1. Nuclear Thermal Rockets
Brice Cassenti
University of Connecticut

2. Nuclear Energy Relativity Fission energy Radioactive decay
Cross-sections
Nuclear thermal rockets

3. Relativistic Energy
For all particles
For photons
For

4. Binding Energy

5. Fission of 92U235 Energy Value (MeV) Fission fragment kinetic energy
166.2
Neutron kinetic energy
4.8
Prompt X-rays
8.0
b particles from fragment decay
7.0
g particles from fragment decay
7.2
Antineutron from fragment decay
9.6
Total released energy
202.8

6. Fission Process

7. Radioactive Decay Consider uranium alpha decay
Decay rate is proportional to number left
Activity measured in Sieverts

8. Fission Fragment Decay

9. Fission Fragment Size

10. Neutrons Emitted

11. Neutron Energy

12. Cross-Section
Cross-section = s
Units
1 barn=10-24cm2

13. Uranium Fission Cross-Sections

14. Some Cross-Sections in barns
Nucleus
Absorption, sa
Capture, sc
Fission, sf
Scattering, ss
92U235
687
107
580 10
94Pu239
1065
315
750
9.6
92U233
585 52
533 ?
92U238
2.75
8.3
U (natural)
7.68
3.50
4.18

15. Neutron Moderator

16. Scattering Cross-Sections

17. Reactor Schematic

18. Nuclear Thermal Propulsion
Solid Core
second Specific Impulse
Gas Core
second Specific Impulse

19. Solid Core Schematic

20. NERVA Program

21. NERVA Core & Fuel Rods

22. Core Layout

23. Gas Core Rocket

24. Nuclear Light Bulb