(CNN) -- A spike in radiation and fears of potential meltdown at a Japanese power plant hit by the country's deadly quake and tsunami are raising concerns about the safety of nuclear energy.
So what will the disaster mean for the global nuclear power industry? And is it time to stop relying on nuclear power? CNN asked experts on the issue for their thoughts on what will happen next -- and the lessons we can learn from the accident.
Professor Paul Ekins
Energy and environment policy specialist, University College London Energy Institute
What has happened in Japan is an extremely rare event, but lots of people in Japan and elsewhere have questioned the wisdom of building a nuclear power plant in an active seismic area, and at the moment it would seem those questions are pretty justified.
We must never forget that nuclear power is potentially a very dangerous way of generating energy (though there are industries which have killed more people on a more regular basis -- not least mining coal).
There have been big accidents in the past, and we have learned lessons from them, but there have been no big nuclear accidents since Chernobyl in 1986. Obviously, that is a very good thing, however we must be careful not to get complacent.
Nuclear power is a difficult and potentially dangerous form of electricity generation, and so if you don't have to go down that route, it is probably better that you don't. It is not an easy option.
We have to reduce our reliance on fossil fuels, and nuclear energy is one of the three big technologies that could help us do that, along with renewables and carbon capture and storage, but we must do it properly.
Undoubtedly, the popular perception of nuclear power will take a knock in the wake of this; we were reminded in 1986 and we have just been reminded again, that it can be dangerous.
We will have to wait and see how the current situation will work out to see its impact on the image of nuclear power: If there is a catastrophic meltdown, then the nuclear energy industry will not be able to maintain its NEW-FOUND 'clean' image.
But if it is contained, and the reactors are successfully shut down without widespread radiation being released, then the nuclear energy industry will claim -- with some justification -- that even when they experienced the worst that nature could throw at them, they got through it.
It is most unlikely the disaster will spell the end for the nuclear energy industry -- as we are already seeing in Germany and India, countries will review their nuclear precautions, and where they have other options, they may reconsider -- but it is hard to see us getting by without it at all.
Dr. Rianne Teule
Anti-nuclear campaigner and radiation scientist , Greenpeace
What has happened in Japan in recent days shows that nuclear energy is inherently unsafe.
Despite their assurances, the nuclear industry is not prepared for this kind of disaster -- even with state-of-the-art technology, and even in Japan, a country well prepared for earthquakes.
I hope that governments will take this incident as a serious warning and rethink their strategy, choosing less risky energy options instead.
We don't know the full scale of the damage yet -- we know that they have pumped sea water into at least one of the reactors, which means it is likely to be completely ruined.
We know that there have been significant releases of radioactivity, though it is not clear how high these were.
It is possible that the whole situation is being downplayed, and the extent of what it means will not be clear for weeks, but anyone who claims this proves the resistance of reactors is in serious denial.
We need to transition to a clean energy future, to reduce our reliance on fossil fuels, coal, oil and gas, and we need to do that without resorting to risky options like nuclear.
This is everybody's worst nightmare, and our thoughts go out to the people affected by it.
It is also the nuclear industry's worst nightmare: Before this, they could say that nuclear energy was safe, that there had been no accidents since Chernobyl, but the accident in Japan proves nuclear energy is not safe, and the industry cannot prevent these things from happening.
Senior research fellow, energy, environment and development program, Chatham House, London
Japanese reactors are built to withstand seismic risks, so the fact they have been overwhelmed shows the scale of what has happened, and what natural disasters can do.
Obviously, this is going to have an impact on the nuclear energy industry in Japan, and the more severe it turns out to be, the more severe the impact it will have on the industry overseas.
Previous disasters, like the ones at Chernobyl and at Three Mile Island, had huge international ramifications, with other countries like Sweden and Italy, scaling back their nuclear plans.
The disaster is not over yet, but already it has had a major cost for Japan: flooding a nuclear reactor with sea water [as has been done at Fukushima Daiichi] is a last resort -- effectively you're writing off the reactor, so this is already a significant economic disaster.
We will have to wait and see how much of an effect it will have elsewhere, for example in China: 40 percent of the nuclear reactors under construction globally are in China, where they will be used to produce 40 gigawatts of power - 5 percent of the country's power usage.
A global review of nuclear safety that recommends building in more redundancies, more backup systems, is likely to make nuclear power more expensive, so that may impact on the industry too.
Any accident has an impact on the public and political view of nuclear energy. Already, Switzerland has announced it is suspending its development of nuclear plants, so this is going to have an impact, the question is how severe, and how long-lasting.
The opinions expressed in this commentary are solely those of the contributors.