Embed Size (px)
DESCRIPTION
Nuclear Thermal Rockets. Brice Cassenti University of Connecticut. Nuclear Energy. Relativity Fission energy Radioactive decay Cross-sections Nuclear thermal rockets. Relativistic Energy. For all particles For photons For. Binding Energy. Fission of 92 U 235. Fission Process. - PowerPoint PPT Presentation
Citation preview
Nuclear Thermal Rockets
Brice CassentiUniversity of Connecticut
Nuclear Energy
• Relativity• Fission energy• Radioactive decay• Cross-sections• Nuclear thermal rockets
Relativistic Energy
• For all particles
• For photons
• For
2
202
22220
2242420
/1 cv
cmmcE
cpEE
cpcmcm
22
00
hhpcE
m
1/ cv22
0 2
1mvcmE
Binding Energy
Fission of 92U235
Energy Value (MeV)
Fission fragment kinetic energy 166.2
Neutron kinetic energy 4.8
Prompt X-rays 8.0
particles from fragment decay 7.0
particles from fragment decay 7.2
Antineutron from fragment decay 9.6
Total released energy 202.8
10
9436
13956
23692
23592
10 3 nKrBaUUn
Fission Process
Radioactive Decay
• Consider uranium alpha decay
• Decay rate is proportional to number left
• Activity measured in Sieverts
42
23490
23892 HeThU
692.02ln
/10
half
mean
t
t
t
eNN
Fission Fragment Decay
Fission Fragment Size
Neutrons Emitted
Neutron Energy
Cross-Section
• Cross-section =
• Units – 1 barn=10-24cm2
nxeII
nIdx
dI
0
Uranium Fission Cross-Sections
Some Cross-Sections in barnsNucleus Absorption, a Capture, c Fission, f Scattering, s
92U235 687 107 580 10
94Pu239 1065 315 750 9.6
92U233 585 52 533 ?
92U238 2.75 2.75 0 8.3
U (natural) 7.68 3.50 4.18 8.3
fca : Note
Neutron Moderator
Scattering Cross-Sections
Reactor Schematic
Nuclear Thermal Propulsion
• Solid Core– 850-950 second Specific Impulse
• Gas Core– 1800-1950 second Specific Impulse
Solid Core Schematic
NERVA Program
NERVA Core & Fuel Rods
Core Layout
Gas Core Rocket
Nuclear Light Bulb
References
Bussard, R.W., and R.D. DeLauer, Nuclear Rocket Propulsion, McGraw-Hill Series in Missile and Space Technology, McGraw-Hill Company, Inc. 1958.
Cork, J.M., Radioactivity and Nuclear Physics, D. Van Nostrand Company, Inc., New York, 1950.
El-Genk. M.S., (editor) A Critical Review of Space Nuclear Power and Propulsion 1984-1993. American Institute of Physics, New York, 1994.
El-Wakil, M.M., Nuclear Power Engineering, McGraw-Hill Book Company, Inc., New York, 1962.
Harper, W.R., Basic Principles of Fission Reactors, Interscience Publishers, Inc., New Your, 1961.
Muhkin, K.N., Experimental Nuclear Physics, Mir Publishers, Moscow, 1987. Murray, R.L., Nuclear reactor Physics, Prentice-Hall, Inc., Englewood Cliffs, NJ,
1957. NASA, Nuclear Thermal Propulsion Workshop, NASA Conference Publication
10079, Cleveland, OH, July 10-12, 1990.
