Why is the detection of radioactive sources important to the solid waste industry? : Radioactive material is used extensively in the United States in research, medicine, education, and industry for the benefit of society (e.g. smoke detectors, industrial process gauges, medical diagnosis/treatment). Generally speaking, the Nuclear Regulatory Commission and state governments regulate the use and disposal of radioactive materials. Licensed radioactive waste disposal facilities receive the bulk of the waste generated in the United States with exceptions for low-level waste (e.g. medical patient waste) that may be disposed of as municipal waste. According to the Conference of Radiation Control Program Directors, Inc (CRCPD)., there has been an increasing number of incidence involving the detection of prohibited radioactive wastes at solid waste management facilities. While the CRCPD acknowledges that the increased incidence may be partially attributed to the growing number of solid waste facilities that have detection systems, undetected sources of ionizing radiation can harm the environment, have a negative impact on employee health and safety, and result in significant remedial actions. Implementing an effective detection/response plan can aid in the proper management of radioactive waste and serve to minimize the potential for negative outcomes.

This paper constitutes a follow-up on a presentation at NAWTEC 10 (2001) [1]. It contains novel insights regarding the operation of the Seghers Boiler Prism and its effectiveness as a primary measure against high temperature boiler corrosion in WtE plants. Starting from the currently available fundamental understanding on high temperature corrosion and the main features of the Boiler Prism, the operation as a primary measure is explained. Since the previous presentation, three additional Boiler Prisms were successfully commissioned as a retrofit at a large WtE facility (3 × 705tons/day at 4,700BTU/lb; 110tons/hour steam at 1,450psi, 750°F) in the Netherlands. Together with the previously installed prisms, this brings the combined operational experience from all trains to more than 15 years. The main data and experience of the retrofit project in the Netherlands are discussed and results regarding the performance of the prism are presented in detail. The latter are based both on existing process monitors as well as dedicated measurement campaigns and include: • temperature and oxygen distribution in the 1 st radiation pass, • feedback on corrosion rates, • influence on the combustion quality, and • impact on the effectiveness of the mechanical cleaning equipment. The results confirm the effectiveness of the prism as a primary measure against high temperature boiler corrosion and highlight the additional operational benefits.