Theoretically...
If you start off defending and go 3 matches killing everyone on the other team that would be 18 kills. Say you're on offense now and you get 5 kills plant it, then die. That would make you 23-1, with the game at 3-1. If you get another 5 kills, plant it, die, that would make you 28-1, get another kill, plant it, die, but your teammates help, then you can go 29-1.
As for the nuke, if you start out on offense and go 3-0, you'd go 18-0. Now you're defending and you kill 5 people on the other team, let him plant, kill him, then let it blow up that makes the game 3-1 and you're 24-0. Kill one more person and you get a nuke. So, yes, it is possible. But likely? Hell no.