An assessment of contamination pickup on ground robotic vehicles for nuclear surveying application

Abstract

Ground robotic vehicles are often deployed to inspect areas where radioactive floor contamination is a prominent risk. However, the accuracy of detection could be adversely affected by enhanced radiation signal through self-contamination of the robot occurring over the course of the inspection. In this work, it was hypothesised that a six-legged robot could offer advantages over the more conventional ground robotic devices such as wheeled and tracked rovers. To investigate this, experimental contamination testing and computational Monte Carlo simulation techniques (GEANT4) were employed to understand how radioactive contamination pick-up on three different robotic vehicles would affect their detection accuracy. Two robotic vehicles were selected for comparison with the hexapod robot based on their type of locomotion; a wheeled rover and a tracked rover. With the aid of a non-toxic fluorescent tracer dust, the contamination received by the all three vehicles when traversing a contaminated area was initially compared through physical inspection using high definition cameras. The parametric results from these tests where used in the computational study carried out in GEANT4. A cadmium zinc telluride detector was simulated at heights ranging from 10 to 50 cm above each contaminated vehicle, as if it were mounted on a plinth. Assuming a uniform activity of 60 Bq cm−2 on all contaminated surfaces, the results suggested that due to the hexapod’s small ground-contacting surface area and geometry, radiation detection rates using an uncollimated detector are likely to be overestimated by between only 0.07%–0.12%, compared with 3.95%–8.43% and 1.75%–14.53% for the wheeled and tracked robot alternatives, respectively.

Phoenix: Towards Designing and Developing a Human Assistant Rover

“…The rover recognized and located a fixed α source embedded in the floor when the authors deployed it in a radiation active area. The findings of these studies [5], [6], [8], [9] show that human assistant rovers can be useful to replace or assist humans in risky environments. National Aeronautics and Space Administration (NASA) intends to bring Mars under human exploration mission reach within the 2030s [10].…”

“…Menon et al [7] developed a solar-powered, autonomous monitoring rover for various agriculture-related tasks such as soil and weather parameter monitoring, fire detection, insect and pest infestation detection, etc. Banos et al [8] conducted a comparative test between three robotic platforms namely wheeled, tracked, and hexapod, and found out that hexapod robotic platforms performed significantly better in terms of picking up and spreading lesser radioactive contamination during operation. Similarly, Bird et al [9] developed Continuous Autonomous Radiation-Monitoring Assistance (CARMA) robot.…”

Vega—A small, low cost, ground robot for nuclear decommissioning

“…The dust was believed to be a comparable substitute to the fine oxide particulates that would be expected in a decommissioning environment (Haskins, 1995). The contamination testing work is discussed at length by Banos et al (2021), where the cleanup effort was compared to that required for a Hexapod robot. The Hexapod robot was found to spread the contamination significantly less due to its smaller ground contact area, however, as with Vega the contamination was difficult to remove completely.…”

An approach for numerical simulating and processing of measured electrical signals from board sensors installed on wheeled electro-mechanical platforms

“…The wheeled platforms are widely used now for different industrial [1], agricultural [2][3][4] and military [5] purposes, for surveying the nuclear hazard [6] and for others. Due to these circumstances, all different researches directed to development, improvement and implementation of different kinds wheeled platforms for different purposes are in current interests now, and a lot of publications like [1][2][3][4][5][6] confirm this.…”

“…One of the principal trends in developing the wheeled platforms is in implementing the partial and fully automation allowing to exclude the staff from executing labour intensive, hazard, monotonous and not creative operating tasks [1][2][3][4][5][6]. It is naturally, the automation of wheeled platforms is significantly restricted by opportunities of instrumental measures for estimating their motion state and their interactions with an environment necessary to define the required controls.…”