PICKERING ‘A’UNIT 4 BOILER 6 HOT SOURCE

Scott Cameron

Pickering B RPM

OUR GOAL

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

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 @ 1cm18,000 rem/h @ 5cm500 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

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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

CLICK HERE TO RETURN TO

PREVIOUS SLIDE

>450,000 rem/h @ 1cm On Boiler Drain Line Elbow

500 rem/h @ 30cm

Boiler Base Boiler Base Pedestals Pedestals BOILER - 6BOILER - 6

1” to 3” of insulation to get to drain line

PICTURES OF AREAPICTURES OF AREA

Drain Line Valve Drain Line Valve Under PHT Pumps Under PHT Pumps Along HT Catwalk, Along HT Catwalk, Flanged Off.Flanged Off.

Perimeter Perimeter Walk WayWalk Way

200 mrem/h

PICTURES OF AREAPICTURES OF AREA

Dance Floor

2.5 rem/h at Surveyor Position

CATWALK

DANCE FLOOR

TRIM VALVE PLATFORM

TRIM VALVE PLATFORM

PERIMETER WALK WAY

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.

OPTION DETAILS (cont’d)

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 doesn’t 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.

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

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

RISKS

a) Resources

b) Timeline

c) Cost

d) Dose Assignment

e) If particle has changed locations and no longer where we think it is

OPTIONS FLOWSHEET

FLUSH AND CAPTURE PARTICLE

YES

IS CAPTURE SUCCESSFUL?

PROCEED WITH REGULAR OUTAGE

SCOPE

NOSHIELD BOILER 6 AS BEST AS POSSIBLE.

MOVE TO EAST BOILERS AND LEAVE FOR NEXT OUTAGE 1041 OR CUT OUT IN PARALLEL ON 941.