1. PICKERING A UNIT 4 BOILER 6 HOT SOURCE Scott Cameron Pickering B RPM

2. OUR GOAL The Elimination or Control of this Hazard will allow P941 Outage work to proceed safely while minimizing extra dose to workers.

3. PROBLEM STATEMENT High Energy Source Identified in the Cold Leg Drain Line of Unit 4, Boiler 6 >450,000 rem/h ESTIMATED CONTACT GAMMA DOSE RATE @ 1cm 18,000 rem/h @ 5cm 500 rem/h @ 30cm 350 rem/h JUST BELOW HOT LEG DRAIN LINE Hot Leg Drain Line Cold Leg Drain Line manway Archived Photo Without Insulation On This is Boiler 12 Not Boiler 6

4. AREA THAT SOURCE AFFECTS 40 top of stairs 27 btm strs 29 WPW wall 26 top strs to feeders 35 BO12-BO6 18 to flange drain line 12 danceflr 2900 mrem/h 450 mrem/h 2500 mrem/h 225 mrem/h 4500 mrem/h 200 mrem/h

5. CLICK HERE TO RETURN TO PREVIOUS SLIDE >450,000 rem/h @ 1cm On Boiler Drain Line Elbow 500 rem/h @ 30cm Boiler Base Pedestals BOILER - 6 1 to 3 of insulation to get to drain line

6. PICTURES OF AREA Drain Line Valve Under PHT Pumps Along HT Catwalk, Flanged Off.

7. Perimeter Walk Way 200 mrem/h

8. PICTURES OF AREA Dance Floor 2.5 rem/h at Surveyor Position

9. CATWALK DANCE FLOOR TRIM VALVE PLATFORM PERIMETER WALK WAY

10. OPTIONS 1.FLUSH AND CAPTURE 2.IF FLUSH AND CAPTURE FAILS: 1) SHIELD BOILER 6 (USING LONG HANDLED TOOLS, ROPES) 2) RUN PARALLEL PLAN TO DO WORK ON EAST SIDE, DEVELOP PLAN FOR CUT OUT DURING P1041 OUTAGE OR 3. DEVELOP PLAN FOR CUT OUT DURING THIS OUTAGE IF TIME PERMITS.

11. OPTION DETAILS (contd) 1.FLUSH AND CAPTURE OPERATIONAL METHOD: Forced drain to a shielded catch container (particle will progress in drain line/drain hose to two IX Columns in parallel. Risk-particle doesnt move Contingency- See Option 2 Above Risk- Particle becomes lodged on route in steel line drain line before reaching tygon hose. Contingency- Shield (depending on location). Continue with boiler campaign on west side, develop plan for next outage to cut out.

12. DRAWING OF FLUSH AND CAPTURE OPTION 2 In Station Flasks With IX Column Inside Ice Plug Here For Double Isolation Drain Manifold Flanged Drain Valve 4-3311-V11 Drain Line - 18ft CRANE 311 B/R North TOTE Hot Spot Cold Leg Drain Line TOTE SIDE VIEW BOILER 6

13. PREREQUISITE ACTIVITIES 1.Draft Work Plan 2.Address assessing requirements 3.Develop and procure tooling 4.Set up mock up 5.Acquire resources 6.Train 7.Transfer of Particle Issues 8.Target Dates 9.Approval of Back-Up Schedule and Implementation

14. RISKS a) Resources b) Timeline c) Cost d) Dose Assignment e) If particle has changed locations and no longer where we think it is

15. OPTIONS FLOWSHEET FLUSH AND CAPTURE PARTICLE YES IS CAPTURE SUCCESSFUL? PROCEED WITH REGULAR OUTAGE SCOPE NO SHIELD BOILER 6 AS BEST AS POSSIBLE. MOVE TO EAST BOILERS AND LEAVE FOR NEXT OUTAGE 1041 OR CUT OUT IN PARALLEL ON 941.