Why three days works well
Fallout radiation drops very quickly (the classic 7-10 rule of thumb):
โข 1 hour after the explosion: reference level (100%)
โข ~7 hours: ~10%
โข ~2 days (~49 hours): ~1%
โข ~3 days (72 hours): further reduced (often on the order of 0.5โ0.6% of the 1-hour rate in standard decay tables)
By the 48โ72 hour mark, the most intense early fallout has largely decayed.
@Maks_NAFO_FELLA WTF, he was having a go at European leaders for buying ruzzian oil and gas before, and now this.
Follow the money and youโll have your answer.