Columbia Energy designed and constructed the first-of-its-kind Mobile Arm Retrieval System (MARS) Bulk for Washington River Protection Solutions. The MARS bulk system is designed to dislodge and retrieve hardened radioactive material within single-shell tanks (SST). This is performed by using high-pressure spray nozzles in an end-effector at the end of a telescoping arm and a centrally located slurry transfer pump.  These nozzles direct the resulting waste slurry stream toward the center of the SST where the adjustable height slurry transfer pump is located.

Full-scale testing demonstrated the ability to remove sludge simulant at approximately 925 gal/hr, sand simulant at approximately 140 gal/hr, and hard heel simulant at approximately 140 gal/hr using water sluicing to mobilize material and a pump to remove the waste.

Columbia Energy designed, engineered, fabricated, and tested the entire system for WRPS.  All fabrication work was performed under Columbia Energy’s NQA-1 program at the Columbia Energy Fabrication and Testing Center in Richland, Washington.  The system was fabricated and assembled by Columbia Energy including all plate fabrications, waste transfer systems along with the associated control racks, electrical distribution, and hydraulic skids.


  • Telescoping arm with 4 extensions. Reach length: 38 ft
  • Turntable rotational range: 380 degrees with 10 degree overlap
  • Rotary Union with Integrated Hose


  • U.S. Department of Energy (DOE)
  • Washington River Protection Solutions (WRPS)
  • Office of River Protection (ORP)

Design Features

  • Robotic / Hydraulic
  • Waste retrieval rate: 100-500 gals/hr
  • Radiation Hardened
  • CGD Components
  • Removing radioactive material from singe shell tanks
  • Remotely Operable


  • Mechanical Engineering
  • Conceptual & Detailed Design
  • 3D Modeling
  • Fabrication
  • NQA-1 Oversight
  • Construction
  • Testing
  • Operator Training