Energy Multiplier Module
Encyclopedia
The Energy Multiplier Module (EM2) is a nuclear fission
power reactor under development by General Atomics
. It is a modified version of the Gas Turbine Modular Helium Reactor
(GT-MHR) and is capable of converting spent nuclear fuel
into electricity and industrial process heat, without separative or conventional nuclear reprocessing
.
, which uses helium
as a coolant. The reactor uses a composite of silicon carbide
as cladding material and beryllium
oxide as neutron reflector
material. The reactor unit is coupled to a high efficiency helium gas turbine
which in turn drives a generator for the production of electricity.
The nuclear core design is based upon a new conversion technique in which an initial “starter” section of the core provides the neutrons required to convert used nuclear fuel or depleted uranium
(DU) into burnable fissile
fuel. First generation EM2 units use uranium starters (approximately 15 percent U235) to initiate the conversion process. The starter U235 is consumed as the used nuclear fuel/DU is converted to fissile fuel. The core life expectancy is approximately 30 years (using used nuclear fuel and DU) without refueling.
Substantial amounts of valuable fissile material remain in the EM2 core. This material is reused as the starter for a second generation of EM2s, without conventional reprocessing. There is no separation of individual heavy metals required and no enriched uranium
needed. Only unusable fission products would be removed and stored.
All EM2 heavy metal discharges could be recycled into new EM2 units, effectively closing the nuclear fuel cycle
, which minimizes nuclear proliferation
risks and the need for long-term repositories to secure nuclear materials.
Unlike light water reactors, the EM2 is gas cooled and does not need to be sited near a water source for cooling.
Each module can be manufactured in either U.S. domestic or foreign facilities using replacement parts manufacturing and supply chain management with large components shipped by commercial truck or rail to a site for final assembly, where it will be fully enclosed in an underground containment structure.
, also referred to as “spent fuel” from light water reactors.
Spent fuel rods from conventional nuclear reactors are put into storage and considered to be nuclear waste, by the nuclear industry and the general public. Nuclear waste retains more than 95% of its original energy; the current U.S. inventory is equivalent to nine trillion barrels of oil - four times more than the known reserves. EM2 uses this nuclear waste to produce energy.
Conventional light water reactors require refueling every 18 months. EM2’s 30-year fuel cycle minimizes the need for fueling handling and can reduce the proliferation concerns associated with refueling.
The EM2’s high-operating temperature can provide process heat for petrochemical
fuel products and alternative fuels, such as biofuels and hydrogen
.
Nuclear fission
In 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...
power reactor under development by General Atomics
General Atomics
General Atomics is a nuclear physics and defense contractor headquartered in San Diego, California. General Atomics’ research into fission and fusion matured into competencies in related technologies, allowing the company to expand into other fields of research...
. It is a modified version of the Gas Turbine Modular Helium Reactor
Gas turbine modular helium reactor
The Gas Turbine Modular Helium Reactor is a nuclear fission power reactor design under development by General Atomics. It is a helium cooled, graphite moderated reactor and uses TRISO fuel compacts in a prismatic core design.-Construction:...
(GT-MHR) and is capable of converting spent nuclear fuel
Spent nuclear fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor...
into electricity and industrial process heat, without separative or conventional nuclear reprocessing
Nuclear reprocessing
Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing...
.
Design specifications
The EM2 is small modular reactor expected to produce 240 MWe (500 MWth) of power at 850 °C and be fully enclosed in an underground containment structure. The EM2 is a gas-cooled fast reactorGas-cooled fast reactor
The Gas-Cooled Fast Reactor system is a nuclear reactor design which is currently in development. Classed as a Generation IV reactor, it features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides...
, which uses helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
as a coolant. The reactor uses a composite of silicon carbide
Silicon carbide
Silicon carbide , also known as carborundum, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been mass-produced since 1893 for use as an abrasive...
as cladding material and 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...
oxide as 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...
material. The reactor unit is coupled to a high efficiency helium gas turbine
Gas turbine
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....
which in turn drives a generator for the production of electricity.
The nuclear core design is based upon a new conversion technique in which an initial “starter” section of the core provides the neutrons required to convert used nuclear fuel or depleted uranium
Depleted uranium
Depleted uranium is uranium with a lower content of the fissile isotope U-235 than natural uranium . Uses of DU take advantage of its very high density of 19.1 g/cm3...
(DU) into burnable fissile
Fissile
In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission. By definition, fissile materials can sustain a chain reaction with neutrons of any energy. The predominant neutron energy may be typified by either slow neutrons or fast neutrons...
fuel. First generation EM2 units use uranium starters (approximately 15 percent U235) to initiate the conversion process. The starter U235 is consumed as the used nuclear fuel/DU is converted to fissile fuel. The core life expectancy is approximately 30 years (using used nuclear fuel and DU) without refueling.
Substantial amounts of valuable fissile material remain in the EM2 core. This material is reused as the starter for a second generation of EM2s, without conventional reprocessing. There is no separation of individual heavy metals required and no enriched uranium
Enriched uranium
Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight...
needed. Only unusable fission products would be removed and stored.
All EM2 heavy metal discharges could be recycled into new EM2 units, effectively closing the nuclear fuel cycle
Nuclear fuel cycle
The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in...
, which minimizes nuclear proliferation
Nuclear proliferation
Nuclear proliferation is a term now used to describe the spread of nuclear weapons, fissile material, and weapons-applicable nuclear technology and information, to nations which are not recognized as "Nuclear Weapon States" by the Treaty on the Nonproliferation of Nuclear Weapons, also known as the...
risks and the need for long-term repositories to secure nuclear materials.
Economics and workforce capacity
The expected cost advantages of EM2 lie in its simplified power conversion system, which operates at high temperatures yielding approximately 50 percent greater efficiency and a corresponding one-third reduction in materials requirements than that of current nuclear reactors.Unlike light water reactors, the EM2 is gas cooled and does not need to be sited near a water source for cooling.
Each module can be manufactured in either U.S. domestic or foreign facilities using replacement parts manufacturing and supply chain management with large components shipped by commercial truck or rail to a site for final assembly, where it will be fully enclosed in an underground containment structure.
Nuclear waste
The EM2 utilizes used nuclear fuelNuclear fuel
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available...
, also referred to as “spent fuel” from light water reactors.
Spent fuel rods from conventional nuclear reactors are put into storage and considered to be nuclear waste, by the nuclear industry and the general public. Nuclear waste retains more than 95% of its original energy; the current U.S. inventory is equivalent to nine trillion barrels of oil - four times more than the known reserves. EM2 uses this nuclear waste to produce energy.
Non-proliferation
By using spent nuclear waste and depleted uranium stockpiles as its fuel source, a large-scale deployment of the EM2 is expected to reduce the long-term need for uranium enrichment and eliminate conventional nuclear reprocessing.Conventional light water reactors require refueling every 18 months. EM2’s 30-year fuel cycle minimizes the need for fueling handling and can reduce the proliferation concerns associated with refueling.
Energy safety and security
EM2 technology is designed to be inherently safe and to automatically shut down using the natural laws of physics.The EM2’s high-operating temperature can provide process heat for petrochemical
Petrochemical
Petrochemicals are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as corn or sugar cane....
fuel products and alternative fuels, such as biofuels and hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
.
See also
- American Association for the Advancement of ScienceAmerican Association for the Advancement of ScienceThe American Association for the Advancement of Science is an international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsibility, and supporting scientific education and science outreach for the...
- Nuclear Energy InstituteNuclear Energy InstituteThe Nuclear Energy Institute is a nuclear industry lobbying group in the United States.- Synopsis :According to its website, the NEI "develops policy on key legislative and regulatory issues affecting the industry. NEI then serves as a unified industry voice before the U.S...
- 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 safety in the United StatesNuclear safety in the United StatesNuclear safety in the U.S. is governed by federal regulations and continues to be studied by the Nuclear Regulatory Commission . The safety of nuclear plants and materials controlled by the U.S...
- Economics of new nuclear power plantsEconomics of new nuclear power plantsThe economics of new nuclear power plants is a controversial subject, since there are diverging views on this topic, and multi-billion dollar investments ride on the choice of an energy source...
- United States Department of EnergyUnited States Department of EnergyThe 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...