Overpack drums are used to contain a wide variety of hazards, from harsh chemicals to combustible materials. One of the more dramatic uses of these drums is to store spent nuclear fuel.
The fuel rods are confined in a welded stainless steel canister that is shielded and protected by a concrete and steel overpack drum, then placed into storage. While this may be the best solution we have right now for our nuclear waste, this process requires regular maintenance and examination to ensure safety. These storage casks need to be frequently inspected for degradation such as stress corrosion cracking. Unsurprisingly, inspecting hundreds of tightly packed irradiated barrels is not the safest task for a human to undertake.
That’s where the lasers come in.
By utilizing laser ultrasonics, a fancy method of shooting pulse lasers at an object, researchers have combined that process with fiber optics and a very specially-developed lens, integrating it into a robot system. That way, their compact set up can provide a clear, nondestructive inspection of the degradation happening to each barrel, specifically pitting. What that all means is that inspectors will have tools that can operate in the harsh, confined and hazardous spaces that are generated situations such as nuclear waste storage, piloting the robot from a safe distance.
This technology can be applied further than merely overpack drums. It’s suited for any environment that is cramped, high temperature, highly irradiated; anywhere that’s unsafe for humans. In particular, the system is great for inspecting defects in pipelines exposed to high temperatures and radiation inside nuclear power plants and inspection of inaccessible, cramped and hazardous areas for preventive maintenance.
Lasers and nuclear waste? Sounds like a dystopian sci-fi plot, but it is very much a current scenario. At this point, research is still ongoing to perfect the system, and it’s unclear how close they are to becoming commercially available tools. As long as we continue to store waste in the current, overpack method, the importance of technology to reduce the risk of hazard will only become more critical as time goes on.