ML20083H762
| ML20083H762 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 12/27/1983 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| NED-83-645, TAC-52483, NUDOCS 8401130340 | |
| Download: ML20083H762 (13) | |
Text
{{#Wiki_filter:- _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ Georgia Fbwer Cortpag - .- 333 Piedrnont Avenue Atlanta. Gengia 30308 Telephone 404 52G6526 Mailing Address: Post Office Box 4545 Atlanta, Georgia 30302 Georgia Power L T. Gucwa rne m *wn entnc system Manager Nuclear Engeneenng - and Chiet Nuclear Engineer December 27, 1983 NED-83-645 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, 011ef Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EIMIN I. HATCH NUCLEAR PLANT UNIT 2 REACTOR COOLANT PRESSURE BOUNDARY PIPING REPLACEMENT Gentlemen: On November 7, 1983, we provided a description of our plans for replacing the Unit 2 reactor coolant recirculation pipe. Following an initial review by your staff, several specific questions concerning radiological controls were raised during a telephcne conference call December 6,1983. The information requested concerning these questions is attached.for your review. I Should you have any questions, please contact this office. Sincerely yours, [ Sw L. T. Gucwa SCE/b1m Attachments l \\ 8401130340 831227 PDR ADOCK 05000366 \\g P PDR
ATTACINENT 1 L RESPONSE TO NRC QUESTIONS CONCERNING RADIOLOGICAL ASPECTS OF THE UNIT 2 RECIRCULATION PIPE REPLACIMENT PROJECT' A. PLANS FOR MINIMIZING DOSE CONTRIBUTION FROM CONTROL BLADES Four actions will be taken to minimize the dose contribution from the control blades: 1. The blades will be inserted to maintain the highly activated stellite bearings at the maximum possible distance from the nozzle areas and minimize the dose contribution from the bearings. 2. A shield-plug will be placed on the vessel side of the' suction nozzles. ne shield plug will be 4" lead sandwiched between 1" stainless steel plates. 3. ~All discharge and suction nozzle bioshield openings will-be shielded by a. 3" equivalent lead shield. ne shield will be composed of 2 layers of lead wool bricks which neasure approximately 1 3/4" x 3 1/2" x 7". 4. A water bladder will be placed in the sue, tion nozzles from the dryweH side to provide shielding during weld preparation, fit up, and welding. ne water bladder will provide approximately 24" of shielding. B. SYSTIN DECO?ffAMINATION High pressure water blasting of the interior of the recirculation system is planned. A DF of 2-3 for vertical pipe runs and 4-5 for horizontal pipe runs is expected. ne entire recirculation systems, with the exception of the recirculation pumps and valves, will be included in this decon. The nozzle interiors and approximately 2' of the jet pump risers will be included.
Page 2 C. AIRBORNE RADIOACTIVITY CONTROL An extensive temporary ventilation system will be installed in the idrywell to aid in airbome radioactivity control during the project. Bis system will cause a flow of air from the reactor building into the drywell. Air from the-drywell will be exhausted to the reactor building through 4 HEPA filtration units. Wo 4000 CBf units will be connected to the standby gas treatment system and take_ a suction near the top of -_ the drywell. Two 24" ring headers, on the 156' el and 120' el, will be ' connected to 12,500 CFM units. Eight - 12" trunks will be connected to the ring header and each will draw 1500-2000 CBf. These trunks will be used to provide local ventilation for welding, grinding, cutting, etc. Additional methods will be used to cid in controlling airborne radioactivity. %ese methods include a continuing decon effort in the .drywell during the project, and use of containment enclosures and tents for evolutions with a significant probability of creating airborne contaminants. D. AIIITNATED WELDING AND CtflTING MACHINES Newport News Industrial- (NNI) had designed and manufactured automatic cutting machines which will be used during the project. He cutting machine is designed to weld prep the cut in conju iction with performing the cut. In those cases where the weld prep does not pass inspection or where weld overlay has been performed, an EP-2 machine will be used to prep the surface. We cutting machine -requires two people to be in the area during operation. A person is stationed on either side of the pipe. Heir responsibilities include lubricating the machine and ensuring that the machine remains properly aligned throughout the cut. Welding will be performed using a Diametrics Gold Track II machine. The machine will be attended by two people during operation. A qualified welder will attend the machine and make any necessary adjustments. He will be assisted by a helper who will also function as the fire watch. E. MAN-RBf ESTIMATE A preliminary man-rem estimate has been developed for the project. The estimate is based on man-hours provided by the various groups involved with the project. The man-h,urs will be refined as the work groups better define the extent of their tasks (i.e. interference removal, as-built measurements required, etc.). 4
Page 3 s A revision will also be made to account for ALARA techniques which are in the final approval stage. Dese techniques are the high pressure water blast of the piping system and the use of the water bladder in the suction nozzles. %e estimate is structured to reflect the major tasks to be performed during the_ project. Data received early in the project will be used to update the estimate on a continuing basis. The current estimates (as of 12/20/83) are attached, however are subject to continuing revision and refinement.
N 3 QA O rT Te tt E .o Est. Ave. Est. Tasks ID Job Description Man-flours l Dose-Rate Person-Rem 1. Install tenporary power 7 lights 60 0.015 0.90 2. Install tenporary ventilation 60 0.015 0.90 3. Install pneumatic system 40 0.C15 0.60 4. Install audio-visual system 32 0.015 0.48 5. Install punp supports,. snubbers, turnbuckles 144 0.025 3.60 ~ 6. Pull recirc pump motors, remove fran drywell 120 0.040 4.8 7. Install pad eyes, beam 16 -0.015 0.24
- 8. -Install scaffolding, work platforms (initial) 300 0.015 4.50 9.
Open nozzle shield doors 32 0.075 2.40 10. Remove insulation, bag, remove fran drywell 2064 0.020 41.28 11. Install tenporary shielding 64 0.075 4.80 12. Move shielding into drywell location l'2 0.015 1.68 13. Establish cut liners 180 0.070 12.60 14. Rig cutting machin'es into drywell for initial cut 24 0.020 0.48 15. Perform ABN measurements 2772 0.015 41.58 16. Remove / replace interferences A. Instrumentation 400 0.015 6.00 B. Electrical 2700 0.015 40.50 C. Structural 1500 0.015 22.50 D. liVAC 2000 0.015 30.00 E. Small piping 3600 0.015 54.00 17. Set up hp equipment in drywell A. RM-16's' 10 0.015 0.15 B. Air sanplers 20 0.015 0.30 18. Make cuts A. 28" pipe, nozzle area - Set up machine 24 0.200 4.80 - Verify cut lines 2 0.200 0.40 - Attach and verify rigging 18 0.075 1.35 - Cut, proceed to 3/4" mark 6 0.075 0.45 - Complete cuts 3 0.075 0.225 - Remove cutting machines 6 0.075 0.45 - Clean and inspect cutting machines 8 0.015 0.12 - Install shield plugs 4 0.400 1.60 x 2 cuts x 2 cuts 142 18.79 3. 28" pipe, valve and punp area -Set up machine 24 0.050 1.20 -Verify cut lines 2 0.060 0.12 -Attach and verify riggin9 18 0.050 0.90 -Cut, proceed to 3/4" mark 6 0.050 0.30 -Complete cuts 3 0.050 0.15 -Remove cutting machines 6 0.050 0.30 -Clean and inspect cutting machines 8 0.015 0.12 x 12 cuts < 12 cuts 834 37.08 C. 28" pipe, garbage cuts -Set up machine 12 0.060 0.72 -Verify cut lines 2 0.060 0.12 -Attach and verify rigging 18 0.050 0.90 -Cut, proceed to 3/4" nurk 6 0.060
- 0. ;6
-Complete cuts 3 0.060 0.180 -Renove cutting mchines 6 0.060 0.36 -Clean and inspect cutting machines 8 0.015 0.12 - x 13 x 13 715 35.88
i ib f.) -{ ~ Est. Ave. Est. ? Task ID Job Description l Man-!!ours Dose-liours Person-Rem D. 24" pipe -Set up machine 16 0.060 0.96 -Verify' cut lines 2 0.060 0.12 -Attach and verify rigging 18 0.050 0.90 -Cut, proceed to 3/4" mark 6 0.060 0.36 -Cmplete cuts 3 0.060 0.18 -Remove cutting machines 6 .0.060 0.36 -Clean and inspect cutting machines 8 0.015 0.12 x 4 cuts x 4 cuts 236 12.00 E.. 22" cuts -Set up machine 20 0.075 1.50 -Verify cut lines 2 0.075 0.15 -Attach and verify rigging 18 0.060 1.08 -Cut, proceed to 3/4" mark 5 0.075 0.375 -Conplete cuts 2 0.075 0.15 -Remove cutting machines 6 0.075 0.45 -Clean and inspect cutting machines 8 0.015 0.12 x 8 cuts x 8 cuts 488 30.6-F. 20" cuts -Set up machine 12 0.070 0.84 -Verify cut lines 2 0.070
- 0. 14
-Attach and verify rigging, 18 0.060 1.08 -Cut, proceed to 3/4" mark 5 0.070 0.35 -Cmplete cuts 2 0.070 0.14 -Remove cutting tr.achines 6 0.070 0.42 -Clean and inspect cutting machines 8 0.015 0.12 x 2 cuts x 2 cuts 106 6.18 G. 12" cuts, nozzle area- -Set up machine 24 0.150 3.60 -Verify cut lines 1 0.150 0.15 -Attach and verify rigging 16 0.150 2.40 -Cut, proceed to 3/4" mark 2 0.150 0.30 -CaTplete cuts 1 0.150 0.15 -Remove cutting machines 4 0.150 0.60 -Clean and inspect cutting machines 8 0.015 0.12 x 10 cuts x 10 cuts 560 73.20 11. 12" cuts, header area -Set up machine 12 0.075 0.90 -Ver..fy cut lines 1 0.075 0.075 -Attach and verify rigging 16 0.060 0.96 -Cut, proceed to 3/4" mark 2 0.075 0.15 -CaTplete cuts 1 0.075 0.075 -Remove cutting machines 4 0.06; 0.24 s -Clean and inspect cutting machines 8 0.015 0.12 x 10 x 10 540 25.2 L s
I~ Estimated Average Estimated Task ID Job Description Man-Hours Dose Rate Person-rem I. 6" Cuts -Set up machine 10 0.100 0.90 -Verify cut lines 1 0.100 0.10 -Attach and verify rigging 8 0.100 0.80 -Cut, proceed to 3/4" mark 4 0.100 0.40 -CcxTplete cuts 1 0.100 0.10 -Remove cutting machines 4 0.100 0.40 -Clean and inspect cutting machines 8 0.150 1.20-x 2 cuts x2 72 8.0 19. Rig out pipe sections A. Move 28" nozzle sections to ride 8 0.150 1.20 x 2 sec x2 16 2.40 B. Have other large pipes to side 8 0.060 0.48 (28", 24", 22", 20") x 20 sec x 20 160 9.60 C. Nove 12" nozzles to side 3 0.100 0.30 x 10 sec x 10 33 3.00 D. Rig out all pipe sections 36 .020 0.72 x 32 sec x 32 1152 23.04 E. Rig out 6" pipe 18 0.030 0.54 20. Weld preps A. 28" nozzles -Inspect and clean end preps 6 0.50 3.00 -Rig in EP-2 machine 6 0.20 1.20 -Set EP-2 machine in place 8 0.20 1.60 -Counter bore end 24 0.20 4.80 -Remove EP-2 machine 6 0.15 0.90 -Clean and flap prep 8 0.50 4.00 -pT prep 8 0.20 1.60 x2 x2 132 34.2 B. Valve and pumps -Inspect and clean end preps 6 0.040 0.24 -Rig in EP-2 machine 6 0.015 0.90 -Set EP-2 machine in place 8 0.040 0.32 -Counter bore end 24 0.040 0.96 -Remove EP-2 machine 6 0.020 0.12 -Clean and flap prep 8 0.050 0.40 l -PT prep 8 0.020 0.16 x 12 x 12 792 37.2-
l w Estimated Average Es timated Task 10 Job Description Ma n-Hours P1se Rate Person-rem C. 20" pipe -Inspect and clean end preps 6 0.030 0.18 -Rig in EP-2 machine 6 0.015 0.90 -Set EP-2 machine in place 8 0.030 0.24 -Counter bore end 16 0.030 0.48 -Renove EP-2 nachine 6 0.020 0.12 -Clean and flap prep 8 0.030 0.24 -PP prep 8 0.020 0.16 58 2.32 D. 24" pipe -Inspect and clean end preps 6 .025 0.15 -Rig in EP-2 machine 6 .015 0.09 -Set EP-2 machine in place 8 .025 0.20 -Counter bore end 18 .025 0.45 -Remove EP-2 nuchine 6 .015 0.09 -Clean and flap prep 8 .025 0.20 -PT prep a .015 0.12 x2 x2 120 2.60 E. 12" Nozzles -Inspect and clean end preps 6 0.200 1.20 -Rig in EP-2 machine 6 0.060 0.36 -Set EP-2 machine in place 8 0.200 1.60 -Counter bore end 12 0.200 2.40 -Remove EP-2 machine 6 0.100 0.60 -Clean and flap prep 8 0.200 1.60 -PT prep 6 0.100 0.60 x 10 x 10 540 83.6 21. Fit up and weld A. 28" nozzle -Renove prep covers 1 0.200 0.20 -Clean preps 8 0.200 1.60 -Fit and tack insert 12 0.150 1.80 -Install purge dam 1 0.200 0.200 -Fit up joint 20 0.150 3.00 -Establish purge 8 0.100 0.80 -Tack joint 10 0.150 1.50 -Install track and welding head 6 0.150 0.90 -Constne insert, two hot passes 8 0.100 0.80 -RT root 4 0.075 0.30 -Install seal plug, flood 18 0.075 1.35 -Weld out joint 110 0.075 8.25 -Essnove track 2 0.150 0.30 -Drain, remove seal plug 6 0.150 0.90 -Weld crown reduction 60 0.200 12.00 -PT 6 0.150 0.90 -RT 3 0.075 0.60 x2 x2 576 70.8 l J
Es tiraated kierage Es tima ted Task 10 Job Description Man-Hours Dose Rate Person-rem B. 28" valves and pumps -Remove prep covers 1 0.040 0.04 -Clean preps 8 0.040 0.32 -Fit and tack insert 12 0.040 0.48 -Install purge dam 1 0.040 0.04 -Fit up joint 20 0.025 0.50 -Establish purge 8 0.015 0.12 -Tack joint 10 0.025 0.25 -Install track and welding head 6 0.025 0.15 -Consunn insert, two hot passes 8 0.025 0.20 -RT root 4 0.015 0.60 -Install seal plug, flood 18 0.015 0.27 -Weld out joint 110 0.015 1.65 -Remove track 2 0.025 0.05 -Drain, renove seal plug 6 0.015 0.09 -Weld crcun reduction 60 0.025 1.50 -Fr 6 0.025 0.15 -RT 8 0.015 0.12 x 12 x 12 3456 7836 C. Other 28" welds -Remove prep covers 1 0.015 0.015 --Clean preps 8 0.015 0.12 -Fit and tack insert 12 0.015 0.18 -Install purge dam 1 0.015 0.015 -Fit up joint 20 0.015 0.30 -Establish purge 8 0.015 0.12 -Tack joint 10 0.015 0.15 -Install track and welding head 6 0.015 0.90 -Constne insert, two hot passes 8 0.015 0.12 -RT root 4 0.015 0.06 -Install seal plug, flood 18 0.015 0.27 -Weld out joint 110 0.015 1.65 -Renove track 2 0.015 0.03 -Drain, remove seal plug 6 0.015 0.09 -Weld crown reduction 60 0.015 0.60 -PT 6 0.015 0.09 -RT 8 0.015 0.12 x 13 x 13 3744 62.79 D. 24" Welds -Remove prep covers 1 0.025 0.025 -Clean props 8 0.025 0.40 -Fit and tack insert 10 0.025 0.25 -Install purge dam 1 0.025 0.025 -Fit up joint 20 0.025 0.50 -Establish purge 8 0.015 0.12 -Tack joint 10 0.025 0.25 -Install track and welding head 6 0.025 0.15
Estimated Average Estimated Task 10 Job Description Man-Hours Dose Rate Person-rem -Constne insert, two hot passes 8 0.025 0.20 -RT root 4 0.015 0.06 -Install seal plug, flood 18 0.015 0.27 -Weld out joint 110 0.025 2.75 -Renove track 2 0.025 0.05 -Drain, remove seal plug 6 0.G15 0.03 -Weld crown reduction 60 0.025 1.50 -PT 6 .025 0.15 -RT 8 .015 0.12 x4 x2 E. 20" Welds -Remove prep covers 1 0.030 0.03 -Clean preps 8 0.030 0.24 -Fit and tack insert 10 0.030 0.30 -Install purge dam 1 0.030 0.03 -Fit up joint 20 0.030 0.60 .-Establish purge 8 0.020 0.16 -Tack joint 9 0.030 0.27 -Install track and welding head 6 0.030 0.18 -Consume insert, two hot passes 8 0.030 0.24 -IU root 4 0.015 0.06 -Install seal plug, flood 18 0.015 0.27 -Weld out joint 110 0.030 3.30 -Remove track 2 0.030 0.06 -Drain. remove seal plug 6 0.015 0.09 -Weld crown reduction 60 0.030 1.80 -PT 6 0.030 0.18 -IU 8 0.015 0.12 x2 2 570 15.86 F. 22" Welds -Remove prep covers 1 0.020 0.02 -Clean preps 8 0.020 0.16 -Fit and tack insert 10 0.020 0.20 -Install purge dam 1 0.020 0.02 -Fit up joint 20 0.020 0.40 -Establish purge 8 0.015 0.12 -Tack joint 9 0.020 0.18 -Install track and welding head 6 0.020 0.12 -Consume insert, two hot passes 8 0.020 0.16 -RT root 4 0.015 0.06 -Install seal plug, flood 18 0.015 0.27 -Weld out joint 110 0.020 2.20 -Remove track 2 0.020 0.04 -Drain, remove seal plug 6 0.015 0.09 -Weld crown reduction 60 0.020 1.20 - I'I' 6 0.020 0.12 -16 8 0.015 0.12. x8 x8 2280 13.84 1
Estimated Average Es tima ted Task 10 Job Description Man-Hours Dose Rate Person-rem G. 12" nozzles -Renove prep covers 1 0.025 0.25 -Clean preps 4 0.250 1.00 -Fit and tack insert 7 0.175 1.225 -Install purge dam 1 0.150 0.15 -Fit up joint 36 0.150 5.40 -Establish purge 8 0.075 0.60 -Tack joint 4 0.150 0.60 -Install track and welding head 4 0.150 0.60 -Coasume insert, two hot passes 6 0.100 0.60 -RT root 4 0.050 0.20 -Install seal plug, flood 12 0.100 1.20 -Weld out joint 60 0.075 4.50 -Renove track 2 0.150 0.30 -Drain, :cmove seal plug 3 0.100 0.30 -Weld crown reduction 40 0.150 6.00 -PT 4 0.100 0.40 -RT 8 0.050 0.40 x 10 x 10 2040 237.25 H. Other 12" welds -Renove prep covers 1 0.020 0.02 -Clean preps 4 0.020 0.08 -Fit and tack insert 7 0.020 0.14 -Install purge dam 1 0.020 0.02 -Fit up joint 36 0.020 0.72 -Establish purge 8 0.020 0.16 -Tack joint 4 0.020 0.08 -Install track and welding head 4 0.020 0.08 -Consune insert, two hot passes 6 0.020 0.12 -RT root 4 0.020 0.08 -Install seal plug, flood 12 0.020 0.24 -Weld out joint 60 0.020 1.20 -Renove track 2 0.020 0.04 -Drain, remove seal plug 3 0.020 0.06 -Weld crown reduction 40 0.020 0.80 -PT 4 0.020 0.08 -RT 8 0.020 0.16 x 10 x 10 2040 40.80 1. 6" welds -Remove prep covers 1 0.025 0.025 -Clean preps 4 0.025 0.10 -Fit and tack insert 8 0.025 0.20 -Install purge dam 1 0.025 0.025 -Fit up joint 36 0.025 0.90 -Establish purge 7 0.025 0.175 -Tack joint 4 0.025 0.10 -Install track and welding head 4 0.025 0.10
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l Estimated Average Estimated Task 'ID Job Description Man-Hours Dose Rate Person-rem I -Consune insert, two hot passes 6 0.025 0.15 -RT root 4 0.025 C.10 -Install seal plug, flood 12 0.025 0.30 -Weld out joint 60 0.025 1.50 -Remove track 2 0.025 0.05 -Drain, remove seal plug 3 0.025 0.075 -Weld crown reduction 40 0.025 1.00 -PT 4 0.025 0.10 -RT 8 0.015 0.12 x2 x2 408 10.04
- 22. Miscellaneous A.
Project drywell coordinators 1260 0.015 18.90 B. Construction supervision 700 0.015 10.50 C. Move scaffolds around 600 0.030 18.00 D. Move electric power and lights It 0 0.020 2.00 E. Erect tents - glove bags 300 0.050 15.00 F. Decon - labor support 2000 0.020 40.00 G. [ngineering Inspections 3000 0.015 45.00 23. Systems testing A. Calibrations 128 0.015 1.92 B. Functional testing 7750 0.010 77.50 24. Ifp coverage A. Control point 8640 0.002 17.28 o B. Routine surveys / air samples 720 0.015 10.80 C. Routine surveillance 3600 0.015 54.00 D. Breach surveys / air sampics 250 0.060 15.00 E. Welding coverage 600 0.015 12.00 25. Remove health physics equipment A. RM-16 10 0.015 .15 B. Air samples 10 0.015 .15
l it! ) Estimated Average Estimated Task ID Job Descrintion N n-Hours __ Dose Rate Person-rem -26. Remove construction machines, pneumatics 150 0.015 2.25 27. Remove tenporary shielding 200 0.015 3.00 28. Reinstall insulation 1500 0.020 30.00 29. Close nozzle doors 25 0.075 1.875 30. Renove scaffolding 100 0.015 1.50 31. Remove rigging 100 0.015 1.50 32. Replace punp motors 120 0.020 2.40 33. Remove pump supports 40 0.020 0.80 34. Remove audio-visual equipment 25 0.015 0.375 35. Rem 3ve ventilation 70 0.015 1.05 36. Remove temporary power and lights 40 0.015 0.60 Total in drywll 71,227 t,Zoi.vu-I60 Y' - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -'}}