Weld &

HAZs (18)

VT-1-89 NRI Both Sides of the Hold Down Assembly to Exhaust Plenum Plate Vertical Weld

& HAZs (4)

VT-1-89 NRI Hold Down Assembly to Trough Base Plate Horizontal Weld & HAZs (2)

VT-1-89 NRI Lifting Assembly - Support Ring Anchor Weld & HAZs (4)

VT-1-89 NRI Lifting Assembly - Bolting (4)

VT-1-89 NRI Lifting Assembly - Lower Bracket and Welds Plus HAZs (4)

VT-1-89 NRI Lifting Assembly - Middle Bracket and Welds Plus HAZs (4)

VT-1-89 NRI Lifting Assembly - Rod to Anchor Weld

& HAZs (4)

VT-1-89 NRI Lifting Assembly - Upper Bracket and Welds Plus HAZs (4)

VT-1-89 NRI Latch Box General Condition for Evidence of Handling Damage (2)

VT-1-89 NRI Lower Guide Channel General Condition for Evidence of Handling Damage (2)

VT-1-89 RI 1810040 Accepted as-is Lower Support Ring to Guide Channel Horizontal Weld & HAZs (2)

VT-1-89 NRI Lower Support Ring to Skirt Horizontal Weld & HAZs (6)

VT-1-89 NRI Lower Support Ring Splice Bar General Condition for Evidence of Handling Damage (2)

VT-1-89 NRI Splice Bar Attachment Weld & HAZs (8)

VT-1-89 NRI Seismic Lug General Condition for Evidence of Handling Damage, also Associated Bolting, Welds & HAZs (2)

VT-1-89 RI 1808890 Accepted as-is Bank Tie Bar Welds & HAZs (34)

VT-1-89 NRI Trough Base Plate Center Horizontal Weld & HAZs (1)

VT-1-89 NRI

Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate 

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Inspection Location Method Inspection

Result

Condition

Report(ifRI)

Disposition

Top Flange to C-Channel to Hood Cover Weld & HAZs (2)

VT-1-89 NRI Upper Support Ring Horizontal Weld &

HAZs (26)

VT-1-89 NRI Upper Support Ring Tapered Pin Seal Weld & HAZs (8)

VT-1-89 NRI Upper Support Ring to Splice Bar Vertical Weld & HAZs (4)

VT-1-89 NRI Upper Support Ring to Guide Channel Horizontal Weld & HAZs (2)

VT-1-89 NRI Upper Support Ring to Skirt Horizontal Weld & HAZs (2)

VT-1-89 NRI Inspection Results Relevant indications were noted and evaluated at two locations during inspections performed in U1R14. They are described as follows:

(1) BFN1-SD OD LGC General 000: Examinations revealed indications described as wear and rolled metal on the 0° RSD Guide Channel inside surfaces on the 270° side of the channel. The indications reported appear to be the result of mechanical damage incurred by removal and reinstallation of the RSD.

(2) BFN1-SD OD Seismic Lug 005 and BFN1-SD OD Seismic Lug 185: Two of the four seismic blocks showed indications of wear during their initial inspection in Unit 1 Refueling Outage 13 (U1R13). These locations were reexamined during U1R14. The previously reported indications showed no change in U1R14 and are described as wear at the contact point of the Steam Dryer Support Lug for the Steam Dryer Seismic Block at 5°, and wear observed on the contact surface and leading edge of the Steam Dryer Seismic Block at 185°. There were two new indications reported on the lower edge of the 185° seismic block lead-ins that saddle the Dryer Support Bracket during installation and normal operations. These new indications were described as rolled metal on the left side of the seismic block and a gouge on the right side. All these indications appear to be the result of mechanical damage incurred by removal and reinstallation of the Replacement Steam Dryer (RSD).

Disposition of Indications Condition Reports (CRs) were initiated to document and disposition the relevant indications reported on the RSD. The dispositions are as follows:

(1) BFN1-SD OD LGC General 000: The main purpose of the guide channel is to encompass the Guide Rod in the Reactor Pressure Vessel and direct the Steam Dryer to and from its installed position during refueling operations. The indications reported appear to be the result of mechanical damage incurred by removal and reinstallation of the RSD and are not expected in any way to interfere with the ability of the Lower Guide Channel to perform its required function.

Browns Ferry Unit 1 Replacement Steam Dryer (RSD) Inspection Results from the Second Refueling Outage (U1R14) Following Installation of RSD and Implementation of Extended Power Uprate 

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Therefore, an Engineering Evaluation was prepared which concluded that these indications have no bearing on the structural integrity of the Lower Guide Channel at 000 and are acceptable as-is with no repair required.

(2) BFN1-SD OD Seismic Lug 005 and BFN1-SD OD Seismic Lug 185: The main purpose of the Steam Dryer Seismic Blocks is to transfer the lateral load from the RSD to the RPV support brackets. The indications that were observed on the Steam Dryer Seismic Blocks at 5 degrees and 185 degrees appeared to be the result of mechanical damage incurred by the removal and reinstallation of the RSD and are not expected in any way to interfere with the ability of the seismic blocks to perform their required function to transfer the lateral load from the RSD to the RPV support brackets. Therefore, an Engineering Evaluation was prepared which concluded that these indications have no bearing on the structural integrity of the seismic blocks and are acceptable as-is with no repair required.

Conclusion A completed second baseline inspection of the Browns Ferry Unit 1 Replacement Steam Dryer (RSD) was performed during the Fall 2022 Refueling Outage 14. This re-baseline inspection included successful visual inspection of all RSD locations required by the Facility Operating License Condition 2.C.(18).(h). All observations were acceptable for the locations inspected.

There were two inspection areas with relevant indications that were adequately dispositioned.

Since two baseline inspections of the RSD have now been completed, future inspections will be performed in accordance with the guidelines specified in GE Hitachi Nuclear Energy Report No.

007N4785, Revision 0 (Tennessee Valley Authority (TVA) Browns Ferry Nuclear Station (BFNS): Recommendations for Future Inspections - Replacement Steam Dryer).