Latin transcription of a Russian reactor type designation:

(reaktor balschoi moschnosti kanalnui, (reactor of high power of the channel type). RBMK (aka LWGR, Light-Water-Cooled, Graphite-Moderated Reactor) is a graphite-moderated boiling water pressure tube reactor in which the steam is not generated in a pressure vessel, but in up to 2 000 separate pressure tubes containing the fuel elements. The use of graphite as a moderator leads to a large-volume reactor core of 12 m diameter and 7 m height. Consequently, the control of the reactor is relatively complicated from the neutron physical point of view and imposes increased requirements on the mode of operation concerning the control rods. In Russia eleven RBMK units with 1 000 MWe each and four with 12 MWe each are in operation.

Nuclear power plant with RBMK