(298j) Aerosol Generation from High-Pressure Sprays: Novel Chamber Method

The Hanford Site in Washington State has 177 underground storage tanks containing complex aqueous slurries of radioactive and chemical waste products.  The Waste Treatment and Immobilization Plant (WTP) at Hanford is being designed and built to treat and vitrify a large portion of this waste.  One of the postulated events in the hazard analysis for the WTP is an accidental breach in process piping that produces aerosols with droplets sizes in the respirable range.  Literature correlations have typically been used for estimating the generation rate and size distribution of aerosol droplets produced during a spray leak.  These correlations, however, are based on results obtained from small engineered spray nozzles using liquids that do not contain solids and thus do not accurately represent the fluids and breaches postulated for accidents in the WTP.  

A testing program was undertaken to measure the aerosol generation rate and droplet size distribution from sprays for a range of fluids, breaches, and spray pressures that encompass conditions encountered at the WTP.  Results will be shown that demonstrate the validity of a new test method that was designed to accommodate sprays ranging from less than 1 to 200 gallons per minute.  Aerosol generation results will be presented for orifices that spanned a 3000 fold range in orifice area, spray pressures that ranged from 100 to 380 psig, and fluid properties that included Newtonian and non-Newtonian liquids and slurries.  A new correlation for aerosol generation rate based on the results along with a comparison with literature correlations will also be presented.