Transcript Why is RAMI important to the fusion?

Why Is Reliability, Availability,
Maintainability, and Inspectability
Important to the Future of Fusion?
L. Waganer
Consultant for The Boeing Company
Harnessing Fusion Power Workshop
2-4 March 2009
University of California-Los Angeles
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Greenwald Theme Harnessing Fusion Power
The state of knowledge must be sufficient to design and
build, with high confidence, robust and reliable
systems which can convert fusion products to useful
forms of energy in a reactor environment, including a
self-sufficient supply of tritium fuel.
Specifically for Reliability, Availability
and Maintainability
Demonstrate the productive capacity of fusion
power and validate economic assumptions about
plant operations by rivaling other electrical
energy production technologies.
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
The End Goal For Fusion Produce Competitive Electrical Power
Our immediate goals are how to:
1) assess our current technology maturity,
2) determine our gaps, and
3) postulate research thrusts to close the gaps
This will enable Demo to validate that the
ultimate goal can be achieved with
acceptable risk
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
How Can RAMI Help?
The busbar cost of electricity is the most important factor
for an electrical generating power plant.
The plant must be an affordable, reliable, maintainable
energy source and all of these factors are contained in the
cost of electricity:
COE = [CAC + (CO&M + CSCR + CF) * (1 + y)Y+ CD&D , where
(8760*PE* Pf)
CAC is the annual capital cost charge (total capital cost x Fixed Charge Rate)
Minor Effect (salaries, equip)
CO&M is the annual operations and maintenance cost
Minor Effect (cost, life)
CSCR is the annual scheduled component replacement cost
CF is the annual fuel costs
y is the annual escalation rate (0.0 for constant dollar and y for current dollar)
Y is the construction and startup period in years
PE is the net electrical power (MWe)
Pf is the plant capacity factor (~ plant availability)
Major Effect
CD&D is the annual decontamination and decommissioning converted to mills/kWhr
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Plant Availability is High Leverage Tool
- Equivalent in Importance to Power Production Availability =
Operational Time
Operational Time + Scheduled Down Time + Unscheduled Down Time
• Operational Time is the power production time over a set period of time.
• Scheduled Down Time is the sum of regularly scheduled maintenance
periods for the power core, other reactor plant equipment, and balance of
plant equipment - Related to component lifetimes, replacement schedules,
and MTTR
• The Unscheduled Down Time is the summation of maintenance times to
repair unexpected operational failures that cause the plant to cease power
production – Determined by MTTR/MTBF of all critical components
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Availability is Determined by:
1. Reliability – The inherent reliability of all the power core and
plant component parts to achieve a very high system
reliability, (> 0.99). This means that individual components are validated
to achieve extremely high levels of reliability.
2. Maintainability – The ability to rapidly and reliably maintain all
the plant parts, especially the remote maintenance of the
power core, is absolutely essential. Power core maintenance may
be highly automated and likely autonomous in 50 years.
3. Inspectability - An examination of plant components to
determine if there are any indications that components might
fail in service, any reduction or increase in performance
and/or service lifetime. This implies extensive pre- and postoperational examinations, along with an embedded, real-time monitoring of
all operational components as a part of an integrated plant health
management system that will predict and schedule preventative maintenance
actions (new technology).
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Vision of Power Core Maintenance
ITER and other DT experimental facilities have, or will
have, provided a wealth of remote handling
experience that will be applicable to CTF, Demo, and
the Commercial Power Plant
However, those machines were never designed to have rapid remote
maintenance to achieve very high levels of availability
Conceptual fusion power plant studies have postulated two general
approaches that have some promise (and a lot of difficulties) to
achieve the required availability goal.
A. Remove large blanket and divertor modules with articulated arms
and installed rails through several large maintenance ports
B. Remove complete sectors containing blankets, divertors, and hot
shield/structure between TF coils and radially out through large
vacuum maintenance ports.
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
A. Modular Maintenance Approach
• Simultaneous maintenance in 3 ports
• Module size limited to several tonnes
• Fixed Transfer Chambers control
contamination and enhance times
• Mobile Transporters transfer used
and new components to/from Hot Cell
• Main Port is used for removing
blanket and divertor modules
• ECH launcher/waveguide removed
• ECH port can then be used as
Auxiliary maintenance port
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Removal of Blanket Modules
• Plumbing would be
disconnected from inside
the plumbing pipes
• A mobile Extractor
machine would enter the
maintenance port and
disconnect the mechanical
attachments
• Modules would be
extracted from core and
returned to Hot Cell
• The above actions
repeated for all modules
• New or refurbished
modules would be
reinstalled and tested insitu (repeated actions)
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
B. Sector Maintenance Approach
• Requires a higher degree of integration between power
core elements, power core building, and maintenance
approach
• Simplifies coolant and mechanical connections outside
of hot shield
• Allows simpler power core maintenance, but more
massive elements to be moved with precision
• More fluid and
structural
connections pretested in hot cell
rather than inside
power core
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Example of AT Sector Replacement
Basic
Operational
Configuration
Cross Section Showing Maintenance
Approach
Plan View Showing the Removable Section Being Withdrawn
Withdrawal of
Power Core
Sector with
Limited Life
Components
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Sector
Removal
Remote equipment
is designed to remove
shields and port doors,
enter port enclosure,
disconnect all coolant
and mechanical
connections, connect
auxiliary cooling to the
sector, and remove
power core sector
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Operational
Configuration
•Bioshield (2.6-m-thick) is
incorporated into building inner
wall
•Building wall radius determined
by transporter length + clear area
access
•Extra space provided at airlock to
assure that docked cask does not
limit movement of other casks
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Power Core
Removal Sequence
•Cask contains debris and dust
•Vacuum vessel door removed
and transported to hot cell
•Core sector replaced with
refurbished sector from hot
cell
•Vacuum vessel door
reinstalled
•Multiple casks and
transporters can be used
•Multiple locations can be
accessed simultaneously
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Power Core
Removal Sequence
•Cask contains debris and dust
•Vacuum vessel door removed
and transported to hot cell
•Core sector replaced with
refurbished sector from hot
cell
•Vacuum vessel door
reinstalled
•Multiple casks and
transporters can be used
•Multiple locations can be
accessed simultaneously
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Shutdown and Start-up Times
Must Be Minimized
Shutdown Timeline
Maintenance Action
Duration of Serial
Operations, h
Shutdown and preparation for maintenance
Cooldown of systems, afterheat decay
De-energize coils, keep cryogenic
Pressurize power core with inert gas
Drain coolants, fill with inert gas
Subtotal for shutdown and preparation
Duration of
Parallel
Operations, h
Dominated by
cooldown of
systems and
core
24
2.0
2.0
6.0
30
Startup Timeline
Assumes
streamlined
processes for
core evacuation,
bakeout, and
coolant fills
Maintenance Action
Duration of Serial
Operations, h
Startup tasks
Move transporters and casks to hot cell
Evacuate core interior
Initiate trace or helium heating
Fill power core coolants
Bake out (clean) power core chamber
Checkout and power up systems
Subtotal for startup
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= 2.6 days
Duration of
Parallel
Operations, h
0.8
10.0
10.0
8.0
12.0
4.0
34.0
12.0
HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Maintenance Action
Estimated Repetitive
Maintenance Times
for Replacement of a
Single Power Core
Sector
•Assumes a single cask
and transporter
•Defines major
maintenance activities
•Assumes all removal and
replacement activities are
remote and automated
•Repetitive actions require
less than 1.5 days
Duration of
Serial
Operations, h
Repetitive maintenance tasks
Move cask to port and dock to port
Open cask door and raise port isolation door
Disengage vacuum vessel door
Move transporter forward to engage vacuum door
Remove weld around vacuum door
Disconnect VS coil electrical and I&C connections
Disconnect vacuum door water coolant connections
Disengage door to prepare for removal
Remove vacuum vessel door into cask
Lower isolation and transporter doors and undock cask
Move to hot cell, unload vacuum door, return, and dock
Open cask door and raise port isolation door
Disengage power core sector
Move transporter forward to engage power core sector
Disconnect I&C connections
Disconnect five coax LiPb coolant connections
Disengage mechanical supports
Disengage sector to prepare for removal
Remove power core sector into cask
Lower isolation and transporter doors and undock cask
Move to hot cell, unload sector, load new sector, return, and dock
Open cask door and raise port isolation door
Move power core sector from cask into near-final core position
Install power core sector
Align sector and finalize position
Engage mechanical supports
Connect five coax LiPb coolant connections
Connect I&C connections
Disengage transporter and move back inside cask
Lower isolation and transporter doors and undock cask
Move to hot cell, load vacuum door, return, and dock
Open cask door and raise port isolation door
Move vacuum door from cask into near-final position
Install vacuum door
Align vacuum door and finalize position
Prep, weld, and inspect door perimeter
Connect door water coolant connections
Connect VS coil and I&C connections
Disengage transporter and move back inside cask
Lower isolation and transporter doors and undock cask
Subtotal for repetitive tasks
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Duration of
Parallel
Operations, h
1.0
0.2
3.6
0.2
2.0
0.2
1.0
0.2
1.0
0.2
2.5
0.2
3.2
0.2
0.2
2.0
0.6
0.2
1.0
0.2
3.0
0.2
1.0
7.7
1.0
1.0
5.0
0.5
0.2
0.2
2.5
0.2
1.0
5.7
1.0
3.0
1.0
0.5
0.2
0.2
34.8
HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Maintenance Times for Replacing
Different Number of Sectors at a Time
One Cask and One Transporter
Number of Shutdown Time to Replace
Sectors and Startup
Sectors, h
Replaced
Time, h
4
64
139.2
5
64
174
6
64
208.8
8
64
278.4
16
64
556.8
Maintenance
Action
Duration, h
203.2
238
272.8
342.4
620.8
Maintenance Availability
Actions Over for Scheduled
Four FPYs, h Core Outages
812.8
0.9773
748.8
0.9791
Incl. in Above
684.8
0.9808
620.8
0.9826
Equivalent
Days/Year
8.47
7.80
7.13
6.47
Note: Blankets, Divertors, and other In-Vessel Components are
designed for a 4 full power year (FPY) lifetime
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Multiple Sets of Casks and
Transporters Can Improve Times
Equivalent Annual Maintenance Times for Multiple Sets
No. of
Sectors
Replaced
4
5&6
8
16
Number of Maintenance Casks and Transporters
1
8.47
7.80
7.13
6.47
2
5.57
4.90
4.23*
3.57
4
4.12
3.45
2.78
2.12
8
3.39
2.73
2.06
1.39
16
3.03
2.36
1.70
1.03
•At least two sets should be used (4.23 equivalent d/y)
•Availability improvements by larger numbers of
casks and transporters probably would not justify
added cost
• Spare maintenance equipment will be provided
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Need to Establish Fusion Power
Plant Availability Goals Consistent
with Energy Community
• All reasonably new electricity-generating plants are now
operating in the 85-90% class
• In 25-40 years, state-of-the-art plant availabilities will be 90+%
• Fusion Power Plant (FPP) needs get to 90% or better
Representative Plant Systems Availability Goals
System Group Maintenance
Power Core, Major,
Scheduled
Power Core, Minor,
Scheduled
Power Core, Unscheduled
RPE, Scheduled and
Unscheduled
BOP, Scheduled and
Unscheduled
Total
Maintenance
Days/FPY
System
Availability
4.23
0.989
6.05
10.28
0.984
0.973
9.37
0.975
9.37
0.975
0.900
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
What Should Be Demo’s Availability
Goal?
This notional graph illustrates how Availabilities
have to grow through ITER, CTF, and DEMO
Projection of Electric Plant Availability
1950
100
2000
2100
2050
FPP Operation?
Now
50
Demo Operation?
CTF Operation?
0
1950
ITER Operation
2000
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2050
2100
HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Summary
• Achieving RAMI goals are imperative to the success
of fusion producing competitive power
• Designs shown are merely ideas at this point to help
point the way to an integrated power plant design
• Power core elements must be highly reliable and
robust through simulation and test
• Efficient maintenance of the power core is highly
design dependent
• High availabilities must be demonstrated by CTF and
Demo
• Demo must look like and act like the first commercial
power plant
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Recommendations
• An integrated power core, maintenance system, and
building design is essential to help select subsystem
options for Demo and the Fusion Power Plant (FPP)
• Pre-cursor facilities and thrusts must mature and
validate subsystems and maintenance systems that
are a part of an integrated design approach leading
to Demo and ultimately to the FPP
• An Integrated Plant Health Management system is
necessary to predict and schedule preventative
maintenance actions
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA
Questions?
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HFP Workshop, RAMI Session, 2-4 Mar 2009k,UCLA