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Sample records for north disposal trench

  1. Corrective action decision document for the Roller Coaster Lagoons and North Disposal Trench (Corrective Action Unit Number 404)

    International Nuclear Information System (INIS)

    1997-01-01

    The North Disposal Trench, located north of the eastern most lagoon, was installed in 1963 to receive solid waste and construction debris from the Operation Roller Coaster man camp. Subsequent to Operation Roller Coaster, the trench continued to receive construction debris and range cleanup debris (including ordnance) from Sandia National Laboratories and other operators. A small hydrocarbon spill occurred during Voluntary Corrective Action (VCA) activities (VCA Spill Area) at an area associated with the North Disposal Trench Corrective Action Site (CAS). Remediation activities at this site were conducted in 1995. A corrective action investigation was conducted in September of 1996 following the Corrective Action Investigation Plan (CAIP); the detailed results of that investigation are presented in Appendix A. The Roller Coaster Lagoons and North Disposal Trench are located at the Tonopah Test Range (TTR), a part of the Nellis Air Force Range, which is approximately 225 kilometers (140 miles) northwest of Las Vegas, Nevada, by air

  2. Corrective action plan for CAU No. 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Roller Coaster Sewage Lagoons and North Disposal Trench Corrective Action Unit (CAU) No. 404. The site is located on the Tonopah Test Range. CAU 404 consists of two Corrective Action Sites (CAS): the Roller Coaster Lagoons (CAS No TA-03-001-TA-RC) and the North Disposal Trench (CAS No TA-21-001-TA-RC). A site map of the lagoons and trench is provided. The Roller Coaster Sewage Lagoons are comprised of two unlined lagoons that received liquid sanitary waste in 1963 from the Operation Roller Coaster Man Camp and debris from subsequent construction and range cleanup activities. The North Disposal Trench was excavated in approximately 1963 and received solid waste and debris from the man camp and subsequent construction and range cleanup activities. A small hydrocarbon spill occurred during the 1995 Voluntary Corrective Action (VCA) activities in an area associated with the North Disposal Trench CAS.

  3. Corrective action plan for CAU No. 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range

    International Nuclear Information System (INIS)

    1997-07-01

    This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Roller Coaster Sewage Lagoons and North Disposal Trench Corrective Action Unit (CAU) No. 404. The site is located on the Tonopah Test Range. CAU 404 consists of two Corrective Action Sites (CAS): the Roller Coaster Lagoons (CAS No TA-03-001-TA-RC) and the North Disposal Trench (CAS No TA-21-001-TA-RC). A site map of the lagoons and trench is provided. The Roller Coaster Sewage Lagoons are comprised of two unlined lagoons that received liquid sanitary waste in 1963 from the Operation Roller Coaster Man Camp and debris from subsequent construction and range cleanup activities. The North Disposal Trench was excavated in approximately 1963 and received solid waste and debris from the man camp and subsequent construction and range cleanup activities. A small hydrocarbon spill occurred during the 1995 Voluntary Corrective Action (VCA) activities in an area associated with the North Disposal Trench CAS

  4. Geology of the Integrated Disposal Facility Trench

    International Nuclear Information System (INIS)

    Reidel, Steve P.; Fecht, Karl R.

    2005-01-01

    This report describes the geology of the integrated Disposal Facility (IDF) Trench. The stratigraphy consists of some of the youngest sediments of the Missoula floods (younger than 770 ka). The lithology is dominated sands with minor silts and gravels that are largely unconsolidated. The stratigraphy can be subdivided into five geologic units that can be mapped throughout the trench. Four of the units were deposited by the Missoula floods and the youngest consists of windblown sand and silt. The sediment has little moisture and is consistent with that observed in the characterization boreholes. The sedimentary layers are flat lying and there are no faults or folds present. Two clastic dikes were encountered, one along the west wall and one that can be traced from the north to the southwall. The north-south clastic dike nearly bifurcates the trench but the west wall clastic dike can not be traced very far east into the trench. The classic dikes consist mainly of sand with clay-lined walls. The sediment in the dikes is compacted to partly cemented and are more resistant than the layered sediments

  5. Closure Report for Corrective Action Unit 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range, Nevada with ROTC 1, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Lynn Kidman

    1998-09-01

    This Closure Report provides the documentation for closure of the Roller Coaster Sewage Lagoons and North Disposal Trench Comective Action Unit (CAU) 404. CAU 404 consists of the Roller Coaster Sewage Lagoons (Corrective Action Site [CAS] TA-03-O01-TA-RC) and the North Disposal Trench (CAS TA-21-001-TA-RC). The site is located on the Tonopah Test Range, approximately 225 kilometers (km) (140 miles [mi]) northwest ofLas Vegas, Nevada. . The sewage lagoons received ~quid sanitary waste horn the Operation Roller Coaster Man Camp in 1963 and debris from subsequent range and construction cleanup activities. The debris and ordnance was subsequently removed and properly dispos~, however, pesticides were detected in soil samples born the bottom of the lagoons above the U,S. Environmental Protection Agency Region IX Prelimimuy Remediation Goals (EPA 1996). . The North Disposal Trench was excavated in 1963. Debris from the man camp and subsequent range and construction cleanup activities was placed in the trench. Investigation results indicated that no constituents of concern were detected in soil samples collected from the trench. Remedial alternative proposed in the Comctive Action Decision Document (CADD) fm the site was “Covering” (DOE, 1997a). The Nevada Division of”Enviromnental Protection (NDEP)-approved Correction Action Plan (CAP) proposed the “Covering” niethodology (1997b). The closure activities were completed in accorhce with the approwil CAP and consisted of baclctllling the sewage lagoons and disposal trench, constructing/planting an engineered/vegetative cover in the area of the sewage lagoons and dikposal trencQ installing a perimeter fence and signs, implementing restrictions on fi~e use, and preparing a Post-Closure Monitoring Plan. “ Since closure activities. for CAU 404 have been completed in accordance with the Nevada Division of Environmental Protection-approved CAP (DOE, 1997b) as documented in this Closure Report, the U.S. Department of

  6. Unreviewed Disposal Question Evaluation: Waste Disposal In Engineered Trench #3

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, L. L.; Smith, F. G. III; Flach, G. P.; Hiergesell, R. A.; Butcher, B. T.

    2013-07-29

    Because Engineered Trench #3 (ET#3) will be placed in the location previously designated for Slit Trench #12 (ST#12), Solid Waste Management (SWM) requested that the Savannah River National Laboratory (SRNL) determine if the ST#12 limits could be employed as surrogate disposal limits for ET#3 operations. SRNL documented in this Unreviewed Disposal Question Evaluation (UDQE) that the use of ST#12 limits as surrogates for the new ET#3 disposal unit will provide reasonable assurance that Department of Energy (DOE) 435.1 performance objectives and measures (USDOE, 1999) will be protected. Therefore new ET#3 inventory limits as determined by a Special Analysis (SA) are not required.

  7. Post-Closure Inspection Report for Corrective Action Unit 404: Roller Coaster Sewage Lagoons and North Disposal Trench Tonopah Test Range, Nevada, Calendar Year 2000

    Energy Technology Data Exchange (ETDEWEB)

    K. B. Campbell

    2001-06-01

    Post-closure monitoring requirements for the Roller Coaster Sewage Lagoons and North Disposal Trench (Corrective Action Unit [CAW 404]) (Figure 1) are described in Closure Report for Corrective Action Unit 404, Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range, Nevada, report number DOE/NV--187. The Closure Report (CR) was submitted to the Nevada Division of Environmental Protection (NDEP) on September 11, 1998. Permeability results of soils adjacent to the engineered cover and a request for closure of CAU 404 were transmitted to the NDEP on April 29, 1999. The CR (containing the Post-Closure Monitoring Plan) was approved by the NDEP on May 18, 1999. Post-closure monitoring at CAU 404 consists of the following: (1) Site inspections done twice a year to evaluate the condition of the unit; (2) Verification that the site is secure; (3) Notice of any subsidence or deficiencies that may compromise the integrity of the unit; (4) Remedy of any deficiencies within 90 days of discovery; and (5) Preparation and submittal of an annual report. Site inspections were conducted on June 19, 2000, and November 21, 2000. The site inspections were conducted after completion of the revegetation activities (October 30, 1997) and NDEP approval of the CR (May 18, 1999). All site inspections were conducted in accordance with the Post-Closure Monitoring Plan in the NDEP-approved CR. This report includes copies of inspection checklists, photographs, recommendations, and conclusions. The Post-Closure Inspection Checklists are found in Attachment A, a copy of the field notes is found in Attachment B, and copies of the inspection photographs are found in Attachment C.

  8. Post-Closure Inspection Report for Corrective Action Unit 404: Roller Coaster Sewage Lagoons and North Disposal Trench Tonopah Test Range, Nevada, Calendar Year 2000; TOPICAL

    International Nuclear Information System (INIS)

    K. B. Campbell

    2001-01-01

    Post-closure monitoring requirements for the Roller Coaster Sewage Lagoons and North Disposal Trench (Corrective Action Unit[CAW 404]) (Figure 1) are described in Closure Report for Corrective Action Unit 404, Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range, Nevada, report number DOE/NV-187. The Closure Report (CR) was submitted to the Nevada Division of Environmental Protection (NDEP) on September 11, 1998. Permeability results of soils adjacent to the engineered cover and a request for closure of CAU 404 were transmitted to the NDEP on April 29, 1999. The CR (containing the Post-Closure Monitoring Plan) was approved by the NDEP on May 18, 1999. Post-closure monitoring at CAU 404 consists of the following: (1) Site inspections done twice a year to evaluate the condition of the unit; (2) Verification that the site is secure; (3) Notice of any subsidence or deficiencies that may compromise the integrity of the unit; (4) Remedy of any deficiencies within 90 days of discovery; and (5) Preparation and submittal of an annual report. Site inspections were conducted on June 19, 2000, and November 21, 2000. The site inspections were conducted after completion of the revegetation activities (October 30, 1997) and NDEP approval of the CR (May 18, 1999). All site inspections were conducted in accordance with the Post-Closure Monitoring Plan in the NDEP-approved CR. This report includes copies of inspection checklists, photographs, recommendations, and conclusions. The Post-Closure Inspection Checklists are found in Attachment A, a copy of the field notes is found in Attachment B, and copies of the inspection photographs are found in Attachment C

  9. Innovative designs for low-level nuclear waste disposal trenches

    International Nuclear Information System (INIS)

    Nowatzki, E.A.; Armstrong, G.; McCray, J.

    1985-01-01

    Shallow land burial of low-level nuclear wastes presents many problems that are within the scope of civil engineering analysis and design. These include groundwater seepage, surface water runoff and collection, and the subsidence of trench backfills. Unfortunately, at the time the first disposal sites were being developed, major emphasis was placed on the health-physics aspects of the problem with the result that many of the civil engineering aspects were overlooked and severe problems relating to site integrity exist today. This paper presents the results of a U.S. Nuclear Regulatory Commission (USNRC) sponsored research project conducted at the University of Arizona, Tucson, Arizona, to assess trench cap design from the viewpoint of stability, water infiltration, and economy. Full-scale trenches were constructed that incorporated four different designs. These designs range from a relatively simple cap consisting of engineered backfill with a sloping, compacted soil crown to a more complex cap-crown system that incorporates compacted backfill and a steel reinforced soil-cement cap with an overlaying ''wick'' drain. The results of structural and hydrological monitoring over a period of approximately 15 months are presented. Recommendations are made regarding standard design criteria for future sites based on the results of this research

  10. Geophysical investigation of the 116-H-1 liquid waste disposal trench, 100-HR-1 operable unit

    International Nuclear Information System (INIS)

    Bergstrom, K.A.; Mitchell, T.H.

    1996-04-01

    A geophysical investigation and data integration were conducted for the 116-H-1 Liquid Waste Disposal Trench, which is located in the 100-HR-1 Operable Unit. The 116-H-1 Liquid Waste Disposal Trench is also known as the 107-H Liquid Waste Disposal Trench, the 107-H Rupture Effluent Trench, and the 107-H Trench (Deford and Einan 1995). The trench was primarily used to hold effluent from the 107-H Retention Basin that had become radioactive from contact with ruptured fuel elements. The effluent may include debris from the ruptured fuel elements (Koop 1964). The 116-H-1 Liquid Waste Disposal Trench was also used to hold water and sludge from the 107-H Retention Basin during the basin's deactivation in 1965

  11. Addendum to the Closure Report for Corrective Action Unit 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Lynn Kidman

    2009-02-01

    This document constitutes an addendum to the September 1998, Closure Report for Corrective Action Unit 404: Roller Coaster Lagoons and Trench, Tonopah Test Range, Nevada as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the modification of the UR for CAS TA-03-001-TARC Roller Coaster Lagoons. This UR was established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and was based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This reevaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to modify the UR for CAS TA-03

  12. Unreviewed Disposal Question Evaluation: Waste Disposal in Engineered Trenches 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-12-12

    Revision 0 of this UDQE addressed the proposal to place Engineered Trench #3 (ET#3) in the footprint designated for Slit Trench #12 (ST#12) and operate using ST#12 disposal limits. Similarly, Revision 1 evaluates whether ET#4 can be located in and operated to Slit Trench #13 (ST#13) disposal limits. Both evaluations conclude that the proposed operations result in an acceptably small risk of exceeding a SOF of 1.0 and approve these actions from a performance assessment (PA) perspective. Because ET#3 will be placed in the location previously designated for ST#12, Solid Waste Management (SWM) requested that the Savannah River National Laboratory (SRNL) determine if the ST#12 limits could be employed as surrogate disposal limits for ET#3 operations. SRNL documented in this Unreviewed Disposal Question Evaluation (UDQE) that the use of ST#12 limits as surrogates for the new ET#3 disposal unit will provide reasonable assurance that Department of Energy (DOE) 435.1 performance objectives and measures (USDOE, 1999) will be protected. Therefore, new ET#3 inventory limits as determined by a Special Analysis (SA) are not required.

  13. Performance monitoring of an improved disposal trench in a humid environment in a fractured geology

    International Nuclear Information System (INIS)

    Mills, D.; Razor, J.

    1988-01-01

    An engineering evaluation of an improved disposal trench at the Maxey Flats Waste Disposal Site is being conducted in order to demonstrate the feasibility of a burial trench suitable for use at a site in a humid environment and underlain by complex and fractured geologic media. This demonstration is one of several proposed final site stabilization alternatives which will have to be evaluated prior to final site closure. Due to requirements in the Central Midwest Compact Commission, no waste generated as a result of the site closure may be disposed in the Commission's disposal site. Hence, the waste will be disposed on-site. The demonstration trench was constructed and filled with waste during the fall of 1985 with final trench capping being completed in July 1986. Since that time the trench has been evaluated utilizing trench settlement monument elevations, leachate production measurements, leachate radionuclide analysis, chemical tracer analysis and trench water balance. Measurements performed to date indicated that the trench lower infiltration barrier has a permeability of about 1E-7 cm/sec. Water balance measurements indicated that less than one percent of the total rainfall crossed the trench capillary barrier. No settlement of the trench cap has been observed. No liquid has appeared in the leachate collection and monitoring sumps

  14. Trench water chemistry at commercially operated low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Dayal, R.; Kinsley, M.T.; Clinton, J.; Czyscinski, K.S.; Weiss, A.J.

    1982-01-01

    Water samples from the disposal trenches of two low-level radioactive-waste-disposal sites were analyzed for their inorganic, organic, and radionuclide contents. Since oxidation of the trench waters can occur during their movement along the groundwater flow path, experiments were performed to measure the chemical and physical changes that occur in these waters upon oxidation. Low concentrations of chelating agents, shown to exist in trench waters, may be responsible for keeping radionuclides, particularly 60 Co, in solution. 4 figures, 5 tables

  15. Trench design and construction techniques for low-level radioactive waste disposal

    International Nuclear Information System (INIS)

    Tucker, P.G.

    1983-02-01

    This document provides information on trench design and construction techniques which can be used in the disposal of LLW by shallow land burial. It covers practices currently in use not only in the LLW disposal field, but also methods and materials being used in areas of hazardous and municipal waste disposal which are compatible with the performance objectives of 10 CFR Part 61. The complexity of a disposal site and its potential problems dictate the use of site-specific characteristics when designing a LLW disposal trench. This report presents the LLW disposal trench as consisting of various elements or unit processes. The term unit processes is used as it more fully relays the impact of the designer's choice of methods and materials. When choosing a material to fulfill the function of a certain trench element, the designer is also stipulating a portion of his operational procedure which must be compatible with the disposal operation as a whole. Information is provided on the properties, selection, and installation of various materials such as bentonite, soil-cement, polymeric materials, asphaltic materials, and geotechnical fabrics. This is not intended to outline step-by-step procedures. Basically, three time frames are addressed with respect to construction techniques; preoperational, operational, and postoperational. Within each of these time frames there are certain construction techniques which can be employed by the designer to enhance the overall ease of construction and ultimate success of the disposal facility. Among the techniques presented are precontouring the disposal area, alignment of the trench axis, sloping the trench bottom, incremental excavation, and surface water (runoff) management

  16. Characterization of trench water at the Maxey Flats low-level radioactive waste disposal site

    International Nuclear Information System (INIS)

    Weiss, A.J.; Francis, A.J.; Colombo, P.

    1977-01-01

    Currently the United States Geological Survey is conducting a study of the hydrogeological and geochemical behavior of commercially operated low-level radioactive waste disposal sites. The data collected from this study will be used to establish criteria for selection of new sites for disposal of radioactive wastes. As part of this study, water samples from trenches at the Maxey Flats, Kentucky site were analyzed at Brookhaven National Laboratory to determine the source terms of the radionuclides and other components in solution in the trenches. Procedures for collection and filtration of the samples under anoxic conditions are described. The samples were analyzed for inorganic, radiochemical and organic constituents. The inorganic analysis includes the measurements of pH, specific conductance, alkalinity, and various cations and anions. The radionuclides were measured by the gross alpha, gross beta, tritium, and gamma activities, followed by specific measurements of strontium-90 and plutonium isotopes. The organics were extracted, concentrated, and identified by gas chromatography/mass spectrometry. Considerable quantities of organics were detected in all of the trench waters sampled. Specific organics were found in most of the trenches, however, the organic composition of the trench waters vary. The presence of a variety of organic compounds in trench waters suggest that they may play an important role in the transport of radionuclides

  17. Microbial activity of trench leachates from shallow-land, low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Francis, A.J.; Dobbs, S.; Nine, B.J.

    1980-01-01

    Trench leachate samples collected anoxically from shallow-land, low-level radioactive waste disposal sites were analyzed for total aerobic and anaerobic populations, sulfate reducers, denitrifiers, and methanogens. Among the several aerobic and anaerobic bacteria isolated, only Bacillus sp., Pseudomonas sp., Citrobacter sp., and Clostridium sp. were identified. Mixed bacterial cultures isolated from the trench leachates were able to grow anaerobically in trench leachates, which indicates that the radionuclides and organic chemicals present were not toxic to these bacteria. Changes in concentrations of several of the organic constituents of the waste leachate samples were observed due to anaerobic microbial activity. Growth of a mixed culture of trench-water bacteria in media containing a mixture of radionuclides, 60 Co, 85 Sr, and 134 137 Cs, was not affected at total activity concentrations of 2.6 x 10 2 and 2.7 x 10 3 pCi/ml

  18. Greater Confinement Disposal trench and borehole operations status

    International Nuclear Information System (INIS)

    Harley, J.P. Jr.; Wilhite, E.L.; Jaegge, W.J.

    1987-01-01

    Greater Confinement Disposal (GCD) facilities have been constructed within the operating burial ground at the Savannah River Plant (SRP) to dispose of the higher activity fraction of SRP low-level waste. GCD practices of waste segregation, packaging, emplacement below the root zone, and waste stabilization are being used in the demonstration. 2 refs., 2 figs., 2 tabs

  19. The design and performance of a low-cost, soil cement cap for LLNW disposal trenches

    International Nuclear Information System (INIS)

    Nowatzki, E.A.

    1986-01-01

    Over the past three years, the University of Arizona has conducted research for the U.S. Nuclear Regulatory Commission (USNRC) to assess various trench cap designs from the viewpoint of structural stability, water infiltration, and economy. As part of that project, four experimental trenches were built and monitored at each of two semi-arid sites in the vicinity of Tucson, Arizona. In this paper, the design and construction of one of those trenches are described in detail. That trench included a cap-crown system that incorporates compacted soil backfill and a steel-reinforced, soil-cement cap with an overlying 'wick' drain. The results of structural monitoring over a period of approximately 2 years are presented and compared to those of a more conventionally designed trench. The results are evaluated with respect to surface subsidence and movements of the cap-crown components as they affect moisture infiltration. Recommendations are made regarding standard design criteria for LLNW disposal trenches based on the results of this research

  20. Design improvements on shallow-land burial trenches for disposing of low-level radioactive waste

    International Nuclear Information System (INIS)

    Takamura, E.S.; Salsman, J.M.

    1984-01-01

    The lack of success of closed low-level radioactive waste disposal sites has prompted the federal government to increase regulation of these facilities. In order to meet these increased requirements, several waste trench improvements are necessary. These improvements to the trench include sandy-clay caps, compacted sandy-clay bottoms, in-place geophysical instruments and vadose zone sampling equipment, and concrete sidewalls. These design improvements presented in this paper should increase the containment of the radionuclides by decreasing the waste contact with infiltrating groundwater. The design improves on the monitoring and sampling methods for detecting radionuclides transported through the leachate or gas effluent streams. 13 references, 4 figures

  1. Dose and risk assessment of norm Contaminated waste released from trench disposal facility

    International Nuclear Information System (INIS)

    Abdel Geleel, M.; Ramadan, A.B.; Tawfik, A.A.

    2005-01-01

    Oil and gas extraction and processing operations accumulate naturally occurring radioactive material (NORM) at concentrations above normal in by-product waste streams. The petroleum industry adopted methods for managing of NORM that are more restrictive than past practices and are likely to provide greater isolation of the radioactivity. Trench was used as a disposal facility for NORM contaminated wastes at one site of the petroleum industry in Egypt. The aim of this work is to calculate the risk and dose assessment received from trench disposal facility directly and after closure (1000 year). RESRAD computer code was used. The results indicated that the total effective dose (TED) received after direct closure of trench disposal facility was 7.7E-4 mSv/y while after 1000 years, it will he 3.4E-4. The health cancer risk after direct closure was 3.3E-8 while after 1000 years post closure it was 6E-8. Results of this assessment will help examine policy issues concerning different options and regulation of NORM contaminated waste generated by petroleum industry

  2. Evaluation of Proposed New LLW Disposal Activity Disposal of Compacted Job Control Waste, Non-compactible, Non-incinerable Waste, And Other Wasteforms In Slit Trenches

    International Nuclear Information System (INIS)

    WILHITE, ELMER L.

    2000-01-01

    The effect of trench disposal of low-level wasteforms that were not analyzed in the original performance assessment for the E-Area low-level waste facility, but were analyzed in the revised performance assessment is evaluated. This evaluation was conducted to provide a bridge from the current waste acceptance criteria, which are based on the original performance assessment, to those that will be developed from the revised performance assessment. The conclusion of the evaluation is that any waste except for materials that would retain radionuclides more strongly than soil that meets the radionuclide concentration of package limits for trench burial based on the revised performance assessment, and presented in Table 1 of this document, is suitable for trench disposal; provided that, for cellulosic material the current 40 percent restriction is retained. Table 2 of this document lists materials acceptable for trench disposal

  3. Fully engineered shallow trench design concepts for disposal of low and intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Locke, J.

    1984-09-01

    In this report, the results of the reviews of design concepts, waste arisings and release mechanisms are described. The basic principles of radiological protection and the proposed strategy for land disposal in the UK are outlined. The essential features of engineered trenches are described with some discussion of the likely material choices and their influence on nuclide release. The radiological protection criteria adopted in this study is that the overall risk of serious health effects arising from any release of radioactivity from a shallow engineered trench should always be less than 10 -6 per annum, which corresponds to a received dose of 0.1 mSv/yr. This approach to radiological protection takes account of the two components of risk of health detriment to future generations; namely the probability that a release of radionuclides will occur and the probability that the subsequent radiation doses will give rise to deleterious effects. A compilation is presented of the waste streams and expected volumes and activities that may be designated for LAND 2 disposal and an initial estimate of the associated nuclide inventory is given. (author)

  4. Special Analysis: Updated Analysis of the Effect of Wood Products on Trench Disposal Limits at the E-Area Low-Level Waste Facility

    International Nuclear Information System (INIS)

    Cook, J.R.

    2001-01-01

    This Special Analysis (SA) develops revised radionuclide inventory limits for trench disposal of low-level radioactive waste in the presence of wood products in the E-Area Low-Level Waste Facility. These limits should be used to modify the Waste Acceptance Criteria (WAC) for trench disposal. Because the work on which this SA is based employed data from tests using 100 percent wood products, the 40 percent limitation on wood products for trench (i.e., slit or engineered trench) disposal is not needed in the modified WAC

  5. Soil prokaryotic communities in Chernobyl waste disposal trench T22 are modulated by organic matter and radionuclide contamination.

    Science.gov (United States)

    Theodorakopoulos, Nicolas; Février, Laureline; Barakat, Mohamed; Ortet, Philippe; Christen, Richard; Piette, Laurie; Levchuk, Sviatoslav; Beaugelin-Seiller, Karine; Sergeant, Claire; Berthomieu, Catherine; Chapon, Virginie

    2017-08-01

    After the Chernobyl nuclear power plant accident in 1986, contaminated soils, vegetation from the Red Forest and other radioactive debris were buried within trenches. In this area, trench T22 has long been a pilot site for the study of radionuclide migration in soil. Here, we used 454 pyrosequencing of 16S rRNA genes to obtain a comprehensive view of the bacterial and archaeal diversity in soils collected inside and in the vicinity of the trench T22 and to investigate the impact of radioactive waste disposal on prokaryotic communities. A remarkably high abundance of Chloroflexi and AD3 was detected in all soil samples from this area. Our statistical analysis revealed profound changes in community composition at the phylum and OTUs levels and higher diversity in the trench soils as compared to the outside. Our results demonstrate that the total absorbed dose rate by cell and, to a lesser extent the organic matter content of the trench, are the principal variables influencing prokaryotic assemblages. We identified specific phylotypes affiliated to the phyla Crenarchaeota, Acidobacteria, AD3, Chloroflexi, Proteobacteria, Verrucomicrobia and WPS-2, which were unique for the trench soils. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. SPECIAL ANALYSIS FOR SLIT TRENCH DISPOSAL OF THE REACTOR PROCESS HEAT EXCHANGERS

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, L.; Collard, L.; Aleman, S.; Gorensek, M.; Butcher, T.

    2012-06-18

    The Savannah River National Laboratory (SRNL), in response to a request from Solid Waste Management (SWM), conducted a Special Analysis (SA) to evaluate the performance of nineteen heat exchangers that are to be disposed in the E-Area low level waste facility Slit Trench 9 (ST 9). Although these nineteen heat exchangers were never decontaminated, the majority of the radionuclides in the heat exchanger inventory list were determined to be acceptable for burial because they are less than the 'generic' waste form inventory limits given in the 2008 Performance Assessment (PA) (WSRC, 2008). However, as generic waste, the H-3 and C-14 inventories resulted in unacceptable sum-of-fractions (SOFs). Initial scoping analyses performed by SRNL indicated that if alterations were made to certain external nozzles to mitigate various potential leak paths, acceptable SOFs could be achieved through the use of a 'Special' waste form. This SA provides the technical basis for this new 'Special' waste form and provides the inventory limits for H-3 and C-14 for these nineteen heat exchangers such that the nineteen heat exchangers can be disposed in ST 9. This 'Special' waste form is limited to these nineteen heat exchangers in ST 9 and applies for H-3 and C-14, which are designated as H-3X and C-14X, respectively. The SA follows the same methodology used in the 2008 PA and the 2008 SA except for the modeling enhancements noted below. Infiltration rates above the heat exchangers are identical to those used in the 2008 PA; however, flow through the heat exchangers is unique. Because it is unknown exactly how sealed heat exchanger openings will perform and how surface and embedded contaminants will be released, multiple base cases or scenarios were established to investigate a set of performances. Each scenario consists of flow options (based on the performance of sealed openings) and a near-field release of contaminants (based on corrosion and

  7. Investigation on proper materials of a liner system for trench type disposal facilities of radioactive wastes from research, industrial and medical facilities

    International Nuclear Information System (INIS)

    Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro; Arikawa, Masanobu; Sakamoto, Yoshiaki

    2011-08-01

    The Low-level Radioactive Waste Disposal Project Center of Japan Atomic Energy Agency will settle on near surface disposal facilities with and without engineered barriers for radioactive wastes from research, industrial and medical facilities. Both of them are so called 'concrete pit type' and 'trench type', respectively. The technical standard of constructing and operating a disposal facility based on 'Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors' have been regulated partly by referring to that of 'Waste Management and Public Cleansing Law'. This means that the concrete pit type and the trench type disposal facility resemble an isolated type for specified industrial wastes and a non leachate controlled type final disposal site for stable industrial wastes, respectively. On the other, We plan to design a disposal facility with a liner system corresponding to a leachate controlled type final disposal site on a crucial assumption that radioactive wastes other than stable industrial wastes to be disposed into the trench type disposal facility is generated. By current nuclear related regulations in Japan, There are no technical standard of constructing the disposal facility with the liner system referring to that of 'Waste Management and Public Cleansing Law'. We investigate the function of the liner system in order to design a proper liner system for the trench type disposal facility. In this report, We investigated liner materials currently in use by actual leachate controlled type final disposal sites in Japan. Thereby important items such as tensile strength, durability from a view point of selecting proper liner materials were studied. The items were classified into three categories according to importance. We ranked proper liner materials for the trench type disposal facility by evaluating the important items per material. As a result, high density polyethylene(HDPE) of high elasticity type polymetric sheet was selected

  8. Compliance matrix for the mixed waste disposal facilities, Trenches 31 ampersand 34, burial ground 218-W-5

    International Nuclear Information System (INIS)

    Carlyle, D.W.

    1994-01-01

    The purpose of the Trench 31 ampersand 34 Mixed Waste Disposal Facility Compliance Matrix is to provide objective evidence of implementation of all regulatory and procedural-institutional requirements for the disposal facilities. This matrix provides a listing of the individual regulatory and procedural-institutional requirements that were addressed. Subject matter experts reviewed pertinent documents that had direct or indirect impact on the facility. Those found to be applicable were so noted and listed in Appendix A. Subject matter experts then extracted individual requirements from the documents deemed applicable and listed them in the matrix tables. The results of this effort are documented in Appendix B

  9. Corrective Action Investigation Plan for Corrective Action Unit 410: Waste Disposal Trenches, Tonopah Test Range, Nevada, Revision No.:0

    International Nuclear Information System (INIS)

    2002-01-01

    This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 410 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 410 is located on the Tonopah Test Range (TTR), which is included in the Nevada Test and Training Range (formerly the Nellis Air Force Range) approximately 140 miles northwest of Las Vegas, Nevada. This CAU is comprised of five Corrective Action Sites (CASs): TA-19-002-TAB2, Debris Mound; TA-21-003-TANL, Disposal Trench; TA-21-002-TAAL, Disposal Trench; 09-21-001-TA09, Disposal Trenches; 03-19-001, Waste Disposal Site. This CAU is being investigated because contaminants may be present in concentrations that could potentially pose a threat to human health and/or the environment, and waste may have been disposed of with out appropriate controls. Four out of five of these CASs are the result of weapons testing and disposal activities at the TTR, and they are grouped together for site closure based on the similarity of the sites (waste disposal sites and trenches). The fifth CAS, CAS 03-19-001, is a hydrocarbon spill related to activities in the area. This site is grouped with this CAU because of the location (TTR). Based on historical documentation and process know-ledge, vertical and lateral migration routes are possible for all CASs. Migration of contaminants may have occurred through transport by infiltration of precipitation through surface soil which serves as a driving force for downward migration of contaminants. Land-use scenarios limit future use of these CASs to industrial activities. The suspected contaminants of potential concern which have been identified are volatile organic compounds; semivolatile organic compounds; high explosives; radiological constituents including depleted uranium

  10. Long-Term Performance of Transuranic Waste Inadvertently Disposed in a Shallow Land Burial Trench at the Nevada Test Site

    International Nuclear Information System (INIS)

    Shott, Gregory J.; Yucel, Vefa

    2009-01-01

    In 1986, 21 m3 of transuranic (TRU) waste was inadvertently disposed in a shallow land burial trench at the Area 5 Radioactive Waste Management Site on the Nevada Test Site. U.S. Department of Energy (DOE) TRU waste must be disposed in accordance with Title 40, Code of Federal Regulations (CFR), Part 191, Environmental Radiation Protection Standard for Management and Disposal of Spent Nuclear Fuel, High-Level, and Transuranic Radioactive Wastes. The Waste Isolation Pilot Plant is the only facility meeting these requirements. The National Research Council, however, has found that exhumation of buried TRU waste for disposal in a deep geologic repository may not be warranted when the effort, exposures, and expense of retrieval are not commensurate with the risk reduction achieved. The long-term risks of leaving the TRU waste in-place are evaluated in two probabilistic performance assessments. A composite analysis, assessing the dose from all disposed waste and interacting sources of residual contamination, estimates an annual total effective dose equivalent (TEDE) of 0.01 mSv, or 3 percent of the dose constraint. A 40 CFR 191 performance assessment also indicates there is reasonable assurance of meeting all requirements. The 40 CFR 191.15 annual mean TEDE for a member of the public is estimated to reach a maximum of 0.055 mSv at 10,000 years, or approximately 37 percent of the 0.15 mSv individual protection requirement. In both assessments greater than 99 percent of the dose is from co-disposed low-level waste. The simulated probability of the 40 CFR 191.13 cumulative release exceeding 1 and 10 times the release limit is estimated to be 0.0093 and less than 0.0001, respectively. Site characterization data and hydrologic process modeling support a conclusion of no groundwater pathway within 10,000 years. Monte Carlo uncertainty analysis indicates that there is reasonable assurance of meeting all regulatory requirements. Sensitivity analysis indicates that the results

  11. Evaluation of 1985--1986 corrective actions at ORNL liquid waste disposal trench 7

    International Nuclear Information System (INIS)

    Spalding, B.P.

    1991-04-01

    Several corrective actions were taken in 1985--1986 at the site of ORNL radioactive liquid waste seepage trench 7 in an effort to reduce the discharge of radionuclides, mostly 60 Co, from a groundwater seep on the eastern side of the site. First, the size of the asphalt cap over the trench was doubled, and cap runoff was diverted away from the site to the west. Second, the buried waste transfer line to the trench was excavated and plugged and its pipe trench was damned with clay backfill. These actions were designed to reduce groundwater recharge in the area that might be the source of water to the seep. Third, a series of grout injections was carried out at 5-ft intervals along a perimeter line on the eastern and northern edges of the site. A total of 65,500 gal of lime-fly-ash grout was injected at 303 locations at depths up to 40 ft in an effort to seal relict contaminated strata with probable hydrologic connection to the seep. However, the grout formulation specified in the contract would not set to a detectable compressive strength nor would the grout samples exhibit a reduction in hydraulic conductivity during over a year of observation. Thus, the material specification for the grout was inappropriate for the desired effect of in situ hydrologic isolation. Core sampling at the site revealed that the grout flowed into the soil formation along discrete thin layers. Only three grout layers, with a maximum thickness of 0.25 in., were found in over 90 ft of core from three locations along the grout injection line. Thus, this grouting action would have little potential to influence containment of radionuclides that leach from contaminated strata. 11 refs., 14 figs., 7 tabs

  12. Draft Level 1 Remedial Investigation Work Plan: 316-3 waste disposal trenches

    International Nuclear Information System (INIS)

    1987-09-01

    This work plan describes the work to be performed for the initial level of site characterization for the 316.3 Trenches at the Hanford Site. This initial site characterization effort will include a review of existing environmental contamination data for the 300 Area as well as collection and analysis of environmental samples to better characterize subsurface contamination at the site. 7 refs., 10 figs., 7 tabs

  13. Paleoseismic Trenching on 1939 Erzincan and 1942 Niksar-Erbaa Earthquake Surface Ruptures, the North Anatolian Fault (Turkey)

    Science.gov (United States)

    Akyuz, H. S.; Karabacak, V.; Zabci, C.; Sancar, T.; Altunel, E.; Gursoy, H.; Tatar, O.

    2009-04-01

    Two devastating earthquakes occurred between Erzincan (39.75N, 39.49E) and Erbaa, Tokat (40.70N, 36.58E) just three years one after another in 1939 and 1942. While 1939 Erzincan earthquake (M=7.8) ruptured nearly 360 km, 1942 Erbaa-Niksar earthquake (M=7.1) has a length of 50 km surface rupture. Totally, more than 35000 citizens lost their lives after these events. Although Turkey has one of the richest historical earthquake records, there is no clear evidence of the spatial distribution of paleoevents within these two earthquake segments of the North Anatolian Fault. 17 August 1668 Anatolian earthquake is one of the known previous earthquakes that may have occurred on the same segments with a probable rupture length of more than 400 km. It is still under debate in different catalogues, if it was ruptured in multiple events or a single one. We achieved paleoseismic trench studies to have a better understanding on the recurrence of large earthquakes on these two faults in the framework of T.C. DPT. Project no. 2006K120220. We excavated a total of 8 trenches in 7 different sites. While three of them are along the 1942 Erbaa-Niksar Earthquake rupture, others are located on the 1939 Erzincan one. Alanici and Direkli trenches were excavated on the 1942 rupture. Direkli trench site is located at the west of Niksar, Tokat (40.62N, 36.85E) on the fluvial terrace deposits of the Kelkit River. Only one paleoevent could be determined from the structural relationships of the trench wall stratigraphy. By radiocarbon dating of charcoal sample from above the event horizon indicates that this earthquake should have occurred before 480-412 BC. The second trench, Alanici, on the same segment was located between Erbaa and Niksar (40.65N, 36.78E) at the western boundary of a sag-pond. While signs of two (possible three) earthquakes were identified on the trench wall, the prior event to 1942 Earthquake is dated to be before 5th century AD. We interpreted this to have possibility of

  14. Preliminary design of a biological treatment facility for trench water from a low-level radioactive waste disposal area at West Valley, New York

    Energy Technology Data Exchange (ETDEWEB)

    Rosten, R.; Malkumus, D. [Pacific Nuclear, Inc. (United States); Sonntag, T. [New York State Energy Research and Development Authority, NY (United States); Sundquist, J. [Ecology and Environment, Inc. (United States)

    1993-03-01

    The New York State Energy Research and Development Authority (NYSERDA) owns and manages a State-Licensed Low-Level Radioactive Waste Disposal Area (SDA) at West Valley, New York. Water has migrated into the burial trenches at the SDA and collected there, becoming contaminated with radionuclides and organic compounds. The US Environmental Protection Agency issued an order to NYSERDA to reduce the levels of water in the trenches. A treatability study of the contaminated trench water (leachate) was performed and determined the best available technology to treat the leachate and discharge the effluent. This paper describes the preliminary design of the treatment facility that incorporates the bases developed in the leachate treatability study.

  15. Low-Level Burial Grounds dangerous waste permit application: Request for exemption from lined trench requirements and from land disposal restrictions for residual liquid at 218-E-12B Burial Ground Trench 94

    International Nuclear Information System (INIS)

    1992-10-01

    This document has been prepared and is being submitted to the respective agencies to satisfy three objectives of the US Department of Energy (DOE) Richland Field Office (DOE-RL) concerning Trench 94 of the 218-E-12B Burial Ground. The 218-E-12B Burial Ground is located in the 200 East Area of the Hanford Facility. Figure 1-1 shows the general location of the Hanford Site. The 218-E-12B Burial Ground is one of eight burial grounds included in the Low-Level Burial Grounds (LLBG), a treatment, storage and/or disposal (TSD) unit. Decommissioned, defueled naval submarine reactor compartments (SRCs) contain radioactivity caused by exposure of structural components to neutrons during normal operation of the submarines. After all the alternatives were evaluated in the US Department of the Navy 1984 environmental impact statement (EIS) (USN 1984), land burial of the SRCs was selected as the preferred disposal option. The SRCs currently are sent to Trench 94 of the 218-E-12B Burial Ground. In addition to radioactivity, the SRCs disposed in. The DOE-RL's three objectives in preparing and submitting this document are as follows. Request from Ecology an exemption from dangerous waste landfill liner and leachate collection and removal system (hereinafter referred to as liner/leachate system) requirements for Trench 94 of the 218-E-12B Burial Ground. Petition Ecology to exempt residual liquid in the SRCs from land disposal restrictions. Obtain EPA Region 10 review and comment on the request to Ecology for exemption from liner/leachate system requirements

  16. Readiness assessment plan for the Radioactive Mixed Waste Land Disposal Facility (Trench 31)

    International Nuclear Information System (INIS)

    Irons, L.G.

    1994-01-01

    This document provides the Readiness Assessment Plan (RAP) for the Project W-025 (Radioactive Mixed Waste Land Disposal Facility) Readiness Assessment (RA). The RAP documents prerequisites to be met by the operating organization prior to the RA. The RAP is to be implemented by the RA Team identified in the RAP. The RA Team is to verify the facility's compliance with criteria identified in the RAP. The criteria are based upon the open-quotes Core Requirementsclose quotes listed in DOE Order 5480.31, open-quotes Startup and Restart of Nuclear Facilitiesclose quotes

  17. Corrective Action Investigation Plan for Corrective Action Unit 410: Waste Disposal Trenches, Tonopah Test Range, Nevada, Revision 0 (includes ROTCs 1, 2, and 3)

    Energy Technology Data Exchange (ETDEWEB)

    NNSA/NV

    2002-07-16

    This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 410 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 410 is located on the Tonopah Test Range (TTR), which is included in the Nevada Test and Training Range (formerly the Nellis Air Force Range) approximately 140 miles northwest of Las Vegas, Nevada. This CAU is comprised of five Corrective Action Sites (CASs): TA-19-002-TAB2, Debris Mound; TA-21-003-TANL, Disposal Trench; TA-21-002-TAAL, Disposal Trench; 09-21-001-TA09, Disposal Trenches; 03-19-001, Waste Disposal Site. This CAU is being investigated because contaminants may be present in concentrations that could potentially pose a threat to human health and/or the environment, and waste may have been disposed of with out appropriate controls. Four out of five of these CASs are the result of weapons testing and disposal activities at the TTR, and they are grouped together for site closure based on the similarity of the sites (waste disposal sites and trenches). The fifth CAS, CAS 03-19-001, is a hydrocarbon spill related to activities in the area. This site is grouped with this CAU because of the location (TTR). Based on historical documentation and process know-ledge, vertical and lateral migration routes are possible for all CASs. Migration of contaminants may have occurred through transport by infiltration of precipitation through surface soil which serves as a driving force for downward migration of contaminants. Land-use scenarios limit future use of these CASs to industrial activities. The suspected contaminants of potential concern which have been identified are volatile organic compounds; semivolatile organic compounds; high explosives; radiological constituents including depleted

  18. North Sea focus on radwaste disposal

    International Nuclear Information System (INIS)

    Cope, D.

    1990-01-01

    At the recent North Sea Conference in the Netherlands possible future strategies for managing radioactive waste (radwaste) proved to be a contentious issue. Several of its North Sea littoral neighbours sought a categorical assurance that the UK would forego the option of constructing a subterranean radwaste repository which though accessed from land, extends under the coastline, or a sub-seabed facility reached from an offshore structure. It was pointed out that the UK has no present plans for such a radwaste repository. However, sub-seabed designs as a possibility for future repositories were not ruled out. NIREX has decided to concentrate its exploration work at two sites -Sellafield and Dounreay. Both sites are coastal locations and the government is aware that detailed geological exploration may favour extension of a radwaste repository beyond the shoreline, even if initially developed entirely on land. The design of such a radioactive waste repository is outlined. The position of NIREX and the Radioactive Waste Management Advisory Committee is discussed. (author)

  19. Trench mouth

    Science.gov (United States)

    ... gingivae). The term trench mouth comes from World War I, when this infection was common among soldiers " ... mouth include: Emotional stress Poor oral hygiene Poor nutrition Smoking Throat, tooth, or mouth infections Trench mouth ...

  20. Request for interim approval to operate Trench 94 of the 218-E-12B Burial Ground as a chemical waste landfill for disposal of polychlorinated biphenyl waste in submarine reactor compartments. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, G.D.

    1994-06-01

    This request is submitted to seek interim approval to operate a Toxic Substances Control Act (TSCA) of 1976 chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Operation of a chemical waste landfill for disposal of PCB waste is subject to the TSCA regulations of 40 CFR 761. Interim approval is requested for a period not to exceed 5 years from the date of approval. This request covers only the disposal of small 10 quantities of solid PCB waste contained in decommissioned, defueled submarine reactor compartments (SRC). In addition, the request applies only to disposal 12 of this waste in Trench 94 of the 218-E-12B Burial Ground (Trench 94) in the 13 200 East Area of the US Department of Energy`s (DOE) Hanford Facility. Disposal of this waste will be conducted in accordance with the Compliance 15 Agreement (Appendix H) between the DOE Richland Operations Office (DOE-RL) and 16 the US Environmental Protection Agency (EPA), Region 10. During the 5-year interim approval period, the DOE-RL will submit an application seeking final 18 approval for operation of Trench 94 as a chemical waste landfill, including 19 any necessary waivers, and also will seek a final dangerous waste permit from 20 the Washington State Department of Ecology (Ecology) for disposal of lead 21 shielding contained in the SRCS.

  1. Request for interim approval to operate Trench 94 of the 218-E-12B Burial Ground as a chemical waste landfill for disposal of polychlorinated biphenyl waste in submarine reactor compartments

    International Nuclear Information System (INIS)

    Cummins, G.D.

    1994-06-01

    This request is submitted to seek interim approval to operate a Toxic Substances Control Act (TSCA) of 1976 chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Operation of a chemical waste landfill for disposal of PCB waste is subject to the TSCA regulations of 40 CFR 761. Interim approval is requested for a period not to exceed 5 years from the date of approval. This request covers only the disposal of small 10 quantities of solid PCB waste contained in decommissioned, defueled submarine reactor compartments (SRC). In addition, the request applies only to disposal 12 of this waste in Trench 94 of the 218-E-12B Burial Ground (Trench 94) in the 13 200 East Area of the US Department of Energy's (DOE) Hanford Facility. Disposal of this waste will be conducted in accordance with the Compliance 15 Agreement (Appendix H) between the DOE Richland Operations Office (DOE-RL) and 16 the US Environmental Protection Agency (EPA), Region 10. During the 5-year interim approval period, the DOE-RL will submit an application seeking final 18 approval for operation of Trench 94 as a chemical waste landfill, including 19 any necessary waivers, and also will seek a final dangerous waste permit from 20 the Washington State Department of Ecology (Ecology) for disposal of lead 21 shielding contained in the SRCS

  2. Phoenix Trenches

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Annotated Version [figure removed for brevity, see original site] Left-eye view of a stereo pair [figure removed for brevity, see original site] Right-eye view of a stereo pair This image is a stereo, panoramic view of various trenches dug by NASA's Phoenix Mars Lander. The images that make up this panorama were taken by Phoenix's Surface Stereo Imager at about 4 p.m., local solar time at the landing site, on the 131st, Martian day, or sol, of the mission (Oct. 7, 2008). In figure 1, the trenches are labeled in orange and other features are labeled in blue. Figures 2 and 3 are the left- and right-eye members of a stereo pair. For scale, the 'Pet Donkey' trench just to the right of center is approximately 38 centimeters (15 inches) long and 31 to 34 centimeters (12 to 13 inches) wide. In addition, the rock in front of it, 'Headless,' is about 11.5 by 8.5 centimeters (4.5 by 3.3 inches), and about 5 centimeters (2 inches) tall. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  3. Bench-scale treatability testing of biological, UV oxidation, distillation, and ion-exchange treatment of trench water from a low-level radioactive waste disposal area at West Valley, New York

    Energy Technology Data Exchange (ETDEWEB)

    Sundquist, J.A.; Gillings, J.C. [Ecology and Environment, Inc. (United States); Sonntag, T.L. [New York State Energy Research and Development Authority (United States); Denault, R.P. [Pacific Nuclear, Inc. (United States)

    1993-03-01

    Ecology and Environment, Inc. (E and E), under subcontract to Pacific Nuclear Services (PNS), conducted for the New York State Energy Research and Development Authority (NYSERDA) treatability tests to support the selection and design of a treatment system for leachate from Trench 14 of the West Valley State-Licensed, Low-Level Radioactive Waste Disposal Area (SDA). In this paper E and E presents and discusses the treatability test results and provides recommendations for the design of the full-scale treatment system.

  4. Disposal of radioactive waste material

    International Nuclear Information System (INIS)

    Cairns, W.J.; Burton, W.R.

    1984-01-01

    A method of disposal of radioactive waste consists in disposing the waste in trenches dredged in the sea bed beneath shallow coastal waters. Advantageously selection of the sites for the trenches is governed by the ability of the trenches naturally to fill with silt after disposal. Furthermore, this natural filling can be supplemented by physical filling of the trenches with a blend of absorber for radionuclides and natural boulders. (author)

  5. Review of potential host rocks for radioactive waste disposal in the Piedmont province of North Carolina

    International Nuclear Information System (INIS)

    Butler, J.R.

    1980-10-01

    This report reviews the geology of the Piedmont province in North Carolina, emphasizing those features most pertinent to selection of potential host rocks for radioactive waste disposal. Discussion of criteria for selection indicates that the outcrop area of the rock body, probable homogeneity, low incidence of fractures, and low permeability are among the prime considerations. Application of the criteria leads to the selection of three large granite batholiths (Castalia, Churchland, and Rolesville) as potential field study areas. The report has an extensive bibliography

  6. North Carolina Geological Survey's role in siting a low-level radioactive (LLRW) waste disposal facility in North Carolina

    International Nuclear Information System (INIS)

    Reid, J.C.; Wooten, R.M.; Farrell, K.M.

    1993-01-01

    The Southeast Compact Commission in 1986 selected North Carolina to host the Southeast's LLRW disposal facility for the next twenty years. The North Carolina Geological Survey (NCGS) for six years has played a major role in the State's efforts by contributing to legislation and administrative code, policy, technical oversight and surveillance and regulation as a member of the State's regulatory team. Future activities include recommendation of the adequacy of characterization and site performance pursuant to federal code, state general statutes and administrative code, and review of a license application. Staff must be prepared to present testimony and professional conclusions in court. The NCGS provides technical advice to the Division of Radiation Protection (DRP), the regulatory agency which will grant or deny a LLRW license. The NCGS has not participated in screening the state for potential sites to minimize bias. The LLRW Management Authority, a separate state agency siting the LLRW facility, hired a contractor to characterize potential sites and to write a license application. Organizational relationships enable the NCGS to assist the DRP in its regulatory role without conflict of interest. Disposal facilities must be sited to ensure safe disposal of LLRW. By law, the siting of a LLRW disposal facility is primarily a geological, rather than an engineering, effort. Federal and State statutes indicate a site must be licensable on its own merits. Engineered barriers cannot make a site licensable. The project is 3 years behind schedule and millions of dollars over budget. This indicates the uncertainty and complexity inherent in siting such as facility, the outcome of which cannot be predicted until site characterization is complete, the license application reviewed and the performance assessment evaluated. State geological surveys are uniquely qualified to overview siting of LLRW facilities because of technical expertise and experience in the state's geology

  7. A new genus of Nanaloricidae (Loricifera) from deep-sea sediments of volcanic origin in the Kilinailau Trench north of Papua New Guinea

    Science.gov (United States)

    Gad, Gunnar

    2004-02-01

    A new genus and species of Nanaloricidae (Loricifera), Phoeniciloricus simplidigitatus, is described inhabiting fine sand covered by a layer of volcanic ash at a water depth of 1,813 m in the New Ireland Basin near the Kilinailau Trench (north of Papua New Guinea). The described specimen is a postlarva enclosed in a larval exuvium. This is the first report of a species belonging to the Nanaloricidae from the deep sea. This occurrence is surprising, because Nanaloricidae are typical inhabitants of coarse sands in the intertidal or littoral zone. Preference for these shallow water habitats is reflected in many morphological features which characterize the Nanaloricidae, and are not normally found in Loricifera inhabiting fine-grained, clayish, deep-sea bottoms. The postlarva of the new species is characterized by a long narrow mouth tube, an urn-shaped lorica divided into ten plates, and 13 small lorica spikes. Distinguishing features of the Higgins-larva include short spinose toes lacking mucros but having small and slightly enlarged bases, short scalids on the introvert, many thoracic plates arranged in 6-8 rows, numerous small papillate flosculi in the collar and caudal regions, and three pairs of filiform, short locomotory appendages on the ventral side. Some features of the new species, especially of the Higgins-larva, are discussed as adaptations to the deep-sea environment.

  8. Trace metal contamination of Beaufort's Dyke, North Channel, Irish Sea: A legacy of ordnance disposal

    International Nuclear Information System (INIS)

    Callaway, Alexander; Quinn, Rory; Brown, Craig J.; Service, Matthew; Benetti, Sara

    2011-01-01

    Highlights: → Our samples are the first trace metal concentrations taken from the valley of Beaufort's Dyke. → There is no clear trend between concentrations of trace metals in Dyke and NMMP sediments. → Particle transport simulations show dispersal of trace metals from Beaufort's Dyke is possible. → Disposed ordnance may also contribute to contamination of surrounding areas. → These methods could help predict areas at risk of future trace metal contamination as a result of ordnance disposal. - Abstract: Beaufort's Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40 year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort's Dyke over a 3 month period. This demonstrated that Beaufort's Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations.

  9. 300 Area Process Trenches Verification Package

    International Nuclear Information System (INIS)

    Lerch, J.A.

    1998-03-01

    The purpose of this verification package is to document achievement of the remedial action objectives for the 300 Area Process Trenches (300 APT) located within the 300-FF-1 Operable Unit (OU). The 300 APT became active in 1975 as a replacement for the North and South Process Pond system that is also part of the 300-FF-1 OU. The trenches received 300 Area process effluent from the uranium fuel fabrication facilities. Waste from the 300 Area laboratories that was determined to be below discharge limits based on monitoring performed at the 307 retention basin was also released to the trenches. Effluent flowed through the headworks sluice gates, down a concrete apron, and into the trenches. From the beginning of operations in 1975 until 1993, a continuous, composite sampler was located at the headwork structure to analyze process effluent at the point of discharge to the environment

  10. Microbial processes in North Atlantic pelagic sediments, and potential risks of deep-sea waste disposal

    International Nuclear Information System (INIS)

    Bolliger, R.; Hanselmann, K.W.; Bachofen, R.

    1989-01-01

    From the results for waste disposal on deep sea sediments, it was concluded: As waste canisters are buried in the sediment to a depth of 15 to 20 cm, they are in contact with the zone that contains the highest potential bacterial activity through a relatively large surface. An input of oxidizable organic matter to the sediment surface zone will stimulate microbial activity and therefore increase the risk for solubilization and redistribution of elements in the ocean water. Waste canisters lying on the sediment surface cut off the oxygen supply from the ocean water and ease the shift to anaerobiosis. This initiates microbial activities through which metals are changed into their mobile species as a consequence of the altered environmental redox potential. The risk for steel corrosion by hydrogen sulfide, which could be produced by sulfate reducing bacteria, is minimal since this physiological group is not active in the North Atlantic sediments examined

  11. In-Situ Grouting Treatability Study for the Idaho National Engineering and Environmental Laboratory Subsurface Disposal Area-Transuranic Pits and Trenches

    International Nuclear Information System (INIS)

    Loomis, G. G.; Jessmore, J. J.; Sehn, A. L.; Miller, C. M.

    2002-01-01

    At the Idaho National Engineering and Environmental Laboratory (INEEL), a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) treatability study is being performed to examine the technology of in situ grouting for final in situ disposal of buried mixed transuranic (TRU) waste. At the INEEL, there is over 56,000 cubic meters of waste commingled with a similar amount of soil in a shallow (3-5 m) land burial referred to as Waste Area Group 7-13/14. Since this buried waste has been declared on the National Priorities List under CERCLA, it is being managed as a superfund site. Under CERCLA, options for this waste include capping and continued monitoring, retrieval and ex situ management of the retrieved waste, in situ stabilization by vitrification or grouting, in situ thermal dissorption, or some combination of these options. In situ grouting involves injecting grout at high pressures (400 bars) directly into the waste to create a solid monolith. The in situ grouting process is expected to both stabilize the waste against subsidence and provide containment against migration of waste to the Snake River Plain Aquifer lying 150-200 m below the waste. The treatability study involves bench testing, implementability testing, and field testing. The bench testing was designed to pick three grouts from six candidate grouts for the implementability field testing in full scale which were designed to down-select from those three grouts to one grout for use in a full-scale field demonstration of the technology in a simulated test pit. During the bench testing, grouts were evaluated for durability using American Nuclear Society 16.1 Leach Protocol as well as evaluating the effect on physical parameters such as hydraulic conductivity and compressive strength due to the presence of interferences such as soil, organic sludge, and nitrate salts. During full-scale implementability testing, three grouts were evaluated for groutability and monolith formation

  12. Comparative Assessment of Status and Opportunities for CO2 Capture and Storage and Radioactive Waste Disposal in North America

    International Nuclear Information System (INIS)

    Oldenburg, C.; Birkholzer, J.T.

    2010-01-01

    Aside from the target storage regions being underground, geologic carbon sequestration and radioactive waste disposal share little in common in North America. The large volume of carbon dioxide (CO 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. There is well-documented capacity in North America for 100 years or more of sequestration of CO 2 from coal-fired power plants. Aside from economics, the challenges of geologic carbon sequestration include lack of fully established legal and regulatory framework for ownership of injected CO 2 , the need for an expanded pipeline infrastructure, and public acceptance of the technology. As for radioactive waste, the U.S. has proposed the unsaturated tuffs of Yucca Mountain, Nevada, as the region's first high-level radioactive waste disposal site. The Canadian radioactive waste program is currently evolving with options that range from geologic disposal to both decentralized and centralized permanent storage in surface facilities. Both the U.S. and Canada have established legal and regulatory frameworks for radioactive waste disposal. The most challenging technical issue for radioactive waste disposal is the need to predict repository performance on extremely long time scales (10 4 - 10 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 radioactive waste repositories. Because of the many significant differences between radioactive waste disposal and geologic carbon sequestration, 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 geologic carbon sequestration and radioactive waste disposal

  13. Retrieval of buried depleted uranium from the T-1 trench

    International Nuclear Information System (INIS)

    Burmeister, M.; Castaneda, N.; Hull, C.; Barbour, D.; Quapp, W.J.

    1998-01-01

    The Trench 1 remediation project will be conducted this year to retrieve depleted uranium and other associated materials from a trench at Rocky Flats Environmental Technology Site. The excavated materials will be segregated and stabilized for shipment. The depleted uranium will be treated at an offsite facility which utilizes a novel approach for waste minimization and disposal through utilization of a combination of uranium recycling and volume efficient uranium stabilization

  14. Oceanographic field observations off North Carolina, summer survey: ocean outfall waste water disposal feasibility and planning study from 22 May 1976 to 23 May 1978 (NODC Accession 8000016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nutrients, temperature profile, waste disposal, and ocean circulation data were collected using CTD from the JOHN DEWOLF in the coastal waters of North Carolina from...

  15. Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

    Science.gov (United States)

    Payne, Timothy E; Harrison, Jennifer J; Hughes, Catherine E; Johansen, Mathew P; Thiruvoth, Sangeeth; Wilsher, Kerry L; Cendón, Dioni I; Hankin, Stuart I; Rowling, Brett; Zawadzki, Atun

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest (239+240)Pu soil activity was 829 Bq/kg in a shallow sample (0-1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the 'bathtub' effect.

  16. Trench ‘Bathtubbing’ and Surface Plutonium Contamination at a Legacy Radioactive Waste Site

    Science.gov (United States)

    2013-01-01

    Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (∼12 Bq/L of 239+240Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest 239+240Pu soil activity was 829 Bq/kg in a shallow sample (0–1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the ‘bathtub’ effect. PMID:24256473

  17. Trench reactor: an overview

    International Nuclear Information System (INIS)

    Spinrad, B.I.; Rohach, A.F.; Razzaque, M.M.; Sankoorikal, J.T.; Schmidt, R.S.; Lofshult, J.; Ramin, T.; Sokmen, N.; Lin, L.C.

    1988-01-01

    Recent fast, sodium-cooled reactor designs reflect new conditions. In nuclear energy these conditions are (a) emphasis on maintainability and operability, (b) design for more transparent safety, and (c) a surplus of uranium and enrichment availability that eases concerns about light water reactor fueling costs. In utility practice the demand is for less capital exposure, short construction time, smaller new unit sizes, and low capital cost. The PRISM, SAFR, and integral fast reactor (IFR) concepts are responses to these conditions. Fast reactors will not soon be deployed commercially, so more radical designs can be considered. The trench reactor is the product of such thinking. Its concepts are intended as contributions to the literature, which may be picked up by one of the existing programs or used in a new experimental project. The trench reactor is a thin-slab, pool-type reactor operated at very low power density and- for sodium-modest temperature. The thin slab is repeated in the sodium tank and the reactor core. The low power density permits a longer than conventional core height and a large-diameter fuel pin. Control is by borated steel slabs that can be lowered between the core and lateral sodium reflector. Shutdown is by semaphore slabs that can be swung into place just outside the control slabs. The paper presents major characteristics of the trench reactor that have been changed since the last report

  18. Trench Advance By the Subduction of Buoyant Features - Application to the Izu-Bonin-Marianas Arc

    Science.gov (United States)

    Goes, S. D. B.; Fourel, L.; Morra, G.

    2014-12-01

    Most subduction trenches retreat, not only today but throughout the Cenozoic. However, a few trenches clearly advance during part of the evolution, including Izu-Bonin Marianas (IBM) and Kermadec. Trench retreat is well understood as a basic consequence of slab pull, but it is debated what causes trench advance. The IBM trench underwent a complex evolution: right after its initiation, it rotated clockwise, leading to very fast retreat in the north and slow retreat in the south. But since 10-15 Ma, IBM trench motions have switched to advance at the southern end, and since 5 Ma also the northern end is advancing. Based on 2-D subduction models, it has been proposed proposed that the change in age of the subducting plate at the IBM trench (from 40-70 m.y. at the initiation of the trench 45 m.y. ago to 100-140 m.y. lithosphere subducting at the trench today) and its effect on plate strength could explain the transition from trench retreat to trench advance, and that the age gradient (younger in the north and older in the south) could explain the rotation of the trench. However, with new 3-D coupled fluid-solid subduction model where we can include such lateral age gradients, we find that this does not yield the observed behaviour. Instead, we propose an alternative mechanism, involving the subduction of the buoyant Caroline Island Ridge at the southern edge of the Mariana trench and show that it can explain both trench motion history and the current morphology of the IBM slab as imaged by seismic tomography.

  19. Monitoring the effects of disposal of fine sediments from maintenance dredging on suspended particulate matter concentration in the Belgian nearshore area (southern North Sea)

    OpenAIRE

    Fettweis, M.; Baeye, M.; Francken, F.; Lauwaert, B.; Van den Eynde, D.; Van Lancker, V.; Martens, C.; Michielsen, T.

    2011-01-01

    The impact of continuous disposal of fine-grained sediments from maintenance dredging works on the suspended particulate matter concentration in a shallow nearshore turbidity maximum was investigated during dredging experiment (port of Zeebrugge, southern North Sea). Before, during and after the experiment monitoring of SPM concentration using OBS and ADV altimetry was carried out at a location 5 km west of the disposal site. A statistical analysis, based on the concept of populations and sub...

  20. Nuclear waste disposal site

    International Nuclear Information System (INIS)

    Mallory, C.W.; Watts, R.E.; Sanner, W.S. Jr.; Paladino, J.B.; Lilley, A.W.; Winston, S.J.; Stricklin, B.C.; Razor, J.E.

    1988-01-01

    This patent describes a disposal site for the disposal of toxic or radioactive waste, comprising: (a) a trench in the earth having a substantially flat bottom lined with a layer of solid, fluent, coarse, granular material having a high hydraulic conductivity for obstructing any capillary-type flow of ground water to the interior of the trench; (b) a non-rigid, radiation-blocking cap formed from a first layer of alluvium, a second layer of solid, fluent, coarse, granular material having a high hydraulic conductivity for blocking any capillary-type flow of water between the layer of alluvium and the rest of the cap, a layer of water-shedding silt for directing surface water away from the trench, and a layer of rip-rap over the silt layer for protecting the silt layer from erosion and for providing a radiation barrier; (c) a solidly-packed array of abutting modules of uniform size and shape disposed in the trench and under the cap for both encapsulating the wastes from water and for structurally supporting the cap, wherein each module in the array is slidable movable in the vertical direction in order to allow the array of modules to flexibly conform to variations in the shape of the flat trench bottom caused by seismic disturbances and to facilitate the recoverability of the modules; (d) a layer of solid, fluent, coarse, granular materials having a high hydraulic conductivity in the space between the side of the modules and the walls of the trench for obstructing any capillary-type flow of ground water to the interior of the trench; and (e) a drain and wherein the layer of silt is sloped to direct surface water flowing over the cap into the drain

  1. Trenching as an exploratory method

    International Nuclear Information System (INIS)

    Hatheway, A.W.; Leighton, F.B.

    1979-01-01

    The critical nature of siting nuclear power plants has led to increased emphasis on exploratory trenching. Trenching is the most definitive of all subsurface exploratory methods; it permits inspection of a continuous geologic section by both geologists and regulatory authorities and makes possible the preparation of a graphic log that delineates both obvious and subtle geologic features. About one of every two nuclear plant licensing efforts utilizes exploratory trenching. Many geologic hazards, such as ''capable'' faults, can be detected from trench exposures; they may otherwise remain undetected. Trenches must be judiciously located, survey-controlled, excavated safely and adequately shored, logged in detail, and properly diagnosed. Useful techniques of trench logging include thorough cleaning of the trench walls, teamwork between geologist and recorder, logging against a carefully surveyed baseline and vertical reference grid, and panoramic photography.Soils, including paleosols, and glacial and glaciofluvial deposits present some of the most difficult media to log. Trench logs must be thoroughly interpreted and correlated so that they document the geologic conditions governing suitability of the site. Age-determination techniques utilized in exploratory trenching include petrographic analyses, quartz inclusion studies, clay mineralogic analyses, and radiometric methods

  2. High Density Faraday Cup Array or Other Open Trench Structures and Method of Manufacture Thereof

    Science.gov (United States)

    Gilchrist, Kristin Hedgepath (Inventor); Bower, Christopher A. (Inventor); Stoner, Brian R. (Inventor)

    2014-01-01

    A detector array and method for making the detector array. The detector array includes a substrate including a plurality of trenches formed therein, and a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charged particles incident on respective ones of the collectors and to output from the collectors signals indicative of charged particle collection. In the detector array, adjacent ones of the plurality of trenches are disposed in a staggered configuration relative to one another. The method forms in a substrate a plurality of trenches across a surface of the substrate such that adjacent ones of the trenches are in a staggered sequence relative to one another, forms in the plurality of trenches a plurality of collectors, and connects a plurality of electrodes respectively to the collectors.

  3. Cleanup Verification Package for the 116-K-2 Effluent Trench

    International Nuclear Information System (INIS)

    Capron, J.M.

    2006-01-01

    This cleanup verification package documents completion of remedial action for the 116-K-2 effluent trench, also referred to as the 116-K-2 mile-long trench and the 116-K-2 site. During its period of operation, the 116-K-2 site was used to dispose of cooling water effluent from the 105-KE and 105-KW Reactors by percolation into the soil. This site also received mixed liquid wastes from the 105-KW and 105-KE fuel storage basins, reactor floor drains, and miscellaneous decontamination activities

  4. Comparative assessment of status and opportunities for carbon dioxide capture and storage and radioactive waste disposal In North America

    International Nuclear Information System (INIS)

    Oldenburg, C.; Birkholzer, J.T.

    2011-01-01

    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 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 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 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 4 -10 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.

  5. Status of the North Carolina/Southeast Compact low-level radioactive waste disposal project

    Energy Technology Data Exchange (ETDEWEB)

    Walker, C.K. [North Carolina Low-Level Radioactive Waste Management Authority, NC (United States)

    1993-03-01

    The Southeast Compact is a sited region for low-level radioactive waste because of the current facility at Barnwell, South Carolina. North Carolina has been designated as the next host state for the compact, and the North Carolina Low-Level Radioactive Waste Management Authority is the agency charged with developing the new facility. Chem-Nuclear Systems, Inc., has been selected by the Authority as its primary site development and operations contractor. This paper will describe the progress currently being made toward the successful opening of the facility in January 1996. The areas to be addressed include site characterization, performance assessment, facility design, public outreach, litigation, finances, and the continued operation of the Barnwell facility.

  6. Characterization of sediment in a leaching trench RCRA (Resource Conservation and Recovery Act) site

    International Nuclear Information System (INIS)

    Zimmerman, M.G.; Kossik, C.D.

    1988-01-01

    Hazardous materials potentially were disposed of into a pair of leaching trenches from 1975 until Resource Conservation and Recovery Act (RCRA) regulations were imposed in 1985. These leaching trenches now are used for disposal of nonhazardous process water. The typical effluent (approximately 3 million gal/d) consisted of water with trace quantities of laboratory, maintenance, and fuel fabrication process chemicals. The largest constituent in the waste stream was uranium in low concentrations. This paper describes the project used to analyze and characterize the sediments in and below the leaching trenches. Two phases of sediment sampling were performed. The first phase consisted of taking samples between the bottom of the trenches and groundwater to locate contamination in the deep sediments under the trenches. To accomplish this sampling, a series of wells were drilled, and samples were obtained for every five feet in depth. The second phase consisted of samples taken at three depths in a series of positions along each trench. Sampling was completed to determine contamination levels in the shallow sediments and loose material washed into the trenches from the process sewer system. The project results were that no measurable contamination was found in the deep sediments. Measurable contamination from metals, such as chromium and nickel, was found in the shallow sediments. The primary contaminant in the shallow sediments was uranium. The concentration of contaminants decreased rapidly to near-background levels at shallow depths below the bottoms of the trenches

  7. Trenching as a exploratory method

    International Nuclear Information System (INIS)

    Hatheway, A.W.; Leighton, F.B.

    1979-01-01

    The critical nature of siting nuclear power plants has led to increased emphasis on exploratory methods; it permits inspection of a continuous geologic section by both geologists and regulatory authorities and makes possible the preparation of a graphic log that delineates both obvious and subtle geologic features. About one of every two nuclear plant licensing efforts utilizes exploratory trenching. Many geologic hazards, such as ''capable'' faults, can be detected from trench exposures; they may otherwise remain undetected. Trenches must be judiciously located, survey-controlled, excavated safetly and adequately shored, logged in detail, and properly diagnosed. Useful techniques of trench logging include thorough cleaning of the trench walls, teamwork between geologist and recorder, logging against a carefully surveyed baseline and vertical reference grid, and panoramic photography. Soils, including paleosols, and glacial and glaciofluvial deposits present some of the most difficult media to log. Trench logs must be thoroughly interpreted and correlated so that they document the geologic conditions governing suitability of the site. Age-determination techniques utilized in exploratory trenching include petrographic analyses, quartz inclusion studies, clay mineralogic analyses, and radiometric methods

  8. Accelerated cleanup of the 316-5 process trenches at the Hanford Site

    International Nuclear Information System (INIS)

    Henckel, G.C.; Johnson, W.L.

    1991-01-01

    In October, 1990, the US Department of Energy, the US Environmental Protection Agency, and the Washington State Department of Ecology signed an Agreement in Principle to accelerate remedial actions on the Hanford Site. Removal of contaminated sediments from the 300 Area (316-5) Process Trenches was one of the three initial candidate locations identified for the accelerated remediation. The trenches have received small quantities of radioactive and hazardous wastes in large volumes of process water (up to 11,360,000 L/day). The trenches are approximately 300 m west of the Columbia River and 7 m above the water table. The trenches are an active interim permitted disposal facility that may remain active for the next few years. In order to reduce the potential for migration of contaminants from the trench sediments into the groundwater, an expedited response action to remove approximately 2,500 m 2 of soil from the active portion of the trenches is being performed. Field activities were initiated in July 1991 with site preparation. The first trench to be excavated was completed by August 15, 1991. Approximately 2 weeks were needed to begin removal activities in the second trench. The second trench should be completed by October 1, 1991, with the subsequent construction of an interim cover over the consolidated materials completed by December 1991

  9. Accelerated cleanup of the 316-5 Process Trenches at the Hanford Site

    International Nuclear Information System (INIS)

    Henckel, G.C.; Johnson, W.L.

    1991-09-01

    In October, 1990, the US Department of Energy, the US Environmental Protection Agency, and the Washington State Department of Ecology signed an Agreement in Principle to accelerate remedial actions on the Hanford Site. Removal of contaminated sediments from the 300 Area (316-5) Process Trenches was on of the three initial candidate locations identified for the accelerated remediation. The trenches have received small quantities of radioactive and hazardous wastes in large volumes of process water (up to 11,360,000 L/day). The trenches are approximately 300 m west of the Columbia River and 7 m above the water table. The trenches are an active interim permitted disposal facility that may remain active for the next few years. In order to reduce the potential for migration of contaminants from the trench sediments into the groundwater, an expedited response action to remove approximately 2,500 m 2 of soil from the active portion of the trenches is being performed. Field activities were initiated in July 1991 with site preparation. The first trench to be excavated was completed by August 15, 1991. Approximately 2 weeks were needed to begin removal activities in the second trench. The second trench should be completed by October 1, 1991, with the subsequent construction of an interim cover over the consolidated materials completed by December 1991

  10. Flow and transport at the Las Cruces trench site: Experiment IIb

    International Nuclear Information System (INIS)

    Vinson, J.; Hills, R.G.; Wierenga, P.J.; Young, M.H.

    1997-07-01

    The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing

  11. Flow and transport at the Las Cruces trench site: Experiment IIb

    Energy Technology Data Exchange (ETDEWEB)

    Vinson, J.; Hills, R.G. [New Mexico State Univ., Las Cruces, NM (United States); Wierenga, P.J.; Young, M.H. [Arizona Univ., Tucson, AZ (United States). Dept. of Soil and Water Science

    1997-07-01

    The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing.

  12. Review of DOE's proposal for Crystalline bedrock disposal of radioactive waste, north-central area

    International Nuclear Information System (INIS)

    Green, J.C.

    1986-01-01

    The DOE's Region-to-Area Screening Methodology for the Crystalline Repository Project (DOE/CH-1), the Final North-Central Region Geologic Characterization Report (DOE/CH-8(1)), and the Draft Area Recommendation Report for the Crystalline Repository Project (DOE/CH-15), with the associated maps, were reviewed. The review has focused on all general information regarding geologic topics and all site-specific data for DOE sites NC-10 and NC-3. This report contains two parts: (1) a point-by-point critique of perceived errors, omissions, or other shortcomings in each of the three documents; and (2) a discussion of the feasibility of crystalline bedrock as a suitable host medium for high-level radioactive waste

  13. Innovative Disposal Practices at the Nevada Test Site to Meet Its Low-Level Waste Generators' Future Disposal Needs

    International Nuclear Information System (INIS)

    Di Sanza, E.F.; Carilli, J.T.

    2006-01-01

    Low-level radioactive waste (LLW) streams which have a clear, defined pathway to disposal are becoming less common as U.S. Department of Energy accelerated cleanup sites enters their closure phase. These commonly disposed LLW waste streams are rapidly being disposed and the LLW inventory awaiting disposal is dwindling. However, more complex waste streams that have no path for disposal are now requiring attention. The U.S. Department of Energy (DOE) National Nuclear Security Administration Nevada Site Office (NSO) Environmental Management Program is charged with the responsibility of carrying out the disposal of onsite and off-site defense-generated and research-related LLW at the Nevada. Test Site (NTS). The NSO and its generator community are constantly pursuing new LLW disposal techniques while meeting the core mission of safe and cost-effective disposal that protects the worker, the public and the environment. From trenches to present-day super-cells, the NTS disposal techniques must change to meet the LLW generator's disposal needs. One of the many ways the NTS is addressing complex waste streams is by designing waste specific pits and trenches. This ensures unusual waste streams with high-activity or large packaging have a disposal path. Another option the NTS offers is disposal of classified low-level radioactive-contaminated material. In order to perform this function, the NTS has a safety plan in place as well as a secure facility. By doing this, the NTS can accept DOE generated classified low-level radioactive-contaminated material that would be equivalent to U.S. Nuclear Regulatory Commission Class B, C, and Greater than Class C waste. In fiscal year 2006, the NTS will be the only federal disposal facility that will be able to dispose mixed low-level radioactive waste (MLLW) streams. This is an activity that is highly anticipated by waste generators. In order for the NTS to accept MLLW, generators will have to meet the stringent requirements of the NTS

  14. 'Dodo' and 'Baby Bear' Trenches

    Science.gov (United States)

    2008-01-01

    NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 11 (June 5, 2008), the eleventh day after landing. It shows the trenches dug by Phoenix's Robotic Arm. The trench on the left is informally called 'Dodo' and was dug as a test. The trench on the right is informally called 'Baby Bear.' The sample dug from Baby Bear will be delivered to the Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA. The Baby Bear trench is 9 centimeters (3.1 inches) wide and 4 centimeters (1.6 inches) deep. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Cleanup Verification Package for the 107-D5 Trench

    International Nuclear Information System (INIS)

    Corpuz, F.M.; Fancher, J.D.; Blumenkranz, D.B.

    1998-03-01

    This document presents the results of remedial action objectives performed at the 107-D5 Sludge Trench, located at the 100-DR-1 Operable Unit in the 100 Area of the Hanford Site in southeastern Washington State. The 107-D5 Sludge Trench is also identified in the Hanford Waste Information Data System as Waste Site 100-D-4 (site code). The selected remedial action was (1) excavation of the site to the extent required to meet specified soil cleanup levels, (2) disposal of contaminated excavation materials at the Environmental Restoration and Disposal Facility at the 200 Area of the Hanford Site, and (3) backfilling the site with clean soil to adjacent grade elevations

  16. Interim safety basis compliance matrix for Trenches 31 and 34

    International Nuclear Information System (INIS)

    Ames, R.R.

    1994-01-01

    The tables provided in this document identify the specific requirements and basis for the administrative controls established in the Westinghouse Hanford Company (WHC) Solid Waste Burial Ground (SWBG) Interim Safety Basis (ISB) for operation of the Project W-025, Mixed Waste Lined Landfill (Trenches 31 and 34). The tables document the necessary controls and implementing procedures to ensure compliance with the requirements of the ISB. These requirements provide a basis for future Unreviewed Safety Questions (USQ) screening of applicable procedure changes, proposed physical modifications, tests, experiments, and occurrences. Table 1 provides the SWBG interim Operational Safety Requirements administrative controls matrix. The specific assumptions and commitments used in the safety analysis documents applicable to disposal of mixed wastes in Trenches 31 and 34 are provided in Table 2. Table 3 is provided to document the potential engineered and administrative mitigating features identified in the Preliminary Hazard Analysis (PHA) for disposal of mixed waste

  17. Hanford's Radioactive Mixed Waste Disposal Facility

    International Nuclear Information System (INIS)

    McKenney, D.E.

    1995-01-01

    The Radioactive Mixed Waste Disposal Facility, is located in the Hanford Site Low-Level Burial Grounds and is designated as Trench 31 in the 218-W-5 Burial Ground. Trench 31 is a Resource Conservation and Recovery Act compliant landfill and will receive wastes generated from both remediation and waste management activities. On December 30, 1994, Westinghouse Hanford Company declared readiness to operate Trench 31, which is the Hanford Site's (and the Department of Energy complex's) first facility for disposal of low-level radioactive mixed wastes

  18. Interim oceanographic description of the North-East-Atlantic site for the disposal of low-level radioactive waste. Vol. 2

    International Nuclear Information System (INIS)

    Dickson, R.R.; Gurbutt, P.A.; Kershaw, P.J.

    1986-01-01

    The NEA Co-ordinated Research and Environmental Surveillance Programme (CRESP) related to sea disposal of radioactive waste was started in 1981 following a recommendation of the Group of experts convened every five years by NEA to review the continued suitability of the dumping site for radioactive waste in the North-East Atlantic. The objective of CRESP is to increase the available scientific data base related to the oceanographic and biological characteristics of the dump site and elaborate a site specific model of the transfers of radionuclides to human populations. Volume one of the ''Interim Oceanographic Description of the North-East Atlantic Site for the Disposal of Low-Level Radioactive Waste'' was published in early 1983. It was an attempt to identify remaining gaps in current knowledge of conditions at the site and relate these conditions to the physical environment of the North-East Atlantic Ocean as a whole. The amount of data obtained by the CRESP Programme is now sufficient to justify publication of this second volume. Scientists present results of research which is of direct relevance to a better assessment of the impact from dumping radioactive waste in the North-East Atlantic, in particular an evaluation of the potential radiation doses to man. These two volumes represent part of the scientific contribution of the CRESP Programme to the 1985 Review of the Continued Suitability of the North-East Atlantic dump site

  19. Release mechanisms from shallow engineered trenches used as repositories for radioactive wastes

    International Nuclear Information System (INIS)

    Locke, J.; Wood, E.

    1987-05-01

    This report has been written for the Department of the Environment as part of their radioactive waste management research programme. The aim has been to identify release mechanisms of radioactivity from fully engineered trenches of the LAND 2 type and, to identify the data needed for their assessment. No direct experimental work has been involved. The report starts with a brief background to UK strategy and outlines a basic disposal system. It gives reviews of existing experience of low level radioactive waste disposal from LAND 1 trenches and of UK experience of toxic waste disposal to provide a practical basis for the next section which covers the implications of identified release mechanisms on the design requirements for an engineered trench. From these design requirements and their interaction with potential site conditions (both saturated and unsaturated zone sites are considered) an assessment of radionuclide release mechanism is made. (author)

  20. Initial SVE Well Testing for the A-Area Miscellaneous Rubble Pile (ARP) Trenches Area

    International Nuclear Information System (INIS)

    RIHA, BRIAN

    2004-01-01

    The A-Area Miscellaneous Rubble Pile (ARP) is a 5.9 acre unit located at the southern end of A/M Area at the Savannah River Site (SRS). Disposal activities at ARP began in the early 1950s. The exact dates of operation and material disposed in the unit remain unknown. Within the ARP exists a smaller, approximately 2 acre, sub unit identified as the Trenches Area. The Trenches Area is dominated by a T-shaped trench (approximately 50 feet wide) containing 8 to 12 feet of ash material. This T-shaped trench will be referred to as the ARP Trench. Vegetation has been removed from the Trenches Area and a lower permeability earthen cover now covers the ARP Trench. The ARP active soil vapor extraction (ASVE) remediation system consists of seven extraction wells and twelve monitoring wells that were pushed into the vadose zone of the ARP Trench. The remediation system was designed based on the pre-design study conducted in 2002. The purpose of the initial soil vapor extraction (SVE) well testing was to verify the integrity and functionality of the nineteen wells installed in the ARP Trench. The well integrity was evaluated based on the flow rate, vacuum, and indication that soil gas and not surface air was pulled from the well. Soil gas was defined as gas with levels of carbon dioxide (CO2) above ambient concentrations (400-700 ppmv). Volatile organic compound (VOC) concentrations were measured at each well to determine the initial distribution of the contamination. In addition, the subsurface vacuum distribution was measured around each extraction well as a relative measure of the influence of each well

  1. 300 Area Process Trenches Modified Closure/Postclosure Plan

    International Nuclear Information System (INIS)

    1997-09-01

    This chapter provides a brief summary of the contents of each chapter of this plan for the closure of the 300 Area Process Trenches (300 APT) treatment, storage, and/or disposal unit. It also provides background information for this unit and discusses how its closure will be integrated with the remedial action for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 300- FF-1 Operable Unit. The 300 APT is located within the 300 Area of the Hanford Site. This area contained reactor fuel fabrication facilities and research and development laboratories. The 300 APT was constructed and began operations in 1975 as the 316-5 Process Trenches. Effluent was discharged to the trenches by way of the 300 Area process sewer system, which has been the sole source of effluent for the 300 APT. The 316-5 Process Trenches gained Resource Conservation and Recovery Act of 1976 (RCRA) interim status as the 300 APT TSD unit on November 11, 1985. The unit has been administratively closed to discharges of dangerous waste since 1985

  2. A decision tool for selecting trench cap designs

    Energy Technology Data Exchange (ETDEWEB)

    Paige, G.B.; Stone, J.J.; Lane, L.J. [USDA-ARS, Tucson, AZ (United States)] [and others

    1995-12-31

    A computer based prototype decision support system (PDSS) is being developed to assist the risk manager in selecting an appropriate trench cap design for waste disposal sites. The selection of the {open_quote}best{close_quote} design among feasible alternatives requires consideration of multiple and often conflicting objectives. The methodology used in the selection process consists of: selecting and parameterizing decision variables using data, simulation models, or expert opinion; selecting feasible trench cap design alternatives; ordering the decision variables and ranking the design alternatives. The decision model is based on multi-objective decision theory and uses a unique approach to order the decision variables and rank the design alternatives. Trench cap designs are evaluated based on federal regulations, hydrologic performance, cover stability and cost. Four trench cap designs, which were monitored for a four year period at Hill Air Force Base in Utah, are used to demonstrate the application of the PDSS and evaluate the results of the decision model. The results of the PDSS, using both data and simulations, illustrate the relative advantages of each of the cap designs and which cap is the {open_quotes}best{close_quotes} alternative for a given set of criteria and a particular importance order of those decision criteria.

  3. Benthic carbon mineralization in hadal trenches

    DEFF Research Database (Denmark)

    Wenzhöfer, F.; Oguri, K.; Middelboe, Mathias

    2016-01-01

    consumption rates and sediment characteristics from the trench axis of two contrasting trench systems in the Pacific Ocean; the Izu-Bonin Trench underlying mesotrophic waters and the Tonga Trench underlying oligotrophic waters. In situ oxygen consumption at the Izu-Bonin Trench axis site (9200 m; 746 +/- 103...... mu mol m(-2) d(-1); n=27) was 3-times higher than at the Tonga Trench axis site (10800 m; 225 +/- 50 pmol m(-2) d(-1); n=7) presumably reflecting the higher surface water productivity in the Northern Pacific. Comparing benthic O-2 consumption rates measured in the central hadal Tonga Trench...... to that of nearby (60 km distance) abyssal settings (6250 m; 92 +/- 44 mu mol m(-2) d(-1); n=16) revealed a 2.5 higher activity at the trench bottom. Onboard investigations on recovered sediment furthermore revealed that the prokaryotic abundance and concentrations of phytopigments followed this overall trend (i...

  4. Benthic carbon mineralization in hadal trenches

    DEFF Research Database (Denmark)

    Wenzhofer, F.; Oguri, K.; Middelboe, M.

    2016-01-01

    Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consump...

  5. Low level waste disposal

    International Nuclear Information System (INIS)

    Barthoux, A.

    1985-01-01

    Final disposal of low level wastes has been carried out for 15 years on the shallow land disposal of the Manche in the north west of France. Final participant in the nuclear energy cycle, ANDRA has set up a new waste management system from the production center (organization of the waste collection) to the disposal site including the setting up of a transport network, the development of assessment, additional conditioning, interim storage, the management of the disposal center, records of the location and characteristics of the disposed wastes, site selection surveys for future disposals and a public information Department. 80 000 waste packages representing a volume of 20 000 m 3 are thus managed and disposed of each year on the shallow land disposal. The disposal of low level wastes is carried out according to their category and activity level: - in tumuli for very low level wastes, - in monoliths, a concrete structure, of the packaging does not provide enough protection against radioactivity [fr

  6. Test Area for Remedial Actions (TARA) site characterization and dynamic compaction of low-level radioactive waste trenches. FY 1988 progress report

    Energy Technology Data Exchange (ETDEWEB)

    Davis, E. C.; Spalding, B. P.; Lee, S. Y.; Hyder, L. K.

    1989-01-01

    As part of a low-level radioactive waste burial ground stabilization and closure technology demonstration project, a group of five burial trenches in Oak Ridge National Laboratory (ORNL) Solid Waste Storage Area (SWSA) 6 was selected as a demonstration site for testing trench compaction, trench grouting, and trench cap installation and performance. This report focuses on site characterization, trench compaction, and grout-trench leachate compatibility. Trench grouting and cap design and construction will be the subject of future reports. The five trenches, known as the Test Area for Remedial Actions (TARA) site, are contained within a hydrologically isolated area of SWSA 6; for that reason, any effects of stabilization activities on site performance and groundwater quality will be separable from the influence of other waste disposal units in SWSA 6. To obviate the chronic problem of burial trench subsidence and to provide support for an infiltration barrier cap, these five trenches were dynamically compacted by repeated dropping of a 4-ton weight onto each trench from heights of approximately 7 m.

  7. Interim Control Strategy for the Test Area North/Technical Support Facility Sewage Treatment Facility Disposal Pond - Two-year Update

    International Nuclear Information System (INIS)

    L. V. Street

    2007-01-01

    The Idaho Cleanup Project has prepared this interim control strategy for the U.S. Department of Energy Idaho Operations Office pursuant to DOE Order 5400.5, Chapter 11.3e (1) to support continued discharges to the Test Area North/Technical Support Facility Sewage Treatment Facility Disposal Pond. In compliance with DOE Order 5400.5, a 2-year review of the Interim Control Strategy document has been completed. This submittal documents the required review of the April 2005 Interim Control Strategy. The Idaho Cleanup Project's recommendation is unchanged from the original recommendation. The Interim Control Strategy evaluates three alternatives: (1) re-route the discharge outlet to an uncontaminated area of the TSF-07; (2) construct a new discharge pond; or (3) no action based on justification for continued use. Evaluation of Alternatives 1 and 2 are based on the estimated cost and implementation timeframe weighed against either alternative's minimal increase in protection of workers, the public, and the environment. Evaluation of Alternative 3, continued use of the TSF-07 Disposal Pond under current effluent controls, is based on an analysis of four points: - Record of Decision controls will protect workers and the public - Risk of increased contamination is low - Discharge water will be eliminated in the foreseeable future - Risk of contamination spread is acceptable. The Idaho Cleanup Project recommends Alternative 3, no action other than continued implementation of existing controls and continued deactivation, decontamination, and dismantlement efforts at the Test Area North/Technical Support Facility

  8. 40 CFR 265 interim status indicator-evaluation ground-water monitoring plan for the 216-B-63 trench

    International Nuclear Information System (INIS)

    Bjornstad, B.N.; Dudziak, S.

    1989-03-01

    This document outlines a ground-water monitoring plan for the 216-B-63 trench located in the northeast corner of the 200-East Area on the Hanford Site in southeastern Washington State. It has been determined that hazardous materials (corrosives) were disposed of to the trench during past operations. Installation of an interim-status ground-water monitoring system is required to determine whether hazardous chemicals are leaching to the ground water from beneath the trench. This document summarizes the existing data that are available from near the 216-B-63 trench and presents a plan to determine the extent of ground-water contamination, if any, derived from the trench. The plan calls for the installation of four new monitoring wells located near the west end of the trench. These wells will be used to monitor ground-water levels and water quality immediately adjacent to the trench. Two existing RCRA monitoring wells, which are located near the trench and hydraulically upgradient of it, will be used as background wells. 46 refs., 15 figs., 12 tabs

  9. Backfilling of trenches exposed to waves

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Fredsøe, Jørgen

    1997-01-01

    This paper treats the numerical prediction of initial and long-term morphology of small pipeline trenches. For this purpose a refined flow and sediment transport description is applied such that the entire mathematical problem is formulated and solved on a curvilinear grid using a k - ε turbulence......-closure. The backfilling process of trenches exposed to either waves or a steady current is of importance in relation to the implementation of pipelines in the marine environment. With respect to the sedimentation of trenches, the non-dimensional Trench-Keulegan-Carpenter number, KC = a/L, where a is the excursion length...

  10. Groundwater suppression and diversion structures applied to closed shallow land burial trenches

    International Nuclear Information System (INIS)

    Davis, E.C.; Melroy, L.A.; Huff, D.D.

    1984-01-01

    Shallow depth to groundwater, surface drainage, and subsurface flow during storm events are major environmental concerns of low-level radioactive waste management operations in humid regions. At two waste disposal sites within the Oak Ridge National Laboratory (ORNL), groups of closed trenches have experienced these problems and have been shown to collect and hold intratrench water with seasonal fluctuations ranging from 1 to 2 m. In an attempt to correct these water-related problems, Solid Waste Storage Area Four (SWSA-4) was equipped in September 1975 with asphalt-lined drainage ways designed to prevent reinfiltration of storm drainage from the 13.8 ha upslope catchment. At 49-Trench Area of SWSA-6 the entire 0.44 ha trench area was capped with a bentonite clay cover in 1976. These early attempts at hydrologic isolation have not corrected the water problems. In September 1983, two similarly designed engineered drainage projects were initiated at the disposal sites. The SWSA-4 project was designed to divert surface runoff around the trench area and drain a portion of the shallow subsurface flow which originates upslope of the site. The second project, a passive French drain constructed in SWSA-6, was aimed strictly at suppressing the site water table thus preventing its intersection with the bottoms of disposal trenches. Post-construction monitoring for performance evaluation has shown that the water table in the 49-trench area has been suppressed to a depth >4.9 m below the ground surface over 50% of the site with a maximum drawdown of 4 m at the drains deepest point. The SWSA-4 project evaluation is just being completed and data show that 56 +/- 15% of the Winter-Spring 1984 runoff was diverted around SWSA 4. As a result, a 44% reduction in 90 Sr flux was calculated from observed discharges and a previously established relation between flow rate and 90 Sr concentration

  11. Disposal project for LLW and VLLW generated from research facilities in Japan: A feasibility study for the near surface disposal of VLLW that includes uranium

    International Nuclear Information System (INIS)

    Sakai, Akihiro; Hasegawa, M.; Sakamoto, Y.; Nakatani, T.

    2016-01-01

    Conclusion and future work: • JAEA plans trench disposal of U-bearing waste with less than 100 Bq/g. • Two safety measures of trench disposal of U-bearing waste have been discussed taking into account increasing radioactivity over a long period of time. 1. First is to carry out dose assessment of site use scenario by using a conservatively stylized condition. 2. Second is to control the average concentration of U in the trench facilities based on the concept of the existing exposure situation. • We are continuously developing the method for safety measures of near surface disposal of VLLW including U-bearing waste.

  12. Defense waste salt disposal at the Savannah River Plant

    International Nuclear Information System (INIS)

    Langton, C.A.; Dukes, M.D.

    1984-01-01

    A cement-based waste form, saltstone, has been designed for disposal of Savannah River Plant low-level radioactive salt waste. The disposal process includes emplacing the saltstone in engineered trenches above the water table but below grade at SRP. Design of the waste form and disposal system limits the concentration of salts and radionuclides in the groundwater so that EPA drinking water standards will not be exceeded at the perimeter of the disposal site. 10 references, 4 figures, 3 tables

  13. Challenges in hardening technologies using shallow-trench isolation

    International Nuclear Information System (INIS)

    Shaneyfelt, M.R.; Dodd, P.E.; Draper, B.L.; Flores, R.S.

    1998-02-01

    Challenges related to radiation hardening CMOS technologies with shallow-trench isolation are explored. Results show that trench hardening can be more difficult than simply replacing the trench isolation oxide with a hardened field oxide

  14. Groundwater suppression and surface water diversion structures applied to closed shallow land burial trenches

    International Nuclear Information System (INIS)

    Davis, E.C.; Stansfield, R.G.; Melroy, L.A.; Huff, D.D.

    1984-01-01

    Shallow depth to groundwater, surface drainage, and subsurface flow during storm events are major environmental concerns of low-level radioactive waste management operations in humid regions. At two waste disposal sites within the Oak Ridge National Laboratory (ORNL), groups of closed trenches have experienced these problems and have been shown to collect and hold water with seasonal fluctuations ranging from 1 to 2 m. In an attempt to correct these water-related problems, the older of the two sites [Solid Waste Storage Area Four (SWSA 4)] was equipped in September 1975 with asphalt lined drainage-ways designed to prevent infiltration of storm drainage from a 13.8-ha upslope catchment. At the second site (49-Trench area of SWSA 6), the entire 0.44-ha trench area was capped with a bentonite clay cover in 1976. These attempts have not corrected the water problems. In September 1983, engineered drainage projects were initiated at both the disposal sites. The SWSA 4 project was designed to divert surface runoff and shallow subsurface flow which originates upslope of the site away from the disposal area. The second project, a passive French drain constructed in SWSA 6, was aimed strictly at suppressing the site water table, thus preventing its intersection with the bottoms of disposal trenches. Postconstruction monitoring for performance evaluation has shown that the water table in the 49-Trench area has been suppressed to a depth > 4.9 m below the ground surface over 50% of the site as compared to a depth of only 2.1 m for certain parts of the same area observed during seasonally wet months prior to drain construction. The SWSA 4 project evaluation indicates that 56% of the Winter-Spring 1984 runoff was diverted around SWSA 4 via the drainage system

  15. The cost of engineered disposal facilities

    International Nuclear Information System (INIS)

    Mallory, C.W.; Razor, J.E.; Mills, D.

    1987-01-01

    An improved disposal trench was designed, constructed and placed into operation at the Maxey Flats Disposal Site during the period April 1985 through July 1986. With the improved trench design, the waste packages are placed in clusters and the surrounding space is filled with gravel and grouted with a sand/cement mixture to form walls and cells that surround the waste package. The walls provide structural support for a poly-ethylene reinforced soil beam which in turn supports a multi-layer protective cap. About 2,700 drums of waste (20,250 CF) were placed into the trench. The total cost of the improved trench was $193,500 and the unit cost was $9.56 per cubic foot not including the placement of the waste. The engineered features of the trench (i.e., sidewall infiltration barrier, grout backfill and the soil beam) cost $82,600 for a unit cost of $4.08 per cubic foot of waste. This is compared to the cost of concrete cannisters used for radioactive waste disposal. On a production basis the cannisters are estimated to cost about $1,260. Depending upon the type waste, the cost of the cannisters will range from $2 to $12 per cubic foot of waste. The slightly higher cost of the concrete cannisters is offset by certain performance advantages

  16. Interim Control Strategy for the Test Area North/Technical Support Facility Sewage Treatment Facility Disposal Pond - Two-year Update

    Energy Technology Data Exchange (ETDEWEB)

    L. V. Street

    2007-04-01

    The Idaho Cleanup Project has prepared this interim control strategy for the U.S. Department of Energy Idaho Operations Office pursuant to DOE Order 5400.5, Chapter 11.3e (1) to support continued discharges to the Test Area North/Technical Support Facility Sewage Treatment Facility Disposal Pond. In compliance with DOE Order 5400.5, a 2-year review of the Interim Control Strategy document has been completed. This submittal documents the required review of the April 2005 Interim Control Strategy. The Idaho Cleanup Project's recommendation is unchanged from the original recommendation. The Interim Control Strategy evaluates three alternatives: (1) re-route the discharge outlet to an uncontaminated area of the TSF-07; (2) construct a new discharge pond; or (3) no action based on justification for continued use. Evaluation of Alternatives 1 and 2 are based on the estimated cost and implementation timeframe weighed against either alternative's minimal increase in protection of workers, the public, and the environment. Evaluation of Alternative 3, continued use of the TSF-07 Disposal Pond under current effluent controls, is based on an analysis of four points: - Record of Decision controls will protect workers and the public - Risk of increased contamination is low - Discharge water will be eliminated in the foreseeable future - Risk of contamination spread is acceptable. The Idaho Cleanup Project recommends Alternative 3, no action other than continued implementation of existing controls and continued deactivation, decontamination, and dismantlement efforts at the Test Area North/Technical Support Facility.

  17. Seepage through a hazardous-waste trench cover

    Science.gov (United States)

    Healy, R.W.

    1989-01-01

    Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216 mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest rates occurred along the edge of the cover, where seepage was highly episodic, with 84% of the total there being traced to wetting fronts from 28 individual storms. Limitations of the zero-flux-plane method were severe enough for the method to be judged inappropriate for use in this study.Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest

  18. Effects of waste-disposal practices on ground-water quality at five poultry (broiler) farms in north-central Florida, 1992-93

    Science.gov (United States)

    Hatzell, H.H.

    1995-01-01

    Waste-disposal areas such as chicken-house floors, litter stockpiles, fields that receive applications of litter, and dead-chicken pits are potential sources of nitrates and other chemical constituents in downward-percolating recharge water. Broiler- farms in north-central Florida are concentrated in a region where the Upper Floridan aquifer is unconfined and susceptible to contamination. Eighteen monitoring wells installed at five sites were sampled quarterly from March 1992 through January 1993. Increases in median concentrations of constituents relative to an upgradient well were used to determine the source of the nitrate at two sites. At these sites, increases in the median concentrations of nitrate as nitrogen in ground water in the vicinity of waste-disposal areas at these sites were: 5.4 mg/L for one chicken house; 9.0 mg/L for a second chicken house; 2.0 mg/L for a fallow field that received an application of litter; and, 2.0 mg/L for a dead-chicken pit. At the three remaining sites where the direction of local ground-water flow could not be ascertained, the sources of concentrations of nitrate and other constituents could not be determined. However, median nitrate concentrations in the vicinity of waste-disposal areas at these sites were: 45.5 mg/L for a set of two chicken houses; 3.0 mg/L for a stockpile area; and 2.1 mg/L for a hayfield that received an application of litter. The nitrate concentration in ground water in the vicinity of a field that had previously received heavy applications of litter increased from 3.0 mg/L to 105 mg/L approximately 4 months after receiving an application of commercial fertilizer. Increases in concentrations of organic nitrogen in ground water in the vicinity of waste-disposal areas may be related to the decomposition of litter and subsequent movement with downward percolating recharge water.(USGS)

  19. Home Sewage Disposal. Special Circular 212.

    Science.gov (United States)

    Wooding, N. Henry

    This circular provides current information for homeowners who must repair or replace existing on-lot sewage disposal systems. Site requirements, characteristics and preparation are outlined for a variety of alternatives such as elevated sand mounds, sand-lined beds and trenches, and oversized absorption area. Diagrams indicating construction…

  20. Universal trench design method for a high-voltage SOI trench LDMOS

    Institute of Scientific and Technical Information of China (English)

    Hu Xiarong; Zhang Bo; Luo Xiaorong; Li Zhaoji

    2012-01-01

    The design method for a high-voltage SOl trench LDMOS for various trench permittivities,widths and depths is introduced.A universal method for efficient design is presented for the first time,taking the trade-off between breakdown voltage (BV) and specific on-resistance (Rs,on) into account.The high-k (relative permittivity)dielectric is suitable to fill a shallow and wide trench while the low-k dielectric is suitable to fill a deep and narrow trench.An SOI LDMOS with a vacuum trench in the drift region is also discussed.Simulation results show that the high FOM BV2/Rs,on can be achieved with a trench filled with the low-k dielectric due to its shortened cell-pitch.

  1. The Micro Trench Gas Counter

    International Nuclear Information System (INIS)

    Schmitz, J.

    1991-07-01

    A novel design is presented for a gas avalanche chamber with micro-strip gas readout. While existing gaseous microstrip detectors (Micro-strip Gas Counters, Knife edge chambers) have a minimum anode pitch of the order of 100 μm, the pitch of the discussed Micro Trench Gas Counter goes down to 30-50 μm. This leads to a better position resolution and two track separation, and a higher radiation resistivity. Its efficiency and signal speed are expected to be the same as the Microstrip Gas Counter. The energy resolution of the device is expected to be equal to or better than 10 percent for the 55 Fe peak. Since the anode strip dimensions are larger than those in a MSGC, the device may be not as sensitive to discharges and mechanical damage. In this report production of the device is briefly described, and predictions on its operation are made based on electric field calculations and experience with the Microstrip Gas Counter. The authors restrict themselves to the application in High Energy Physics. (author). 10 refs.; 9 figs

  2. Mariana Trench Bathymetric Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) created a bathymetric digital elevation model (DEM) for the Mariana Trench and adjacent seafloor in the Western...

  3. Diode having trenches in a semiconductor region

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2016-03-22

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  4. Fire hazard analysis of the radioactive mixed waste trenchs

    International Nuclear Information System (INIS)

    McDonald, K.M.

    1995-01-01

    This Fire Hazards Analysis (FHA) is intended to assess comprehensively the risk from fire associated with the disposal of low level radioactive mixed waste in trenches within the lined landfills, provided by Project W-025, designated Trench 31 and 34 of the Burial Ground 218-W-5. Elements within the FHA make recommendations for minimizing risk to workers, the public, and the environment from fire during the course of the operation's activity. Transient flammables and combustibles present that support the operation's activity are considered and included in the analysis. The graded FHA contains the following elements: description of construction, protection of essential safety class equipment, fire protection features, description of fire hazards, life safety considerations, critical process equipment, high value property, damage potential--maximum credible fire loss (MCFL) and maximum possible fire loss (MPFL), fire department/brigade response, recovery potential, potential for a toxic, biological and/or radiation incident due to a fire, emergency planning, security considerations related to fire protection, natural hazards (earthquake, flood, wind) impact on fire safety, and exposure fire potential, including the potential for fire spread between fire areas. Recommendations for limiting risk are made in the text of this report and printed in bold type. All recommendations are repeated in a list in Section 18.0

  5. Effectiveness of a ground-surface polymer membrane covering as a method for limiting infiltration into burial trenches at Maxey Flats, Kentucky

    International Nuclear Information System (INIS)

    Lyverse, M.A.

    1987-01-01

    The Maxey Flats Disposal Site (MFDS) was operated as a shallow land burial site for low-level radioactive wastes for a period of 14 years (1963-1977). In 1977, radionuclides were found to be migrating from a closed disposal trench into an adjacent newly constructed trench. This discovery prompted closure of the site. Over time, deterioration of the shale and clay cover on the trenches had resulted from subsidence due to the collapse of buried metallic containers and the decomposition of various organic wastes within the trenches. This subsidence increased infiltration of water into the trenches as surface water was retained over the waste in potholes and small ponds. Although infiltration rates to the waste increased, seepage rates of leachate out of the bottom and sides of the trenches were very slow due to the low permeability of surrounding native shale soils (average hydraulic conductivity 4 x 10 -3 ft/day). In 1981, a program was implemented to correct deficiencies and stabilize the site. This paper describes the effectiveness of one design method where a low permeable (hydraulic conductivity -9 ft/sec) polyvinylchloride membrane cover (PVC) 0.015 to 0.020 inches thick was placed over the burial trenches. The covers were installed over trenches beginning in the fall of 1981. Each trench is equipped with several sumps for the collection and removal of leachate. Water-level data were collected on sumps from five trenches during the study period May 1978 to October 1984, which spanned a period prior to and after installation of the PVC cover. 3 references, 4 figures, 1 table

  6. Groundwater monitoring plan for the 300 Area process trenches

    Energy Technology Data Exchange (ETDEWEB)

    Lindberg, J.W.; Chou, C.J.; Johnson, V.G.

    1995-05-23

    This document describes the groundwater monitoring program for the Hanford Site 300 Area Process Trenches (300 APT). The 300 APT are a Resource Conservation and Recovery Act of 1976 (RCRA) regulated unit. The 300 APT are included in the Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste, Permit No. WA890008967, and are subject to final-status requirements for groundwater monitoring. This document describes a compliance monitoring program for groundwater in the uppermost aquifer system at the 300 APT. This plan describes the 300 APT monitoring network, constituent list, sampling schedule, statistical methods, and sampling and analysis protocols that will be employed for the 300 APT. This plan will be used to meet groundwater monitoring requirements from the time the 300 APT becomes part of the Permit and through the postclosure care period until certification of final closure.

  7. Interim oceanographic description of the North-East Atlantic site for the disposal of low-level radioactive waste

    International Nuclear Information System (INIS)

    Gurbutt, P.A.; Dickson, R.R.

    1983-01-01

    Within the terms of the Surveillance Mechanism for Sea Dumping of Radioactive Wastes, NEA is requested to assess the suitability of dumping sites proposed by Participating countries and to keep under review those previously thought suitable. The aim of this volume is to provide a further interim description of the North-East Atlantic dumpsite itself. Quantities of known wastes dumpings are summarized. A review of the available data on sediment distribution in the area is presented. The flow field at the site is described so that an experiment to determine the influence on the deep flow of large scale topographic features at the dumpsite. The tide gauge results are briefly presented. The state of knowledge of the hydrographic and chemical conditions prior to 1977 is reviewed; recent results are added. The results of the radioactivity determination in the surface layer (3cm thick) of box cored sediments and the vertical radioactivity profiles are presented in tables. Some results on adsorption and geochemical partitioning of long-lived radionuclides on dumpsite sediments are briefly reviewed. Biological studies have been undertaken: concentration of radionuclides in biological materials, radiation effects on the dumpsite fauna. A dose-limit (critical group) calculation model is presented. Collective dose commitment and mass transfer are briefly discussed. The concentration of radionuclides in sediments and some organisms of the Bay of Biscay has been evaluated. Some isopycnal data for the eastern Atlantic, windstress and stratification are briefly mentioned

  8. Trench angle: a key design factor for a deep trench superjunction MOSFET

    International Nuclear Information System (INIS)

    Kang, Hyemin; Lee, Jaegil; Lee, Kwangwon; Choi, Youngchul

    2015-01-01

    Why is the development of a deep trench superjunction (SJ) MOSFET above 600 V and under 8.0 mohm · cm 2 difficult? A deep trench SJ MOSFET is expected to have a low turn-on resistance because the post thermal process after the epitaxial process, which is normally used in a multi-step epitaxy structure, is unnecessary. When designing a deep trench SJ MOSFET, the trench angle is the most important factor because this determines the breakdown voltage (BV) and BV variations. In this paper, we investigated how the trench angle affects the BV and BV window as a condition of the possible thermal process. By employing a physical concept, ΔCharge, we explained why the maximum BV is decreased and the BV window is increased as the trench angle decreases. Also, we systematically scrutinized the transition of the vertical electric field by varying the trench angle. Furthermore, in a real case, the principle of the trench angle which contributes to the deviation of the charge imbalance and specific resistance of SJ is described. Finally, we discuss the challenge of SJ MOSFET development in the industry. (paper)

  9. Revised ground-water monitoring compliance plan for the 300 area process trenches

    Energy Technology Data Exchange (ETDEWEB)

    Schalla, R.; Aaberg, R.L.; Bates, D.J.; Carlile, J.V.M.; Freshley, M.D.; Liikala, T.L.; Mitchell, P.J.; Olsen, K.B.; Rieger, J.T.

    1988-09-01

    This document contains ground-water monitoring plans for process-water disposal trenches located on the Hanford Site. These trenches, designated the 300 Area Process Trenches, have been used since 1973 for disposal of water that contains small quantities of both chemicals and radionuclides. The ground-water monitoring plans contained herein represent revision and expansion of an effort initiated in June 1985. At that time, a facility-specific monitoring program was implemented at the 300 Area Process Trenches as part of a regulatory compliance effort for hazardous chemicals being conducted on the Hanford Site. This monitoring program was based on the ground-water monitoring requirements for interim-status facilities, which are those facilities that do not yet have final permits, but are authorized to continue interim operations while engaged in the permitting process. The applicable monitoring requirements are described in the Resource Conservation and Recovery Act (RCRA), 40 CFR 265.90 of the federal regulations, and in WAC 173-303-400 of Washington State's regulations (Washington State Department of Ecology 1986). The program implemented for the process trenches was designed to be an alternate program, which is required instead of the standard detection program when a facility is known or suspected to have contaminated the ground water in the uppermost aquifer. The plans for the program, contained in a document prepared by the US Department of Energy (USDOE) in 1985, called for monthly sampling of 14 of the 37 existing monitoring wells at the 300 Area plus the installation and sampling of 2 new wells. 27 refs., 25 figs., 15 tabs.

  10. 'Dodo-Goldilocks' Trench Dug by Phoenix

    Science.gov (United States)

    2008-01-01

    This color image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on the 19th day of the mission, or Sol 19 (June 13, 2008), after the May 25, 2008, landing. This image shows one trench informally called 'Dodo-Goldilocks' after two digs (dug on Sol 18, or June 12, 2008) by Phoenix's Robotic Arm. The trench is 22 centimeters (8.7 inches) wide and 35 centimeters (13.8 inches) long. At its deepest point, the trench is 7 to 8 centimeters (2.7 to 3 inches) deep. White material, possibly ice, is located only at the upper portion of the trench, indicating that it is not continuous throughout the excavated site. According to scientists, the trench might be exposing a ledge, or only a portion of a slab, of the white material. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  11. 'Dodo-Goldilocks' Trench Elevation Map

    Science.gov (United States)

    2008-01-01

    This color-coded elevation map shows the 'Dodo-Goldilocks' trench dug by the Robotic Arm on NASA's Phoenix Mars Lander. The trench, originally two separate trenches nicknamed 'Dodo' (left) and 'Goldilocks' (right), became one after further digging on the 18th Martian day, or Sol 18, of the mission (June 12, 2008). The trench is 7 to 8 centimeters (2.7 to 3 inches) at its deepest (blue). Because the terrain itself is inclined at a 14-degree angle, the highest areas (pink) are about 20 centimeters (7.8 inches) above the lowest areas. The trench is 22 centimeters (8.7 inches) wide and 35 centimeters (13.8 inches) long. Its deepest portion is closest to the lander. This picture was taken by Phoenix's Surface Stereo Imager on Sol 19 (June 13, 2008). The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. Disposal configuration options for future uses of greater confinement disposal at the Nevada Test Site

    International Nuclear Information System (INIS)

    Price, L.

    1994-09-01

    The US Department of Energy (DOE) is responsible for disposing of a variety of radioactive and mixed wastes, some of which are considered special-case waste because they do not currently have a clear disposal option. The DOE's Nevada Field Office contracted with Sandia National Laboratories to investigate the possibility of disposing of some of this special-case waste at the Nevada Test Site (NTS). As part of this investigation, a review of a near-surface and subsurface disposal options that was performed to develop alternative disposal configurations for special-case waste disposal at the NTS. The criteria for the review included (1) configurations appropriate for disposal at the NTS; (2) configurations for disposal of waste at least 100 ft below the ground surface; (3) configurations for which equipment and technology currently exist; and (4) configurations that meet the special requirements imposed by the nature of special-case waste. Four options for subsurface disposal of special-case waste are proposed: mined consolidated rock, mined alluvium, deep pits or trenches, and deep boreholes. Six different methods for near-surface disposal are also presented: earth-covered tumuli, above-grade concrete structures, trenches, below-grade concrete structures, shallow boreholes, and hydrofracture. Greater confinement disposal (GCD) in boreholes at least 100 ft deep, similar to that currently practiced at the GCD facility at the Area 5 Radioactive Waste Management Site at the NTS, was retained as the option that met the criteria for the review. Four borehole disposal configurations are proposed with engineered barriers that range from the native alluvium to a combination of gravel and concrete. The configurations identified will be used for system analysis that will be performed to determine the disposal configurations and wastes that may be suitable candidates for disposal of special-case wastes at the NTS

  13. Greater-confinement disposal

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Schubert, J.P.

    1989-01-01

    Greater-confinement disposal (GCD) is a general term for low-level waste (LLW) disposal technologies that employ natural and/or engineered barriers and provide a degree of confinement greater than that of shallow-land burial (SLB) but possibly less than that of a geologic repository. Thus GCD is associated with lower risk/hazard ratios than SLB. Although any number of disposal technologies might satisfy the definition of GCD, eight have been selected for consideration in this discussion. These technologies include: (1) earth-covered tumuli, (2) concrete structures, both above and below grade, (3) deep trenches, (4) augered shafts, (5) rock cavities, (6) abandoned mines, (7) high-integrity containers, and (8) hydrofracture. Each of these technologies employ several operations that are mature,however, some are at more advanced stages of development and demonstration than others. Each is defined and further described by information on design, advantages and disadvantages, special equipment requirements, and characteristic operations such as construction, waste emplacement, and closure

  14. Grout testing and characterization for shallow-land burial trenches at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Tallent, O.K.; Sams, T.L.; Tamura, T.; Godsey, T.T.; Francis, C.L.; McDaniel, E.W.

    1986-10-01

    An investigation was conducted to develop grout formulations suitable for in situ stabilization of low-level and transuranic (TRU) waste in shallow-land burial trenches at Idaho National Engineering Laboratory (INEL). The acceptabilities of soil, ordinary particulate, and fine particulate grouts were evaluated based on phase separation, compressive strength, freeze/thaw, penetration resistance, rheological, water permeability, column, and other tests. Soil grouts with soil-to-cement weight ratios from 0.91 to 1.60 were found to be suitable for open trench or drum disposal. Ordinary particulate grouts containing type I,II Portland cement, class C fly ash, bentonite, water, and a fluidizer were formulated to fill large voids within the soil/waste matrix of a closed shallow-land burial trench. Fine particulate grouts containing fine (mean particle size, 9.6 m) cement and water were formulated to fill smaller voids and to establish a grout-soil barrier to prevent water intrusion into the grouted waste trench. Solution, or chemical grouts, were evaluated as possible substitutes for the fine particulate grouts

  15. Trends of radioactive waste management policy and disposal of LLW/ILW in the UK

    International Nuclear Information System (INIS)

    Miyasaka, Yasuhiko

    2003-01-01

    In 1997, the UK program for the deep disposal of radioactive waste was stopped with the refusal by the Secretary of State for the Environment to allow Nuclear Industry Radioactive Waste Executive, Ltd. (Nirex) to go ahead with its plans for an underground Rock Characterization Facility (RCF) at Sellafield, seen as the precursor of an underground repository for LLW/ILW. Department of Environment, Food and Rural Affairs (DEFRA) and the Developed Administrations published a white paper 'Managing Radioactive Waste Safety' Proposal for developing a policy for managing solid radioactive waste in the UK on 12 September 2001. The paper set out five-stage program of action for reaching decisions until 2007. It suggests their view can be sought via opinion polls, the Internet, workshops, citizens, juries, consensus conferences, stakeholder, local authority and community groups and research panels. With the exception of a disposal facility associated with the operation of the Dounreay site on the north coast of Scotland, essentially all LLW in the UK is disposed of at the Drigg site, near Sellafield. The site has been in operation since 1959. Until 1988, disposals were solely in trenches, cut into the glacial tills underlying the site. In 1988, an engineered concrete vault was brought into operation and is currently in use. Drigg only has a finite capacity in the currently area and may be full by about 2050, hence new arrangements will have to examine. This report describes the trends of radioactive waste management policy and disposal of LLW/ILW in the UK. These include: NDA(Nuclear Decommissioning Authority) organization plan, Feb. 2003; Encapsulation of LLW/ILW and safe store for ILW; Summary of LLW repository at the Drigg site; Nirex concept for underground storage/disposal of LLW/ILW. This information and new approach of the safe management of radioactive waste in the UK will prove helpful to the planning for future management and disposal of LLW in Japan. (author)

  16. Radiological performance assessment for the E-Area Vaults Disposal Facility

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.R.; Hunt, P.D. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1994-04-15

    The E-Area Vaults (EAVs) located on a 200 acre site immediately north of the current LLW burial site at Savannah River Site will provide a new disposal and storage site for solid, low-level, non-hazardous radioactive waste. The EAV Disposal Facility will contain several large concrete vaults divided into cells. Three types of structures will house four designated waste types. The Intermediate Level Non-Tritium Vaults will receive waste radiating greater than 200 mR/h at 5 cm from the outer disposal container. The Intermediate Level Tritium Vaults will receive waste with at least 10 Ci of tritium per package. These two vaults share a similar design, are adjacent, share waste handling equipment, and will be closed as one facility. The second type of structure is the Low Activity Waste Vaults which will receive waste radiating less than 200 mR/h at 5 cm from the outer disposal container and containing less than 10 Ci of tritium per package. The third facility, the Long Lived Waste Storage Building, provides covered, long term storage for waste containing long lived isotopes. Two additional types of disposal are proposed: (1) trench disposal of suspect soil, (2) naval reactor component disposal. To evaluate the long-term performance of the EAVs, site-specific conceptual models were developed to consider: (1) exposure pathways and scenarios of potential importance; (2) potential releases from the facility to the environment; (3) effects of degradation of engineered features; (4) transport in the environment; (5) potential doses received from radionuclides of interest in each vault type.

  17. Radiological performance assessment for the E-Area Vaults Disposal Facility

    International Nuclear Information System (INIS)

    Cook, J.R.; Hunt, P.D.

    1994-01-01

    The E-Area Vaults (EAVs) located on a 200 acre site immediately north of the current LLW burial site at Savannah River Site will provide a new disposal and storage site for solid, low-level, non-hazardous radioactive waste. The EAV Disposal Facility will contain several large concrete vaults divided into cells. Three types of structures will house four designated waste types. The Intermediate Level Non-Tritium Vaults will receive waste radiating greater than 200 mR/h at 5 cm from the outer disposal container. The Intermediate Level Tritium Vaults will receive waste with at least 10 Ci of tritium per package. These two vaults share a similar design, are adjacent, share waste handling equipment, and will be closed as one facility. The second type of structure is the Low Activity Waste Vaults which will receive waste radiating less than 200 mR/h at 5 cm from the outer disposal container and containing less than 10 Ci of tritium per package. The third facility, the Long Lived Waste Storage Building, provides covered, long term storage for waste containing long lived isotopes. Two additional types of disposal are proposed: (1) trench disposal of suspect soil, (2) naval reactor component disposal. To evaluate the long-term performance of the EAVs, site-specific conceptual models were developed to consider: (1) exposure pathways and scenarios of potential importance; (2) potential releases from the facility to the environment; (3) effects of degradation of engineered features; (4) transport in the environment; (5) potential doses received from radionuclides of interest in each vault type

  18. A dual model approach to ground water recovery trench design

    International Nuclear Information System (INIS)

    Clodfelter, C.L.; Crouch, M.S.

    1992-01-01

    The design of trenches for contaminated ground water recovery must consider several variables. This paper presents a dual-model approach for effectively recovering contaminated ground water migrating toward a trench by advection. The approach involves an analytical model to determine the vertical influence of the trench and a numerical flow model to determine the capture zone within the trench and the surrounding aquifer. The analytical model is utilized by varying trench dimensions and head values to design a trench which meets the remediation criteria. The numerical flow model is utilized to select the type of backfill and location of sumps within the trench. The dual-model approach can be used to design a recovery trench which effectively captures advective migration of contaminants in the vertical and horizontal planes

  19. 300 Area Process Trenches Closure Plan

    International Nuclear Information System (INIS)

    Luke, S.N.

    1994-01-01

    Since 1987, Westinghouse Hanford Company has been a major contractor to the US Department of Energy, Richland Operations Office and has served as co-operator of the 300 Area Process Trenches, the waste management unit addressed in this closure plan. For the purposes of the Resource Conservation and Recovery Act, Westinghouse Hanford Company is identified as ''co-operator.'' The 300 Area Process Trenches Closure Plan (Revision 0) consists of a Resource Conservation and Recovery Act Part A Dangerous Waste Permit Application, Form 3 and a Resource Conservation and Recovery Act Closure Plan. An explanation of the Part A Permit Application, Form 3 submitted with this document is provided at the beginning of the Part A Section. The closure plan consists of nine chapters and six appendices. The 300 Area Process Trenches received dangerous waste discharges from research and development laboratories in the 300 Area and from fuels fabrication processes. This waste consisted of state-only toxic (WT02), corrosive (D002), chromium (D007), spent halogenated solvents (F001, F002, and F003), and spent nonhalogented solvent (F005). Accurate records are unavailable concerning the amount of dangerous waste discharged to the trenches. The estimated annual quantity of waste (item IV.B) reflects the total quantity of both regulated and nonregulated waste water that was discharged to the unit

  20. Color View 'Dodo' and 'Baby Bear' Trenches

    Science.gov (United States)

    2008-01-01

    NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 14 (June 8, 2008), the 14th Martian day after landing. It shows two trenches dug by Phoenix's Robotic Arm. Soil from the right trench, informally called 'Baby Bear,' was delivered to Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA, on Sol 12 (June 6). The following several sols included repeated attempts to shake the screen over TEGA's oven number 4 to get fine soil particles through the screen and into the oven for analysis. The trench on the left is informally called 'Dodo' and was dug as a test. Each of the trenches is about 9 centimeters (3 inches) wide. This view is presented in approximately true color by combining separate exposures taken through different filters of the Surface Stereo Imager. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  1. A case of bilateral trench foot.

    Science.gov (United States)

    Parsons, S L; Leach, I H; Charnley, R M

    1993-12-01

    A case of severe bilateral trench foot is presented in a patient who lived rough for 3 weeks without removing his boots. Non-operative management yielded no clinical improvement and bilateral below-knee amputation was necessary. Histology revealed subcutaneous and muscle necrosis with secondary arterial thrombosis.

  2. Trench capacitor and method for producing the same

    NARCIS (Netherlands)

    2009-01-01

    A method of fabricating a trench capacitor, and a trench capacitor fabricated thereby, are disclosed. The method involves the use of a vacuum impregnation process for a sol-gel film, to facilitate effective deposition of high- permittivity materials within a trench in a semiconductor substrate, to

  3. Trench motion-controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake

    Science.gov (United States)

    Yang, Ting; Gurnis, Michael; Zhan, Zhongwen

    2017-07-01

    The subducted old and cold Pacific Plate beneath the young Philippine Sea Plate at the Izu-Bonin trench over the Cenozoic hosts regional deep earthquakes. We investigate slab morphology and stress regimes under different trench motion histories with mantle convection models. Viscosity, temperature, and deviatoric stress are inherently heterogeneous within the slab, which we link to the occurrence of isolated earthquakes. Models expand on previous suggestions that observed slab morphology variations along the Izu-Bonin subduction zone, exhibited as shallow slab dip angles in the north and steeper dip angles in the south, are mainly due to variations in the rate of trench retreat from the north (where it is fast) to the south (where it is slow). Geodynamic models consistent with the regional plate tectonics, including oceanic plate age, plate convergence rate, and trench motion history, reproduce the seismologically observed principal stress direction and slab morphology. We suggest that the isolated 680 km deep, 30 May 2015 Mw 7.9 Bonin Islands earthquake, which lies east of the well-defined Benioff zone and has its principal compressional stress direction oriented toward the tip of the previously defined Benioff zone, can be explained by Pacific slab buckling in response to the slow trench retreat.

  4. Changes in soil hydraulic properties caused by construction of a simulated waste trench at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Shakofsky, S.

    1995-03-01

    In order to assess the effect of filled waste disposal trenches on transport-governing soil properties, comparisons were made between profiles of undisturbed soil and disturbed soil in a simulated waste trench. The changes in soil properties induced by the construction of a simulated waste trench were measured near the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory (INEL) in the semiarid southeast region of Idaho. The soil samples were collected, using a hydraulically-driven sampler to minimize sample disruption, from both a simulated waste trench and an undisturbed area nearby. Results show that the undisturbed profile has distinct layers whose properties differ significantly, whereas the soil profile in the simulated waste trench is, by comparison, homogeneous. Porosity was increased in the disturbed cores, and, correspondingly, saturated hydraulic conductivities were on average three times higher. With higher soil-moisture contents (greater than 0.32), unsaturated hydraulic conductivities for the undisturbed cores were typically greater than those for the disturbed cores. With lower moisture contents, most of the disturbed cores had greater hydraulic conductivities. The observed differences in hydraulic conductivities are interpreted and discussed as changes in the soil pore geometry

  5. Co-disposal of mixed waste materials

    International Nuclear Information System (INIS)

    Phillips, S.J.; Alexander, R.G.; Crane, P.J.; England, J.L.; Kemp, C.J.; Stewart, W.E.

    1993-08-01

    Co-disposal of process waste streams with hazardous and radioactive materials in landfills results in large, use-efficiencies waste minimization and considerable cost savings. Wasterock, produced from nuclear and chemical process waste streams, is segregated, treated, tested to ensure regulatory compliance, and then is placed in mixed waste landfills, burial trenches, or existing environmental restoration sites. Large geotechnical unit operations are used to pretreat, stabilize, transport, and emplace wasterock into landfill or equivalent subsurface structures. Prototype system components currently are being developed for demonstration of co-disposal

  6. Concept and Idea-Project for Yugoslav Low and Intermediate level Radioactive Waste Materials Final Disposal Facility

    International Nuclear Information System (INIS)

    Peric, A.

    1997-01-01

    Encapsulation of rad waste in a mortar matrix and displacement of such solidified waste forms into the shallow land burial system, engineered trench system type is suggested concept for the final disposal of low and intermediate level rad waste. The mortar-rad waste mixtures are cured in containers of either concrete or metal for an appropriate period of time, after which solidified rad waste-mortar monoliths are then placed in the engineered trench system, parallelepiped honeycomb structure. Trench consists of vertical barrier-walls, bottom barrier-floors, surface barrier-caps and permeable-reactive walls. Surroundings of the trench consists of buffer barrier materials, mainly clay. Each segment of the trench is equipped with the independent drainage system, as a part of the main drainage. Encapsulation of each filled trench honeycomb segment is performed with concrete cap. Completed trench is covered with impermeable plastic foil and soil leaner, preferably clay. Paper presents an overview of the final disposal facility engineered trench system type. Advantages in comparison with other types of final disposal system are given. (author)

  7. Disposal safety

    International Nuclear Information System (INIS)

    Bartlett, J.W.

    International consensus does not seem to be necessary or appropriate for many of the issues concerned with the safety of nuclear waste disposal. International interaction on the technical aspects of disposal has been extensive, and this interaction has contributed greatly to development of a consensus technical infrastructure for disposal. This infrastructure provides a common and firm base for regulatory, political, and social actions in each nation

  8. Waste disposal

    International Nuclear Information System (INIS)

    Neerdael, B.; Marivoet, J.; Put, M.; Verstricht, J.; Van Iseghem, P.; Buyens, M.

    1998-01-01

    The primary mission of the Waste Disposal programme at the Belgian Nuclear Research Centre SCK/CEN is to propose, develop, and assess solutions for the safe disposal of radioactive waste. In Belgium, deep geological burial in clay is the primary option for the disposal of High-Level Waste and spent nuclear fuel. The main achievements during 1997 in the following domains are described: performance assessment, characterization of the geosphere, characterization of the waste, migration processes, underground infrastructure

  9. Benchmarking Exercises To Validate The Updated ELLWF GoldSim Slit Trench Model

    International Nuclear Information System (INIS)

    Taylor, G. A.; Hiergesell, R. A.

    2013-01-01

    The Savannah River National Laboratory (SRNL) results of the 2008 Performance Assessment (PA) (WSRC, 2008) sensitivity/uncertainty analyses conducted for the trenches located in the EArea LowLevel Waste Facility (ELLWF) were subject to review by the United States Department of Energy (U.S. DOE) Low-Level Waste Disposal Facility Federal Review Group (LFRG) (LFRG, 2008). LFRG comments were generally approving of the use of probabilistic modeling in GoldSim to support the quantitative sensitivity analysis. A recommendation was made, however, that the probabilistic models be revised and updated to bolster their defensibility. SRS committed to addressing those comments and, in response, contracted with Neptune and Company to rewrite the three GoldSim models. The initial portion of this work, development of Slit Trench (ST), Engineered Trench (ET) and Components-in-Grout (CIG) trench GoldSim models, has been completed. The work described in this report utilizes these revised models to test and evaluate the results against the 2008 PORFLOW model results. This was accomplished by first performing a rigorous code-to-code comparison of the PORFLOW and GoldSim codes and then performing a deterministic comparison of the two-dimensional (2D) unsaturated zone and three-dimensional (3D) saturated zone PORFLOW Slit Trench models against results from the one-dimensional (1D) GoldSim Slit Trench model. The results of the code-to-code comparison indicate that when the mechanisms of radioactive decay, partitioning of contaminants between solid and fluid, implementation of specific boundary conditions and the imposition of solubility controls were all tested using identical flow fields, that GoldSim and PORFLOW produce nearly identical results. It is also noted that GoldSim has an advantage over PORFLOW in that it simulates all radionuclides simultaneously - thus avoiding a potential problem as demonstrated in the Case Study (see Section 2.6). Hence, it was concluded that the follow

  10. Benchmarking Exercises To Validate The Updated ELLWF GoldSim Slit Trench Model

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, G. A.; Hiergesell, R. A.

    2013-11-12

    The Savannah River National Laboratory (SRNL) results of the 2008 Performance Assessment (PA) (WSRC, 2008) sensitivity/uncertainty analyses conducted for the trenches located in the EArea LowLevel Waste Facility (ELLWF) were subject to review by the United States Department of Energy (U.S. DOE) Low-Level Waste Disposal Facility Federal Review Group (LFRG) (LFRG, 2008). LFRG comments were generally approving of the use of probabilistic modeling in GoldSim to support the quantitative sensitivity analysis. A recommendation was made, however, that the probabilistic models be revised and updated to bolster their defensibility. SRS committed to addressing those comments and, in response, contracted with Neptune and Company to rewrite the three GoldSim models. The initial portion of this work, development of Slit Trench (ST), Engineered Trench (ET) and Components-in-Grout (CIG) trench GoldSim models, has been completed. The work described in this report utilizes these revised models to test and evaluate the results against the 2008 PORFLOW model results. This was accomplished by first performing a rigorous code-to-code comparison of the PORFLOW and GoldSim codes and then performing a deterministic comparison of the two-dimensional (2D) unsaturated zone and three-dimensional (3D) saturated zone PORFLOW Slit Trench models against results from the one-dimensional (1D) GoldSim Slit Trench model. The results of the code-to-code comparison indicate that when the mechanisms of radioactive decay, partitioning of contaminants between solid and fluid, implementation of specific boundary conditions and the imposition of solubility controls were all tested using identical flow fields, that GoldSim and PORFLOW produce nearly identical results. It is also noted that GoldSim has an advantage over PORFLOW in that it simulates all radionuclides simultaneously - thus avoiding a potential problem as demonstrated in the Case Study (see Section 2.6). Hence, it was concluded that the follow

  11. Evaluation of isotope migration: land burial. Water chemistry at commercially operated low-level radioactive waste disposal sites. Progress report No. 6, July--September 1977. [Maxey Flats, Kentucky

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, P.; Weiss, A. J.; Francis, A. J.

    1978-04-01

    A survey of the Maxey Flats, Kentucky, low-level radioactive waste disposal site was conducted to obtain an overview of the radioactivity in the trench waters for the purpose of selecting specific trenches for comprehensive study. Water samples collected from trenches and wells were analyzed for specific conductance, pH, temperature, dissolved organic carbon, tritium, gross alpha, gross beta, and gamma radioactivities. The results indicate that there are large differences in the composition of trench waters at the site. Several trenches, that represent extreme and average values of the major parameters measured, have been tentatively selected for further study. 10 fig, 6 tables.

  12. The Evolution of Low-Level Radioactive Waste (LLW) Disposal Practices at the Savannah River Site Coupled with Vigorous Stakeholder Interaction

    International Nuclear Information System (INIS)

    Goldston, W. T.; Wilhite, E. L.; Cook, J. R.; Sauls, V. W.

    2002-01-01

    Low-level radioactive waste (LLW) disposal practices at SRS evolved from trench disposal with little long-term performance basis to disposal in robust concrete vaults, again without modeling long-term performance. Now, based on an assessment of long-term performance of various waste forms and methods of disposal, the LLW disposal program allows for a ''smorgasbord'' of various disposal techniques and waste forms, all modeled to ensure long-term performance is understood. New disposal techniques include components-in-grout, compaction/volume reduction prior to disposal, and trench disposal of extremely low activity waste. Additionally, factoring partition coefficient (Kd) measurements based on waste forms has been factored into performance models. This paper will trace the development of the different disposal methods, and the extensive public communications effort that resulted in endorsement of the changes by the SRS Citizens Advisory Board

  13. Source of high tsunamis along the southernmost Ryukyu trench inferred from tsunami stratigraphy

    Science.gov (United States)

    Ando, Masataka; Kitamura, Akihisa; Tu, Yoko; Ohashi, Yoko; Imai, Takafumi; Nakamura, Mamoru; Ikuta, Ryoya; Miyairi, Yosuke; Yokoyama, Yusuke; Shishikura, Masanobu

    2018-01-01

    Four paleotsunamis deposits are exposed in a trench on the coastal lowland north of the southern Ryukyu subduction zone trench. Radiocarbon ages on coral and bivalve shells show that the four deposits record tsunamis date from the last 2000 yrs., including a historical tsunami with a maximum run-up of 30 m in 1771, for an average recurrence interval of approximately 600 yrs. Ground fissures in a soil beneath the 1771 tsunami deposit may have been generated by stronger shaking than recorded by historical documents. The repeated occurrence of the paleotsunami deposits supports a tectonic source model on the plate boundary rather than a nontectonic source model, such as submarine landslides. Assuming a thrust model at the subduction zone, the seismic coupling ratio may be as low as 20%.

  14. Field evaluation of two shallow land burial trench cap designs for long-term stabilization and closure of waste repositories at Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Nyhan, J.; Drennon, B.; Hakonson, T.

    1989-02-01

    The results from several field experiments on methods to control soil erosion, biointrusion, and water infiltration were used to design and test a burial site cover which improves the ability of the disposal site to isolate the wastes. The performance of the improved cover design in managing water and biota at the disposal site was compared with a more conventional design widely used in the industry. The conventional trench cover design consists of 15 cm of sandy loam topsoil over 75 cm of sandy silt backfill, whereas the improved trench cover design consists of 75 cm of topsoil over a minimum of 25 cm of gravel and 90 cm of river cobble. Each plot was lined with an impermeable liner to allow for mass balance calculation of water dynamics and contains hydrologic tracer ions (iodide and bromide) to demonstrate movement of water through the various zones of the trench cap. Cesium was emplaced beneath the trench cap to indicate root penetration through the trench cap, observed by sampling plant samples collected on the plots and assaying them for cesium. The field data are summarized and discussed in terms of its usefulness for waste management decisions. 67 refs., 44 figs., 4 tabs

  15. Remedial action planning for Trench 1

    International Nuclear Information System (INIS)

    Primrose, A.; Sproles, W.; Burmeister, M.; Wagner, R.; Law, J.; Greengard, T.; Castaneda, N.

    1998-01-01

    The accelerated action to remove the depleted uranium chips and associated soils and wastes from Trench 1 at the Rocky Flats Environmental Technology Site (RFETS) will begin in June 1998. To ensure that the remedial action is conducted safely, a rigorous and disciplined planning process was followed that incorporates the principles of Integrated Safety Management and Enhanced Work Planning. Critical to the success of the planning was early involvement of project staff (salaried and hourly) and associated technical support groups and disciplines. Feedback was and will continue to be solicited, and lessons learned incorporated to ensure the safe remediation of this site

  16. Process hazards review of the 904-A trench

    International Nuclear Information System (INIS)

    Snyder, D.E.

    1988-01-01

    The 904-A trench is an enclosed underground concrete containment for high level and low level radioactive waste lines between the main Laboratory Building 773-A and waste storage and shipping Building 776-A. The waste generated in laboratories and other facilities in 773-A flows by gravity into the high level and low level drain lines, which proceed from 773-A through the 904-A trench. The trench ends at 776-2A, where the underground was handling tanks for both high level and low level liquids are located. The trench serves to contain any leaks originating in the drain lines. The trench is sloped downward toward the Building 776-2A pipe gallery. Any liquid collected from the sump can be pumped automatically to a waste tank sampled. The review of the 904-A trench system included a study of the trench and piping itself, as well as a study of the high level and low level drain lines from the laboratories to the trench. The present review emphasized on examination of the hazards involved in chemical reactions in the drain lines, misuse of the drains, and criticality. The following items were examined: Process Hazards Review of the Liquid Waste Collection System, Nuclear Criticality Review of the High Level Drain System, Improvements in the 904-A Trench System, Operating Procedures, and Unusual Incidents

  17. Evaluation of a prototype decision support system for selecting trench cap designs

    International Nuclear Information System (INIS)

    Paige, G.B.; Stone, J.J.; Lane, L.J.

    1996-01-01

    A computer-based prototype decision support system (PDSS) to assist the risk manager in selecting an appropriate trench cap design for waste disposal sites is evaluated. The selection of the open-quotes bestclose quotes design among feasible alternatives requires consideration of multiple and often conflicting objectives. The methodology used in the selection process consists of. selecting and parameterizing decision variables, using data, simulation models, or expert opinion; selecting feasible trench cap design alternatives; ordering the decision variables and ranking the design alternatives. The simulation models incorporated in the PDSS are the Hydrologic Evaluation of Landfill Performance (HELP) model which is used to simulate the trench cap water balance and the Chemicals, Runoff, and Erosion from Agricultural Management Systems (CREAMS) erosion component that is used to simulate trench cap erosion. The decision model is based on multi-objective decision theory and uses a unique approach to order the decision variables and rank the design alternatives. The PDSS is evaluated using the Hill Air Force Base landfill cover demonstration project. The water balance and surface erosion of four alternative landfill cover designs were monitored for a 4-yr period. Two of the cover designs were used to calibrate and test the simulation models. The results of the PDSS, using both data from all four designs and long-term simulations from two of the designs, illustrate the relative advantages of each of the cover designs and which cover is the open-quotes bestclose quotes alternative for a given set of criteria and a particular importance order of those decision criteria. 22 refs., 6 figs., 4 tabs

  18. Burial trench dynamic compaction demonstration at a humid site

    International Nuclear Information System (INIS)

    Spalding, B.P.

    1985-01-01

    This task has the objective of determining the degree of consolidation which can be achieved by dynamic compaction of a closed burial trench within a cohesive soil formation. A seven-year-old burial trench in Solid Waste Storage Area (SWSA) 6 of Oak Ridge National Laboratory (ORNL) was selected for this demonstration. This 251 m 3 trench contained about 80 Ci of mixed radionuclides, mostly 90 Sr, in 25 m 3 of waste consisting of contaminated equipment, dry solids, and demolition debris. Prior to compaction, a total trench void space of 79 m 3 was measured by pumping the trench full of water with corrections for seepage. Additional pre-compaction characterization included trench cap bulk density (1.68 kg/L), trench cap permeability (3 x 10 -7 m/s), and subsurface waste/backfill hydraulic conductivity (>0.01 m/s). Compaction was achieved by repeatedly dropping a 4-ton steel-reinforced concrete cylinder from heights of 4 to 8 m using the whipline of a 70-ton crane. The average trench ground surface was depressed 0.79 m, with some sections over 2 m, yielding a surveyed volumetric depression which totaled to 64% of the measured trench void space. Trench cap (0 to 60 cm) bulk density and permeability were not affected by compaction indicating that the consolidation was largely subsurface. Neither surface nor airborne radioactive contamination were observed during repeated monitoring during the demonstration. Dynamic compaction was shown to be an excellent and inexpensive (i.e., about $20/m 2 ) method to collapse trench void space, thereby hastening subsidence and stabilizing the land surface. 15 refs., 10 figs., 3 tabs

  19. Assessment of microbial processes on gas production at radioactive low-level waste disposal sites

    International Nuclear Information System (INIS)

    Weiss, A.J.; Tate, R.L. III; Colombo, P.

    1982-05-01

    Factors controlling gaseous emanations from low level radioactive waste disposal sites are assessed. Importance of gaseous fluxes of methane, carbon dioxide, and possible hydrogen from the site, stems from the inclusion of tritium and/or carbon-14 into the elemental composition of these compounds. In that the primary source of these gases is the biodegradation of organic components of the waste material, primary emphasis of the study involved an examination of the biochemical pathways producing methane, carbon dioxide, and hydrogen, and the environmental parameters controlling the activity of the microbial community involved. Initial examination of the data indicates that the ecosystem is anaerobic. As the result of the complexity of the pathway leading to methane production, factors such as substrate availability, which limit the initial reaction in the sequence, greatly affect the overall rate of methane evolution. Biochemical transformations of methane, hydrogen and carbon dioxide as they pass through the soil profile above the trench are discussed. Results of gas studies performed at three commercial low level radioactive waste disposal sites are reviewed. Methods used to obtain trench and soil gas samples are discussed. Estimates of rates of gas production and amounts released into the atmosphere (by the GASFLOW model) are evaluated. Tritium and carbon-14 gaseous compounds have been measured in these studies; tritiated methane is the major radionuclide species in all disposal trenches studied. The concentration of methane in a typical trench increases with the age of the trench, whereas the concentration of carbon dioxide is similar in all trenches

  20. THE BC CRIBS & TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT ONE STEP FORWARD IN HANFORDS CLEANUP PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    BENECKE, MN.W.

    2006-02-22

    A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50 acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and cribs. The data were compiled to form a three-dimensional representation of low resistivity values. Low resistivity, or high conductivity, is indicative of high ionic strength soil and porewater resulting from the migration of nitrate and other inorganic constituents through the vadose zone. High spatial density soil data from a single borehole, that included coincident nitrate concentrations, electrical conductivity, and Tc-99, were used to transform the electrical resistivity data into a nitrate plume. The plume was shown to extend laterally beyond the original boundaries of the waste site and, in one area, to depths that exceeded the characterization strategy. It is

  1. THE BC CRIBS and TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT: ONE STEP FORWARD IN HANFORD'S CLEANUP PROCESS

    International Nuclear Information System (INIS)

    BENECKE, M.W.

    2005-01-01

    A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50-acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and cribs. The data were compiled to form a three-dimensional representation of low resistivity values. Low resistivity, or high conductivity, is indicative of high ionic strength soil and porewater resulting from the migration of nitrate and other inorganic constituents through the vadose zone. High spatial density soil data from a single borehole, that included coincident nitrate concentrations, electrical conductivity. and Tc-99, were used to transform the electrical resistivity data into a nitrate plume. The plume was shown to extend laterally beyond the original boundaries of the waste site and, in one area, to depths that exceeded the characterization strategy

  2. Review of corrective measures to stabilize subsidence in shallow-land burial trenches

    International Nuclear Information System (INIS)

    Roop, R.D.; Staub, W.P.; Hunsaker, D.B. Jr.; Ketelle, R.H.; Lee, D.W.; Pin, F.G.; Witten, A.J.

    1983-05-01

    Shallow-land burial of low-level radioactive wastes is frequently followed by subsidence: the slumping, cave-in, or depression of the trench's surface. This report describes and evaluates the measures proposed for correcting subsidence, including roller compaction, grouting, explosives, surcharging, falling mass, pile driving, in situ incineration, and accelerated decomposition. Subsidence, which has occurred at all the major waste disposal sites, has two major causes: filling of packing voids (spaces between waste containers) and filling of interior voids (spaces within containers). Four additional mechanisms also contribute to subsidence: collapse of trench walls, chemical and biological degradation, soil consolidation, and shrink and swell phenomena. Corrective measures for subsidence are evaluated on three criteria: effectiveness, applicability, and cost. The evaluation indicates that one method, falling mass, is considered to be effective, widely applicable, and relatively low in cost, suggesting that this would be the most generally useful technique and would yield the greatest payoff from further development and field trials. There are many uncertainties associated with the cost and effectiveness of corrective measures which can best be resolved by experimental field demonstrations. Site-specific analyses for each disposal area are recommended, to determine which techniques are appropriate and to evaluate the overall desirability of applying corrective measures

  3. Interpretation of vadose zone monitoring system data near Engineered Trench 1

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Whiteside, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-12

    The E-Area Vadose Zone Monitoring System (VZMS) includes lysimeter sampling points at many locations alongside and angling beneath the Engineered Trench #1 (ET1) disposal unit footprint. The sampling points for ET1 were selected for this study because collectively they showed consistently higher tritium (H-3) concentrations than lysimeters associated with other trench units. The VZMS tritium dataset for ET1 from 2001 through 2015 comprises concentrations at or near background levels at approximately half of locations through time, concentrations up to about 600 pCi/mL at a few locations, and concentrations at two locations that have exceeded 1000 pCi/mL. The highest three values through 2015 were 6472 pCi/mL in 2014 and 4533 pCi/mL in 2013 at location VL-17, and 3152 pCi/mL in 2007 at location VL-15. As a point of reference, the drinking water standard for tritium and a DOE Order 435.1 performance objective in the saturated zone at the distant 100-meter facility perimeter is 20 pCi/mL. The purpose of this study is to assess whether these elevated concentrations are indicative of a general trend that could challenge 2008 E-Area Performance Assessment (PA) conclusions, or are isolated perturbations that when considered in the context of an entire disposal unit would support PA conclusions.

  4. Scattering and extinction from high-aspect-ratio trenches

    DEFF Research Database (Denmark)

    Roberts, Alexander Sylvester; Søndergaard, Thomas; Chirumamilla, Manohar

    2015-01-01

    We construct a semi-analytical model describing the scattering, extinction and absorption properties of a high aspect-ratio trench in a metallic film. We find that these trenches act as highly efficient scatterers of free waves. In the perfect conductor limit, which for many metals is approached...

  5. Slurry walls and slurry trenches - construction quality control

    International Nuclear Information System (INIS)

    Poletto, R.J.; Good, D.R.

    1997-01-01

    Slurry (panel) walls and slurry trenches have become conventional methods for construction of deep underground structures, interceptor trenches and hydraulic (cutoff) barriers. More recently polymers mixed with water are used to stabilize the excavation instead of bentonite slurry. Slurry walls are typically excavated in short panel segments, 2 to 7 m (7 to 23 ft) long, and backfilled with structural materials; whereas slurry trenches are fairly continuous excavations with concurrent backfilling of blended soils, or cement-bentonite mixtures. Slurry trench techniques have also been used to construct interceptor trenches. Currently no national standards exist for the design and/or construction of slurry walls/trenches. Government agencies, private consultants, contractors and trade groups have published specifications for construction of slurry walls/trenches. These specifications vary in complexity and quality of standards. Some place excessive emphasis on the preparation and control of bentonite or polymer slurry used for excavation, with insufficient emphasis placed on quality control of bottom cleaning, tremie concrete, backfill placement or requirements for the finished product. This has led to numerous quality problems, particularly with regard to identification of key depths, bottom sediments and proper backfill placement. This paper will discuss the inspection of slurry wall/trench construction process, identifying those areas which require special scrutiny. New approaches to inspection of slurry stabilized excavations are discussed

  6. Vertically distinct microbial communities in the Mariana and Kermadec trenches

    Science.gov (United States)

    Donaldson, Sierra; Osuntokun, Oladayo; Xia, Qing; Nelson, Alex; Blanton, Jessica; Allen, Eric E.; Church, Matthew J.; Bartlett, Douglas H.

    2018-01-01

    Hadal trenches, oceanic locations deeper than 6,000 m, are thought to have distinct microbial communities compared to those at shallower depths due to high hydrostatic pressures, topographical funneling of organic matter, and biogeographical isolation. Here we evaluate the hypothesis that hadal trenches contain unique microbial biodiversity through analyses of the communities present in the bottom waters of the Kermadec and Mariana trenches. Estimates of microbial protein production indicate active populations under in situ hydrostatic pressures and increasing adaptation to pressure with depth. Depth, trench of collection, and size fraction are important drivers of microbial community structure. Many putative hadal bathytypes, such as members related to the Marinimicrobia, Rhodobacteraceae, Rhodospirilliceae, and Aquibacter, are similar to members identified in other trenches. Most of the differences between the two trench microbiomes consists of taxa belonging to the Gammaproteobacteria whose distributions extend throughout the water column. Growth and survival estimates of representative isolates of these taxa under deep-sea conditions suggest that some members may descend from shallower depths and exist as a potentially inactive fraction of the hadal zone. We conclude that the distinct pelagic communities residing in these two trenches, and perhaps by extension other trenches, reflect both cosmopolitan hadal bathytypes and ubiquitous genera found throughout the water column. PMID:29621268

  7. Radioactive waste disposal

    International Nuclear Information System (INIS)

    Cluchet, J.; Roger, B.

    1975-10-01

    After mentioning the importance of the problem of the disposal of wastes produced in the electro-nuclear industry, a short reminder on a few laws of radioactivity (nature and energy of radiations, half-life) and on some basic dosimetry is given. The conditioning and storage procedures are then indicated for solid wastes. The more active fractions of liquid wastes are incorporated into blocks of glass, whereas the less active are first concentrated by chemical treatments or by evaporation. The concentrates are then embedded into concrete, asphalt or resins. Storage is done according to the nature of each type of wastes: on a hard-surfaced area or inside concrete-lined trenches for the lowest radioactivity, in pits for the others. Transuranium elements with very long half-lives are buried in very deep natural cavities which can shelter them for centuries. From the investigations conducted so far and from the experience already gained, it can be concluded that safe solutions are within our reach [fr

  8. Trial coring in LLRW trenches at Chalk River

    International Nuclear Information System (INIS)

    Donders, R.E.; Killey, R.W.D.; Franklin, K.J.; Strobel, G.S.

    1996-11-01

    As part of a program to better characterize the low-hazard radioactive waste managed by AECL at Chalk River Laboratories, coring techniques in waste trenches are being assessed. Trial coring has demonstrated that sampling in waste regions is possible, and that boreholes can be placed through the waste trenches. Such coring provides a valuable information-gathering technique. Information available from trench coring includes: trench cover depth, waste region depth, waste compaction level, and detailed stratigraphic data; soil moisture content and facility drainage performance; borehole gamma logs that indicate radiation levels in the region of the borehole; biochemical conditions in the waste regions, vadose zone, and groundwater; site specific information relevant to contaminant migration modelling or remedial actions; information on contaminant releases and inventories. Boreholes through the trenches can also provide a means for early detection of potential contaminant releases. (author). 4 refs., 4 tabs., 4 figs

  9. Waste disposal

    International Nuclear Information System (INIS)

    2005-01-01

    Radioactive waste, as a unavoidable remnant from the use of radioactive substances and nuclear technology. It is potentially hazardous to health and must therefore be managed to protect humans and the environment. The main bulk of radioactive waste must be permanently disposed in engineered repositories. Appropriate safety standards for repository design and construction are required along with the development and implementation of appropriate technologies for the design, construction, operation and closure of the waste disposal systems. As backend of the fuel cycle, resolving the issue of waste disposal is often considered as a prerequisite to the (further) development of nuclear energy programmes. Waste disposal is therefore an essential part of the waste management strategy that contributes largely to build confidence and helps decision-making when appropriately managed. The International Atomic Energy Agency provides assistance to Member States to enable safe and secure disposal of RW related to the development of national RWM strategies, including planning and long-term project management, the organisation of international peer-reviews for research and demonstration programmes, the improvement of the long-term safety of existing Near Surface Disposal facilities including capacity extension, the selection of potential candidate sites for different waste types and disposal options, the characterisation of potential host formations for waste facilities and the conduct of preliminary safety assessment, the establishment and transfer of suitable technologies for the management of RW, the development of technological solutions for some specific waste, the building of confidence through training courses, scientific visits and fellowships, the provision of training, expertise, software or hardware, and laboratory equipment, and the assessment of waste management costs and the provision of advice on cost minimisation aspects

  10. French surface disposal experience. The disposal of large waste

    International Nuclear Information System (INIS)

    Dutzer, Michel; Lecoq, Pascal; Duret, Franck; Mandoki, Robert

    2006-01-01

    delivered at the end of June 2005 and the 55 vessel heads should be disposed by 2013. The safety approach of the facility was adapted to take into account the disposal of such large waste. This methodology and the disposal technique can be generalised to receive large waste from decommissioning activities for which cutting works and conditioning in standard packages would not be relevant. For instance this option is investigated for steam generators and could be helpful to manage waste from the important decommissioning program that is starting up in France in particular for the first generation power reactors. This decommissioning program also motivated the implementation of a facility for the disposal very low level waste, in agreement with French regulation for the management of waste in nuclear facilities. It is located in Morvilliers village, close to Centre de l'Aube facility. Disposal is performed in trenches in clay that are protected from rainwater by removable roofs. Standard packages were developed even if handling techniques are more 'rustic' due to very low dose rate. First deliveries were done in October 2003. Since start up large waste, as concrete blocks or heat exchangers, have been disposed. For very heavy waste, the interest of dedicated disposal cells is investigated. (authors)

  11. Frost seen on Snow White Trench

    Science.gov (United States)

    2008-01-01

    The Surface Stereo Imager (SSI) on NASA's Phoenix Mars Lander took this shadow-enhanced false color image of the 'Snow White' trench, on the eastern end of Phoenix's digging area. The image was taken on Sol 144, or the 144th day of the mission, Oct. 20, 2008. Temperatures measured on Sol 151, the last day weather data were received, showed overnight lows of minus128 Fahrenheit (minus 89 Celsius) and day time highs in the minus 50 F (minus 46 C) range. The last communication from the spacecraft came on Nov. 2, 2008. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. Planning for greater confinement disposal

    International Nuclear Information System (INIS)

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1985-01-01

    A report that provides guidance for planning for greater-confinement disposal (GCD) of low-level radioactive waste is being prepared. The report addresses procedures for selecting a GCD technology and provides information for implementing these procedures. The focus is on GCD; planning aspects common to GCD and shallow-land burial are covered by reference. Planning procedure topics covered include regulatory requirements, waste characterization, benefit-cost-risk assessment and pathway analysis methodologies, determination of need, waste-acceptance criteria, performance objectives, and comparative assessment of attributes that support these objectives. The major technologies covered include augered shafts, deep trenches, engineered structures, hydrofracture, improved waste forms, and high-integrity containers. Descriptive information is provided, and attributes that are relevant for risk assessment and operational requirements are given. 10 refs., 3 figs., 2 tabs

  13. Waste Disposal

    International Nuclear Information System (INIS)

    Neerdael, B.; Marivoet, J.; Put, M.; B-Verstricht, J.; Van Iseghem, P.; Buyens, M.

    1998-01-01

    This contribution describes the main activities of the Waste and Disposal Department of the Belgian Nuclear Research Center SCK-CEN. Achievements in 1997 in three topical areas are reported on: performance assessments, waste forms/packages and near-and far field studies

  14. STRENGTHENING OF TRENCH COVER PLATES FOR SWITCHGEAR BUILDING

    International Nuclear Information System (INIS)

    M.S. RUBEN

    2000-01-01

    The objective of this calculation is to strengthen the existing trench cover plates of the Electrical Switchgear Building (BLDG 5010) of the Exploratory Studies Facility. A remodeling effort will change the portion of the facility that has the trenches for electrical cables to a craft/shop area. The users of the building will be using a forklift in this area (Clark CGP 30 forklift with a capacity of 3 tons). The trench covers require strengthening to support the wheel loads from the forklift. The output of this calculation will be sketches revising the floor plate details of DWG YMP-025-1-7007-ST103,2. (Details 4 and 5)

  15. First Dodo Trench with White Layer Visible in Dig Area

    Science.gov (United States)

    2008-01-01

    These color images were taken by NASA's Phoenix Mars Lander's Stereo Surface Imager on the ninth Martian day of the mission, or Sol 9 (June 3, 2008). The images of the trench shows a white layer that has been uncovered by the Robotic Arm (RA) scoop and is now visible in the wall of the trench. This trench was the first one dug by the RA to understand the Martian soil and plan the digging strategy. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. An oxide filled extended trench gate super junction MOSFET structure

    International Nuclear Information System (INIS)

    Cai-Lin, Wang; Jun, Sun

    2009-01-01

    This paper proposes an oxide filled extended trench gate super junction (SJ) MOSFET structure to meet the need of higher frequency power switches application. Compared with the conventional trench gate SJ MOSFET, new structure has the smaller input and output capacitances, and the remarkable improvements in the breakdown voltage, on-resistance and switching speed. Furthermore, the SJ in the new structure can be realized by the existing trench etching and shallow angle implantation, which offers more freedom to SJ MOSFET device design and fabrication. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  17. R/V Endeavor cruise EN-024. Seabed Disposal Program: North Atlantic study area MPG-III 35030'N 61000'W, June 30--July 11, 1978. Final report

    International Nuclear Information System (INIS)

    Heath, G.R.; Laine, E.P.

    1978-09-01

    During 7 days in the vicinity of 35 0 30'N, 61 0 00'W (Seabed Disposal Program mid-late, mid-gyre study area MPG-III) we carried out 1830 km of subbottom acoustic profiling and 2 camera lowerings, and took 7 standard piston cores, 3 large diameter piston cores, 9 large diameter gravity cores and 2 dredge hauls of surface sediment. Pore fluids were extracted from 3 gravity cores and 1 piston core and on-board physical property measurements were made on 2 large diameter piston cores and 1 large diameter gravity core. These data and samples will be used to assess the lateral homogeneity and recent geologic history of the area, as well as to compare the sorption and physical barrier properties of the sediments with deposits from the MPG I and II areas in the Pacific

  18. 300 Area Process Trenches Postclosure Plan

    International Nuclear Information System (INIS)

    Badden, J.W.

    1998-05-01

    The 300 Area Process Trenches (300 APT) certified closure under a modified closure option and in compliance with Condition II.K.3 oft he Hartford Facility Dangerous Waste Permit (Penit) (Ecology 1994). Modified closure has been determined to be the appropriate closure option for this unit due to groundwater that remains contaminated from past operations at the 300 APT. Corrective actions required for dangerous waste constituents remaining in groundwater will occur pursuant to the 300 APT Resource Conservation and Recovery Act (RCRA) Final Status Facility Ground Water Monitoring Plan, the Hanford Site Wide Dangerous Waste Permit, and in conjunction with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial actions at the 300-FF-5 Groundwater Operable Unit (OU) pursuant to the Record of Decision (ROD) (EPA 1996). This postclosure plan identifies the modified closure actions required at the unit under postclosure care. It contains a description of the unit, past closure actions, and postclosure care requirements subject to compliance under the Permit (condition II.K.3)

  19. Neglecting safety precautions may lead to trenching fatalities.

    Science.gov (United States)

    Deatherage, J Harold; Furches, Lisa K; Radcliffe, Mike; Schriver, William R; Wagner, John P

    2004-06-01

    Trench collapses ranked as the seventh leading cause of the possible twenty-nine causes of OSHA-inspected fatal construction events during the period 1991-2001. This study aims to examine why these fatalities occurred. Forty-four case files from OSHA inspections of fatal trench collapses were reviewed. Improper protection of the excavation site where work was taking place was the leading fatality cause. Several organizational or physical conditions were present at many fatal sites; the most frequent was that no training had been provided for trenching. Presence of a competent, diligent person at the site would have prohibited most fatalities. The top cited violation was lack of protection, that is, benching, shoring, sloping, trench boxes, etc. (29 CFR 1926.652 (a) (1)). Copyright 2004 Wiley-Liss, Inc.

  20. Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

    International Nuclear Information System (INIS)

    1997-02-01

    This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the CAU No. 426, which includes the Cactus Spring Waste Trenches, CAS No. RG-08-001-RG-CS. The Cactus Spring Waste Trenches are located at the Tonopah Test Range (TTR) which is part of the Nellis Air Force Range, approximately 255 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada, by air. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below the Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or without remediation), or no further action

  1. Sustainable sanitary landfills for neglected small cities in developing countries: The semi-mechanized trench method from Villanueva, Honduras

    Energy Technology Data Exchange (ETDEWEB)

    Oakley, Stewart M., E-mail: soakley@csuchico.edu [Department of Civil Engineering, Chico State University, California State University, Chico, CA 95929 (United States); Jimenez, Ramon, E-mail: rjimenez1958@yahoo.com [Public Works, Municipality of Villanueva, Cortes (Honduras)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Open dumping is the most common form of waste disposal in neglected small cities. Black-Right-Pointing-Pointer Semi-mechanized landfills can be a sustainable option for small cities. Black-Right-Pointing-Pointer We present the theory of design and operation of semi-mechanized landfills. Black-Right-Pointing-Pointer Villanueva, Honduras has operated its semi-mechanized landfill for 15 years. Black-Right-Pointing-Pointer The cost of operation is US$4.60/ton with a land requirement of 0.2m{sup 2}/person-year. - Abstract: Open dumping is the most common practice for the disposal of urban solid wastes in the least developed regions of Africa, Asia and Latin America. Sanitary landfill design and operation has traditionally focused on large cities, but cities with fewer than 50,000 in population can comprise from 6% to 45% of a given country's total population. These thousands of small cities cannot afford to operate a sanitary landfill in the way it is proposed for large cities, where heavy equipment is used to spread and compact the waste in daily cells, and then to excavate, transport and apply daily cover, and leachate is managed with collection and treatment systems. This paper presents an alternative approach for small cities, known as the semi-mechanized trench method, which was developed in Villanueva, Honduras. In the semi-mechanized trench method a hydraulic excavator is used for 1-3 days to dig a trench that will last at least a month before it is filled with waste. Trucks can easily unload their wastes into the trench, and the wastes compact naturally due to semi-aerobic biodegradation, after which the trenches are refilled and covered. The exposed surface area is minimal since only the top surface of the wastes is exposed, the remainder being covered by the sides and bottom of the trench. The surplus material from trench excavation can be valorized for use as engineering fill onsite or off. The landfill in

  2. Sustainable sanitary landfills for neglected small cities in developing countries: The semi-mechanized trench method from Villanueva, Honduras

    International Nuclear Information System (INIS)

    Oakley, Stewart M.; Jimenez, Ramón

    2012-01-01

    Highlights: ► Open dumping is the most common form of waste disposal in neglected small cities. ► Semi-mechanized landfills can be a sustainable option for small cities. ► We present the theory of design and operation of semi-mechanized landfills. ► Villanueva, Honduras has operated its semi-mechanized landfill for 15 years. ► The cost of operation is US$4.60/ton with a land requirement of 0.2m 2 /person-year. - Abstract: Open dumping is the most common practice for the disposal of urban solid wastes in the least developed regions of Africa, Asia and Latin America. Sanitary landfill design and operation has traditionally focused on large cities, but cities with fewer than 50,000 in population can comprise from 6% to 45% of a given country’s total population. These thousands of small cities cannot afford to operate a sanitary landfill in the way it is proposed for large cities, where heavy equipment is used to spread and compact the waste in daily cells, and then to excavate, transport and apply daily cover, and leachate is managed with collection and treatment systems. This paper presents an alternative approach for small cities, known as the semi-mechanized trench method, which was developed in Villanueva, Honduras. In the semi-mechanized trench method a hydraulic excavator is used for 1–3 days to dig a trench that will last at least a month before it is filled with waste. Trucks can easily unload their wastes into the trench, and the wastes compact naturally due to semi-aerobic biodegradation, after which the trenches are refilled and covered. The exposed surface area is minimal since only the top surface of the wastes is exposed, the remainder being covered by the sides and bottom of the trench. The surplus material from trench excavation can be valorized for use as engineering fill onsite or off. The landfill in Villanueva has operated for 15 years, using a total land area of approximately 11 ha for a population that grew from 23,000 to 48

  3. Waste disposal

    CERN Multimedia

    2006-01-01

    We should like to remind you that you can have all commonplace, conventional waste (combustible, inert, wood, etc.) disposed of by the TS-FM Group. Requests for the removal of such waste should be made by contacting FM Support on tel. 77777 or by e-mail (Fm.Support@cern.ch). For requests to be acted upon, the following information must be communicated to FM Support: budget code to be debited for the provision and removal of the skip / container. type of skip required (1m3, 4 m3, 7 m3, 15 m3, 20 m3, 30 m3). nature of the waste to be disposed of (bulky objects, cardboard boxes, etc.). building concerned. details of requestor (name, phone number, department, group, etc.). We should also like to inform you that the TS-FM Group can arrange for waste to be removed from work-sites for firms under contract to CERN, provided that the prior authorisation of the CERN Staff Member in charge of the contract is obtained and the relevant disposal/handling charges are paid. You are reminded that the selective sorting o...

  4. Waste disposal

    CERN Multimedia

    2006-01-01

    We should like to remind you that you can have all commonplace, conventional waste (combustible, inert, wood, etc.) disposed of by the TS-FM Group. Requests for the removal of such waste should be made by contacting FM Support on tel. 77777 or by e-mail (Fm.Support@cern.ch). For requests to be acted upon, the following information must be communicated to FM Support: budget code to be debited for the provision and removal of the skip / container; type of skip required (1m3, 4 m3, 7 m3, 15 m3, 20 m3, 30 m3); nature of the waste to be disposed of (bulky objects, cardboard boxes, etc.); building concerned; details of requestor (name, phone number, department, group, etc.). We should also like to inform you that the TS-FM Group can arrange for waste to be removed from work-sites for firms under contract to CERN, provided that the prior authorisation of the CERN Staff Member in charge of the contract is obtained and the relevant disposal/handling charges are paid. You are reminded that the selective sorting...

  5. A radiochemical study of sedimentation onto the Japan Trench floor

    International Nuclear Information System (INIS)

    Yamada, M.; Kitaoka, H.; Tsunogai, S.

    1983-01-01

    Box cores were taken from the Japan Trench (water depth, 8260 m) and two neighboring shallower stations (water depth, 2970 and 4310 m) and analyzed for uranium isotopes, thorium isotopes, 210 Pb, CaCO 3 , Fe, Mn, Al, and Cu. The 230 Th: 232 Th activity ratios in the top layer (0 to 1 cm) were 12 to 15 at the three stations, indicating no appreciable addition of 230 Th during descent through the water column below 4 km depth. There are no significant differences in the concentrations of 238 U, 232 Th, and 230 Th on a carbonate-free basis at the three stations. The 230 Th: 232 Th activity ratios of the Japan Trench sediments in the upper 30 cm are nearly constant with depth, indicating rapid sedimentation or active vertical mixing of the sediments. The mixing depth of the Japan Trench sediments is estimated to be 7 cm from the vertical distribution of excess 210 Pb. The maximum concentration of 210 Pb in the Japan Trench sediment is at 2- to 3-cm depth. The results suggest that sediment deposited on the shallower slope of the trench slides down and accumulates on the trench floor. (author)

  6. Morning Frost in Trench Dug by Phoenix, Sol 113

    Science.gov (United States)

    2008-01-01

    This image from the Surface Stereo Imager on NASA's Phoenix Mars Lander shows morning frost inside the 'Snow White' trench dug by the lander, in addition to subsurface ice exposed by use of a rasp on the floor of the trench. The camera took this image at about 9 a.m. local solar time during the 113th Martian day of the mission (Sept. 18, 2008). Bright material near and below the four-by-four set of rasp holes in the upper half of the image is water-ice exposed by rasping and scraping in the trench earlier the same morning. Other bright material especially around the edges of the trench, is frost. Earlier in the mission, when the sun stayed above the horizon all night, morning frost was not evident in the trench. This image is presented in approximately true color. The trench is 4 to 5 centimeters (about 2 inches) deep, about 23 centimeters (9 inches) wide. Phoenix landed on a Martian arctic plain on May 25, 2008. The mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  7. Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete

    International Nuclear Information System (INIS)

    Blanco, A.; Pujadas, R.; Fernández, C.; Cavalaro, S.H.P.; Aguado, A.

    2017-01-01

    Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience. [es

  8. Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete

    Directory of Open Access Journals (Sweden)

    A. Blanco

    2017-09-01

    Full Text Available Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience.

  9. Trench Safety–Using a Qualitative Approach to Understand Barriers and Develop Strategies to Improve Trenching Practices

    Science.gov (United States)

    FLYNN, MICHAEL A.; SAMPSON, JULIE M.

    2015-01-01

    Despite efforts to ensure workplace safety and health, injuries and fatalities related to trenching and excavation remain alarmingly high in the construction industry. Because properly installed trenching protective systems can potentially reduce the significant number of trenching fatalities, there is clearly a need to identify the barriers to the use of these systems and to develop strategies to ensure these systems are utilized consistently. The current study reports on the results of focus groups with construction workers and safety management personnel to better understand these barriers and to identify solutions. The results suggest several factors, from poor planning to pressures from experienced workers and supervisors, which present barriers to safe trenching practices. Based on the results, it is recommended that safety trainings incorporate unique messages for new workers, experienced workers and management in an effort to motivate each group to work safely as well as provide them with solutions to overcome the identified barriers. PMID:26550006

  10. Some interactive factors affecting trench-cover integrity on low-level waste sites

    International Nuclear Information System (INIS)

    Hakonson, T.E.; Lane, L.J.; Steger, J.G.; DePoorter, G.L.

    1982-01-01

    This paper describes important mechanisms by which radionuclide can be transported from low-level waste disposal sites into biological pathways, discuss interactions of abiotic and biotic processes, and recommends environmental characteristics that should be measured to design sites that minimize this transport. Past experience at shallow land burial sites for low-level radioactive wastes suggest that occurrences of waste exposure and radionuclide transport are often related to inadequate trench cover designs. Meeting performance standards at low-level waste sites can only be achieved by recognizing that physical, chemical, and biological processes operating on and in a trench cover profile are highly interactive. Failure to do so can lead to improper design criteria and subsequent remedial action procedures that can adversely affect site stability. Based upon field experiments and computer modeling, recommendations are made on site characteristics that require measurement in order to design systems that reduce surface runoff and erosion, manage soil moisture and biota in the cover profile to maximize evapotranspiration and minimize percolation, and place bounds on the intrusion potential of plants and animals into the waste material. Major unresolved problems include developing probabilistic approaches that include climatic variability, improved knowledge of soil-water-plant-erosion relationships, development of practical vegetation establishment and maintenance procedures, prediction and quantification of site potential and plant succession, and understanding the interaction of processes occurring on and in the cover profile with deeper subsurface processes

  11. Opening of the Gulf of Guayaquil: quantifying the motion from the trench to the Andean Cordillera

    Science.gov (United States)

    Santana, E.; Dumont, J. F.; Vilema, W.; Pedoja, K.

    2003-04-01

    The Gulf of Guayaquil is a complex pull-apart opened at the south tip of the North Andean Block. The Guayaquil-Caracas Megashear (i.e. Dolores-Guayaquil Megashear) which bounds the North Andean Block to the east crosses the Western Andean Cordillera along the Pallatanga fault, and joins southwestward the Ecuadorian trench. According to paleogeographic data the Gulf of Guayaquil began to open about 9 Ma ago, which is evidenced now by about 100 km offset of the Early Neogene Progresso and Loja basins. A lesser post orogenic offset of about 60 km is observed along the Pallatanga fault, coherent with the offset of the piedmont of the Western Andean Cordillera. The discrepancy suggests a partition of the deformation at the south tip of the North Andean Block, part of the motion being accommodated by other small faults north of the Pallatanga fault zone and resulting in a pull apart motion and subsidence of the Daule-Babahoyo basin. The main curve of the Tallara Arc described by the trend of the trench from north Peru to north Ecuador shows a significant anomaly in front of the Gulf of Guayaquil. A 60 to 70 km minimum right hand deviation of the curve is observed, displayed in three segments delimited by faults. Neotectonic studies in the Santa Clara and Puná Islands located in the Gulf of Guayaquil show a regional E-W shortening during the Pleistocene, characterised by right lateral motion along the Zambapala Cordillera in Puná. Offset of river drainage and morphostructures in South Puná gives evidence of 3 km dextral offset which post-date marine terraces with an estimated age of M.I.S. 9 or 11, giving mean offset rates of 9 mm/y or 6.8 mm/y respectively. The conclusion underlines the following points: (1) These data suggest that the offset rate inside the Gulf of Guayaquil during the Late Quaternary is lower than the mean rate observed since 9 Ma. The apparent slow down may be due to the partition of the deformation of the Gulf of Guayaquil towards the Guayas

  12. Calculations of the radiological impact of disposal of unit activity of selected radionuclides for use in waste management system studies

    International Nuclear Information System (INIS)

    Smith, G.M.

    1985-03-01

    The purpose of the work described is to provide estimates of the radiological impact following disposal of unit activity via each of several options, including shallow burial, engineered trench disposal, disposal in a geologic repository and disposal on the deep ocean bed. Results are presented for a range of important representative radionuclides. No single option is clearly the best from the radiological point of view. However, in conjunction with waste inventory data the results may be used to provide a preliminary view of the relative radiological merits of the various disposal options. (author)

  13. Response of Microbial Community Function to Fluctuating Geochemical Conditions within a Legacy Radioactive Waste Trench Environment.

    Science.gov (United States)

    Vázquez-Campos, Xabier; Kinsela, Andrew S; Bligh, Mark W; Harrison, Jennifer J; Payne, Timothy E; Waite, T David

    2017-09-01

    During the 1960s, small quantities of radioactive materials were codisposed with chemical waste at the Little Forest Legacy Site (Sydney, Australia) in 3-meter-deep, unlined trenches. Chemical and microbial analyses, including functional and taxonomic information derived from shotgun metagenomics, were collected across a 6-week period immediately after a prolonged rainfall event to assess the impact of changing water levels upon the microbial ecology and contaminant mobility. Collectively, results demonstrated that oxygen-laden rainwater rapidly altered the redox balance in the trench water, strongly impacting microbial functioning as well as the radiochemistry. Two contaminants of concern, plutonium and americium, were shown to transition from solid-iron-associated species immediately after the initial rainwater pulse to progressively more soluble moieties as reducing conditions were enhanced. Functional metagenomics revealed the potentially important role that the taxonomically diverse microbial community played in this transition. In particular, aerobes dominated in the first day, followed by an increase of facultative anaerobes/denitrifiers at day 4. Toward the mid-end of the sampling period, the functional and taxonomic profiles depicted an anaerobic community distinguished by a higher representation of dissimilatory sulfate reduction and methanogenesis pathways. Our results have important implications to similar near-surface environmental systems in which redox cycling occurs. IMPORTANCE The role of chemical and microbiological factors in mediating the biogeochemistry of groundwaters from trenches used to dispose of radioactive materials during the 1960s is examined in this study. Specifically, chemical and microbial analyses, including functional and taxonomic information derived from shotgun metagenomics, were collected across a 6-week period immediately after a prolonged rainfall event to assess how changing water levels influence microbial ecology and

  14. Alternate Methods of Effluent Disposal for On-Lot Home Sewage Systems. Special Circular 214.

    Science.gov (United States)

    Wooding, N. Henry

    This circular provides current information for homeowners who must repair or replace existing on-lot sewage disposal systems. Several alternatives such as elevated sand mounds, sand-lined beds and trenches and oversized absorption areas are discussed. Site characteristics and preparation are outlined. Each alternative is accompanied by a diagram…

  15. Conceptual design report for Central Waste Disposal Facility

    International Nuclear Information System (INIS)

    1984-01-01

    The permanent facilities are defined, and cost estimates are provided for the disposal of Low-Level Radioactive Wastes (LLW) at the Central Waste Disposal Facility (CWDF). The waste designated for the Central Waste Disposal Facility will be generated by the Y-12 Plant, the Oak Ridge Gaseous Diffusion Plant, and the Oak Ridge National Laboratory. The facility will be operated by ORNL for the Office of Defense Waste and By-Products Management of the Deparment of Energy. The CWDF will be located on the Department of Energy's Oak Ridge Reservation, west of Highway 95 and south of Bear Creek Road. The body of this Conceptual Design Report (CDR) describes the permanent facilities required for the operation of the CWDF. Initial facilities, trenches, and minimal operating equipment will be provided in earlier projects. The disposal of LLW will be by shallow land burial in engineered trenches. DOE Order 5820 was used as the performance standard for the proper disposal of radioactive waste. The permanent facilities are intended for beneficial occupancy during the first quarter of fiscal year 1989. 3 references, 9 figures, 7 tables

  16. Libraries as Trenches: Resistance, Militancy and Politics

    Directory of Open Access Journals (Sweden)

    Edgardo Civallero

    2017-02-01

    Full Text Available This essay considers how libraries and librarians resist and mobilize by sharpening the mind and strengthening solidarity, withstanding adverse conditions and providing shelter, and allowing for new community paths to be traveled despite the neoliberal insistence that there is no alternative. Militancy and commitment on the part of librarians are both discussed in terms of reading, literacy, identity, learning, training, and a form of leisure linked to culture.Everyday engagement in community-level activities and problem-solving by libraries goes hand-in-hand with supporting values such as justice, equality, solidarity, pluralism, freedom, equity, and respect. Trenches are used as a metaphor for libraries because the resistance work and struggle of librarians create spaces where certain fires are kept burning to inspire people sitting around them, and where resistance, planning, building, and counteracting are all possible. Cet essai prend en compte comment les bibliothèques et les bibliothécaires résistent et se mobilisent en façonnant l’esprit, en renforçant la solidarité, en résistant à des conditions défavorables et en fournissant des abris, et en permettant de prendre de nouveaux sentiers communautaires malgré l’insistance néolibérale qu’il n’y pas de solution de rechange. Le militantisme et l’engagement de la part des bibliothécaires sont tous deux examinés en fonction de la lecture, la littératie, l’identité, l’apprentissage, la formation et une forme de loisir liée à la culture. L’engagement quotidien dans les activités de la communauté et la résolution de problème des bibliothèques vont main dans la main avec le soutien des valeurs tels la justice, l’égalité, la solidarité, le pluralisme, la liberté, l’équité et le respect. La métaphore de la tranchée peut être employée pour les bibliothèques, car leur travail de résistance et les défis qu’ont les bibliothécaires à créer des

  17. Greater confinement disposal program at the Savannah River Plant

    International Nuclear Information System (INIS)

    Cook, J.R.; Towler, O.A.; Peterson, D.L.; Johnson, G.M.; Helton, B.D.

    1984-01-01

    The first facility to demonstrate Greater Confinement Disposal (GCD) in a humid environment in the United States has been built and is operating at the Savannah River Plant. GCD practices of waste segregation, packaging, emplacement below the root zone, and waste stabilization are being used in the demonstration. Activity concentrations to select wastes for GCD are based on a study of SRP burial records, and are equal to or less than those for Class B waste in 10CFR61. The first disposal units to be constructed are 9-foot diameter, thirty-foot deep boreholes which will be used to dispose of wastes from production reactors, tritiated wastes, and selected wastes from off-site. In 1984 an engineered GCD trench will be constructed for disposal of boxed wastes and large bulky items. 2 figures, 1 table

  18. Subduction of a buoyant plateau at the Manila Trench: Tomographic evidence and geodynamic implications

    Science.gov (United States)

    Fan, Jianke; Zhao, Dapeng; Dong, Dongdong

    2016-02-01

    We determined P-wave tomographic images by inverting a large number of arrival-time data from 2749 local earthquakes and 1462 teleseismic events, which are used to depict the three-dimensional morphology of the subducted Eurasian Plate along the northern segment of the Manila Trench. Dramatic changes in the dip angle of the subducted Eurasian Plate are revealed from the north to the south, being consistent with the partial subduction of a buoyant plateau beneath the Luzon Arc. Slab tears may exist along the edges of the buoyant plateau within the subducted plate induced by the plateau subduction, and the subducted lithosphere may be absent at depths greater than 250 km at ˜19°N and ˜21°N. The subducted buoyant plateau is possibly oriented toward NW-SE, and the subducted plate at ˜21°N is slightly steeper than that at ˜19°N. These results may explain why the western and eastern volcanic chains in the Luzon Arc are separated by ˜50 km at ˜18°N, whereas they converge into a single volcanic chain northward, which may be related to the oblique subduction along the Manila Trench caused by the northwestern movement of the Philippine Sea Plate. A low-velocity zone is revealed at depths of 20-200 km beneath the Manila Accretionary Prism at ˜22°N, suggesting that the subduction along the Manila Trench may stop there and the collision develops northward. The Taiwan Orogeny may originate directly from the subduction of the buoyant plateau, because the initial time of the Taiwan Orogeny is coincident with that of the buoyant plateau subduction.

  19. Design and construction of a deep slurry trench barrier

    International Nuclear Information System (INIS)

    Deming, P.W.

    1997-01-01

    A 24 m (80 ft) deep slurry trench surrounding a former chromium manufacturing facility on the Patapsco River in Baltimore, Maryland was constructed in 1995 to contain groundwater and site Soils, and to reduce the volume of groundwater extracted to maintain an inward gradient. In 1992, an embankment made of crushed stone was constructed in the Patapsco River to make land for barrier construction outboard of the bulkheads, and to protect the barrier. Stability of the slurry-supported trench excavation in the embankment required construction from an elevated work platform. An extended reach backhoe was used to excavate the deep slurry trench and to clean the trench bottom. Soil-Bentonite backfill was prepared at a central mixing area and transported by truck to the perimeter barrier. A synthetic membrane was inserted partially into the backfill for connection to a multimedia cap, and for redundancy and erosion control in the tidal zone. Hydraulic testing of the aquitard contained by the barrier demonstrated excellent performance of the barrier and bottom closure. Detailed definition of subsurface conditions and the closure stratum was necessary for the design and successful construction of the barrier, and is recommended for comparable slurry trench construction projects

  20. Novel vertical silicon photodiodes based on salicided polysilicon trenched contacts

    International Nuclear Information System (INIS)

    Kaminski, Yelena; Shauly, Eitan; Paz, Yaron

    2015-01-01

    The classical concept of silicon photodiodes comprises of a planar design characterized by heavily doped emitters. Such geometry has low collection efficiency of the photons absorbed close to the surface. An alternative, promising, approach is to use a vertical design. Nevertheless, realization of such design is technologically challenged, hence hardly explored. Herein, a novel type of silicon photodiodes, based on salicided polysilicon trenched contacts, is presented. These contacts can be prepared up to 10 μm in depth, without showing any leakage current associated with the increase in the contact area. Consequently, the trenched photodiodes revealed better performance than no-trench photodiodes. A simple two dimensional model was developed, allowing to estimate the conditions under which a vertical design has the potential to have better performance than that of a planar design. At large, the deeper the trench is, the better is the vertical design relative to the planar (up to 10 μm for silicon). The vertical design is more advantageous for materials characterized by short diffusion lengths of the carriers. Salicided polysilicon trenched contacts open new opportunities for the design of solar cells and image sensors. For example, these contacts may passivate high contact area buried contacts, by virtue of the conformity of polysilicon interlayer, thus lowering the via resistance induced recombination enhancement effect

  1. Novel vertical silicon photodiodes based on salicided polysilicon trenched contacts

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Yelena [Department of Chemical Engineering, Technion, Haifa (Israel); TowerJazz Ltd. Migdal Haemek (Israel); Shauly, Eitan [TowerJazz Ltd. Migdal Haemek (Israel); Paz, Yaron, E-mail: paz@tx.technion.ac.il [Department of Chemical Engineering, Technion, Haifa (Israel)

    2015-12-07

    The classical concept of silicon photodiodes comprises of a planar design characterized by heavily doped emitters. Such geometry has low collection efficiency of the photons absorbed close to the surface. An alternative, promising, approach is to use a vertical design. Nevertheless, realization of such design is technologically challenged, hence hardly explored. Herein, a novel type of silicon photodiodes, based on salicided polysilicon trenched contacts, is presented. These contacts can be prepared up to 10 μm in depth, without showing any leakage current associated with the increase in the contact area. Consequently, the trenched photodiodes revealed better performance than no-trench photodiodes. A simple two dimensional model was developed, allowing to estimate the conditions under which a vertical design has the potential to have better performance than that of a planar design. At large, the deeper the trench is, the better is the vertical design relative to the planar (up to 10 μm for silicon). The vertical design is more advantageous for materials characterized by short diffusion lengths of the carriers. Salicided polysilicon trenched contacts open new opportunities for the design of solar cells and image sensors. For example, these contacts may passivate high contact area buried contacts, by virtue of the conformity of polysilicon interlayer, thus lowering the via resistance induced recombination enhancement effect.

  2. Expedited response action proposal for 316-5 process trenches

    International Nuclear Information System (INIS)

    1991-07-01

    A summary of the evaluation of remedial alternatives for the 300 Area Process Trench sediment removal at Hanford is presented. Based on the preliminary technology screening, screening factors, and selection criteria the preferred alternative for the 300 Area Process Trench is to remove and interim stabilize the sediments within the fenced area of the process trenches. This alternative involves proven technologies that are applied easily at this mixed waste site. This alternative removes and isolates contaminated sediments from the active portion of the trenches allowing continued used of the trenches until an inspection and treatment facility is constructed. The alternative does not incorporate any materials or actions that preclude consideration of a technology for final remediation of the operable unit. The estimated initial and annual costs would enable this alternative to be implemented under the guidelines for an EPA- funded ERA ($2 million). Implementation of the alternative can be accomplished with trained personnel using familiar procedures to provide a safe operation that accomplishes the objective for removing a potential source of contamination, thereby reducing potential environmental threat to groundwater. 18 refs., 5 figs., 9 tabs

  3. The medical response to trench nephritis in World War One.

    Science.gov (United States)

    Atenstaedt, R L

    2006-08-01

    Around the 90-year anniversary of the Battle of the Somme, it is important to remember the international effort that went into responding to the new diseases, which appeared during the First World War, such as trench nephritis. This condition arose among soldiers in spring 1915, characterized by breathlessness, swelling of the face or legs, headache, sore throat, and the presence of albumin and renal casts in urine. It was speedily investigated by the military-medical authorities. There was debate over whether it was new condition or streptococcal nephritis, and the experts agreed that it was a new condition. The major etiologies proposed were infection, exposure, and diet (including poisons). Research pointed to the origin of the disease as being infective rather than toxic, but no definite cause was discovered. A number of labels were given to the disease, including war nephritis. However, trench nephritis was the one used most widely. Trench nephritis was a serious problem for the Allies, leading to 35 000 casualties in the British and 2000 in the American forces. There were also hundreds of deaths. The condition was treated in line with pre-war regimens designed for acute nephritis. No significant preventative methods were implemented for trench nephritis, as there was no consensus regarding causation. The medical response to trench nephritis was largely ineffective, with medical commentators recognizing that there had been a lack of medical progress.

  4. Leaching studies of low-level waste as input to radiological assessment at the Drigg disposal site, Cumbria

    International Nuclear Information System (INIS)

    Poulton, J.; Rushbrook, P.E.

    1989-01-01

    Over the period of operation of the low-level waste disposal site at Drigg in Cumbria, several radiological assessments have been carried out. This paper discusses data requirements for such an assessment and in particular describes a project to measure the leaching behaviour of wastes. This project, jointly set up by the staff of BNFL and Environmental Safety Centre at Harwell, began in 1985. The objectives were to determine the processes operating within the waste disposal trenches at Drigg and conditions affecting them. The paper describes the installation and operation of the first of a series of lysimeters designed to simulate conditions in current trenches. (author)

  5. Evaluation and design of drained low-level radioactive disposal sites. Final report

    International Nuclear Information System (INIS)

    Eichholz, G.G.

    1984-12-01

    Low-level disposal in shallow trenches has been the subject of much critical assessment in recent years. Historically most trenches have been located in fairly permeable settings and any liquid waste stored has migrated at rates limited mainly by hydraulic effects and the ion exchange capacity of underlying soil minerals. Attempts to minimize such seepage by choosing sites in very impermeable settings lead to overflow and surface runoff, whenever the trench cap is breached by subsidence or erosion. The work described in this report was directed to an optimum compromise situation where less reliance is placed on cap permanence, any ground seepage is directed and controlled, and the amount of waste leaching that would occur is minimized by keeping the soil surrounding the waste at only residual moisture levels at all times. Measurements have been conducted to determine these residual levels for some representative soils, to estimate the impact on waste migration of mainly unsaturated flow conditions, and to generate a conceptual design of a disposal facility which would provide adequate drainage to keep the waste from being exposed to continuous leaching by standing water. An attempt has also been made to quantify the reduced source terms under such periodic, unsaturated flow conditions, but those tests have not been conclusive to date. For low-permeability soils the waste should be placed about 1 ft. above the saturated layer formed by suction forces immediately above the gravel layer. Since most disposal sites, even in humid regions of the United States, are exposed only to intermittent rainfall and as most trench designs incorporate some gravel base for drainage, the results of this project have broader applications in assessing actual migration conditions in shallow trench disposal sites. Similar considerations may also apply to disposal of hazardous wastes

  6. Lessons Learned Report for the radioactive mixed waste land disposal facility (Trench 31, Project W-025)

    International Nuclear Information System (INIS)

    Irons, L.G.

    1995-01-01

    This report presents the lessons learned from a project that involved modification to the existing burial grounds at the Hanford Reservation. This project has been focused on the development and operation of a Resource Conservation and Recovery Act compliant landfill which will accept low-level radioactive wastes that have been placed in proper containers

  7. Durability test of geomembrane liners presumed to avail near surface disposal facilities for low-level waste generated from research, industrial and medical facilities

    International Nuclear Information System (INIS)

    Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro; Kurosawa, Ryohei; Sakamoto, Yoshiaki; Kanno, Naohiro; Kashima, Takahiro

    2014-02-01

    The Low-level Radioactive Waste Disposal Project Center will construct near surface disposal facilities for radioactive wastes from research, industrial and medical facilities. The disposal facilities consist of “concrete pit type” for low-level radioactive wastes and “trench type” for very low level radioactive wastes. As for the trench type disposal facility, two kinds of facility designs are on projects – one for a normal trench type disposal facility without any of engineered barriers and the other for a trench type disposal facility with geomembrane liners that could prevent from causing environmental effects of non radioactive toxic materials contained in the waste packages. The disposal facility should be designed taking basic properties of durability on geomembrane liners into account, for it is exposed to natural environment on a long-term basis. This study examined mechanical strength and permeability properties to assess the durability on the basis of an indoor accelerated exposure experiment targeting the liner materials presumed to avail the conceptual design so far. Its results will be used for the basic and detailed design henceforth by confirming the empirical degradation characteristic with the progress of the exposure time. (author)

  8. Russian low-level waste disposal program

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, L. [L. Lehman and Associates, Inc., Burnsville, MN (United States)

    1993-03-01

    The strategy for disposal of low-level radioactive waste in Russia differs from that employed in the US. In Russia, there are separate authorities and facilities for wastes generated by nuclear power plants, defense wastes, and hospital/small generator/research wastes. The reactor wastes and the defense wastes are generally processed onsite and disposed of either onsite, or nearby. Treating these waste streams utilizes such volume reduction techniques as compaction and incineration. The Russians also employ methods such as bitumenization, cementation, and vitrification for waste treatment before burial. Shallow land trench burial is the most commonly used technique. Hospital and research waste is centrally regulated by the Moscow Council of Deputies. Plans are made in cooperation with the Ministry of Atomic Energy. Currently the former Soviet Union has a network of low-level disposal sites located near large cities. Fifteen disposal sites are located in the Federal Republic of Russia, six are in the Ukraine, and one is located in each of the remaining 13 republics. Like the US, each republic is in charge of management of the facilities within their borders. The sites are all similarly designed, being modeled after the RADON site near Moscow.

  9. Effect of surface roughness of trench sidewalls on electrical properties in 4H-SiC trench MOSFETs

    Science.gov (United States)

    Kutsuki, Katsuhiro; Murakami, Yuki; Watanabe, Yukihiko; Onishi, Toru; Yamamoto, Kensaku; Fujiwara, Hirokazu; Ito, Takahiro

    2018-04-01

    The effects of the surface roughness of trench sidewalls on electrical properties have been investigated in 4H-SiC trench MOSFETs. The surface roughness of trench sidewalls was well controlled and evaluated by atomic force microscopy. The effective channel mobility at each measurement temperature was analyzed on the basis of the mobility model including optical phonon scattering. The results revealed that surface roughness scattering had a small contribution to channel mobility, and at the arithmetic average roughness in the range of 0.4-1.4 nm, there was no correlation between the experimental surface roughness and the surface roughness scattering mobility. On the other hand, the characteristics of the gate leakage current and constant current stress time-dependent dielectric breakdown tests demonstrated that surface morphology had great impact on the long-term reliability of gate oxides.

  10. Ocean Disposal Site Monitoring

    Science.gov (United States)

    EPA is responsible for managing all designated ocean disposal sites. Surveys are conducted to identify appropriate locations for ocean disposal sites and to monitor the impacts of regulated dumping at the disposal sites.

  11. Waste disposal: preliminary studies

    International Nuclear Information System (INIS)

    Carvalho, J.F. de.

    1983-01-01

    The problem of high level radioactive waste disposal is analyzed, suggesting an alternative for the final waste disposal from irradiated fuel elements. A methodology for determining the temperature field around an underground disposal facility is presented. (E.G.) [pt

  12. Control and tracking arrangements for solid low-level waste disposals to the UK Drigg disposal site

    International Nuclear Information System (INIS)

    Elgie, K.G.; Grimwood, P.D.

    1993-01-01

    The Drigg disposal site has been the principal disposal site for solid low-level radioactive wastes (LLW) in the United Kingdom since 1959. It is situated on the Cumbrian coast, some six kilometers to the south of the Sellafield nuclear reprocessing site. The Drigg site receives LLW from a wide range of sources including nuclear power generation, nuclear fuel cycle activities, defense activities, isotope manufacture, universities, hospitals, general industry and clean-up of contaminated sites. This LLW has been disposed of in a series of trenches cut into the underlying clay layer of the site, and, since 1988, also into concrete lined vault. The total volume of LLW disposed of at Drigg is at present in the order of 800,000m 3 , with disposals currently approximately 25,000m 3 per year. British Nuclear Fuels plc (BNFL) owns and operates the Drigg disposal site. To meet operational and regulatory requirements, BNFL needs to ensure the acceptability of the disposed waste and be able to track it from its arising point to its specific disposal location. This paper describes the system that has been developed to meet these requirements

  13. Disposal of radioactive waste in the Atlantic

    International Nuclear Information System (INIS)

    1982-06-01

    An operation to dispose of low-level radioactive waste in the North Atlantic deeps is undertaken each year. This leaflet seeks to answer questions which are sometimes asked about the operation. It deals with origin, composition, quantity, reason for sea- rather than land-disposal, packaging, transport (rail, road), route of transport, safety precautions, radiation protection, personnel, contamination, site of dump, international regulations, neutral observers, safety standards of containers and control of level of radioactivity of wastes. (U.K.)

  14. Studies involving proposed waste disposal facilities in Turkey

    International Nuclear Information System (INIS)

    Uslu, I.; Fields, D.E.; Yalcintas, M.G.

    1987-01-01

    Today principal sources of radioactive wastes are hospitals, research institutions, biological research centers, universities, industries and two research reactors in Turkey. These wastes will be treated in a pilot waste treatment facility located in Cekmece Nuclear Research and Training Center, Istanbul. In this temporary waste disposal facility, the wastes will be stored in 200 liter concrete containers until the establishment of the permanent waste disposal sites in Turkey, in 1990. The PRESTO - II (Prediction of Radiation Effects From Shallow Trench Operations) computer code was applied for the general probable sites for LLW disposal in Turkey. The model is non-site specific screening model for assessing radionuclide transport, ensuring exposure, and health impacts to a static local population for a chosen time period, following the end of the disposal operation. The methodology that this codes takes into consideration is versatile and explicitly considers infiltration and percolation of surface water into the trench, leaching of radionuclides, vertical and horizontal transport of radionuclides and use of this contaminated ground water for farming, irrigation, and ingestion

  15. Studies involving proposed waste disposal facilities in Turkey

    International Nuclear Information System (INIS)

    Uslu, I.; Fields, D.E.; Yalcintas, M.G.

    1987-01-01

    The Turkish government is in the process of planning two nuclear reactors in Turkey. The Turkish Atomic Energy Authority has been given the task of developing plans for improved control of low-level wastes (LLW) in Turkey. Principal sources of radioactive wastes are hospitals, research institutions, biological research centers, universities, industries, and two research reactors in Turkey. These wastes will be treated in a pilot water treatment facility located in Cekmece Nuclear Research and Training Center, Istanbul. In this temporary waste disposal facility, the wastes will be stored in 200-l concrete containers until the establishment of the permanent waste disposal sites in Turkey in 1990. The PRESTO-II (prediction of radiation effects from shallow trench operations) computer code has been applied for the general probable sites for LLW disposal in Turkey. The model is intended to serve as a non-site-specific screening model for assessing radionuclide transport, ensuring exposure, and health impacts to a static local population for a chosen time period, following the end of the disposal operation. The methodology that this code takes into consideration is versatile and explicitly considers infiltration and percolation of surface water into the trench, leaching of radionuclides, vertical and horizontal transport of radionuclides, and use of this contaminated ground water for farming, irrigation, and ingestion

  16. Installation and instrumentation of a test-trench facility in the unsaturated zone at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Lewis, B.D.

    1984-01-01

    Two simulated waste trenches have been constructed just north of the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory. Sections of culvert occupy part of these trenches and are accessible through vertical caissons. These structures therefore allow personnel access for installing instrumentation, maintenance, and observation. Instrumented simulated waste containers will occupy the remainder of the trenches, in order that soil-moisture migration may be observed in relation to waste container forms. The installation will be used to determine, under actual and simulated conditions at a shallow land-burial site in an arid environment, typical soil-moisture content, unsaturated hydraulic conductivity, matric potential, soil-moisture flux, and soil-moisture velocity. The information will be collected using instrumentation located in disturbed and undisturbed soils, simulated waste containers, and the underlying basalt layer. Therefore, data collected from the facility will (a) help characterize the hydrogeologic and geochemical properties of the surficial sediments, (b) contribute to understanding the hydrogeologic phenomena associated with buried waste (including leachate formation and radionuclide migration), (c) provide information on water and solute movement at the sediment/basalt interface, and (d) be used in a radionuclide migration model

  17. Characterization of organics in leachates from low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Francis, A.J.; Iden, C.R.; Nine, B.; Chang, C.

    1979-01-01

    Low-level radioactive wastes generated by the nuclear industry, universities, research institutions, and hospitals are disposed of in shallow-land trenches and pits. In 1962 the first commercial disposal site was opened in Beatty, Nevada. Since then, the industry has grown to include three private companies operating six disposal areas located in sparsely populated areas: at Maxey Flats (Morehead), Kentucky; Beatty, Nevada; Sheffield, Illinois; Barnwell, South Carolina; West Valley, New York; and Richland, Washington. Although the facilities are operated by private industry, they are located on public land and are subject to federal and state regulation. Although inventories of the radioactive materials buried in the disposal sites are available, no specific records are kept on the kinds and quantities of organic wastes buried. In general, the organic wastes consist of contaminated paper, packing materials, clothing, plastics, ion-exchange resins, scintillation vials, solvents, chemicals, decontamination fluids, carcasses of experimental animals, and solidification agents. Radionuclides such as 14 C, 3 H, 90 Sr, 134 137 Cs, 60 Co, 241 Am, and 238 239 240 Pu have been identified in leachate samples collected from several trenches at Maxey Flats and West Valley. The purpose of this report is to identify some of the organic compounds present in high concentrations in trench leachates at the disposal sites in order to begin to evaluate their effect on radionuclide mobilization and contamination of the environment

  18. Advocacy for Kids: A View from the Residential Trenches.

    Science.gov (United States)

    Parsons, Jon R.

    1995-01-01

    Presents the concept of advocacy in the trenches, wherein residential care staff intercede with and for dysfunctional families, dysfunctional children, and the bureaucracy. This advocacy emphasizes individualized treatment and case-by-case networking, focusing not on broad causes but on what is in the best interest of each child. (ET)

  19. Monitored Retrievable Storage conceptual system study: cask-in-trench

    International Nuclear Information System (INIS)

    1983-11-01

    This report provides a description of the Cask-in-Trench Storage Concept which meets a specified set of requirements; an estimate of the costs of construction, operation and decommissioning of the concept; the costs required to expand the facility throughput and storage capability; and the life cycle costs of the facility. 22 figures, 34 tables

  20. Convective mixing by internal waves in the Puerto Rico Trench

    NARCIS (Netherlands)

    van Haren, H.; Gostiaux, L.

    2016-01-01

    A2.4 km long deep-sea mooringwas deployed for 14 months in the Puerto Rico Trench, the deepestpart of the Atlantic Ocean. Below its top buoyancy package, the mooring line held a 200 m long stringof high-resolution temperature sensors and a current meter. Over the instrumented range between6,004 and

  1. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    International Nuclear Information System (INIS)

    Ernest E. Carter, P.E.

    2002-01-01

    EarthSaw(trademark) is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file

  2. A Generic Water Balance Model for a Trench Repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Choi, Hee Joo

    2016-01-01

    To quantify the exposure dose rates from the nuclide release and transport through the various pathways possible in the near- and far-fields of the LILW repository system, various scenarios are to be conveniently simulated in a straightforward manner and extensively with this GoldSim model, as similarly developed for other various types of repositories in previous studies. Through this study, a result from four scenario cases, each of which is or is not associated with water balance, are compared to each other to see what happens in different cases in which an overflow over a trench rooftop, stochastic rainfall on the trench cover, and an unsaturated flow scheme under the trench bottom are combined. The other two latter elements vary periodically owing to stochastic behavior of the time series data for the past rain-fall records. This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various scenarios that can occur after a failure of waste packages with associated uncertainty. An illustration conducted through a study with a new water balance scheme shows the possibility of a stochastic evaluation associated with the stochastic behavior and various pathways that happen around the trench repository.

  3. A Generic Water Balance Model for a Trench Repository

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youn Myoung; Choi, Hee Joo [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    To quantify the exposure dose rates from the nuclide release and transport through the various pathways possible in the near- and far-fields of the LILW repository system, various scenarios are to be conveniently simulated in a straightforward manner and extensively with this GoldSim model, as similarly developed for other various types of repositories in previous studies. Through this study, a result from four scenario cases, each of which is or is not associated with water balance, are compared to each other to see what happens in different cases in which an overflow over a trench rooftop, stochastic rainfall on the trench cover, and an unsaturated flow scheme under the trench bottom are combined. The other two latter elements vary periodically owing to stochastic behavior of the time series data for the past rain-fall records. This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various scenarios that can occur after a failure of waste packages with associated uncertainty. An illustration conducted through a study with a new water balance scheme shows the possibility of a stochastic evaluation associated with the stochastic behavior and various pathways that happen around the trench repository.

  4. Trench infiltration for managed aquifer recharge to permeable bedrock

    Science.gov (United States)

    Heilweil, V.M.; Watt, D.E.

    2011-01-01

    Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

  5. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    Energy Technology Data Exchange (ETDEWEB)

    Ernest E. Carter, P.E.

    2002-09-20

    EarthSaw{trademark} is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file.

  6. Field and laboratory investigations on pavement backfilling material for micro-trenching in cold regions

    OpenAIRE

    Leila Hashemian; Mohammad Rezaei; Alireza Bayat

    2017-01-01

    Micro-trenching is an innovative utility installation method that involves creating a narrow trench to place cable or conduit in the road pavement. Compared to other installation methods, micro-trenching provides minimal disturbance to the community and surrounding environment. Despite the advantages of micro-trenching, it is not widely accepted by municipalities because of its potential to damage the existing pavement. Quality of backfilling is an important factor in long-term sustainability...

  7. Geohydrologic problems at low-level radioactive waste disposal sites in the United States of America

    International Nuclear Information System (INIS)

    Fischer, J.N.; Robertson, J.B.

    1984-01-01

    Several commercial and US Department of Energy low-level radioactive waste disposal sites in the USA have not adequately contained the waste products. Studies of these sites indicate a number of causes for the problems, including water accumulation in filled trenches, breaches of trench cap integrity, erosion, high water table, hydrogeological complexity, flooding, complex leachate chemistry, and rapid radionuclide migration in groundwater. These problems can be avoided through the application of practical, comprehensive, and common sense earth-science guidelines discussed in this paper. (author)

  8. Chemical Characteristics of Seawater and Sediment in the Yap Trench

    Science.gov (United States)

    Ding, H.; Sun, C.; Yang, G.

    2017-12-01

    In June 2016, seawater samples at sediment-seawater interface and sediment samples were collected by the he Jiaolong, China's manned submersible, at four sampling sites located in the Yap Trench. Seawater samples from different depths of the trench were also collected by CTD. Chemical parameters, including pH, alkanility, concentrations of dissolved inorganic carbon, dissolved and total organic carbon, methane, dimethylsulfoniopropionate, nutrients, carbohydrates, and amino acids were analyzed in the seawater samples. Concentrations of total organic carbon, six constant elements and nine trace elements were determined in the sediment samples. All the vertical profiles of the chemical parameters in the seawater have unique characteristics. Our resluts also showed that the carbonate compensation depth (CCD) was between 4500 m and 5000 m in the trench. The hadal sediment at 6500 m depth under the CCD line was siliceous ooze favored for the burial of orgaic carbon, attributed to accumulation of surface sediment by gravity flow. The abyssal sediment at the 4500 m depth was calcareous ooze. Various microfossils, such as discoasters and diatoms, were identified in different sediment layers of the sediment samples.Based on the ratios of Fe/Al and Ti/Al, and the correlation between different elements, the sediment in the Yap Trench were derived from biogenic, terrestrial, volcanic and autogenic sources. The ratios of Ni/Co and V/Cr showed that the deposition environment of the trench should be oxidative, arributed to inflow of the Antractic bottom oxygen-rich seawater.The high concentraiont of Ca in the sediment from the station 371-Yap-S02 below 4 cm depth indicated that there was no large-scale volcanic eruption in the research area and the volcanic materials in the sediment might orginated from the Mariana Volcanic Arc, and the Carolyn Ridge has been slowly sinking on the east side of the trench due to plate subduction. This study is the first systematic study of

  9. Ultra-low specific on-resistance SOI double-gate trench-type MOSFET

    International Nuclear Information System (INIS)

    Lei Tianfei; Luo Xiaorong; Ge Rui; Chen Xi; Wang Yuangang; Yao Guoliang; Jiang Yongheng; Zhang Bo; Li Zhaoji

    2011-01-01

    An ultra-low specific on-resistance (R on,sp ) silicon-on-insulator (SOI) double-gate trench-type MOSFET (DG trench MOSFET) is proposed. The MOSFET features double gates and an oxide trench: the oxide trench is in the drift region, one trench gate is inset in the oxide trench and one trench gate is extended into the buried oxide. Firstly, the double gates reduce R on,sp by forming dual conduction channels. Secondly, the oxide trench not only folds the drift region, but also modulates the electric field, thereby reducing device pitch and increasing the breakdown voltage (BV). ABV of 93 V and a R on,sp of 51.8 mΩ·mm 2 is obtained for a DG trench MOSFET with a 3 μm half-cell pitch. Compared with a single-gate SOI MOSFET (SG MOSFET) and a single-gate SOI MOSFET with an oxide trench (SG trench MOSFET), the R on,sp of the DG trench MOSFET decreases by 63.3% and 33.8% at the same BV, respectively. (semiconductor devices)

  10. Design and operational experience of low level radioactive waste disposal in the United Kingdom

    International Nuclear Information System (INIS)

    Grimwood, P. D.

    1997-01-01

    Low level radioactive wastes have been disposed of at the Drigg near-surface disposal site for over 30 years. These are carried out under a disposal authorization granted by the UK Environment Agency. This is augmented by a three tier comprehensive system of waste controls developed by BNFL involving wasteform specification, consignor and waste stream qualification and waste consignment verification. Until 1988 wastes were disposed of into trench facilities. However, based on a series of integrated optioneering studies, new arrangements have since been brought into operation. Central to these is a wasteform specification based principally on high force compaction of wastes, grouting within 20 m 3 steel overpack containers to essentially eliminate associated voidage and subsequent disposal in concrete lined vaults. These arrangements ensure efficient utilisation of the Drigg site capacity and a cost-effective disposal concept which meets both national and international standards. (author). 7 figs

  11. Estimation of doses to individuals from radionuclides disposed of in Solid Waste Storage Area 6

    International Nuclear Information System (INIS)

    Fields, D.E.; Boegly, W.J. Jr.; Huff, D.D.

    1986-01-01

    A simple methodology has been applied to estimate maximum possible doses to individuals from exposure to radionuclides released from Solid Waste Storage Area No. 6. This is the only operating shallow-land disposal site for radioactive waste at the Oak Ridge National Laboratory. The methodology is based upon simple, conservative assumptions. A data base of radionuclides disposed of in trenches and auger holes was prepared, and several radionuclide transport and ingestion scenarios were considered. The results of these simulations demonstrate the potential for adverse health effects associated with this waste disposal area, and support the need for further calculations using more complete and realistic assumptions

  12. A survey of possible microbiological effects within shallow land disposal sites designed to accept intermediate-level radioactive wastes

    International Nuclear Information System (INIS)

    Rushbrook, P.E.

    1985-01-01

    A literature survey was conducted to assess the current knowledge on microbial activity that may occur within a shallow intermediate-level waste disposal trench. Relatively little published information exists that is directly based on intermediate radioactive wasteforms, but relevant work was identified from other scientific fields. The likely environmental conditions within a disposal trench and their influence on microbial activity are considered. Also discussed are specific microbiological effects on waste packagings, backfill materials and concrete structures. Overall, it is unlikely that there will be extensive activity within the trenches and little evidence exists to suggest microbiologically-enhanced radionuclide migration,. The quantitative effect of microbial action is not possible to ascertain from the literature, but the general impression is that it will be low. Physical or chemical degradation processes are likely to predominate over those of a microbiological nature. Areas where further research would be valuable are also recommended. (author)

  13. In situ grouting of low-level burial trenches with a cement-based grout

    International Nuclear Information System (INIS)

    Francis, C.W.; Spalding, B.P.

    1991-01-01

    A restoration technology being evaluated for use in the closure of one of the low-level radwaste burial grounds at Oak Ridge National Laboratory (ORNL) is trench stabilization using a cement-based grout. To demonstrate the applicability and effectiveness of this technology, two interconnecting trenches in Solid Waste Storage Area 6 (SWSA 6) were selected as candidates for in situ grouting with a particulate grout. The primary objective was to demonstrate the increased trench stability and decreased potential for leachate migration following in situ injection of a particulate grout into the waste trenches. Stability against trench subsidence is a critical issue. After grouting, soil-penetration tests disclosed that stability had been improved greatly. For example, refusal (defined as > 100 blows to penetrate 1 ft) was encountered in 17 of the 22 tests conducted within the trench area. Mean refusal depths for the two trenches were 3.5 and 2.6 m. Stability of the trench was significantly better than pregrout conditions, and at depths > 2.4 m, the stability was very near that observed in the native soil formation outside the trench. Tests within the trench showed lower stability within this range probably because of the presence of intermediate-sized soil voids (formed during backfilling) that were too small to be penetrated and filled by the conventional cement grout formulation. Hydraulic conductivity within the trench remained very high (>0.1 cm/s) and significantly greater than outside the trench. Postgrout air pressurization tests also revealed a large degree of intervoid linkage within and between the two trenches. To effectively reduce hydraulic conductivity and to develop stability within the upper level of the trench, injection of a clay/microfine cement grout into the upper level of the grouted trench is planned

  14. Source term development for tritium at the Sheffield disposal site

    International Nuclear Information System (INIS)

    MacKenzie, D.R.; Barletta, R.E.; Smalley, J.F.; Kempf, C.R.; Davis, R.E.

    1984-01-01

    The Sheffield low-level radioactive waste disposal site, which ceased operation in 1978, has been the focus of modeling efforts by the NRC for the purpose of predicting long-term site behavior. To provide the NRC with the information required for its modeling effort, a study to define the source term for tritium in eight trenches at the Sheffield site has been undertaken. Tritium is of special interest since significant concentrations of the isotope have been found in groundwater samples taken at the site and at locations outside the site boundary. Previous estimates of tritium site inventory at Sheffield are in wide disagreement. In this study, the tritium inventory in the eight trenches was estimated by reviewing the radioactive shipping records (RSRs) for waste buried in these trenches. It has been found that the tritium shipped for burial at the site was probably higher than previously estimated. In the eight trenches surveyed, which amount to roughly one half the total volume and activity buried at Sheffield, approximately 2350 Ci of tritium from non-fuel cycle sources were identified. The review of RSRs also formed the basis for obtaining waste package descriptions and for contacting large waste generators to obtain more detailed information regarding these waste packages. As a result of this review and the selected generator contacts, the non-fuel cycle tritium waste was categorized. The tritium releases from each of these waste categories were modeled. The results of this modeling effort are presented for each of the eight trenches selected. 3 references, 2 figures

  15. Subproject L-045H 300 Area Treated Effluent Disposal Facility

    International Nuclear Information System (INIS)

    1991-06-01

    The study focuses on the project schedule for Project L-045H, 300 Area Treated Effluent Disposal Facility. The 300 Area Treated Effluent Disposal Facility is a Department of Energy subproject of the Hanford Environmental Compliance Project. The study scope is limited to validation of the project schedule only. The primary purpose of the study is to find ways and means to accelerate the completion of the project, thereby hastening environmental compliance of the 300 Area of the Hanford site. The ''300 Area'' has been utilized extensively as a laboratory area, with a diverse array of laboratory facilities installed and operational. The 300 Area Process Sewer, located in the 300 Area on the Hanford Site, collects waste water from approximately 62 sources. This waste water is discharged into two 1500 feet long percolation trenches. Current environmental statutes and policies dictate that this practice be discontinued at the earliest possible date in favor of treatment and disposal practices that satisfy applicable regulations

  16. Geochemical investigations at Maxey Flats radioactive waste disposal site

    International Nuclear Information System (INIS)

    Dayal, R.; Pietrzak, R.F.; Clinton, J.

    1984-09-01

    As part of the NRC efforts to develop a data base on source term characteristics for low level wastes, Brookhaven National Laboratory (BNL) has produced and analyzed a large amount of data on trench leachate chemistry at existing shallow land burial sites. In this report, we present the results of our investigations at the Maxey Flats, Kentucky disposal site. In particular, data on trench leachate chemistry are reviewed and discussed in terms of mechanisms and processes controlling the composition of trench solutes. Particular emphasis is placed on identifying both intra- and extra-trench factors and processes contributing to source term characteristics, modifications, and uncertainties. BNL research on the Maxey Flats disposal site has provided important information not only on the source term characteristics and the factors contributing to uncertainties in the source term but also some generic insights into such geochemical processes and controls as the mechanics of leachate formation, microbial degradation and development of anoxia, organic complexation and radionuclide mobility, redox inversion and modification of the source term, solubility constraints on solute chemistry, mineral authigenesis, corrosion products and radionuclide scavenging, and the role of organic complexants in geochemical partitioning of radionuclides. A knowledge of such processes and controls affecting the geochemical cycling of radionuclides as well as an understanding of the important factors that contribute to variability and uncertainties in the source term is essential for evaluating the performance of waste package and the site, making valid predictions of release for dose calculations, and for planning site performance monitoring as well as remedial actions. 43 references, 47 figures, 30 tables

  17. Chemical mechanisms of /sup 60/Co transport in ground water from intermediate-level liquid waste trench 7: progress report for period ending June 30, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Means, J.L.; Crerar, D.A.; Duguid, J.O.

    1976-11-01

    A seep approximately 50 meters east of trench 7 within the ORNL restricted area contains /sup 60/Co in concentrations of 10/sup 4/ to 10/sup 6/ dpm/g in the soil and 10/sup 3/ dpm/ml in the water. Traces of /sup 125/Sb and various transuranics have also been detected in the soil. However, because the volume of water discharge from the seep is small, the total radionuclide contribution from the trench 7 area to White Oak Creek and the Clinch River is insignificant. The /sup 60/Co is transported in the ground-water from the trench to the seep as organic complexes and is absorbed by manganese oxides and to a lesser extent by iron sesquioxides in the shale and soil. In the absence of these organic complexing agents, /sup 60/Co mobilization would be negligible because the sediment absorption capacity for inorganic forms of /sup 60/Co is extremely high. The primary objective of this study has been to investigate /sup 60/Co transport and absorption mechanisms as observed in the study area. Because the organic complexing characteristics of transition metals and transuranics are similar, the mechanisms of /sup 60/Co transport determined in this study may also apply to plutonium and other alpha-emitters. Also the experimental and analytical methods employed in this study apply to the identification of other migrating radionuclide complexes from other disposal trenches and pits at ORNL. The increased knowledge of transport and adsorption mechanisms will provide insight into methods of controlling the movement of radionuclides from these and future disposal areas.

  18. Chemical mechanisms of 60Co transport in ground water from intermediate-level liquid waste trench 7: progress report for period ending June 30, 1975

    International Nuclear Information System (INIS)

    Means, J.L.; Crerar, D.A.; Duguid, J.O.

    1976-11-01

    A seep approximately 50 meters east of trench 7 within the ORNL restricted area contains 60 Co in concentrations of 10 4 to 10 6 dpm/g in the soil and 10 3 dpm/ml in the water. Traces of 125 Sb and various transuranics have also been detected in the soil. However, because the volume of water discharge from the seep is small, the total radionuclide contribution from the trench 7 area to White Oak Creek and the Clinch River is insignificant. The 60 Co is transported in the ground-water from the trench to the seep as organic complexes and is absorbed by manganese oxides and to a lesser extent by iron sesquioxides in the shale and soil. In the absence of these organic complexing agents, 60 Co mobilization would be negligible because the sediment absorption capacity for inorganic forms of 60 Co is extremely high. The primary objective of this study has been to investigate 60 Co transport and absorption mechanisms as observed in the study area. Because the organic complexing characteristics of transition metals and transuranics are similar, the mechanisms of 60 Co transport determined in this study may also apply to plutonium and other alpha-emitters. Also the experimental and analytical methods employed in this study apply to the identification of other migrating radionuclide complexes from other disposal trenches and pits at ORNL. The increased knowledge of transport and adsorption mechanisms will provide insight into methods of controlling the movement of radionuclides from these and future disposal areas

  19. In situ grouting of low-level burial trenches with a cement-based grout

    International Nuclear Information System (INIS)

    Francis, C.W.; Spalding, B.P.

    1991-01-01

    A restoration technology being evaluated for use in the closure of one of the low-level radwaste burial grounds at Oak Ridge National Laboratory (ORNL) is trench stabilization using a cement-based grout. To demonstrate the applicability and effectiveness of this technology, two interconnecting trenches in Solid Waste Storage Area 6 (SWSA 6) were selected as candidates for in situ grouting with a particulate grout. The primary objective was to demonstrate the increased trench stability and decreased potential for leachate migration following in situ injection of a particulate grout into the waste trenches. Stability against trench subsidence is a critical issue. 7 refs., 3 figs., 5 tabs

  20. Derivation of activity limits for the disposal of radioactive waste in near surface disposal facilities

    International Nuclear Information System (INIS)

    2003-12-01

    Radioactive waste must be managed safely, consistent with internationally agreed safety standards. The disposal method chosen for the waste should be commensurate with the hazard and longevity of the waste. Near surface disposal is an option used by many countries for the disposal of radioactive waste containing mainly short lived radionuclides and low concentrations of long lived radionuclides. The term 'near surface disposal' encompasses a wide range of design options, including disposal in engineered structures at or just below ground level, disposal in simple earthen trenches a few metres deep, disposal in engineered concrete vaults, and disposal in rock caverns several tens of metres below the surface. The use of a near surface disposal option requires design and operational measures to provide for the protection of human health and the environment, both during operation of the disposal facility and following its closure. To ensure the safety of both workers and the public (both in the short term and the long term), the operator is required to design a comprehensive waste management system for the safe operation and closure of a near surface disposal facility. Part of such a system is to establish criteria for accepting waste for disposal at the facility. The purpose of the criteria is to limit the consequences of events which could lead to radiation exposures and in addition, to prevent or limit hazards, which could arise from non-radiological causes. Waste acceptance criteria include limits on radionuclide content concentration in waste materials, and radionuclide amounts in packages and in the repository as a whole. They also include limits on quantity of free liquids, requirements for exclusion of chelating agents and pyrophoric materials, and specifications of the characteristics of the waste containers. Largely as a result of problems encountered at some disposal facilities operated in the past, in 1985 the IAEA published guidance on generic acceptance

  1. California's disposal plan goes nowhere fast

    International Nuclear Information System (INIS)

    Cohen, J.

    1994-01-01

    California desperately needs a place to store as much as 5.5 million cubic feet of low-level radioactive waste over the next 30 years. Ward Valley, a barren stretch of the Mojave Desert located some 250 miles east of Los Angeles, was supposed to be that place. Last year, trenches dug in the arid, seismically stable valley were supposed to be that place. Last year, trenches dug in the arid, seismically stable valley were supposed to begin holding wastes like the gadolinium-153 used to detect osteoporosis and the selenium-75 used to study proteins, as well as wastes from nuclear power plants. But construction crews haven't even begun to dig, because Ward Valley has become ground zero in the fierce national debate over radioactive waste disposal. Lawsuits filed by opponents, who fear the waste will contaminate the environment, and the intervention of influential politicians such as Sen. Barbara Boxer (D-CA) have blocked the Interior Department from selling the federally owned Ward Valley land to California to begin construction. As a result, universities, biotechnology companies, and hospitals may be stuck with wastes piling up at their institutions, which could have repercussions

  2. Variably-saturated groundwater modeling for optimizing managed aquifer recharge using trench infiltration

    Science.gov (United States)

    Heilweil, Victor M.; Benoit, Jerome; Healy, Richard W.

    2015-01-01

    Spreading-basin methods have resulted in more than 130 million cubic meters of recharge to the unconfined Navajo Sandstone of southern Utah in the past decade, but infiltration rates have slowed in recent years because of reduced hydraulic gradients and clogging. Trench infiltration is a promising alternative technique for increasing recharge and minimizing evaporation. This paper uses a variably saturated flow model to further investigate the relative importance of the following variables on rates of trench infiltration to unconfined aquifers: saturated hydraulic conductivity, trench spacing and dimensions, initial water-table depth, alternate wet/dry periods, and number of parallel trenches. Modeling results showed (1) increased infiltration with higher hydraulic conductivity, deeper initial water tables, and larger spacing between parallel trenches, (2) deeper or wider trenches do not substantially increase infiltration, (3) alternating wet/dry periods result in less overall infiltration than keeping the trenches continuously full, and (4) larger numbers of parallel trenches within a fixed area increases infiltration but with a diminishing effect as trench spacing becomes tighter. An empirical equation for estimating expected trench infiltration rates as a function of hydraulic conductivity and initial water-table depth was derived and can be used for evaluating feasibility of trench infiltration in other hydrogeologic settings

  3. Air monitoring data reveal previously unknown contamination at radioactive waste disposal area, Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Kraig, D.H.; Conrad, R.C.

    2000-01-01

    Air monitoring at Area G, the low-level radioactive waste disposal area at Los Alamos National Laboratory, revealed increased air concentrations of 239 Pu and 241 Am at one location along the north boundary. This air monitoring location is a couple of meters north of a dirt road used to access the easternmost part of Area G. Air concentrations of 238 Pu were essentially unaffected which was puzzling because both 238 Pu and 239 Pu are present in the local, slightly contaminated soils. Air concentrations of these radionuclides increased about a factor of ten in early 1995 and remained at those levels until the first quarter of 1996. During the spring of 1996 air concentrations again increased by a factor of about ten. No other radionuclides were elevated, and no other Area G stations showed elevations of these radionuclides. After several formal meetings did not provide an adequate explanation for the elevations, a gamma-survey was performed and showed a small area of significant contamination just south of the monitor location. We found that in February 1995, a trench for a water line had been dug within a meter or so of the air stations. Then, during early 1996, the dirt road was rerouted such that its new path was directly over the unknown contamination. It appears that the trenching brought contaminated material to the surface and caused the firs rise in air concentrations and then the rerouting of the road over the contamination caused the second rise, during 1996. We also found that during 1976 and 1977 contaminated soils from the clean-up of an old processing facility had been spread over the filled pits in the vicinity of the air monitors. These soils, which were probably the source of the air contamination, were very low in 238 Pu which explains why we saw very little 238 Pu in the increased air concentrations. A layer of gravel and sand was spread over the contaminated area. Although air concentrations of 239 Pu and 241 Am dropped considerably, they have

  4. Planning for greater-confinement disposal

    International Nuclear Information System (INIS)

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1984-01-01

    This contribution is a progress report for preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (GCD) of low-level radioactive waste. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. This progress report is limited to Phase I. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objectives and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives. 16 references

  5. Greater confinement disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive waste (LLW) includes a broad spectrum of different radionuclide concentrations, half-lives, and hazards. Standard shallow-land burial practice can provide adequate protection of public health and safety for most LLW. A small volume fraction (approx. 1%) containing most of the activity inventory (approx. 90%) requires specific measures known as greater-confinement disposal (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics

  6. Planning for greater-confinement disposal

    International Nuclear Information System (INIS)

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1984-01-01

    This contribution is a progress report for preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (GCD) of low-level radioactive waste. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. This progress report is limited to Phase I. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objecties and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives. 16 refs

  7. The East Garrington Trench and Gate system: it works

    International Nuclear Information System (INIS)

    Bowles, M.; Rimbey, S.; Bentley, L.; Thomas, D.; Hoyne, B.

    1997-01-01

    A 'trench and gate' system (a modification of the 'funnel and gate' system) has been installed at the Amoco-operated East Garrington gas plant in Alberta to provide long-term remediation for treating contaminated groundwater plumes hosted by low hydraulic conductivity sediments. Modification to the funnel and gate design includes an up gradient high hydraulic conductivity trench and a down gradient infiltration gallery which was found to be effective in biodegrading BTEX (benzene, toluene, ethylbenzene and xylene) compounds. A comprehensive monitoring program was set up to characterize the groundwater flow system. Several indigenous hydrocarbon degrading organisms have been identified. It was shown that locally, under aerobic conditions, phosphorus was the limiting nutrient. 13 refs., 3 tabs., 10 figs

  8. Electrochemical trench etching of silicon triggered via mechanical nanocontacts

    Energy Technology Data Exchange (ETDEWEB)

    Gassilloud, R.; Michler, J. [EMPA, Materials Science and Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Schmuki, P. [Department of Materials Science, LKO, University of Erlangen-Nuernberg, Martensstrasse 7, D-91058 Erlangen (Germany)

    2007-12-01

    We report a method to produce microstructures on silicon wafers using a microscratching technique followed by a subsequent electrochemical trench etching in hydrofluoric-based electrolyte. Micro-scratches are used to trigger macropore formation. We show that mask-less dissolved trenches with aspect ratios up to 1:7 are formed at the scratched regions on (0 0 1)Si surface. The micro-scratches orientate the macropores formation by aligning them in the scratching direction. We propose that dislocations formed during scratching are firstly dissolved leading to the formation of V-shape grooves. The V-shape geometries obtained by this way are used to initiate the macropores nucleation; i.e. due to the geometry, an avalanche current occurs at the grooves base and thus induces local dissolutions of the substrate. High rate local dissolutions are achieved by back-side illumination of the Si wafer. (author)

  9. Technological study about a disposal measures of low-level radioactive waste including uranium and long-half-life radionuclides

    International Nuclear Information System (INIS)

    Sugaya, Toshikatsu; Nakatani, Takayoshi; Sakai, Akihiro; Sakamoto, Yoshiaki; Sasaki, Toshihisa; Nakamura, Yasuo

    2017-02-01

    Japan Atomic Energy Agency (JAEA) performed the technical studies contributed for the disposal measures of uranium-bearing waste with low concentration and intermediate depth disposal-based waste occurring from the process of the nuclear fuel cycle. (1) Study of the trench disposal of uranium-bearing waste. As a part of the study of disposal measures of the uranium-bearing waste, we carried out the safety assessment (exposure dose assessment) and derived the upper limit of radioactivity concentration of uranium which was allowed to be included in radioactive waste for trench disposal. (2) Preliminary study for the expansion of material applied to clearance in uranium-bearing waste. Currently, the clearance level of uranium handling facilities was derived from the radioactivity concentration of uranium corresponding to dose criterion about the exposure pathways of the reuse and recycle of metal. Therefore, we preliminarily evaluated whether metal and concrete were able to be applied to clearance by the method of the undergrounding disposal. (3) Study of the concentration limitation scenarios for the intermediate depth disposal-based waste. We carried out dose assessment of intermediate depth disposal of radioactive waste generated from JAEA about radioactive concentration limitation scenarios of which the concept was shown by the study team in Nuclear Regulation Authority. Based on the results, we discussed whether the waste was applied to radioactive waste conforming to concept of intermediate depth disposal. (author)

  10. Three-dimensional imaging, change detection, and stability assessment during the centerline trench levee seepage experiment using terrestrial light detection and ranging technology, Twitchell Island, California, 2012

    Science.gov (United States)

    Bawden, Gerald W.; Howle, James; Bond, Sandra; Shriro, Michelle; Buck, Peter

    2014-01-01

    A full scale field seepage test was conducted on a north-south trending levee segment of a now bypassed old meander belt on Twitchell Island, California, to understand the effects of live and decaying root systems on levee seepage and slope stability. The field test in May 2012 was centered on a north-south trench with two segments: a shorter control segment and a longer seepage test segment. The complete length of the trench area measured 40.4 meters (m) near the levee centerline with mature trees located on the waterside and landside of the levee flanks. The levee was instrumented with piezometers and tensiometers to measure positive and negative porewater pressures across the levee after the trench was flooded with water and held at a constant hydraulic head during the seepage test—the results from this component of the experiment are not discussed in this report. We collected more than one billion three-dimensional light detection and ranging (lidar) data points before, during, and after the centerline seepage test to assess centimeter-scale stability of the two trees and the levee crown. During the seepage test, the waterside tree toppled (rotated 20.7 degrees) into the water. The landside tree rotated away from the levee by 5 centimeters (cm) at a height of 2 m on the tree. The paved surface of the levee crown had three regions that showed subsidence on the waterside of the trench—discussed as the northern, central, and southern features. The northern feature is an elongate region that subsided 2.1 cm over an area with an average width of 1.35 m that extends 15.8 m parallel to the trench from the northern end of the trench to just north of the trench midpoint, and is associated with a crack 1 cm in height that formed during the seepage test on the trench wall. The central subsidence feature is a semicircular region on the waterside of the trench that subsided by as much as 6.2 cm over an area 3.4 m wide and 11.2 m long. The southern feature is an elongate

  11. Geological mapping of investigation trench OL-TK9 at the Olkiluoto study site, Eurajoki, SW Finland

    International Nuclear Information System (INIS)

    Nordbaeck, N.; Talikka, M.

    2006-07-01

    and associated granitic leucosome veining usually strike NE-SW and dip gently to the southeast (the mean dip/dip direction is 38/158 deg). The foliation gradually turns from NE-SW striking in the southern part of the trench to E-W striking in the northern part. No pre-D 2B structures were identified in the OL-TK9. The leucosome veins show isoclinal D 2 folds in places. During the third deformation phase (D 3 ), the isoclinal F2 folds of the mica gneiss and the granite leucosome veins were refolded by F 3 folding mainly producing small-scale, tight folds with fold axis moderately plunging towards east and rarely to the west. During the fracture mapping, all fractures intersecting the central thread were measured. Dip direction and dip, rock type, length, form, undulation, character, aperture, and infilling if present were recorded for each fracture. A total of 1197 fractures were measured including several fracture clusters (cluster = many identical fractures in a small area). The mean fracture density of the trench is 3.23 fractures/m. From the fracture orientation data, three different fracture sets were interpreted: Set (I) fractures dip gently to the south-southeast, set (II) fractures dip steeply to the east or west, and set (III) fractures dip moderately towards the north. Partly due to the width of the trench most fractures have trace length less than two metres. Most fractures (51,4 %) are open or partially open and 32.4 % of the fractures have infillings. Fracture infillings include chlorite, calcite, kaolinite, epidote, pyrite, illite, mica minerals, quartz, Fe-oxide (hematite), and soil. Several deformation zone intersections were observed in the investigation trench. Four Brittle Joint cluster Intersections (parallel to the foliation), one N-S striking Brittle Fault zone Intersection, one Semi-brittle Fault zone Intersection, and one N-S striking Ductile Shear zone Intersection intersect the trench. (orig.)

  12. Hydrogeologic Characterization Data from the Area 5 Shallow Soil Trenches

    International Nuclear Information System (INIS)

    Bechtel Nevada Geotechnical Sciences

    2005-01-01

    Four shallow soil trenches excavated in the vicinity of the Area 5 Radioactive Waste Management Site at the Nevada Test Site were sampled in 1994 to characterize important physical and hydrologic parameters which can affect the movement of water in the upper few meters of undisturbed alluvium. This report describes the field collection of geologic samples and the results of laboratory analyses made on these samples. This report provides only qualitative analyses and preliminary interpretations

  13. Control of paleoshorelines by trench forebulge uplift, Loyalty Islands

    Science.gov (United States)

    Dickinson, William R.

    2013-07-01

    Unlike most tropical Pacific islands, which lie along island arcs or hotspot chains, the Loyalty Islands between New Caledonia and Vanuatu owe their existence and morphology to the uplift of pre-existing atolls on the flexural forebulge of the New Hebrides Trench. The configuration and topography of each island is a function of distance from the crest of the uplifted forebulge. Both Maré and Lifou are fully emergent paleoatolls upon which ancient barrier reefs form highstanding annular ridges that enclose interior plateaus representing paleolagoon floors, whereas the partially emergent Ouvea paleoatoll rim flanks a drowned remnant lagoon. Emergent paleoshoreline features exposed by island uplift include paleoreef flats constructed as ancient fringing reefs built to past low tide levels and emergent tidal notches incised at past high tide levels. Present paleoshoreline elevations record uplift rates of the islands since last-interglacial and mid-Holocene highstands in global and regional sea levels, respectively, and paleoreef stratigraphy reflects net Quaternary island emergence. The empirical uplift rates vary in harmony with theoretical uplift rates inferred from the different positions of the islands in transit across the trench forebulge at the trench subduction rate. The Loyalty Islands provide a case study of island environments controlled primarily by neotectonics.

  14. Color Image of Snow White Trenches and Scraping

    Science.gov (United States)

    2008-01-01

    This image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on the 31st Martian day of the mission, or Sol 31 (June 26, 2008), after the May 25, 2008 landing. This image shows the trenches informally called 'Snow White 1' (left), 'Snow White 2' (right), and within the Snow White 2 trench, the smaller scraping area called 'Snow White 3.' The Snow White 3 scraped area is about 5 centimeters (2 inches) deep. The dug and scraped areas are within the diggiing site called 'Wonderland.' The Snow White trenches and scraping prove that scientists can take surface soil samples, subsurface soil samples, and icy samples all from one unit. Scientists want to test samples to determine if some ice in the soil may have been liquid in the past during warmer climate cycles. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver

  15. High aspect ratio titanium nitride trench structures as plasmonic biosensor

    DEFF Research Database (Denmark)

    Shkondin, Evgeniy; Repän, Taavi; Takayama, Osamu

    2017-01-01

    High aspect ratio titanium nitride (TiN) grating structures are fabricated by the combination of deep reactive ion etching (DRIE) and atomic layer deposition (ALD) techniques. TiN is deposited at 500 ◦C on a silicon trench template. Silicon between vertical TiN layers is selectively etched...... to fabricate the high aspect ratio TiN trenches with the pitch of 400 nm and height of around 2.7 µm. Dielectric functions of TiN films with different thicknesses of 18 - 105 nm and post-annealing temperatures of 700 - 900 ◦C are characterized by an ellipsometer. We found that the highest annealing temperature...... of 900 ◦C gives the most pronounced plasmonic behavior with the highest plasma frequency, ωp = 2.53 eV (λp = 490 nm). Such high aspect ratio trench structures function as a plasmonic grating sensor that supports the Rayleigh-Woods anomalies (RWAs), enabling the measurement of changes in the refractive...

  16. Monitoring plan for borehole logging at 216-Z-1A Tile Field, 216-Z-9 Trench, and 216-Z-12 Crib

    International Nuclear Information System (INIS)

    Horton, D.G.

    1998-04-01

    This plan describes the fiscal year 1998 vadose monitoring of three inactive, liquid waste disposal facilities associated with the Plutonium Finishing Plant (Z-Plant): the 216-Z-1A Tile Field, the 216-Z-9 Trench, and the 216-Z-12 Crib. Monitoring will consist of spectral gamma ray logging of 21 boreholes. This plan describes the physical characteristics of the facilities, their operational histories, the subsurface geology and known contamination distribution at each facility. The plan then describes the specific monitoring to be done including the boreholes to be logged, the methods of data acquisition, data reduction, and data evaluation, and finally, the quality control, data management and data reporting for this effort. The three liquid waste disposal facilities at the Z Plant were chosen to be monitored because they were identified as containing some of the most significant sources of radioactive contamination in the Hanford vadose zone. Johnson's analysis was based on the relative hazard obtained by combining curie quantities disposed to the facilities with appropriate health risk standards. The basic question to be addressed by this logging activity addresses the configuration of subsurface contamination since it was last measured. Historical data from the 216-Z-1A Tile Field, the 216-Z-9 Trench, and the 216-Z-12 Crib form the baseline for comparisons to answer this question

  17. Evaluation of shale hosted low-level waste disposal sites in semi-arid environments: Final report

    International Nuclear Information System (INIS)

    Roggenthen, W.M.; Rahn, P.H.; Arthur, R.C.; Miller, J.R.; Bangsund, W.J.; Eberlin, J.

    1985-09-01

    This report covers the findings of a multidisciplinary investigation intended to delineate critical factors and concerns associated with shale hosted, low-level radioactive waste disposal sites located in semiarid environments. The investigations focus primarily upon concerns regarding the hydrology, geochemistry, and meteorology of such an environment. The studies described within this report specifically do not constitute an evaluation of any one particular site nor even a particular class of sites. Rather, it is the intention of the report to present data and insights that would assist private concerns and governmental agencies in the efficient and prudent development of such disposal areas. This report assumes that the hypothetical waste site in question would be developed as a trench type operation similar to that used at Barnwell, South Carolina, with variations upon the techniques used at Beatty Flat, Nevada, and Hanford, Washington. The trench design (Figures 1 and 2) is assumed to be similar to that generic design described in ''Procedures and Technology for Shallow Land Burial, DOE/LLw-13Td, 1983) although it is also assumed that improvements and adaptations will be made upon this basic design to meet the individual needs of a particular site. During the preparation of this report it became apparent that new types of trench design are being studied. Discussions of these trench design proposals are not central to this report. The examples of trench design in Figures 1 and 2 are presented only to give an idea as to the general philosophy of construction of shallow burial facilities

  18. Hungary. Closure issues for centralized waste treatment and disposal facility in Puspokszilagy, Hungary

    International Nuclear Information System (INIS)

    2001-01-01

    The facility was commissioned in 1976. At the time that its mission was formulated, the facility was designed to collect, transport, treat as necessary and dispose all radioactive waste originating from institutional use of radioactivity. The facility is government owned and presently operated by the Budapest branch of the State Public Health and Medical Officer Services. The disposal site is located on the ridge of a hill near Puspokszilagy village approximately 40 km Northeast of Budapest. The disposal units are located in Quaternary layers of silt and clay sequences. Annual average precipitation is approximately 650-700 mm. The facility is a typical shallow land, near surface engineered type disposal unit. There are concrete trenches and shallow wells for waste disposal purposes

  19. Habitat heterogeneity of hadal trenches: Considerations and implications for future studies

    Science.gov (United States)

    Stewart, Heather A.; Jamieson, Alan J.

    2018-02-01

    The hadal zone largely comprises a series of subduction trenches that do not form part of the continental shelf-slope rise to abyssal plain continuum. Instead they form geographically isolated clusters of deep-sea (6000-11,000 m water depth) environments. There is a growing realization in hadal science that ecological patterns and processes are not driven solely by responses to hydrostatic pressure, with comparable levels of habitat heterogeneity as observed in other marine biozones. Furthermore, this heterogeneity can be expressed at multiple scales from inter-trench levels (degrees of geographical isolation, and biochemical province), to intra-trench levels (variation between trench flanks and axis), topographical features within the trench interior (sedimentary basins, ridges, escarpments, 'deeps', seamounts) to the substrate of the trench floor (seabed-sediment composition, mass movement deposits, bedrock outcrop). Using best available bathymetry data combined with the largest lander-derived imaging dataset that spans the full depth range of three hadal trenches (including adjacent slopes); the Mariana, Kermadec and New Hebrides trenches, the topographic variability, fine-scale habitat heterogeneity and distribution of seabed sediments of these three trenches have been assessed for the first time. As well as serving as the first descriptive study of habitat heterogeneity at hadal depths, this study also provides guidance for future hadal sampling campaigns taking into account geographic isolation, total trench particulate organic matter flux, maximum water depth and area.

  20. Solution speciation of plutonium and Americium at an Australian legacy radioactive waste disposal site.

    Science.gov (United States)

    Ikeda-Ohno, Atsushi; Harrison, Jennifer J; Thiruvoth, Sangeeth; Wilsher, Kerry; Wong, Henri K Y; Johansen, Mathew P; Waite, T David; Payne, Timothy E

    2014-09-02

    During the 1960s, radioactive waste containing small amounts of plutonium (Pu) and americium (Am) was disposed in shallow trenches at the Little Forest Burial Ground (LFBG), located near the southern suburbs of Sydney, Australia. Because of periodic saturation and overflowing of the former disposal trenches, Pu and Am have been transferred from the buried wastes into the surrounding surface soils. The presence of readily detected amounts of Pu and Am in the trench waters provides a unique opportunity to study their aqueous speciation under environmentally relevant conditions. This study aims to comprehensively investigate the chemical speciation of Pu and Am in the trench water by combining fluoride coprecipitation, solvent extraction, particle size fractionation, and thermochemical modeling. The predominant oxidation states of dissolved Pu and Am species were found to be Pu(IV) and Am(III), and large proportions of both actinides (Pu, 97.7%; Am, 86.8%) were associated with mobile colloids in the submicron size range. On the basis of this information, possible management options are assessed.

  1. Radiological assessments of land disposal options: recent model developments

    International Nuclear Information System (INIS)

    Fearn, H.S.; Pinner, A.V.; Hemming, C.R.

    1984-10-01

    This report describes progress in the development of methodologies and models for assessing the radiological impact of the disposal of low and intermediate level wastes by (i) shallow land burial in simple trenches (land 1), (ii) shallow land burial in engineered facilities (land 2), and (iii) emplacement in mined repositories or existing cavities (land 3/4). In particular the report describes wasteform leaching models, for unconditioned and cemented waste, the role of engineered barriers of a shallow land burial facility in reducing the magnitude of doses arising from groundwater contact and a detailed consideration of the interactions between radioactive carbon and various media. (author)

  2. Treated Effluent Disposal Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Treated non-hazardous and non-radioactive liquid wastes are collected and then disposed of through the systems at the Treated Effluent Disposal Facility (TEDF). More...

  3. Heat transfer analyses for grout disposal of radioactive double-shell slurry and customer wastes

    International Nuclear Information System (INIS)

    Robinson, S.M.; Gilliam, T.M.; McDaniel, E.W.

    1987-04-01

    Grout immobilization is being considered by Rockwell Hanford Operations (Rockwell Hanford) as a permanent disposal method for several radioactive waste streams. These include disposal of customer and double-shell slurry wastes in earthen trenches and in single-shell underground waste storage tanks. Heat transfer studies have previously been made to determine the maximum heat loading for grout disposal of various wastes under similar conditions, but a sensitivity analysis of temperature profiles to input parameters was needed. This document presents the results of heat transfer calculations for trenches containing grouted customer and double-shell slurry wastes and for in situ disposal of double-shell wastes in single-shell, domed concrete storage tanks. It discusses the conditions that lead to maximum grout temperatures of 250 0 F during the curing stage and 350 0 F thereafter and shows the dependence of these temperatures on input parameters such as soil and grout thermal conductivity, grout specific heat, waste loading, and disposal geometries. Transient heat transfer calculations were made using the HEATING6 computer code to predict temperature profiles in solidified low-level radioactive waste disposal scenarios at the Rockwell Hanford site. The calculations provide guidance for the development of safe, environmentally acceptable grout formulas for the Transportable Grout Facility. 11 refs

  4. Nematode communities in sediments of the Kermadec Trench, Southwest Pacific Ocean

    Science.gov (United States)

    Leduc, Daniel; Rowden, Ashley A.

    2018-04-01

    Hadal trenches are characterized by environmental conditions not found in any other deep-sea environment, such as steep topography and periodic disturbance by turbidity flows, which are likely responsible for the distinct nature of benthic communities of hadal trenches relative to those of the abyssal plain. Nematodes are the most abundant metazoans in the deep-sea benthos, but it is not yet clear if different trenches host distinct nematode communities, and no data are yet available on the communities of most trenches, including the Kermadec Trench in the Southwest Pacific. Quantitative core samples from the seafloor of the Kermadec Trench were recently obtained from four sites at 6000-9000 m depth which allowed for analyses of meiofauna, and nematodes in particular, for the first time. Nematode community and trophic structure was also compared with other trenches using published data. There was a bathymetric gradient in meiofauna abundance, biomass, and community structure within the Kermadec Trench, but patterns for species richness were ambiguous depending on which metric was used. There was a change in community structure from shallow to deep sites, as well as a consistent change in community structure from the upper sediment layers to the deeper sediment layers across the four sites. These patterns are most likely explained by variation in food availability within the trench, and related to trench topography. Together, deposit and microbial feeders represented 48-92% of total nematode abundance in the samples, which suggests that fine organic detritus and bacteria are major food sources. The relatively high abundance of epigrowth feeders at the 6000 and 9000 m sites (38% and 31%, respectively) indicates that relatively freshly settled microalgal cells represent another important food source at these sites. We found a significant difference in species community structure between the Kermadec and Tonga trenches, which was due to both the presence/absence of

  5. Radioecological activity limits for radioactive waste disposal

    International Nuclear Information System (INIS)

    Ahmet, E. Osmanlioglu

    2006-01-01

    Full text: Near surface disposal is an option used by many countries for the disposal of radioactive waste containing mainly short lived radionuclides. Near surface disposal term includes broad range of facilities from simple trenches to concrete vaults. Principally, disposal of radioactive waste requires the implementation of measures that will provide safety for human health and environment now and in the future. For this reason preliminary activity limits should be determined to avoid radioecological problems. Radioactive waste has to be safely disposed in a regulated manner, consistent with internationally agreed principles and standards and with national legislations to avoid serious radioecological problems. The purpose of this study, presents a safety assessment approach to derive operational and post-closure radioecological activity limits for the disposal of radioactive waste. Disposal system has three components; the waste, the facility (incl. engineered barriers) and the site (natural barriers). Form of the waste (unconditioned or conditioned) is effective at the beginning of the migration scenerio. Existence of the engineered barriers in the facility will provide long term isolation of the waste from environment. The site characteristics (geology, groundwater, seismicity, climate etc.) are important for the safety of the system. Occupational exposure of a worker shall be controlled so that the following dose limits are not exceeded: an effective dose of 20mSv/y averaged over 5 consecutive years; and an effective dose of 50mSv in any single year. The effective dose limit for members of the public recommended by ICRP and IAEA is 1 mSv/y for exposures from all man-made sources [1,2]. Dose constraints are typically a fraction of the dose limit and ICRP recommendations (0.3 mSv/y) could be applied [3,4]. Radioecological activity concentration limits of each radionuclide in the waste (Bq/kg) were calculated. As a result of this study radioecological activity

  6. The borehole disposal of spent sources (BOSS)

    International Nuclear Information System (INIS)

    Heard, R.G.

    2002-01-01

    During the International Atomic Energy Agency (IAEA) Regional Training Course on 'The Management of Low-Level Radioactive Waste from Hospitals and Other Nuclear Applications' hosted by the Atomic Energy Corporation of SA Ltd. (AEC), now NECSA, during July/August 1995, the African delegates reviewed their national radioactive waste programmes. Among the issues raised, which are common to most African countries, were the lack of adequate storage facilities, lack of disposal solutions and a lack of equipment to implement widely used disposal concepts to dispose of their spent sources. As a result of this meeting, a Technical Co-operation (TC) project was launched to look at the technical feasibility and economic viability of such a concept. Phase I and II of the project have been completed and the results can be seen in three reports produced by NECSA. The Safety Assessment methodology used in the evaluation of the concept was that developed during the ISAM programme and detailed in Van Blerk's PhD thesis. This methodology is specifically developed for shallow land repositories, but was used in this case as the borehole need not be more than 100m deep and could fit into the definition of a shallow land disposal system. The studies found that the BOSS concept would be suitable for implementation in African countries as the borehole has a large capacity for sources and it is possible that an entire country's disused sources can be placed in a single borehole. The costs are a lot lower than for a shallow land trench, and the concept was evaluated using radium (226) sources as the most limiting inventory. The conclusion of the initial safety assessment was that the BOSS concept is robust, and provides a viable alternative for the disposal of radium needles. The concept is expected to provide good assurance of safety at real sites. The extension of the safety assessment to other types of spent sources is expected to be relatively straightforward. Disposal of radium needles

  7. United Kingdom. Development plan for the eventual closure of the UK Drigg nuclear surface low level waste disposal facility

    International Nuclear Information System (INIS)

    2001-01-01

    The Drigg site, owned and operated by BNFL, is the UK's principal site for the disposal of low level radioactive waste. The site has operated since 1959 and receives wastes from a wide range of sources including nuclear power stations, nuclear fuel cycle facilities, isotope manufacturing sites, universities, general industry and cleanup of historically contaminated sites. Disposals until the late 1980s were solely by tipping essentially loose wastes into excavated trenches. More recently, trench disposals have been phased out in preference to emplacement of containerised, conditioned wastes in concrete vaults. The standardised wasteform consists of high force compacted (or non-compactable) waste immobilised within 20 m 3 steel overpack containers by the addition of cementitious grout. Larger items of wastes are grouted directly, in situ in the vault. The disposal trenches have been completed with an interim cap, as will the vaults when filled. It is currently estimated that sufficient capacity remains at Drigg for disposals to continue until at least 2050. Post-operations it is planned that the site will enter a phase including shut down of operational facilities, emplacement of long term site closure features including a final closure cap and then to an institutional management phase. Planning has therefore been carried out as to the strategy for eventual closure of the site. This closure strategy is also underpinned by an engineering evaluation studies programme to develop and evaluate appropriate closure measures including assessment of the long term performance of such measures. This appendix summarizes some of this work

  8. The Remote Handled Immobilization Low-Activity Waste Disposal Facility Environmental Permits and Approval Plan

    International Nuclear Information System (INIS)

    DEFFENBAUGH, M.L.

    2000-01-01

    The purpose of this document is to revise Document HNF-SD-ENV-EE-003, ''Permitting Plan for the Immobilized Low-Activity Waste Project, which was submitted on September 4, 1997. That plan accounted for the interim storage and disposal of Immobilized-Low Activity Waste at the existing Grout Treatment Facility Vaults (Project W-465) and within a newly constructed facility (Project W-520). Project W-520 was to have contained a combination of concrete vaults and trenches. This document supersedes that plan because of two subsequent items: (1) A disposal authorization that was received on October 25, 1999, in a U. S. Department of Energy-Headquarters, memorandum, ''Disposal Authorization Statement for the Department of Energy Hanford site Low-Level Waste Disposal facilities'' and (2) ''Breakthrough Initiative Immobilized Low-Activity Waste (ILAW) Disposal Alternative,'' August 1999, from Lucas Incorporated, Richland, Washington. The direction within the U. S. Department of Energy-Headquarters memorandum was given as follows: ''The DOE Radioactive Waste Management Order requires that a Disposal authorization statement be obtained prior to construction of new low-level waste disposal facility. Field elements with the existing low-level waste disposal facilities shall obtain a disposal authorization statement in accordance with the schedule in the complex-wide Low-Level Waste Management Program Plan. The disposal authorization statement shall be issued based on a review of the facility's performance assessment and composite analysis or appropriate CERCLA documentation. The disposal authorization shall specify the limits and conditions on construction, design, operations, and closure of the low-level waste facility based on these reviews. A disposal authorization statement is a part of the required radioactive waste management basis for a disposal facility. Failure to obtain a disposal authorization statement or record of decision shall result in shutdown of an operational

  9. ORNL Solid Waste Storage Area 6 trench photos and geologic descriptions, July 1984-September 1985

    International Nuclear Information System (INIS)

    Davis, E.C.; Marshall, D.S.; Stansfield, R.G.; Dreier, R.B.

    1986-03-01

    The Environmental Sciences Division of the Oak Ridge National Laboratory has initiated a photographic and descriptive geologic study of low-level waste trenches opened in Solid Waste Storage Area 6 (SWSA-6). From July 1984 through September 1985, trenches were excavated, geologically described, and photographed before being filled and closed. Only three trenches (Nos. 438, 448, and 465) were excavated and closed before photography could be scheduled. It is recommended that the systematic trench characterization procedure outlined in this report be continued under the direction of ORNL's Operations Division with support from both Environmental Sciences and the Engineering divisions. Publication of such a compilation of trench photos on a yearly basis will serve not only as a part of Department of Energy trench documentation requirements but also as a component of a SWSA-6 geologic data base being developed for current research and development activities. 2 refs., 38 figs

  10. Determining the extent of groundwater interference on the performance of infiltration trenches

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

    2015-01-01

    Infiltration trenches are widely used in stormwater management, but their capacity decreases when installed in areas with shallow groundwater where infiltration is limited by groundwater drainage. Here the hydrological performance of single infiltration trenches in areas with shallow water tables...... is quantified in terms of their capability to reduce peak flow, peak volume and annual stormwater runoff volume. To simulate the long term hydrological performance of infiltration trenches two different models are employed. The models continuously simulate infiltration rates from infiltration trenches using...... to quantify the impact of parameter variability for each scenario. Statistical analysis of the continuous long term model simulations was used to quantify the hydrological performance of infiltration trenches. Results show that infiltration trenches are affected by groundwater when there is an unsaturated...

  11. Process optimization of a deep trench isolation structure for high voltage SOI devices

    International Nuclear Information System (INIS)

    Zhu Kuiying; Qian Qinsong; Zhu Jing; Sun Weifeng

    2010-01-01

    The process reasons for weak point formation of the deep trench on SOI wafers have been analyzed in detail. An optimized trench process is also proposed. It is found that there are two main reasons: one is over-etching laterally of the silicon on the surface of the buried oxide caused by a fringe effect; and the other is the slow growth rate of the isolation oxide in the concave silicon corner of the trench bottom. In order to improve the isolation performance of the deep trench, two feasible ways for optimizing the trench process are proposed. The improved process thickens the isolation oxide and rounds sharp silicon corners at their weak points, increasing the applied voltage by 15-20 V at the same leakage current. The proposed new trench isolation process has been verified in the foundry's 0.5-μm HV SOI technology. (semiconductor devices)

  12. Determining the extent of groundwater interference on the performance of infiltration trenches

    OpenAIRE

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Wong, Tony; Binning, Philip John

    2015-01-01

    Infiltration trenches are widely used in stormwater management, but their capacity decreases when installed in areas with shallow groundwater where infiltration is limited by groundwater drainage. Here the hydrological performance of single infiltration trenches in areas with shallow water tables is quantified in terms of their capability to reduce peak flow, peak volume and annual stormwater runoff volume. To simulate the long term hydrological performance of infiltration trenches two differ...

  13. Inversion kinematics at deep-seated gravity slope deformations revealed by trenching techniques

    OpenAIRE

    Pasquaré Mariotto, Federico; Tibaldi, Alessandro

    2016-01-01

    We compare data from three deep-seated gravitational slope deformations (DSGSDs) where palaeoseismological techniques were applied in artificial trenches. At all trenches, located in metamorphic rocks of the Italian Alps, there is evidence of extensional deformation given by normal movements along slip planes dipping downhill or uphill, and/or fissures, as expected in gravitational failure. However, we document and illustrate – with the aid of trenching – evidenc...

  14. Scaling Rule for Very Shallow Trench IGBT toward CMOS Process Compatibility

    OpenAIRE

    Tanaka, Masahiro; Omura, Ichiro

    2012-01-01

    Deep trench gate is used for latest IGBT to improve device performance. By large difference from deep submicron CMOS structure, there is no process compatibility among CMOS device and trench gate IGBT. We propose IGBT scaling rule for shrinking IGBT cell structure both horizontally and vertically. The scaling rule is theoretically delivered by structure based equations. Device performance improvement was also predicted by TCAD simulations even with very shallow trench gate. The rule enables t...

  15. Engineering design study for storage and disposal of intermediate level waste

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, J R; Hackney, S; Richardson, J A; Heafield, W

    1982-11-01

    A conceptual design study is presented which covers both the storage and disposal of intermediate level waste; repositories in several rock formations are considered at a 300m depth. A total system is proposed including an engineered trench for ..beta gamma.. waste, emplacement systems and off site transportation. Safety during the emplacement phase and the radiological effects of human intrusion and geological catastrophies are considered.

  16. Trench sampling report Salmon Site Lamar County, Mississippi

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    This report describes trench excavation and sample-collection activities conducted by IT Corporation (IT) as part of the ongoing Remedial Investigation and Feasibility Study at the Salmon Site, Lamar County, Mississippi (DOE, 1992). During construction, operation, and closure of the site wastes of unknown composition were buried in pits on site. Surface-geophysical field investigations were conducted intermittently between November 1992 and October 1993 to identify potential waste-burial sites and buried metallic materials. The geophysical investigations included vertical magnetic gradient, electromagnetic conductivity, electromagnetic in-phase component, and ground-penetrating radar surveys. A number of anomalies identified by the magnetic gradiometer survey in the Reynolds Electrical & Engineering Co., Inc., (REECo) pits area indicated buried metallic objects. All of the anomalies were field checked to determine if any were caused by surface features or debris. After field checking, 17 anomalies were still unexplained; trenching was planned to attempt to identify their sources. Between December 8, 1993, and December 17, 1993, 15 trenches were excavated and soil samples were collected at the anomalies. Samples were collected, placed in 250- and 500-milliliter (m{ell}) amber glass containers, and shipped on ice to IT Analytical Services (ITAS) in St. Louis, Missouri, using standard IT chain-of-custody procedures. The samples were analyzed for various chemical and radiological parameters. Data validation has not been conducted on any of the samples. During excavation and sampling, soil samples were also collected by IT for the MSDEQ and the Mississippi Department of Radiological Health, in accordance with their instructions, and delivered into their custody.

  17. Trench sampling report Salmon Site Lamar County, Mississippi

    International Nuclear Information System (INIS)

    1994-07-01

    This report describes trench excavation and sample-collection activities conducted by IT Corporation (IT) as part of the ongoing Remedial Investigation and Feasibility Study at the Salmon Site, Lamar County, Mississippi (DOE, 1992). During construction, operation, and closure of the site wastes of unknown composition were buried in pits on site. Surface-geophysical field investigations were conducted intermittently between November 1992 and October 1993 to identify potential waste-burial sites and buried metallic materials. The geophysical investigations included vertical magnetic gradient, electromagnetic conductivity, electromagnetic in-phase component, and ground-penetrating radar surveys. A number of anomalies identified by the magnetic gradiometer survey in the Reynolds Electrical ampersand Engineering Co., Inc., (REECo) pits area indicated buried metallic objects. All of the anomalies were field checked to determine if any were caused by surface features or debris. After field checking, 17 anomalies were still unexplained; trenching was planned to attempt to identify their sources. Between December 8, 1993, and December 17, 1993, 15 trenches were excavated and soil samples were collected at the anomalies. Samples were collected, placed in 250- and 500-milliliter (m ell) amber glass containers, and shipped on ice to IT Analytical Services (ITAS) in St. Louis, Missouri, using standard IT chain-of-custody procedures. The samples were analyzed for various chemical and radiological parameters. Data validation has not been conducted on any of the samples. During excavation and sampling, soil samples were also collected by IT for the MSDEQ and the Mississippi Department of Radiological Health, in accordance with their instructions, and delivered into their custody

  18. Field and laboratory investigations on pavement backfilling material for micro-trenching in cold regions

    Directory of Open Access Journals (Sweden)

    Leila Hashemian

    2017-07-01

    Full Text Available Micro-trenching is an innovative utility installation method that involves creating a narrow trench to place cable or conduit in the road pavement. Compared to other installation methods, micro-trenching provides minimal disturbance to the community and surrounding environment. Despite the advantages of micro-trenching, it is not widely accepted by municipalities because of its potential to damage the existing pavement. Quality of backfilling is an important factor in long-term sustainability of the micro-trench, particularly in cold regions. This paper investigates the performance of two typical micro-trench backfilling methods in cold climates by studying a pilot project in a parking lot in Edmonton, Alberta, followed by a laboratory evaluation of the material used. For this purpose, the installations were monitored through ground-penetrating radar, optical time-domain reflectometer, and visual observations for three years. The monitoring results revealed that conduit had significant vertical movement inside the trench; several premature failures were also observed in the backfilling material. Laboratory investigation showed that the backfilling material did not meet the criteria for use in cold climates, and micro-trench performance could be enhanced using alternative materials. Keywords: Micro-trench, Pavement backfilling material, Fiber optic installation, Ground-penetrating radar

  19. A brief analysis and description of transuranic wastes in the Subsurface Disposal Area of the radioactive waste management complex at INEL

    International Nuclear Information System (INIS)

    Arrenholz, D.A.; Knight, J.L.

    1991-08-01

    This document presents a brief summary of the wastes and waste types disposed of in the transuranic contaminated portions of the Subsurface Disposal Area of the radioactive waste management complex at Idaho National Engineering Laboratory from 1954 through 1970. Wastes included in this summary are organics, inorganics, metals, radionuclides, and atypical wastes. In addition to summarizing amounts of wastes disposed and describing the wastes, the document also provides information on disposal pit and trench dimensions and contaminated soil volumes. The report also points out discrepancies that exist in available documentation regarding waste and soil volumes and make recommendations for future efforts at waste characterization. 19 refs., 3 figs., 17 tabs

  20. A brief analysis and description of transuranic wastes in the subsurface disposal area of the radioactive waste management complex at INEL

    International Nuclear Information System (INIS)

    Arrenholz, D.A.; Knight, J.L.

    1991-02-01

    This document presents a brief summary of the wastes and waste types disposed of in the transuranic contaminated portions of the Subsurface Disposal Area during the period 1954 through 1970. Wastes included in this summary are organics, inorganics, metals, radionuclides, and special-case wastes. In addition to summarizing amounts of wastes disposed and describing the wastes, the document also provides information on disposal pit and trench dimensions and contaminated soil volumes. The report also points out discrepancies that exist in available documentation regarding waste and soil volumes and makes recommendations for future efforts at waste characterization. 20 refs., 3 figs., 17 tabs

  1. A brief analysis and description of transuranic wastes in the Subsurface Disposal Area of the radioactive waste management complex at INEL

    Energy Technology Data Exchange (ETDEWEB)

    Arrenholz, D.A.; Knight, J.L.

    1991-08-01

    This document presents a brief summary of the wastes and waste types disposed of in the transuranic contaminated portions of the Subsurface Disposal Area of the radioactive waste management complex at Idaho National Engineering Laboratory from 1954 through 1970. Wastes included in this summary are organics, inorganics, metals, radionuclides, and atypical wastes. In addition to summarizing amounts of wastes disposed and describing the wastes, the document also provides information on disposal pit and trench dimensions and contaminated soil volumes. The report also points out discrepancies that exist in available documentation regarding waste and soil volumes and make recommendations for future efforts at waste characterization. 19 refs., 3 figs., 17 tabs.

  2. Movement of a tritium plume in shallow groundwater at a legacy low-level radioactive waste disposal site in eastern Australia.

    Science.gov (United States)

    Hughes, C E; Cendón, D I; Harrison, J J; Hankin, S I; Johansen, M P; Payne, T E; Vine, M; Collins, R N; Hoffmann, E L; Loosz, T

    2011-10-01

    Between 1960 and 1968 low-level radioactive waste was buried in a series of shallow trenches near the Lucas Heights facility, south of Sydney, Australia. Groundwater monitoring carried out since the mid 1970s indicates that with the exception of tritium, no radioactivity above typical background levels has been detected outside the immediate vicinity of the trenches. The maximum tritium level detected in ground water was 390 kBq/L and the median value was 5400 Bq/L, decay corrected to the time of disposal. Since 1968, a plume of tritiated water has migrated from the disposal trenches and extends at least 100 m from the source area. Tritium in rainfall is negligible, however leachate from an adjacent and fill represents a significant additional tritium source. Study data indicate variation in concentration levels and plume distribution in response to wet and dry climatic periods and have been used to determine pathways for tritium migration through the subsurface.

  3. Results of 1998 spectral gamma-ray monitoring of boreholes at the 216-Z-1A tile field, 216-Z-9 trench, and 216-Z-12 crib

    International Nuclear Information System (INIS)

    Horton, D.G.; Randall, R.R.

    1998-09-01

    This document describes the results of fiscal year 1998 vadose zone monitoring of three inactive liquid waste disposal facilities associated with the Plutonium Finishing Plant: the 216-Z-1A tile field, the 216-Z-9 trench, and the 216-Z-12 crib. Monitoring consisted of spectral gamma-ray logging of 21 boreholes. This work was performed by Pacific Northwest National Laboratory in conjunction with Three Rivers Scientific and Waste management Federal Services, inc. Northwest Operations. These three liquid waste disposal facilities were chosen for monitoring because they were identified as containing some of the most significant sources of radioactive contamination in the Hanford Site vadose zone. The basic question addressed by this logging activity is ''Has the configuration of subsurface contamination changed since it was last measured?'' Previous borehole logging and laboratory analyses provide the baseline data to help answer this question

  4. Discussion on some issues for near surface disposal of L/I LW sandy soil

    International Nuclear Information System (INIS)

    Yu Mingde

    2006-01-01

    It is possible that very low level waste (VLLW) is defined from among LLW and disposed of through a simple/easy engineering method. Enhancing the barrier-function of buffer/backfill material will be favorable in a long-term way for controlling long-lived α-nuclides in near field. Designing the trench cover must suit measures to local conditions and lay stress on the key points. For long-term and efficacious supervision on L/I LW disposal facilities, it is very important to change managing ideologies. (authors)

  5. The Incident in Trench A - Follow-up and Lessons

    CERN Multimedia

    Olga Beltramello; Peter Jenni

    An incident happened on 12th October during the dismounting of the HF truck platform in Trench A in the ATLAS cavern. Nobody was injured or in direct danger to be hurt, thanks in particular to the vigilance of the lifting operation crew. However, there is ample matter to reflect upon, and to recall safety measures applicable at any time in the cavern. What happened? During the lifting operation of a lateral platform from the orange HF Truck, used for example for the calorimeter assembly, one of the ~7 m long pillars fell on the access stairs into the ATLAS detector (sector 13). The standard operation to dismount the platform consisted in first unbolting the platform from its support pillars and removing it. Then, after securing a given pillar with the crane, this pillar is unbolted from the floor and removed. By mistake, this pillar was not bolted onto the floor, and fell when the platform was removed. Nobody was present in the trench during the lifting operation and the fall of the pillar. The contractor in...

  6. Kinematics and age of Early Tertiary trench parallel volcano-tectonic lineaments in southern Mexico: Tectonic implications

    Science.gov (United States)

    Martini, M.; Ferrari, L.; Lopez Martinez, M.; Cerca Martinez, M.; Serrano Duran, L.

    2007-05-01

    We present new geological, structural, and geochronological data that constrain the timing and geometry of Early Tertiary strike slip deformation in southwestern Mexico and its relation with the concurrent magmatic activity. Geologic mapping in Guerrero and Michoacan States documented two regional WNW trending volcano-tectonic lineaments sub parallel to the present trench. The southernmost lineament runs for ~140 km from San Miguel Totolapan area (NW Guerrero) to Sanchiqueo (SE Michoacan), and passes through Ciudad Altamirano. Its southeastern part is marked by the alignment of at least eleven silicic to intermediate major domes as well as by the course of the Balsas River. The northwestern part of the lineament is characterized by ductile left lateral shear zones in Early Tertiary plutonic rocks observed in the Rio Chiquito valley. Domes near Ciudad Altamirano are unaffected by ductile shearing and yielded a ~42 Ma 40Ar/39Ar age, setting a minimum age for this deformation. The northern volcano-tectonic lineament runs for ~190 km between the areas of Huitzuco in northern Guerrero and the southern part of the Tzitzio fold in eastern Michoacan. The Huautla, Tilzapotla, Taxco, La Goleta and Nanchititla silicic centers (all in the range 37-34 Ma) are emplaced along this lineament, which continues to the WNW trough a mafic dike swarm exposed north of Tiquicheo (37-35 Ma) and the Purungueo subvolcanic body (~42 Ma). These rocks, unaffected by ductile shearing, give a minimum age of deformation similar to the southern Totolapan-Sanquicheo lineament. Post ~42 Ma deformation is essentially brittle and is characterized by several left lateral and right lateral transcurrent faults with typical Riedel patterns. Other trench-parallel left lateral shear zones active in pre-Oligocene times were recently reported in western Oaxaca. The recognizing of Early Tertiary trench-parallel and left-lateral ductile shearing in internal areas of southern Mexico suggest a field of widely

  7. Radionuclide migration pathways analysis for the Oak Ridge Central Waste Disposal Facility on the West Chestnut Ridge site

    International Nuclear Information System (INIS)

    Pin, F.G.; Witherspoon, J.P.; Lee, D.W.; Cannon, J.B.; Ketelle, R.H.

    1984-10-01

    A dose-to-man pathways analysis is performed for disposal of low-level radioactive waste at the Central Waste Disposal Facility on the West Chestnut Ridge Site. Both shallow land burial (trench) and aboveground (tumulus) disposal methods are considered. The waste volumes, characteristics, and radionuclide concentrations are those of waste streams anticipated from the Oak Ridge National Laboratory, the Y-12 Plant, and the Oak Ridge Gaseous Diffusion Plant. The site capacity for the waste streams is determined on the basis of the pathways analysis. The exposure pathways examined include (1) migration and transport of leachate from the waste disposal units to the Clinch River (via the groundwater medium for trench disposal and Ish Creek for tumulus disposal) and (2) those potentially associated with inadvertent intrusion following a 100-year period of institutional control: an individual resides on the site, inhales suspended particles of contaminated dust, ingests vegetables grown on the plot, consumes contaminated water from either an on-site well or from a nearby surface stream, and receives direct exposure from the contaminated soil. It is found that either disposal method would provide effective containment and isolation for the anticipated waste inventory. However, the proposed trench disposal method would provide more effective containment than tumuli because of sorption of some radionuclides in the soil. Persons outside the site boundary would receive radiation doses well below regulatory limits if they were to ingest water from the Clinch River. An inadvertent intruder could receive doses that approach regulatory limits; however, the likelihood of such intrusions and subsequent exposures is remote. 33 references, 31 figures, 28 tables

  8. Bathymetric Atlas of the North Pacific Ocean.

    Science.gov (United States)

    1978-01-01

    U.S. Coast and Geodetic Survey provided nearshore from Novel Oceenoglphic Office neutical chert of various detils around islands and reefs. Nautical...Easter Islands , 1961. Middle America Trench: Topography and struc- Bernice P. Bishop Mus. Bull. 110, p. 1-44. ture, Geol. Sec. Amer. Bull., v. 72, p...of volcanic ash layers and turbidito% ini 1956. Clipperton fracture zone in the northeastern equa- the north Pacific, Gal. Soc. Amer. Bull., v. 80, p

  9. Disposal of Radioactive Waste

    International Nuclear Information System (INIS)

    2011-01-01

    This Safety Requirements publication applies to the disposal of radioactive waste of all types by means of emplacement in designed disposal facilities, subject to the necessary limitations and controls being placed on the disposal of the waste and on the development, operation and closure of facilities. The classification of radioactive waste is discussed. This Safety Requirements publication establishes requirements to provide assurance of the radiation safety of the disposal of radioactive waste, in the operation of a disposal facility and especially after its closure. The fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. This is achieved by setting requirements on the site selection and evaluation and design of a disposal facility, and on its construction, operation and closure, including organizational and regulatory requirements.

  10. Regional waste treatment with monolith disposal for low-level radioactive waste

    International Nuclear Information System (INIS)

    Forsberg, C.W.

    1983-01-01

    An alternative system is proposed for the disposal of low-level radioactive waste. This system, called REgional Treatment with MOnolith Disposal (RETMOD), is based on integrating three commercial technologies: automated package warehousing, whole-barrel rotary kiln incineration, and cement-based grouts for radioactive waste disposal. In the simplified flowsheet, all the sludges, liquids, resins, and combustible wastes are transported to regional facilities where they are incinerated. The ash is then mixed with special cement-based grouts, and the resulting mixture is poured into trenches to form large waste-cement monoliths. Wastes that do not require treatment, such as damaged and discarded equipment, are prepositioned in the trenches with the waste-cement mixture poured on top. The RETMOD system may provide higher safety margins by conversion of wastes into a solidified low-leach form, creation of low-surface area waste-cement monoliths, and centralization of waste processing into a few specialized facilities. Institutional problems would be simplified by placing total responsibility for safe disposal on the disposal site operator. Lower costs may be realized through reduced handling costs, the economics of scale, simplified operations, and less restrictive waste packaging requirements

  11. Evaluation of proposed shallow-land burial sites using the PRESTO-II [Prediction of Radiation Effects from Shallow Trench Operations] methodology and code

    International Nuclear Information System (INIS)

    Fields, D.E.; Uslu, I.; Yalcintas, M.G.

    1987-01-01

    PRESTO-II (Prediction of Radiation Effects from Shallow Trench Operations) is a computer code designed to evaluate possible doses and risks (health effects) from shallow-land burial sites. The model is intended to serve as a non-site-specific screening model for assessing radionuclide transport, ensuing exposure, and health impacts to a static local population for a 1000-year period following the end of disposal operations. Human exposure scenarios include normal releases (including leaching and operational spillage), human intrusion, and limited site farming or reclamation. Pathways and processes of transport from the trench to an individual or population include ground-water transport, overland flow, erosion, surface water dilution, suspension, atmospheric transport and deposition, inhalation, external exposure, and ingestion of contaminated beef, milk, crops, and water. The proposed waste disposal area in Koteyli, Balikesir, Turkey, has been evaluated using the PRESTO-II methodology. The results have been compared to those obtained for the Barnwell, South Carolina, site. Dose estimates for both sites are below regulatory limits, for the release and exposure scenarios considered. The doses for the sites are comparable, with slightly higher estimates obtained for the Turkish site. 7 refs., 1 tab

  12. Air Monitoring Leads to Discovery of New Contamination at Radioactive Waste Disposal Site (Area G) at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Kraig, D.H.; Conrad, R.C.

    1999-01-01

    Air monitoring at Area G, the low-level radioactive waste disposal area at Los Alamos National Laboratory, revealed increased air concentrations of 239 Pu and 241 Am at one location along the north boundary. This air monitoring location is a couple of meters north of a dirt road used to access the easternmost part of Area G. Air concentrations of 238 Pu were essentially unaffected, which was puzzling because the 238 Pu and 239 Pu are present in the local, slightly contaminated soils. Air concentrations of these radionuclides increased about a factor of ten in early 1995 and remained at those levels until the first quarter of 1996. During the spring of 1996 air concentrations again increased by a factor of about ten. No other radionuclides were elevated and no other Area G stations showed elevations of these radionuclides. After several formal meetings didn't provide an adequate cause for the elevations, a gamma survey was performed and showed a small area of significant contamination just south of the monitor location. We found in February, 1995, a trench for a water line had been dug within a meter of so of the air stations. Then, during early 1996, the dirt road was rerouted such that its new path was directly over the unknown contamination. It appears that the trenching brought contaminated material to the surface and caused the first rise in air concentrations and then the rerouting of the road over the contamination caused the second rise, during 1996. We also found that during 1976 and 1977 contaminated soils from the clean-up of an old processing facility had been spread over the filled pits in the vicinity of the air monitors. These soils were very low in 238Pu which explains why we saw very little 238 Pu in the increased air concentrations. A layer of gravel and sand was spread over the contaminated area. Although air concentrations of 239 Pu and 241 Am dropped considerably, the y have not returned to pre-1995 levels

  13. Regional waste treatment facilities with underground monolith disposal for all low-heat-generating nuclear wastes

    International Nuclear Information System (INIS)

    Forsberg, C.W.

    1982-01-01

    An alternative system for treatment and disposal of all ''low-heat-generating'' nuclear wastes from all sources is proposed. The system, Regional Waste Treatment Facilities with Underground Monolith Disposal (RWTF/UMD), integrates waste treatment and disposal operations into single facilities at regional sites. Untreated and/or pretreated wastes are transported from generation sites such as reactors, hospitals, and industries to regional facilities in bulk containers. Liquid wastes are also transported in bulk after being gelled for transport. The untreated and pretreated wastes are processed by incineration, crushing, and other processes at the RWTF. The processed wastes are mixed with cement. The wet concrete mixture is poured into large low-cost, manmade caverns or deep trenches. Monolith dimensions are from 15 to 25 m wide, and 20 to 60 m high and as long as required. This alternative waste system may provide higher safety margins in waste disposal at lower costs

  14. Hadal disturbance in the Japan Trench induced by the 2011 Tohoku-Oki earthquake

    DEFF Research Database (Denmark)

    Oguri, K.; Kawamura, K.; Sakaguchi, A.

    2013-01-01

    In situ video observations and sediment core samplings were performed at two hadal sites in the Japan Trench on July, 2011, four months after the Tohoku-Oki earthquake. Video recordings documented dense nepheloid layers extending similar to 30-50 m above the sea bed. At the trench axis, benthic...

  15. Chasing the Ghost of Melesina Trench: A film by Qina Liu in collaboration with Katharine Kittredge

    Directory of Open Access Journals (Sweden)

    Katherine Kittredge

    2013-04-01

    Full Text Available Filmmaker Qina Liu has created a short documentary about Katharine Kittredge's decade-long quest to learn about the life and work of Anglo-Irish diarist and poet Melesina Trench. The story tells of remarkable coincidences, documents lost and found, and the emergence of Trench's descendants in the project's final chapter.

  16. Influence of lateral slab edge distance on plate velocity, trench velocity, and subduction partitioning

    NARCIS (Netherlands)

    Schellart, W. P.; Stegman, D. R.; Farrington, R. J.; Moresi, L.

    2011-01-01

    Subduction of oceanic lithosphere occurs through both trenchward subducting plate motion and trench retreat. We investigate how subducting plate velocity, trench velocity and the partitioning of these two velocity components vary for individual subduction zone segments as a function of proximity to

  17. Ground-water flow and transport modeling of the NRC-licensed waste disposal facility, West Valley, New York

    International Nuclear Information System (INIS)

    Kool, J.B.; Wu, Y.S.

    1991-10-01

    This report describes a simulation study of groundwater flow and radionuclide transport from disposal at the NRC licensed waste disposal facility in West Valley, New York. A transient, precipitation driven, flow model of the near-surface fractured till layer and underlying unweathered till was developed and calibrated against observed inflow data into a recently constructed interceptor trench for the period March--May 1990. The results suggest that lateral flow through the upper, fractured till layer may be more significant than indicated by previous, steady state flow modeling studies. A conclusive assessment of the actual magnitude of lateral flow through the fractured till could however not be made. A primary factor contributing to this uncertainty is the unknown contribution of vertical infiltration through the interceptor trench cap to the total trench inflow. The second part of the investigation involved simulation of the migration of Sr-90, Cs-137 and Pu-239 from the one of the fuel hull disposal pits. A first-order radionuclide leach rate with rate coefficient of 10 -6 /day was assumed to describe radionuclide release into the disposal pit. The simulations indicated that for wastes buried below the fractured till zone, no significant migration would occur. However, under the assumed conditions, significant lateral migration could occur for radionuclides present in the upper, fractured till zone. 23 refs., 68 figs., 12 tabs

  18. Relationships between environment and characteristics of marine Fe-Mn deposits in the Romanche trench

    International Nuclear Information System (INIS)

    Bonte, Philippe.

    1981-11-01

    The geological characteristics and Fe-Mn deposits from the North wall of the Romanche trench (Atlantic ocean) were studied in order to investigate possible relationships of these deposits with hydrothermalism. The results indicate diffuse hydrothermal activity in all of the rock samples which may explain the notable mineralogical associations observed, such as talc-dolomite-hematite-serpentine. All rock outcrops were covered with Fe-Mn deposits, but no such deposits were noted on sedimentary platforms. The variations in average chemical composition are very low among the different deposits. Hence, the phenomenon which produces these deposits is not localized. From this study, we conclude that marine Fe-Mn deposits result from the continuous supply of terrigenous iron and discontinuous supply of manganese, probably hydrothermal in origin. Detrital particles and numerous chemical elements are scavenged during the accretion process itself, whereas some trace elements, among the least soluble (Co, Ti, Th, Ce), are adsorbed on these deposits, independently of the accretion. This explains the inverse variation of the content of these elements versus deposit thickness [fr

  19. Greater-Than-Class C Low Level Radioactive Waste Characteristics and Disposal Aspects

    International Nuclear Information System (INIS)

    Arlt, Hans D.; Brimfield, Terrence; Grossman, Chris

    2016-01-01

    Conclusions • Due to the way LLRW is defined in the US, there is a category of LLRW (i.e., GTCC waste) that was categorized in the 1980’s and is similar to ILW and not generally acceptable for near-surface disposal. • Three decades later, it cannot be excluded that future NRC analyses may find some GTCC waste type suitable for near-surface disposal, and a proposed rule may be developed for licensing the disposal of such waste. • Current regulations only allow individual proposals for GTCC LLRW disposal to be evaluated on a case-by-case basis to determine the acceptability of land disposal other than in a geologic repository • Based on current regulations, the variability and diversity of FEPs associated with such safety cases is theoretically large: - The range of activity concentrations, half-lives, and volumes of GTCC waste types is large; - The range of physical forms is large: metal pieces to soils and sludges; - The range of potential disposal methods is large: trench, vault, landfill, shaft, borehole; - The range of potential disposal environments is large: arid vs. humid, unsaturated vs. saturated, sediment vs. rock, nearsurface to intermediate; - The stability and past natural history of a specific disposal site must also be adequately known. • Examples of potential site-specific cases designed to demonstrate the acceptability of GTCC LLRW land disposal other than deep geologic: - Proposals for disposal could entail concepts that have been relatively well assessed by NRC staff in the past; e.g., trench disposal of a moderate volume of GTCC Other Waste in an arid, unsaturated, near-surface environment; - Proposals for disposal could also entail concepts that have been less frequently assessed; e.g., borehole disposal of higher activity sealed sources in a humid, saturated, intermediate depth environment. • However, if one potential site and design was under consideration, the variability and diversity of FEPs associated with that site

  20. Interim-status groundwater monitoring plan for the 216-B-63 trench. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, M.D.

    1995-06-13

    This document outlines the groundwater monitoring plan for interim-status detection-level monitoring of the 216-B-63 Trench. This is a revision of the initial groundwater monitoring plan prepared for Westinghouse Hanford Company (WHC) by Bjornstad and Dudziak (1989). The 216-B-63 Trench, located at the Hanford Site in south-central Washington State, is an open, unlined, earthern trench approximately 1.2 m (4 ft) wide at the bottom, 427 m (1400 ft) long, and 3 m (10 ft) deep that received wastewater containing hazardous waste and radioactive materials from B Plant, located in the 200 East Area. Liquid effluent discharge to the 216-B-63 Trench began in March 1970 and ceased in February 1992. The trench is now managed by Waste Tank Operations.

  1. Note: long range and accurate measurement of deep trench microstructures by a specialized scanning tunneling microscope.

    Science.gov (United States)

    Ju, Bing-Feng; Chen, Yuan-Liu; Zhang, Wei; Zhu, Wule; Jin, Chao; Fang, F Z

    2012-05-01

    A compact but practical scanning tunneling microscope (STM) with high aspect ratio and high depth capability has been specially developed. Long range scanning mechanism with tilt-adjustment stage is adopted for the purpose of adjusting the probe-sample relative angle to compensate the non-parallel effects. A periodical trench microstructure with a pitch of 10 μm has been successfully imaged with a long scanning range up to 2.0 mm. More innovatively, a deep trench with depth and step height of 23.0 μm has also been successfully measured, and slope angle of the sidewall can approximately achieve 67°. The probe can continuously climb the high step and exploring the trench bottom without tip crashing. The new STM could perform long range measurement for the deep trench and high step surfaces without image distortion. It enables accurate measurement and quality control of periodical trench microstructures.

  2. Interim-status groundwater monitoring plan for the 216-B-63 trench. Revision 1

    International Nuclear Information System (INIS)

    Sweeney, M.D.

    1995-01-01

    This document outlines the groundwater monitoring plan for interim-status detection-level monitoring of the 216-B-63 Trench. This is a revision of the initial groundwater monitoring plan prepared for Westinghouse Hanford Company (WHC) by Bjornstad and Dudziak (1989). The 216-B-63 Trench, located at the Hanford Site in south-central Washington State, is an open, unlined, earthern trench approximately 1.2 m (4 ft) wide at the bottom, 427 m (1400 ft) long, and 3 m (10 ft) deep that received wastewater containing hazardous waste and radioactive materials from B Plant, located in the 200 East Area. Liquid effluent discharge to the 216-B-63 Trench began in March 1970 and ceased in February 1992. The trench is now managed by Waste Tank Operations

  3. Geophysical investigation of trench 4, Burial Ground 218-W-4C, 200 west area

    International Nuclear Information System (INIS)

    Kiesler, J.P.

    1994-01-01

    This report contains the results of a geophysical investigation conducted to characterize Trench 4, located in Burial Ground 218-W-4C, 200 West Area. Trench 4 is where transuranic (TRU) waste is stored. The primary objective of these geophysical investigations was to determine the outer edges of the trench/modules and select locations for plate-bearing tests. The test locations are to be 5 to 8 ft. beyond the edges of the trench. Secondary objectives include differentiating between the different types of waste containers within a given trench, determining the amount of soil cover over the waste containers, and to locate the module boundaries. Ground-penetrating radar (GPR) and electromagnetic induction (EMI) were the methods selected for this investigation

  4. Field demonstration of in situ grouting of radioactive solid waste burial trenches with polyacrylamide

    International Nuclear Information System (INIS)

    Spalding, B.P.; Fontaine, T.A.

    1990-01-01

    Demonstrations of in situ grouting with polyacrylamide were carried out on two undisturbed burial trenches and one dynamically compacted burial trench in Solid Waste Storage Area (SWSA) 6 at Oak Ridge National Laboratory (ORNL). The injection of polyacrylamide was achieved quite facilely for the two undisturbed burial trenches which were filled with grout, at typical pumping rates of 95 L/min, in several batches injected over several days. The compacted burial trench, however, failed to accept grout at more than 1.9 L/min even when pressure was applied. Thus, it appears that burial trenches, stabilized by dynamic compaction, have a permeability too low to be considered groutable. The water table beneath the burial trenches did not respond to grout injections indicating a lack of hydrologic connection between fluid grout and the water table which would have been observed if the grout failed to set. Because grout set times were adjusted to less than 60 min, the lack of hydrologic connection was not surprising. Postgrouting penetration testing revealed that the stability of the burial trenches was increased from 26% to 79% that measured in the undisturbed soil surrounding the trenches. In situ permeation tests on the grouted trenches indicated a significant reduction in hydraulic conductivity of the trench contents from a mean of 2.1 x 10 -3 to 1.85 x 10 -5 cm/s. Preliminary observations indicated that grouting with polyacrylamide is an excellent method for both improved stability and hydrologic isolation of radioactive waste and its incidental hazardous constituents

  5. Disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Blomeke, J.O.

    1979-01-01

    Radioactive waste management and disposal requirements options available are discussed. The possibility of beneficial utilization of radioactive wastes is covered. Methods of interim storage of transuranium wastes are listed. Methods of shipment of low-level and high-level radioactive wastes are presented. Various methods of radioactive waste disposal are discussed

  6. Biological intrusion of low-level-waste trench covers

    Science.gov (United States)

    Hakonson, T. E.; Gladney, E. S.

    The long-term integrity of low-level waste shallow land burialsites is dependent on the interaction of physical, chemical, and biological factors that modify the waste containment system. The need to consider biological processes as being potentially important in reducing the integrity of waste burial site cover treatment is demonstrated. One approach to limiting biological intrusion through the waste cover is to apply a barrier within the profile to limit root and animal penetration with depth. Experiments in the Los Alamos Experimental Engineered Test Facility were initiated to develop and evaluate biological barriers that are effective in minimizing intrusion into waste trenches. The experiments that are described employ four different candidate barrier materials of geologic origin. Experimental variables that will be evaluated, in addition to barrier type, are barrier depth and sil overburden depth.

  7. Control of water infiltration through SLB trench covers

    International Nuclear Information System (INIS)

    Schulz, R.K.; Ridky, R.W.

    1986-01-01

    A technique for control of water infiltration into waste burial trenches is described. Initial results show the procedure to be very promising. In essence, the technique combines engineered or positive control of run-off, along with a vegetative cover, and is named bioengineering management. To investigate control of infiltration, lysimeters are being used to make complete water balance measurements. The studies are underway at the Maxey Flats, Kentucky, low-level waste burial site. Where the original Maxey Flats site closure procedure is followed, it is necessary to pump large amounts of water out of the lysimeters to prevent the water table from rising closer than 2 meters from the surface. Using the fescue grass bioengineering management procedure, no pumping is required. Encouraged by the initial findings in the rather small-scale lysimeters, a large scale demonstration of the bioengineering management technique has been initiated in Beltsville, Maryland. 6 references, 14 figures

  8. A synthetic seismicity model for the Middle America Trench

    Science.gov (United States)

    Ward, Steven N.

    1991-01-01

    A novel iterative technique, based on the concept of fault segmentation and computed using 2D static dislocation theory, for building models of seismicity and fault interaction which are physically acceptable and geometrically and kinematically correct, is presented. The technique is applied in two steps to seismicity observed at the Middle America Trench. The first constructs generic models which randomly draw segment strengths and lengths from a 2D probability distribution. The second constructs predictive models in which segment lengths and strengths are adjusted to mimic the actual geography and timing of large historical earthquakes. Both types of models reproduce the statistics of seismicity over five units of magnitude and duplicate other aspects including foreshock and aftershock sequences, migration of foci, and the capacity to produce both characteristic and noncharacteristic earthquakes. Over a period of about 150 yr the complex interaction of fault segments and the nonlinear failure conditions conspire to transform an apparently deterministic model into a chaotic one.

  9. Identifying Preserved Storm Events on Beaches from Trenches and Cores

    Science.gov (United States)

    Wadman, H. M.; Gallagher, E. L.; McNinch, J.; Reniers, A.; Koktas, M.

    2014-12-01

    Recent research suggests that even small scale variations in grain size in the shallow stratigraphy of sandy beaches can significantly influence large-scale morphology change. However, few quantitative studies of variations in shallow stratigraphic layers, as differentiated by variations in mean grain size, have been conducted, in no small part due to the difficulty of collecting undisturbed sediment cores in the energetic lower beach and swash zone. Due to this lack of quantitative stratigraphic grain size data, most coastal morphology models assume that uniform grain sizes dominate sandy beaches, allowing for little to no temporal or spatial variations in grain size heterogeneity. In a first-order attempt to quantify small-scale, temporal and spatial variations in beach stratigraphy, thirty-five vibracores were collected at the USACE Field Research Facility (FRF), Duck, NC, in March-April of 2014 using the FRF's Coastal Research and Amphibious Buggy (CRAB). Vibracores were collected at set locations along a cross-shore profile from the toe of the dune to a water depth of ~1m in the surf zone. Vibracores were repeatedly collected from the same locations throughout a tidal cycle, as well as pre- and post a nor'easter event. In addition, two ~1.5m deep trenches were dug in the cross-shore and along-shore directions (each ~14m in length) after coring was completed to allow better interpretation of the stratigraphic sequences observed in the vibracores. The elevations of coherent stratigraphic layers, as revealed in vibracore-based fence diagrams and trench data, are used to relate specific observed stratigraphic sequences to individual storm events observed at the FRF. These data provide a first-order, quantitative examination of the small-scale temporal and spatial variability of shallow grain size along an open, sandy coastline. The data will be used to refine morphological model predictions to include variations in grain size and associated shallow stratigraphy.

  10. Experience and related research and development in applying corrective measures at the major low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    Rose, R.R.; Mahathy, J.M.; Epler, J.S.; Boing, L.E.; Jacobs, D.G.

    1983-07-01

    A review was conducted of experience in responding to problems encountered in shallow land burial of low-level radioactive waste and in research and development related to these problems. The operating histories of eleven major disposal facilities were examined. Based on the review, it was apparent that the most effective corrective measures administered were those developed from an understanding of the site conditions which caused the problems. Accordingly, the information in this document has been organized around the major conditions which have caused problems at existing sites. These include: (1) unstable trench cover, (2) permeable trench cover, (3) subsidence, (4) ground water entering trenches, (5) intrusion by deep-rooted plants, (6) intrusion by burrowing animals, and (7) chemical and physical conditions in trench. Because the burial sites are located in regions that differ in climatologic, geologic, hydrologic, and biologic characteristics, there is variation in the severity of problems among the sites and in the nature of information concerning corrective efforts. Conditions associated with water-related problems have received a great deal of attention. For these, corrective measures have ranged from the creation of diversion systems for reducing the contact of surface water with the trench cover to the installation of seals designed to prevent infiltration from reaching the buried waste. On the other hand, corrective measures for conditions of subsidence or of intrusion by burrowing animals have had limited application and are currently under evaluation or are subjects of research and development activities. 50 references, 20 figures, 10 tables

  11. Special Analysis of Transuranic Waste in Trench T04C at the Area 5 Radioactive Waste Management Site, Nevada Test Site, Nye County, Nevada, Revision 1

    International Nuclear Information System (INIS)

    Greg Shott; Vefa Yucel; Lloyd Desotell

    2008-01-01

    This Special Analysis (SA) was prepared to assess the potential impact of inadvertent disposal of a limited quantity of transuranic (TRU) waste in classified Trench 4 (T04C) within the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS). The Area 5 RWMS is a low-level radioactive waste disposal site in northern Frenchman Flat on the Nevada Test Site (NTS). The Area 5 RWMS is regulated by the U.S. Department of Energy (DOE) under DOE Order 435.1 and DOE Manual (DOE M) 435.1-1. The primary objective of the SA is to evaluate if inadvertent disposal of limited quantities of TRU waste in a shallow land burial trench at the Area 5 RWMS is in compliance with the existing, approved Disposal Authorization Statement (DAS) issued under DOE M 435.1-1. In addition, supplemental analyses are performed to determine if there is reasonable assurance that the requirements of Title 40, Code of Federal Regulations (CFR), Part 191, Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level, and Transuranic Radioactive Wastes, can be met. The 40 CFR 191 analyses provide supplemental information regarding the risk to human health and the environment of leaving the TRU waste in T04C. In 1989, waste management personnel reviewing classified materials records discovered that classified materials buried in trench T04C at the Area 5 RWMS contained TRU waste. Subsequent investigations determined that a total of 102 55-gallon drums of TRU waste from Rocky Flats were buried in trench T04C in 1986. The disposal was inadvertent because unclassified records accompanying the shipment indicated that the waste was low-level. The exact location of the TRU waste in T04C was not recorded and is currently unknown. Under DOE M 435.1-1, Chapter IV, Section P.5, low-level waste disposal facilities must obtain a DAS. The DAS specifies conditions that must be met to operate within the radioactive waste management basis, consisting of a

  12. Special Analysis of Transuranic Waste in Trench T04C at the Area 5 Radioactive Waste Management Site, Nevada Test Site, Nye County, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Greg Shott, Vefa Yucel, Lloyd Desotell

    2008-05-01

    This Special Analysis (SA) was prepared to assess the potential impact of inadvertent disposal of a limited quantity of transuranic (TRU) waste in classified Trench 4 (T04C) within the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS). The Area 5 RWMS is a low-level radioactive waste disposal site in northern Frenchman Flat on the Nevada Test Site (NTS). The Area 5 RWMS is regulated by the U.S. Department of Energy (DOE) under DOE Order 435.1 and DOE Manual (DOE M) 435.1-1. The primary objective of the SA is to evaluate if inadvertent disposal of limited quantities of TRU waste in a shallow land burial trench at the Area 5 RWMS is in compliance with the existing, approved Disposal Authorization Statement (DAS) issued under DOE M 435.1-1. In addition, supplemental analyses are performed to determine if there is reasonable assurance that the requirements of Title 40, Code of Federal Regulations (CFR), Part 191, Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level, and Transuranic Radioactive Wastes, can be met. The 40 CFR 191 analyses provide supplemental information regarding the risk to human health and the environment of leaving the TRU waste in T04C. In 1989, waste management personnel reviewing classified materials records discovered that classified materials buried in trench T04C at the Area 5 RWMS contained TRU waste. Subsequent investigations determined that a total of 102 55-gallon drums of TRU waste from Rocky Flats were buried in trench T04C in 1986. The disposal was inadvertent because unclassified records accompanying the shipment indicated that the waste was low-level. The exact location of the TRU waste in T04C was not recorded and is currently unknown. Under DOE M 435.1-1, Chapter IV, Section P.5, low-level waste disposal facilities must obtain a DAS. The DAS specifies conditions that must be met to operate within the radioactive waste management basis, consisting of a

  13. Maxey Flats low-level waste disposal site closure activities

    International Nuclear Information System (INIS)

    Haight, C.P.; Mills, D.; Razor, J.E.

    1987-01-01

    The Maxey Flats Radioactive Waste Disposal Facility in Fleming County, Kentucky is in the process of being closed. The facility opened for commercial business in the spring of 1963 and received approximately 4.75 million cubic feet of radioactive waste by the time it was closed in December of 1977. During fourteen years of operation approximately 2.5 million curies of by-product material, 240,000 kilograms of source material, and 430 kilograms of special nuclear material were disposed. The Commonwealth purchased the lease hold estate and rights in May 1978 from the operating company. This action was taken to stabilize the facility and prepare it for closure consisting of passive care and monitoring. To prepare the site for closure, a number of remedial activities had to be performed. The remediation activities implemented have included erosion control, surface drainage modifications, installation of a temporary plastic surface cover, leachate removal, analysis, treatment and evaporation, US DOE funded evaporator concentrates solidification project and their on-site disposal in an improved disposal trench with enhanced cover for use in a humid environment situated in a fractured geology, performance evaluation of a grout injection demonstration, USGS subsurface geologic investigation, development of conceptual closure designs, and finally being added to the US EPA National Priority List for remediation and closure under Superfund. 13 references, 3 figures

  14. Greater confinement disposal program at the Savannah River Plant

    International Nuclear Information System (INIS)

    Towler, O.A.; Cook, J.R.; Peterson, D.L.; Reddick, J.A.

    1984-01-01

    A facility to demonstrate Greater Confinement Disposal (GCD) of low-level solid radioactive waste in a humid environment has been built and is operating at the Savannah River Plant (SRP). GCD practices of waste segregation into high and low activity concentrations, emplacement of waste below the root zone, waste stabilization, and capping are being used in the demonstration. Activity concentrations to select wastes for GCD are based on the volume/activity distribution of low-level solid wastes as obtained from SRP burial records, and are equal to or less than those for Class B waste in 10 CFR 61. The first disposal units constructed are twenty 9-ft-diam, 30-ft-deep boreholes. These holes will be used to dispose of wastes from the production reactors, tritiated wastes, and selected wastes from offsite. In 1984, construction will begin on an engineered GCD trench for disposal of boxed waste and large bulky items that meet the activity concentration criteria. 4 references, 5 figures, 2 tables

  15. Closure Report for Corrective Action Unit 139: Waste Disposal Sites, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2009-01-01

    Corrective Action Unit (CAU) 139 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Waste Disposal Sites' and consists of the following seven Corrective Action Sites (CASs), located in Areas 3, 4, 6, and 9 of the Nevada Test Site: CAS 03-35-01, Burn Pit; CAS 04-08-02, Waste Disposal Site; CAS 04-99-01, Contaminated Surface Debris; CAS 06-19-02, Waste Disposal Site/Burn Pit; CAS 06-19-03, Waste Disposal Trenches; CAS 09-23-01, Area 9 Gravel Gertie; and CAS 09-34-01, Underground Detection Station. Closure activities were conducted from December 2008 to April 2009 according to the FFACO (1996, as amended February 2008) and the Corrective Action Plan for CAU 139 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2007b). The corrective action alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. Closure activities are summarized. CAU 139, 'Waste Disposal Sites,' consists of seven CASs in Areas 3, 4, 6, and 9 of the NTS. The closure alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. This CR provides a summary of completed closure activities, documentation of waste disposal, and confirmation that remediation goals were met. The following site closure activities were performed at CAU 139 as documented in this CR: (1) At CAS 03-35-01, Burn Pit, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (2) At CAS 04-08-02, Waste Disposal Site, an administrative UR was implemented. No postings or post-closure monitoring are required. (3) At CAS 04-99-01, Contaminated Surface Debris, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (4) At CAS 06-19-02, Waste Disposal Site/Burn Pit, no work was performed. (5) At CAS 06-19-03, Waste Disposal Trenches, a native soil cover was installed, and a UR was

  16. Closure Report for Corrective Action Unit 139: Waste Disposal Sites, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2009-07-31

    Corrective Action Unit (CAU) 139 is identified in the Federal Facility Agreement and Consent Order (FFACO) as 'Waste Disposal Sites' and consists of the following seven Corrective Action Sites (CASs), located in Areas 3, 4, 6, and 9 of the Nevada Test Site: CAS 03-35-01, Burn Pit; CAS 04-08-02, Waste Disposal Site; CAS 04-99-01, Contaminated Surface Debris; CAS 06-19-02, Waste Disposal Site/Burn Pit; CAS 06-19-03, Waste Disposal Trenches; CAS 09-23-01, Area 9 Gravel Gertie; and CAS 09-34-01, Underground Detection Station. Closure activities were conducted from December 2008 to April 2009 according to the FFACO (1996, as amended February 2008) and the Corrective Action Plan for CAU 139 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2007b). The corrective action alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. Closure activities are summarized. CAU 139, 'Waste Disposal Sites,' consists of seven CASs in Areas 3, 4, 6, and 9 of the NTS. The closure alternatives included No Further Action, Clean Closure, and Closure in Place with Administrative Controls. This CR provides a summary of completed closure activities, documentation of waste disposal, and confirmation that remediation goals were met. The following site closure activities were performed at CAU 139 as documented in this CR: (1) At CAS 03-35-01, Burn Pit, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (2) At CAS 04-08-02, Waste Disposal Site, an administrative UR was implemented. No postings or post-closure monitoring are required. (3) At CAS 04-99-01, Contaminated Surface Debris, soil and debris were removed and disposed as LLW, and debris was removed and disposed as sanitary waste. (4) At CAS 06-19-02, Waste Disposal Site/Burn Pit, no work was performed. (5) At CAS 06-19-03, Waste Disposal Trenches, a native soil cover was installed

  17. RESULTS OF GROUNDWATER MONITORING FOR THE 183-H SOLAR EVAPORATION BASINS AND 300 AREA PROCESS TRENCHES JANUARY - JUNE 2008

    International Nuclear Information System (INIS)

    Hartman, M.J.

    2008-01-01

    This is one of a series of reports on Resource Conservation and Recovery Act of 1976 (RCRA) monitoring at the 183-H solar evaporation basins and the 300 Area process trenches. It fulfills the requirement of Washington Administrative Code (WAC) 173-303-645(11)(g), 'Release from Regulated Units', to report twice each year on the effectiveness of the corrective action program. This report covers the period from January through June 2008. The current objective of corrective action monitoring the 183-H basins is simply to track trends. Although there is short-term variability in contaminant concentrations, trends over the past 10 years are downward. The current Hanford Facility RCRA Permit (Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste (Permit No. WA 7890008967)) and monitoring plan remain adequate for the objective of tracking trends. The objective of groundwater monitoring at the 300 Area process trenches is to demonstrate the effectiveness of the corrective action program by examining the trend of the constituents of interest to confirm that they are attenuating naturally. The overall concentration of uranium in network wells remained above the 30 (micro)g/L drinking water standard in the three downgradient wells screened at the water table. Fluctuations of uranium concentration are caused by changes in river stage. The concentration of cis-1,2-dichloroethene remained above the 70 (micro)g/L drinking water standard in one well (399-1-16B). Concentrations are relatively steady at this well and are not affected by river stage. Trichloroethene and tetrachloroethene concentrations were below detection limits in all wells during the reporting period

  18. Characterization of 618-11 solid waste burial ground, disposed waste, and description of the waste generating facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hladek, K.L.

    1997-10-07

    The 618-11 (Wye or 318-11) burial ground received transuranic (TRTJ) and mixed fission solid waste from March 9, 1962, through October 2, 1962. It was then closed for 11 months so additional burial facilities could be added. The burial ground was reopened on September 16, 1963, and continued operating until it was closed permanently on December 31, 1967. The burial ground received wastes from all of the 300 Area radioactive material handling facilities. The purpose of this document is to characterize the 618-11 solid waste burial ground by describing the site, burial practices, the disposed wastes, and the waste generating facilities. This document provides information showing that kilogram quantities of plutonium were disposed to the drum storage units and caissons, making them transuranic (TRU). Also, kilogram quantities of plutonium and other TRU wastes were disposed to the three trenches, which were previously thought to contain non-TRU wastes. The site burial facilities (trenches, caissons, and drum storage units) should be classified as TRU and the site plutonium inventory maintained at five kilograms. Other fissile wastes were also disposed to the site. Additionally, thousands of curies of mixed fission products were also disposed to the trenches, caissons, and drum storage units. Most of the fission products have decayed over several half-lives, and are at more tolerable levels. Of greater concern, because of their release potential, are TRU radionuclides, Pu-238, Pu-240, and Np-237. TRU radionuclides also included slightly enriched 0.95 and 1.25% U-231 from N-Reactor fuel, which add to the fissile content. The 618-11 burial ground is located approximately 100 meters due west of Washington Nuclear Plant No. 2. The burial ground consists of three trenches, approximately 900 feet long, 25 feet deep, and 50 feet wide, running east-west. The trenches constitute 75% of the site area. There are 50 drum storage units (five 55-gallon steel drums welded together

  19. Characterization of 618-11 solid waste burial ground, disposed waste, and description of the waste generating facilities

    International Nuclear Information System (INIS)

    Hladek, K.L.

    1997-01-01

    The 618-11 (Wye or 318-11) burial ground received transuranic (TRTJ) and mixed fission solid waste from March 9, 1962, through October 2, 1962. It was then closed for 11 months so additional burial facilities could be added. The burial ground was reopened on September 16, 1963, and continued operating until it was closed permanently on December 31, 1967. The burial ground received wastes from all of the 300 Area radioactive material handling facilities. The purpose of this document is to characterize the 618-11 solid waste burial ground by describing the site, burial practices, the disposed wastes, and the waste generating facilities. This document provides information showing that kilogram quantities of plutonium were disposed to the drum storage units and caissons, making them transuranic (TRU). Also, kilogram quantities of plutonium and other TRU wastes were disposed to the three trenches, which were previously thought to contain non-TRU wastes. The site burial facilities (trenches, caissons, and drum storage units) should be classified as TRU and the site plutonium inventory maintained at five kilograms. Other fissile wastes were also disposed to the site. Additionally, thousands of curies of mixed fission products were also disposed to the trenches, caissons, and drum storage units. Most of the fission products have decayed over several half-lives, and are at more tolerable levels. Of greater concern, because of their release potential, are TRU radionuclides, Pu-238, Pu-240, and Np-237. TRU radionuclides also included slightly enriched 0.95 and 1.25% U-231 from N-Reactor fuel, which add to the fissile content. The 618-11 burial ground is located approximately 100 meters due west of Washington Nuclear Plant No. 2. The burial ground consists of three trenches, approximately 900 feet long, 25 feet deep, and 50 feet wide, running east-west. The trenches constitute 75% of the site area. There are 50 drum storage units (five 55-gallon steel drums welded together

  20. Disposal of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-01-15

    The problem of disposal can be tackled in two ways: the waste can be diluted and dispersed so that the radiation to which any single individual would be subjected would be negligible, or it can be concentrated and permanently isolated from man and his immediate environment. A variety of methods for the discharge of radioactive waste into the ground were described at the Monaco conference. They range from letting liquid effluent run into pits or wells at appropriately chosen sites to the permanent storage of high activity material at great depth in geologically suitable strata. Another method discussed consists in the incorporation of high level fission products in glass which is either buried or stored in vaults. Waste disposal into rivers, harbours, outer continental shelves and the open sea as well as air disposal are also discussed. Many of the experts at the Monaco conference were of the view that most of the proposed, or actually applied, methods of waste disposal were compatible with safety requirements. Some experts, felt that certain of these methods might not be harmless. This applied to the possible hazards of disposal in the sea. There seemed to be general agreement, however, that much additional research was needed to devise more effective and economical methods of disposal and to gain a better knowledge of the effects of various types of disposal operations, particularly in view of the increasing amounts of waste material that will be produced as the nuclear energy industry expands

  1. Disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Dlouhy, Z.

    1982-01-01

    This book provides information on the origin, characteristics and methods of processing of radioactive wastes, as well as the philosophy and practice of their storage and disposal. Chapters are devoted to the following topics: radioactive wastes, characteristics of radioactive wastes, processing liquid and solid radioactive wastes, processing wastes from spent fuel reprocessing, processing gaseous radioactive wastes, fixation of radioactive concentrates, solidification of high-level radioactive wastes, use of radioactive wastes as raw material, radioactive waste disposal, transport of radioactive wastes and economic problems of radioactive wastes disposal. (C.F.)

  2. Subseabed disposal safety analysis

    International Nuclear Information System (INIS)

    Koplick, C.M.; Kabele, T.J.

    1982-01-01

    This report summarizes the status of work performed by Analytic Sciences Corporation (TASC) in FY'81 on subseabed disposal safety analysis. Safety analysis for subseabed disposal is divided into two phases: pre-emplacement which includes all transportation, handling, and emplacement activities; and long-term (post-emplacement), which is concerned with the potential hazard after waste is safely emplaced. Details of TASC work in these two areas are provided in two technical reports. The work to date, while preliminary, supports the technical and environmental feasibility of subseabed disposal of HLW

  3. Performance Modeling Applied to the Treatment and Disposal of a Mixed Waste at the SRS

    International Nuclear Information System (INIS)

    Pickett, J.B.; Jantzen, C.M.; Cook, J.R.; Whited, A.R.; Field, R.A.

    1997-05-01

    Performance modeling for Low Level Mixed Waste disposal was conducted using the measured leach rates from a number of vitrified waste formulations. The objective of the study was to determine if the improved durability of a vitrified mixed waste would allow trench disposal at the Savannah River Site (SRS). Leaching data were compiled from twenty-nine diverse reference glasses, encompassing a wide range of exposed glass surface area to leachant volume ratios (SA/V), and various leachant solutions; all of which had been leached at 90 degrees Celsius, using the MCC-1 or PCT procedures (ASTM Procedures C1220-92 and C1285-94, respectively). The normalized leach rates were scaled to the ambient disposal temperature of 25 degrees Celsius, and compared to the allowable leach rate of uranium - which would meet the performance assessment requirements. The results indicated that a glass of above average durability (vs. the reference glasses) would meet the uranium leaching concentration for direct SRS trench disposal

  4. Beatty, Nevada: A section in U.S. Geological Survey research in radioactive waste disposal - Fiscal years 1986-1990 (WRI 91-4084)

    Science.gov (United States)

    Andraski, Brian J.; Fisher, Jeffrey M.; Prudic, David E.; Trask, N.J.; Stevens, P.R.

    1991-01-01

    A low-level radioactive-waste disposal facility in the Amargosa Desert of Nevada, about 17 km southeast of Beatty and 169 km northwest of Las Vegas, has been operating since 1962. This was the first commercially operated radioactive waste disposal facility in the United States. Wastes at the facility are emplaced in 2 to 15-m deep trenches and covered by backfilling with previously excavated materials. Annual precipitation in the area averages about 112 mm. Vegetation is sparse with creosote bush (Larrea tridentata) being the dominant species. Soils in the area are skeletal and are underlain by more than 170 m of unconsolidated alluvial-fan, fluvial, and ephemeral-lake deposits. Depth to water is about 85 m.Initial field investigations (1976-1980) included monitoring of soil-water content and water potential in an unvegetated soil profile, and collection of meteorological data at the disposal facility. Design of additional hydrogeologic investigations and long-term studies of soil-water movement in a vegetated soil profile began in 1982 and field data collection has been ongoing since 1984. Studies to evaluate the modifying effects of trench construction on the natural site environment and to determine changes in trench structural stability began in 1987. Design of studies to measure gas and vapor movement in the trenches at the facility began in 1989.

  5. In situ grouting of a low-level radioactive waste trench

    International Nuclear Information System (INIS)

    Spence, R.D.; Godsey, T.T.; McDaniel, E.W.

    1987-11-01

    A shallow land burial trench containing low level radioactive waste was injected with a particulate grout to help control subsidence and radionuclide migration. The trench's accessible voids have been estimated at 20 vol %, and most of these voids appear to have been filled with grout. This injection was accomplished with a simple, labor intensive technique, and an inexperienced crew at an estimated cost of about $55,000. The grout costs $0.21/gal and 8081 gal was injected into the trench. 5 refs., 10 figs., 4 tabs

  6. Benthic carbon mineralization in hadal trenches: Insights from in situ determination of benthic oxygen consumption

    DEFF Research Database (Denmark)

    Lou, Mín; Glud, Ronnie N.; Pan, Binbin

    2018-01-01

    and exhibited relatively high diagenetic activity given the great water depths, that is, the Mariana Trench (2.0 × 102 μmol O2m2 d1, 10,853 m), the Mussau Trench (2.7 ± 0.1 × 102 μmol O2m2 d1, 7,011 m), and the New Britain Trench (6.0 ± 0.1 × 102 μmol O2m2  d1, 8,225 m). Combined with the analyses of total...

  7. Electrostatic potential fluctuation induced by charge discreteness in a nanoscale trench

    International Nuclear Information System (INIS)

    Lee, Taesang; Kim, S. S.; Jho, Y. S.; Park, Gunyoung; Chang, C. S.

    2007-01-01

    A simplified two-dimensional Monte Carlo simulation is performed to estimate the charging potential fluctuations caused by strong binary Coulomb interactions between discrete charged particles in nanometer scale trenches. It is found that the discrete charge effect can be an important part of the nanoscale trench research, inducing scattering of ion trajectories in a nanoscale trench by a fluctuating electric field. The effect can enhance the ion deposition on the side walls and disperse the material contact energy of the incident ions, among others

  8. Nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Merrett, G.J.; Gillespie, P.A.

    1983-07-01

    This report discusses events and processes that could adversely affect the long-term stability of a nuclear fuel waste disposal vault or the regions of the geosphere and the biosphere to which radionuclides might migrate from such a vault

  9. Disposal leachates treatment

    Energy Technology Data Exchange (ETDEWEB)

    Coulomb, I.; Renaud, P. (SITA, 75 - Paris (France)); Courant, P. (FD Conseil, 78 - Gargenville (France)); Manem, J.; Mandra, V.; Trouve, E. (Lyonnaise des Eaux-Dumez, 78 - Le Pecq (France))

    1993-12-01

    Disposal leachates are complex and variable effluents. The use of a bioreactor with membranes, coupled with a reverse osmosis unit, gives a new solution to the technical burying centers. Two examples are explained here.

  10. Safe Disposal of Pesticides

    Science.gov (United States)

    ... Toxics Environmental Information by Location Greener Living Health Land, Waste, and Cleanup Lead Mold Pesticides Radon Science ... or www.earth911.com . Think before disposing of extra pesticides and containers: Never reuse empty pesticide containers. ...

  11. Disposal of Iodine-129

    International Nuclear Information System (INIS)

    Morgan, M.T.; Moore, J.G.; Devaney, H.E.; Rogers, G.C.; Williams, C.; Newman, E.

    1978-01-01

    One of the problems to be solved in the nuclear waste management field is the disposal of radioactive iodine-129, which is one of the more volatile and long-lived fission products. Studies have shown that fission products can be fixed in concrete for permanent disposal. Current studies have demonstrated that practical cementitious grouts may contain up to 18% iodine as barium iodate. The waste disposal criterion is based on the fact that harmful effects to present or future generations can be avoided by isolation and/or dilution. Long-term isolation is effective in deep, dry repositories; however, since penetration by water is possible, although unlikely, release was calculated based on leach rates into water. Further considerations have indicated that sea disposal on or in the ocean floor may be a more acceptable alternative

  12. Nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Allan, C.J.

    1993-01-01

    The Canadian concept for nuclear fuel waste disposal is based on disposing of the waste in a vault excavated 500-1000 m deep in intrusive igneous rock of the Canadian Shield. The author believes that, if the concept is accepted following review by a federal environmental assessment panel (probably in 1995), then it is important that implementation should begin without delay. His reasons are listed under the following headings: Environmental leadership and reducing the burden on future generations; Fostering public confidence in nuclear energy; Forestalling inaction by default; Preserving the knowledge base. Although disposal of reprocessing waste is a possible future alternative option, it will still almost certainly include a requirement for geologic disposal

  13. Integrated Disposal Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Located near the center of the 586-square-mile Hanford Site is the Integrated Disposal Facility, also known as the IDF.This facility is a landfill similar in concept...

  14. Shallow land disposal technology

    Energy Technology Data Exchange (ETDEWEB)

    Pillette-Cousin, L. [Nuclear Environment Technology Insitute, Taejon (Korea, Republic of Korea )

    1997-12-31

    This paper covers the radioactive waste management policy and regulatory framework, the characteristics of low and intermediate level radioactive waste, the characteristics of waste package, the waste acceptance criteria, the waste acceptance and related activities, the design of the disposal system, the organization of waste transportation, the operation feature, the safety assessment of the Centre de L`Aube, the post closure measures, the closure of the Centre de la Mache disposal facility, the licensing issues. 3 tabs., 7 figs.

  15. Shallow land disposal technology

    International Nuclear Information System (INIS)

    Pillette-Cousin, L.

    1997-01-01

    This paper covers the radioactive waste management policy and regulatory framework, the characteristics of low and intermediate level radioactive waste, the characteristics of waste package, the waste acceptance criteria, the waste acceptance and related activities, the design of the disposal system, the organization of waste transportation, the operation feature, the safety assessment of the Centre de L'Aube, the post closure measures, the closure of the Centre de la Mache disposal facility, the licensing issues. 3 tabs., 7 figs

  16. Disposal Of Waste Matter

    International Nuclear Information System (INIS)

    Kim, Jeong Hyeon; Lee, Seung Mu

    1989-02-01

    This book deals with disposal of waste matter management of soiled waste matter in city with introduction, definition of waste matter, meaning of management of waste matter, management system of waste matter, current condition in the country, collect and transportation of waste matter disposal liquid waste matter, industrial waste matter like plastic, waste gas sludge, pulp and sulfuric acid, recycling technology of waste matter such as recycling system of Black clawson, Monroe and Rome.

  17. Sediment properties and water movement through shallow unsaturated alluvium at an arid site for disposal of low-level radioactive waste near Beatty, Nye County, Nevada

    Science.gov (United States)

    Fischer, Jeffrey M.

    1992-01-01

    A commercial disposal facility for low-level radioactive waste has been in operation near Beatty, Nevada, since 1962. The facility is in the arid Amargosa Desert where wastes are buried in trenches excavated into unsaturated alluvial sediments. Thick unsaturated zones in arid environments offer many potential advantages for disposal of radioactive wastes, but little is known about the natural movement of water near such facilities. Thus, a study was begun in 1982 to better define the direction and rates of water movement through the unsaturated zone in undisturbed sediments near the disposal facility. This report discusses the analyses of data collected between 1983 and 1988.

  18. Biological intrusion of low-level-waste trench covers

    International Nuclear Information System (INIS)

    Hakonson, T.E.; Gladney, E.S.

    1981-01-01

    The long-term integrity of low-level waste shallow land burial sites is dependent on the interaction of physical, chemical, and biological factors that modify the waste containment system. Past research on low-level waste shallow land burial methods has emphasized physical (i.e., water infiltration, soil erosion) and chemical (radionuclide leaching) processes that can cause waste site failure and subsequent radionuclide transport. The purpose of this paper is to demonstrate the need to consider biological processes as being potentially important in reducing the integrity of waste burial site cover treatments. Plants and animals not only can transport radionuclides to the ground surface via root systems and soil excavated from the cover profile by animal burrowing activities, but they modify physical and chemical processes within the cover profile by changing the water infiltration rates, soil erosion rates and chemical composition of the soil. One approach to limiting biological intrusion through the waste cover is to apply a barrier within the profile to limit root and animal penetration with depth. Experiments in the Los Alamos Experimental Engineered Test Facility were initiated to develop and evaluate biological barriers that are effective in minimizing intrusion into waste trenches. The experiments that are described employ four different candidate barrier materials of geologic origin. Experimental variables that will be evaluated, in addition to barrier type, are barrier depth and soil overburden depth. The rate of biological intrusion through the various barrier materials is being evaluated through the use of activatable stable tracers

  19. Oceanographic cruise: Coral Sea, Arafura Sea, and Java Trench, April - May 1969 (NODC Accession 7100914)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard HMAS DIAMANTINA during an oceanographic cruise in the Coral Sea, Arafura Sea, and Java Trench...

  20. Subsidence evaluation in 218-E-E12B, trench 38

    International Nuclear Information System (INIS)

    Streit, J.J.

    1995-01-01

    An area in Trench 38 of the 218-E-12B Burial Ground has been gradually sinking over the past few years. The area spans the width of the trench and extends approximately 80 feet down the trench. The depth of the depression is approximately 3 feet in the center and gradually rises to existing grade at the trench edge. It has been determined that the most likely cause of the subsidence is decomposition of buried waste material. Fifty-six percent of the waste buried in the subject area is decomposable and has been in the ground for nine years. Waste packaging is largely plastic lined dump trucks and fiberboard boxes. It is recommended that this area be treated with dynamic compaction to stabilize the waste and minimize the reoccurrence of subsidence in this area

  1. Oceanographic cruise Indian Ocean and Java Trench June 1969 (NODC Accession 7100908)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard H.M.A.S DIAMANTINA during an oceanographic cruise in the Java Trench and the Indian Ocean during...

  2. Comparison between infaunal communities of the deep floor and edge of the Tonga Trench

    DEFF Research Database (Denmark)

    Leduc, Daniel; Rowden, Ashley A.; Glud, Ronnie N.

    2016-01-01

    at the Horizon Deep site is consistent with a recent turbidite event, and may also reflect high rates of bioturbation by larger fauna resulting from high food availability. Determining the relative influences of different environmental factors on hadal trench benthic communities will require further...... factors. In this study, we describe and compare the abundance, biomass, vertical distribution in the sediment, diversity, and community structure of nematodes and other infauna in sediments from the Horizon Deep (similar to 10 800 m) in the Tonga Trench and a site on the edge of the trench (similar...... to 6250 m). Mean nematode abundance was six times greater at the Horizon Deep site (387 ind. 10 cm(-2)) than at the trench edge site (65 ind. 10 cm(-2)). A similar pattern was observed for biomass (15 vs 2 mu gDW 10 cm(-2), respectively), which likely resulted from elevated organic matter supply...

  3. Wavelength-dependent Crosstalk in Trench-Assisted Multi-Core Fibers

    DEFF Research Database (Denmark)

    Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

    2014-01-01

    Analytical expressions for wavelength-dependent crosstalk in homogeneous trench-assisted multi-core fibers are derived. The calculated results from the expressions agree well with the numerical simulation results based on finite element method.......Analytical expressions for wavelength-dependent crosstalk in homogeneous trench-assisted multi-core fibers are derived. The calculated results from the expressions agree well with the numerical simulation results based on finite element method....

  4. STUDY OF ELECTRICAL CHARACTERISTIC OF NEW P-TYPE TRENCHED UMOSFET

    OpenAIRE

    Akansha Ephraim*, Neelesh Agrawal, Anil Kumar, A.K. Jaiswal

    2017-01-01

    In this paper p-type trenched UMOSFET was designed without super junction and constructed like any other conventional MOSFET. Characteristic curve was studied between drain current verses drain voltage and drain current verses gate voltage. The trench was designed under TCAD simulation tool Silvaco software using etching process. The specific channel length of the p-type UMOSFET has been concentrated as 0.9 microns. The device structures are designed using Silvaco Athena and characteristics w...

  5. Vadose Zone Contaminant Fate and Transport Analysis for the 216-B-26 Trench

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Andy L.; Gee, Glendon W.; Zhang, Z. F.; Keller, Jason M.

    2004-10-14

    The BC Cribs and Trenches, part of the 200 TW 1 OU waste sites, received about 30 Mgal of scavenged tank waste, with possibly the largest inventory of 99Tc ever disposed to the soil at Hanford and site remediation is being accelerated. The purpose of this work was to develop a conceptual model for contaminant fate and transport at the 216-B-26 Trench site to support identification and development and evaluation of remediation alternatives. Large concentrations of 99Tc high above the water table implicated stratigraphy in the control of the downward migration. The current conceptual model accounts for small-scale stratigraphy; site-specific changes soil properties; tilted layers; and lateral spreading. It assumes the layers are spatially continuous causing water and solutes to move laterally across the boundary if conditions permit. Water influx at the surface is assumed to be steady. Model parameters were generated with pedotransfer functions; these were coupled high resolution neutron moisture logs that provided information on the underlying heterogeneity on a scale of 3 inches. Two approaches were used to evaluate the impact of remedial options on transport. In the first, a 1-D convolution solution to the convective-dispersive equation was used, assuming steady flow. This model was used to predict future movement of the existing plume using the mean and depth dependent moisture content. In the second approach, the STOMP model was used to first predict the current plume distribution followed by its future migration. Redistribution of the 99Tc plume was simulated for the no-action alternative and on-site capping. Hypothetical caps limiting recharge to 1.0, 0.5, and 0.1 mm yr-1 were considered and assumed not to degrade in the long term. Results show that arrival time of the MCLs, the peak arrival time, and the arrival time of the center of mass increased with decreasing recharge rate. The 1-D convolution model is easy to apply and can easily accommodate initial

  6. Chemical characteristics of hadal waters in the Izu-Ogasawara Trench of the western Pacific Ocean.

    Science.gov (United States)

    Gamo, Toshitaka; Shitashima, Kiminori

    2018-01-01

    Vertical profiles of potential temperature, salinity, and some chemical components were obtained at a trench station (29°05'N, 142°51'E; depth = 9768 m) in the Izu-Ogasawara (Bonin) Trench in 1984 and 1994 to characterize the hadal waters below ∼6000 m depth. We compared portions of both the 1984 and 1994 profiles with nearby data obtained between 1976 and 2013. Results demonstrated that the hadal waters had slightly higher potential temperature and nitrate and lower dissolved oxygen than waters at sill depths (∼6000 m) outside the trench, probably due to the effective accumulation of geothermal heat and active biological processes inside the trench. The silicate, iron, and manganese profiles in 1984 showed slight but significant increases below ∼6000 m depth, suggesting that these components may have been intermittently supplied from the trench bottom. Significant amounts of 222 Rn in excess over 226 Ra were detected in the hadal waters up to 2675 m from the bottom, reflecting laterally supplied 222 Rn from the trench walls.

  7. Morning Frost in Trench Dug by Phoenix, Sol 113 (False Color)

    Science.gov (United States)

    2008-01-01

    This image from the Surface Stereo Imager on NASA's Phoenix Mars Lander shows morning frost inside the 'Snow White' trench dug by the lander, in addition to subsurface ice exposed by use of a rasp on the floor of the trench. The camera took this image at about 9 a.m. local solar time during the 113th Martian day of the mission (Sept. 18, 2008). Bright material near and below the four-by-four set of rasp holes in the upper half of the image is water-ice exposed by rasping and scraping in the trench earlier the same morning. Other bright material especially around the edges of the trench, is frost. Earlier in the mission, when the sun stayed above the horizon all night, morning frost was not evident in the trench. This image is presented in false color that enhances the visibility of the frost. The trench is 4 to 5 centimeters (about 2 inches) deep, about 23 centimeters (9 inches) wide. Phoenix landed on a Martian arctic plain on May 25, 2008. The mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  8. A low on-resistance SOI LDMOS using a trench gate and a recessed drain

    International Nuclear Information System (INIS)

    Ge Rui; Luo Xiaorong; Jiang Yongheng; Zhou Kun; Wang Pei; Wang Qi; Wang Yuangang; Zhang Bo; Li Zhaoji

    2012-01-01

    An integrable silicon-on-insulator (SOI) power lateral MOSFET with a trench gate and a recessed drain (TGRD MOSFET) is proposed to reduce the on-resistance. Both of the trench gate extended to the buried oxide (BOX) and the recessed drain reduce the specific on-resistance (R on,sp ) by widening the vertical conduction area and shortening the extra current path. The trench gate is extended as a field plate improves the electric field distribution. Breakdown voltage (BV) of 97 V and R on,sp of 0.985 mΩ·cm 2 (V GS = 5 V) are obtained for a TGRD MOSFET with 6.5 μm half-cell pitch. Compared with the trench gate SOI MOSFET (TG MOSFET) and the conventional MOSFET, R on,sp of the TGRD MOSFET decreases by 46% and 83% at the same BV, respectively. Compared with the SOI MOSFET with a trench gate and a trench drain (TGTD MOSFET), BV of the TGRD MOSFET increases by 37% at the same R on,sp . (semiconductor devices)

  9. Trench foot: the medical response in the first World War 1914-18.

    Science.gov (United States)

    Atenstaedt, Robert L

    2006-01-01

    The approaching 90-year anniversary of United States entry into the Great War is an apt time to examine the response to trench foot (now called nonfreezing cold injury [NFCI]) in this conflict. Trench foot appeared in the winter of 1914, characterized by pedal swelling, numbness, and pain. It was quickly recognized by military-medical authorities. There was little debate over whether it was frostbite or new condition, and it was quickly accepted as a specific disease. The major etiologies proposed were exposure, diet, and infection. The opinion emerged that it was caused by circulatory changes in the foot caused by cold, wet, and pressure. Predisposing factors included dietary inadequacy and fatigue. A number of labels were first given to the disease. However, the name "trench foot" was eventually officially sanctioned. Trench foot became a serious problem for the Allies, leading to 75 000 casualties in the British and 2000 in the American forces. Therapy for trench foot involved a number of conventional, tried-and-tested, and conservative methods. Some more innovative techniques were used. Amputation was only used as a last resort. Prevention involved general measures to improve the trench environment; modification of the footwear worn by the men; and the provision of greases to protect them from moisture. The medical reaction to this condition seems to have been relatively effective. The causation was identified, and prophylactic measures were introduced to fit this model; these seem to have been successful in reducing the prevalence of the condition by 1917-18.

  10. Study of shallow trench isolation technology with a poly-Si sidewall buffer layer

    International Nuclear Information System (INIS)

    Juang, M H; Chen, C L; Jang, S L

    2008-01-01

    Shallow trench isolation (STI) technology with a poly-Si buffer layer at the trench sidewall has been studied. At the densification temperature of 950 °C, for the samples without using a poly-Si buffer layer, the resulting junction shows a leakage of about 700 nA cm −2 for a diode area of 100 × 100 µm 2 , primarily due to large peripheral junction leakage. The large leakage is ascribed to the defect generation caused by a thermally induced stress near the trench sidewall. The usage of a poly-Si buffer layer in the trench sidewall is found to significantly improve the junction characteristics. As a result, when a 40 nm poly-Si buffer layer is sandwiched between the Si substrate and the trench-fill silicon oxide, the resultant junctions show a leakage of only about 8 nA cm −2 . This result may reflect the considerably reduced thermally induced stress near the trench sidewall. Furthermore, at the densification temperature of 1100 °C, the usage of a poly-Si buffer layer can help to achieve excellent junctions with a leakage smaller than 5 nA cm −2 for a diode area of 100 × 100 µm 2

  11. Long-term safety assessment of trench-type surface repository at Chernobyl, Ukraine - computer model and comparison with results from simplified models

    International Nuclear Information System (INIS)

    Haverkamp, B.; Krone, J.; Shybetskyi, I.

    2013-01-01

    The Radioactive Waste Disposal Facility (RWDF) Buryakovka was constructed in 1986 as part of the intervention measures after the accident at Chernobyl NPP (ChNPP). Today, the surface repository for solid low and intermediate level waste (LILW) is still being operated but its maximum capacity is nearly reached. Long-existing plans for increasing the capacity of the facility shall be implemented in the framework of the European Commission INSC Programme (Instrument for Nuclear Safety Co-operation). Within the first phase of this project, DBE Technology GmbH prepared a safety analysis report of the facility in its current state (SAR) and a preliminary safety analysis report (PSAR) for a future extended facility based on the planned enlargement. In addition to a detailed mathematical model, also simplified models have been developed to verify results of the former one and enhance confidence in the results. Comparison of the results show that - depending on the boundary conditions - simplifications like modeling the multi trench repository as one generic trench might have very limited influence on the overall results compared to the general uncertainties associated with respective long-term calculations. In addition to their value in regard to verification of more complex models which is important to increase confidence in the overall results, such simplified models can also offer the possibility to carry out time consuming calculations like probabilistic calculations or detailed sensitivity analysis in an economic manner. (authors)

  12. In situ grouting of low-level burial trenches with a cement-based grout at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Francis, C.W.; Spence, R.D.; Tamura, T.; Spalding, B.P.

    1993-01-01

    A technology being evaluated for use in the closure of one of the low-level radwaste burial grounds at ORNL is trench stabilization using a cement-based grout. To demonstrate the applicability and effectiveness of this technology, two interconnecting trenches in SWSA 6 were selected as candidates for in situ grouting with a particulate grout. The primary objective was to demonstrate the increased trench stability (characterized by trench penetration tests) and the decreased potential for leachate migration (characterized by hydraulic conductivity tests) following in situ injection of a particulate grout into the waste trenches. Stability against trench subsidence is a critical issue. For example, construction of impermeable covers to seal the trenches will be ineffectual unless subsequent trench subsidence is permanently suspended. A grout composed of 39% Type 1 Portland cement, 55.5% Class F fly ash, and 5.5% bentonite mixed at 12.5 lb/gal of water was selected. Before the trenches were grouted, the primary characteristics relating to physical stability, hydraulic conductivity, and void volume of the trenches were determined. Their physical stability was evaluated using soil-penetration tests

  13. Water and tritium movement through the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois, 1981-85

    Science.gov (United States)

    Mills, Patrick C.; Healy, Richard W.

    1993-01-01

    The movement of water and tritium through the unsaturated zone was studied at a low-level radioactive-waste disposal site near Sheffield, Bureau County, Illinois, from 1981 to 1985. Water and tritium movement occurred in an annual, seasonally timed cycle; recharge to the saturated zone generally occurred in the spring and early summer. Mean annual precipitation (1982-85) was 871 mm (millimeters); mean annual recharge to the disposal trenches (July 1982 through June 1984) was estimated to be 107 mm. Average annual tritium flux below the study trenches was estimated to be 3.4 mCi/yr (millicuries per year). Site geology, climate, and waste-disposal practices influenced the spatial and temporal variability of water and tritium movement. Of the components of the water budget, evapotranspiration contributed most to the temporal variability of water and tritium movement. Disposal trenches are constructed in complexly layered glacial and postglacial deposits that average 17 m (meters) in thickness and overlie a thick sequence of Pennsylvanian shale. The horizontal saturated hydraulic conductivity of the clayey-silt to sand-sized glacial and postglacial deposits ranges from 4.8x10 -1 to 3.4x10 4 mm/d (millimeters per day). A 120-m-long horizontal tunnel provided access for hydrologic measurements and collection of sediment and water samples from the unsaturated and saturated geologic deposits below four disposal trenches. Trench-cover and subtrench deposits were monitored with soil-moisture tensiometers, vacuum and gravity lysimeters, piezometers, and a nuclear soil-moisture gage. A cross-sectional, numerical ground-water-flow model was used to simulate water movement in the variably saturated geologic deposits in the tunnel area. Concurrent studies at the site provided water-budget data for estimating recharge to the disposal trenches. Vertical water movement directly above the trenches was impeded by a zone of compaction within the clayey-silt trench covers. Water entered

  14. Landfill disposal risk assessment

    International Nuclear Information System (INIS)

    Mininni, G.; Passino, R.; Spinosa, L.

    1993-01-01

    Landfill disposal is the most used waste disposal system in Italy, due to its low costs and also to the great opposition of populations towards new incineration plants and the adjustment of the existing ones. Nevertheless, landfills may present many environmental problems as far as leachate and biogas are concerned directly influencing water, air and soil. This paper shows the most important aspects to be considered for a correct evaluation of environmental impacts caused by a landfill of urban wastes. Moreover, detection systems for on site control of pollution phenomena are presented and some measures for an optimal operation of a landfill are suggested

  15. Disposal of hazardous wastes

    International Nuclear Information System (INIS)

    Barnhart, B.J.

    1978-01-01

    The Fifth Life Sciences Symposium entitled Hazardous Solid Wastes and Their Disposal on October 12 through 14, 1977 was summarized. The topic was the passage of the National Resources Conservation and Recovery Act of 1976 will force some type of action on all hazardous solid wastes. Some major points covered were: the formulation of a definition of a hazardous solid waste, assessment of long-term risk, list of specific materials or general criteria to specify the wastes of concern, Bioethics, sources of hazardous waste, industrial and agricultural wastes, coal wastes, radioactive wastes, and disposal of wastes

  16. Reversible deep disposal

    International Nuclear Information System (INIS)

    2009-10-01

    This presentation, given by the national agency of radioactive waste management (ANDRA) at the meeting of October 8, 2009 of the high committee for the nuclear safety transparency and information (HCTISN), describes the concept of deep reversible disposal for high level/long living radioactive wastes, as considered by the ANDRA in the framework of the program law of June 28, 2006 about the sustainable management of radioactive materials and wastes. The document presents the social and political reasons of reversibility, the technical means considered (containers, disposal cavities, monitoring system, test facilities and industrial prototypes), the decisional process (progressive development and blocked off of the facility, public information and debate). (J.S.)

  17. Radioactive waste (disposal)

    International Nuclear Information System (INIS)

    Jenkin, P.

    1985-01-01

    The disposal of low- and intermediate-level radioactive wastes was discussed. The following aspects were covered: public consultation on the principles for assessing disposal facilities; procedures for dealing with the possible sites which the Nuclear Industry Radioactive Waste Executive (NIREX) had originally identified; geological investigations to be carried out by NIREX to search for alternative sites; announcement that proposal for a site at Billingham is not to proceed further; NIREX membership; storage of radioactive wastes; public inquiries; social and environmental aspects; safety aspects; interest groups; public relations; government policies. (U.K.)

  18. A parylene-filled-trench technique for thermal isolation in silicon-based microdevices

    International Nuclear Information System (INIS)

    Lei Yinhua; Wang Wei; Li Ting; Jin Yufeng; Zhang Haixia; Li Zhihong; Yu Huaiqiang; Luo Yingcun

    2009-01-01

    Microdevices prepared in a silicon substrate have been widely used in versatile fields due to the matured silicon-based microfabrication technique and the excellent physical properties of silicon material. However, the high thermal conductivity of silicon restricts its application in most thermal microdevices, especially devices comprising different temperature zones. In this work, a parylene-filled-trench technique was optimized to realize high-quality thermal isolation in silicon-based microdevices. Parylene C, a heat transfer barricading material, was deposited on parallel high-aspect-ratio trenches, which surrounded the isolated target zones. After removing the remnant silicon beneath the trenches by deep reactive ion etching from the back side, a high-quality heat transfer barrier was obtained. By using narrow trenches, only 5 µm thick parylene was required for a complete filling, which facilitated multi-layer interconnection thereafter. The parylene filling performance inside the high-aspect-ratio trench was optimized by two approaches: multiple etch–deposition cycling and trench profile controlling. A 4 × 6 array, in which each unit was kept at a constant temperature and was well thermally isolated individually, was achieved on a silicon substrate by using the present parylene-filled-trench technique. The preliminary experimental results indicated that the present parylene-filled-trench structure exhibited excellent thermal isolation performance, with a very low power requirement of 0.134 mW (K mm 2 ) −1 for heating the isolated silicon unit and a high thermal isolation efficiency of 72.5% between two adjacent units. Accompanied with high-quality isolation performance, the microdevices embedded the present parylene-filled-trench structure to retain a strong mechanical connection larger than 400 kPa between two isolated zones, which is very important for a high-reliability-required micro-electro-mechanical-system (MEMS) device. Considering its room

  19. Ocean disposal of heat generating radioactive waste

    International Nuclear Information System (INIS)

    1985-12-01

    The feasibility of safe ocean disposal options for heat-generating radioactive waste relies on the existence of suitable disposal sites. This review considers the status of the development of site selection criteria and the results of the study area investigations carried out under various national and international research programmes. In particular, the usefulness of the results obtained is related to the data needed for environmental and emplacement modelling. Preliminary investigations have identified fifteen potential deep ocean study areas in the North Atlantic. From these Great Meteor East (GME), Southern Nares Abyssal Plan (SNAP) and Kings Trough Flank (KTF) were selected for further investigation. The review includes appraisals of regional geology, geophysical studies, sedimentology, geotechnical studies, geochemical studies and oceanography. (author)

  20. A study on optimum technology for the treatment and disposal of low and medium radioactive wastes

    International Nuclear Information System (INIS)

    Kim, Y.E.; Chun, K.S.; Kim, K.J.; Lee, H.G.; Kim, K.I.

    1983-01-01

    The purpose of this report is to provide a comprehensive compilation and data base of the various treatment techniques available for processing the low- and medium-level radioactive wastes to be generated at nuclear power plants. This enables standardization and localization of the treatment facilities and provodes a data base for selection of the optimum technology for the low- and intermediate-level radioactive solid waste disposal. This present systems which are applied at the Korean Nuclear Power Plant Units No. 2 through No.7 for treatment of radioactive gaseous and liquid wastes should be optimized in respect of radiation protection and economics. However, alternative techniques for solidification of wet solid wastes might be required instead of cementation (for example, bituminization). In addition the application of a shredding technique to the present system would be the most economically effective means of volume reduction. Improved shallow land burial in trenches lined with compacted clay should be most suitable for disposal of the 900,000 drums of radwaste projected by the year 2007. An area of thick clay deposite will be selected as a disposal site, but if no suitable site can be found, a mined cavity or concrete trench facility would be utilized. (Author)

  1. Studies on disposal of low-level radioactive wastes in Turkey

    International Nuclear Information System (INIS)

    Uslu, I.; Fields, D.E.; Yalcintas, M.G.

    1989-08-01

    The Turkish Government is in the process of planning two nuclear reactors in Turkey. Studies have begun for improved control of low level wastes (LLW) in Turkey before establishment of these reactors. In this study, the PRESTO-II (Prediction of Radiation Exposures form Shallow Trench Operations) computer code is used to assess the risk associated with the shallow land disposal of low level waste (LLW) in various sites in Turkey. PRESTO-II is a computer code developed under the United States Environmental Protection Agency, Department of Energy and Nuclear Regulatory Commission funding to evaluate possible health effects from radioactive releases from shallow, radioactive waste disposal trenches and from areas contaminated with operational spillage. A preliminary simulation using the PRESTO-II computer code has been run for the site in Koteyli, Balikesir, Turkey. This example simulation was performed using the same radionuclide data set believed representative of the LLW disposal facility in Barnwell, South Carolina. Site environmental variables were selected to typify credible worst case exposure scenarios. Radionuclide inventories are primarily based on estimated waste composition rather than measured values. 9 refs., 4 figs., 1 tab

  2. Deep-Sea Trench Microbiology Down to 10.9 Kilometers Below the Surface

    Science.gov (United States)

    Bartlett, D. H.

    2012-12-01

    Deep-sea trenches, extending to more than 10.9 km below the sea surface, are among the most remote and infrequently sampled habitats. As a result a global perspective of microbial diversity and adaptation is lacking in these extreme settings. I will present the results of studies of deep-sea trench microbes collected in the Puerto Rico Trench (PRT), Tonga Trench, New Britain Trench and Mariana Trench. The samples collected include sediment, seawater and animals in baited traps. The analyses to be described include microbial community activity and viability measurements as a function of hydrostatic pressure, microbial culturing at high pressure under various physiological conditions, phylogenetics and metagenome and single-cell genome characterizations. Most of the results to date stem from samples recovered from the PRT. The deep-sea PRT Trench microbes have more in common at the species level with other deep-sea microbial communities previously characterized in the Pacific Ocean and the Mediterranean Sea than with the microbial populations above them in shallow waters. They also harbor larger genomes with more genes assigned to signal transduction, transcription, replication, recombination and repair and inorganic ion transport. The overrepresented transporters in the PRT metagenome include di- and tri-carboxylate transporters that correspond to the prevailing catabolic processes such as butanoate, glyoxylate and dicarboxylate metabolism. A surprisingly high abundance of sulfatases for the degradation of sulfated polysaccharides were also present in the PRT. But, perhaps the most dramatic adaptational feature of the PRT microbes is heavy metal resistance, as reflected in the high numbers of metal efflux systems present. Single-cell genomics approaches have proven particularly useful for placing PRT metagenomic data into context.

  3. Lateral-delivered organic matter boosts hadal bacterial abundance in the Mariana Trench: A hypothesis

    Science.gov (United States)

    Zhang, C.; Liu, H.; Lu, F.; Zou, L.; Tian, J.

    2017-12-01

    Hadal trenches are part of the least investigated biosphere on Earth due to the great challenge of sampling. Limited studies on microbiology by far have suggested that the hadalsphere hosts a heterotrophic microbial community that is likely fed by organic matter from surface-sinking biomass or re-suspended and laterally transported sediments. The uniqueness of trench environment and its potential role in global carbon sequestration entitle a detailed study on microbial-driven carbon cycle of the trench system. In this study, we conducted a vertical sampling of the microbial community and measured the environmental factors from the epipelagic zone down to the hadal zone at the Mariana Trench. 16S rRNA gene composition showed high stratification at the first 1000 meters below surface (mbs) but a nearly uniformed microbial community composition was observed at the abyssopelagic and the hadalpelagic water columns. The deep-sea bacteria were generally chemoheterotrophs and the majority of them were similar to those present at the ocean surface, suggesting influence of epipelagic primary production on deep sea bacterial communication at the trench location. Several deep-sea-enriched but surface-depleted bacteria could be characterized by potential degraders of polysaccharides and n-alkanes. Therefore, recalcitrant hydrocarbons or carbohydrates are likely important carbon sources supporting the deep-sea biosphere. In spite of consistent community composition, a remarkable increase in biomass of small-sized microbial aggregates was detected at 8727 mbs. Enhanced CDOM proportions in the trench imply intensified microbial activity in hadal water compared to the above water column, which agree with the notion of possible extra carbon input from lateral transportation of slope material. These observations extend our understanding in carbon cycle driven by metabolically diverse microorganisms at the trench and may shed light on the complexity of hadal biogeochemistry.

  4. 300 Area Process Trenches Supplemental Information to the Hanford Contingency Plan (DOE/RL-93-75)

    International Nuclear Information System (INIS)

    R.A. Carlson

    1997-01-01

    The 300 Area Process Trenches are surface impoundments which were used to receive routine discharges of nonregulated process cooling water from operations in the 300 Area and dangerous waste from several research and development laboratories and the 300 Area Fuels Fabrication process. Discharges to the trenches ceased in 1994, and they were physically isolated in 1995. Remediation of the trenches is scheduled to begin during July 1997. Currently, there are no waste management activities required at the 300 Area Process Trenches and the unit does not present any significant hazards to adjacent units, personnel, or the environment. It is unlikely that any incidents presenting hazards to public health or the environment would occur at the 300 Area Process Trenches, however, during remediation, exposure, spill, fire, and industrial hazards will exist. This contingency plan addresses the emergency organization, equipment and evacuation routes pertinent to the process trenches during remediation

  5. Radioactive waste disposal package

    Science.gov (United States)

    Lampe, Robert F.

    1986-11-04

    A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

  6. Manufacture of disposal canisters

    International Nuclear Information System (INIS)

    Nolvi, L.

    2009-12-01

    The report summarizes the development work carried out in the manufacturing of disposal canister components, and present status, in readiness for manufacturing, of the components for use in assembly of spent nuclear fuel disposal canister. The disposal canister consist of two major components: the nodular graphite cast iron insert and overpack of oxygen-free copper. The manufacturing process for copper components begins with a cylindrical cast copper billet. Three different manufacturing processes i.e. pierce and draw, extrusion and forging are being developed, which produce a seamless copper tube or a tube with an integrated bottom. The pierce and draw process, Posiva's reference method, makes an integrated bottom possible and only the lid requires welding. Inserts for BWR-element are cast with 12 square channels and inserts for VVER 440-element with 12 round channels. Inserts for EPR-elements have four square channels. Casting of BWR insert type has been studied so far. Experience of casting inserts for PWR, which is similar to the EPR-type, has been got in co-operation with SKB. The report describes the processes being developed for manufacture of disposal canister components and some results of the manufacturing experiments are presented. Quality assurance and quality control in manufacture of canister component is described. (orig.)

  7. Oil ''rig'' disposal

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    A comparison of the environmental impacts of disposing of the Brent Spar oil platform on land and at sea is presented, with a view to establishing the best decommissioning option in the light of recent controversy. The document is presented as an aid to comprehension of the scientific and engineering issues involved for Members of Parliament. (UK)

  8. Nuclear waste disposal

    International Nuclear Information System (INIS)

    Lindblom, U.; Gnirk, P.

    1982-01-01

    The subject is discussed under the following headings: the form and final disposal of nuclear wastes; the natural rock and groundwater; the disturbed rock and the groundwater; long-term behavior of the rock and the groundwater; nuclear waste leakage into the groundwater; what does it all mean. (U.K.)

  9. Chemical Stockpile Disposal Program

    Energy Technology Data Exchange (ETDEWEB)

    Krummel, J.R.; Policastro, A.J.; Olshansky, S.J.; McGinnis, L.D.

    1990-10-01

    As part of the Chemical Stockpile Disposal Program mandated by Public Law 99--145 (Department of Defense Authorization Act), an independent review is presented of the US Army Phase I environmental report for the disposal program at the Umatilla Depot Activity (UMDA) in Hermiston, Oregon. The Phase I report addressed new and additional concerns not incorporated in the final programmatic environmental impact statement (FPEIS). Those concerns were addressed by examining site-specific data for the Umatilla Depot Activity and by recommending the scope and content of a more detailed site-specific study. This independent review evaluates whether the new site-specific data presented in the Phase I report would alter the decision in favor of on-site disposal that was reached in the FPEIS, and whether the recommendations for the scope and content of the site-specific study are adequate. Based on the methods and assumptions presented in the FPEIS, the inclusion of more detailed site-specific data in the Phase I report does not change the decision reached in the FPEIS (which favored on-site disposal at UMDA). It is recommended that alternative assumptions about meteorological conditions be considered and that site-specific data on water, ecological, socioeconomic, and cultural resources; seismicity; and emergency planning and preparedness be considered explicitly in the site-specific EIS decision-making process. 7 refs., 1 fig.

  10. Nanomaterial disposal by incineration

    Science.gov (United States)

    As nanotechnology-based products enter into widespread use, nanomaterials will end up in disposal waste streams that are ultimately discharged to the environment. One possible end-of-life scenario is incineration. This review attempts to ascertain the potential pathways by which ...

  11. Geological disposal concept hearings

    International Nuclear Information System (INIS)

    1996-01-01

    The article outlines the progress to date on AECL spent-nuclear fuel geological disposal concept. Hearings for discussion, organised by the federal Environmental Assessment Review Panel, of issues related to this type of disposal method occur in three phases, phase I focuses on broad societal issues related to long term management of nuclear fuel waste; phase II will focus on the technical aspects of this method of disposal; and phase III will consist of community visits in New Brunswick, Quebec, Ontario, Manitoba and Saskatchewan. This article provides the events surrounding the first two weeks of phase I hearings (extracted from UNECAN NEWS). In the first week of hearings, where submissions on general societal issues was the focus, there were 50 presentations including those by Natural Resources Canada, Energy Probe, Ontario Hydro, AECL, Canadian Nuclear Society, Aboriginal groups, environmental activist organizations (Northwatch, Saskatchewan Environmental Society, the Inter-Church Uranium Committee, and the Canadian Coalition for Nuclear responsibility). In the second week of hearings there was 33 presentations in which issues related to siting and implementation of a disposal facility was the focus. Phase II hearings dates are June 10-14, 17-21 and 27-28 in Toronto

  12. Plumbing and Sewage Disposal.

    Science.gov (United States)

    Sutliff, Ronald D.; And Others

    This self-study course is designed to familiarize Marine enlisted personnel with the principles of plumbing and sewage disposal used by Marine Hygiene Equipment Operators to perform their mission. The course contains three study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the…

  13. Radwaste treatment and disposal

    International Nuclear Information System (INIS)

    Ehn, L.; Breza, M.; Pekar, A.

    2000-01-01

    In this lecture is given the basic information, that is concerning on the RAW treatment and long term disposal of the treated RAW in repository at Mochovce. Then here is given the basic technical and technological information, that is concerning bituminization, plant, the vitrification unit, center for the RAW-treatment (BSC) and repository at Mochovce. (authors)

  14. Waste disposal package

    Science.gov (United States)

    Smith, M.J.

    1985-06-19

    This is a claim for a waste disposal package including an inner or primary canister for containing hazardous and/or radioactive wastes. The primary canister is encapsulated by an outer or secondary barrier formed of a porous ceramic material to control ingress of water to the canister and the release rate of wastes upon breach on the canister. 4 figs.

  15. Unrestricted disposal of minimal activity levels of radioactive wastes: exposure and risk calculations

    International Nuclear Information System (INIS)

    Fields, D.E.; Emerson, C.J.

    1984-08-01

    The US Nuclear Regulatory Commission is currently considering revision of rule 10 CFR Part 20, which covers disposal of solid wastes containing minimal radioactivity. In support of these revised rules, we have evaluated the consequences of disposing of four waste streams at four types of disposal areas located in three different geographic regions. Consequences are expressed in terms of human exposures and associated health effects. Each geographic region has its own climate and geology. Example waste streams, waste disposal methods, and geographic regions chosen for this study are clearly specified. Monetary consequences of minimal activity waste disposal are briefly discussed. The PRESTO methodology was used to evaluate radionuclide transport and health effects. This methodology was developed to assess radiological impacts to a static local population for a 1000-year period following disposal. Pathways and processes of transit from the trench to exposed populations included the following considerations: groundwater transport, overland flow, erosion, surface water dilution, resuspension, atmospheric transport, deposition, inhalation, and ingestion of contaminated beef, milk, crops, and water. 12 references, 2 figures, 8 tables

  16. The effect of alternative cost and environmental impact minimisation strategies on radioactive waste disposal strategies

    International Nuclear Information System (INIS)

    Laundy, R.S.; James, A.R.; Groom, M.S.; Dalrymple, G.J.

    1985-06-01

    The study reported here investigates the effects of different cost and environmental impact minimisation strategies for a single waste disposal scenario. Four disposal options are considered. The study examines the environmental impacts from waste storage and transport and the disposal impacts in terms of collective dose, maximum individual dose and individual dose from intrusion. The total cost of disposing of waste takes account of storage, transport and disposal costs to each of the four facilities. Two minimum cost scenarios and seven minimum impact assessments were performed. The results showed clearly that a trade-off has to be made between the environmental impacts from transport and storage of waste. A low objective risk of transport is achieved by directing waste to the engineered trench, assumed to have a central location. This waste is stored until the facility is available in 1995 thus increasing the potential impact from storage. The results also show a trade-off has to be made between minimising the maximum individual dose from disposal and collective dose. The study shows that for relatively little cost large reductions in the impacts can be obtained particularly in short and long-term collective dose and the individual dose from intrusion. (author)

  17. The Remote Handled Immobilization Low Activity Waste Disposal Facility Environmental Permits & Approval Plan

    Energy Technology Data Exchange (ETDEWEB)

    DEFFENBAUGH, M.L.

    2000-08-01

    The purpose of this document is to revise Document HNF-SD-ENV-EE-003, ''Permitting Plan for the Immobilized Low-Activity Waste Project, which was submitted on September 4, 1997. That plan accounted for the interim storage and disposal of Immobilized-Low Activity Waste at the existing Grout Treatment Facility Vaults (Project W-465) and within a newly constructed facility (Project W-520). Project W-520 was to have contained a combination of concrete vaults and trenches. This document supersedes that plan because of two subsequent items: (1) A disposal authorization that was received on October 25, 1999, in a U. S. Department of Energy-Headquarters, memorandum, ''Disposal Authorization Statement for the Department of Energy Hanford site Low-Level Waste Disposal facilities'' and (2) ''Breakthrough Initiative Immobilized Low-Activity Waste (ILAW) Disposal Alternative,'' August 1999, from Lucas Incorporated, Richland, Washington. The direction within the U. S. Department of Energy-Headquarters memorandum was given as follows: ''The DOE Radioactive Waste Management Order requires that a Disposal authorization statement be obtained prior to construction of new low-level waste disposal facility. Field elements with the existing low-level waste disposal facilities shall obtain a disposal authorization statement in accordance with the schedule in the complex-wide Low-Level Waste Management Program Plan. The disposal authorization statement shall be issued based on a review of the facility's performance assessment and composite analysis or appropriate CERCLA documentation. The disposal authorization shall specify the limits and conditions on construction, design, operations, and closure of the low-level waste facility based on these reviews. A disposal authorization statement is a part of the required radioactive waste management basis for a disposal facility. Failure to obtain a disposal authorization statement

  18. Geological disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Sato, Tsutomu

    2000-01-01

    For disposing method of radioactive wastes, various feasibilities are investigated at every nations and international organizations using atomic energy, various methods such as disposal to cosmic space, disposal to ice sheet at the South Pole and so forth, disposal into ocean bed or its sediments, and disposal into ground have been examined. It is, however, impossible institutionally at present, to have large risk on accident in the disposal to cosmic space, to be prohibited by the South Pole Treaty on the disposal to ice sheet at the South Pole, and to be prohibited by the treaty on prevention of oceanic pollution due to the disposal of wastes and so forth on the disposal into oceanic bed or its sediments (London Treaty). Against them, the ground disposal is thought to be the most powerful method internationally from some reasons shown as follows: no burden to the next generation because of no need in long-term management by human beings; safety based on scientific forecasting; disposal in own nation; application of accumulated technologies on present mining industries, civil engineering, and so forth to construction of a disposal facility; and, possibility to take out wastes again, if required. For the ground disposal, wastes must be buried into the ground and evaluated their safety for long terms. It is a big subject to be taken initiative by engineers on geoscience who have quantified some phenomena in the ground and at ultra long term. (G.K.)

  19. Characterization of shallow trench isolation CMP process and its application

    Science.gov (United States)

    Li, Helen; Zhang, ChunLei; Liu, JinBing; Liu, ZhengFang; Chen, Kuang Han; Gbondo-Tugbawa, Tamba; Ding, Hua; Li, Flora; Lee, Brian; Gower-Hall, Aaron; Chiu, Yang-Chih

    2016-03-01

    Chemical mechanical polishing (CMP) has been a critical enabling technology in shallow trench isolation (STI), which is used in current integrated circuit fabrication process to accomplish device isolation. Excessive dishing and erosion in STI CMP processes, however, create device yield concerns. This paper proposes characterization and modeling techniques to address a variety of concerns in STI CMP. In the past, majority of CMP publications have been addressed on interconnect layers in backend- of-line (BEOL) process. However, the number of CMP steps in front-end-of-line (FEOL) has been increasing in more advanced process techniques like 3D-FinFET and replacement metal gate, as a results incoming topography induced by FEOL CMP steps can no longer be ignored as the topography accumulates and stacks up across multiple CMP steps and eventually propagating to BEOL layers. In this paper, we first discuss how to characterize and model STI CMP process. Once STI CMP model is developed, it can be used for screening design and detect possible manufacturing weak spots. We also work with process engineering team to establish hotspot criteria in terms of oxide dishing and nitride loss. As process technologies move from planar transistor to 3D transistor like FinFet and multi-gate, it is important to accurately predict topography in FEOL CMP processes. These incoming topographies when stacked up can have huge impact in BEOL copper processes, where copper pooling becomes catastrophic yield loss. A calibration methodology to characterize STI CMP step is developed as shown in Figure 1; moreover, this STI CMP model is validated from silicon data collected from product chips not used in calibration stage. Additionally, wafer experimental setup and metrology plan are instrumental to an accurate model with high predictive power. After a model is generated, spec limits and threshold to establish hotspots criteria can be defined. Such definition requires working closely with foundry

  20. Geomembranes as an interim measure to control water infiltration at a low-level radioactive waste disposal area

    International Nuclear Information System (INIS)

    Weishan, M.R.; Sonntag, T.L.; Shehane, W.D.

    1997-01-01

    Using an exposed geomembrane an interim measure to cover a closed, Low-Level Radioactive Waste Disposal Area requires unique design and construction considerations. In response to a Resource Conservation and Recovery Act Administrative Consent Order, the New York State Energy Research and Development Authority (NYSERDA) used very low-density polyethylene (VLDPE) geomembrane as an interim measure to cover two soil-capped, grass-covered waste trenches to address a rapid increase in water accumulation in the trenches. Two years later, NYSERDA covered the remaining grass-covered trench caps with a reinforced ethylene interpolymer alloy (EIA-R) geomembrane to reduce water accumulation in these trenches. This paper addresses the differences in geomembrane materials and discusses the lessons learned during design, construction, and operation since installation of the covers. Discussed are the successes and obstacles regarding the use of both geomembrane materials as an exposed cover, selecting the geomembrane materials, anchoring the geomembrane from wind uplift, and mitigating the increased surface water runoff from the geomembrane covered area

  1. Disposal of decontaminated salts at the Savannah River Plant by solidification and burial

    International Nuclear Information System (INIS)

    Dukes, M.D.; Wolf, H.C.; Langton, C.A.

    1983-01-01

    The current plan for disposal of waste salt at the Savannah River Plant (SRP) is to immobilize the decontaminated salt solution by mixing with cement and SRP soil, and bury the resulting grout (saltstone) in a landfill. The grout which contains 37.8 wt % salt solution, 22.8 wt % Portland I-P cement, and 39.2 wt % SRP soil, was specially formulated to have a low permeability ( -10 cm/sec). This material will be mixed and placed in trenches. After setting, the saltstone will be covered with a clay cap, and an overburden of compacted native soil will be replaced. 6 references

  2. HLW disposal dilemma

    International Nuclear Information System (INIS)

    Andrei, V.; Glodeanu, F.

    2003-01-01

    The radioactive waste is an inevitable residue from the use of radioactive materials in industry, research and medicine, and from the operation of generating electricity nuclear power stations. The management and disposal of such waste is therefore an issue relevant to almost all countries. Undoubtedly the biggest issue concerning radioactive waste management is that of high level waste. The long-lived nature of some types of radioactive wastes and the associated safety implications of disposal plans have raised concern amongst those who may be affected by such facilities. For these reasons the subject of radioactive waste management has taken on a high profile in many countries. Not one Member State in the European Union can say that their high level waste will be disposed of at a specific site. Nobody can say 'that is where it is going to go'. Now, there is a very broad consensus on the concept of geological disposal. The experts have little, if any doubt that we could safely dispose of the high level wastes. Large sectors of the public continue to oppose to most proposals concerning the siting of repositories. Given this, it is increasingly difficult to get political support, or even political decisions, on such sites. The failure to advance to the next step in the waste management process reinforces the public's initial suspicion and resistance. In turn, this makes the political decisions even harder. In turn, this makes the political decisions even harder. The management of spent fuel from nuclear power plant became a crucial issue, as the cooling pond of the Romanian NPP is reaching saturation. During the autumn of 2000, the plant owner proceeded with an international tendering process for the supply of a dry storage system to be implemented at the Cernavoda station to store the spent fuel from Unit 1 and eventually from Unit 2 for a minimum period of 50 years. The facility is now in operation. As concern the disposal of the spent fuel, the 'wait and see

  3. Multiple faulting events revealed by trench analysis of the seismogenic structure of the 1976 Ms7.1 Luanxian earthquake, Tangshan Region, China

    Science.gov (United States)

    Guo, Hui; Jiang, Wali; Xie, Xinsheng

    2017-10-01

    The Ms7.8 Tangshan earthquake occurred on 28 July 1976 at 03:42 CST. Approximately 15 h later, the Ms7.1 Luanxian earthquake occurred approximately 40 km northeast of the main shock. The two earthquakes formed different surface rupture zones. The surface rupture of the Tangshan earthquake was NNE-trending and more than 47 km long. The surface rupture of the Luanxian earthquake was more than 6 km long and consisted of two sections, forming a protruding arc to the west. The north and south sections were NE- and NW-trending and 2 km and 4 km long, respectively. A trench was excavated in Sanshanyuan Village across the NE-trending rupture of the Luanxian earthquake, at the macroscopic epicenter of the Luanxian earthquake. Analysis of this trench revealed that the surface rupture is connected to the underground active fault. The following major conclusions regarding Late Quaternary fault activity have been reached. (1) The Sanshanyuan trench indicated that its fault planes trend NE30° and dip SE or NW at angles of approximately 69-82°. (2) The fault experienced four faulting events prior to the Luanxian earthquake at 27.98 ka with an average recurrence interval of approximately 7.5 ka. (3) The Ms7.1 Luanxian earthquake resulted from the activity of the Luanxian Western fault and was triggered by the Ms7.8 Tangshan earthquake. The seismogenic faults of the 1976 Ms7.1 Luanxian earthquake and the 1976 Ms7.8 Tangshan earthquake are not the same fault. This example of an M7 earthquake triggered by a nearly M8 earthquake after more than 10 h on a nearby fault is a worthy topic of research for the future prediction of strong earthquakes.

  4. ALARA review for the decontamination and decommissioning of the 233-S pipe trench

    International Nuclear Information System (INIS)

    Kornish, M.J.

    1998-01-01

    The 233-S Facility was completed in 1955 to expand plutonium production by further concentrating the plutonium nitrate product solution from the Reduction Oxidation (REDOX) Plant. The facility is radiologically contaminated because of operations and accidents. Isolation from REDOX and removal of the product transfer lines from the pipe trench is the second step in the decontamination and decommissioning of the entire 233-S Facility. The work scope is to isolate all piping from REDOX and then to remove all the piping/equipment from the pipe trench. The building is presently a Hazard Category 2 Nuclear Facility. A formal as low as reasonably achievable (ALARA) review is required by BHI-SH-02, Vol. 1, Procedure No. 1.22, Planning Radiological Work, when radiological conditions exceed trigger levels. The level of contamination inside the pipe trench and the process fluid piping is unknown. The potential exists to exceed the level of loose surface contamination, which requires a formal ALARA review when opening the pipe trench and cutting of piping commences. This ALARA review is for task instruction 1997-03-18-009 Revision 1, 233-S Pipe Trench Decon and Pipe Removal

  5. Modeling the flow of water in and around shallow burial trenches

    International Nuclear Information System (INIS)

    Suen, C.J.

    1988-01-01

    Water flow through a generic low-level waste burial trench has been modeled for a vertical cross-section perpendicular to the longitudinal axis of an elongated trenched, using the finite element code, FEMWATER, in two-dimensional vertical mode. The grid consists of 513 nodes and 468 variable-size quadrilateral elements, and the simulation domain is about 56 m (H) /times/ 34 m (V). The traench, which is situated in the unsaturated zone, measures approximately 28 m wide and 10 m deep in cross-section, and is composed of three types of soil - a high-conductivity gravel cap on top, a low-conductivity clay layer beneath it, and backfill soil in the waste burial region. The rest of the domain is made up of undisturbed soil. Different cases have been simulated by varying boundary conditions, geometry and hydraulic properties. These results are used in radionuclide transport calculations to determine the ''source term'' (4). In addition, numerical experiments provide valuable information in trench design, such as, the geometry of the moisture barrier. Results from these experiments indicates that a moderate extension (8 m) of the clay layer beyond the sides of the trench can significantly reduce the net water flow (by 42%). They also show that sparsely distributed waste package have minimal effect on the net flow through the trench. 10 refs., 7 figs., 3 tabs

  6. Near-trench slip potential of megaquakes evaluated from fault properties and conditions

    Science.gov (United States)

    Hirono, Tetsuro; Tsuda, Kenichi; Tanikawa, Wataru; Ampuero, Jean-Paul; Shibazaki, Bunichiro; Kinoshita, Masataka; Mori, James J.

    2016-01-01

    Near-trench slip during large megathrust earthquakes (megaquakes) is an important factor in the generation of destructive tsunamis. We proposed a new approach to assessing the near-trench slip potential quantitatively by integrating laboratory-derived properties of fault materials and simulations of fault weakening and rupture propagation. Although the permeability of the sandy Nankai Trough materials are higher than that of the clayey materials from the Japan Trench, dynamic weakening by thermally pressurized fluid is greater at the Nankai Trough owing to higher friction, although initially overpressured fluid at the Nankai Trough restrains the fault weakening. Dynamic rupture simulations reproduced the large slip near the trench observed in the 2011 Tohoku-oki earthquake and predicted the possibility of a large slip of over 30 m for the impending megaquake at the Nankai Trough. Our integrative approach is applicable globally to subduction zones as a novel tool for the prediction of extreme tsunami-producing near-trench slip. PMID:27321861

  7. Resisting and pinning of a nanodrop by trenches on a hysteresis-free surface

    Science.gov (United States)

    Chang, Cheng-Chung; Wu, Cyuan-Jhang; Sheng, Yu-Jane; Tsao, Heng-Kwong

    2016-10-01

    The encounter of a nanodrop with a trench on a hysteresis-free surface is explored by many-body dissipative particle dynamics to show the effect of surface roughness on droplet wetting. A free nanodrop exhibits Brownian motion and the diffusivity decays exponentially with the liquid-solid contact area. In contrast, as the nanodrop sits on a trench, its random motion is constrained. Work must be done to overcome the energy barriers for the transition between free and trapped states. The potential energy landscape is thus constructed based on the force-displacement plot. It is shown that the trench acts as a hydrophobic blemish for capture but like a hydrophilic blemish for escape. A drop always breaks up after detachment from a hydrophilic trench. Therefore, the drop tends to bypass a small trench when it meets one. The macroscopic experiments are performed by fabricating liquid-infused surfaces with extremely low contact angle hysteresis. The experimental observations agree qualitatively with simulation outcomes.

  8. Salt disposal: Paradox Basin, Utah

    International Nuclear Information System (INIS)

    1983-04-01

    This report presents the findings of a study conducted for the National Waste Terminal Storage (NWTS) Program. Permanent disposal options are examined for salt resulting from the excavation of a waste repository in the bedded salt deposits of the Paradox Basin of southeastern Utah. The study is based on a repository salt backfill compaction of 60% of the original density which leaves a total of 8 million tons of 95% pure salt to be disposed of over a 30-year period. The feasibility, impacts, and mitigation methods are examined for five options: commercial disposal, permanent onsite surface disposal, permanent offsite disposal, deepwell injection, and ocean and Great Salt Lake disposal. The study concludes the following: Commercial marketing of all repository salt would require a subsidy for transportation to major salt markets. Permanent onsite surface storage is both economically and technically feasible. Permanent offsite disposal is technically feasible but would incur additional transportation costs. Selection of an offsite location would provide a means of mitigating impacts associated with surface storage at the repository site. Deepwell injection is an attractive disposal method; however, the large water requirement, high cost of development, and poor performance of similar operating brine disposal wells eliminates this option from consideration as the primary means of disposal for the Paradox Basin. Ocean disposal is expensive because of high transportation cost. Also, regulatory approval is unlikely. Ocean disposal should be eliminated from further consideration in the Paradox Basin. Great Salt Lake disposal appears to be technically feasible. Great Salt Lake disposal would require state approval and would incur substantial costs for salt transportation. Permanent onsite disposal is the least expensive method for disposal of all repository salt

  9. Geological disposal of nuclear waste

    International Nuclear Information System (INIS)

    1979-01-01

    Fourteen papers dealing with disposal of high-level radioactive wastes are presented. These cover disposal in salt deposits, geologic deposits and marine disposal. Also included are papers on nuclear waste characterization, transport, waste processing technology, and safety analysis. All of these papers have been abstracted and indexed

  10. Preliminary disposal limits, plume interaction factors, and final disposal limits

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2018-01-11

    In the 2008 E-Area Performance Assessment (PA), each final disposal limit was constructed as the product of a preliminary disposal limit and a plume interaction factor. The following mathematical development demonstrates that performance objectives are generally expected to be satisfied with high confidence under practical PA scenarios using this method. However, radionuclides that experience significant decay between a disposal unit and the 100-meter boundary, such as H-3 and Sr-90, can challenge performance objectives, depending on the disposed-of waste composition, facility geometry, and the significance of the plume interaction factor. Pros and cons of analyzing single disposal units or multiple disposal units as a group in the preliminary disposal limits analysis are also identified.

  11. Disposal of fly ash

    International Nuclear Information System (INIS)

    Singh, B.; Foley, C.

    1991-01-01

    Theoretical arguments and pilot plant results have shown that the transport of fly-furnace ash from the power station to the disposal area as a high concentration slurry is technically viable and economically attractive. Further, lack of free water, when transported as a high concentration slurry, offers significant advantages in environmental management and rehabilitation of the disposal site. This paper gives a basis for the above observations and discusses the plans to exploit the above advantages at the Stanwell Power Station. (4 x 350 MWe). This will be operated by the Queensland Electricity Commission. The first unit is to come into operation in 1992 and other units are to follow progressively on a yearly basis

  12. Nuclear waste disposal

    International Nuclear Information System (INIS)

    Hare, Tony.

    1990-01-01

    The Save Our Earth series has been designed to appeal to the inquiring minds of ''planet-friendly'' young readers. There is now a greater awareness of environmental issues and an increasing concern for a world no longer able to tolerate the onslaught of pollution, the depletion of natural resources and the effects of toxic chemicals. Each book approaches a specific topic in a way that is exciting and thought-provoking, presenting the facts in a style that is concise and appropriate. The series aims to demonstrate how various environmental subjects relate to our lives, and encourages the reader to accept not only responsibility for the planet, but also for its rescue and restoration. This volume, on nuclear waste disposal, explains how nuclear energy is harnessed in a nuclear reactor, what radioactive waste is, what radioactivity is and its effects, and the problems and possible solutions of disposing of nuclear waste. An awareness of the dangers of nuclear waste is sought. (author)

  13. Development of a prototype plan for the effective closure of a waste disposal site in Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Nyhan, J.; Barnes, F.

    1989-02-01

    The purpose of this study was to develop a prototype plan for the effective closure and stabilization of a semiarid low-level waste disposal site. This prototype plan will provide demonstrated closure techniques for a trench in a disposal site at Los Alamos based on previous shallow land burial (SLB) field research both at the Los Alamos Experimental Engineered Test Facility (EETF), and at a waste disposal area at Los Alamos. The accuracy of modeling soil water storage by two hydrologic models was tested by comparing simulation results with field measurements of soil moisture in eight experimental landfill cover systems at Waste Disposal Area B having a range of well-defined soil profiles and vegetative covers. Regression analysis showed that one of the two models tested represented soil moisture more accurately than the second model. The accuracy of modeling all of the parameters of the water balance equation was then evaluated using field data from the Integrated Systems Demonstration plots at the EETF. Optimized parameters were developed for one model to describe observed values of deep percolation, evapotranspiration, and runoff from the field plots containing an SLB trench cap configuration

  14. Whither nuclear waste disposal?

    International Nuclear Information System (INIS)

    Cotton, T.A.

    1990-01-01

    With respect to the argument that geologic disposal has failed, I do not believe that the evidence is yet sufficient to support that conclusion. It is certainly true that the repository program is not progressing as hoped when the Nuclear Waste Policy Act of 1982 established a 1998 deadline for initial operation of the first repository. The Department of Energy (DOE) now expects the repository to be available by 2010, and tat date depends upon a finding that the Yucca Mountain site - the only site that DOE is allowed by law to evaluate - is in fact suitable for use. Furthermore, scientific evaluation of the site to determine its suitability is stopped pending resolution of two lawsuits. However, I believe it is premature to conclude that the legal obstacles are insuperable, since DOE just won the first of the two lawsuits, and chances are good it will win the second. The concept of geologic disposal is still broadly supported. A recent report by the Board on Radioactive Waste Management of the National Research Council noted that 'There is a worldwide scientific consensus that deep geological disposal, the approach being followed in the United States, is the best option for disposing of high-level radioactive waste'. The U.S. Nuclear Regulatory Commission (USNRC) recently implicitly endorsed this view in adopting an updated Waste Confidence position that found confidence that a repository could be available in the first quarter of the next century - sufficient time to allow for rejection of Yucca Mountain and evaluation of a new site

  15. Disposal of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-11-15

    A discussion on the disposal of radioactive wastes was held in Vienna on 20 September 1960. The three scientists who participated in the discussion were Mr. Harry Brynielsson (Sweden), Head of the Swedish Atomic Energy Company; Mr. H. J. Dunster (United Kingdom), Health Physics Adviser to the United Kingdom Atomic Energy Authority; and Mr. Leslie Silverman (United States), Professor of Harvard University, and Chairman of the US AEC Advisory Committee on Reactor Safeguards, as well as consultant on air cleaning

  16. Whither nuclear waste disposal?

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, T A [JK Research Associates, Silver Spring, MD (United States)

    1990-07-01

    With respect to the argument that geologic disposal has failed, I do not believe that the evidence is yet sufficient to support that conclusion. It is certainly true that the repository program is not progressing as hoped when the Nuclear Waste Policy Act of 1982 established a 1998 deadline for initial operation of the first repository. The Department of Energy (DOE) now expects the repository to be available by 2010, and tat date depends upon a finding that the Yucca Mountain site - the only site that DOE is allowed by law to evaluate - is in fact suitable for use. Furthermore, scientific evaluation of the site to determine its suitability is stopped pending resolution of two lawsuits. However, I believe it is premature to conclude that the legal obstacles are insuperable, since DOE just won the first of the two lawsuits, and chances are good it will win the second. The concept of geologic disposal is still broadly supported. A recent report by the Board on Radioactive Waste Management of the National Research Council noted that 'There is a worldwide scientific consensus that deep geological disposal, the approach being followed in the United States, is the best option for disposing of high-level radioactive waste'. The U.S. Nuclear Regulatory Commission (USNRC) recently implicitly endorsed this view in adopting an updated Waste Confidence position that found confidence that a repository could be available in the first quarter of the next century - sufficient time to allow for rejection of Yucca Mountain and evaluation of a new site.

  17. Disposal of radioactive waste

    International Nuclear Information System (INIS)

    Critchley, R.J.; Swindells, R.J.

    1984-01-01

    A method and apparatus for charging radioactive waste into a disposable steel drum having a plug type lid. The drum is sealed to a waste dispenser and the dispenser closure and lid are withdrawn into the dispenser in back-to-back manner. Before reclosing the dispenser the drum is urged closer to it so that on restoring the dispenser closure to the closed position the lid is pressed into the drum opening

  18. Radium bearing waste disposal

    International Nuclear Information System (INIS)

    Tope, W.G.; Nixon, D.A.; Smith, M.L.; Stone, T.J.; Vogel, R.A.; Schofield, W.D.

    1995-01-01

    Fernald radium bearing ore residue waste, stored within Silos 1 and 2 (K-65) and Silo 3, will be vitrified for disposal at the Nevada Test Site (NTS). A comprehensive, parametric evaluation of waste form, packaging, and transportation alternatives was completed to identify the most cost-effective approach. The impacts of waste loading, waste form, regulatory requirements, NTS waste acceptance criteria, as-low-as-reasonably-achievable principles, and material handling costs were factored into the recommended approach

  19. Disposing of fluid wastes

    International Nuclear Information System (INIS)

    Bradley, J.S.

    1984-01-01

    Toxic liquid waste, eg liquid radioactive waste, is disposed of by locating a sub-surface stratum which, before removal of any fluid, has a fluid pressure in the pores thereof which is less than the hydrostatic pressure which is normal for a stratum at that depth in the chosen area, and then feeding the toxic liquid into the stratum at a rate such that the fluid pressure in the stratum never exceeds the said normal hydrostatic pressure. (author)

  20. Rock disposal problems identified

    Energy Technology Data Exchange (ETDEWEB)

    Knox, R

    1978-06-01

    Mathematical models are the only way of examining the return of radioactivity from nuclear waste to the environment over long periods of time. Work in Britain has helped identify areas where more basic data is required, but initial results look very promising for final disposal of high level waste in hard rock repositories. A report by the National Radiological Protection Board of a recent study, is examined.

  1. Detection and delineation of waste trenches by geophysical methods at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Selfridge, R.J.

    1987-01-01

    Detection and delineation of waste trenches at hazardous waste sites are needed before actual implementation of site corrective measures. In a field study conducted in Solid Waste Storage Area 4 (SWSA4) at Oak Ridge National Laboratory (ORNL), surface geophysical techniques were used to assist in the delineation of waste trenches. A magnetometer/gradiometer survey was used to detect ferrous metals buried at the site. An electromagnetic ground conductivity survey was used to measure the electrical conductivity of the subsurface and aided in supporting the magnetometer/gradiometer results. Results from the two techniques were complimentary and easily integrated into a final interpretation. The reliability, efficiency, and worker safety benefits of these techniques offer a nondestructive surface technique for locating buried waste trenches

  2. Elimination of trench defects and V-pits from InGaN/GaN structures

    International Nuclear Information System (INIS)

    Smalc-Koziorowska, Julita; Grzanka, Ewa; Czernecki, Robert; Schiavon, Dario; Leszczyński, Mike

    2015-01-01

    The microstructural evolution of InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor phase epitaxy was studied as a function of the growth temperature of the GaN quantum barriers (QBs). We observed the formation of basal stacking faults (BSFs) in GaN QBs grown at low temperature. The presence of BSFs terminated by stacking mismatch boundaries (SMBs) leads to the opening of the structure at the surface into a V-shaped trench loop. This trench may form above an SMB, thereby terminating the BSF, or above a junction between the SMB and a subsequent BSF. Fewer BSFs and thus fewer trench defects were observed in GaN QBs grown at temperatures higher than 830 °C. Further increase in the growth temperature of the GaN QBs led to the suppression of the threading dislocation opening into V-pits

  3. Charge deposition model for investigating SE-microdose effect in trench power MOSFETs

    International Nuclear Information System (INIS)

    Wan Xin; Zhou Weisong; Liu Daoguang; Bo Hanliang; Xu Jun

    2015-01-01

    It was demonstrated that heavy ions can induce large current—voltage (I–V) characteristics shift in commercial trench power MOSFETs, named single event microdose effect (SE-microdose effect). A model is presented to describe this effect. This model calculates the charge deposition by a single heavy ion hitting oxide and the subsequent charge transport under an electric field. Holes deposited at the SiO 2 /Si interface by a Xe ion are calculated by using this model. The calculated results were then used in Sentaurus TCAD software to simulate a trench power MOSFET's I–V curve shift after a Xe ion has hit it. The simulation results are consistent with the related experiment's data. In the end, several factors which affect the SE-microdose effect in trench power MOSFETs are investigated by using this model. (paper)

  4. Charge deposition model for investigating SE-microdose effect in trench power MOSFETs

    Science.gov (United States)

    Xin, Wan; Weisong, Zhou; Daoguang, Liu; Hanliang, Bo; Jun, Xu

    2015-05-01

    It was demonstrated that heavy ions can induce large current—voltage (I-V) characteristics shift in commercial trench power MOSFETs, named single event microdose effect (SE-microdose effect). A model is presented to describe this effect. This model calculates the charge deposition by a single heavy ion hitting oxide and the subsequent charge transport under an electric field. Holes deposited at the SiO2/Si interface by a Xe ion are calculated by using this model. The calculated results were then used in Sentaurus TCAD software to simulate a trench power MOSFET's I-V curve shift after a Xe ion has hit it. The simulation results are consistent with the related experiment's data. In the end, several factors which affect the SE-microdose effect in trench power MOSFETs are investigated by using this model.

  5. Close-range geophotogrammetric mapping of trench walls using multi-model stereo restitution software

    International Nuclear Information System (INIS)

    Coe, J.A.; Taylor, E.M.; Schilling, S.P.

    1991-01-01

    Methods for mapping geologic features exposed on trench walls have advanced from conventional gridding and sketch mapping to precise close-range photogrammetric mapping. In our study, two strips of small-format (60 x 60) stereo pairs, each containing 42 photos and covering approximately 60 m of nearly vertical trench wall (2-4 m high), were contact printed onto eight 205 x 255-mm transparent film sheets. Each strip was oriented in a Kern DSR15 analytical plotter using the bundle adjustment module of Multi-Model Stereo Restitution Software (MMSRS). We experimented with several systematic-control-point configurations to evaluate orientation accuracies as a function of the number and position of control points. We recommend establishing control-point columns (each containing 2-3 points) in every 5th photo to achieve the 7-mm Root Mean Square Error (RMSE) accuracy required by our trench-mapping project. 7 refs., 8 figs., 1 tab

  6. Close-range geophotogrammetric mapping of trench walls using multi-model stereo restitution software

    Energy Technology Data Exchange (ETDEWEB)

    Coe, J.A.; Taylor, E.M.; Schilling, S.P.

    1991-06-01

    Methods for mapping geologic features exposed on trench walls have advanced from conventional gridding and sketch mapping to precise close-range photogrammetric mapping. In our study, two strips of small-format (60 {times} 60) stereo pairs, each containing 42 photos and covering approximately 60 m of nearly vertical trench wall (2-4 m high), were contact printed onto eight 205 {times} 255-mm transparent film sheets. Each strip was oriented in a Kern DSR15 analytical plotter using the bundle adjustment module of Multi-Model Stereo Restitution Software (MMSRS). We experimented with several systematic-control-point configurations to evaluate orientation accuracies as a function of the number and position of control points. We recommend establishing control-point columns (each containing 2-3 points) in every 5th photo to achieve the 7-mm Root Mean Square Error (RMSE) accuracy required by our trench-mapping project. 7 refs., 8 figs., 1 tab.

  7. Simple analytical expression for crosstalk estimation in homogeneous trench-assisted multi-core fibers

    DEFF Research Database (Denmark)

    Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

    2014-01-01

    An analytical expression for the mode coupling coe cient in homogeneous trench-assisted multi-core fibers is derived, which has a sim- ple relationship with the one in normal step-index structures. The amount of inter-core crosstalk reduction (in dB) with trench-assisted structures compared...... to the one with normal step-index structures can then be written by a simple expression. Comparison with numerical simulations confirms that the obtained analytical expression has very good accuracy for crosstalk estimation. The crosstalk properties in trench-assisted multi-core fibers, such as crosstalk...... dependence on core pitch and wavelength-dependent crosstalk, can be obtained by this simple analytical expression....

  8. Formation of metal and dielectric liners using a solution process for deep trench capacitors.

    Science.gov (United States)

    Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

    2012-07-01

    We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor.

  9. Work plan for monitor well/groundwater elevation data recorder installation at the Cheney Disposal site, Grand Junction, Colorado

    International Nuclear Information System (INIS)

    1994-09-01

    In May 1990, during the excavation for the Grand Junction, Colorado, Cheney Reservoir disposal cell (Cheney), a water bearing paleochannel was encountered along the northern boundary of the excavation (designated the Northwest Paleochannel). To ensure the long-term integrity of the disposal embankment, remedial actions were taken including the excavation of the paleochannel and underlying material to bedrock, backfilling of the trapezoidal trench with granular material, and placement of a geotextile liner above the granular material. Compacted clay backfill was placed above the reconstructed paleochannel trench, and the northwest corner was restored to the designated grade. Investigation of other paleochannels determined that ground water flow terminated before it migrated as far west as the disposal cell. Therefore, flow in these paleochannels would have no impact on the disposal cell. Although characterization efforts did not indicate the presence of a ground water-bearing paleochannel south of the disposal cell, the potential could not be ruled out. As a best management practice for long-term monitoring at Cheney, two monitor wells will be installed within the paleochannels. One well will be installed within 50 feet (ft) west of the reconstructed Northwest Paleochannel. The second well will be installed near the southwestern (downgradient) corner of the disposal cell. The purposes of these wells are to characterize ground water flow (if any) within the paleochannels and to monitor the potential for water movement (seepage) into or out of the disposal cell. Initial monitoring of the paleochannels will consist of water level elevation measurement collection and trend analysis to evaluate fluctuations in storage. The purpose of this document is to describe the work that will be performed and the procedures that will be followed during installation of two ground water monitor wells and two ground water elevation data recorders (data loggers) at Cheney

  10. Disposal of spent fuel

    International Nuclear Information System (INIS)

    Blomeke, J.O.; Ferguson, D.E.; Croff, A.G.

    1978-01-01

    Based on preliminary analyses, spent fuel assemblies are an acceptable form for waste disposal. The following studies appear necessary to bring our knowledge of spent fuel as a final disposal form to a level comparable with that of the solidified wastes from reprocessing: 1. A complete systems analysis is needed of spent fuel disposition from reactor discharge to final isolation in a repository. 2. Since it appears desirable to encase the spent fuel assembly in a metal canister, candidate materials for this container need to be studied. 3. It is highly likely that some ''filler'' material will be needed between the fuel elements and the can. 4. Leachability, stability, and waste-rock interaction studies should be carried out on the fuels. The major disadvantages of spent fuel as a disposal form are the lower maximum heat loading, 60 kW/acre versus 150 kW/acre for high-level waste from a reprocessing plant; the greater long-term potential hazard due to the larger quantities of plutonium and uranium introduced into a repository; and the possibility of criticality in case the repository is breached. The major advantages are the lower cost and increased near-term safety resulting from eliminating reprocessing and the treatment and handling of the wastes therefrom

  11. Waste and Disposal: Demonstration

    International Nuclear Information System (INIS)

    Neerdael, B.; Buyens, M.; De Bruyn, D.; Volckaert, G.

    2002-01-01

    Within the Belgian R and D programme on geological disposal, demonstration experiments have become increasingly important. In this contribution to the scientific report 2001, an overview is given of SCK-CEN's activities and achievements in the field of large-scale demonstration experiments. In 2001, main emphasis was on the PRACLAY project, which is a large-scale experiment to demonstrate the construction and the operation of a gallery for the disposal of HLW in a clay formation. The PRACLAY experiment will contribute to enhance understanding of water flow and mass transport in dense clay-based materials as well as to improve the design of the reference disposal concept. In the context of PRACLAY, a surface experiment (OPHELIE) has been developed to prepare and to complement PRACLAY-related experimental work in the HADES Underground Research Laboratory. In 2001, efforts were focussed on the operation of the OPHELIE mock-up. SCK-CEN also contributed to the SELFRAC roject which studies the self-healing of fractures in a clay formation

  12. Energy policy of North Korea

    International Nuclear Information System (INIS)

    Rueth, G.

    2006-01-01

    Since the year 1990, North Korea suffers internal-policy problems as well as foreign-political problems. The gross domestic investment decreased by 3.8% yearly between the years 1990 and 1998. Many actual problems of North Korea correspond with the energy crisis in this land affecting nearly all sectors of economy and society. This energy crisis was released by the fact, that the former Soviet Union has stopped the supply of primary energy in the year 1991. In the contribution under consideration, the author reports on the energy policy of North Korea. The main themes of this contribution are: (a) Development and characteristics of the energy sector; (b) Crisis of the energy sector; (c) Consequences of the energy crisis in North Korea; (d) Possibilities of the solution of the energy crisis. For the U.S.A. and the international community, the energy crisis offers the possibility to turn North Korea to negotiations by means of remedial measures in the energy sector. In response, North Korea should drop its nuclear energy program. Apart from such positive incentives, the threat of sanctions is conceivable. North Korea imports nearly 70 % of its oil demand from the People's Republic of China. Therefore, China has an great influence on North Korea. The energy crisis of North Korea shows the fatal consequences of a falsely performed energy policy with respect to the population of this land and with respect to the stability and disposing capacity of the political leadership

  13. Waste Disposal: Long-term Performance Studies for Radioactive Waste Disposal and Hydrogeological Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Marivoet, J

    2000-07-01

    The main objectives of SCK-CEN's R and D programme on long-term performance studies are: (1) to develop a methodology and associated tools for assessing the long-term safety of geological disposal of all types of radioactive waste in clay formations and of the shallow-land burial of low-level waste; (2) to assess the performance and to identify the most influential elements of integrated repository systems for the disposal of radioactive waste; (3) to collect geological, piezometric and hydraulic data required for studying the hydrogeological system in north-eastern Belgium; (4) to develop a regional aquifer model for north-easter Belgium and to apply it in the performance assessments for the Mol site; (5) to test, verify and improve computer codes used in the performance assessment calculations of waste disposal concepts and contaminated sites (the computer codes simulate water flow and transport of radionuclides in engineered barriers, aquifers and contaminated sites). The scientific programme and achievements in 1999 are described.

  14. Cosmic disposal of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Y; Morisawa, S [Kyoto Univ. (Japan). Faculty of Engineering

    1975-03-01

    The technical and economical possibility and safety of the disposal of highly radioactive waste into cosmos are reviewed. The disposal of highly radioactive waste is serious problem to be solved in the near future, because it is produced in large amounts by the reprocessing of spent fuel. The promising methods proposed are (i) underground disposal, (ii) ocean disposal, (iii) cosmic disposal and (iv) extinguishing disposal. The final disposal method is not yet decided internationally. The radioactive waste contains very long life nuclides, for example transuranic elements and actinide elements. The author thinks the most perfect and safe disposal method for these very long life nuclides is the disposal into cosmos. The space vehicle carrying radioactive waste will be launched safely into outer space with recent space technology. The selection of orbit for vehicles (earth satellite or orbit around planets) or escape from solar system, selection of launching rocket type pretreatment of waste, launching weight, and the cost of cosmic disposal were investigated roughly and quantitatively. Safety problem of cosmic disposal should be examined from the reliable safety study data in the future.

  15. Removal of the radioactive materials from the trench submergence in Fukushima

    International Nuclear Information System (INIS)

    Okita, Takeshi; Ikeda, Akira; Oomura, Hisao; Kojima, Chiaki; Nozawa, Keiji

    2014-01-01

    Toshiba has been contributing for stabilization from the accident of Fukushima Daiichi nuclear power plant. One of the contribution areas is the treatment of highly contaminated water accumulated in the piping trench of Unit 2 and Unit 3. As an emergency countermeasure, Toshiba installed the mobile type water treatment system which is named SMARTS (Simplified Mobile Adsorption and Retrieve for Trench Submergence) for removal of radionuclide. SMARTS has achieved 10 3 ∼ 10 4 decontamination factor (DF) for Cesium (Cs) in the actual operation. This paper describes the formation of SMARTS and the result of performance. (author)

  16. Preliminary Hazard Classification for the 116-N-3 Crib and Trench Remediation Activities

    International Nuclear Information System (INIS)

    Adam, W. J.

    1999-01-01

    The purpose of this document is to provide a preliminary hazard classification (PHC) for the remediation of the 116-N-3 crib and trench, also known as the 1325-N crib and trench, which are located within the 100-NR-1 Operable Unit of the Hanford Site's 100-N Area. In addition to the work scope described below, current planning also includes removal of some of the pipelines located downstream from the 13 15-N valve box and sampling of other pipelines to determine if remedial actions goals have been met and the pipelines can be left in place

  17. The politics of radioactive waste disposal

    International Nuclear Information System (INIS)

    Kemp, R.

    1992-01-01

    Plans for radioactive waste disposal have been among the most controversial of all environmental policies, provoking vociferous public opposition in a number of countries. This book looks at the problem from an international perspective, and shows how proposed solutions have to be politically and environmentally, as well as technologically acceptable. In the book the technical and political agenda behind low and intermediate level radioactive waste disposal in the UK, Western Europe, Scandinavia and North America is examined. The technical issues and the industrial proposals and analyses and factors which have been crucial in affecting relative levels of public acceptability are set out. Why Britain has lagged behind countries such as Sweden and France in establishing Low Level Waste (LLW) and Intermediate Level Waste (ILW) sites, the strength of the 'not in my backyard' syndrome in Britain, and comparisons of Britain's decision-making process with the innovative and open pattern followed in the US and Canada are examined. An important insight into the problems facing Nirex, Britain's radioactive waste disposal company, which is seeking to establish an underground waste site at Sellafield in Cumbria is given. (author)

  18. Submarine slope failures along the convergent continental margin of the Middle America Trench

    Science.gov (United States)

    Harders, Rieka; Ranero, CéSar R.; Weinrebe, Wilhelm; Behrmann, Jan H.

    2011-06-01

    We present the first comprehensive study of mass wasting processes in the continental slope of a convergent margin of a subduction zone where tectonic processes are dominated by subduction erosion. We have used multibeam bathymetry along ˜1300 km of the Middle America Trench of the Central America Subduction Zone and deep-towed side-scan sonar data. We found abundant evidence of large-scale slope failures that were mostly previously unmapped. The features are classified into a variety of slope failure types, creating an inventory of 147 slope failure structures. Their type distribution and abundance define a segmentation of the continental slope in six sectors. The segmentation in slope stability processes does not appear to be related to slope preconditioning due to changes in physical properties of sediment, presence/absence of gas hydrates, or apparent changes in the hydrogeological system. The segmentation appears to be better explained by changes in slope preconditioning due to variations in tectonic processes. The region is an optimal setting to study how tectonic processes related to variations in intensity of subduction erosion and changes in relief of the underthrusting plate affect mass wasting processes of the continental slope. The largest slope failures occur offshore Costa Rica. There, subducting ridges and seamounts produce failures with up to hundreds of meters high headwalls, with detachment planes that penetrate deep into the continental margin, in some cases reaching the plate boundary. Offshore northern Costa Rica a smooth oceanic seafloor underthrusts the least disturbed continental slope. Offshore Nicaragua, the ocean plate is ornamented with smaller seamounts and horst and graben topography of variable intensity. Here mass wasting structures are numerous and comparatively smaller, but when combined, they affect a large part of the margin segment. Farther north, offshore El Salvador and Guatemala the downgoing plate has no large seamounts but

  19. Electrical Resistivity Correlation to Vadose Zone Sediment and Pore-Water Composition for the BC Cribs and Trenches Area

    International Nuclear Information System (INIS)

    Serne, R. Jeffrey; Ward, Anderson L.; Um, Wooyong; Bjornstad, Bruce N.; Rucker, Dale F.; Lanigan, David C.; Benecke, Mark W.

    2009-01-01

    This technical report documents the results of geochemical and soil resistivity characterization of sediment obtained from four boreholes drilled in the BC Cribs and Trench area. Vadose zone sediment samples were obtained at a frequency of about every 2.5 ft from approximately 5 ft bgs to borehole total depth. In total, 505 grab samples and 39 six-inch long cores were obtained for characterization. The pore-water chemical composition data, laboratory-scale soil resistivity and other ancillary physical and hydrologic measurements and analyses described in this report are designed to provide a crucial link between direct measurements on sediments and the surface-based electrical-resistivity information obtained via field surveys. A second goal of the sediment characterization was to measure the total and water-leachable concentrations of key contaminants of concern as a function of depth and distance from the footprints of inactive disposal facilities. The total and water-leachable concentrations of key contaminants will be used to update contaminant distribution conceptual models and to provide more data for improving base-line risk predictions and remedial alternative selections. The ERC 'ground truthing' exercise for the individual boreholes showed mixed results. In general, the high concentrations of dissolved salts in the pore waters of sediments from C5923, C5924 and C4191 produced a low resistivity 'target' in the processed resistivity field surveys, and variability could be seen in the resistivity data that could relate to the variability in pore- water concentrations but the correlations (regression R2 were mediocre ranging from 0.2 to 0.7 at best; where perfect correlation is 1.0). The field-based geophysical data also seemed to suffer from a sort of vertigo, where looking down from the ground surface, the target (e.g., maximum pore-water salt concentration) depth was difficult to resolve. The best correlations between the field electrical resistivity

  20. Electrical Resistivity Correlation to Vadose Zone Sediment and Pore-Water Composition for the BC Cribs and Trenches Area

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey; Ward, Anderson L.; Um, Wooyong; Bjornstad, Bruce N.; Rucker, Dale F.; Lanigan, David C.; Benecke, Mark W.

    2009-06-01

    This technical report documents the results of geochemical and soil resistivity characterization of sediment obtained from four boreholes drilled in the BC Cribs and Trench area. Vadose zone sediment samples were obtained at a frequency of about every 2.5 ft from approximately 5 ft bgs to borehole total depth. In total, 505 grab samples and 39 six-inch long cores were obtained for characterization. The pore-water chemical composition data, laboratory-scale soil resistivity and other ancillary physical and hydrologic measurements and analyses described in this report are designed to provide a crucial link between direct measurements on sediments and the surface-based electrical-resistivity information obtained via field surveys. A second goal of the sediment characterization was to measure the total and water-leachable concentrations of key contaminants of concern as a function of depth and distance from the footprints of inactive disposal facilities. The total and water-leachable concentrations of key contaminants will be used to update contaminant distribution conceptual models and to provide more data for improving base-line risk predictions and remedial alternative selections. The ERC “ground truthing” exercise for the individual boreholes showed mixed results. In general, the high concentrations of dissolved salts in the pore waters of sediments from C5923, C5924 and C4191 produced a low resistivity “target” in the processed resistivity field surveys, and variability could be seen in the resistivity data that could relate to the variability in pore- water concentrations but the correlations (regression R2 were mediocre ranging from 0.2 to 0.7 at best; where perfect correlation is 1.0). The field-based geophysical data also seemed to suffer from a sort of vertigo, where looking down from the ground surface, the target (e.g., maximum pore-water salt concentration) depth was difficult to resolve. The best correlations between the field electrical

  1. Paleoseismological data from a new trench across the El Camp Fault(Catalan Coastal Ranges, NE Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    K. Boydell

    2003-06-01

    Full Text Available The El Camp Fault (Catalan Coastal Ranges, NE Iberian Peninsula is a slow slipping normal fault whose seismic potential has only recently been recognised. New geomorphic and trench investigations were carried out during a training course across the El Camp Fault at the La Porquerola alluvial fan site. A new trench (trench 8 was dug close to a trench made previously at this site (trench 4. With the aid of two long topographic profiles across the fault scarp we obtained a vertical slip rate ranging between 0.05 and 0.08 mm/yr. At the trench site, two main faults, which can be correlated between trenches 8 and 4, make up the fault zone. Using trench analysis three paleoseismic events were identified, two between 34.000 and 125.000 years BP (events 3 and 2 and another event younger than 13 500 years BP (event 1, which can be correlated, respectively, with events X (50.000- 125.000 years BP, Y (35.000-50.000 years BP and Z (3000-25.000 years BP. The last seismic event at the La Porquerola alluvial fan site is described for the first time, but with some uncertainties.

  2. 78 FR 7385 - Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll...

    Science.gov (United States)

    2013-02-01

    ...-BA98 Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll... Presidential proclamations that created the Marianas Trench, Pacific Remote Islands, and Rose Atoll Marine..., 2009). Proclamation 8337 of January 6, 2009, ``Establishment of the Rose Atoll Marine National Monument...

  3. The potential influence of subduction zone polarity on overriding plate deformation, trench migration and slab dip angle

    NARCIS (Netherlands)

    Schellart, W. P.

    2007-01-01

    A geodynamic model exists, the westward lithospheric drift model, in which the variety of overriding plate deformation, trench migration and slab dip angles is explained by the polarity of subduction zones. The model predicts overriding plate extension, a fixed trench and a steep slab dip for

  4. Isostatic anomaly characteristics and dynamic environment of New Britain Ocean trenches and neighboring Area in Papua New Guinea

    Science.gov (United States)

    Yang, G.; Shen, C.; Wang, J.

    2017-12-01

    we calculated the Bouguer gravity anomaly and the Airy-Heiskanen isostatic anomaly in the New Britain ocean trenches and its surrounding areas of Papua New Guinea using the topography model and the gravity anomaly model from Scripps Institute of Oceanography, and analyzed the characteristics of isostatic anomaly and the earthquake dynamic environment of this region. The results show that there are obviously differences in the isostatic state between each block in the region, and the crustal tectonic movement is very intense in the regions with high positive or negative isostatic gravity anomalies; A number of sub-plates in this area is driven by the external tectonic action such as plate subduction and thrust of the Pacific plate, the Indian - Australian plate and the Eurasian plate. From the distribution of isostatic gravity anomaly, the tectonic action of anti-isostatic movement in this region is the main source of power; from the isostatic gravity and the spatial distribution of the earthquake, with the further contraction of the Indian-Australian plate, the southwestern part of the Solomon Haiya plate will become part of the Owen Stanley fold belt, the northern part will enter the lower part of the Bismarck plate, eastern part will enter the front of the Pacific plate, the huge earthquake will migrate to the north and east of the Solomon Haiya plate.

  5. Environmental monitoring considerations for low-level waste disposal sites

    International Nuclear Information System (INIS)

    Sedlet, J.

    1982-01-01

    All waste disposal sites are required to monitor the environment. The proposed NRC licensing rule, 10 CFR Part 61, requires that such monitoring be conducted before, during, and after a site is operated. An adequate monitoring program consists of measuring concentrations of radionuclides, chemically-toxic substances, and leachate indicators in environmental media and of evaluating specific physical properties of the site. In addition, the composition of the buried waste must be known. Methods for obtaining this information are discussed and monitoring programs are presented for the preoperational, operational, and postclosure phases of a disposal site. Environmental monitoring is considered in a broad context, since it includes monitoring burial trenches onsite, as well as surveillance in the offsite environment. Postclosure monitoring programs will be strongly influenced by the operational monitoring results. In some respects, this phase will be easier since the migration pathways should be well known and the number of radionuclides of concern reduced by radioactive decay. The results of the environmental monitoring program will be vital to successful site operation. These results should be used to determine if operational changes are needed and to predict future environmental impacts

  6. The disposal of radioactive waste in Sweden, West Germany and France

    International Nuclear Information System (INIS)

    1987-01-01

    Representatives from Humberside, Lincolnshire and Bedford County Councils have visited radioactive waste disposal sites in Sweden (Forsmak), West Germany (Konrad) and France (Centre de la Manche). The British regions are those in which there are sites which NIREX (Nuclear Industry Radioactive Waste Executive) have been investigating with a view to disposing of low and intermediate level radioactive waste. The sites, methods of disposal, cost and radiation levels are detailed for the three countries visited and compared with the NIREX proposals for shallow trench disposal for wastes at low and intermediate levels. The general findings were that the three countries visited are more advanced in the development of policies and practices for radioactive waste disposal with better technical alternatives to the NIREX proposals. Secondly, that the overall cost may be greater than for a shallow repository but would still be less than 1% of the nuclear electricity generation cost. Thirdly, the need to gain and sustain public acceptance for what was being done was more clearly understood and acted on than in the UK. (U.K.)

  7. Study of applicable methods on safety verification of disposal facilities and waste packages

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Three subjects about safety verification on the disposal of low level radioactive waste were investigated in FY. 2012. For radioactive waste disposal facilities, specs and construction techniques of covering with soil to prevent possible destruction caused by natural events (e.g. earthquake) were studied to consider verification methods for those specs. For waste packages subject to near surface pit disposal, settings of scaling factor and average radioactivity concentration (hereafter referred to as ''SF'') on container-filled and solidified waste packages generated from Kashiwazaki Kariwa Nuclear Power Station Unit 1-5, setting of cesium residual ratio of molten solidified waste generated from Tokai and Tokai No.2 Power Stations, etc. were studied. Those results were finalized in consideration of the opinion from advisory panel, and publicly opened as JNES-EV reports. In FY 2012, five JNES reports were published and these have been used as standards of safety verification on waste packages. The verification method of radioactive wastes subject to near-surface trench disposal and intermediate depth disposal were also studied. For radioactive wastes which will be returned from overseas, determination methods of radioactive concentration, heat rate and hydrogen generation rate of CSD-C were established. Determination methods of radioactive concentration and heat rate of CSD-B were also established. These results will be referred to verification manuals. (author)

  8. Exposure and risk calculations for disposal of wastes having minimal radioactivity

    International Nuclear Information System (INIS)

    Fields, D.E.

    1984-01-01

    The US Nuclear Regulatory Commission is currently considering revision of rules 10 CFR 20 and 10 CFR 61, which cover disposal of solid wastes containing minimal activity radioactivity. In support of these revised rules, we have evaluated the consequences of disposing of four waste streams at four types of disposal areas located in three different geographic regions. Consequences are expressed in terms of human exposures and associated health effects. Each geographic region has its own climate and geology. Example waste streams, waste disposal methods, and geographic regions chosen for this study are clearly specified. The PRESTO-II methodology was used to evaluate radionuclide transport and health effects. This methodology was developed to assess radiological impacts to a static local population for a 1000-year period following disposal. The modeling of pathways and processes of migration from the trench to exposed populations included the following considerations: groundwater transport, overland flow, erosion, surface water dilution, resuspension, atmospheric transport, deposition, inhalation, and ingestion of contaminated beef, milk, crops, and water. 9 references, 2 figures, 3 tables

  9. Radioactive waste disposal

    International Nuclear Information System (INIS)

    Petit, J.C.

    1998-04-01

    A deep gap, reflecting a persisting fear, separates the viewpoints of the experts and that of the public on the issue of the disposal of nuclear WASTES. The history of this field is that of the proliferation with time of spokesmen who pretend to speak in the name of the both humans and non humans involved. Three periods can be distinguished: 1940-1970, an era of contestation and confusion when the experts alone represents the interest of all; 1970-1990, an era of contestation and confusion when spokespersons multiply themselves, generating the controversy and the slowing down of most technological projects; 1990-, an era of negotiation, when viewpoints, both technical and non technical, tend to get closer and, let us be optimistic, leading to the overcome of the crisis. We show that, despite major differences, the options and concepts developed by the different actors are base on two categories of resources, namely Nature and Society, and that the consensus is built up through their 'hydridation'. we show in this part that the perception of nuclear power and, in particular of the underground disposal of nuclear wastes, involves a very deep psychological substrate. Trying to change mentalities in the domain by purely scientific and technical arguments is thus in vain. The practically instinctive fear of radioactivity, far from being due only to lack of information (and education), as often postulated by scientists and engineers, is rooted in archetypical structures. These were, without doubt, reactivated in the 40 s by the traumatizing experience of the atomic bomb. In addition, anthropological-linked considerations allow us to conclude that he underground disposal of wastes is seen as a 'rape' and soiling of Mother Earth. This contributes to explaining, beyond any rationality, the refusal of this technical option by some persons. However, it would naturally be simplistic and counter-productive to limit all controversy in this domain to these psychological aspects

  10. Municipal sludge disposal economics

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J L [SRI International, Menlo Park, CA; Bomberger, Jr, D C; Lewis, F M

    1977-10-01

    Costs for disposal of sludges from a municipal wastewater treatment plant normally represents greater than or equal to 25% of the total plant operating cost. The following 5 sludge handling options are considered: chemical conditioning followed by vacuum filtration, and incineration; high-pressure wet-air oxidation and vacuum filtration or filter press prior to incineration; thermal conditioning, vacuum filtraton, and incineration; high-pressure wet-air oxidation and vacuum filtration, with ash to landfill; aerobic or anaerobic digestion, followed by chemical conditioning, vacuum filtration, and disposal on land; and chemical conditioning, followed by a filter press, flash dryer, and sale as fertilizer. The 1st 2 options result in the ultimate disposal of small amounts of ash in a landfill; the digestion options require a significant landfill; the fertilizer option requires a successful marketing and sales effort. To compare the economies of scale for the options, analyses were performed for 3 plant capacities - 10, 100, and 500 mgd; as plant size increases, the economies of scale for incineration system are quite favorable. The anaerobic digestion system has a poorer capital cost-scaling factor. The incinerator options which start with chemical conditioning consume much less electrical power at all treatment plant sizes; incinerator after thermal conditioning uses more electricity but less fuel. Digestion requires no direct external fossil fuel input. The relative use of fuel is constant at all plant sizes for other options. The incinerator options can produce a significant amount of steam which may be used. The anaerobic digestion process can be a significant net producer of fuel gas.

  11. Underground disposal of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1979-08-15

    Disposal of low- and intermediate-level radioactive wastes by shallow land burial, emplacement in suitable abandoned mines, or by deep well injection and hydraulic fracturing has been practised in various countries for many years. In recent years considerable efforts have been devoted in most countries that have nuclear power programmes to developing and evaluating appropriate disposal systems for high-level and transuranium-bearing waste, and to studying the potential for establishing repositories in geological formations underlaying their territories. The symposium, organized jointly by the IAEA and OECD's Nuclear Energy Agency in cooperation with the Geological Survey of Finland, provided an authoritative account of the status of underground disposal programmes throughout the world in 1979. It was evidence of the experience that has been gained and the comprehensive investigations that have been performed to study various options for the underground disposal of radioactive waste since the last IAEA/NEA symposium on this topic (Disposal of Radioactive Waste into the Ground) was held in 1967 in Vienna. The 10 sessions covered the following topics: National programme and general studies, Disposal of solid waste at shallow depth and in rock caverns, underground disposal of liquid waste by deep well injection and hydraulic fracturing, Disposal in salt formations, Disposal in crystalline rocks and argillaceous sediments, Thermal aspects of disposal in deep geological formations, Radionuclide migration studies, Safety assessment and regulatory aspects.

  12. Remedial action and waste disposal project -- 300-FF-1 remedial action readiness assessment report

    International Nuclear Information System (INIS)

    Carson, J.W.; Carlson, R.A.; Greif, A.A.; Johnson, C.R.; Orewiler, R.I.; Perry, D.M.; Remsen, W.E.; Tuttle, B.G.; Wilson, R.C.

    1997-09-01

    This report documents the readiness assessment for initial startup of the 300-FF-1 Remedial Action Task. A readiness assessment verifies and documents that field activities are ready to start (or restart) safely. The 300-FF-1 assessment was initiated in April 1997. Readiness assessment activities included confirming the completion of project-specific procedures and permits, training staff, obtaining support equipment, receipt and approval of subcontractor submittals, and mobilization and construction of site support systems. The scope of the 300-FF-1 Remedial Action Task includes excavation and disposal of contaminated soils at liquid waste disposal facilities and of waste in the 618-4 Burial Ground and the 300-FF-1 landfills. The scope also includes excavation of test pits and test trenches

  13. The significance of natural ground-water recharge in site selection for mill tailings disposal

    International Nuclear Information System (INIS)

    Stephens, D.B.

    1985-01-01

    Milling operations throughout the world have created vast amounts of waste by-products, or tailings, which are often disposed on the land surface. The wastes may be disposed behind dams, on untreated ground, or on compacted clay or synthetic liners of impoundments and trenches. Often one of the principle concerns of environmental regulatory agencies is whether seepage from the waste pile could move through the vadose zone to the water table and possibly contaminate an aquifer. The seepage may be generated by the drainage of liquids initially deposited along with the tailings or by infiltrating meteoric water which leaches soluted from the tailings. The purpose of this article is to discuss some of the commonly held assumptions regarding storage of seepage wastes in the unsaturated zone. The significance of recent studies of water movement in dry climates which pertain to tailings site selection are presented

  14. Role of the unsaturated zone in radioactive and hazardous waste disposal

    International Nuclear Information System (INIS)

    Mercer, J.W.; Marine, I.W.; Rao, P.S.C.

    1983-01-01

    The problems of hazardous and low-level radioactive waste disposal caused by the physical and chemical processes active in the unsaturated zone are explored in this book. The focus is on the use of laboratory analyses, field observations, and numerical and analytical calculations to create a clear picture of both problems and potential solutions. Topics include policy modeling, statistical techniques, liners, and field applications. Contents include: Modeling of Moisture Movement through Layered Trench Covers; Role of Partially Saturated Soil in Liner Design for Hazardous Waste Disposal Sites; Field Experiments to Determine Saturated Hydraulic Conductivity in the Vadose Zone; Role of Desaturation on Transport through Fractured Rock; Nuclear Waste Isolation in the Unsaturated Zone of Arid Regions

  15. Radioactive waste material disposal

    Science.gov (United States)

    Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

    1995-01-01

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide.

  16. Disposal - practical problems

    International Nuclear Information System (INIS)

    Hycnar, J.; Pinko, L.

    1995-01-01

    Most Polish power plants have stockyards for storage of fly ash and slag. This paper describes the: methods of fly ash and slag storage used, methods of conveying the waste to the stockpiles (by railway cars, trucks, belt conveyors or hydraulically); construction of wet stockyards and dry stockyards and comparison of the ash dumped, development of methods of ash disposal in mine workings; composition and properties of fly ash and slag from hard coal; and the effects of ash storage yards on the environment (by leaching of trace elements, dust, effect on soils, and noise of machinery). 16 refs., 3 figs., 6 tabs

  17. Nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    1982-01-01

    This film for a general audience deals with nuclear fuel waste management in Canada, where research is concentrating on land based geologic disposal of wastes rather than on reprocessing of fuel. The waste management programme is based on cooperation of the AECL, various universities and Ontario Hydro. Findings of research institutes in other countries are taken into account as well. The long-term effects of buried radioactive wastes on humans (ground water, food chain etc.) are carefully studied with the help of computer models. Animated sequences illustrate the behaviour of radionuclides and explain the idea of a multiple barrier system to minimize the danger of radiation hazards

  18. Waste disposal experts meet

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-01-15

    Problems connected with the disposal into the sea of radioactive wastes from peaceful uses of atomic energy are being examined by a panel of experts, convened by the International Atomic Energy Agency. These experts from eight different countries held a first meeting at IAEA headquarters in Vienna from 4-9 December 1958, under the chairmanship of Dr. Harry Brynielsson, Director General of the Swedish Atomic Energy Company. The countries represented are: Canada, Czechoslovakia, France, Japan, Netherlands, United Kingdom and United States. The group will meet again in 1959. (author)

  19. HLW Disposal System Development

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J. W.; Choi, H. J.; Lee, J. Y. (and others)

    2007-06-15

    A KRS is suggested through design requirement analysis of the buffer and the canister which are the constituent of disposal system engineered barrier and HLW management plans are proposed. In the aspect of radionuclide retention capacity, the thickness of the buffer is determined 0.5m, the shape to be disc and ring and the dry density to be 1.6 g/cm{sup 3}. The maximum temperature of the buffer is below 100 .deg. which meets the design requirement. And bentonite blocks with 5 wt% of graphite showed more than 1.0 W/mK of thermal conductivity without the addition of sand. The result of the thermal analysis for proposed double-layered buffer shows that decrease of 7 .deg. C in maximum temperature of the buffer. For the disposal canister, the copper for the outer shell material and cast iron for the inner structure material is recommended considering the results analyzed in terms of performance of the canisters and manufacturability and the geochemical properties of deep groundwater sampled from the research area with granite, salt water intrusion, and the heavy weight of the canister. The results of safety analysis for the canister shows that the criticality for the normal case including uncertainty is the value of 0.816 which meets subcritical condition. Considering nation's 'Basic Plan for Electric Power Demand and Supply' and based on the scenario of disposing CANDU spent fuels in the first phase, the disposal system that the repository will be excavated in eight phases with the construction of the Underground Research Laboratory (URL) beginning in 2020 and commissioning in 2040 until the closure of the repository is proposed. Since there is close correlation between domestic HLW management plans and front-end/back-end fuel cycle plans causing such a great sensitivity of international environment factor, items related to assuring the non-proliferation and observing the international standard are showed to be the influential factor and acceptability

  20. Vertical slab sinking and westward subduction offshore of Mesozoic North America

    Science.gov (United States)

    Sigloch, Karin; Mihalynuk, Mitchell G.

    2013-04-01

    Subducted slabs in the mantle, as imaged by seismic tomography, preserve a record of ancient subduction zones. Ongoing debate concerns how direct this link is. How long ago did each parcel of slab subduct, and where was the trench located relative to the imaged slab position? Resolving these questions will benefit paleogeographic reconstructions, and restrict the range of plausible rheologies for mantle convection simulations. We investigate one of the largest and best-constrained Mesozoic slab complexes, the "Farallon" in the transition zone and lower mantle beneath North America. We quantitatively integrate observations from whole-mantle P-wave tomography, global plate reconstructions, and land geological evidence from the North American Cordillera. These three data sets permit us to test the simplest conceivable hypothesis for linking slabs to paleo-trenches: that each parcel of slab sank only vertically shortly after entering the trench That is, we test whether within the limits of tomographic resolution, all slab material lies directly below the location where it subducted beneath its corresponding arc. Crucially and in contrast to previous studies, we do not accept or impose an Andean-style west coast trench (Farallon-beneath-continent subduction) since Jurassic times, as this scenario is inconsistent with many geological observations. Slab geometry alone suggests that trenches started out as intra-oceanic because tomography images massive, linear slab "walls" in the lower mantle, extending almost vertically from about 800 km to 2000+ km depth. Such steep geometries would be expected from slabs sinking vertically beneath trenches that were quasi-stationary over many tens of millions of years. Intra-oceanic trenches west of Mesozoic North America could have been stationary, whereas a coastal Farallon trench could not, because the continent moved westward continuously as the Atlantic opened. Overlap of North American west-coast positions, as reconstructed in a

  1. Thermal loading effects on geological disposal

    International Nuclear Information System (INIS)

    Come, B.; Venet, P.

    1984-01-01

    A joint study on the thermal loading effects on geological disposal was carried out within the European Community Programme on Management and Storage of Radioactive Waste by several laboratories in Belgium, France and the Federal Republic of Germany. The purpose of the work was to review the thermal effects induced by the geological disposal of high-level wastes and to assess their consequences on the 'admissible thermal loading' and on waste management in general. Three parallel studies dealt separately with the three geological media being considered for HLW disposal within the CEC programme: granite (leadership: Commissariat a l'energie atomique (CEA), France), salt (leadership: Gesellschaft fuer Strahlen- und Umweltforschung (GSF), Federal Republic of Germany), and clay (leadership: Centre d'etude de l'energie nucleaire (CEN/SCK), Belgium). The studies were based on the following items: only vitrified high-level radioactive waste was considered; the multi-barrier confinement concept was assumed (waste glass, container (with or without overpack), buffer material, rock formation); the disposal was foreseen in a deep mined repository, in an 'in-land' geological formation; only normal situations and processes were covered, no 'accident' scenario being taken into account. Although reasonably representative of a wide variety of situations, the data collected and the results obtained are generic for granite, formation-specific for salt (i.e. related to the north German Zechstein salt formation), and site-specific for clay (i.e. concentrated on the Boom clay layer at the Mol site, Belgium). For each rock type, realistic temperature limits were set, taking into account heat propagation, thermo-mechanical effects inside the rock formations, induced or modified groundwater or brine movement, effects on the buffer material as well as effects on the waste glass and canister, and finally, nuclide transport

  2. Finite-element model evaluation of barrier configurations to reduce infiltration into waste-disposal structures: preliminary results and design considerations

    International Nuclear Information System (INIS)

    Lu, A.H.; Phillips, S.J.; Adams, M.R.

    1982-09-01

    Barriers to reduce infiltration into waste burial disposal structures (trenches, pits, etc.) may be required to provide adequate waste confinement. The preliminary engineering design of these barriers should consider interrelated barrier performance factors. This paper summarizes preliminary computer simulation activities to further engineering barrier design efforts. Several barrier configurations were conceived and evaluated. Models were simulated for each barrier configuration using a finite element computer code. Results of this preliminary evaluation indicate that barrier configurations, depending on their morphology and materials, may significantly influence infiltration, flux, drainage, and storage of water through and within waste disposal structures. 9 figures

  3. Ancient engineering geology projects in China; A canal system in Ganzu province and trenches along the Great Wall in Ningxia Hui Autonomous Region

    Science.gov (United States)

    Wallace, R.E.; Bucknam, R.C.; Hanks, T.C.

    1994-01-01

    Two major construction projects of ancient times in China involved what today would be considered engineering geology. We describe an ancient canal system in Gaotai County, Gansu province that was possibly begun in the Han dynasty (206 BC-220 AD). The canal system heads at the Dasha River and extends northwestward for about 55 km to the City of Camels and Xusanwan village. Four parallel canals are present at the local site we examined. The canals were likely built primarily to transport water but may also have served as defensive military barriers. A second project involves trenches and berms along the north side of the Great Wall, clearly part of the Great Wall defensive system. This site is in Ningxia Autonomous Region near the town of Shizuishan. ?? 1994.

  4. Ultrahigh-density trench cpacitors in silicon and their application to integrated DC-DC conversion

    NARCIS (Netherlands)

    Roozeboom, F.; Bergveld, H.J.; Nowak, K.; Le Cornec, F.; Guiraud, L.; Bunel, C.; Iochem, S.; Ferreira, J.; Ledain, S.; Pieraerts, E.; Pommier, M.

    2009-01-01

    This paper addresses silicon-based integration of passive components applied to 3D integration with dies of other technologies within one package. Particularly, the development of high-density trench capacitors has enabled the realization of small-formfactor DC-DC converters. As illustration, an

  5. Light extinction and scattering from individual and arrayed high-aspect-ratio trenches in metal

    DEFF Research Database (Denmark)

    Roberts, Alexander; Søndergaard, Thomas; Chirumamilla, Manohar

    2016-01-01

    for a two-dimensional scatterer. We construct a simple resonator model which predicts the wavelength-dependent extinction, scattering, and absorption cross section of the trench and compare the model findings with full numerical simulations. Both extinction and scattering cross sections are mainly...

  6. Ship motion effects in CTD-data from weakly stratified waters of the Puerto Rico trench

    NARCIS (Netherlands)

    van Haren, H.

    2015-01-01

    Shipborne SBE 911plus Conductivity Temperature Depth (CTD)-casts have been made to maximum 7220 m in the Puerto Rico Trench (PRT). In PRT-waters from 5500 m and deeper and specifically below the 6500 m transition to the hadal-zone, the vertical density stratification is found very weak, with

  7. Interim-status groundwater monitoring plan for the 216-B-63 trench

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, M.D.

    1995-02-09

    This document outlines the groundwater monitoring plan, under RCRA regulations in 40 CFR 265 Subpart F and WAC173-300-400, for the 216-B-63 Trench. This interim status facility is being sampled under detection monitoring criteria and this plan provides current program conditions and requirements.

  8. Magnetron target designs to improve wafer edge trench filling in ionized metal physical vapor deposition

    International Nuclear Information System (INIS)

    Lu Junqing; Yoon, Jae-Hong; Shin, Keesam; Park, Bong-Gyu; Yang Lin

    2006-01-01

    Severe asymmetry of the metal deposits on the trench sidewalls occurs near the wafer edge during low pressure ionized metal physical vapor deposition of Cu seed layer for microprocessor interconnects. To investigate this process and mitigate the asymmetry, an analytical view factor model based on the analogy between metal sputtering and diffuse thermal radiation was constructed. The model was validated based on the agreement between the model predictions and the reported experimental values for the asymmetric metal deposition at trench sidewalls near the wafer edge for a 200 mm wafer. This model could predict the thickness of the metal deposits across the wafer, the symmetry of the deposits on the trench sidewalls at any wafer location, and the angular distributions of the metal fluxes arriving at any wafer location. The model predictions for the 300 mm wafer indicate that as the target-to-wafer distance is shortened, the deposit thickness increases and the asymmetry decreases, however the overall uniformity decreases. Up to reasonable limits, increasing the target size and the sputtering intensity for the outer target portion significantly improves the uniformity across the wafer and the symmetry on the trench sidewalls near the wafer edge

  9. A systematic study of BNL's 3D-Trench Electrode detectors

    International Nuclear Information System (INIS)

    Montalbano, A.; Bassignana, D.; Li, Z.; Liu, S.; Lynn, D.; Pellegrini, G.; Tsybychev, D.

    2014-01-01

    New types of silicon pixel detectors have been proposed because of the need for more radiation hard semiconductor devices for the high luminosity tracking detector upgrades at the Large Hadron Collider. A novel type of 3D Si pixel detectors is proposed, with each cell of the 3D-Trench Electrode pixel detector featuring a concentric trench electrode surrounding the central collecting column electrode. The pixel sensor is an array of those individual cells. Systematic 3D simulations using Silvacos TCAD programs have been carried out to study the characteristics of this novel 3D pixel design and to compare to the traditional 3D column electrode pixel design. The 3D simulations show a much lower depletion voltage and a more uniform electric field in the new 3D-Trench Electrode pixel detectors as compared to the traditional 3D column Electrode detectors. The first prototype 3D-Trench Electrode pixel detectors have been manufactured at the Centro Nacional De Microelectronica. Preliminary electrical measurements are discussed and charge collection efficiency measurements are presented

  10. Closure Report for Corrective Action Unit 426: Cactus Spring Waste Trenches, Tonopah Test Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Dave Madsen

    1998-08-01

    This Closure Report provides the documentation for closure of the Cactus Spring Waste Trenches Corrective Action Unit (CAU) 426. The site is located on the Tonopah Test Range, approximately 225 kilometers northwest of Las Vegas, NV. CAU 426 consists of one corrective action site (CAS) which is comprised of four waste trenches. The trenches were excavated to receive solid waste generated in support of Operation Roller Coaster, primary the Double Tracks Test in 1963, and were subsequently backfilled. The Double Tracks Test involved use of live animals to assess the biological hazards associated with the nonnuclear detonation of plutonium-bearing devices. The Nevada Division of Environmental Protection approved Corrective Action Plan (CAP)which proposed ''capping'' methodology. The closure activities were completed in accordance with the approved CAP and consisted of constructing an engineered cover in the area of the trenches, constructing/planting a vegetative cover, installing a perimeter fence and signs, implementing restrictions on future use, and preparing a Post-Closure Monitoring Plan.

  11. Conductive Oxides Trench Structures as Hyperbolic Metamaterials in Mid-infrared Range

    DEFF Research Database (Denmark)

    Takayama, Osamu; Shkondin, Evgeniy; Panah, Mohammad Esmail Aryaee

    ,2]. Moreover plasmonics for mid-infrared offer unique applications such as bio-sensing, thermal imaging and quest for novel materials and structures has been continuing [3]. In this report we show that vertical trench structures made of, for example, aluminum-doped ZnO (AZO) or other transparent conductive...

  12. Design of homogeneous trench-assisted multi-core fibers based on analytical model

    DEFF Research Database (Denmark)

    Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

    2016-01-01

    We present a design method of homogeneous trench-assisted multicore fibers (TA-MCFs) based on an analytical model utilizing an analytical expression for the mode coupling coefficient between two adjacent cores. The analytical model can also be used for crosstalk (XT) properties analysis, such as ...

  13. Preliminary fire hazard analysis for the PUTDR and TRU trenches in the Solid Waste Burial Ground

    International Nuclear Information System (INIS)

    Gaschott, L.J.

    1995-01-01

    This document represents the Preliminary Fire Hazards Analysis for the Pilot Unvented TRU Drum Retrieval effort and for the Transuranic drum trenches in the low level burial grounds. The FHA was developed in accordance with DOE Order 5480.7A to address major hazards inherent in the facility

  14. Partial liquid-penetration inside a deep trench by film flowing over it

    Science.gov (United States)

    Nguyen, Phuc-Khanh; Dimakopoulos, Yiannis; Tsamopoulos, John

    2014-11-01

    Liquid film flow along substrates featuring a deep trench may not wet the trench floor, but create a second gas-liquid interface inside the trench. The liquid penetration inside the trench depends on the location and shape of this inner interface. The penetration increases by decreasing the two three-phase contact lines between the inner interface and the two side-walls or the flow rate and depends on the liquid properties. This partial-penetration is studied by employing the Galerkin / finite element method to solve the two-dimensional steady-state Navier-Stokes equations in a physical domain that is adaptively remeshed. Multiple branches of steady solutions connected via turning points are revealed by pseudo arc-length continuation. Flow hysteresis may occur in a certain range of liquid penetration depth, when the interaction of the two interfaces changes qualitatively. This induces an abrupt jump of penetration distance and deformation amplitude of the outer interface. Work supported by the General Secretariat of Research & Technology of Greece through the program ``Excellence'' (Grant No. 1918) in the framework ``Education and Lifelong Learning'' co-funded by the ESF.

  15. Eocene extension in Idaho generated massive sediment floods into Franciscan trench and into Tyee, Great Valley, and Green River basins

    Science.gov (United States)

    Dumitru, Trevor A.; Ernst, W.G.; Wright, James E.; Wooden, Joseph L.; Wells, Ray E.; Farmer, Lucia P.; Kent, Adam J.R.; Graham, Stephan A.

    2013-01-01

    The Franciscan Complex accretionary prism was assembled during an ∼165-m.y.-long period of subduction of Pacific Ocean plates beneath the western margin of the North American plate. In such fossil subduction complexes, it is generally difficult to reconstruct details of the accretion of continent-derived sediments and to evaluate the factors that controlled accretion. New detrital zircon U-Pb ages indicate that much of the major Coastal belt subunit of the Franciscan Complex represents a massive, relatively brief, surge of near-trench deposition and accretion during Eocene time (ca. 53–49 Ma). Sediments were sourced mainly from the distant Idaho Batholith region rather than the nearby Sierra Nevada. Idaho detritus also fed the Great Valley forearc basin of California (ca. 53–37 Ma), the Tyee forearc basin of coastal Oregon (49 to ca. 36 Ma), and the greater Green River lake basin of Wyoming (50–47 Ma). Plutonism in the Idaho Batholith spanned 98–53 Ma in a contractional setting; it was abruptly superseded by major extension in the Bitterroot, Anaconda, Clearwater, and Priest River metamorphic core complexes (53–40 Ma) and by major volcanism in the Challis volcanic field (51–43 Ma). This extensional tectonism apparently deformed and uplifted a broad region, shedding voluminous sediments toward depocenters to the west and southeast. In the Franciscan Coastal belt, the major increase in sediment input apparently triggered a pulse of massive accretion, a pulse ultimately controlled by continental tectonism far within the interior of the North American plate, rather than by some tectonic event along the plate boundary itself.

  16. Liquid metal coolant disposal from UKAEA reactors at Dounreay

    International Nuclear Information System (INIS)

    Adam, E.R.

    1997-01-01

    As part of the United Kingdom's Fast Reactor Development programme two reactors were built and operated at Dounreay in the North of Scotland. DFR (Dounreay Fast Reactor) was operated from 1959-1977 and PFR (Prototype Fast Reactor) was operated from 1974-1994. Both reactors are currently undergoing Stage 1 Decommissioning and are installing plant to dispose of the bulk coolant (DFR ∼ 60 tonne; PFR ∼ 1500 tonne). The coolant (NaK) remaining at DFR is mainly in the primary circuit which contains in excess of 500 TBq of Cs137. Disposal of 40 tonnes of secondary coolant has already been carried out. The paper will describe the processes used to dispose of this secondary circuit coolant and how it is intended the remaining primary circuit coolant will be handled. The programme to process the primary coolant will also be described which involves the conversion of the liquid metal to caustic and its decontamination. No PFR coolant Na has been disposed off to date. The paper will describe the current decommissioning programme activities relating to liquid metal disposal and treatment describing the materials to be disposed of and the issue of decontamination of the effluents. (author)

  17. 10 CFR 61.52 - Land disposal facility operation and disposal site closure.

    Science.gov (United States)

    2010-01-01

    ... DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.52 Land disposal... wastes by placing in disposal units which are sufficiently separated from disposal units for the other... between any buried waste and the disposal site boundary and beneath the disposed waste. The buffer zone...

  18. Borehole disposal design concept

    International Nuclear Information System (INIS)

    RANDRIAMAROLAHY, J.N.

    2007-01-01

    In Madagascar, the sealed radioactive sources are used in several socioeconomic sectors such as medicine, industry, research and agriculture. At the end of their useful lives, these radioactive sources become radioactive waste and can be still dangerous because they can cause harmful effects to the public and the environment. This work entitled 'Borehole disposal design concept' consists in putting in place a site of sure storage of the radioactive waste, in particular, sealed radioactive sources. Several technical aspects must be respected to carry out such a site like the geological, geomorphologic, hydrogeologic, geochemical, meteorological and demographic conditions. This type of storage is favorable for the developing countries because it is technologically simple and economic. The cost of construction depends on the volume of waste to store and the depth of the Borehole. The Borehole disposal concept provides a good level of safety to avoid the human intrusion. The future protection of the generations against the propagation of the radiations ionizing is then assured. [fr

  19. Research on geological disposal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The aims of this research are to develop criteria for reviewing reliability and suitability of the result from Preliminary Investigations to be submitted by the implementer, and to establish a basic policy for safety review. For development of reliability and suitability criteria for reviewing the result of Preliminary Investigations, we evaluated the uncertainties and their influence from limited amount of investigations, as well as we identified important procedures during investigations and constructions of models, as follows: (1) uncertainties after limited amount of geological exploration and drilling, (2) influence of uncertainties in regional groundwater flow model, (3) uncertainties of DFN (Discrete Fracture Network) models in the fractured rock, (4) analyzed investigation methods described in implementer's report, and (5) identified important aspects in investigation which need to be reviewed and follow QA (Quality Assurance). For development of reliability and suitability criteria for reviewing the result of Detailed Investigations, we analyzed important aspects in investigation which supplies data to design and safety assessment, as well as studied the applicability of pressure interference data during excavation to verify hydrogeological model. Regarding the research for safety review, uncertainties of geologic process in long time-scale was studied. In FY2012, we started to evaluate the structural stabilities of concrete and bentonite in disposal environment. Finally, we continued to accumulate the knowledge on geological disposal into the database system. (author)

  20. Geoenvironment and waste disposal

    International Nuclear Information System (INIS)

    1983-07-01

    Within the activities planned by UNESCO in its Water and Earth Science programme, an interdisciplinary meeting on geology and environment was scheduled by this organization to be held by the beginning of 1983. At this meeting it was intended to consider geological processes in the light of their interaction and influence on the environment with special emphasis on the impact of various means of waste disposal on geological environment and on man-induced changes in the geological environment by mining, human settlements, etc. Considering the increasing interest shown by the IAEA in the field, through environmental studies, site studies, and impact studies for nuclear facilities and particularly nuclear waste disposal, UNESCO expressed the wish to organize the meeting jointly so as to take into account the experience gained by the Agency, and in order to avoid any duplication in the activities of the two organizations. This request was agreed to by the IAEA Secretariat and as a result, the meeting was organized by both organizations and held at IAEA Headquarters in Vienna from 21-23 March 1983. The report of this meeting is herewith presented

  1. Mine tailings disposal

    International Nuclear Information System (INIS)

    Gonzales, P.A.; Adams, B.J.

    1980-06-01

    The hydrologic evaluation of mine tailings disposal sites after they are abandoned is considered in relation to their potential environmental impact on a long term basis. There is a direct relation between the amounts and types of water leaving a disposal site and the severity of the potential damage to the environment. The evaluation of the relative distribution of the precipitation reaching the ground into evaporation, runoff and infiltration is obtained for a selected site and type of tailings material whose characteristics and physical properties were determined in the soils laboratory. A conceptual model of the hydrologic processes involved and the corresponding mathematical model were developed to simulate the physical system. A computer program was written to solve the set of equations forming the mathematical model, considering the physical properties of the tailings and the rainfall data selected. The results indicate that the relative distribution of the precipitation depends on the surface and upper layer of the tailings and that the position of the groundwater table is governed by the flow through the bottom of the profile considered. The slope of the surface of the mass of tailings was found to be one of the principal factors affecting the relative distribution of precipitation and, therefore, the potential pollution of the environment

  2. Paleoseismic evidence of earthquakes and tsunamis along the southern part of the Japan Trench

    Science.gov (United States)

    Pilarczyk, Jessica; Sawai, Yuki; Horton, Ben; Namegaya, Yuichi; Shinozaki, Tetsuya; Tanigawa, Koichiro; Matsumoto, Dan; Dura, Tina; Fujiwara, Osamu; Shishikura, Masanobu

    2016-04-01

    The northern part of the Japan Trench has frequently generated tsunamigenic-earthquakes with magnitudes up to ~M 8.0. In contrast, the middle and southern parts of the Japan Trench were considered relatively inactive until the 2011 Tohoku (M 9.0) event generated one of the largest tsunamis in recorded history. Geologic evidence from the Sendai plain revealed an event in CE 869 that could have forecast the severity of the Tohoku tsunami in 2011. Seismic models indicate that the Tohoku earthquake may have transferred stress southwards down the fault to the potentially locked southern part of the Japan Trench. This transfer of stress towards a locked section of the trench could produce an earthquake in the near future that would be comparable in magnitude to the Tohoku event. Reconstructing the history of individual great earthquakes and accompanying tsunamis using geological records from the coastal zone adjacent to the southern part of the Japan Trench provides an assessment of the seismic hazard for metropolitan areas in east-central Japan. We have found two anomalous marine sand layers intercalated with muddy peat, which can be traced 3.8 km inland and 5.5 km along the present Kujukuri coastline, approximately 50 km east of Tokyo. Both sand layers have features consistent with tsunami deposits, such as a distinct erosional base, rip-up clasts, normal grading, a mud drape, and marine foraminifera. Results of radiocarbon dating constrain the age of the upper sand to 337 - 299 cal. yrs. BP, which likely corresponds to the only known southern Japan Trench rupture ever recorded, the Empo tsunami of CE 1677. The age of the lower sand is 979 - 903 cal. yrs. BP; marking an event for which there is no historical documentation at present. Preliminary tsunami simulation models indicate that a middle trench (Tohoku-style) rupture is not responsible for significant inundation of the Kujukuri coastline and would likely not have been capable of depositing either sand layer

  3. Disposal of low-level radioactive waste using high-calcium fly ash. Final report

    International Nuclear Information System (INIS)

    Cogburn, C.O.; Hodgson, L.M.; Ragland, R.C.

    1986-04-01

    The feasibility of using calcium-rich fly ash from coal-fired power plants in the disposal of low-level radioactive waste was examined. The proposed areas of use were: (1) fly-ash cement as a trench lining material; (2) fly ash as a backfill material; and (3) fly ash as a liquid waste solidifier. The physical properties of fly-ash cement were determined to be adequate for trench liner construction, with compressive strengths attaining greater than 3000 psi. Hydraulic conductivities were determined to be less than that for clay mineral deposits, and were on the order of 10 -7 cm/sec, with some observed values as low as 10 -9 cm/sec. Removal of radioisotopes from acidified solutions by fly ash was good for all elements tested except cesium. The removal of cesium by fly ash was similar to that of montmorillonite clay. The corrosive effects on metals in fly ash environments was determined to be slight, if not non-existent. Coatings at the fly-ash/metal interfaces were observed which appeared to inhibit or diminish corrosion. The study has indicated that high-calcium fly ash appears to offer considerable potential for improved retention of low-level radioactive wastes in shallow land disposal sites. Further tests are needed to determine optimum methods of use. 8 refs., 4 figs., 7 tabs

  4. Marine disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Woodhead, D.S.

    1980-01-01

    In a general sense, the main attraction of the marine environment as a repository for the wastes generated by human activities lies in the degree of dispersion and dilution which is readily attainable. However, the capacity of the oceans to receive wastes without unacceptable consequences is clearly finite and this is even more true of localized marine environments such as estuaries, coastal waters and semi-enclosed seas. Radionuclides have always been present in the marine environment and marine organisms and humans consuming marine foodstuffs have always been exposed, to some degree, to radiation from this source. The hazard associated with ionizing radiations is dependent upon the adsorption of energy from the radiation field within some biological entity. Thus any disposal of radioactive wastes into the marine environment has consequences, the acceptability of which must be assessed in terms of the possible resultant increase in radiation exposure of human and aquatic populations. In the United Kingdom the primary consideration has been and remains the safe-guarding of public health. The control procedures are therefore designed to minimize as far as practicable the degree of human exposure within the overall limits recommended as acceptable by the International Commission on Radiological Protection. There are several approaches through which control could be exercised and the strenghs and weaknesses of each are considered. In this review the detailed application of the critical path technique to the control of the discharge into the north-east Irish Sea from the fuel reprocessing plant at Windscale is given as a practical example. It will be further demonstrated that when human exposure is controlled in this way no significant risk attaches to the increased radiation exposure experienced by populations of marine organisms in the area. (orig.) [de

  5. Saltstone: cement-based waste form for disposal of Savannah River Plant low-level radioactive salt waste

    International Nuclear Information System (INIS)

    Langton, C.A.

    1984-01-01

    Defense waste processing at the Savannah River Plant will include decontamination and disposal of approximately 400 million liters of waste containing NaNO 3 , NaOH, Na 2 SO 4 , and NaNO 2 . After decontamination, the salt solution is classified as low-level waste. A cement-based waste form, saltstone, has been designed for disposal of Savannah River Plant low-level radioactive salt waste. Bulk properties of this material have been tailored with respect to salt leach rate, permeability, and compressive strength. Microstructure and mineralogy of leached and unleached specimens were characterized by SEM and x-ray diffraction analyses. The disposal system for the DWPF salt waste includes reconstitution of the crystallized salt as a solution containing 32 wt % solids. This solution will be decontaminated to remove 137 Cs and 90 Sr and then stabilized in a cement-based waste form. Laboratory and field tests indicate that this stabilization process greatly reduces the mobility of all of the waste constitutents in the surface and near-surface environment. Engineered trenches for subsurface burial of the saltstone have been designed to ensure compatibility between the waste form and the environment. The total disposal sytem, saltstone-trench-surrounding soil, has been designed to contain radionuclides, Cr, and Hg by both physical encapsulation and chemical fixation mechanisms. Physical encapsulation of the salts is the mechanism employed for controlling N and OH releases. In this way, final disposal of the SRP low-level waste can be achieved and the quality of the groundwater at the perimeter of the disposal site meets EPA drinking water standards

  6. High‐resolution trench photomosaics from image‐based modeling: Workflow and error analysis

    Science.gov (United States)

    Reitman, Nadine G.; Bennett, Scott E. K.; Gold, Ryan D.; Briggs, Richard; Duross, Christopher

    2015-01-01

    Photomosaics are commonly used to construct maps of paleoseismic trench exposures, but the conventional process of manually using image‐editing software is time consuming and produces undesirable artifacts and distortions. Herein, we document and evaluate the application of image‐based modeling (IBM) for creating photomosaics and 3D models of paleoseismic trench exposures, illustrated with a case‐study trench across the Wasatch fault in Alpine, Utah. Our results include a structure‐from‐motion workflow for the semiautomated creation of seamless, high‐resolution photomosaics designed for rapid implementation in a field setting. Compared with conventional manual methods, the IBM photomosaic method provides a more accurate, continuous, and detailed record of paleoseismic trench exposures in approximately half the processing time and 15%–20% of the user input time. Our error analysis quantifies the effect of the number and spatial distribution of control points on model accuracy. For this case study, an ∼87  m2 exposure of a benched trench photographed at viewing distances of 1.5–7 m yields a model with <2  cm root mean square error (rmse) with as few as six control points. Rmse decreases as more control points are implemented, but the gains in accuracy are minimal beyond 12 control points. Spreading control points throughout the target area helps to minimize error. We propose that 3D digital models and corresponding photomosaics should be standard practice in paleoseismic exposure archiving. The error analysis serves as a guide for future investigations that seek balance between speed and accuracy during photomosaic and 3D model construction.

  7. Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 10, Basin analysis, formation and stability of gas hydrates of the Aleutian Trench and the Bering Sea

    Energy Technology Data Exchange (ETDEWEB)

    Krason, J.; Ciesnik, M.

    1987-01-01

    Four major areas with inferred gas hydrates are the subject of this study. Two of these areas, the Navarin and the Norton Basins, are located within the Bering Sea shelf, whereas the remaining areas of the Atka Basin in the central Aleutian Trench system and the eastern Aleutian Trench represent a huge region of the Aleutian Trench-Arc system. All four areas are geologically diverse and complex. Particularly the structural features of the accretionary wedge north of the Aleutian Trench still remain the subjects of scientific debates. Prior to this study, suggested presence of the gas hydrates in the four areas was based on seismic evidence, i.e., presence of bottom simulating reflectors (BSRs). Although the disclosure of the BSRs is often difficult, particularly under the structural conditions of the Navarin and Norton basins, it can be concluded that the identified BSRs are mostly represented by relatively weak and discontinuous reflectors. Under thermal and pressure conditions favorable for gas hydrate formation, the relative scarcity of the BSRs can be attributed to insufficient gas supply to the potential gas hydrate zone. Hydrocarbon gas in sediment may have biogenic, thermogenic or mixed origin. In the four studied areas, basin analysis revealed limited biogenic hydrocarbon generation. The migration of the thermogenically derived gases is probably diminished considerably due to the widespread diagenetic processes in diatomaceous strata. The latter processes resulted in the formation of the diagenetic horizons. The identified gas hydrate-related BSRs seem to be located in the areas of increased biogenic methanogenesis and faults acting as the pathways for thermogenic hydrocarbons.

  8. Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada

    International Nuclear Information System (INIS)

    Taylor, E.M.; Huckins, H.E.

    1995-01-01

    Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ''carbonate'' in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes

  9. Report on radioactive waste disposal

    International Nuclear Information System (INIS)

    1993-01-01

    The safe management of radioactive wastes constitutes an essential part of the IAEA programme. A large number of reports and conference proceedings covering various aspects of the subject have been issued. The Technical Review Committee on Underground Disposal (February 1988) recommended that the Secretariat issue a report on the state of the art of underground disposal of radioactive wastes. The Committee recommended the need for a report that provided an overview of the present knowledge in the field. This report covers the basic principles associated with the state of the art of near surface and deep geological radioactive waste disposal, including examples of prudent practice, and basic information on performance assessment methods. It does not include a comprehensive description of the waste management programmes in different countries nor provide a textbook on waste disposal. Such books are available elsewhere. Reviewing all the concepts and practices of safe radioactive waste disposal in a document of reasonable size is not possible; therefore, the scope of this report has been limited to cover essential parts of the subject. Exotic disposal techniques and techniques for disposing of uranium mill tailings are not covered, and only brief coverage is provided for disposal at sea and in the sea-bed. The present report provides a list of references to more specialized reports on disposal published by the IAEA as well as by other bodies, which may be consulted if additional information is sought. 108 refs, 22 figs, 2 tabs

  10. ORNL results for Test Case 1 of the International Atomic Energy Agency's research program on the safety assessment of Near-Surface Radioactive Waste Disposal Facilities

    International Nuclear Information System (INIS)

    Thorne, D.J.; McDowell-Boyer, L.M.; Kocher, D.C.; Little, C.A.; Roemer, E.K.

    1993-01-01

    The International Atomic Energy Agency (IAEA) started the Coordinated Research Program entitled '''The Safety Assessment of Near-Surface Radioactive Waste Disposal Facilities.'' The program is aimed at improving the confidence in the modeling results for safety assessments of waste disposal facilities. The program has been given the acronym NSARS (Near-Surface Radioactive Waste Disposal Safety Assessment Reliability Study) for ease of reference. The purpose of this report is to present the ORNL modeling results for the first test case (i.e., Test Case 1) of the IAEA NSARS program. Test Case 1 is based on near-surface disposal of radionuclides that are subsequently leached to a saturated-sand aquifer. Exposure to radionuclides results from use of a well screened in the aquifer and from intrusion into the repository. Two repository concepts were defined in Test Case 1: a simple earth trench and an engineered vault

  11. Superfund Record of Decision (EPA Region 4): Maxey Flats Nuclear Disposal site, Fleming County, KY. (First remedial action), September 1991. Final report

    International Nuclear Information System (INIS)

    1991-01-01

    The 280-acre Maxey Flats Nuclear Disposal site is an inactive low-level radioactive waste disposal facility in Fleming County, Kentucky. The estimated 663 people who reside within 2.5 miles of the site use the public water supply for drinking purposes. From 1962 to 1977, Nuclear Engineering Company, Inc. (NECO), operated a solid by-product, source, and special nuclear material disposal facility under a license with the State. Several State investigations in the 1970's revealed that leachate contaminated with tritium and other radioactive substances was migrating from the disposal trenches to unrestricted areas. The Record of Decision (ROD) addresses final remediation of soil, debris, and associated leachate. The primary contaminants of concern affecting the soil and debris are VOCs including benzene, TCE, and toluene; metals including arsenic and lead; and radioactive materials. The selected remedial action for the site is included

  12. Macrobenthic succession following the cessation of sewage sludge disposal

    Science.gov (United States)

    Birchenough, Silvana N. R.; Frid, Chris L. J.

    2009-11-01

    Half a million tonnes of sewage sludge was disposed annually over an 18-yr period at a licensed area off the Northumberland coast, UK. The disposal operation ceased in December 1998, providing the ecological opportunity to study macrobenthic changes in relation to theoretical succession models. A transect from the centre of the disposal site to a control station was monitored three times a year (i.e. March, August and December). This study provides a description of the changes in the macrobenthos and physical environment in the initial '3 years' (i.e. 1999 - 2001). During the period of sewage sludge disposal there were indications of an impact on the macrobenthic community with a high total abundance of individuals ( N) and high total number of species ( S) at the stations located in the centre of the disposal ground. During the immediate post-disposal phase the site continued to show a localised increased of individuals and species in the disposal area. Over time the communities showed signs of successional changes when the reduction of organic matter source was eliminated from the natural system. Multivariate analysis demonstrated a clear gradient of change in the community composition between impacted and control stations. While most benthic studies assess re-colonisation and succession stages of macrobenthos by using manipulative field experiments, this study provides an in situ long-term assessment in the offshore environment. This study contributes with information on: i) initial colonization and succession of macrobenthic communities over a large scale and real world data; ii) macrobenthic data into existing successional models and iii) resilience of benthic communities following the cessation of sewage sludge disposal. This information has the potential to contribute to an effective management of the marine communities in the North Sea.

  13. Fire analyses in central and disposal tunnels by APROS

    International Nuclear Information System (INIS)

    Peltokorpi, L.; Kukkola, T.; Nieminen, J.

    2012-12-01

    The central tunnels and the disposal tunnels on the north-east disposal area are the target areas of the fire studies. Target is to maintain under pressure in the fire zone in case of a fire. In the central tunnels a fire of a drilling jumbo with moderate fire propagation is used as heat release rate. In the disposal tunnel the heat release rate of a canister transfer and installation vehicle fire received as a result of the pyrolysis analyze as well as an average heat release rate of a van fire are used. Inlet air is to be conducted to the back end of the fire zone and the exhaust is to be lead out from the beginning of the fire zone. The worst location of the fire is in the beginning of the fire zone just below of the exhaust air clap valve. The size of the fire zone does not have big impact on pressure. In all analyzed cases the fire zone remains too long time over pressurized. Inlet air flow of a 30 m 3 /s is too much. The rotation controlled booster blowers will solve the pressure problems of the fire zone in fire cases. The rotation is controlled by the fire zone pressure. The fire of the canister transfer and installation vehicle in the central tunnel will not cause problems. The disposal tunnel fire door should be kept open, if the canister transfer and installation vehicle or the bentonite blocks transfer and installation vehicle is driven into the disposal tunnel. If a fire is caught in the disposal tunnel then the fire zone in the central tunnel is to be closed and the pressure is controlled by the rotation controlled booster blowers. If a personnel car or a van is driven into the disposal tunnel, then fire door of the disposal is to be kept closed against fires in the central tunnel. (orig.)

  14. Submarine geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Hollister, C.D.; Corliss, B.H.; Anderson, D.R.

    1980-01-01

    Site suitability characteristics of submarine geological formations for the disposal of radioactive wastes include the distribution coefficient of the host medium, permeability, viscoelastic nature of the sediments, influence of organic material on remobilization, and effects of thermal stress. The submarine geological formation that appears to best satisfy these criteria is abyssal ''red'' clay. Regions in the ocean that have coarse-grained deposits, high or variable thermal conductivity, high organic carbon content, and sediment thickness of less than 50 m are not being considered at this time. The optimum geological environment should be tranquil and have environmental predictability over a minimum of 10 5 years. Site selection activities for the North Atlantic and North Pacific are reviewed and future activities which include international cooperation are discussed. A paleoenvironmental model for Cenozoic sedimentation in the central North Pacific is presented based on studies of a long core from the Mid-Plate Gyre MPG-1 area, and is an example of the type of study that will be carried out in other seabed study areas. The data show that the MPG-1 region has been an area of slow, continuous accumulation during the past 65 million years. (author)

  15. Radioactive mixed waste disposal

    International Nuclear Information System (INIS)

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste

  16. Radioactive waste disposal

    International Nuclear Information System (INIS)

    Bohm, H.; Closs, K.D.; Kuhn, K.

    1981-01-01

    The solutions to the technical problem of the disposal of radioactive waste are limited by a) the state of knowledge of reprocessing possibilites, b) public acceptance of the use of those techniques which are known, c) legislative procedures linking licensing of new nuclear power plants to the solution of waste problems, and d) other political constraints. Wastes are generated in the mining and enriching of radioactive elements, and in the operation of nuclear power plants as well as in all fields where radioactive substances may be used. Waste management will depend on the stability and concentration of radioactive materials which must be stored, and a resolution of the tension between numerous small storage sites and a few large ones, which again face problems of public acceptability

  17. Disposal of tritiated effluents

    International Nuclear Information System (INIS)

    Hartmann, K.; Bruecher, H.

    1981-06-01

    After some introductory remarks on the origin of tritium, its properties and its behaviour in a reprocessing plant three alternative methods for the disposal of tritiated effluents produced during reprocessing are described (deep well injection, in-situ solidification, deep-sea dumping) and compared with each other under various aspects. The study is based on the concept of a 1400 t/a reprocessing plant for LWR fuel, which annually produces 3000 m 3 of tritiated waste water with a tritium content of 6.5 x 10 12 Bq/m 3 as well as a residual fission product and actinide content. An assessment of the three methods under the aspects of simplicity, reliability, safety, costs, state of development and materials handling revealed advantages in favour of 'injection', followed by 'dumping' and 'in-situ solidification'. (orig./HP) [de

  18. Toxic waste liquor disposal

    International Nuclear Information System (INIS)

    Burton, W.R.

    1985-01-01

    Toxic waste liquors, especially radio active liquors, are disposed in a sub-zone by feeding down a bore hole a first liquid, then a buffer liquid (e.g. water), then the toxic liquors. Pressure variations are applied to the sub-zone to mix the first liquid and liquors to form gels or solids which inhibit further mixing and form a barrier between the sub-zone and the natural waters in the environment of the sub-zone. In another example the location of the sub-zone is selected so that the environement reacts with the liquors to produce a barrier around the zone. Blind bore holes are used to monitor the sub-zone profile. Materials may be added to the liquor to enhance barrier formation. (author)

  19. Radwaste Disposal Safety Analysis

    International Nuclear Information System (INIS)

    Hwang, Yong Soo; Kang, C. H.; Lee, Y. M.; Lee, S. H.; Jeong, J. T.; Choi, J. W.; Park, S. W.; Lee, H. S.; Kim, J. H.; Jeong, M. S.

    2010-02-01

    For the purpose of evaluating annual individual doses from a potential repository disposing of radioactive wastes from the operation of the prospective advanced nuclear fuel cycle facilities in Korea, the new safety assessment approaches are developed such as PID methods. The existing KAERI FEP list was reviewed. Based on these new reference and alternative scenarios are developed along with a new code based on the Goldsim. The code based on the compartment theory can be applied to assess both normal and what if scenarios. In addition detailed studies on THRC coupling is studied. The oriental biosphere study ends with great success over the completion of code V and V with JAEA. The further development of quality assurance, in the form of the CYPRUS+ enables handy use of it for information management

  20. Conceptual designs of near surface disposal facility for radioactive waste arising from the facilities using radioisotopes and research facilities for nuclear energy development and utilization

    International Nuclear Information System (INIS)

    Sakai, Akihiro; Yoshimori, Michiro; Okoshi, Minoru; Yamamoto, Tadatoshi; Abe, Masayoshi

    2001-03-01

    Various kinds of radioactive waste is generating from the utilization of radioisotopes in the field of science, technology, etc. and the utilization and development of nuclear energy. In order to promote the utilization of radionuclides and the research activities, it is necessary to treat and dispose of radioactive waste safely and economically. Japan Nuclear Cycle Development Institute (JNC), Japan Radioisotope Association (JRIA) and Japan Atomic Energy Research Institute (JAERI), which are the major waste generators in Japan in these fields, are promoting the technical investigations for treatment and disposal of the radioactive waste co-operately. Conceptual design of disposal facility is necessary to demonstrate the feasibility of waste disposal business and to determine the some conditions such as the area size of the disposal facility. Three institutes share the works to design disposal facility. Based on our research activities and experiences of waste disposal, JAERI implemented the designing of near surface disposal facilities, namely, simple earthen trench and concrete vaults. The designing was performed based on the following three assumed site conditions to cover the future site conditions: (1) Case 1 - Inland area with low groundwater level, (2) Case 2 - Inland area with high groundwater level, (3) Case 3 - Coastal area. The estimation of construction costs and the safety analysis were also performed based on the designing of facilities. The safety assessment results show that the safety for concrete vault type repository is ensured by adding low permeability soil layer, i.e. mixture of soil and bentonite, surrounding the vaults not depending on the site conditions. The safety assessment results for simple earthen trench also show that their safety is ensured not depending on the site conditions, if they are constructed above groundwater levels. The construction costs largely depend on the depth for excavation to build the repositories. (author)

  1. Recent sediment dynamics in hadal trenches: Evidence for the influence of higher-frequency (tidal, near-inertial) fluid dynamics

    Science.gov (United States)

    Turnewitsch, Robert; Falahat, Saeed; Stehlikova, Jirina; Oguri, Kazumasa; Glud, Ronnie N.; Middelboe, Mathias; Kitazato, Hiroshi; Wenzhöfer, Frank; Ando, Kojiro; Fujio, Shinzou; Yanagimoto, Daigo

    2014-08-01

    In addition to high hydrostatic pressure, scarcity of food is viewed as a factor that limits the abundance and activity of heterotrophic organisms at great ocean depths, including hadal trenches. Supply of nutritious food largely relies on the flux of organic-rich particulate matter from the surface ocean. It has been speculated that the shape of hadal trenches helps to ‘funnel' particulate matter into the deeper parts of the trench, leading to sediment ‘focussing' and improved benthic food supply. Here we investigate for five Northwest Pacific trenches the efficiency of sediment focussing by evaluating ratios of measured (sediment-derived) and expected (water-column-derived) sedimentary inventories of the naturally occurring and radioactive particulate-matter tracer 210Pbxs. The sites comprise a broad range of surface-ocean productivity and physical-oceanographic regimes. Across the five trench-axis settings the inventory ratio varies between 0.5 and 4.1, with four trench-axis settings having ratios>1 (sediment focussing) and one trench-axis setting a ratiowinnowing). Although the fluid- and sediment-dynamical forcing behind sediment focussing remains unclear, this study finds evidence for another mechanism that is superimposed on, and counteracts, the focussing mechanism. This superimposed mechanism is related to higher-frequency (tidal, near-inertial) fluid dynamics. In particular, there is evidence for a strong and negative relation between the intensity of propagating internal tides and the extent of sediment focussing in the trench-axis. The relation can be approximated by a power function and the most intense drop in sediment focussing already occurs at moderate internal-tide intensities. This suggests that propagating internal tides may have a subtle but significant influence on particulate-matter dynamics and food supply in hadal trenches in particular, but possibly also in the deep seas in general. A mechanism for the influence of internal tides on

  2. 1994 Characterization report for the state approved land disposal site

    International Nuclear Information System (INIS)

    Swanson, L.C.

    1994-01-01

    This report summarizes the results of characterization activities at the proposed state-approved land disposal site (SALDS); it updates the original characterization report with studies completed since the first characterization report. The initial characterization report discusses studies from two characterization boreholes, 699-48-77A and 699-48-77B. This revision includes data from implementation of the Groundwater Monitoring Plan and the Aquifer Test Plan. The primary sources of data are two down-gradient groundwater monitoring wells, 699-48-77C and 699-48-77D, and aquifer testing of three zones in well 699-48-77C. The SALDS is located on the Hanford Site, approximately 183 m north of the 200 West Area on the north side of the 200 Areas Plateau. The SALDS is an infiltration basin proposed for disposal of treated effluents from the 200 Areas of Hanford

  3. A new model for the disposal of low level radioactive waste in Turkey

    International Nuclear Information System (INIS)

    Kahraman, A.

    1999-08-01

    the first known permeability value of natural soil, in time scale. Intermediatery values are calculated from that line. In our study, a new approach has been developed in this subject. It has been pointed out that the change of Darcy velocity can occur as more optimistic or pessimistic than the linear change. For this purpose, instead of linear line, a curve of y=A(e''L''x) for the pessimistic and y=A(1-e''-''L''x) for the optimistic assumptions have been used during the safety analyses and results have been compared with the results of linear change approach. For this purpose, the computer code has been modified by inserting these two different formulae in its calculation routines. The disposal model of radioactive waste introduced in this study has been developed according to the specifications of conditioned radioactive waste in interim storage building at Cekmece Nuclear Research and Training Center (CNAEM) and in the framework of existing legal situation in the country. According to our model, one burial unit consist of 75 waste drums (200 L) is assumed as a facility which holds radioactive materials. The legal discharge limit has been applied at a location beneath the facility where unsaturated zone and saturated zone connects each other (the limit is approximately 0.013 Ci/year for ''1''3''7Cs). Low level waste of the nuclear power plant which is expected to be erected in near future can also be disposed off with our model by additional analyses for the different nuclides according to the method introduced in this study. The site specific data of this study belongs to the CNAEM site. Data obtained from previous exploratory wells and experiments for the absorption capacity of ''1''3''7Cs with the site soil have been evaluated. The burial unit of this study has been assessed with three different cap materials. These are; the simple trench with ordinary site soil, the progressed trench with compacted clay and the vault with concrete and clay together

  4. Cost effective disposal of whey

    Energy Technology Data Exchange (ETDEWEB)

    Zall, R R

    1980-01-01

    Means of reducing the problem of whey disposal are dealt with, covering inter alia the pre-treatment of cheese milk e.g., by ultrafiltration to lower the whey output, utilization of whey constituents, use of liquid whey for feeding, fermenting whey to produce methane and alcohol, and disposal of whey by irrigation of land or by purification in sewage treatment plants.

  5. Melter Disposal Strategic Planning Document

    Energy Technology Data Exchange (ETDEWEB)

    BURBANK, D.A.

    2000-09-25

    This document describes the proposed strategy for disposal of spent and failed melters from the tank waste treatment plant to be built by the Office of River Protection at the Hanford site in Washington. It describes program management activities, disposal and transportation systems, leachate management, permitting, and safety authorization basis approvals needed to execute the strategy.

  6. Korean Reference HLW Disposal System

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Heui Joo; Lee, J. Y.; Kim, S. S. (and others)

    2008-03-15

    This report outlines the results related to the development of Korean Reference Disposal System for High-level radioactive wastes. The research has been supported around for 10 years through a long-term research plan by MOST. The reference disposal method was selected via the first stage of the research during which the technical guidelines for the geological disposal of HLW were determined too. At the second stage of the research, the conceptual design of the reference disposal system was made. For this purpose the characteristics of the reference spent fuels from PWR and CANDU reactors were specified, and the material and specifications of the canisters were determined in term of structural analysis and manufacturing capability in Korea. Also, the mechanical and chemical characteristics of the domestic Ca-bentonite were analyzed in order to supply the basic design parameters of the buffer. Based on these parameters the thermal and mechanical analysis of the near-field was carried out. Thermal-Hydraulic-Mechanical behavior of the disposal system was analyzed. The reference disposal system was proposed through the second year research. At the final third stage of the research, the Korean Reference disposal System including the engineered barrier, surface facilities, and underground facilities was proposed through the performance analysis of the disposal system.

  7. Disposal options for radioactive waste

    International Nuclear Information System (INIS)

    Olivier, J.P.

    1991-01-01

    On the basis of the radionuclide composition and the relative toxicity of radioactive wastes, a range of different options are available for their disposal. Practically all disposal options rely on confinement of radioactive materials and isolation from the biosphere. Dilution and dispersion into the environment are only used for slightly contaminated gaseous and liquid effluents produced during the routine operation of nuclear facilities, such as power plants. For the bulk of solid radioactive waste, whatever the contamination level and decay of radiotoxicity with time are, isolation from the biosphere is the objective of waste disposal policies. The paper describes disposal approaches and the various techniques used in this respect, such as shallow land burial with minimum engineered barriers, engineered facilities built at/near the surface, rock cavities at great depth and finally deep geologic repositories for long-lived waste. The concept of disposing long-lived waste into seabed sediment layers is also discussed, as well as more remote possibilities, such as disposal in outer space or transmutation. For each of these disposal methods, the measures to be adopted at institutional level to reinforce technical isolation concepts are described. To the extent possible, some comments are made with regard to the applicability of such disposal methods to other hazardous wastes. (au)

  8. Underground disposal of radioactive wastes

    International Nuclear Information System (INIS)

    1981-01-01

    This report is an overview document for the series of IAEA reports dealing with underground waste disposal to be prepared in the next few years. It provides an introduction to the general considerations involved in implementing underground disposal of radioactive wastes. It suggests factors to be taken into account for developing and assessing waste disposal concepts, including the conditioned waste form, the geological containment and possible additional engineered barriers. These guidelines are general so as to cover a broad range of conditions. They are generally applicable to all types of underground disposal, but the emphasis is on disposal in deep geological formations. Some information presented here may require slight modifications when applied to shallow ground disposal or other types of underground disposal. Modifications may also be needed to reflect local conditions. In some specific cases it may be that not all the considerations dealt with in this book are necessary; on the other hand, while most major considerations are believed to be included, they are not meant to be all-inclusive. The book primarily concerns only underground disposal of the wastes from nuclear fuel cycle operations and those which arise from the use of isotopes for medical and research activities

  9. Nuclear waste disposal in space

    Science.gov (United States)

    Burns, R. E.; Causey, W. E.; Galloway, W. E.; Nelson, R. W.

    1978-01-01

    Work on nuclear waste disposal in space conducted by the George C. Marshall Space Flight Center, National Aeronautics and Space Administration, and contractors are reported. From the aggregate studies, it is concluded that space disposal of nuclear waste is technically feasible.

  10. Chemical Waste Management and Disposal.

    Science.gov (United States)

    Armour, Margaret-Ann

    1988-01-01

    Describes simple, efficient techniques for treating hazardous chemicals so that nontoxic and nonhazardous residues are formed. Discusses general rules for management of waste chemicals from school laboratories and general techniques for the disposal of waste or surplus chemicals. Lists specific disposal reactions. (CW)

  11. Safe disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Hooker, P.; Metcalfe, R.; Milodowski, T.; Holliday, D.

    1997-01-01

    A high degree of international cooperation has characterized the two studies reported here which aim to address whether radioactive waste can be disposed of safely. Using hydrogeochemical and mineralogical surveying techniques earth scientists from the British Geological Survey have sought to identify and characterise suitable disposal sites. Aspects of the studies are explored emphasising their cooperative nature. (UK)

  12. Argentina's radioactive waste disposal policy

    International Nuclear Information System (INIS)

    Palacios, E.

    1986-01-01

    The Argentina policy for radioactive waste disposal from nuclear facilities is presented. The radioactive wastes are treated and disposed in confinement systems which ensure the isolation of the radionucles for an appropriate period. The safety criteria adopted by Argentina Authorities in case of the release of radioactive materials under normal conditions and in case of accidents are analysed. (M.C.K.) [pt

  13. Marine disposal of radioactive wastes - the debate

    International Nuclear Information System (INIS)

    Blair, I.

    1985-01-01

    The paper defends the case for marine disposal of radioactive wastes. The amount of packaged waste disposed; the site for marine disposal; the method of disposal; the radioactivity arising from the disposal; and safety factors; are all briefly discussed. (U.K.)

  14. Study on filling materials suitable for seawater piping trench closure work at Fukushima Daiichi Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yanai, Shuji; Hibi, Yasuki; Nishikori, Kazumasa; Sato, Keita

    2016-01-01

    Highly contaminated water leaking from the reactor buildings and turbine buildings damaged by the 2011 Great East Japan Earthquake has accumulated in the seawater piping trenches of Fukushima Daiichi Nuclear Power Station Units 2, 3, and 4. In November 2014, work commenced to replace and remove this contaminated water by filling the trenches with filling materials, and this work was completed in December 2015. This paper summarizes the contents of this study on various filling materials, including special fillers with long-distance underwater flowability applied to the horizontal tunnel parts of the trenches. (author)

  15. Influence of geometrical and electrical parameters of masking layers on the electrochemical etching of silicon for single trench formation

    International Nuclear Information System (INIS)

    Gautier, G; Ventura, L; Jerisian, R

    2005-01-01

    Deep single trenches can be produced at the edge of apertures of protective films masking the surface of silicon samples. This macropore formation, from polarized HF based solutions, is electrically activated depending on the mask geometrical and physical parameters whatever the silicon type or the electrolyte composition. The mask thickness increase is known to induce deeper trenches. In this paper, we show that we can predict and localize this phenomenon by simulating two dimensional hole current distributions below the mask. We demonstrate also the influence of the material permittivity on trench depth. These 2D simulation results are correlated with experimental results

  16. Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

    Science.gov (United States)

    Schmidt, Christina; Martínez Arbizu, Pedro

    2015-01-01

    We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

  17. radioactive waste disposal standards abroad

    International Nuclear Information System (INIS)

    Lu Yan; Xin Pingping; Wu Jian; Zhang Xue

    2012-01-01

    With the world focus on human health and environmental protection, the problem of radioactive waste disposal has gradually become a global issue, and the focus of attention of public. The safety of radioactive waste disposal, is not only related to human health and environmental safety, but also an important factor of affecting the sustainable development of nuclear energy. In recent years the formulation of the radioactive waste disposal standards has been generally paid attention to at home and abroad, and it has made great progress. In China, radioactive waste management standards are being improved, and there are many new standards need to be developed. The revised task of implement standards is very arduous, and there are many areas for improvement about methods and procedures of the preparation of standards. This paper studies the current situation of radioactive waste disposal standards of the International Atomic Energy Agency, USA, France, Britain, Russia, Japan, and give some corresponding recommendations of our radioactive waste disposal standards. (authors)

  18. Engineering geology of waste disposal

    International Nuclear Information System (INIS)

    Bentley, S.P.

    1996-01-01

    This volume covers a wide spectrum of activities in the field of waste disposal. These activities range from design of new landfills and containment properties of natural clays to investigation, hazard assessment and remediation of existing landfills. Consideration is given to design criteria for hard rock quarries when used for waste disposal. In addition, an entire section concerns the geotechnics of underground repositories. This covers such topics as deep drilling, in situ stress measurement, rock mass characterization, groundwater flows and barrier design. Engineering Geology of Waste Disposal examines, in detail, the active role of engineering geologists in the design of waste disposal facilities on UK and international projects. The book provides an authoritative mix of overviews and detailed case histories. The extensive spectrum of papers will be of practical value to those geologists, engineers and environmental scientists who are directly involved with waste disposal. (UK)

  19. Activity of Small Repeating Earthquakes along Izu-Bonin and Ryukyu Trenches

    Science.gov (United States)

    Hibino, K.; Matsuzawa, T.; Uchida, N.; Nakamura, W.; Matsushima, T.

    2014-12-01

    There are several subduction systems near the Japanese islands. The 2011 Mw9.0 Tohoku-oki megathrust earthquake occurred at the NE Japan (Tohoku) subduction zone. We have revealed a complementary relation between the slip areas for huge earthquakes and small repeating earthquakes (REs) in Tohoku. Investigations of REs in these subduction zones and the comparison with Tohoku area are important for revealing generation mechanism of megathrust earthquakes. Our target areas are Izu-Bonin and Ryukyu subduction zones, which appear to generate no large interplate earthquake. To investigate coupling of plate boundary in these regions, we estimated spatial distribution of slip rate by using REs. We use seismograms from the High Sensitivity Seismograph Network (Hi-net), Full Range Seismograph Network of Japan (F-net), and permanent seismic stations of Japan Meteorological Agency (JMA), Tohoku University, University of Tokyo, and Kagoshima University from 8 May 2003 (Izu-Bonin) and 14 July 2005 (Ryukyu) to 31 December 2012 to detect REs along the two trenches, by using similarity of seismograms. We mainly follow the procedure adopted in Uchida and Matsuzawa (2013) that studied REs in Tohoku area to compare our results with the REs in Tohoku. We find that the RE distribution along the Ryukyu trench shows two bands parallel to the trench axis. This feature is similar to the pattern in Tohoku where relatively large earthquakes occur between the bands. Along the Izu-Bonin trench, on the other hand, we find much fewer REs than in Tohoku or Ryukyu subduction zones and only one along-trench RE band, which corresponds to the area where the subducting Pacific plate contacts with the crust of the Philippine Sea plate. We also estimate average slip rate and coupling coefficient by using an empirical relationship between seismic moment and slip for REs (Nadeau and Johnson, 1998) and relative plate motion model. As a result, we find interplate slip rate in the deeper band is higher than

  20. Criteria and techniques for field characterization and modeling related to selecting and evaluating performance of LILW disposal sites

    International Nuclear Information System (INIS)

    Faybishenko, Boris; Witherspoon, Paul A.

    2007-01-01

    Argentina is faced with the challenging problem of developing technology for near-surface disposal and isolation of low- and intermediate-level radioactive waste (LILW). The preferred option for disposal of LILW (including both relatively short-lived and long-lived radionuclides) is to use disposal facilities that are near-surface--either above or below ground level [IAEA, 1985; 2001a;2004]. How individual components of a waste disposal system perform (including waste forms, waste containers, engineered barriers and host environment) will determine system safety and the safety of the surrounding environment [IAEA, 1999]. The lack of appropriate engineering for the backfill, and for the selection of sealing and covering materials for trenches, vaults, and ditches, could result in the escape of radionuclides from the disposed wastes [IAEA, 1994a; 2001b]. Therefore, assessment and design of backfill, barriers, and cover materials are very important, both for preventing invasion of water into the disposal system, and for retarding radionuclides that could potentially migrate from the system into the atmosphere or groundwater [IAEA, 1982; 1994b;2001a

  1. Disposal of waste from the cleanup of large areas contaminated as a result of a nuclear accident

    International Nuclear Information System (INIS)

    1992-01-01

    The report provides an overview of the methodology and technology available to load, transport and dispose of large volumes of contaminated material arising from the cleanup of areas after a nuclear accident and includes data on the planning, implementation, management and costing of such activities. To demonstrate the use of this information, three cleanup and disposal scenarios are examined, ranging from disposal in many small mounds or trenches within the contaminated area to disposal in a large facility away from the plant. As in the two companion reports, it is assumed that the population has been evacuated from the affected area. The report reviews the generic types of low level radioactive waste which are likely to arise from such a cleanup. The report does not deal with the recovery and disposal of intermediate and high level radioactive material on or near the plant site. This material will have to be recovered, packaged, transported and stored on-site or disposed of at an appropriate facility. These operations should be done by specialist teams using shielded or remotely operated equipment. Also not included are methods of in situ stabilization of contamination, for example ploughing to bury the top contaminated layer at a suitable depth. These techniques, which are likely to be widely used in part of the evacuated are, are discussed in IAEA Technical Reports Series No. 300, Vienna, 1989. 50 refs, 18 figs, 4 tabs

  2. Technical responsibilities in low-level waste disposal

    International Nuclear Information System (INIS)

    Murray, R.L.; Walker, C.K.

    1989-01-01

    North Carolina will be the host state for a low-level radioactive waste (LLRW) disposal facility serving the Southeast Compact for 20 yr beginning in 1993. Primary responsibility for the project rests with the North Carolina Low-Level Radioactive Waste Management Authority, a citizen board. The North Carolina project embodies a unique combination of factors that places the authority in a position to exercise technical leadership in the LLRW disposal field. First, the Southeast Compact is the largest in the United States in terms of area, population, and waste generation. second, it is in a humid rather than an arid region. Third, the citizens of the state are intensely interested in preserving life style, environment, and attractiveness of the region to tourists and are especially sensitive to the presence of waste facilities of any kind. Finally, disposal rules set by the Radiation Protection Commission and enforced by the Radiation Protection Section are stricter than the U.S. Nuclear Regulatory Commission's 10CFR61. These four factors support the authority's belief that development of the facility cannot be based solely on engineering and economics, but that social factors, including perceptions of human risk, concerns for the environment, and opinions about the desirability of hosting a facility, should be integral to the project. This philosophy guides the project's many technical aspects, including site selection, site characterization, technology selection and facility design, performance assessment modeling, and waste reduction policies. Each aspect presents its own unique problems

  3. Concepts and data-collection techniques used in a study of the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Illinois

    Science.gov (United States)

    Healy, R.W.; DeVries, M.P.; Striegl, Robert G.

    1986-01-01

    A study of water and radionuclide movement through the unsaturated zone is being conducted at the low level radioactive waste disposal site near Sheffield, Illinois. Included in the study are detailed investigations of evapotranspiration, movement of water through waste trench covers, and movement of water and radionuclides (dissolved and gaseous) from the trenches. An energy balance/Bowen ratio approach is used to determine evapotranspiration. Precipitation, net radiation, soil-heat flux, air temperature and water vapor content gradients, wind speed, and wind direction are measured. Soil water tension is measured with tensiometers which are connected to pressure transducers. Meteorological sensors and tensiometers which are connected to pressure transducers. Meteorological sensors and tensiometers are monitored with automatic data loggers. Soil moisture contents are measured through small-diameter access tubes with neutron and gamma-ray attenuation gages. Data beneath the trenches are obtained through a 130-meter-long tunnel which extends under four of the trenches. Water samples are obtained with suction lysimeters, and samples of the geologic material are obtained with core tubes. These samples are analyzed for radiometric and inorganic chemistry. Gas samples are obtained from gas piezometers and analyzed for partial pressures of major constituents, Radon-222, tritiated water vapor, and carbon-14 dioxide. (USGS)

  4. A mathematical model for the performance assessment of engineering barriers of a typical near surface radioactive waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, Raphaela N.; Rotunno Filho, Otto C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Lab. de Hidrologia e Estudos do Meio Ambiente]. E-mail: otto@hidro.ufrj.br; Ruperti Junior, Nerbe J.; Lavalle Filho, Paulo F. Heilbron [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)]. E-mail: nruperti@cnen.gov.br

    2005-07-01

    This work proposes a mathematical model for the performance assessment of a typical radioactive waste disposal facility based on the consideration of a multiple barrier concept. The Generalized Integral Transform Technique is employed to solve the Advection-Dispersion mass transfer equation under the assumption of saturated one-dimensional flow, to obtain solute concentrations at given times and locations within the medium. A test-case is chosen in order to illustrate the performance assessment of several configurations of a multi barrier system adopted for the containment of sand contaminated with Ra-226 within a trench. (author)

  5. A mathematical model for the performance assessment of engineering barriers of a typical near surface radioactive waste disposal facility

    International Nuclear Information System (INIS)

    Antonio, Raphaela N.; Rotunno Filho, Otto C.

    2005-01-01

    This work proposes a mathematical model for the performance assessment of a typical radioactive waste disposal facility based on the consideration of a multiple barrier concept. The Generalized Integral Transform Technique is employed to solve the Advection-Dispersion mass transfer equation under the assumption of saturated one-dimensional flow, to obtain solute concentrations at given times and locations within the medium. A test-case is chosen in order to illustrate the performance assessment of several configurations of a multi barrier system adopted for the containment of sand contaminated with Ra-226 within a trench. (author)

  6. Quantities of uranium-235 buried in disposal boxes, 1985--1991

    International Nuclear Information System (INIS)

    Cook, J.R.

    1991-01-01

    IWT was asked by J. R. Schornhorst of NPSR to determine the distribution of the quantity of enriched uranium per disposal box (B-25) of the years 1985--1991 to provide input to an uptake of the E Area Safety Analysis. This information was considered important since the issue of criticality is an important concern in safety analyses. Information found in the COBRA data base shows no disposal containers exceeded 100 grams of U-235. The COBRA data base was queried in a two-step process. First a short program in the NATURAL language was used to retrieve all records beginning with January 1983 having a Burial Code of less than 4, indicating low-level waste disposed in trenches. These records were then passed to a temporary storage file and read into a program written in Statistical Analysis System (SAS) language. SAS was used to eliminate waste from the Naval Fuel Facility, which will not operate in the future, and to sort the records in order of increasing amounts of U-235. The SAS procedure FREQ was then used to produce a cumulative frequency distribution of grams of U-235. A total of 53,198 packages were disposed of during this time period, 277 of which contained U-235. The programs used and resulting output are attached as Appendix I

  7. Bending-related faulting and mantle serpentinization at the Middle America trench.

    Science.gov (United States)

    Ranero, C R; Morgan, J Phipps; McIntosh, K; Reichert, C

    2003-09-25

    The dehydration of subducting oceanic crust and upper mantle has been inferred both to promote the partial melting leading to arc magmatism and to induce intraslab intermediate-depth earthquakes, at depths of 50-300 km. Yet there is still no consensus about how slab hydration occurs or where and how much chemically bound water is stored within the crust and mantle of the incoming plate. Here we document that bending-related faulting of the incoming plate at the Middle America trench creates a pervasive tectonic fabric that cuts across the crust, penetrating deep into the mantle. Faulting is active across the entire ocean trench slope, promoting hydration of the cold crust and upper mantle surrounding these deep active faults. The along-strike length and depth of penetration of these faults are also similar to the dimensions of the rupture area of intermediate-depth earthquakes.

  8. Evaluation of two stormwater infiltration trenches in central Copenhagen after 15 years of operation

    DEFF Research Database (Denmark)

    Bergman, Maria Kerstin; Hedegaard, Mathilde Jørgensen; Petersen, Mette Fjendbo

    2011-01-01

    to see whether the reduction in performance has continued and to determine how the system performs today. Water levels in the trenches were monitored for almost 4 months, and from this period seven events were selected to analyse the infiltration rate. A comparison with similar analyses on storm......Two stormwater infiltration trenches were installed in 1993 in an area in central Copenhagen. The system was monitored continuously for almost three years after establishment, and a small reduction in performance over that time, possibly due to clogging, was noted. A new study was conducted in 2009...... sequences from the first 3 years of operation shows that the infiltration has decreased since the establishment of the system 15 years ago. The decrease is statistically significant (p

  9. Uniform lateral etching of tungsten in deep trenches utilizing reaction-limited NF3 plasma process

    Science.gov (United States)

    Kofuji, Naoyuki; Mori, Masahito; Nishida, Toshiaki

    2017-06-01

    The reaction-limited etching of tungsten (W) with NF3 plasma was performed in an attempt to achieve the uniform lateral etching of W in a deep trench, a capability required by manufacturing processes for three-dimensional NAND flash memory. Reaction-limited etching was found to be possible at high pressures without ion irradiation. An almost constant etching rate that showed no dependence on NF3 pressure was obtained. The effect of varying the wafer temperature was also examined. A higher wafer temperature reduced the threshold pressure for reaction-limited etching and also increased the etching rate in the reaction-limited region. Therefore, the control of the wafer temperature is crucial to controlling the etching amount by this method. We found that the uniform lateral etching of W was possible even in a deep trench where the F radical concentration was low.

  10. The GaN trench gate MOSFET with floating islands: High breakdown voltage and improved BFOM

    Science.gov (United States)

    Shen, Lingyan; Müller, Stephan; Cheng, Xinhong; Zhang, Dongliang; Zheng, Li; Xu, Dawei; Yu, Yuehui; Meissner, Elke; Erlbacher, Tobias

    2018-02-01

    A novel GaN trench gate (TG) MOSFET with P-type floating islands (FLI) in drift region, which can suppress the electric field peak at bottom of gate trench during the blocking state and prevent premature breakdown in gate oxide, is proposed and investigated by TCAD simulations. The influence of thickness, position, doping concentration and length of the FLI on breakdown voltage (BV) and specific on-resistance (Ron_sp) is studied, providing useful guidelines for design of this new type of device. Using optimized parameters for the FLI, GaN FLI TG-MOSFET obtains a BV as high as 2464 V with a Ron_sp of 3.0 mΩ cm2. Compared to the conventional GaN TG-MOSFET with the same structure parameters, the Baliga figure of merit (BFOM) is enhanced by 150%, getting closer to theoretical limit for GaN devices.

  11. Plastic pollution of the Kuril-Kamchatka Trench area (NW pacific)

    Science.gov (United States)

    Fischer, Viola; Elsner, Nikolaus O.; Brenke, Nils; Schwabe, Enrico; Brandt, Angelika

    2015-01-01

    During the German-Russian expedition KuramBio (Kuril-Kamchatka Biodiversity Studies) to the northwest Pacific Kuril-Kamchatka Trench and its adjacent abyssal plain, we found several kinds and sizes of plastic debris ranging from fishing nets and packaging to microplastic in the sediment of the deep-sea floor. Microplastics were ubiquitous in the smaller fractions of the box corer samples from every station from depths between 4869 and 5766 m. They were found on the abyssal plain and in the sediments of the trench slope on both sides. The amount of microplastics differed between the stations, with lowest concentration of 60 pieces per m2 and highest concentrations of more than 2000 pieces per m2. Around 75% of the microplastics (defined here as particles plastic debris we found, as a documentation of human impact into the deep sea of this region of the Northwest Pacific.

  12. A Generic Safety Assessment Model for a Trench Type LILW Repository

    International Nuclear Information System (INIS)

    Lee, Youn-Myoung; Choi, Hee-Joo

    2015-01-01

    This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various normal circumstances, disruptive events, and scenarios that can occur after a failure of waste packages with associated uncertainty. Despite the conceptual design of a trench type LILW repository system, all parameter values associated with the repository system were assumed for the time being, and the generic model developed through this study should be helpful because the evaluation of such releases is very important. A simple and effective model for a safety assessment of a conceptual trench repository system, in which an LILW that arises from a nuclear power plant and other sources, has been developed. The computer program based on this model has also been developed as a GoldSim template using the commercial GoldSim development tool

  13. A Generic Safety Assessment Model for a Trench Type LILW Repository

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youn-Myoung; Choi, Hee-Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various normal circumstances, disruptive events, and scenarios that can occur after a failure of waste packages with associated uncertainty. Despite the conceptual design of a trench type LILW repository system, all parameter values associated with the repository system were assumed for the time being, and the generic model developed through this study should be helpful because the evaluation of such releases is very important. A simple and effective model for a safety assessment of a conceptual trench repository system, in which an LILW that arises from a nuclear power plant and other sources, has been developed. The computer program based on this model has also been developed as a GoldSim template using the commercial GoldSim development tool.

  14. Initial formulation results for in situ grouting of a waste trench at ORNL Site No. 6

    International Nuclear Information System (INIS)

    Tallent, O.K.; McDaniel, E.W.; Spence, R.D.; Godsey, T.T.

    1987-01-01

    An investigation is being conducted by the Chemical Technology Division to assist the Environmental Sciences Division in developing a grout formulation for use in testing in situ grouting in a waste trench at ORNL Site 6. This final report satisfies the milestone of Subtack 12 entitled, ''Low Level Waste (LLW) Trench Grouting Assessment,'' which was initially issued as RAP-86-7, December 31, 1985. Grouts prepared from dry-solid blends containing Type I Portland cement, ASTM Class C or Class F fly ash, and bentonite, mixed water at ratios of 10 to 15 lb/gal, were evaluated. The grouts prepared with ASTM Class C fly ash exhibited significantly better properties than those prepared with ASTM Class F fly ash. The grouts containing ASTM Class C fly ash satisfy tentative performance criteria for the project. 8 refs., 7 tabs

  15. Geological disposal system development

    International Nuclear Information System (INIS)

    Kang, Chul Hyung; Kuh, J. E.; Kim, S. K. and others

    2000-04-01

    Spent fuel inventories to be disposed of finally and design base spent fuel were determined. Technical and safety criteria for a geological repository system in Korea were established. Based on the properties of spent PWR and CANDU fuels, seven repository alternatives were developed and the most promising repository option was selected by the pair-wise comparison method from the technology point of view. With this option preliminary conceptual design studies were carried out. Several module, e.g., gap module, congruent release module were developed for the overall assessment code MASCOT-K. The prominent overseas databases such as OECD/NEA FEP list were are fully reviewed and then screened to identify the feasible ones to reflect the Korean geo-hydrological conditions. In addition to this the well known scenario development methods such as PID, RES were reviewed. To confirm the radiological safety of the proposed KAERI repository concept the preliminary PA was pursued. Thermo-hydro-mechanical analysis for the near field of repository were performed to verify thermal and mechanical stability for KAERI repository system. The requirements of buffer material were analyzed, and based on the results, the quantitative functional criteria for buffer material were established. The hydraulic and swelling property, mechanical properties, and thermal conductivity, the organic carbon content, and the evolution of pore water chemistry were investigated. Based on the results, the candidate buffer material was selected

  16. Research on geological disposal

    International Nuclear Information System (INIS)

    Uchida, Masahiro

    2011-01-01

    The aims of this research are to develop criteria for reviewing acceptability of the adequacy of the result of Preliminary and Detailed Investigations submitted by the implementor, and to establish a basic policy to secure safety for safety review. In FY 2010, 13 geology/climate related events for development of acceptance criteria for reviewing the adequacy of the result of Preliminary and Detailed Investigations were extracted. And the accuracy of geophysical exploration methods necessary for the Preliminary Investigation was evaluated. Regarding the research for safety review, we developed an idea of safety concept of Japanese geological disposal, and analyzed basic safety functions to secure safety. In order to verify the groundwater flow evaluation methods developed in regulatory research, the hydrological and geochemical data at Horonobe, northern Hokkaido were obtained, and simulated result of regional groundwater flow were compared with measured data. And we developed the safety scenario of geology/climate related events categorized by geological and geomorphological properties. Also we created a system to check the quality of research results in Japan and other countries in order to utilize for safety regulation, and developed a database system to compile them. (author)

  17. Researching radioactive waste disposal

    International Nuclear Information System (INIS)

    Feates, F.; Keen, N.

    1976-01-01

    At present it is planned to use the vitrification process to convert highly radioactive liquid wastes, arising from nuclear power programme, into glass which will be contained in steel cylinders for storage. The UKAEA in collaboration with other European countries is currently assessing the relative suitability of various natural geological structures as final repositories for the vitrified material. The Institute of Geological Sciences has been commissioned to specify the geological criteria that should be met by a rock structure if it is to be used for the construction of a repository though at this stage disposal sites are not being sought. The current research programme aims to obtain basic geological data about the structure of the rocks well below the surface and is expected to continue for at least three years. The results in all the European countries will then be considered so that the United Kingdom can choose a preferred method for isolating their wastes. It is only at that stage that a firm commitment may be made to select a site for a potential repository, when a far more detailed scientific research study will be instituted. Heat transfer problems and chemical effects which may occur within and around repositories are being investigated and a conceptual design study for an underground repository is being prepared. (U.K.)

  18. Geological disposal system development

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Chul Hyung; Kuh, J. E.; Kim, S. K. and others

    2000-04-01

    Spent fuel inventories to be disposed of finally and design base spent fuel were determined. Technical and safety criteria for a geological repository system in Korea were established. Based on the properties of spent PWR and CANDU fuels, seven repository alternatives were developed and the most promising repository option was selected by the pair-wise comparison method from the technology point of view. With this option preliminary conceptual design studies were carried out. Several module, e.g., gap module, congruent release module were developed for the overall assessment code MASCOT-K. The prominent overseas databases such as OECD/NEA FEP list were are fully reviewed and then screened to identify the feasible ones to reflect the Korean geo-hydrological conditions. In addition to this the well known scenario development methods such as PID, RES were reviewed. To confirm the radiological safety of the proposed KAERI repository concept the preliminary PA was pursued. Thermo-hydro-mechanical analysis for the near field of repository were performed to verify thermal and mechanical stability for KAERI repository system. The requirements of buffer material were analyzed, and based on the results, the quantitative functional criteria for buffer material were established. The hydraulic and swelling property, mechanical properties, and thermal conductivity, the organic carbon content, and the evolution of pore water chemistry were investigated. Based on the results, the candidate buffer material was selected.

  19. Radwaste disposal drum centrifuge

    International Nuclear Information System (INIS)

    Rubin, L.S.; Deltete, C.P.; Crook, M.R.

    1988-01-01

    The drum or processing bowl of the DDC becomes the disposal container when the filling operation is completed. Rehandling of the processed resin is eliminated. By allowing the centrifugally compacted resin to remain in the processing container, extremely efficient waste packaging can be achieved. The dewatering results and volume reductions reported during 1986 were based upon laboratory scale testing sponsored by the Electric Power Research Institute (EPRI) and the Department of Energy (DOE). Since the publication of these preliminary results, additional testing using a full-scale prototype DDC has been completed, again under the auspices of the DOE. Full-scale testing has substantiated the results of earlier testing and has formed the basis for preliminary discussions with the U.S. Nuclear Regulatory Commission (NRC) regarding DDC licensing for radioactive applications. A comprehensive Topical Report and Process Control Program is currently being prepared for submittal to the NRC for review under a utility licensing action. Detailed cost-benefit analyses for actual plant operations have been prepared to substantiate the attractiveness of the DDC. Several methods to physically integrate a DDC into a nuclear power plant have also been developed

  20. P-wave Velocity Structure Across the Mariana Trench and Implications for Hydration

    Science.gov (United States)

    Eimer, M. O.; Wiens, D.; Lizarralde, D.; Cai, C.

    2017-12-01

    Estimates of the water flux at subduction zones remain uncertain, particularly the amount of water brought into the trench by the subducting plate. Normal faulting related to the bending of the incoming plate has been proposed to provide pathways for water to hydrate the crust and upper mantle. A passive and active source seismic experiment spanning both the incoming plate and forearc was conducted in 2012 in central Mariana to examine the role of hydration at subduction zones. The active-source component of the survey used the R/V M.G. Langsethairgun array and 68 short period sensors, including suspended hydrophones, deployed on 4 transects. This study at the Mariana trench offers a comparison to related studies of incoming plate hydration in Middle America, where differing thermal structures related to plate age predict different stability fields for hydrous minerals. The forearc structure is also of interest, since Mariana is characterized by large serpentine seamounts and may have a serpentinized mantle wedge. The velocity structure will also be important for the relocation of earthquakes in the incoming plate, since the seismicity can offer a constraint for the depth extent of these bending faults. We examine the P-wave velocity structure along a 400-km long wide-angle refraction transect perpendicular to the trench and spanning both the forearc and incoming plate. Preliminary results indicate a velocity reduction in the crust and uppermost mantle at the bending region of the incoming plate, relative to the plate's structure away from the trench. This reduction suggests that outer-rise faults extend into the upper mantle and may have promoted serpentinization of that material. Mantle Pn refraction phases are not observed in the forearc, consistent with the ambient noise tomography results that show upper-mantle velocities similar to that of the lower crust. The lack of contrast between the upper mantle and crustal velocities from the ambient noise has been