BRITISH VITRIFICATION PROCESS SAFETY ISSUES

British Nuclear Fuels pic (BNFL) provide a complete nuclear fuel cycle service with its sites at Springfields (AGR/Magnox Fuel Fabrication) near Preston and Sellafield (MOX Fuel Fabrication and Reprocessing) in Cumbria. BNFL also generates electricity using Magnox Reactors at Sellafield (Calder Hall) and Chaplecross in Scotland. This paper provides an overview of the Windscale Vitrification Plant (WVP) and reviews the major safety issues associated with vitrification operations. The practicalities of vitrification of Pu using the current WVP process are briefly discussed. 

The Windscale Vitrification Plant vitrifies high level (highly active) liquid waste arising from reprocessing operations at Sellafield. The plant operates two identical vitrification lines with a current combined throughput of 350 product containers per year. A third line is currently under construction and will commence operation in the year 2000. The key safety function of the plant is to convert mobile material into a solid immobile form which can be more easily managed, stored, and transported. 

Jardine and MM. Moshkov (eds.). Nuclear Materials Safety Management, Vol. II, 105-11 999 Kluwer Academic Publishers. 

The Vitrification Plant processes HAL into a solid vitrified waste form that is then stored in a dedicated storage facility. The vitrification plant process is described below, considering each of the main cells in the plant in sequential process order  

Control Cell The cell contains a posting-in facility from the decontamination cell, an in-cell crane, a smear test machine to externally scrub the container, a pneumatic scrub transfer machine to allow swab monitoring, and a gamma gate for flasking out containers to the product store. The function of the cell is to monitor the external surface of containers prior to discharge to the product store viewing is via closed circuit television. 

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