Rudolf Schulten (16 August 1923 – 27 April 1996)—professor at

RWTH Aachen University RWTH Aachen University (), also known as North Rhine-Westphalia Technical University of Aachen, Rhine-Westphalia Technical University of Aachen, Technical University of Aachen, University of Aachen, or ''Rheinisch-Westfälische Technische Hoch ...

—was the main developer of the

pebble bed reactor The pebble-bed reactor (PBR) is a design for a graphite-moderated, gas-cooled nuclear reactor. It is a type of very-high-temperature reactor (VHTR), one of the six classes of nuclear reactors in the Generation IV initiative. The basic desig ...

design, which was originally invented by

Farrington Daniels Farrington Daniels (March 8, 1889 – June 23, 1972) was an American physical chemist who is considered one of the pioneers of the modern direct use of solar energy. Biography Daniels was born in Minneapolis, Minnesota on March 8, 1889. Dani ...

. Schulten's concept compacts silicon carbide-coated uranium granules into hard, billiard-ball-like graphite spheres to be used as fuel for a new high temperature, helium-cooled type of

nuclear reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nu ...

AVR reactor

The idea took root and in due course a 46 MWth (megawatt thermal) experimental pebble bed reactor (the Arbeitsgemeinschaft Versuchsreaktor, or

AVR reactor The AVR reactor (german: Arbeitsgemeinschaft Versuchsreaktor) was a prototype pebble-bed reactor, located immediately adjacent to Jülich Research Centre in West Germany, constructed in 1960, grid connected in 1967 and shut down in 1988. It was ...

) was built at the

Jülich Research Centre Jülich (; in old spellings also known as ''Guelich'' or ''Gülich'', nl, Gulik, french: Juliers, Ripuarian: ''Jöllesch'') is a town in the district of Düren, in the federal state of North Rhine-Westphalia, Germany. As a border region betwe ...

Jülich Jülich (; in old spellings also known as ''Guelich'' or ''Gülich'', nl, Gulik, french: Juliers, Ripuarian: ''Jöllesch'') is a town in the district of Düren, in the federal state of North Rhine-Westphalia, Germany. As a border region betwe ...

West Germany West Germany is the colloquial term used to indicate the Federal Republic of Germany (FRG; german: Bundesrepublik Deutschland , BRD) between its formation on 23 May 1949 and the German reunification through the accession of East Germany on 3 O ...

. It operated for 21 years but was shut down in the wake of

Chernobyl Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about no ...

HTR-MODUL project

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 project design by Interatom/

SIEMENS Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...

South African Pebble Bed Modular Reactor

Based on the AVR, South Africa along with international partners developed an updated version called the

PBMR The Pebble Bed Modular Reactor (PBMR) is a particular design of pebble bed reactor developed by South African company PBMR (Pty) Ltd from 1994 until 2009. PBMR facilities include gas turbine and heat transfer labs at the Potchefstroom Campus of ...

. The

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 undergoing ...

fuel elements could use either Thorium or U-235 in the form of LEU as fuel. The project was cancelled in 2010 due to lack of investment, even though the technology has essentially been completely developed.

HTR-10 China, HTR-PM

The technology is currently being developed mainly in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

who currently operate a 10 MW test reactor (

HTR-10 HTR-10 is a 10 MWt prototype pebble bed reactor at Tsinghua University in China. Construction began in 1995, achieving its first criticality in December 2000, and was operated in full power condition in January 2003. Two HTR-PM reactors, scale ...

) of this type. The Chinese are, as of 2015, building a commercial pebble-bed reactor:

HTR-PM The HTR-PM (球床模块式高温气冷堆核电站) is a small modular nuclear reactor in China. It is the world’s first prototype of a high-temperature gas-cooled (HTGR) pebble-bed generation IV reactor. The reactor unit has a thermal capac ...

, with two 100MWe reactors.''China's HTR-PM reactor achieves first criticality'' Sept 2021
/ref> One achieved a sustained chain reaction (criticality) in Sept 2021.

References

* Kirchner, Ulrich: ''Der Hochtemperaturreaktor - Konflikte, Interessen, Entscheidungen'', Campus Verlag, Frankfurt/New York, Campus Forschung Vol. 667, 1991. Werner von Siemens Ring laureates RWTH Aachen University faculty Commanders Crosses of the Order of Merit of the Federal Republic of Germany 1920 births 1996 deaths Karlsruhe Institute of Technology faculty {{physicist-stub