Both Uses of

radiation
in
Hunger Games Book #3 (Mockingjay)

Nuclear missiles would release radiation into the atmosphere, with incalculable environmental results.†
Chpt 10 *

radiation = particles emitted by nuclear decay

And even if they were one hundred percent effective at sealing out the radiation, which is really unlikely, would we ever be able to leave this place?†
Chpt 10

Definitions:

(1) (radiation as in: nuclear radiation)
particles emitted by unstable atomic nuclei

Generally, radiation is discussed in terms of harmful levels of radiation that cause sickness. However, there is a normal level of radiation that is not harmful and sometimes radiation is carefully used for beneficial purposes such as medical treatments.
(2) (radiation as in: electromagnetic radiation)
energy sent out as invisible rays such as from heat, light, or radio waves
(3) (meaning too rare to warrant focus)
meaning too rare to warrant focus