TOKYO: Tokyo Electric Power Company Holdings Inc. resumed on Tuesday morning experimental work to remove nuclear fuel debris from a reactor at its meltdown-stricken Fukushima No. 1 nuclear power plant in northeastern Japan.

The trial is the first attempt to remove the debris since the March 2011 nuclear accident at the plant.

The work at the No. 2 reactor of the plant was scheduled to begin Aug. 22, but was halted as five pipes to be attached to a debris-removal device turned out to have been arranged in the wrong order.

The pipes were arranged by a partner company in July, but TEPCO never checked the order in which they were arranged. After the halt, TEPCO officials engaged in related confirmation work in an effort to prevent a recurrence of problems in the preparation phase. TEPCO President Tomoaki Kobayakawa checked the order of the pipes himself Monday, the officials said.

If portions of the debris are removed successfully, efforts to decommission the disaster-crippled plant will enter a new stage.

According to TEPCO, Tuesday’s work started around 6:35 a.m. A remotely operated telescopic-type device, shaped like a fishing rod, was inserted into the reactor containment vessel after being moved through the isolation valve leading to the vessel around 7:20 a.m. The device then started the trial extraction.

The device will collect up to about 3 grams of debris from the bottom of the vessel. The work is expected to take up to two weeks to complete.

The collected debris will be examined at a facility of the Japan Atomic Energy Agency and the information obtained from the examination, including on the hardness and characteristics of the debris, will be used for research toward carrying out full-scale removal work.

A total of some 880 tons of debris, or a mixture of melted fuel and reactor structures, is estimated to be left in the No. 1 to No. 3 reactors at the plant. But conditions and other details of the debris are unknown.

The debris removal work is seen as the most difficult part of the process to decommission the plant due to extremely high radiation levels.

TEPCO had initially planned to begin the experimental removal work in 2021, but postponed it three times due to delays in developing related devices abroad and other issues in the preparation phase.

In response to the resumption of the debris-removal work, Chief Cabinet Secretary Yoshimasa Hayashi, Japan’s top government spokesman, told a news conference Tuesday: “We are entering the most difficult work phase, which is the fundamental part of the decommissioning process. We would like to call on TEPCO to handle the task with an even stronger sense of tension than before.”

“The government will also manage the situation in a responsible way so as to achieve a safe and steady decommissioning of the plant,” Hayashi added.

JIJI Press