Results 1 - 10 of 218
Results 1 - 10 of 218. Search took: 0.02 seconds
|Sort by: date | relevance|
[en] This document establishes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO), Nevada National Security Site Waste Acceptance Criteria (NNSSWAC). The NNSSWAC provides the requirements, terms, and conditions under which the Nevada National Security Site (NNSS) will accept the following: DOE low-level radioactive waste (LLW); DOE mixed low-level waste (MLLW); DOE classified waste/matter; U.S. Department of Defense (DOD) classified waste/matter The LLW and MLLW listed above may also be classified waste. Non-radioactive classified waste is accepted for disposal and shall meet the waste acceptance criteria for radioactive waste as specified in this document. Classified matter may be shipped to the NNSS for permanent burial as classified waste in accordance with the provisions in Section 3.1.18 of this document.
[en] Aluminum-clad nuclear fuel has been at the forefront in research and commercial reactors. After being removed from the reactor, the spent nuclear fuel is placed in large-volume water basins (wet storage) that are constantly monitored for water quality to minimize corrosion/deterioration. The water provides both radiation shielding and cooling for the freshly removed fuel. It is highly desired to have a pathway for fuel to be transitioned to dry storage in sealed casks, so that spent nuclear fuel can be safely transported and dispositioned in a permanent repository, and basin capacity can be made available for temporary wet storage of fresher spent fuel. A challenge for safe, road-ready dry storage is the hydrated aluminum oxides (oxyhydroxides) that are prevalent on aluminum spent nuclear fuel that has been stored under water for years. If water is released from the oxyhydroxides during dry storage, it can create corrosion within the storage canister, and hydrogen can be generated through radiolysis of the oxyhydroxides, causing pressurization and flammability risks. The focus of this project is to develop knowledge of the oxyhydroxide growth and production of gases through radiolysis and to apply empirical models for predicting these phenomena. The expertise developed will be used to formulate conditions and parameters for oxyhydroxide removal/dehydration from fuel cladding through vacuum or forced-air gas drying, to prevent problems during permanent dry storage.
[en] Thermal conductivities of La_3Cu_3X_4(X=P,As,Sb,Bi) compounds are examined using first-principles density functional theory and Boltzmann transport methods. We observe a trend of increasing lattice thermal conductivity (κl) with increasing atomic mass, challenging our expectations, as lighter mass systems typically have larger sound speeds and weaker intrinsic scattering. In particular, we find that La_3Cu_3P_4 has the lowest κ_l, despite having larger sound speed and the most restricted available phase space for phonon-phonon scattering, an important criterion for estimating and comparing κ_l among like systems. The origin of this unusual behavior lies in the strength of the individual anharmonic phonon scattering matrix elements, which are much larger in La_3Cu_3P_4 than in the heavier La_3Cu_3Bi_4 system. Lastly, our finding provides insights into the interplay of harmonic and anharmonic properties of complex, low-thermal-conductivity compounds, of potential use for thermoelectric and thermal barrier coating applications.
[en] This report documents the well development and testing (WDT) data and analysis of Wells ER-3-3 and ER-4-1 during fiscal year (FY) 2017. Wells ER-3-3 and ER-4-1 were constructed to evaluate possible radionuclides (RNs) in groundwater from nearby underground tests (UGTs), to provide hydrogeologic information to support refinement of the Yucca Flat hydrostratigraphic framework model (HFM) (BN, 2006), and to provide supplemental data to the Yucca Flat groundwater flow and contaminant transport model (N-I, 2013) to help address priority concerns and recommendations of the Yucca Flat External Peer Review Team. Of particular interest is the characterization of specific groundwater flow pathways (i.e., faults, fractured aquifers) along which RNs in groundwater could migrate from individual UGTs. Another important objective is to determine the hydraulic properties of the volcanic aquifers (VAs) and carbonate aquifers (CAs) in the former underground testing areas in Yucca Flat, and specifically in the areas proximal to existing UGTs.
[en] This document summarizes the flow-down of requirements from TFR-483 and SAR-419 and provides a roadmap for a verification of the requirements. The project vital safety systems include the vault shield plugs (VSP) and the cask-to-vault adapting structure (CVAS).
[en] This report is required by the Underground Test Area (UGTA) Quality Assurance Plan (QAP) and identifies the UGTA quality assurance (QA) activities from October 1, 2014, through September 30, 2015 (fiscal year [FY] 2015). All UGTA organizations—U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO); Desert Research Institute (DRI); Lawrence Livermore National Laboratory (LLNL); Los Alamos National Laboratory (LANL); National Security Technologies, LLC (NSTec); Navarro-Intera, LLC (N-I); Navarro Engineering and Research Inc (Navarro); and the U.S. Geological Survey (USGS)—conducted QA activities in FY 2015. The activities included conducting oversight assessments for QAP compliance, identifying findings and completing corrective actions, evaluating laboratory performance, and publishing documents.
[en] The Nuclear Science Advisory Committee (NSAC) of the Department of Energy (DOE) Office of Nuclear Physics (NP) recommended in the 2015 Long Range Plan (LRP) for Nuclear Science that the proposed Electron Ion Collider (EIC) be the highest priority for new construction. This report noted that, at that time, two independent designs for such a facility had evolved in the United States, each of which proposed using infrastructure already available in the U.S. nuclear science community.
[en] This report is required by the Underground Test Area (UGTA) Activity Quality Assurance Plan (QAP) (NNSA/NFO, 2015) and identifies the UGTA quality assurance (QA) activities from October 1, 2015, through December 31, 2016 (hereafter, called “the reporting period”). This expanded reporting period allows this report to be converted to a calendar-year (CY) reporting cycle. This change is being made to better align this report with the annual UGTA sampling and the Nevada National Security Site (NNSS) environmental reports. All UGTA organizations—U.S. Department of Energy (DOE) Office of Environmental Management (EM) Nevada Program; Desert Research Institute (DRI); Lawrence Livermore National Laboratory (LLNL); Los Alamos National Laboratory (LANL); National Security Technologies, LLC (NSTec); Navarro Research and Engineering, Inc. (Navarro); and the U.S. Geological Survey (USGS)—conducted QA activities in the reporting period. The activities included conducting oversight assessments for QAP compliance, identifying findings and completing corrective actions, evaluating laboratory performance, reviewing technical work, and publishing documents.
[en] This Corrective Action Decision Document/Corrective Action Plan provides the rationale and supporting information for the selection and implementation of corrective actions at Corrective Action Unit (CAU) 414, Clean Slate III Plutonium Dispersion (TTR). This document has been developed in accordance with the Federal Facility Agreement and Consent Order. CAU 414 is located on the Tonopah Test Range and includes one corrective action site, TA-23-03CS, Pu Contaminated Soil.
[en] The Corrective Action Unit (CAU) 412 Closure Report (CR) was published in August 2016 (NNSA/NFO, 2016). The purpose of this addendum is to reference a letter from the U.S. Air Force (USAF) regarding the closure of CAU 412.