Calcining process emission screening test for polychlorinated dibenzodioxins

Since 1963, the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory has been using fluidized-bed technology to convert high-level radioactive liquid waste into a granular solid for interim storage before eventual long-term storage. The calcining process uses kerosene, oxygen, air and a cooling jacket to maintain the temperature of the fluidized bed at approximately 400 C. The solids are moved to storage bins and the combustion gases and fine particles are swept from the bed to an atmospheric protection system. This atmospheric protection system includes a cyclone to collect larger particles; a nitric acid scrubber to cool gases and collect small particles; a condenser to reduce water content; silica gel beds to adsorb volatile ruthenium, water, and hydrocarbons; and a series of high efficiency particulate air (HEPA) filters to collect minute particles. The calcination process solidifies waste solutions containing molar levels of acid, nitrate, fluoride, zirconium, aluminum, iron, boron, and cadmium; minor levels (<0.1%) of various fission products and organics; and trace levels (<50 ppm) of chloride and sulfate. Because the process burns kerosene in the presence of other organics and chloride salts; the calciner was considered a potential production source of polychlorinated dibenzo-p-dioxins (PCDD). Therefore, it was necessary to determine if PCDD were being released from the calcination process. Because a gas chromatograph mass spectrometer (GC-MS) and PCDD standards were not available, a screening procedure using two gas chromatographs with electron capture detectors and no PCDD calibration standards was developed