ML061110072

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License Presentation Materials from Meeting with FPL Regarding SG Inspection at St. Lucie
ML061110072
Person / Time
Site: Saint Lucie  NextEra Energy icon.png
Issue date: 04/20/2006
From:
Florida Power & Light Co
To:
Office of Nuclear Reactor Regulation
References
Download: ML061110072 (10)
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FLORIDA POWER & LIGHT ST. LUCIE UNIT 2 STEAM GENERATOR INSPECTION PLANNING FOR SL2-16, APRIL 2006 St Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 AGENDA

. Purpose of Meeting

. Background & S/G Condition

  • SL2-16 Inspection Scope

. Projected Tube Plugging

  • Operating Experience
  • Contingency Planning

. Summary & Closing 2

FPL 1

V St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Purpose of Meeting

  • Review SL2 S/G Condition
  • Review SL2-15 Inspection Planning
  • Address Staff Concerns St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & S/G Condition
  • SIG Design
  • cEModel 3410
  • 84l1 Tubes I SG
  • A-600 HTMA Tubing
  • CS Lattice Support System (eggcrates)
  • Tubesheet Joint - Explosive
  • Total Tubes Plugged

- SG A - 1469 (17.5%)

- SG B - 1709 (20.3%)

  • T-Hot -600OF FPL ./

2

r St Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & S/G Condition FPL Steam Generator Program

  • Committed to Safe Operation
  • Full Implementation of NEI 97-06, S/G Program Guidelines

' Inspection

' Chemistry Leak Monitoring

  • Incorporate Industry Experience
  • Extensive Examination History at Unit 2 XConservative Approach

&In Situ Pressure Test at Last 6 Inspections ,,- - -

FP 5 FPLop St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & S/G Condition

  • Last Inspection - SL2-15 in January 2005 a Results Discussed with NRR During Outage

' Damage Mechanisms Generally as Expected 1Tube Ding with ODSCC Limited PWSCC in Tubesheet (3in Upper 2", 1 at Tack Roll)

'Increase in Axial ODSCC at Eggcrate Supports

'RCL Indications Detected During Pull Out Scans

'Addressed in OA Model

'Tested with Qualified Technique if > .35 Volts

'No Tube Integrity Issues. A FPL 3

V St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Indication Count Summary for SL2-15 Mechanism SIG A SIG B Total Axial ODSCC at Eggcrate Supports 1184 1266 2450 Axial ODSCC at Diagonal Supports 1 8 9 Axial ODSCC at Tube Dings 0 1 1 Axial ODSCC in Freespans 0 1 1 Axial ODSCC at Top of HL Tubesheet 14 2 16 Axial IDSCC Below Top of HL Tubesheet 1 1 2 Circ. ODSCC at Top of HL Tubesheet 7 10 17 Circ. IDSCC at Top of HL Tubesheet 0 1 1 Circ. IDSCC at HL Tube End 0 1 1 Wear Due to Foreign Objects 1 1 2 Wear at Diagonal & Vertical Supports 672 443 1115 Wear at Eggcrate Tube Supports 67 73 140 FPL St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & S/G Condition TUBE PLUGGING HISTORY Damaae Mechanism (1) 4100 11101 4103 1105 OD Cracks at Tube Supports 14 259 482 1592 Mech. Wear at Tube Supports 18 11 1 OD Cracks at Tubesheet 17 20 27 20 Preservice, FO, Preventative 51 6 2 Circ. OD Cracks at Tubesheet 5 13 10 15 OD Volumetric - Various 2 ID Cracks in Tubesheet 4 3 OD Cracks at Dings 5 1 OD Cracks in Freespan _ 1 1 54 361 530 1635 Cumulative Plugging 652 1013 1543 3178 ,

Cumulative Percent 3.9% 6.0% 9.2% -1B.9%:..

'I (1) Axial unless noted otherwise a_ '8 ot-FPL 4

V St Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & SIG Condition Benchmark of Predicted (best estimate) vs. Observed Indications Mechanism Case Predicted Observed Axial ODSCC at Eggcrates Worst SG 928 1217 Axial ODSCC at Tube Dings All SGs 2 1 Axial ODSCC at Transition All SGs 43 16 Axial IDSCC below Transition All SGs 15 2 Circ. ODSCC at Transition All SGs 25 17 FPL St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & SIG Condition Probability of Burst (POB)

Mechanism SG A SIG B ODSCC' at E c029crats 0.0777 ODSCC at D)ings 0.00(Y O)SCC at Topofa-Tubcshect -0 Cumulatisv P0I3 0.0356

  • Significant Axial Degradation Mechanisms
  • Cycle 15 Length for 10% POB Criterion - 17.4 EFPM
  • Cycle 15 Length for 5% POB Criterion - 16.2 EFPM _ o
  • Planned Cycle 15 Length is -14.5 EFPM ,

FPLI S

-i St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Background & S/G Condition In Situ Pressure Testing SL2-9 Through SL2-15

  • 73 Total Indications (19 at SL2-15)
  • Mechanisms Include Axial ODSCC at Eggcrates Axial ODSCC at Dings

'LAxial ODSCC at TTS

' Axial IDSCC below TTS Circ ODSCC at TTS

' Circ IDSCC at TTS OD Volumetric TTS

  • No Leakage or Burst 5 .- - Bl y . ". . .
  • 11 FPL St. Lucie Unit 2- Steam Generator Inspection Planning for SL2-16 SL2-16 Inspection Scope
  • Visual Examination of All Tube Plugs
  • Bobbin Probe All Active Tubes Screen Dings <5 Volts in Straight Sections

' Full Length Row 3-140, Straight Length Row 1-2

  • Plus Point Probe 100% Hot Leg Top of Tubesheet (+3" /-13")

Cold Leg Periphery Tubes (+3"/-2")

20% Row 1-2 U-bends (A-23, B-25) 20% Wear at Vertical Straps (A-86, B-58)

' .00% Wear at Eggcrates, HL & CL Diagonals (A-274,;B-202)

Full Tubesheet if No Tube Expansion (A-21,-B-1) 1-FPL 6

I St Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 SL2-16 Inspection Scope (con't)

  • Plus Point Probe for Dings SGA SGB

' All Dings Hot Leg Tubesheet to 1st Support 68 78

' All Dings >5 volts 1st Support to HL Bend 57 80 All Dings in HL & CL Square Bends Row 19-140 90 68

' All Dings >5 volts in Horizontal Run Row 19-140 71 102

' All Dings in Rows 1-18 U-Bends 113 89

' 20% Dings >5 volts CL Tubesheet to CL Bend 17 23 416 440

  • In Situ Testing Based on Industry Screening Guidance FPL - 13 St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Projected Tube Plugging Pr~dictdcNumbir PrchictedNurnm.r of Indliations at of Tub.. R*paired EO :i5 atE FOCIS Mochanismitocation SIG A SIG B SIG A SIC B Axial ODS('C at ls '.cratr Sulqxirts ILtwer 5t 21_00 2178 145S 1257 BLkt Estinlatc 2561 2331 1556 1345 tUppcr954% 2722 2485 165.1 1434 Aexial ODSCC Near TTS 30 I0 30 10 ircuinfermntial ODSCC2at 171S I 20 15 20 ANial I DSCC fICAow TriS 5 , S 5 C.irunircrcntiiil iScc. tcibw rrs s 5 S 5 Axi¶,l Oi)SCC at Dings 5 S 5 Best Estimate Cumulative Repairs -3050 -3075 Current Tube Plugging Limit 2520 .;252  :

FPL 14 7

I St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Tube Sleeving Plans Westinghouse Alloy 800 Leak Limiting Sleeve

  • 60-70% of Repairable Tubes are Candidates
  • Maintain 30% Effective Tube Plugging Margin
  • Contingency for 42% Tube Plugging

> Required Repairs Exceed Expectations

' Sleeving Field Effort Difficulties

- ' 15 FPL St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Operating Experience

  • Continue Emphasis on Dings/Dents &

Anomalous Indications

  • Foreign Object Damage
  • Batwing Support Condition (Waterford)
  • Fabrication Issues (Byron & Davis Besse)
  • Tube to Tube Wear (Tube Sever)

' Susceptible Locations to be Reviewed by Lead Analysts

. -16 FPL 8

St. Lucie Unit 2 - Siteam Generator Inspection Plannin,g for SL2-16 Contingenc y Planning Issue or Inspection Item ContinQency Action Leaking Plug Replace as Necessary Crack in Row 1&2 U-bend Test 100% Affected Rows

& 20% Row 3, etc.

Crack in U-bend Wear Scar Test All (A-430, B-290)

Crack in Cold Leg Ding Test All (A-85, B-1 15)

Foreign Object Wear Bound FO Wear CL Expansion Transition Cracking Test 100% in Affected SG Freespan Cracking Validate Bobbin POD RCL Indications on Pull Out Scan Retest if >.35 Volts ,,,¢ <tws-7 17 FPL St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Generic Letter 2006-01 Submit LAR to Adopt TSTF-449 By May 31, 2006

> Replacement SG Program

> Original SG Program

  • Include Sleeving Repair Method
  • Include Tubesheet Inspection Provisions (C*)
  • Administrative Controls

- Limit Pri-Sec Leakage to 108 gpd/SG

- Address Leakage Predictions for 1 7 Tubesheet & Sleeves 18 FPL ,es 9

I St. Lucie Unit 2 - Steam Generator Inspection Planning for SL2-16 Summary & Closing

  • FPL Program Meets Industry Guidance

. Comprehensive Inspection Program

  • Reasonable Assurance of Tube Integrity
  • Compliance with Tech Specs & NRC Positions
  • Identify & Address Staff Concerns FPL 19 10
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