Design and Stress Analysis of Extraterrestrial ... - The Black Vault

CHAPTER
II
ERE POWER GENERATORS
2.1. NUCLEAR REACTOR UNIT
A nuclear reactor is the most promising source of power of
an extraterrestrial rocket engine. It exhibits high power capabilities,
makes it possible to obtain sufficiently high temperatures for
the working medium,
its entire operating time.
and has a constant mass characteristic during
Disadvantages of a reactor include its
high cost, construction difficulties, necessity for crew protection
from nuclear radiation during operation, repair limitations, and
the danger present during emergencies. The problem. of obtainIng
the best structural materials for the core is presently in the
stage of solution.
Based on the energy of neutrons which determine the nuclear
fission, reactors are broken down into those operating on fast,
intermediate, and thermal neutrons. Reactors on fast neutrons
are simple in construction and have comparatively small size and mass.
They are also simple technologically, have a small number of parts,
are not sensitive to the use of structural materials which absorb
neutrons in the core. A disadvantage is the large load of fissionable
material that they require and, therefore, in many cases, they are
more expensive than other reactors.
Reactors on thermal neutrons are more complex in construction,
have greater mass and size with the same power, and are more sensitive
to the use of structural materials in the core. However, these
reactors have a number of merits. They are usually cheaper since,
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