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At least 829 records · Page 46

Individuals Who Build Solutions Across Boundaries for Environmental Remediation and Nuclear Waste Disposal - 16204

This paper profiles individuals who shifted from developing solutions primarily from within one organization to across multiple organizations for decisions requiring input from multiple parties. These individuals are engineers and scientists who work as government employees or government contractors. This paper contains six areas of discussion: 1. Why individuals build solutions across organizational boundaries, 2. The results they achieve, 3. Supporting skills and personal characteristics, 4. Means to build solutions across boundaries, 5. How they enlist others to participate, and 6. The importance of a catalyst. This paper is based on three sources of information. The primary source are interviews with nine engineers and scientists with direct experience building solutions across organizational boundaries in the fields of environmental remediation or nuclear energy/waste management and disposal. The second source are selected research studies. The third source is the author's experience both as a government employee and a consultant. The author's hope is that this paper will strengthen people's desire and ability to engage multiple parties in decisions requiring their input. (authors)

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Criticality effect of long-term changes in material compositions and geometry in disposal canisters

For the Swedish final repository the basic requirement concerning margin to criticality is that k{sub eff} should be less than 0.95. This criterion is always fulfilled if the disposal canister is dry. If it is assumed that a canister is filled with water it is shown that the criticality criterion is fulfilled using burnup-credit for PWR fuel and credit for burnable poison for BWR fuel. If water is assumed to leak in, long term chemical processes will change the material compositions and geometries in the canister during the one million year analysis period. The main process expected to affect significantly the chemical composition of the materials in the canister is the corrosion of cast iron and carbon steel of the insert, the corrosion of the stainless steel, Inconel or Zircaloy in the fuel element structural material, the corrosion of Zircaloy cladding and finally the corrosion of spent fuel itself. During metal corrosion, various anoxic corrosion products are formed, usually with lower density than the metal itself, causing thus a volume increase in the canister, accompanied by geometrical changes. In this paper the reactivity effects of these changes are analysed and results presented. It is shown that the largest reactivity increase is due to the decrease of the water gap between the fuel and the fuel channel, due to the formation of Magnetite. Other process that possibly will increase the reactivity is if Siderite is produced besides from Magnetite, the production of Hydrogen, corrosion of the fuel and radial movements of fuel rods. (authors)

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WIPP Space Faces TRU Waste Disposal Limits; The Volume Reducing Solution - 18365

Transuranic (TRU) waste packaging for removal from a glovebox has for many years involved the use of bags as the primary containment. In many cases, many hydrogenous layers of bags, yards of tape, and multiple filters are added to the waste stream in order to get the TRU waste into the final 55 gallon drum package to be shipped and buried at the Waste Isolation Pilot Plant (WIPP). The WIPP is currently limited to a total finite disposed volume of Contact Handled (CH) and Remote Handled (RH) TRU waste. As of early 2014 over half of the allotted WIPP volume had been filled with mainly CH-TRU waste. Based on current bag operation packaging methods used, the Department of Energy's (DOE) remaining CH and RH waste will not fit in the remaining limited WIPP space. Bag operations, can be performed safely by good operators following tedious repetitive processes and many Administrative Safety Controls. Since the bag is the only confinement layer between the contamination and the operator, contamination incidents can occur. Bag-out operations require close proximity to the waste to perform the process. With some waste streams, this close to waste proximity increases operator radiation dose. Central Research Laboratories (CRL), based in Red Wing Minnesota, who for many decades has developed proven engineered material transfer solutions based around their Rapid Transfer Port (RTP) technology, has worked with DOE sites to develop a TRU Waste Management Solution. The solution is a single filtered large Polyethylene (PE) or Stainless Steel (SST) Rapid Transfer Port container in a standard Department of Transportation (DOT) 7A, Type A drum, which allows for loading of TRU waste directly from the operational glovebox without the use of bags, sleeves or tapes to provide leak tight containment. All operator interventions to connect and disconnect a drum to and from the glovebox are achieved in an upright ergonomic position by one (1) operator in less than three (3) minutes. Minimal As Low As Reasonably Achievable (ALARA) levels are achieved during connect and disconnect of the drum, due to the engineered safety controls of the RTP. The CRL RTP solution allows glovebox or re-packaged TRU waste to be safely transferred to the final 55 Gallon drum container without additional bags or tape. The high diffusion coefficient filter on the CRL RTP 55G container and elimination of added hydrogenous packaging, improves the Decay Heat Limit (DHL) per drum for most TRU waste types compared with bagged drums, and in most cases allows more TRU waste to be loaded per drum. Inorganic TRU waste materials can be packaged directly into the CRL RTP SST drum container to the maximum DHL and Fissile Gram Equivalent (FGE) allowable for a drum. This paper will show how highly efficient TRAMPAC approved TRU waste packaging of CH and RH TRU waste can be accomplished in a safer, cost effective manner without adding any additional packaging materials to the waste stream, thus increasing the chance of placing all DOE's legacy and to be generated TRU waste in the remaining WIPP space. (authors)

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French Geological Disposal Project: From Siting to Permitting - 19018

The future 'Cigeo' geological repository will be located in eastern France, at the border between the Meuse and Haute-Marne. Research has been carried out in this area since the 1990's, leading to the identification of a zone within the Paris basin whose geological characteristics make it suitable for the deep geological disposal of high- and intermediate-level long-lived radioactive waste, as well as a smaller zone of approximately 250 km{sup 2} (proposed in 2005) within which the characteristics of the host layer are very similar to those observed in the Underground Research Laboratory (URL). In 2010, based on additional surveys, a zone of approximately 30 km{sup 2} called ZIRA, in which the industrial underground facility would be constructed was defined. The repository structures within the ZIRA will be located at a depth of 525 metres. Half the surface area of the ZIRA is located in a wooded area, the other half being situated in grassland or farmland. All the subsequent design studies (preliminary and detailed) of Cigeo as well as the preparation of the licensing files (to be submitted in 2020) were conducted on the basis on this precise siting. (authors)

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A Study of a Monitoring Program for Intermediate Depth Disposal of Low- Level Radioactive Waste - 20167

This study investigated a monitoring program for intermediate depth disposal of low-level radioactive waste. At first, it extracted monitoring targets, such as the status of cracks in the low diffusion layer after closure of the facility. Secondly, it focused on distributed optical fiber sensors which can minimize the amount of cable, and measurement positions and methods were specifically determined to propose the monitoring method. Finally, conformity to regulatory requirements was verified to clarify key points and issues to be addressed in performing monitoring. (authors)

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A novel nanoparticle-based disposable electrochemical immunosensor for diagnosis of exposure to toxic organophosphorus agents

We present a novel disposable electrochemical immunosensor for highly selective and sensitive detection of organophosphorylated butyrylcholinesterase (OP-BChE), a specific biomarker for exposure to toxic organophosphorus agents. In our new approach, the zirconia nanoparticles (ZrO-2) were employed to selectively capture the OP moiety of OP-BChE adducts, and followed by quantum dot (QD)-tagged anti-BChE antibodies for amplified quantification. The captured CdSe-QD tags can be sensitively detected by stripping voltammetry using in situ bismuth-plating method. The OP agent, diisopropylfluorophosphate (DFP), was selected to prepare OP-BChE adducts in various matrices. The formation of OP-BChE adducts in plasma sample was confirmed using mass spectroscopy. The developed electrochemical immunosensor demonstrates a highly linear voltammetric response over the range of 0.1 to 30 nM OP-BChE. Moreover, the immunosensor has been successfully applied for the detection of OP-BChE adducts in the plasma samples. This novel nanoparticle-based electrochemical immunosensor thus provides an alternative way for designing simple, fast, sensitive, and cost-effective sensing platform for on-site screening/evaluating exposure to a variety of OP agents.

60 APPLIED LIFE SCIENCES↗

Electrochemical Detection of SNP in Human Mitochondrial DNA Using Cyclic Primer Extension with Biotinylated Nucletides and Enzymatic Labeling at Disposable Pencil Graphite Electrodes

Abstract A novel method of SNP typing in human mitochondrial DNA utilizing enzymatic labeling and electrochemical detection at disposable pencil graphite electrodes is described. The procedure is based on amplification of DNA stretches by cyclic primer extension (PEx) of SNP‐specific diagnostic primers in a mixture of biotinylated and natural nucleotides. The diagnostic primers are designed to recognize, by its 3'‐terminal nucleotide, the SNP‐site in target template. Under optimized conditions of the PEx reaction, efficient polymerase synthesis of biotin‐labeled strands takes place only in the case of full complementarity between the diagnostic primer and the target SNP site. There is also benefit from introducing many biotin molecules per extended DNA strand, resulting in another level of signal amplification. After adsorption of biotinylated PEx products at the electrode surface, streptavidin‐alkaline phosphatase conjugate was bound to the biotin tags, 1‐naphthol was enzymatically produced and electrochemically detected. Several critical steps and parameters of the assay, including termination of 3’‐OH ends of residual amplification primers, temperature for annealing of diagnostic primers, relative amount of biotinylated deoxynucleoside triphosphate in the PEx mixture and number of PEx cycles were optimized in this study to attain best SNP resolution, and reduction of time needed for the analysis.

Plucnara, Medard↗

Disposable Biosensor Based on Amidase/CeO2/GNR Modified Inkjet-printed CNT Electrodes-droplet Based Paracetamol Detection in Biological Fluids for “Point-of-care” Applications

A disposable acetaminophen biosensor based on inkjet-printed CNT electrodes (IJPCNT) modified with amidase/cerium dioxide@graphene nanoribbons composite was developed (ACeO2@GNR/IJPCNT). The enzyme amidase A was used for the first time as a recognition element. Inkjet-printed CNT electrodes served as a basis for the construction of a biosensor that enables droplet detection using 5 μL sample volume. The biosensor showed high selectivity, sensitivity, a low detection limit of 0.18 μM and a wide working linear range from 1 to 100 μM. The proposed approach allows fast and reliable detection of acetaminophen in biological fluids with negligible matrix effect and remarkable reproducibility. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Thermophysical properties of the Ghareb formation relevant for nuclear waste disposal

The Ghareb formation, a shallowly buried porous chalk in Israel, is currently a candidate for nuclear waste disposal. The potential repository is somewhat unique for its host rock and emplacement in shallow (500 m) engineered large diameter boreholes. Herein, the thermal properties of the Ghareb are determined to support design and performance assessment; the relevant properties measured are thermal conductivity, specific heat capacity, thermal diffusivity, and thermal expansion coefficient along with their relationship with varying temperature. For the temperature range of 40 to 275 °C, the thermal conductivity ranges from 0.30 to 1.10 W/m·K, the thermal diffusivity ranges from 0.20 to 0.72 mm 2 /s, and volumetric heat capacity ranges from 0.86 to 2.00 MJ/m 3 ·K. Thermal strain measurements were used to estimate the linear thermal expansion coefficient to be 6·10 –4 –9·10 –2 °C -1 from 40 to 300 °C. These measured properties were used in a thermomechanical model to estimate near-field stresses an hour and 10 years after waste emplacement; the borehole was found to be stable. Thermal loading after 10 years was predicted to elevate local pore pressures by 1–1.5 MPa. The laboratory measurements coupled with analyses are the first attempts at performance assessment characterization for this first of its kind potential repository setting with this chosen host rock.

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Graphite waste classification and disposal cost estimation for high temperature gas and salt reactors

As high-temperature reactor designs progress to demonstration, managing the radioactive wastes from these systems presents unique challenges. This work explores the irradiated graphite source term produced by three reactor designs: The Modular High Temperature Gas reactor (MHTGR), a pebble-bed High Temperature Gas Reactor (pb-HTGR), and a Fluoride-cooled High-temperature Reactor (FHR). We predicted a C-14 concentration of 4.3 Ci/m 3 for the MHTGR, 1.2 Ci/m 3 for the pebble bed HTGR, and 2.5 Ci/m 3 for the gFHR after 20 years of operation. The final C-14 concentration highly depended on the graphite nitrogen impurity, a major precursor for C-14. The C-14 concentration in all reactor types exceeded the 0.8 Ci/m3 threshold, resulting in a Class C waste classification. The costs associated with accepting the graphite after 20 years in a low-level waste disposal facility were projected to be 255 dollars per kWe for the MHTGR, 248 dollars per kWe for the pb-HTGR, and 56.8 dollars per kWe for the FHR.

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Monte Carlo characterization of the cosmic ray muon flux in shallow subsurface geological repositories intended for disposal of radioactive materials

Recent challenges in monitoring subsurface geological repositories intended for disposal of radioactive materials such as spent nuclear fuel call for new, innovative concepts that are facility independent, cost-effective, passive, and reliable. Once nuclear material is in place at these facilities, reverifying the inventory may no longer be feasible if continuity of knowledge is lost or unavailable to the inspectors. Using cosmic ray muons may present several potential advantages over conventional photon/neutron signatures, and their use in safeguards applications have only received attention in the past decade. However, there have been limited efforts to explore the integration of cosmic ray muons into repository safeguards and study potential gains, risks, and costs. This paper presents a Monte Carlo-based methodology to characterize the cosmic ray muon flux, including muon angular and energy differential distributions at depths representative of subsurface geological repositories. Since there have been limited measurements at these sites and a measurement made in one site is not always transferable to another site, the objective is to develop an efficient simulation method and useful parametrizations to provide a convenient tool for enabling muon simulations at any geological repository site. It is expected these results will provide a better understanding of how muons can be integrated into an existing geological repository safeguards framework.

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Evolving radon diffusion through earthen barriers at uranium waste disposal sites

Field measurements of Rn-222 fluxes from the tops and bottoms of compacted clay radon barriers were used to calculate effective Rn diffusion coefficients (D Rn ) at four uranium waste disposal sites in the western United States to assess cover performance after more than 20 years of service. Values of D Rn ranged from 7.4 × 10 -7 to 6.0 × 10 -9 m 2 /s, averaging 1.42 × 10 -7 . Water saturation (S W ) from soil cores indicated that there was relatively little control of D Rn by S W , especially at higher moisture levels, in contrast to estimates from most steady-state diffusion models. Further, this is attributed to preferential pathways intrinsic to construction of the barriers or to natural process that have developed over time including desiccation cracks, root channels, and insect burrows in the engineered earthen barriers. A modification to some models in which fast and slow pathway D Rn values are partitioned appears to give a good representation of the data; 4% of the fast pathway was needed to fit the data regression. For locations with high S w and highest D Rn (and fluxes) at each site, the proportion of fast pathway ranged from 1.7% to 34%, but for many locations with lower fluxes, little if any fast pathway was needed.

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Public perception of odour and environmental pollution attributed to MSW treatment and disposal facilities: A case study

Highlights: ► Effects of closing MSW facilities on perception of odour and pollution studied. ► Residents’ perception of odour nuisance considerably diminished post closure. ► Odour perception showed an association with distance from MSW facilities. ► Media coverage increased knowledge about MSW facilities and how they operate. ► Economic compensation possibly affected residents’ views and concerns. - Abstract: If residents’ perceptions, concerns and attitudes towards waste management facilities are either not well understood or underestimated, people can produce strong opposition that may include protest demonstrations and violent conflicts such as those experienced in the Campania Region of Italy. The aim of this study was to verify the effects of the closure of solid waste treatment and disposal facilities (two landfills and one RDF production plant) on public perception of odour and environmental pollution. The study took place in four villages in Southern Italy. Identical questionnaires were administered to residents during 2003 and after the closure of the facilities occurred in 2008. The residents’ perception of odour nuisance considerably diminished between 2003 and 2009 for the nearest villages, with odour perception showing an association with distance from the facilities. Post closure, residents had difficulty in identifying the type of smell due to the decrease in odour level. During both surveys, older residents reported most concern about the potentially adverse health impacts of long-term exposure to odours from MSW facilities. However, although awareness of MSW facilities and concern about potentially adverse health impacts varied according to the characteristics of residents in 2003, substantial media coverage produced an equalisation effect and increased knowledge about the type of facilities and how they operated. It is possible that residents of the village nearest to the facilities reported lower awareness of and concern about odour and environmental pollution because the municipality received economic compensation for their presence.

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Using MCDA and GIS for hazardous waste landfill siting considering land scarcity for waste disposal

Highlights: • Wasting land for the siting of hazardous waste landfills must be avoided. • The siting procedure is based on a land use map of potentially suitable areas. • All the waste facilities of the management system are simultaneously considered. • A case study is developed considering two multi-criteria techniques. • An innovative criteria weighting tool (PSW) is used in combination with the AHP. - Abstract: The main aim of this study was to develop a procedure that minimizes the wasting of space for the siting of hazardous waste landfills as part of a solid waste management system. We wanted to tackle the shortage of land for waste disposal that is a serious and growing problem in most large urban regions. The procedure combines a multi-criteria decision analysis (MCDA) approach with a geographical information system (GIS). The GIS was utilised to obtain an initial screening in order to eliminate unsuitable areas, whereas the MCDA was developed to select the most suitable sites. The novelty of the proposed siting procedure is the introduction of a new screening phase before the macro-siting step aimed at producing a “land use map of potentially suitable areas” for the siting of solid waste facilities which simultaneously takes into consideration all plant types. The issue of obtaining sites evaluations of a specific facility was coupled with the issue of not wasting land appropriate to facilitate other types of waste management options. In the developed case study, the use of an innovative criteria weighting tool (the “Priority Scale”) in combination with the Analytic Hierarchy Process was useful to easier define the priorities of the evaluation criteria in comparison with other classic methods such as the Paired Comparison Technique in combination with the Simple Additive Weighting method.

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Disposable ultrasound-sensing chronic cranial window by soft nanoimprinting lithography

Chronic cranial window (CCW) is an essential tool in enabling longitudinal imaging and manipulation of various brain activities in live animals. However, an active CCW capable of sensing the concealed in vivo environment while simultaneously providing longitudinal optical access to the brain is not currently available. Here we report a disposable ultrasound-sensing CCW (usCCW) featuring an integrated transparent nanophotonic ultrasonic detector fabricated using soft nanoimprint lithography process. We optimize the sensor design and the associated fabrication process to significantly improve detection sensitivity and reliability, which are critical for the intend longitudinal in vivo investigations. Surgically implanting the usCCW on the skull creates a self-contained environment, maintaining optical access while eliminating the need for external ultrasound coupling medium for photoacoustic imaging. Using this usCCW, we demonstrate photoacoustic microscopy of cortical vascular network in live mice over 28 days. Finally, this work establishes the foundation for integrating photoacoustic imaging with modern brain research.

47 OTHER INSTRUMENTATION↗