18-Env-B5 Industrial & Hazardous Waste Management · May 2013
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Reference texts: Nemerow & Dasgupta, Industrial and Hazardous Waste Treatment, 2nd ed.; Metcalf & Eddy, Wastewater Engineering: Treatment and Resource Recovery, 5th ed.; Davis & Cornwell, Introduction to Environmental Engineering, 6th ed.; LaGrega, Buckingham & Evans, Hazardous Waste Management, 2nd ed.; CCME, Guidelines for the Management of Biomedical Waste in Canada (1992); Canadian Nuclear Safety Commission (CNSC) regulatory framework and NWMO Adaptive Phased Management; Canadian Environmental Protection Act (CEPA), 1999.
All nineteen questions are compulsory on this paper and are answered in full below.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
Yellowcake is the solid concentrate produced at a uranium mill from crushed and chemically-leached uranium ore, consisting predominantly of triuranium octoxide (U3O8), typically 80–85% uranium by weight, with the balance made up of residual impurities carried through the milling process. It is precipitated from the leach solution (commonly as ammonium or sodium diuranate), then filtered, dried and calcined into a coarse powder or granular solid — historically often yellow-to-orange in colour, which gives the product its common name, though the colour actually varies from yellow through dark green to black depending on the calcination temperature and exact chemical form. Yellowcake is the shippable product of the mining/milling stage of the fuel cycle: it is packaged in steel drums and transported to a conversion/refining facility, where it is purified and converted to uranium dioxide (for CANDU fuel fabrication, with no enrichment step) or to uranium hexafluoride (for light-water-reactor fuel requiring enrichment).
