Nuclear Submarine
noun
The original (often associated with atoms and nuclear tech) concealing machine is the nuclear submarine. It is nuclear, and it conceals itself.
げんせん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
原子力潜水艦は、略して原潜と呼ばれることもある。
Nuclear submarines are sometimes called Gensen, for short.