かく分裂 ぶんれつ物質 ぶっしつではありませんでした
kakubunretsubusshitsudewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 核分裂物質

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

Past/Perfective
Negative
Polite
Formal Register
Physics