A Low-Cost and Semi-Autonomous Robotic Scanning System for Characterising Radiological Waste

Stephen David Monk,David Cheneler,Allahyar Montazeri,Nile Dixon,C James Taylor,Manuel Bandala,Craig West

doi:10.3390/robotics10040119

Abstract

A novel, semi-autonomous radiological scanning system for inspecting irregularly shaped and radiologically uncharacterised objects in various orientations is presented. The system utilises relatively low cost, commercial-off-the-shelf (COTS) electronic components, and is intended for use within relatively low to medium radioactive dose environments. To illustrate the generic concepts, the combination of a low-cost COTS vision system, a six DoF manipulator and a gamma radiation spectrometer are investigated. Three modes of vision have been developed, allowing a remote operator to choose the most appropriate algorithm for the task. The robot arm subsequently scans autonomously across the selected object, determines the scan positions and enables the generation of radiological spectra using the gamma spectrometer. These data inform the operator of any likely radioisotopes present, where in the object they are located and thus whether the object should be treated as LLW, ILW or HLW.

Highlights

The determination of radioactivity within waste is of vital importance within the nuclear industry in general
Sorting and segregation operations are an example of this, in which waste is categorised into very low-level waste (VLLW), low-level waste (LLW), intermediate-level waste (ILW) and high-level waste (HLW), depending on the type and activity of radioactivity emitted
The aim of the work was to aid in the reduction in disposal costs of items such as PPE by roughly determining the specific activity of items

Summary

Introduction

The determination of radioactivity within waste is of vital importance within the nuclear industry in general. Sorting and segregation operations are an example of this, in which waste is categorised into very low-level waste (VLLW), low-level waste (LLW), intermediate-level waste (ILW) and high-level waste (HLW), depending on the type and activity of radioactivity emitted. Depending on which category the item corresponds to, the disposal cost can vary dramatically with rough costs of ~GBP 3000/m3 for LLW, ~GBP 50,000/m3 for ILW and ~GBP 500,000/m3 for HLW [1,2,3]. Rather than taking a worst-case scenario approach and treating everything as HLW, it is financially prudent to categorise waste correctly before disposal. The robotic systems used within sorting and segregation operations are still typically tele-operational, since automated systems are not yet at a stage where trust levels are such that the industry would allow a “no human in loop” situation. Research into robotics within the nuclear industry has increased significantly over the last decade or so, with numerous projects in this area such as the RoMaNs project based at the National Nuclear Laboratory [4], the extensive work by Stolkin et al [5,6,7,8] and work inspired by events such as the Fukushima Daiichi NPP disaster of 2011 [9,10,11,12,13,14,15,16]

Objectives

Results

Discussion

Conclusion