Apparatus for passively generating electric power during a nuclear power station blackout by utilizing the temperature difference between the hot inlet of a residual heat removal circuit and the surrounding containment environment. A heat engine, such as a thermoelectric generator, a Sterling Cycle Engine or Rankine Cycle Engine, is coupled in heat exchange relationship with an uninsulated portion of the inlet to a passive residual heat removal heat exchanger and/or passive residual heat removal heat exchanger channel head to generate the power required to operate essential equipment needed to maintain the nuclear power station in a safe condition during a loss of normal onsite and offsite power.