IR 05000313/1993022
| ML20044G866 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 05/24/1993 |
| From: | Powers D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20044G852 | List: |
| References | |
| 50-313-93-22, 50-368-93-22, NUDOCS 9306040370 | |
| Download: ML20044G866 (8) | |
Text
{{#Wiki_filter:. _ - . . - - , " . APPENDIX U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
Inspection Report: 50-313/93-22 50-368/93-22 Operating Licenses: DPR-51 NPF-6 Licensee: Entergy Operations, Inc.
Route 3, Box 137G , Russellville, Arkansas 72801 Facility Name: Arkansas Nuclear One, Units 1 and 2 , Inspection At: Russellville, Arkansas Inspection Conducted: May 7-12, 1993 Inspector: L. D. Gilbert, Reactor Inspector, Maintenance Section
Division of Reactor Safety Approved: W Dr. Dale A. Powers, Chief, Maintenance Section .Date Division of Reactor Safety i Inspection Summary Areas Inspected (Unit 11: No inspection of Unit I activities was performed.
Areas Inspected (Unit 21: Routine, announced inspection of the activities > associated with the eddy current examination of steam generatar tubing.
Results (Unit 1): Not applicable.
~ . Results (Unit 21: The licensee'successfully completed the steam generator inspection
commitments addressed in the December 1992 meeting with personnel from > Region IV and the Office of Nuclear Reactor Regulation (Section 2).
The inspections for circumferential cracks at the steam generator
tubesheet transitions were performed by qualified contract. personnel that had received additional specific training and performance testing (Section 2).
The inspection with the motorized' rotating pancake coil identified 48
tubes containing circumferential cracking at the tubesheet transitions and which were subsequently plugged (Section 2).
9306040370 930525 PDR ADDCK 05000313 G PDR -
il . . -2-The inspections were successfully completed ahead of schedule by using
dual eddy current probes and a fiber optics link between the data acquisition computers and analyst computers (Section 2).
The licensee's oversight of the contractor's eddy current examinations
and related activities was good (Section 2).
Summary of Inspection Findinal: No inspection findings were opened or closed.
- Attachment:
Attachment - Persons Contacted and Exit Meeting
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-3- , DETAILS 1 PLANT STATUS During this inspection, the Arkansas Nuclear One (AN0), Unit 2, plant was in a planned outage for the examination of steam generator tubes.
2 INSERVICEId3PECTION-OBSERVATIONOFWORKANDWORKACTIVITIESANDFOLLOWUP - (73753 AND $1201) " The objectives of this inspection were to ascertain the completion of licensee commitments made in the December 2, 1992, meeting in Rockville, Maryland, with personnel from Region IV and the Office of Nuclear Reactor Regulation. The commitments related to eddy current examination, with the motorized rotating pancake coil, of approximately 6,000 tubes in each steam generator in the region of the sludge pile above the tube sheet and eddy current examination , with the bobbin coil of the two tubes missed during the last refueling outage.
This inspection was also a followup to NRC Inspection Report 50-313/92-26; 50-368/92-26, regarding the effectiveness of the licensee programs for
detecting and repairing degraded tubing in the Unit 2 steam generators.
- 2.1 Discussion The inspector reviewed the improvements and changes made to the Unit 2 steam i
generator eddy current program since the last refueling outage-(2R9). The
following improvements and changes were found to be in place and incorporated-into the current planned outage (2P9) eddy. current examination activities for , the steam generator tubes in Unit 2.
! Software programs were changed to address the concerns from missing two
tubes during performance of the 2R9 bobbin coil eddy current . examinations.
Procedure ANO-410-007, " Procedure for Control of Eddy ! Current Data for use with Multiforth or Eddynet Acquisition Systems," Revision 1, included requirements for performance demonstration of the . ' ' software programs used during steam generator examinations. The inspector reviewed the documentation, dated May 5,'1993, that reported the satisfactory completion of the challenge tests for the Eddynet , Version 21 and ISIS Tube Release Version 2.42CE-3 software program. The , challenge test for the Eddynet program was designed to verify that all postulated discrepant conditions between the primary and secondary analysis reports were correctly identified. The challenge test lof the ' 1515 Tube Release program. s oesigned to verify that all data _ input was consistent with established reporting conventions and that all tubes , scheduled to be examined were, in fact, examined.
Engineering Standard HES-28, "ANO-2 Steam Generator ECT Data Analysis
Guidelines," Revision 1, was revised to: delete information applicable to Waterford, Unit 3, add a resolution flowchart for rotating pancake , i - - + < - - = = -,,,. ~ =.-.e-- ,, wee--w-w--w,,ww--* -n.= w aw e ,=w , + - - e-- vv-rri-+ev.
-w, . -
- , . .
. -4-coil data analysis, and add guidance for dispositioning noisy eddy current data.
.' Equipment was upgraded for the use of optical disks for recording the-
acquisition of eddy current data and a fiber optic link between acquisition and analyses, which expedited analyses, retest, and evaluation of data.
The inspector verified that the primary and secondary eddy current data analysts had received the indoctrination training and passed the performance testing requirements of Engineering Standard HES-29, "ANO-2 Steam Generator ECT Performance Demonstration," Revision 1.
The indoctrination training included an overview of the AND Unit 2 steam generator design, operating history, eddy current examination history, status of tubes plugged or sleeved, correlation of eddy current data to metallographic examination'results on tubes pulled and tested, circumferential cracking verses false _ positive indications, and importance of entering correct data.
The inspector toured the plant to observe the equipment setup inside the containment building that was being used for pushing and retracting the eddy current dual probes in the steam generator tubes. The inspector was shown the full-size steam generator mockup that was used for training personnel for , installing nozzle dams and setting up the eddy current manipulator and video . camera inside the steam generator bowl. Since the radiation levels were very - high inside the steam generator bowl,'the mockup training and remotely controlled equipment allowed examination and plugging operations to be performed remotely, thus, reducing exposure of personnel to radiation.
The inspector also observed the eddy current testing of six tubes in the "A" steam generator using the manipulator mounted with the dual guidetubes. The inspectoi verified that the tube position indicators for both guidetubes were in agreement with the tubesheet drawing. A calibration standard was attached to the end of each guidetube. The eddy current data collected for a group of tubes included the calibration standard at the beginning and ending of each group of tubes. The eddy current examinations were performed using
independently controlled motorized rotating pancake coil probes and probe pushers for each guidetube that was operated by different operators using a separate work station.
I For the examination of the tube transition area above the tubesheets, the inspector was informed that the eddy current data was taken for a segment of tubing approximately 2 inches above and 1 inch below the top of the tubesheets.
The inspector verified that the certifications for personnel, equipment, and calibration standards were approved by the licensee's nondestructive i examination section, engineering, and authorized nuclear inservice inspector, j in addition to being consistent with requirements of Section XI of the ASME Boiler and Pressure Vessel Code, 1986 edition. The personnel performing the '
. t . .
' i . -5- ! f examinations were found to be knowledgeable of and complying with the eddy current data acquisition requirements specified in Work Plan 2409.413, " Inservice Inspection in ANO-2 RSG Tubing by CENS," Revision 0.
During the inspection, the inspector also reviewed the foreign material exclusion accountability logs for the four steam generator bowl areas. The tools, parts, and materials taken in and out of the steam generators were appropriately documented in accordance with the instructions specified in Procedure 1025.019, " System Cleanliness Controls During Modification and Maintenance," Revision 4.
The eddy current data collected on each steam generator tube were independently evaluated by a primary analyst and a secondary analyst who were employed by different companies and had their own work stations and computers.
, The responsibility of the primary and secondary analysts was to independently evaluate each steam generator tube in accordance with the analysis guidelines of Engineering Standard HES-28, which included screening the data from the , motorized rotating pancake coil for possible indications of undesirable noise.
The results from the primary and secondary analysts would be compared using the Eddynet computer program.
If the results of the primary analyst and the secondary analyst _ agreed, the tubes with possible indications would be marked for evaluation by the senior analyst. Where the results did not agree, the lead primary and lead secondary analysts, who were certified Level IIIA examiners in eddy current testing, would review the data.- If they could not agree on a resolution, the data would be given to the senior analyst for , evaluation. The senior analyst, a certified Level IIIA eddy current examiner, was responsible for evaluating each tube containing a possible indication and quantifying any indications. The inspector observed the data analyses performed on approximately 50 steam generator tubes, which included evaluations performed by the primary analyst, the secondary analyst, the resolution analysts, and the senior analyst. The inspector concluded that the data analyses were performed consistent with the requirements in the guidelines.
, The inspector observed the plugging of the three tubes on the cold leg side of Steam Generator B and verified that the requirements of Work Plan 2409.412, " Installation of Plugs and Stakes in ANO-2 RSG Tubing by CENS," Revision 0, were followed for the manual plugging operation. The items verified incluaed tube location, plug material and certification, tube cleaning and sizing, plug expansion rolling and torque values, and quality control verification and documentation of designated steps in the work plan.
The material requirements r for the Inconel 690 plugs were contained in Design Specification ANO-M2544 and certif:.'.:an for the plugs was satisfactorily doc'_... anted in Material
Inspection Report M00022.
The inspector reviewed the licensee's oversight of the contractors performing ' the eddy current examinations and related activities.
The oversight of the contractors included surveillance by a quality auditor and a quality nondestructive examination specialist, and monitoring of the senior analyst's evaluation by an eddy current specialist from the Entergy corporate office.
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. . . . -6 - , , The inspector was informed of the scope and status of the surveillance,. Surveillance Reports SR-93-20 and CSR-002E-2, respectively, in addition to the monitoring activities by the corporate of fice and concluded that the oversight by the licensee was good.
The inspector reviewed the final inspection maps prepared by data management , for each generator and verified that the tubes examined at the top of the tubesheet with the motorized rotating pancake coil satisfied the licensee's commitment. The tubes depicted on the final inspection map for examination using the motorized rotating pancake coil were consistent with the tube locations specified by engineering for examination during the current outage.
Of the 5,614 tubes inspected in Steam Generator A, 45 were identified as having circumferential cracks at the tubesheet transition and 2 others showed material loss on the tubing outer surface. Of the 5,832 tubes inspected in Steam Generator B, three were identified as having circumferential cracks at the tubesheet transition. All 50 tubes were repaired by plugging the hot and cold ends of the tubes. The following Table which was developed and discussed in NRC Inspection Report 50-313/92-26; 50-368/92-26, was updated to include the repairs from the current outage.
Table , , Time of Operational - > Repair Time (EFPYs) Steam Generator A Steam Generator B (Outage) u Plugged l Sleeved Plugged Sleeved Preservice
15
29
2R2 (1982) 1.69
0
0 2R6 (1988) 5.38
0
0 , 2R8 (1991) 7.67
0
0 , 2F92 (1992) 8.51
392
56 2R9 (1992) 8.85
-4 132
2P9 (1993) 9.36
0
0 Total 158 388 255
Repairs The inspector was informed that the engineering analyses of the eddy current examination results would be included in a 60-day voluntary report to NRC, e
'~ .
, -7-2.2 Conclusions The licensee successfully completed the steam generator inspection commitments addressed in the December 1992 meeting with personnel from Region IV and the Office of Nuclear Reactor Regulation. The inspections for circumferential cracks at the steam generator tubesheet transitions were performed by qualified contractor personnel that had received additional specific training and passed a performance test. The inspector concluded that the licensee's oversight of the contractor's work was good.
As a result of the inspections, 48 tubes were identified with circumferential cracks at the tubesheet transition and which were subsequently plugged.
Two other tubes were plugged as a result of tube wastage.
The inspections were successfully completed ahead of schedule by using dual eddy current probes and a fiber optics link between the data acquisition computers and analyst computers.
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. , ATTACHME][[ - 1 PERSONS CONTACTED , 1.1 Enterav Personnel ,
- S. Boncheff, Licensing Specialist
- B. Eaton, Director, Design Engineering
- R. Edington, Plant Manager, Unit 2
- C. Eubanks, Supervisor, Engineering Prcgrams
- J.
Fisicaro, Director, Licensing '
- D. Harrison, Senior Lead Engineer
- L. Humphrey, Director, Quality
- R. King, Supervisor, Licensing
- D. Lomax, Manager, Engineering Programs
- J. McKenzie, Quality Nondestructive Examination M. Sellman, General Manager, Plant Operations 1.2 NRC Personnel
- A. Gaines, Resident Inspector (Acting)
In addition to the personnel listed above, the inspector contacted other personnel during this inspection period.
- Denotes personnel that attended the exit meeting.
, 2 EXIT MEETING An exit meeting was conducted on May 12, 1993. During this meeting, the inspector summarized the scope and findings of the inspection. The licensee-did not identify as proprietary, any information provided to, or reviewed' by the inspector.
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