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Encyclopedia > Gas cooled fast reactor

The Gas-Cooled Fast Reactor (GFR) system is a Generation IV reactor that features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides. The reactor is a, helium-cooled system operating with an outlet temperature of 850°C using a direct Brayton cycle gas turbine for high thermal efficiency. Several fuel forms are being considered for their potential to operate at very high temperatures and to ensure an excellent retention of fission products: composite ceramic fuel, advanced fuel particles, or ceramic clad elements of actinide compounds. Core configurations are being considered based on pin- or plate-based fuel assemblies or prismatic blocks. Generation IV reactors (Gen IV) are a set of theoretical nuclear reactor designs currently being researched. ... The nuclear fuel cycle consists of front end steps that lead to the preparation of uranium for use as fuel for reactor operation and back end steps that are necessary to safely manage, prepare, and dispose of radioactive waste. ... Fertile material is a term used to describe nuclides which generally themselves do not undergo induced fission (fissionable by thermal neutrons) but from which fissile material is generated by neutron absorption and subsequent nuclei conversions. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... The Brayton cycle is a cyclic process generally associated with the gas turbine. ... This machine has a single-stage radial compressor and turbine, a recuperator, and foil bearings. ... In general fission is a splitting or breaking up into parts. ... The word ceramic is derived from the Greek word Κεραμεικος (the name of a suburb of Athens), and in its strictest sense refers to clay in all its forms. ...

Contents


Nuclear reactor design

The GFR base design is generally similar to those of a standard high temperature gas-cooled reactor (HTGR). It generally differs from standard HTGR designs in that the core has a higher fissile fuel content as well as a non-fissile, fertile, breeding component. Due to the higher fissile fuel content, the design has a higher power density than the traditional HTGR base design.


Research History

Past pilot and demonstration projects include decommissioned reactors such as the Dragon Project, built and operated in the United Kingdom, the AVR and the THTR, built and operated in Germany, and Peach Bottom and Fort St Vrain, built and operated in the United States. Ongoing demonstrations include the HTTR in Japan, which reached full power (30 MWth) using fuel compacts in 1999, and the HTR-10 in China, which may reach 10 MWth in 2002 using pebble fuel. A 300 MWth pebble bed modular demonstration plant is being designed by PBMR Pty for deployment in South Africa, and a consortium of Russian institutes is designing a 300 MWth GT-MHR in cooperation with General Atomics. Check [AVR] ... Peach Bottom Township is a township located in York County, Pennsylvania. ... 1999 (MCMXCIX) is a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ... General Atomics is a nuclear physics and defense contractor in southern California. ...


The main challenges that have yet to be overcome are in-vessel structural materials, both in-core and out-of-core, that will have to withstand fast-neutron damage and high temperatures, (up to 1600°C) and low thermal inertia and poor heat removal capability at low helium pressures.


References

1: THE GAS-COOLED FAST REACTOR SYSTEM


2: Flexibility of the Gas Cooled Fast Reactor to Meet the Requirements of the 21st Century


3: INL GFR summary


See also

Generation IV reactors (Gen IV) are a set of theoretical nuclear reactor designs currently being researched. ... The Pebble Bed Reactor is an advanced nuclear reactor design. ...

External links

  • IAEA Fast Reactors and Accelerator Driven Systems Knowledge Base
  • INL GFR workshop summary

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THTR-300 - Wikipedia, the free encyclopedia (663 words)
The THTR-300 served as a prototype for high-temperature reactors (HTR) and was the first to use a pebble bed design and TRISO fuel.
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A prototype fast reactor, Monju (280 MW), was completed in 1995, but an incident at the plant in December of that year drained public and regulatory confidence in the plant and it is highly unlikely the plant will run again.
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