かく分裂 ぶんれつ物質 ぶっしつじゃありませんでした
kakubunretsubusshitsujārimasendeshita

Noun
Desu Copula

The polite, past negative form of 核分裂物質

1. Was not nuclear material.; Was not a nuclear substance.

Past/Perfective
Negative
Polite
Terminal Form
Physics