Reply #176: It's hard to say without specs on the military-grade detectors

[TheWraith]

In theory, no, underground blasts don't emit radiation, however in practice, I don't know what the tolerances of the military grade radiation detectors are, or what kind of leakage they would need to ID the site. Add to that the question of the fission/fusion ratio and yield of the bomb that they used, and it's an open question. (The higher the fusion percentage, the "cleaner" the bomb in terms of radiation.)

However, what can't be so easily contained is the EM pulse from the detonation, which would definitely be noticible even from an underground detonation.