The challenge

Workers at the American National Laboratory had the task of maintaining an overhead crane. The customer needed to reduce worker dose rate to make operations more efficient and safe. It was unclear what strategy would achieve greatest reduction in dose rate. It was possible to shield the drums in the working area, but it was also possible to remove them completely. The challenge was to understand what intervention would work best. It was difficult to ascertain the levels of radioactivity as the drums were surrounded by shielding walls. Whilst it was possible to view the drums from above it would have put a worked at risk from working at heights.

The approach

The N-Visage Scanner was fixed to the crane and a number of scans were completed remotely while the operators remained safely behind the shield wall. The data was then combined in N-Visage Fusion to model the effects of different interventions. Different scenarios were simulated to calculate to most optimal strategy. Shielding individual drums was found to be impractical and less effective than removing the highest active drums.

The solution

Combining the data captured using the N-Visage Scanner with the N-Visage Fusion software we were able to estimate the best action to minimise the dose uptake to the crane maintenance workers. Time was saved by the customer as a number of trial-and-error simulations could be observed relatively quickly before committing to the real operation. The customer then carried out the recommended operation which involved removing drums with the highest radioactivity.