page 1 of 14 reflections on the energy mission and goals of a fusion test reactor aries design...
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Reflections on the energy mission and goals of a fusion test reactor
ARIES Design Brainstorming Workshop
24-25 April 2005
M. S. Tillack
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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
Metricwaste 3 need to deal with it, but wrong materials
reliability 3 some machine operation, no fluence
maintenance 5 unprototypic construction, modules replaced
fuel 3 tritium handling, but no breeding, no cycle
safety 6 hazards are lower, and operations different
partial power 2
thermal efficiency 0 no power production, low temp., wrong materials
power density 5 somewhat low power density
cost 7 realistic 1st of a kind costs
ITER
Metricwaste 0 little relevance
reliability 1 some machine operation, no fluence
maintenance 1 experience moving tokamak equipment
fuel 1 Some tritium handling, no breeding, no cycle
safety 2 hazards much lower, operations much different
partial power 2
thermal efficiency 0 no power conversion
power density 1 low power handling required
cost 1 not relevant to a power plant
D3/JET
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Existing and planned facilities fail to address essential features of a fusion energy source
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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.)
1-frad,div
Pfusion
Pneutron
P
Divertor
First wall
Prad,chamb
Pdiv
80%
20%
Pcond
Prad,div
frad,core
1-frad,core
frad,div
Fdiv,peak
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Fuel management: Demonstrate “birth to death” tritium management in a closed loop with self-sufficient breeding.
inventory
pumps
breeder
coolant
breeder processing
coolant processing
vacuum processing
fueling
D+T
D+T+
n
TFuelprocessing
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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.
R&DR&D needs
Design
This part is absent
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Summary
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”