Igor Gramotkin is not a man you would necessarily expect to tell you that nuclear power is essential to the future progress of humankind. He is the manager of the Chernobyl nuclear power plant in Ukraine, and has spent more than two decades at the site of the most devastating nuclear accident in history, trying to stop further radiation emissions and cleaning the area.
The control room at the plant's destroyed Reactor Number Four, now unlit and strewn with debris, is where a risky experiment designed to test the reactor's cooling systems went horribly wrong early on 26 April 1986, causing a huge explosion that spewed radioactive material high into the air.
During a tour of the site, Mr Gramotkin admitted that the destroyed reactor, still full of radioactive waste and nuclear fuel, remains "a threat not only to Ukraine but to the whole world" until it is encased in a vast steel structure that is being built. But, he said, Chernobyl was a unique event and unlikely to be repeated.
In the months after the accident, a makeshift "sarcophagus" had been constructed to encase the reactor, but it is now unstable and, despite work to shore it up, experts say a new shelter is desperately needed in case the old one collapses. At more than 100m tall, the shelter will be the largest moveable structure ever built. Those building it still have to be extremely careful. Standing in the area immediately around the plant subjects a person to radiation equivalent to about one old-style chest X-ray per day, said Laurin Dodd, who is in charge of the project.
The tour of the site was organised ahead of the 25th anniversary of the disaster to raise awareness as well as funding to complete the shelter. But the timing of the visit proved eerily prescient, just a couple of weeks before the crisis at the Fukushima plant in Japan again raised issues about the safety of nuclear energy.
Mr Gramotkin said: "I think this kind of accident [Chernobyl] could only have happened in a very closed society like the Soviet Union, and it's impossible that an accident like this could happen again. I don't believe in alternative energy, because humanity's use of electricity is going up and alternative sources won't be able to satisfy demands."
What happened at Chernobyl was worse even than the worst possible outcome at Fukushima. There was no container at Chernobyl to shield the reactor, and the blast, due to an experiment going wrong, struck when the reactor was at full power; the Japanese plant automatically cut power when the tsunami struck, meaning any potential nuclear explosion would have been a fraction of the magnitude.
But the Fukushima incident has caused a worldwide reappraisal of nuclear energy. There is a new uneasiness about safety of nuclear power, a renewal of debates that raged after Chernobyl but had abated in recent years as the world embarked on a nuclear spree.
Closer to the reactor, and inside the sarcophagus, the levels can be thousands of times higher. There are some rooms that can be entered only for a few seconds. Before we reached the area around Reactor Number Four, we had to pass through several scanners and change into protective clothing and masks.
Plant workers have developed black humour to deal with the catastrophe. After Vladimir Malyshev, head of security at the plant, told us no women work there, due to radiation effects on fertility and childbirth, he said there were also implications for male fertility. That was followed by a rhyme very loosely translated as, "No amount of Geiger counter clicks, can prove harmful to big Russian dicks".
The humour masks a disturbing reality. The human costs of the Chernobyl accident are still disputed, but are horrific by any estimate. Even the most conservative figures suggest that 4,000 people died prematurely from radiation, in addition to the dozens who died in the immediate aftermath. Other studies put the figure in the hundreds of thousands. There are incidences of genetic mutations, children born lacking organs, and dramatically elevated thyroid cancer levels in local children, who drank milk contaminated with radioactive iodine in the years after the accident.
"About 600,000 people were involved in mitigating the consequences of the accident," said Vladimir Holosha, the Ukrainian government official in charge of the exclusion zone the size of Luxembourg, a radius of 30km (19 miles). "About 300,000 of them were Ukrainians. Out of those, 100,000 are disabled now."
Inhabitation is banned inside the exclusion zone around the plant. The land has become a ghost country, save 200 pensioners who have defied the ban and returned to their homes, and the few thousand employees at the plant, who are moved in and out by bus.
Villages lie abandoned; the roads are lined with decaying gingerbread bungalows, embraced by the wild, snaking branches of trees that have grown out of control, their pathways hidden under metre-high grass. They have no future. Mr Gramotkin said it would be 20,000 years before vegetables in the area would be safe to eat.
Perhaps even more chilling than the site of the destroyed reactor is the town of Pripyat, a few kilometres away, Already, morbidly curious tourists can organise day-trips here, and the Ukrainian government has said certain routes inside the exclusion zone may be opened up to larger-scale tourism. Along the main thoroughfare, called Lenin Avenue of course, abandoned high-rise Khrushchev-era apartment blocks stand decaying.Some of them are topped with Soviet slogans meant to inspire: "Glory to the Workers!" says one or, at least, that is what it said before several letters fell off. There is nothing there. Everything of value was pilfered long ago by looters who defied radiation warnings and army checkpoints.
But echoes of the life that once abounded here are everywhere. The evacuation was so sudden – and people were so sure that they would return – that Pripyat has become a Soviet Pompeii. Textbooks filled with squiggly writing litter the floors of school classrooms; a charred abacus lies among shards of glass in what 25 years ago was a grocery shop.
"We were told late in the evening on the day after the accident to evacuate," says Andrei Glukhov, a former resident and now a plant worker. "In the morning, 700 buses came and picked everyone up. We were told we were leaving for three days." Some residents were forced to realise they would never see their homes again. Mr Glukhov returned briefly that autumn; everything from his house had been looted. But he too is equivocal about the future of nuclear energy, smiling wryly and asking: "How can we live without energy?"
Russia, which despite being the successor state of the Soviet Union, has only recently begun to take an interest in contributing significant money to fund the shelter for Chernobyl, remains staunchly pro-nuclear. There are plans to build a further 14 nuclear plants over 20 years, as well as help neighbouring states and countries across the world develop their own nuclear industries. Even as the crisis in Japan developed last month, Prime Minister Vladimir Putin was in Belarus signing a deal to build a nuclear power plant.
But many people feel feel that the severity of the consequences of reactor accidents means nuclear energy should be consigned to the dustbin forever. Rianne Teule, of Greenpeace, said: "The reactor in Japan was much more advanced than at Chernobyl, and it's not as if we're dealing with a backward country here. This latest incident proves that nuclear energy is inherently unsafe."
But Mr Dodd, a lifelong nuclear expert who has spent the past five years managing the project to make the Chernobyl site safe, said last month that he was confused by the response to the nuclear incident in Japan. "Of course, you could make the argument that actually given the severity of the earthquake, the nuclear plant has coped very well. It seems strange that you have tens of thousands of people dead and everyone is focusing on the nuclear aspect."