Two Irish film-makers have set out to discover why a growing number of environmentalists are changing their minds about nuclear power.

They believe they have found that an innovative reactor design using thorium instead of uranium is safe enough and green enough to convince heavyweight anti-nuclear campaigners that these reactors should be built.

This design first appeared in the US in the 1960s where an experimental reactor successfully ran on thorium for five years.

It was soon shelved, however, in large part because these reactors do not produce the plutonium required to make atomic bombs.

After gathering dust for four decades, recent years have seen a resurgence of interest in the technology with Australia, China, India and the Czech Republic all announcing major funding for research.

Independent film-makers Frankie Fenton and Des Kelleher have been filming this global resurgence and are close to finishing their documentary on the subject 'The Good Reactor'.

Mr Fenton explained: "We've always been concerned with the planet's energy supply and what will replace oil when it runs out. When we found out about these thorium reactors we thought they sounded too good to be true.

"When we then found out there was a surprisingly large and very well qualified community of nuclear experts online who think they can work we realised we had to make a documentary.

"After extensive research, we got in contact with Kirk Sorensen, who is perhaps the biggest figure in the modern thorium movement, and asked him for an interview."

He explained that the reasons they had found for the recent explosion of interest in the technology.

He said: "The main reason the US had for cancelling the research, that the reactors can’t produce weapons-grade material, is ironically a reason to pick up the research today. That coupled with the fact that there is much more thorium than uranium on the planet plus the astonishing safety of these reactors means that people are paying attention."

Thorium reactors have many advantages, according to the film-maker.

He said: "You could fly a plane into one of these things and all that would happen is the fuel would leak out and solidify. No radioactive gas cloud, no meltdown. Safety in standard nuclear reactors comes from complicated electronics and high-pressure cooling systems.

"Safety in thorium reactors comes from some basic physical principles and physics doesn't malfunction.

"Add to that these things can actually burn existing stockpiles of nuclear waste, including material in nuclear warheads, plus produce extremely small and short-lived amounts of waste themselves and you can see why people are getting so excited."

The film-makers have launched a Kickstarter campaign to raise the funds required to finish the movie.

Kickstarter is a crowd-funding website that helps people fund creative endeavours.

The film-makers have set a fund-raising target of £40,000 which, they say, are the funds required to finish the movie. This will go to editing, computer animations, stock footage and distribution.

"None of the money will go to us. This is a labour of love but if it’s going to make the grade for film festivals we need some of the budget that festival films require.

"The biggest danger is producing an hour-long college lecture rather than a documentary. We want our film to appeal to as broad an audience as possible and this requires quality animations for the technical concepts as well as archive footage to provide grounding. Unfortunately these cost money.

"And of course, all of that is wasted if you don’t have a decent editor to stitch it all together. Our team is fantastic and fully committed. We’ll publish the film on YouTube if we have to but we’d much rather see it get recognition at festivals."