IR 05000266/1988010
| ML20154S179 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 05/27/1988 |
| From: | Danielson D, Schapker J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20154S176 | List: |
| References | |
| 50-266-88-10, IEIN-86-106, NUDOCS 8806080411 | |
| Download: ML20154S179 (8) | |
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U. S. NUCLEAR REGULATORY COMMISSION
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REGION III
Report No. 50-266/88010(DRS)
Docket No. 50-266 License No. DPR-24 Licensee:
Wisconsin Electric Power Company t
231 West Michigan Milwaukee, WI 53203 Facility Name:
Point Beach Nuclear Plant, Unit 1 Inspection At:
Point Beach Site, Two Creeks, Wisconsin InspectionConductep:
April 12-14, 19-21, and May 10-12, 1988
Inspector:
. F. Schapker 07!d6 s
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dt W in Approved By:
D. H. Danielson, Chief 6!s7[96 Materials and Processes Section Date Inspection Summary Inspection on April 12-14, 19-21, and May 10-12, 1988 (Report No. 50-266/88010(DRS))
Areas Inspected:
Routine unannounced inspection of inservice inspection (ISI)
activities including review of program (73051), procedures (73052), observation of work and work activities'(73753), and data review and evaluation (73755); of unresolved items (92701); of fuel rod assembly examinations (73753); of the ultrasonic examination (UT) of the steam generator transition field weld and the reactor coolant loop piping (73052, 73753); of the eddy current examination of the steam generator tubes, (73052, 73753); and of the balance of plant piping examinations (73052, 73753).
Resuits:
No violations or deviations were identified.
8806080411 880531 PDR ADOCK 05000266 O
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DETAILS 1.
Persons Contacted Wisconsin Electric Power Company (WEPC0)
J. Reisenbuechler, Superintendent S. Pullins, ISI Engineer
- J. Kohlwey, Nuclear Engineer K. Crowly, Nuclear Engineer
- J. Knorr, Regulatory Engineer J. Schewitzer, Maintenance Mechanical Engineer R. Winjet, Nuclear Engineer
- G. Sherwood, Nuclear Engineer J. Kenefich, Quality Assurance, Level III EBASCo Services, Inc. (EBASCo)
J. Sengenberger, Level III Hartford Steam Boiler Engineering and Insurance Company R. Motguin, ANII Nuclear Regulatory Comnission (NRC)
- R. Hague, Senior Resident Inspector R. Leemon, Resident Inspector
- Denotes those attending the exit meeting.
2.
Licensee Action on Previous Inspection Findings a.
(0 pen) Unresolved Item (266/87009-01(DRS)):
The licensee previously discovered evidence which indicated certain portions of the reactor coolant piping were fabricated with welded long seams, which had not
been previously examined in accordance with ASME Section XI Code requirements.
The licensee has confirmed the existence of the welded long seams and additional girth welds (4) not previously examined as required by Section XI. The exclusion of these welds resulted from inaccurate as-built drawing records where some shop welds were not recorded, thereby, being excluded from the Inservice Inspection (ISI) Plan.
The licensee h6s implemented the following corrective action:
1) All welds not previously inspected have been examined in accordance with ASME Section XI Code requirements, 2) A nonconformance report has been issued to address the inaccuracy of the ISI plan due
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to the as-built drawing discrepancies. 3) A review of shop drawings and construction documentation to verify the accuracy of as-built is being performed to assure other systems ISI programs are accurate,
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and 4) Examination of the previously unidentified longitudinal
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welds utilizing special ultrasonic equipment and procedure developed
for cast stainless steel has been performed with no recordable j
indications.
(Reference Paragraph 3 of this report)
This item remains unresolved pending further action by the licensee,
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and review by the NRC.
b.
(0 pen) Unresolved Item (266/86015-01(DRP)):
During a review of the technical manual for the Model 44F steam generators installed in a
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Unit 1 during the six-month outage ending in March of 1984, it was l
noted that the testing section for primary and secondary side-hydrostatic testing listed a minimum test temperature of 120*F.
The technical manual for the steam generators that were removed from
Unit I and for the steam generator presently being used in Unit 2 j
list a minimum temperature of 70'F.
The actual acceptance hydros J
done by the licensee were performed at a temperature of 147*F.
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Technical Specifications 15.3.1.B.2 states:
"The secondary side of
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the steam generator will not be pressurized above 200 psig if the temperature of the steam generator vessel shell is below 70 F " The licensee is checking with the vendor to determine what the Technical Specification temperature value should be.
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The inspector reviewed the licensee's Technical Specification, Technical Manual for the Model 44 steam generators (SG), and
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secondary side leak and hydrostatic test procedures. The Point l
Beach Technical Specification 15.3.1.B.1 states:
"The Reactor Coolant system temperature and pressures shall be limited in
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accordance with the limit lines shown in Figures 15.3.1-1 and i
l 15.3.1-2."
This includes the primary side of the steam generators.
Therefore, the primary side temperature / pressure limitations is specified adequately within the Technical Specification.
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secondary side as described above is not similarly prescribed and pressurization above 200 psig.
l The licensee's hydrotest/ leak test procedures for the secondary side i
specify the temperature / pressure requirements; however, these j
temperatures do not meet the requirement as stated in the Technical Manual for the 44F steam generators installed in Point Beach Unit 1.
j The licensee has inquired to the equipment manufacturer, a preliminary report was received and reviewed by the NRC inspector. Additional
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i information has been requested.
Pending the review and acceptance l
of this data this item remains unresolved.
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Ultrasonic Examination of Primary Loop Reactor Coolant Piping i
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The licensee acquired ultrasonic procedures and special equipment to i
examine the primary loop cast stainless steel (CSS) piping.
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j The metallurgical structure of cast stainless steel has historically presented a significant detriment to producing the optimum UT wave
propagation mode needed to perfom volumetric examinations. The
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manufacturing process of cast stainless steel results in a variation of i
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isotropic and anisotropic micro structures. Although the variation in
velocity of wave propagation is small in isotropic grain structures, the
anisotropic grain structures show a marked in impingement on the velocity i
of wave propagation, especially for the shorter shear wave velocities.
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Conclusion x
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The licensee employed the services of a NDE contractor (EBASCo Services, i
Inc.)todevelopaUTprocedureadequatetomeettheASMESectionXI criteria for volumetric examination of Primary Lcop cast stainless steel
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piping welds. The NDE contractor developed a UT procedure utilizing l
special eqt..
....c, UT machine with special bandpass filters, an'd special
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transducers (focused dual, refracted longitudinal wave mode) <With the L
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modified UT equipment the NDE contractor demonstrated the detection of
the axial and circumferential I.D. notches' with a signal to noise ratio
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of 4 to 1 (with system parameters optimized).
The aver (go signal to noise i
ratio during scanning of the reactor coolant piping was, about 2 to 1.
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This is due to the variance of metallurgical structures and scanning at
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+ 8 to 10 db.
The NRC inspector concluded that the licensee's special
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UT equipment and procedure was adequate to resolve the calibration standard l
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I.D. notch and provides adequate resolution to identify any significant
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defect in the area of interest.
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The ultrasonic examination observed by the NRC inspector was effective
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with respect to meeting the safety objectives as required by the
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applicable Code requirements.
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j No violations or deviations were identified.
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4.
Inservice Inspection (ISI)
a.
Gereral_
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The NRC inspector reviewed the second ten year Inservice Inspection
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Plan for the third period, first outage.
The ISI plan conforms to
i the American Society of Mechanical Engineers (ASME), Boiler and
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Pressure Vessel Code,Section XI,1977 Edition, Sumer 1979 l
Addenda.
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i The services of an Authorized Nuclear Inservice Inspector (ANII)
were procured and the ISI procedures, examinations and personnel certifications have been reviewed by the ANII.
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, EBASCo and the WEPCo Quality Assurance departments performed the ISI l
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i in accordance with ASME Section XI, 1977 Edition, Summer 1979 Addenda.
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The majority of the ultrasonic examinations (UT) were perforr.1ed by
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EBASCo, using pulse echo UT detection instruments and transducers
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i utilizing straight beam and angle beam examinations. No i
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intergranular stress corrosion cracking (IGSCC) was apparent, i
j Westinghouse Electric Co. (WEC) performed eddy current examination
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(ET) of the steam generators tubing.
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-b.
ISI Documentation Review The NRC inspactor reviewed documents relating to the following:
Eddy current'(ET) equipment calibration.
Ultrasonic instruments, calibration blocks, transducers and UT couplant certifications.
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b Liquid penetrant material certifications.
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Magnetic particle equipment. certifications.
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NDE personnel certifications in accordance with SNT-TC-1A.
NDE procedures utilized for ISI.
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NDE calibrations and examination reports.
ET data reports.
c.
Observation of Work Activities The NRC inspector observed work and discussed examinations with NDE exam'ners.
These activities included observation of calibrations
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and examination performance, and review of documentation of the s
following NDE:
Liquid Penetrant examination of Residual Heat Removal (RHFd piping welds.
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Visual Examinations of Reactor Pressure Vessel to Head Hold Down Studs (RPVS).
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Ultrasonic examination of RPVS and Safety Injection System (SIS) piping welds.
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Eddy Current examination of Steam Generator tube'.-
s Hydrostatic test of the Chemical and Volume Control System (CVCS),
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No violations or deviations were identified.
5.
Fuel Rod Assembly Examinations b
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l The Brown Boveri (BBC) Failed Fuel Rod Detection System (FFRDS) was b'
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utilized to examine the fuel rods for defects in the fuel cladding. Tnis l
system uses a remotely controlled automatic ultrasonic (UT) detection f.
J-system. ThelicenseehaspurchasedtheUTsystemandisintheprocess)
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l of training personnel in its operation. Thecontractor(BBC)performeu i
the examination and ultrasonic evaluation of the data.
Licensee
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personnel in training assisted BBC in the examination as part of the i
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on-the-job training program.
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I The NM)kuspector observed examinations in progress and recording of UT
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a data ar i reports.
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g NoviolatiUh r' deviations were identified.
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6.
Ultrasonic-Exag na, tion of Steam Generator (SG)
"B" Transition Girth Weld a
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Thelicenseeperhoi.hedultrasonicexamination(UT)oftheuppershellto transition cone girth weld on SG "B".
This veld is a field weld that was performed when the SG was replaced in 1983.
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Recent examinations performed at another site (Indian Point) of the SG girth weld reveahd ultrannic reflectors at the inside weld circumference.
Visual examinations of the inside circumference revealed essentially horizontal intermittent linear indications around the weld length 360.
Ultrasonic and magnetic particle examinations were extended to 100% of the weld and removal of f.e indications was made by grinding'.
Point Beach, Unit 1, replaced their steam generators in 1983. Thdn'4 replacement steam generators consist of the lower shell and tube bundle up to the Number 4 weld (transition weld).
The upper SG shell above'tbi Number 4 weld is removed and installed from the old steam generators. ',
Comequently, the transition weld for the Unit 1 SG's have previously
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been ultrasonic examined and have seen minimal operatlonal time.
In addition the licensee has changedsfrom copper (suspected contributor to the development of the cracks at Indian Peint) tube condensers to
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stainless steel tube condensers.
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The examination was performed utilizing pulse echo type UT ostection
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O instruments with A-Scan presentation.
Piezoelectric transducers at nominal beam angles of 0 (longitudHal), 45' and 60 (transverse)
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The UT procedure complie6 witn the requirements specified j
f n ASME SecHon XI,1977 Edition, u,J ld and including Sumer 1979 Addenda.
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Qualification of the UT inspectors ns verified to comply with SNT-TC-1A 5 "
and ASME Section XI requirements.
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Five fydications matched or exceeded the 50% DAC reportability criteria,
as specified in ASME Section XI. All indications were spot reflectors
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with no measurable size.
Four of the indications were determined to be i
geometric reflectors from the ID root. The remaining inlicr Jon was det9raired to be a small inclusion within the weld. The indicatior.s were i
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veri)@dasrecordedinthebaselineUT.
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No violations or deviations were identified.
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Eddy Current Examination of Steam Generators
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The licensee employed Westinghouse Electric Corporation (WEC) to perform eddy current examination (ET) of steam generator tubes as required by Technical Specification. WEC utilized the MIZ 18 multi-frequency acqyisition and analyser system to conduct the examinations.
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The NRC inspector observed the ET of the steam generator tubes in progress, verified certifications of ET equipment and calibration standards, and reviewed the qualifications and certifications of the ET examiners.
No defective tubes were identified.
Previously reportable distorted indications (01) were reclassified as fabrication induced due to buffing to remove scratches induced during fabrication. The reclassification was predicated by research performed by WEC on other units in which removal of tubing was performed to verify the ET indications.
Subsequent to the ET examination two tubes were damaged in SG "A" during the wrapper seal plates modification.
This modification was performed to enhance sludge lancing accessibility.
In perfonning the modification a hole saw accidentally came into contact with two steam generator tubes.
ET examination was performed on five tubes within the area of the penetration.
The two damaged tubes were detected at Row 1, Column 1 (66%) and Row 2, Column 1 (22%).
These two tubes were plugged.
In addition, all peripheral steam generator tubes in SG "B" were ET examined due to discovery of a metallic wedge found during visual examination of the annulus adjacent to the tube bundle after completion of the wrapper seal plate modification.
The source of the wedge was not readily apparent, therefore, the licensee elected to ET the peripheral tubes to assure no damage was caur-d by the foreign object during operations. The wedge was resting on the tube sheet adjacent to the tubes.
The NRC inspector observed the visual examination via remote VCR camera. The licensee performed adequate corrective action to assure the safe operation of the steam generators.
8.
Secondary Side Piping Examinations l
The licensee developed a piping inspection program to inspect balance of plant (80P) piping that has a temperature greater than 140 F, diameter i
l greater than or equal to two inches, and pressure greater than I
atmospheric. Previous to this outage over 700 inspection points were selected for ultrasonic, magnetic particle, liquid penetrant, and visual l
examinations. The inspection points included piping with single and dual I
phase flow. The licensee utilized EPRI guidelines to establish the criteria for these inspections.
The licensee performed inspections nn 75 inspection areas during this outage.
The following systems were included in this inspection program:
Feedwater piping Main Steam piping Condensate piping l
Steam Generator blowdown piping Turbine exhaust piping l
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Low pressure trap headers Condenser steam dump lines
Moisture Separator Reheaters feedwater drains Examination of the condenser. steam dump lines disclosed an area where 65%
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of the pipe wall thickness was eroded.
The corrosion was contributed to low pressure trap header flow and not to steam dump flow. Repairs were
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made to this area to correct the discrepant condition.. The NRC inspector observed inspections in progress and reviewed inspection results and data.
The licensee's inspection program for B0P piping is effective with respect to meeting the safety objectives as described in IE Information Notice 86-106.
9.
Exit Meeting The inspector met with licensee representatives (denoted in Paragraph 1)
at the conclusion of the inspection on May 12, 1988. The inspector summarized the scope and findings of the inspector also discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspectors during the inspection.
The licensee did not identify any such documents / processes as proprietary.
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