Nuclear power drive
Among nuclear-powered means the driving of vehicles , aircraft , ships or space vehicles by means of nuclear power . Since nuclear reactors require extensive shielding due to their strong neutron radiation , nuclear power drives cannot be manufactured so compactly that they can be used in conventional cars or trucks . They are therefore reserved for larger vehicles.
Because of their potential massive radioactive environmental pollution in accidents of various degrees and other incidents, nuclear power drives are considered controversial , and not only because of the high level of radioactive waste that is generated . In recent years, therefore, research in this area has largely been discontinued or severely restricted.
This article therefore describes the state of research and other theoretical considerations, some of which are now very outdated.
Radioisotope generators , which use the decay heat of certain atomic nuclei ( half-life ) and usually generate electrical current from it via thermocouples , have found a certain spread, especially in space travel.
Nuclear energy propulsion of ships and submarines
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Usually pressurized water reactors with an output of around 100 megawatts are used to drive ships and submarines with nuclear power . They generate steam that is directed to steam turbines that drive either the propellers or generators and auxiliary equipment. However, due to the high speed of steam turbines, the propeller cannot be driven directly; a gearbox is usually required.
Nuclear propulsion is mainly used for military ships and submarines, but there are also civilian ships with nuclear propulsion . These are or were the Soviet icebreakers Lenin , Arktika and Sibir , the German research ship Otto Hahn , the American Savannah , the Japanese Mutsu and the Soviet freighter Sevmorput . The Russian icebreakers Rossiya , Tajmyr , Sovetskiy Soyuz , Waigatsch , Yamal and 50 Let Pobedy are still in operation (2011).
Nuclear power for locomotives
Studies have been conducted in the United States for nuclear powered locomotives , including the X-12 . They should have nuclear reactors with complete cooling circuits on board that generate electricity for the traction motors. These plans were discarded because they were too complicated. In Germany too, Krauss-Maffei considered building an approximately 35 m long nuclear locomotive in the mid-1950s; the design was closely related to the well-known V 200 diesel locomotive .
In principle, locomotives are mostly electrically powered on the axles. The nuclear reactor would have powered a generator to generate electrical energy, which in turn would have powered the traction motors on the axles. However, the generation of energy on board - similar to a diesel-electric locomotive - causes high weight. In addition, such a motor-generator combination cannot be loaded as evenly as external energy generation. The departure from the principle of generating electrical energy on board was primarily due to cost reasons.
Nuclear power for automobiles
In the 1950s, the concept of the Ford Nucleon , a car with a nuclear drive, was born. Ford only built a 3: 8 scale model of the vehicle without a reactor. Like many other nuclear-powered designs of this time, this project can be classified against the background of the then new atomic technology and its as yet unknown but highly valued development potential.
In addition to the use in civil land vehicles, the usability of nuclear energy drives in tanks and other large military equipment was evaluated in the 1950s. Proposed tank concepts from the United States included the R-32 and the Chrysler TV-8 . All design proposals were discarded by the end of the 1950s. Only a demonstration model with a conventional drive was made of the Chrysler TV-8 .
Radionuclide batteries have been used as energy sources in space travel since the early 1960s . In the Mars Science Laboratory mission launched in 2011, this type of energy source is used to drive the vehicle in the unmanned Mars rover Curiosity .
Nuclear energy propulsion of aircraft
Planes
United States
In the case of a nuclear-powered aircraft, a compressor should be driven with the help of a small, lightweight reactor , the compressed air of which should then be ejected from a nozzle , whereby a propulsion would arise like a normal jet aircraft. Various studies and experiments were carried out in the USA from the mid-1950s. As part of the Aircraft Nuclear Propulsion Program (ANP), air-cooled reactors of the General Electric X39 were developed that were based on conventional General Electric J47 engines , which were modified for propulsion by means of the heat input via a nuclear reactor. The three prototypes HTRE-1, HTRE-2 and HTRE-3 ( HTRE = Heat Transfer Reactor Experiment ) were created. The last two systems are stationary on the site of the Idaho Falls nuclear research center and are available to the public for inspection ( location ) . Another nuclear reactor of the Pratt & Whitney company with the designation PWAR-1 ( Pratt & Whitney Aircraft Reactor-1 ) was tested from 1957 on the premises of the nuclear research center Oak Ridge .
From 1951 the United States Air Force tested another nuclear reactor (Aircraft Shield Test Reactor - ASTR) in a converted Convair B-36 . The aircraft itself was still powered conventionally, however, it completed a total of 47 flights over the airspace of the states of Texas and New Mexico as part of the program .
In March 1961, for safety reasons, the experimental program was discontinued by order of President John F. Kennedy .
Soviet Union
In the former Soviet Union in 1961, a few flights of a Tu-95LaL with a reactor on board were carried out. Another project followed in 1972 with the An-22PLO . Both aircraft were only used for test flights to check the radiation protection equipment and the behavior of the reactors on board. There was no energy transfer for the drive. Both projects have been discontinued.
There were similar ideas for airships , especially in the 1960s, but a nuclear airship was never built.
Other missiles
In the US project Pluto between 1956 and 1964, a nuclear-powered cruise missile with a practically unlimited range was developed at great expense . A reactor-heated ramjet was supposed to carry the missile at Mach 3 at low altitude in enemy territory, where it would attack up to 24 targets with H-bombs . The project was successful for engine testing and the resolution of a number of technical problems after the Cuban missile crisis ended in 1964 - on the grounds that the project is too provocative is ( "too provocative").
Nuclear power propulsion of spacecraft
Drive with reactor
In a spacecraft powered by nuclear reactors, hydrogen is heated to 3000 degrees Celsius using a nuclear reactor and then ejected. As with a normal rocket engine, recoil is generated. Since hydrogen and no combustion product is emitted, the specific impulse is very high. In the USA, such devices were examined as part of the NERVA and Timberwind projects .
The US satellite Snapshot used a nuclear reactor for the first time in 1965 to operate an ion thruster.
Propulsion with atomic bombs
If a small atomic bomb is detonated in a vacuum at a sufficient safety distance from a parabolic reflector , a spacecraft can be propelled with the help of the resulting radiation pressure. Since there are no pressure waves in space , the reflector does not need to be too massive. With such a spacecraft one could in principle cross the solar system. In the USA there were corresponding studies in the context of the Orion project in the late 1950s .
Others
In May 2018, a first Russian floating nuclear power plant was towed to Murmansk . It is supposed to function as a stationary heating power plant in Pewek and has no drive.
Web links
- Dreams of Nuclear Flight - The NEPA and ANP programs
- Atomic locomotive X-12, article from 1954
- Atomic locomotive, article 1957
- Article: nuclear plane
- Flying with nuclear power