Control rod drive mechanism with heat pipe cooling

A cooling system for a nuclear reactor control rod drive mechanism (CRDM);

• comprising:
• a drive shaft housing extending up from a top end of a nuclear reactor pressure vessel;
• a drive shaft having a top end extending into the drive shaft housing and a bottom end coupled to a control rod assembly located at a bottom end of the nuclear reactor pressure vessel;
• a drive mechanism coupled to the drive shaft housing configured to linearly displace the drive shaft and raise and lower the control rod assembly;
• heat pipes located in or next to the drive mechanism;
• and
• fluid located in the heat pipes configured to circulate through the heat pipes via evaporation and condensation to remove heat from the drive mechanism.

A system for cooling a control rod drive mechanism (CRDM) in a nuclear reactor, comprising:

• pipes containing a fluid, the pipes including:
• an evaporation section located in or next to the CRDM, the fluid in the evaporation section configured to evaporate from heat generated by the CRDM;
• and
• a condensation section fluidly coupled to the evaporation section configured to condensate the evaporated fluid and circulate the condensed fluid back to the evaporation section via gravity or capillary action.