Atomic explosion get away

The army advised us that 20 minutes after the explosion of a tactical nuclear device is was safe to move troops through the area.

They were not to linger in the area.

Obviously if driving through, keep the windows wound up to minimize dust ingress.

When safely clear of the area, wash yourself and everything else thoroughly (including the car, then move elsewhere. Don't stay near the wash water.

I do not doubt that the army told you this. But you have to recognize both the source of this advise and the conditions. The army would presumably know what type of tactical device was used and how it was used because they presumably used it. Also during war, soldiers go into harms way. That's their job. Lastly, the fallout was most likely still suspended high in the air. So even if it would be falling on your position soon, it would not be there a half hour after the blast.

Hello sceptic,

Well, that's the Arm for you!

When in the Army, the advice given is very often more like an 'ORDER', so you do not really have any choice but to do as 'advised'?

The bit about moving to water to get or keep clean would not have works because in all likelihood the water would be contaminated

In all respects the Army knows probably as little as the general public anyway. We can now look back and say what 'should' have been done..............at the time they could have had little idea of the fallout, or even what fallout was, other than the visible strength and power of the blast itself?

It is easy to comment on 'hind-site' though?

Even if the water is contaminated, it enables you to wash off the dust.

Most of the radioactive dust comes from the fission products, the majority of which have extremely short half lives. This is why the army settled on 20 minutes to let the most powerful emitters die away.

There are, of course longer lived nasties like Iodine 135(?), Strontium 90 and Co 60, the last being especially nasty as it is a powerful gamma ray emitter and these are not readily attenuated by most materials.

Sr absorbs into the skeletal structure displacing Ca, I is preferentially absorbed by the Thyroid. Obviously ingestion or inhalation of any of these is undesirable.

This is why you want to get clear of the area as fast as possible and get rid of all dust as quickly as possible, even if you have to use contaminated sources to do so.

As a side issue, the risks of radiation, while they should not be taken lightly, may not be as drastic as usually painted.

Years ago, I saw a documentary showing the test range of Maralinga. The aboriginals and all other people were banned from the area as the radiation levels were unsafe. This didn't bother either the vegetation or the kangaroos and rabbits which were present in plague proportions and looking quite healthy!

If I had the choice, I would get out of the area a few hours after the blast.