En vista del proximo 25 aniversario del reactor nuclear peruano RP10, cuando se puso a crítico por primera vez el 30 de noviembre de 1988.
The Inventors Hall of Fame states that,
"Enrico Fermi and Leo
Szilard discovered
the first nuclear reactor in which nuclear chain reactions are initiated,
controlled, and sustained at a steady observable rate." Today, Enrico
Fermi’s nuclear reactor is in common use in nuclear power plants. Enrico Fermi
and Leo Szilard received U.S. patent #2,708,656 for the nuclear reactor.
Enrico Fermi Biography
Enrico Fermi was born in Rome, Italy, on
September 29, 1901. The son of a railroad official, he studied at the
University of Pisa from 1918 to 1922 and later at the universities of Leyden
and Gottingen. He became professor of theoretical physics at the University of
Rome in 1927.
In
1933, he developed the theory of beta decay, postulating that the
newly-discovered neutron decaying to a proton emits an electron and a particle
which he called a "neutrino". The theory developed to explain this
interaction later resulted in recognition of the weak interaction force.
Investigation into the weak force has been one of the major areas of study at
Fermilab.
Experimentally, Enrico
Fermi and his colleagues, during the early 1930's, studied in detail the theory
of neutrons; they bombarded most of the elements in the periodic table with
them. They slowed down the neutrons, and among other things, produced a strange
new product when bombarding uranium with neutrons which later was recognized to
be a splitting of the uranium atoms.
Enrico Fermi - 1938 Nobel Prize
Enrico Fermi received the Nobel Prize in
1938 for "his discovery of new radioactive elements produced by neutron
irradiation, and for the discovery of nuclear reactions brought about by slow
neutrons." Fermi and his family used the opportunity offered by his trip
to Sweden for the awards ceremonies to come to the United States where Fermi
accepted a position as professor of physics at Columbia University.
At that time it was recognized that nuclear fission
(the splitting of the atom) had taken place in Fermi's and other similar
experiments. Scientists felt that this principle might be applied to construct
an "atomic bomb". With World War II raging in Europe, the
ability to produce such a bomb was of the greatest importance in the balance of
power in the world.
Enrico Fermi - Work on
Atomic Bomb
Enrico Fermi moved to the University of
Chicago to be in charge of the first major step in making feasible the building
of the atomic
bomb.
In
the squash courts under the west stand of the University's Stagg Field, Fermi
supervised the design and assembly of an "atomic pile", a code word
for an assembly that in peacetime would be known as a "nuclear
reactor". Today, a plaque at the site reads: "On December 2, 1942,
man achieved here the first self-sustaining chain reaction and thereby
initiated the controlled release of nuclear energy."
Enrico Fermi was the
prime mover in the design of the synchrocyclotron at the university which was,
at the time of its completion, one of the most powerful atom smashers in the
world.
Fermi’s momentous
accomplishments caused him to be recognized as one of the great scientists of
the 20th century. Following his death on November 28, 1954, a number of science
institutions and awards have been named in his honor.
US PATENT 2,206,634 (Process for the Production of Radioactive
Substances); E. Fermi, E. Amaldi, F. Rasetti, E. Segre, B. Pontecorvo; July 2,
1940.
The process, for production of isotopes
including transuranic elements by reaction of neutrons, employs means for
generating neutrons having a high average energy, slowing down and scattering
the neutrons by projecting them through a medium of an element of a class
including H, He, Be, C, Si, and Pb, and then passing the neutrons into a mass
of material containing an element capable of forming a radioactive isotope by
neutron capture, including radioactive isotopes capable of emitting beta rays.
US PATENT
2,524,379 (Neutron Velocity Selector), Enrico Fermi, Oct 3, 1950.
The present invention relates to neutron velocity selector apparatus and
particularly to apparatus of this type which utilizes a rotating shutter.
US PATENT
2,708,656 (Neutronic Reactor), Enrico Fermi and Leo Szilard, May 17, 1955.
The present invention relates to the general subject of nuclear fission and
particularly to the establishment of self-sustaining neutron chain fission
reactions in systems embodying uranium having a natural isotopic content.
US PATENT
2,714,577 (Neutronic Reactor); E. Fermi, W.H. Zinn; August 2, 1955.
A heavy water moderated neutron reactor has been designed to employ as fuel
uranium metal of natural isotopic composition. The composite fuel rods are
suspended from the cover so as to extend well into the reactor tank. Each rod
is composed of an aluminum portion extending vertically into the tank from the
cover and a thermal neutron fissionable portion secured to the lower end of the
aluminum portion. Heavy water fills the tank to a level above the juncture of
the aluminum portion with the fissionable portion of each composite rod so as
to cause the fissionable portion to be wholly immersed.
US PATENT
2,768,134 (Testing Material in a Neutronic Reactor); E. Fermi et al.; October
23, 1956.
A means of testing the nuclear properties of materials to be used in a nuclear
reactor is given. This is accomplished by placing in an operating reactor the
materials loaded on a transverse stringer or tray-type device of sufficient
length that upon withdrawing the portion containing the materials tested a
portion containing the customary reactor components is drawn into place,
thereby completing the reactor core integrity. A cadmium control rod suitably
indexed is used to maintain constant flux density in the reactor, thus, by
comparing the two readings of the control rod positions, a relationship may be
established between the nuclear properties of the tested material and the
normal reactor components. Such information is
an important aid in atomic research.
US PATENT
2,780,595 (Test Exponential Pile); E. Fermi; February 5, 1957.
A nuclear fission test pile is described which is designed to measure the
fissioning chain reaction induced in a sub-critical mass of natural U by a
neutron source. The pile comprises a number of cells containing natural U,
disposed in a graphite moderator, and adjacent to an independent source of
neutrons for the purpose of causing in the test pile a chain reaction that
cannot be self-sustaining. Measurements are made of the radioactivity induced
in strips of indium foil which are inserted in appropriate slots or channels in
the core. This pile permits the taking of such measurements from a reactor
requiring a reduced amount of valuable material, and eliminates the possibility
of a dangerous buildup of reactivity.
US PATENT
2,798,847 (Method of Operating a Neutronic Reactor); E. Fermi et al.; July 9,
1957.
A method of operating a reactor and particularly the operation of the shim and
control rods to maintain an operational reactivity factor of unity is
described. The shim rods of a highly neutron absorbent material are gradually
withdrawn to compensate for the build up of fission product poisons, which
would otherwise decrease the innate reactivity factor, whereas the control rods
compensate for the normal fluctuations of the power level and for the power demand
of varying loads or start up procedure.
US PATENT
2,807,581 (Neutronic Reactor); E. Fermi, L. Szilard; September 24, 1957.
Reactors of the type employing plates of natural uranium in a moderator are
discussed wherein the plates are uniformly disposed in parallel relationship to
each other thereby separating the moderator material into distinct and
individual layers. Each plate has an uninterrupted surface area substantially
equal to the cross-sectional area of the active portion of the reactor, the particular
size of the plates and the volume ratio of moderator to uranium required to
sustain a chain reaction being determinable from the known purity of these
materials and other characteristics such as the predictable neutron losses due
to the formation of radioactive elements of extremely high neutron capture
cross section
US PATENT 2,807,727 (Neutronic Reactor Shield); E. Fermi, W.H. Zinn;
September 24, 1957.
The reactor radiation shield material is
comprised of alternate layers of iron-containing material and compressed
cellulosic material, such as masonite. The shielding material may be
prefabricated in the form of blocks, which can be stacked together in any
desired fashion to form an effective shield.
US PATENT
2,813,070 (Method of Sustaining a Neutronic Chain Reacting System); E. Fermi,
M.C. Leverett; November 12, 1957.
This patent relates to neutronic reactors and a method of sustaining a chain
reaction. The reactor shown in the patent for carrying out the method is the
gas-cooled type comprised of a solid moderator having a plurality of passages
therethrough for receiving bodies of fissionable material. In carrying out the
method, the reactor is loaded by inserting in the passages fuel elements and
moderator material in a proportion to sustain a chain reaction. As the
reproduction ratio decreases below the desired figure due to impurities formed
during operation of the reactor, the moderator material is gradually replaced
with additional fuel material to maintain the reproduction ratio above unity.
US PATENT
2,836,554 (Air Cooled Neutronic Reactor); E. Fermi, L. Szilard; May 27, 1958.
A nuclear reactor of the air-cooled, graphite moderated type is described. The
active core consists of a cubical mass of graphite, approximately 25 feet in
each dimension, having horizontal channels of square cross section extending
between two of the opposite faces, a plurality of cylindrical uranium slugs
disposed in end to end abutting relationship within said channels providing a
space in the channels through which air may be circulated, and a cadmium
control rod extending within a channel provided in the moderator. Suitable
shielding is provided around the core, as are also provided a fuel element
loading and discharge means, and a means to circulate air through the coolant
channels through the fuel channels to cool the reactor.
US PATENT
2,837,477 (Chain Reacting System); E. Fermi, M.C. Leverett; June 3, 1958.
A nuclear reactor of the gas-cooled, graphite-moderated type is described. In
this design, graphite blocks are arranged in a substantially cylindrical
lattice having vertically oriented coolant channels in which uranium fuel
elements having through passages are disposed. The active lattice is contained
within a hollow body, such as a steel shell, which, in turn, is surrounded by
water and concrete shields. Helium is used as the primary coolant and is
circulated under pressure through the coolant channels and fuel elements. The
helium is then conveyed to heat exchangers, where its heat is used to produce
steam for driving a prime mover, thence to filtering means where radioactive
impurities are removed. From the filtering means the helium passes to a
compressor and an after cooler and is ultimately returned to the reactor for
recirculation. Control and safety rods are provided to stabilize or stop the
reaction. A space is provided between the graphite lattice and the internal
walls of the shell to allow for thermal expansion of the lattice during
operation. This space is filled with a resilient packing, such as asbestos, to
prevent the passage of helium.
US PATENT
2,852,461 (Neutronic Reactor); E. Fermi, W.H. Zinn, H.L. Anderson; September
16, 1958.
Means are presented for increasing the reproduction ratio of a
graphite-moderated neutronic reactor by diminishing the neutron loss due to
absorption or capture by gaseous impurities within the reactor. This means
comprised of a fluid-tight casing or envelope completely enclosing the reactor
and provided with a valve through which the casing, and thereby the reactor,
may be evacuated of atmospheric air.
US PATENT
2,931,762 (Neutronic Reactor); E. Fermi; April 5, 1960.
A nuclear reactor is described consisting of blocks of graphite arranged in
layers, natural uranium bodies disposed in holes in alternate layers of
graphite blocks, and coolant tubes disposed in the layers of graphite blocks
which do not contain uranium.
US PATENT
2,969,307 (Method of Testing Thermal Neutron Fissionable Material for Purity);
E. Fermi, H.L. Anderson; January 24, 1961.
A process is given for determining the neutronic purity of fissionable material
by the so-called shotgun test. The effect of a standard neutron absorber of
known characteristics and amounts on a neutronic field also of known
characteristics is measured and compared with the effect which the impurities
derived from a known quantity of fissionable material has on the same neutronic
field. The two readings are then made the basis of calculation from which the
amount of impurities can be computed
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