New Czech research reactor commissioned

06 June 2023

The VR-2 research reactor, construction of which began last year, has entered operation at the Faculty of Nuclear Sciences and Physical Engineering (FNSPE) at the Czech Technical University (CTU) in Prague. The reactor will mainly be used for teaching nuclear engineering students.

The VR-2 research reactor (Image: CTU)

FNSPE launched the VR-2 project in 2014. It received a siting permit for the reactor in 2020 and obtained permission in March 2022 from the State Office for Nuclear Safety (SÚJB) to build the reactor.

"Its construction was facilitated by situating the VR-2 reactor in the same reactor hall as the VR-1 - the hall as such already complying with the placement regulations for VR-1 and still offering enough space for both," CTU said. The VR-1 lightwater, zero-power research reactor with enriched uranium has been in operation since 1990.

The VR-2 is subcritical, which means that there will be insufficient fuel in it to sustain a fission chain reaction. Its operation can only be achieved with an external neutron source. Once the source is switched off, fission stops. This allows for simpler reactor design and construction. It is based on a pool arrangement of the reactor vessel, in which there is an internal installation with fuel rods forming the active zone. The moderator is demineralised water.

The vessel of the VR-2 (Image: CTU)

The cylindrical stainless steel reactor vessel has a diameter of 1.3 metres, a height of 1.7 metres and a wall thickness of 8mm and a bottom of 10mm. The vessel has two symmetrical holes with a diameter of 128 mm for the installation of aluminum radial channels. One channel will be permanently part of the reactor vessel and will serve to house a type-DD neutron source to control the reactor. The second channel will be for experimental purposes.

The core contains a combination of enriched and natural uranium fuel in the form of fuel rods. In the case of enriched fuel, it is UO2 with 10% enrichment of U235, natural uranium is in the form of uranium metal. The faculty already has fuel for the new reactor. It arrived in Prague in June 2018 from Aalto University in Finland.

The VR-2 will offer a range of experimental and training opportunities. The main part of the activities will consist of teaching nuclear engineering students. The equipment will be used in the teaching of laboratory tasks. It will also be used for experiments in student bachelor's, master's and doctoral theses. In addition to teaching activities, it will also be used to carry out research experiments.

Excluding the cost of fuel and the time of the department's staff, the estimated cost of constructing VR-2 is about CZK8 million (USD360,000), of which CZK6.6 million will be financed by the Ministry of Education, Youth and Sports.

"With the new VR-2 fission reactor teaching and research activities will be easier to schedule, because with the VR-1 we have been facing capacity limits," said FNSPE Dean Václav Čuba. "VR-1 serves not only students from our home Faculty but also students from other faculties at CTU and other universities. It is open to train foreign students and even staff from industry".

"Launching VR-2 proves to be the climax of the process we started in 2014," added Jan Rataj, head of the Department of Nuclear Reactors. "The actual construction was very quick and took approximately one year due to the small size of the facility, which cannot even compare with the VR-1. And yet, it is still a nuclear facility subject to various regulations that must be complied with."

CTU noted that the VR-2 reactor becomes the tenth nuclear reactor currently in operation in the Czech Republic. In addition to the VR-1 and VR-2 training reactors, the Research Centre in Řež operates two research reactors, and six reactors are in operation at ČEZ's Dukovany and Temelín nuclear power plants.

"We can say that a nuclear renaissance is dawning in the world because more and more people are becoming aware that without nuclear energy mankind cannot generate enough clean energy, and this also implies that we need qualified experts," said CTU Rector Vojtěch Petráček. "It is their training and education the VR-2 will serve before all."

Researched and written by World Nuclear News