Transcript High damage threshold metal mirrors using nanostructured

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Reflections on the energy mission
and goals of a fusion test reactor
M. S. Tillack
ARIES Design Brainstorming Workshop
24-25 April 2005
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“ITER is the experimental step between
today’s studies of plasma physics and
tomorrow’s electricity-producing fusion
power plants” (www.iter.org)
Is this credible?
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Fusion energy development should be guided
by requirements for a fusion energy source
 No public evacuation plan is required
 Generated waste can be returned to environment or recycled in less than a
few hundred years (i.e., not geological time-scales)
 No disturbance of public’s day-to-day activities
 No exposure of workers to a higher risk than other power plants
 Closed tritium fuel cycle on site
 Ability to operate at partial load conditions (50% of full power)
 Ability to efficiently maintain power core for acceptable plant availability
 Ability to operate reliably with less than 0.1 major
unscheduled shut-down per year
Above requirements must be achieved
consistent with a competitive life-cycle
cost-of-electricity goal.
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Existing and planned facilities fail to address
essential features of a fusion energy source
Metric
waste
reliability
maintenance
fuel
safety
partial power
thermal efficiency
power density
cost
ITER
Metric
waste
reliability
maintenance
fuel
safety
partial power
thermal efficiency
power density
cost
D3/JET
3 need to deal with it, but wrong materials
3 s ome mac hine operation, no fluenc e
5 unprototypic c ons truc tion, modules replac ed
3 tritium handling, but no breeding, no c yc le
6 hazards are lower, and operations different
2
0 no power produc tion, low temp., wrong materials
5 s omewhat low power dens ity
7 realis tic 1 s t of a kind c os ts
0 little relevanc e
1 s ome mac hine operation, no fluenc e
1 experienc e moving tokamak equipment
1 S ome tritium handling, no breeding, no c yc le
2 hazards muc h lower, operations muc h different
2
0 no power c onvers ion
1 low power handling required
1 not relevant to a power plant
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Existing and planned facilities fail to address
essential features of a fusion energy source
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ITER/
FIRE
ARIES “next step”
Starlite
2010
2030
2050
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An experimental power reactor is needed
to establish the credibility of fusion as a
competitive ENERGY SOURCE

Essential features:
Power plant relevant materials
 Full nuclear operations
 Reasonable lifetime fluence (1-10 MW-yr/m2)

Closed fuel cycle operation
 Etc
 Fill these in…
 Etc

Parameters do not need to replicate a power plant; rather, the
device should be optimized to meet the requirements of a device on
the pathway to a power plant.
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Our study should emphasize holistic R&D
needs and their design implications
Holistic : relating to or concerned with wholes or with
complete systems rather than with the analysis of,
treatment of, or dissection into parts.
Plasma
Blankets
Divertors
Magnets
Vacuum vessel
Power management
Reactor control
Fuel management
Maintenance
Safety
Waste
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Examples of holistic issues for system
studies of experimental power reactors

Thermal power management: Demonstrate divertor power and
particle handling, extraction of power core high-grade heat,
nuclear performance of ancillary equipment (rf, magnets, etc.)

Fuel management: Demonstrate “birth to death” tritium
management in a closed loop with self-sufficient breeding.

Safety: Demonstrate public and worker safety of the integral
facility, capturing system to system interactions.

Plant operations: Establish the operability of a fusion energy
facility, reliability of components, inspectability and
maintainability of a power plant relevant tokamak.

Flexibility: Explore alternative operating modes and power core
technologies with high duty cycle, but flexible operations.
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Thermal power management: Demonstrate divertor power and
particle handling, extraction of power core high-grade heat, nuclear
performance of ancillary equipment (rf, magnets, etc.)
First wall
80%
Pfusion
Pneutron
20%
frad,core P
rad,chamb
Pa
1-frad,core
frad,div
Divertor
Prad,div
Pdiv
1-frad,div Pcond
Fdiv,peak
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Fuel management: Demonstrate “birth to death” tritium
management in a closed loop with self-sufficient breeding.
fueling
inventory
breeder processing
n
breeder
T
D+T
coolant processing
coolant
D+T+a
vacuum processing
pumps
Fuel
processing
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Plant operations: Establish the operability of a fusion energy
facility, reliability of components, inspectability and
maintainability of a power plant relevant tokamak.
If power plant blankets can
be replaced in 1-2 months,
then a test reactor blanket
should be replaceable too.
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Challenges for an ARIES interface with
domestic energy R&D programs

The US is not actively pursuing energy technologies for fusion.

EU and Japan have serious technology programs;
coordination between ARIES and international activities
(including the “ITER broad approach”) will be essential.
Design
R&D
needs
R&D
This part is absent
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Summary
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The time is right to explore remaining facilities on the
path to fusion energy
ARIES is accepted as an appropriate venue to explore
fusion energy, even in an era emphasizing “basic science”.
Any device on the path to fusion energy should advance
features that lead to a commercially attractive end
product.
A strength of the ARIES team is our integrated “holistic”
approach to design studies. Key device features and
mission elements should reflect overarching goals of
fusion energy.
The mission should complement existing and planned
facilities, including consideration of the “ITER broad
approach”