Here's some quick background info and what I've done with it:

First off, move out of the cities. The farthur you are from the NuDet, the better off you will be. (Hint: Government agencies are moving their Admin and Supply records, and much of their HQ staffs to points that are 50 miles outside of Washington D.C. What does this tell you?)

Gamma Radiation is released at the time of the NuDet and then it is gone. The really bad radioactive particles will, for the most part, be airborne and stay airborne until they have become radioisotopes (dead) by the time they land on the ground.

The main radioactive materials that one will have to deal with are Alpha and Beta particles. Alpha particles can be stopped with tightly woven clothing and Beta particles can't penetrate unbroken skin.

My plan is to convert my 2 car garage into a shelter. I place my bookshelves against the garage doors. I've got 1" plywood cut for the garage door's exterior framing and for the 2 windows frames. I run air supply, CO2 removal, and antenna conduits through 1 of the window covers. The garage has a porta-potty in one corner, beds down 1 wall, workbench in 1 corner, communications and Intel files down 1 wall, cooking, food storage, and water storage down 1 wall, and a community area in the middle of 1 of the car bays.

I lay extra shielding (wood and cardboard, mostly)in the attic over the garage area.

In case of emergency, we have a place to shelter, eat, drink, poop, and entertain ourselves.