Detector-carrying vans and aircraft helped in the search. Of course, finding the nuclear device might be the easy part. Dismantling it without a catastrophic explosion would be the ultimate in bomb squad jobs. X-rays, infrared sensors, and other devices would be used to try and get a picture of what the disablement team faces. A 30mm cannon might just blow the device apart, if the team deems that safe.
NEST also has a large tent which can be erected over a suspected bomb, and then pumped full of foam.
Reportedly, NEST has a liquid abrasive cutter which can be used to slice into suspected bombs. Sparks from a metallic saw or cutter could set off a nuclear detonation. Forty NEST personnel were sent to help in the wake of the Three Mile Island nuclear reactor accident. Every few years security personnel contact NEST members to make sure they want to continue their membership in America's version of a nuclear National Guard. But I'm still doing it.