Fears of a nuclear meltdown in Japan will lead to major soul searching about the future of the industry in Canada and around the world, says an energy analyst.

Ontario-based Tom Adams predicts people will be asking themselves whether nuclear power is worth the risk as the crisis unfolds following the 8.9-magnitude quake.

"At minimum, it's going to send us back to the drawing board on the safety of existing reactors," Adams said in an interview.

"We just know from history that there are gong to be huge consequences."

In the past, Adams said nuclear accidents and near-accidents have led to more stringent safety requirements.

That's a good thing, he said, but it also means nuclear power will become even more costly to produce.

Japanese officials have been scrambling to prevent the meltdowns of five nuclear reactors at two power plants after their units lost cooling ability after the powerful tremor and tsunami on Friday.

An explosion Saturday shattered a building housing one nuclear reactor, though officials said the radiation leak was decreasing.

A government spokesman said the explosion destroyed the exterior walls of the building where the reactor is placed, not the actual metal enveloping the reactor.

Canada's nuclear regulator, meanwhile, said it's confident Canadian reactors could withstand such an event.

The Canadian Nuclear Safety Commission issued a statement saying the country's nuclear plants "are among the most robust designs in the world" in the world.

It says they have tools in place to prevent damage in the case of a quake.

A spokeswoman for Atomic Energy of Canada Ltd., the country's nuclear energy research program, said reactor sites in Canada are built on sturdy ground.

Robin Forbes said the sites have been "geologically screened to make sure that they are built in a location that is seismically stable."

With files from The Associated Press