I reactors to modern generation III+ reactor designs. The fission in a nuclear reactor heats the reactor coolant. A nuclear submarine is a submarine powered by a nuclear reactor. Tritium is a radioisotope of concern in nuclear reactor waste streams. Such fluxes require a research nuclear reactor. Samples are exposed to neutrons in a nuclear reactor. Used as the primary coolant in the British advanced gas-cooled reactor for nuclear power generation. InHour is a unit of reactivity of a nuclear reactor. It is made by bombarding uranium-238 with neutrons in a nuclear reactor. Lithium-7 gained interest for use in nuclear reactor coolants. Polish nuclear research reactor Maria is named after her. The 3 MW (thermal) boiling water reactor (BWR) used 93.20% highly enriched uranium fuel. This is typically done in a fluidized bed reactor heated to . Though named thorium high temperature reactor, mostly U-235 was fissioned. Oxides could result in the deposition of solid particles in reactor operation.