1CAN060601, Steam Generator Tubing Inspection Report

Steam Generator Tubing Inspection Report

ML061730358
Person / Time
Site:	Arkansas Nuclear
Issue date:	06/14/2006
From:	James D Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
1CAN060601
Download: ML061730358 (6)

Text

-Entergy Operations, Inc.

--- t-- 1448 S.FR.333 RusseLlville, AR 72801 Tel 501 858-5000 1CAN060601 June 14, 2006 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Steam Generator Tubing Inspection Report Arkansas Nuclear One - Unit I Docket No. 50-313 License No. DPR-51

Dear Sir or Madam:

Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specification (TS) 5.6.7 requires the results of ANO-1 steam generator (SG) tubing inspections to be submitted to the NRC within 180 days after the initial entry into mode 4 following completion of the inspection.

Attached is the Steam Generator Tubing Inspection Report which presents the results from ANO-1's scheduled refueling outage (1R19) baseline inspection of the replacement SGs.

These inspections were conducted during December 2005.

The 1R19 inspection performed on both SGs involved an initial full-length bobbin coil examination of 100%.

Should you have any questions regarding this issue, please contact Mr. Fred Van Buskirk of my staff at (479) 858-3155. This submittal contains no commitments.

Sincerely, DEJ/fpv Attachment AQO0J

1CAN060601 Page 2 cc: Dr. Bruce S. Mallett Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Drew Holland Mail Stop 0-7 D1 Washington, DC 20555-0001

-S Attachment I I CAN060601 Steam Generator Tubing Pre-Service Inspection Report

' Attachment to Page 1 of 3 1CAN060601 ARKANSAS NUCLEAR ONE, UNIT I STEAM GENERATOR TUBING INSPECTION REPORT I INTRODUCTION Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specification (TS) 5.6.7 requires Entergy Operations to submit a 180 day report to the NRC that presents the details of the steam generator (SG) tubing inspections that were peiformed during the reporting period. The report shall include:

1. The scope of inspections performed on each steam generator.

2. Active degradation mechanisms found.

3. Nondestructive examination techniques utilized for each degradation mechanism.

4. Location, orientation (if linear), and measured sizes (if available) of service induced indications.

5. Number of tubes plugged during the inspection outage for each active degradation mechanism.

6. Total number and percentage of tubes plugged to date.

7. The results of condition monitoring, including the results of tube pulls and in-situ testing.

The operating period for this report includes one outage, a refueling inspection (1R1 9) in December 2005 which was the steam generator replacement outage. This report details the result of the baseline inspection performed prior to placing the generators in service.

2 DESIGN The replacement steam generators for ANO-1 are Enhanced Once-Through Steam Generators (EOTSG) manufactured by AREVA. The EOTSG is a straight shell and tube type heat exchanger installed in a vertical position with bottom supports and such emergency supports as required to accommodate normal and accident loads. The tubing consists of Inconel 690 thermally treated tubing that is 5/8" in diameter with a 0.037" wall thickness. The tubes are expanded full depth hydraulically in the tubesheet. There are 15 tube supports that are constructed of stainless steel (SA 240 type 410) and are a broached trefoil-hole design.

3 REPORT REQUIREMENTS 3.1 The scope of inspections performed on each steam generator.

Table 3.1 1R19 Inspection Scope SG "A" Examination Type Inspections Conducted  % Scope Extent Tested Bobbin Initial 15595 100 TEC to TEH Bobbin I-Codes 0 N/A N/A X-Probe Full Length 15595 100 TEC to TEH SG "B" Examination Type Inspections Conducted  % Scope Expansion Rea'd Bobbin Initial 15597 100 TEC to TEH Bobbin I-Codes 0 N/A N/A X-Probe Full Length 15597 100 TEC to TEH

Attachment to Page 2 of 3 1CAN060601 3.2 Active degradation mechanisms found.

This was the initial baseline inspection prior to operation of the generators.

The only mechanisms identified were fabrication induced. These are listed in Table 3.2.1 for SG "A"and 3.2.2 for SG "B".

TABLE 3.2.1 SG "A" INDICATION LIST FOR 1R19 Item No. Row Tube Percent Location Mechanism Through Wall 1 6 22 N/A LTE +16.54 BLG 2 19 34 N/A 14S+13.05 MBM 3 74 118 N/A LTS + 0.60 BLG Legend:

LTE - Lower Tube End BILG - Bulge 14S - 14th Tube Support Plate MBM - Manufacturing Burnish Mark LTS - Lower Tubesheet TABLE 3.2.2 SG "B" INDICATION LIST FOR 1R19 Item No. Row Tube Percent Location Mechanism Through Wall 1 45 22 N/A LTS +5.22 MBM 2 10 27 N/A 15S+38.79 MBM Legend:

LTS - Lower Tubesheet 15S - 15th Tube Support Plate M13M - Manufacturing Burnish Mark 3.3 Nondestructive examination techniques utilized for each degradation mechanism.

NDE Mechanism Location Probe Detection POD Sizing RMSE Technique ETSS @ 90% CL ETSS (%TW) Uncertainty

(%TW)

MBM/BLG Bobbin 96010.1 0.886@0-4%TW 96010.1 0.92 1.14 Rev. 6 0.848@5-11%TW Rev. 6 Legend:

ETSS - Examination Technique Specification Sheet RMSE - Root Mean Square Error

Attachment to Page 3 of 3 1CAN060601 3.4 Location, orientation (if linear), and measured sizes (if available) of service induced indications.

There were no service induced indications identified.

3.5 Number-of tubes plugged during the inspection outage for each active degradation mechanism.

There were no plugs installed during the baseline inspection. There were 2 tubes plugged as a preventive measure during fabrication in SG "A"due to failed expander tooling. These are listed in Table 3.5.1 Table 3.6.1 Tubes Plugged SG "A" SG "B" Year Outage Installed Cumulative Installed Cumulative 2005 Fabrication 2 2 0 0 2005 Baseline 0 2 0 0 3.6 Total number and percentage of tubes plugged to date.

This information is listed in Table 3.6.1.

Table 3.6.1 Cumulative Plugs and Sleeves in Service SG "A" SG "B" Pre-service Sleeves 0 0 1R19 Sleeves Installed 0 0 Total Sleeves Installed 0 0 Pre-service 1-690 Welded 2 0 1R19 Plugs Installed 0 0 Total Plugged 2 0 Percent Plugged 0.012 % 0.000 %

3.7 The results of condition monitoring, including the results of tube pulls and in-situ testing.

Since this was the baseline inspection, there were no service induced indications identified that would challenge the performance criteria and no in-situ test required. There were a total of five manufacturing induced indications identified. This included three MBMs, 1 bulge and 1 over expansion also characterized as a bulge. The MBMs were. very small and had a bobbin voltage of approximately 0.5 volts each. One of the bulges was identified within the tubesheet and had a bobbin voltage of 3.89 volts. Profilometry was performed and resulted in a change in diameter of 0.0006 inches or 0.6 mils.

The second bulge which would be considered the most limiting was at the top of the tubesheet at the expansion transition on the lower tubesheet.

Profilometry was performed and the result was a change in diameter of 0.0005 inches or 0.5 mils. None of these indications would challenge the structural integrity of the tubing. Therefore, all performance criteria were met so condition monitoring was acceptable. There were no tube pulls performed.