Two Oxfordshire Army bomb disposal experts have been awarded the George Medal for helping to prevent an explosion at the Harwell nuclear and chemical research station.

Schoolchildren were led to safety and the area sealed off when an experiment, conducted by AEA Technology, went wrong in a laboratory on September 9, 1999.

Unstable silver compounds built up in the laboratory and an emergency was declared. The 11th Explosive Ordnance Disposal Regiment of the Royal Logistic Corps based at Vauxhall Barracks in Didcot was then called in.

Capt Justin Priestley, 31, and Capt Richard Baker, 30, spent 36 hours at Harwell making the building safe. Capt Baker is still with the regiment but Capt Priestley has since left the army and has taken up a civilian job in Stratford-on-Avon. Their citation revealed that the material was an unstable explosive compound liable to spontaneously detonate or explode if subjected to movement of any kind.

In a nail-biting process that demanded the highest levels of concentration and skill the two officers very gradually had to introduce nitric acid into the tank where there was a build up of compounds. The citation praised their "great nerve, courage and total professionalism".

A Royal Logistic Corps Officer at Didcot said: "We are all very proud of what the two officers achieved.

They were working in very difficult circumstances. Had there been an explosion they would have been in deep trouble."

Managers at the United Kingdom Atomic Energy Authority, and its tenant AEA Technology, now face charges of breaching the Heath and Safety Act.

Mark Wheeler, a spokesman for the Health and Safety Executive's nuclear installations department, said a hearing was due to take place at Oxford Magistrates Court on March 2.

The two agencies are charged with failing to ensure the health and safety of employees and others.