Experience of reducing PCDD/Fs emission from a low-level radwaste incinerator in Taiwan

In this paper, the experience of reducing PCDD/Fs emission from a low-level radwaste incinerator in Taiwan Power Company (TPC) is presented and discussed. The emission standard for dioxins from an incinerator with design capacity of under 4,000 kg/hr must be less than 0.5 ng-TEQ/Nm(3), which was set by Taiwan EPA regulation and came into force on January 1, 2004. TPC executed both short-term and long-term improvement programs for incineration systems. In 2002, the short-term program used catalytic filter bags instead of tefaire filter bags to bring down the dioxin concentration; however, it didn't meet emission standards. In 2003, the long-term program was then submitted and conducted, in this program, new equipment, such as a powdered activated carbon injection device, bag filter were installed. Sampling and analysis at the stack, the dioxin concentration was 1.271 ng-TEQ/Nm(3) which was not accepted. Finally, TPC replaced worn packing rings with new rings, cleaned the apparatus in the packed tower, induce draft fan, heater, stack, and a part of the piping. The results of the dioxin emission from the stack then consistently met Taiwan EPA regulation.