Earlier quoted context omitted.
I'm pretty sure he means the Ukrainians inside the nuclear plant, not Ukrainians in general.
Operators of nuclear plant are civilians. They are not part of force. Civilians can be captured, they cannot surrender, because nobody asks them to do that. I never heard that police or army asks somebody unarmed to surrender.
I don't understand the statement. Either it is completely oblivious to daily reality, or it is hinging on some pedantic / language dependent semantic detail that should really be explicitly addressed.