Global use of nuclear energy could increase by as much as 100 percent in the next two decades on the back of growth in Asia, even though groundbreakings for new reactors fell last year after the Fukushima disaster, a U.N. report says. The report by the International Atomic Energy Agency (IAEA), which has not yet been made public but has been seen by Reuters, said a somewhat slower capacity expansion than previously forecast is likely after the world\'s worst nuclear accident in a quarter of a century. But, it said: \"Significant growth in the use of nuclear energy worldwide is still anticipated - between 35 percent and 100 percent by 2030 - although the Agency projections for 2030 are 7-8 percent lower than projections made in 2010.\" Japan\'s reactor meltdowns at the Fukushima nuclear plant triggered by a deadly earthquake and tsunami on March 11 last year shook the nuclear world and raised a question mark over whether atomic energy is safe. Germany, Switzerland and Belgium decided to move away from nuclear power to grow reliance on renewable energy instead. The IAEA document, obtained by Reuters on Friday, said the number of new reactor construction starts fell to only three last year - two in Pakistan and one in India - from 16 in 2010. Also last year, 13 reactors were officially declared as permanently shut down, including the four units at Fukushima as well as eight in Germany. \"This represents the highest number of shutdowns since 1990, when the Chernobyl accident had a similar effect,\" the Vienna-based U.N. agency said in its annual Nuclear Technology Review. \"As a comparison, 2010 saw only one shutdown and 2009 three.\" In 1986, a reactor exploded and caught fire at Chernobyl in the then Soviet Union, sending radiation billowing across Europe. TEMPORARY DELAYS? At Fukushima one year ago, fires and explosions caused a full meltdown in three reactors while a fourth was also damaged. Today, the four reactors are in a stable, cold shutdown state and clean-up of the site continues, but the final phase of decommissioning will not happen for 30 or 40 years. Almost all of Japan\'s 54 reactors sit idle, awaiting approvals to restart. \"The 7-8 percent drop in projected growth for 2030 reflects an accelerated phase-out of nuclear power in Germany, some immediate shutdowns and a government review of the planned expansion in Japan, as well as temporary delays in expansion in several other countries,\" the IAEA report said. But many countries are still pushing ahead with nuclear energy, with 64 reactors under construction at the end of 2011, most of them in Asia, said the document prepared for a closed-door meeting of the IAEA\'s 35-nation board last week. Factors that had contributed to growing interest in nuclear energy before Fukushima - increasing demand for energy, concerns about climate change, energy security and uncertainty about fossil fuel supplies - had not changed, it said. \"In countries considering the introduction of nuclear power, interest remained strong. Although some countries indicated that they would delay decisions to start nuclear power programs, others continued with their plans to introduce nuclear energy.\" China and India are expected to remain the main centers of expansion in Asia and Russia is also forecast to see strong growth, it said.