放射性固体廃棄物焼却処理設備の排ガス処理系における除染性能

抄録

At the Tokai Research Establishment of Japan Atomic Energy Research Institute, the radioactive solid waste incineration unit with a capacity of 100 kg/h was installed in 1979, since then the unit has been routinly operated. An off-gas cleaning system of the unit consists mainly of a primary and secondary ceramic filters, a heat resistant HEPA filter and a scrubber. A series of hot test was carried out to examine the decontamination performance for radionuclides in the off-gas cleaning system. In the test, simulated wastes contaminated with a known quantity of radionuclides were burned in the unit, and radioactive concentrations in the off-gas were measured. And then, the following data were obtained: a retention factor of radionuclides in a furnace and a decontamination factor for radionuclides in each of off-gas cleaning components. And also overall decontamination factors, defined as the ratio of radioactivities input to the furnace to radioactivities passed through outlet of the HEPA filter, were 9×10⁶(2×10⁷) or more for ⁵⁸Co (⁶⁰Co), 1×10² for ⁷⁵Se, 4×10⁴ for ¹⁰⁶Ru and 1×10⁸ or more for ¹³⁴Cs.