Crawling through a pipe at a defunct nuclear materials facility to check for hazardous residual waste is not what one would call a rad job.
But it is the perfect job for RadPiper.
A team at Carnegie Mellon University has designed a robot to roll down sections of potentially contaminated pipe and measure precise amounts of Uranium 235, said Red Whittaker, a robotics professor that led the team. The robot could shave tens of millions of dollars from the cost to inspect shuttered nuclear sites and prevent humans from undertaking an often dangerous, difficult and tedious job.
A pair of RadPiper robots will begin crawling through pipes in May at a former uranium enrichment plant about 70 miles south of Columbus in Piketon, Ohio.
“It will go where no human has or will,” Whittaker said.
Members of the CMU team are in Arizona this week to present papers on RadPiper and demo a prototype at the Waste Management Symposia.
RadPiper crawls down sections of pipe on a pair of tank-like tracks. The robot has a LiDAR sensor and fisheye camera lens to look for obstacles.
The robot’s sodium iodide sensors, which count gamma rays and are capable of ultra-precise measurements, are sandwiched between two lead plates to keep radiation from other sections of the pipe from contaminating the results. CMU is seeking a patent on the sensor setup, Whittaker said.
The robot, which operates without a tether, will travel a length of pipe, take measurements and automatically return to its base, where it will upload the data and auto-generate reports.
RadPiper could save tens of millions of dollars in finishing work at the Portsmouth Gaseous Diffusion Plant in Piketon and perhaps save $50 million more at a similar plant in Paducah, Ky.
It took crews more than three years and 1.4 million measurements to complete work in only one of the Piketon plant’s three buildings. Rodrigo V. Rimando Jr., director of technology development for DOE’s Office of Environmental Management, expects RadPiper to do the job eight times faster in the next building in Piketon.
“With more than 15 miles of piping to be characterized in the next process building, there is a need to seek a smarter method,” Rimando said in a statement.
The Piketon plant spans the equivalent of 158 football fields and has more than 75 miles of pipe to inspect. The plant started enriching uranium, including weapons-grade materials, in 1954. It closed in 2000. The U.S. Department of Energy has hired a contractor to begin decommissioning the plant.
The DOE paid CMU $1.4 million to develop the robots. Rimando said the robots could be useful elsewhere in the department’s nuclear cleanup program, which isn’t even half complete.
“It’s important to the nation. It’s important to the world,” Whittaker said. “This will ripple. It will be embraced. It will really change the way this is done.”
Whittaker is no stranger to sending robots into toxic nuclear sites. In the mid-1980s, Whittaker and students at CMU built some of the first robots designed to go places contaminated with nuclear fallout or waste. The robots were designed to help clean up after the 1979 partial meltdown at the Three Mile Island nuclear power plant near Harrisburg and the Chernobyl nuclear reactor disaster in Ukraine.
Whittaker said 30 years ago, there were no digital cameras or controls, no printed circuit boards or solid state electronics. The early teams at CMU were wrestling with how to design a robot to endure radiation. Combining manipulation and mobility into a single machine were big breakthroughs.
Technology is far more advanced than what was used at Three Mile Island.
“This project called to me,” Whittaker said. “It’s always wonderful to marry a bold technology with a compelling motivation that really matters.”