かく分裂 ぶんれつ せい物質 ぶっしつじゃなかったです
kakubunretsu sei busshitsujanakattadesu

Noun
Desu Copula

The polite, past negative form of 核分裂性物質

1. Wasn't fissile material.

Past/Perfective
Negative
Polite
Casual Register