BNFL has made a positive response to our findings and has initiated a programme to implement the necessary improvements

Laurence Williams HM Chief Inspector of Nuclear Installations

The incident took place at the British Nuclear Fuels-run (BNFL) power station, near Annan.

The accident happened during a refuelling operation for reactor three.

The 12kg rods - bars of uranium metal clad in an outer magnox can - were in a large cylindrical basket which came loose as it was being lowered into a cooling pond.

Twelve of the rods remained in the basket and were quickly accounted for.

The other 12 dropped 50ft down a discharge shaft and were found following an inspection of the area around the reactor.

Safety recommendations

The rods are placed inside reactors as part of the nuclear fission process that generates heat and ultimately electricity.

Members of the plant's incident team were called to deal with the situation as carbon dioxide was sprayed over the basket to ensure it did not catch fire.

Laurence Williams, HM Chief Inspector of Nuclear Installations, said the report into the incident had made several recommendations to improve the safety of the defuelling operation.

The Chapelcross plant is at Annan

"BNFL has made a positive response to our findings and has initiated a programme to implement the necessary improvements.

"Whilst I have no doubts that BNFL will deliver the required improvements, we shall monitor progress via our normal process of regulation," he said.

He said the NII, part of the Health and Safety Executive, would take the necessary action if inadequate progress was made at the plant.

Mr Williams said: "The incident ... occurred as a result of a combination of procedural and hardware deficiencies.

"As a result of our investigation, I am satisfied that no worker or member of the public incurred any harm from release of radioactive material.

"I am also satisfied that there was no deliberate attempt by BNFL to deceive NII in relation to the reporting of the event or the status of plant at the time."

While it is reassuring that the public were not exposed to danger, it is not reassuring that the incident was the result of procedural difficulties

Kevin Dunion Friends of the Earth

Friends of the Earth Scotland's chief executive Kevin Dunion welcomed the report.

But he said: "We remain concerned that the accident was not immediately made public, even though the Chapelcross emergency plans were activated and the regulatory authorities were informed.

"Also, while it is reassuring that the public were not exposed to danger, it is not reassuring that the incident was the result of procedural difficulties."

Scottish National Party MSP Fiona McLeod said: "BNFL must immediately implement the recommendations of this report and I am confident that the HSE will be monitoring the situation closely to ensure that this happens."