I've been thinking a lot about New Vegas' "hardcore" mode, with all the extra "survival factors" like your basic trilogy of food, water, and shelter, the forced sleeping, and extra medical factors (fresh in my mind is Call of Cthulhu: Dark Corners of the Earth's medkit usage system, where you actually had to find a safe and quite corner to spend time patching yourself up). One of the things I haven't seen in any Fallout games is absorbing rads via direct sunlight. One of the things I learned in high school JROTC was that one of the first punches in the hole in the Ozone layer was the testing of the "Ivy Mike" hydrogen bomb.
Given that World War III in the Fallout universe ended in hundreds of nuclear explosions (of what yield, though, I'm not privy to), the Ozone layer most certainly must have been torn away. According to the plot of New Vegas, 203 years have past since the Apocalypse. Assuming the survivors haven't been using any aerosol products in the interim (it was, after all, based in Golden Age American culture), and canonically the Wanderer didn't detonate the Megaton bomb, is 203 years enough time for the Ozone Layer to repair itself after being obliterated? Is self-repair even an option at this point?

Fallout is all about the 60s expectations of the future. That includes their understanding of nuclear war. That's why you see cities still standing (more or less) and don't see the whole place completely reclaimed by nature.

Easy solution, make a mod to turn the survival triad into a 4 part grouping of food, water, shelter & sunblock (or would sunblock count as a form of shelter?)
As I understand ozone, its formed when O2 is split into its individual O's and those then combine with undamaged O2 to form O3. Given the number if nukes that the maniacs (who blew it all up! Damn you! DAMN YOU ALL TO HELL!) tossed around, they could have broken and repaired the ozone layer a dozen times

Sunblock 5000?

If you really want random rad exposure you can try the enhanced weather mod which includes options for radioactive rain and snow. It's likely to be one of the first mods ported to NV.

Assuming that the modding will work like Fallout 3 and Dark0ne doesn't shut down the Nexus sites (both are extremely likely), then I'd imagine someone would make a mod with that senario.

Which reminds me of a mod which pretty much turns the landscape "green" in FO3:
http://www.fallout3nexus.com/downloads/file.php?id=2456

I've read that the Fallout universe is not just set in an alternate time line but in an alternate universe. By the 60s we were already well aware that a single nuke could level an entire city, since the US had leveled 2 cities with them nearly 20 years prior (watch the HBO documentary White Light, Black Rain for extensive footage and images of the destruction if you're curious).
In the Fallout universe they have opted to change some physical laws, there's some super nerdy list of them and an article explaining all of this on one of the Fallout fansites (probably No Mutants Allowed).

Yeah, I've seen that. Yet to try it. But it looks good. There's also another one that gets rid of the green filter. I don't know if that's an improvement or not. A matter of taste I suppose.
Those bombs were detonated above the city. The idea being to maximise damage and radiation poisoning.
In the Fallout universe there are enough craters to suggest that the bombs detonated at ground level, which would explain the comparative lack of damage... to some degree at least. Then there's also the yield of the bombs. Many of them could even have been dirty bombs for all we know.
Basically it's fiction and fiction that's deliberately based on poor interpretations of the future.

This is the article which I was talking about: http://fallout.wikia.com/wiki/Divergence
The specific part about laws of physics is at the bottom. In the Fallout universe the "Great War" happened on October 23, 2077. Specifically the war started with a bunch of nuclear missile launches. I suppose they could have been ground detonations but I'm not sure the story supports it. At any rate I don't want to argue about the finer points of the Fallout world, I was just pointing out that it is my understanding that it occurs in an alternate universe. The stuff these guys go on about on that wiki is mainly taken from background materials provided with the games (back when game companies actually did that!). It's called The Fallout Bible (there's 9 I think). No I've never read them, but all the fansites post copies if you're so inclined.

The Fallout Bible is actually included as a PDF with Fallout on GOG. But yes, it does happen in an alternate universe. It has to have. After all, in many ways we're more advanced now than Fallout's 2077.

I'll just file it under suspension of disbelief to enhance the overall atmosphere rather than worry about a physics based explanation.

Let's not forget they were of Chinese, or at least some communist nation, manufacture.

Typical, isn't it? Everything the US gets from China is always of inferior quality.

Never try to apply science to Fallout, any of them. It is a fantasy within a fantasy within a fantasy... a video game of a future reality based on the 50's idea of a future reality.
I only wish all games were so uniquely conceptualized.