How powerful is this reaction? I’ve heard it’s about the same as dynamite (assuming the same amount of sodium), but that seems like an exaggeration. Fight my ignorance.
There is a Mythbusters episode that gives good examples of the Sodium water reaction. I think it’s the McGuyver special.
here it is.
My 8th grader science teacher tossed a hunk of sodium into a bucket of water with all of us standing around watching. It looked like a pack of matches being set off. Unimpressive.
This is the same guy who taught us about an electric circuit by having all 30 of us hold hands in a chain, and he gave one guy on each end a live wire. We all got a big buzz for a second. If he did that today, he’d be the headliner on Nancy Grace.
There are oodles of demos on youtube.
Maybe it’s just as well it’s not up there with TNT. 
When I was in HS back in the dinosaur age, my hobby was chemistry, and I had an extensive lab. Back then I was able to buy almost any chemical via mail order. For example, I got some white phosphorus sticks that had to be kept under water for safety’s sake.
I also bought a big chunk of metalic sodium that came in a container filled with kerosene. I could cut out little pieces to use in experiments. Outside of the kersosene, it was still dangerous if a drop of water touched it, or even if the humidity was too high, supposedly it could ignite.
Anyhow, when I was about to graduate HS (I passed the Chemistry class without ever haviing to take the course), I still had about a half pound of the stuff left.
I took the container down to a secluded spot on a nearby river. I crossed over the railroad trestle, and dropped the chunk of sodium into the river. Believe me, it was spectacular. It blew up with a satisfying boom and several little pieces skittered around on fire, reached the banks and started grass fires.
I got the hell out of there quickly, as the grass was not dry and quickly burnt out, but I figured if caught, it would be hard to explain.
Ah, those were the days.
(I also made fulimanate of mercury, which us used in blasting caps and made a lovely explsion. I refrained from making nitroglycerin, although it is that that difficult to make.)