Depends on the size and power rating of the reactor. Some low power experimental reactors like CP-1 (first reactor in the world) and CP-2 (made from parts of CP-1 after it was shutdown) have none at all. CP-1 never operated at more than 1/2 watt power at any time.
A lot
coolant is used to keep the reactor cool and prevent it from melting down. The amount of cooling that is required really depends on the the amount of heat being put into the coolant.
Up to 1500MWe per reactor
The amount of coolant used in a nuclear power reactor can vary depending on the design of the reactor. Generally, a nuclear power reactor may use thousands to millions of gallons of water or a different coolant material to remove heat generated during the nuclear fission process. The coolant circulates through the reactor core to transfer heat and help regulate the temperature of the reactor.
A typical nuclear power plant requires approximately 27 metric tons of uranium fuel per year to produce electricity. This amount can vary depending on the specific reactor design and fuel cycle used. The energy produced from uranium in a nuclear reactor is much more concentrated than energy from other traditional sources like coal or natural gas.
Depending on: - the type of the nuclear reactor - the electrical power of the nuclear reactor - the type of the nuclear fuel - the enrichment of uranium - the estimated burnup of the nuclear fuel etc.
This depends on the type and power of the reactor; say tens of metric tons.
An Ark reactor as currently describe in comic is very much like a Nuclear Fuel Cell. Possibly convert energy from Nuclear reaction to power. Possibly a plasma nuclear fusion reactor. I believe in the future it could be made. See the link and compare the similarity of fusion reactor and Ark reactor.
The power required to start a nuclear reactor varies depending on the size and type of reactor, but typically ranges from a few hundred megawatts to several gigawatts. Once the reactor is operating, it generally requires a smaller amount of power to maintain criticality and sustain the fission chain reaction, usually around 1-5% of the total reactor power output.
The efficiency of a PWR or BWR reactor power plant is about 33 percent, so this means that about 67 percent of the reactor's thermal output is rejected to the cooling water
The amount of uranium-235 used in a nuclear reactor depends on the design and size of the reactor. Typically, a reactor core contains several tons of uranium fuel, with the concentration of uranium-235 ranging from 3-5%. The fuel is arranged in fuel assemblies to sustain a controlled nuclear fission chain reaction.
The amount of electrical energy generated by a nuclear power reactor in one day can vary depending on its capacity and efficiency. However, a typical nuclear power reactor can generate around 1-2 billion joules of electrical energy per day.