

It’s a combination of conservative designs, robust training, and a zero tolerance safety stance where even minor misses that have any relationship to the reactor or power systems get throughly investigated through a formal process that seeks to understand and learn from mistakes rather than assign blame.
If anyone is curious, the Naval Nuclear Propulsion Program (NNPP) publishes the Gray Book with some history of the Program, the various arms that are involved to make it successful, and how the Program is managed including training, suppliers, labs, and fleet operations and maintenance.
Turn the Ship Around is a leadership book that also touches on safety and operations of a nuclear sub and is just a good read overall if your looking for a different way to think about bringing a leader in an organization.

What you want is a reverse proxy, something like Trafik or Nginx Proxy Manager makes it really easy to setup and even then lets yous apply a lets encrypt certificate for HTTPS support getting rid of the browser warnings.