FUKUSHIMA, Japan -- Tokyo Electric Power Co. Holdings will use a survey robot to make direct contact with the radioactive fuel at its Fukushima Daiichi nuclear power plant this week, the first such attempt since the meltdown eight years ago in March.

A 15-meter device divided into several parts has been placed outside the No. 2 reactor building. "The probe is on standby," Takahiro Kimoto, a Tepco spokesperson, said during a tour of the plant Tuesday with Nikkei.

The apparatus will be assembled early Wednesday morning and then will be inserted into the reactor containment vessel through a side hole. The debris has solidified after melting under high temperatures. Touching the debris will help the machine assess how hard or fragile the material is.

Based on the results, the government and Tepco will decide in fiscal 2019 from which of the Fukushima reactors the fuel will be extracted, with work starting in 2021.

But the debris remains highly radioactive and comes in various forms, from rigid material to claylike substances, making removal extremely difficult. It is unclear whether the cleanup will go according to plan.

"I do not know if they will be able to extract everything," one expert said. "They may have to stop midway."

The earthquake and tsunami in March 2011 knocked off the fuel-cooling systems at the plant's reactors, triggering fuel meltdowns.

Japan envisions taking 30 to 40 years to decommission the crippled reactors. The process generally involves dismantling the facility and returning the land to a vacant lot, but Tepco has avoided saying whether it can accomplish this in 40 years. Issues with debris removal will cast a shadow on the utility's restructuring and Fukushima's recovery.

The area surrounding the No. 2 reactor remains dangerous as well. Though the light aquamarine building that houses the reactor still stands -- no explosion occurred during the accident -- radiation levels just outside still reach about 300 microsieverts per hour. This reporter was allowed to approach the building but only for five minutes or so.

The control room is located between the Nos. 3 and 4 reactors. Levers with labels like "containment vessel vent" and memos apparently scribbled during the catastrophe could be seen with small penlights. A set of keys scattered on the floor suggests that workers may have been searching for something, illustrating the chaos.

The situation inside the plant is improving, however. Only about 4% of the area requires full radiation suits as decontamination and the paving of roads progress.

But the estimated cleanup costs have swelled to 8 trillion yen ($72.4 billion) from 2 trillion yen initially, and all that money must come from Tepco's profits. And these expenses may balloon further depending on how the work progresses, affecting Tepco's restructuring plans.

Japan plans to decommission over 20 aging reactors all together. Building expertise and handing it down to the next generation is also crucial.

Mitsubishi Heavy Industries is collaborating with French partner Framatome on decommissioning work, pairing up to dismantle the Nos. 1 and 2 reactors at Kansai Electric Power's Mihama nuclear plant in Fukui Prefecture. Hitachi also partnered with demolition company Besterra in July, anticipating greater demand for scrapping nuclear facilities.