In those historical cases, the priority was cooling the core, the easiest method (especially if a substantial amount of plumbing is wrecked or questionable) is

In those historical cases, the priority was cooling the core, the easiest method (especially if a substantial amount of plumbing is wrecked or questionable) is dumping water into it. Which then becomes irradiated, and pools via gravity in any lower voids, and then eventually needs to be dealt with.