Transcript 12_Vacuum_Vessel_Segmenting.PPT

Vacuum Vessel Segmenting
Bob Parsells
D&D Lessons Learned Workshop
June 25-26, 2002
PPPL
June 25-26, 2002
D&D Lessons Learned Workshop
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Operations End
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D&D Lessons Learned Workshop
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Finding a Solution
• Impact evaluation of
dismantling.
• Program and technology
development.
• Successes and problems.
Diamond Wire Cutting Saw
June 25-26, 2002
D&D Lessons Learned Workshop
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Overview
1
3
1.
Enclosure for diamond
wire saw
2.
Hydraulic drive unit
external
3.
Containment for wire
2
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D&D Lessons Learned Workshop
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Equipment Arrangement
2
4
3
1.
Diamond wire saw
2.
Pulley support frame
3.
Pulleys
4.
Particulate collection
1
4
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D&D Lessons Learned Workshop
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The Vacuum Vessel
1.
Long racetrack port
2.
Short racetrack port
3.
Parting joint
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Impact Evaluation
• Health physics.
– ALARA, tritium
contamination,
activation, bioassay,
airborne tritium.
• Industrial hygiene.
– O2 monitoring,
confined space, noise,
particulate respirators.
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D&D Lessons Learned Workshop
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Industry Survey
• History.
– 25 years ago, safer stone quarry
operation begat DWC.
• Applications.
– Bridge piers; Raising the Kursk.
• Limitations.
– Non-ferrous metals; Cooling &
cleaning; Wire breakage.
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D&D Lessons Learned Workshop
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The Case for Diamond Wire
– Provides accessibility not
available to individuals with
cutting/burning devices.
– Minimizes evolution of
vapors and fumes associated
with burning techniques.
– Keeps workers further away
from hazards.
– Has proven to be the least
time consuming overall.
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D&D Lessons Learned Workshop
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Process Prototyping
Industry Standards
PPPL Adaptations
Wire feed rate
3200 fpm
450 fpm
Wire tension load
1200 lb
150 lb
Cooling fluid
Water
C02 2-phase slurry
Wire life
1 to 2 hrs
Up to 12 hrs
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D&D Lessons Learned Workshop
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Prototyping Achievements
• Wire life greatly
extended.
• Cutting rate greatly
increased.
• VV segmenting duration
shortened.
• Personnel exposure to
hazard from enclosure
entries minimized.
• CO2 slurry cleans
stainless residue from
cutting beads better than
concrete. Allows use of
low density, aerated
concrete.
June 25-26, 2002
D&D Lessons Learned Workshop
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Prototype Surrogate
1” 304 S.S.
bellows
cover plates
Parting
Joint
½ inch 304 S.S.
vessel wall
1.5 inch
Graphite Tile
5/8 “ Inconel
backing plates
• Vacuum vessel surrogate prior to filling
June 25-26, 2002
D&D Lessons Learned Workshop
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Low Density Concrete
• The surrogates and the
vacuum vessel were
filled with an aerated
concrete.
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D&D Lessons Learned Workshop
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Parting Joint
• This detail of the
vacuum vessel parting
joint shows limited
access location where
the cuts were made.
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D&D Lessons Learned Workshop
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Technology Transfer
• New harder materials.
– Inconel; Nitronic.
• Tritium contamination
constraints.
– Controls; Containment.
• Configuration constraints.
– Limited access; Small
clearances.
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Configuration Constraints
The transfer of cutting technology from the
prototype to the vacuum vessel is
tightly constrained by configuration.
The items involved are:
1. The TF Coils
2. The PF Coils
3. The Inner Support Structure (ISS)
4. The Inner & Outer VV supports
5. The VV parting joint
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Equipment
Samples
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Diamond Wire Saw
• Diamond wire rope
and pulleys.
• Diamond wire saw.
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Process Implementation
• Concrete in VV June 2001, first cut August 2001.
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Procedures
• Containment
– CO2
– Airborne tritium
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D&D Lessons Learned Workshop
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Configuration
• Saw, pulleys, enclosure
CAD model of TF and DWC saw
enclosures. The two enclosure are
connected by an “access” box.
DWC setup with enclosures and
ventilation system. Set up for
“pull” cut.
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D&D Lessons Learned Workshop
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Pull Cut
Supply CO2 to cool/clean cable.
VACUUM VESSEL
TF ENCLOSURE
MOVEABLE PULLEY
INNER SUPPORT
STRUCTURE
TF COIL
PULL CUT
SAWENCLOSURE
Diamond Wire SAW
Vacuum Vessel Elevation
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Push Cut
Supply CO2 to cool/clean cable.
VACUUM VESSEL
TF ENCLOSURE
MOVEABLE PULLEY
INNER SUPPORT
STRUCTURE
TF COIL
PUSH CUT
SAWENCLOSURE
Dia Wire SAW
Vacuum Vessel Elevation
June 25-26, 2002
D&D Lessons Learned Workshop
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Engineering Controls
• Containment
• Contamination
• Particulate
removal
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Cooling & Cleaning
• Water
• Cryogenic
– Nitrogen
– Carbon dioxide
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Wire Failures
• Wire failures and enclosure entries.
• Technicians wear two
layers of protective
clothing (PCs), and are
using full face, suppliedair breathing masks.
• Stay times limited by
worker fatigue.
• “Jammed” wires are
usually freed in one
entry.
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Pulley System
• Adjustment of pulleys is very important
•Last upper and lower
pulley is mounted on
adjustable gear rack. Pulley
is re-positioned to ensure
that wire does not bend
sharply around edge of cut.
•Camera provided real-time
visual feedback to DWC
saw operator for accurate
positioning of pulleys.
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D&D Lessons Learned Workshop
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Pulley Drive System
1.
Moveable pulley
2.
Pulley frame
3.
Air motor
4.
Gear box
5.
VV segment
6.
Diamond wire
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D&D Lessons Learned Workshop
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Operating Parameters
•
•
•
•
•
Configuration
Speed
Tension
Cooling
Cleaning
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Performance
– Best effort is ~23 hours cutting, over 3-4 day period.
– No broken wires.
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Lessons Learned
• First cut timeline.
• Setup harder than
cutting.
• Cable crimping
stories.
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New Technology Orientation
• The first cut took the longest.
The HP and IH personnel were
on a steep learning curve due to
technology that was as new to
them as it was to the
developers.
• Setup took more time than
cutting. The constraints of
working in a radiological
environment made the low-tech
tasks of moving and cleaning
time consuming.
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The Future
• Wide application to D&D
– This technology has now demonstrated the ability to cut
large metal structures containing softer metals, such as
stainless steel, and one of the hardest metals, Inconel, in
conjunction with a concrete-matrix.
• Access limited configurations
– Room to thread the diamond wire cable is the only
configuration constraint.
• Mitigation of contamination generation
– Diamond wire cutting technology is particularly
advantageous when compared to the significant health and
safety concerns associated with the baseline technology.
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D&D Lessons Learned Workshop
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The End
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