Study of evaporating the irradiated graphite in equilibrium low-temperature plasma

E. V. Bespala, I. Yu Novoselov, A. O. Pavlyuk, S. G. Kotlyarevskiy

Research output: Contribution to journalArticle

Abstract

The paper describes a problem of accumulation of irradiated graphite due to operation of uranium-graphite nuclear reactors. The main noncarbon contaminants that contribute to the overall activity of graphite elements are iso-topes 137Cs, 60Co, 90Sr, 36Cl, and 3H. A method was developed for processing of irradiated graphite ensuring the volu-metric decontamination of samples. The calculation results are presented for equilibrium composition of plasma-chemical reactions in systems “irradiated graphite−argon” and “irradiated graphite−helium” for a wide range of tem-peratures. The paper describes a developed mathematical model for the process of purification of a porous graphite surface treated by equilibrium low-temperature plasma. The simulation results are presented for the rate of sublimation of radioactive contaminants as a function of plasma temperature and plasma flow velocity when different plasma-forming gases are used. The extraction coefficient for the contaminant 137Cs from the outer side of graphite pores was calculated. The calculations demonstrated the advantages of using a lighter plasma forming gas, i.e., helium.

Original languageEnglish
Pages (from-to)109-117
Number of pages9
JournalThermophysics and Aeromechanics
Volume25
Issue number1
DOIs
Publication statusPublished - 1 Jan 2018

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Keywords

  • decontamination
  • irradiated graphite
  • plasma
  • processing

ASJC Scopus subject areas

  • Radiation
  • Nuclear and High Energy Physics

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