The Sellafield community is mourning the death of a contract worker who fell to his death inside No 1 Windscale Pile reactor chimney on 9th January.
No 1 Pile, currently under a programme of decommissioning, was permanently closed down with its sister Pile No 2 in 1957 following the infamous Windscale Fire which released a plume of radioactive material over north west England and areas further afield. Labelled then as the world’s worst nuclear accident, the job of dismantling No 1 Pile is rated by international decommissioning experts as second only to dismantling Chernobyl 4.
The contractor was one of the first of a group of workers employed by a contracting firm to be allowed to work inside the top of the 125 metre Pile chimney on the task of removing radioactive debris. Local media reports indicate that the worker fell over 100 metres from a platform inside the chimney when he became separated from his safety harness whilst lowering metal joists.
Because of the high radiation levels inside the disused chimney, the body of the contractor had to be decontaminated before it could be removed by medical staff and health physics monitors dressed in full protective clothing. The circumstances of the accident are being investigated by BNFL, the police and the Health & Safety Executive (HSE).
A programme of decommissioning of both Piles was initiated in the mid 1980’s and was due for completion around 2005. Whilst No 2 Pile chimney was dismantled some time ago, the radiological hazards of working on the fire-ravaged No 1 Pile which still contains around 15 tonnes of damaged reactor fuel have delayed work on its chimney. Since 1997 an Anglo-German consortium headed by BNFL and including Rolls Royce Nuclear Engineering Services, Nukem Nuklear GmbH and the United Kingdom Atomic Energy Authority (UKAEA) has faced major decommissioning problems (see CORE Briefing 12/00). In March last year the HSE’s Nuclear Installations Inspectorate warned that they had lost confidence in the ability of the UKAEA to carry out Pile 1 decommissioning safely.
The shaft of No 1 Pile chimney has an internal diameter of 12.5 metres and is lined with thermal insulation contained in aluminium faced boxes supported on structural steel framework. During the 1957 fire the chimney lining became highly contaminted, particularly with Caesium 137. The chimney material is today classified as Intermendiate Level Waste (ILW).