The explosions at the Russian military depot went on for at least a full day. The inventory will never be known by The West, but, they need to protect from radiation dispersed by the continuous explosions and carried by wind AND water.
Cesium 137 was found in the muscle of the Russian brought to the hospital because it was a projectile. The radiation wasn't the only emission, the actual cesium was exploded. That means wherever the cesium landed became radioactive. The explosion is not contained. The cesium isotope was exploded by outside forces. The contamination area is large. The waters are worrisome and should be approached with caution. Isotopes in the men are mostly likely in the water as well for the same reason, it was pulverized to small projectiles.
Please be careful with human life when investigating any of these dynamics.
You will excuse me, but, the same thing happened at Chernobyl. Is this a particular talent Russia has when it comes to using nuclear material? Russia is doing it wrong. Very wrong.