Mammalian end binding proteins control persistent microtubule growth
UK PubMed Central (United Kingdom)
End binding proteins (EBs) are highly conserved core components of microtubule plus-end tracking protein networks. Here we investigated the roles of the three mammalian EBs in controlling microtubule...Full Text Available
2009-03-09
UK PubMed Central (United Kingdom)
The carboxyl-terminal region of tubulin alpha and beta subunits plays a major role in regulating its assembly into microtubules and constitutes an essential domain for the selective interaction of microtubule-associated...Full Text Available
1988-09-01
Thermodynamic and structural analysis of microtubule assembly: the role of GTP hydrolysis.
UK PubMed Central (United Kingdom)
Different models have been proposed that link the tubulin heterodimer nucleotide content and the role of GTP hydrolysis with microtubule assembly and dynamics. Here we compare the thermodynamics of...Full Text Available
1997-03-01
UK PubMed Central (United Kingdom)
SummaryFor mammalian somatic cells the importance of microtubule cytoskeleton integrity in interphase cell cycle progression is uncertain. The loss, diminishment, or stabilization...Full Text Available
2007-12-04
The Growth Cone Cytoskeleton in Axon Outgrowth and Guidance
UK PubMed Central (United Kingdom)
Axon outgrowth and guidance to the proper target requires the coordination of filamentous (F)-actin and microtubules (MTs), the dynamic cytoskeletal polymers that promote shape change and locomotion....Full Text Available
UK PubMed Central (United Kingdom)
We have studied the self-association reactions of purified GDP-liganded tubulin into double rings and taxoid-induced microtubules, employing synchrotron time-resolved x-ray solution scattering. The...Full Text Available
1996-05-01
The Caenorhabditis elegans Elongator Complex Regulates Neuronal ?-tubulin Acetylation
UK PubMed Central (United Kingdom)
Although acetylated α-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate α-tubulin acetylation are, to date, largely unknown. Therefore,...Full Text Available
2010-01-01
UK PubMed Central (United Kingdom)
Centrioles are intriguing cylindrical organelles composed of triplet microtubules. Proteomic data suggest that a large number of proteins besides tubulin are necessary for the formation and maintenance...Full Text Available
2009-02-15
Use of polarized light microscopy in porcine reproductive technologies
British Library Electronic Table of Contents (United Kingdom)
The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted...
2011-01-01
Tau inhibits tubulin oligomerization induced by prion protein
British Library Electronic Table of Contents (United Kingdom)
In previous studies we have demonstrated that prion protein (PrP) interacts with tubulin and disrupts microtubular cytoskeleton by inducing tubulin oligomerization. These observations may explain the molecular mechanism of toxicity of cytoplasmic PrP in transmissible spongiform encephalopathies (TSEs). Here, we check whether microtubule associated proteins (MAPs) that regulate microtubule stability, influence the PrP-induced oligomerization of tubulin. We show that tubulin preparations depleted of MAPs are more prone to oligomerization by PrP than those containing traces of MAPs. Tau protein, a major neuronal member of the MAPs family, reduces the effect of PrP. Importantly, phosphorylation of Tau abolishes its ability to affect the PrP-induced oligomerization of tubulin. We propose that t...
2011-01-01
International Nuclear Information System (INIS)
Remote-controlled handling systems are required for work to be done in the decommissioning and dismantling of nuclear facilities. These systems are equipped with electronic devices suitable for use in working environments affected by ionizing radiation. The publication explains the step-wise progress achieved for improving the radiation resistance of electronic devices with the example of a four-quadrant controlling device for the motors of a manipulator. The radiation resistance of the device could be enhanced to radiation energies of 5.500 Gy. This means that a manipulator vehicle equipped with this controlling device can take up to approx. 15 kGy all in all, taking into account its own shielding properties. (DG).
Inhibition of tau fibrillization by oleocanthal via reaction with the amino groups of tau
Tau is a microtubule-associated protein that promotes microtubule assembly and stability. In Alzheimer's disease and related tauopathies, tau fibrillizes and aggregates into neurofibrillary tangles. Recently, oleocanthal isolated from extra virgin olive oil was found to display non-steroidal anti-inflammatory activity similar to ibuprofen. Since our unpublished data indicates an inhibitory effect of oleocanthal on A? fibrillization, we reasoned that it might inhibit tau fibrillization as well. Herein we demonstrate that oleocanthal abrogates fibrillization of tau by locking tau into the naturally unfolded state. Using PHF6 consisting of the amino acid residues VQIVYK, a hexapeptide within the third repeat of tau that is essential for fibrillization, we show that oleocanthal forms an adduct with the lysine via initial Schiff base formation. Structure and function studies demonstrate that the two aldehyde groups of oleocanthal are required for ...
2009-06-15
Energy Technology Data Exchange (ETDEWEB)
Explosives have rarely been used in decommissioning of nuclear reactors. Nevertheless, controlled blasting can be used advantageously during careful destruction of nuclear power plants for removal of concrete, pipe systems, and other components. Experiments performed within a former nuclear power plant demonstrate the feasibility of this method, employing explosive masses up to 15 kg per blast. The loadings of the components and the total plant structure were measured and compared with code predictions. The experiments show a response of the containment predominantly in frequency ranges above 100 Hz, thus keeping the building and components below German regulation limits for shock excitation. The blast wave pressures are reduced drastically within short distances in the building. Dust and debris can be contained with simple methods such as curtains. Use of this method seems to be applicable to actual dismantling projects.
1989-08-01
Teleobservation in hostile environment
International Nuclear Information System (INIS)
In order to meet the needs of remote servicing performed in nuclear power plants, in fuel reprocessing plants and in atomic research centers three companies: - STMI, subsidiary of CEA, EDF and SGN, specialized in decontamination and dismantling, - La Calhene, subsidiary of CEA and SGN, specialized in robotics, - Inspectronic, manufacturer of closed circuit television cameras, have combined to create the Visionic Society, the main objectives of which are observation by television and inspections in radioactive environment.
Lifting the lid off the Windscale AGR
Energy Technology Data Exchange (ETDEWEB)
With the lifting of the top dome of the Windscale (AGR) Advanced Gas-cooled Reactor earlier this year, the decommissioning team has begun to dismantle the heaviest of the reactor components. In defining the tasks involved, the most important criterion was to minimise the radiation exposure expected to be received by the team members. The manager of the WAGR decommissioning project describes the preparation undertaken and the final lifting of the top dome in this article. (author).
1991-10-01
Decommissioning of facility for use of radioisotopes on waste management and disposal facility
Energy Technology Data Exchange (ETDEWEB)
All the tests have been finished up in the Waste Management and Disposal Facility which has been used for the safety tests of solidified radioactive waste on sea dumping disposal. The decommissioning of this facility was performed for use of radioisotopes. This report describes the plan on decommissioning of facility for use of radioisotopes, the contamination checking methods and measurement of radioactivity, the fore case and practice for amount of generated radioactive wastes, the operation procedures for dismantlement, the safety measures, the expenses for decommissioning and so on. (author)
1999-09-01
Decommissioning of French nuclear submarines
Energy Technology Data Exchange (ETDEWEB)
Since the beginning of the sixties, France has developed a fleet of nuclear powered vessels. Insofar as the ships of the 2. generation are being built, the older ones are decommissioned and enter the dismantling process. The average rate is presently one submarine decommissioned every two or three years. The overall strategy for the decommissioning of French nuclear submarines can be brought down to 3 phases: 1. Level 1 dismantling which essentially consists in: - unloading the spent fuel and storing it in a pool ; - possibly emptying the circuits which contain radioactive liquids. The level 1 is easily achieved, as it is not very different from the plant situation during ship overhaul or major refits. 2. Level 2 dismantling which consists in isolating the nuclear reactor compartment from the rest of the submarine and conditioning it for interim storage on a ground facility located inside Cherbourg Naval Dockyard. The rest ...
2003-07-01
British Library Electronic Table of Contents (United Kingdom)
The mature spermatozoon of Cricocephalus albus is filiform, tapered at both ends and shows the following features: 2 axonemes of different lengths presenting the 9+''1'' trepaxonematan pattern, 2 bundles of parallel cortical microtubules, a mitochondrion and a nucleus. Nevertheless, the particularity of the spermatozoon of C. albus is its anterior extremity with an apical electron-dense material associated with extramembranar ornamentation, a cytoplasmic dorsolateral expansion and spine-like bodies. To our knowledge, such an anterior extremity of the spermatozoon has not previously been described from a species of the superfamily Pronocephaloidea. Our study provides new data on the mature gamete of C. albus in order to improve our understanding of the pronocephaloidean phylogenetic relatio...
2011-01-01
Crystal structure of the human centromeric nucleosome containing CENP-A
British Library Electronic Table of Contents (United Kingdom)
In eukaryotes, accurate chromosome segregation during mitosis and meiosis is coordinated by kinetochores, which are unique chromosomal sites for microtubule attachment. Centromeres specify the kinetochore formation sites on individual chromosomes, and are epigenetically marked by the assembly of nucleosomes containing the centromere-specific histone H3 variant, CENP-A. Although the underlying mechanism is unclear, centromere inheritance is probably dictated by the architecture of the centromeric nucleosome. Here we report the crystal structure of the human centromeric nucleosome containing CENP-A and its cognate ?-satellite DNA derivative (147 base pairs). In the human CENP-A nucleosome, the DNA is wrapped around the histone octamer, consisting of two each of histones H2A, H2B, H4 and CENP...
2011-01-01
Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins
International Nuclear Information System (INIS)
Cholera toxin catalyzes transfer of radiolabel from ["3"2P]NAD"+ to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and ["3"2P]NAD"+ caused radiolabeling of purified microtubule and intermediate filament proteins.
1981-01-01
On Cost Estimate for Decommissioning of one Isotope Central
International Nuclear Information System (INIS)
The main scope of this study has been to calculate the future cost for decommission and dismantling the Isotope central at the Studsvik site using the OMEGA CODE. Detailed empirical information is used in the study for 'bench-marking' purposes, in such cases when there is a need to supplement and correct field data from the industry. In the present study, data has been retrieved and organized such that the estimated costs for decommissioning of the Isotope Central become transparent and reliable. This approach gives a preliminary qualitative indication about the accuracy of the cost estimate delivered by the industry
1994-04-25
Los Alamos DP West Plutonium Facility decontamination project
Energy Technology Data Exchange (ETDEWEB)
The DP West Plutonium Facility operated by the Los Alamos National Laboratory, Los Alamos, New Mexico, was decontaminated between April 1978 and April 1981. The facility was constructed in 1944 to 1945 to produce plutonium metal and fabricate parts for nuclear weapons. It was continually used as a plutonium processing and research facility until mid-1978. Decontamination operations included dismantling and removing gloveboxes and conveyor tunnels; removing process systems, utilities, and exhaust ducts; and decontaminating all remaining surfaces. This report describes glovebox and conveyor tunnel separations, decontamination techniques, health and safety considerations, waste management procedures, and costs of the operation.
1982-01-01
Downstream natural gas in Europe-High hopes dashed for upstream oil and gas companies
International Nuclear Information System (INIS)
Access for independents to retail gas markets was a central concern in European policy reform efforts in the 1990s. Upstream oil and gas companies reacted with strategic intentions of forward integration. By late 2004, forward integration was still weak, however. An important explanation of the gap between announced strategic re-orientation and actual strategy implementation lies in the political failure of EU member states to dismantle market barriers to entry for independents. Variations between companies in downstream strategy implementation are explained by variations in business opportunities and internal company factors.
2007-01-01
International Nuclear Information System (INIS)
The purpose of the present study was to examine the in vitro effects of low-dose cadmium (Cd) on developing cortical cells. The cortical cells removed from fetuses (embryonic day 15) were treated with 10 nM of Cd for 24 h. The effects of Cd on dendritic and synaptic development were immunocytochemically observed with anti-microtubule associated protein-2 (MAP2) and anti-synapsin I antibodies, respectively. Administration of Cd suppressed dendritic as well as synaptic development at 10 nM. By two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometric (LC/MS/MS) analysis, we identified three proteins with different expression after Cd-treatment; dihydropyrimidinase-related protein 2 (DRP-2/CRMP-2), 14-3-3-epsillon and calmodulin (CaM). Though the number of identified proteins was small, these proteins are known to be involved in neuronal development. The present study demonstrated the morphological effects as well as affected proteins in ...
2008-11-20
Nanomechanical properties of vimentin intermediate filament dimers
International Nuclear Information System (INIS)
The cell's cytoskeleton, providing the cell with structure and shape, consists of a complex array of structural proteins, including microtubules, microfilaments and intermediate filaments. Intermediate filaments play a crucial role in mechanotransduction and in providing mechanical stability to cells, in particular under large deformation. By utilizing molecular simulation, here we report a nanomechanical analysis of vimentin intermediate filament dimers, the basic building blocks of intermediate filaments. We describe a detailed analysis of the mechanical properties and associated deformation mechanisms, and find that mechanical stretch induces a transition from alpha-helices to beta-sheets, a phenomenon known as alpha-beta transition. A comparison of the Young's modulus predicted from simulation with experimental measurements is provided, and good agreement is found. We present an analysis of structural changes during deformation, domain unfolding patterns, rate ...
2009-10-21
Motor Proteins Have Highly Correlated Brownian Engines
Two headed motor proteins, such as kinesin and dynein, hidrolyze environmental ATP in order to propel unidirectionally along cytoskeletal filaments such as microtubules. In the case of kinesin, protein heads bind primarily on the alpha tubulin site of asymmetric alpha-beta 8nm-long tubulin dimers that constitute the microtubular protofilaments. Kinesin dimers overcome local binding forces up to 5pN and are known to move on protofilaments with ATP concentration-dependent speeds while hydrolizing on average one ATP molecule per 8nm step. The salient features of protein trajectories are the distinct abrupt usually 8nm-long steps from one tubulin dimer to the next interlaced with long quiescent binding periods at a tubulin site. Discrete walks of this type are characterized by substantially reduced variances compared to pure biased random walks, and as a result rule out flashing-type ratchet models as possible mechanisms for motor movement. On the other hand, simple ...
1998-01-01
Energy Technology Data Exchange (ETDEWEB)
Because of past military operations, lack of upkeep and looting there are now enormous radioactive waste problems in Iraq. These waste problems include destroyed nuclear facilities, uncharacterized radioactive wastes, liquid radioactive waste in underground tanks, wastes related to the production of yellow cake, sealed radioactive sources, activated metals and contaminated metals that must be constantly guarded. Iraq currently lacks the trained personnel, regulatory and physical infrastructure to safely and securely manage these facilities and wastes. In 2005 the International Atomic Energy Agency (IAEA) agreed to organize an international cooperative program to assist Iraq with these issues. Soon after, the Iraq Nuclear Facility Dismantlement and Disposal Program (the NDs Program) was initiated by the U.S. Department of State (DOS) to support the IAEA and assist the Government of Iraq (GOI) in eliminating the threats from poorly controlled radioactive materials. ...
2009-03-01
Those nuclear wastes nobody knows what to do with; Ces dechets nucleaires dont on ne sait que faire
Energy Technology Data Exchange (ETDEWEB)
The important use of nuclear energy in Europe, and in particular in France, has a beneficial impact on the air quality but raises important problems of radioactive waste management. The technical problems encountered by the French government with the dismantling of Superphenix reactor are a good example. Moreover, despite its reassuring talks, the electronuclear industry lobby, particularly powerful, has never been able to propose any satisfactory solution for the elimination of radioactive wastes. This article makes a criticism of the lack of visibility and democratic debate in France about the sensible subject of nuclear waste management. A comparison with the situation in other countries is made. (J.S.)
1998-01-01
Scientific report 1997; Rapport scientifique 1997
Energy Technology Data Exchange (ETDEWEB)
In this book are found technical and scientific papers on the main works of the Direction of the Fuel Cycle (DCC) in France. The study fields are: the up-side of the nuclear fuel cycle with theoretical studies (plasma simulation) and technological developments and instrumentation (lasers diodes, carbides plasma projection, carbon 13 enrichment); the down-side nuclear fuel cycle with theoretical studies (ion Eu{sup 3+} complexation simulation, decay simulation, uranium and plutonium diffusion study, electrolyser operating simulation), scenario studies ( recycling, wastes management), experimental studies; dismantling and cleaning (soils cleaning, surface-active agent for decontamination, fault tree analysis); analysis with expert systems and mass spectrometry. (A.L.B.)
1998-07-01
Practical technological benefits of SRE decommissioning
Energy Technology Data Exchange (ETDEWEB)
The decommissioning of the Sodium Reactor Experiment is essentially complete. Contaminated materials, equipment, and soil were removed, decreasing the residual radioactivity to levels acceptable for future unrestricted use of the site. The fuel was removed and declad, tooling and techniques to support the decommissioning were developed, bulk sodium and residual sodium films were removed, coolant systems were dismantled, the reactor vessel was dissected, the interior surfaces of the facilities were decontaminated, and waste materials were packaged and shipped to burial sites. Radiation exposure to workers and the public was within the guidelines and as low as reasonably achievable. In performing the project, new decontamination techniques were tested, decontamination equipment was evaluated, and waste disposal methods were developed.
1982-01-01
Influence of calcite on the electrokinetic treatment of a natural clay
British Library Electronic Table of Contents (United Kingdom)
After presenting a geochemical model for the interaction between calcite and varying environmental conditions, the paper discusses the experimental results of long duration electrokinetic tests, run on a natural clayey soil in unbuffered conditions. Local measurements of electrical potential, temperature and water flow were performed during the tests, while pH and fluid conductivity were measured locally once the tests had been dismantled. Sharp change of pH and reduction of the soil electrical conductivity, that in pure clays usually occur in the proximity of the cathode, were observed in the region close to the anode. As well, the soil in the anode area systematically tended to develop fractures, that mostly persisted until the end of the experiments. The features observed, that are not ...
2009-01-01
ETE-EVAL: a methodology for D and D cost estimation
International Nuclear Information System (INIS)
In compliance with Article 20 of the sustainable radioactive materials and waste management act dated 28 June 2006, the CEA and AREVA are required every three years to revise the cost of decommissioning their facilities and to provide the necessary assets by constituting a dedicated fund. For the 2007 revision the CEA used ETE-EVAL V5. Similarly, AREVA reevaluated the cost of decontaminating and dismantling its facilities at La Hague, as the previous estimate in 2004 did not take into account the complete cleanup of all the structural work. ETE-EVAL V5 is a computer application designed to estimate the cost of decontamination and dismantling of basic nuclear installations (INB). It has been qualified by Bureau Veritas and audited. ETE-EVAL V5 has become the official software for cost assessment of CEA civilian and AREVA decommissioning projects. It has been used by the DPAD (Decontamination and Dismantling Projects ...
Energy Technology Data Exchange (ETDEWEB)
The study abstracted aims at analyzing the economic effects of energy policies using simulations. Emphasis is on assessing the effects of decisions in favour of an expanding electric power industry based on nuclear energy and hard coal. The study discusses alternative assumptions concerning the cost involved, pollution abatement measures, shutdown and dismantling costs etc. Input-output analyses make the simulation model a consistent vehicle. Besides, the model in question is characterized by its explaining the investment demand of the different sectors by referring to the continuous annual development of innovative technologies.
1986-01-01
Construction progress of the cooling & ventilation in the LHC project
After the LEP dismantling Phase the Cooling and Ventilation Group has started the LHC construction work. Year 2001 through to 2004 will certainly be the most important period of activity for the CV group in the erection phase The author will report on the current works that are in progress on the different LHC Points distinguishing between the Ventilation and the Water Cooling installations. The Ventilation work completed in the new surface buildings in Points 1, 4,5,6 and 8. The work for the Cooling plants comprehend to the pumping stations, the cooling towers and the chilled water production stations in Points 1 and 5, For all of these activities, an updated report of the progress the work, the planning and of the expenses are given. Finally, a brief overview of the future activities is presented.
2002-01-01
Construction Progress of the Cooling and Ventilation in the LHC Project
The Cooling and Ventilation Group has started the LHC construction work in September 1999 and will get into full activity when LEP will be stopped and dismantled: in total 12 major contracts for an amount of about 120 MCHF will be established to build the needed installations for the LHC. The author will report on the current works that are in progress on the different LEP Points distinguishing between the Ventilation and the Water Cooling installations. The Ventilation work, completed in the new surface buildings in Points 18, is currently held in Points 4 and 5. Point 1 will follow in the near future. The work for the Cooling plants comprehend the pumping stations, the cooling towers and the chilled water production stations in Points 1 and 5, the buried pipes in Points 1 and 4. For all of these activities, an updated report of the progress of the work, of the planning and of the expenses is given. Finally, a short overview of the future activities is presented.
2001-01-01
Treatment for dismantled radioactive solid waste from the TRIGA Mark-2 and 3
Energy Technology Data Exchange (ETDEWEB)
Radioactive wastes are generally classified into 3 type depending on their physical property: liquid, solid and gaseous type. State-of -the art concerning liquid waste treatment has already been published; KAERI/TR-1315/99. Solid wastes classification package and treatment method will be studied to effectively manage them during the practical decommissioning work. All of the spent fuel produced during the operation of the TRIGA Mark-2 and 3 have been transported to the US last year, 1998, according to the spent fuel management strategy set-up by the US government for the non-proliferation of nuclear energy. Solid wastes are mainly all equipment existing inside of the reactors, activated concrete among the bio-shielded concrete, pipes, pimps, resin filter and it's housings, heat-exchangers, liquid waste storage tanks, to radioactive waste storage treatment facilities and so on. Solid wastes are generally low-level. They are classified according to the national regulation and ...
1999-06-01
Energy Technology Data Exchange (ETDEWEB)
This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible relationship with the gaseous effluents of ...
2007-07-01
Energy Technology Data Exchange (ETDEWEB)
In order to watch the environment of the construction site of dismantling of the former pipe of releases in sea of Cogema-La Hague, the special and permanent commission of Information near the establishment Cogema of La Hague (C.S.P.I.) asked the association for the radiation monitoring in the West (A.C.R.O.) to realize a specific campaign of measures, on the basis of a protocol accepted by the C.S.P.I.. During the three years of the building work, two significant increases of the concentration in {sup 137}Cs in the marine flora with at most, 9.3 Bq/kg dry, are noticed so be it ten times the concentration that could be measured before the building work begins. We note a net improvement of the situation after the works. The {sup 137}Cs tends finally to disappear. For the sedimentary masses and the sands of beaches, it is outlined no increase of the contamination in {sup 137}Cs (during the works and in posteriori) which translates in a irrefutable way contributions ...
2005-02-15
Energy Technology Data Exchange (ETDEWEB)
Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the injected fuel was adsorbed into the carbon, part of it remained ...
1992-04-01
International Nuclear Information System (INIS)
The main problems arising in decommissioning nuclear-powered submarines (NPS) relate to choosing a concept of handling reactor compartments followed by handling technology development. Reactor compartments (RC) are characterized with extremely space-saving or integral layout of large-size power equipment and systems, restricted access for dismantling, high radiation dose rates in a number of bays of RC. The above RC features pose a problem to find optimum option of RC utilization which on the one hand would be the most cost efficient, and the safest as possible on the other, i.e. dose commitments of personnel involved should be minimum, and effect on population and environment should be negligible. The main radiation factors specifying safety in RC handling at any decommissioning stage are as follows: (1) total radioactivity integrated in reactor facility (RF); (2) distribution of this radioactivity through RF equipment and structures; (3) forms the radioactivity ...
1996-03-10
Overview of the 1995 NATO ARW on nuclear submarine decommissioning and related problems
International Nuclear Information System (INIS)
The NATO Advanced Research Workshop on Nuclear Submarine Decommissioning and Related Problems was held in Moscow June 19--22, 1995. It was preceded by a visit to the Zvezdotchka Shipyard at Severodvinsk, a repair and maintenance yard for Russian nuclear submarines, for a subgroup of the workshop attendees. Most of the material in this paper is drawn directly form the workshop proceedings. Slightly less than 500 nuclear ships and submarines (the vast majority are submarines) have been constructed by the countries with nuclear navies. This includes approximately 250 by Russia, 195 by the United States, 23 by the United Kingdom, 11 by France and 6 by China. By the year 2000 it is expected that approximately one-half of these nuclear vessels will be removed from service and in various states of decommissioning. A newspaper account in June 1997 indicated that 156 Russian nuclear submarines had been removed from service. In August 1996 it was reported that 55 reactor compartment sections ...
1997-11-21
Nigerian Urban Women's Use of Information Media: The Challenges for Women in Leadership
The study surveyed urban women's use of information media and drew attention to the implications for women in leadership positions and non-formal education. A questionnaire containing structured and unstructured items was administered to 300 women resident at Nsukka urban town Enugu State, Nigeria. One hundred and twenty-five usable copies were used for the data analysis. The findings show that oral media are the most popular among women irrespective of level of education and type of occupation. The level of education influenced the use of radio and television. Popular radio and television programmes among women include newscasts, socio-cultural programmes, music and drama. Problems hindering women's use of radio and television include time constraint, poor reception, poor condition of available sets and lack of money for repairs among others. Based on these findings the implication for the achievement of the Universal Basic Education (UBE) objectives with reference to non-formal ...
2008-10-01
Energy Technology Data Exchange (ETDEWEB)
This document describes the geology and hydrogeology at the former Advanced Coal Liquefaction Research and Development (ACLR&D) facility in Wilsonville, Alabama. The work was conducted by personnel from the Oak Ridge National Laboratory Grand Junction office (ORNL/GJ) for the U.S. Department of Energy (DOE) Pittsburgh Energy Technology Center (PETC). Characterization information was requested by PETC to provide baseline environmental information for use in evaluating needs and in subsequent decision-making for further actions associated with the closeout of facility operations. The hydrogeologic conceptual model presented in this report provides significant insight regarding the potential for contaminant migration from the ACLR&D facility and may be useful during other characterization work in the region. The ACLR&D facility is no longer operational and has been dismantled. The site was characterized in three phases: the first two phases were an ...
1996-09-01
Energy Technology Data Exchange (ETDEWEB)
One bundle of Hanaro fuel irradiated up to 50%-burnup and cooled for 6 months was transported to IMEF for PIE, which has 6 elements. At first we measured the longitudinal distribution and the rotational distribution of several dominant peaks intensities from the bundle. After dismantling of the bundle we measured the longitudinal distribution of {sup 137}Cs and {sup 134}Cs peaks in each fuel element to see the burn-up feature. And finally we found out the relative number distribution of {sup 137}Cs and {sup 134}Cs for each detection point, which would be used for burn-up calculation. The relative detection efficiency of the scanning system was obtained experimentally by using the {sup 134}Cs peaks. We also checked up the azimuthal difference of peak intensity for each element, which are resulted about 2% of difference. These data will be used for the further analysis of Hanaro fuel performance evaluation. (author)
1999-09-01
HEMISPHERIC CENTER FOR ENVIRONMENTAL TECHNOLOGY
Energy Technology Data Exchange (ETDEWEB)
FIU-HCET participated in an ICT meeting at Mound during the second week of December and presented a brief videotape of the testing of the Robotic Climber technology. During this meeting, FIU-HCET proposed the TechXtract technology for possible testing at Mound and agreed to develop a five-page proposal for review by team members. FIU-HCET provided assistance to Bartlett Inc. and General Lasertronics Corporation in developing a proposal for a Program Opportunity Notice (PON). The proposal was submitted by these companies on January 5, 1999. The search for new equipment dismantlement technologies is continuing. The following vendors have responded to requests for demonstration: LUMONICS, Laser Solutions technology; CRYO-BEAM, Cryogenic cutting technology; Waterjet Technology Association, Waterjet Cutting technology; and DIAJET, Waterjet Cutting technology. Based on the tasks done in FY98, FIU-HCET is working closely with Numatec Hanford Corporation (NHC) and Pacific ...
1999-01-31
Feasibility of optical sensing for robotics in highly radioactive environments
International Nuclear Information System (INIS)
The application of robotics for repair, refurbishing or dismantling of nuclear installations implies eventually severe radiation resistance requirements on embarked components and subsystems. This is particularly critical when optical sensing is considered. Optoelectronic components and optical fibers are indeed quite sensitive to radiation, and without special design are rapidly out-of-operation in such an environment. This paper reports the results of a series of #gamma# irradiation experiments on such devices, and identify their behavior under radiation. Test results show that carefully selected optical fibers can keep their radiation induced attenuation lower than 0.3 dB/m even up to a total dose of 10 MGy. Temperature annealing can even lower this attenuation down to 0.1 dB/m. On the other hand, commercially available light emitting diodes and photodiodes present attenuations figures up to 15 dB, even after a gamma irradiation as low as 250 kGy. However, ...
1992-10-25
International Nuclear Information System (INIS)
Decommissioning of radiological and nuclear installations is for this century the new challenge. One of the performance criteria is the reduction of total quantities of radioactive materials (liquid or solid) arising from dismantling and decontamination of radiological and nuclear installations. In this work we present a new application of the water soluble polymers used as: - flocculation agents in treatment and conditioning process within the management of radioactive liquid materials; - strippable coatings on solid materials based on the water soluble polymers. The parameters of water soluble polymers made in our Institute by radiation processing have been analysed, namely the molecular average weight, composition, and efficiency of utilization of these polymeric materials as well as the content of ash, additives, decontamination factor, consumption per surfaces/liter, corrosion aspects, compatibility with various surfaces (of metal, concrete, plastics, etc). ...
2003-10-20
Energy Technology Data Exchange (ETDEWEB)
The contribution is concerned from a legal point of view with the systematic recording, classification and assessment of specific problems concerning the post-operational phase of a nuclear power plant. As an introduction, present experience with decommissioning in the Federal Republic of Germany is dealt with. The first part treats the factual side of section 7 III AtG, explains the terms mentioned, the concrete extent of licensing and priority relations. In part 2 the preconditions for licensing pursuant to section 7 III AtG are dealt with, the stipulations of which are made difficult in particular on account of the reference in section 7 III sentence 2 AtG. The third part is concerned with the legal consequence of section III AtG, i.e. the extent of official discretionary powers, whereby aspects of radioactive waste management carry great weight. In part four administrative and procedural particularities in the legal sense relating to licensing according to section III AtG are ...
1990-01-01
International Nuclear Information System (INIS)
Many mechanical parts are subjected to stresses and strains that may eventually lead to their failure. In order to prevent the costly delays associated with equipment down-time, many parts have to be tested for weaknesses and defects when machinery is constructed or dismantled for maintenance. These procedures are known as Non-Destructive Testing (NDT) methods. Five types of non-destructive testing methods routinely used are radiographic testing, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. Out of these five techniques industrial radiography plays an important role in non-destructive testing to reveal interior defects in materials. In radiography almost two-thirds of the radiation reaching the film is scattered radiation which does not form the image of defects. Scattered radiation generated inside and outside a material has a very large effect on sensitivity of flaw detection since it reduces image contrast. ...
1998-02-01
The German-Russian project that is part of the G8 initiative on Global Partnership Against the Spread of Weapons and Materials of Mass Destruction focuses on the speedy construction of a land-based interim storage facility for nuclear submarine reactor compartments at Sayda Bay near Murmansk. This project includes the required infrastructure facilities for long-term storage of about 150 reactor compartments for a period of about 70 years. The interim storage facility is a precondition for effective activities of decommissioning and dismantlement of almost all nuclear-powered submarines of the Russian Northern Fleet. The project also includes the establishment of a computer-assisted waste monitoring system. In addition, the project involves clearing Sayda Bay of other shipwrecks of the Russian navy. On the German side the project is carried out by the Energiewerke Nord GmbH (EWN) on behalf of the Federal Ministry of Economics and Labour (BMWi). On the Russian side ...
2007-07-01
Gel-based proteomics of liver cancer progression in rat.
A significant challenge in proteomics biomarker research is to identify the changes that are of highest diagnostic interest, among the many unspecific aberrations associated with disease burden and inflammation. In the present study liver tissue specimens (n=18) from six experimental stages were collected from the resistant hepatocyte (RH) rat model of liver cancer and analyzed by 2D DIGE. The study included triplicates of regenerating liver, control "sham-operated" liver, three distinct premalignant stages and hepatomas. Out of 81 identified proteins two-thirds were differentially abundant in rat hepatomas compared to control rat liver and, secondly, the majority of proteins were also changed in precursor stages. This underscores the importance of adequate control samples in explorative cancer biomarker research. We confirm several proteomic changes previously identified in human hepatocellular carcinoma (HCC) and we identify novel candidate proteomic aberrations for further analysis ...
2011-06-06
The performance tests used the water scrubber for ruthenium rejection
Energy Technology Data Exchange (ETDEWEB)
LEDF (Large Equipment Dismantling Facility) will be constructed for the purpose of decontaminating the high level {alpha} solid waste generated in oarai engineering center of JNC. And, main processing process of LEDF is incineration and melting system. LEDF will be intended to reduce the secondary waste that occurs along with the operation of the off gas processing equipment of incineration and melting system. It assumed that we are able to eliminate the adsorption tower using silica gel, if the decontamination factor to volatile ruthenium is able to expect in the packed scrubber that is established to remove harmful gas. Thereupon, we carried out this tests that eliminates the adsorption tower and reduces the secondary waste. The decontamination factor (DF) to the volatile ruthenium by the water scrubber is confirmed in the established institution which is in Tokai Works. However, decontamination factor differs and depends on the ruthenium concentration, harmful ...
2002-11-01
The performance tests used the water scrubber for ruthenium rejection
International Nuclear Information System (INIS)
LEDF (Large Equipment Dismantling Facility) will be constructed for the purpose of decontaminating the high level #alpha# solid waste generated in oarai engineering center of JNC. And, main processing process of LEDF is incineration and melting system. LEDF will be intended to reduce the secondary waste that occurs along with the operation of the off gas processing equipment of incineration and melting system. It assumed that we are able to eliminate the adsorption tower using silica gel, if the decontamination factor to volatile ruthenium is able to expect in the packed scrubber that is established to remove harmful gas. Thereupon, we carried out this tests that eliminates the adsorption tower and reduces the secondary waste. The decontamination factor (DF) to the volatile ruthenium by the water scrubber is confirmed in the established institution which is in Tokai Works. However, decontamination factor differs and depends on the ruthenium concentration, harmful ...
Stationary low power reactor No. 1 (SL-1) accident site decontamination & dismantlement project
The Army Reactor Area (ARA) II was constructed in the late 1950s as a test site for the Stationary Low Power Reactor No. 1 (SL-1). The SL-1 was a prototype power and heat source developed for use at remote military bases using a direct cycle, boiling water, natural circulation reactor designed to operate at a thermal power of 3,000 kW. The ARA II compound encompassed 3 acres and was comprised of (a) the SL-1 Reactor Building, (b) eight support facilities, (c) 50,000-gallon raw water storage tank, (d) electrical substation, (e) aboveground 1,400-gallon heating oil tank, (f) underground 1,000-gallon hazardous waste storage tank, and (g) belowground power, sewer, and water systems. The reactor building was a cylindrical, aboveground facility, 39 ft in diameter and 48 ft high. The lower portion of the building contained the reactor pressure vessel surrounded by gravel shielding. Above the pressure vessel, in the center portion of the building, was a turbine generator and plant support ...
1995-11-01
Radiological characterization of the GRR-1 pool
International Nuclear Information System (INIS)
GRR-1 is a 5MW open pool type research reactor with MTR-type fuel elements cooled and moderated by light water with beryllium reflectors at the two opposing sides of the core. A graphite thermal neutron column is adjusted to one side of the core. Six radial horizontal beam tubes are available, of which three contain in-pile collimators for neutron scattering instruments. The reactor is currently out of operation for inspection and refurbishment purposes. The core has been dismantled and the fuel elements are stored in the used fuel storage tank. The GRR-1 inspection and refurbishment plan involves inspection and eventually replacement of the reactor's primary cooling circuit. The health physics procedures to be implemented during inspection of the main water outlet are divided in three stages: a) pool dose rate survey from pool top, b) pool drainage by decreasing water level in steps and c) inspection of the water main outlet. urpose of the present work is the ...
2007-11-05
Fabrication of zircon for disposition of weapons plutonium
International Nuclear Information System (INIS)
This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). In an effort to address the problems of long term storage and nuclear waste minimization, zircon has been proposed as a host medium for plutonium and other actinides recovered from dismantled nuclear weapons. The objective of this work is to investigate the feasibility of large scale fabrication of Pu-bearing zircon. Since PuO_2 is thermodynamically less stable than ZrO_2, it is expected that the process parameters determined for synthesizing ZrSiO_4 (zircon) would be applicable to those for PuSiO_4 (Pu-zircon). Furthermore, since the foremost concern in plutonium processing is the potential for contamination release, this work emphasizes the development of process parameters, using zircon first, to anticipate potential material problems in the containment system for reaction mixtures during processing. Stoichiometric ...
International Nuclear Information System (INIS)
The Department of Energy (DOE), Western Area Power Administration (Western) proposes to consolidate segments of two transmission lines near the Gering Substation in Gering, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska, within the city of Gering. Presently, there are three parallel 115-kilovolt (kV) transmission lines on separate rights-of-way (ROW) that terminate at the Gering Substation. The project would include dismantling the Archer-Gering wood-pole transmission line and rebuilding the remaining two lines on single-pole steel double circuit structures. The project would consolidate the Gering-Stegall North and Gering-Stegall South 115-kV transmission lines on to one ROW for a 1.33-mile segment between the Gering Substation and a point west of the Gering Landfill. All existing wood-pole H-frame structures would be removed, and the Gering-Stegall North ...
1999-05-01
Energy Technology Data Exchange (ETDEWEB)
The Department of Energy (DOE), Western Area Power Administration (Western) proposes to consolidate segments of two transmission lines near the Gering Substation in Gering, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska, within the city of Gering. Presently, there are three parallel 115-kilovolt (kV) transmission lines on separate rights-of-way (ROW) that terminate at the Gering Substation. The project would include dismantling the Archer-Gering wood-pole transmission line and rebuilding the remaining two lines on single-pole steel double circuit structures. The project would consolidate the Gering-Stegall North and Gering-Stegall South 115-kV transmission lines on to one ROW for a 1.33-mile segment between the Gering Substation and a point west of the Gering Landfill. All existing wood-pole H-frame structures would be removed, and the Gering-Stegall North ...
1995-05-01
Development of low-level liquid-waste treatment systems: April-September 1982
Energy Technology Data Exchange (ETDEWEB)
A preliminary investigation was conducted on ion specific membranes. This investigation concentrated on testing candidate organic compounds for transporting cesium ions through a membrane composed of the organic compound supported on a substrate. Solid PVC membranes were initially tried, but were found to be too slow. Thereafter, only liquid membranes were tested. These were faster and cesium concentration factors up to 2.96 were achieved in a single membrane cell. A cell with two membranes achieved a cesium concentration factor of 4.19. Cesium precipitation with sodium tetraphenyl borate in high sodium concentrations was explored. No interference from sodium was found until the sodium nitrite concentration reached 4.5 moles. Concurrently, cesium concentrations as high as 5.4 g/L were precipitated. Potassium tetraphenyl borate is being investigated for use in exchange columns for the removal of cesium from solutions. Initial investigations show that cesium removal is affected by (K/sup ...
1982-12-22
Development of low-level liquid-waste treatment systems: April-September 1982
International Nuclear Information System (INIS)
A preliminary investigation was conducted on ion specific membranes. This investigation concentrated on testing candidate organic compounds for transporting cesium ions through a membrane composed of the organic compound supported on a substrate. Solid PVC membranes were initially tried, but were found to be too slow. Thereafter, only liquid membranes were tested. These were faster and cesium concentration factors up to 2.96 were achieved in a single membrane cell. A cell with two membranes achieved a cesium concentration factor of 4.19. Cesium precipitation with sodium tetraphenyl borate in high sodium concentrations was explored. No interference from sodium was found until the sodium nitrite concentration reached 4.5 moles. Concurrently, cesium concentrations as high as 5.4 g/L were precipitated. Potassium tetraphenyl borate is being investigated for use in exchange columns for the removal of cesium from solutions. Initial investigations show that cesium removal is affected by [K"+] ...
A.C.R.O. activity report 2001; A.C.R.O. rapport d'activite 2001
Energy Technology Data Exchange (ETDEWEB)
As regards the environmental protection, the A.C.R.O. maintained in 2001 its programs of surveillance around the main western nuclear installations of France. The radioecological surveillance of the site of Cogema La-Hague for the dismantling of the former pipe of release in sea was one of the key points of this action environmental surveillance. The two accidents of atmospheric release in may and october 2001 at Cogema La Hague have shown the interest of an association as A.C.R.O.. It is thank to the measure, by our laboratory, of repercussions on environment of these incidents that it has been possible to bring to light a dysfunction of the measurement system of the gaseous effluents released by the facility operator. To improve the public information, A.C.R.O. concerns its main efforts on the development of the consumer technical information available on-line via its web site and in its regular publication 'the nuclear chronicle'. Besides, the ...
2001-07-01
Energy Technology Data Exchange (ETDEWEB)
LEDF(Large Equipment Dismantling Facility) is the solid waste processing technology development facility that carries out high-volume reduction and low dosage processing. The high-volume reduction processing of the high dose {alpha}-waste configured with combustible waste, pvc and rubber, spent ion exchange resin, and noncombustible waste have been planned the incinerating and melting facility using the in-can type high frequency induction heating in LEDF. This test is intended to clarify the design data. It was confirmed that the incinerating and melting performance, molten solid properties and exhaust gas processing performance with pilot testing equipment and bench scale equipment. The result of this test are as follows. 1. Processing speed is 6.7 kg/h for the combustible waste, 13.0 kg/h for the ion exchange resin, and 30.0 kg/h for the noncombustible waste. For above optimum processing conditions are as follows. Operating temperature is 1000degC for the ...
1999-12-01
TRITEX. A ferritic steel loop with Pb-15.8Li. Facility and operation
Energy Technology Data Exchange (ETDEWEB)
TRITEX was a pumped loop with Pb-15.8Li, fabricated from steel 1.4922. In contact with the molten eutectic were also molybdenum, vanadium and armco-iron. The loop was originally designed to investigate tritium extraction using solid getter metals. Over the years the goal changed to the study of metals, corrosion products and purification of the eutectic mixture. Therefore many modifications were done. The first part of this report describes TRITEX. All parts were enclosed in thermoboxes for a homogeneous temperature. One test section was in an argon glove box and could be opened during operation. Other special equipment`s were: permeation membranes and liquid-metal-covergas-interfaces to study the transport of H{sub 2}, D{sub 2} and {sup 3}H, different purification devices, a quartz observation window to see the liquid metal surface, 4 different kinds of flow measurements, level indicators, freeze valves. The second part describes loop operation. Between 1989 and 1996, the eutectic ...
1999-05-01
Challenges for Lithuania: Ignalina NPP Early Closure
International Nuclear Information System (INIS)
As a condition of accession into the European Union (EU), Lithuania is committed to the closure and decommissioning of Ignalina NPP comprising two RBMK-1500 reactor units (Fig. 1). It was agreed in a special protocol to the Accession Treaty that, in return for adequate EU financial assistance, Unit 1 would be closed before 2005 and Unit 2 by the end of 2009. The first unit was duly shut down on December 31, 2004. Lithuania, which has borders with Russia (Kaliningrad territory), Poland, Latvia and Belarus, spent fifty years as part of the Soviet Union and was deeply integrated into its economy and electrical infrastructure. At the break-up of the USSR, Lithuania inherited electricity generating capacity designed to supply the north-west region including ownership of Ignalina NPP located in the north-east of the country. Ignalina NPP Unit 1 was commissioned in 1983, Unit 2 in 1987; the planned lifespan of each unit was 30 years. Construction of a third unit was started but never ...
2008-01-01
Website Policies and Important Links Comments
WorldWideScience.org is maintained by the U.S. Department of Energy's
Office of Scientific and Technical Information as the Operating Agent
for the WorldWideScience Alliance.
