In January 2020, the TORONE robot saw its first active deployment at the TRIGA Mark II research nuclear reactor operated by the Jožef Stefan Institute, Ljubljana, Slovenia. Part of the characterisation capabilities of TORONE is to produce 2D maps of radiation intensity, for unknown environments in the nuclear sector being able to highlight possible radiation sources is important.
In real-world scenarios, the distribution of radioactive materials could be anything, but in the lab we are typically limited to point sources of radiation. The TRIGA reactor can produce non-point source radiation fields in a controlled manner, replicating more realistic scenarios which could be found during nuclear decommissioning challenges.
Radiation sensors were integrated with the Clearpath Jackal robot, then manually driven around the reactor hall, recording the number of radiation events per second and the position of the robot from on-board LiDARs and SLAM (Simultaneous Localisation and Mapping). The reactor was operated at low power (1kW, just 0.4% full power), and a beam port of the reactor core opened to create a low level radiation field around one portion of the reactor hall.
The robot was capable of correctly detecting this radiation, as well as successfully identifying radioactive sources in storage containers around the reactor hall in general. For example, the port plugs placed on the floor next to the open beam port, which are slightly radioactive due to the bombardment by neutrons when in their usual position installed in the port, were recognised as sources of radiation.
These maps will be useful for decision makers when tackling issues such as how to decommission nuclear facilities safely and effectively, and are just one of the many characterisation problems TORONE is striving to overcome.