炉心 ろしん溶融 ようゆうではありませんでした
roshin'yōyūdewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 炉心溶融

1. Was not molten at the core.; Was not melted within.

Past/Perfective
Negative
Polite
Formal Register