Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “siting”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Fiscal Year 2020 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada National Security Site, Nye County, Nevada

U.S. Department of Energy Standard DOE-STD-5002-2017, “Disposal Authorization Statement and Tank Closure Documentation,” requires preparation of an Annual Summary Report comparing low-level radioactive waste disposal facilities operations with the Disposal Authorization Statement (DAS) and its supporting technical documents including the performance assessment (PA) and the composite analysis (CA). The fiscal year (FY) 2020 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) was prepared by reviewing planned and discovered changes, waste receipts, monitoring results, research and development (R&D) results, and the status of DAS conditions and issues to assess the validity of the DASs, PAs, and CAs.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Nevada National Security Site Environmental Report 2024 with Attachment A Site Description and Summary Report

This Nevada National Security Site Environmental Report (NNSSER) summarizes actions taken in 2024 to protect the environment and the public while achieving the NNSA/NFO mission goals. It is prepared for the public and our stakeholders in hopes that it is readily understandable and usable. It is a key component in our efforts to keep the public informed of environmental conditions at the NNSS and its support facilities in Las Vegas, Nevada.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Rhodium pair-sites on magnesium oxide: Synthesis, characterization, and catalysis of ethylene hydrogenation

Supported rhodium acetate dimers were prepared by the reaction of Rh2(OAc)4 (OAc is acetate) with highly dehydroxylated MgO powder and characterized by extended X-ray absorption fine structure and infrared (IR) spectra, which show that the supported species were well represented as Rh2(OAc)3, with each Rh atom on average bonded to one oxygen atom of the MgO surface. Aberration-corrected scanning transmission electron microscopy gave images of Rh atoms in pairs on the MgO. The supported rhodium dimers were probed with a pulse of CO, and the IR spectra indicate a Rh(II) species with weakly bonded carbonyl ligands; the sharpness of the νCO band indicates highly uniform surface species. Further treatment in CO led to breakup of the rhodium dimers into mononuclear species; such fragmentation took place in other treatment gases as well, with the degree of fragmentation decreasing in the order CO > C2H4 > helium. The fragmentation is inferred on the basis of IR spectra to have proceeded through intermediate Rh2 species without acetate ligands. In contrast, rhodium dimers were reduced and not fragmented in the presence of H2 at 353 K, but at higher temperatures the rhodium aggregated to give larger clusters. The supported species catalyzed ethylene hydrogenation at 298 K and 1 bar at a H2 to ethylene molar ratio of 4; after 27 h of catalysis in a once-through flow reactor, acetate ligands were removed from the dimers, and some of them fragmented, as shown by IR spectroscopy. The intermediate dirhodium species without acetate ligands are two or three orders of magnitude more active as catalysts than the supported mononuclear rhodium species or those present predominantly as Rh2(OAc)3, respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2011

Errata Sheet for the Closure Report for Corrective Action Unit 538: Spill Sites, Nevada Test Site, Nevada with ROTC-1, Revision 0

This Erratum is being issued to DOE/NV--1185 ROTC-1 for the CAU 538 Closure Report to correct three items. The original ROTC which was issued on November 30, 2011 corrected the Use Restriction for CAS 12-29-06 to remove a coordinate point from the Use Restriction. However, the ROTC contained three errors as follows: 1. The number of digits after the decimal place on the UR form was one while the map displayed two digits after the decimal place. The UR form and map were aligned as part of this Erratum so that only a single digit was shown after the decimal place. 2. On the figure (Figure 1) included with the UR form issued as part of ROTC-1, CAU 538 was incorrectly called out as CAU 583. This error was corrected as part of this Erratum. 3. The coordinates on the UR form were developed from NAD 27 while the coordinate system stated on the form was UTM, Zone 11, NAD 83 meters. The coordinates were corrected on the UR form, developed as part of this Erratum, to reflect the UTM, Zone 11, NAD 83 meters system.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Corrective Action Decision Document/Closure Report for Corrective Action Unit 571: Area 9 Yucca Flat Plutonium Dispersion Sites, Nevada National Security Site, Nevada, Revision 0 with ROTC 1

The purpose of this CADD/CR is to provide documentation and justification that no further corrective action is needed for the closure of CAU 571 based on the implementation of corrective actions. This includes a description of investigation activities, an evaluation of the data, and a description of corrective actions that were performed. The CAIP provides information relating to the scope and planning of the investigation. Therefore, that information will not be repeated in this document.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Radionuclide Migration at a Plowshare Program Site: the Gasbuggy Underground Nuclear Test Site, San Juan County, New Mexico - 17019

Project Gasbuggy in northwest New Mexico was the first of three subsurface nuclear tests the U.S. Atomic Energy Commission conducted to evaluate the potential to enhance the production of natural gas from low-permeability geologic formations. In 1967, a 29-kiloton nuclear device was detonated in the Lewis Shale (marine shale and siltstone), 1,292 m below the land surface. The detonation vaporized a cavity into which overlying rock collapsed, forming a 101-m high rubble-filled chimney with a radius of 25 m. Explosion-generated fractures extended between 120 m and 150 m from the working point (detonation location). Most of the radionuclides generated from the explosion remain in the cavity melt glass or have decayed to negligible amounts; tritium radioactivity, however, is still high enough and potentially mobile enough to be of concern. Tritium is able to exchange with stable hydrogen and form liquid water and water vapor; under two-phase (liquid and gas) reservoir conditions the majority of tritium is stored as liquid water and volatilises only to restore equilibrium conditions as gas is removed. A numerical model was developed to examine the migration of tritium in both phases through the fractured shale and sandstone under present conditions. The results suggest that tritium has migrated only 110 m from the working point between 1967 and 2014. Although tritium is able to exchange between the gas and aqueous phases, the faster-diffusing gas phase is responsible for most of the tritium transport from the chimney. A hypothetical producing gas well located 340 m from the working point was added to the model to determine if tritiated water vapor (HTO) could migrate toward the well; results show that, because the low gas velocities could not compete with the high rate of radioactive decay, tritium would not reach the well. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Global parameterization and validation of a two-leaf light use efficiency model for predicting gross primary production across FLUXNET sites: TL-LUE Parameterization and Validation

We present the first extended validation of satellitemicrowave (MW) liquidwater path (LWP) for low nonprecipitating clouds, from four operational sensors, against ship-borne observations from a three-channel MW radiometer collected along ship transects over the northeast Pacific during May–August 2013. Satellite MW retrievals have an overall correlation of 0.84 with ship observations and a bias of 9.3 g/m2. The bias for broken cloud scenes increases linearly with water vapor path and remains below 17.7 g/m2. In contrast, satelliteMWLWP is unbiased in overcast scenes with correlations up to 0.91, demonstrating that the retrievals are accurate and reliable under these conditions. Satellite MW retrievals produce a diurnal cycle amplitude consistent with ship-based observations (33 g/m2). Observations taken aboard extended ship cruises to evaluate not only satellite MW LWP but also LWP derived from visible/infrared sensors offer a new way to validate this important property over vast oceanic regions.

Zhou, Yanlian↗
DOE OSTI2017

Modeling CO 2 emissions from A rctic lakes: Model development and site‐level study

Abstract Recent studies indicated that Arctic lakes play an important role in receiving, processing, and storing organic carbon exported from terrestrial ecosystems. To quantify the contribution of Arctic lakes to the global carbon cycle, we developed a one‐dimensional process‐based Arctic Lake Biogeochemistry Model (ALBM) that explicitly simulates the dynamics of organic and inorganic carbon in Arctic lakes. By realistically modeling water mixing, carbon biogeochemistry, and permafrost carbon loading, the model can reproduce the seasonal variability of CO 2 fluxes from the study Arctic lakes. The simulated area‐weighted CO 2 fluxes from yedoma thermokarst lakes, nonyedoma thermokarst lakes, and glacial lakes are 29.5, 13.0, and 21.4 g C m −2 yr −1 , respectively, close to the observed values (31.2, 17.2, and 16.5 ± 7.7 g C m −2 yr −1 , respectively). The simulations show that the high CO 2 fluxes from yedoma thermokarst lakes are stimulated by the biomineralization of mobilized labile organic carbon from thawing yedoma permafrost. The simulations also imply that the relative contribution of glacial lakes to the global carbon cycle could be the largest because of their much larger surface area and high biomineralization and carbon loading. According to the model, sunlight‐induced organic carbon degradation is more important for shallow nonyedoma thermokarst lakes but its overall contribution to the global carbon cycle could be limited. Overall, the ALBM can simulate the whole‐lake carbon balance of Arctic lakes, a difficult task for field and laboratory experiments and other biogeochemistry models.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Covalent Organic Frameworks as a Decorating Platform for Utilization and Affinity Enhancement of Chelating Sites for Radionuclide Sequestration

The potential consequences of nuclear events and the complexity of nuclear waste management motivate the development of selective solid-phase sorbents to provide enhanced protection. Herein, we show that two dimensional covalent organic frameworks (COFs) with unique structures possess all the traits to be well-suited as a platform for the deployment of highly efficient sorbents such that they exhibit remarkable performance, as demonstrated by uranium capture. The chelating groups laced on the open one dimensional channels exhibit exceptional accessibility, allowing significantly higher utilization efficiency. In addition, the two dimensional extended polygons packed closely in an eclipsed fashion bring chelating groups in adjacent layers parallel to each other, which may facilitate their cooperation, thereby leading to high affinity towards specific ions. As a result, the amidoxime functionalized COFs far outperform their corresponding amorphous analogues in terms of adsorption capacities, kinetics, and affinities

Sun, Qi↗