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All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Local-Regional Surface Wave Dispersion Analysis using Ambient Noise Data of the Southern Nevada National Security Site Area

This report details seismic ambient noise analysis to improve seismic velocity estimates of the southeastern Nevada National Security Site (NNSS). We compare two different methods for estimating surface wave dispersion curves from ambient noise cross-correlations: frequency time analysis (FTAN) and Aki’s cross-spectral method (XSpec). We find that XSpec performs better for our local-regional dataset and frequency content. Using phase velocity estimates from XSpec, we build a preliminary phase velocity dispersion dataset, which contains data for 1,054 station pairs and 8,905 discrete phase velocity measurements for periods between 0.5 and 13 s. This phase velocity dataset will be incorporated into an updated local-regional P and S wave velocity model of the southeastern NNSS in the future and is expected to improve upon shallow velocity estimates.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Non-Resource Conservation and Recovery Act Corrective Action Unit (CAU) Post-Closure Inspection Report, Nevada National Security Site, Nevada For Calendar Year 2024

This report includes visual inspection results, descriptions of maintenance and repair activities, and recommendations for calendar year 2024 for use restrictions at corrective action sites located on the Nevada National Security Site (NNSS) and on the Nevada Test and Training Range that are accessed through the NNSS Main Gate.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Mitigation for the Demolition of Dormitory Buildings 12-32, 12-34, 12-35, and 12-37 in the Area 12 Camp Historic District, Nevada National Security Site, Nye County, Nevada

The purpose of this letter report is to document the mitigation of adverse effects of a proposed undertaking in compliance with the stipulations in the Programmatic Agreement DE-GM58-22NA25554 Among the U.S. Department of Energy and the Nevada State Historic Preservation Officer and the Advisory Council on Historic Preservation Concerning the Protection of Historic Properties on the Nevada National Security Site, Nye County, Nevada, hereafter referred to as the NNSS PA. The proposed undertaking would demolish Buildings 12-32 (State Historic Preservation Office [SHPO] Resource No. B18291), 12-34 (SHPO Resource No. B18292), 12-35 (SHPO Resource No. B18293), and 12-37 (SHPO Resource No. B18294) in the Area 12 Camp Historic District (SHPO Resource No. D372) on the Nevada National Security Site (NNSS). The Area 12 Camp Historic District has been determined eligible for listing in the National Register of Historic Places (NRHP) under Criteria A and C (Reed 2021; Reno et al. 2021).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Capturing plume behavior in complex terrain: an overview of the Nevada National Security Site Meteorological Experiment (METEX21)

METEX21 was an atmospheric tracer release experiment executed at the Department of Energy’s Nevada National Security Site (NNSS) in the southwestern U.S to study terrain-induced wind and thermodynamic conditions that influence local-scale (<5-km) plume transport under varying atmospheric forcing conditions. Meteorological observations were collected using 10-m tall meteorological towers, 2-m tall tripods with 3-d sonic anemometers, a 3-m tall eddy covariance flux tower, Doppler profiling lidars, Doppler scanning lidars, weather-balloon launched radiosondes, and a tethered balloon equipped with wind, temperature, and aerosol sensors at heights up to 800 m. A smoke tracer was released along three transects in the horizontal and vertical directions and observed with video cameras, aerosol sensors and lidars (via aerosol backscatter). The observations showed evidence of large-scale/synoptic transience as well as local-scale upslope and downslope flows, along-axis valley flows, recirculation eddies on leeward slopes, and periods of strong shear and veer aloft. The release days were classified as either synoptically-driven or locally-driven, and a single case day is presented in detail for each. Synoptically-forced days show relatively narrow smoke plumes traveling down the valley from north to south (with the predominant wind direction), with little deviation in transport direction regardless of the elevation or ground locations of the smoke releases, except near the presence of leeside recirculation eddies. Locally-forced days exhibit a wider range of plume behavior due to the combination of thermally-induced valley and slope flows, which are often flowing in different cardinal directions, and wind shear found aloft at higher altitudes and elevations. We saw evidence of smoke lofting on top of the mesas due to strong upslope flows on these days. A major finding of this experiment was the effectiveness of scanning lidars to measure 2-dimensional plume transport out to a 2–3 km distance; much farther than could be visibly observed. METEX21 was the first of three planned tracer experiments at NNSS, and future experiments will incorporate multiple tracers to improve individual plume identification so that finer resolution flow details can be attained from these measurements, as well as deploy a larger suite of meteorological instrumentation, including more temperature profiling data.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Environmental Management

Another key aspect of the NNSS mission is Environmental Management program, which addresses the environmental legacy from historic nuclear weapons related activities while also ensuring the health and safety of present day workers, the public, and the environment as current and future missions are completed. The Area 5 Radioactive Waste Management site receives low-level and mixed low-level waste from some 28 different generators from across the DOE complex in support of the legacy clean-up DOE Environmental Management project. Without this capability, the DOE would not be able to complete the clean up and proper disposition of these wastes. The program includes environmental protection, compliance, and monitoring of the air, water, plants, animals, and cultural resources at the NNSS. Investigation and implementation of appropriate corrective actions to address the contaminated ground water facilities and soils resulting from historic nuclear testing activities, the demolition of abandoned nuclear facilities, as well as installation of ground water wells to identify and monitor the extent of ground water contamination.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Waste Characterization Process

The purpose is to provide guidance to the Radiological Characterization Reviewer to complete the radiological characterization of waste items. This information is used for Department of Transportation (DOT) shipping and disposal, typically at the Nevada National Security Site (NNSS). Complete characterization ensures compliance with DOT shipping laws and NNSS Waste Acceptance Criteria (WAC). The fines for noncompliance can be extreme. This does not include possible bad press, and endangerment to the public, employees and the environment. A Radiological Characterization Reviewer has an important role in the organization. The scope is to outline the characterization process, but does not to include every possible situation. The Radiological Characterization Reviewer position requires a strong background in Health Physics; therefore, these concepts are minimally addressed. The characterization process includes many Excel spreadsheets that were developed by Michael Enghauser known as the WCT software suite. New Excel spreadsheets developed as part of this project include the Ra- 226 Decider and the Density Calculator by Jesse Bland, MicroShield Density Calculator and Molecular Weight Calculator by Pat Lambert.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

2nd Quarter Transportation Report FY2015: Radioactive Waste Shipments to and from the Nevada National Security Site

This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of radioactive waste shipments to and from the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) at Area 5. There were no shipments sent for offsite treatment and returned to the NNSS this quarter. This report summarizes the 2nd quarter of Fiscal Year (FY) 2015 low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW) shipments.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Special Analysis for the Disposal of the West Valley Demonstration Project Extraction Cell 2 Low Density Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the West Valley Demonstration Project (WVDP) Extraction Cell 2 Low Density waste stream is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). The WVDP Low Density waste stream consists of debris contaminated during the decontamination and decommissioning (D&D) of Extraction Cell 2 at the WVDP (WVDP 2015). The WVDP Low Density waste stream required an SA because the radium-226 (226Ra) activity concentration exceeds the NNSS Waste Acceptance Criteria (WAC) Action Level (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2013). The effect of adding the WVDP Low Density waste stream inventory to the inventory of waste disposed through the end of FY 2014 was evaluated with the A5 RWMS v 4.119 PA model. The results indicate that all performance objectives can be met with disposal of the WVDP Low Density in a SLB trench. Addition of the WVDP Low Density inventory slightly increases the 222Rn flux density, but the maximum mean and 95th percentile flux density remain less than the performance objective throughout the compliance period. The WVDP Low Density waste stream had no significant effect on the maximum mean and 95th percentile for all other PA results. The WVDP Low Density waste stream, therefore, is suitable for disposal by SLB at the Area 5 RWMS.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Special Analysis for the Disposal of the Oak Ridge National Laboratory General Radioactive Sources Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the Oak Ridge National Laboratory (ORNL) General Radioactive Sources waste stream (ORNLSOURCES01, Revision 3) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The ORNL General Radioactive Sources waste stream consists of sealed sources and solid radioactive sources that are no longer needed (ORNL 2015). The ORNL General Radioactive Sources waste stream required a special analysis because 26 radionuclides exceeded the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015). However, review of the generator’s method to calculate waste concentration indicates that the concentrations are significantly overestimated. Waste concentrations are recalculated in this analysis using a list of individual sources provided by the generator. One radionuclide, radium-226 (226Ra), still exceeds its action level and a Special Analysis (SA) is required. The results indicate that all performance objectives can be met with disposal of the ORNL General Radioactive Sources in a SLB trench. Addition of the ORNL General Radioactive Sources inventory slightly increases the 222Rn flux density. The maximum mean and 95th percentile flux density remain less than the performance objective throughout the compliance period. The ORNL General Radioactive Sources waste stream had no significant effect on the maximum mean and 95th percentile for all other performance assessment results. The ORNL General Radioactive Sources waste stream is suitable for disposal by SLB at the Area 5 RWMS. However, because the activity concentrations on the waste profile sheet are significantly overestimated, approval of the sheet could potentially allow the disposal of high activity radiation sources. To ensure the generator does not include large radiation sources in its waste stream, a control is recommended on the maximum individual source activity from this generator.

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DOE OSTI2014

Waste Acceptance and Disposal at the Nevada National Security Site

The U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) relies on the Performance Assessment (PA) and the PA model of the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS) to make disposal decisions on waste stream profiles submitted by waste generators. Disposal decisions are made following a formal process called the PA review process. This paper presents the PA review process, which is a part of the NNSA/NFO’s Waste Generator Documentation Approval Process. The review process includes three major steps and employs quantitative tools such as the PA-derived factors and probabilistic inventory and PA models developed in GoldSim. The PA-derived radionuclide action levels for waste characterization and reporting are included in the NNSS Waste Acceptance Criteria. Each year, NNSA/NFO reviews approximately 100 to 150 new or revised waste stream profiles. The PA review group ensures that, with the disposal of approved waste streams, the Area 5 RWMS will remain in compliance with the performance objectives of DOE O 435.1, “Radioactive Waste Management.” Examples of the PA review process are given that demonstrate how waste streams with special characteristics are evaluated and disposal decisions are made. The most rigorous profile evaluation is done with the PA model, run with the proposed profile inventory added and results compared to the PA results. Additional analysis and process-modeling are performed for those waste streams with unique features not addressed with the PA model. The results of these analyses and modeling are documented in special analysis reports, reviewed and approved by NNSA/NFO. The examples include (1) profiles with radionuclides not in the PA, (2) profiles including radionuclides with high radon-generation potential, and (3) profiles with high-heat generating radionuclides.

Yucel, Vefa↗
DOE OSTI2018

Emergency Planning and Preparedness, Mission Support and Test Services

This presentation is for the Community Environmental Monitoring Program (CEMP), comprising a network of monitoring stations located in communities surrounding and downwind of the Nevada National Security Site (NNSS) that monitor the airborne and groundwater environments for manmade radioactivity that could result from NNSS activities. The CEMP is a collaborative effort of the Department of Energy's National Nuclear Security Administration Nevada Field Office (NNSA/NFO), and the Desert Research Institute (DRI) of the Nevada System of Higher Education.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2019

Analysis of Cygnus Electrical Signals

The United States initiated the Subcritical Experiment (SCE) program to support a stockpile stewardship mission shortly after the 1992 moratorium on underground nuclear testing was established. Many SCE’s are conducted at the Nevada National Security Site (NNSS) in Nevada. Cygnus is a high-energy radiation generating device (RGD) located and operated at the NNSS and is a primary diagnostic for the SCE program. The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources, Cygnus 1 and Cygnus 2. From creation of the high power V-I drive to energy transport and X-ray conversion at the rod-pinch diode, the Cygnus machines utilize the following components: oil-filled Marx generator, water-filled pulse-forming line (PFL), water-filled coaxial transmission line (CTL), three-cell vacuum induction voltage adder (IVA), and rod-pinch diode. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. Each source has the following X-ray specifications: 1 mm diameter, 4 rad at 1 m, and 50 ns radiation pulse. SCEs are both single-event and high-value; therefore, a high level of performance in reliability and reproducibility are key issues of Cygnus. Prior to executing such a SCE, there are a formidable number of shots (e.g., each of the two Cygnus RGDs charging and discharging properly into the rod-pinch diode load) that must be executed to determine reliability and reproducibility of the Cygnus RGDs. For every shot on Cygnus, voltages and currents along the machine are recorded and analyzed. In this paper we summarize attributes of the voltage and current waveforms at different locations using distribution plots. These distribution plots are used to quantify the reliability and reproducibility for Cygnus. This analysis methodology will provide a standard to trouble shoot results of individual Cygnus shots, and also to monitor long term Cygnus performance. Accordingly, this type of extensive analysis will contribute to optimized Cygnus performance on SCEs.

42 ENGINEERING↗
DOE OSTI2019

Western Red-tailed Skink ( Plestiodon Gilberti Rubricaudatus ) Distribution and Habitat Use in Southern Nevada, USA

Western Red-tailed Skinks ( Plestiodon Gilberti Rubricaudatus ) are a Species of Conservation Priority in Nevada and a Species of Greatest Conservation Need in Arizona. Information about this species is lacking, especially for Nevada. We conducted a study from 2006–2011 to determine distribution, abundance, and habitat use of the Western Red-tailed Skink on the Nevada National Security Site (NNSS) in southern Nevada, USA. We used stand-alone funnel traps set in rocky habitats as our primary trapping method. We detected skinks at 28 of the 154 trapping sites and documented 38 individual skinks during 31,119 trap days. Occupied sites occurred in 10 vegetation associations and 12 geological formations at an average elevation of 1,727 m ± 197 m (range, 1,310–2,095 m). Using an occupancy modeling framework, we found that skinks were most likely to occur at mid-elevation sites with south-facing slopes. The model also weakly suggested that Sagebrush-dominated sites and wet or mesic sites were more likely to harbor skinks. Other measurable sources of variation among sampled sites (e.g., vegetation and substrate classifications) had little apparent effect on skink occurrence. Genetic analysis of 33 skinks from the NNSS indicated all belong to a mitochondrial clade that is restricted to central-eastern California and southwestern Nevada (Inyo clade).

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Modelling Proton Interactions with Magnetodynamic Targets for Electromagnetic Field Mapping

This paper does not describe NNSS work on this project. I am a co-author due to our experimental support which will be described in future papers. The principal authors want to include all authors on all papers as a team, so I am included. The primary authors want to ensure NNSS is recognized as part of that team. My work related to this specific paper was limited to intellectual conversations and experimental planning.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Ecological Monitoring and Compliance Program 2020 Report

The Ecological Monitoring and Compliance Program (EMAC), funded through the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO), monitors the ecosystem of the Nevada National Security Site (NNSS) and ensures compliance with laws and regulations pertaining to NNSS biota. This report summarizes the program’s activities conducted by Mission Support and Test Services, LLC (MSTS), during calendar year 2020. Program activities included (a) biological surveys at proposed activity sites, (b) desert tortoise compliance, (c) ecosystem monitoring, (d) sensitive and protected/regulated plant monitoring, (e) sensitive and protected/regulated animal monitoring, and (f) habitat restoration monitoring. During 2020, all applicable laws, regulations, and permit requirements were met, enabling EMAC to achieve its intended goals and objectives.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

Stakeholder Involvement in the Revegetation of the 92-Acre Area - 17152

The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) works closely with stakeholders that have an interest in the revegetation of a closed landfill on the Nevada National Security Site (NNSS). Located at the Radioactive Waste Management Complex on the NNSS, the 92-Acre Area was operational from 1961 to 2010. In 2009, the Nevada Division of Environmental Protection (NDEP) and NNSA/NFO agreed on a closure path consisting of a vegetative cover. Closure activities were initially completed in 2012. Although revegetation was initially promising, subsequent monitoring revealed that a viable plant community had not been established. Subsequently, sections of the site were chosen as test plot locations to determine the best path forward. Despite various seeding methods, mulching techniques, and irrigation frequencies, the test plots failed to produce viable plant communities in 2013 and 2014. NNSA/NFO had been in communication with one stakeholder, NDEP, during the revegetation process. NDEP agreed that after three failed revegetation attempts, a change in strategy was necessary. The Consolidated Group of Tribes and Organizations (CGTO), a coalition of tribal members representing seventeen culturally affiliated tribes and one organization, agreed to provide guidance using traditional ecological knowledge for re-vegetating the 92-Acre Area. A Tribal Revegetation Committee (TRC) was formed and tasked with developing guidance from a unique tribal perspective. After visiting the 92-Acre Area and receiving background information, the TRC held several meetings and deliberated on how to address the revegetation challenges. The TRC submitted recommendations to NNSA/NFO identifying approaches that incorporate tribal perspectives in re-vegetating the site. The Nevada Site-Specific Advisory Board (NSSAB), which is made up of community members who represent Nevada stakeholders, was also asked for input regarding the 92-Acre Area. After a public meeting in May 2016, the NSSAB submitted recommendations, which included a suggestion to consider input from the CGTO. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Applications Of The Advanced Simulation Capability For Environmental Management (ASCEM) - 17253

Three applications were completed using the Advanced Simulation Capability for Environmental Management (ASCEM), supported by the U.S. Department of Energy's Office of Environmental Management. These analyses were performed for the Savannah River Site (SRS) F-Area, the Los Alamos National Laboratory (LANL) Site, and the Nevada National Security Site (NNSS). At the SRS F-Area, ASCEM simulations were used to help develop cost-effective, long-term monitoring approaches for science-based site closure and management. The simulation results were used to develop a mechanistic understanding of correlations between contaminant concentrations and master variables that can be used for monitoring. At LANL, the ASCEM simulator Amanzi was integrated with a LANL-based decision support tool for the LANL onsite program. A saturated-zone site model focused on a key area of interest was developed and calibrated to measured data. This model was applied to quantify uncertainty and provide decision support to inform chromium remediation efforts. To support assessment of groundwater contamination at NNSS, ASCEM was used to calibrate hydrologic properties and flow directions using water levels observed under steady-state conditions and during four different pump tests on Pahute Mesa. The flow fields generated from these pump tests will be used to simulate transport pathways from underground nuclear tests to compare with field observations and to test alternative conceptual models of transport, which will ultimately facilitate better placement of monitoring wells. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗