bluuebunny/crossref_metadata_2025_split huggingface dataset:
Moving HLW-EBS Concepts into the 21st Century
Authors: McKinley I.G. , Kawamura H. , Tsuchi H. 
Published: May 2011

ABSTRACTMost national high-level waste (HLW) disposal programs actually reflect, or are based on, concepts which were developed during the '70s or early '80s. Although suitable for demonstration of concept feasibility, designs of the engineered barrier system (EBS) do not take into account the tremendous developments in system understanding and materials technology over the last two decades, the practicality (and cost) of their quality assurance and implementation on an industrial scale and the transparency of the demonstration of the safety case. In many ways, due to the increased significance of popular acceptance over the last decade, the last point may be of particular relevance.This paper reviews the work already carried out on “2nd generation” concepts and extends this to identify the key attributes of an ideal design for the specific case of disposal of vitrified HLW from reprocessing in a “wet” host rock (either crystalline or sedimentary). Based on the concept developed, key R&D requirements are identified.
SR-97: Canister Performance under Normal Disposal Conditions
Authors: Werme Lars 
Published: May 2011

ABSTRACTThe SR-97 disposal canister consists of an inner load bearing cast iron component and an outer corrosion barrier of copper. The mechanical strength of the insert must be such that it withstands, with sufficient safety margins, the combined forces of hydrostatic pressure at the disposal depth (7 MPa) and the bentonite swelling pressure (7 MPa). It must also withstand an increased hydrostatic pressure during a future glaciation. This pressure increase may be as high as 30 MPa. For this load situation, no extra safety margins will be required. Uneven pressure may occur during the water saturation of the buffer and to some extent some uneven pressure may also persist after water saturation. Calculations have been performed for such design basis uneven loads and the present canister design has been shown to withstand them. Under the oxygen-free conditions at the disposal depth, copper will be thermodynamically stable. Only dissolved sulfide will be able to corrode the copper. The supply of sulfide is expected to be low and, consequently, the service life of the canister will be very long. Calculations indicate that no known corrosion processes will lead to canister failure during a shorter time than at least 1 million years.
Approaches to Comparative Risk Assessments of National and International Radioactive Waste Disposal Options
Authors: Heathcote J A , Rintoul A H , Waite P J 
Published: May 2011

ABSTRACTPangea Resources International AG, Switzerland, has put forward the concept of an international geological repository in an Australian desert area, for final disposal of certain of the world's high-level radioactive wastes and surplus fissile materials. Already publicly contentious in Australia, the concept raises unusual issues in safety and environmental assessment. It is timely, therefore, to consider why and how an initial case for such a repository might be made, in comparison with national options for high-level waste disposal that it might displace.There are several stages ahead of development of a formal safety case for an international repository. The first, and almost certainly the most challenging, is winning of public and political acceptance in the host country that such a repository is the ‘best’ solution to a global problem.We consider the basic need to identify and encompass the concerns of widely disparate stakeholders — industry, governments, national and international regulators, environmental interest groups and the public at large — so that public and political debates can be informed effectively. Many key issues will require comparison both of risks arising from very different operations, and of dissimilar prospective safety performances of complete disposal systems over periods spanning thousands of generations. Nevertheless, we conclude that the validity of such a comparative assessment could be assured by consistent application of a judicious blend of assessment techniques across the alternatives. We also conclude that its usefulness as a vehicle for public discussion would be enhanced by careful attention to public concerns, and by transparently independent review by scientific, technical, sociological and ethical specialists.
Effects of Confining Pressure on Gas and Water Permeabilities of Rocks
Authors: Zhang M. , Takeda M. , Esaki T. , Takahashi M. , Endo H. 
Published: May 2011

ABSTRACTKnowledge of the permeability of hydraulically-tight rock at great depth is crucially important for the design and/or assessment of facilities associated with underground disposal of radioactive nuclear wastes. This paper presents a recently developed laboratory permeability test system capable of testing low permeability rocks either by using air as a permeant or by the transient-pulse method under high confining pressure conditions that simulate ground pressures at depths. The new system was used to test Shirahama sandstone and Inada granite, which are two types of rock widely available in Japan. To investigate the effects of heterogeneity on rock permeability, specimens cored parallel to and perpendicular to bedding for sandstone, and specimens cored in the direction perpendicular to Rift Plane, Grain Plane and Hardway Plane for granite, were used. The results of this study showed that: 1) gas permeabilities of a dried rock specimen tested by air permeation are almost the same values as water permeabilities of the same saturated rock specimen tested by the transient-pulse method; 2) the intrinsic permeabilities of Shirahama sandstone and Inada granite range from about 8.33E-16 to 7.38E-17 m2 and from 1.86E-17 to 6.94E-20 m2, respectively. They decrease monotonously with increase in effective confining pressure (defined as the difference between the confining and pore pressures), while the rate of decrease diminishes at higher confining pressures. The reduction in permeabilities is due to the closure of microcracks that control fluid flow at low confining pressures; and 3) Inada granite is a heterogeneous and isotropic material. Its hydraulic heterogeneity is more significant in Rift Plane than in Hardway and Grain Planes.
Retrievability; Rationale, Measures, Impacts
Authors: McCombie C. , Zuidema P. 
Published: May 2011

ABSTRACTThe concept of deep geological disposal was developed in order to permanently remove radioactive wastes from the human environment. Retrieval of wastes was reckoned to be a scenario of such low probability that little effort was initially devoted to its study. In recent years, however, there has been an increasingly active debate on whether fully passive (and safe) systems provide a sufficient level of practicability of retrievability. This debate is linked directly to practical, technical matters, such as the design of the facility, the operating procedures and also the institutional programs throughout the lifetime of a repository. But there are also philosophical issues involved in addition to these purely technical issues.For retrievability, the questions are: How easy does retrieval have to be in the different stages of repository development? What is the rationale for requiring retrievability? What technical measures and methods are feasible? Should specific features facilitating retrievability be introduced into the repository design? How do such measures impact on other aspects of system performance and on other issues (such as safeguards)? This paper addresses the questions raised and presents a subjective set of conclusions, as a means to stimulate further debate on this topical issue.
Radiation Effects on Materials in the Near-Field of a Nuclear Waste Repository
Authors: Gu B.X. , Wang L.M. , Wang S.X. , Ewing R.C. 
Published: May 2011

ABSTRACTThe long-term radiation effects on materials in the near-field of a nuclear waste repository have been evaluated using accelerated laboratory experiments with energetic electron or ion beam irradiation. The materials studied include: zeolites, layered silicates (smectite clay and mica), as well as crystalline silicotitanate (CST) which is an important ion exchange material for the chemical separation of high-level liquid radioactive wastes.In situ transmission electron microscopy (TEM) during irradiation by energetic electrons and ions has shown that all of the studied materials are susceptible to irradiation-induced amorphization. At room temperature, complete amorphization was observed after ionizing doses of 1010 ∼ 1012 Gy or displacement doses on the order of 0.1 dpa (equivalent to doses received in 400-1,000 years for a high-loading nuclear waste form). Amorphization may be preceded or accompanied by dehydration, layer spacing reduction and gas bubble formation. In the case of zeolites, CST and some layered silicates, radiation effects are significantly enhanced at higher temperatures. Our experiments have shown that amorphization or even partial amorphization will cause a dramatic reduction in ion exchange and sorption/desorption capacities for radionuclides, such as Cs and Sr. Because the near-field or chemical processing materials (e.g. zeolites or CST) will receive a substantial radiation dose after they have incorporated radionuclides, our results suggest that radiation effects may, in some cases, retard the release of sorbed or ion-exchanged radionuclides.
Partitioning of Actinides, Rare Earth Elements, and Other Trace Elements In Titanium-Rich Veins From Adamello, Italy
Authors: Lumpkin Gregory R. , Gieré Reto , Payne T.E. , McGlinn P.J. , Hart K.P. 
Published: May 2011

ABSTRACTExtensive mineralogical and chemical studies have been carried out on the Ti-rich hydrothermal veins emplaced within the contact aureole of the Adamello batholith. In addition to other actinide and rare earth element host phases, the veins contain both zirconolite and betafite and provide information relevant to ceramic wasteforms designed for the disposal of actinide-rich nuclear wastes. In this paper, we describe the results of element partitioning studies based on dissolution experiments using 9M HCl. Generally, the acid-resistant minerals include allanite, baddeleyite, betafite, chalcopyrite, geikielite, titanite, spinel, and zirconolite. We also found that the major silicate minerals forsterite, phlogopite, and titanian clinohumite and the sulfide mineral pyrrhotite are partially dissolved by the acid treatment, whereas calcite and apatite are highly soluble (as expected). In particular, the distributions of Th and U between the acid-resistant and acid-soluble fractions indicate that they partition mainly between zirconolite, titanite, betafite, and apatite. However, there is a considerable increase in the amounts of Zr, Nb, Th, and U released in certain actinide-rich samples that may result from enhanced dissolution following radiation damage.
Surveying for Migration Pathways in the Granitic Rock Using Nuclear Track Detectors, Autoradiography and Digital Image Analysis as an Aid To Construct the Basis for Heterogeneous Diffusion Modeling
Authors: Kemppainen M. , Oila E. , Siitari-Kauppi M. , Sardini P. , Hellmuth K-H. 
Published: May 2011

ABSTRACTRadioelement migration within a rock matrix under natural long-term conditions is a complex process controlled by various parameters. Pure physical parameters such as porosity, hydraulic conductivity and diffusivity are usually sufficient to describe transport in well-defined laboratory systems. In natural rock matrices transport is influenced by physical pore properties such as pore size distribution, connectivity, tortuosity, constrictivity and petrological and chemical nature and charge on the fluid-rock interface. The overall characterization of heterogeneous rock structures is needed for the accurate heterogeneous diffusion modeling.Here we describe a method for the detection of μ-particles from uranium in cm-scale rock samples based on the analysis of the tracks formed in organic polymer, CR-39. On the other hand the uranium tracks were compared with the migration pathways and porosity distribution produced with the 14C-polymethylmethacrylate impregnation method (14C-PMMA). For analyzing mineral specific uranium occurrence and porosities the staining methods were used to produce the mineral map of the rock sample. Digital image analysis techniques were applied to the different cm-scale pictures of rock samples. Scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDS) were performed in order both to study the pore apertures of grain boundaries and fissures in greater detail and to detect the uranium phases.The high uranium content was found to be congruent with the porous mineral phases; altered plagioclase and biotite grains, and the intra- and intergranular fissures detected with the 14C-PMMA technique. Plenty of microfractures transsecting potassium feldspar and quartz grains were filled with calcite together with precipitated uranium.
Effects of syringomyelia on electrodiagnostic test results in Cavalier King Charles Spaniels
Authors: Harcourt-Brown Thomas R. , Belshaw Zoe , Parker John E. , Jeffery Nick D. , Granger Nicolas 
Published: May 2011

Abstract
Objective—To determine the effects of syringomyelia on electromyography (EMG) findings, somatosensory-evoked potentials (SEPs), and transcranial magnetic motor-evoked potentials (TMMEPs) in Cavalier King Charles Spaniels (CKCSs).
Animals—27 client-owned CKCSs that underwent prebreeding magnetic resonance imaging screening or investigation of clinical signs consistent with syringomyelia.
Procedures—In dogs with (n = 11) and without (16) magnetic resonance imaging-confirmed syringomyelia, the median nerve in each thoracic limb was stimulated and SEPs were recorded over the C1 vertebra; onset latency and latency and amplitude of the largest negative (N1) and positive (P1) peaks were measured. The TMMEPs were recorded bilaterally from the extensor carpi radialis and tibialis cranialis muscles; onset latencies in all 4 limbs were measured. Bilateral systematic needle EMG examination was performed on the cervical epaxial musculature, and the number of sites with spontaneous activity was recorded.
Results—In dogs with syringomyelia, amplitudes of N1 and P1 and the amplitude difference between P1 and N1 were significantly smaller than those recorded for dogs without syringomyelia (approx 2-fold difference). No difference in SEP latencies, TMMEP latencies, or the proportion of dogs with > 2 sites of spontaneous activity detected during EMG examination was detected between groups.
Conclusions and Clinical Relevance—Results indicated that SEP amplitude at the C1 vertebra was a more sensitive measure of spinal cord function in CKCSs with syringomyelia, compared with results of EMG or TMMEP assessment. Measurement of SEP amplitude may have use as an objective assessment of the evolution and treatment of this disease.
Reliability and validity of a visual analogue scale used by owners to measure chronic pain attributable to osteoarthritis in their dogs
Authors: Hielm-Björkman Anna K. , Kapatkin Amy S. , Rita Hannu J. 
Published: May 2011

Abstract
Objective—To assess validity and reliability for a visual analogue scale (VAS) used by owners to measure chronic pain in their osteoarthritic dogs.
Sample—68, 61, and 34 owners who completed a questionnaire.
Procedures—Owners answered questionnaires at 5 time points. Criterion validity of the VAS was evaluated for all dogs in the intended-to-treat population by correlating scores for the VAS with scores for the validated Helsinki Chronic Pain Index (HCPI) and a relative quality-of-life scale. Intraclass correlation was used to assess repeatability of the pain VAS at 2 baseline evaluations. To determine sensitivity to change and face validity of the VAS, 2 blinded, randomized control groups (17 dogs receiving carprofen and 17 receiving a placebo) were analyzed over time.
Results—Significant correlations existed between the VAS score and the quality-of-life scale and HCPI scores. Intraclass coefficient (r = 0.72; 95% confidence interval, 0.57 to 0.82) for the VAS indicated good repeatability. In the carprofen and placebo groups, there was poor correlation between the 2 pain evaluation methods (VAS and HCPI items) at the baseline evaluation, but the correlation improved in the carprofen group over time. No correlation was detected for the placebo group over time.
Conclusions and Clinical Relevance—Although valid and reliable, the pain VAS was a poor tool for untrained owners because of poor face validity (ie, owners could not recognize their dogs' behavior as signs of pain). Only after owners had seen pain diminish and then return (after starting and discontinuing NSAID use) did the VAS have face validity.
Effect of duration and type of anesthetic on tear production in dogs
Authors: Shepard Molly K. , Accola Peter J. , Lopez Luis A. , Shaughnessy Michael R. , Hofmeister Erik H. 
Published: May 2011

Abstract
Objective—To determine effects of duration and type of anesthetic on tear production in dogs.
Animals—8 female Beagles.
Procedures—Each dog was randomly allocated into 1 of 4 groups according to a Latin square design to receive anesthesia as follows: 1 hour with isoflurane, 1 hour with desflurane, 4 hours with isoflurane, and 4 hours with desflurane. Each dog was anesthetized with the selected inhalant 4 times during a 4-week period, with at least 5 days separating anesthetic episodes. Aqueous tear production was measured via the Schirmer I tear test at baseline and 10 minutes, 30 minutes, and 1 hour after induction of anesthesia as well as 2, 3, and 4 hours after induction for the 4-hour groups. Tear production was also measured after the dogs were standing after recovery from anesthesia and 2, 10, and 22 hours after recovery from anesthesia.
Results—Aqueous tear production was significantly reduced in dogs during anesthesia and returned to baseline values immediately after recovery and until 10 hours after anesthesia in all treatment groups. Inhalant type and duration had no significant effect. Neither lateral recumbency nor left versus right eyes had a significant effect.
Conclusions and Clinical Relevance—Results suggested that inhalant anesthetics did not reduce tear production after anesthesia and that longer-duration anesthesia did not cause decreased tear production, compared with shorter-duration anesthesia.
Determination of the concentrations of trilostane and ketotrilostane that inhibit ex vivo canine adrenal gland synthesis of cortisol, corticosterone, and aldosterone
Authors: McGraw Andrew L. , Whitley Elizabeth M. , Lee Hollie P. , Boothe Dawn M. , Behrend Ellen N. 
Published: May 2011

Abstract
Objective—To determine whether trilostane or ketotrilostane is more potent in dogs and determine the trilostane and ketotrilostane concentrations that inhibit adrenal gland cortisol, corticosterone, and aldosterone secretion by 50%.
Sample—24 adrenal glands from 18 mixed-breed dogs.
Procedures—Adrenal gland tissues were sliced, placed in tissue culture, and stimulated with 100 pg of ACTH/mL alone or with 5 concentrations of trilostane or ketotrilostane. Trials were performed independently 4 times. In each trial, 6 samples (1 for each time point) were collected for each of the 5 concentrations of trilostane and ketotrilostane tested as well as a single negative control samples. At the end of 0, 1, 2, 3, 5, and 7 hours, tubes were harvested and media and tissue slices were assayed for cortisol, corticosterone, aldosterone, and potassium concentrations. Data were analyzed via pharmacodynamic modeling. One adrenal slice exposed to each concentration of trilostane or ketotrilostane was submitted for histologic examination to assess tissue viability.
Results—Ketotrilostane was 4.9 and 2.4 times as potent in inhibiting cortisol and corticosterone secretion, respectively, as its parent compound trilostane. For trilostane and ketotrilostane, the concentrations that inhibited secretion of cortisol or corticosterone secretion by 50% were 480 and 98.4 ng/mL, respectively, and 95.0 and 39.6 ng/mL, respectively.
Conclusions and Clinical Relevance—Ketotrilostane was more potent than trilostane with respect to inhibition of cortisol and corticosterone secretion. The data should be useful in developing future studies to evaluate in vivo serum concentrations of trilostane and ketotrilostane for efficacy in the treatment of hyperadrenocorticism.
Effect of combined lignan phytoestrogen and melatonin treatment on secretion of steroid hormones by adrenal carcinoma cells
Authors: Fecteau Kellie A. , Eiler Hugo , Oliver Jack W. 
Published: May 2011

Abstract
Objective—To investigate the in vitro effect of the combination of lignan enterolactone (ENL) or lignan enterodiol (END) with melatonin on steroid hormone secretion and cellular aromatase content in human adrenal carcinoma cells. Sample—Human adrenocortical carcinoma cells.
Procedures—Melatonin plus ENL or END was added to cell culture medium along with cAMP (100μM); control cells received cAMP alone. Medium and cell lysates were collected after 24 and 48 hours of cultivation. Samples of medium were analyzed for progesterone, 17-hydroxyprogesterone, androstenedione, aldosterone, estradiol, and cortisol concentration by use of radioimmunoassays. Cell lysates were used for western blot analysis of aromatase content.
Results—The addition of ENL or END with melatonin to cAMP-stimulated cells (treated cells) resulted in significant decreases in estradiol, androstenedione, and cortisol concentrations at 24 and 48 hours, compared with concentrations in cells stimulated with cAMP alone (cAMP control cells). The addition of these compounds to cAMP-stimulated cells also resulted in higher progesterone and 17-hydroxyprogesterone concentrations than in cAMP control cells; aldosterone concentration was not affected by treatments. Compared with the content in cAMP control cells, aromatase content in treated cells was significantly lower.
Conclusions and Clinical Relevance—The combination of lignan and melatonin affected steroid hormone secretion by acting directly on adrenal tumor cells. Results supported the concept that this combination may yield similar effects on steroid hormone secretion by the adrenal glands in dogs with typical and atypical hyperadrenocorticism.