Topaz Nuclear Reactor
Encyclopedia
The TOPAZ nuclear reactor is a lightweight nuclear reactor
developed for long term space use by the Soviet Union
. Cooled by liquid metal, it uses a high-temperature moderator
containing hydrogen and highly enriched fuel and produces electricity using a thermionic converter
.
(LASL) in 1957. Following the visit of Soviet scientists to LASL in 1958, they carried out tests on TI systems in 1961, initially developing the single cell ENISY reactor (also known as TOPAZ-II). Work was carried out by the Kurchatov Institute of Atomic Energy
and the Central Bureau for Machine Building to develop the multi-cell TOPAZ (also known as TOPAZ-I), a Russian acronym for "Thermionic Experiment with Conversion in Active Zone". It was first ground tested in 1971, when its existence was acknowledged. It was under the auspices of Krasnaya Zvezda
.
The first TOPAZ reactor operated for 1,300 hours and then was shut down for detailed examination. It was capable of delivering 5 kW of power for 3-5 years from 12 kg (26.5 lb) of fuel. Reactor mass was ~ 320 kg (705.5 lb).
TOPAZ was first flown in 1987 on the experimental Plazma-A satellites Cosmos 1818 and 1867, which were intended to test both the TOPAZ reactor and the Plasma-2 SPT
electric engine. A follow-up Plasma-2 was to have been equipped with an improved reactor. One reactor operated for 6 months, the other for a year. The program was later abandoned on the instructions of Mikhail Gorbachev
in 1988.
) is sheathed in an emitter which is in turn surrounded by a collector, and these form the 37 fuel elements which penetrate the cylindrical zirconium hydride
(ZrH) moderator. This in turn is surrounded by a beryllium
neutron reflector
with 12 rotating control drums. Liquid metal coolant (NaK
) surrounds each fuel element. The mass of the reactor is ~ 1061 kg (2,339.1 lb).
In January 1991 a model of the TOPAZ-II was exhibited at a scientific symposium in Albuquerque, generating interest in the US in the possible purchase of it and the Strategic Defense Initiative Organization
arranged to buy two Topaz-2 reactors from Russia for a total of $13 million, planning to use the reactors to improve US models. However, the Nuclear Regulatory Commission
ruled that US law prohibited the "export" of such a device to the Soviet Union - even though it was Soviet-made and only a model rather than an actual reactor. It took a month before the situation was resolved by a new NRC ruling and the model returned to Russia.
The United States Department of State
then put a hold on the deal, which was only lifted when Secretary of State
James Baker
intervened. One of the reactors was to be used in a flight test in 1995 to power experimental electrical thrusters, but there were objections from scientists concerned about the possible impact of radiation emitted by the reactor on instruments aboard space satellites and protests from opponents of space-based weapons and nuclear power. In addition, the Department of Energy
was slow to grant the necessary approval and in 1993 budget restrictions forced the cancellation of the program.
Six TOPAZ-II reactors and their associated support equipment were flown to the US, where they were extensively ground tested by US, British, French, and Russian engineers. The reactors' unique design allowed them to be tested without being fuelled. Although the test program was considered a success, no plans were pursued to fly any of the reactors.
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...
developed for long term space use by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
. Cooled by liquid metal, it uses a high-temperature 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....
containing hydrogen and highly enriched fuel and produces electricity using a thermionic converter
Thermionic converter
A thermionic converter consists of a hot electrode which thermionically emits electrons over a potential energy barrier to a cooler electrode, producing a useful electric power output...
.
Nomenclature
In initial discussions, it was unclear that TOPAZ and the somewhat similar ENISY (Daisy) reactors were different systems, and when the existence of the two Russian thermionic reactors became generally known, US personnel began referring to TOPAZ as TOPAZ-I and ENISY as TOPAZ-II.TOPAZ-I
The first thermionic (TI) reactors were mooted by scientists at the Los Alamos Scientific LaboratoryLos Alamos National Laboratory
Los Alamos National Laboratory is a United States Department of Energy national laboratory, managed and operated by Los Alamos National Security , located in Los Alamos, New Mexico...
(LASL) in 1957. Following the visit of Soviet scientists to LASL in 1958, they carried out tests on TI systems in 1961, initially developing the single cell ENISY reactor (also known as TOPAZ-II). Work was carried out by the Kurchatov Institute of Atomic Energy
Kurchatov Institute
The Kurchatov Institute is Russia's leading research and development institution in the field of nuclear energy. In the Soviet Union it was known as I. V. Kurchatov Institute of Atomic Energy , abbreviated KIAE . It is named after Igor Kurchatov....
and the Central Bureau for Machine Building to develop the multi-cell TOPAZ (also known as TOPAZ-I), a Russian acronym for "Thermionic Experiment with Conversion in Active Zone". It was first ground tested in 1971, when its existence was acknowledged. It was under the auspices of Krasnaya Zvezda
Krasnaya Zvezda State Enterprise
Krasnaya Zvezda State Enterprise is a Russian state enterprise that research and produce nuclear power systems for spacecraft. It was established in 1972, is located in Moscow and is subordinated to Rosatom.Krasnaya Zvezda developed the Bouk and TOPAZ reactors for spacecraft...
.
The first TOPAZ reactor operated for 1,300 hours and then was shut down for detailed examination. It was capable of delivering 5 kW of power for 3-5 years from 12 kg (26.5 lb) of fuel. Reactor mass was ~ 320 kg (705.5 lb).
TOPAZ was first flown in 1987 on the experimental Plazma-A satellites Cosmos 1818 and 1867, which were intended to test both the TOPAZ reactor and the Plasma-2 SPT
Hall effect thruster
In spacecraft propulsion, a Hall thruster is a type of ion thruster in which the propellant is accelerated by an electric field. Hall thrusters trap electrons in a magnetic field and then use the electrons to ionize propellant, efficiently accelerate the ions to produce thrust, and neutralize the...
electric engine. A follow-up Plasma-2 was to have been equipped with an improved reactor. One reactor operated for 6 months, the other for a year. The program was later abandoned on the instructions of Mikhail Gorbachev
Mikhail Gorbachev
Mikhail Sergeyevich Gorbachev is a former Soviet statesman, having served as General Secretary of the Communist Party of the Soviet Union from 1985 until 1991, and as the last head of state of the USSR, having served from 1988 until its dissolution in 1991...
in 1988.
TOPAZ-II
In the TOPAZ-II or ENISY reactor each fuel pin (96% enriched UO2Uranium dioxide
Uranium dioxide or uranium oxide , also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used...
) is sheathed in an emitter which is in turn surrounded by a collector, and these form the 37 fuel elements which penetrate the cylindrical zirconium hydride
Zirconium(II) hydride
Zirconium hydride is a chemical compound, a hydride of zirconium. The commercial form is usually a flammable, gray-black powder.It is used in powder metallurgy, as a hydrogenation catalyst, and as a reducing agent, vacuum tube getter, and a foaming agent in production of metal foams...
(ZrH) moderator. This in turn is surrounded by a beryllium
Beryllium
Beryllium is the chemical element with the symbol Be and atomic number 4. It is a divalent element which occurs naturally only in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl and chrysoberyl...
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...
with 12 rotating control drums. Liquid metal coolant (NaK
NaK
NaK, or sodium-potassium alloy, an alloy, of potassium , and sodium , is usually liquid at room temperature. Various commercial grades are available. NaK is highly reactive with water and may catch fire when exposed to air, so must be handled with special precautions...
) surrounds each fuel element. The mass of the reactor is ~ 1061 kg (2,339.1 lb).
In January 1991 a model of the TOPAZ-II was exhibited at a scientific symposium in Albuquerque, generating interest in the US in the possible purchase of it and the Strategic Defense Initiative Organization
Strategic Defense Initiative
The Strategic Defense Initiative was proposed by U.S. President Ronald Reagan on March 23, 1983 to use ground and space-based systems to protect the United States from attack by strategic nuclear ballistic missiles. The initiative focused on strategic defense rather than the prior strategic...
arranged to buy two Topaz-2 reactors from Russia for a total of $13 million, planning to use the reactors to improve US models. However, the Nuclear Regulatory Commission
Nuclear Regulatory Commission
The Nuclear Regulatory Commission is an independent agency of the United States government that was established by the Energy Reorganization Act of 1974 from the United States Atomic Energy Commission, and was first opened January 19, 1975...
ruled that US law prohibited the "export" of such a device to the Soviet Union - even though it was Soviet-made and only a model rather than an actual reactor. It took a month before the situation was resolved by a new NRC ruling and the model returned to Russia.
The United States Department of State
United States Department of State
The United States Department of State , is the United States federal executive department responsible for international relations of the United States, equivalent to the foreign ministries of other countries...
then put a hold on the deal, which was only lifted when Secretary of State
United States Secretary of State
The United States Secretary of State is the head of the United States Department of State, concerned with foreign affairs. The Secretary is a member of the Cabinet and the highest-ranking cabinet secretary both in line of succession and order of precedence...
James Baker
James Baker
James Addison Baker, III is an American attorney, politician and political advisor.Baker served as the Chief of Staff in President Ronald Reagan's first administration and in the final year of the administration of President George H. W. Bush...
intervened. One of the reactors was to be used in a flight test in 1995 to power experimental electrical thrusters, but there were objections from scientists concerned about the possible impact of radiation emitted by the reactor on instruments aboard space satellites and protests from opponents of space-based weapons and nuclear power. In addition, the Department of Energy
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...
was slow to grant the necessary approval and in 1993 budget restrictions forced the cancellation of the program.
Six TOPAZ-II reactors and their associated support equipment were flown to the US, where they were extensively ground tested by US, British, French, and Russian engineers. The reactors' unique design allowed them to be tested without being fuelled. Although the test program was considered a success, no plans were pursued to fly any of the reactors.