ML20129C048

Summary of Repair Methodology of Ultrasonic Testing Indications in Byron Unit 1 Steam Generator Shell Welds

ML20129C048
Person / Time
Site:	Byron
Issue date:	05/24/1985
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20129B995	List: ML20129B993 ML20129C016 ML20129C048 ML20129C079
References
NUDOCS 8506050394
Download: ML20129C048 (9)

Text

. .

,, ATTACHMENT I i SUMARY OF REPAIR METHODOLOGY OF UT INDICATIONS' IN BYRON UNIT 1 STEAM GENERATOR SHELL WELDS I. STEAM GENERATOR SERIAL #CBGT-1731 Indication No. Ebasco Def. No. Location Weld Seam 1 D-147 95.25" CW SGC-06 2 D-148 113.0" CW SGC-06 -

3 D-160 - 69J5",CCW- SGC-06

r. .

A brief synopsis of the removal / repair process is as follows:

1. A reference point was established from which to work.

2 U.T. examined for wall thickness and compared to minimum wall thickness requirements. -

3 ~ Removed indications by grinding. ,

4. M.T. and U.T. examined groundout areas to ensure complete removal.

5. Recorded length, width and depth of. grind out these were: _.

Indication No. Length Width Depth 1 8" 1.15" 3.0" 2 8.75" 2.0" 3.75" 3 8.75" 1.81 " 3.0" -

6. Cleaned repair area. Installed thermocouples and preheat elements.

7. Preheat: Maintained preheat to 250 degrees F min.-500 degrees F. max.

. 8. Perfom weld repair using E9018, SMAW process, Heat #32230

9. Perfom M.T. and U.T. Examination.

10. Attach Thermocouples and PWHT Elements.

i

~

. k77ACHMENT $ CON T! n .

s l

11. Performed PWT at a maximum heating rate of 100 degrees F. per hour; maximum cooling rate of 100 degrees F per hour; soaking ,

I temperature: 11/25 degrees F. (plus/minus 25 degrees F.) hours i at soaking temperature: 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, 45 minutes. l

l

12. After PWT: ,

l A. MT examined repaired areas and thermocouple removal areas.

B. UT examined repaired areas to ensure defect removal.

C. UT examined for wall thickness.

Note: A completed 2033 form (ASME Section XI) was submitted to Ceco after Hydrostatic Test was completed ~ on 1/3/84.

II. STEAM GENERATOR SERIAL #CBGT-1732 Indication No. Ebasco Def. No. Location Wel d Seam -

4 1 D-139 93" CCW SGC-03 2 D-144 113" CCW SGC-03 The repair was accomplished by machining a 5.0" diameter and a 2.5" diameter ope; sing with bolted cover plates. The 5.0" diameter ,

opening received a weld pad build-up of 13" diameter and approxi-  !

mately)2.25" 5.087 . thick (machined to 10.50" diameter and minimum wall A brief synopsis of the removal / repair is as follows:

1. Preheat: maintained preheat to 250 degrees F. min.-

500 degrees F. maximum.

2. Preheat and welded with E9018, SMAW process, Heat #32230 and 48409.

3. M.T. examined each 1/2 inch of deposited weld metal .

4. Checked minimum pad thickness.

5. Manually ground surfaces of the pad to an acceptable finish for U.T.

6. M.T. examined final finish.

7. U.T. examined for. acceptance to minimum pad thickness.

M.T. examined for indication, if any, removal .

4 9 g

% e e

e 4 , , -er, y,-,e, .- .w.-. ..,-,-,--9,--,.-, _,,..---.-.-,,.,,~m,. ..w---, ..-=-..r-.... . . - . , , , -,,-,,c-, -.~.-,,-,.vmy.,---.w.,.y-,-wr%_e.w.

,,..' Ar,xcitstear 8 con r io

8. Attached thermocouples and PWT elements. I

9. Heat treated as foll ows:

A. Heat uniformly at any rate up to 800. Degrees F'

-B. Above 800 Degrees F heat unifornly at 100 Degrees F. per hour maximum to 1125 Degrees F. (+/-) 25 Degrees F.

C. Held at 1125 Degrees F. (+/-) 25 Degrees F. for 2-1/2 Hours. 1 D. Cooled uniformly to 800 Degrees F. at a maximum rate of '

100 Degrees F. per hour, thereafter steam generator.my cool to ambient.

10. Removed thermocouples and PWT elements.

11. M.T. examined removal areas.

-12. M.T. examined weld pad build-up.

13. U.T. examined weld pad build-up.

14. Finish machining finishes and spot facing of bolt holes.

15. Performed M.T. examination of finished machine work. -

Note: A completed 2033 form (Section XI) was submitted to CECO .>

after hydrostatic test was completed on 1/3/84.

l l

.. - - -- - . - - - -- . . - -I

. r-

+

, 0h ATTACHMENT III I

_