Japan will continue to use nuclear power as its 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 reactor-fault coverup involving Tokyo Electric Power Co. two years ago that led to a shutdown of all of its reactors, the government says in the report it will continue promoting nuclear power as a key source of energy. The basic premise is that safety should be ensured.

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

After the Tepco fiasco, the government implemented steps to tighten safety regulations on nuclear power generation, making inspections mandatory instead of voluntary.

The government report focuses on the merits of nuclear energy, which it says is recyclable and free of carbon dioxide.

The report says the government should implement safety regulations, and power companies must try to restore public trust, which has been damaged by other scandals and accidents.

The International Energy Agency said Japan's self-sufficiency rate in energy supply is 4 percent, the lowest among the Group of Seven leading industrial countries. The nation's self-sufficient energy supply comes mostly from hydroelectric power.

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

But about 90 percent of the nation's oil supply comes from the politically unstable Middle East, the report says.

To promote the use of new energy sources, the government put a new law into force in April 2003 that requires power suppliers to use a certain percentage of designated new energy sources, including wind power and ground heat.