Clean And Environmentally Safe Advanced Reactor
Encyclopedia
| Disputed Science: CAESAR nuclear reactor |
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|---|---|
| Disciplines: | Nuclear engineering; Nuclear technology; Nuclear physics |
| Core Tenets: | |
Self-sustained fissioning of Uranium 238 can be accomplished via steam moderated neutrons |
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| Year Proposed: | 1998 |
| Original Proponents: | Dr. Claudio Filippone |
| Current Proponents: | Dr. Claudio Filippone |
The Clean And Environmentally Safe Advanced Reactor (CAESAR) is a nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
concept that uses steam
Steam
Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air...
as a moderator
Neutron moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235....
. Steam's density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
can be controlled very finely so, according to its developer Dr. Claudio Filippone, it can be used to fine tune neutron flux
Neutron flux
The neutron flux is a quantity used in reactor physics corresponding to the total length travelled by all neutrons per unit time and volume . The neutron fluence is defined as the neutron flux integrated over a certain time period....
es to ensure that neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s are moving with an optimal neutron energy profile to split nuclei.
The CAESAR reactor design exploits the fact that the fission product
Fission product
Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The...
s and daughter isotopes produced via nuclear reactions also decay to produce additional delayed neutron
Delayed neutron
In nuclear engineering, a delayed neutron is a neutron emitted after a nuclear fission event by one of the fission products anytime from a few milliseconds to a few minutes later....
s. Dr. Filippone claims that unlike conventional water-cooled fission reactors, where fission occurring in enriched fuel rods moderated by liquid water coolant ultimately creates a Maxwellian
Maxwellian
* Maxwell's equations * Maxwell–Boltzmann distribution* Maxwell's electromagnetic wave equation...
thermal neutron flux profile, the neutron energy profile from delayed neutrons varies widely. In a conventional reactor, he theorizes, the moderator slows these neutrons down so that they cannot contribute to the reaction; has a comparatively large cross-section for neutrons at high energies.
Dr. Filippone maintains that when steam is used as the moderator, the average neutron speed/energy is increased from that of a liquid water moderated reactor and the delayed neutrons keep going until they hit another nucleus. He claims that the resulting extremely high neutron economy
Neutron economy
Neutron economy is defined as the ratio of an adjoint weighted average of the excess neutron production divided by an adjoint weighted average of the fission production....
will make it possible to maintain a self-sustaining reaction in fuel rods of pure , once the reactor has been started by enriched fuel.
Skeptics, however point out that it is generally believed that a controlled, sustained chain reaction is not possible with . It can undergo fission when impacted by an energetic neutron with over 1 MeV of kinetic energy. But the number of high-energy neutrons produced by fission are not, themselves, sufficient to induce enough successive fissions in to create a critical system (one in which the number of neutrons created by fission is equal to the number absorbed). Instead, bombarding with neutrons below the 1 MeV fission threshold causes it to absorb them without fissioning (becoming ) and decay by beta emission to (which is itself fissile).
The CAESAR Project is headed by Dr. Filippone, who is a nuclear scientist and the Director of the Center for Advanced Energy Concepts at the University of Maryland, College Park
University of Maryland, College Park
The University of Maryland, College Park is a top-ranked public research university located in the city of College Park in Prince George's County, Maryland, just outside Washington, D.C...
.
See also
- Nuclear fissionNuclear fissionIn nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
- Nuclear reactorNuclear reactorA nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
- Nuclear reactor physicsNuclear reactor physicsNuclear reactor physics is the branch of science that deals with the study and application of chain reaction to induce controlled rate of fission for energy in reactors....
- Nuclear powerNuclear powerNuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
- Nuclear power plantNuclear power plantA nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...
- Future energy development
- Energy amplifierEnergy amplifierIn nuclear physics, an energy amplifier is a novel type of nuclear power reactor, a subcritical reactor, in which an energetic particle beam is used to stimulate a reaction, which in turn releases enough energy to power the particle accelerator and leave an energy profit for power generation...
- Nuclear waste
- Supercritical Water Reactor
External links
- The Clean And Environmentally Safe Advanced Reactor (CAESAR) Project
- Hail, Caesar Economist article
- Putting Nuclear Waste to Work Popular Mechanics article from 1998 describing a related reactor design (NPTRE) proposed by Dr. Filippone.
- A Second Caesar to Change the Course of History? Article from University of Maryland newsletter.