IR 05000348/1993025
| ML20058P613 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 12/02/1993 |
| From: | Blake J, Economos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20058P605 | List: |
| References | |
| 50-348-93-25, 50-364-93-25, NUDOCS 9312270200 | |
| Download: ML20058P613 (17) | |
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- [p Mch UNITED STATES - NUCLEAR REGULATORY COMMISSION y '- -
. '$ REGION 11
.$ g 101 MARIETTA STREET, N.W., SUITE 2900 0 ;y ATLANTA, GEORGIA 30323-0199
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Report No.: 50-348/93-25 and 50-364/93-25
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Licensee: Southern Nuclear Operating Company, In North 18th Street Birmingham, AL 35291-0400 Docket No.: 50-348 and 50-364 License No.: NPF-2 and NPF-8 l Facility Name: Farley I and 2
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Inspection Conducted: October 18-22 and November 1-5, 1993
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Inspector: , / /& 3
.fc6ndmos Date Signed Approved b : -
/2!z J
. J'/Blake, Chief Date Signed aterials and Processes Section Edgineering Branch Division of Reactor Safety SUMMARY L
Scope:
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This routine, announced inspection was conducted in order to observe Eddy Current (ET) examination activities of Unit 2 steam generator (S/G) tubes, review laser welding procedures to be used for securing sleeves and review design changes and plant modifications involving welding and nondestructive , testing performed during this outag Results: This inspection showed that the licensee is implementing the inspection plan ' for steam generator tubes in a satisfactory manner. The inspector found the ET activities including S/G tube examination, evaluation, disposition, and plans for repairs were consistent with technical specification requirements i regulatory guidelines and commitments. One non-cited violation'(NCV), was t identified for failure to assure that welders had demonstrated adequate proficiency to perform their assigned tasks in a satisfactory manner (see paragraph 5).
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I i 9312270200 931203 PDR ADOCK 05000348 G PDR
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Westinghouse Nuclear Services Division (WNSD) was authorized by the li;ensee to perform a direct tube repair (DTR), in S/G "B", using a laser beam velding procedure without filler metal. The selected tube, 26-46, was welded at two tube. support intersections. Following the repair, the initial attempt to remove it from the S/G was unsuccessful in that the tube broke just above the lower wel WNSD was studying different approaches to remove the remaining tube section at the close of this inspectio Cracks found in emergency diesel engine air intake manifolds are being investigated to determine root cause. A preliminary evaluation suggests that the manifolds are capable of performing their design function with the identified indications. Repair welding is under consideration as an alternate to replacemen Except for the NCV, other violations or deviations were not identifie .
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- i REPORT DETAILS Persons Contacted
.1 Licensee Employees -l
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S. Casey, Supervisor, System Performance and Engineering l
*R. Coleman, Manager Plant Modification ;
M. Dove, Senior Engineer, Maintenance Support Group , J. Fitzgerald, Plant Modifications Contract Support
*D. Hartline, ISI/ST Supervisor
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*R. Hill, Nuclear Plant General Manager
*R. Martin, Engineering Group Supervisor .
L. McClain, NDE Level III Examiner i J. Osterholtz, Assistant General Manager - Technical Support T. Smith, NDE Level III Examiner j M. Stinson, Assistant General Manager - Operations i B. Yance, Manager Systems Performance ; Contractor Personnel Westinghouse Nuclear Services Division (WNSD) l P. Hawkins, Mechanical Engineer Laser Welding W. Holasek, Level III Ultrasonic Examination (UT) , J. Marburger, QA Engineer ! G. Ripple, Technician, Laser Welding
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Fluor Company (FLOOR) l T. Cooper, Pipe Fitter General Foreman I M. Faust, Welding Foreman Other licensee and contractor employees contacted during this inspection-included engineers, technicians, and administrative personne NRC Resident Inspectors
*T. Ross, Senior Resident Inspector M. Morgan, Resident Inspector M. Scott, Resident Inspector * Attended exit interview l Inservice Inspection (ISI)
At the time of this inspection, ISI activities had been completed, , except for Eddy Current Testing (ET) of a few steam. generator (S/G) ; tubes. As such the inspector reviewed selected documents and records as ! indicated b91ow and observed ET activities to ascertain whether ISI was ; being conduced in accordance with the applicable code, procedures, j l l
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regulatory requirements and licensee commitments. The applicable code for ISI activities is ASME Code Section XI, 1983 Edition with Summer 1983 Addenda. With regards to Unit 2, the current scheduled refueling outage was indicated as the second outage of the First 40 month period : of the second ten (10) year interval. The ISI Plan and examinations performed during this outage are discussed in Report 50-348,364/93-2 ! 3. Eddy Current Examination of S/G Tubes (73753) Unit 2 i As stated above, ET examination of S/G tubes for this outage was approaching completion when the inspector first arrived on site on October 18, 1993. Through discussions with cognizant licensee personnel and by review of related documents, the inspector ascertained that the ET examination program for this scheduled refueling outage, was being performed in accordance with Technical Specification Amendment No. 94 regarding S/G tube interim plugging criteria for. Unit 2, dated October 20, 1993. The subject amendment applies only to operating cycle 10 and provides for:
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100 percent bobbin probe examination of the hot and cold leg S/G tube support plate intersections in all three S/G(s).
- Degradation attributed to outside diameter stress corrosion cracking within the bounds of the tube support plate, with bobbin voltage less than or equal to 1.0 volt will be allowed to remain-in servic Degradation attributed to outside diameter stress corrosion cracking, within the bounds of the tube support plate, with a bobbin voltage greater than 1.0 volt will be repaired or plugged except as noted below:
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Indications of potential degradation attributed to outside diameter stress corrosion cracking, within the bounds'of the tube support plate, with a bobbin voltage greater than 1.0 volt, but less than or equal to 3.6 volts may remain in service if a rotating pancake coil probe (RPC) inspection does not detect degradation. Indications of outside diameter stress corrosion cracking degradation with a bobbin voltage greater than 3.6 volts will be plugged or repaire The inspector also ascertained that the S/G tube examination plan for this outage was as follows:
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100% bobbin examination of all 3 S/G(s).
- Motorized rotating pancake coil examination of:
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All distorted indications (DI's) and pluggable tubes with > 40% through wall indication )
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100% of hot leg (HL) roll transition % of all indications with a peak to peak bobbin voltage > 1.0 vol Confirmation and characterization of flaw '
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Verification that flaw is within the bounds of TS Augmented Inspection Program (100 intersections).
100% of row I and 2 U-bends with special Zetec prob * Baseline examination of sleeves with crosswound prob The examination, analysis and repair of tubes was being conducted by . WNSD, following applicable code and Technical Specifications requirements, regulatory guidelines and commitments. Some of the ' controlling documents reviewed are as follows: i NMS-93-0160, Rev. 3 Farley Unit 2 Ninth Refueling Outage, Steam Generator Examination and Maintenance Progra NEL-93-033 Amendment Number 94 to Unit 2 Technical Specifications Concerning i the Interim Plugging Criteri DAT-GYD-001, Rev. 6 Westinghouse Data Analysis Guidelines, APR-2
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Westinghouse Specific Analysis Guidelines, Farley Unit , Westinghouse Data Analysis Guidelines, APR-2, Rev. As stated above, analysis of indications was performed by Westinghouse (W) who provided primary and secondary analysts. Primary analysis was performed on site while the secondary was performed by )! technical personnel in Pittsburgh, Pennsylvania. Independent analysis was , performed by level III Examiners from the two organizations. ET examinations were conducted with the MIZ-18A system and 0.720" diameter, , multifrequency, bobbin, differential coil In some instances smaller diameter coils were utilized to accommodate the tight radii in the first two rows in the S/G Because scheduled examination were essentially completed just prior to the start of this inspection, the inspector observed analysis of RPC examination on the following tubes of steam generator "C".
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Tube Findinos R41 - C36 Single axial indications in- ; intersections of 1st &:2nd hot leg ';
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tube supports
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R44 - C36 Multiple axial indications at the i , 2nd hot leg tube support plate ! R45 - 36 Multiple.and single axial indications were i observed in.1st & 2nd tube support plates respectivel j
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L Although this observation was limited in terms of numbers of tubes , observed, the inspector noted that the analysis was consistent with the - aforementioned guidelines and was' performed by well trained technical personnel. Following this work effort, the inspector obtained the '
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following preliminary results on repairs and Steam Generator tube ; statu j S/G "A" S/G "B" S/G "C"- )
:- 3 Tubes Returned 31 45 81 ;
to Service Plugs Installed 6 6 9-during Present Outage
^1 ~ Total Number Tubes 28 d Plugge !
Sleeves Installed 6 ) during Present ' Outage Steam Generator Tube Repairs - Sleeving Welding Tube Repair - Background By letter dated October 22, 1990, the NRC issued Amendments No. 85 and No. 78 to the _Farley Units 1 and 2 Technical Specifications (TS), authorizing the use of a laser welded sleeves for the repai ! of steam generator tubes per WCAP-12672. The laser welded tube sleeve and sleeving process has.been described in WCAP-13115 and as such has been reviewed and approved by the NRC.- This process allows' installation of thermally treated Alloy 690 sleeves in both-the hot and cold legs of steam generator tubes at tubesheet and support plate elevations,-see Report 50-364/92-1 .-
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Applicable code (s) which controlled design installation and testing requirements, included ASME Boiler and Pressure Vessel Code, Sections III (68 through S70), XI (83S83) and IX Edition and Addenda in affect at time of qualification, and Code Case N-395 Laser Welding Section III. Division Review of Repair Procedures (73052 B) Technical procedures used to control and document site activities which were reviewed for content and technical adequacy were as follows: STD-FP-1990-5150 Rev. 5 Laser Welder Operation with Field Change 1 ROSA III, Laser Welded Sleeving.875 x.050" wall S/G Tubes STD-FP-1990-5151 Rev. 4 Ultrasonic Testing System with Field Change 2 Rosa III Laser Welded Sleeving, .875 x .050 wall S/G Tubes STD-FP-1990-5153 Rev. 4 Heat Treatment System, ROSA III, Laser Welded Sleeving
.875" OD x 0.50" Wall S/G Tubes STD-FP-1993-6407 Rev. O Direct Tube Repair Demo >
Program STD-FP-1993-6454 Rev. O Support Plate Intersection Heat Treat MRS-2.3.2.- APC-2 Rev. 4 Improved Mechanical Plugging System for Mechanical Plugging of S/G Tubes MRS 2.3.2 - APC-14 Rev. 4 Machining of S/G tube and l Plugs RRS 2.3.2 - APC - 6 Rev. 1 Weld Repair of S/G Tubes / Plugs QAIP-1-VT Rev. 8 Visual Inspection of Welded . Tube / Plugs l' Inconel 600 Plug Removal and Replacement The program for inspection and repair of S/G tubes during this outage provides for replacement of Inconel - 600 plugs with others made of Inconel - 690 material which has demonstrated higher resistance to intergranular stress corrosion cracking. A total of i
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64 Inconel 600 plugs were identified for replacement; 24 in S/GA, 22 in S/G "B" and 18 in S/G "C". These plugs were made from six heats of material identified by the licensee as being suspec The inspector observed the " drilling-out" operation in steam generators "B" and "C", which was being performed by WSND personnel using the aforementions procedures. Plugs were drilled using a specially designed one-step drilling fixture. After drilling, the plugs were pulled and the vacated tuberheet hole reamed to a specified diameter and inspected. Replacement mechanical plugs were subsequently installed using the aforementioned procedur ; As part of this work observation effort the inspector reviewed personnel qualification records and quality records of the replacement plugs identified below. As stated earlier in this , report, the plugs were made of SB-166, Inconel 690 T alloy material and purchased per W, specification STOMS - 1989-4397 Re . The applicable code was identified as ASME Sections II and III NB-2000, 1989 Edition with no addenda and ASME Code Case N-329, Examination of Bar Material. The plugs were manufactured per WCAP
- 9245 Rev. 1 Heat Number Serial Number (S/H1 Plua TYDe #7252 HK 4J373 - 412 %'O Tappered Expansion Mechanical Plugs #7221 HK 3P396 - 3P446 %'O Tappered Expansion 3P274 - 3P295 Mechanical Plugs #7222 HK 3P445 - 3P447 %'O Tappered Expansion Mechanical Plugs NX6441 HK 2V36 - 2V367 %'O Tappered Expansion Mechanical Plugs NX713 HK MANY %'O Tappered Expansion Mechanical Plugs NX6977 HK 4E684 - 4E688 %'O Tappered Expansion Mechanical Plugs d. Sleeve Installation Steam generator tubes with indications exceeding acceptance criteria were either plugged or sleeved as determined appropriate by the licensee and Westinghouse. Sleeves used for this operation during this outage were made from Inconnel I-690 material, produced in accordance with ASME Code Section III, NB and Section
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XI 1986 Addition with Code Case N-20 (use of SB-163, 690 nickel - chromium - iron.... seamless condenser tubing at 40.0 ksi yield strength .... ; Following is a tabulation of sleeves installed per steam generato S/G "A" S/G "B" S/G "C" Number of Sleeves Installed 66 67 139 These sleeves were produced under W specification number STD-MS-1987-2895 Rev. 1, drawing number 3658C03 Rev. 10, from the following heats of material: HEAT N Purchase Order Dimensions 764371 MA71482 0.740"0D x 0.040" ! wall x 30" long 764336 MA80083-M 0.740"0D x 0.040" l wall x 12" long '
Quality records for these materials were reviewed and found to be j in orde j e. Sleeve Welding Tubes scheduled for repair were cleaned and prepped. The sleeves were installed, expanded, welded using a qualified laser beam , procedure, volumetrically examined, stress relieved and ET teste , As documented in previous report (s), (50-348/92-11) the sleeves u were welded to the parent tube using the laser beam welding process-without the use of filler metal.- To perform these ! weldments, }{ used three qualified procedures, two of which were used for welding sleeves at different S/G locations and one l procedure was used for repairs as required. The sub'ect i procedures were as follows: ; Weldino Procedures Title WPS-74361 Rev. 2 Weld Process Specifications for Span Weld WPS-74362 Rev. 3 Weld Process Specification of Tubesheet Lower Weld WPS-74370 Rev. I Weld Process Specification for Free span Weld Repair
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These welding procedures and accompanying procedure qualification l records (PQR(s)), were reviewed in detail for content and - accuracy. In addition, the inspector reviewed performance qualification records of nine weld operators used on this projec J The above personnel records and procedure qualifications were , found to be in orde ! Ultrasonic examination is used to determine acceptability of ! completed welds. Defects which occur more frequently and result { in weld rejection include lack of fusion, burn through, rough - surface and other UT conditions described as indeterminate. The ; latter is a weld condition which is observed in the weld but ! cannot be defined by the analyst. The status of completed welds during the second week of this inspection were as follows: ! S/G "A" Approximately 76 free span welds made. 4 welds ! rejected and rewelded, but failed to pass UT j examination and the tubes were plugged. These ; tubes were identified as R5-019, R5-C73, R4-C74 l and R4-C7 ,
S/G "B" Approximately 103 free span welds made. 13 ! welds rejected, rewelded, and subsequently ; accepted by U ; S/G "C" Approximately 225 free span welds made. 50 welds rejected, rewelded, and subsequently j accepted by U In reference to the S/G "C", high weld rejection rate, the records I showed that the majority of the rejects occurred following a : mirror change at about 3:00 am; at which time the technician had ' been on the job for a period of approximately 10 hours out of his 12 hour shif By procedure these mirrors, which are basically used to redirect the laser beam are changed after completion / fabrication of about thirty welds. Following replacement, the. new mirror is tested and if acceptable, work continues until a total of about 30 welds are , produced. The laser system is computer driven but constantly l monitored by qualified personnel. Under the present program there ' is a significant lag time (could be the length of a shift), between the weld production and the UT examination which is used , to accept or reject the welds. As such, conditions which can I cause unacceptable welds to be fabricated could go undetected , during a production run. Consequently, unacceptable welds are not I discovered until long after the weld (s) are completed such as in the case described abov , Through discussions the inspector ascertained that the licensee and )! had interviewed the technician who made the mirror change but could provide no credible explanation. Other possible
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explanations under review including problems with the cover gas, weld head, and mirror. The records showed that the problem was illuminated when the mirror was again changed at the end of the production ru On November 4, 1993, the previously rejected welds in S/G "C" i discussed earlier in this report were rewelded using weld procedure / specification WPS 74370 discussed earlier in this report. The inspector observed welding of the sleeve welds in the following tubes in S/G "C".
S/G "C" R 10-C77 Tubesheet upper weld R 6-C78 Tubesheet epper weld R 8-078 Tubesheet upper weld R 8-C79 Tubesheet upper weld R 3-080 Tubesheet upper weld R 32-C62 First support upper weld R 32-C61 First-support upper weld R 34-C61 First support lower weld R 34-70 First support upper weld f. Stress Relief of Sleeve Welds Completed welds are stress relieved in accordance with STD-FP-1990-5153 Rev. Heat is generated with the aid of a light emitting heating element. Temperature is controlled by controlling the power, measured in watts, through the heating ; element. The stress relief treatment is a two step process ; involving heat-up or ramp-up and soaking. Initially the weld is : brought up to temperature by increaseing power (voltage) to the o element for a pre-determined amount of time followed by a reduction of power where the temperature is stabilized and held at l the specified level for a pre-determined amount of time. The 4 whole process takes a period of about 9 to 91 minute The inspector observed stress relief applied to sleeve welds in the following tubes of S/G (s) "A" and "B".
S/G "A" S/G "B" R 36-C47 R35-C38 R 40-055 R37-C38 R 34-050 R 33 C55 R 21-C56
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I g. Direct Tube Repair (DTR) . Direct tube repair is a process that M is attempting to develop as , an alternative to the use of sleeves' to repair tubes with' '
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rejectable crack indications. A qualified laser. beam weld . . i procedure is used to repair weld the crack indication without the '; use of filler metal. The completed weld is subsequently examined l volumetrically and stress relieved using variable wattage light l > cmitting elements as the heating sourc i ,
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Tube number R26-C46 in S/G "B" hot leg was selected for testing i this repair method. The tube was repaired in this manner at the first and second tube support plate intersections. Following the . repair, the tube was severed below the third tube support' plate and above the tube sheet in preparation for its removal and i shipment to M for analysis. However, during the pull a section of - 'l the tube, about- 15 inches in length, broke off just above the top - * edge of the lower weld. The upper-section of the severed tube-measuring approximately 96 inches remained in the steam generato : At the end of this inspection M was exploring possible methods of_ ! remcVing the remaining section left in the steam generator.- 1 t h. Thermal Treatment of Tube with crack Indications This thermal treatment is an attempt by M to determine if the growth rate of less than one volt-in S/G tubes in service, can be , retarded or arrested through thermal treatment. The heat source- ! used for this process was similar to that discussed earlier. in i this report except that the temperature level was significantly ! higher than that.used for stress relief. Tubes selected' for this ! test were in S/G "C" and are listed below: S/G "C" i R 19-C10 2nd tube support' plate R 27-C47 1st tube support plate i R 3-C80 2nd tube support plate , R 18-88 1st. tube support plate ] These tubes are to be reexamined during the next ischeduled ;l refueling outage in order to evaluate results of this treatment l under field condition Through. discussions with the licensee,.the inspector. ascertained i that the baseline ET examination of the thermally treated tube j sections, performed with a bobbin probe, showed evidence of 1' denting in the order of 60 to 100 volts. Also the test showed evidence of bulging in the subject area. The' licensee was performing MRPC examinations to further characterize the above condition !
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11 R 5. Plant Modifications (37100B) The inspection reviewed a Modification for replacement of existing
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'I carbon steel pipe with stainless steel pipe material for the service- !
water line to the reactor coolant pump motor air coolers at th l containment penetration numbers 60 and 32 at elevation 129_ f l
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This work was performed under Plant Change Notice (PCN), B-87.-2-4106, ! Rev. 34, " Replacement of SW Piping" which addressed design- j considerations for the pipe replacemen Field activities were ' performed under Maintenance Work' Request (MWR) No. 250377, Service Water- : Piping to RCP Motor Air Cooler, and work order Nos. 20966, 250377. Th ; subject travelers referenced Drawing No. Q.2.P16 (B87-2-4106) and ASME Code Section III, Class 2,1971 Edition as_ the applicable code. The 1 inspector reviewed the subject documents and applicable field records, ; including field weld data sheets of welds in process, for technical j content and adequacy. Welds in process selected for observation and < record review were'as follows: Weld Size Line/ Type ; Penetration ~ IF 6.00" x 280" 6HCB-8/60 Pipe to valve #071 18F 6.00" x 280" 6HCB-8/60 Pipe to valve #075 l 19F 6.00" x 280" 6HCP-9/32 Pipe to Valve #081 ' 34F 6.00" x 280" 6HCP-9/32 Pipe to Valve #072
17F 14.00" x Penet.-60/ schedule 80 Elevation 129 Through observation of field activities, discussions with' cognizant licensee / vendor personnel and records review the Mspector noted the j followin ; Weld IF: This weld was rejected by radiography (RT) on October 19, l 1993, because of lack of fusion, porosity and suck back i observed on three of the four films ~ used to shoot the wel Repairs were underway on October 21, 199 ,
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Weld IBF: Weld was cutout because of- extensive lack of fusion and' sugaring / oxidation on approximately i of the' circumference.' i Pipe cut back about one inch, re-prepped, and welded.-
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l Weld 19F: Weld was rejected because of lack of fusion. The repair was ; in progress i l Weld 34F: Weld rejected and subsequently cut out because of lack of i
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fusion. During the second attempt to fabricate this. weld,. the welder burned through the root and hot pass. Welder : i
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violated procedure by grinding out lack of fusion -! indications without authorization, violating minimum wall i and adding metal to the inside of the weld. Upon : discovering this violation the licensee rejected the weld
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and terminated the_ welder. The weld was subsequently cut-out and a new weld was in the process of being fabricate ' Weld 17F: When fit up inspection discovered that root clearance exceeded tolerance by 1/32" at two -locations a repair procedure was issued to build up the face of the joint and , thereby meet fitup tolerance requirements.- Procedure wa * violated when buildup was performed without QC notificatio : A new repair procedure was issued to remake this wel By review of travelers, logs, and radiographs and through discussions with contractor and licensee personnel, the inspector noted two distinct problems which suggested a possible programmatic weakness in. welding; (1) All four bi-metallic welds exhibited lack of fusion defects on the dissimilar metal side of the weld joints; (2) two of the five welds were rejected because of welders failure to follow procedure l The inspector met with the licensee's technical supervisors and management and discussed the aforementioned problems. In reference to the fabrication-related weld rejections, the inspector stated that this : high rejection rate suggests the welders had not been given sufficient- 1 training in the fabrication of bi-metallic welds to the extent that would assure suitable proficiency was achieved prior to making . production weld The inspector made-it clear that he was not questioning the welders' qualifications under ASME Code Section IX rules; what was being questioned was the. apparent lack of additional training required to develop the welders ability and confidence to fabricate dissimilar-metal welds (i'.e. stainless pipe to carbon steel. valve body) of radiographic quality, under field conditions. During'this discussion the inspector- i ascertained that welders had undergone mockup training and that their- ! welds had been visually inspected at the intermediate and completed
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levels but had not been radiographe Following the licensee's completion of an investigation into the root cause of the problem, the inspector met with management and supervision to review their findings and corrective actions. Results of the licensee's investigation were as follows-i New portable welding machines were ' purchased for use on site. The new machines have a significantly lower power output rating than , the older more powerful machines on site. While the new portable welding machines- have proved satisfactory in most applications, the amperage required to use %"O wire on dissimilar metal welds with the valve side being a significant heat sink, presents-problems when making a radiograph quality weld. This problem was ,
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not initially identified which resulted in welders not getting l sufficient training to successfully perform this type of weld ; prior to making production welds in the. fiel i All welders qualification tests were performed in the weld test shop utilizing the older machines.- Corrective actions taken to correct the problem were as follows:- !
! Procedure FNP-0-PHP-504 Installation of Piping and Tubing Systems, was revised (Rev.16), such that welders will be. required to weld : :
mockups in the same position as the production weld. The subject- ! coupon will .be volumetrically examined prior to_ making the production weld and the welders will be monitored prior, to making- , the production wel .j
, The older machines were used to make two dissimilar welds in the ;
auxiliary building ~ l The new machines were used in the containment building using 3/32" l filler metal when dissimilar metal welds were involve ,
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, Two other dissimilar welds, not requiring radiography were tested
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and found to contain lack of fusion indications. These welds were cut out and new welds made using the older machine i Ot.her possible future actions include, discontinue the use of new welding machines if their use poses unacceptable risks in weld quality; ' and train and qualify welders' on the new welding machines'to ensure r familiarizatio Most of the above corrective actions were in place prior to the closing- .; date of this inspection. ~ 1e procedural revision was issued on-November 9,-199 P Because of the licensee's positive response with respect to - ; investigating the root cause of.the problem and taking appropriate " action (s) to prevent its recurrence, (i.e. procedural revision, i' personnel training,. equipment monitoring) this findir g was identified as a non-cited violation, NCV 50-364/93-25-01.z This NRC identified ! violation is not being cited because the criteria specified-in Section : VIIB of the NRC- Enforcenent Policy were satisfie ; Weld procedure qualifications, related PQR(s), welder-performance d qualifications and filler metal material certification were reviewed for' i technical content', completeness, accuracy and applicable code compliance- : 6. Followup on Inspector Identified-Items (92701) b
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(Closed)' Unresolved Item 50-364/93-24-01, Unavailable Drawings Required i to Locate ISI Weld '
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This item was identified when the inspector of record noted that surface examinations were being performed on certain branch-connection to pipe welds and nozzle-to-vessel welds, even though the NDE examiners were unable to show the inspector the exact location of the welds being examined. The examiners indicated to the inspector of record that they had overcome this difficulty by expanding the area of examination which provided reasonable assurance that the area of interest required by code had been examined. At the end of that inspection (93-24), drawings that would show more accurately the weld boundaries were being retrieved from the vendor. During the present inspection (October 18, 1993 to November 5, 1993), this inspector revisited this area with the licensee to review the program applicable procedures and corrective actions to address this problem. The licensee provided the inspector the applicable drawings showing the subject weld boundaries and state the following: During the first ten (10) years of operation Farley operated under the rules of ASME Code Section XI,1974 Edition. This edition of the code did not require a reference system for all welds and areas subject to surface or volumetric examinations. As such, Farley had not proceduralized a referencing system for welds subject to these examination In other words welds were not marke The 1983 Edition through Summer 1983 Addenda of Section XI, approved for Farley Unit 2, second ten-year interval on August 29, 1991, contains provisions for a reference system, per INA-2600, to be used for all welds and areas subject to surface and volumetric examination. By Relief Request RR-17, the licensee requested and received relief from this code requiremen The licensee instead offered, as an alternative to establish administrative controls detailed in procedures that provide adequate instructions to assure measurements are repeatable and that any indications can be accurately located. The Commission granted the relief request with the provision that each weld examined receive the required reference markings when examinations are performed. Farley has implemented this requirement through Appendix B, Weld marking to procedure FNP-2-STP-1570, Inservice Inspection of class 1 and 2 Systems and Components. By revision 9 dated November 3, 1993, to this procedure, the licensee now requires that welds be marked prior to ISI examination and, in the case where weld boundaries are not visible, as-built drawings, volumetric examinations or other means are to be used to locate the weld boundaries. By review of forms Data Sheet B-1, the inspector verified the welds under discussion had been marke This item is close _ _ _ _ . . _ _ _ _
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15 1 7. Maintenance (62700) i Crack Indications Found in Air Intake Manifolds of Emergency Diesel Engines r i At the request of the resident inspector, this inspector performed a ,
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visual inspection of emergency diesel engines IB, 2B and 1-2A to observe crack indications in the air intake manifolds. The inspector noted that most of the cracks were tight and small in length but could not determine if they were through-wall. They were for the most part located in the radius at the base of the support bracket. Judging from the appearance, crack size and location it would appear that the air loss from these cracks would be minimal at best, and therefore should have no impact on engine performanc The licensec and the vendor, Coltec Industries, are investigating the root cause of this phenomenon and the possibility of repairing the manifolds by welding. A review of correspondence between the licensee, " Southern Company Services and the vendor disclosed that the manifolds - are made of an aluminum material similar to A356 aluminum alloy which is possible to weld. Also by review of correspondence the inspector ascertained that engineering believes the diesels air intake manifolds r are capable of satisfying diesel engine support functions with the identified indication This matter will be pursued further for informational purposes during a future inspection. Within the area inspected violations or deviations were not identifie . Exit Interview The inspection scope and results were summarized on November 5,1993, 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 repor i Dissenting comments were not received from the license Closed NCV 50-364/93-25-01: Failure to Adequately Train Welders in ; Fabrication of Dissimilar Welds, paragraph . I
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