HELSINKI (AFP) - While Japan struggles to cool an overheating quake-damaged nuclear power plant, Finland on Monday called for a study on how its own nuclear network could withstand floods and other natural disasters.

"The report ... must especially look at how the nuclear power plants' internal and external electricity supply functions during disruptions and accidents," the Finnish labour and economic affairs ministry said in a statement.

The key issue that needed to be studied was the electrical supply to nuclear reactor safety mechanisms, ministry nuclear expert Jorma Aurela told AFP.

"In the end, it's simply up to the electricity supply. If the safety systems get electricity, you don't have to go to such extreme measures as using sea water as coolant," Aurela said, referring to emergency measures being taken in Japan to cool fuel rods at the badly damaged Fukushima plant.

For this reason, each of Finland's four nuclear reactors is connected to four backup generators, which according to Finland's Radiation and Nuclear Safety Authority, STUK, is more than Japan built for its reactors.

Japan's backup generators were wiped out by the tsunami which followed Friday's 8.9-magnitude earthquake.

"The case in Japan teaches us that we also should take a close look at our systems. Have we prepared enough for large floods and other situations, so that nothing serious could ever happen?" Economic Affairs Minister Mauri Pekkarinen asked in an interview with public broadcaster YLE.

In Finland, extreme flooding is the most likely natural disaster that could affect the country's reactors, Aurela said, especially as a result of the occasional massive winter storms that roll in from the west.

The ministry said it had the assurance of STUK experts that Finnish nuclear reactors were extremely safe, but that a report on its readiness in the face of natural disasters was still needed.

Four nuclear reactors are in use in Finland, while power company TVO is building a fifth and the parliament last year voted in favour of building two more.