Academic fission reactor VR-1 has served at the Faculty of Nuclear Sciences and Physical Engineering CTU in Prague for 30 years

For 30 years, the academic fission reactor VR-1 has served students from the Czech Republic and abroad, but it is also used for research activities. The reactor is operated by the Department of Nuclear Reactors of the Faculty of Nuclear Science and Physical Engineering (FNSPE) of the Czech Technical University in Prague. The VR-1 reactor reached the so-called first critical state on December 3, 1990 at 4:25 p.m. However, preparations for its construction began in 1982.

ČVUT FJFI reaktor VR 1 Vrabec vystavba"The Czech Technical University in Prague is one of the few universities in the world that has both types of nuclear reactors available for teaching and scientific activities - fission and fusion. The importance and use of the VR-1 fission reactor is demonstrated by the fact that it will get a little brother - the construction of the second academic fission reactor, called VR-2, is already being prepared in the reactor hall. The demand for educational and research activities exceeds the capacity of one reactor," explains doc. Vojtěch Petráček, Rector of CTU.

"The FNSPE has been trying to build its own academic reactor since its foundation in 1955. Preparation of the VR-1 “Vrabec” reactor construction project began in 1982 and the VR-1 “Vrabec” reactor reached its first critical state 30 years ago," explains prof. Igor Jex, Dean of FNSPE. In the Czech language, the reactor VR-1 has been given the nickname “Vrabec,” which means sparrow.

The VR-1 “Vrabec” reactor is a world-unique device that ranks the Czech Republic among the elite institutions in the field of nuclear energy. In addition, its power is very low - less than that of a conventional kettle. It is therefore not even necessary to cool the water in the reactor pool. Thanks to the low power and unique design of the reactor and its surroundings, the device is perfectly optimized for teaching and training. The design allows students to literally touch physics. "In addition to our students, nuclear power plant operators also use the opportunity to test the reactor's reactions to various conditions. There was also the crew from a nuclear submarine from Great Britain," says Jan Rataj, head of the KJR, about the benefits of the school reactor beyond university use.


VR-1 Vrabec reactor construction schedule

• 1981–84 - project preparation

• 1985–88 - construction activity (foundations, steel structure, electrical installation)

• 1988–89 - reactor components, control system, reactor vessels

• 1989–90 - inactive tests, gradual start-up of individual parts

• November to December 1990 - physical start-up of the reactor

• December 3, 1990 at 16.25 - reaching the first critical state

• 1991 - trial operation (experimental verification of parameters)

• 1992 - start of permanent operation

Despite producing zero power, similar safety measures apply to this reactor as to reactors in nuclear power plants. The process of building it, which took eight years, was similarly demanding.

Starting this year, the VR-1 reactor has been part of an international network of reactors that have been equipped with the Internet Reactor Laboratory system for distance learning in cooperation with the International Atomic Energy Agency. The IAEA helped with distance learning during anti-epidemic measures, when students could not go to the laboratories. The department also uses it for virtual presentations for high school students within the educational program called “The Sparrow Flies to Schools,” which it started in the autumn of 2020.

In addition to teaching and training at the reactor, it is also used for research, especially in the field of reactor and neutron physics, safety of nuclear facilities, and computational tools for the analysis of nuclear reactors. The department also deals with advanced nuclear reactors, nuclear fuel cycles and spent fuel. The reactor is used, for example, for non-destructive analysis of various elements – even Tibetan medicine and mammoth bones have been studied.

The exhibition that was launched in October 2020 at the Prague National Technical Museum (NTM) displays the history of the reactor, the use of the nuclear fission reaction, and examples of the use of the academic reactor. Unfortunately the exhibition is currently closed to visitors due to anti-epidemic measures. The panels and exhibits are located in the hall of the main staircase on the second floor of the NTM and the exhibition is planned to last until February 28, 2021.


Prague, December 1, 2020

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