Question

what is the main reason why many nuclear power plants are located near bodies of water?
to wash wastes out of the power plant
to be close to shipping lanes for frequent fuel delivery
to have easy access to a coolant for the reactor
to avoid problems with water supply during a drought

Explanation:

Nuclear reactors generate a large amount of heat. Water is an effective coolant. Bodies of water provide a readily - available source of coolant for the reactor to prevent overheating.

Answer:

to have easy access to a coolant for the reactor