The blast will probably occur in a city, or all the cities. If they do it, they'll likely go all in with a 500 nuke strike. How many will actually make it to mainland or hit their intended target is another thing. We do have reasonable knowledge that most of their deployable nuclear weapons are ~150kt range. Surviving a direct hit isn't possible, but assuming you aren't hit, there's a few basic things you can do to survive the fallout.
Here's the most likely target map. The purple triangles are in a 500 warhead scenario, the black dots are in a 2000 warhead scenario.
Fortunately for me, I'm in-between targets, but fallout would rain down considerably over my head. Unfortunately for me, my house didn't come with a fallout shelter.
The thing about fallout is, once the bomb lands, it spreads in the air and follows the wind. If Baltimore, MD or Washington DC got hit, their fallout would make a bee-line for me.
https://nuclearsecrecy.com/nukemap/
Fallout is tiny particles blasting radiation around in all directions. If it is outside, and you are inside behind a concrete wall, you have a degree of protection. However if you are inside and it lands on your roof, and your roof is made of shingles and wood rafters, you are not very protected. The key to protection from fallout is mass. Lead offers a high density per volume, but is expensive. Concrete and steel are good, followed by dirt.
So, hiding in the sub-basement of a brick five story apartment building will leave you exposed to just 1/200 the amount of fallout radiation outside; hanging out in the living room of your one story wood frame house will only cut down the radiation by about one-half, which, if you are next to a nuclear explosion, will not do much to help you.
Fortunately, fallout typically runs it's course in 48-72 hours, but if you're seeking shelter, it's probably a good idea to stay a week just in case. So it's a good idea to have a week's supplies in your shelter. Personally, my shelter is in my basement, a 12x12 room with 8" solid concrete walls and roof. My house is made of concrete block, so leaving the shelter for a short period to use the bathroom is generally ok, making it easier.
As fallout particles are airborne, think of snowfall. Fallout will blanket everywhere snow does. If there are open windows or doors, fallout will come in them. So sealing your house to be as air tight as possible will be to your advantage. Close and tape all windows, door seems, anywhere that air can get in. Fallout will lay on the ground, roof, window ledges, anywhere snow can get to. And it will be blasting radiation in all directions.
If you have a direct line of sight to it, you are only protected by what is between you and it. Stand in your basement and look up, you are protected by the floor, carpet, ceiling drywall on first floor, plywood on the roof, and shingles. if you look at a wall, you're protected by the wall, and what the wall is made of. Don't count the studs or joists or trusses, they are not useful. If you stand in front of a window, you are protected by the glass in that window alone.
I have some pdf's with more information that are to large to attach, but if anyone would like I can email it to them.
I'm open to constructive criticism, or any corrections, or if anyone wants to contribute to this they are welcome to.
