TOPAZ nuclear reactor

Cooled by liquid metal, it uses a high-temperature moderator containing hydrogen and highly enriched fuel and produces electricity using a thermionic converter.

Following the visit of Soviet scientists to LASL in 1958, they carried out tests on TI systems in 1961, initially developing the single cell ENISY reactor (also known as TOPAZ-II).

Work was carried out by the Kurchatov Institute of Atomic Energy and the Central Bureau for Machine Building to develop the multi-cell TOPAZ (also known as TOPAZ-I), a Russian acronym for "Thermionic Experiment with Conversion in Active Zone".

However, the Nuclear Regulatory Commission ruled that US law prohibited the "export" of such a device to the Soviet Union - even though it was Soviet-made and only a model rather than an actual reactor.

[5] Six TOPAZ-II reactors and their associated support equipment were flown to the US, where they were extensively ground tested by US, British, French, and Russian engineers.

[6] The TOPAZ reactor is manufactured by the State Research Institute, Scientific Industrial Association (also known as Luch), which is operated by Russia's Ministry of Atomic Energy.

Scaled-down model of Topaz reactor
TOPAZ-II TFE -scheme of the thermionic converter. The U 2 O nucleus is heated of 808K to 1923K. The heated shell of the Mo/W core emits electrons. The Mo/Nb electron collector absorbs electrons. Both are insulated from each other by a high-temperature-resistant insulating pad Sc 2 O 3 , which is anchored in the Nb ring. The gap is filled with Cs vapors. The collector is separated from casing by an Al 2 O 3 insulating pad. This gap is filled with Helium gas. The stainless steel double shell is sodium cooled. [ 2 ]