Question about Nuclear Dampres and Repulsors

[blackblood]

1. Do Repulsers basically act as an extra layer of armour against missiles and do the work against BPL missiles or does the attack fail if the Repulsor role succeeds ? Can they be used to repulse anything else e.g. asteroids etc

2. Nuclear Dampers, from reading the book it would seem even a USP of 1 would stop a nuclear missile from causing damage or do they just add hteir USP rating to the armour against radiation weapons ?

Thanks

Nick