DESCRIPTION OF THE BUDAPEST RESEARCH REACTOR

The research reactor in Budapest was first put into operation in 1959. A full scale reconstruction and upgrading project started in 1986, aiming at the substitution of aged components, the enhancement of reactor safety, and the increase of reactor power to 10 MW. Regular operation was resumed on 25 November 1993.

The reactor serves for basic and applied research (condensed matter, radiochemistry, biological irradiation, and reactor technology), technological and commercial applications (production of radioisotopes, neutron radiography, activation analysis, and pressure vessel surveillance), education and training: (undergraduates, PhD students, IAEA training courses, etc.).

The Budapest Research Reactor is a tank type reactor, moderated and cooled by light water. The fuel of the research reactor is made of an alloy of aluminium and uranium-aluminium eutectic with aluminium cladding. Fuel enrichment is 36 %, the fuel elements are hexagonal. The equilibrium core consists of 229 fuel elements, with a lattice pitch of 35 mm. The core is surrounded radially by a solid beryllium reflector.

Some technical data:

• thermal power:   10 MW
• approx. max. thermal flux density: 2.2 × 10¹⁴ n/cm²s
• approx. max. fast flux density:        1.0 × 10¹⁴ n/cm²s

The reactor has 10 horizontal beam tubes (8 radial and 2 tangential). At one of the horizontal beam tubes a cold neutron source (CNS) is installed. Three neutron guides lead the cold neutrons into the guide hall, adjacent to the reactor hall, where the experiments can be carried out. The neutron guides can also be used to provide thermal neutrons when the cooling system is not switched on.

At the other horizontal channels fast and/or thermal neutron beams are available for experiments. Special filtering systems are built in to enhance the required energy range.

Irradiation may also be carried out by inserting samples into the 51 special vertical channels. In one of these channels a pneumatic rabbit system is operated, serving for neutron activation analysis.

Dosimetry and flux measurements are carried out routinely in addition to beam monitoring.

The reactor is operated in cycles of different continuous periods of 114, 270 and 450 hours.