A Delicate Operation at Fukushima
The decommissioning of the Fukushima Daiichi nuclear power plant continues to face significant challenges, particularly the removal of melted nuclear fuel debris from the damaged reactors. This delicate operation is crucial for the long-term safety and stability of the site.
To tackle this task, Tokyo Electric Power Company (TEPCO), the plant operator, has developed a specialized device resembling a fishing rod. This device will be used to "hook" tiny bits of melted fuel from the No. 2 reactor, where radiation levels are relatively low.
The device, designed like a 22-meter-long fishing pole, was demonstrated at a facility in Kobe. It was inserted into a model of the pedestal supporting the reactor's pressure vessel to test its ability to grasp fuel debris with its claw-like arm.
The removal of melted fuel is considered the most challenging phase of the decommissioning process due to the extremely high radiation levels within the wrecked facility. TEPCO plans to begin the operation with a simple rod-style system before deploying a more sophisticated robotic arm at a later stage.
Originally scheduled to start in 2021, the fuel removal process has been postponed three times due to the COVID-19 pandemic and mechanical issues. The initial robotic arm design lacked sufficient precision, necessitating a change in approach.
With an estimated 880 tons of fuel debris remaining in the No. 1 to No. 3 reactors, the successful removal of this material is critical for the long-term safety and environmental remediation of the Fukushima Daiichi site. The fishing rod device represents a crucial step in this complex and ongoing process.