Actinic radiation and Ultraviolet

Actinic radiation noun - Electromagnetic radiation that can produce photochemical reactions.

Ultraviolet and actinic radiation are semantically related. In some cases you can replace term "Ultraviolet" with "Actinic radiation", this terms are similar.

Ultraviolet noun - Radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays.

Actinic radiation and ultraviolet are semantically related. Sometimes you can use "Actinic radiation" instead a noun "Ultraviolet".