How long after a nuclear attack does the radiation last for? ?

Question

How long after a nuclear attack does the radiation last for? ?

Answer 1

It depends a great deal on the design of the weapon.

Some designs have isotopes which last for decades. Other designs have isotopes which burn off quickly allowing troops to quickly move into the area.

Hiroshima is a park today.

Answer 2

Here is a good link on how food is affected by nuclear detonation.

Go down to the section F3, which outlines precautions on storage and use of contaminated food, based on exposure.

I posted a bit of the radioactive halflife data here, but there is much more.

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Strontium-89 (Sr-89) and Strontium-90 (Sr-90) are beta emitters and have half-lives of 51 days and 28 years respectively. Therefore, Sr-90 is the greatest radiation hazard in the long term. These two isotopes are absorbed in the body and used in the same way as calcium. They accumulate in bone, where bone marrow with its blood forming cells is vulnerable. Milk and other dairy products are the primary sources of Sr-89 and Sr-90 in the human diet.

Iodine-131 (I-131) is a beta and gamma emitter and has a short physical half-life of approximately 8 days. It is efficiently absorbed and used by the body. Iodine-131 will contaminate plants which will be eaten by grazing animals. Smaller amounts can also be absorbed by breathing contaminated air. Cattle will excrete a large amount of I-131 in milk. Milk and other dairy products are the primary sources of I-131 intake. One can also get smaller amounts by eating contaminated fruits and vegetables. Iodine-131 will be concentrated in the thyroid gland. The intake of I-131 will have its greatest impact the first few days to weeks following a nuclear explosion.

Cesium-137 (Cs-137) is a beta emitter and has a half-live of 30 years, but is eliminated relatively quickly from the body. The biological half-live is 70 to 140 days. Cesium-137 is found in most tissues of the body, but it will concentrate in muscle tissue. Cesium-137 is absorbed and used the same way as potassium. Meat and milk are the primary sources of Cs-137. Much precipitation, lack of minerals in the soil, and extensive cultivation increase the plants' absorption of Cs-137; thus, the contamination of plant products.

Answer 3

Here is a good website for your question.  

It depends on the materials used.

http://www-personal.umich.edu/~jmoilane/...

Answer 4

a lot longer than you will live .the bomb will take out a lot of the radiation goes with the wind and ten minutes more and everything it lands on .

Answer 5

30 years give or take.