TOKYO, May 14 (Xinhua) -- Japan will hang on to nuclear power as a main energy source while trying to expand other energy sources to diversify risks, according to an annual report on national energy policy released Friday.

Despite a data cover-up scandal involving Tokyo Electric Power Co. two years ago, the government vows in the report to continue promoting an energy policy that designates nuclear power generation as a key source of energy with the basic premise that safety should be ensured.

It is the first annual report compiled on energy issues by the Natural Resources and Energy Agency, an organization under the Ministry of Economy, Trade and Industry.

After the TEPCO scandal, the government implemented steps to tighten safety regulations on nuclear power generation such as making inspections mandatory instead of voluntary, the report says.

The report stresses the merits of nuclear energy, saying it is recyclable and free of carbon dioxide, a global warming gas.

At the same time, it is necessary for the government to fully implement safety regulations while power companies must do their utmost to restore public trust, the report says.

As an energy resource-scarce country, Japan has been trying to diversify its energy sources with the dependency ratio on oil dropping to 49.4 percent in fiscal 2001 from 77 percent in fiscal 1973.

Nevertheless, oil accounts for nearly half of national energy supply, and about 90 percent of it comes from the politically unstable Middle East region, the report says.

As part of efforts to promote use of new energy sources, the government put a new law into force in April 2003 which requires power suppliers to use a certain percentage of designated new energy sources such as wind power and ground heat.