Dr. Dennis Whyte, the Director of the Plasma Science and Fusion Center at MIT, presents on how to develop demonstration fusion power faster and cheaper

1. 1Whyte, ASP Fusion Lunch, 06/15
MIT Plasma Science & Fusion Center
Smaller & Sooner:
Key New Technologies to Accelerate the
Development of Fusion Energy
Dennis Whyte
MIT Plasma Science and Fusion Center
MIT Nuclear Science and Engineering
With grateful acknowledgement to colleagues students
at MIT and Princeton Plasma Physics Lab
American Security Project “Energy Week” Luncheon
New York, June 2015

2. 2Whyte, ASP Fusion Lunch, 06/15
The fusion of light nuclei is the energy
source of stars, and basically, the universe
Big ball of hydrogen “plasma”
Interior temperature ~ 15 Million C

3. 3Whyte, ASP Fusion Lunch, 06/15
The fusion of light nuclei is the energy
source of stars, and basically, the universe
On Earth
Heavy types of hydrogen
100 million degrees C
10 atmospheres of pressure

4. 4Whyte, ASP Fusion Lunch, 06/15
Fusion is the ultimate energy source
• Limitless fuel
• No radioactive waste in fuel cycle
• No proliferation
• Inherently safe
• No greenhouse gases
• Million times power density of “chemical” energy
Ø Minimized environmental footprint
• Can rapidly scale to large % of energy demand

5. 5Whyte, ASP Fusion Lunch, 06/15
Slide Title
• Points

6. 6Whyte, ASP Fusion Lunch, 06/15
Fusion is the ultimate energy source
• Limitless fuel
• No radioactive waste in fuel cycle
• No proliferation
• Inherently safe
• No greenhouse gases
• Million times power density of “chemical” energy
Ø Minimized environmental footprint
• Can rapidly scale to large % of energy demand

7. 7Whyte, ASP Fusion Lunch, 06/15
Magnetic bottles in toroidal (“donut”) shape have been
extremely successful at reaching fusion conditions
On Earth
Heavy types of hydrogen ✓ A
100 million degrees C ✓ A
2 atmospheres ✓ B

8. 8Whyte, ASP Fusion Lunch, 06/15
The magnetic bottle is produced with a set of external coils
with very large electrical currents passing through them
Current
In coil

9. 9Whyte, ASP Fusion Lunch, 06/15
Fusion is real, made everyday in experiments of
different size and configurations around US and world
Alcator C-Mod (MIT)
3 atmospheres
100 million C JET (UK)
15 million watts fusion power
0.7 m
3 m

10. 10Whyte, ASP Fusion Lunch, 06/15
Outside the US the world is escalating its investment
magnetic fusion science by using “superconductor”
technology to produce the magnetic bottle
South Korea
China
Japan
Germany

11. 11Whyte, ASP Fusion Lunch, 06/15
Yet fusion energy’s development timeline
has stalled…
EnergyGain
Year

12. 12Whyte, ASP Fusion Lunch, 06/15
The ITER fusion experiment:
The science of fusion is ready, but it takes
very large size with ~90’s superconductor technology

13. 13Whyte, ASP Fusion Lunch, 06/15
Smaller, modular fusion devices are the key to
accelerating fusion’s development towards
net energy on decade timescale
!
Shippingport:+1954+
“Pilot”+Fission+Plant++
ITER+
Pthermal)(MW)) 230+ 500++
Core)volume)(m3)) 60++ 1000+
Cost)(2012)US)B$)) 0.6+ ~+20+
Cost)/)volume)(M$/m3)) 10+ ~+20+
Construction)time)(y)) 3.5+ +20+
!

14. 14Whyte, ASP Fusion Lunch, 06/15
Smaller, modular fusion devices are the key to
accelerating fusion’s development towards
net energy on decade timescale
!
Shippingport:+1954+
“Pilot”+Fission+Plant++
ITER+
Pthermal)(MW)) 230+ 500++
Core)volume)(m3)) 60++ 1000+
Cost)(2012)US)B$)) 0.6+ ~+20+
Cost)/)volume)(M$/m3)) 10+ ~+20+
Construction)time)(y)) 3.5+ +20+
!
JET tokamak: 100 m3 ✓
~4 years construction ca. 1980 ✓
But only 10 MW fusion power

15. 15Whyte, ASP Fusion Lunch, 06/15
Breakthrough superconductor technology provides a
stronger magnetic bottle that does not use electricity à
smaller, sooner fusion energy
“ARC” Volume ~ 100 m3 JET (UK): Volume ~ 100 m3
Bmax = 23 T Bmax = 9 T
Pfusion =10 MWPfusion ~ 500 MW

16. 16Whyte, ASP Fusion Lunch, 06/15
The way to decrease the size of fusion devices,
and accelerate fusion energy development,
is to achieve higher magnetic field strength
βN
2
q*
2
RB4
Fusion power density
Physics parameters
R = linear size, volume cost ∝ R3
B = magnetic field strength

17. 17Whyte, ASP Fusion Lunch, 06/15
The way to decrease the size of fusion devices,
and accelerate fusion energy development,
is to achieve higher magnetic field strength
βN
2
q*
2
RB4
Fusion power density
Physics parameters
R = linear size, volume cost ∝ R3
B = magnetic field strength
Increase B two-fold à Gain 24 = 16 advantage!
Well known 20+ years ago but could only be done in resistive, energy
consuming copper coils à no net energy

18. 18Whyte, ASP Fusion Lunch, 06/15
Last few years: A new generation of high-
temperature, high-field superconductors is
revolutionary for fusion energy
• Zero resistance
• Form of strong, flexible
tapes à can form
joints

19. 19Whyte, ASP Fusion Lunch, 06/15
REBCO: coated superconductors in
robust tape form, commercially available
• Strong in tension due to steel
• Flexible
• Outer Cu coating à simple
solder low-resistance joint
• Stark contrast with old NbSn
superconductor strand CIC!
REBCO tape composition
(not to scale)

20. 20Whyte, ASP Fusion Lunch, 06/15
Breakthrough superconductor technology provides a
stronger magnetic bottle that does not use electricity à
smaller, sooner fusion energy
REBCO superconductors ~4 years construction
Bmax = 23 T Bmax = 9 T
Pfusion =10 MWx B4Pfusion ~ 500
MW

21. 21Whyte, ASP Fusion Lunch, 06/15
April 2015: New world record of 26.5 Tesla
with REBCO-only, “no-insulation” coil
S. Hahn, J.M. Kim, et al.
NNFML, FSU, SUNAM, MIT
Applied Phys Lett 2015

22. 22Whyte, ASP Fusion Lunch, 06/15
REBCO superconductor technology is primed to
make smaller, sooner fusion possible!
Bcoil(T) 26.5 23
Je (A/mm2) 400 400-500
T (K) 4.2 25
Materials REBCO, SS316L
σmax (MPa) 593 660
Diameter (m) 0.03 ~ 6

23. 23Whyte, ASP Fusion Lunch, 06/15
Tape superconductors à Demountable coils
à Open the magnetic bottle!
F. Mangiorotti, J. Minervini
MIT Ph.D. thesis

24. 24Whyte, ASP Fusion Lunch, 06/15
Demountable superconductor coils have a profound
effect on modularity of fusion design
• Core is designed as a single
integrated unit
Ø Synergy with keeping
design of small total mass
and volume
• Fabrication + qualification
done completely off-site
Replaceable
“core”
module

25. 25Whyte, ASP Fusion Lunch, 06/15
Demountable superconductor coils have a profound
effect on modularity of fusion design
😀😕

26. 26Whyte, ASP Fusion Lunch, 06/15
Modular core has a profound effect on fusion design:
The liquid immersion “blanket”
• Simple -- No gaps
• Energy fuel extraction with
liquid low-velocity flow
• No damage limits in blanket
• Minimize solid replacement ~ 1
m3
FLiBe blanket
Fusion
source

27. 27Whyte, ASP Fusion Lunch, 06/15
Immersion blanket + 3D printing:
Another revolution for fusion manufacturing and
removing intense heat
External
motor
Internalpumps
FLiBe
3D printed car
W
Flibe
2 mm
thick
+
Internal
Fin

28. 28Whyte, ASP Fusion Lunch, 06/15
High magnetic field à Reliable, stable physics
regimes that have already been demonstrated
Operational limit diagram
βN
2
q*
2
RB4

29. 29Whyte, ASP Fusion Lunch, 06/15
The revolution of new superconductor technologies
is ready to be started
Large size
Sector replacement
20 year timeline
Modest size
Modular replacement
10 year timeline
Fusion power: 500 MW
Electrical power: 200 MW
Fusion power: 500 MW
Same
Science!

30. 30Whyte, ASP Fusion Lunch, 06/15
Near-term, small-scale research can pursue this
exciting path for fusion energy

31. 31Whyte, ASP Fusion Lunch, 06/15
Fusion Energy: Can be soon enough
to make a difference!
• Fusion energy to solve the
world’s needs has always been
“50 years in the future”.
• But times have changed!
Breakthrough technologies +
established fusion science
= New design paradigm
• Demonstration plants can be
ready in decade, at reasonable
cost size.
• Let’s do it.

32. 32Whyte, ASP Fusion Lunch, 06/15
Thank you!

33. 33Whyte, ASP Fusion Lunch, 06/15
Additional Materials

34. 34Whyte, ASP Fusion Lunch, 06/15
Roadmaps to fusion energy should take on risk with
variety of weightings in science vs. technology
Lockheed Martin
General Fusion
TriAlpha
Large science risk
“Simpler” technology
Flexible geometry
Reduced scale
Minimal science risk
Breakthrough technologies
Geometry same but modular
Reduced scale
Science success
Too big
Too slow

35. 35Whyte, ASP Fusion Lunch, 06/15
Slide Title
• Points

36. 36Whyte, ASP Fusion Lunch, 06/15
Detachable magnetic coils à
Idealized liquid immersion blanket à
Improved power density with high-T molten salt
Liquid: 450 – 1450 C
Non-toxic, inert
High resistivity
Global heat removal
Internal
heat removal

37. 37Whyte, ASP Fusion Lunch, 06/15
Immersion blanket: high-T molten salt FLiBe
Single-phase, low-pressure flow with
minimum MHD effects
External
motor
Internalpumps
• Fuel Breeding Ratio ~ 1.14
• High thermal efficiency ~ 0.4 - 0.5
• Shielding: ~10 FPY coil lifetime
FLiBe

38. 38Whyte, ASP Fusion Lunch, 06/15
A fusion energy device heats itself and recycles
neutrons internally for tritium hydrogen fuel
Energy Before (MeV)
~ 0.01
~0.01
Energy After (MeV)
14.1
3.5
Plasma physics: T=10 keV

39. 39Whyte, ASP Fusion Lunch, 06/15
A fusion energy device heats itself and recycles
neutrons internally for tritium hydrogen fuel
Energy Before
~0.01
~0.01
Energy After
14.1
3.5
+
+
Alphas heat plasma through scattering
Plasma physics, MAlfven 1

40. 40Whyte, ASP Fusion Lunch, 06/15
A fusion energy device heats itself and recycles
neutrons internally for tritium hydrogen fuel
14.1 MeV
+
+
Escapes plasma
Nuclear Physics

41. 41Whyte, ASP Fusion Lunch, 06/15
A fusion energy device heats itself and recycles
neutrons internally for tritium hydrogen fuel
14.1 à 0
+
+
Heat
ElectricityNuclear Engineering

42. 42Whyte, ASP Fusion Lunch, 06/15
A fusion energy device heats itself and recycles
neutrons internally for tritium hydrogen fuel
+
+
6-Li + n à He + T
Nuclear Engineering, Radiochemistry

43. 43Whyte, ASP Fusion Lunch, 06/15
A fusion energy device heats itself and recycles
neutrons internally for tritium hydrogen fuel
+
+
Surrounding materials
Nuclear Material Science
sheath
Low-T Plasma Material Science

44. 44Whyte, ASP Fusion Lunch, 06/15
The recipe for fusion energy success is well known:
Gain Power density Steady-state
Q =
Fusion Power
Input Power
Fusion Power
Heat out
Input
Power
BlanketareaS
Fusion Power
Unit Size
Gain
Power
Density
Steady-
State

45. 45Whyte, ASP Fusion Lunch, 06/15
REBCO superconductors performance is constantly
improving for application in high-B coils:
E.g. Challenge of field anisotropy in jcrit
B
tape
B
tape

46. 46Whyte, ASP Fusion Lunch, 06/15
REBCO superconductors performance is constantly
improving for application in high-B coils:
E.g. Field anisotropy in jcrit nearly eliminated last year
“Progress in coated conductor
development for high magnetic field
applications.” V. Selvamanickam, et al.
U. Houston Superconductor Workshop,
Napa, CA Feb. 2015