Originally Posted by
langleybaston
What level interests you?
Very light drift W to E at surface and 1000mb
Depends on the bucket.
As commented on before, tactical detonations tend to be airburst, and have relatively low fall out, compared at least to Tzar Bomba I guess. (trust us, we are after all talking about TNW's up to 4 times the Hiroshima size... anyone who assumes TNW's are minor issues should go visit both Hiroshima and Nagasaki).... There will be fallout, but if the detonation is at an altitude it should be minimal, not zero. In that case, low and mid level winds would be of interest.
For a meltdown, which results in loss of containment, then the mess can be extensive, still less than a ground burst of a TNW, but not pretty. In that case, the fallout we have seen before, in Apr 86. That followed mid and high-level wind patterns and left contamination all over Europe, from Scandinavia to Western Europe. The boys at Sandia will have fair ideas of where the stuff will go, but go, it will.
The system has been in shutdown for a number of weeks, and the thermal flux drops off promptly but doesn't go to zero for a number of years. For Fukushima, a week after the shutdown, a loss of water flow would boil off all the water above the fuel rods in 11 hrs, at which point the fuel rods would start to heat up without control.... When the fuel rod gets hot enough, it can mess up the cladding and that sets it off towards a bad day with H2 buildup, just one of the fun bits. At 7 days, it takes 11 hrs to boil off all the water... at 30 days, it takes about 16.5 hrs to get to the same point... the water within the cooling system may be more or less, but that is the rough order change in time to start having a rise of the fuel rod temps. Want a bucket brigade of Putin types if the water supply fails and the fuel rods are not in a large water body. The tertiary cooling is from external sources, like the lake... if they can sort out the feed. There are only 66 tons of Uranium in each reactor apparently, x 6, trivial for Vlad.
The problem with ZNPP isn't going critical, it is overheating causing H2 buildup and the potential for an explosion within the containment structure leading to the sort of problem that Chornobyl experienced, although the design of the fuel rods there was itself a major badness. ZNPP's risk is H2 explosion, and a subsequent corium event once more.
P.S.: the ~ 400 tons of fuel in the reactors is the current fuel load, onsite there would be the prior 5-25 years worth of spent fuel rods which still need cooling. the rods are good for.., what? 5 years? That's a fair amount of fuel in the residual heat state needing cooling and water protection.
