IR 05000269/1992005
| ML16148A630 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/02/1992 |
| From: | Blake J, Coley J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16148A629 | List: |
| References | |
| 50-269-92-05, 50-269-92-5, 50-270-92-05, 50-270-92-5, 50-287-92-05, 50-287-92-5, NUDOCS 9203180159 | |
| Download: ML16148A630 (14) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION
..
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report Nos.:
50-269/92-05, 50-270/92-05, and 50-287/92-05 Licensee:
Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos.: 50-269, 50-270, Licensee Nos.: DPR-38, DPR-47, and 50-287 and DPR-55 Facility Name:
Oconee 1, 2, and 3 Inspection Conducted:
January 27-31, 1992 Inspector:
,.
J._U
&_A T
e Date Signed Approved By:A Sake, ChiefSigned erials and Processes Section gineering Branch Division of Reactor Safety SUMMARY Scope:
This routine, announced inspection was conducted in the area of Unit 2 inservice inspection (ISI) activities which included observation of automated ultrasonic examinations of the reactor vessel and evaluation of the examination data, review of radiograph film for ISI welds, and visual examination of main steam system snubbers and support In addition, radiographs for modification welds fabricated for Unit 2 this outage were examined, steam generator tube welding and certifications of welders were reviewed, and the status of erosion/corrosion and eddy-current work activities was discussed with Duke's cognizant maintenance engineer Results:
The inspector's interface with licensee management, engineering, and inspection personnel revealed that they were very knowledgeable, professional, and proficient in performing their work activities within the guide lines provided by various station instructions. However, one unresolved item was
.
identified which will be addressed as Unresolved Item No. 50 269,270,287/92-05-01, "Maintenance Corrective Action on Failed Supports", which is scheduled for follow-up inspection by 9203160159 920304 PDR ADOCK 05000269 Q
O Region II. This item is discussed in detail in paragraph In addition, the inspector expressed concern that of the nine supports released for visual inservice inspection only one was found be adequately prepare Problems encountered included insulation not removed, welds not clean, scaffolding not installed, and in one case where the support had been previously examined and fasteners reported missing, the fasteners were still missin Apparently work is not being properly coordinated or supervised for completeness prior to releasing it for inspectio In the areas inspected, no violations or deviations were identifie REPORT DETAILS Persons Contacted Licensee Employees
- B. Barron, Station Manager
- W. Cabe, Engineer, NDE Tech Support
- T. Coleman, Engineer, Component Engineering
- J. Davis, Safety Assurance
- F. Linsley, Engineer, Component Engineering
- M. Patrick, Regulatory Compliance
- Peny, Regulatory Compliance
- T. Royal, Supervisor, Component Engineering
- G. Rothenberger, Work Control
- R. Rouse, Engineer, QA Technical Support/ISI Other licensee employees contacted during this inspection included engineers, inspectors, craftsman, and administrative personne Other Organizations Babcock and Wilcox (B&W) Nuclear Services A. Richmond, ARIS Data Acquisition Foreman H. Stoppelman, Level III Examiner NRC Resident Inspectors
- Harmon, Senior Resident Inspector
- B. Desai, Resident Inspector
- W. Poertner, Resident Inspector
- Attended exit interview Acronyms and initialisms used throughout this report are listed in the last paragrap.
Inservice Inspection (ISI) Unit 2 (73052)(73753)(73755)
The inspectors observed work activities, reviewed procedures, and documentation as indicated below, to determine whether ISI work was being conducted in accordance with applicable procedures, regulatory requirements, and licensee commitment The applicable code for ISI is the American Society of Mechanical Engineers Boiler and Pressure Vessel (ASME B&PV)
Code,Section XI, 1980 edition throughout Winter 1980 addenda with the exception of the outlet nozzle to vessel weld and the nozzle to pipe welds which will meet or exceed the 1989 edition with no addend In addition the examination of the reactor vessel welds applicable to the examination procedure is also in accordance with NRC Regulatory Guide 1.150 to the extent specified there-i Volumetric Examination of Unit 2 Reactor Vessel Welds Using the Automated Ultrasonic Technique Babcock and Wilcox Nuclear Services Company was the vendor contracted by the licensee to perform the automated ultrasonic examinations on the Unit 2 reactor vessel for the second 10 year ISI interval exami-nation B&W used their Automated Reactor Inspection System (ARIS II)
with its quick change contact examination head and the core flood examination attachment tool to perform the ultrasonic scanning of the vessel weld Data was collected and analyzed using B&W's Accusonex Computerized Ultrasonic Syste The inspector reviewed B&W's ISI Examination Procedure No. 138 Rev.11, entitled: "Remote Ultrasonic Examination for Reactor Vessel and Associated Piping Welds using Accusonex", and reviewed certification records of all B&W examiners on-site and at Lynchburg V which were to be utilized for the Unit 2 Vessel examinations and analysis of the dat The inspector also observed the examiners acquire data and the onsite Level III examiner evaluated the recorded indication (1) Observation of Ultrasonic Data Acquisition activities The inspector observed work activities involving the acquisition of ultrasonic data for Weld WR13 which is the outlet nozzle to shell weld. During this review the inspector verified the following:
approved procedures were available and that they were being followed, examination personnel with proper level of qualification and certification were performing the various examination activities, examination personnel were knowledgeable of the examination method and operation of the test equipment, and the acquisition equipment was performing the examinations and acquiring the ultrasonic data effectivel On Wednesday morning (1-29-92)
the inspector was notified that during calibration for the core flood nozzle an ARIS equipment operator incorrectly positioned the examination attachment tool for the nozzle and the tool had hit the calibration block support attached to the ARIS ring heade This resulted in a 180 degree crack in the weld attaching the core flood attachment base plate to the X-Drive of the ARIS boom. The operator error did not damage the transducers, the calibration block or the reactor vessel but data acquisition
activities were delayed until late Thursday afternoon when repair welding activities were completed and the ARIS positioning tool had been properly verified for alignmen (2) Review of data and evaluation of indications The inspector. analyzed the ultrasonic data concurrently with B&W's Level III examiner for Weld No. WR1 (circumferential scan, segment 180 degrees to 360 degrees).
In addition the inspector reviewed recorded indications for Weld No WR13A and WR1 With the exception of one indication described below each of the indications reviewed were of little consequence for acceptance of the weld because they were either located in the clad weld material or they were very smal However, one indication was detected in the outlet nozzle to shell weld which is located at 270 degrees clockwise around from the W-axis of the vessel while scanning from the nozzle bor The Nozzle contains a 15 degree taper which extends back into the bore for approximately 19 inches at the horizontal cross sectio Initial detection was made with a 15 degree L-wave transducer scanning from the nozzle taper and directed towards the vessel centerline to provide an angle nearly normal to the weld axi Detection was also made with a 45 degree S-wave transducer from the nozzle taper and directed toward the vessel centerlin The following information was recorded:
1 250%
DAC Angle Amplitude
_____
250% DAC TWD Length 15 De % DAC 7.8" 1.2" 4.2" 45 Deg. 44% DAC*
7.8" N/A N/A
- Not of recordable amplitude 1 Depth dimension is from the nozzle taper surfac The depth from the vessel ID is 5.2".
The shell thickness is 12".
At the conclusion of the inspector's visit the above information was the only information available and evaluation of the data indicated a code rejectable indication. However, B&W had plans to more fully characterize the indication using additional scans, and enhanced sizing technique They demonstrated these during investigations with the B&W Owners group in 1991 on a full scale reactor vessel nozzle mocku It contained implanted volumetric and planar flaws of known dimension typical of those required for the new Appendix VIII of the 1989 ASME Code performance demonstration requirement On February 5, 1992, the licensee and B&W's Level III Examiner notified the inspector by telephone that the additional examinations had detected the indication in multiple directions which would indicate a volumetric construction flaw (slag stringer)
and the enhanced sizing examinations using diffraction features of the indication similar to the way tip diffraction measurements are made of planar flaws indicated the flaw to be acceptabl Data faxed to the inspector for review revealed that from a technical standpoint B&W's evaluation was sound if post-qualification of B&W's enhanced sizing techniques to Appendix VIII proves to be as effective as B&W currently attes With the exception of the personnel error described in (1) above B&W's ISI procedures, work activities, personnel certifications, and analysis/evaluation efforts appeared to be very effectiv Review of Radiographic Film for Volumetric Examination of ISI Welds The inspector reviewed the radiographic film for the welds listed below to determine if the radiographic quality and the evaluation of the examination results were in accordance with the requirements of the approved radiographic procedure (NDE-12).
ISI PROGRAM ITEM N WELD ID N PIPE SIZE C05.021.121**See Note 2-01A-5.4-33 26"DIA X.875"TH C05.021.102 2-01A-5.2-43 26"DIA X.875" TH C05.021.069 2-03-18.1-15 24"DIA X 1.219" TH C05.021.105 2-01A-5.2-42 26"DIA X.875" TH C05.021.106 2-01A-5.2-45 26"DIA X.875" TH ISI PROGRAM ITEM N WELD ID N PIPE SIZE (cont'd)
C05.022.006 2-01A-5.2-45 Longitudinal Seam C05.022.005 2-01A-5.2-42 Longitudinal Seam C05.021.102 2-01A-5.2-43 26"DIA X.875" TH.021.068 2-03-18-1-14 24"DIA X 1.219" TH.021.066 2-03-FWD79-A 24"DIA X 1.219" TH C05.022.008 2-01A-5.4-33 Longitudinal Seam C05.021.065 2-03-18.1-07 24"DIA X 1.219"TH C05.022.007 2-01A-5.4-26 Longitudinal Seam C05.021.120 2-01A-5.4-26 26"DIA X.875" TH Note** The licensee rejected film interval 2-3 for slag indication These indications were not reported during the previous interval or during construction because the quality of the radiographs was not as good and they could not be seen. During the inspector's visit the licensee was attempting to ultrasonic examine the indications to determine their throughwall dimensions and resolution of the problem was incomplet Dyring subsequent telephone discussions with licensee on February 5, 1992, the inspector inquired about the disposition of this weld. The licensee stated that ultrasonic examination was unable to characterized the indications because of unfavorable configuration of the pip Therefore, Duke had decided to repair the weld. The licensee however, was seeking relief from NRC for having to expand the inspection sample because slag is not an inservice defec The inspector's review of the above radiographic film and film of same welds taken during construction and the first interval revealed that Duke's radiographic examiners are presently obtaining better radiographic film quality and conducting better film reviews than examiners achieved in the pas Visual Inspection of ISI Pipe Supports The inspector observed the licensee's visual examiners attempt to conduct ISI visual examinations on the supports delineated belo The examinations were performed in accordance with the requirements of Duke's ISI Visual Examination Procedure No. QAL-14, Rev.1 The inspector observed the examinations to determine whether the approved procedure was being followed, if the examination personnel were knowledgeable of examination method, and if the examination results were correct and being recorded as specified in the ISI program and NDE procedure ISI PROGRAM SUPPORT N IDENTIFICATION N COMMENTS FL.02.035 2-01A-0-1401B-Rll R4 Complete Sa FL.03.215 2-03A-1-0-1437A-SR-13R2 Insulation 0 Needs to be
Removed FL.03.172 2-03A-1401A-DE032 Previously Examined Suppport, Jam Nuts Still Missing FL.02.041 2-01A-DEO60 Clean Welds FL.02.015 2-01A-H15 Scaffolding Needed R
e m
o v
e Insulation FL.02.025 2-01A-R1 Embed Plate Pulled Out Concrete, Snubber Froze up, Remove Insulation, Scaffolding Needed FL.02.033 2-01A-R9-1 Clean Weld, Previously Cracked Concrete, Crack Appears to be Propagating FL.02.042 2-01A-DEO61 R e m o v e Insulation FL.02.17 2-01A-0-1441-H17 Clean Weld The failed snubber on Support No.2-01A-R1 above had been reported to ISI by maintenance and ISI informed the inspector that a Problem Investigation Report (PIR) would be issued on this item when ISI completed their examination of the suppor ISI also stated that they would expand their sample per Code to determine whether other supports had received any damag However, the examiners and the inspector noted problems on other supports in the area during the above inspections and the inspector subsequently discussed these problems with the cognizant maintenance engineer who also accompanied the inspector to perform a visual inspection of the inspector's concern These concerns consisted of the following on Unit * Support No. 2-O1A-0-1441-R9-2 Concrete Cracking Around Embed Plate, Embed Plate Bowed, and a
Mixture of Snubbers (hydraulic/
mechanical)
are Used for This Support Application
- Support No. 2-01A-0-1441-R9-3 Bolt Missing on Angle Support
- Support No. 2-01A-0-1441-R2-1 Concrete Cracking Around Emb ed Plate, Embed Plate has Bow in it, and Mixture of Snubbers in Total Support Applicatio * Support No. 2-01A-0-1441-R2-2 Previously Patched Concrete Cracking Loose Again, and Mixture of Snubbers in Total Support Applicatio In addition to the above questions on Unit 2, the inspector noted that the same Unit 2 Main Steam support (R1) whose snubber had frozen-up and had partially pulled the embed plate out of the concrete shearing two Nelson studs in the process, was missing on Unit 1 and the Unit was operatin The inspector was told that Unit 1 had experienced a snubber failure in 1990 and that the snubber had been removed at that time and not replace The inspector requested the PIR which should have covered the removal of this snubber. However, discussions with maintenance engineering revealed that a PIR had not been issued on the support when it failed, but a lower tier document (Special Station Report No.3098) had been issued for corrective actio An Exempt Change (No.3178) was also issued to repair the suppor However, Variation Notice No.OP-3433 had subsequently been issued deleting the exempt chang The variation notice stated that after re-analyzing the supports on the main steam line, design engineering had determined that the R1 support was no longer require The inspector however, was concerned that the lower tier process used to handle this problem may not have considered all of the essential factors necessary for resolution of the problem such as an analysis of the failure, sample expansion, generic application, and
-8 reportabilit By the conclusion of the inspection, the inspector had received a failure analysis on the snubber, and the design re-analysi The cognizant maintenance engineer at the time was interviewed to find out if an expanded inspection had been performed and generic application considere The inspector's preliminary review of the design re analysis however, revealed new questions concerning the sizing of snubbers on the remaining pipin Initially the pipe had been modeled as 24" pipe and in fact the pipe was 28" diameter pipin Time did not allow the inspector to resolve the questions on Unit 1 or Unit 2 and design engineers in Region II would be necessary to review the design re-analysis therefore, the inspector reported that this item would be reported as Unresolved Item N,270,287/92-05-01,
"Maintenance Corrective Action on failed supports" scheduled for followup inspection by Region II design engineer Code Repair and Replacement Activities (Steam Generator Plug Welding) Unit 2 The inspector observed reaming and plug welding activities on the "B" Steam Generator lower tube shee This observation was conducted to determine whether an approved procedure for welding was being used and whether personnel responsible for the performance of the welding and inspection activities were properly certified and knowledgeable of the procedural requirements governing the wor The inspector concluded from the review of the following B&W documents:
Traveler No. 50-1205405-00, Welding Procedure N A, Visual Inspection Procedure No.02-1210920A, Welder and Inspector Certifications, and interview and observation of personnel, that these activities were being conducted in accordance with the above instructions, licensee commitments, and regulatory requirements. Third party inspection (ANI) was provided by Hartford Boiler Compan Within the areas examined above, no violation or deviation was identifie.
Review of Radiographic Film for Plant Modification Pipe Welding -
Unit 2 (57090)
The inspector reviewed the radiographic film for the welds listed below to determine if the radiographic quality and the evaluation of the examination results were in accordance with the requirements of the approved radiographic procedure (NDE- )
IDENTIFICATION No. WELD N SIZE 2-51A-35-119 119 2.5"DIA. X.375" TH A-35-121 121 2.5"DIA. X.375" TH A-34097-1
8" DIA. X.875" TH A-34097-1
8" DIA. X.875" TH The above radiographic film and weld quality met or exceeded the requirements of the approved procedur Within the area examined above, no violation or deviation was identifie.
Independent Inspector Activities Although, not examined during this inspection, the inspector held discussions with cognizant maintenance engineers concerning the status of inspection and repair activities in the areas of eddy current examination of steam generator tubes and erosion/corrosion of piping and component The inspector requested and received the following end-of-the-week (January 27 thru 31, 1992)
summary of the licensee's activities in these areas: Pipe Erosion/Corrosion Control Program The Oconee Unit 2 Pipe Erosion/Corrosion Program Plan consisted of 98 piping components to be ultrasonically inspecte The systems included in these inspections are: High Pressure Turbine Extraction, Low Pressure Turbine Extraction, Main Steam, Steam Supply Moisture Separator Reheaters, Feedwater, Condensate, Heater Drains (which include Moisture Separator Heaters drains), Steam Supply to Emergency Feedwater Pump Turbine, Steam Supply to Main Feedpump Turbine, and Low Pressure Steam Seal System. Forty-two of the scheduled inspections have been completed to dat There have been two expansions to the pre-outage pla One involved a scheduled replacement on the "B" Bleed system which was expanded to include additional component The additional components showed signs of wear, but were not below code allowable wall thickness or in any danger of failur The other sample expansion involved the addition of a "like train" component due to scheduled inspection results on the heater drain syste The End of Cycle (EOC) 12 outage plan included pipe and component replacements on portions of the High Pressure
Extraction and Heater Drain System Six different areas were identified for repair or replacement wor Replacements were also scheduled on two small bore (<2")
drain lines which had previously shown indications of erosion problem Minor weld repairs are being performed on the 42" High Pressure Turbine Exhaust pipin Stainless steel piping and components are being used in the replacement wor The replacement/repair scope was expanded in two areas on the Heater Drain system due to the results of scheduled inspections. As previously stated, the replacement work on the "B" Bleed system was extended to include a reducer and piping downstream of the turbine nozzl The Oconee Erosion Inspection Program is based on an extensive engineering review of plant systems, Keller equation evaluations, current and previous industry events, a review of past inspection data, and the Electric Power Research Institute (EPRI)
"CHEC" computer program for modeling of single phase system The licensee is presently evaluating a total plant modeling project utilizing EPRI's new compute code
"CHECMATE" which can be used for single phase and two phase piping system Status of Steam Generator Eddy Current Activities - Unit
The licensee was examining an initial sample of 60% of the steam generator tubes in both generators utilizing the bobbin coil this outag The eddy current data however, was being transmitted by telephone linked computers to Duke's McGuire site for analysi Eddy current acquisition activities, procedure and personnel certification reviews had also been audited by a Region II Inspector the previous week and reported in Regional Inspection Report No. 50-269,270,287/92-0 This inspector however, wanted to keep abreast of eddy current activities during the current week in case significant problems arose that demanded the inspector's attentio Therefore, several visits were made. to discuss the eddy current status with the maintenance engineer cognizant of the projec In addition, the following status for plug removal, remote plug welding, and plugging activities resulting from current evaluation of eddy current data was submitted by the cognizant engineer at end of the week per request of the inspector:
- One rolled plug was removed from the "A" Lower Header to retrieve an eddy current probe which was stuck in the tube last refueling outag This location will be
replugged with a rolled plu * Two rolled plugs were removed from "B" Upper Header due to defect indications discovered with. the mechanized rotating probe coil examinations. These locations will be replugged with a rolled plu * Nine ribbed plugs, of material heats more susceptible to intergranular attack, were removed preventivel Seven of these locations will be replugged with rolled plug Two will have remote welded plugs installed because the ribbed plugs had the heads pulled off during remova * Four welded "studs" plugs in "B" Upper Header were to be drilled out for restabilization of the tube Three have been completed. The fourth, in tube B77-15, has a drill bit broken off and stuck in the welded plug. This situation is under investigation for resolutio The three completed locations have remote welded plugs with stabilizers installed in the * Fifteen locations in "B" Upper Header are to be prepped (spotfaced) and have remote welded plugs installe Fourteen of these have been done to date. The fifteenth is location B77-15 with the drill bit stuck in the welded plu * Explosive plugs: The Oconee Unit 2 Steam Generators have a total of 42 explosive plugs installe All locations. are having a remote welded plug installed behind the explosive plu Quantity of explosive plugs:
A Upper -
A Lower -
B Upper -
B Lower -
Current Plugging required:
As of January 31, 1992, the exact quantity of tubes in the A and B Once-Through-Steam Generator (OTSG) to be plugged due to eddy current indications is unknow A guess however, would be that the A
OTSG will have
approximately 13 tubes to be plugged either due to pluggable eddy current indications or preventively..
A guess for the B OTSG would be
tubes for the same reason Within the areas discussed above, no violation or deviation was identifie.
Exit Interview The inspection scope and results were summarized on January 31, 1992, with those persons indicated in paragraph The inspector described the areas inspected and discussed in detail the inspection results listed belo Proprietary information is not contained in this repor Dissenting comments were not received from the license (Open) Unresolved Item 50-269,270,287/92-05-01, "Maintenance Corrective Action on Failed Supports" paragraph. Acronyms and Initialisms ANI
-
Authorized Nuclear Inspector ARIS
-
Automated Reactor Inspection System ASME
-
American Society of Mechanical Engineers B&PV
-
Boiler and Pressure Vessel B&W
-
Babcock and Wilcox DAC
-
Distance Amplitude Curve DEG
-
Degree DIA
-
Diameter DPC
-
Duke Power Company EOC
-
End of Cycle EPRI
-
Electric Power Research Institute ID
-
Inside Diameter ISI
-
Inservice Inspection N/A
-
Not Applicable NDE
-
Nondestructive Examination N Number No Numbers NRC
-
Nuclear Regulatory Commission OTSG
-
Once Through Steam Generator PIR
-
Problem Investigation Report QA
-
Quality Assurance REV
-
Revision SG
-
Steam Generator THK
-
Thickness TWD
-
Through Wall Distance