Transcript PPT

Summary Slides on
FNST Top-level Technical Issues and on
FNSF objectives, requirements and R&D
Mohamed Abdou
Presented at FNST Meeting, UCLA
August 18-20, 2009
1
Summary of Top- Level Technical Issues for
Fusion Nuclear Science and Technology (FNST)
1.
2.
3.
4.
5.
D-T fuel cycle tritium self-sufficiency in a practical system
Tritium extraction, inventory, and control in solid/liquid breeders and
blanket, PFC, fuel processing and heat extraction systems
MHD Thermofluid phenomena and impact on transport processes in
electrically-conducting liquid coolants/breeders
Structural materials performance and mechanical integrity under the
effect of radiation and thermo-mechanical loadings in blanket and
PFC
Functional materials property changes and performance under irradiation
and high temperature and stress gradients (including ceramic breeders, beryllium
multipliers, flow channel inserts, electric and thermal insulators, tritium permeation and corrosion barriers, etc. )
6.
Fabrication and joining of structural and functional materials
7. Fluid-materials interactions including interfacial phenomena, chemistry,
compatibility, surface erosion and corrosion
8. Interactions between plasma operation and blanket and PFC materials
systems, including PMI, electromagnetic coupling, and off-normal events
9. Identification and characterization of synergistic phenomena and failure
modes, effects, and rates in blankets and PFC’s in the fusion environment
10. System configuration and Remote maintenance with acceptable machine
down time
2
Highlights of the Top- Level Technical Issues for FNST
Will be given this afternoon by :
D-T fuel cycle tritium self-sufficiency in a practical system Abdou
2. Tritium extraction, inventory, and control in solid/liquid breeders and
blanket, PFC, fuel processing and heat extraction systems Morley
3. MHD Thermofluid phenomena and impact on transport processes in
electrically-conducting liquid coolants/breeders Smolentsev
4. Structural materials performance and mechanical integrity under the
effect of radiation and thermo-mechanical loadings in blanket and
PFC Sharafat
5. Functional materials property changes and performance under irradiation
and high temperature and stress gradients
6. Fabrication and joining of structural and functional materials Sharafat
7. Fluid-materials interactions including interfacial phenomena, chemistry,
compatibility, surface erosion and corrosion
Smolentsev
8. Interactions between plasma operation and blanket and PFC materials
systems, including …….
Morley
9. Identification and characterization of synergistic phenomena and failure
modes, effects, and rates in ………………. Ying
10. System configuration and Remote maintenance with acceptable machine
down time Ying
1.
3
Fusion Nuclear Science and Technology (FNST)
Fusion Power & Fuel Cycle Technology
FNST includes the scientific issues and
technical disciplines as well as materials,
engineering and development of fusion
nuclear components:
From the edge of Plasma to TF Coils:
1. Blanket Components (includ. FW)
2. Plasma Interactive and High Heat Flux
Components (divertor, limiter, rf/PFC elements)
3. Vacuum Vessel & Shield Components
Other Systems / Components affected by
the Nuclear Environment:
4. Tritium Processing Systems
5. Remote Maintenance Components
6. Heat Transport and Power Conversion
Systems
4
Science-Based Framework for FNST R&D involves modeling
and experiments in non-fusion and fusion facilities
Theory/Modeling/Data
Basic
Separate
Effects
Property
Measurement
Multiple
Interactions
Design Codes
Partially
Integrated
Phenomena Exploration
Integrated
Component
•Fusion Env. Exploration Design
Verification &
•Concept Screening
•Performance Verification Reliability Data
Non-Fusion Facilities
(non neutron test stands,
fission reactors and accelerator-based
neutron sources)
Testing in Fusion Facilities
• Experiments in non-fusion facilities are essential and are prerequisites to testing in
fusion facilities
• Testing in Fusion Facilities is NECESSARY to uncover new phenomena, validate the
science, establish engineering feasibility, and develop components
5
R&D Tasks to Be Accomplished Prior to Demo
1) Plasma
- Confinement/Burn
- Disruption Control
- Current Drive/Steady State
- Edge Control
2) Plasma Support Systems
- Superconducting Magnets
- Fueling
- Heating
3) Fusion Nuclear Science and Technology (FNST)
-Blanket
- Divertors
- rf (PFC elements)
- VV & Shield
4) Systems Integration
Where Will These Tasks be Done?!
• Burning Plasma Facility (ITER) and other plasma devices will address 1, 2, & much of 4
• The BIG GAP is Fusion Nuclear Science and Technology (FNST)
• Where, How, and When will it be done?
6
Stages of FNST Testing in Fusion Facilities
Fusion “Break-in” &
Scientific Exploration
Stage I
0.1 – 0.3 MW-y/m2
 0.5 MW/m2, burn > 200 s
Sub-Modules/Modules
• Initial exploration of coupled
phenomena in a fusion environment
• Uncover unexpected synergistic effects,
Calibrate non-fusion tests
• Impact of rapid property changes in
early life
• Integrated environmental data for
model improvement and simulation
benchmarking
• Develop experimental techniques and
test instrumentation
• Screen and narrow the many material
combinations, design choices, and
blanket design concepts
Engineering Feasibility
& Performance
Verification
Stage II
1 - 3 MW-y/m2
1-2 MW/m2
steady state or long pulse
COT ~ 1-2 weeks
Modules
• Uncover unexpected synergistic
effects coupled to radiation
interactions in materials, interfaces,
and configurations
• Verify performance beyond beginning
of life and until changes in properties
become small (changes are substantial
2
up to ~ 1-2 MW · y/m )
• Initial data on failure modes & effects
• Establish engineering feasibility of
blankets (satisfy basic functions &
performance, up to 10 to 20 % of
lifetime)
• Select 2 or 3 concepts for further
development
Component Engineering
Development &
Reliability Growth
Stage III
D
E
M
O
> 4 - 6 MW-y/m2
1-2 MW/m2
steady state or long burn
COT ~ 1-2 weeks
Modules/Sectors
• Identify lifetime limiting failure modes
and effects based on full environment
coupled interactions
• Failure rate data: Develop a data base
sufficient to predict mean-timebetween-failure with confidence
• Iterative design / test / fail / analyze /
improve programs aimed at reliability
growth and safety
• Obtain data to predict mean-time-toreplace (MTTR) for both planned
outage and random failure
• Develop a database to predict overall
availability of FNT components in
DEMO
7
FNSF (CTF/VNS) MISSION
The mission of FNSF is to test, develop, and qualify Fusion Nuclear
Components (fusion power and fuel cycle technologies) in
prototypical fusion power conditions.
The FNSF facility will provide the necessary integrated testing
environment of high neutron and surface fluxes, steady state plasma (or
long pulse with short dwell time), electromagnetic fields, large test area
and volume, and high “cumulative" neutron fluence.
The testing program on FNSF and the FNSF device operation will
demonstrate the engineering feasibility, provide data on reliability /
maintainability / availability, and enable a “reliability growth”
development program sufficient to design, construct, and operate
blankets, plasma facing and other FNST components for DEMO.
FNSF will solve the serious tritium supply problem for fusion
development by a- not consuming large amounts of tritium, bbreeding much of its own tritium, c- accumulating excess
tritium (in later years) sufficient to provide the tritium inventory
required for startup of DEMO, and d- developing the blanket
technology necessary to ensure DEMO tritium self sufficiency
8
Fusion environment is unique and complex:
multi-component fields with gradients
•Neutron and Gamma fluxes
•Particle fluxes
•Heat sources (magnitude and gradient)
– Surface (from plasma radiation)
– Bulk (from neutrons and gammas)
• Magnetic Field (3-component)
– Steady field
– Time varying field
• With gradients in magnitude and direction
Plasma
Width
B
0
(for ST)
BT
Inner
Edge
Bp
Outer
Edge
R
Multi-function blanket in multi-component field environment leads to:
- Multi-Physics, Multi-Scale Phenomena
Rich Science to Study
9
- Synergistic effects that cannot be anticipated from simulations & separate effects
tests. Modeling and Experiments are challenging
The most Challenging Phase of Fusion Development
still lies ahead – the development of Fusion Nuclear
Science and Technology is the Biggest GAP
 Achieving high availability is a challenge for Magnetic Fusion Concepts
•
•
Device has many components
Blanket/PFC are located inside the vacuum vessel
 Tritium available for fusion development other than ITER is rapidly diminishing
•
•
Any DT fusion development facility other than ITER must breed its own tritium, making the
Breeding Blanket an Enabling Technology
Where will the initial inventory for the world DEMOs (~ 10 kg per DEMO) come from?
How many DEMOs in the world?
 FNSF is a Required and Exciting Step in Fusion Development.
(Building FNF in the US, parallel to ITER, is a most important element in restoring
US leadership in the world fusion program.)
•
Each country aspiring to build a DEMO will most likely need to build its own FNF —
not only to have verified breeding blanket technology, but also to generate the initial tritium
inventory required for the startup of DEMO.
 We must start now the R&D modeling and testing in non-fusion facilities for US
Selected Blanket Concepts.
•
This R&D is needed prior to testing in ANY fusion facility. What is needed to qualify
a test module for ITER is the same as that required for a test module, or a base
10
breeding blanket, on FNSF. Such R&D takes > 10 years.