ML082830032
| ML082830032 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/31/2008 |
| From: | AREVA NP, Entergy Operations |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML082830032 (73) | |
Text
Al En rgy ANOl Steamý h AREVA G2e a ef at" =Q NRC Presentation Arkansas Nuclear One -Unit One Entergy/AREVA NP August 2008 1 ANO1 Steam CccarsARE\
m Introductions
-Bob Clark -Licensing L] Jaime McCoy -EP&C Manager u Bill Greeson -EP&C Supervisor u Dan Meatheany
-SG Program Lead AREVA NP* Jim Begley* John Remark* Dennis Lang* Linda McConnell IA 2
.-Etery ANO 1 Steam________AREVA.AGENDA ji Opening Remarks -Jaime McCoy u Description of EOTSG -Dan Meatheany ui 1 R20 Outage Results -Dan Meatheany Proprietary Section"I Review of Root Cause -Jim Begley" Outage Plans for 1R21 Bill Greeson Li Acceptance Criteria -Bill Greeson Li Contingency Plans -Dan Meatheany Li Closing Comments -Jaime McCoy 3 AES SEntergy AN01 Steam Generators ARE VA Opening Comments Jaime McCoy 4 Entergy Root Cause Review z AREVA EOTSG Design and 1R20 Results Dan Meatheany 5 Entergy ANO1 EOTSG Design A AREVA-Description of EOTSG -Dan Meatheany Ll Generators Replaced in Fall of 2005 (1R19)L] First ISI was Spring 2007 (1 R20)Ll Next Inspection is October 2008 (1 R21)Li EOTSG was Manufactured by AREVA NP El Design Enhanced from Originals (EOTSG).L First of a Kind Design in Several Areas 6 A:t--Enterg, ANO1 EOTSG* 15 Tube Support Plates* External FW and EFW Rings* Floating TSP/Tie Rod* TSP are Trefoil Broach SS* Aspirating Port in 1Oth Span* Upper and Lower Shroud* FW into Downcomer* EFW Penetrates Shroud* 52 Tie Rods in 4 Concentric Circles R A AREVA 7 a A EtryANO1 EOTSG Design A* Design Changes" 690TT Tubing with Flush Tube Ends" No Open Lane Lj Full Depth Hydraulic Expansion (Both Heads)ai TSP are Stainless Steel not Carbon Steel Li Use of a "Filler Plate" on the 1 st, 14th and 1 5 th -Original was 1 st and 1 5 th Only and was a Wedge Design Attached to TSP[]. Use of Modified TSP Wedges (AREVA NP Design)Lj First Span Tie Rods Reduced in Diameter and Longest Span -46 inches u Tie Rods Are Different in Design/Material Lj Use of a Main Steam Venturi 8 Atk--Ent er 1R20 Inspection Results A AREVA* Cycle 20 and 1 R20 Inspection Findings -Dan Meatheany L1 Cycle 20 had 2 Thermal Cycles and. 1 EFW Injection LIThree Significant Inspection Findings: N Proximity Indications in the First Span in SGA Indicative of Bowed Tie Rods E General TSP Wear Growth Greater than Anticipated
- Population of Wear at the 8th TSP in SGA was Larger and had a Distinct Pattern 9 AIML, Entergy 1R20 Inspection Results A AREVA Location of Wear at 8b TSP Location of Bowed Tie Rods 10
-,-Entergy 1R20 Inspection Results A AREVA Bowed Tie Rods 11 Atr 1R20 Inspection AREVA* Initially Detected 7 Tie Rod Locations with Contact in SGA Only -None in SGB -All in First Span.Upon Re-Analysis, Additional Bowing in First and 14th and 15th -not to the Extent of the Original Locations e Bowing was Toward the Center of the Bundle* Bowing was Symmetrical around the "Z" Axis" Reviewed all 52 Tie Rod Locations in Both Generators" No Wear on Adjacent Tubes -Not the Condition While at Operating Conditions 12
- Enturgy 1R20 Inspection Results I- AIN-ýAREVA Red symbol =proximity of tube to tie rod Blue symbol =proximity of tube to tube Green symbol =proximity of tube to both a tie rod and another tube First Span Z Axis 13 Enatergy 1R20 Inspection Results A AREVA Red symbol =proximity signal in 14th and 15th span Blue symbol =proximity signal in 15th span only Upper Spans Z Axis 14 AEnturgy 1R20 Inspection Results A AREVA.4 Maximum Lateral Bow in 1 R20 was 0.89 Inches 15 Entergy 1R20 Inspection Results AE AREVA 0 0 0 Tie Rod Tube Interaction at Location Row 64 0 0 16 A&--ýEnterLgv 1R20 Inspection Results A AREVA TSP Wear Growth Rate 17 AEr 1R20 Inspection Results AREVA SGA SGB Outage 1 R20 1 R20 Total Number of Tubes 15595 15597# of Wear Indications jj 90 I 5i. -I# of Tubes with Wear 651 435% of Tubes with Wear 4.20% 2.80%Average Depth C 830%Maximum Depth 23 28# of Indications
> 40% TW 0 0# of Indications
> 20% but < 39% 4 8# of Indications
> 1% but < 19% 686 504 EFPY for Cycle 1.31 1.31 Average Growth 7.40% 8.30%95/50 Growth 1 2% C1 5 Maximum Growth per EFPY 17.70% 21.50%# Tubes Plugged in 1 R20 0 1 Total Number of Tubes Plugged 2 1 18 Al JEn teray 1R20 Inspection Results AREVA 19
--Entergy 1R20 Inspection Results A AREVA Distribution of TSP Wear 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 I I I I I I I I I I I-u- SGA---SGB co) LO Ný- 0')(Y) LO'r- r-I N.- 0) T- co U') L N-lc- -C\J C\ C\1 (N 0')Depth 20 En tergy 1R20 Inspection Results AE V AREVA 8 th TSP Wear in SGA 21 Entergy 1R20 Inspection ResulIts A A REVA.... ... -..... .......... 4.... .. ...Z Axis on SGA 8th TSP Indications in SGA and SGB -Note crescent shape in SGA..............
.Z Axis on SGB..... ... .. .22 A: t......E nr-1R20 Inspection IReut AREVA...............
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...- .-.-.- .-.- -.- ----.._- ---.- -. -. --. -Z Axis on SGA--.-- ---x---...-.....-.
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23 Ent ffgy 1R20 Inspection Results A AREVA 1 R20 WEAR DISTRIBUTION C0 z 0 U z U-0 450 400 350 300 250 200 150 100 50 0 ESGA M SGB_l~m -4 1 2 3 4 5 6 7 8 9 10 11 TUBE SUPPORT PLATE 12 13 14 15 24 Ak En tergy Root Cause Review AREVA Proprietary Section ANO Unit I Tie Rod Bowing and Wear Root Cause Review Jim Begley 25 AEe Enrtergy Root Cause Review-PROPRIETARY A AREVA I-J 26 Azt ,.Entffgy Root Cause Review-PROPRIETARY A AREVA\1-i 27 Aty Root Cause Review-PROPRIETARY
- AREVA I\-28 Entergy Root Cause Review-PROPRIETARY A AREVA J 29
__ Array Probe Terrain Map-.Entergy of Tapered Wear-PROPRIETARY A AREVA I 30
-Entergy Root Cause Review-A PROPRIETARY AREVA I 31 Afik-"-ý-Entergy Root Cause Review-PROPRIETARY AREVA 32 Ak E.-uE-tergy Tie Rod Bowing Apparent Root Cause Summary-A AREVA-4% 4-l- 4% -6 33 Tie Rod Bowing Apparent Root Summary (Cont.) -PROPRIETARY AR EVA 34 Al En turgy Root Cause Review-PROPRIETARY A AREVA 35
, ~Root Cause Review-PROPRIETARY A AREVA I/Axial Displacement Mismatches
-Locking to Upper Shroud is Key\J 36 A t Root Cause Review-PROPRIETARY A AREVA 37 Enatergy Nature of Locking-PROPRIETARY A AREVA J 38 Aittergy Sources of Locking-PROPRIETARY AR A AREVA 39 AQk-Entergy"Ovalization" of the Inner Shroud and Shell -PROPRIETARY AR AREVA 40 Ai*Adjusted Time History of TSP Periphery Gap-PROPRIETARY 1L XI.AREVA (41 Bowing Calculations (exaggerated scale)--- !ntergyfor Itockinp ScenariO-PROPRIETARa AR EVA* I * --I ...........i 42 AEr-"-Entergy Single Tube Bowing Calculations and Measiirements-PROPRiFTARY A AREVA 43 1'trg Eddy Current Observations versus Calcul ation S-PROPRIF.TARY AREVA 44 En tergy Permanence of Locking-PROPRIETARY A AREVA J 45
Permanence of Locking (cont.)-PROPRIETARY A AREVA 46 Atr Summary and Expectations-PROPRIETARY A AREVA I 47
.-Entergy ANO1 Steam A AREVA ANO Unit I 1R21 Inspection Plan and Acceptance Criteria Bill Greeson 48 lddmll-ýCurrent 1R21 Inspection Plans A AREVA" Purpose of Inspections" Scope of Inspection" Acceptance Criteria-Definition of Success 49
-Enterav Purpose of InspectionsR EVA* Evaluate/Confirm Apparent Root Cause and Analysis Inputs 13 Determine locations and magnitudes of tie rod bowing L3 Determine locations and degree of locking of support plates to shroud L3 Verify as built condition of steam generators (visual SSI)L3 Determine if free-span wear exists on tubes around tie rods* Evaluate general wear for comparison to predictions
- Evaluate wear on 8 th TSP* Identify possible unexpected conditions 50 Scope of Inspections
_- , ,AREVA* Primary -Both Generators
- 100% Bobbin both generators
- Array Probe/ RPC of all wear for locations relative to TSP edge and wear on land orientation
- Emphasis on tubes around tie rods for proximity signals* Secondary
-Affected Generator(s).Visual inspection of first span -worse case bowed locations, threaded tie rod connections, lower shroud supports*l4th and 15th Tube support plate periphery visual -wedge, filler plate condition* Upper shroud annular gap -alignment pin condition, upper shroud support ring 51 E e iy Current 1R21 Secondary Side R A AREVA is Visual Inspections U Secondary Side Inspections
- LI -Annulus and FOSAR in Lower Span and Lower Shroud Support Lugs* L2 -Inner Bundle to Look at Tie Rod Connections
& Bowing N L3-Underside of 1 st TSP to look at Wedges and Filler Plate* U4 -Annular Gap to look at Alignment Pins* U5 -Annular Gap to look at Upper Shroud Support Ring* U6-Upper Spans to look at 14th and 1 5 th Wedges, Filler Plates, Alignment Pins and Anti-rotation Keys 52
,,,,.Enterg)(Secondary Side Visual Inspection Example AREVA Secondary Side Mockup Fabricated by AREVA* Full Scale Mockup e Full Tube First Span* Filler-Plates and Wedges* Anti-rotation Keys* Alignment Pins" 15th Upper Span" 14th Upper Span" First Span with Tie Rods 53 En tergy Secondary Side Visual Inspection pA Example AREVA Annulus And FOSAR -LI 54 Ak 277 Entergy Secondary Side Exa Visual Inspection A Lmple AREVA Lower Shroud Support Lug -LI 55 En tergy Secondary Side Visual Inspection Example AREVA Inner Bundle Inspection of Lower Connection on Tie Rod -L2 56 AMEntergy.,.-- ., ....Secondary Side Visual Inspection A Example AREVA Bottom View of 1st TSP Wedges-L3 57 EntergRy MP ýSecondary Side Visual Inspection Example AREVA Alignment Pin in Gap Between Shell and Shroud -U4 58 Ent fg Secondary Side Visual Inspection Example AREVA TSP Anti-Rotation Alignment Key -U6 59 En tergy Secondary Side Visual Inspection Example AREVA TSP with Filler Plate -U6 60 En tee Secondary Side Visual Inspection A Example AREVA TSP Wedge -U6 61
- ,,-Entergy Secondary Side Visual Inspection ,A Example AREVA TSP Wedge -U6 62
,.-Entergy Secondary Side Visual Inspection A Example AREVA TSP Underside View -U6 07/30/2008 11:17:52 63 Acceptance Criteria E- Et ergy_AR EVA mAll observations of the 1 R21 inspection will be compared to the apparent root cause for tie rod bowing to ensure that the root cause is fully understood and provides a correct basis for operability assessments mAcceptance criteria have been developed to facilitate this comparison mThese criteria are based on calculations using the apparent root cause as the base model-Secondary side inspections are to validate primary inspection results and identify gross defects-It is possible that inspection results other than those listed under acceptance criteria may force a re-evaluation of the root cause scenario 64 "l-Entergy Acceptance Criteria for T Tie Ro-d L~ateral Bowing AREVA Category 1R20 Inspection Value Acceptance Criteria Potential Additional Analysis, Repairs or Inspections Maximum Lateral Extent of 0.89 inch <1.2 inch > 1.2 inch Tie Rod Bowing in First Span, Outermost Ring Maximum Lateral Extent of 0.38 inch < 0.48 inch >0.48 inch Tie Rod Bowing in First Span, Second Outermost Ring Maximum Lateral Extent of 0.11 inch < 0.17 inch >0.17 inch Tie Rod Bowing in 1 4 th and 1 5 th Spans, Outermost Ring Maximum Lateral Extent of No bowing detected < 0.06 inch > 0.06 inch Tie Rod Bowing in 1 4 th and 1 5 th Spans, Second Outermost Ring Bowed Rods in Contact with 0 0 >1 Tubes outside of First Span 65
-"-Entergy7-Cc Acceptance Criteria for Wear/Dents caused by Tie Rod Lateral Bowing A AREVA Category 1R20 Inspection Value Acceptance Criteria Potential Additional Analysis, Repairs or Inspections Freespan Wear on Tube 0 0 > 5% TW from Tie Rod Tube to Tube Freespan 0 0 > 5% TW Wear as a Result of Tie Rod Bowing Dents in Tubes Exclusively 0 0> 1 Around Bowed Tie Rods >1 volt Locking of the Upper Tube TSP 10-15 Locking of Only the Upper Locking of the Lower TSPs 1-9 Support Plates TSPs 66 A ty Acceptance Criteria for General Wear AR AREVA Initial Depth Distribution 5 I 0.9 0.8 0.7-0.6 05-0.4-0.3 0.2 0.1 0 5 10 15 20 Depth, %TW 35 67 ADefinition of Success (1R21),,__Entergy AR EVA" Root cause for tie rod bowing verified" Tie rod bowing magnitude is as predicted" No freespan wear found in tubes around tie rods" No excessive denting found in tubes adjacent to tie rods" General wear depths (including 8th TSP) Consistent with 1 R20 Results" Max new wear depth is -28%" Results of inspection will support an ASME code qualified stress calculation for "A" steam generator 68 A:M--En tergy Root Cause Review A AREVA Contingency Plans Dan Meatheany 69 ENt Contingency Plans Enter AREVA* What Contingencies Were Evaluated* Wear Growth Greater than Expected o Based on actual values -potentially plug largest depths or limit operating interval until next inspection
- Bowing Slightly Greater than Expected ji Depending on amount, re-evaluate conditions/adjust operating interval* Bowing in Excess of Operability Li Potential to cut hole in shell and shroud to free up tube support plate" Lock in the tube support plate to prevent further ratcheting" Potential to capture a broken tie rod 70 Entergy Contingency Plans A AREVA Bowed Tie Rods Identified iDecision Matrix 71
,Enterg)ANO1 Steam Generators A AREVA QUESTIONS?
72 ANO1 Steam Generators A AREVA Closing Comments Jaime McCoy 73