The Gas Turbine Modular Helium Reactor (GT-MHR) is a class of nuclear fission power reactor designed that was under development by a group of Russian enterprises (

OKBM Afrikantov OKBM Afrikantov (full name: OAO I. I. Afrikantov OKB Mechanical Engineering, russian: Опытное конструкторское бюро машиностроения им. И. И. Африкантова) is a nuclear engineering com ...

Kurchatov Institute The Kurchatov Institute (russian: Национальный исследовательский центр «Курчатовский Институт», 'National Research Centre "Kurchatov Institute) is Russia's leading research and developmen ...

, VNIINM and others), an American group headed by

General Atomics General Atomics is an American energy and defense corporation headquartered in San Diego, California, specializing in research and technology development. This includes physics research in support of nuclear fission and nuclear fusion energy. Th ...

, French

Framatome Framatome () is a French nuclear reactor business. It is owned by Électricité de France (EDF) (75.5%), Mitsubishi Heavy Industries (19.5%), and Assystem (5%). The company first formed in 1958 to license Westinghouse's pressurized water react ...

and Japanese

Fuji Electric , operating under the brand name FE, is a Japanese electrical equipment company, manufacturing pressure transmitters, flowmeters, gas analyzers, controllers, inverters, pumps, generators, ICs, motors, and power equipment. History Fuji Electric ...

. It is a

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

cooled,

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on lar ...

moderated Moderation is the process of eliminating or lessening extremes. It is used to ensure normality throughout the medium on which it is being conducted. Common uses of moderation include: *Ensuring consistency and accuracy in the marking of stud ...

reactor and uses

TRISO Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoin ...

fuel compacts in a prismatic

core Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...

design. The power is generated via a gas turbine rather than via the more common steam turbine. A conceptual design was produced by 1997, and it was hoped to have a final design by 2005, and a prototype plant commissioning by 2010.

Construction

The core consists of a graphite cylinder with a radius of and a height of which includes axial reflectors at top and bottom. The cylinder allocates three or four concentric rings, each of 36 hexagonal blocks with an interstitial gap of . Each hexagonal block contains 108 helium coolant channels and 216 fuel pins. Each fuel pin contains a random lattice of TRISO particles dispersed into a graphite matrix. The reactor exhibits a

thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

spectrum with a peak neutron energy located at about 0.2 eV. The

fuel concept allows the reactor to be inherently safe. The reactor and containment structure is located below grade and in contact with the ground, which serves as a passive safety measure to conduct heat away from the reactor in the event of a coolant failure.

Advantages

The Gas Turbine Modular Helium Reactor utilizes the

Brayton cycle The Brayton cycle is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. The original Brayton engines used a piston compressor and piston expander, but modern gas tu ...

turbine arrangement, which gives it an efficiency of up to 48% – higher than any other reactor, as of 1995. Commercial

light water reactors The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron reac ...

(LWRs) generally use the

Rankine cycle The Rankine cycle is an idealized thermodynamic cycle describing the process by which certain heat engines, such as steam turbines or reciprocating steam engines, allow mechanical work to be extracted from a fluid as it moves between a heat sourc ...

, which is what coal-fired power plants use. Commercial LWRs average 32% efficiency, again as of 1995.

Legacy

Energy Multiplier Module (EM2)

In 2010 General Atomics conceptualized a new reactor that utilizes the power conversion features of the GT-MHR, the Energy Multiplier Module (EM2). The EM2 uses

fast neutrons The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with ...

and is a

gas-cooled fast reactor The gas-cooled fast reactor (GFR) 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 ...

, enabling it to reduce

nuclear waste Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapons ...

considerably by transmutation.

References

External links