Power generation systems, such as nuclear power generation systems, are described herein. A representative power generation system includes a heat source, a heat pipe, and a thermophotovoltaic cell. The heat pipe includes a first region and a second region. The first region is positioned to absorb heat from the heat source, and the second region is positioned to radiate at least a portion of the absorbed heat away from the heat pipe as thermal radiation. The thermophotovoltaic cell is positioned to receive the thermal radiation from the second region of the heat pipe and to convert at least a portion of the thermal radiation to electrical energy. The power generation system can further include another heat pipe positioned to remove waste heat from the thermophotovoltaic cell.

A system for monitoring a condition of a nuclear reactor pressure vessel disposed in a radioactive environment includes an instrument structured to monitor a condition of the nuclear reactor pressure vessel; a powered wireless transmitting modem disposed in the radioactive environment, the wireless transmitting modem being electrically coupled to the instrument; a receiving modem disposed in the line of sight of the transmitting modem, the receiving modem being in wireless communication with the transmitting modem; and a signal processing unit electrically coupled to the receiving modem, the signal processing unit being structured to determine the condition of the nuclear reactor pressure vessel from the instrument. The transmitting modem is powered by a thermocouple disposed in or on the reactor pressure vessel.

A method, system, and apparatus for the thermoelectric conversion of nuclear reactor generated heat including thermoelectrically converting gas cooled nuclear reactor generated heat to electrical energy and supplying the electrical energy to an operation system of the nuclear reactor system.

A method, system, and apparatus for the thermoelectric conversion of nuclear reactor generated heat including thermoelectrically converting gas cooled nuclear reactor generated heat to electrical energy and supplying the electrical energy to an operation system of the nuclear reactor system.

A method for generating electricity includes generating electricity at a first reactor with a nuclear fuel element and removing the nuclear fuel element from the first reactor. The method also includes providing the nuclear fuel element at a second reactor and generating electricity at the second reactor with the nuclear fuel element.

A method for generating electricity includes generating electricity at a first reactor with a nuclear fuel element and removing the nuclear fuel element from the first reactor. The method also includes providing the nuclear fuel element at a second reactor and generating electricity at the second reactor with the nuclear fuel element.

A drillhole plug includes a frame or housing of a corrosion-resistant material and sized to fit within a milled portion of a directional drillhole that includes a hazardous waste repository; and a material that fills at least a portion of the frame or housing. The material exhibits creep such that the material fills one or more voids between the frame or housing and a subterranean formation adjacent the milled portion of the directional drillhole.

A method for generating electricity includes generating electricity at a first reactor with a nuclear fuel element and removing the nuclear fuel element from the first reactor. The method also includes providing the nuclear fuel element at a second reactor and generating electricity at the second reactor with the nuclear fuel element.

A method for generating electricity includes generating electricity at a first reactor with a nuclear fuel element and removing the nuclear fuel element from the first reactor. The method also includes providing the nuclear fuel element at a second reactor and generating electricity at the second reactor with the nuclear fuel element.

A power generator system includes one or more heat transfer members configured to contact: a heat source in a hazardous waste repository of a directional drillhole that stores nuclear waste in one or more nuclear waste canisters, and a heat sink in the hazardous waste repository; and one or more thermoelectric generators thermally coupled to the one or more heat transfer members and configured to generate electric power based on a temperature difference between the heat source and the heat sink.