Here is a short list of foods and habits that can take radiation out of your body or have shown to help people who have had high exposures to radiation.
Common foods:
Foods high in pectin: Quince, apples.
Seaweeds; make sure you have eaten a little that is raw to digest it better.
Miso don’t heat it, just add it to the soup after it is in the serving bowl.
Iodine (if your not allergic to it).
A bath of 1 lb salt, 1 lb baking soda, and if you can find it, a cup of clay.
Green vegetables.
Max gxl , Glutathion recycler by Apex Energetics, or any like product that has the co-factors for glutathion production.