Scores of nuclear power plants worldwide are at risk from tsunamis or earthquakes similar to those that crippled Japan's Fukushima reactors, according to new research.
Many at-risk plants are in countries less able to cope with a disaster than Japan, experts have warned.
Seventy-six operating power stations in Japan, Taiwan, China, South Korea, India, Pakistan and the US are located in areas close to coastlines deemed vulnerable to tsunamis.
Of 442 nuclear power stations globally, more than one in 10 are in places deemed to be at high or extreme risk of earthquakes - in Japan, the US, Taiwan, Armenia and Slovenia - according to a new study by the analysts Maplecroft.
Helen Hodge, Maplecroft's natural hazards analyst, said: "Although Japanese nuclear facilities are particularly exposed, other countries could also face similar risks. South Korea, Taiwan, southern China, India, Pakistan and the west coast of the US have operating or planned nuclear facilities on tsunami-exposed coastlines, while nuclear sites in areas of high or extreme risk of earthquakes can be found in western US, Taiwan, Armenia, Iran and Slovenia."
Emeritus Professor Keith Barnham, a physicist from Imperial College London, commented: "Japan is one of the most advanced technological counties but one can see the problems they are having in coping with the aftermath. One fears for the reactors planned or operational in the environmentally unsafe areas of less technologically developed countries."
Nuclear safety experts cite the example of an ageing Russian-built nuclear reactor 30km from the Armenian capital, Yerevan. In December 1988, a powerful earthquake, which led to the deaths of at least 25,000 people, occurred in northwest Armenia. Although one of its reactors is being decommissioned, another remains operational. The International Atomic Energy Association has been involved in safety improvements at the plant for more than a decade.
But, according to the World Nuclear Association, "The present Metsamor plant is a concern to the European Union and to neighbouring Turkey, 16km away. There have been various calls to shut it down ... but Armenia is very dependent on it and has said that it will remain open until a replacement is commissioned."
* Fukushima officials confirmed two workers died in the tsunami.
* Officials are trying to seal a crack in a concrete pit at the No 2 reactor.
* It has been leaking radiation into the ocean.
* Concrete poured into the pit did not stop the leaks and Tepco was turning to water-absorbent polymers to fill the pipe.
* Officials are looking at alternatives to pumping in cooling water, including an improvised air conditioning system, spraying the reactor fuel rods with vapourised water or using the plant's cleaning system.