Electric utilities' output from thermal power plants rose to a record in January as the nation's nuclear power stations remained idled until they clear new safety rules established following the March 2011 Fukushima disaster.

The country's 10 power utilities generated 65.5 billion kilowatt-hours of electricity at their fossil-fuel burning thermal plants in January, the Federation of Electric Power Companies said in a statement Monday. That is a record since the industry group started compiling data in April 1972, according to the FEPC.

All of the 48 operable reactors are shut for inspections, with no fixed date for restarting them.

Japan, which imports almost 100 percent of its energy resources, is relying on thermal power generation to fill the void left by the shutdowns.

The 10 utilities consumed 5.6 million tons of coal in January, a record for the month and 12 percent more than a year earlier, according to FEPC.

Liquefied natural gas usage declined 0.8 percent to 5.12 million tons.