ML051190330

Steam Generator Inspection Presentation

ML051190330
Person / Time
Site:	Crystal River
Issue date:	04/26/2005
From:	Progress Energy Florida
To:	Office of Nuclear Reactor Regulation
References
Download: ML051190330 (30)

Text

PROGRIESS IENERGY Crystal River - Unit 3 Steam Generator Inspection Presentation 1 April 26, 2005 OS Efle9V

AGENDA Introduction / Overview Danny Roderick Engineering Manager Comments Mike Annacone OTSG Design and Operation Scot Stewart Licensing Basis of Alternate Sid Powell Repair Criteria Alternate Repair Criteria Scot Stewart Application Corrective Actions Mike Annacone Closing Remarks Danny Roderick 2 April 26, 2005 e.? A,

Acronyms OTSG - Once-Through Steam Generator EFPY - Effective Full Power Year QDA - Qualified Data Analyst UTS - Upper Tubesheet LTS - Lower Tubesheet UTE - Upper Tube End IGA - Inter-Granular Attack PWSCC - Primary Water Stress Corrosion Cracking SCC - Stress Corrosion Cracking TEC - Tube End Crack 3 April 26, 2005 $g rrn

Acronyms (con'd)

ECT - Eddy Current Testing ARC - Alternate Repair Criteria RC - Rotating Coil POD - Probability Of Detection EDM - Electrical Discharge Machine Refuel 11 - 1999 Refuel 12 - 2001 Refuel 13 - 2003 Refuel 14 - 2005 4 April26, 2005 P gress.Bergy.

Once-Through Steam Generator Design Data

• SG Model - B&W Model 177FA in a Lowered Loop Configuration

• No. of SGs/Tubes - 2 OTSGs with 15,531 tubes each

• Tubes - 5/8 inch OD on a triangular pitch, tube wall 0.034 inch thick

• Tube Material - Stress Relieved Mill Annealed Inconel 600

• Tube Support Plates and Type - 15 Carbon Steel Plates with Trifoil Broached Openings

• Tubesheets - 24 inch Thick Carbon Steel with Inconel Cladding

• Tube Length - 56 feet 2-3/8 inch long 5 April 26,- 2005 Progress Energy

OTSG Flow Diagram 6 April 26, 2005 V rogress Energy

OTSG Typical Operating Conditions

• Thermal Power - 2568 MWt

• Primary Temperature (T-Hot) - 603 Deg F

• Primary Temperature (T-Cold) - 557 Deg F

• Primary Flow - 6.57E+07 Ibs/hr

• Primary Pressure - 2155 psig

• Secondary Feed Temperature - 455 Deg F

• Secondary Steam Outlet Temperature - 595 Deg F

• Secondary Flow - 5.5E+06 Ibs/hr

• Secondary Pressure - 925 psig 7 April 26, 2005 t Progress Eergy

CR-3 OTSG Status Age of Steam Generators - 17.6 EFPY as of October 2003 Total Plugged in "A" OTSG - 299 Tubes (1.9%)

Total Plugged in "B" OTSG - 783 Tubes (5.0%)

Plug Material & Type (Totals) 28 Alloy 600 Welded Plugs

• 67 Alloy 600 Rolled Plugs

• 987 Alloy 690 Rolled Plugs In Service Alloy 690 Sleeves in "A" OTSG - 159 Tubes In Service Alloy 690 Sleeves in "B" OTSG - 156 Tubes In Service Tubes with Rerolls in "A" OTSG - 936 Tubes In Service Tubes with Rerolls in "B" OTSG - 1355 Tubes 8 April 26, 2005 Prgre$ss Energ9

OTSG Tubesheet Map (upper/inlet) 9 April 26, 2005 4 Progress Energy

OTSG ECT Inspection

• Why o CR-3 Improved Technical Specifications, Section 5.6.2.10

) Steam Generator Integrity Program (NEI 97-06, Rev. 1)

) Alloy 600 Inconel Mill Annealed

) Degradation Assessment

• How i Techniques based on the EPRI or site qualification

• Performed by certified technicians i Analyzed by two independent qualified data analysts (primary and secondary)

• Any discrepancy between the primary and secondary QDAs is reviewed by two additional independent Level Ill QDAs

• Also reviewed by an oversight Level Ill QDA (independent)

• CR-3 also has a Progress Energy Level Ill QDA (site) review all indications 10 April 26, 2005 i Enrgy srOg

OTSG ECT Inspection (con'd)

X What o Based on the degradation assessment and EPRI guidelines i CR-3 has performed a bobbin coil inspection technique of 100% of the tubes in-service every outage since (and including) the 1997 outage as well as 100% rotating coil of the upper tubesheet roll region. Performed 100% rotating coil of the lower tubesheet roll region in 2003.

11 April26,2005 Progre'ssbienrg

Typical Refuel Outage OTSG Scope 100% Bobbin Coil ofAll In-service. T b e 100% Rotating Coil Upper and Lower Roll Transition (Non-Sleeved) Tubes Inservice 34% Bobbin Coil of the Full Length of In-service 1-690 Sleeves 34% Rotating Coil of the Sleeve Rolled Joints in the Upper Tubesheet (UTS) and 15th Support Plate (15S) 34% Rotating Coil exam UTS and 15S of Lane Region Un-sleeved tubes plus a One Tube Boundary Visual Inspection of ALL Plugs 100% Rotating Coil of the 1-600 Rolled Plugs 100% Rotating Coil of the Tubes in the Lower Tubesheet (LTS) [2003 was the first 100% examination]

100% Rotating Coil of the Dents Adjacent to Explosively Plugged Tubes 34% Rotating Coil of all Dents LTS +4"to Upper Tube End (UTE) 34% Rotating Coil in the Lower Tubesheet Crevice Area, +4"to -8" in the Sludge Pile Region 100% Rotating Coil and Bobbin Coil of the Inservice Tubes with IGA in the First Span - Only B-OTSG i 12 April26, 2005 0 X $ e g

Typical OTSG Degradation Mechanism Locations (typ. Upper and Lower Tubesheets)

F LI IL Claddina

.:ar

.:.,GA,--

Ir 13:..: ~^

April 26, 2005 Ikl Progress Ene~rgy

Typical Tube End Cracks Tube End Cracking Seal Weld Heat Affected Zone eal Weld Inconel Cladding

(-5/16" thick)

Clad Region Carbon Steel Tubesheet (24" Thick)

Tubesheet-to-Clad Interface 14 Progres's Energy

Typical Tube End Crack Repair ECT Indications

-1/2" Characteristics Axial or Circumferential Adjacent to Tubesheet Clad Region 15 April 26, 2005 _ Or

Tube End Crack History

• Prior to 1998 o Indications in the clad region considered outside of the pressure boundary o Recorded as Anomalies,

• Left in service since they were outside of the pressure boundary P No requirement to record indications outside of the pressure boundary o 1997 was the first 100% inspection of the upper tubesheet (UTS) roll area using a rotating coil

• 1998 b A B&W plant identified a Dotential Drimary-to-secondary leak path through tube end cracks (TECs)

P CR-3 re-analyzed 271 tubes identified with TEC o Requested and received approval for an exigent Technical Specification to operate with TEC in service 16 April 26, 2005 R 0Srors EnefY

TEC History (con'd) 1999 P Requested and received approval for an Alternate Repair Criteria (ARC) for TEC

• Applied only to axial indications in the clad region

• A leakage value applied to each indication, with a maximum of 1 gpm (minus 150 gpd) from all leakage sources o OTSG inspection - 100% of the tubes inservice using rotating coil (RC) in the UTS

• ARC applied to 435 tubes with 622 indications left in service in "A" OTSG

• ARC applied to 437 tubes with 549 indications left in service in "B" OTSG 17 April26,2005 POgess ber§gy

TEC History (con'd)

• 2001 o OTSG inspection - 100% of the tubes inservice using RC in the UTS

• ARC applied to 830 tubes with 11 18 indicatic)ns left in service in "A" OTSG

• ARC applied to 675 tubes with 840 indicatioris left in service in "B" OTSG

• 2003 o OTSG inspection -100% of the tubes inservice using RC in the UTS

• ARC applied to 957 tubes with 1228 indicatic)ns left in service in "A" OTSG

• ARC applied to 804 tubes with 1071 indicaticrns left in service in "B" OTSG 18 April 26, 2005 rogress ffiergy 6VA"

Licensing Basis of TEC ARC

• TEC Definition License Amendment 188 (October 1999) approved an Alternate Repair Criteria (ARC) in accordance with Topical Report BAW-2346P, Revision 0 0 Only axially oriented TEC which do not extend beyond the clad to carbon steel interface of the tubesheets is allowed to remain in service 0 TEC may remain in service provided the leakage criteria are met 19 April 26, 2005 4 Po'rsEnegy

Licensing Basis of TEC ARC (con'd)

• Inspection of TEC 0 Tubes with TEC that are left in service must be maintained on a list within the OTSG Inservice Inspection Surveillance Procedure 0 The portion of the tube with axial TEC must be inspected using RC each subsequent outage 0 Detected TEC must be increased by 1/POD to account for undetected TEC 20 April 26, 2005 Progress Energy

Licensing Basis of TEC ARC (con'd)

• Assessment of Inspection Results 0 Leakage value assigned to each TEC indication left in service 0 Operation Assessment to ensure projected TEC estimated leakage will not exceed the leakage limit under accident conditions 0 The alternate repair criteria requires the licensee to repair tubes with TEC indications until the leakage limit is satisfied 0 Evaluate and monitor growth rate (distance between the tip of the TEC indication and the clad to carbon steel interface) of TEC indications 21 April 26, 2005 PrO'g'S Energy

Licensing Basis of TEC ARC (con'd)

• Reporting Criteria of Inspection Results 0 Following each in-service inspection of steam generator (OTSG) tubes, the NRC shall be notified of the following prior to ascension into MODE 4:

Number of tubes and axially oriented TEC indications left in-service, the projected accident leakage, and an assessment of growth for the TEC 22 April 26, 2005 1ProgressEnergY

CR-3 Leak Rates 23 April 26, 2005 Progress Energy

CR-3 OTSG Radial Zones 24 April 26, 2005 . Progress Energy

TEC Leakage Calculation Method 25 April26,2005 Pgre'ssEne g

Leakage Value Calculation Conservative Assumptions

• Assumptions from BAW-2346P, Rev. 0

• A 100% through-wall EDM notch was used to simulate the tight TECs observed in actual SG tubes

• The axial EDM notch was aligned to maximize the effect of dilation on leak rate

• The ARC assumes that all axial indications are 100%

through-wall for the entire length of the tubesheet cladding

• All indications are assumed to contribute to the leakage 26 April 26, 2005 Progrsiery

Crystal River Unit 3 TEC Status

• The primary-to-secondary operational leakage during 2003 was - 2 gpd

• During the Fall 2003 outage CR-3 exceeded the Condition Monitoring and Maintenance Rule performance criteria, which resulted in the OTSG being categorized as (a)(1)

• The as-found Main Steam Line Break (MSLB) leakage was 1.029 gpm for "A" OTSG and 1.241 gpm for "B" OTSG

• The calculated TEC as-found leakage was 0.945 gpm for "A" OTSG and 1.226 gpm for "B" OTSG. This is - 92% of the as-found total for "A" OTSG and - 98% of the as-found total for "B" OTSG 27 April 26, 2005 Progress Energy

CR-3 Corrective Actions From 13R

• OTSG Program Manual Revision P Added information related to use of proper TEC leak rate table o Added guidance to ensure accounting of new TECs beyond POD o Added requirement for vendor notification for use of correct leak rate table prior to the outage

• OTSG Inspection Procedure o Added signature confirmation that correct leak rate table was utilized

• Ensured 13R assessment used correct leak rate table

• Repaired TECs in 13R to gain margin for 14R

• Revised 12R TEC calculation to correct errors L 28 April 26, 2005 Progress Energy

CR-3 New Corrective Actions

• Re-evaluate method to account for rate of new TECs for 15R projection based upon:

P 14R as-found data i Recent outage trends P Lessons learned from RAls i Status of LAR 290 (Probabilistic Calculation of TEC leakage)

• Require Plant Nuclear Safety Committee approval of methodology and as-left results for Main Steam Line Break leakage for future outages

• Perform review of RAls for recent submittals to identify process improvements:

o More early face-to-face communications on complex issues 29 April26, 2005 PgressEnergy.

CLOSING REMARKS 30 April 26, 2005 @ E00I$ gy