Evaluation of Microbiological Factors that Influence Degradation of Low-level Waste Containers in Shovel Trench Repositories in a Desert Environment

摘要

Low-level waste is stored in shallow trenches at the Nevada Test Site. After burial a cap closure of the trench isrnconstructed and maintained. If decomposition of stored containers is accelerated by application of microorganisms, it mayrnbe possible to control the rate of subsidence of the cap closure. Control would provide the opportunity to reducernmaintenance costs and the probability of cap closure failure. In the first phase substantial colonization of cardboard, woodrnand metal coupons, formed from container materials and arranged in microcosms, did not occur. In the second phaserntreatments of coupons was augmented by applying microorganisms in a cellulose gel paste. Extensive colonization of therncardboard, wood and metal coupons was indicated by increases in heterotrophic plate counts and equitability indices, asrnwell as by examination with the scanning electron microscope. Thus, microbial amendments can be utilized that willrnpromote biofilm formation on typical container materials used for burial storage in desert soil.