IR 05000269/1991020
| ML16148A553 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 09/04/1991 |
| From: | Blake J, Economos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16148A552 | List: |
| References | |
| 50-269-91-20, 50-270-91-20, 50-287-91-20, NUDOCS 9109240301 | |
| Download: ML16148A553 (7) | |
Text
REG UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report Nos.:
50-269/91-20, 50-270/91-20, and 50-287/91-20 Licensee:
Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos.: 50-269, 50-270, License Nos.: DPR-38, DPR-47, and and 50-287 DPR-55 Facility Name:
Oconee 1, 2, and 3 Inspection Co gust. 12-16, 1991 Inspecto :
omos Date Signed Approv d by:
J J,Kake, Chief ate Signed a rials and Processes Section E gineering Branch Division of Reactor Safety SUMMARY Scope:
This routine, unannounced inspection was conducted in the areas of Unit 1 inservice inspection activities including eddy current examination of once through steam generator (OTSG),
tubes,plans for plugging previously installed explosive plugs that exhibit cracking, and replacement of letdown cooler "1 A" and associated pipin Results:
By observation, interviews and records/procedures reviews the inspector ascertained that inservice inspection (ISI), activities i.e., plans, procedures and component examinations were consistent with code and regulatory requirement Site engineering continues to maintain a strong position in planning and implementing plant maintenance and modification In the areas inspected, violations or deviations were not identifie PDR ADOCK 05000269
REPORT DETAILS 1. Persons Contacted Licensee Employees
- H. B. Baron, Station Manager J. Batton, Nuclear Production Engineer J. M. Baumann, Supervisor Nuclear Eddy Current (EC)
C. B. Cheezem, Manager, Inservice Inspection
- T. J. Coleman, ISI Coordinator
- W. W. Foster, Maintenance Superintendent B. Millsaps, Maintenance Service Manager
- R. A. Morgan, QA Director D. L. Robinson, NDE Examiner Other licensee employees contacted during this inspection included technical and administrative personne NRC Resident Inspectors P. Harmon, Senior Resident Inspector
- B. B. Desai, Resident Inspector
- W. K. Poertner, Resident Inspector
- Attended exit interview 2. Inservice Inspection, Unit 1 This is the thirteenth refueling outage and the second ten year outage for this uni In a meeting held at NRC Headquarters on June 18, 1991, the licensee presented to the staff, their plan for inspection of the reactor vesse The presentation outlined the vessel welds scheduled for inspection including nozzles, dissimilar metal welds and main loop piping welds, previously submitted relief requests, augmented inspections, alternate examination methods, and technological enhancements in ultrasonic examination which will be implemented for improved inspection result The applicable code for this examination and the scheduled ISI activity was the ASME Section XI 1980 Edition with Addenda through Winter 1980. At the site, the inspector reviewed the current outage inspection plan including applicable code cases, code relief requests and augmented inspection Also the inspector reviewed, randomly selected records of previous results involving approximately thirty-five (35) welds scheduled for inspection during this outage and related NDE/QA procedure The inspector observed ISI activities, indicated below to determine whether examinations/inspections were being conducted in accordance with requirements of the applicable code, procedures, regulatory requirements and licensee commitment Independent third party inspection service(s)
(ANII/ANI), was provided by Hartford Boiler Compan At the time of this inspection, manual ISI examinations were in progres Removal of reactor fuel was in the final stage of completio Following removal of the fuel, the lower reactor vessel internals were removed and visually inspected. On August 15, the automatic remote control inspection tool (ARIS) was placed on the vesse Following calibration, inspection of reactor vessel welds commenced. Within these areas, the inspector elected to observe a representative sample of the on-going ultrasonic and eddy current examinations, including placement of ARIS on the reactor vessel, and review QA documents relative to procedures, personnel qualifications and certification of materials and equipment used in these examination a. Review of NDE Procedures (73052)
The inspector reviewed the procedures listed below to determine whether they were consistent with regulatory requirements and licensee commitments. The procedures were also reviewed in the areas of procedure approval, requirements for qualification of NDE personnel, and compilation of required record NDE-12 Rev. 8 General Radiography Procedure for Preservice and Inservice Inspection NDE-25 Rev. 14 Magnetic Particle Examination Procedure and Technique NDE-35 Rev. 13 Liquid Penetrant Examination NDE-600 Rev. 0 Ultrasonic Examination of Similar Metal Piping Welds in Wrought Ferretic and Austenitic Material NDE-610 Rev. 0 Ultrasonic Examination of Welds Using Refracted Longitudinal Waves NDE-620 Rev. 0 Ultrasonic Examination of Welds in Wrought Ferretic Pressure Vessels less than 2" In Thickness NDE-701 Rev. 1 Multifrequency Eddy Current Examination of Steam Generator Tubing at McGuire, Catawba and Oconee Station Only NDE-703 Rev. 3 Evaluation of Eddy Current Data for Steam Generator Tubing NDE-705 Rev. 0 Multifrequency Eddy Current Examination of Nonferrous Tubing
b. Observation of Work and Work Activities Unit 1 (73753)
The inspector observed work activities, reviewed certification records of NDE equipment and materials, and reviewed NDE personnel qualifications for personnel, utilized for ISI examinations observe The observations and reviews conducted by the inspector are documented belo (1) Ultrasonic Examination Figure N Item Description Search Units 809.011.036 B1 Circ. Seam 450 and 610 PC 57 to PC 62 Shear Wave 809.011.088 B Hot Leg Terminal 450 Shear End PC 36 to PC 70 809.012.025 B1 Long Seam 450 and 610 PC 62R to 62L Shear Wave B09.012.026 B1 Long Seam 450 and 610 PC 62L to PC62R Shear Wave With respect to these items, the inspector noted the following:
The examination of weld 1PIB15, figure B09.011.036 exhibited an indication near the root of the weld that had sufficient amplitude (50%),
and depth to require further investigatio The indication was observed during the 450 shear wave examination and had an approximate length of 1.6 inche Duke's corporate Level III has requested further examinations with associated plotting to help characterize it more accuratel Items B09.012.25 and.26 are long seams on the elbow, on the suction side of steam generator "B" primary pipin These seams were scheduled for a 450 and 600 shear wave examinatio However during the examination the technicians discovered that the geometry of the weld crown was such that it precluded satisfactory examination of the code required weld volume and related base meta The examination, as observed by the inspector, was partially successful with the 450 transducer and almost totally unsuccessful with the 600/610 transducer. Discussions with cognizant licensee personnel resulted in the decision to grind down the weld crown to a level that would permit full examination of the code required weld volum Within the areas inspected violations or deviations were not identifie c. Record Review and Evaluation (73755)
The following listed ultrasonic equipment and materials certification records were reviewe Ultrasonic Instrument:
Serial Number 31501-921 Model USD-10, Krautkramer Spectrum analysis data was reviewed for the following ultrasonic transducers:
E01705 2.25 Mhz 610 shear 1" di E15769 2.25 Mhz 450 1" di Ultrasonic couplant: Ultragel II Batch #8981 PO# 30307, 4/8/89 Thermometer: S/N 32916 Ultrasonic Calibration block:
40350 Eddy Current Examination of S/G(s) Tubes, Unit 1 As stated earlier, ISI activities during this outage included eddy current (EC)
examination of tubes in "A" and "B" steam generator Data acquisition and analysis were being performed in accordance with procedures identified earlier in this repor Controlling documents/code by reference, included ASME Code Section XI (80W80),
Regulatory Guide 1.83 July 1975 and Code Case N-401, Digitized Data Collection for Eddy Current Examinatio Data acquisition was being performed by licensee personnel while data analysis was conducted by Zetec and Babcock & Wilcox (B&W) personne Examinations were being performed with a multifrequency bobbin coil technique, utilizing the computerized MIZ-18 syste Current plans called for the inspection of 9351 tubes in S/G "A" and 9442 in.S/G "B".
In addition to these tubes, the licensee scheduled for inspection the explosive plugs in both S/G(s) to determine the extent of cracking, since a number of them, about eleven, had been found with crack indication The number of explosive plugs to be inspected were as follows:
S/G "A" S/G
"B" Hot Leg
108 Cold Lea
33 By completion of this inspection, examination of these plugs was still in.progres Preliminary evaluations disclosed that S/G "lA" had approximately sixteen plugs with crack indications on the primary pressure end of the plug while S/G "lB" had approximately fourteen plugs with crack indications in the same region. These were included in the population of sixty (60)
plugs in the hot and cold legs of
S/G,
"B" and were still under investigatio The licensee had contracted the services of B&W Nuclear Technologies to help with the development of and assistance with a plan to repair the cracked plug Through discussions with the cognizant engineer, the inspector ascertained that B&W had developed a repair procedure which called for welding a plug, approximately 0.300" thick, on top of the existing plug thus capping the cracked plug and therefore isolating it from the primary water environmen At the close of this inspection, the inspector ascertained that B&W had provided the licensee with a copy of the qualified welding procedure qualification record for review and approval. The welding procedure specification, number 51-1205304-01, had been qualified for use with the automatic tungsten arc welding (TIG)
process using ERNiCr-3 filler metal wire to deposit a continuous fillet weld with a minimum throat of 0.035 inches around each plu The licensee indicated that B&W had qualified their operators on mock-ups to simulate field condition The welding would be done with remote control equipment for ALARA consideration Finally, the inspector indicated that although the repair seemed technically feasible, the entire matter should be discussed with NRR before proceeding with the repai Following this inspection, the inspector ascertained that the licensee had contacted NRR to discuss and receive permission for using the provisions of ASME Code Section XI, 1989 Edition IWB-4239 to qualify the weld procedure. This edition of the Code has not been published in the Federal Register and as such has not been accepted by the Commissio In reference to the EC inspection of S/G tubes still in-service, on August 16, 1991, the inspector ascertained that, the following number of tubes had been inspected and analyze S/G "A" S/G "B" Tubes Examined 3725 2700 Tubes Analyzed 3530 2506 Of these, no tube had been identified as requiring pluggin Within this area, the inspector observed inspection activities for, in-service tubes and defective plugs including in-line calibratio Personnel qualifications as well as equipment and calibration standards certifications were also reviewe Within the areas inspected violations or deviations were not identifie. Letdown Cooler "lA" Replacement Unit 1 (62700)
At the time of this inspection, the "lA" letdown cooler was being removed and-replaced with a refurbished one from Unit The replacement was being performed on work-request (WR) number 09432C. Associated piping and fitting replacements included the following:
450 Ell 3" schedule 160 SA403 Ht# 464671 Piping 3" schedule 160 SA312/376 Ht# 475132
Because the replaced piping was made from stainless steel type 316 material, an Exempt Change (EC),
number 4132 was issued to address and to justify this change in material specificatio The applicable code for this replacement activity included ANSI 831.7 and ASME Code Section XI. A total of seven welds were involved in this replacement effor Weld number 24 on ISO 1-51A-134A Rev. 5 was selected for a review of radiographic film quality, weld procedure qualification records, material certifications and personnel qualifications. The weld was fabricated with a combination TIG/shielded metal arc procedure. The technique sheets were identified as L-231 Rev 18 and L-304 Rev 16, respectivel Welders used to fabricate this joint were identified by stencil numbers FBD/A65 and TUB/H16. The latter was qualified on the TIG process only and therefore fabricated only a portion of this wel Filler material used was as follows:
Material Lot/Ht#
QA Tag#
Size ER-308 30536 62806 1/8" di ER308-16 5A111QO1 62127 3/32" di The weld was radiographed with the radiographic procedure identified earlier in this report as required by code. A review of the film and associated records disclosed the weld was repaired twice to remove rejactable indications in radiographic stations one through fou The final radiographs met code requirements and had been approved by QA and the Code/ANI inspector With the areas inspected violations or deviations were not identifie. Exit Interview The inspection scope and findings were summarized on August 16, 1991, with those persons indicated in paragraph 1 above. The inspector described the areas inspected and discussed in detail the inspection result No dissenting comments were received from the license Proprietary information is not contained in.this repor II