IR 05000374/1987002

Insp Rept 50-374/87-02 on 870109-0331.No Violations or Deviations Noted.Major Areas Inspected:Inservice Insp Activities,Including Review of Programs,Procedures, Observation of Work Activities & IE Info Notices

ML20206H420
Person / Time
Site:	LaSalle
Issue date:	04/08/1987
From:	Danielson D, Ward K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20206H269	List: IR 05000374/1987002 ML20206H266
References
50-374-87-02, 50-374-87-2, IEIN-86-099, IEIN-86-106, IEIN-86-99, NUDOCS 8704150351
Download: ML20206H420 (12)

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U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No. 50-374/87002(DRS) License No. NPF-18 Docket No. 50-374 Licensee: Commonwealth Edison Company P. O. Box 767 Chicago, IL 60690 Facility Name: LaSalle County Station, Unit 2 Inspection At: LaSalle Site, Marseilles, Illinois Inspection Conducted: January 9,14, 21-23, 27-29 February 3-5, 10-11, 17-18, 20, 24-25, March 3, 10, 17, 24, and 31, 1987 M

Inspector: K. D. Ward Th7

'Date M c: ,/

Approved By: D. H. Danielson, Chief 4/' #7 Materials and Processes Date Section Inspection Summary:

Inspection on January 9, 14, 21-23, 27-29, February 3-5, 10-11, 17-18, 20, 24-25, March 3, 10, 17, 24, and 31, 198/ (Report No. 50-3/4/87002(DRS))

Areas Inspected: Routine, unannounced inspection of inservice inspection (ISI) activities including review of programs (73051), procedures (73052),

observation of work and work activities (73753), and data review and evaluation (73755); an open item (92701); an IE Information Notice

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(92704); and various modifications (37701).

Results: No violations or deviations were identified.

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8704150351 87040s PDR ADOCK 05000374

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DETAILS Persons Contacted Commonwealth Ediso'n Company (CECO)

• G. Diederich, Station Manager-

.*R. Bishop, Services Superintendent

• P.' Manning, Assistant Superintendent, Technical Services

• R. Cozzi, Quality Assurance

• M.-Richter, Technical Staff Engineer

• Zoloty, ISI Coordinator R. Chark, QC Supervisor R. Kinsinger, Technical Staff Engineer K. Keller, Mechanical Modification Enginee J.- Speiler,. Technical Staff Enginee J. Hoffman, QC Inspecto Nuclear Regulatory Commission (NRC)

• M.~ Jordan, Senior ~ Resident Inspector R. Kopriva, Resident Inspector J. Malloy, Resident Inspector General Electric Company (GE)

M. Heath, Site Supervisor, Level III

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D. Tinley, Assistant Supervisor, level II

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Hartford Steam Boiler Inspection and Insurance Company (HSB)

W. Calwell, ANII P. Fisher, Assistant Regional Manager Personnel Attending the Feedwater Sparger Meeting on January 9, 1987 B. Kirchhoff, Assistant Technical Staff Supervisor (CECO)

J. Foy, Engineer (CECO)

M. Horbaczewski, ISI Engineer (CECO)

M. Oclon, QC Inspector (CECO)

D. Zoloty, ISI Coordinator (CECO)

R. Sagmoe, IST. Coordinator (CECO)

J. Ahlman, Technical Staff (CECO)

C. Maney, Work Planning (CECO)

R. Kopriva, Resident Inspector (NRC)

K. Ward, Reactor Inspector (NRC)

The inspector also contacted and interviewed other licensee and contractor employee * Denotes those present at the final exit interview March 31, 198 _ _

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2. $ licensee Nction on~ Previous Inspection Finding' -

(Closed)OpenItem-(374/83030-01;374/81000-60)': Disposition'of welds not receiving IHSI. -There were various reasons why welds did not receive IHSI: welds were inaccessible, there was not a coil-design.for:

sweep-o-let welds, etc. The Mechanical Stress Improvement Process (MSIP)

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was performed on.the remaining welds that'were accessible. .See Section-4 of this report for_ details. This~ item is considered close . Licensee' Action on IE Information Notices- 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 corrosion. Licensees were expected to review the information for applicability to their facilities and:

consider actions, if appropriate, to preclude similar problems occurring at their facilitie However, suggestions contained in the Information Notice did not constitute NRC requirements; therefore,:no specific action or written response was require The Oyster Creek Nuclear Generating-Station first discovered water ~ .

in the gap between the. boiling water reactor drywell and the concrete shield in 1980, and began investigation of the cause in 1983. The bellows at the drywell was found to be leaking.- A seal was repaired and a gasket replaced, thus stopping the leakag To determine if the water in the gap had caused damage to the steel containment, the licensee measured the wall thickness, using an-ultrasonic examining (UT) technique at two elevations. The 51' level near the drywell seal was sound, but there appeared.to be loss of metal i on the gap side at the 11' 3" level immediately above the concrete

! floor. In this area, the gap was packed'with sand and contained five

equally spaced drain pipes. One hundred and-forty-three measurements

were made at this level and 60 indicated a reduction in thickness of

[ more than 1/4" from the drawing' thickness of 1.154".. These readings;

, were found throughout seven of the ten downcomer bays.

! Ceco investigated and found that LaSalle's drywell steel liner had i

no safety problems. The steel containment at Oyster' Creek actually provided the support for its concrete exterior; that is not:the case _

at LaSalle. LaSa11e's containment liner ~provides a leak tight l barrier. CECO stated that the degradation of the leak tight membrane

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i would be detected during the integrated leak rate test (ILRT),.if significant. LaSalle's containment walls do:not include a layer of: y sand or-other com)ressible material between the steel liner and the '

, concrete wall.. T1e concrete is laying directly in contact with the=

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liner at LaSalle. CECO stated that the LaSalle containments are

! designed differently from the Oyster Creek containment and will En ot i allow water leakage into the steel liner / concrete interface and that

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no action was necessary.

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.N'o: violations or deviations were identifie IE Information Notice No. 86-106: Feedwater line break.' :This

, Information Notice was to alertvlicensees of a potentially generic problem with feedwater pipe thinning and other problems related-

-.to this' event. . Licensees were expected to review the information 3-forapplicability.totheirfacilities-and.consideractions(i appropriate, to preclude similar, problems occurring at thei facilities. Howeveri suggestions contained in the Information

-Notice did not constitute NRCirequirements; therefore, no specific j action or written resnoon was require ;

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20n December 9,-1986, 1oth units at the'Surry Power Station were~

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operating at full power when'the 18" suction line to the main ..

. feedwater pump "A" for Unit 2 failed catastrophically. The event :

was initiated by the. main steam isolation valve on steam generator-I-

' "C"failingclosed. Because of-the increased pressure in steam generator C" that Nilapsed the void in the water, the reactor.

j tripped on lcw-lcw level in that steam generator.' A two by four foot seeU on m the wall of the suction line to the "A" main-feedwater pw, was blown out and came to rest in an overhead cable tra The break was located in.an elbow in the 18" line i

about one foot from the 24" header. .The lateral reactive force'  :

generated by escaping feedwater completely severed the suction.'

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. line. The free end whipped and came to rest against the discharge'

line for the other pum '

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CECO selected five locations along the Unit 2 feedwater pump suction-piping to be inspected for pipe wall thinning due to erosion / corrosion

. during the Unit 2 first refueling outage. The inspection locations:

, were based on the following piping geometrics, and all were found to

): be acceptable:

$ e 2CB06CA-30" - A 90* elbow immediately downstream of a-45*

elbow causing changes in the fluid direction within short i piping distances.

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! .* 2CB06CA-30"/2C806-36" - A reducer which causes flow

turbulence and an increase in fluid velocit * 2CB06CA-30" - A 90* elbow immediately following'a-

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reducer causing a change in turbulent fluid-(due to' reducer) direction.

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* 2CB06CB-30"'- A 45* elbow immediately following a'"Y" branch -

connection,

"T" connect ion which failed:at-Surry Unit 2.most closely simulating

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• 2CB06CB-30'! - A 90* elbow causing a change in fluid direction '

following a vertical pipe drop.-

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l The acceptance' criteria applied to the pipe wa'll thicknes l measurements at the locations--outlined above were based on-the nominal wall thicknessestfor the appropriate schedules of piping. involved minus'the piping manufacturer's~ tolerance: ;

of 12.5%.  ;

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No violations or deviations were identified'.

4. -Inservice Inspection (ISI) Unit 2 General- j This is the.first outage of the first period of the first ten year pla !

GE performed the'ISI in accordance with ASME Section XI, 1980 Edition, Winter 1980 Addenda. .The Level II and III UT personnel performing UT were qualified for detection and discrimination of intergranular stress corrosion cracking (IGSCC) by Electric Power Research Institute (EPRI)

after September 10, 1985. Level I-personnel.not qualified at'.EPRI performing UT scanning duties were trained by EPRI qualified GE-personnel onsite. CECO's Level III UT personnel who reviewe GE's results ~and procedures used were also EPRI qualified. No IGSCC was identified during this outag All manual UT was performed by GE using the pulse-echo UT flaw detection instruments and various angles and MHZ transducer Also on many welds the master / slave ultrasonic system was use The master / slave is used where radiation environments require that the Level II, who is interpreting the UT, be out of the area.while the Level I is inside the area examining-the weld.- Both personnel are in direct communication and view the'UT video presentation. The master unit may be any portable-instrument which meets the ASME Code requirements for amplifier and attenuator'linearity. There are no controlsontheslaveunittoadjustduringtheperformanceofan examinatio Changes in sensitivity are made at the master, where the Level II is in an environment free from distraction During this outage there was no chemical decontamination. performed on any system During the preservice. inspection, Induction Heat Stress Improvement (IHSI) was performed on a) proximately 80 welds. IHSI is defined as-the practice of heating tie outer: surface of a-pipe by induction techniques,.while simultaneously water cooling the inner surfac The objective of this process is to relieve the inner surface of tensile residual stress in the vicinity of the weld and heat'

affected zone. It is applicable to-joints which have been in BWR. service, as well as joints which have not been in servic _ _

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During this outage the Mechanical Stress Improvement Process (MSIP):

was performed on 39 welds. In addition to the IGSCC susceptible stainless steel welds _ treated, CECO elected to treat 15. Class 1 welds which were buttered with Inconel-182, because of GE Service Information Letter 411, dated September 28, 1984, stating problems-withstresscorrosioncrackinginthismaterial. The MSIP was first applied by Westinghou'se and 0 Donnell Associates (0AI) to 53 weldments at Dresden~ Unit 3. A study was conducted by the Argonne National Laboratory (ANL) to evaluate the MSIP being proposed by.several other utilities as a remedy to mitigate IGSCC of stainless steel piping

'in BWR The evaluation was requested by the NRC staff.

The MSIP is a development of 0A Like IHSI it is intended to prodea 1 m #(vorable state of residual stress on the inner j ur face of piping veldments es)ecially in the vicinity of heat'

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/ affected zones (HAZ) and there)y mitigate' stress corrosion cracking

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in'BWR piping. Alth ghthetwoprocesseshavesimilarobjectives, MSIP is a purely mech ical process are induced by the pla t y ompres of [. The favorable residual stresses split-ring-like tool mounib en -ttie pip)e.he weldment The plastic. strain produced imposed by a on the pipe is controlled by the openin"g between the split-rings, whichisadjustedbyinsertingappropriateshims. The final stress state in the HAZ appears similar for the two processes according to

the study. In this study, ANL reviewed information on MSIP submitted to the NRC Headquarters by O'Donnell & Associates, Inc., and Westinghouse Electric Company, the developers of the process. Also, ANL performed analysis and tests to determine the residual stress state changes using two MSIP treated, large diameter pipe sections supplied by Vermont Yankee. This research concluded that the basic concept of MSIP is valid and sound. Analysis and test.results established that the process is an effective means of improving the i residual stress state of piping at weldments. .The process was found to be equivalent to IHSI in-terms of mitigating the susceptibility

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of pipes to stress corrosion cracking and was found as effective

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for large diameter piping as it was for small pipin A mock-up 12" pipe with welds was used to train personnel on using the mechanical clam The following table provided the sampling plan for addressing the IGSCC concerns during this outage. The augmented inspection consisted of 48 weld examinations. In some cases the minimum NRC GenericLetter84-11samplewasexceededbecauseMSIPwasapplied to a greater number of welds in certain categories (e.g. 12  ;

. recirculation system) and new baseline examinations were require j

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LASALLE UNIT N0. 2 84-11 AUGMENTED INSPECTION PLAN 1 2 3 4 5 6 Minimum 84-11 Total Total Stress Welds System Size Total Sample Improved Examine Recirculation Risers 12" 60 6 10 10 Headers 16" 16 4 0 '4 Outlets 24" 46~ 8 4 8 Residual Heat Removal Discharge 12" 15 4 7 8 Suction 20" 11 4 8 8 JPI 4" 31 5 10 10 10lAL 1/9 31 39 48 Column 3 - Total stainless steel welds susceptible to IGSCC on a particular system or siz Generic letter 84-11 total sample on original inspection pla Total welds that were MSIP this outag A total of 48 welds actually examine Programs and Procedures The NRC inspector reviewed the ISI procedures and programs and found-them to be acceptable. Where these rules were determined

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to be impractical,. specific ~ relief was requested in writin The NRC inspector reviewed the specific relief ~ requests including the related correspondence between the licensee and the NR Review of Material, Equipment and Personnel Certifications, Audits and Data

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The NRC inspector reviewed documents relating to the following:

• Data reports, this outage and las ~

• - Ultrasonic instruments, calibration blocks, transducers and couplant certification * -Liquidpenetrant(PT),cleaneranddevelopermaterial * Magnetic particle (MT), materials and equipmen * NDE personnel certifications in accordance with SNT-TC-1 * Audits and surveillance Observation of Work Activities The NRC inspector observed work and had discussions with personnel during the ISI activities. These observations included a hydro of vent valve No.102 on the control rod drive that was replaced,

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calibration for various welds (including the reactor vessel. head and dissimilar metal safe-end-to-nozzle welds with Inconel-182 buttering), and performance and documentation of the following:

• UT of main steam - welds No. 2044-1 and * PT of main steam - weld No. 2045-2 * MT of main steam - weld No. 2037-2 * GEs Level III qualifying Level I personnel on IGSCC block * GEs Level III administering tests to an UT Level I and an UT Level II on the Master / Slave UT_ Syste * GE using the Master / Slave UT System on welds, RH 2031-9, RI 2001-2, RR 2005-13C, and RR 2001-22 *. Visual Examination (VT) of 18 reactor vessel closure washer * Training of personnel by Westinghouse on using the mechanical clamp for MSI No violations or deviations were identifie . Examining Feedwater Spargers On January 9,1987, there was a meeting held between CECO personnel and the NRC (see Section 1 for personnel attending) to discuss a contingency plan in case cracking was found in the feedwater sparger elbow weld If cracking was found, GE was prepared to fabricate and deliver up to 110

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.sparger; flow elbow ' retaining ~ clamps and all documents necessary to install'

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.the clamps within five weeks after receiving authorization. GE fabricated- -

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a_sparger mock-up with a prototype clamp and provided'it to CECO for

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practice purpose ~ CECO' performed vis'ual examinations in'.accordance with CECO's:SPPM

' Procedure VT-1-1. :In examining.the feedwater spargers the examination-was concentrated on.the sparger. nozzle elbow welds. The unit used forr

'the' visual examination was a Westinghouse Model ETV1250: underwater TV camera with a video cassette recorder, camera lights:and a black and white monitor. The resolution device was a. stainless steel.(SS)~1 mil.

, wire mounted on a 4" x 4" SS plate painted gray. LThere were six sparger,s

with 18 nozzles on each sparge ,

The NRC' inspector viewed.the mock'up, observed by TV' camera the 1 mil .

i stainless steel wire resolution device and visually examined several i

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elbow welds. The welds-were found~to have no unacceptable' indications.

The NRC inspector also reviewed data,-ths procedure and other related-

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i No~ violations or deviations were. identified.'

l Modifications I' Modification M-1-2-84-048: Replacement'of the containment vent and purge butterfly isolation valves and actuators. The modification was for the replacement of eight-26" limitorque. valves-on the vent

lines and two 8" limitorque valves'on the tie-lines using the respective size wafer stop valves.- The'new valves are operated by.

high torque producing Bettis actuators. Minor piping modification .

! were required in the vicinity of these valves. The design was suc '

that it meets a five second closing criterion for post .TMI mandated inerting requirement The new valves have an_ air operated solenoid actuator.

All work for this modification was performed in accordance with-g ASME Section XI, Class II requirements. The NRC inspector observed L

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welding, grinding, fit-ups, etc.; also reviewed radiographs,.

traveler, procedures, and'other related documentatio No violations or. deviations were identified.

t j~ Modification M-1-2-84-061: alternate rod. insertion (ARI) and.

tain steam isolation valve (MSIV) closure design change. This-F modification was part of the preventive measures taken to recover from an anticipated transient without scram (ATWS) event.

! The MSIV closure modification-lowers the.RPV water level sensing trip-i . point from level 2 (-50") to Level 1 (-130") to cause MSIV isolation

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of'the RPV at a later time during a decreasing water level transien I i

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1 Twelve instruments'were installed for the ARI and the MSIV closure--

' design modification. The transmitters were-locally mounted on:

instrument stands. 'Eight new transmitters, four. level transmitters:

-and four pressure transmitters were installed for the-ARI portion of this modification. Four new level. transmitters.were installed-for the MSIV' portion of this modification to. monitor Level 1. The existing Level 2 transmitters were required to be~left in place to

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serve other' functions. Ten new solenoid valves were installed for the ARI portion of this modification. -

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-Alliwork for this' modification was" performed in accordance with'

ASME.Section~XI, Class II. requirement The NRC inspector: observed various stages of installation, including welding, fit-ups, liquid penetrant examination (PT) of-nine welds (No. W-37-789 to No. W-37-797); also' reviewed travelers,- procedures, ECN and -

other related documentatio No violations and deviations were' identifie Modification M-1-2-84-094: Modif accommodate internal hydrolyzing.y.the scram discharge This modification. involved theheader'to addition of sixteen branch connection fittings'on the control. rod drive scram discharge volume headers to allow the system to be hydrolyzed occasionally to prevent radiation build-u All work for this modification was performed in accordance wit ASMESectionXI,ClassIIrequirements.-TheNRCinspectorobserve welding of the 3/4"- 45* lateral connections to the 8' sch.100 scram discharge header arms; also reviewed bill of. material, drawings,.'

ECN and other related documentatio No violations or deviations were ' identifie Modi *ication M-1-2-84-111: Installation of a thermowell on the common shutdown (S/0) cooling line. This modification provided the installation of a thermowell in the RHR S/D cooling common suction headec 2RH04C 20". A thermocouple provides the control room with an accurate indication of the reactor moderator temperature via the RHR recorder 2E12-R60 Anannunciatorwillalarm,alertingthe operator that S/D cooling is approaching condition 3 at 190 All work for this modification was performed in accordance wit ASME Section XI, Class II requirement The NRC inspector observed part of the installation of the thermocouple and reviewed traveler, ECN, drawings, and other related documentatio No violations or deviations were-identifie .

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e. Modification M-1-0-86-023: Addition of a SCFM pump, 3/4" piping, valves, flowmeter and electrical work to increase flow rate of the sample gas to prevent iodine plate-out. This modification improved the arevious method of sampling the flow in the mid/hi range portion of t1e standby gas treatment wide range gas monitor. This change minimized the amount of iodine plate-out in the same lin The piping system affected was ASME Section III and the modification was in accordance with ASME Section XI, 1980 Edition. The NRC inspector observed welding, grinding, and a fit-up; also reviewed drawings, traveler, ECN and other related documentatio No violations or deviations were identifie f. Modification M-1-2-85-027: Relocate 2RE043 valve and 2E12-D3108-orifice and delete 2E12-0310A orifice to allow the "B" RHR loop the same warmup capabilities as the "A" RHR loop. This modification allows the more efficient use of the "B" RHR system for shutdown cooling. If the "A" RHR system was unavailable it would take approximately ten hours to heatup the "B" RHR system on the shutdown cooling mode and required.over flowing the reactor building equipment drain tank (RBEDT) to the flow drains. This modification allows the flow of the condensate to the main condenser instead of the ABEDT tank, thereby, eliminating the overflow problem and allowing-continuous flow to expedite the "B" RHR loop warmu The modification involved ASME Section III, Class II piping, ANSI B31.1-1973 piping, and the relocation of the valve and orifice was ASME Section XI, Class I The NRC inspector observed fit-ups grinding, welding; also reviewed drawings, traveler and other related documentatio No violations and deviations were identifie g. Modification M-1-2-86-040: Relocate high loint vent valves 2E12-F399 and 2E12-F400 to a point above valve 2E12 340, and plug a sock-o-le Modification adds a high point' vent to the existing, piping of the RHR system on line 2RH33A-16". These vents are to improve pipe venting reducing the potential of water hammer and possible snubber damage during normal operating cycle All work for this modification was performed in accordance with ASME Section XI, Class II requirement The NRC inspector observed various stages of-installation; also reviewed P0, receiving and inspection report, NDE report and other related documentatio h. Modification M-1-2-86-044: Relocate high point vent valves 2E12-F371B and 2E12-F372B on line 2RH40AB-1 This modification adds a high l point vent to the existing piping of the RHR system on-line 2RH40AB-12".

These vents are to improve pipe venting reducing the potential of water hammer and possible snubber damage during normal operating cycles.

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a All work for this modification was performed in accordance with i ASME Section XI, Class II requirements. The NRC inspector observed l various stages of installation, also reviewed the ECN, procedures-and other related documentatio No violations or deviations were identifie . Exit Meeting The inspector met with site representatives (denoted in' Persons Contacted paragraph) at the conclusion of the inspection. The inspector summarized the scope and findings of the inspection noted in this report. The inspector also discussed the likely informational content of the inspection report =-

with regard to documents or processes reviewed by the inspector during'the inspection. The licensee did not identify any such documents / processes as proprietar