ML100970031

Summary of March 18, 2010 Conference Calls Regarding the Spring 2010 Steam Generator Inservice Inspections

ML100970031
Person / Time
Site:	Davis Besse
Issue date:	04/12/2010
From:	Michael Mahoney Plant Licensing Branch III
To:	Allen B FirstEnergy Nuclear Operating Co
Mahoney, M NRR/DORL/LPLIII- 2 415-3867
References
tac me3427
Download: ML100970031 (14)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 12, 2010 Mr. Barry S. Allen Site Vice President FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station Mail Stop A-DB-3080 5501 North State Route 2 Oak Harbor, OH 43449-9760 SUB~IECT: DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 -

SUMMARY

OF MARCH 18, 2010, CONFERENCE CALL REGARDING THE SPRING 2010 REFUELING OUTAGE STEAM GENERATOR INSERVICE INSPECTIONS (TAC NO. ME3427)

Dear Mr. Allen:

On March 18, 2010, the U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with FirstEnergy Nuclear Operating Company (FENOC) staff, regarding the spring 2010, refueling outage, steam generator inspections at the Davis-Besse Nuclear Power Station, Unit 1. A summary of the notes by the NRC staff of the March 18, 2010, conference call is enclosed. In addition, a handout provided by FENOC to support the conference call is also enclosed. The NRC staff did not identify any issues that would require follow-up action at this time; however, the staff asked to be notified in the event any unusual conditions were detected during the remainder of the outage.

If you have any questions, please call me at (301) 415-3867.

SiniAY Lh~e~ Mahoney, Proje Plant Licensing Branc 11-2 anager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346

Enclosures:

1. Summary of conference call

2. DBNPS Steam Generator Inspections data March 18, 2010 cc w/encl: Distribution via Listserv

CONFERENCE CALL

SUMMARY

DAVIS-BESSE NUCLEAR POWER STATION REGARDING SPRING 2010, REFUELING OUTAGE, STEAM GENERATOR INSPECTION RESULTS On March 18, 2010, the staff of the Steam Generator Tube Integrity and Chemical Engineering Branch of the Division of Component Integrity participated in a conference call with FirstEnergy Nuclear Operating Company (the licensee), regarding the ongoing steam generator (SG) inspection activities at Davis-Besse Nuclear Power Station (DBNPS) Unit 1.

There are two Babcock and Wilcox once-through steam generators (OTSG), designated 1-B and 2-A, at DBNPS. Each SG has approximately 15,500 Alloy 600 tubes in the mill-annealed condition. The tUbes have a nominal outside diameter of 0.625 inches and a nominal wall thickness of 0.037 inches. Both OTSG 1-B and 2-A contain tubes with sleeves.

Additional clarifying information or information not included in the document (Enclosure 2) provided by the licensee is summarized below.

At the time of the call, DBNPS SGs had operated for 21.2 effective full power years. In the recently completed cycle, they operated for 717 effective full power days. SG 2A has 625 (or 4 percent) tubes plugged, 199 sleeves, and 131 repair rolls. SG 1B has 279 (or 1.8 percent) tubes plugged, 212 sleeves, and 31 repair rolls. These two SGs are scheduled to be replaced in 2014 during refueling outage 18.

The primary-to-secondary leakage rate during the recently completed cycle (Cycle 16) was approximately 0.02 gallons per day, until April 2009. In April 2009, the plant was shut down and restarted for maintenance on a pressurizer safety valve. After the plant restart, the primary-to-secondary leak rate increased from 0.02 to 0.1 gallons per day.

This increase in leak rate was suspected to be the result of a welded plug that cracked during the shutdown/startup transient. Due to the low leak rate, a secondary side pressure test was not performed.

No exceptions were taken to the industry Pressurized-Water Reactor Steam Generator Examination Guidelines.

In the Table, "Steam Generator Inspection Data - March 18, 2010: Davis-Besse 16RFO Eddy Current Exam Scope" (Enclosure 2, page 1) provided by the licensee:

The periphery auxiliary feedwater (AFW) header-to-tube gap analysis is performed to determine if the position of the AFW header is changing relative to the inservice tubing. The analysis is performed with a bobbin coil and was approximately 95 percent complete at the time of the call. The AFW header does not appear to be moving.

The "full length bobbin examination of all in-service non-sleeved tubing" includes the non-sleeved portion of sleeved tubes.

The full length bobbin examination of 100 percent of sleeves is a bobbin exam of the sleeves only.

Enclosure 1 Page 1 of 4

NSRT means non-stress relieved roll transition.

The +Point' inspection of in-service stress relieved lower tube roll expansions and tube ends in SG 1-B included the second roll above the original roll, because primary water stress corrosion cracking (PWSCC) had been found between the two rolls in the heel transition of the upper roll.

The 50 percent +Point' coil inspection of the defined lower tubesheet sludge pile region tubes was from three inches above to three inches below the tubesheet, unless the sludge pile went higher than 3 inches above the top of the tubesheet (in which case the entire portion of the tube in the sludge pile was examined).

The geometric distortions are small indentations in the sleeves.

All installed rolled plUgs are made from Alloy 690.

In the table titled "Davis-Besse 16 RFO March 2010: Axial Indications" (Enclosure 2, page 2):

The first four entries should state Reroll Transition PWSCC" instead of "Roll Transition PWSCC" (Primary Water Stress-Corrosion Cracking), and these indications were found in the heel of the roll transition.

The repair rolls installed at Davis-Besse are 1 5/8 inches long, which is longer than the 1 inch required by the topical report that was used for obtaining approval of the repair rolls.

At the time of the call, the licensee had completed more than 95 percent of the tubesheet exams.

Groove intergranular attack (IGA) was found in the free span of 1-B SG. The Groove IGA was a form of outside diameter stress-corrosion cracking and there was sufficient margin on the tubes (R73C60 and R73C64) that structural integrity was maintained, despite the long length of the groove IGA. All Groove IGA detected during the refueling outage was found with the bobbin coil. None of these indications were scheduled to be in-situ pressure tested since they did not pass the screening criteria based on +Point' voltage or depth. A tertiary review of the bobbin data was performed to increase the probability of detecting Groove IGA.

In the table titled "Davis-Besse 16 RFO March 2010: 2.C (7) Steam Generator Tube Circumferential Crack Report" (Enclosure 2, page 3):

The indications listed as "Roll Trans[ition] PWSCC [primary water stress corrosion cracking]" are in the heel transition of the repair roll (i.e., reroll transition PWSCC).

Page 2 of 4

32 Roll Trans PWSCC indications were detected in the lower tube end in SG 1-B.

These indications are located in the heel transition of the second (upper) roll.

The 0.105 gallon per minute leak rate indicated in row 136, tube 1 is a 50/50 estimate.

The volumetric (VOL) IGA indications are in repair rolls.

The tube end PWSCC indication is in the weld's heat affected zone.

In the table titled "Davis-Besse 16 RFO March 2010: Volumetric Indications (Not in Previously Rerolled Tubes)"

(Enclosure 2, page 4), the portion in parentheses "(Not in Previously Rerolled Tubes)"

should be deleted.

The indications in this table are also in the previous table titled, "2.C(7) Steam Generator Tube Circumferential Crack Report."

Both indications shown in the table are located in a repair roll.

In the table titled "Davis-Besse 16 RFO March 2010: New Tube End Indications (Not in Previously Rerolled Tubes)" (Enclosure 2, pages 5 through 7):

There are 92 indications in SG 2-A and 43 indications in SG 1-B. Many of these tubes will be repaired by re-rolling. The potential for these indications to leak will be addressed in the condition monitoring and operational assessment.

In the table titled "Davis-Besse 16 RFO March 2010: Top 10 Wear Calls by Bobbin Depth" (Enclosure 2, page 8):

The licensee has never had to plug any tubes as a result of a wear indication.

The upper 95 th percentile growth rate was 1.84 percent per effective full power year. There is a slight increase in the number of wear scars, which the licensee attributes to the power uprate that was implemented during the last operating cycle. The increase in wear scars falls within the bounds that were predicted prior to implementation of the power uprate. All the new indications are within 4 to 6 percent through-wall.

At the time of the call, the licensee was projecting that they would plug approximately 180 tubes and repair approximately 120 tubes using the rolling process. The licensee was still performing special interest examinations at the time of the call.

No in-situ pressure testing was scheduled, but the licensee stated that they would notify the staff if their plans changed. If any in-situ pressure testing would be performed, the licensee was planning on performing it on Sunday, March 21,2010.

Manual and automatic analysis for loose parts had not detected any loose parts.

Inspections with the +Point' coil at the lower tube sheet (LTS) had not revealed any Page 3 of 4

loose parts. No degradation due to loose parts had been found. To date, no potential loose part indications had ever been found at Davis-Besse with eddy current testing.

The licensee attributes this condition to the spray plates through which the incoming feedwater must pass that have very small holes and act to keep out debris.

SG secondary side inspections were performed on the auxiliary feedwater header in SG 1-B during this outage as part of the 1O-year inspection program. The inspections were performed through the upper secondary manway and some auxiliary feedwater spray nozzles. These inspections had just started, but the licensee did not expect to find anything based on eddy current examination. The licensee stated they would inform the staff if anything was found.

The licensee stated that when compared to the last outage, there was an increase in wear that they attributed to the power uprate. There was also an increase in the occurrence of LTS heel transition cracking in SG 1-B.

A VT-1 inspection of installed plugs revealed a cracked welded plug in SG 1-8. The plug was scheduled to be replaced with a rolled plug, but that would be the last procedure performed in the SG since removal of the old plug generates debris.

The licensee predicts closeout of eddy current testing in the SGs by Sunday, March 21,2010, and repairs will be made on Monday and Tuesday.

Per license condition 2.C.7 - the licensee notified the staff of the results of their assessment. They found no circumferential cracking inboard of the repair rolls.

Circumferential cracking in an original roll was found (as shown on page 3 of 8 in Enclosure 2) with an estimate leakage of 0.105 gallons per day.

Some of the installed plugs have a thermal cycle limit of 170 cycles. The plant has currently undergone 110 actual thermal cycles.

The welded plug that cracked had signs of poor fusion in the weld. The cracked plug was compared to the other 17 manufacturer-installed plugs and the licensee noted that all the other plugs had better weld quality than the plug that cracked. The cracks in the plug were very small and there was no concern for plug ejection.

The staff did not identify any issues that required follow-up action at this time; however, the staff asked to be notified in the event that any unusual conditions were detected during the remainder of the outage.

Page 4 of 4

Davis-Besse Steam Generator Inspection Data - March 18, 2010 Davis Besse 16RFO Eddy Current Exam Scope SG 2-A SG l-B Inspection of all newly installed repair rolls. ] 00 estimate ] 00 estimate Periphery AFW Header to tube gap analysis to determine if the header is moving. 366 396 Full length bobbin examination of all in-service non-sleeved tubing. 14832 15178 Full length bobbin examination of 100% sleeves. 199 212

+Point' exam of the sleeve at the point of entry (USE) and parent tube pressure boundary 199 212 portion extending approximately 6 inches past the sleeve end (LSE) of] 00% of the sleeves (the parent tube between the bottom of the upper most sleeve roll and the top of the middle sleeve roll may be excluded from inspection since it is not a pressure boundary).

+Point' inspection of non-sleeved in-service upper tube roll expansions (100%) including ]4633 14966 non stress relieved upper repair roll expansions and factory re-rolls.

+Point' coil examination of 50% of the non-sleeved in-service tubes in the upper tube sheet 7317 7483 region from tube end including tube end, upper roll expansion and crevice to upper tube sheet exit.

+Point' inspection of 20% of the in-service stress relieved lower tu be roll expansions and 3126 0 tube ends in OTSG 2-A. (including tube 127-67 with NSRT)

+Point' inspection of in-service stress relieved lower tube roll expansions and tube ends in 0 15178 S/G ]-B 100%.

+Point' coil examination of the tubes bordering the sleeve region. 89 80

+Point' coil examination of all of the flaw-like indications (l codes, TWD per the DA, and 550 estimate 530 estimate new dents) reported from bobbin.

+Point' coil examination of all Non Quantifiable Signal (NQS) and Manufacturing Burnish 220 estimate 240 estimate Mark (MBM) indications above] OS-2".

+Point' coil examination of all dent indications below 14S (100% sample of all previously 350 estimate 300 estimate reported and new dents using a 2:2.5 volt bobbin threshold).

+Point' coil examination of all dent indications greater than or equal to ] volt above] 4S in 330 estimate 430 estimate the non-periphery region.

+Point' coil examination of all dent indications greater than or equal to 0.5 volts above] 4S 29 estimate 19 estimate in the periphery region.

+Point' coil sample inspection of 50% of the defined lower tubesheet sludge pile region 1447 1709 tubes.

Sleeve Bobbin and +Point' coil inspection of all previously identified geometric distortions 0 40 (40 tubes SG I-B).

+Point' coil inspection of all previously identified and new magnetic stain (MAG) 0 23 indications (23 tubes SG ] -B)

+Point' inspection of 20% of the Hot Leg rolled Plugs. 121 54 Visual Welded Plug Exam (VT-]) (] 00%) 33 19 Visual Plug exams of all Plugs in Upper and Lower (] 00%) 1250 558 Total Exams 45191 57727 ENCLOSURE 2 Page 1 of 8 Results as of: 11 :23 AM,3/18/201 0

Davis-Besse 16 RFO March 2010 Axial Indications SG Count Row Tube Ind Volts TSP Inch1 Probe Depth Ax Len Deg Mode 2-A 1 117 103 SAl 2.14 UTE -2.55 520PP 86 0.61 Roll Transition PWSCC 2-A 2 114 112 SAl 0.68 UTE -1.36 520PP 52 0.17 Roll Transition PWSCC 2-A 3 63 12 SAl 0.57 UTE -1.48 520PP 80 0.19 Roll Transition PWSCC 2-A 4 25 47 SAl 0.80 UTE -1.54 520PP 46 0.20 Roll Transition PWSCC 2-A 5 132 2 MAl 0.55 UTE -3.20 520PP 65 0.19 ReRoll Transition PWSCC 2-A 6 125 14 MAl 1.26 UTE -2.92 520PP 95 0.26 ReRo11 Transition PWSCC 2-A 7 124 101 MAl 0.78 UTE -2.82 520PP 69 0.18 ReRoll Transition PWSCC 2-A 8 118 105 SAl 2.42 UTE -2.77 520PP 68 0.17 ReRoll Transition PWSCC 2-A 9 116 111 MAl 2.13 UTE -3.16 520PP 96 0.34 ReRoll Transition PWSCC 2-A 10 94 3 MAl 2.09 UTE -3.02 520PP 97 0.31 ReRoll Transition PWSCC 2-A 11 92 3 SAl 2.76 UTE -3.14 520PP 98 0.27 ReRoll Transition PWSCC 2-A 12 92 9 SAl 1.44 UTE -3.04 520PP 53 0.34 ReRo11 Transition PWSCC 2-A 13 91 10 SAl 1.87 UTE -3.03 520PP 86 0.22 ReRoll Transition PWSCC 2-A 14 87 122 MAl 1.02 UTE -3.26 520PP 73 0.27 ReRoll Transition PWSCC 2-A 15 85 31 MAl 1.23 UTE -3.21 520PP 78 0.25 ReRoll Transition PWSCC 2-A 16 80 12 MAl 1.26 UTE -3.05 520PP 97 0.49 ReRoll Transition PWSCC 2-A 17 68 4 MAl 0.71 UTE -3.13 520PP 48 0.26 ReRoll Transition PWSCC 2-A 18 65 1 SAl 1.52 UTE -3.13 520PP 36 0.17 ReRoll Transition PWSCC 2-A 19 32 83 MAl 0.43 UTE -3.56 520PP 83 0.14 ReRoll Transition PWSCC 2-A 20 24 18 SAl 1.20 UTE -3.18 520PP 72 0.22 ReRo11 Transition PWSCC 2-A 21 19 75 MAl 0.63 UTE -3.58 520PP 53 0.27 ReRoll Transition PWSCC 2-A 22 83 74 SAl 0.15 UTS -17.79 520PP 1 0.15 Groove IGA 2-A 23 65 1 SAl 0.14 15S -1.10 520PP 1 0.15 Groove IGA 1-8 24 111 48 MAl 0.83 LTE 1.54 520PP 57 0.20 Roll Transition PWSCC 1-8 25 52 93 SAl 0.58 UTE -1.10 520PP 48 0.21 Roll Transition PWSCC 1-8 26 52 95 SAl 0.63 UTE -1.17 520PP 62 0.17 Roll Transition PWSCC 1-8 27 48 93 SAl 0.75 UTE -1.32 520PP 62 0.12 Roll Transition PWSCC 1-8 28 46 33 SAl 0.89 LTE 1.41 520PP 68 0.21 Roll Transition PWSCC 1-8 29 41 103 SAl 0.55 LTE 1.31 520PP 91 0.35 Roll Transition PWSCC 1-8 30 31 31 SAl 0.80 LTE 1.81 520PP 99 0.21 Roll Transition PWSCC 1-8 31 56 104 MAl 0.64 UTE -3.75 520PP 98 0.14 ReRoll Transition PWSCC 1-8 32 43 92 MAl 3.05 UTE -2.95 520PP 81 0.27 ReRoll Transition PWSCC 1-8 33 36 99 SAl 0.93 UTE -4.89 520PP 67 0.15 ReRoll Transition PWSCC 1-8 34 35 88 MAl 0.98 UTE -2.80 520PP 76 0.15 ReRoll Transition PWSCC 1-8 35 30 14 MAl 0.67 UTE -2.94 520PP 66 0.37 ReRoll Transition PWSCC 1-8 36 73 60 SAl 0.32 15S 39.78 520PP 34 2.91 Groove IGA 1-8 37 73 64 SAl 0.23 15S 28.03 520PP 61 2.54 Groove IGA Page 2 of 8 Results as of : 11 :23 AM,3/18/201 0

Davis-Besse 16RFO March 2010 2.C(7) Steam Generator Tube Circumferential Crack Report SIG Count Row Tube Ind Volts TSP Inch Probe %TW Ci Ext Degradation Mechanism Section a Section b Section c 2-A 1 15 10 SCI 0.54 UTE -3.78 520PP 43 0.23 Roll Trans PWSCC x 2-A 2 16 27 SCI 1.18 UTE -3.61 520PP 75 0.53 Roll Trans PWSCC x 2-A 3 19 15 MCI 0.56 UTE -3.64 520PP 62 0.42 Roll Trans PWSCC x 2-A 4 26 22 SCI 0.71 UTE -3.64 520PP 50 0.25 Roll Trans PWSCC x 2-A 5 93 7 SVI 0.16 UTE -4.07 520PP 2 0.28 VOL IGA in Roll x 2-A 6 93 7 SVI 0.19 UTE -4.1 520PP 1 0.16 VOL IGA in Roll x 2-A 7 136 1 SCI 1.71 UTE -0.38 520PP 96 0.28 Tube End PWSCC x 0.105aom 1-8 8 44 72 SCI 0.2 LTE 1.59 520PP 76 0.12 Roll Trans PWSCC x 1-8 9 44 73 SCI 0.57 LTE 1.88 520PP 49 0.16 Roll Trans PWSCC x 1-8 10 44 75 SCI 0.44 LTE 1.77 520PP 68 0.18 Roll Trans PWSCC x 1-8 11 45 74 SCI 0.34 LTE 1.62 520PP 46 0.16 Roll Trans PWSCC x 1-8 12 45 74 SCI 0.43 LTE 1.63 520PP 46 0.18 Roll Trans PWSCC x 1-8 13 46 74 SCI 0.23 LTE 1.55 520PP 34 0.16 Roll Trans PWSCC x 1-8 14 46 74 SCI 0.43 LTE 1.59 520PP 99 0.27 Roll Trans PWSCC x 1-8 15 46 74 SCI 0.56 LTE 1.63 520PP 53 0.37 Roll Trans PWSCC x 1-8 16 47 77 SCI 0.52 LTE 1.73 520PP 50 0.21 Roll Trans PWSCC x 1-8 17 47 77 SCI 0.85 LTE 1.72 520PP 96 0.25 Roll Trans PWSCC x 1-8 18 48 77 SCI 0.46 LTE 1.65 520PP 95 0.23 Roll Trans PWSCC x 1-8 19 49 25 MCI 0.48 LTE 1.62 520PP 76 0.25 Roll Trans PWSCC x 1-8 20 49 78 SCI 0.42 LTE 1.64 520PP 67 0.18 Roll Trans PWSCC x 1-8 21 50 74 SCI 0.3 LTE 1.59 520PP 85 0.18 Roll Trans PWSCC x 1-8 22 50 74 SCI 0.66 LTE 1.6 520PP 99 0.96 Roll Trans PWSCC x 1-8 23 50 77 SCI 0.71 LTE 1.63 520PP 76 0.53 Roll Trans PWSCC x 1-8 24 51 76 SCI 0.57 LTE 1.44 520PP 89 0.27 Roll Trans PWSCC x 1-8 25 51 78 SCI 0.62 LTE 1.34 520PP 98 0.3 Roll Trans PWSCC x 1-8 26 53 77 SCI 0.55 LTE 1.47 520PP 98 0.25 Roll Trans PWSCC x 1-8 27 58 98 SCI 0.44 LTE 1.31 520PP 50 0.18 Roll Trans PWSCC x 1-8 28 59 76 SCI 0.47 LTE 1.24 520PP 66 0.3 Roll Trans PWSCC x 1-8 29 60 80 SCI 0.58 LTE 1.38 520PP 97 0.23 Roll Trans PWSCC x 1-8 30 62 30 SCI 0.33 LTE 1.59 520PP 99 0.19 Roll Trans PWSCC x 1-8 31 91 72 SCI 0.34 LTE 1.6 520PP 88 0.18 Roll Trans PWSCC x 1-8 32 91 72 SCI 0.42 LTE 1.47 520PP 83 0.18 Roll Trans PWSCC x 1-8 33 92 74 SCI 0.46 LTE 1.66 520PP 55 0.18 Roll Trans PWSCC x 1-8 34 92 74 SCI 0.57 LTE 1.57 520PP 81 0.18 Roll Trans PWSCC x 1-8 35 94 72 SCI 0.33 LTE 1.5 520PP 60 0.18 Roll Trans PWSCC x 1-8 36 103 33 SCI 0.51 LTE 1.6 520PP 88 0.28 Roll Trans PWSCC x 1-8 37 106 31 SCI 0.47 LTE 1.57 520PP 99 0.19 Roll Trans PWSCC x 1-8 38 110 61 SCI 0.28 LTE 0.45 520PP 100 0.18 Tube End PWSCC x 1-8 39 111 29 SCI 0.27 LTE 1.64 520PP 69 0.18 Roll Trans PWSCC x 1-8 40 111 29 SCI 0.53 LTE 1.66 520PP 89 0.62 Roll Trans PWSCC x Page 3 of 8 Results as of: 11 :23 AM,3/18/2010

Davis-Besse 16 RFO March 2010 Volumetric Indications (Not in Previously Rerolled Tubes)

SG Row Tube Ind Volts TSP Ineh1 Probe Depth Ax Len eire Len Deg Mode 2-A 93 7 SVI 0.16 UTE -4.07 520PP 2 0.20 0.28 VOL IGA in Roll 2-A 93 7 SVI 0.19 UTE -4.10 520PP 1 0.14 0.16 VOL IGA in Roll Page 4 of 8 Results as of : 11 :23 AM,3/18/201 0

Davis-Besse 16 RFO March 2010 New Tube End Indications (Not in Previously Rerolled Tubes)

SG Count Row Tube Ind Volts TSP Inch1 Probe 2-A 1 55 1 SAA 0.83 UTE -0.25 520PP 2-A 2 115 112 SAA 1.09 UTE -0.31 520PP 2-A 3 115 113 MAA 0.79 UTE -0.30 520PP 2-A 4 114 112 SAA 1.46 UTE -0.27 520PP 2-A 5 114 111 SAA 1.10 UTE -0.31 520PP 2-A 6 2 20 SAA 2.10 UTE -0.27 520PP 2-A 7 11 37 SAA 1.15 UTE -0.32 520PP 2-A 8 147 44 SAA 1.55 UTE -0.22 520PP 2-A 9 20 72 MAA 2.25 UTE -0.29 520PP 2-A 10 4 27 SAA 1.77 UTE -0.22 520PP 2-A 11 27 81 SAA 1.20 UTE -0.25 520PP 2-A 12 28 81 SAA 1.24 UTE -0.27 520PP 2-A 13 94 6 SAA 1.21 UTE -0.23 520PP 2-A 14 93 8 MAA 2.23 UTE -0.24 520PP 2-A 15 92 7 SAA 1.94 UTE -0.28 520PP 2-A 16 66 3 SAA 1.31 UTE -0.25 520PP 2-A 17 65 2 SAA 2.73 UTE -0.26 520PP 2-A 18 129 7 MAA 1.63 UTE -0.27 520PP 2-A 19 11 4 SAA 1.20 UTE -0.25 520PP 2-A 20 106 105 SAA 1.55 UTE -0.29 520PP 2-A 21 108 112 SAA 1.08 UTE -0.24 520PP 2-A 22 135 70 MAA 1.99 UTE -0.31 520PP 2-A 23 137 69 SAA 1.30 UTE -0.31 520PP 2-A 24 96 6 SAA 1.55 UTE -0.38 520PP 2-A 25 27 94 SAA 1.27 UTE -0.23 520PP 2-A 26 28 82 SAA 1.43 UTE -0.27 520PP 2-A 27 149 17 SAA 1.59 UTE -0.20 520PP 2-A 28 23 19 MAA 1.82 UTE -0.27 520PP 2-A 29 14 8 SAA 1.79 UTE -0.27 520PP 2-A 30 21 31 SAA 1.14 UTE -0.20 520PP 2-A 31 133 4 SAA 2.33 UTE -0.26 520PP 2-A 32 134 4 SAA 0.90 UTE -0.28 520PP 2-A 33 84 8 MAA 2.12 UTE -0.24 520PP 2-A 34 81 11 SAA 1.50 UTE -0.28 520PP 2-A 35 72 115 SAA 0.91 UTE -0.21 520PP 2-A 36 81 32 SAA 0.86 UTE -0.25 520PP 2-A 37 66 113 SAA 1.61 UTE -0.32 520PP 2-A 38 126 44 SAA 1.17 UTE -0.21 520PP 2-A 39 126 10 MAA 2.17 UTE -0.23 520PP 2-A 40 132 6 SAA 1.52 UTE -0.26 520PP 2-A 41 96 2 MAA 1.64 UTE -0.29 520PP 2-A 42 25 47 MAA 1.11 UTE -0.29 520PP 2-A 43 150 1 SAA 2.86 UTE -0.28 520PP 2-A 44 90 7 SAA 1.80 UTE -0.27 520PP 2-A 45 90 3 SAA 1.49 UTE -0.26 520PP 2-A 46 95 9 MAA 1.05 UTE -0.27 520PP 2-A 47 96 8 MAA 2.83 UTE -0.26 520PP 2-A 48 94 26 SAA 1.08 UTE -0.21 520PP 2-A 49 110 3 SAA 1.95 UTE -0.18 520PP 2-A 50 100 7 SAA 1.09 UTE -0.25 520PP Page 5 of 8 Results as of : 11 :23 AM,3/18/201 0

Davis-Besse 16 RFO March 2010 New Tube End Indications (Not in Previously Rerolled Tubes)

SG Count Row Tube Ind Volts TSP Inch1 Probe 2-A 51 28 19 8M 1.40 UTE -0.26 520PP 2-A 52 7 13 MAA 1.72 UTE -0.22 520PP 2-A 53 122 13 8M 0.89 UTE -0.22 520PP 2-A 54 87 10 8M 0.99 UTE -0.26 520PP 2-A 55 87 8 8M 1.74 UTE -0.27 520PP 2-A 56 86 11 8M 1.61 UTE -0.29 520PP 2-A 57 67 2 8M 2.31 UTE -0.27 520PP 2-A 58 24 33 8M 1.90 UTE -0.28 520PP 2-A 59 24 19 MAA 2.01 UTE -0.22 520PP 2-A 60 19 35 8M 0.86 UTE -0.23 520PP 2-A 61 92 8 8M 2.43 UTE -0.25 520PP 2-A 62 92 6 MAA 2.08 UTE -0.26 520PP 2-A 63 99 3 8AA 1.75 UTE -0.28 520PP 2-A 64 91 9 MAA 1.58 UTE -0.25 520PP 2-A 65 91 121 8M 1.81 UTE -0.19 520PP 2-A 66 21 48 8M 1.77 UTE -0.24 520PP 2-A 67 19 71 MAA 1.65 UTE -0.20 520PP 2-A 68 10 61 8M 1.50 UTE -0.28 520PP 2-A 69 17 70 8M 1.63 UTE -0.24 520PP 2-A 70 10 36 MAA 1.51 UTE -0.27 520PP 2-A 71 26 95 8M 1.84 UTE -0.27 520PP 2-A 72 127 76 MAA 1.62 UTE -0.21 520PP 2-A 73 36 42 8M 0.86 UTE -0.16 520PP 2-A 74 36 26 8M 1.51 UTE -0.07 520PP 2-A 75 79 28 8M 0.79 UTE -0.28 520PP 2-A 76 85 10 8M 1.69 UTE -0.28 520PP 2-A 77 83 6 8M 1.26 UTE -0.31 520PP 2-A 78 68 9 8M 1.46 UTE -0.28 520PP 2-A 79 130 93 8M 0.43 UTE -0.16 520PP 2-A 80 137 74 8M 0.89 UTE -0.18 520PP 2-A 81 105 6 MAA 1.73 UTE -0.26 520PP 2-A 82 89 7 MAA 1.69 UTE -0.26 520PP 2-A 83 88 7 8M 1.34 UTE -0.26 520PP 2-A 84 13 41 8AA 2.25 UTE -0.21 520PP 2-A 85 13 67 8AA 1.73 UTE -0.20 520PP 2-A 86 14 41 8M 1.00 UTE -0.21 520PP 2-A 87 114 109 8AA 0.91 UTE -0.27 520PP 2-A 88 81 10 8M 1.67 UTE -0.26 520PP 2-A 89 58 9 8M 1.70 UTE -0.26 520PP 2-A 90 103 18 MAA 1.92 UTE -0.13 520PP 2-A 91 146 49 MAA 2.22 UTE -0.22 520PP 2-A 92 147 46 8M 2.18 UTE -0.30 520PP 1-8 93 102 10 8AA 1.25 UTE -0.32 520PP 1-8 94 28 12 8AA 1.07 UTE -0.30 520PP 1-8 95 31 14 MAA 1.77 UTE -0.27 520PP 1-8 96 20 54 MAA 2.78 UTE -0.17 520PP 1-8 97 84 116 8AA 2.13 UTE -0.26 520PP 1-8 98 104 114 8AA 0.97 UTE -0.25 520PP 1-8 99 61 29 8AA 1.16 UTE -0.29 520PP 1-8 100 110 45 8AA 1.04 UTE -0.20 520PP 1-8 101 18 57 8AA 0.94 UTE -0.27 520PP Page 6 of 8 Results as of : 11 :23 AM ,3/18/2010

Davis-Besse 16 RFO March 2010 New Tube End Indications (Not in Previously Rerolled Tubes)

SG Count Row Tube Ind Volts TSP Inch1 Probe 1-8 102 18 55 SAA 1.68 UTE -0.25 520PP 1-8 103 20 83 SAA 1.19 UTE -0.21 520PP 1-8 104 45 90 SAA 1.58 UTE -0.29 520PP 1-8 105 53 94 MAA 1.83 UTE -0.18 520PP 1-8 106 53 96 SAA 1.25 UTE -0.18 520PP 1-8 107 29 65 SAA 2.46 UTE -0.16 520PP 1-8 108 40 89 MAA 1.24 UTE -0.11 520PP 1-8 109 48 96 SAA 1.06 UTE -0.27 520PP 1-8 110 50 92 SAA 1.23 UTE -0.11 520PP 1-8 111 53 97 SAA 0.86 UTE -0.19 520PP 1-8 112 27 12 MAA 1.61 UTE -0.21 520PP 1-8 113 33 68 SAA 1.86 UTE -0.33 520PP 1-8 114 117 40 SAA 1.08 UTE -0.23 520PP 1-8 115 43 105 MAA 2.56 UTE -0.28 520PP 1-8 116 132 76 SAA 1.27 UTE -0.22 520PP 1-8 117 30 66 MAA 1.18 UTE -0.36 520PP 1-8 118 8 42 SAA 3.18 UTE -0.14 520PP 1-8 119 29 83 SAA 2.65 UTE -0.35 520PP 1-8 120 121 5 SAA 1.18 UTE -0.33 520PP 1-8 121 121 4 SAA 2.08 UTE -0.30 520PP 1-8 122 19 56 SAA 2.15 UTE -0.18 520PP 1-8 123 19 75 SAA 2.23 UTE -0.16 520PP 1-8 124 47 74 SAA 1.00 UTE -0.43 520PP 1-8 125 14 51 SAA 1.27 UTE -0.24 520PP 1-8 126 100 78 SAA 1.30 UTE -0.42 520PP 1-8 127 61 80 SAA 3.18 UTE -0.20 520PP 1-8 128 113 110 SAA 2.28 UTE -0.28 520PP 1-8 129 108 106 SAA 1.08 UTE -0.21 520PP 1-8 130 36 102 SAA 0.81 UTE -0.33 520PP 1-8 131 43 93 SAA 1.74 UTE -0.23 520PP 1-8 132 43 106 SAA 0.57 UTE -0.22 520PP 1-8 133 59 94 SAA 2.33 UTE -0.32 520PP 1-8 134 56 77 SAA 1.80 UTE -0.15 520PP 1-1::5 1jb OU \:1\:1 ';jAA 1.jlj UIl:: -U.1\:1 OLU~~

Page 7 of 8 Results as of : 11 :23 AM,3/18/201 0

Davis-Besse 16 RFO March 2010 Top 10 Wear Calls By Bobbin Depth SG Row Tube Depth Volts TSP Inch1 Prev Depth 2-A 147 36 23 0.98 108 0.61 22 2-A 16 2 21 1.34 138 -0.68 28 2-A 84 32 20 0.80 098 0.63 14 2-A 52 1 20 0.95 138 -0.70 12 2-A 146 34 19 0.75 108 0.59 14 2-A 43 1 18 0.93 138 -0.66 14 2-A 12 1 17 0.91 138 -0.68 17 2-A 150 27 17 0.97 108 -0.78 16 2-A 146 33 17 0.99 108 0.60 20 1-8 2 27 17 0.66 128 0.66 14 Page 8 of 8 Results as of: 11:23 AM,3/18/2010

Mr. Barry S. Allen Site Vice President FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station Mail Stop A-DB-3080 5501 North State Route 2 Oak Harbor, OH 43449-9760

SUBJECT:

DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 -

SUMMARY

OF MARCH 18, 2010, CONFERENCE CALL REGARDING THE SPRING 2010 REFUELING OUTAGE STEAM GENERATOR INSERVICE INSPECTIONS (TAC NO. ME3427)

Dear Mr. Allen:

On March 18, 2010, the U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with FirstEnergy Nuclear Operating Company (FENOC) staff, regarding the spring 2010, refueling outage, steam generator inspections at the Davis-Besse Nuclear Power Station, Unit 1. A summary of the notes by the NRC staff of the March 18, 2010, conference call is enclosed. In addition, a handout provided by FENOC to support the conference call is also enclosed. The NRC staff did not identify any issues that would require follow-up action at this time; however, the staff asked to be notified in the event any unusual conditions were detected during the remainder of the outage.

If you have any questions, please call me at (301) 415-3867.

Sincerely, IRA!

Michael Mahoney, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346

Enclosures:

1. Summary of Conference Call

2. DBNPS Steam Generator Inspections data March 18, 2010 cc w/encl: Distribution via Listserv DISTRIBUTION:

PUBLIC RidsNrrPMMMahoney AJohnson. NRR LPL3-2 R/F RidsNrrLATHarris Resource KKarwoski, NRR RidsNrrOorlLpl3-2 Resource RidsRgn3MailCenter Resource ADAM S Accession No. ML100970031 NRR- 06 *Biy Merno Date d OFFICE NRRlLPL3-2/PM NRRlLPL3-2/LA NRRlDCI/CSGB/BC NRRlLPL3-2/BC NAME MMahoney THarris RTaylor SCampbell DATE 04/08/10 04/08/10 03/23/10' 04/12/10 OFFICIAL RECORD COPY