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At least 433 records · Page 24
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DOE OSTI2011

Elemental characterization of LL-MA radioactive waste packages with the associated particle technique

The French Alternative Energies and Atomic Energy Commission (CEA) and National Radioactive Waste Management Agency (ANDRA) are conducting an R and D program to improve the characterization of long-lived and medium activity (LL-MA) radioactive waste packages with analytical methods and with non-destructive nuclear measurements. This paper concerns fast neutron interrogation with the associated particle technique (APT), which brings 3D information about the waste material composition. The characterization of volume elements filled with iron, water, aluminium, and PVC in bituminized and fibre concrete LL-MA waste packages has been investigated with MCNP [1] and MODAR data analysis software [2]. APT provides usable information about major elements presents in the volumes of interest. However, neutron scattering on hydrogen nuclei spreads the tagged neutron beam out of the targeted volume towards surrounding materials, reducing spatial selectivity. Simulation shows that small less than 1 L targets can be characterised up to the half-radius of a 225 L bituminized drum, the matrix of which is very rich in hydrogen. Deeper characterization in concrete is possible but limited by counting statistics due to photon attenuation in this dense matrix and, unless large inspection volumes are considered, by the lack of spatial selectivity of the tagged neutron beam due to neutron scattering. (authors)

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DOE OSTI2011

The use of non-destructive passive neutron measurement methods in dismantling and radioactive waste characterization

The cleaning up and dismantling of nuclear facilities lead to a great volume of technological radioactive wastes which need to be characterized in order to be sent to the adequate final disposal or interim storage. The control and characterization can be performed with non-destructive nuclear measurements such as gamma-ray spectrometry. Passive neutron counting is an alternative when the alpha-gamma emitters cannot be detected due to the presence of a high gamma emission resulting from fission or activation products, or when the waste matrix is too absorbing for the gamma rays of interest (too dense and/or made of high atomic number elements). It can also be a complement to gamma-ray spectrometry when two measurement results must be confronted to improve the confidence in the activity assessment. Passive neutron assays involve the detection of spontaneous fission neutrons emitted by even nuclides ({sup 238}Pu, {sup 240}Pu, {sup 242}Pu, {sup 242}Cm, {sup 244}Cm...) and neutrons resulting from ({alpha}, n) reactions with light nuclides (O, F, Be...). The latter is conditioned by the presence of high {alpha}-activity radionuclides ({sup 234}U, {sup 238}Pu, {sup 240}Pu, {sup 241}Am...) and low-Z elements, which depends on the chemical form (metallic, oxide or fluorine) of the plutonium or uranium contaminant. This paper presents the recent application of passive neutron methods to the cleaning up of a nuclear facility located at CEA Cadarache (France), which concerns the Pu mass assessment of 2714 historic, 100 litre radioactive waste drums produced between 1980 and 1997. Another application is the dismantling and decommissioning of an uranium enrichment facility for military purposes, which involves the {sup 235}U and total uranium quantifications in about a thousand, large compressors employed in the gaseous diffusion enrichment process. (authors)

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DOE OSTI2013

The analysis of metal melting application in the management of metallic radioactive materials arising from decommissioning of nuclear installations

Basic characterization of the waste management process during decommissioning of nuclear installations is described in the presented paper. A brief description is given of conditional and unconditional release of materials into the environment. The paper deals also with metal melting as prospective decontamination technique which can significantly reduce metallic radioactive waste. The material and radioactivity flow in the decommissioning process should be followed using the integrated material flow tool that is implemented into the standardized analytical decommissioning parameters calculation code OMEGA. Applying the integrated material flow tool, it is possible to monitor radiological and physical properties of individual material items listed in the nuclear installation input database, from dismantling up to their release into the environment or disposal in repository. Using the OMEGA code and two model databases, several scenarios related to metal melting are evaluated. The impact of applying different input decommissioning parameters on the metal distribution is the main result discussed in the paper. (authors)

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DOE OSTI2013

Development and testing of techniques for in-ground stabilization, size reduction, and safe removal of radioactive wastes stored in containments buried in ground

Since the 1950's radioactive wastes from a number of laboratories have been stored below ground at the Hanford site, Washington State, USA, in vertical pipe units (VPUs) made of five 200 litre drums without tops or bottoms, and in caissons, made out of corrugated pipe, or concrete and typically 2,500 mm in diameter. The VPU's are buried of the order of 2,100 mm below grade, and the caissons are buried of the order of 6,000 mm below grade. The waste contains fuel pieces, fission products, and a range of chemicals used in the laboratory processes. This can include various energetic reactants such as un-reacted sodium potassium (NaK), potassium superoxide (KO{sub 2}), and picric acid, as well as quantities of other liquids. The integrity of the containments is considered to present unacceptable risks from leakage of radioactivity to the environment. This paper describes the successful development and full scale testing of in-ground augering equipment, grouting systems and removal equipment for remediation and removal of the VPUs, and the initial development work to test the utilization of the same basic augering and grouting techniques for the stabilization, size reduction and removal of caissons. (authors)

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DOE OSTI2011

Result Summary for the Area 5 Radioactive Waste Management Site Performance Assessment Model Version 4.110

Results for Version 4.110 of the Area 5 Radioactive Waste Management Site (RWMS) performance assessment (PA) model are summarized. Version 4.110 includes the fiscal year (FY) 2010 inventory estimate, including a future inventory estimate. Version 4.110 was implemented in GoldSim 10.11(SP4). The following changes have been implemented since the last baseline model, Version 4.105: (1) Updated the inventory and disposal unit configurations with data through the end of FY 2010. (1) Implemented Federal Guidance Report 13 Supplemental CD dose conversion factors (U.S. Environmental Protection Agency, 1999). Version 4.110 PA results comply with air pathway and all-pathways annual total effective dose (TED) performance objectives (Tables 2 and 3, Figures 1 and 2). Air pathways results decrease moderately for all scenarios. The time of the maximum for the air pathway open rangeland scenario shifts from 1,000 to 100 years (y). All-pathways annual TED increases for all scenarios except the resident scenario. The maximum member of public all-pathways dose occurs at 1,000 y for the resident farmer scenario. The resident farmer dose was predominantly due to technetium-99 (Tc-99) (82 percent) and lead-210 (Pb-210) (13 percent). Pb-210 present at 1,000 y is produced predominantly by radioactive decay of uranium-234 (U-234) present at the time of disposal. All results for the postdrilling and intruder-agriculture scenarios comply with the performance objectives (Tables 4 and 5, Figures 3 and 4). The postdrilling intruder results are similar to Version 4.105 results. The intruder-agriculture results are similar to Version 4.105, except for the Pit 6 Radium Disposal Unit (RaDU). The intruder-agriculture result for the Shallow Land Burial (SLB) disposal units is a significant fraction of the performance objective and exceeds the performance objective at the 95th percentile. The intruder-agriculture dose is due predominantly to Tc-99 (75 percent) and U-238 (9.5 percent). The acute intruder scenario results comply with all performance objectives (Tables 6 and 7, Figures 5 and 6). The acute construction result for the SLB disposal units decreases significantly with this version. The maximum acute intruder dose occurs at 1,000 y for the SLB disposal units under the acute construction scenario. The acute intruder dose is caused by multiple radionuclides including U-238 (31 percent), Th-229 (28 percent), plutonium-239 (8.6 percent), U-233 (7.8 percent), and U-234 (6.7 percent). All results for radon-222 (Rn-222) flux density comply with the performance objective (Table 8, Figure 7). The mean Pit 13 RaDU flux density is close to the 0.74 Bq m{sup -2} s{sup -1} limit.

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DOE OSTI2012

Special Analysis of the Area 3 Radioactive Waste Management Site at the Nevada National Security Site, Nye County, Nevada

This report describes the methods and results of a special analysis (SA) of the Area 3 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). The purpose of the SA is to determine if the approved performance assessment (PA) and composite analysis (CA) (Shott et al., 2001) remain valid. The Area 3 RWMS PA and CA were prepared as a single document and received conditional approval on October 6, 1999. A conditional Disposal Authorization Statement (DAS) for the Area 3 RWMS was issued on October 20, 1999. Since preparation of the approved PA and CA, new information and additional environmental monitoring data have been used to update the PA and CA. At the same time, continual advancements in computer processors and software have allowed improvement to the PA and CA models. Annual reviews of the PA and CA required by U.S. Department of Energy (DOE) Order DOE O 435.1 have documented multiple changes occurring since preparation of the PA and CA. Potentially important changes include: Development of a new and improved baseline PA and CA model implemented in the probabilistic GoldSim simulation platform. A significant increase in the waste inventory disposed at the site. Revision and updating of model parameters based on additional years of site monitoring data and new research and development results. Although changes have occurred, many important PA/CA issues remain unchanged, including the site conceptual model, important features, events, and processes, and the points of compliance. The SA is performed to document the current status of the PA/CA model and to quantitatively assess the impact of cumulative changes on the PA and CA results. The results of the SA are used to assess the validity of the approved PA/CA and make a determination if revision of the PA or CA is necessary. The SA was performed using the Area 3 RWMS, version 2.102, GoldSim model, the current baseline PA/CA model. Comparison of the maximum SA results with the PA performance objectives indicates that there continues to be a reasonable expectation of compliance. The resident exposure scenario was evaluated for compliance with the air pathway and all-pathways annual total effective dose (TED) performance objectives. The maximum mean air pathway TED, 7E-6 millisievert (mSv) at 1,000 years (y) has decreased relative to the approved PA and is significantly less than the 0.1 mSv limit. The maximum mean all-pathways annual TED, 7E-5 mSv at 1,000 y has increased but remains a small fraction of the 0.25 mSv limit. The SA maximum mean radon-222 (222Rn) flux density, 0.03 becquerel per square meter per second (Bq m-2 s-1), has increased relative to the PA results but is significantly less than the 0.74 Bq m-2 s-1 limit. The SA results continue to support a conclusion that the disposed waste inventory is protective of intruders and groundwater resources. The maximum mean intruder TED, 0.01 mSv for an acute construction scenario at the U-3ah/at disposal unit, was less than the 5 mSv performance measure. Site monitoring data and research results continue to support a conclusion that a groundwater pathway will not exist within the 1,000 y compliance period. Projected releases to the environment are a small fraction of the performance objectives. Cost-effective options for reducing releases further are unlikely to exist. Therefore, releases from the Area 3 RWMS are judged to be as low as reasonably achievable. Comparison of the maximum CA result with the 0.3 mSv CA dose constraint indicates that no action is required to reduce the dose from the Area 3 RWMS and all interacting sources of residual radioactive contamination. The SA maximum mean CA annual TED, 0.02 mSv at 1,000 y, has increased from the approved CA result but remains less than 10% of the dose constraint. The CA TED continues to be due predominantly to inhalation of plutonium-239 resuspended from soils contaminated by nuclear weapons tests conducted near the Area 3 RWMS. The SA results estimated with the Area 3 RWMS version 2.102 model indicate that changes to the PA and CA do not significantly alter the PA/CA results or conclusions. Although increases occur for the all-pathways annual TED, the 222Rn flux density, and the CA annual TED, all PA and CA results are a small fraction of the performance objectives or dose constraints. The same conclusion was reached for the approved PA and CA. The SA results continue to support a conclusion that there is a reasonable expectation of meeting all performance objectives and the CA dose constraint. There is no need to revise the DAS at this time. The SA results support a conclusion that the Area 3 RWMS PA and CA remain valid, and revision is not necessary at this time.

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DOE OSTI2013

Special Analysis for the Disposal of the Consolidated Edison Uranium Solidification Project Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

The purpose of this Special Analysis (SA) is to determine if the Oak Ridge (OR) Consolidated Edison Uranium Solidification Project (CEUSP) uranium-233( 233 U) waste stream (DRTK000000050, Revision 0) is acceptable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). The CEUSP 233 U waste stream requires a special analysis because the concentrations of thorium- 229 ( 229 Th), 230 Th, 232 U, 233 U, and 234 U exceeded their NNSS Waste Acceptance Criteria action levels. The acceptability of the waste stream is evaluated by determining if performance assessment (PA) modeling provides a reasonable expectation that SLB disposal is protective of human health and the environment. The CEUSP 233 U waste stream is a long-lived waste with unique radiological hazards. The SA evaluates the long-term acceptability of the CEUSP 233 U waste stream for near-surface disposal as a two tier process. The first tier, which is the usual SA process, uses the approved probabilistic PA model to determine if there is a reasonable expectation that disposal of the CEUSP 233 U waste stream can meet the performance objectives of U.S. Department of Energy Manual DOE M 435.1-1, “Radioactive Waste Management,” for a period of 1,000 years (y) after closure. The second tier addresses the acceptability of the OR CEUSP 233 U waste stream for near-surface disposal by evaluating long-term site stability and security, by performing extended (i.e., 10,000 and 60,000 y) modeling analyses, and by evaluating the effect of containers and the depth of burial on performance. Tier I results indicate that there is a reasonable expectation of compliance with all performance objectives if the OR CEUSP 233 U waste stream is disposed in the Area 5 RWMS SLB disposal units. The maximum mean and 95 th percentile PA results are all less than the performance objective for 1,000 y. Monte Carlo uncertainty analysis indicates that there is a high likelihood of compliance with all performance objectives. Tier II results indicate that the long-term performance of the OR CEUSP 233 U waste stream is protective of human health and the environment. The Area 5 RWMS is located in one of the least populated and most arid regions of the U.S. Site characterization data indicate that infiltration of precipitation below the plant root zone at 2.5 meters (8.2 feet) ceased 10,000 to 15,000 y ago. The site is not expected to have a groundwater pathway as long as the current arid climate persists. The national security mission of the NNSS and the location of the Area 5 RWMS within the Frenchman Flat Corrective Action Unit require that access controls and land use restrictions be maintained indefinitely. PA modeling results for 10,000 to 60,000 y also indicate that the OR CEUSP 233 U waste stream is acceptable for near-surface disposal. The mean resident air pathway annual total effective dose (TED), the resident all-pathways annual TED, and the acute drilling TED are less than their performance objectives for 10,000 y after closure. The mean radon-222 (222Rn) flux density exceeds the performance objective at 4,200 y, but this is due to waste already disposed at the Area 5 RWMS and is only slightly affected by disposal of the CEUSP 233 U. The peak resident all-pathways annual TED from CEUSP key radionuclides occurs at 48,000 y and is less than the 0.25 millisievert performance objective. Disposal of the OR CEUSP 233 U waste stream in a typical SLB trench slightly increases PA results. Increasing the depth was found to eliminate any impacts of the OR CEUSP 233 U waste stream. Containers could not be shown to have any significant impact on performance due to the long half-life of the waste stream and a lack of data for pitting corrosion rates of stainless steel in soil. The results of the SA indicate that all performance objectives can be met with disposal of the OR CEUSP 233 U waste stream in the SLB units at the Area 5 RWMS. The long-term performance of the OR CEUSP 233 U waste stream disposed in the near surface is protective of human health and the environment. The waste stream is recommended for disposal without conditions.

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DOE OSTI2017

Unreviewed Disposal Question Evaluation: Disposal of the Lawrence Livermore National Laboratory EnergyX Macroencapsulation Waste at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This Unreviewed Disposal Question Evaluation (UDQE) assesses whether the Lawrence Livermore National Laboratory (LLNL) EnergyX Macroencapsulation mixed low-level waste (MLLW) (BCLAMACRONCAP, Revision 2 [LLNL 2017]) is suitable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). Disposal of the LLNL EnergyX Macroencapsulation MLLW meets all U.S. Department of Energy (DOE) Manual DOE M 435.1-1, Radioactive Waste Management Manual, Chapter IV, Section P performance objectives (DOE 1999). The LLNL EnergyX Macroencapsulation waste stream is recommended for acceptance without conditions.

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DOE OSTI2018

FY 2017 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada National Security Site, Nye County, Nevada

The U.S. Department of Energy Standard Disposal Authorization Statement and Tank Closure Documentation (DOE-STD-5002-2017) 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) 2017 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.

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DOE OSTI2019

Unreviewed Disposal Question Evaluation: Disposal of the Idaho Nuclear Technology and Engineering Center Mixed Low-Level Waste Requiring Macroencapsulation at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This Unreviewed Disposal Question Evaluation (UDQE) assesses whether the Idaho National Laboratory (INL), Idaho Nuclear Technology and Engineering Center (INTEC) Mixed Low-Level Waste (MLLW) requiring macroencapsulation (INEL166322NR1, Revision 0 [INL 2019]) is suitable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). Disposal of the INTEC MLLW requiring macroencapsulation waste stream meets all the performance objectives contained in U.S. Department of Energy (DOE) Manual DOE M 435.1-1, “Radioactive Waste Management Manual,” Chapter IV, Section P (DOE 2011). The INTEC MLLW requiring macroencapsulation waste stream is recommended for acceptance without conditions.

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DOE OSTI2019

Unreviewed Disposal Question Evaluation: Disposal of the Oak Ridge National Laboratory Contaminated Debris at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This Unreviewed Disposal Question Evaluation (UDQE) assesses whether the Oak Ridge National Laboratory (ORNL) Contaminated Debris (ORNLDEBRIS001, Revision 11 [ORNL 2019a]) is suitable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). Disposal of the waste stream meets all performance objectives in U.S. Department of Energy (DOE) Manual DOE M 435.1-1, Radioactive Waste Management Manual, Chapter IV, Section P (DOE 2011). The ORNL Contaminated Debris waste stream is recommended for acceptance with conditions on the total activity disposed of tritium ( 3 H), niobium-94 ( 94 Nb), technetium-99 ( 99 Tc), cesium-137 ( 137 Cs), iridium-192 ( 192 mIr), radium-226 ( 226 Ra), uranium-234 ( 234 U), and 238 U. The total activity disposed shall not exceed the following limits: 3 H: 2E12 Bq, 94 Nb: 2E9 Bq, 99 Tc: 8E10 Bq, 137 Cs: 1E11 Bq, 192 mIr: 1E9 Bq, 226 Ra: 3E11 Bq, 234 U: 2E9 Bq, 238 U: 5E9 Bq.

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DOE OSTI2018

Unreviewed Disposal Question Evaluation: Disposal of the Transuranic Waste Processing Center Mixed Low-Level Waste at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This Unreviewed Disposal Question Evaluation (UDQE) assesses whether the Transuranic Waste Processing Center (TWPC) Mixed Low-Level Waste (MLLW) (FWORCHMLLW103, Revision 11 [TWPC 2018]) is suitable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). Disposal of the TWPC MLLW waste stream meets all performance objectives of U.S. Department of Energy (DOE) Manual DOE M 435.1-1, Radioactive Waste Management Manual, Chapter IV, Section P (DOE 1999). The TWPC MLLW waste stream is recommended for acceptance without conditions.

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DOE OSTI2018

UNREVIEWED DISPOSAL QUESTION EVALUATION: Disposal of the Los Alamos National Laboratory Regulated Asbestos-Contaminated Low-Level Waste at the Area 5 Radioactive Waste Management Sited, Nevada National Security Site, Nye County, Nevada

This Unreviewed Disposal Question Evaluation (UDQE) assesses whether the Los Alamos National Laboratory (LANL) Regulated Asbestos-Contaminated Low-Level Waste (LANL000000029, Revision 5 [LANL 2017]) is suitable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). Disposal of the LANL Regulated Asbestos-Contaminated Low-Level Waste meets all U.S. Department of Energy (DOE) Manual DOE M 435.1-1, Radioactive Waste Management Manual, Chapter IV, Section P performance objectives (DOE 1999). The LANL Regulated Asbestos Contaminated Low-Level Waste is recommended for acceptance without conditions.

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DOE OSTI2016

Special Analysis for the Disposal of the Transuranic Waste Processing Center Mixed Low-Level Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the Transuranic Waste Processing Center (TWPC) Mixed Low-Level 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). Disposal of the TWPC Mixed Low-Level waste was meets all U.S. Department of Energy (DOE) Manual DOE M 435.1-1, “Radioactive Waste Management Manual,” Chapter IV, Section P performance objectives. The TWPC Mixed Low-Level waste stream is recommended for acceptance without conditions.

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DOE OSTI2011

Comparative assessment of status and opportunities for carbon Dioxide Capture and storage and Radioactive Waste Disposal In North America

Aside from the target storage regions being underground, geologic carbon sequestration (GCS) and radioactive waste disposal (RWD) share little in common in North America. The large volume of carbon dioxide (CO{sub 2}) needed to be sequestered along with its relatively benign health effects present a sharp contrast to the limited volumes and hazardous nature of high-level radioactive waste (RW). There is well-documented capacity in North America for 100 years or more of sequestration of CO{sub 2} from coal-fired power plants. Aside from economics, the challenges of GCS include lack of fully established legal and regulatory framework for ownership of injected CO{sub 2}, the need for an expanded pipeline infrastructure, and public acceptance of the technology. As for RW, the USA had proposed the unsaturated tuffs of Yucca Mountain, Nevada, as the region's first high-level RWD site before removing it from consideration in early 2009. The Canadian RW program is currently evolving with options that range from geologic disposal to both decentralized and centralized permanent storage in surface facilities. Both the USA and Canada have established legal and regulatory frameworks for RWD. The most challenging technical issue for RWD is the need to predict repository performance on extremely long time scales (10{sup 4}-10{sup 6} years). While attitudes toward nuclear power are rapidly changing as fossil-fuel costs soar and changes in climate occur, public perception remains the most serious challenge to opening RW repositories. Because of the many significant differences between RWD and GCS, there is little that can be shared between them from regulatory, legal, transportation, or economic perspectives. As for public perception, there is currently an opportunity to engage the public on the benefits and risks of both GCS and RWD as they learn more about the urgent energy-climate crisis created by greenhouse gas emissions from current fossil-fuel combustion practices.

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DOE OSTI2013

Blending of Radioactive Salt Solutions in Million Gallon Tanks - 13002

Research was completed at Savannah River National Laboratory (SRNL) to investigate processes related to the blending of radioactive, liquid waste, salt solutions in 4920 cubic meter, 25.9 meter diameter storage tanks. One process was the blending of large salt solution batches (up to 1135 - 3028 cubic meters), using submerged centrifugal pumps. A second process was the disturbance of a settled layer of solids, or sludge, on the tank bottom. And a third investigated process was the settling rate of sludge solids if suspended into slurries by the blending pump. To investigate these processes, experiments, CFD models (computational fluid dynamics), and theory were applied. Experiments were performed using simulated, non-radioactive, salt solutions referred to as supernates, and a layer of settled solids referred to as sludge. Blending experiments were performed in a 2.44 meter diameter pilot scale tank, and flow rate measurements and settling tests were performed at both pilot scale and full scale. A summary of the research is presented here to demonstrate the adage that, 'One good experiment fixes a lot of good theory'. Experimental testing was required to benchmark CFD models, or the models would have been incorrectly used. In fact, CFD safety factors were established by this research to predict full-scale blending performance. CFD models were used to determine pump design requirements, predict blending times, and cut costs several million dollars by reducing the number of required blending pumps. This research contributed to DOE missions to permanently close the remaining 47 of 51 SRS waste storage tanks. (authors)

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DOE OSTI2013

On-Site Decontamination System for Liquid Low Level Radioactive Waste - 13010

This study is based on an evaluation of purification methods for liquid low-level radioactive waste (LLLW) by using natural zeolite. Generally the volume of liquid low-level waste is relatively large and the specific activity is rather low when compared to other radioactive waste types. In this study, a pilot scale column was used with natural zeolite as an ion exchanger media. Decontamination and minimization of LLLW especially at the generation site decrease operational cost in waste management operations. Portable pilot scale column was constructed for decontamination of LLW on site. Effect of temperature on the radionuclide adsorption of the zeolite was determined to optimize the waste solution temperature for the plant scale operations. In addition, effect of pH on the radionuclide uptake of the zeolite column was determined to optimize the waste solution pH for the plant scale operations. The advantages of this method used for the processing of LLLW are discussed in this paper. (authors)

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DOE OSTI2013

Opportunities for Cost Effective Disposal of Radioactively Contaminated Solid Waste on the Oak Ridge Reservation, Oak Ridge, TN - 13045

Department of Energy (DOE) requirements for the release of non-real property, including solid waste, containing low levels of residual radioactive materials are specified in DOE Order 458.1 and associated guidance. Authorized limits have been approved under the requirements of DOE Order 5400.5, predecessor to DOE Order 458.1, to permit disposal of solid waste containing low levels of residual radioactive materials at solid waste landfills located within the DOE Oak Ridge Reservation (ORR). Specifically, volumetric concentration limits for disposal of solid waste at Industrial Landfill V and at Construction/Demolition Landfill VII were established in 2003 and 2007, respectively, based on the requirements in effect at that time, which included: an evaluation to ensure that radiation doses to the public would not exceed 25 mrem/year and would be as low as reasonably achievable (ALARA), with a goal of a few mrem/year or less (in fact, these authorized limits actually were derived to meet a dose constraint of 1 mrem/year); an evaluation of compliance with groundwater protection requirements; and reasonable assurance that the proposed disposal is not likely to result in a future requirement for remediation of the landfill. Prior to approval as DOE authorized limits, these volumetric concentration limits were coordinated with the Tennessee Department of Environment and Conservation (TDEC) and documented in a Memorandum of Understanding (MOU) between the TDEC Division of Radiological Health and the TDEC Division of Solid Waste Management. These limits apply to the disposal of soil and debris waste generated from construction, maintenance, environmental restoration, and decontamination and decommissioning (D and D) activities on the DOE Oak Ridge Reservation. The approved site-specific authorized limits were incorporated in the URS/CH2M Oak Ridge LLC (UCOR) waste profile system that authorizes disposal of special wastes at either of the RCRA Subtitle D landfills. However, a recent DOE assessment found that implementation of the site-specific authorized limits for volumetrically contaminated waste was potentially limited due in part to confusion regarding the applicability of volumetric concentration limits and/or surface activity limits to specific wastes. This paper describes recent efforts to update the authorized limits for Industrial Landfill V and Construction/Demolition Landfill VII and to improve the procedures for implementation of these criteria. The approved authorized limits have been evaluated and confirmed to meet the current requirements of DOE Order 458.1, which superseded DOE Order 5400.5 in February 2011. In addition, volumetric concentration limits have been developed for additional radionuclides, and site-specific authorized limits for wastes with surface contamination have been developed. Implementing procedures have been revised to clarify the applicability of volumetric concentration limits and surface activity limits, and to allow the use of non-destructive waste characterization methods. These changes have been designed to promote improved utilization of available disposal capacity of the onsite disposal facilities within the DOE Oak Ridge Reservation. In addition, these changes serve to bring the waste acceptance requirements at these DOE onsite landfills into greater consistency with the requirements for commercial/ public landfills under the TDEC Bulk Survey for Release (BSFR) program, including two public RCRA Subtitle D landfills in close proximity to the DOE Oak Ridge Reservation. (authors)

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