ML111030188

Enclosure 3 - Dose Estimates

ML111030188
Person / Time
Site:	Byron
Issue date:	04/08/2011
From:	Exelon Generation Co, Exelon Nuclear
To:	Office of Nuclear Reactor Regulation
Shared Package
ML111010578	List: ML111010535 ML111010538 ML111010542 ML111010549 ML111010562 ML111030188 RS-11-062, Report No. 901348-04, Exelon Relief Request 13R-19, Penetration 64, Page 3 of 4
References
RS-11-062
Download: ML111030188 (4)

Text

ATTACHMENT 3 DOSE ESTIMATES

Dose Pen Ind Character/Loc. Repair steps Time Repair Comments mRem 64 1 Mark indication 6 420 12:00 J-Weld Light Grinding 20 1400 Light Grind to reduce to 3/32" x 1/4" Welding Supv Perform Visual 2 140 acceptable Linear Weld over if depth required Rejectable Remark Penetration and Clean 3 210 Enter/Exit All Jumps 94 6819 QC inspection @ 5X PT of area 20 1400 64 2 Mark indication 0 0 12:00 J-Weld 1/16" x 1/16" Light Grinding 0 0 Repaired incidently with #1 Rounded Welding Supv Perform Visual 2 140 Acceptable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 64 3 Mark indication 0 0 11:00 Light Grind to reduce to 1/16" x 1/2" Light Grinding 15 1050 acceptable Linear Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 64 4 Mark indication 0 0 3:00 Light Grind to reduce to 1/4" x 1/4" Light Grinding 22 1540 acceptable Rounded Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 64 5 Mark indication 0 0 3:00 Light Grinding 0 0 Possibly will be 1/8" x 1/8" Repaired incidently with #1 Rounded Welding Supv Perform Visual 0 0 Acceptable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 64 6 Mark indication 10 700 2:00 Light Grind to reduce to 1/8" x 1/2" Light Grinding 15 1050 acceptable Linear Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70

Dose Pen Ind Character/Loc. Repair steps Time Repair Comments mRem 64 7 Mark indication 0 0 2:00 Light Grinding 15 1050 Light Grind to reduce to 0

acceptable Rounded Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 64 8 Mark indication 0 0 5:00 Light Grinding 15 1050 Light Grind to reduce to 1/16" x 3/16" acceptable Linear Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 64 9 Mark indication 0 0 6:00 Light Grinding 10 700 Light Grind to reduce to 1/16" x 3/16" acceptable Linear Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 31 1 Mark indication 6 420 11:00 Light Grinding 15 1050 Light Grind to reduce to 1/8" x 3/8" acceptable Linear Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 15.5 1085 31 2 Mark indication 0 0 1:00 Light Grinding 15 1050 Light Grind to reduce to 1/16" x 1" acceptable Linear Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 31 3 Mark indication 0 0 1:00 Light Grinding 15 1050 Light Grind to reduce to 1/4" x 1/4" acceptable Rounded Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70

Dose Pen Ind Character/Loc. Repair steps Time Repair Comments mRem 31 4 Mark indication 0 0 8:00 Light Grinding 22 1540 Local Excavate to reduce to 1/2" x 5/8" acceptable Rounded Welding Supv Perform Visual 2 140 Weld over if depth required Rejectable Remark Penetration and Clean 3 210 QC inspection @ 5X PT of area 1 70 Total REM 28..554 Assumptions:

Only covers penetration 64 and 31 Both options include grinding on 64-4 and 31-4 (pen-Indication)

Both options include weld repair (overlay) on all indications in 64 and 31 No extra time for chasing indications after grinding Actuals for dose used:

Dose at head 70 mrem/min Dose in and out 36 mrem/min Dose on turnovers .1 mrem/min

==

Conclusions:==

Relief request will yield a 7 REM savings for pen 64 and 31 MINIMUM Additional saving should be less for the remaining penetrations since we expect less indication repair.

Overall savings of approx 35% in dose.