NEI, 18 January 2008 - UK firm JGC Engineering and Technical Services has won a £7.4 million contract to replace an old ventilation network at the Dounreay nuclear plant in Scotland.
The old system, in the site’s fuel cycle area, is not up to modern standards and has been earmarked for upgrading for some time, partly due to radiological contamination.
JGC, which is based in north Scotland, will be working with local subcontractors Arch Henderson, M M Miller, and Alpha Engineering to complete the work.
The contract is expected to sustain 86 jobs in the local community during various stages of the project.
Completion is scheduled for May 2010.
UKAEA Dounreay director Simon Middlemass said the new ventilation system is needed to comply with Radioactive Substances Act discharge permissions and pollution prevention and control law. This includes appropriate and functional stack discharge monitoring systems adjacent to the base of new stacks.
The work, which has already gained planning permission, includes two replacement stacks. These will be smaller than the existing fuel cycle area stack giving a reduction in height from 55m to 35m, and a diameter reduction from 4.5m to less than 2m. The new stacks have a design life of 20 to 30 years.
The plans also contain a duct depression building and a discharge monitoring system. The duct depression building is a fan/filter house to the north end of the old fuel cycle area corridor duct, which is contaminated.
The old duct will be isolated and placed under depression. The forced extract stream from this duct will be heat-treated to protect the HEPA filters from the adverse effects of moisture prior to discharging into the proposed above-ground system.
It is hoped that this will virtually eliminate the potential of any particulate from the old duct migrating into and contaminating the replacement ventilation system.