A whole bunch of welds in nuclear reactors are visually inspected using cameras duct taped onto the end of incredibly long poles which also get duct taped together. This would be the inside of BWR plants near the fuel and jet pumps. There is also an “art” to moving the cameras and poles around to get the shots you need. And if you get stuck the talented people know how to get you unstuck. There are also cameras just duct taped to ropes that the camera handler “swims” to certain spots.
Don’t get me wrong, we have cool ultrasonic inspecting robots as well, but I was absolutely blown away by what visual inspection looked like in practice.
PS: The high dose fields make the camera look like it is being blasted with colorful confetti because of the high energy particles bombarding the camera module.