Cannonball-like underwater robots being developed for nuclear reactors


July 21, 2011

Researchers are developing small, round swimming robots that could check pipes in nuclear reactors for leaks (Image: MIT)

Researchers are developing small, round swimming robots that could check pipes in nuclear reactors for leaks (Image: MIT)

According to the Associated Press, a recent study has revealed that three quarters of America's nuclear reactors have leaked radioactive tritium from buried pipes that transport water for the cooling of reactor vessels. This tritium could in turn find its way into the groundwater. While industry officials do reportedly check these pipes for leaks, they can only do so in either indirect or costly, labor-intensive manners. Now, however, researchers from MIT are developing tiny, spherical swimming robots that could check on the pipes directly, relaying their findings in real time.

Using present technology, the easiest ways of looking for leaks include applying an electrical current to pipes to check for corrosion, or applying ultrasonic waves to identify cracks. These methods are both indirect, however, and could potentially miss things. The only truly direct approach is to dig the pipes up and look at them, which is obviously a very involved process.

The egg-sized MIT robots would be placed inside the pipes and move through them, observing their inner surfaces with a built-in video camera, and transmitting live images up to 100 meters (328 feet) via a laser optic system.

Because protruding propellers or rudders could cause the robots to get stuck, they would instead be propelled simply by harnessing the existing flow of the water. They would be steered using a series of Y-shaped valves in their outer skins, that connected to a network of tiny internal pipelines. Selectively opening and closing theses valves would determine which pipelines the water could flow into and jet out of, taking advantage of a phenomenon known as the Coanda effect. This jetting action would control the direction in which the robots moved.

The researchers are also developing a system that would allow the camera to pan and tilt. This would be achieved through a two-axis gimbal inside the robot, that would shift its mass back and forth and up and down, thus allowing it - and the camera - to face in any direction on command.

Pipes filled with radioactive material are not a friendly environment, needless to say, so the robots are being designed with the assumption that they would only last for a few missions before needing to be replaced. They could nonetheless be performing a very valuable service.

"We have 104 reactors in this country," said MIT's Harry Asada, a professor of engineering. "Fifty-two of them are 30 years or older, and we need immediate solutions to assure the safe operations of these reactors."

About the Author
Ben Coxworth An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth

Is this really news? I assumed that the local civil engineers in every locality had these devices numerously & readily available in every water supply on the planet.

But then I\'m not a civil engineer. Perhaps they are all professionally negligent?

Greg Zeng

Hey GIZMAG - do your homework before posting in support of the nuclear industry.

You say 'This tritium could in turn find its way into the groundwater.'

AP has reported that radioactive tritium HAS ALREADY contaminated well water at high levels. Keep it straight...


BEKRL: that why I can\'t take anti-nuclear people serious. You apparently take an associated press investigations for face value... how about some source criticism


Jasper - because the Associated Press ranks right up there with the World Astrology Federation and the Psychic Friends Network in terms of credibility issues???? Or do you just automatically label any source dubious that tells you something you don\'t want to hear? At least BEKRL sourced his claim.


On a slightly different note may be some one can enlighten me but: \"transmitting live images up to 100 meters (328 feet) via a laser optic system\" strikes me as a line of site system?

Any waste pipes with bends, flow monitoring equipment, valves etc will not have a line of site, and on the reactors I worked on in the UK in the past, the water pipes were measured in kilometer lengths not meters, Where or to what are these robots communicating with?

Surely some sort of RF communications would be better?

Just wondering!


Hey Jasper - apparently the pro-nuke side is so lazy you can't even read a whole article before you talk crap.

AP's source info is:

Tritium, which is a radioactive form of hydrogen, has leaked from at least 48 of 65 sites, according to U.S. Nuclear Regulatory Commission records reviewed as part of the AP's yearlong examination of safety issues at aging nuclear power plants.

The source is the NRC.

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