Television Review

Horizon (BBC2) marked the tenth anniversary of the explosion at Chernobyl with an anniversary of its own. It is five years since a film crew travelled to the damaged reactor to record the courageous - some would say suicidal - attempts by Russian scientists to find out what had happened and whether it could happen again. Last night they repeated some of that award-winning film, and added a gloomy footnote - suggesting that the danger isn't over yet. "In 1,000 years people will still shudder at the name of Chernobyl," said one of the scientists in the original film, but this was a conservative prediction. According to one estimate it will be some 100,000 years before the site is completely safe; the final inheritors of the Sarcophogus, as the containment chamber is known, will be as distant from us as we are from Neanderthal man.

Unfortunately, the Sarcophogus looks unlikely to make it that far. It has a 90 per cent chance of falling down within the next 20 years, which can't even be said to constitute a good try at immemorial durability. The outside of Chernobyl has now been normalised - fountains, green grass, flowers, even a commuter-train carrying workers to the two reactors that are still in operation - but inside the Sarcophogus the mass of rubble is still changing, rusting its way towards a new disaster, in which the reactor cap would collapse into the void, expelling a cloud of plutonium dust into the surrounding country. The camera lingered for a moment on two white-garbed men carrying scythes: an image of death in a labcoat.

This prospect may be more frightening for members of the nuclear industry than it is for the average British citizen - such a dust-cloud, it was suggested, would settle within 10 miles of the plant - but there would be a much wider fallout in terms of public confidence. For this reason, some people want Chernobyl's remaining reactors switched off, a decision that would deprive Ukraine of desperately needed electricity. In addition, nobody has yet come up with the vast sums needed to construct a containment chamber for the crumbling containment chamber - a Russian doll of radioactive concrete.

What's worse, they don't even seem to have come up with enough money to give the scientists decent safety equipment. Five years ago they were venturing into hideously radioactive areas with little more than dust filters and Sellotape around their ankles. Even the Russian troops ordered to clear the debris were dressed as if taking part in a bad school pageant - lead-foil tabards their only protection against the massive radiation. As they prepared to dart through these ruined interiors to fight a deadly and invisible enemy, it all looked uncannily like the cliched science- fiction vision of a post-apocalyptic society - scraping together a technology from left-overs. Paradoxically, the scientists who have since died succumbed to stress rather than radiation sickness - fear and bureacracy, it seems, are as poisonous as plutonium.

Donning state-of-the-art protective clothing, complete with triple-valve pretension filters and military-grade embarrassment-exclusion devices, I settled down to watch Acting with... Prunella Scales (BBC2), a comedy workshop. There were several moments at which the detector shrieked a warning - in particular when Scales said, "Try it as an exercise, luvvy," and then went into a paroxysm of retraction: "No! Not luvvy! No actor ever calls each other luvvy." But she proved herself to be a rather sharp director, neatly identifying the mistakes of her guinea-pigs. She was herself the soul of thespian solidarity: "It doesn't need quite that amount of detachment," she said, after a young man had read a Pinter line as if it had been written for the speaking clock. But the truth was that the worse the actor was, the more illuminating her interventions were. It's mostly assumed that a masterclass stands or falls on the knowledge of the master, but an incompetence to be tutored is often just as important.