Shepley Engineers were contacted by the National Nuclear Laboratory based on the Sellafield site to determine the viability of decontaminating a transport bowser which had been historically used for transporting radioactive liquors.
The Bowser had a remnant heel of liquor which contained radioactive solid residues. As part of the scope of work, SDS were also asked to provide a methodology of filtering the solids prior to any liquor being disposed of to the building effluent liquor treatment tank.
SDS provided a concept which used high pressure water jetting to refluidise the remnant solids in the heel liquor and also decontaminate the internal walls of the tanker. A bespoke filter system was designed, which allowed the effluent to be pumped out to a mobile dual filter assembly unit, that used removable filter bags (100μm, 50μm and 25μm) to extract the radiactive solids.
The initial readings on the bowser were 26,500 cps, this was reduced to 167cps after decontamination, with radiation dose readings being reduced from 800μSv/hr down to 2μSv/hr.