ML20083B090

Forwards Core Shroud Insp Results for LaSalle County Nuclear Power Station Unit 2 Sixth Refuel Outage (L2R06),as Required by GL 94-03.Core Shroud Insp for L2R06 Completed on 950410

ML20083B090
Person / Time
Site:	LaSalle
Issue date:	05/05/1995
From:	Benes G COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-94-03, GL-94-3, NUDOCS 9505110270
Download: ML20083B090 (10)

Text

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Osmmonwealth hlimn G>mpany  ;

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lh m ners Grove, !!dd615 May 5,1995 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555

Subject:

LaSalle County Nuclear Power Station Unit 2 L2R06 Core Shroud Inspection Results NRC Docket No. 50-374

Reference:

G. G. Benes letter to W. T. Russell, dated August 23,1994 The above Reference provided Comed's response to Generic Letter 94-03, "Intergranular Stress Corrosion Cracking of Core Shrouds in Boiling Water Reactors". As indicated in our response (and required by the Generic Letter), we committed to providing the NRC with our core shroud inspection results within 30 days from the completion of the inspection. Attached is the Core Shroud  ;

Inspection Results for the LaSalle 2 Sixth Refuel Outago (L2R06). The Core Shroud inspection for L2R06 was completed on April 10,1995. <

To the best of my knowledge and belief, the statements contained above are true and correct. In some respect these statements are not based on my personal knowledge, but obtained information furnished by other Commonwealth Edison employees, contractor employees, and consultants. Such information has been reviewed in accordance with company practice, and I believe it to be reliable.

Please direct any questions you may have regarding this matter to this ,

office.

Very truly yours, fB&

Gary G. Benes Nuclear Licensing Administrator 9505110270 950505 PDR ADDCK 05000374 P PDR A I' unum (lutilp.tn)

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Subscribed and Sworn to before me '

5d day of ' ' ' ' ^ ^ ^ ^ ^ ^ ^ ^ ^ ~ ~ ^ ^ ~ ~ ~ ~ ~ ^ ^' ^^ " ' ' '

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ohthis g,< ,1995.  ! OFFICIAL SEAL j,;

/ r ll MARY JO YACK l l NO1 ARY PU0 llc. STATE oF ILLINDISl l>

I; uv couusssioN Emats:nnse;

% g,,,n, y # L ----------------------------t Not'ap P%jd j Attachment  ;

cc: J'. B. Martin, Regional Administrator - RIII P. G. Brochman, Senior Resident Inspector - NRC, LaSalle W. D. Reckley, Project Manager, NRR Office Of Nuclear Facility Safety - IDNS .

t no ~,,

1 I

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, .- s  !

n Response to Generic Letter 94-03  ;

References:

i

1. BWRVIP document GENE-523-113-0894, BWR Core Shroud Inspection and .

Evaluation Guidelines, dated September of 1994.  !

2. Letter from G.G. Benes to W. T. Russell, dated November 17,1994.

3. Letter from W.D. Reckley to D. L. Farrar, dated February 6,1995.  !

! This document is the LaSalle County Station (LSCS) response pursuant to the i Station's commitment to comply with the additional reporting requirements _ of -

item 3., of USNRC Generic Letter 94-03; "Intergranular Stress Corrosion Crocking i of Core Shrouds in Boiling Water Reactors", as that item applies to LSCS Unit 2. -

Additional responses to address these reporting requirements for LSCS Unit I will  !

be submitted in accordance with the time frame requested in the Generic Letter.  !

The format of this LSCS response retains the numbering sequence of the Genenc  :

Letter.

As a utility, Comed is committed to the BWRVIP. Comed has been, and will ,

continue to be an integral part of the BWRVIP. LaSalle County Station will

- follow the guidance provided by the BWRVIP with respect to flaw assessment,  ;

inspection, and repair options as this guidance is provided, and ifit should be  :

subsequently revised.  !

t Reporting Reauirements l

3. Within 30 days from the completion of the inspection, provide the i results of the inspection. ,

The examination plan docketed under the letter of reference 2, and approved by USNRC in the letter of reference 3, was completed during the sixth refueling i outage of LSCS Unit 2. Data collection began on March 20,1995 with data ,

analysis and review concluding on April 10,1995. As described in the inspection i plan,100% of the accessible length of welds designated as H3, H4, H5, H6 & H8 i 4

were examined using the ultrasonic method. Welds H1, H2 & H7 were not i examined, nor did they require examination as part of the Category B (Limited  ;

Inspection) described in the reference 1 BWRVIP document. .

l For those welds which were inspected, examination of the far (inside diameter) j surface was accomplished using standard 45 degree Shear wave, and 60 degree i Refracted Longitudinal wave ultrasonic (UT) testing. The near (outside diameter) i surface of the welds were examined using the " Creeping Wave" UT method. i Ultrasonic data for Welds H3, H4, H5 & H6 was collected using an automated j u-  !

scanner known as the "O.D. Tracker". Ultrasonic data for Weld H8 was collected using a second automated scanner known as the " Suction Cup Scanner".

While non-relevant indications, and geometric reflectors were recorded, no indications of cracking were detected in any of the welds examined. Accessibility for UT scanning was limited by vessel internal components such as Guide Pins, Core Spray Piping, Low Pressure Coolant Injection Bellows, Jet Pumps, and Jet Pump Riser Braces. The effective examined length of each weld is listed below as well as the inspected length as a percentage of the total weld length. The effective length is the length of weld metal interrogated by all three of the UT transducers.

EFFECTIVE WELD LEMSTH EXAMINED Weld H3 - 422.6" examined representing 64.8% of the total weld length.

Weld H4 - 447.76" examined representing 68.7% of the total weld length.

Weld H5 - 318.8" examined representing 48.9% of the total weld length.

Weld H6 - 318.8" examined representing 48.9% of the total weld length.

Weld H8 - 27.16" examined representing 4.3% of the total weld length.

The ligaments into which each effective length was split are represented pictorially for each weld on the attached sketches. A conversion factor of 1.81" per degree is applicable to welds H3, H4, H5 & H6 based on a 207.12" outside diameter for the Core Shroud at these elevations. A conversion factor of.57 degrees per inch is applicable to weld H8 based on a 200.75" shroud outside diameter at the H8 elevation.

In conclusion, the LSCS Unit 2 Core Shroud has been examined during the sixth refueling outage in accordance with its approved plan using the best available industry methods and technology with no evidence of cracking discovered in any of the welds inspected.

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_ASA__E .\::- 2 PERCENTAGE OF VELD LENGTH EXAMINED H3, H4, H5, H6, AND H8 360 270 180 90 0 M adsdudedualumism&mdumsmAmalmdadadedsdudsummlmeAndedsdudsm&md HI j'-- O-------------{

H2 -

' O O 360 270 180 90 0 malaismindesmindesummandmindedmaludadunushmiedensdudadelms manindesminimismius H3 6'4.8% =

H4 68.7% .

H5 48.9%

H6 -

48.9% .

H8 4.3% = - -

=

, ,y _ - ,,.,_c -y- . . . - . . . , . . - - - - , . . . - - - . . . , _ . -,

_ _ ,y_____m__ _ _ _ __ _ . _ _ _ . ____,m_._ . _ . _ _ . _ _ . . . _ _ _ _ _ _ _ _ _ _

L ASALLE UNIT 2 SHROUD INSPECTION H3' VELD FLAV & COVERAGE MAP 1

II'38' 347.48' 334.90*

326.48*

O' -- VEST 303 96*

• 55.9*

l Core spray doenconer

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315* 45' N /

LPCI lines (3)

N ,

135*

4 Core spray downconer . }-

118.48' SCAN AREA M NC F AVS ias 9- DETECTED 190.38 167.48'

_ _ - _ ___ m - m i- w w' _ a _' _ __' _ - _ _ _ _ _ . ___.__._-.__---_m _. ___.-._

LASALLE UNIT 2 SHROUD INSPECTION -

l H4 WELD FLAV & COVERAGE MAP 347.48* 11.3 8*

3396*

i 32s.9*

l 0* - VEST 303.96*

55.9*

, . \ \

Core spray downconer -

31s* 45*

E $

LPCI lines (3) i N 135*

Core spray downconer. ,"

\ 123.96*

SCAN AREA M NO ILAVS i4s 9- DETECTED l

l 190.38 167.48*

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w/. ,

g +

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LASALLE UNIT 2 SHROUD INSPECTION

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H5 VELD FLAV & COVERAGE MAP 0* - VEST l 303 96*

ddo2 33.9 k i Core spray downconer .

315* 45' N /

E }

LPCI imes (3)

I $

135*

Core spray downconer .-

118.48*

NO FLAVS DETECTED SCAN AREA M ** NOT TO SCALE **

, .s i .

LASALLE UNIT 2 SHROUD INSPECTION '

H6 WELD FLAW & COVERAGE MAP l

0* - VEST t 303.96* ,

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~ * '

Core spray downconer -

315' 45' N /

LPCI tines (3)

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135*

Core spray downconer .

• 110.48'

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NO FLAVS DETECTED 190.38*

SCAN AREA M ** NOT TO SCALE um

_ _ _ . - - _ _ , . . . .. . - . , _ , . _ , _ . , _ . _ ~ ,, , _ , _ . . _ . _ _ . , _ . _ . _ _ _ _ _ _ , . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _

LASALLE UNIT 2 SHROUD INSPECTION H8 VELD FLAV & COVERAGE MAP 352.19' O.31*

348.31* 12 I9' 0* - VEST

. Core spray downconer .,

315*, . 45' ,,

N /

E $

LPCI lines (3) 135' Core spray downconer .-

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SCAN AREA NO FLAVS DETECTED 192.19* 188.31* 172.19' n- - - - - , ,