Protection from Radioaerosols and Volatile Radionuclides^*

* This paper is from “New Trends in Nuclear System Thermohydraulics,” an international conference that took place in Pisa, Italy, May 30-June 2, 1994.

Abstract

Increasing the safety of nuclear power plants is a problem of the utmost importance in the nuclear energy industry. Particular attention is given to severe accidents at nuclear reactors. Although the probability of these accidents is low (<10⁻⁵), their consequences are the most disastrous. Severe accidents result in the release of tens of thousands of curies of radioactive products into the area under the containment. Modern protective systems for the localization of radioactive aerosols and volatile radionuclides are based mainly on the filtration of gas flow, using various solid and liquid sorbents. The main principle of these filters is based on the precipitation of suspended particles on any surface (grids, liquid drops, or film, fiber, and electrode surfaces). In these processes, physical phenomena such as gravitation, inertia, diffusion, electricity, magnetism, and supersonics are used. A disadvantage of the available systems is that they may not trap radioaerosols present in the vapor-gas mixture in the form of finely dispersed (much smaller than 0.1 µm) hydrophobic particles.

A new concept of protection from radioaerosols and volatile radionuclides has been suggested. A basically new method of the localization of radioactive aerosols and volatile radionuclides is based on the physicochemical process occurring in the gas phase. The proposed concept of protection from radioaerosols and volatile fission products uses unconventional approaches based not on the filtration of vapor-gas flow but on the extraction of radioaerosols and radioiodine from them by the formation of mixed micelles with manufactured hydrophilic aerosols, such as MoO₃ and NH₄CI-(NH₄)₂SO₃, and the cocrystallization of ionic iodine with them. The new concept may be used for protection from radioaerosols at various types of nuclear reactors.

Notes

* This paper is from “New Trends in Nuclear System Thermohydraulics,” an international conference that took place in Pisa, Italy, May 30-June 2, 1994.