I am suspecting that this doubt is raised by an Argentine. "Irradial" does not exist, should send the query to radiate, especially because it is badly drafted; but as something more anecdotal and very local, I will mention the history here. It is there a country song, a hymn to the Argentina flag that is taken from an aria from the opera Aurora, of Héctor Paniza with lyrics in Italian of Luigi Illica. The problem was just that it was in Italian, and to sing it (for example) in Argentine schools had to translate it; and they entrusted him the task to the duo Josué Quesada (h) and Angel Petitta, who did not know a damn Italian and his poetic translation to the Spanish. The original phrase was "aura irradiale", which is the aura at the head of the Saints, or the rays that the Sun at dawn; and it was versioned as "irradial aurora". It is not the only nonsense in that translation, so I suggest a deeper search to those interested in the topic.
