Evaluation of Hazardous Waste Disposal Criteria for NORM/TENORM Waste
W.E. Kennedy, Jr.1 and P.G. Retallick2 (1Dade Moeller & Associates, Inc.; 2Clean Harbors Environmental Services)
Dade Moeller & Associates was asked by Clean Harbors to evaluate waste disposal criteria for the potential disposal of naturally occurring radioactive material (NORM) and technologically enhanced radioactive material (TENORM) at Clean Harbor's Deer Trail RCRA Subtitle C facility, located 70 miles east of Denver, Colorado. The waste disposal criteria analysis and recommendations would apply to a wide variety of NORM/TENORM wastes with similar radionuclide content. This analysis was conducted using the RESRAD family of computer models for the identified conditions, with representative scenarios, and compared against measured operational data obtained from thermoluminescent dosimeters (TLDs) installed at the Clean Harbors Buttonwillow RCRA Subtitle C landfill near Bakersfield, California. The Buttonwillow operational data are relevant since Buttonwillow has been permitted to receive NORM/TENORM waste from geothermal and oil and gas production for several years. For exposure to TENORM waste, Deer Trail worker's were considered as members of the public and radiation exposures were limited to 1 mSv/y, plus ALARA, with a goal of 0.25 mSv/y or less. In practice, if it is determined from worker dosimetry results that selected worker doses could exceed 0.25 mSv/y, an assessment will be conducted of the potential for other man-made exposures to Deer Trail workers to assure that maximum individual doses from man-made sources will not exceed 1 mSv/y. If required, this worker dose assessment will consider real individuals working at Deer Trail, not hypothetical members of the public. The results of the waste disposal criteria analysis recommended that the total activity of NORM/TENORM waste, including the alpha and beta emitting radionuclides, be enforced to the limit of 74 Bq/g (2,000 pCi/g), which is also used to define radioactive waste in Colorado, as long as a radium concentration limit of 15 Bq/g (400 pCi/g) per shipment is also maintained.