IR 05000338/1993025
| ML20059A420 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/13/1993 |
| From: | Blake J, Economos N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20059A419 | List: |
| References | |
| 50-338-93-25, 50-339-93-25, NUDOCS 9310260326 | |
| Download: ML20059A420 (9) | |
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NUCLEAR REGULATORY COMMISSION e
UNITED STATES
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REG!oN 11
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101 MARIETTA STREET, N.W., SUITE 2900 v
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ATLANT A, GEORGIA 30323 0199 j
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Report Nos.:
50-338/93-25 and 50-339/93-25
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Licensee: Virginia Electric and Power Company
Glen Allen, VA 23060 Docket Nos.:
50-338 and 50-339 License Nos.: NPF-4 and NPF-7 i
Facility Name: North Anna 1 and 2 Inspection Conducted:
September 14-17, 1993
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Inspector:(
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N. Ec6nomos F pate Signed Approved by:
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/J Blake, Chief Date Signed aferials Process Section ngineering Branch
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Division of Reactor Safety
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SUMMARY Scope:
This routine, announced inspection was conducted in the areas of Eddy Current
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(ET) examination of Steam Generator (S/G) tubes in Unit-2, a review of
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inservice inspection (IS!.) procedures and observation'of nondestructive
examinations relative to this activity.
Results:
By observation of the ISI work effort and review of procedures relative to this area, the inspector ascertained that the licensee is meeting code requirements and regulatory commitments in this area.
Personnel directing and performing ISI work, appear to be well trained to carry-out their assigned tasks.
Eddy Current of steam generator tubes is being conducted by
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Westinghouse Nuclear Services Division (WNSD). The inspection plan and data analysis guidelines contain adequate conservatism to give reasonable assurance that suspect tubes will be identified and dispositioned in a satisfactory (
manner. An augmented examination of the.feedwater nozzle to pipe welds on
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the three S/G(s) showed no evidence of service related indications.
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l Within the areas inspected violations or deviations were not identified.
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9310260326 931014
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i REPORT DETAILS
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Persons Contacted Licensee Employees
- D. Heacock, Superintendent Engineering
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- J. Leberstein, Staff Engineer
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- G. Kane, Station Manager
- P. Kemp, Acting Assistant Station Manager NS&L
- P. Smith, Manager Quality Assurance (QA)
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- H. Travis, Supervisor, NDE
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t Other licensee employees contacted during this inspection included QA/QC inspectors, engineers and technicians.
i Other Organizations Westinghouse Nuclear Service Division V. Ingraham, level III Examiner, Eddy Current i
NRC Resident Inspectors D. Taylor, Resident Inspector
- J. York, Senior Resident Inspector
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- Attended exit interview
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2.
Steam Generator Tube Eddy Current Inspection, Unit 2 (IP73753)
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At the time of this inspection, the Eddy Current examination activity had just begun.
The inspector met with VEPC0's site Nondestructive Examination (NDE) supervisor to discuss technical aspects of the
inspection and obtain a progress report on the subject activity.
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acquisition procedures and data analysis guidelines were provided for i
review.
Westinghouse (W) was the primary contractor, in charge of data j
acquisitions and analysis.
The ET inspection plan, which had been
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approved by Virginia Power Company's Steam Generator Advisory Committee, was written to meet ASME Section XI 'and Technical Specifications requirements. A summary of the scope of stem generator (S/G) tube j
examinations during this outage is as follows-
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S/G "A" S/G "f!"
S/G "C" l
Bobbin, Cold Leg:
3053 3080 2864 j
Bobbin, Hot Leg:
513 528 487-
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Rotating Pancake
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Coil, Top of Tube
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Sheet (wextex area),
Hot Leg:
3199 3239 3014 l
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S/G "a" S/G "B" S/G "C" Rotating Pancake Coil, Row 2 U-Bend,
Hot Leg:
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Rotating Pancake Coil, Tube Support Plate, Hot Leg:
115 117 2736 The subject inspection plan was implemented using W data acquisition and analysis guidelines reviewed and approved by the licensee's Level III Examiner.
The inspector reviewed the following controlling documents / procedures for technical content and adequacy:
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MRS 2.4.2 - VRA-21, Rev. 1 Eddy Current Inspection of Preservice and Inservice Heat
Exchanger Tubing at North Anna 1 and 2.
North Anna Unit 2 Steam Generator Eddy Current Data Analysis Program (EDAP), July, 1993 Rev. 3.
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DAT-GYD-001 Rev. 6 Westinghouse Generic Data Analysis Guidelines Rev. 6.
The-applicable code and regulatory requirements, as referenced in the above documents, was ASME Section XI 1974 Edition with Summer 1976 Addenda through the 1989 Edition with Code Cases N-401 and N-402.
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addition, by review of the subject documents the inspector ascertained i
the following specifics to this examination:
o Data evaluation will be performed by two analysts totally independent of each other.
Conflicts between the two
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analysts will be resolved by resolution analysts or higher
and eventually by the Licensee's level III as needed.
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Primary and secondary analysis will be performed remotely at W Waltz Mill site. The resolution analyst will be located at North Anna.
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Bobbin analysis criteria provide specific evaluation and recording requirements for indications found at various
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locations over the length of S/G tubes and more importantly at tube support plate (TSP) intersections,-(dented and non-dented) and at the top of the tubesheet (TTS).
For the latter, there is no minimum or maximum voltage requirements.
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o Rotating pancake coil (RPC) examination will be performed on
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all distorted-indications (DI(s)), at TSP intersections to
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characterize respective bobbin calls made during the initial phase of inspection.
O A 100 percent RPC, TTS hot leg inspection of all SG tubes-will be performed. This test will be used to disposition the TTS(s) and Tubesheet' Indications (tis) found during the initial bobbin coil inspection. All dents in intersections
with signals > 2.0 volts will be subject to RPC, which will
be used to disposition TSP DI(s) at these locations.
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O Resolution analysts are required to review all DI and TI calls by Bobbin and RPC before the BcSbin and RPC coil
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inspection programs can be declared couplete.
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In conjunction with this inspection program, the licensee is conducting i
an assessment of denting growth in steam generator "C".
This assessment
will be done by analyzing a small sample of bobbin coil data during the I
early part of the bobbin examination program. This program is a repeat
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of a similar study done on two previous outages performed for the i
purpose of comparing growth rates of indications in the same tube population.
A breakdown of plugged tubes per SG in this plant prior to the present outage is as follows:
j S/G "A" S/G "B"-
S/G "C" Tubes Plugged:
189 149 374
% of Tubes Plugged:
5.58%
4.40%
11.04%
Data acquisition was being performed with multifrequency, multiparameter digital data collection equipment, optical disc recording media and remote control acquisition unit (s) MIZ-18 or MIZ-18A.
Personnel qualification requirements included those prescribed by ASNT-TC-1A for Level II A or Level III as applicable. and successfully passing a site specific examination on specific probe types, i.e., bobbin, 8XI
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or RPC, used to acquire ET data.
Site specific examinatic,ns included actual flaw signals from previous North Anna evaluations. Test results were reviewed and approved by the licensee's Level III NDE Examiner.
Within these areas the inspector reviewed personnel qualification records for 28 ET examiners including eye examination results, equipment
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certifications, equipment and standards calibration records and _ receipt
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inspection results as applicable.
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By observation and through discussions, the inspector determined that j
this activity was being performed by well trained personnel following i
conservatively written guidelines.
In addition, the inspector noted that the licensee was closely monitoring this activity through frequent i
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4 inspections, data reviews and progress reports on tube inspections and findings. On September 30, 1993, the inspector discussed the outcome of the ET examination with the licensee's NDE supervisor who indicated that the scheduled examination for this outage was completed. The number oftubes scheduled for plugging in S/G(s) "A" and
"B" was finalized, while the list for S/G "C" was undergoing evaluation. The number of tubes scheduled for plugging were provided for information purposes:
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S/G "A" S/G "B" S/G "C"*
Total New Pluggable 108
139 Tubes
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Total Tubes Plugged 297 221 513 l
Total Percent Tubes 8.77%
6.52%
15.14%
Plugged
- For S/G "C", this number is preliminary as engineering was continuing to review the data. The licensee indicated that this examination showed the rate of tube degradation was as anticipated. The type of indications observed were similar to i
those observed during previous examinations.
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3.
Inservice Inspection, Unit 2.
The plant is undergoing the second refueling outage in the first period of the second 10-year interval. The inspector observed in-progress examinations, and reviewed procedures and records indicated below, to determine whether ISI examinations were being conducted in accordance with applicable procedures, regulatory requirements and licensee
commitments. The applicable code for ISI activities was the American l
Society of Mechanical Engineers Boiler and Pressure Vessel (ASME B&PV)
Code,Section XI 1986 Edition.
Volumetric and surface examinations were
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being performed by Virginia Corporation of Richmond (VCR), using the i
licensee's QA program and procedures, see NRC Inspect!on Reoprt 50-339/92-06.
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ISI Program Review (73051) (Unit 2)
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The inspector reviewed the following documents relating to the ISI
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program to determine whether relief requests had been approved by NRR, the services of an Authorized Nuclear Inservice Inspector (ANII) had been procured and was involved in ISI activities, the
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plan had been approved by the licensee and to assure that procedures and plans had been established (written, reviewed, i
approved and issued) to control and accomplish the following i
applicable activities: program organization including i
identification of commitments and regulatory requirements, j
preparing plans and schedules, and qualification, training,
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5 responsibilities, and duties of personnel responsible for ISI;'
personnel qualification requirements; and guidance for identifying and processing relief requests.
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Inservice Inspection Plan for Components and Component Supports (Second Interval).
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Inservice Inspection Manual, Component Examination Program
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Section 6.1 Revision 6.
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NASES 6.05 Revision 1, ASME Section XI Component Examination Program.
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Safety Evaluation for North Anna Power Station Unit No. 2.
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(NA-2)/second 10-year Inservice Inspection (ISI) program-with associated relief requests.
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NDE-2.4 Revision 3, Requesting and Reporting of NDE Services.
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NDE-3.1, Revision 6, Preparation, Issue and Control of i
Nondestructive Examination Procedures.
NDE-4.1, Revision 11, Virginia Power Written Practice for
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Certification of Nondestructive Examination Personnel.
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NDE-6.3, Storage and Control of NDE Calibration Equipment, Calibration Standards and Consumable NDE Materials.
NDE-6.4, Selection of Calibration blocks for PSI and ISI
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Ultrasonic Examinations.
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Review of NDE Procedures (73052) (Unit 2)
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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, compilation of required records, and division of
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responsibility between the licensee and contractor personnel, as applicable.
NDE-PT-501, Revision 1, Liquid Penetrant Examination
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NDE-MT-501, Revision 1, Magnetic Particle Examination
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NDE-UT-50), Revision 1, Ultrasonic Examination of Piping Welds
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NDE-MT-502, Revision 1, Magnetic Particle Examination of Bolting
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NDE-UT-502, Revision 1,' Ultrasonic Examination of Vessel
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Welds s 2" thickness
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NDE-UT-503, Revision 1, Ultrasonic Examination of Vessel-Weld > 2" in thickness
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NDE-UT-505, Revision 1, Ultrasonic Examination of Reactor.
Coolant Piping Welds
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Observation of Work and Work Activities (73753) (Unit 2)
i The inspector observed work activities, reviewed NDE personnel qualification records, and reviewed certification records of NDE equipment materials, as detailed below. During the examinations,-
the inspector verified:
availability of and compliance with approved NDE procedures, use of knowledgeable NDE personnel, and
use of NDE personnel qualified to the proper level.
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Work Observation Item Weld Line.0wo. Number Examination Comment C5.51
6"-SHP 438-601-Q2 MT/UT-Reportable UT indication,
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evaluated as weld j
fabrication
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indication, confirmed by radiography, per j
IWC-3112.b.
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12050-U/MKS-RC-E-2 UT Acceptable -
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Auomented Inspections
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Nozzle to
16"-WFPD-423-601-02 UT Acceptable J'
Pipe SG "B"
Nozzle to
16-WFPD-422-601-Q2 UT Acceptable
Pipe SG "C"
- Records from two previous examinations (1978, 1982), were reviewed and
the results.were found acceptable.
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Personnel Qualifications U
l The inspector reviewed personnel qualification documentation l
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as indicated below for examiners who performed the examinations detailed above.
These personnel qualifications-were reviewed in the following areas: employer's name;-
person certified; activity qualified to perform; current J
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c period of certification; signature of employer's designated representative; basis used for certification; and, annual visual acuity, color vision examination, and periodic
recertification.
Examiner Records Examined i
Method level Employer Number
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i PT Il VCR
MT II VCR
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UT II VCR
VT II VCR
In addition, qualification records for one VEPC0 level III (PT, MT, and UT) examiner was reviewed.
O Equipment Certification Records Equipment certification records as listed below, for
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equipment used in the inspections detailed above, were reviewed to ensure compliance with all applicable requirements.
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Eauipment Tvoe Eauipment Identification-MT Powder Batch 7802-252 l-UT Calibration Blocks VRA-18, VRA-27
-Transducers 0*, M18205, KB8, 2.25 MHz.75'O
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45*, 49229, Panametrics 2.25 MHz-
.50" x 1.0" 60*, 56745, Panametrics 2.25 MHz
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45*, 78640, KB, 5.0 MHz,.375'O.
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45*, 78641, KB, 5.0 MHz,.3753 45*, 156010, Panametrics 5.0 MHz,
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P 60*, 167632, Panametrics 5.0MHz,
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45, F076067, Aerotech 5. MHz,.25'O
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-Instruments 91059612, Panametrics Epoch II 91062212, Panametrics Epoch II 91062012, Panametrics Epoch II-Couplant 92220 Sound Safe In reference to the augmented examinations on the two feedwater nozzle-to-pipe welds discussed above, the-licensee completed the examination in S/G "A".
Through discussions and record review, the inspector ascertained that two low amplitude spot indications (12% to 15% DAC), were identified by UT examination which were evaluated as acceptable root condition. A subsequent radiographic examination disclosed that one of these was root geometry while the other corresponds with slag / porosity indications shown also in the construction radiograph. At the close of this inspection, the inspector stated that an unresolved item would be identified pending a review of the radiographic examination results. However in that the review was dcne and no concerns were identified, the unresolved item discussed during the exit will not be issued. This decision was communicated to the licensee through the NRC resident.
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Within the areas inspected, violations or deviations were not identified.
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Action on Previous Inspection Findings (92701)
(Closed) Unresolved Item 339/92-08-01, Multiple Circumferential Indications Tube R15-C61 S/G "B".
This item was opened in order to allow for a review of a W response to a Licensee Deviation Report (N-92-800). The deviation report, dated-March 13, 1992, was issued when it was determined that the subject tube exhibited an ET signal, interpreted as a circumferential indication of 324*.
Records from the previous examination, performed during the 1990
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outage, showed that some degradation was evident at this location and the licensee requested that W review the data and provide an explanation
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for the 1990 call and possible implications.
By review of the W response to the subject deviation report, dated April 3, 1992, the inspector ascertained that the behavior of the signal, during the 1990 outage, led the analyst to believe it was the result of a permeability variation in the material. Also it was stated that a poor signal to noise ratio in the area in question (WEXTEX) made identification of flaw components in the composite signals difficult and unreliable.
The W report stated that the 1992 data analysis showed indications exhibiting flaw-like behavior which was judged to be consistent with previously verified WEXTEX, circumferential cracks.
The W report included that signals of the type described, which present
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obvious visual features comparable to long circumferential cracks should be flagged for further analysis by the H level III lead analyst.
In conclusion the report stated that this practice was implemented during the 1992 North Anna 1.and 2 RPC inspections. The tube in question was removed from service during the 1992 outage. This item is closed.
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5.
Exit Interview l
The inspection scope and results were summarized on September 17, 1993, with those persons indicated in paragraph 1.
-The inspector described
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listed below. Proprietary information is not contained in this report.
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Dissenting comments were not received from. licensee.
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