It is unprecedented: four atomic reactors in dire trouble at once, three threatening meltdown from overheating, and a fourth hit by a fire in its storage pond for radioactive spent fuel.

All day yesterday, dire reports continued to circulate about the Fukushima Daiichi nuclear plant, faced with disaster after Japan's tsunami knocked out its cooling systems. Some turned out to be false: for example, a rumour, disseminated by text message, that radiation from the plant had been spreading across Asia. Others were true: that radiation at about 20 times normal levels had been detected in Tokyo; that Chinese airlines had cancelled flights to the Japanese capital; that Austria had moved it embassy from Tokyo to Osaka; that a 24-hour general store in Tokyo's Roppongi district had sold out of radios, torches, candles and sleeping bags.

But perhaps the most alarming thing was that although Naoto Kan, Japan's Prime Minister, once again appealed for calm, there are many – in Japan and beyond – who are no longer prepared to be reassured.

The scale of the alarm is the remarkable thing: how it has gone round the world (Angela Merkel has imposed a moratorium on nuclear energy; in France, there are calls for a referendum); how it's even displaced the terrible story of Japan's tsunami itself from the front-page headlines. But then, public alarm about nuclear safety, as the Fukushima emergency proves, is very easy to raise – and, as the Japanese authorities are now discovering, very hard to calm.

The reason is an industry which from its inception, more than half a century ago, has taken secrecy to be its watchword; and once that happens, cover-ups and downright lies often follow close behind. The sense of crisis surrounding Japan's stricken nuclear reactors is exacerbated a hundredfold by the fact that, in an emergency, public trust in the promoters of atomic power is virtually non-existent. On too many occasions in Britain, in America, in Russia, in Japan – pick your country – people have not been told the truth (and have frequently been told nothing at all) about nuclear misadventures.

To understand the mania for secrecy, we have to go back to nuclear power's origins. This was not a technology dreamt up as a replacement for coal-fired power stations; this is a military technology, conceived in a life-or-death struggle, which has been modified for civilian purposes. At its heart is the nuclear chain reaction, the self-sustaining atom-splitting process ("fission") which occurs when enough highly radioactive material is brought together, and which produces other radioactive elements ("fission products"), and a release of energy.

When it was first achieved by the physicists Enrico Fermi and Leo Szilard, in an atomic "pile" built in a squash court of the University of Chicago in December 1942, it merely produced heat; but all those involved understood that if it could be speeded up, it would produce the biggest explosive power ever known. And so was born the Manhattan Project, the US undertaking to build the atom bomb which was, while it lasted, history's biggest secret.

Secrecy came with nuclear energy, like a birthmark, and, indeed, for 10 years after the first A-bomb was dropped on Hiroshima in August 1945, it remained a covert military technology, although first the Russians, and then the British, followed the Americans in developing it. Britain built a pair of atomic reactors at Windscale on the Cumbrian coast, which produced (as a fission product) plutonium, the material used in the first British nuclear weapon. That was exploded off the coast of Australia in 1952. And it was in one of these reactors that the world's first really serious nuclear accident occurred: the Windscale fire of October 1957. The reactor's core, made of graphite, caught light, melted and burned substantial amounts of the uranium fuel, and released large amounts of radioactivity. It was the most serious nuclear calamity until Chernobyl nearly 30 years later, but the British government did all it could to minimise its significance, trying at first to keep it a complete secret (the local fire brigade was not notified for 24 hours) and keeping the official report confidential until 1988.

It was to be the first of many such nuclear alarms and cover-ups at Windscale. In 1976, for example, the secrecy surrounding a major leak of radioactive water infuriated the then Technology Minister, Tony Benn, who supported nuclear power, when he learnt of it. But similar cover-ups were happening all around the world.

At the US atomic weapons plant at Rocky Flats, Colorado, there were numerous mishaps involving radioactive material which were kept secret over four decades, from the 1950s to the 1980s. In Russia, the province of Chelyabinsk, just east of the Urals, housed a major atomic weapons complex, which was the site of three major nuclear disasters: radioactive waste dumping and the explosion of a waste containment unit in the 1950s, and a vast escape of radioactive dust in 1967. It is estimated that about half a million people in the region were irradiated in one or more of the incidents, exposing them to as much as 20 times the radiation suffered by the Chernobyl victims. None of which, of course, was disclosed at the time. Chelyabinsk is sometimes referred to now as "the most polluted place on the planet".

When we turn to Japan, we find an identical culture of nuclear cover-up and lies. Of particular concern has been the Tokyo Electric Power Company (Tepco), Asia's biggest utility, which just happens to be the owner and operator of the stricken reactors at Fukushima.

Tepco has a truly rotten record in telling the truth. In 2002, its chairman and a group of senior executives had to resign after the Japanese government disclosed they had covered up a large series of cracks and other damage to reactors, and in 2006 the company admitted it had been falsifying data about coolant materials in its plants over a long period.

Last night it was reported that the International Atomic Energy Agency warned Japan more than two years ago that strong earthquakes would pose "serious problems", according to a Wikileaks US embassy cable published by The Daily Telegraph.

Even Chernobyl, the world's most publicised nuclear accident, was at first hidden from the world by what was then the Soviet Union, and might have remained hidden had its plume of escaping radioactivity not been detected by scientists in Sweden.

So why do they do it? Why does the instinct to hide everything persist, even now, when the major role of nuclear energy has decisively shifted from the military to the civil sector? Perhaps it is because there is an instinctive and indeed understandable fear among the public about nuclear energy itself, about this technology which, once its splits its atoms, releases deadly forces.

The nuclear industry is terrified of losing public support, for the simple reason that it has always needed public money to fund it. It is not, even now, a sector which can stand on its own two feet economically. So when it finds it has a problem, its first reaction is to hide it, and its second reaction is to tell lies about it. But the truth comes out in the end, and then the public trusts the industry even less than it might have done, had it admitted the problem.

It doesn't have to be like this. A quarter of a century ago, Britain's nuclear industry acquired a leader who for a few years transformed its public image: Christopher Harding. He was an open and honest man who thought that the paranoia and secrecy surrounding nuclear power should be swept away.

When he became chairman of British Nuclear Fuels, which ran the Windscale plant, he decided on a new order of things. He renamed it Sellafield, and, to general astonishment, decreed that instead of sullenly turning its back to the public, it should welcome them with open arms. He did the unthinkable: he opened a visitor centre!

Harding died young in 1999, but he was, in his lifetime an exceptional man: not only for his charm and his personal kindness – he was revered by Sellafield employees – but for his vision of a nuclear industry which would be better off dealing with its problems through transparency and honesty, rather than through obfuscation and deceit. But he was, unfortunately, the exception who proved the rule.