In the 1950s

1950s

The 1950s or The Fifties was the decade that began on January 1, 1950 and ended on December 31, 1959. The decade was the sixth decade of the 20th century...

, Dr. Rudolf Schulten

- professor at RWTH Aachen University - was the originator of the pebble bed reactor

Pebble bed reactor

The pebble bed reactor is a graphite-moderated, gas-cooled, nuclear reactor. It is a type of very high temperature reactor , one of the six classes of nuclear reactors in the Generation IV initiative...

 design, which compacts silicon carbide-coated uranium granules into hard, billiard-ball-like spheres to be used as fuel for a new high temperature, helium-cooled type of nuclear reactor

Nuclear reactor

A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

. The idea took root and in due course a 46 MW_th (megawatt thermal) experimental pebble bed reactor (the Arbeitsgemeinschaft Versuchsreaktor, or AVR) was built at the Jülich Research Centre

Jülich Research Centre

Forschungszentrum Jülich GmbH is a member of the Helmholtz Association of German Research Centres and is one of the largest interdisciplinary research centres in Europe...

 in Jülich

Jülich

Jülich is a town in the district of Düren, in the federal state of North Rhine-Westphalia, Germany. Jülich is well known as location of a world-famous research centre, the Forschungszentrum Jülich and as shortwave transmission site of Deutsche Welle...

, West Germany

West Germany

West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....

. It operated successfully for 21 years but was shut down because the pebble fuel testing program came to a halt. Some of the last pebble fuel tested in the AVR was for a low enriched uranium (LEU) fuel cycle anticipated for use in the HTR-MODUL design by Interatom/SIEMENS.

The technology is currently being developed in South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

, the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

, and China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

who currently operate a demonstration reactor of this type.