かく分裂 ぶんれつ生成 せいせい ものでしょう
kakubunretsuseiseimonodeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 核分裂生成物

1. Fission product, likely.; Probably a fission product.

Polite
Presumptive
Conjecture