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Title: S300 support documents for DTSC surprise inspection, January 2017

  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
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Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
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DOE Contract Number:
Resource Type:
Technical Report
Country of Publication:
United States

Citation Formats

Woollett, J. S. S300 support documents for DTSC surprise inspection, January 2017. United States: N. p., 2017. Web. doi:10.2172/1357343.
Woollett, J. S. S300 support documents for DTSC surprise inspection, January 2017. United States. doi:10.2172/1357343.
Woollett, J. S. Thu . "S300 support documents for DTSC surprise inspection, January 2017". United States. doi:10.2172/1357343.
title = {S300 support documents for DTSC surprise inspection, January 2017},
author = {Woollett, J. S.},
abstractNote = {},
doi = {10.2172/1357343},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 09 00:00:00 EST 2017},
month = {Thu Feb 09 00:00:00 EST 2017}

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  • The Gnome-Coach, New Mexico, Site was the location of an underground nuclear test in 1961 and a groundwater tracer test in 1963. Residual contamination remaining in the subsurface from these events requires long-term oversight. The Long-Term Surveillance and Maintenance Plan for the site describes the U.S. Department of Energy Office of Legacy Management’s (LM’s) plan for monitoring groundwater (radiochemical sampling and hydraulic head measurements), inspecting the site, maintaining the site’s institutional controls, evaluating and reporting data, and documenting the site’s records and data management processes. Groundwater monitoring and site inspection activities are conducted annually. This report summarizes the results ofmore » these activities conducted during the October 2015 through September 2016 reporting period. The site inspection and annual sampling were conducted on January 27, 2016. At the time of the site inspection, the signs installed near the emplacement shaft, near well USGS-1, and around the perimeter of the site were observed as being in good condition, as were the roads, wellheads, and Project Gnome monument. No new groundwater extraction wells or oil and gas wells were installed during this reporting period on the site or in the sections that surround the site. One new application was received by the New Mexico Oil Conservation Division to install a salt water disposal well approximately 0.8 miles northeast of the Project Gnome monument. The proposed well has a planned completion depth of 15,500 feet below ground surface, but as of November 2016 a drill date has not been established.« less
  • A trend summary of three Solvent Hold Tank (SHT) monthly samples; MCU-16-1488-1493 (December 2016), MCU-17-86-88 (January 2017), and MCU-17-119-121 (February 2017) are reported. Analyses indicate that the modifier (CS-7SB) and the extractant (MaxCalix) concentrations are at their nominal recommended levels (169,000 mg/L and 46,300 mg/L respectively). The suppressor (TiDG) level has decreased to a steady state level of 673 mg/L well above the minimum recommended level (479 mg/L). This analysis confirms the Isopar™ addition to the solvent in January 18, 2017. This analysis also indicates the solvent did not require further additions. Based on the current monthly sample, the levelsmore » of TiDG, Isopar™L, MaxCalix, and modifier are sufficient for continuing operation but are expected to decrease with time. Periodic characterization and trimming additions to the solvent are recommended. No impurities above the 1000 ppm level were found in this solvent by the Semi-Volatile Organic Analysis (SVOA). No impurities were observed in the Hydrogen Nuclear Magnetic Resonance (HNMR). Another impurity observed in the samples was mercury. Up to 38 ± 8 micrograms of mercury per mL of solvent was detected in these samples (the average of the CV-AA and XRF methods). The higher mercury concentration in the solvent (as determined in the last three monthly samples) is possibly due to the higher mercury concentration in Salt Batches 8 and 9 (Tank 49H) or mixing of previously undisturbed areas of high mercury concentration in Tank 49H. The gamma level (0.21E5 dpm/mL) measured in the February SHT sample was one order of magnitude lower than the gamma levels observed in the December and January SHT samples. The February gamma level is consistent with the solvent being idle (since January 10, 2017). The gamma levels observed in the December and January SHT samples were consistent with previous monthly measurements where the process operated normally. The laboratory will continue to monitor the quality of the solvent in particular for any new impurities or degradation of the solvent components.« less
  • Corrective Action Unit (CAU) 98: Frenchman Flat on the Nevada National Security Site was the location of 10 underground nuclear tests. CAU 98 underwent a series of investigations and actions in accordance with the Federal Facility Agreement and Consent Order to assess contamination of groundwater by radionuclides from the tests. A Closure Report completed that process in 2016 and called for long-term monitoring, use restrictions (URs), and institutional controls to protect the public and environment from potential exposure to contaminated groundwater. Three types of monitoring are performed for CAU 98: water quality, water level, and institutional control. These are monitoredmore » to determine whether the URs remain protective of human health and the environment, and to ensure that the regulatory boundary objectives are being met. Monitoring data will be used in the future, once multiple years of data are available, to evaluate consistency with the groundwater flow and contaminant transport models because the contaminant boundaries calculated with the models are the primary basis of the UR boundaries. Six wells were sampled for water-quality monitoring in 2017. Contaminants of concern were detected only in the two source/plume wells already known to contain contamination as a result of a radionuclide migration experiment. The 86,000-picocuries-per-liter (pCi/L) tritium concentration in one of the wells is about 12 percent higher than measured in 2016 but is over an order of magnitude less than the peak value measured in the well in 1980. The concentration in the other source/plume well is lower than measured in 2016. The water-level monitoring network includes 16 wells. Depth to water measured in 2017 is generally consistent with recent measurements for most wells. Water-level declines differing from long-term trends were observed in four wells. Three of these (WW-4, WW-4A, and WW-5B) are water-supply wells that experienced increases in pumping during the year. No definitive cause for the sharp decline in the fourth well (ER-5-3-2) in 2016 is known as yet. Institutional control monitoring confirmed the URs are recorded in U.S. Department of Energy and U.S. Air Force land management systems, and that no activities within Frenchman Flat basin are occurring that could potentially affect the contaminant boundaries. Survey of groundwater resources in basins surrounding Frenchman Flat similarly identify no current or pending development that would indicate the need to increase monitoring activities or would otherwise cause concern for the closure decision. The URs continue to prevent exposure of the public, workers, and the environment to contaminants of concern by preventing use of potentially contaminated groundwater.« less
  • This letter serves as the post-closure inspection letter report for CAUs on the NNSS for Calendar Year 2016. Issues that were identified in the 2015 inspections were repaired in 2016.
  • This report provides the results of the annual post-closure inspections conducted at the closed corrective action units (CAUs) located on the Tonopah Test Range (TTR) and the Nevada Test and Training Range (NTTR). This report covers calendar year 2017 and includes visual inspection and repair activities completed at the following CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR) CAU 407: Roller Coaster RadSafe Area (TTR) CAU 424: Area 3 Landfill Complexes (TTR) CAU 453: Area 9 UXO Landfill (TTR) CAU 487: Thunderwell Site (TTR) Visual inspections were conducted according to the post-closure plans in the approved closure reportsmore » and subsequent correspondence with the Nevada Division of Environmental Protection. The annual post-closure inspections were conducted on May 23, 2017. No maintenance or repair issues were noted at CAU 400 and CAU 487. Maintenance items and subsequent repairs include the following: CAU 407: A large animal burrow was observed in the southeast corner of the cover during the inspection. Two additional animal burrows were discovered during repair actions. All cover defects were repaired on January 9, 2018. CAU 424: CAS 03-08-002-A304 (Landfill Cell A3-4): A new monument was installed and the subsidence area was repaired on January 9, 2018. CAU 424: CAS 03-08-002-A308 (Landfill Cell A3-8): Lava rock, used to mark the two eastern monument locations, was noted as missing during the inspection. The lava rock was replaced on January 9, 2018. CAU 453: Five large animal burrows, located near the east–central portion of cover, was noted during the inspection. Eight additional animal burrows were discovered during repair actions. All cover defects were repaired on January 9, 2018.« less