It should in fact be a pretty language neutral book.
The math reads the same in any language.
That said, it is difficult to understand where a Portuguese author would gather in depth expertise on nuclear explosions.
My guess is that you would get more insight from serious study of reactor dynamics, along perhaps with some grad level fusion papers.
Nuclear explosions per se are pretty well understood, so much so that the Hiroshima bomb was never tested before being used, unlike the Nagasaki device. The latter design was proof tested beforehand mostly because the compression implosion was a novel design feature.