Progress Towards International Repositories (open access)

Progress Towards International Repositories

The nuclear fuel cycle is designed to be very international, with some specialist activities (e.g. fuel fabrication, reprocessing, etc.) being confined to a few countries. Nevertheless, political and public opposition has in the past been faced by proposals to internationalise the back-end of the cycle, in particular waste disposal. Attitudes, however, have been changing recently and there is now more acceptance of the general concept of shared repositories and of specific proposals such as that of Pangea. However, as for national facilities, progress towards implementation of shared repositories will be gradual. Moreover, the best vehicle for promoting the concept may not be a commercial type of organization. Consequently the Pangea project team are currently establishing a widely based Association for this purpose.
Date: February 27, 2002
Creator: McCombie, C. & Chapman, N.
System: The UNT Digital Library
ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS (open access)

ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS

This paper describes and presents the findings from two studies undertaken for the European Commission to assess the long-term impact upon the environment and human health of non-radioactive contaminants found in various low level radioactive waste streams. The initial study investigated the application of safety assessment approaches developed for radioactive contaminants to the assessment of nonradioactive contaminants in low level radioactive waste. It demonstrated how disposal limits could be derived for a range of non-radioactive contaminants and generic disposal facilities. The follow-up study used the same approach but undertook more detailed, disposal system specific calculations, assessing the impacts of both the non-radioactive and radioactive contaminants. The calculations undertaken indicated that it is prudent to consider non-radioactive, as well as radioactive contaminants, when assessing the impacts of low level radioactive waste disposal. For some waste streams with relatively low concentrations of radionuclides, the potential post-closure disposal impacts from non-radioactive contaminants can be comparable with the potential radiological impacts. For such waste streams there is therefore an added incentive to explore options for recycling the materials involved wherever possible.
Date: February 27, 2003
Creator: R.H. Little, P.R. Maul, J.S.S. Penfoldag
System: The UNT Digital Library
COMPLETION OF THE TRANSURANIC GREATER CONFINEMENT DISPOSAL BOREHOLE PERFORMANCE ASSESSMENT FOR THE NEVADA TEST SITE (open access)

COMPLETION OF THE TRANSURANIC GREATER CONFINEMENT DISPOSAL BOREHOLE PERFORMANCE ASSESSMENT FOR THE NEVADA TEST SITE

Classified transuranic material that cannot be shipped to the Waste Isolation Pilot Plant in New Mexico is stored in Greater Confinement Disposal boreholes in the Area 5 Radioactive Waste Management Site on the Nevada Test Site. A performance assessment was completed for the transuranic inventory in the boreholes and submitted to the Transuranic Waste Disposal Federal Review Group. The performance assessment was prepared by Sandia National Laboratories on behalf of the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office using an iterative methodology that assessed radiological releases from the intermediate depth disposal configuration against the regulatory requirements of the 1985 version of 40 CFR 191 of the U.S. Environmental Protection Agency. The transuranic materials are stored at 21 to 37 m depth (70 to 120 ft) in large diameter boreholes constructed in the unsaturated alluvial deposits of Frenchman Flat. Hydrologic processes that affect long- term isolation of the radionuclides are dominated by extremely slow upward rates of liquid/vapor advection and diffusion; there is no downward pathway under current climatic conditions and there is no recharge to groundwater under future ''glacial'' climatic conditions. A Federal Review Team appointed by the Transuranic Waste Disposal Federal Review Group reviewed the …
Date: February 27, 2003
Creator: Colarusso, Angela; Crowe, Bruce & Cochran, John R.
System: The UNT Digital Library
Presentation of the ERFB Bitumenized Waste Drum Retrieval Facility (open access)

Presentation of the ERFB Bitumenized Waste Drum Retrieval Facility

The bitumenized waste drum facility (ERFB) is built on the Marcoule site and is intended to handle the historic bitumenized waste of the site, that were conditioned in metallic drums. The purpose of the facility is to retrieve the drums stored in pits, condition them in stainless steel overpacks and produce packages ready to be shipped to the multipurpose interim storage (EIP) facility. The ERBF includes a mobile frame structure capable to shift from one pit to another. It is used to recover drums and characterizes them (weight, radiological properties, etc.) and to repack them according to their state. The first operation results are provided.
Date: February 27, 2002
Creator: Cauquil, G.; Mistral, J. P.; Themines, R.; Fulleringer, D. & Hauss, S.
System: The UNT Digital Library
Preliminary Study of Radioactive Waste Package Made of High-Strength and Ultra Low-Permeability Concrete for Geological Disposal of TRU Wastes (open access)

Preliminary Study of Radioactive Waste Package Made of High-Strength and Ultra Low-Permeability Concrete for Geological Disposal of TRU Wastes

We have been developing a radioactive waste package made of high-strength and ultra low-permeability concrete (HSULPC) for geological disposal of TRU wastes, which is expected to be much more impervious to water than conventional concrete. In this study, basic data for the HSULPC regarding its the impervious character and the thermodynamics during cement hydration were obtained through water permeability measurements using cold isostatic pressing (CIP) and adiabatic concrete hydration experiments, respectively. Then, a prediction tool to find concrete package construction conditions to avoid thermal cracking was developed, which could deal with coupled calculations of cement hydration, heat transfer, stress, and cracking. The developed tool was applied to HSULPC hydration on a small-scale cylindrical model to examine whether there was any effect on cracking which depended on the ratio of concrete cylinder thickness to its inner diameter. The results were compared to experiments. For concrete with a compressive strength of 200MPa, the water permeability coefficient was 4 x 10{sup 19} m/s. Dependences of activation energy and frequency factor on degree of cement hydration had a sharp peaking due to the nucleation rate-determining step, and a gradual increase region due to the diffusion rate-determining step. From analyses of the small-scale cylindrical model, …
Date: February 27, 2003
Creator: Matsuo, T.; Kawasaki, T.; Sakamoto, H.; Asano, E.; Takei, A.; Shibuya, K. et al.
System: The UNT Digital Library
Recent Developments in Nuclear Waste Management in Canada (open access)

Recent Developments in Nuclear Waste Management in Canada

This paper describes recent developments in the field of nuclear waste management in Canada with a focus on management of nuclear fuel waste. Of particular significance is the April 2001 tabling in the Canadian House of Commons of Bill C-27, An Act respecting the long-term management of nuclear fuel waste. At the time of finalizing this paper (January 15, 2002), Bill C-27 is in Third Reading in the House of Commons and is expected to move to the Senate in February. The Nuclear Fuel Waste Act is expected to come into force later in 2002. This Act requires the three nuclear utilities in Canada owning nuclear fuel waste to form a waste management organization and deposit funds into a segregated fund for nuclear fuel waste long-term management. The waste management organization is then required to perform a study of long-term management approaches for nuclear fuel waste and submit the study to the federal government within three years. The federal government will select an approach for implementation by the waste management organization. The paper discusses the activities that the nuclear fuel waste owners currently have underway to prepare for the formation of the waste management organization. As background, the paper reviews …
Date: February 27, 2002
Creator: King, F.
System: The UNT Digital Library
Subsurface Contaminants Focus Area (SCFA) Lead Laboratory Providing Technical Assistance to the DOE Weapons Complex in Subsurface Contamination (open access)

Subsurface Contaminants Focus Area (SCFA) Lead Laboratory Providing Technical Assistance to the DOE Weapons Complex in Subsurface Contamination

The Subsurface Contaminants Focus Area (SCFA), a DOE-HQ EM-50 organization, is hosted and managed at the Savannah River Site in Aiken, South Carolina. SCFA is an integrated program chartered to find technology and scientific solutions to address DOE subsurface environmental restoration problems throughout the DOE Weapons Complex. Since its inception in 1989, the SCFA program has resulted in a total of 269 deployments of 83 innovative technologies. Until recently, the primary thrust of the program has been to develop, demonstrate, and deploy those remediation technology alternatives that are solutions to technology needs identified by the DOE Sites. Over the last several years, the DOE Sites began to express a need not only for innovative technologies, but also for technical assistance. In response to this need, DOE-HQ EM-50, in collaboration with and in support of a Strategic Lab Council recommendation directed each of its Focus Areas to implement a Lead Laboratory Concept to enhance their technical capabilities. Because each Focus Area is unique as defined by the contrast in either the type of contaminants involved or the environments in which they are found, the Focus Areas were given latitude in how they set up and implemented the Lead Lab Concept. The …
Date: February 27, 2002
Creator: Wright, J. A. Jr. & Corey, J. C.
System: The UNT Digital Library
Current Status and Reclamation Plan of Former Uranium Mining and Milling Facilities at Ningyo-Toge in Japan (open access)

Current Status and Reclamation Plan of Former Uranium Mining and Milling Facilities at Ningyo-Toge in Japan

The Japan Nuclear Cycle Development Institute (JNC) conducted research and development projects on uranium exploration in Japan from 1956 to 1987. Several mine facilities, such as waste rock yards and a mill tailing pond, were retained around Ningyo-toge after the projects ended. Although there is no legal issue in the mine in accordance with related law and agreements at present, JNC has a notion that it is important to reduce the burden of waste management on future generations. Thus, the Ningyo-toge Environmental Engineering Center of JNC proposed a reclamation plan for these facilities with fundamental policy, an example of safety analysis and timetables. The plan has mainly three phases: Phase I is the planning stage, and this paper corresponds to this: Phase II is the stage to perform various tests for safety analysis and site designing: Phase III is the stage to accomplish measures. Preliminarily safety analyses suggested that our supposed cover designs for both waste rock and m ill tailing are enough to keep dose limit of 1mSv/y at site boundaries. The plan is primarily based on the Japanese Mine Safety Law, also refers to ICRP recommendations, IAEA reports, measures implemented overseas, etc. because this is the first case …
Date: February 27, 2003
Creator: Sato, Kazuhiko & Tokizawa, Takayuki
System: The UNT Digital Library
Health Physics Considerations for Remediation and Exposure Monitoring of a Th-232 Waste Stream in a Commercially Active Environment (open access)

Health Physics Considerations for Remediation and Exposure Monitoring of a Th-232 Waste Stream in a Commercially Active Environment

This paper discusses some of the unique regulatory conditions and operational challenges facing a team performing a thorium-232 cleanup in a commercially active environment, as well as the implemented and proposed solutions that can be applied to other programs, particularly those operating in an OSHA-regulated environment.
Date: February 27, 2003
Creator: Winters, Michael S. & Hays, David C. Jr.
System: The UNT Digital Library
AN ADVANCED LIQUID WASTE TREATMENT SYSTEM USING A HIGH EFFICIENCY SOLIDIFICATION TECHNIQUE (open access)

AN ADVANCED LIQUID WASTE TREATMENT SYSTEM USING A HIGH EFFICIENCY SOLIDIFICATION TECHNIQUE

An advanced system using High Efficiency Solidification Technology (HEST) was developed to treat PWR liquid waste and the first unit is operating in Taiwan (1) and a detailed design is being carried out for the second unit in Japan. The HEST system consists of two subsystems, a super-concentration subsystem and a solidification subsystem. The super-concentration subsystem is able to concentrate the waste solution to a total boron content as high as 130,000 ppm prior to solidification. The higher boron content will result in greater volume reduction efficiency of solidification. The solidification subsystem consists of an in-drum mixing and a conveyor units. Representative features of this advanced system are as follows. (1) Simple system: The system consists of the super-concentration and cement solidification subsystems; it is as simple as the conventional cement solidification system. (2) High volume reduction efficiency: The number of solidified waste drums is about 1/2.5 that of bitumen solidification. (3) Stable Package: Essentially no organic material is used, and the final package will be stable under the final disposal conditions. (4) Zero secondary waste: Washing water used in the in-drum mixer is recycled. This paper describes the outline of HEST technology, treatment system and pilot plant tests.
Date: February 27, 2003
Creator: Kikuchi, M.; Hirayama, S.; Noshita, K.; Yatou, Y. & Huang, C. T.
System: The UNT Digital Library
Multiple Ion Exchange Column Tests for Technetium Removal from Hanford Tank Waste Supernate (open access)

Multiple Ion Exchange Column Tests for Technetium Removal from Hanford Tank Waste Supernate

Five cycles of loading, elution, and regeneration were performed to remove technetium from a Hanford waste sample retrieved from Tank 241-AW-101 using SuperLig 639 resin. The waste sample was diluted to 4.95 M Na plus and then was processed to remove 137Cs through dual ion exchange columns each containing 15 mL of SuperLig 644. To remove 99Tc, the cesium decontaminated solution was processed downwards through two ion exchange columns, each containing 12 mL of SuperLig 639 resin. The columns, designated as lead and lag, each had an inside diameter of 1.45 cm and a height of 30 cm. The columns were loaded in series, but were eluted and then regenerated separately. The average technetium loading for the cycles was 250 BV at 10 percent breakthrough. There was no significant difference in the loading performances among the five cycles. The percent removal of 99Tc was greater than 99.94 percent and the average decontamination factor (DF) was approximately 1.7 x 103. Approximately 99 percent of the 99Tc loaded on the resin was eluted with less than 15 BV of de-ionized water at 65 degrees C.
Date: February 27, 2004
Creator: Hassan, N. M.
System: The UNT Digital Library
A Holistic Approach for Disposition of Long-Lived Radioactive Materials (open access)

A Holistic Approach for Disposition of Long-Lived Radioactive Materials

During the past 45 years, one of the most challenging scientific, engineering, socio-economic, and political tasks and obligations of our time has been to site and develop technical, politically acceptable, solutions to the safe disposition of long-lived radioactive materials (LLRMs). However, at the end of the year 2002, the Waste Isolation Pilot Plant (WIPP) site in the United States of America (USA) hosts the world's only operating LLRM-disposal system, which (1) is based on the LLRM-disposal principles recommended by the National Academy of Sciences (NAS) in 1957, i.e., deep geological disposal in a ''stable'' salt vault/repository, (2) complies with the nation's ''Environmental Radiation Protection Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes'', and (3) may receive 175,584 cubic meters (m3) of transuranic radioactive waste (TRUW)a. Pending the scheduled opening of repositories for once-used nuclear fuel (OUNF) in the USA, Sweden, and Finland in the years 2010, 2015, and 2017, respectively, LLRM-disposal solutions remain the missing link in all national LLRM-disposition programs. Furthermore, for a variety of reasons, many nations with nuclear programs have chosen a ''spectator'' stance in terms of enhancing the global nuclear safety culture and the nuclear renaissance, and have either …
Date: February 27, 2003
Creator: Eriksson, Leif G.; Dials, George E. & Parker, Frank L.
System: The UNT Digital Library
Development of a Fuel Containing Material Removal and Waste Management Strategy for the Chernobyl Unit 4 Shelter (open access)

Development of a Fuel Containing Material Removal and Waste Management Strategy for the Chernobyl Unit 4 Shelter

A study was performed to develop a strategy for the removal of fuel-containing material (FCM) from the Chernobyl Unit 4 Shelter and for the related waste management. This study was performed during Phase 1 of the Shelter Implementation Plan (SIP) and was funded by the Chernobyl Shelter Fund. The main objective for Phase 2 of the SIP is to stabilize the Shelter and to construct a New Confinement (NC) by the year 2007. In addition, the SIP includes studies on the strategy and on the conceptual design implications of the removal of FCM from the Shelter. This is considered essential for the ultimate goal, the transformation of the Shelter into an environmentally safe system.
Date: February 27, 2002
Creator: Tokarevsky, V. V.; Shibetsky, Y. A.; Leister, P.; Davison, W. R.; Follin, J. F.; McNair, J. et al.
System: The UNT Digital Library
Associating Physical and Chemical Properties to Evaluate Buffer Materials by Th and U Sorption (open access)

Associating Physical and Chemical Properties to Evaluate Buffer Materials by Th and U Sorption

The physical and chemical properties of buffer materials to be used for a radwaste disposal repository should be evaluated prior to use. In a conventional approach, independent studies of physical and/or chemical characteristics are conducted. This study investigated the relationship between the plastic index (PI) and distribution ratio (Rd) of buffer materials composed of varying ratios of quartz sand and bentonite. Thorium (Th) and Uranium (U) were the nuclides of interest, and both synthetic groundwater and seawater were used as the liquid phases to simulate conditions representative of deep geological disposal within an island. Atterberg tests were used to determine PI values, and batch sorption experiments were employed to measure Rd values. The results show that Th reached maximum sorption behavior when the bentonite content exceeded 30 % of the mixture. Contrariwise, the sorption of U increased linearly with bentonite content, up to bentonite contents of 100%, and this correlation was present regardless of the liquid phase used. A further result is that U has a better additivity with respect to Rd than Th in both synthetic groundwater and synthetic seawater. These results will allow a determination of more effective buffer material composition, and improved estimates of the overall Rd …
Date: February 27, 2003
Creator: Jan, Yi-Lin; Chen, Tzu-Yun; Cheng, Hwai-Ping; Hsu, Chun-Nan; Tseng, Chia-Liang; Wei,Yuan-Yaw et al.
System: The UNT Digital Library
Utilization of a Technical Peer Review to Support the Mission of the Nevada Test Site Community Advisory Board (open access)

Utilization of a Technical Peer Review to Support the Mission of the Nevada Test Site Community Advisory Board

The U. S. Department of Energy's (DOE) National Nuclear Security Administration Nevada Operations Office (NNSA/NV) Environmental Management (EM) Underground Test Area (UGTA) project addresses the characterization and needs for long-term monitoring of the subsurface contamination resulting from 828 underground nuclear weapon tests at the Nevada Test Site (NTS). EM promotes, and is required, to include stakeholders in its program. However, UGTA is a very complex program not easily understood by members of the public. The NTS Community Advisory Board (CAB), a federally chartered Site Specific Advisory Board (SSAB), has studied the UGTA project since 1996, and has found it a challenge to completely comprehend and provide NNSA/NV meaningful citizen input. The CAB realized the benefit of a technical peer review and in 2000 recommended to NNSA/NV that a peer review of the UGTA strategy would provide valuable feedback to the program to address underground contamination at the NTS. N NSA agreed to the CAB's recommendation, and moved forward with a scope of work to have the American Society of Mechanical Engineers (ASME) perform the peer review of the UGTA strategy. The ASME began the peer review in June 2001, and their final report was published in November 2001. In January …
Date: February 27, 2003
Creator: Dixon, Earle C. & Peterson, Kathleen
System: The UNT Digital Library
ENVIRONMENTALLY SOUND DISPOSAL OF RADIOACTIVE MATERIALS AT A RCRA HAZARDOUS WASTE DISPOSAL FACILITY (open access)

ENVIRONMENTALLY SOUND DISPOSAL OF RADIOACTIVE MATERIALS AT A RCRA HAZARDOUS WASTE DISPOSAL FACILITY

The use of hazardous waste disposal facilities permitted under the Resource Conservation and Recovery Act (''RCRA'') to dispose of low concentration and exempt radioactive materials is a cost-effective option for government and industry waste generators. The hazardous and PCB waste disposal facility operated by US Ecology Idaho, Inc. near Grand View, Idaho provides environmentally sound disposal services to both government and private industry waste generators. The Idaho facility is a major recipient of U.S. Army Corps of Engineers FUSRAP program waste and received permit approval to receive an expanded range of radioactive materials in 2001. The site has disposed of more than 300,000 tons of radioactive materials from the federal government during the past five years. This paper presents the capabilities of the Grand View, Idaho hazardous waste facility to accept radioactive materials, site-specific acceptance criteria and performance assessment, radiological safety and environmental monitoring program information.
Date: February 27, 2003
Creator: Romano, Stephen; Welling, Steven & Bell, Simon
System: The UNT Digital Library
A World View: The Coming Nuclear Century (open access)

A World View: The Coming Nuclear Century

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Date: February 27, 2003
Creator: Ritch, John
System: The UNT Digital Library
Current Status of the Iaea's Net Enabled Waste Management Database (open access)

Current Status of the Iaea's Net Enabled Waste Management Database

The International Atomic Energy Agency's Net Enabled Waste Management Database (NEWMDB) contains information on national radioactive waste management programs and organizations, plans and activities, relevant laws and regulations, policies and radioactive waste inventories. The NEWMDB, which was launched on the Internet July 6, 2001, is the successor to the Agency's Waste Management Database (WMDB), which was in use during the 1990's. The NEWMDB's first data collection cycle took place from July 2001 to March 2002. Agency Member State participation in the first data collection cycle was low--only 22 submissions were received. However, the first data collection cycle demonstrated that: the NEWMDB could be used to collect information on national radioactive waste management programs and radioactive waste inventories annually, the NEWMDB data can support the routine reporting of status and trends in radioactive waste management based on quantitative data, the NEWMDB can support the compilation of a consolidated, international radioactive waste inventory based on a unified waste classification scheme, the data needed to compute an indicator of sustainable development for radioactive waste management are available at the national level, NEWMDB data can be used to assess the development and implementation of national systems for radioactive waste management, and the NEWMDB can …
Date: February 27, 2003
Creator: Csullog, G. W.; Pozdniakov, I. & Bell, M. J.
System: The UNT Digital Library
Mixed Waste Treatment Cost Analysis for a Range of GeoMelt Vitrification Process Configurations (open access)

Mixed Waste Treatment Cost Analysis for a Range of GeoMelt Vitrification Process Configurations

GeoMelt is a batch vitrification process used for contaminated site remediation and waste treatment. GeoMelt can be applied in several different configurations ranging from deep subsurface in situ treatment to aboveground batch plants. The process has been successfully used to treat a wide range of contaminated wastes and debris including: mixed low-level radioactive wastes; mixed transuranic wastes; polychlorinated biphenyls; pesticides; dioxins; and a range of heavy metals. Hypothetical cost estimates for the treatment of mixed low-level radioactive waste were prepared for the GeoMelt subsurface planar and in-container vitrification methods. The subsurface planar method involves in situ treatment and the in-container vitrification method involves treatment in an aboveground batch plant. The projected costs for the subsurface planar method range from $355-$461 per ton. These costs equate to 18-20 cents per pound. The projected cost for the in-container method is $1585 per ton. This cost equates to 80 cents per pound. These treatment costs are ten or more times lower than the treatment costs for alternative mixed waste treatment technologies according to a 1996 study by the US Department of Energy.
Date: February 27, 2002
Creator: Thompson, L. E.
System: The UNT Digital Library
Deactivation and Decommissioning Environmental Strategy for the Plutonium Finishing Plant Complex, Hanford Nuclear Reservation (open access)

Deactivation and Decommissioning Environmental Strategy for the Plutonium Finishing Plant Complex, Hanford Nuclear Reservation

Maintaining compliance with environmental regulatory requirements is a significant priority in successful completion of the Plutonium Finishing Plant (PFP) Nuclear Material Stabilization (NMS) Project. To ensure regulatory compliance throughout the deactivation and decommissioning of the PFP complex, an environmental regulatory strategy was developed. The overall goal of this strategy is to comply with all applicable environmental laws and regulations and/or compliance agreements during PFP stabilization, deactivation, and eventual dismantlement. Significant environmental drivers for the PFP Nuclear Material Stabilization Project include the Tri-Party Agreement; the Resource Conservation and Recovery Act of 1976 (RCRA); the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA); the National Environmental Policy Act of 1969 (NEPA); the National Historic Preservation Act (NHPA); the Clean Air Act (CAA), and the Clean Water Act (CWA). Recent TPA negotiation s with Ecology and EPA have resulted in milestones that support the use of CERCLA as the primary statutory framework for decommissioning PFP. Milestones have been negotiated to support the preparation of Engineering Evaluations/Cost Analyses for decommissioning major PFP buildings. Specifically, CERCLA EE/CA(s) are anticipated for the following scopes of work: Settling Tank 241-Z-361, the 232-Z Incinerator, , the process facilities (eg, 234-5Z, 242, 236) and the process facility …
Date: February 27, 2003
Creator: Hopkins, A.M.; Heineman, R.; Norton, S.; Miller, M. & Oates, L.
System: The UNT Digital Library
Characterizing Tritum Waste Using Helium Ratios (open access)

Characterizing Tritum Waste Using Helium Ratios

When routine sampling revealed greatly elevated tritium levels (3.14 x 105 Bq/L [8.5-million pCi/liter]) in the groundwater near a solid waste landfill at the Hanford Site, an innovative technique was used to assess the extent of the plume. Helium-3/helium-4 ratios, relative to ambient air-in-soil gas samples, were used to identify the tritium source and initially delineate the extent of the groundwater tritium plume. This approach is a modification of a technique developed in the late 1960s to age-date deep ocean water as part of the GEOSECS ocean monitoring program. Poreda, et al. (1) and Schlosser, et al. (2) applied this modified technique to shallow aquifers. A study was also conducted to demonstrate the concept of using helium-3 as a tool to locate vadose zone sources of tritium and tracking groundwater tritium plumes at Hanford (3). Seventy sampling points were installed around the perimeter and along four transects downgradient of the burial ground. Soil gas samples were collected, analyzed for helium isotopes, and helium-3/helium-4 ratios were calculated for these 70 points. The helium ratios indicated a vadose zone source of tritium along the northern edge of the burial ground that is likely the source of tritium in the groundwater. The helium …
Date: February 27, 2003
Creator: Ovink, R. W.; McMahon, W. J.; Borghese, J. V. & Olsen, K. B.
System: The UNT Digital Library
Gas-Generation Experiments for Long-Term Storage of Tru Wastes at WIPP (open access)

Gas-Generation Experiments for Long-Term Storage of Tru Wastes at WIPP

An experimental investigation was conducted for gas generation in contact-handled transuranic (CH-TRU) wastes subjected for several years to conditions similar to those expected to occur at the Waste Isolation Pilot Plant (WIPP) should the repository eventually become inundated with brine. Various types of actual CH-TRU wastes were placed into 12 corrosion-resistant vessels. The vessels were loosely filled with the wastes, which were submerged in synthetic brine having the same chemical composition as that in the WIPP vicinity. The vessels were also inoculated with microbes found in the Salado Formation at WIPP. The vessels were sealed, purged, and the approximately 750-ml headspace was pressurized with nitrogen gas to approximately 146 atmospheres to create anoxic conditions at the lithostatic pressure expected in the repository were it inundated. The temperature was maintained at the expected 30 C. The test program objective was to measure the quantities and species of gases generate d by metal corrosion, radiolysis, and microbial activity. These data will assist in the specification of the rates at which gases are produced under inundated repository conditions for use in the WIPP Performance Assessment computer models. These experiments were very carefully designed, constructed, instrumented, and performed. Approximately 6-1/2 years of continuous, undisturbed …
Date: February 27, 2003
Creator: Felicione, F. S.; Carney, K. P.; Dwight, C. C.; Cummings, D. G. & Foulkrod, L. E.
System: The UNT Digital Library
CAMX - A High Performance Cutting Technique for Underwater Use (open access)

CAMX - A High Performance Cutting Technique for Underwater Use

During the past years a new cutting technology, the CAMX-process-family (Contact-Arc-Metal-X [X is for Cutting, Grinding and Drilling]) was developed at the Institute of Materials Science in Hanover. These are electro-thermal underwater separation processes for metallic structures. The CAMX technology covers the Contact-Arc-Metal- Cutting (CAMC) with a sword-like cutting electrode, the Contact-Arc-Metal-Grinding (CAMG) with a rotating electrode and the Contact-Arc-Metal-Drilling (CAMD) with a wrap mechanism to fix and carry the workpiece. There are no limitations of CAMC concerning the capability of cutting complicated structures of workpieces. Undercuts and cavities in the workpiece do not affect the CAMC. The CAMG is a separation process for straight cuts with a very high cutting speed. The CAMD is a technology to drill holes or pocket holes of any geometry. With the integrated wrap mechanism it is possible to fix and carry workpieces, which are not to handle with conventional mechanisms.
Date: February 27, 2003
Creator: Bach, Fr.-W.; Versemann, R.; Bienia, H. & Kremer, G.
System: The UNT Digital Library
Characterization of Plutonium Contaminated Soils From the Nevada Test Site in Support of Evaluation of Remediation Technologies (open access)

Characterization of Plutonium Contaminated Soils From the Nevada Test Site in Support of Evaluation of Remediation Technologies

The removal of plutonium from Nevada Test Site (NTS) area soils has previously been attempted using various combinations of attrition scrubbing, size classification, gravity based separation, flotation, air flotation, segmented gate, bioremediation, magnetic separation and vitrification. Results were less than encouraging, but the processes were not fully optimized. To support additional vendor treatability studies soil from the Clean Slate II site (located on the Tonopah Test Range, north of the NTS) were characterized and tested. These particular soils from the NTS are contaminated primarily with plutonium-239/240 and Am-241. Soils were characterized for Pu-239/240, Am-241 and gross alpha. In addition, wet sieving and the subsequent characterization were performed on soils before and after attrition scrubbing to determine the particle size distribution and the distribution of Pu- 239/240 and gross alpha as a function of particle size. Sequential extraction was performed on untreated soil to provide information about how tightly bound the plutonium was to the soil. Magnetic separation was performed to determine if this could be useful as part of a treatment approach. The results indicate that about a 40% volume reduction of contaminated soil should be achievable by removing the >300 um size fraction of the soil. Attrition scrubbing does …
Date: February 27, 2003
Creator: Torrao, Guilhermina; Carlino, Robert; Hoeffner, Steve L. & Navratil, James D.
System: The UNT Digital Library