Sea water is used to cool nuclear reactors in emergency situations when fresh water is not available. We usually find very pure water used in nuclear reactors as a primary coolant. This water stays quite pure and retains little radiation after shutdown and cooldown. But if an emergency situation arises and the "regular" primary coolant (the fresh water) is lost, it must be replaced with any water to cool the reactor. Sea water is better than nothing.
Well, as nuclear reactors are nuclear reactors, nuclear reactors are not used inside nuclear reactors.
Water is used as coolant in most reactor plants to keep the reactor cool and prevent over heating. They do not necessarily need to be near a source of water; water just has to be available. However, a lot of nuclear reactors are build by a natural source of water so that the water can be used as an emergency source of coolant to keep the reactor covered with water in case of a rupture.
Current nuclear reactors rely on nuclear fission as their nuclear reaction.
Nuclear fission
mining for the mineral used, and the heating of local lakes by the discharging the water used to kool down the reactors.
Well, as nuclear reactors are nuclear reactors, nuclear reactors are not used inside nuclear reactors.
The most common coolant used in nuclear reactors is water. There are light water reactors (using "regular" water), and the heavy water kind of reactor.
If you are talking about the Nuclear Reactors in Japan, they were damaged because when they lost power, the water pumps used to cool them stopped, and all of the nuclear material overheated.
Water is used as coolant in most reactor plants to keep the reactor cool and prevent over heating. They do not necessarily need to be near a source of water; water just has to be available. However, a lot of nuclear reactors are build by a natural source of water so that the water can be used as an emergency source of coolant to keep the reactor covered with water in case of a rupture.
Heavy water is used in nuclear reactors as moderator for neutrons.
Regular Water is used to cool the reactors, and for steam production. The cooling water evaporates into the air...so it has to be replaced. Therefore the Plant has to have a source of fresh water for replacement.
Current nuclear reactors rely on nuclear fission as their nuclear reaction.
We use nuclear fission in nuclear reactors to tap nuclear energy.
Sewage water. No, seriously. The cooling effect from evaporating water from the sewage of nearby communities is used to keep the circulating (extremely pure) coolant in the sealed cooling systems cool.
No, at least not for power reactors
All current nuclear reactors are fission reactors, tritium has no function in a fission reactor, in standard water moderated reactors deuterium also has no function, in heavy water moderated reactors deuterium is the moderator. If we are ever able to make a fusion reactor, deuterium/tritium mix will be used as fuel.
Primarily, nuclear reactors are used to generate heat, which is used to flash water to steam, which is used to spin turbines, which are used to generate electricity. It is also possible to use reactors for research, as well as for weapons development, such as in the generation of weapons grade Plutonium-239.