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At least 1,171 records · Page 65
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Annual Radioactive Waste Tank Inspection Program – 2017

The Department of Energy (DOE) requires that Savannah River Remediation LLC (SRR), the Liquid Waste contractor, maintain a robust and timely Structural Integrity Program for waste tanks that are leak-tight and for waste tanks that have leaked or are suspect. These requirements are promulgated in DOE Manual 435.1-1, Section II.Q.(2). A key aspect of SRR’s implementation of these requirements is its annual tank inspection program.

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DOE OSTI2019

Designing Flexibility into the Authorized Radioactive Contents of the 9982 Shipping Package (Midterm Report)

With regards to the planned contents for the 9982, three sets of radionuclides have been analyzed. A set of percentages by weight for plutonium from 3013 canisters, training sources sent in 9977’s, and americium standards from 9978’s were used as the bases for realistic contents that could be shipped in a 9982 package. Using the tables and limits located in G-BDR-A-00001 Rev. E, the calculations began by determining the mass limits for the radionuclides in each source. These mass limits were then used alongside the mass of the radionuclides in the sum-of-the-fractions methodology present in the content description. If this summation is less than or equal to one, the contents are allowed for shipment in the 9982. For the aforementioned sets, the listed radionuclides could be shipped as-is; however, the goal of the calculations is to determine the maximum content mass allowed. To do so, the percentages of weight were used to find where the summations would equal one rather than simply satisfy the inequality. By solving for the content mass when the inequality equals one, the maximum content mass is calculated, which can then be multiplied by each percent weight to get each radionuclide’s mass. The MCNP input files have also been compared to find differences between the oxide and metals forms of the radionuclides. While there are several differences present that make sense, such as oxides have more mass and a lower density due to the presence of oxygen in the oxide forms, there are other differences that are possibly unintentional. With the input files for the metals, both with and without a shielding pig, neutrons are being used in the photon models, seen by “imp:n” being present within the file instead of “imp:p”, where “imp” stands for the importance of a region for either neutrons or photons. Effectively, this results in the dose due to photons being modelled with neutrons instead, potentially resulting in the calculated dose rates being incorrect. As MCNP is proprietary, I do not have access to it here and must consult with the person handling the shielding calculations to discuss what these differences may affect and how to change them. If he remains out of the office or if fixing these files takes longer than expected, the final report may focus more on the contents while discussing these differences; however, it could potentially lack discussion on finalizing the planned contents due to the mass limits still needing to be calculated.

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DOE OSTI2019

International Collaborations on Radioactive Waste Disposal in Salt

This report is a summary of the international collaboration and laboratory work funded by the US Department of Energy Office (DOE) of Nuclear Energy Spent Fuel and Waste Science & Technology (SFWST) as part of the Sandia National Laboratories Salt R&D work package. This report satisfies milestone level-four milestone M4SF-19SNO10303064. Several stand-alone sections make up this summary report, each completed by the participants. The first two sections discuss international collaborations on geomechanical benchmarking exercises (WEIMOS), granular salt reconsolidation (KOMPASS), engineered barriers (RANGERS), and documentation of Features, Events, and Processes (FEPs).

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DOE OSTI2019

Quantifying Holocene Cliff Retreat Rates at Technical Area 54, a Low- and Mixed-Level Radioactive Waste Disposal Site, Los Alamos National Laboratory, Los Alamos, New Mexico [Slides]

Cliff failure is occurring and threatens to expose pits and shafts. Steep slope angles = FoS < 1 = high probability of failure and retreat. EQ magnitude > 5.5 could initiate failure where FoS > 1. Fracture characterization (location, orientation, etc.) is essential for predictive analysis of at-risk cliff failure locations. Additional surface exposure dating would be helpful and further constrain the effect of fracture characteristics. Continued monitoring is essential for change detection and identification of areas with higher cliff retreat rates.

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DOE OSTI2018

Public Views on Nuclear Facility Siting and Radioactive Waste Management in the United States: Methodology and Response Reference Report for the 2017 Energy and Environment Survey

This report presents the questions and responses to a nationwide survey of U.S. residents taken May 2017. The focus of the 2017 survey is public perceptions on (1) nuclear energy and new nuclear technology, such as small modular reactors; (2) the risks and benefits of nuclear energy; (3) different options for managing spent nuclear fuel (SNF); and (4) the role of individuals, organizations and elected officials in locating SNF facilities. Highlights of survey results related to nuclear energy found the U.S. public (1) wants nuclear energy to continue to contribute 20% of total electrical power produced for the next 20 years; (2) is more supportive of adding new reactors at existing sites than at new sites; and (3) is more supportive of small modular reactors than traditional reactors. Highlights related to risks and benefits of nuclear energy include (1) the public believes that terrorist attacks are the greatest threat and that energy independence is the greatest benefit; (2) 56% of the public believes that nuclear power has both high benefit and high risk; (3) the 2011 accident at the Fukushima nuclear facility continues to negatively influence the perceived benefits and risks of nuclear energy except for those who perceive nuclear power as low risk and high benefit; (4) building new reactors is supported by those who perceive nuclear power as low risk and high benefit, and opposed by those who perceive it as high risk and low benefit. Highlights related to SNF management options include (1) support remains higher for permanent disposal than either consolidated interim storage or continued on-site storage; (2) support for private initiatives for interim storage in New Mexico and Texas are higher than generic storage and disposal options; (3) the general public is more likely to increase support if a majority of the local and state residents support an SNF facility. Highlights related to the role of individuals, organizations, and elected officials include (1) 54% of the public agrees that if an SNF facility is deemed safe by regulators, political considerations should not derail the location; (2) 47% of the US public agrees that non-governmental organizations should be able to provide input to locating an SNF facility; (3) 36% of the public believes that the federal government should lead siting of an SNF facility while 25% believes private companies should lead; (4) 81% of the public believes local residents and farmers/ranchers should have a say in the final decision on locating a SNF facility and 56% believe that they should have veto power; and (5) only 27% of the public believes the state governor should have a say and veto power.

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DOE OSTI2020

International Collaborations on Radioactive Waste Disposal in Salt (FY20)

This report is a summary of the international collaboration work conducted by Sandia and funded by the US Department of Energy Office (DOE) of Nuclear Energy Spent Fuel and Waste Science & Technology (SFWST) as part of the Sandia National Laboratories Salt R&D and Salt International work packages. This report satisfies milestone level-three milestone M3SF-205N010303062. Several stand-alone sections make up this summary report, each completed by the participants. The first two sections discuss international collaborations on geomechanical benchmarking exercises (WEIMOS), granular salt reconsolidation (KOMPASS), engineered barriers (RANGERS), and documentation of Features, Events, and Processes (FEPs).

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DOE OSTI2020

Default Radioactive and Hazardous Waste Management (RHWM) Dose Conversion Factors (DCFs) and Weighting Factors and plutonium-239 equivalent Curie (PE-Ci) methodology for acceptance into the Waste Storage Facilities

DOE-STD-5506-2007 (Ref. 1) is the standard that provides the methodology for preparing hazard analysis and accident analysis for transuranic (TRU) waste facilities. The Waste Storage Facilities hazard and accident analysis for the DSA is developed in accordance with DOE-STD- 5506-2007. Two related issues need to be addressed when implementing DOE-STD-5506-2007 regarding the calculation of consequences from TRU waste releases in accident analysis: Consequences determined in accident analysis must be modeled using inhalation Dose Conversion Factors (DCFs) that are consistent with those from the International Commission on Radiological Protection Publication 72 (ICRP-72, Ref. 2).; The use of a statistical Material at Risk (MAR) representing the distribution of radiological loading of TRU waste containers based on the use of a plutonium-239 equivalent Curie (PE-Ci) methodology. The PE-Ci methodology simplifies accident analysis by allowing one to model releases based on the Curie value of one standard nuclide (e.g., Pu-239) instead of needing to model releases for every potential nuclide of interest. This is accomplished by normalizing the Curie value of all nuclides to a single Curie value of a standard nuclide by using a Weighting Factor that is a ratio of the DCFs associated with the nuclides and that of the standard nuclide. By using the ICRP-72 DCFs to calculate PE-Ci values used in the statistical MAR, the accident analysis that uses that statistical MAR will be consistent with the consequence methodology identified in DOE-STD- 5506-2007.

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DOE OSTI2021

Sludge Batch 10 Flowsheet Testing with Non-radioactive Simulants

Fourteen Chemical Processing Cell (CPC) simulations were performed with nonradioactive sludge simulants at the Aiken County Technology Laboratory in Aiken, SC. Four of these experiments were performed with Tank 51 sludge simulant. The remaining ten were performed with Tank 40 sludge simulant. The purpose of these experiments was to elucidate the chemistry and characteristics of Sludge Batch (SB) 10 as anticipated in the Defense Waste Processing Facility (DWPF). Experiments were performed at acid stoichiometries between 76% and 138% of the Koopman Minimum Acid requirement (85% - 144% of the Hsu acid requirement) and at REDuction/OXidation (REDOX) targets between 0.1 and 0.3. Testing examined the impact of coupled operations and sludge-only operations during Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) processing at both design basis and nominal boilup rates. This report shares conclusions made as a result of this testing.

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DOE OSTI2022

Radioactive Waste Sludge Washing and Demonstration of the Nitric-Glycolic Acid Flowsheet for Sludge Batch 10 Qualification

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch (SB) is processible. During processing of SB9, DWPF will be transitioning from the Nitric-Formic Acid (NFA) flowsheet to the Nitric-Glycolic Acid (NGA) flowsheet. Thus, the qualification of SB10 was requested to only be performed using the NGA flowsheet. In order to qualify the batch for the NGA flowsheet, Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles, designated SC-19, were performed using SB10 Tank 51 sample material. SRNL received Tank 51 material in the midst of Tank Farm washing. SRNL continued the washing in the SRNL Shielded Cells. The SRNL process included the addition of Sodium Reactor Experiment (SRE) material from H Canyon, simulating the transfer of SRE from H Canyon to Tank 51 during Tank Farm washing. The washed SB10 Tank 51 material, with SRE, was characterized prior to flowsheet qualification testing.

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DOE OSTI2023

Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 3

This chapter summarizes safety functions and features, events, and processes; conceptual models which apply to all DUs; property data packages; and modeling tools developed and implemented in this PA to analyze ELLWF performance. Conceptual models of GW flow and transport in the VZ, which are specific to type of DU, are presented in Chapter 4.

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DOE OSTI2023

Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 4

This chapter describes the GW flow and transport conceptual models in the VZ for both generic and special waste forms in STs, ETs, LAWV, ILV, and NRCDAs. The development and implementation of the GoldSim® system model for trenches is also introduced. The Trench System Model is used for sensitivity analysis and uncertainty quantification as reported in Chapter 6.

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DOE OSTI2023

Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 5

This chapter presents selected GW flow and radionuclide contaminant transport results from PORFLOW for the VZ and aquifer zone for each type of DU (STs, ETs, LAWV, ILV, and NRCDAs). Results for the nominal PA compliance case and various sensitivity cases are given. Results for the VZ include water saturation spatial profiles and radionuclide flux-to-the-water- table time profiles. Aquifer zone results include maximum concentration spatial contours; radionuclide concentration time profiles at the 100-meter POA; and peak concentrations at the 100-meter POA and time of occurrence for each modeled radionuclide.

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DOE OSTI2023

Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 6

This chapter provides a description of the methods used for the sensitivity and uncertainty quantification analyses and identifies the parameters and assumptions found to be most important in the determination of compliance with PA performance objectives, development of WAC, establishment of individual DU inventory limits, and other regulatory decisions.

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DOE OSTI2023

Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 8

This chapter, together with Appendix H, provides the necessary CWTS inventory limits and trigger values for every parent radionuclide not screened out in Sections 2.3.6, 2.3.7, and 2.3.8. Also provided are details associated with how generic and special waste forms are handled on a DU-specific basis, and a discussion of the conversion of preliminary inventory limits (via transport runs summarized in Chapter 5) into final inventory limits for use in the CWTS limits system. Using the final inventory limits, a projected 2065 CWTS inventory is generated for use in the PA closure analysis outlined in Chapter 9.

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DOE OSTI2023

Performance Assessment for the E-Area Low-Level Radioactive Waste Disposal Facility at the Savannah River Site: Chapter 9

This chapter summarizes the results of PA compliance against all relevant PA POs and measures. The final inventory limits presented in Chapters 7 and 8, as well as the methodology employed, provide assurance that POs will be met throughout the compliance periods. Deterministic and stochastic closure analyses also demonstrate a minimal likelihood of exceeding POs. Potential peaks post compliance are also addressed where future work is proposed to improve the understanding in actual uncertainties.

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