Tokyo Electric Power Co. (TEPCO) will release a new management plan later Wednesday which suggests it may need up to 10 trillion yen ($125 billion) -- around 2 percent of Japan's GDP, the Yomiuri Shimbun newspaper said.

The company would need more government help to meet the colossal figure.

The Mainichi Shimbun newspaper reported the company believes the cost of decontamination and decommissioning alone will reach 10 trillion yen.

In its previous plan, submitted in April, TEPCO offered the Japanese government a controlling stake in return for a huge cash injection -- around 1 trillion yen -- that would prevent it going under.

At that time, TEPCO estimated the total cost of compensation and decontamination would be up to five trillion yen.

It said it had received financial backing from new government bond issuance to cover the amount.

However, unexpectedly difficult decontamination is likely to see costs soar, the Yomiuri said.

Under the new plan, TEPCO will also announce additional cost-cutting efforts aimed at saving 100 billion yen a year, the Yomiuri reported.

The devastating tsunami of March 2011 swamped cooling systems at the Fukushima plant, sending reactors into meltdown and spewing radiation over a large area.

The clean-up is expected to take decades, with scientists warning that some settlements may have to be abandoned.