Characterization of Microbial Communities in Subsurface Nuclear Blast Cavities of the Nevada Test Site

Moser, Duane ; Russell, Chuck ; Marshall, Matthew ; Czerwinski, Ken ; Daly, Michael J ; Zavarin, Mavrik

关键词: RADIOISOTOPES;    MICROORGANISMS;    NUCLEAR WEAPONS;    NEVADA TEST SITE Radionuclide;    microorganisms;    subsurface;    nuclear weapons;    Nevada Test Site;   

DOI  :  10.2172/923303
RP-ID  :  DOE/ER/64406-1
PID  :  OSTI ID: 923303

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

This exploratory research project is designed to test fundamental hypotheses concerning the possible existence and nature of indigenous microbial populations in Nevada Test Site (NTS) subsurface nuclear blast cavities. Although subsurface microbiological studies have been performed at the NTS in the past, radioactive zones have yet to be addressed. Nuclear blast zone microbiology is a completely new field and our team is well-positioned to collect and analyze samples that have never before been available to microbiologists. Relevant samples are now being obtained by incorporating microbiological collections into an ongoing annual hot well sampling program being conducted by other agencies. A combination of cultivation-based and molecular microbial detection protocols is being utilized at multiple locations to survey for uncultivable microorganisms and to develop a culture collection which will be characterized for radionuclide- and metal-reduction capabilities. Given that redox manipulations mediated by microorganisms can impact the mobility of DOE contaminants, a positive outcome from this work would have significant implications for management strategies at this and other DOE sites. A primary objective of the project has been the establishment of the regulatory and technical framework necessary to enable our acquisition of samples. Thus, much of our activity in the first phase of this work has involved the development an approved Field Area Work Plan (FAWP), Radiological Work Permit (RWP), and other documentation required for radiological work at the NTS. We have also invested significant time into ensuring that all personnel possess the required training (e.g. Radworker II and 40 hr. HAZWOPER) for access to the hot well sampling sites. Laboratory facilities, required for field processing of radioactive samples as well as DNA extraction and other manipulations, have been secured both the NTS (Mercury, NV) and UNLV. Although our year-1 field work was delayed due to non-availability of samples, an aggressive sampling campaign is now underway and our first hot well samples were collected on Feb 5th, 2008. The unique nature of this site, coupled with the combined expertise of the collaborating laboratories (DRI, LLNL, PNNL, and the Harry Reid Center) makes the likelihood of our achieving discoveries of value to DOE, the individual researchers, and society high. As the selective pressures at atomic blast sites are probably different from those of production and disposal sites, these habitats may contain novel organisms of utility for bioremediation. Such organisms will have had to develop physiological mechanisms to survive high doses of ionizing radiation over the variety of rock types and hydrologic environments present at the NTS.