IR 05000269/1995012
| ML16154A820 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/26/1995 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16154A819 | List: |
| References | |
| 50-269-95-12, 50-270-95-12, 50-287-95-12, NUDOCS 9508020042 | |
| Download: ML16154A820 (14) | |
Text
e.REGU, UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900 ATLANTA, GEORGIA 30323-0199 Report Nos.:
50-269/95-12, 50-270/95-12 and 50-287/95-12 Licensee:
Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos.:
50-269, 50-270, and 50-287 License Nos.:
DPR-38, DPR-47, and DPR-55 Facility Name:
Oconee Nuclear Station Units 1, 2 and 3 Inspection Conducted: June 19-23, and July 11, 1995 Inspector:
7.- /L
/5 J. L. 1 y J Date Signed Approved b X 5 J..
ake, Chief ate igned Ma e ials and Processes Section E gi eering Branch D vision of Reactor Safety SUMMARY Scope:
This routine, announced inspection was conducted in the areas of inservice inspection (Inspection Procedure No. 73753) and review of radiographic'film (Inspection Procedure No. 57090). The inspector also held discussions with DPC's cognizant engineers, reviewed completed records, and observed work activities in the areas of; erosion/corrosion and resulting pipe replacement activities; and system upgrade activities for the low pressure injection piping. In addition, on July 11, 1995, the inspector visited the Electric Power Research Institute (EPRI) in Charlotte North Carolina to reviewed Duke Power Company's (DPC) examiner performance demonstration records and observed a demonstration of DPC's flaw interpretation techniques delineated in Ultrasonic Examination Procedure No. NDE-600. The review at the EPRI center was the result of examiner/procedure weaknesses observed at the Oconee sit Enclosure 9508020042 950726 PDR ADOCK 05000269 G
Results:
In the areas inspected, no violations or deviations were identifie Relative to ISI, one unresolved item was reported which dealt with apparent ultrasonic examiner and procedural weaknesses (paragraph 2.c.(1)).
Radiographic examination activities were observed to be functioning in an excellent manner. Erosion/corrosion, eddy current, and pipe repair and replacement activities appeared to be satisfactor One weakness was also observed: clear Saran Wrap type material and clear plastic bags were observed being used extensively for protection of components and for carrying tools and materials in and out of the reactor containment building. Green or yellow bags and protective plastic materials are the standard used by the industry to prevent their inadvertent loss in components, the refueling canal, or the reactor vessel since clear plastic is difficult to detect in water. In addition the yellow plastic material/bags are used to indicate whether the material inside is contaminated or not (paragraph 4).
REPORT DETAILS Persons Contacted
- G. Bibb, Technician, Nondestructive Examination (NDE)
- M. Boyle, General Supervisor, Radiation Protection
- E. Burchfield, Manager, Regulatory Compliance
- T. Coleman, Inservice Inspection (ISI) Coordinator E. Few, Senior Technical Specialist
- C. Freeman, NDE Supervisor
- B. Foster, Manager, Safety Assurance
- J. Hampton, Site Vice President
- M. Hipps, Manager, Maintenance
- J. McArdle, Level III, NDE Examiner
- B. Millsaps, Manager, Mechanical Engineering
- D. Nix, Engineer, Safety Assurance
- B. Peele, Station Manager
- G. Rothenberger, Superintendent, Operations
- T. Royal, Mechanical Engineering Supervisor Other licensee and contractor employees contacted during this inspection included engineers, NDE technicians, and administrative personne Electric Power Research Institute L. Becker, Manager, Performance Demonstration Initiative (PDI)
D. Holthaus, Quality Control (QC) Specialist
- C. Latiolais, Manager, PDI Piping and Bolting NRC Employees
- P. Harmon, Senior Resident Inspector
- L. Keller, Resident Inspector
- Attended preliminary exit interview on June 22, 1995
- Attended exit on June 23, 1995
- Attended exit on July 11, 1995 Acronyms and initialisms used throughout this report are listed in the last paragrap.
Inservice Inspection (ISI) - Unit 3 (Inspection Procedure 73753)
The inspector reviewed documents and records, and observed activities, as indicated below, to determine whether ISI was being conducted in accordance with applicable procedures, regulatory requirements, and licensee commitments. The applicable code for ISI is the American Society of Mechanical Engineers Boiler and Pressure Vessel (ASME B&PV)
Code,Section XI, 1989 Edition (no Addenda).
Oconee 3 was in the 15th refueling outage, the first period of the 3rd ten year ISI interva The current outage is the 1st refueling outage of the 3rd ten year interva *II2 The licensee's Electric System Support Department is responsible for the ISI program and furnishes nondestructive examination (NDE) inspection personne The site Mechanical/Civil Engineering Group is responsible for implementing the ISI progra ISI Program Review The inspector reviewed the licensee's Third Ten Year Interval ISI Plan including the plan for the current outage to verify that the plan had been approved by the licensee, services of an Authorized Nuclear Inservice Inspector (ANII) had been procured, administrative procedures had been developed to implement the program, and procedures required to perform test and examinations had been revised to meet the requirements of the "Code of Record" (ASME Section XI, 1989 Edition) for the third ten year interval examination The inspector's review revealed that the above programmatic documentation was in accordance with DPC's Technical Specifications, the applicable ASME Code, correspondence between NRC's Office of Nuclear Reactor Regulations (NRR) and the licensee concerning relief requests and Code cases and requirements imposed by NRC/industry initiative Review of Nondestructive Examination (NDE) Procedures The Inspector reviewed the following procedures to verify that they had been approved by the licensee and the ANII, contained requirements for qualification of personnel and that they had been revised to implement the requirements of the 1989 Edition of Section XI to the ASME Cod Procedure Reviewed Title NDE - 12 Revision 9 General Radiography Procedure for Preservice and Inservice Inspection NDE - 600 Revision 5 Ultrasonic Examination of Similar Metal Welds in Wrought Ferritic and Austenitic Piping NDE - 640 Revision 1 Ultrasonic Examination Using Longitudinal Wave and Shear Wave, Straight Beam Techniques
NDE -
670 Revision 0 Ultrasonic Sizing of Planar Flaws in Ferritic and Austenitic Steels with Nominal Thicknesses from 0.2 Inch Through 2.0 Inches NDE - 701 Revision 2 Multifrequency Eddy Current Examination of Steam Generator Tubing NDE - 702 Revision 0 Eddy Current Data Screening Program NDE - 703 Revision 4 Evaluation of Eddy Current Data for Steam Generator Tubing NDE - 707 Revision 2 Multifrequency Eddy Current Examination of Nonferrous Tubing Sleeves and Plugs Using a Motorized Pancake Coil NDE - 708 Revision 2 Evaluation of Eddy Current Data for Non Ferrous Tubing, Sleeve and Plugs Using a Motorized Rotating Coil Probe NDE - 710 Revision 1 Multifrequency Eddy Current Examination of Non Ferrous Sleeve Tubes for Oconee Nuclear Station NDE - 711 Revision 1 Evaluation of Eddy Current Data of Sleeved Once Thru Steam Generator Tubing The review of the above procedures revealed that they met the ASME Code and NRC's/Industry initiatives in the areas described abov Observation of ISI Work Activities The inspector observed work activities, reviewed personnel qualification records, and reviewed certification/calibration records for equipment/materials, as detailed below. The inspector verified: availability of and compliance with approved procedures, compliance with Code requirements, use of knowledgeable personnel, and use of personnel qualified to the proper leve In addition, general inspection quality, including in-process documentation,
- 0 and inspection results were evaluate *I
(1) Manual Ultrasonic Examination (UT)
The inspector observed the in-process examination of the welds listed below. Observations were compared with the inspection attributes of the applicable procedure and the ASME Code to verify the performance of acceptable examination Item Number Weld ID N Weld Configuration C05.021.047 3-51A-59-6 4 Inch Dia. Pipe Weld B09.012.010 3-PDAl-53LO Longitudinal Seam Weld B09.012.009 3-PDAl-53LI Longitudinal Seam Weld B09.011.007 3-PIAl-8 Safe-end to Nozzle Weld During the 60* examination of Longitudinal Seam Weld N PDAl-53LO an indication was detected by the UT examine When the examiner inspected the applicable weld area from the other surface of the weld the indication was also readily detected. To interpret whether the indication was the result of a flaw in the material the examiner changed the 600 transducer and examined the indication with a 700 transducer. When the 700 transducer was used, the height of the signal dropped to approximately 5 percent of screen height. The examiner informed the inspector that since the signal decreased, in accordance with paragraphs 10.1.a. and 10.2.a of DPC's examination procedure No. NDE-600, the indication was caused by a geometrical condition not a fla The inspector questioned the examiner's interpretation, and the procedural requirements used to derive this interpretation, and was informed that Duke had qualified this method of flaw interpretation at the Electric Power Research Institute during their performance demonstration for Appendix VIII to the ASME Code. However, since Appendix VIII is not presently invoked, the examination procedure was demonstrated to the Authorized Nuclear Inspector as a alternative method of examination in accordance with Paragraph IWA-2240 of Section XI to the ASME Cod The inspector requested that the examiner scan the area of the weld using a 450 transducer to determined the condition of the ID and to see if the indication was ID connecte This was done and no signal was obtained, which indicated that discontinuity was a planar flaw and not connected to the pipe ID. The examiner then placed a 0* transducer over the flaw and obtained a signal that indicated the flaw was at a depth of 1.75 inches from the outside diameter of the
pipe and above the inspection zone of the wel Since the flaw could be seen from two pipe surfaces and from the top of the weld, the inspector did not consider the procedure's method of flaw/geometry interpretation satisfactory, particularly when scanning in a circumfer ential direction. The inspector phoned DPC's Level III Test examiner to ascertain if during the EPRI Procedure Performance Demonstration axial defects scanned in the circumferential direction had been demonstrated using the procedure's flaw/geometric interpretation criteria. The Level III stated that it had and that the qualification records could be reviewed at the EPRI Center in Charlotte, North Carolina. The Level III also stated that he could demonstrate the interpretation criteria techniques if the inspector was intereste The flaw indication detected above was later found to be outside the inspection zone, but was evaluated and found to be acceptable. However, as stated above this indication was first interpreted as root geometry using only a portion of the procedure's flaw interpretation criteri In addition, upon further review of the NDE procedure and discussions with the examiner it was determined that the circumferential scan of the longitudinal weld should have been performed initially with a 45* transducer in lieu of the 600 transducer used in order to insure that the bottom 1/3 of the weld was examine Because of the apparent examination and procedural weaknesses observed, and the possibility of similar errors made on other welds by examiners, the inspector requested to see the performance demonstration records and observe a demonstration of the interpretation criteri The inspector was subsequently notified by the licensee on July 5, 1995, that on July 11, 1995, the inspector could see the EPRI qualification results and observe a demonstration of the interpretation criteria on flawed samples of different materials, pipe diameters, and thicknesses using different wave mode transducers, and scanning in the axial and circumferential directions. This issue was reported to the licensee as Unresolved Item 50-269,270,287/95-12-01,
"Apparent Examiner and Procedural Weaknesses."
While at the Oconee site Certification and qualification records administered in accordance with SNT-TC-1A for nine ultrasonic examiners were reviewed and determined to be adequate. Certification and calibration records for the equipment and materials used in the above examinations observed by the inspector were also reviewed and determined to be satisfactor On July 11, 1995, the inspector met with DPC's Level III Examiner at the EPRI NDE Center and reviewed the examiner's performance demonstration records. The records revealed that the examiner in question had experienced problems with the identification of axial cracks, but had subsequently managed to pass the examination with a missed axial crack cal The data also revealed that DPC examiners only demonstrated the use of a 450or a 380 transducer to detect axial crack The practical demonstration on cracked samples revealed that none of the procedural criteria attributes for inter pretation of flaws/geometry could be met in the axial and circumferential scanning directions in every case. In particular the attribute which required the examiner to change from his primary inspection angle to a 700 transducer (if the 70* transducer detected the same reflector at an equal or higher amplitude the indication is consider to be crack if not it is considered to be geometry) did not work reliably when scanning in the axial or circumferential directions. It however, seem to work best in the axial scanning directio The DPC Level III examiner stated that, this was the first outage which utilized the version of NDE-600 demonstrated at the EPRI NDE Center. The Level III examiner also stated that the following actions would be taken to clarify the procedural requirements, improve performance, and insure ISI examinations of welds have been performed satisfactorily:
-
The procedure will be revised to specify that all of the flaw interpretation criteria will be attempted as far as practical, but that each attribute does not have to be met to be considered a flaw or a geometric indicatio Geometric/flaw interpretation criteria given in paragraphs 10.1 and 10.2 of procedure NDE-600 will be re-worded to define the applicability of each of the interpretation criteria attributes when scanning in the axial or the circumferential directions. Since most of the attributes given for interpretation are for circumferential indications scanned in the axial directio All examination data which recorded geometry or flaws during the Oconee summer 1995 outage of Unit 3 will be reviewed by the Level III examiner to insure the evaluations/interpretations were performed properly and that the correct transducer was use Additional training will be held on the procedures requirements and the procedural clarifications delineated abov The effectiveness of the licensee's corrective actions will be verified during subsequent inspection In the mean time this item will remain an unresolved issu (2) Review of Radiographic (RT) Film for ISI, Modifications, and System Upgrade Piping Welds (Inspection Procedures 73753 and 57090) Unit 3 The inspector examined the RT film and associated records for the welds listed below to determine whether they had been processed, examined, evaluated, dispositioned, and maintained in accordance with the licensee's approved procedure. The inspector also reviewed the radiographs to determine if the licensee's enhanced preventive maintenance actions taken to improve the effectiveness of the film processor at Oconee had resulted in a reduction of film artifacts. Several previous NRC inspection reports had addressed concern that film artifacts noted on radiographs were becoming a problem. In addition, the Senior Resident Inspector requested that the inspector review the radiographs for the Low Pressure Injection Upgrade Piping because of the frequency of reported weld rejects. The procedure used by the licensee for the RT examination process on modification and system upgrade piping was DPC's Procedure No. NDE-10, Revision 1 The procedure used by the licensee for ISI RT of piping welds was DPC Procedure No. NDE-12, Revision Radiographic Film Reviewed Weld ID N Size Area of Inspection 3-51A-59-87 4"Dia.X 0.674" TH Modification Weld 3-51A-59-88 4"Dia.X 0.674" TH Modification Weld 3-51A-59-89 4"Dia.X 0.674" TH Modification Weld 3-51A-59-90 4"Dia.X 0.674" TH Modification Weld 3-51A-121-16 4"Dia.X 0.674" TH Modification Weld 3-51A-121-17 4"Dia.X 0.674" TH Modification Weld 3-51A-121-18 4"Dia.X 0.674" TH Modification Weld 3-51A-121-19 4"Dia.X 0.674" TH Modification Weld 3-51A-121-21 4"Dia.X 0.674" TH Modification Weld 3-01A-23-9 24"Dia.X 0.969"TH ISI Piping Weld 3-53B-39-12 14"Dia.X 0.250"TH System Upgrade 3-53B-39-78 14"Dia.X 0.250"TH System Upgrade 3-53B-39-2 14"Dia.X 0.250"TH System Upgrade 3-53B-39-77 14"Dia.X 0.250"TH System Upgrade
3-53B-39-110 14"Dia.x 0.250"TH System Upgrade 3-53B-39-5 14"Dia.X 0.250"TH System Upgrade 3-53B-39-109 14"Dia.X 0.250"TH System Upgrade The inspector's review of the above radiographs revealed that excellent radiographic quality had been achieved. The film had been interpreted, evaluated, and disposition correctly. Film artifacts noted on the radiographic interpretation records were minor and did not represent a problem for interpretation. In addition, the licensee uses two film in each film cassette package. Both radiographs for each film segment in the welds listed above had achieved sufficient radiographic quality that either film could be used for acceptance of the welds. Therefore, eliminating concern for the cases where artifacts were noted because they were only on one film. The inspector also went to the field office and performed an inspection of the preventive maintenance practice for the processor. The inspector found the rollers in the processor to be clean and in excellent condition. The licensee appears to have taken sufficient corrective action. If this corrective action is maintained, film artifacts should not affect film interpretatio In response to the Senior Resident Inspector's concern regarding the low pressure injection piping, the inspector's review revealed that lack of fusion had been found in some of these welds since the licensee was upgrading portions of this system. The welds in question had never previously been radiographed. However, the lack of fusion was identified in the weld root area of pipe to valve welds and was being systematically corrected by grinding the ID diameter of the piping. The inspector reviewed the upgrade film and determined that the licensee was evaluating the welds correctly and taking the appropriate correct actio The inspector also observed the repair activities in the plant and no problems were identified. As of June 20, 1995, the repair activities on the low pressure injection piping had only been by grindin Certification and qualification records were reviewed for 12 radiographic examiners and found to be adequat Calibration was also verified to be satisfactory for DPC's densitometer No. 018454 and film strip No. 05926 (3) Eddy Current Examination of Unit 3, A and B Steam Generator Tubing, Sleeves and Plugs This outage the licensee will examine 100 Percent of the tubes in both "A" and "B" Steam Generators using a.510" bobbin coi In addition a select sample of special interest tubes, sleeves, expanded lane/wedge, and roll plugs
(I@
will be examined using coils such as the rotating pancake coil, the Plus Point rotating pancake coil, and a.410" bobbi Controlling documents/code by reference, included ASME Code Section XI, 1989 Edition, DPC's Oconee's Technical Specification, Regulatory Guide 1.83 (July 1975), and Code Cases N-401 and N-402. Acquisition activities are performed by DPC using DPC, Babcock and Wilcox (B&W) and Zetec examiners. The analysis of data was performed off site at the McGuire Nuclear facilit The inspector observed eddy current examiners perform bobbin coil examinations of tubes on Rows 123, 124, and 125 in the
"B" Steam Generator. Eddy current procedures were also reviewed to determine if any procedure had been revised since the previous NRC review reported in Inspection Report No. 95-35 dated November 30, 1995. Certification and qualification records for twelve DPC examiners, ten B&W examiners and one Zetec examiner were reviewed. The inspector's review of the eddy current examination activities revealed that they were performed in a satisfactory manner using current procedures and sufficiently qualified personne Within the areas examined, no violation or deviation was identifie.
Review of Erosion\\Corrosion (E/C) Examination and.Repair Activities Upon arriving at the Oconee facility the inspector discovered that the licensee had detected ultrasonic thickness readings during their in process E/C examinations which required piping immediately downstream of both Unit 3 feedwater pumps to be replaced (Inspection location No FDW42 and 3FDW43).
The inspector subsequently reviewed the licensee's E/C activities to insure that these activities were being performed in accordance with the licensee's approved procedures and that proper sample expansion was considered. The inspector discovered that this outage the licensee had selected 82 inspection locations to examine for material lost due to E/C. The inspector's review of examination data sheets for the completed inspection locations revealed that the licensee was adhering to their program in a conservative manne For the feedwater system the inspector found that the licensee had examined the other two units during their previous outage and had not discovered any problem with these units. However, the previous examination of the Unit 3 feedwater piping required that it be re examined this outage because of noted pipe wall thickness reduction The inspector also noted that the data sheets for inspection locations Nos. 3C0003 and 3C0006 had some erratic thickness reading. The licensee stated that they were in the process of re-examining these location The inspector also went in the plant and observed the piping which had
there was anything unusual about its configuration that had made it more susceptible to erosion/corrosion than the piping in the other two Unit In addition the inspector went to the fab shop to see what preps had been made on the replacement piping. The inspector found that the licensee was applying good judgement in their control of the E/C progra Within the areas examined, no violation or deviation was identifie.
Independent Inspection Observations During routine trips to the refueling floor the inspector noted that clear Saran Wrap type material and clear plastic bags were being used extensively in the reactor containment building for protection of components and for carrying tools and materials in out of the buildin Green or yellow bags and protective plastic materials are the standard used by the nuclear industry to prevent their inadvertent lost in components, the refueling canal, or the reactor vessel since clear plastic materials are difficult to detect and retrieve in water. In addition, the industry uses the green and yellow plastic materials/bags to indicate whether the materials inside are contaminated or no On the refueling floor the licensee had a foreign material exclusion (FME) barrier and control point set-up around the reactor vessel to control materials entering though this barrier. However, the refueling canal only had a 4" kickplate around it and there is a floor above the refueling floor at Oconee. Materials could be blown from this upper floor over the FME barrier and into the reactor vessel or refueling canal. The licensee stated that they had been using clear plastic instead of green or yellow materials since the plant was constructed and that chemistry verifications had not detected any chloride intrusion, which would result if plastic material had inadvertently entered the system. The licensee also stated that their good housekeeping practices would minimize the chance for materials inadvertently entering the reactor coolant syste The inspector reiterated that nuclear industry position was also based on previous experience (good and bad) and good work practice and for years the nuclear industry has used green and yellow materials for FME control purposes. This is done because, the yellow or green materials can be easily seen visually in water and contaminated materials can be easily identified when every worker knows that they are required to be wrapped in yellow plastic materials or bags. In addition, paragraph 104.7.3(11) of DPC's Nuclear System Directive No. 104 entitled: "
Housekeeping, Material Condition and Foreign Material Exclusion," states in part that, for temporary covers: clear plastic will not be used near the fuel pools, refueling canal and reactor cavity since detection and retrieval are very difficult. The inspector expressed concern that DPC's other two nuclear plants had interpreted the same procedure to mean that no clear plastic would be allowed and that industry standards would be followed. This issue was initially reported to the licensee as an unresolved item until NRC management could be consulted by the
inspector. The inspector returned to the Region II Office on July 5, 1995, and after consulting with management, a conference telephone call was initiated between NRC Regional Project Management, the inspector, and DPC's Manager of Safety Assurance. During this call the licensee stated that, they now realize that they are an outlier in control of plastic materials (bags/sealing materials) and that they intended to conform to industry practice. The licensee also stated that they will immediately start sealing and wrapping components with yellow or green plastic material and that they are buying new bags and plastic wrap for this purpose. However, the licensee stated that they may not have all clear wrap removed by the next refueling outage in October, 1995, because of the volume of components involve After discussing this matter with the licensee and hearing their position for corrective action, Region II Project Management elected to report this issue as a weakness for which immediate action is being taken. Completion of the licensee's corrective actions will be monitored during subsequently inspections by regional and resident personne Within the areas examined, no violation or deviation was identifie.
5. Exit Interview The inspection scope and results were summarized on June 22, 23, and July 11, 1995, with those persons indicated in paragraph 1. The inspector described the areas inspected and discussed in detail the inspection results listed below. Proprietary information is not contained in this report. Dissenting comments were not received from the license (Open) Unresolved Item No. 50-269,270,287/95-12-01, "Apparent Examiner and Procedural Weaknesses," paragraph 2.c.(1) Acronyms and Initialisms ANII
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Authorized Nuclear Inservice Inspector ASME -
American Society of Mechanical Engineers B&PV -
Boiler and Pressure Vessel Dia. -
Diameter DPC
-
Duke Power Company E/C
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Erosion/Corrosion EPRI -
Electric Power Research Institute FME
-
-
Feedwater System ID
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Inside Diameter ISI
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Inservice Inspection LPI
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Low Pressure Injection System NDE
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Nondestructive Examination N Number No Numbers NRC
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Nuclear Regulatory Commission
-
Nuclear Reactor Regulation ONS
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Oconee Nuclear Station PDI
-
Performance Demonstration Initiative RII
-
NRC Region II RT
-
Radiographic Test SG
-
Steam Generator THK. -
Thickness TS
-
Technical Specification UT
-
Ultrasonic Test