the fission-fusion hybrid at last! a solution that has found a problem jeff freidberg mit
TRANSCRIPT
![Page 1: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/1.jpg)
The Fission-Fusion Hybrid
At last! A solution that has found a
problem
Jeff Freidberg MIT
![Page 2: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/2.jpg)
What problem are we trying to solve?
• Future large demand for CO2-free base load electricity
• May need 10 TW CO2-free electricity by mid-century
• 20 times more CO2-free electricity than now
• Only coal and nuclear fission are realistic options
• Coal must solve the sequestration problem - tough job
• Nuclear must solve waste and proliferation problems – plausible solutions exist
• Nuclear must also solve the fuel supply problem – only 30 years of proven reserves at 10 TW level
![Page 3: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/3.jpg)
What problem are we trying to solve? (con’t)
• Mid-century uncertainties
1. Coal Sequestration
2. Discovery of new uranium
• Prudent to have other options
• Problem to be solved:
Produce large amounts of fissile fuel so that fission becomes a sustainable source of electricity
![Page 4: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/4.jpg)
How are we going to solve the problem?
• Revisit an old idea
Use a fission-fusion hybrid to produce fissile fuel
• What has changed to make this old idea interesting?
1. We may need a lot more uranium than we
thought
2. The fission community, at least at MIT, is
interested and receptive to the idea
![Page 5: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/5.jpg)
The fission-fusion energy park
• One 200 MWe-equivalent (i.e. 500 MWt) tokamak fusion core
• Surround with a thorium-lithium blanket – produces about 5500 kg of U-233 plus 20 kg of tritium per year
• Separate the U-233 and combine it with U-238 to form fissile fuel for a LWR
• This fuel is sufficient to power two 800 MWe LWRs
• Power gain = 8!
• Burn the resulting Pu and actinides in an onsite 300 MWe fast reactor.
• Store short lived radioactive byproducts on site
• Transmute long lived radioactive byproducts in the hybrid blanket
![Page 6: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/6.jpg)
Why is this good for fusion
• How can fusion make a contribution by mid-century?
– Fusion electricity is tough from a plasma physics and fusion
engineering point of view
• Fissile fuel from fusion is much easier
– Need Q = 2 -5 for success rather than Q = 50 for electricity
– Do not need steady state or ultra-high availability
– Even if fusion electricity is successful, it will likely cost more than
a comparable fission reactor
• What about tainting fusion with fission? If we can help fission
produce electricity we must do so and not be dilettantes posturing in
the wind
![Page 7: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/7.jpg)
Why is this good for fission?
• The fission-fusion hybrid converts fission energy from an
intermediate stop-gap energy source into one that is
sustainable for over 10,000 years
• Making fissile fuel from a fission-fusion hybrid may be
better than alternate options
![Page 8: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/8.jpg)
Comparison of options
• What are the options for producing fissile fuel?
Fuel Source Cost (cents/kW-hr)
Direct mining of U 0.5
Sea water extraction 1.6
Accelerator production 7.4
Breeder reactor 1.8
Fission-fusion hybrid 1.7
![Page 9: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/9.jpg)
From ITER to a fission-fusion DEMO
• Plasma physics1. MHD, transport, heating OK
2. Divertor and first wall scale-up problems remain
3. Current drive may not be necessary
4. Larger B field very desirable for plasma physics
• Fusion engineering1. Materials for the first wall and divertor
2. Tritium and fissile fuel breeding
3. Increased neutron fluence
4. Increased availability
![Page 10: The Fission-Fusion Hybrid At last! A solution that has found a problem Jeff Freidberg MIT](https://reader036.vdocument.in/reader036/viewer/2022082710/56649e685503460f94b6533d/html5/thumbnails/10.jpg)
Recommendations for OFES
• Initiate a 2 year pre-ARIES scoping study
on the fission-fusion hybrid system
• Increase emphasis on the first wall and
divertor problems
• Initiate a superconducting magnet R&D
program to make higher field magnets