The BM-40A reactor is the nuclear fission reactor used to power four of the seven boats of the Soviet Navy's Project 705 Лира (Lira or Alfa in NATO designation) fourth generation submarines. It is a liquid metal cooled reactor (LMR), using highly enriched uranium-235 fuel to produce 155 MWt of power.
BM-40A has two steam circulation loops.
- Project 705 Lira Alfa class at the Federation of American Scientists website.
- Lead-bismuth cooled reactor plants for nuclear submarines at the Gidropress website.