Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: thedoc on 29/01/2016 20:50:01
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Linda asked the Naked Scientists:
If the North Koreans set off a hydrogen bomb 10k below the earth will it have implications for the water table or radioactivity of the soil in that area?
What do you think?
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will it have implications for the soil
The explosion creates a cavity by melting the rock, and produces blast waves that shatter the nearby rock. The cavity collapses, and then the rock above that collapses. There will be a zone of radioactive rock below ground.
If the rock is soft, these cascading collapses leave a conical depression at the surface, through which some radioactive gas can escape.
If they decide to dig down into the blast cavity, they will bring much more of that radioactive rock to the surface (and endanger workers).
will it have implications for the water table?
If they have selected the bomb test site carefully, they will select an area with low rainfall, with rock which is dry and impervious to water, and has no nearby fault lines. They will seal the shaft thoroughly, and leave it sealed (not digging back down).
If this is done, there should be no impact on the water table - at least until weather patterns change, or inactive fault lines reactivate.
The major risk from nuclear weapons is not from well-planned below-ground tests. Above-ground tests are a very real problem, and have been banned. But the major risk comes from them being used in anger - and the bizarre behavior that can occur (and be tolerated) when a nation believes it is in an unassailable position.