Not that the locals have any real reason to fear: it reassures them that there will be no `immediate danger' to anyone. On Sunday, The Observer provided proof that this confidence is indeed misplaced and all is not well inside Aldermaston. The newspaper revealed an appalling catalogue of over 100 errors and safety breaches in the past 12 months, as well as details of an incident in 1993 which might have killed thousands of people. In September 1993, top nuclear scientists at Aldermaston were facing a crisis. Shavings of highly enriched uranium -- one of the most dangerous substances known to mankind -- had been discovered in an oil tank placed beneath a lathe.

The machinery had been used to cut theuranium into the correct shape so that it could fit in the core of a nuclear warhead. To their horror, the scientists quickly realised that one false move could trigger an atomic fission explosion leading to nuclear catastrophe. It only takes a few hundredths of a gramme of highly enriched uranium in a water-based oil for `criticality' to be breached. Criticality occurs when too much fissile material collects together and triggers a nuclear explosion. This is exactly what happened at Japan's Tokaimura plant last month and such an event at Aldermaston would lead to a massive release of radioactive material over Reading, with devastating consequences for the town's population of 250,000.

According to a letter passed to The Observer from a senior source working at Aldermaston, it was only by pure chance that the uranium was discovered after a small oil leak under the lathe was checked.Despite the seriousness of the 1993 episode -- which has been officially confirmed by a senior director at Aldermaston-- only sketchy details were made public.

This is the first time citizens who live in Reading will have learnt of how close they came to a nuclear disaster. In 1978 high doses of plutonium were found in the lungs of 12 workers at Aldermaston. The then Labour Government sent Sir Edward Pochin, an eminent radiologist, to the site in 1978 to conduct an inquiry into the safety of the site. Pochin's report detailed 73 recommendations for changes. Criticisms included that buildings had ventilation systems that blew radioactive contaminants into workers' faces.

The Campaign for Nuclear Disarmament's report into Aldermaston published earlier this month found that the Atomic Weapons Establishment was still guilty of concealing vital information about dangerous accidents and pollution. It listed several serious incidents at Aldermaston between 1993 and 1998 where the public had never been officially notified. Six years after one of the most damning reports on the operations at Aldermaston was published byGreenpeace, little has really changed. Entitled Inside the Citadel, after the site's top-security inner sanctum where plutonium is handled, the pamphlet revealed that almost 100 workers had been contaminated, injured or killed at Aldermaston since 1951.

Frustrated by the political cul-de-sac in 1994, Reading Borough Council decided to set up its own `community' inquiry chaired by leading lawyer Helena Kennedy. But the Conservative Government still refused to launch an inquiry. In 1997, the Health and Safety Executive launched its first prosecution against AWE when two workers were contaminated with uranium.

-- The Observer News Service