(Adds economy minister comment in paragraphs 11-12)
SOFIA Jan 12 (Reuters) - Bulgaria might be forced to restart a nuclear power reactor it shut in 2006 if the cut-off in Russia gas supplies drags on, Prime Minister Sergei Stanishev said on Monday.
The Balkan country, one of the hardest-hit in the Moscow-Kiev gas price spat, had been able to cover the rise in power demand as many consumers switched to electric heaters and did not need additional power capacity for now, Stanishev said.
"We have informed the European Commission that if the gas crisis continues we would be faced with a situation where we would need to restart one of the shut nuclear reactors," he told parliament which held an extraordinary meeting over the gas cut.
Stanishev referred to two 440 megawatt Soviet-era units at Bulgaria's only nuclear power plant, Kozloduy.
Sofia closed down the two reactors at the end of 2006 as a condition to becoming a European Union member. Kozloduy has two remaining reactors at 1,000 MW each.
Slovakia, which last week declared a state of emergency, also plans to restart a nuclear power unit it shut down at the end of 2008.
The government in Bratislava said on Monday it would give the order for the restart of its Bohunice plant, criticised by neighbouring Austria as unsafe, if Monday's talks in Brussels did not give assurances of gas supply resumption.
Nuclear industry officials in Sofia said Bulgaria needed a green light from Brussels to restart one of the shut reactors and at least 30 days to prepare the unit for operations.
Stainshev said daily electricity consumption had jumped to nearly 7,000 MW and Bulgaria kept exporting 632 MW, mainly to Greece and the western Balkans.
Bulgaria has capacity to produce another 1,100 MW of power from hydro and thermal-power plants but that would not be enough to cover demand if the gas disruption continued for longer, Stanishev said.
In Brussels, Dimitrov said reopening old reactors would be unavoidable in a crisis situation and urged the EU to reconsider its reliance on gas.
"The European Union should consider if it should continue to be very dependent on gas, or whether to consider the lesser dependency of nuclear," Dimitrov said.
The cut-off in gas supplies left hundreds of thousands without heat for several days in freezing weather last week and forced dozens of factories across eastern Europe to shut down.
Heat has been restored since Friday after utilities switched to alternative fuels. (Reporting by Anna Mudeva; Additional reporting by Pete Harrison in Brussels; editing by James Jukwey)