A small robot is roving around a massive U.S. nuclear waste site to gather critical samples of potential air and water contamination after an emergency was declared Tuesday. The machine was deployed after a tunnel that stores rail cars filled with radioactive waste partially collapsed at Hanford Nuclear Reservation in Washington state. The mishap raised fears of a radiation leak at the nation's most contaminated nuclear site, though officials said there was no actual indication of a release of plutonium radiation as of 2:20 p.m. PDT. The air- and soil-sampling robot is monitoring for any changes on the scene. This robot is being used at Hanford right now to sample contamination in the air and on the ground.

Few people ever need to deal with a stricken nuclear reactor, but that skill could turn out to be important for the evolution of smarter robots. In Pomona, California, this week, 25 of the world's most advanced humanoid robots will take part in a contest inspired by the challenge of stabilizing a nuclear reactor that's leaking dangerous radioactive material. Teams from universities across the U.S., as well as Japan, China, and Europe, are bringing robots that will try to walk across piles of rubble, climb ladders, operate power tools, and drive buggies, among other chores. Each challenge is inspired by something that might have helped stabilize the Fukushima Daiichi nuclear plant in Japan after it was damaged by an earthquake in 2011. Considerable academic kudos will go to whichever team completes the most tasks within the allotted time by the end of the contest.

How do you bring a bad drone down? New kinds of drones that can fly autonomously can't be stopped with traditional techniques, the US Air Force has warned. It's put out a call for ideas to yank drones right out of the sky. Millions of drones are sold worldwide each year. Most are flown for fun, but a few have been put to criminal use: carrying cameras to bedroom windows, flying into secure airspace over nuclear power stations, and smuggling contraband into prisons.

Atlas, the humanoid robot created by Alphabet (GOOGL, Tech30) company Boston Dynamics, can open doors, balance while walking through the snow, place objects on a shelf and pick itself up after being knocked down. The new version of Atlas is smaller and more nimble than its predecessor. It's fully mobile too -- the previous version had to be tethered to a computer. Atlas was created to perform disaster recovery in places unsafe for humans, such as damaged nuclear power plants. The robot made its debut in 2013 during a competition held by the Defense Advanced Research Projects Agency.