TRIGA

Picture of a TRIGA reactor core. Notice the glow caused by Cherenkov radiation.

TRIGA is a class of small nuclear reactor designed and manufactured by General Atomics of the USA. TRIGA is an acronym of "Training, Research, Isotopes, General Atomics". The design team for TRIGA was led by the physicist Freeman Dyson.

Design

TRIGA is a pool-type reactor that can be installed without a containment building, and is designed for use by scientific institutions and universities for purposes such as undergraduate and graduate education, private commercial research, non-destructive testing and isotope production.

The TRIGA reactor uses uranium-zirconium-hydride (UZrH) fuel, which has a large, prompt negative thermal coefficient of reactivity, meaning that as the temperature of the core increases, the reactivity rapidly decreases — so it is highly unlikely, though not impossible for a meltdown to occur. TRIGA was originally designed to be fuelled with highly enriched uranium, but in 1978 the U.S. Department of Energy launched its Reduced Enrichment for Research Test Reactors program, which promoted reactor conversion to low-enriched uranium fuel.^[1]

History

The TRIGA was developed to be a reactor that, in the words of Frederic de Hoffmann, head of General Atomics, was designed to be "safe even in the hands of a young graduate student."^[2] Edward Teller headed a group of young nuclear physicists in San Diego in the summer of 1956 to design a reactor which could not, by its design, suffer from a meltdown. The design was largely the suggestion of Freeman Dyson. The prototype for the TRIGA nuclear reactor (TRIGA Mark I) was commissioned on 3 May 1958 in San Diego and operated until shut down in 1997. It has been designated as a nuclear historic landmark by the American Nuclear Society.

Mark II, Mark III and other variants of the TRIGA design have subsequently been produced, and a total of 35 TRIGA reactors have been installed at locations across the USA. A further 35 reactors have been installed in other countries. Many of these installations were prompted by US President Eisenhower's 1953 policy of "Atoms for Peace" which sought to extend access to nuclear physics to countries in the American sphere of influence. Consequently, TRIGA reactors can be found in such diverse locations as Colombia, Austria, Finland, Slovenia, Italy, Japan, Malaysia, Bangladesh, Congo, Brazil, Germany, Philippines, Puerto Rico, Vietnam, Mexico and Indonesia.

TRIGA International, a joint venture between General Atomics and CERCA — a subsidiary of AREVA of France — was established in 1996. Since then TRIGA fuel assemblies have been manufactured at CERCA's plant in Romans-sur-Isère, France.

As of 2008^[update], the U.S. Nuclear Regulatory Commission has licensed over 60 TRIGA-type reactors.^[3]

New TRIGA installations by General Atomics are underway in Morocco, Thailand and Romania.

Some of the main competitors to General Atomics in the supply of research reactors are Areva of Europe and INVAP of Argentina.

See also

• List of nuclear reactors

References

• Edward Teller, Memoirs: A Twentieth-Century Journey in Science and Politics (Cambridge, MA: Perseus Publishing, 2001).

Notes

1. ^ NA-25 Radiological Threat Reduction Program
2. ^ Teller, Memoirs, p. 423.
3. ^ "Interview with John Deal, Hyperion Power Generation". techrockies.com. September 22, 2008. http://www.techrockies.com/story/0017490.html. Retrieved 2009-05-22. 

External links

• General Atomics official TRIGA website
• TRIGA history webpage
• Technical Specifications