Graphite-moderated reactor
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- "Graphite reactor" directs here. For the graphite reactor at Oak Ridge National Laboratory, see X-10 Graphite Reactor.
A graphite-moderated reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows natural uranium to be used as nuclear fuel.
The first artificial nuclear reactor, the Chicago Pile-1, used nuclear graphite as a moderator. Graphite-moderated reactors were involved in two of the best-known nuclear disasters: an untested graphite annealing process contributed to the Windscale fire (but the graphite itself did not catch fire), while a graphite fire during the Chernobyl disaster contributed to the spread of radioactive material.
Types
Several types of
- Gas-cooled reactors
- Magnox
- UNGG reactor
- Advanced gas-cooled reactor(AGR)
- Water-cooled reactors
- RBMK
- MKER
- EGP-6
- Hanford N-Reactor (dual use)
- High-temperature gas-cooled reactors (past)
- Dragon reactor
- AVR
- Peach Bottom Nuclear Generating Station, Unit 1
- THTR-300
- Fort St. Vrain Generating Station
- High temperature gas-cooled reactors (in development or construction)
- Pebble-bed reactor
- Very high temperature reactor
- Prismatic fuel reactor
- UHTREX Ultra-high-temperature reactor experiment
- Other
- Molten salt reactor
Research reactors
There have been a number of research or test reactors built that use graphite as the moderator.
- Chicago Pile-1
- Chicago Pile-2
- Transient Reactor Test Facility (TREAT)
- Molten Salt Reactor Experiment(MSRE)
History
The first artificial nuclear reactor,
Accidents
There have been several major
In the Windscale fire, an untested annealing process for the graphite was used, and that contributed to the accident – however it was the uranium fuel rather than the graphite in the reactor that caught fire. The only graphite moderator damage was found to be localized around burning fuel elements.[1][2]
In the Chernobyl disaster, the graphite was a contributing factor to the cause of the accident. Due to overheating from lack of adequate cooling, the fuel rods began to deteriorate. After the
In addition, the French Saint-Laurent Nuclear Power Plant and the Spanish Vandellòs Nuclear Power Plant – both UNGG graphite-moderated natural uranium reactors – suffered major accidents. Particularly noteworthy is a partial core meltdown on 17 October 1969 and a heat excursion during graphite annealing on 13 March 1980 in Saint-Laurent, which were both classified as INES 4. The Vandellòs NPP was damaged on 19 October 1989, and a repair was considered uneconomical.
References
- ^ "Meeting of RG2 with Windscale Pile 1 Decommissioning Project Team" (PDF). Nuclear Safety Advisory Committee. 2005-09-29. NuSAC(2005)P 18. Archived from the original (PDF) on 2020-10-19. Retrieved 2008-11-26.
- AEA Technology. IAEA. IAEA-TECDOC—1043. Retrieved 13 November 2010.
- ^ "Frequently Asked Chernobyl Questions". International Atomic Energy Agency – Division of Public Information. May 2005. Archived from the original on 23 February 2011. Retrieved 23 March 2011.