ML030860662
| ML030860662 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/20/2003 |
| From: | Florida Power & Light Co |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML030860662 (10) | |
Text
STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT AGENDA
"*Purpose of Meeting
"*Background
"*SL2-14 Inspection Scope
"*Projected Tube Plugging
" Inspection Criteria Changes
"*Contingency Planning
"*Contingency License Amendment Request
"*Summary & Closing 1
- STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Purpose of Meeting
"*Review SL2 S/G Condition
"*Review SL2-14 Inspection Plans
"*Address Staff Request to NEI on Tubesheet Inspections
"*Identify &Address Any Staff Concerns 2
Attachment 2
- STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT
Background
FPL Steam Generator Program
"*Committed to Safe Operation
"*Full Implementation of NEI 97-06, S/G Program Guidelines SInspection SChemistry SLeak Monitoring
"*Incorporate Industry Experience
"*Extensive Examination History at Unit 2
"*Conservative Approach Situ Pressure Test at Last 4 Inspections 2
ISPETIONPLANIN STEA GEERATR S~STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT
Background
"*Last Inspection - SL2-13 in December 2001
"*Operational Assessment Presented May 2, 2002
ýMost Damage Mechanisms as Expected
' Increase in Axial ODSCC at Eggcrate Supports SOn-set of Axial ODSCC at Dings SDegradation Trend Typical for Unit with A-600 MA Tubing 5
" STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT
Background
Indication Count at SL2-13 (11/01)
Mechanism SIG A SIG B Total Axial ODSCC at Eggcrates 97 201 298 Axial ODSCC at Dings 5 1 6 Axial ODSCC at Tubesheet (Hot) 8 16 24 Axial IDSCC below Tubesheet (Hot) 2 0 2 Circumferential ODSCC at Tubesheet (Hot) 4 9 13 OD Volumetnc 0 2 2 Wear at Tubesheet (Cold) 0 5 5 Wear at Tube Diagonal and Vertical Supports 581 397 978 Tubes Plugged at SL2-13 129 232 361 3
STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT
Background
In Situ Pressure Testing at SL2-13
_Mechanism Tested Pressure 9 4950 psi Axial ODSCC at Eggcrates 5 4950 psi Axial 005CC at Dents 6 4950 psi Axial ODSCC at rrS 2 4950 psi Axial IDSCC below TTS 4 5550 psi Ciro ODSCC at TTS 1 4950 psi 00 Volumetric UTS 27 Total Tested Not LekgIous STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT SL2-14 Inspection Scope nVisual Examination of All Tube Plugs
- Bobbin Probe All Active Tubes SFull Length Row 3-140 SStraight Length Row 1-2 SScreening of Dings <5 Volts
- Plus Point Probe
ý 100% Hot Leg Top of Tubesheet (+3"/-5")
S20% Cold Leg Top of Tubesheet (+3"/-5")*
S25% Row 1-2 U-bends S20%Wear Scars in U-bends*
- Added for SL2-14 4
STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT SL2-14 Inspection Scope (Con't)
- Plus Point Probe for Dings SAll Dings Hot Leg Tubesheet to 1st Support (A=45, B=36)
' All Dings >5 volts 1st Support to Hot Leg Bend (A=73, B=90)
SAll Dings in HL & CL Square Bends Row 19-140 (A=8, B=5)
SAll Dings >5 volts in Horizontal Run Row 19-140 (A=76, B=117)
SAll Dings in U-Bend Region Rows 1-18 (A=1 07, B=114) 20% of Dings >5 volts TSC to CL Bend (A=17, B=25)*
- SL2-13 Included All Dings >10 volts TSC to CL Bend 9
STEAM GENERATOR INSPECTION PLANNING STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Projected Tube Plugging Predicted Number Mechanism/Location EOC 13 Axial ODSCC at Eggcrate Supports 150-200 Axial ODSCC at Top of Tubesheet 40-60 Circumferential ODSCC at Expansion Transitions 15-25 Axial ODSCC at Dings 5-20 Axial IDSCC Below Secondary Face of Tubesheet 5-10 TOTAL PROJECTED 215-315 10 5
-$ STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Inspection Criteria Changes to Address Operating Experience
- Look Backs & Reporting Issues
ý Look Backs Over Longer Period
ý Apply Low Frequency Screen to U-bends & Square Bends
ý Modify Reporting Criteria to Include Flaw-like Indications <1%
- High Residual Stress - Manufacturing
ý Existing Issue for MA Tubing Plants
ý Screening Addressed by Existing Data Analysis Guidelines 11 STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Contingency Planning
"*Cold Leg Top of Tubesheet - Complete 100%
"*Row 1 &2 U-bends - Complete 100% and 20% Row 3
ý Continue Until No Defective U-bends
"*U-bend Wear Scars - 100% Hot Leg & 20% Cold Leg
"-Cold Leg Dings >5Volts - Complete 100%
"*Freespan Cracking - See Next Pages 12 6
STEAM GENERATOR INSPECTION PLANNING S~STEAM GENERATOR SL2-14 APRIL 2003INSPECTION FLINT
- NRR, WHITEPLANNING Contingency Planning (Con't)
Overview Of Freespan Contingency Plan
' Discussed with NRC prior to Last 4 Inspections
ý Sampling Methodology to Optimize Use of Resources
ý Statistical Basis for Operational Assessment
ý Reduces Risk of not Inspecting Affected Areas
ý Modified for SL2-14 Based on Industry Experience 13 STEAM GENERATOR INSPECTION PLANNING
- STEAM GENERATOR SL2-14 APRIL 2003INSPECTION FLINT
- NRR, WHITEPLANNING Contingency Planning (Con't)
Free Span Cracking Plan
"*Complete 100% Bobbin Coil Screening
"*Plus Point Inspect Indications that are New or Show Change
"*If Cracking is Confirmed:
"*Inspect Entire Straight Length On Side With Crack
"*Inspect 6 Neighbor Tubes at Same Span
"*Validate Bobbin Probe POD
"*If Acceptable - End Free Span Program
"*If Not Acceptable - Proceed to Sampling Schemes 14 7
STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Contingency Planning (Con't)
.Evaluate Locations of All Confirmed Free Span Cracks wDetermine Applicable Inspection Scenario
.Select Appropriate Sample Scheme
ý Maximize Use of Resources
ý Maximize Potential to Demonstrate Full Cycle Tube Integrity QCENARIO DfGRFE CLUSTERED #CRACKS SAMPLE SCHEME
- A*I J*lV ......................
CASE I NONE NIA 0 NONE CASE 2 MINIMAL YES <15 LHS CASE 3 MINIMAL NO <15 LHS CASE 4 MODERATE YES 15-50 IMPORTANCE CASE 5 MODERATE NO 15-50 REDUCED LHS CASE 6 SEVERE YES >50 IMPORTANCE CASE 7 SEVERE NO >50 SYSTEMATIC*
LHS - Latin Hypercube Sampling
- Optimized to support bobbin POD 15
- STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Contingency Planning (Con't)
Case 2 or 3 Most Likely Scenario for Free Span Cracking mLatin Hypercube Sampling Scheme
ý Proven Efficiency vs. Random Sampling
ý Provides Optimal Coverage
ý Widely Used Strategy in Monte-Carlo Simulation Approach for Uncertainty in Extent of Condition SRobust Approach 16 8
- STEAM GENERATOR INSPECTION PLANNING S~STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Contingency License Amendment Request Change Definition of a Tube Inspection SContingency for Cycle 14 Only if Circumferential Cracks Detected in Tubesheet SLimit Inspection Within the Tubesheet to 5" to Recent Requests Approved for 1 Cycle on CEOG Work & Site Specific Topical Letter of February 3, 2003 Responded to Staff Request for Information (15 Plants) 18 9
STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Contingency License Amendment Request Recent Inspections & Results for Indications Below the Hot Leg Top-of-Tubesheet (TTS) a No Circumferential Indications To Date Below TTS HL-T'rs Test Outage Scope Extent Axials Location Deoth I
Length I =
SL2-10 100% -2" 1 1.10" 93% (1) 0.22" (1) 1 0.17" 90% (2) 0.12" (2)
SL2-12 100% -2" 2* 2.10" 75% (2) 0.23" (2)
SL2-13 100% -5"
- 2 Indications In 1 Tube - Passed In Situ Pressure Test (1) Max Depth/Length (2) Structural Depth/Length
-* STEAM GENERATOR INSPECTION PLANNING SL2-14 APRIL 2003 - NRR, WHITE FLINT Summary & Closing
"*FPL Program Meets Industry Guidance
"*Reasonable Assurance of Tube Integrity
"*Basis for Limiting Inspections Tubesheet SContingency for Cycle 14 Only SContinue Effort Through NEI for Long-Term Resolution
"*Identify & Address Staff Concerns 20 10