This Scene file showcases how to achieve the atomic bomb explosion video made for Houdini 19.0 by Miguel Pérez Senent. The file contains the lopnet used for rendering, as well as a topnet to generate the entire shot at once. This is necessary as the shot is built up of many caching steps needed to be generated in the right order. To do that, jump into the topnet1 network and cook the atomic_bomb top node.
Miguel's presentation about making this explosion available HERE