SSTAR
Encyclopedia
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...
" - being primarily researched and developed in the USA by Lawrence Livermore National Laboratory
Lawrence Livermore National Laboratory
The Lawrence Livermore National Laboratory , just outside Livermore, California, is a Federally Funded Research and Development Center founded by the University of California in 1952...
. It is designed as a fast breeder nuclear
Nuclear power
Nuclear 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...
reactor that is passively safe. It has a self-contained fuel source of Uranium-235
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...
containing also Uranium-238
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...
which will be partly consumed by fast-neutron fission and, more important, converted into more fissile material ("breeding" Plutonium). It should have an operative life of 30 years, providing a constant power source between 10 and 100 megawatts.
The 100 megawatt version is expected to be 15 meters high by 3 meters wide, and weigh 500 tonnes. A 10 megawatt version is expected to weigh less than 200 tonnes. To obtain the desired 30 year life span, the design calls for a movable neutron reflector
Neutron reflector
A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, and tungsten carbide, or other materials...
to be placed over a column of fuel. The reflector's slow downward travel over the column would cause the fuel to be burned from the top of the column to the bottom. Because the unit will be sealed, it is expected that a breeder reaction will be used to further extend the life of the fuel.
SSTAR is meant to be tamper resistant, which would prevent the leasing country from opening the reactor to use the generated plutonium for nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
s. The tamper-resistant features will include radio monitoring and remote deactivation. The leasing country will therefore have to accept the capability for remote foreign intervention in the facility. The feature might, however, interfere with possible recovery work during an accident.
Currently, no prototypes for SSTAR exist - one is expected by 2015, and they are being researched as a possible replacement for today's light water reactors
Light water reactor
The light water reactor is a type of thermal reactor that uses normal water as its coolant and neutron moderator. Thermal reactors are the most common type of nuclear reactor, and light water reactors are the most common type of thermal reactor...
. and as a possible design for use in developing countries (which would use the reactor for several decades and then return the entire unit to the manufacturing country).