The fact that you got Island level for what seems to be a very small nuclear explosion should give you a hint.
Yes nuclear explosions can reach very high temperatures, exceeding those of the core of our Sun but they are achieved for a very small amount of time.
Since the Stefan-Boltzmann law gives you the power radiated (aka energy per second) you could multiply the result you got by that small timeframe but it would be better to just calc it taking into account the fusion reactions.
I can help with them, they aren't so difficult as they seem.
Are you the guy, who created the page about Great red(and every character from DxD)? If so i must ask you to correct some of the stats or at least allow me to do it, because there are clearly a lot of things you or whoever made the page got things veeeery wrong...
Hi, for several months we have been referred to those who have calculated on Naruto to you, telling us that we will wait for you to be on vacation so that the calculations are checked to see if they are accepted or not. I asked Antvasima about it and he told me that you are in it with your review of Naruto feats. However I did not think it will be that when they told me about it months ago, I thought that you would be the one in charge of evaluating the calculations and see if the changes were coming, and well, given the past tense I wonder if those calculations will be evaluated by you or really that will happen about it.