Navy nuclear program experience?

[mofo]

So, I'm about one week away from signing my dep contract with the navy nuclear rating. I'm having some anxiety about commiting because it's 6 years of my life that I'm giving. My primary concern is how difficult is the training pipeline? I got a 99 on the practice asvab and a 93 on the actual one. Everyone says I'm smart enough to complete the program, but how high is the attrition rate exactaly? I guess I'm really just looking for anyone out there who has experience in the nuclear field to tell me anything that they possibly could!! Thanks Cory