Nuclear power plants produce energy in terms of electricity from radioactive materials. These elements are highly unstable due to their high neutron-to-proton ratio. That's why they spontaneously decay by giving off sub-atomic particles which yields a new element. So, nuclear reactions, fission and fusion, produce 'clean' energy because they do not produce gaseous by-products that could harm the environment. They only yield radioactive materials that could be harmful to the health of people nearby the area. Because of this risk, safety precautions are needed in a nuclear power plant.
Smokestacks are no longer used in nuclear power plants because there are no gases. So, the first choice is eliminated. Next, you should NOT ventilate the radioactive materials. Remember this radiation travels through all types of matter so it is harmful. These type of materials are strictly contained and handled. The third choice is correct because it prevents radiation to reach the outside environment. The last option, on the other hand, is not justifiable. Before a nuclear power plant is approved by the government, it is made sure that all its employees and employers are inherently safe. Otherwise, it would not be put into operation.
