ML120790479

March 14, 2012 Telecon Slides

ML120790479
Person / Time
Site:	Prairie Island
Issue date:	03/14/2012
From:	Northern States Power Co, Xcel Energy
To:	Division of Operating Reactor Licensing
Wengert T
References
TAC ME7371
Download: ML120790479 (26)

Text

Prairie Island 2R27 Outage NRC Phone Call and NRC Discussion Points March 14, 2012

2R27 NRC Phone Call March 14, 2012 z

Participants:

z Prairie Island (NSP MN) z Kari Den Herder (SG Program Engineer) z Jennie Eckholt (Licensing) z Mike Heller (SG Project Supervisor) z Scott Redner (ET Level III QDA) z Jeff Ricker (Inspection & Materials Supervisor) z Carl Lane (Engineering Programs Manager) z Richard Pearson (SGR Engineering Supervisor) z Ben Stephens (Contract SG Engineer) z AREVA (Lynchburg) z Jim Begley (CMOA analyst) 2

2R27 NRC Phone Call March 14, 2012 z The attached information has not been validated.

In many cases, it is preliminary information from ongoing activities. To our knowledge, it is the best information available as of 7 AM on the date prior to this report and may be changed following further review and analysis.

z NRC Discussion Points are provided in italic font and are used as a template for this presentation.

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2R27 NRC Phone Call March 14, 2012 Current Status of 2R27 SG Inspection (As of 0700 on March 13, 2012)

Category 21 SG 22 SG ET Acquisition (% completed) 97 92 ET Analysis (% completed) 96 88

1. of Pluggable Tubes 80 21

1. of Re-Roll Candidates 330 215

1. of In Situ Candidates 0 0 4

2R27 NRC Phone Call March 14, 2012 Q1: Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.

z 21 Steam Generator maximum steady state leakage by tritium was 0.5 GPD to < 3.5 GPD over the last cycle.

z 22 Steam Generator maximum steady state leakage by tritium was 0.5 GPD to < 4.0 gallon per day over the last cycle.

z Steam Generator Tube Leakage is slightly elevated as compared to leakage over the last three cycles.

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2R27 NRC Phone Call March 14, 2012 6

2R27 NRC Phone Call March 14, 2012 Q2: Discuss whether any secondary side pressure tests were performed during the outage and the associated results.

z Due to the slightly elevated primary to secondary leakage, a hydrostatic pressure test is scheduled for each SG to look for tube leakage.

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2R27 NRC Phone Call March 14, 2012 Q3: Discuss any exceptions taken to the industry guidelines.

z No exceptions were or will be taken from industry guidelines.

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2R27 NRC Phone Call March 14, 2012 Q4: For each SG, provide a description of the inspections performed including the areas examined and the probes used, (e.g., dents/dings, sleeves, expansion-transition, U-bends with a rotating probe) the scope of the inspection (e.g., 100 percent of the dents/dings greater than 5 volts and a 20 percent sample between 2 and 5 volts), and the expansion criteria.

z Prairie Island 2R27 steam generator inspection plan is attached on the following sheet.

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2R27 NRC Phone Call March 14, 2012 2R27 Steam Generator Inspection Plan SCOPE PROBE TYPE S/G 21 S/G 22 Full Length n Bobbin 100% 100%

Rows 1 through 4 U-Bends MRPC 100% 100%

Rows 5 through 8 U-Bends o MRPC 33% 33%

Hot Leg Tubesheet MRPC 100% 100%

I690 Hot Leg Roll Plugs p MRPC 25% 25%

Supplemental q MRPC 100% 100%

Post In Situ Pressure Test MRPC 100% 100%

Plug Visual N/A 100% 100%

Baseline New Re-Rolls MRPC 100% 100%

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2R27 NRC Phone Call March 14, 2012 2R27 Steam Generator Inspection Plan (cont.)

n Except the bend portion of row 1 through 4 u-bends.

o Expansion plan defined in plant procedure 2H25.1.

p Plug samples are considered proactive informational sample plans that are not subject to the periodicity requirements of T.S.5.5.8.d.3.

q ADR, CUD, DEP, DNI, TSP DNT 2.0V, Freespan DNT 5.0V, DRI, DSI, DTI, TSP INR 1.5V, MBM, NQI, PLP (Bound MRPC PLPs), PSI, Cold Leg Thinning 40% or < 40% and 1.5V.

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2R27 NRC Phone Call March 14, 2012 zQ5: For each area examined (e.g., tube supports, dents/dings, sleeves, etc), provide a summary of the number of indications identified to-date for each degradation mode (e.g., number of circumferential primary water stress corrosion cracking indications at the expansion transition). For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).

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2R27 NRC Phone Call March 14, 2012 PI 2R27 Analysis Status Analysis Status (percent completed) as of SG 21 SG 22 0700 on March 13, 2012: Hot Cold Hot Cold Bobbin 100 95 100 90 U-Bend MRPC 89 N/A 75 N/A Tubesheet Crevice MRPC 100 N/A 91 N/A Hot Leg Roll Plug MRPC 83 N/A 90 N/A Supplemental MRPC 95 0 63 0 Post In Situ MRPC 0 0 0 0 Plug Visual 100 100 100 100 Baseline New Re-Rolls 0 0 0 0 13

SG 21 Analysis Results to Date Degradation Mode and Location (Indications) # Volt Depth Length New Excludes all indications below the F* and EF* Distance Mech.

Volumetric Wear at New Anti-Vibration Bars (AVB)(< + 1) 22 1.77 32 N/A N Volumetric Wear at Old AVBs (free span)(> 1) 48 2.63 40 N/A N Volumetric Wear at PLPs (1998 In Situ Neighbors) 2 0.81 34 N/A N Volumetric Thinning at Cold Leg Tube Support Plates 78 4.06/1.36 55/70 N/A N Volumetric Thinning at Cold Leg Top of Tubesheet 0 N/A N/A N/A N Volumetric Thinning at Hot Leg Tube Support Plates 0 N/A N/A N/A N Volumetric Thinning at Hot Leg Top of Tubesheet 0 N/A N/A N/A N Axial ODSCC at Hot Leg Sludge Pile 1 0.12 N/A 0.15 N Axial ODSCC at Hot Leg Crevice 9 0.41/0.15 N/A 0.51/1.34 N Axial ODSCC at Hot Leg Tube Support Plates 0 N/A N/A N/A N Axial PWSCC at Hot Leg Roll Expansions/Tube Ends 458 6.19/4.81 N/A 0.67/0.71 N Circ. PWSCC at Hot Leg Roll Expansions/Tube Ends 0 N/A N/A N/A N Circ. ODSCC at a Re-Roll Expansion 0 N/A N/A N/A N Axial PWSCC at U-bends 0 N/A N/A N/A N Circ. PWSCC at U-bends 0 N/A N/A N/A N ODSCC/PWSCC at Dents 0 N/A N/A N/A N ODSCC/PWSCC at Plugs 0 N/A N/A N/A N 14

SG 22 Analysis Results to Date Degradation Mode and Location (Indications) # Volt Depth Length New Excludes all indications below the F* and EF* Distance Mech.

Volumetric Wear at New Anti-Vibration Bars (AVB)(< + 1) 34 2.67 41 N/A N Volumetric Wear at Old AVBs (free span)(> 1) 34 2.45 40 N/A N Volumetric Wear at PLPs 0 N/A N/A N/A N Volumetric Thinning at Cold Leg Tube Support Plates 108 3.73/2.85 19/54 N/A N Volumetric Thinning at Cold Leg Top of Tubesheet 0 N/A N/A N/A N Volumetric Thinning at Hot Leg Tube Support Plates 0 N/A N/A N/A N Volumetric Thinning at Hot Leg Top of Tubesheet 0 N/A N/A N/A N Axial ODSCC at Hot Leg Sludge Pile 3 0.29/0.19 N/A 0.38/0.51 N Axial ODSCC at Hot Leg Crevice 1 0.17 N/A 0.16 N Axial ODSCC at Hot Leg Tube Support Plates 0 N/A N/A N/A N Axial PWSCC at Hot Leg Roll Expansions/Tube Ends 169 2.68/0.62 N/A 0.1/0.23 N Circ. PWSCC at Hot Leg Roll Expansions/Tube Ends 3 3.36 N/A 83º N Circ. ODSCC below Top of Tubesheet with 11.26 Volt Dent 1 0.18 N/A 49º Y Axial PWSCC at U-bends 0 N/A N/A N/A N Circ. PWSCC at U-bends 0 N/A N/A N/A N ODSCC/PWSCC at Dents 0 N/A N/A N/A N ODSCC/PWSCC at Plugs 0 N/A N/A N/A N 15

2R27 NRC Phone Call March 14, 2012 Analysis Status (Continued) z Structural and accident induced leakage integrity was maintained during the previous cycle.

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2R27 NRC Phone Call March 14, 2012 Q6: Describe repair/plugging plans.

Pre Outage Predicted Repairs SCOPE S/G 21 S/G 22 In Situ Pressure Test 5 5 AR1 - 6 Re-Roll 270 288 AR2 - 8 Re-Roll 138 67 ARE - Elevated Re-Roll N/A N/A Hot Leg Roll Plugs 91 34 Cold Leg Roll Plugs 91 34 17

2R27 NRC Phone Call March 14, 2012 Planned Repairs (Based on 92% inspected)

SCOPE S/G 21 S/G 22 In Situ Pressure Test 0 0 AR1 - 6 Re-Roll 157 144 AR2 - 8 Re-Roll 173 52 ARE - Elevated Re-Roll N/A N/A Hot Leg Roll Plugs 80 21 Cold Leg Roll Plugs 80 21 18

2R27 NRC Phone Call March 14, 2012 Q7: Describe in-situ pressure test and tube pull plans and results (as applicable and if available).

z We have no plans to pull tubes for Unit 2, as part of a licensed repair program.

z Status - No tube pull is needed.

z We are planning on performing up to 10 In Situ tests based on inspection results.

z Status - No In Situ tests are needed.

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2R27 NRC Phone Call March 14, 2012 Q8: Discuss the following regarding loose parts:

1) what inspections are performed to detect loose parts.

A) All bobbin data is evaluated for possible loose parts (PLP) and PLP wear using manual analysis by primary.

B) Secondary uses Computer Data Screening (CDS) with a PLP specific sort from TSH +

0.3 to 07H + 2.00 and from TSC + 0.3 to 07C + 2.00 and various wear detection sorts from TSH - 1.0 to TSC - 1.0.

C) Resolution tertiary review is conducted on all bobbin coil periphery tubes, two tubes deep for PLPs.

D) All MRPC data is evaluated for PLPs.

E) All bobbin PLP indications are tested with MRPC.

F) All MRPC PLP indications are bounded radially by one tube at the same elevation.

G) Any top of tubesheet PLP that cannot be resolved with ECT are inspected from the secondary side for resolution.

H) Top of Tubesheet Remote Visual Inspection: Peripheral & In-bundle.

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2R27 NRC Phone Call March 14, 2012 Q8: Discuss the following regarding loose parts:

2) a description of any loose parts detected and their location within the SG (including the source or nature of the part, if known).

New MRPC PLP Indications:

SG HL Top of TSH CL Top of TSH 21 0 0 22 0 0 21

2R27 NRC Phone Call March 14, 2012 Q8: Discuss the following regarding loose parts:

3) if the loose parts were removed from the SG.

A). SG 21 secondary side FOSAR will be done this week.

B). SG 22 secondary side FOSAR is a contingency.

Q8: Discuss the following regarding loose parts:

4) indications of tube damage associated with the loose parts.

There is no wear associated with any of the PLP indications.

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2R27 NRC Phone Call March 14, 2012 z Q9: Discuss the scope and results of any secondary side inspection and maintenance activities (e.g., in-bundle visual inspections, feedring inspections, sludge lancing, assessing deposit loading, etc.).

z FOSAR results previously discussed.

z SP 2534 Steam Generator Internals Inspection for 21 SG z SG Steam Drum Inspection planned this week:

z Tube Bundle Wrapper z Feedwater Ring/Thermal Sleeve z Moisture Separation Equipment z SG Feedwater Nozzle ISI Inspections of:

z Knuckle Region, Nozzle to Reducer and Reducer to Pipe Welds, Transition Cone Girth Weld, Feedwater Ring Hangers, and FAC Inspection of FW Tee 23

2R27 NRC Phone Call March 14, 2012 z Q10: Discuss any unexpected or unusual results.

z No unexpected or unusual conditions detected during 2R27.

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2R27 NRC Phone Call March 14, 2012 z Q11: Provide the schedule for steam generator-related activities during the remainder of the current outage.

z ET examinations are scheduled to be completed later this week.

z In-situ testing is not required at this time.

z Repairs are projected to be completed by March 24.

z Manway installation is scheduled to be completed on April 4-5.

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