Finland's nuclear safety authority STUK on Thursday denied reports that it had found any new or serious safety shortcomings in the country's nuclear reactors.

"We submitted a report to the government in mid-May concluding that there was no danger of a Fukushima-like accident occurring in Finland," STUK nuclear safety expert Petteri Tiippana told AFP, adding that nothing had changed since then.

Regional Finnish daily Laensi-Suomi reported Thursday that according to STUK several reactors in Finland could suffer a core meltdown if, for some reason, they simultaneously lost power from all sources including the elctricity grid, diesel generators and gas turbines.

Tiippana said STUK did recommend in May that power companies Fortum and TVO make some improvements to things like guaranteeing electricity supply to the reactors and ensuring sea water could be used for cooling an overheating core.

This followed a survey of domestic nuclear power plants in light of the nuclear disaster at Japan's Fukushima plant.

"This is about fine-tuning safety procedure as a result of surveys done after Fukushima, but Finnish power stations fulfil all the current safety requirements which in principle take the Fukushima accident into consideration," Tiippana said.

Both TVO and Fortum have been asked to submit a report addressing these issues by mid-December, said Tiippana.

Japan's massive March 11 earthquake and tsunami sparked the world's worst nuclear accident since Chernobyl, resulting in explosions and core meltdowns in three reactors.