Leading Article: The need to prevent another Chernobyl

The explosion and fire at the Chernobyl nuclear power station a decade ago was a modern horror. According to the World Health Organisation, the total amount of radioactivity released in the disaster was 200 times more than the combined fallout from the atomic bombs dropped on Hiroshima and Nagasaki. The precise death toll will never be known, though Western scientists believe many thousands will eventually die because they suffered exposure to radiation.

Given these facts, why, as the 10th anniversary of the disaster approaches, does the Chernobyl plant remain open? Not only that, but 15 Chernobyl- style reactors continue to operate in the former Soviet Union- 11 in Russia and two each in Ukraine and Lithuania. The International Atomic Energy Agency has said clearly that Chernobyl-style RBMK reactors represent a much greater safety risk than other types used in nuclear power generation. Most Western nuclear experts regard the RBMK, an exclusively Soviet model, as inherently unstable.

Design flaws were only part of the explanation for the Chernobyl disaster. The other was the fact that, in an operation which still boggles the mind, technicians at the plant were conducting experiments in which safety systems were shut down. How far have safety procedures improved since then? Not far enough. Last November, fuel rods were removed from one of Chernobyl's two working reactors. Their hermetic seal was broken and an employee was exposed to radiation.

Despite compelling arguments for closing down Chernobyl, there is official resistance. Ukraine authorities say the plant supplies 7 per cent of the country's energy and provides jobs for 30,000 people. They contend, unconvincingly, that Chernobyl has enjoyed an excellent, accident-free record in recent years. Since the government has in fact promised to close the plant by 2000 - a pledge repeated yesterday - it is hard to avoid the conclusion that the real reason for Ukrainian procrastination is a desire to extract as much money as possible from the West to cover the costs involved.

The Group of Seven industrialised countries has offered about pounds 2bn in aid. That is a generous sum. If the West is to offer more, the Ukrainian authorities need to show they are serious about closing the plant - ideally, before 2000. What is needed is a programme for repairing and eventually shutting down every one of these Chernobyl-type reactors. The financial costs will be high. Yet at a time when relations between the West and Russia have hit choppy water, making a well-financed programme of closing the remaining reactors could be made the basis of renewing trust.