The Power of the Atom is just one of the silliest Fallout 3 quests.
Why?
Sheriff Lucas Simms: Hey, you there, totally unknown guy/gal from a vault. I like you, we got a armed nuclear bomb in town, no one to disarm.
Player: Can I disarm it?
Sheriff: Sure, feel free to do it.
In the bar...
Burke: Good day. I'm sitting in this bar and I feel kinda crazy today, wanna blow this town? I can give you some caps for it.
Player: Eeeer, sure?
It's kinda strange that both Simms and Burke somehow instantly trust you with deadly matters. It would be much better if both gave you, say, two or three quests first, so Power of the Atom would be given to you because you proved to be trustworthy, reliable and competent to Simms/Burke.
Problem 1: The quest and Moira's dialogue pretty much tell you that IF you disarm that bomb, the Cult will come pissed at you with Torches and Pitchfork, which is both a risk and a interesting outcome. Problem is, that never happens at all. They don't even care that you are messing with the bomb to rig/disarm it. Not even a "please stop messing with our holy artifact." If they don't get pissed, why Moira didn't disarm the bomb? It seems she had the skills to do it.
Problem 2: Disarming a nuclear bomb is easier than disarming a mine. With 25 explosives skill, you just go there and... *disarm* the bomb. Somehow. And it takes just a moment... WTF?! So some noob who knows a bit about explosives leaves out of the vault and then disarms a nuclear explosive... That simply makes no fucking sense. The Power of the Atom would've a much better quest if you had to seek in some places the means, the tools and the info to disarm that bomb, maybe tripping into Burke's band of merry hired mercenaries on the way, then returning to Megaton and disarming that bomb, gaining a lot of money, a well-deserved house and the gratitude of the townsfolk and being well-know as a nice guy by wastelanders in general.
Problem 3: Why Tenpenny wants to explode that godforsaken literal hole of a town? Because he likes pretty lights? Because he thinks it's ugly? Holy shit... It would make much more sense if Burke was a Enclave Agent using Tenpenny's senile mind to get the means to eliminate Megaton and also spread a lot of radiated fallout all over Washington DC, killing a lot of wastelanders who the Enclave wants to see gone. Also, NO ONE comments on the nuclear fallout of the explosion. AT ALL. The falling fallout could easily kill Arefu and force all the people in Tenpenny's Tower to get inside for a freaking week. After the explosion, you don't even see any nuclear fallout in the DC area. At all. FALLOUT. It's on the name of the game.
This quest could've been much, much better. But it failed. Utterly.