Underwater Nuclear Cleaning Vehicle (UNC-V)

Team: Jameson Chamberlain, Tyson Clyde, Travis Slade, Alyssa Smith, Kameron Sparks, Avery Stewart Stewart and Jacob Tolman

Problem Specifications

Performance Requirements

  • Robot weight ≤ 50 lb (goal: 30 lb)
  • Continuous operation ≥ 48 hours (goal: 72 hours)
  • Designed for autonomous operation
  • Operates on 120–480 VAC power

Environmental & Safety Constraints

  • Must comply with NEC 682 electrical safety standards
  • Operates at depths up to 50 ft
  • Withstands radiation exposure up to 1 R/hr

Operational Requirements

  • Capable of maneuvering entire 20 × 30 × 50 ft pool
  • Designed for cleaning both pool floor and walls

Design Description

Robot designed to

  • Traverse pool floor and walls
  • Agitate and remove debris
  • Collect scum via suction and filtration

Key Design Features

  • Waterproof structure
  • The subsystems are described in the system overview
  • Tethered power system
  • Integrated cleaning + mobility system

Design Decisions

  • Long operation time
  • Maneuverability in confined space
  • Autonomous
Full assembly of UNC-V underwater cleaning vehicle showing all major components including chassis, motors, pump, filter box, and electrical enclosure
Fig 1. Full assembly of UNC-V. Subsystems are described in figures 2-5.

System Overview

Labeled diagram showing thruster mount, motor mounts, electrical box mounts, front wheel mounts, rear wheels, DC motors, front wheels, agitator, thruster, vacuum tubing box, filter box, filters, and pump
Fig 2. Pump and Filtration Draws in water via pump, routes it through tubing to a filter box and four panel filters, then ejects it out the back.
  • 5500 GPH pump + 48-hour operational window.
  • Four panel filters arranged in a gradient to maximize surface area.
  • Flexible tubing and custom housing that mounts directly to the aluminum extrusion slots.
Fig 3. Chassis Structural skeleton of the UNC-V, maintaining component alignment under hydrostatic pressure via modular aluminum extrusions and high-strength brackets.
Fig 3. Chassis Structural skeleton of the UNC-V, maintaining component alignment under hydrostatic pressure via modular aluminum extrusions and high-strength brackets.
  • Primary framework made of T-slotted aluminum.
  • High-strength corner brackets keep the frame rigid load.
Fig 4. Movement and Agitation Handles motion and surface scrubbing via dual-drive motor configuration, four wheels, treads, and thruster
Fig 4. Movement and Agitation Handles motion and surface scrubbing via dual-drive motor configuration, four wheels, treads, and thruster
  • Two high-torque DC motors power left and right drivetrains.
  • Brush mechanically linked to the front wheel at a 1:3.67 ratio.
  • Treads over standard wheels provide navigation over drains and minor obstacles.
  • Thruster mounted at a downward angle to press the robot against the floor.
Fig 5. Electronics Manages power distribution, sensor processing, and autonomous navigation logic.
Fig 5. Electronics Manages power distribution, sensor processing, and autonomous navigation logic.
  • Waterproof central enclosure housing all logic components.
  • Arduino Portenta H7 handles navigation and sensor tasks.
  • Carrier board that interfaces the Portenta H7's connectors with the rest of the system.
  • H-Bridges and Relays allow Arduino to switch motors and pump on and off.
  • Pressure Sensors are in filtration tubing and trigger a filter replacement alert when pressure drops below a threshold.
  • Ultrasonic dual sensors enable SLAM, allowing the robot to triangulate its position and ensure full floor coverage.

Performance Review

Requirements/Constraints Target Threshold Predicted or Tested Performance*
Requirements
Weight (not including tether) 30 pounds 50 pounds 37.2 pounds
Operation Time 48 hours 72 hours 48 hours
Autonomous Fully autonomous N/A Fully autonomous
Voltage 120 VAC 480 VAC 120 VAC
Constraints
NEC 682 N/A Compliant Compliant
Operation Depth N/A 50 feet 65.6 feet
Radiation Resistance N/A 1 Roentgens/hour 1 Roentgens/hour for 7.4 years
Operability N/A Maneuver entire 20x30x50 cubic foot pool Maneuvers any pool size

Table 1. Compiled performance review of UNC-V. See also * in Performance Review Continued.

Graph plotting radiation shielding effectiveness for different materials, showing thickness in millimeters versus shielding effectiveness
Fig 6. Plot of radiation shielding for different materials.

Performance Review Continued

Tether Length: The 75 ft tether provides 13.36 ft of slack beyond the geometric worst-case pool diagonal, ensuring zero cable tension at the furthest point of the mission.

Buoyancy: The robot maintains an apparent submerged weight of 16.09 lbs, intentionally designed to keep the treads pressed firmly against the pool floor during high-flow pump operation.

Conclusion

Requirements Met: The UNC-V met or exceeded all major requirements — 37.2 lbs (under 50 lb threshold), 120 VAC input, NEC 682 compliant, and rated to 65.6 ft depth.

Proof of concept validated: The robot successfully demonstrated autonomous linear navigation, continuous pump and motor operation, and structural integrity in a submerged environment.

Key limitation: Tread traction and ultrasonic sensor blind spots of within 1.5 ft are preventing full autonomous turning, meaning complete pool coverage was not yet achieved.

Waterproofing caveat: A gasket failure after 60 minutes limited the operation time test, though all other subsystems remained stable — a seal replacement is expected to resolve this.

Path forward: With improved treads, short-range sensors, and a refreshed enclosure seal, the UNC-V is well-positioned to meet the full 48-hour autonomous cleaning requirement.

Acknowledgements & Contact Info

The authors would like to thank the Naval Nuclear Laboratory, the College of Engineering, and Utah State University for making this project possible.