Passive heat removal system for nuclear reactors

A nuclear reactor, comprising:

• a reactor vessel;
• a reactor core within the reactor vessel;
• a primary heat exchanger within the reactor vessel;
• a coolant loop configured to circulate coolant through the primary heat exchanger, the coolant loop having a hot leg and a cold leg through which coolant flows;
• a pump in fluid communication with the coolant loop and configured to circulate coolant through the coolant loop;
• and
• a decay heat removal system, comprising:
• a secondary heat exchanger disposed along a bypass flowpath between the hot leg and the cold leg of the coolant loop;
• and
• a fluidic diode disposed along the bypass flowpath to asymmetrically restrict fluid flow of the coolant along the bypass flowpath and configured to allow natural circulation of the coolant along the bypass flowpath to remove decay heat from the reactor core, wherein the fluidic diode is configured to provide a flow resistance against the pump circulating the coolant across the bypass flowpath;
• and
• wherein the fluidic diode comprises no moving parts and is configured to passively provide differential flow resistance based solely on flow direction through fixed geometry of the fluidic diode.