The delay is due to accidents that claimed the lives of two workers last month at the Fukushima 1 and Fukushima 2 nuclear plants, according to sources cited by the news agency.
The frozen soil shields are necessary to prevent radioactively contaminated water inside the plant from reaching the ocean. TEPCO began construction in June.
In 2013, TEPCO president Naomi Hirose made a promise to finish all cleanup work by March 2015.
On Tuesday, the company resumed other cleanup works after a two-week break to review the plant's security measures. The workers have also started constructing temporary repositories for radioactive soil and waste not far from the site. The repositories, under construction in the towns of Okuma and Futaba in Fukushima Prefecture, will hold 30 million tons of radioactive waste, according to Kyodo.
At the moment, 280,000 tons of water contaminated by radiation is being stored in tanks at the nuclear power plant. The water is to be filtered of 62 radioactive elements with the help of the Advanced Liquid Processing System (ALPS).
The Fukushima Daiichi nuclear plant disaster on March 11, 2011 was triggered by a 9.0-magnitude earthquake followed by a tsunami. Several of the plant's reactors suffered a partial meltdown and radioactive material leaked into the atmosphere, soil and sea. The nuclear disaster is considered the world's worst since Chernobyl.
