Remembering Chernobyl 35 years later

* This story waspublished on Apr. 26, 2017, the 31st anniversary of the Chernobyl disaster. The episode first aired in 2006, when IDEAS producer Philip Coulter visited the site.

On April 26 1986, in the middle of the night, a group of workers at the Chernobyl Nuclear Power Plant Number 4 Reactor in northern Ukraine attempted to carry out a safety test. But things went horribly wrong. Number 4 Reactor exploded, shooting a vast column of radioactive debris into the night sky. The toxic cloud drifted mainly to the northwest at first, over Belarus, before passing over Scandinavia, Holland, Belgium and the UK. As the weather changed, the cloud travelled south, eventually covering much of the rest of Europe.

The disaster at Chernobyl remains the worst nuclear accident in history, worse even than what happened in Fukushima.

Thirty-one people died as an immediate consequence, and a great many more were treated for radiation poisoning. But what is less-well understood are the long-term consequences: who is sick today more than 30 years later? There's another question which may be even more important: what are the consequences for the trust people have in their leaders?

Around Chernobyl itself there's a 30 km zone, where no one is supposed to live, and nothing should be harvested. But many have returned to the zone, and many others are scarred by their time there.

In 2006, IDEAS producer Philip Coulter went into the zone and found tales of individual bravery and recklessness, lives forever changed, and communities shattered.

"At about 9 a.m., my wife returned from the market and told me that people were gossiping about an explosion at Reactor #4, and that it was not advisable to buy local produce. And my wife said that since I said it was impossible that such an explosion could happen, I should take our child out for a walk,"Senior EngineerYuriAndreev told Coulter, recallingthe morning of April 26, 1986 inPripyat.

Zone of absolute exclusion

There is no going back to these villages, or to the town of Pripyat, where the power plant workers lived. Around the epicentre of the disaster there is a zone with a 30 km radius the zone of absolute exclusion farms, villages, and towns from which some 116,000 people were evacuated.

The explosion at Reactor 4 was not a nuclear explosion. Basically, the reactor overheated, and the explosion that followed scattered about 6 tonnes of radioactive debris into the night sky. The effects were felt all over Europe, but much of the debris fell back into the exclusion zone. The ground is hopelessly contaminated, and the zone itself is surrounded by fences and security checkpoints. The road weaves through wild and abandoned farmland.

Chernobyl has shaken our perceptions about nuclear power.

Thirty-five years have passed, but we're reluctant to believe again, as we once did, that nuclear energy is the clean environmental fix for our energy needs. There's a new, permanent dome now, but in 2006 Reactor 4 at Chernobyl was covered by a leaky enclosure, a tomb for a certain dream of the future, an outworn icon of the Soviet Union.

The debate still rages about what exactly happened that night, but most sources indicate that it unfolded like this: there was a test in progress. Reactors generate power, but they also need power to drive the pumps for the cooling system.
So if the power were to fail, for how long would the slowing turbines generate enough electricity to drive the cooling pumps, before the emergency generators cut in?

As the test began, emergency systems were shut off, and the reactor output was allowed to drop. What the operators didn't know was that there was a design flaw in the RBMK 1000: at low levels the reactor could be prone to power surges. Output dropped below 1 per cent, and at 1:23 AM, when the operators tried to bring the power levels up, there was a power surge. In seconds, output jumped to 100 times beyond normal. The reactor overheated and exploded, blowing the 1,000 ton lid clear off the core, hurling a great plume of radioactivity and debris into the night sky.

The plume rose high up into the air and was carried northwest by the wind, first over Belarus, and eventually over most of Europe. Immediately after the explosion, fires broke out that continued for nine days. Pripyat and the surrounding area was evacuated. Then the longer job of clean-up began.

Over the next few years, some 600,000 workers took part, each working for only a few minutes a day, as the human body can withstand only a limited amount of radiation over a lifetime.

Today Reactor 4 slumbers fitfully under its new $2 billion protective dome. But there's still a nuclear power station at Chernobyl, if not quite awake, then not asleep either. Reactors 1, 2 and 3 are still there, carefully monitored, but no longer generating power.

When you go to the Reactor 1 control room, you walk along the 1 km Golden Corridor that links the reactors, passing through full-body radiation meters and electronic security checks. Finally you are in the control room, identical to the control room for Reactor 4.

Not much has changed since 1986.

Guests heardin the series:

• Dennis Zabarin, Philip Coulter'sguide at Chernobyl
• Anatoly Gritsak,senior engineer, Reactor #4,1986
• Yuri Andreev, duty manager, Reactor #4, 1986
• Yuri Kunakov, shift chief, Reactor #1, 2006
• Sergei Martinenko, chief engineer, Reactor #1, 2006
• Asher Atofzhanov, military helicopter pilot, cleanup, 1986
• Natalia Preobrazenska, doctor, Kiev, 1986
• Vladimir Usatenko,army reservist, cleanup, 1986
• Vladimir Verbitsky, soldier, cleanup, 1986
• Mychaelo and Maria Radkowitz, village residents, Chernobyl

Special thanks to Philip Coulter's fixer in Ukraine,Taras Burnos.