TOKYO (AP) — Images taken by miniature drones from deep inside a badly damaged reactor at the Fukushima nuclear plant show displaced control equipment and misshapen materials but leave many questions unanswered, underscoring the daunting task of decommissioning the plant.

The plant’s operator recently shared 12 photographs of the pedestal, the main structural support of the No. 1 reactor’s primary containment vessel. This area is directly below the core and was greatly affected by the damage caused by a powerful earthquake and tsunami in 2011. Officials have been eager to access this area in order to assess the condition of the core and the melted nuclear fuel that had accumulated there.

Previous efforts utilizing robots were unsuccessful in accessing the location. A two-day investigation utilizing miniature aerial vehicles was conducted last week by Tokyo Electric Power Company Holdings, also known as TEPCO, who shared the images on Monday.

Approximately 880 tons of extremely radioactive molten nuclear fuel remains within the three impaired reactors. TEPCO is working towards gaining a better understanding of its whereabouts and state to aid in its retrieval, allowing for the decommissioning of the plant to take place.

The drones recorded high-quality images in color that display brown objects of varying shapes and sizes hanging from different points on the pedestal. The control-rod drive mechanism, responsible for regulating the nuclear chain reaction, and other equipment attached to the core were displaced.

According to TEPCO officials, they were not able to determine if the suspended masses depicted in the images were melted fuel or melted equipment without gathering additional information, such as radiation levels. The drones used in the investigation did not have dosimeters to measure radiation due to the need for them to be lightweight and highly maneuverable.

According to officials, the cameras attached to the drone were unable to capture the base of the reactor core due to the darkness inside the containment vessel. The data gathered from the drone could be crucial in researching and developing technologies and robots for removing the melted debris in the future.

However, the significant amount of uncertainty surrounding the reactors’ interior indicates the daunting challenge that lies ahead. Critics argue that the government and TEPCO’s goal of completing the plant’s cleanup within 30-40 years is overly optimistic.

The process of decommissioning has been put off for several years due to technical difficulties and inadequate information.

Source: wral.com