A worker, wearing protective suits and masks, takes notes in front of storage tanks for radioactive water at Tokyo Electric Power Co's (TEPCO) tsunami-crippled Fukushima Daiichi nuclear power plant in Okuma town, Fukushima prefecture, Japan February 10, 2016. REUTERS/Toru Hanai

TOKYO (Reuters) - Japan's government on Friday nearly doubled its projections for costs related to the Fukushima nuclear disaster to 21.5 trillion yen ($188 billion), increasing pressure on Tokyo Electric Power (Tepco) 9501.T to step up reform and improve its performance.

The new estimates could mean a heavier burden for Tepco and other utilities that are helping to pay the costs, and could result in higher power bills for consumers in the long run.

In 2013, the Ministry of Economy, Trade and Industry (METI) had calculated the costs of the Fukushima meltdowns at 11 trillion yen. METI boosted its estimate as industry experts now see decommissioning of the wrecked Fukushima reactors at 8 trillion yen, quadruple an earlier estimate of 2 trillion yen.

The new projection, part of a recommendation from a government panel considering the future of Tepco and Fukushima Daiichi, also calls for 7.9 trillion yen in reparations, up from 5.4 trillion yen, and 5.6 trillion yen for the treatment and storage of contaminated soil, up from 3.6 trillion yen.

“For now, we don’t expect the costs to increase further, but new developments and unforeseen factors mean there is a chance they could go higher,” METI Minister Hiroshige Seko told a press conference.

“Decommissioning technological innovation and a speedier clean up could help reduce costs and it is important that we put effort into that,” he said.

Tepco’s portion of the burden has more than doubled to 15.9 trillion yen from 7.2 trillion yen, while other major utilities will need to pay 3.7 trillion. New electric companies will have to shoulder 240 billion yen.

A METI official said the new projections of the decommissioning costs are an estimate based on certain assumptions and the costs of the Three Mile Island nuclear accident, and does not represent a loss Tepco needs to book.

In the world’s worst nuclear calamity since Chernobyl in 1986, three reactors at Tepco’s Fukushima plant melted down after a magnitude 9 earthquake struck Japan in March 2011, triggering a tsunami that devastated a swathe of Japan’s northeastern coastline and killed more than 15,000 people.