During a nuclear attack a radio may be necessary for you to keep in touch with military announcements but the challenge is to keep it operating. However being in contact with news about where the fall-out area is, where attacks of happen and food and disaster relief measures could greatly increase your chances of survival.
Radio contact can be maintained if you remember to bring all hand cranked and portable radios with you. Make sure that you buy radios with metal parts as ones that are plastic are more subject to damage from electromagnetic impacts.
It also is helpful to use radios with short-loop antennas that are built in. Any other type of antenna can be subjected to damaging surges of current. This is also why it is important to keep all radios that do have antennas in a mode where their extendable antennas are as short as possible. Do not try to get better reception by attaching it to any type of metal like a pipe or metal pole. Damage from electromagnetic pulses after a nuclear explosion can suddenly wreck the diodes and transistors in a radio for weeks to come after the initial impact.
Shield the radio best you can but not with metal, wire, ducts or any of the metals commonly found in basements and other shelters. This can encourage a power surge to deliver a fatal surge of current to your radio.
When it is not in use disconnect the radio antenna. If you r car radio is working get rid of the antenna on the hood and remove outside rear view mirrors. That is because the metal of an outside mirror is a grounding point for destructive energy.
Park your car as near to your shelter as practical, so that after fallout has decayed sufficiently you may be able to use the car radio to get distant stations that are still broadcasting.
Radios can also be hurt by moisture. Keep it sealed in a plastic container that is further sealed in a plastic bag to prevent it from moisture.
You should conserve your power whenever possible because after an attack you may not be able to get a replacement for many months. If you are listening be sure to do so at the lowest volume setting possible because the battery life of transistor radios can be doubled this way. Use the radio as little as possible and be aware that the electromagnetic pulses could affect its efficiency for a while.