放射 ほうしゃ せい核種 かくしゅじゃなかったです
hōshaseikakushujanakattadesu

Noun
Desu Copula

The polite, past negative form of 放射性核種

1. Wasn't radioactive.; Wasn't a radioisotope.

Past/Perfective
Negative
Polite
Casual Register
Physics