Microbial effects on radioactive wastes at SLB sites

Abstract

The objectives of this study are to determine the significance of microbial degradation of organic wastes on radionuclide migration on shallow land burial for humid and arid sites, establish which mechanisms predominate and ascertain the conditions under which these mechanisms operate. Factors contolling gaseous eminations from low-level radioactive waste disposal sites are assessed. Importance of gaseous fluxes of methane, carbon dioxide and possibly hydrogen from the site stems from the inclusion of tritium and/or /sup 14/C into the elemental composition of these compounds. In that the primary source of these gases is the biodegradation of organic components of the waste materials, primary emphasis of the study involved on examination of the biochemical pathways producing methane, carbon dioxide and hydrogen, and the environmental parameters controlling the activity of the microbial community involved. Although the methane and carbon dioxide production rate indicates the degradation rate of the organic substances in the waste, it does not predict the methane evolution rate from the trench site. Methane fluxes from the soil surface are equivalent to the net synthesis minus the quantity oxidized by the microbial community as the gas passes through the soil profile. Gas studies were performed at three commercial low-level radioactive waste disposal sites (West Valley, New York; Beatty, Nevada; Maxey Flats, Kentucky) during the period 1976 to 1978. The results of these studies are presented. 3 tables.