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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Cliff Retreat Rates Associated with a Low-Level Radioactive Waste Disposal Facility in Los Alamos, New Mexico, USA

We present an analysis and interpretation of potential cliff stability at a low-level waste disposal facility at Los Alamos National Laboratory, New Mexico, using cliff morphologic and fracture characteristics coupled with carbon-14 surface exposure dating. Our study is important as it directly bears on the licensing criteria for low-level radioactive waste sites. We find that future characteristic cliff failures will likely not breach disposal pits and shafts over the 1000-year minimum regulatory period. Further, we find, using a multivariate regression model, that slope angle and cliff face aspect are sub-equal in importance to predict regions of high risk of failure when combined with surface exposure ages and assuming that old exposure ages are most indicative of stability (instability) and therefore can aid decision making in final design implementation.

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DOE OSTI2011

Measuring Radioactivity from Fukushima Daiichi in New Mexico

On March 11, 2011, the Fukushima Daiichi nuclear power plant was damaged by the tsunami that followed the 'Great East Japan Earthquake,' and the reactor subsequently leaked radioactive material. In response, LANL augmented the routine ambient (AIRNET) and stack (Rad-NESHAP) measurements with three high-volume samplers: No.167 at the Old White Rock Fire Station; No.173 at the TA-49 gate, and No.211 at the Los Alamos Medical Center. Previous accidents, such as the Three-Mile-Island accident in 1979 and the Chernobyl accident in 1986, indicated that the most likely releases were (a) the noble gases: krypton and xenon; and (b) the volatile elements: cesium, tellurium, and iodine. At the latitude of Fukushima, the predominant winds across the Pacific Ocean are from west to east, and models predicted that the plume would arrive in the western US on about March 18. By this time the shorter-lived isotopes would have decayed. Therefore, the expected radionuclides were xenon-133, cesium-134, cesium-136, cesium-137, tellurium-132, iodine-131, and iodine-132. As expected, cesium-134, cesium-136, cesium-137, tellurium-132, iodine-131, and iodine-132 were all detected by all three high-volume samplers during March 17-21. The concentrations peaked during the March 24-28 period. After this, concentrations of all nuclides declined. In general, the concentrations were consistent with those measured by the EPA RadNet system and many other monitoring systems throughout the world. At the time of writing, preliminary results from the AIRNET and Rad-NESHAP systems are being reported. More detailed results are described in LA-UR-11-10304 and will be reported in full in the annual environmental report for 2011. All previous releases from nuclear reactors have been dominated by noble gases, primarily krypton and xenon, which are not measured by the high-volume samplers or the AIRNET system. However, in sufficient concentrations these and other fission products would be detected by NEWNET. Consistent with this possibility, all NEWNET detectors recorded an increase of 0.2 {micro}R/h from March 19-1, followed by an additional increase of 0.1 {micro}R/h on March 24 (Figure 1). The consistency of the NEWNET stations is indicated by the error bars, which represent the standard error of the mean of the individual stations. Over the next 10 days, the NEWNET readings declined with approximately the 5-day half life of xenon-133, returning to near normal levels on April 2. After this, any further decrease was masked by high radon concentrations on April 3, by a weather system that moved into New Mexico on April 4, and by rainfall on April 6-9. Furthermore, it is likely that all NEWNET detectors responded to a gradually increasing trend in terrestrial radiation during the month of March as the ground dried out. It is difficult to distinguish the hypothetical effects of xenon-133 from the fluctuations of radon decay products. However, at present we do not have an alternative hypothesis for the sharp increase that was observed in all NEWNET stations from March 19-21. Perhaps some of the increase was caused by radon or terrestrial radiation, in which case the observed increase is an upper limit to that caused by releases from Fukushima. LANL data are consistent with those of the EPA RadNet monitoring system. The EPA has repeatedly stated that 'The levels detected are far below levels of concern.'

CESIUM 134↗
DOE OSTI2012

Crystal-Tolerant Glass Approach For Mitigation Of Crystal Accumulation In Continuous Melters Processing Radioactive Waste

High-level radioactive waste melters are projected to operate in an inefficient manner as they are subjected to artificial constraints, such as minimum liquidus temperature (T{sub L}) or maximum equilibrium fraction of crystallinity at a given temperature. These constraints substantially limit waste loading, but were imposed to prevent clogging of the melter with spinel crystals [(Fe, Ni, Mn, Zn)(Fe, Cr){sub 2}O{sub 4}]. In the melter, the glass discharge riser is the most likely location for crystal accumulation during idling because of low glass temperatures, stagnant melts, and small diameter. To address this problem, a series of lab-scale crucible tests were performed with specially formulated glasses to simulate accumulation of spinel in the riser. Thicknesses of accumulated layers were incorporated into empirical model of spinel settling. In addition, T{sub L} of glasses was measured and impact of particle agglomeration on accumulation rate was evaluated. Empirical model predicted well the accumulation of single crystals and/or smallscale agglomerates, but, excessive agglomeration observed in high-Ni-Fe glass resulted in an under-prediction of accumulated layers, which gradually worsen over time as an increased number of agglomerates formed. Accumulation rate of ~14.9 +- 1 nm/s determined for this glass will result in ~26 mm thick layer in 20 days of melter idling.

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DOE OSTI2013

ENTERPRISE SRS: LEVERAGING ONGOING OPERATIONS TO ADVANCE RADIOACTIVE WASTE MANAGEMENT TECHNOLOGIES

The Savannah River Site (SRS) is repurposing its vast array of assets to solve future national issues regarding environmental stewardship, national security, and clean energy. The vehicle for this transformation is Enterprise SRS which presents a new, strategic view of SRS as a united endeavor for “all things nuclear” as opposed to a group of distinct and separate entities with individual missions and organizations. Key among the Enterprise SRS strategic initiatives is the integration of research into facilities in conjunction with ongoing missions to provide researchers from other national laboratories, academic institutions, and commercial entities the opportunity to demonstrate their technologies in a relevant environment and scale prior to deployment. To manage that integration of research demonstrations into site facilities, The DOE Savannah River Operations Office, Savannah River Nuclear Solutions, and the Savannah River National Laboratory (SRNL) have established a center for applied nuclear materials processing and engineering research (hereafter referred to as the Center). The key objective of this initiative is to bridge the gap between promising transformational nuclear materials management advancements and large-scale deployment of the technology by using SRS assets (e.g. facilities, staff, and property) for those critical engineering-scale demonstrations necessary to assure the successful deployment of new technologies. The Center will coordinate the demonstration of R&D technologies and serve as the interface between the engineering-scale demonstration and the R&D programs, essentially providing cradle-to-grave support to the R&D team during the demonstration. While the initial focus of the Center will be on the effective use of SRS assets for these demonstrations, the Center also will work with research teams to identify opportunities to perform R&D demonstrations at other facilities. Unique to this approach is the fact that these SRS assets will continue to accomplish DOE’s critical nuclear material missions (e.g., processing in H-Canyon and plutonium storage in K-Area). These demonstrations can be accomplished in a more cost-effective manner through the use of existing facilities in conjunction with ongoing missions. Essentially, the R&D program would not need to pay the full operational cost of a facility, just the incremental cost of performing the demonstration. Current Center activities have been focused on integrating advanced safeguards monitoring technology demonstrations into the SRS H-Canyon and advanced location technology demonstrations into K-Area Materials Storage. These demonstrations are providing valuable information to researchers and program owners. In addition these demonstrations are providing the Center with an improved protocol for demonstration management that can be exercised across the entire SRS (and to offsite venues) to ensure that future demonstrations are done efficiently and provide an opportunity to use these unique assets for multiple purposes involving national laboratories, academia, and commercial entities. Key among the envisioned future use of SRS assets is the demonstration of new radioactive waste management technologies critical for advancing the mission needs of the DOE-EM program offices in their efforts to cleanup 107 sites across the United States. Of particular interest is the demonstration of separations technologies in H-Canyon. Given the modular design of H-Canyon, those demonstrations would be accomplished using a process frame. The demonstration equipment would be installed on the process frame and that frame would then be positioned into an H-Canyon cell so that the demonstration is performed in a radiological environment involving prototypic nuclear materials.

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DOE OSTI2013

Mixed-layered bismuth-oxygen-iodine materials for capture and waste disposal of radioactive iodine

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

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DOE OSTI2013

FABRICATION AND DEPLOYMENT OF THE 9979 TYPE AF RADIOACTIVE WASTE PACKAGING FOR THE DEPARTMENT OF ENERGY

This paper summarizes the development, testing, and certification of the 9979 Type A Fissile Packaging that replaces the UN1A2 Specification Shipping Package eliminated from Department of Transportation (DOT) 49 CFR 173. The DOT Specification Package was used for many decades by the U.S. nuclear industry as a fissile waste container until its removal as an authorized container by DOT. This paper will discuss stream lining procurement of high volume radioactive material packaging manufacturing, such as the 9979, to minimize packaging production costs without sacrificing Quality Assurance. The authorized content envelope (combustible and non-combustible) as well as planned content envelope expansion will be discussed.

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DOE OSTI2012

Corrosion Control Measures For Liquid Radioactive Waste Storage Tanks At The Savannah River Site

The Savannah River Site has stored radioactive wastes in large, underground, carbon steel tanks for approximately 60 years. An assessment of potential degradation mechanisms determined that the tanks may be vulnerable to nitrate- induced pitting corrosion and stress corrosion cracking. Controls on the solution chemistry and temperature of the wastes are in place to mitigate these mechanisms. These controls are based upon a series of experiments performed using simulated solutions on materials used for construction of the tanks. The technical bases and evolution of these controls is presented in this paper.

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DOE OSTI2013

TRANSIENT HEAT TRANSFER ANALYSIS FOR SRS RADIOACTIVE TANK OPERATION

The primary objective of the present work is to perform a heat balance study for type-I waste tank to assess the impact of using submersible mixer pumps during waste removal. The temperature results calculated by the model will be used to evaluate the temperatures of the slurry waste under various tank operating conditions. A parametric approach was taken to develop a transient model for the heat balance study for type-I waste tanks such as Tank 11, during waste removal by SMP. The tank domain used in the present model consists of two SMP's for sludge mixing, one STP for the waste removal, cooling coil system with 36 coils, and purge gas system. The sludge waste contained in Tank 11 also has a decay heat load of about 43 W/m{sup 3} mainly due to the emission of radioactive gamma rays. All governing equations were established by an overall energy balance for the tank domain, and they were numerically solved. A transient heat balance model used single waste temperature model, which represents one temperature for the entire waste liquid domain contained in the tank at each transient time.

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DOE OSTI2013

Collaboration, Automation, and Information Management at Hanford High Level Radioactive Waste (HLW) Tank Farms

Washington River Protection Solutions (WRPS), operator of High Level Radioactive Waste (HLW) Tank Farms at the Hanford Site, is taking an over 20-year leap in technology, replacing systems that were monitored with clipboards and obsolete computer systems, as well as solving major operations and maintenance hurdles in the area of process automation and information management. While WRPS is fully compliant with procedures and regulations, the current systems are not integrated and do not share data efficiently, hampering how information is obtained and managed.

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DOE OSTI2013

ADMINISTRATIVE AND ENGINEERING CONTROLS FOR THE OPERATION OF VENTILATION SYSTEMS FOR UNDERGROUND RADIOACTIVE WASTE STORAGE TANKS

Liquid radioactive wastes from the Savannah River Site are stored in large underground carbon steel tanks. The majority of the waste is confined in double shell tanks, which have a primary shell, where the waste is stored, and a secondary shell, which creates an annular region between the two shells, that provides secondary containment and leak detection capabilities should leakage from the primary shell occur. Each of the DST is equipped with a purge ventilation system for the interior of the primary shell and annulus ventilation system for the secondary containment. Administrative flammability controls require continuous ventilation to remove hydrogen gas and other vapors from the waste tanks while preventing the release of radionuclides to the atmosphere. Should a leak from the primary to the annulus occur, the annulus ventilation would also serve this purpose. The functionality of the annulus ventilation is necessary to preserve the structural integrity of the primary shell and the secondary. An administrative corrosion control program is in place to ensure integrity of the tank. Given the critical functions of the purge and annulus ventilation systems, engineering controls are also necessary to ensure that the systems remain robust. The system consists of components that are constructed of metal (e.g., steel, stainless steel, aluminum, copper, etc.) and/or polymeric (polypropylene, polyethylene, silicone, polyurethane, etc.) materials. The performance of these materials in anticipated service environments (e.g., normal waste storage, waste removal, etc.) was evaluated. The most aggressive vapor space environment occurs during chemical cleaning of the residual heels by utilizing oxalic acid. The presence of NO{sub x} and mercury in the vapors generated from the process could potentially accelerate the degradation of aluminum, carbon steel, and copper. Once identified, the most susceptible materials were either replaced and/or plans for discontinuing operations are executed.

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DOE OSTI2013

Operating Experience and Lessons Learned in the Use of Soft-Sided Packaging for Transportation and Disposal of Low Activity Radioactive Waste

This paper describes the operating experience and lessons learned at U.S. Department of Energy (DOE) sites as a result of an evaluation of potential trailer contamination and soft-sided packaging integrity issues related to the disposal of low-level and mixed low-level (LLW/MLLW) radioactive waste shipments. Nearly 4.3 million cubic meters of LLW/MLLW will have been generated and disposed of during fiscal year (FY) 2010 to FY 2015—either at commercial disposal sites or disposal sites owned by DOE. The LLW/MLLW is packaged in several different types of regulatory compliant packaging and transported via highway or rail to disposal sites safely and efficiently in accordance with federal, state, and local regulations and DOE orders. In 1999, DOE supported the development of LLW containers that are more volumetrically efficient, more cost effective, and easier to use as compared to metal or wooden containers that existed at that time. The DOE Idaho National Engineering and Environmental Laboratory (INEEL), working in conjunction with the plastic industry, tested several types of soft-sided waste packaging systems that meet U.S. Department of Transportation requirements for transport of low specific activity and surface contaminated objects. Since then, soft-sided packaging of various capacities have been used successfully by the decontamination and decommissioning (D&D) projects to package, transport, and dispose D&D wastes throughout the DOE complex. The joint team of experts assembled by the Energy Facility Contractors Group from DOE waste generating sites, DOE and commercial waste disposal facilities, and soft-sided packaging suppliers conducted the review of soft-sided packaging operations and transportation of these packages to the disposal sites. As a result of this evaluation, the team developed several recommendations and best practices to prevent or minimize the recurrences of equipment contamination issues and proper use of soft-sided packaging for transport and disposal of waste.

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DOE OSTI2015

Mixed-layered bismuth--oxygen--iodine materials for capture and waste disposal of radioactive iodine

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

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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.

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DOE OSTI2015

Special Analysis for the Disposal of the Lawrence Livermore National Laboratory EnergyX Macroencapsulated Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the Lawrence Livermore National Laboratory (LLNL) EnergyX Macroencapsulated waste stream (B LAMACRONCAP, Revision 1) 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 LLNL EnergyX Macroencapsulated waste stream is macroencapsulated mixed waste generated during research laboratory operations and maintenance (LLNL 2015). The LLNL EnergyX Macroencapsulated waste stream required a special analysis due to tritium (3H), cobalt-60 (60Co), cesium-137 (137Cs), and radium-226 (226Ra) exceeding the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015).The results indicate that all performance objectives can be met with disposal of the waste stream in a SLB trench. Addition of the LLNL EnergyX Macroencapsulated inventory slightly increases multiple performance assessment results, with the largest relative increase occurring for the all-pathways annual total effective dose (TED). The maximum mean and 95th percentile 222Rn flux density remain less than the performance objective throughout the compliance period. The LLNL EnergyX Macroencapsulated waste stream is suitable for disposal by SLB at the Area 5 RWMS. The waste stream is recommended for approval without conditions.

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DOE OSTI2015

Special Analysis for the Disposal of the Lawrence Livermore National Laboratory Low Activity Beta/Gamma 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 Lawrence Livermore National Laboratory (LLNL) Low Activity Beta/Gamma Sources waste stream (BCLALADOEOSRP, Revision 0) 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 LLNL Low Activity Beta/Gamma Sources waste stream consists of sealed sources that are no longer needed. The LLNL Low Activity Beta/Gamma Sources waste stream required a special analysis because cobalt-60 (60Co), strontium-90 (90Sr), cesium-137 (137Cs), and radium-226 (226Ra) exceeded the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015). The results indicate that all performance objectives can be met with disposal of the LLNL Low Activity Beta/Gamma Sources in a SLB trench. The LLNL Low Activity Beta/Gamma Sources waste stream is suitable for disposal by SLB at the Area 5 RWMS. However, the activity concentration of 226Ra listed on the waste profile sheet significantly exceeds the action level. Approval of the waste profile sheet could potentially allow the disposal of high activity 226Ra sources. To ensure that the generator does not include large 226Ra sources in this waste stream without additional evaluation, a control is need on the maximum 226Ra inventory. A limit based on the generator’s estimate of the total 226Ra inventory is recommended. The waste stream is recommended for approval with the control that the total 226Ra inventory disposed shall not exceed 5.5E10 Bq (1.5 Ci).

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DOE OSTI2019

FX2 Fogging Fixative Deployment for Radioactive Contamination Control

Idaho National Laboratory’s FX2 fixative solution was deployed as part of the decontamination and decommissioning (D&D) of an alpha-contaminated glovebox. The fixative was dispensed via fogging. The goal of the deployment was to reduce friable alpha radioactive contamination prior to removal of the glovebox. Information about the deployment and the efficacy of the treatment is presented.

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