conduction transfers the heat throughout the extractor medium however instead of cycling the molten sodium to a conventional heat exchanger for production of steam the molten sodium is simply confined by the pressure vessel and employed as a thermal bath into which is immersed a plurality of thermal conductor rods 22 the thermal conductor rods 22 are arranged in a geometric bundle each rod spaced from its neighbor to maximize the effective surface area of the rod bundle therefore in interfacing the substantial quantity of liquid sodium in an upper central segment 24 of the pressure vessel the heat transfer is maximized the elongated conductor rods 22 extend the length of the upper central segment 24 of the pressure vessel and pass through a seal and support gasket 26 which hermetically isolates an upper segment 28 of the pressure vessel from the upper central segment 24 the gasket 26 concurrently supports the conductor rods 22 in mutual displacement for the heat transfer optimization as noted above the rods may be solid steel or iron rod stock or steel or iron tube encasing a more conductive aluminum core the conductor rods extend through the gasket 26 into a chamber 30 defined by the upper segment 28 of the pressure vessel the chamber 30 has an inlet fitting 32 and an enlarged outlet fitting 34 for cycling a gas preferably superheated steam through the chamber during cycling through the chamber 30 on the path defined by the baffles 35 the gas encircles the conductor rods 22 and absorbs the heat transferred by the rods from the sodium bath the added thermal energy substantially increases the heat content of the steam which is used to drive a multi stage steam turbine 36 preferably designed for equal stage nozzle velocity and low pressure.