Radball ready to roll

24 June 2008

Nuclear decontamination and clean-up jobs could be simplified in future by a novel tennis-ball-sized device able to help map radiation sources. Using the device should be cheaper and easier than robotic or manual surveying.


The two components of the Radball
(Image: Nexia Solutions)
The Radball is based on a translucent polymer which responds to radiation. By surrounding a globe of the material in a lead colimer, the device can be used to create a map of radiation sources in a given space.


The colimer is a lead sheath with about 120 small holes. The lead stops virtually all radiation, but its holes allow radiation to enter the polymer, where its ionizing effects conjoin polymer chains, leaving tracks which hold information on the type and strength of radiation from the area beyond the holes in the colimer.


The next step is to analyse the information stored in the core tracks. This is done optically, taking snapshots through the core from multiple angles to build up a 3D model of the radiation paths. It is then possible to project this information onto a model of the space that has been analysed, allowing nuclear project managers to identify hotspots within the space.


Steven Stanley, who developed the device as part of his work at the UK's Nexia Solutions research company, told World Nuclear News: "This is all about radiation surveys without having to deploy an operator. Usually hand- or robot-held radiation surveys lack accuracy and directionality. Therefore we believe there are significant safety, cost and operational benefits to the device."


The Radball could be left in a radioactive area, for example a glovebox to be decommissioned, until it has had enough radiation exposure to form a data-rich 'image'. Then, project mangers would be able to more accurately characterise and prioritise its decommissioning. "It is suitable to particularly high radiation fields which would frazzle electrical-based equipment," said Stanley.


While different types of polymer can be used for different radiation intensities, the Radball remains most suited to detecting gamma radiation from uranium and plutonium. The material in the polymer core has been used in the medical industry to analyse radiotherapy dosages.


Stanley said the Radball was already being deployed in the UK, while the analytical software was still under development. "A first version should be out soon," he said.