IR 05000266/1987009

Insp Rept 50-266/87-09 on 870415-0529.No Violations Noted. Major Areas Inspected:Inservice Insp Activities,Including Review Program,Procedures & Observation of Work & Work Activities

ML20215B885
Person / Time
Site:	Point Beach
Issue date:	06/08/1987
From:	Danielson D, Ward K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20215B849	List: IR 05000266/1987009 ML20215B847
References
50-266-87-09, 50-266-87-9, IEIN-86-099, IEIN-86-106, IEIN-86-99, NUDOCS 8706170494
Download: ML20215B885 (11)

Text

2-U.S. NUCLEAR REGULATORY COMMISSION

' REGION III Report No. 50-266/87009(DRS)

Docket No 50-266~ License No. DPR-24-Licensee: Wisconsin Electric Power Company .

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231 West ~ Michigan Milwaukee, WI 53201'

Facility Name: Point Beach Nuclear Plant, Unit 1 Inspection At: Point Beach Site, Two Creeks, Wisconsin 1 l Inspection Conducted: April 15-16, 20-22, 29-30 and May 1, 6-7, 13-14, 18-19, 28-29, 1987 i

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Inspector K. D. Ward

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.Date

' Approved By: f 4!/!/7'

Materials and Processes.Section Date .,

1 Inspection Summary Inspection on April '15-16, 20-22, 29-30 and May 1, 6-7, 13-14, 18-19, 28-29, 1 1981 (Report No. 50-266/87009(ORS))

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); i of IE Information Notices (92704); of the visual examinations of the reactor i vessel = intervals (73052, 73753, 73755); of the fuel assembly rod examinations )

(73052,.73753, 73755); of_the evaluation of the thirty one inch 90 elbows not '

previously included in the ISI program (73051); and of various modifications

.(37701).

Results: No violations or deviations were identified.

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06170494 870608 R

G-ADOCK 05000266, PDR

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l DETAILS Persons Contacted Wisconsin Electric Power Company (WEPCo)

• J.'Reisenbuechler,. Superintendent' ,

• S. Pullins, ISI Engineer

• J. Kohlwey, Nuclear Engineer R. Zyduck, Superintendent

'J.:Schweitzer, Leak Mechanical Engineer EBASCo Services, Inc. (EBASCo)

J. Sengenberger, Level III-Southwest Research Institute (SWRI)' j F./Medgden,. Supervisor Hartford Steam Boiler Engineering and Insurance Company R. Motquin, ANII Nuclear' Regulatory Commission (NRC)

• R. Hague, Senior Resident Inspector R. Leemon, Resident Inspector The NRC inspector also contacted and interviewed other licensee and :

contractor employee l

• Denotes those present at the final' exit interview on May 29, 198 ' Licensee Action on IE Information Notices (Closed) IE Information Notice No. 86-99: Degradation of. steel' ,

containment This information notice was to provide licensees with information of a potentially significant safety problem regarding the degradation of a steel containment resulting from corrosio Point Beach does not have a sand cushion under the containment liner :

plate. -The liner is constructed in direct contact with the base mat concrete. In addition, an impressed current cathodic protection 4 system designed for 40 years service is installed to protect the l liner plate and other metallic components'in the base mat concret l Therefore, this notice is not applicable to Point Beac l

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b. (Closed) IE Information Notice No. 86-106: Feedwater line brea This information notice was to alert licensees of a potentially generic problem with feedwater pipe thinning and other problems related to this even On December 9, 1986, both units at the Surry Power Station were operating at full power when the 18" suction line to the main feedwater Pump "A" for Unit 2 failed catastrophicall The event was initiated by the main steam isolation valve on steam generator

"C" failing close Because of the increased pressure in steam generator "C" that collapsed the voids in the water, the reactor tripped on a low-low level in that steam generator. A two-by-four foot section of the wall of the suction line to the "A" main feedwater pump was blown out and came to rest in an overhead cable tra The break was located in an elbow in the 18" line about one foot from the 24" header. The lateral reactive force generated by i escaping feedwater completely severed the suction line. The free end whipped and came to rest against the discharge line for the other pum WEPCo has conducted inspections to detect thinning of materials ,

in the past. These inspections were limited to ultrasonic (UT)

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thickness measurements of two phase flow piping. Results of this program were the basis for replacement of the extraction steam lines with stainless stee WEPCo developed a more extensive program to inspect balance of plant piping that has a temperature greater than 140 F, diameter greater than or equal to 2" and pressure greater than atmospheri Approximately 200 inspection points were chosen where ultrasonics, magnetic particle, liquid penetrant and visual examinations were performed. The points included piping with single and dual phase flo WEPCo relied heavily on EPRI to assist in establishing the criteria for the inspection; e.g.,

erosion / 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 thickness measurements, and UT of weld The following are the results of the inspection:

• Four areas in the high pressure turbine exhaust lines showed thinning by ultrasonics. The eroded areas were filled by cladding and found to be acceptabl * A flaw was found in the weld on an elbow by UT on a feed pump discharge line to No. 58 feed water heater. The flaw was ground out, rewelded and found to be acceptabl l

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A flaw was found in a 30" mainsteam line weld by UT at the )

atmospheric dump header tee. A fracture mechanics analysis proved that the flaw was well within the fracture toughness !

of the material and the weld was cleared for servic j

A crack was found by magnetic particle examination (MT) in a I spool piece down stream of a radwaste steam reducing valv The crack was ground out, rewelded and found to be acceptabl :

3. Reactor Vessel Internals Visual Inspection The NRC inspector observed the deep sea Minirover MKII vehicles being used by WEPCo and Westinghouse to perform visual examinations on the reactor vessel internals in accordance with Procedure No. SMP-613, Revision 1 and Section XI, 1977 Edision, Summer 1979 Addenda. Each MKII was equipped with a tilting, low-light level, high resolution, color TV camera in which the sensitivity was very goo The visual examinations were performed by manipulating the cameras downward along the vessel wall looking for various conditions; cracks, abnormal wear, debris, etc. The inlet and outlet nozzles, vessel bottom and support structures were also examined. No unacceptable indications were found by the visual examination The NRC inspector reviewed technical specifications of the Underwater Video Delivery System, procedure, drawings, and related documentatio No violations or deviations were identifie . Fuel Assembly Rod Examinations  !

The BBC Brown Boveri Failed Fuel Rod Detection System (FFRDS) permits an operator to quickly inspect the individual rods in a rod assembly and accurately pinpoint those through wall defects. Through the use of a remotely controlled automatic ultrasonic (UT) detection system, the inspection can be done without having to disassemble the bundl One hundred forty-four assemblies were UT'd. Each assembly has 179 rods, 16 guide tubes and one instrumentation tube. Rods J3 and J4 in the R08 assembly, H12 core location, were found to be unacceptable. The rods were repaired by Westinghouse and found to be acceptabl The NRC inspector observed various examinations and also reviewed procedures, including repair procedures, drawings, data, and related documentatio No violations or deviations were identifie .

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5. . U1trasonic Examination (UT) of Reactor' Vessel The NRC. inspector observed SWRI' perform UT on.the reactor vessel in accordance with ASME Section XI,1977 Edition, Summer 1979 Addend ~

nacon S-The Data inspector Recording andalsoProcessing observed System the NES/Dy(UDRPS) ystems, analyzing Inc. Ultrasonic the result In early 1983, utilities were confronted with the pressurized thermal

. shock (PTS) issue. This, along with recent events addressed by NRC Regulatory Guide 1.150, placed emphases on reliable detection and I sizing of near-surface and embedded flaws in nuclear reactor vessel A possible response to the problem was the UDRPS, an UT data collection and processing system developed under the auspices. of Pacific Gas and Electric Company but terminated before its full capabilities had been-demonstrated., Thus, EPRI sponsored this project to evaluate the UDRPS and compare its performance with conventional methods of pressure vessel inspection. EPRI's results were that the UDRPS demonstrated detection and sizing capabilities sufficient to meet concerns over PTS and NRC Regulatory Guide 1.150 requirements. .The system performed better at detecting near-surface' flaws than any of the manual techniques, but only'slightly better at sizing than the best of the other system The evaluation of the UDRPS was according to the following criteria:

Detection and discrimination of near surface crack Detection and location of embedded defect Sizing of near surface and embedded flaw Discriminating small, innocuous reflectors such as slag inclusions from defects of interes Speed of inspection and evaluatic ,

Ability to meet or exceed ASME Boiler and Pressure Vessel Code and NRC Regulatory Guide 1.150 requirement The performance of UDRPS was compared, where possible, to conventional methods of pressure vessel inspections. The detection of flaws was the primary concern. EPRI also stated that these results compare favorably with the best available automated systems anywhere in the world and that the UDRPS can effectively solve the problem of performing high sensitivity inspections on older vessels with high noise backgrounds because it records

'all acquired data with an adequate sensitivity. The EPRI results of this -

evaluation show that. the UDRPS can be used to reliably detect and size near surface and embedded flaws in reactor pressure vessel :

J The vessel was found to be acceptable in accordance with ASME Section X j All welds were acceptable by ultrasonics except for the safety injection l nozzle to shell weld RPV-687-C1-A. There is an indication approximately 1 1.44" through wall, 2.25" long in the 9.4" material, excluding cla This indication may be slag and porosity in various areas of the 2.25",

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but because of the transducers beam spread going through the material, the display on the ultrasonic instruments CRT screen shows the indication as a continuous plane. This indication was also found in 1976 and was interpreted as not being a defect. It is a mutual feeling between WEPCo and the NRC inspector that the defect was welded in the vessel during fabrication of the vessel prior to the 1970 "startup" and has not i propagated in the seventeen years of service. During this outage, there 3 was a more detailed investigation, also different personnel performed the '

examinations, different instruments, calibration blocks and transducers were used. A revised procedure, but basically the same technique was used. Indications that exceed the UT acceptance criteria and are not i repaired must be evaluated by fracture mechanics. If the results of the fracture mechanics are acceptable to the Code, the indication will also i require additional inservice inspection in the future, as discussed in ASME Section XI, Paragraph IWB 2420 of the Code. On May 30, 1987, the licensee and his consultants met with the NRR staff at Bethesda, Maryland, and discussed the indication and the associated fracture mechanics analysis. After the meeting, permission was given to "startup."

6. ISI Program for Four 31" 90 Elbows In reviewing previous correspondence and ISI documentation, WEPCo personnel found that the 31" I.D. 90 elbows in the Unit 1 and Unit 2 reactor coolant system may have longitudinal welds which should have been examined in accordance with the FSAR but had not been scheduled or examine The electroslag welding process was utilized in the manufacture of the 31" 1.D. 90 elbows. In the course of developing the manufacturing procedure for these large fittings, the two piece casting was adopted requiring two longitudinal welds. This approach offered the advantage of ease and assurance of meeting Westinghouse's quality control requirements of the open castings and half splitter elements. Since the electroslag ,

process had already been developed and qualified for application to the j austenitic stainless steel pump castings, it was selected and separately {

qualified for joining the two halves of the elbows. For the specific i application to these fittings, the electroslag process was qualified in accordance with ASME Section IX and Code Case No. 1355 without exception prior to 1969.

)' WECPo attempted to locate the weldments using an etchant that was l a combination of nitric, acetic and hydrochloric acids. WEPCo also i performed ultrasonic examinations and could not find a weldment. WEPCo L plans to perform more etchants using other types of combinations. WEPCo will also perform a detailed research into the elbows that were received on site approximately 1967. This is considered an unresolved item (266/87009-01).

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-7. : Inservice Inspection (ISI) Unit 1 >

, General This was the third outage of the second period of the second ten-year plan, s

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EBASCo and WEPCo Quality Assurance Departments performed the.ISI in accordance with ASME Section XI, 1977 Edition, Summer 1979 Addend o Most of the UT's were performed by EBASCo, using pulse echo UTJ detection instruments and transducers from 45 -70 . No intergranular , ibl ;

i stress corrosion' cracking (IGSCC) was foun \

Several of EBASCo's personnel were qualified at the EPRI NDE center for detection of 4A )j IGSC d

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' Programs and Procedures

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The NRC inspector reviewed _the ISI procedures and program and found them to be acceptable. Where these rules were detennined to be impractical, specific relief was requested in writing. V4 The NRC inspector reviewed the specific relief requests and ',~

related documentation and had no question Review of Material Equipment and Personnel Cer'tifications,

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Audits and Data nq g The NRC inspector reviewed documents relating to the following:

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Ultrasonic instruments, calibration block, transducers ande s UT couplant certification ,

Magnetic particle equipment certification s

Liquid penetrant material certification NDE'personnelcertificationsinaccordancewithSNT-TC-1A.y) 4 y

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Audits and surveillance NDE report *

Data report Observation of Work Activities The NRC inspector observed work and had discussions with personnel performing ISI activities. These observations included calibration h and performance of the following NDE. Related documentation was also reviewed, s

Ultrasonic examination (UT) of regenerative heat exchanger t welds , RHE-3, RHE-6, N-1, N-2, and N- t 'b y

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1 Liquid penetrant examination (PT) of regeaccative heat exchanger welds, N-2, 1, 14, and 39 !

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\Nd vioMions or deviations were identifie )

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!Modlfications

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.. [ Reactor Internals 'Jpflow Conversion: ~

Since 1971, some plants with 1

's West.inghouse design and manut'actured reactor vessel internals have  ! A experienced fuel rod f ailures3 resulting from flow induced vibratio !

,: , ' h 'This vibration was initiated by reactor ccolant cross flow jetting s I

\through the joints between the bafflef plate In response'to such

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' 4' - an occurrence, Westinghouse conducted,a ccmprehensive evaluation i

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,' prograra which confirmed the cause of such f;el damage (i.e., cross  !

( flow jettin,g through baffla (,oints)3 for csrtain, designs in'some j

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plants,swith downerd %w in the core barrel / baffle regior<.

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In brder to substantially reduce the possil'ility of the " baffle '

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jetting phenomenon la such plpnts, Westinghcuse developed an "- ,

approach whergby the reactor vessel internals are field modified ,

, 3 to; reverse the secondary coolog flow pattern.in the baffle / barrel ,.

re'gion and reduce the jet-driving pressure differential'across' the 1 \ baffle joints. This "vaflow(conversion" has been successfully implemented by Westin@ouse at s Farley Unit '1, Kori Unit I hnd j 1

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Point Beach Unit 2. i. 3 u '

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, Westinghouse plugged d61.25A,"i f' low holes k in the core ibarrV1 t e>een U the top a'nd second former lqYd3 and Power Cutting, hk n t h eight 2.50" new flow holes in the top former plate. '/nh,em.scpinedpiltatica ( ([ of these modifications was accomplished remotely and un69 weter

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( because af the work piece being extremely radioactive. ,

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I Plugging and drilling were accomplished inan area of limited '  ;

acftss and all work generated debris was corarolled/ collected

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TheNRqinspectorobservedtheactivitie6tvaricastimes y during the modifications and reviewed prb9 rams 91ncluding t training program), procedures, material certifications N nd 1

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o No violations or deviations w6,rc(identifie Amtor Coolarrt Qystem RTD Bysans N fold Modificatio ksolation N s t b.[Tdves, verds, drains, and fhinged orifice connectEnTwere i

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A' to eliminh I ,

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The contrac% tor, potential leak pathi yRo, installed and other straight lengths radiation hot spots.,

of piping and r l , fittings to replate the removed cc yanents. The hot leg orifice s was removed arid replaced with , straight pipe. The flegged cold leg 1

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l' 'and common flow orifices were replacet q1 welded-in flow orifice '

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All work for this modification was performed in accordance with ASME Section XI, Class 1 requirements. The NRC inspector observed cutting, welding, and grinding and also reviewed the purchase order, drawings, specifications and related documentatio No violations or deviations were identifie c. Installation of HP Turbine Exhaust Moisture Separator: The mainsteam crossunder piping exhibited excessive erosion / corrosion such that it became more likely that a significant failere would occur that would injure personnel and/or create the need for unscheduled outages to repair the crossunder piping. A moisture preparator was installed in the exhaust leg piping of the high pressure turbine which will remove sufficient moisture to prevent erosion corrosion of the crossunder pipin All work for this modification was performed in accordance with B31.1.0, 1983 Edition requirements. The NRC inspector observed cutting, welding and fitting and also reviewed the purchase order, visual _ reports, welding procedures, and related documentatio No violations or deviations were identifie d. Redesian Floor Restreints: It was determined the the failures of the floor restraints in the Reheat Steam System resulted from thermal expansion differences between the floor restraints and the moisture separator reheaters shell at the time of load chang The floor restraints were broken loose on the reheat steam inlet end of the moisture separator reheater "A". The floor restraints were redesigned to preclude future failure All work for this modification was performed in accordance with ASME Section VIII, 1986 Edition requirements. The NRC inspector observed cutting, welding and fitting and also reviewed the engineering change request, procedures, drawings, and related documentatio No violations or deviations were identifie e. Bypass Valve 742 in the Residual Heat Removal (RHR) System: Due to the large size, and minimum back pressure, Valve 742 (RHR to refueling water storage tank (RWST)) is greatly over sized. This necessitated WEPCo to throttle down very tight on a gate valv The main purpose of the bypass was to allow for low flow from the refueling cavity to the RWS All work for this modification was performed in accordance with B31.1, 1967 Edition requirements. The NRC inspector visually examined the completed welds and also reviewed the purchase order, welder and NDE personnel certifications, drawings and related documentatio No violations or deviations were identifie ,

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7 Installation of Steam Generator Blowdown Line Throttling Valves and 5 trainers: During operation, an unusual noise was heard while throttling the flow with the blowdown floor control valves. The noise was reduced to a constant hiss when the downstream gate valve was also throttled. New anti-cavitation valves were installed to

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replace the previous Hancock valve All work for this modification was performed in accordance with ;

B31.1, 1967 Edition requirements. The NRC inspector observed !

cutting, welding and fittup and also reviewed the purchase order, drawings, specifications and related documentatio No violations or deviations were identifie . Installation of Main Feed Pump (MFP) Suction Isolation Valves Bypass Line: A bypass line was installed around the MFP suction isolation valves as a means of equalizing pressure, hence easing valve operation. The piping was socket welded with schedule 80 pipe and 3000 pound fittings. The feedwater piping on either side of the suction vales has been inspected for wall thinning as part of the erosion / corrosion assessment stud '

l All work for this modification was performed in accordance with B31.1, 1967 Edition requirements. The NRC inspector visually examined the completed welds and also reviewed the bill of material,

' drawings, modification requests and related documentatio No violations or deviations were identified, Installation of Bypass Valves in Condensate Drain Line: The overboard piping configuration was inadequate for controlling flow within the desired range of the condensate system. Gate valves were used and were poor for throttling service. The installation of the bypass valve in the condensate drain line facilitates the controlled discharge of condensate waste water during plant startup and normal ,

operation !

All work for this modification was performed in accordance with B31.1, 1967 Edition requirements. The NRC inspector visually i examined the completed welds and also reviewed the purchase order, !

bill of material, drawings and related documentatio No violations or deviations were identifie . U_nresolved Items Unresolved items are matters about which more infonnation is required in order to ascertain whether they are acceptable items, items of noncompliance or deviations. An unresolved item disclosed during the inspection is discussed in Paragraph ;

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10. . Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1)

throughout'the' inspection period and at the conclusion of the inspection

, to sunnarize the scope and. findings of the inspection activities. The

' licensee acknowledged the_ inspectors' comments. The inspectors 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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