This is the 3795th most frequent Russian word.
ядерную
"Nuclear."
Adjective describing 'энергетику', denotes the type of energy being nuclear.
Мы обсуждали ядерную энергетику на уроке физики.
We discussed nuclear energy in the physics class.
Adjective describing 'атаку', implies the nature of the attack being nuclear.
Во время учений они отработали ядерную атаку.
During the drills, they practiced a nuclear attack.
Adjective describing 'лабораторию', signifies the laboratory's purpose being related to nuclear studies.