放射 ほうしゃ せん分解 ぶんかいじゃなかったです
hōshasembunkaijanakattadesu

Noun
Desu Copula

The polite, past negative form of 放射線分解

1. Wasn't radiation decomposition.; Wasn't radiolytic degradation.

Past/Perfective
Negative
Polite
Casual Register