First fast nuclear reactor BR-1

Fast nuclear reactors allow for extended nuclear fuel reproduction by converting uranium-238 to plutonium-239. The pioneer and first Research Director of the work on fast nuclear reactors was academician A. I. Leyipunsky.

In 1955, the country's first experimental fast nuclear reactor, BR-1 (a zero-power reactor based on metallic plutonium), was launched. During the next year, the second experimental BR-2 reactor (100 kW of thermal power, using metallic plutonium, mercury-cooled) has been launched. These reactors became the main base for further research.

A year later, the BR–2 reactor was dismantled, and experimental BR–5 reactor was created in its place in the shortest possible time. In June 1959, the BR-5 reactor was brought to its design capacity of 5 MW. Operation of this reactor, which was the first to use a liquid sodium coolant, offered a unique experience in the technology of radioactive sodium, reactor physics, and the durability of structural and fuel materials subsequently used in the development of a number of installations – the experimental BOR–60 reactor and the BN–350 and BN–600 power reactors.

The BR-1 reactor has a compact reactor core with a height and diameter of 13 cm, made up of plutonium rods canned with stainless steel. The critical load of the reactor is about 12 kg; the maximum power is 100 W. Uranium, thorium, copper, nickel, iron, and other materials were used as materials for replacement screens in the reactor. Raising the output of the reactor and maintaining of the operational mode can be carried out either manually or automatically.

Scientists performed a wide range of fundamental and applied works at the BR–1 reactor:

gained the very first experimental prove of the possibility of extended reproduction of nuclear fuel;

in 1956 a chain reaction of plutonium fission on fast neutrons was carried out for the first time in Europe;

studied neutron propagation in media of various materials, and measured nuclear-physical constants;

developed methods of experimental research of neutron physical characteristics of power reactors;

studied various models of units and systems of designed reactor installations.

Currently, this reactor is used as a source of neutrons and gamma rays of variable intensity for metrological certification and verification of the performance of measuring instruments.

The experimental BR-1 reactor was launched in the laboratory "B" under the direction of A. I. Leypunsky.

Academician of the Academy of Sciences of the Ukrainian SSR Aleksandr Ilyich Leypunsky was an outstanding scientist and research organizer, the originator of the creation and construction of fast nuclear reactors in our country.

A. I. Leypunsky rightfully gained one of the leading places among the scientists due to whom the problem of nuclear breeding for the world energy sector was solved, and our country became the leader in this area of industry. The development of nuclear power engineering on the basis of the use of the existing reserves of uranium and thorium in advanced fast reactors was the main goal that A. I. Leypunsky devoted his life to.