Years ago, I read an article about detection of nuclear submarines could be done via neutrino detection if the detectors were small enough. This one seems to fit the bill. Like the SOSUS array that is placed in ocean choke points to monitor for submarines acoustically I would think this may also work. Just a little mental meandering I don't know if it is really practical.
An Ultrahigh Neutrino Detection Makes Waveshttps://physics.aps.org/articles/v18/35
