IR 05000266/1987023

Insp Repts 50-266/87-23 & 50-301/87-21 on 871013-1124.No Violations or Deviations Noted.Major Areas Inspected: Inservice Insp Activities Including Review of Program, Procedures & Observation of Work

ML20237C548
Person / Time
Site:	Point Beach
Issue date:	12/14/1987
From:	Danielson D, Schapker J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20237C544	List: IR 05000266/1987023 ML20237C542
References
50-266-87-23, 50-301-87-21, IEIN-86-106, NUDOCS 8712210374
Download: ML20237C548 (8)

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U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Reports No. 50-266/87023(DRS); 50-301/87021(DRS)

Docket Nos. 50-266; 50-301 Licenses No. DPR-24; DPR-27

} Licensee: Wisconsin Electric Power Company 231 West Michigan Milwaukee, WI 53203 Facility Name: Point Beach Nuclear Plant, Units 1 and 2 Inspection At: Point Beach Site, Two Creeks, Wisconsin Inspection Conducted: October 3-16 ,2 ,-29, and November 2-4, 17-19, 23-24, 1987 Inspector: J. F. Schapker /

Y!- /.2/ v/r 7 Dat'e '

df}4&O W Approved By: D. H. Danielson, Chief /2//v// 7

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Materials and Processes Section

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Date Inspection Summary Inspection on October 13-16, 26-29, and November 2-4, 17-19, 23-24, 1987

[ Reports No. 50-266/87023(DRS); No. 50-301/87021(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 IE Information Notices (92704) and unresolved items (92701); of the fuel assemblies rod examinations (73052, 73753, 73755); of the evaluation of the thirty one inch 90 elbows not previously included in the ISI program (73051)

and modifications (37701).  ;

Results: No violations or deviations were identifie l l

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DETAILS / ; i'

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Wiscon/plectricPowerCompany(WEPCO) f 'l j.3 ,

• J. ReisnWehler, Superintendent 'l l S. Pull % ,' ISI_ Engineer ,i 1

• J. KohF,)/, Nucl er Eng heer

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K. Crowl9. Nuclear Engineer ,

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J. Krvr, r egulat'bry Emineer l'

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, J. Schevetzer, Maintenance Mechanical Engineer t <

, R. Wii. jet, Nuclear Engineer '

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, G. SherworrJ, Nuclear Engineer '

7 l J. Kenefich, Quality Assurance, level III 1 i .

EBASCo Services, Inc. (EBASCo) "0 J. Sengenberger, I,evel III!

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Y lartford Steam $si" n Engineering and Insurance Company V

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Westinghume Electric Corporation (M,0

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~FT'Garofalo, Manager, Steam Generator Paintenanceciervices J. Snee, Superintendent, Eddy Current Examination,

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, . ) i NuclearRegulatoryCsmmist. ion (MnQ }

• R. Nague"l, SeniorMelf dent Inspector ' - >

• R. Leemon, rem 6ent Inspector a The inspector also etntacted and interviewed other licensee ard contractor employet '

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• Denotes those atdr iding the exit meet 4n . Licensee Action,on IE_(nformation Notices (Closed) IE 1r;'or:,ation Notices No. 86-106: Feedwater line break

~ I'hi s information r'oTice:

i vas to >Iert lice 1 sees of a potentially generic problem with feedwater pioe, thinnir.g n f other problems rep.ted t this. even On Decemtur 9 '98f, bot'ucniti, at the Surry Power,ci.at,on',were operatir.] .

at full pwar1...ter the JW' st.ction line to the mait fee.iwaar Pupp "A",

for Unit 2 f'.dled, citist ophicall The event was init;a;ed by the main stea.n isolation valve e steam generator "C" failing closW. Becaust of l the increased pressure fit steam generator "C" thit collapsed the void:

in the water, the reactor tripped on a low-low level in that steam generator. A tro-by-four foot section of the wall of the suction line

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to the "A" tain f eedwater pump was blown oat _ and came to rest in an s overhead cable tray. The brerk Was located fe' co elbow Pt thei18" line about one foot from the 24" header. The lateral reactive force generated by escaping feedwater completely severed the suction line. The free end whipped ard,came to rest against the discharge line for the other pum WEPCc has conducted inspections to detect thinning of materilis' in the pasi. These inspections were limited to ultrasonic (UT) thicbuss 'i measurements of two phase flow piping. Results of this program vere the basis for replacement of the extraction steam lines with steinless steel. WEPCo developed a more extensive program to inspect balance of. plant pipir.g that has a temperature greater:than 140 F., di6 meter greater. than or equal to two anches, .ind pressure greater than atmospheric. Approximately, 700 inspection pcints were chosen where ultrasor!c, magnetic particle, liquid penetrant and visual examinations were performed. The points included piping with single and dual phase flow. WEPl.o relied heavily cs EPRI to assist in establishing the criteria

,i for the insprition; e.g. , eros'on/ corrosion as a function of temperature, moisture, geometry, and fluid velocity. WEPCo examined welds of dissimilar materials in areas such as No. 4 FWH, extraction lines, welds experiencing high stress or fatigue, internal visual inspections whenever possible, UT thickr.ess measurements, and UT of weld The following are the results of the Unit 2 inspectio Ultrasonic Weld Examinations:

One indication was found in a weld on the stainless steal extractio9 line to the 4A Feedwater Heater. The ir.dicat ion was evaluated to be j within the fracture toughness of the material and was acceptable for 1 i servic Magnetic Particle _ Examina_tions:  !

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Five welds had reportable indications, four were ground out and rewelded, and ode was mapped and .arked for future observatio These indications appeared to be hot tearing cracks on the surface of the components caused by uneven cooling during fabricatio Dye Penetrant Examynt(f ons:

Five reportable indications were foun Four were repaired, the other was evaluated and accepted as i <

' ' Ultrasonic Thickness Examinations:

The licensee examfaed 118 components of which 52 components had thickness less th.an the manufacturer's tolerance. The 50 were evaluated to USAS B31.1 Code requirements. The minimum al~.owable j

^ wall thickness was calculated for each component and confirmed l acceptable for all but two fittings with less than code allowable thickness. The licensee performed seismic and pressure stress ,

calculations for these fittings and found them to be acceptable j

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. Licensee Action on Previous Inspection Findings (0 pen) Unresolved Item (266/86015-01(DRP)): During a review of the technical manual for the model 44F. steam generators installed in Unit 1 yO during the six-month: outage ending in March of 1984, it was noted tha the testing section for primary and secondary side hydrostatic testing m 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 list a minimum temperature of 70 F. The actual acceptance hydros done by the licensee were performed at a temperature of 147 Technical Specification 15.3.1.B.2 states:

"The secondary side of the steam generator will not be pressurized v 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 b The inspector reviewed the licensee's Technical Specification, technical manual for the model 44 steam generators (SG), and secondary side leak and hydrostatic test procedures. The Point Beach Technical Specification 15.3.1.B..I states: "The' Reactor Coolant system temperature

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and pressures shall be limited in accordance with the limit lines shown in Figures 15.3.1-1 and 15.3.1-2." This includes the primary side of the steam ger,arators. Therefore, the primary side temperature / pressure limitations is specified adequately within the Technical Specificatio The secondary side as described above is not similarly prescribed and only specifies that the 70 F temperature be acquired before pressurization above 200 psi The licensee's hydrotest/ leak test procedures for the secondary side specify the temperature / pressure requirements; however, these temperatures do not meet the requirements as stated in the Technical

. Manual for the 44F steam generators installed in Point Beach Unit The licensee has inquired to the equipment manufacturer, a preliminary report was received and reviewed by the NRC inspector. Additional information has been requested. Pending the review and acceptance of this data this item remains unresolve . Inservice Inspection (ISI) Unit 2 General The NRC inspector reviewed the second ten year Inservice Inspection Plan for the second period, fifth outage. The Inservice Inspection Plan conforms to the American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code,Section XI, 1977 Edition, Summer.1979 Addenda. Relief request in accordance with 10 CFR 50.55a(g)(5)(iv) had been applied for and accepted by NRR fcr those inservice examinations to be performed during this perio The services of an Authorized Nuclear Inservice Ir spector (ANII)

were procured and the ISI procedures and personnel certifications have been reviewed by the ANI l

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EBASCo and WEPCo Quality Assurance departments performed the ISI in accordance with ASME Section XI,.1977 Edition, Summer 1979 Addenda. The majority of the ultrasonic examinations (UT) were performed by EBASCo, using pulse echo UT detection instruments and transducers utilizing straight beam and angle beam examinations, j No intergranular stress corrosion cracking.(IGSCC) was apparen Westinghouse ' Electric Co. (WEC) performed eddy current examination (ET) of the. steam generators tubin ISI Documentation Review  !

The NRC inspector reviewed documents relating to the following:

Eddy current (ET) equipment calibratio Ultrasonic instruments, calibration blocks, transducers and UT couplant certification Liquid penetrant material certification *

Magnetic particle equipment certification NDE personnel certifications in accordance with SNT-TC-IA

NDE procedures utilized'for IS Audits performed by WECCo Quality Assuranc *

NDE calibration and examination report ET data reports, Observation of Work Activities The NRC inspector observed work and discussed examinations with NDE examiners. These activities included observation of calibrations and examination performance, and review of documentation of the following NDE:

Liquid penetrant examination of electrical penetration wel Ultrasonic examination of steam generator feedwater, and main steam piping weld Eddy current examination of steam generator tube *

Radiography of RTD bypass manifold replacement piping weld Visual examination of steam generator feedwater piping weld ID for surface reflectors detected by ultrasonic examinatio Ultrasonic examination of steam generator feedwater piping Weld No.18,. FW-16-FW-2002, revealed recordable indications on the ID of the surface near.the root of the weld. The indications were evaluated to be counterbore offset from the three to nine o' clock position. A remote TV camera was utilized to verify the surface condition at the weld roo Visual examination confirmed the l counterbore geometry was the reflecting media detected by the ultrasonic examinatio ISI Program for 31" 90 Elbows 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, (reference unresolved item 266/87009-01).

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i The licensee has-confirmed the~ existence of the welded long seams through. fabrication-records. :The licensee performed a best effort ultrasonic examination (UT) of the welded long seams. Although the UT.was unable to penetrate.a 100. percent due to the grain structure of the stainless steel cast material, the ISI contractor was successful inLresolving'the three fourths T-side drilled hole of the calibration standard. The UT was performed with no indications apparent. .The licensee has contracted with the ISI contractor (EBASCo) to perform further research in an attempt to perform 100. percent volumetric examination. The NRC inspector' informed the ' licensee that this item remains unresolved pending further evaluation by the licensee and review by the NRC (301/87021-01).

No violations or. deviations were identifie . Fuel Rod Assembly Examinations The Brown Boveri (BBC) Failed Fuel Rod Detection System (FFRDS) was utilized to examine the fuel rods for defects in the fuel claddin This system uses a remotely controlled automatic ultrasonic (UT)

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detection system. The licensee has purchased the UT system and is in the process of training personnel in its operation. The contractor (BBC) performed the examination and ultrasonic evaluation of the dat Licensee personnel in training assisted BBC in the examination as part of the on-the-job training progra The NRC inspector observed examinations in progress, recording of UT data and reports, training of inspectors and documentation of examination results .

No violations or deviations were observe . Modifications Reactor Coolant System RTD Bypass Modification: Isolation valves, vents, drains, and flanged orifice connections were removed to eliminate potential leak paths and other radiation hot spots. Through record review, the NRC inspector verified that the design change was made in accordance with 10 CFR 50.59; and that the design change was reviewed in accordance with technical specifications and the Quality Assurance progra The licensee contracted AZCo to perform the RTD Bypass modificatio The hot leg orifice was removed and replaced with straight pipe, the flanged cold leg and common flow orifices were replaced with welded-in flow orifices. All work was performed in accordance with ASME Section XI, Class 1 requirements. The NRC inspector observed fabrication, of the

, replacement components, non destructive examination, including radiograph review, review of certified material test reports, drawings, weld material certification, welders qualifications, and quality assurance documentatio No violations or deviations were identified.

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- Sleeving Repair of Steam Generator (SG)

The NRC inspector observed.the sleeving of-SG tubes in the Unit 2 "B" SG. The licensee elected to install mechanical sleeves in SG tubes in accordance with Technical Specification 15.4.2.A.6. Selection of tubes to be sleeved was based.on the eddy. current testing (ET) data. As part of the ongoing maintenance and inspection programs.by the licensee, ET has been' performed on the Unit 2 SG's during past outages. Results from the most recent inspections, conducted during the Fall 1986 outage, indicated that a significant number of Unit 2 SG "B" tubes with increase in tube wall degradation. However, the degradation was less than the plugging limit defined in Technical Specification 15.4.2.A.5(a). The majority of this degradation was in the cold leg where previous tube thinning was detecte i The. sleeving program included both repair and preventive sleevin Repair sleeves were performed on those tubes which had degradation in excess.of the plugging limit but were technically capable of being sleeve Preventive sleeving was performed on the tubes having ET indications which may exceed the plugging limit in the futur A total of 89 sleeves were installed during this outage. The 89 sleeves were ET examined which disclosed two defective sleeves which were subsequently plugged. A total of 31 plugs were installed in SG "A" and 17 in SG "B" where sleeving was not technically achievable. Two tubes were pulled for destructive examination to assess cold leg tube corrosion mechanisms. The results have confirmed the presence of tube thinning in the sludge pile region above the tube sheet and intergranular corrosion

.at the first support plate. The destructive test confirm the eddy current data previously recorded. Comparison of previous eddy current data indicated no further progression of intergranular corrosion at-the support plat No violations or deviations were identifie . Steam Generator Tubes Susceptibility to High Cycle Fatigue Failure On July 15, 1987, a steam generator tube rupture event occurred at North Anne Unit 1. The leakage location was found to be at the top tube support plate on the cold leg side of the tube. The cause of the tube rupture has been determined to be high cycle fatigue. The source of the loads is believed to be a combination of a mean stress level (produced by

" denting" of the tube), and an alternating stress (due to out-of plane deflection of the tube above the top support caused by flow induced vibration). The most significant contributor to the occurrence of excessive vibration is the reduction in damping at the tube-to-tube support plate interface caused by denting. The absence of antivibration bar (AVB) support is necessary for requisite vibration to occur, together with the reduction in damping. The presence of AVB support will restrict tube motion and thus preclude the deflection amplitude required for fatigue. The original design configuration required AV8s to be inserted i

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to Row 11. No AVB support was present for the Row 9 Column 51 tube that ruptured at North Anna. Also contributing to the level of vibration, i and thus loading, 1s the local flow field associated with the detailed '

geometry of the steam generato The NRC inspector observed eddy current examinations performed on SG tubes for presence of AVB's. These examinations were performed on rows 8 through 12 of the steam generators. Evaluation of tube wear at the AVB or tube support plate was also evaluated. Results of these examinations were submitted to the equipment manufacturer for engineering analysis of the inspection data recorded. The resulting analysis determined conditions were within design safety margin However, it was recommended that increased surveillance of leakage monitoring to detect tube failure prior to complete rupture of the tube was appropriate. This augmented primary-to-secondary leakage monitoring program was implemented by the license No violations or deviations were identifie . Unresolved Ibems Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance or deviations. Unresolved items disclosed during the inspection is discussed in paragraphs 3 and . Exit Meeting The inspector met with licensee representatives (denoted in paragraph 1)

at the conclusion of the inspection on November 24, 1987. 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 inspectio The licensee did not identify any such documents / processes as proprieta r _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -