Task-failure-driven rebalancing of disassembly lines

OpenAIRE

Altekin, Fatma Tevhide; Akkan, Can

2011-01-01

Many reverse-logistics systems that collect and reprocess end-of-life products require a disassembly stage. The nature of variability in incoming products, and damages, which are more likely to occur during disassembly than assembly, create a significant uncertainty in disassembly tasks, namely, possibility of failed tasks. Such failures may lead to some successor tasks being infeasible, which changes work contents of downstream stations. To improve the profitability of such a disassembly lin...

Generation of control sequences for a pilot-disassembly system

Science.gov (United States)

Seliger, Guenther; Kim, Hyung-Ju; Keil, Thomas

2002-02-01

Closing the product and material cycles has emerged as a paradigm for industry in the 21st century. Disassembly plays a key role in a life cycle economy since it enables the recovery of resources. A partly automated disassembly system should adapt to a large variety of products and different degrees of devaluation. Also the amounts of products to be disassembled can vary strongly. To cope with these demands an approach to generate on-line disassembly control sequences will be presented. In order to react on these demands the technological feasibility is considered within a procedure for the generation of disassembly control sequences. Procedures are designed to find available and technologically feasible disassembly processes. The control system is formed by modularised and parameterised control units in the cell level within the entire control architecture. In the first development stage product and process analyses at the sample product washing machine were executed. Furthermore a generalized disassembly process was defined. Afterwards these processes were structured in primary and secondary functions. In the second stage the disassembly control at the technological level was investigated. Factors were the availability of the disassembly tools and the technological feasibility of the disassembly processes within the disassembly system. Technical alternative disassembly processes are determined as a result of availability of the tools and technological feasibility of processes. The fourth phase was the concept for the generation of the disassembly control sequences. The approach will be proved in a prototypical disassembly system.

Impact of different disassembly line balancing algorithms on the performance of dynamic kanban system for disassembly line

Science.gov (United States)

Kizilkaya, Elif A.; Gupta, Surendra M.

2005-11-01

In this paper, we compare the impact of different disassembly line balancing (DLB) algorithms on the performance of our recently introduced Dynamic Kanban System for Disassembly Line (DKSDL) to accommodate the vagaries of uncertainties associated with disassembly and remanufacturing processing. We consider a case study to illustrate the impact of various DLB algorithms on the DKSDL. The approach to the solution, scenario settings, results and the discussions of the results are included.

Multikanban model for disassembly line with demand fluctuation

Science.gov (United States)

Udomsawat, Gun; Gupta, Surendra M.; Al-Turki, Yousef A. Y.

2004-02-01

In recent years, the continuous growth in consumer waste and dwindling natural resources has seriously threatened the environment. Realizing this, several countries have passed regulations that force manufacturers not only to manufacture environmentally conscious products, but also to take back their used products from consumers so that the components and materials recovered from the products may be reused and/or recycled. Disassembly plays an important role in product recovery. A disassembly line is perhaps the most suitable setting for disassembly of products in large quantities. Because a disassembly line has a tendency to generate excessive inventory, employing a kanban system can reduce the inventory level and let the system run more efficiently. A disassembly line is quite different from an assembly line. For example, not only can the demand arrive at the last station, it can also arrive at any of the other stations in the system. The demand for a component on the disassembly line could fluctuate widely. In fact, there are many other complicating matters that need to be considered to implement the concept of kanbans in such an environment. In this paper, we discuss the complications that are unique to a disassembly line. We discuss the complications in utilizing the conventional production control mechanisms in a disassembly line setting. We then show how to overcome them by implementing kanbans in a disassembly line setting with demand fluctuation and introduce the concept of multi-kanban mechanism. We demonstrate its effectiveness using a simulation model. An example is presented to illustrate the concept.

AGC-2 Disassembly Report

Energy Technology Data Exchange (ETDEWEB)

William Windes

2014-05-01

The Next Generation Nuclear Plant (NGNP) Graphite Research and Development (R&D) Program is currently measuring irradiated material properties for predicting the behavior and operating performance of new nuclear graphite grades available for use within the cores of new very high temperature reactor designs. The Advanced Graphite Creep (AGC) experiment, consisting of six irradiation capsules, will generate irradiated graphite performance data for NGNP reactor operating conditions. The AGC experiment is designed to determine the changes to specific material properties such as thermal diffusivity, thermal expansion, elastic modulus, mechanical strength, irradiation induced dimensional change rate, and irradiation creep for a wide variety of nuclear grade graphite types over a range of high temperature, and moderate doses. A series of six capsules containing graphite test specimens will be used to expose graphite test samples to a dose range from 1 to 7 dpa at three different temperatures (600, 900, and 1200°C) as described in the Graphite Technology Development Plan. Since irradiation induced creep within graphite components is considered critical to determining the operational life of the graphite core, some of the samples will also be exposed to an applied load to determine the creep rate for each graphite type under both temperature and neutron flux. All six AGC capsules in the experiment will be irradiated in the Advanced Test Reactor (ATR). AGC-1 and AGC-2 will be irradiated in the south flux trap and AGC-3–AGC-6 will be irradiated in the east flux trap. The change in flux traps is due to NGNP irradiation priorities requiring the AGC experiment to be moved to accommodate Fuel irradiation experiments. After irradiation, all six AGC capsules will be cooled in the ATR Canal, sized for shipment, and shipped to the Materials and Fuels Complex (MFC) where the capsule will be disassembled in the Hot Fuel Examination Facility (HFEF). During disassembly, the metallic

The effect of sudden server breakdown on the performance of a disassembly line

Science.gov (United States)

Udomsawat, Gun; Gupta, Surendra M.

2005-11-01

Product and material recovery relies on the disassembly process to separate target components or materials from the end-of-life (EOL) products. Disassembly line is especially effective when products in large quantity are disassembled. Unlike an assembly line, a disassembly line is more complex and is subjected to numerous uncertainties including stochastic and multi-level arrivals of component demands, stochastic arrival times for EOL products, and process interruption due to equipment failure. These factors seriously impair the control mechanism in the disassembly line. A common production control mechanism is the traditional push system (TPS). TPS responds to the aforementioned complications by carrying substantial amounts of inventories. An alternative control mechanism is a newly developed multi-kanban pull system (MKS) that relies on dynamic routing of kanbans, which tends to minimize the system's inventories while maintaining demand serviceability. In this paper we explore the impact of sudden breakdown of server on the performance of a disassembly line. We compare the overall performances of the TPS and MKS by considering two scenarios. We present the solution procedure and results for these cases.

Disassembly automation automated systems with cognitive abilities

CERN Document Server

Vongbunyong, Supachai

2015-01-01

This book presents a number of aspects to be considered in the development of disassembly automation, including the mechanical system, vision system and intelligent planner. The implementation of cognitive robotics increases the flexibility and degree of autonomy of the disassembly system. Disassembly, as a step in the treatment of end-of-life products, can allow the recovery of embodied value left within disposed products, as well as the appropriate separation of potentially-hazardous components. In the end-of-life treatment industry, disassembly has largely been limited to manual labor, which is expensive in developed countries. Automation is one possible solution for economic feasibility. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

A reactor vessel and its internals disassembled and packaged

International Nuclear Information System (INIS)

Eisenmann, B.; Prechtl, E.; Suessdorf, W.

2008-01-01

2007 was a successful year for the Disassembly Unit of the Karlsruhe Research Center: dismantling the highly activated Karlsruhe Multipurpose Research Reactor (MZFR) was completed successfully and without any incident. A vote of thanks is expressed at this point to all staff members, participating industries and institutions for their extraordinary commitment and their outstanding innovation and work. Preserving and advancing existing knowledge is one of the important pillars securing a sustainable future for generations to come in Germany. Securing and advancing know-how in nuclear technology was defined as a major duty last in late January 2008 by Dr. Peter Fritz, Chairman of the Kerntechnische Gesellschaft e.V. (KTG) and member of the Executive Board of the Karlsruhe Research Center, for instance, in cooperation between the KERNTECHNIK (i.e. nuclear technology) Southwestern Research and Teaching Association and the Karlsruhe Institute of Technology (KIT). The borders of Germany do not constitute a natural radiological barrier, despite the efforts by political groups in this country to convey this impression. This report therefore is to document that the demolition of a nuclear reactor with a high radioactivity inventory can be managed safely. In the light of the experience accumulated with the MZFR, this is feasible only if demolition is carried out immediately instead of the 'problem' of disassembly and conditioning being shifted to future generations. The article is also meant to be a piece of advice by showing the unplannable difficulties which came up, and the technical solutions implemented by the competence team successfully and efficiently. (orig.)

Theoretical interpretation of high-energy nuclear collisions

International Nuclear Information System (INIS)

Fai, G.

1990-08-01

In the following, I briefly summarize the research results and progress under this project in the time period January 1, 1988--July 31, 1990. Published and unpublished research in this time period focused on aspects of nuclear disassembly, nuclear dynamics, and subnucleonic degrees of freedom in model field theories

Recycling of electrical motors by automatic disassembly

Science.gov (United States)

Karlsson, Björn; Järrhed, Jan-Ove

2000-04-01

This paper presents a robotized workstation for end-of-life treatment of electrical motors with an electrical effect of about 1 kW. These motors can, for example, be found in washing machines and in industry. There are two main steps in the work. The first step is an inspection whereby the functionality of the motor is checked and classification either for re-use or for disassembly is done. In the second step the motors classified for disassembly are disassembled in a robotized automatic station. In the initial step measurements are performed during a start-up sequence of about 1 s. By measuring the rotation speed and the current and voltage of the three phases of the motor classification for either reuse or disassembly can be done. During the disassembly work, vision data are fused in order to classify the motors according to their type. The vision system also feeds the control system of the robot with various object co-ordinates, to facilitate correct operation of the robot. Finally, tests with a vision system and eddy-current equipment are performed to decide whether all copper has been removed from the stator.

Pit disassembly and conversion demonstration environmental assessment and research and development activities

International Nuclear Information System (INIS)

1998-08-01

A significant portion of the surplus plutonium is in the form of pits, a nuclear weapons component. Pits are composed of plutonium which is sealed in a metallic shell. These pits would need to be safely disassembled and permanently converted to an unclassified form that would be suitable for long-term disposition and international inspection. To determine the feasibility of an integrated pit disassembly and conversion system, a Pit Disassembly and Conversion Demonstration is proposed to take place at the Los Alamos National Laboratory (LANL). This demonstration would be done in existing buildings and facilities, and would involve the disassembly of up to 250 pits and conversion of the recovered plutonium to plutonium metal ingots and plutonium dioxide. This demonstration also includes the conversion of up to 80 kilograms of clean plutonium metal to plutonium dioxide because, as part of the disposition process, some surplus plutonium metal may be converted to plutonium dioxide in the same facility as the surplus pits. The equipment to be used for the proposed demonstration addressed in this EA would use some parts of the Advanced Recovery and Integrated Extraction System (ARIES) capability, other existing equipment/capacities, plus new equipment that was developed at other sites. In addition, small-scale R and D activities are currently underway as part of the overall surplus plutonium disposition program. These R and D activities are related to pit disassembly and conversion, MOX fuel fabrication, and immobilization (in glass and ceramic forms). They are described in Section 7.0. On May 16, 1997, the Office of Fissile Materials Disposition (MD) notified potentially affected states and tribes that this EA would be prepared in accordance with NEPA. This EA has been prepared to provide sufficient information for DOE to determine whether a Finding of No Significant Impact (FONSI) is warranted or whether an EIS must be prepared

Illustrating the disassembly of 3D models

KAUST Repository

Guo, Jianwei; Yan, Dongming; Li, Er; Dong, Weiming; Wonka, Peter; Zhang, Xiaopeng

2013-01-01

We present a framework for the automatic disassembly of 3D man-made models and the illustration of the disassembly process. Given an assembled 3D model, we first analyze the individual parts using sharp edge loops and extract the contact faces

Disassembly and removal of sodium instrumentation test loop

International Nuclear Information System (INIS)

Ishikawa, Okinobu; Onojima, Takamitu; Nagai, Keiichi

2000-07-01

In 1999, the Sodium Instrumentation Test Loop was disassembled and removed. This report describes the tasks and experiences obtained in removing sodium from a storage tank, disassembling, and cleansing components and related activities. Overall the disassembly, handling and cleansing tasks proceeded as planned and the activities were carried out efficiently and safely. Documentation of the process is meant to establish not only a procedure, but also a guideline for future similar tasks. (author)

A Label Correcting Algorithm for Partial Disassembly Sequences in the Production Planning for End-of-Life Products

Directory of Open Access Journals (Sweden)

Pei-Fang (Jennifer Tsai

2012-01-01

Full Text Available Remanufacturing of used products has become a strategic issue for cost-sensitive businesses. Due to the nature of uncertain supply of end-of-life (EoL products, the reverse logistic can only be sustainable with a dynamic production planning for disassembly process. This research investigates the sequencing of disassembly operations as a single-period partial disassembly optimization (SPPDO problem to minimize total disassembly cost. AND/OR graph representation is used to include all disassembly sequences of a returned product. A label correcting algorithm is proposed to find an optimal partial disassembly plan if a specific reusable subpart is retrieved from the original return. Then, a heuristic procedure that utilizes this polynomial-time algorithm is presented to solve the SPPDO problem. Numerical examples are used to demonstrate the effectiveness of this solution procedure.

Disassembly for remanufacturing: A systematic literature review, new model development and future research needs

Directory of Open Access Journals (Sweden)

Anjar Priyono

2016-11-01

develop an index of factors affecting disassembly, and how to most appropriate relationship between original equipment manufacturers and contract remanufacturers to share knowledge gained from remanufacturing operations to improve product remanufacturability. Practical implications: Remanufacturers should not focus on product attributes only in order to manage their disassembly process efficiently. Rather, more strategic factors such organisational factors and process choices should also be considered as well. Originality/value: This is the first study that identifies a comprehensive factors affecting disassembly in remanufacturing. In addition, it is for the first time that disassembly is not only viewed as a physical activity, but it is a process that consists of a series of step.

Disassembly for remanufacturing: A systematic literature review, new model development and future research needs

International Nuclear Information System (INIS)

Priyono, A.; Ijomah, W.; Bititci, U.

2016-01-01

factors affecting disassembly, and how to most appropriate relationship between original equipment manufacturers and contract remanufacturers to share knowledge gained from remanufacturing operations to improve product remanufacturability. Practical implications: Remanufacturers should not focus on product attributes only in order to manage their disassembly process efficiently. Rather, more strategic factors such organisational factors and process choices should also be considered as well. Originality/value: This is the first study that identifies a comprehensive factors affecting disassembly in remanufacturing. In addition, it is for the first time that disassembly is not only viewed as a physical activity, but it is a process that consists of a series of step.

Disassembly for remanufacturing: A systematic literature review, new model development and future research needs

Energy Technology Data Exchange (ETDEWEB)

Priyono, A.; Ijomah, W.; Bititci, U.

2016-07-01

factors affecting disassembly, and how to most appropriate relationship between original equipment manufacturers and contract remanufacturers to share knowledge gained from remanufacturing operations to improve product remanufacturability. Practical implications: Remanufacturers should not focus on product attributes only in order to manage their disassembly process efficiently. Rather, more strategic factors such organisational factors and process choices should also be considered as well. Originality/value: This is the first study that identifies a comprehensive factors affecting disassembly in remanufacturing. In addition, it is for the first time that disassembly is not only viewed as a physical activity, but it is a process that consists of a series of step.

Hybrid disassembly system for cellular telephone end-of-life treatment

Energy Technology Data Exchange (ETDEWEB)

Kniebel, M.; Basdere, B.; Seliger, G. [Technical Univ. Berlin, Inst. for Machine Tools and Factory Management, Dept. of Assembly Technology and Factory Management, Berlin (Germany)

2004-07-01

Concern over the negative environmental impacts associated with the production, use, and end-of-life (EOL) of cellular telephones is particularly high due to large production volumes and characteristically short time scales of technological and stylistic obsolescence. Landfilled or incinerated cellular telephones create the potential for release of toxic substances. The European legislation has passed the directive on Waste of Electrical and Electronic Equipment (WEEE) to regulate their collection and appropriate end-of-life treatment. Manufacturers must conduct material recycling or remanufacturing processes to recover resources. While recovery rates can hardly be met economically by material recycling, remanufacturing and reusing cellular phones is developing into a reasonable alternative. Both end-of-life options require disassembly processes for WEEE compliant treatment. Due to the high number of different cell phone variants and their typical design that fits components into tight enclosing spaces, cellular phone disassembly becomes a challenging task. These challenges and the expected high numbers of phones to be returned in the course of the WEEE urges for automated disassembly. A hybrid disassembly system has been developed to ensure the mass-treatment of obsolete cellular phones. It has been integrated into a prototypical remanufacturing factory for cellular phones that has been planned based on market data. (orig.)

The United States pit disassembly and conversion project -- Meeting the MOX fuel specification

International Nuclear Information System (INIS)

Nelson, T.O.; James, C.A.; Kolman, D.G.

1998-01-01

The US is actively involved in demonstrating the disassembly of nuclear weapons pits to an unclassified form readied for disposition. The MOX option is the most likely path forward for plutonium that originated from nuclear weapon pits. The US demonstration line for pit disassembly and conversion is known as ARIES, the advanced recovery and integrated extraction system. The ARIES demonstration line is being used to gather data in an integrated fashion of the technologies needed for pit disassembly and conversion. These activities include the following modules: pit bisection, hydride-dehydride, oxide conversion, canning, electrolytic decontamination, and nondestructive assay (NDA). Pit bisection swages in a pit in half. Hydride-dehydride converts the pit plutonium metal to an unclassified metal button. To convert the plutonium metal to an oxide the US is investigating a number of options. The primary oxide conversion approach involves variations of combining plutonium hydriding and subsequent oxidation. Another approach is to simply oxidize the metal under controlled conditions-direct metal oxidation (DMO). To remove the gallium from the plutonium oxide, a thermal distillation approach is being used. These pyrochemical approaches will substantially reduce the wastes produced for oxide conversion of weapon plutonium, compared to traditional aqueous processing. The packaging of either the plutonium metal or oxide to long term storage criteria involves the canning and electrolytic decontamination modules. The NDA suite of instruments is then used to assay the material in the containers, which enables international verification without the need to open the containers and repackage them. All of these processes are described

Multi-kanban mechanism for appliance disassembly

Science.gov (United States)

Udomsawat, Gun; Gupta, Surendra M.

2005-11-01

The use of household appliances continues to rise every year. A significant number of End-Of-Life (EOL) appliances are generated because of the introduction of newer models that are more attractive, efficient and affordable. Others are, of course, generated when they become non-functional. Many regulations encourage recycling of EOL appliances to reduce the amount of waste sent to landfills. In addition, EOL appliances offer the appliance manufacturing and remanufacturing industries a source of less expensive raw materials and components. For this reason product recovery has become a subject of interest during the past decade. In this paper, we study the disassembly line for appliance disassembly. We discuss and incorporate some of the complications that are inherent in disassembly line including product arrival, demand arrival, inventory fluctuation and production control mechanisms. We show how to overcome such complications by implementing a multi-kanban system in the appliance disassembly line setting. The multi-kanban system (MKS) relies on dynamic routing of kanbans according to the state of the system. We investigate the multi-kanban mechanism using simulation and explore the effect of product mix on performance of the traditional push system (TPS) and MKS in terms of controlling the system's inventory while attempting to achieve a decent customer service level.

Shape memory polymer nanocomposites for application of multiple-field active disassembly: experiment and simulation.

Science.gov (United States)

Carrell, John; Zhang, Hong-Chao; Wang, Shiren; Tate, Derrick

2013-11-19

Active disassembly (AD) uses innovative materials that can perform a designed disassembly action by the application of an external field. AD provides improvements over current disassembly processes by limiting machine or manual labor and enabling batch processing for end-of-life products. With improved disassembly operations, more reuse of components and purer recycling streams may be seen. One problem with AD, however, has been with the single-field actuation because of the probability of accidental disassembly. This presentation will discuss the application of shape memory polymer (SMP) nanocomposites in a new AD process. This novel AD process requires multiple-field actuation of the SMP nanocomposite fastener. In the analysis of this AD process, thermal and magnetic field tests were performed on the SMP nanocomposite. From these tests, finite-element analysis was performed to model and simulate the multiple-field AD process. The results of the simulations provide performance variables for the AD process and show a better performance time for the SMP nanocomposite fastener than for a comparable SMP fastener.

Methods for otpimum and near optimum disassembly sequencing

NARCIS (Netherlands)

Lambert, A.J.D.; Gupta, S.M.

2008-01-01

This paper considers disassembly sequencing problems subjected to sequence dependent disassembly costs. In practice, the methods for dealing with such problems rely mainly on metaheuristic and heuristic methods, which intrinsically generate suboptimum solutions. Exact methods are NP-hard and

Mathematical and Simulation Modelling of Moisture Diffusion Mechanism during Plastic IC Packages Disassembly

Directory of Open Access Journals (Sweden)

Peng Mou

2013-01-01

Full Text Available Reuse of plastic IC packages disassembled from printed circuit boards (PCBs has significant environmental benefits and economic value. The interface delamination caused by moisture diffusion is the main failure mode of IC packages during the disassembling process, which greatly reduces the reusability and reliability of disassembled IC packages. Exploring moisture diffusion mechanism is a prerequisite to optimize prebaking processes before disassembling that is an effective way to avoid the interface delamination. To this end, a computational model with variable boundary conditions is developed based on the different combination state of water in IC packages. The distribution characteristics and mechanism of moisture diffusion behavior are analyzed including the humidity distribution field and the relation among baking temperature, water loss rate, and baking time during baking process, and then the results are validated by FEA simulation based on the improved definition of relative moisture concentration. Baking under variable temperature is proposed and compared with the baking process and baking efficiency under constant temperature to find out the optimized baking parameters. Finally, a set of curves which indicate the relation between baking energy consumption and temperature are determined under actual industrial baking experiments, which could be used as references to develop industrial standards for PCB disassembling process.

An Intelligent Agent-Controlled and Robot-Based Disassembly Assistant

Science.gov (United States)

Jungbluth, Jan; Gerke, Wolfgang; Plapper, Peter

2017-09-01

One key for successful and fluent human-robot-collaboration in disassembly processes is equipping the robot system with higher autonomy and intelligence. In this paper, we present an informed software agent that controls the robot behavior to form an intelligent robot assistant for disassembly purposes. While the disassembly process first depends on the product structure, we inform the agent using a generic approach through product models. The product model is then transformed to a directed graph and used to build, share and define a coarse disassembly plan. To refine the workflow, we formulate “the problem of loosening a connection and the distribution of the work” as a search problem. The created detailed plan consists of a sequence of actions that are used to call, parametrize and execute robot programs for the fulfillment of the assistance. The aim of this research is to equip robot systems with knowledge and skills to allow them to be autonomous in the performance of their assistance to finally improve the ergonomics of disassembly workstations.

Modelling disassembled fuel bundles using CATHENA MOD-3.5a under LOCA/LOECC conditions

Energy Technology Data Exchange (ETDEWEB)

Lei, Q M; Sanderson, D B; Dutton, R [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

1996-12-31

CATHENA MOD-3.5a is a multipurpose thermalhydraulic computer code developed primarily to analyse postulated loss-of-coolant scenarios for CANDU nuclear reactors. The code contains a generalized heat transfer package that enables it to model the behaviour of a fuel channel in great detail. Throughout the development of the CATHENA code, considerable effort has been devoted to evaluating, validating and documenting its overall capability as a design and safety assessment tool. Specific attention has focused on its ability to predict fuel channel behaviour under postulated accident conditions. This paper describes an investigation of CATHENA`s ability to predict the thermal-chemical responses of a fuel channel in which the 37-element bundles were assumed to disassemble and rearrange into a closed-packed stack of elements at the bottom of the pressure tube. A representative disassembled bundle geometry was modelled during a simulated loss-of-coolant accident scenario using CATHENA MOD-3.5a/Rev 0, with superheated steam being the only coolant available. Thermal conduction in the radial and circumferential directions was calculated for individual fuel elements, the pressure tube, and the calandria tube. Radiation view factors for the intact and disassembled bundle geometries were calculated using a CATHENA utility program. Inter-element metal-to-metal contact was accounted for using the CATHENA solid-solid contact model. An offset pressure-tube configuration, representing a partially sagged pressure tube, and the effect of steam starvation on the exothermic zirconium-steam reaction, were included in the CATHENA model. The CATHENA-predicted results show a dramatic suppression of heat generation from the zirconium-steam reaction when bundle disassembly is initiated. The predicted results show a smaller temperature increase in the fuel sheaths and the pressure tube for the disassembled bundle geometry, compared to the temperature excursion for the intact bundle. (author

Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

International Nuclear Information System (INIS)

Zygmunt, S.; Christensen, L.; Richardson, C.

1997-01-01

This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation's inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned

Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

Energy Technology Data Exchange (ETDEWEB)

Zygmunt, S.; Christensen, L.; Richardson, C.

1997-12-12

This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation`s inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned.

Design and analysis of sustainable computer mouse using design for disassembly methodology

Science.gov (United States)

Roni Sahroni, Taufik; Fitri Sukarman, Ahmad; Agung Mahardini, Karunia

2017-12-01

This paper presents the design and analysis of computer mouse using Design for Disassembly methodology. Basically, the existing computer mouse model consist a number of unnecessary part that cause the assembly and disassembly time in production. The objective of this project is to design a new computer mouse based on Design for Disassembly (DFD) methodology. The main methodology of this paper was proposed from sketch generation, concept selection, and concept scoring. Based on the design screening, design concept B was selected for further analysis. New design of computer mouse is proposed using fastening system. Furthermore, three materials of ABS, Polycarbonate, and PE high density were prepared to determine the environmental impact category. Sustainable analysis was conducted using software SolidWorks. As a result, PE High Density gives the lowers amount in the environmental category with great maximum stress value.

ARC: A compact, high-field, disassemblable fusion nuclear science facility and demonstration power plant

Science.gov (United States)

Sorbom, Brandon; Ball, Justin; Palmer, Timothy; Mangiarotti, Franco; Sierchio, Jennifer; Bonoli, Paul; Kasten, Cale; Sutherland, Derek; Barnard, Harold; Haakonsen, Christian; Goh, Jon; Sung, Choongki; Whyte, Dennis

2014-10-01

The Affordable, Robust, Compact (ARC) reactor conceptual design aims to reduce the size, cost, and complexity of a combined Fusion Nuclear Science Facility (FNSF) and demonstration fusion pilot power plant. ARC is a 270 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has Rare Earth Barium Copper Oxide (REBCO) superconducting toroidal field coils with joints to allow disassembly, allowing for removal and replacement of the vacuum vessel as a single component. Inboard-launched current drive of 25 MW LHRF power and 13.6 MW ICRF power is used to provide a robust, steady state core plasma far from disruptive limits. ARC uses an all-liquid blanket, consisting of low pressure, slowly flowing Fluorine Lithium Beryllium (FLiBe) molten salt. The liquid blanket acts as a working fluid, coolant, and tritium breeder, and minimizes the solid material that can become activated. The large temperature range over which FLiBe is liquid permits blanket operation at 800-900 K with single phase fluid cooling and allows use of a high-efficiency Brayton cycle for electricity production in the secondary coolant loop.

Nuclear Zpif-type plots

International Nuclear Information System (INIS)

Ma Yugang

2000-01-01

Isospin dependent classical molecular dynamics model is used to investigate the nuclear disassembly of 129 Xe. Zpif-type plot in the field of linguistics is tested for the rank-classified cluster arrangement from this nuclear disassembly. It is found that the average cluster charge (or mass) of rank n in the charge (or mass) list is exactly inverse to its rank, i.e. there exists Zpif's law at the point of the liquid gas phase transition. This novel criterion can be used to diagnose the nuclear liquid gas phase transition experimentally and theoretically

Balancing Disassembly Line in Product Recovery to Promote the Coordinated Development of Economy and Environment

Directory of Open Access Journals (Sweden)

Jia Liu

2017-02-01

Full Text Available For environmentally conscious and sustainable manufacturing, many more manufacturers are acting to recycle and remanufacture their post-consumed products. The most critical process of remanufacturing is disassembly, since it allows for the selective extraction of the valuable components and materials from returned products to reduce the waste disposal volume. It is, therefore, important to design and balance the disassembly line to work efficiently due to its vital role in effective resource usage and environmental protection. Considering the disassembly precedence relationships and sequence-dependent parts removal time increments, this paper presents an improved discrete artificial bee colony algorithm (DABC for solving the sequence-dependent disassembly line balancing problem (SDDLBP. The performance of the proposed algorithm was tested against nine other approaches. Computational results evidently indicate the superior efficiency of the proposed algorithm for addressing the environmental and economic concerns while optimizing the multi-objective SDDLBP.

Disassembling and modification of RA-3

International Nuclear Information System (INIS)

Tarizzo, R.D.

1990-01-01

The objective of this paper is to describe the partial disassembling and modification of RA-3, called the Modernization Project. It comprises all the technical and administrative steps directly related with this task. The improvement of RA-3 is a result of the lack of 90% enriched uranium obliging a change over to 20% enriched uranium. This brought about design modifications both in fuel elements and the reactor. The presentation of documents for the licensing authority as well as are detailed separately. The modernization project was divided in 25 tasks: 1) changing fuel element support table, 2) changing heat exchanger, 3) repairing of cooling towers, 4) repairing of primary circuit valves, 5) repairing of irradiation channels, 6) construction of a new sampler, 7) changing tangential channel, 8) cleaning and disassembling of reactor (inside), 9) changing continuous demineralizer (ion exchange column), 10) detection of failure in fuel elements, 11) modification of nuclear instrumentation, 12) modification of conventional instrumentation, 13) modification of electrical system, 14) changing telemanipulators, 15) construction of mechanism bridge, 16) changing a primary circuit valve when the heat exchanger is changed too, 17) painting ground floor, hall floor, and pump room floor with epoxy resin levelling, 18) installation of fire alarm system, 19) radioactive liquid discharge, 20) modification of secondary circuit (This task involves: a) installation of a third secondary pump, b) extension of this piping, c) installation of two 12 inch valves to the present cooling towers pools independent, d) installation of filtering system), 21) optimization hot water bed, 22) changing detector support table, 23) removal, decontamination and reinstallation of shielding, 25) changing pneumatic system

Studies of fast reactor disassembly using a Bethe-Tait computer code

International Nuclear Information System (INIS)

Ludwig, J.C.

1978-10-01

The advantages of the fast reactor are given and the general design outlined. Loss of Flow and Transient Overpower faults are possible; the potential consequences of such incidents are analysed using a deterministic approach. The course of an incident is split into several stages; of these only predisassembly and disassembly are considered. Predisassembly computer codes are described in general, and several particular codes are examined in more detail, based on a literature survey. The results and implications of disassembly calculations using the code EXTRA are presented. Here, the effects of several factors, such as the presence of retained fission gases and possible restraints on fuel motion, are investigated. Some comparisons are made with published results from the VENUS-II disassembly code. A general conclusion is that under some circumstances, the yield predicted during disassembly is relatively insensitive to modelling assumptions, and a simple code such as EXTRA may prove adequate if explicit core displacements are not required. A major factor in determining the yield of the disassembly phase is confirmed as being the rate of reactivity insertion during disassembly, as predicted by a predisassembly code. (U.K.)

Illustrating the disassembly of 3D models

KAUST Repository

Guo, Jianwei

2013-06-11

We present a framework for the automatic disassembly of 3D man-made models and the illustration of the disassembly process. Given an assembled 3D model, we first analyze the individual parts using sharp edge loops and extract the contact faces between each pair of neighboring parts. The contact faces are then used to compute the possible moving directions of each part. We then present a simple algorithm for clustering the sets of the individual parts into meaningful sub-assemblies, which can be used for a hierarchical decomposition. We take the stability of sub-assemblies into account during the decomposition process by considering the upright orientation of the input models. Our framework also provides a user-friendly interface to enable the superimposition of the constraints for the decomposition. Finally, we visualize the disassembly process by generating an animated sequence. The experiments demonstrate that our framework works well for a variety of complex models. © 2013 Elsevier Ltd.

Coordination of substrate binding and ATP hydrolysis in Vps4-mediated ESCRT-III disassembly.

Science.gov (United States)

Davies, Brian A; Azmi, Ishara F; Payne, Johanna; Shestakova, Anna; Horazdovsky, Bruce F; Babst, Markus; Katzmann, David J

2010-10-01

ESCRT-III undergoes dynamic assembly and disassembly to facilitate membrane exvagination processes including multivesicular body (MVB) formation, enveloped virus budding, and membrane abscission during cytokinesis. The AAA-ATPase Vps4 is required for ESCRT-III disassembly, however the coordination of Vps4 ATP hydrolysis with ESCRT-III binding and disassembly is not understood. Vps4 ATP hydrolysis has been proposed to execute ESCRT-III disassembly as either a stable oligomer or an unstable oligomer whose dissociation drives ESCRT-III disassembly. An in vitro ESCRT-III disassembly assay was developed to analyze Vps4 function during this process. The studies presented here support a model in which Vps4 acts as a stable oligomer during ATP hydrolysis and ESCRT-III disassembly. Moreover, Vps4 oligomer binding to ESCRT-III induces coordination of ATP hydrolysis at the level of individual Vps4 subunits. These results suggest that Vps4 functions as a stable oligomer that acts upon individual ESCRT-III subunits to facilitate ESCRT-III disassembly.

Mathematical and Simulation Modelling of Moisture Diffusion Mechanism during Plastic IC Packages Disassembly

OpenAIRE

Peng Mou; Dong Xiang; Guanghong Duan

2013-01-01

Reuse of plastic IC packages disassembled from printed circuit boards (PCBs) has significant environmental benefits and economic value. The interface delamination caused by moisture diffusion is the main failure mode of IC packages during the disassembling process, which greatly reduces the reusability and reliability of disassembled IC packages. Exploring moisture diffusion mechanism is a prerequisite to optimize prebaking processes before disassembling that is an effective way to avoid the ...

Disassembly of JT-60 tokamak device and ancillary facilities for JT-60 tokamak

International Nuclear Information System (INIS)

Okano, Fuminori; Ichige, Hisashi; Miyo, Yasuhiko; Kaminaga, Atsushi; Sasajima, Tadayuki; Nishiyama, Tomokazu; Yagyu, Jun-ichi; Ishige, Youichi; Suzuki, Hiroaki; Komuro, Kenichi; Sakasai, Akira; Ikeda, Yoshitaka

2014-03-01

The disassembly of JT-60 tokamak device and its peripheral equipments, where the total weight was about 5400 tons, started in 2009 and accomplished in October 2012. This disassembly was required process for JT-60SA project, which is the Satellite Tokamak project under Japan-EU international corroboration to modify the JT-60 to the superconducting tokamak. This work was the first experience of disassembling a large radioactive fusion device based on Radiation Hazard Prevention Act in Japan. The cutting was one of the main problems in this disassembly, such as to cut the welded parts together with toroidal field coils, and to cut the vacuum vessel into two. After solving these problems, the disassembly completed without disaster and accident. This report presents the outline of the JT-60 disassembly, especially tokamak device and ancillary facilities for tokamak device. (author)

Desmosome Assembly and Disassembly Are Membrane Raft-Dependent

Science.gov (United States)

Faundez, Victor; Koval, Michael; Mattheyses, Alexa L.; Kowalczyk, Andrew P.

2014-01-01

Strong intercellular adhesion is critical for tissues that experience mechanical stress, such as the skin and heart. Desmosomes provide adhesive strength to tissues by anchoring desmosomal cadherins of neighboring cells to the intermediate filament cytoskeleton. Alterations in assembly and disassembly compromise desmosome function and may contribute to human diseases, such as the autoimmune skin blistering disease pemphigus vulgaris (PV). We previously demonstrated that PV auto-antibodies directed against the desmosomal cadherin desmoglein 3 (Dsg3) cause loss of adhesion by triggering membrane raft-mediated Dsg3 endocytosis. We hypothesized that raft membrane microdomains play a broader role in desmosome homeostasis by regulating the dynamics of desmosome assembly and disassembly. In human keratinocytes, Dsg3 is raft associated as determined by biochemical and super resolution immunofluorescence microscopy methods. Cholesterol depletion, which disrupts rafts, prevented desmosome assembly and adhesion, thus functionally linking rafts to desmosome formation. Interestingly, Dsg3 did not associate with rafts in cells lacking desmosomal proteins. Additionally, PV IgG-induced desmosome disassembly occurred by redistribution of Dsg3 into raft-containing endocytic membrane domains, resulting in cholesterol-dependent loss of adhesion. These findings demonstrate that membrane rafts are required for desmosome assembly and disassembly dynamics, suggesting therapeutic potential for raft targeting agents in desmosomal diseases such as PV. PMID:24498201

Multi-kanban mechanism for personal computer disassembly

Science.gov (United States)

Udomsawat, Gun; Gupta, Surendra M.; Kamarthi, Sagar V.

2004-12-01

The use of personal computers (PCs) continues to increase every year. According to a 1999 figure, 50 percent of all US households owned PCs, a figure that continues to rise every year. With continuous development of sophisticated software, PCs are becoming increasingly powerful. In addition, the price of a PC continues to steadily decline. Furthermore, the typical life of a PC in the workplace is approximately two to three years while in the home it is three to five years. As these PCs become obsolete, they are replaced and the old PCs are disposed of. It is estimated that between 14 and 20 million PCs are retired annually in the US. While 20 to 30% of the units may be resold, the others are discarded. These discards represent a significant potential source of lead for the waste stream. In some communities, waste cathode ray tubes (CRTs) represent the second largest source of lead in the waste stream after vehicular lead acid batteries. PCs are, therefore, not suitable for dumping in landfills. Besides, several components of a PC can be reused and then there are other valuable materials that can also be harvested. And with the advent of product stewardship, product recovery is the best solution for manufacturers. Disassembly line is perhaps the most suitable set up for disassembling PCs. However, planning and scheduling of disassembly on a disassembly line is complicated. In this paper, we discuss some of the complications including product arrival, demand arrival, inventory fluctuation and production control mechanisms. We then show how to overcome them by implementing a multi-kanban mechanism in the PC disassembly line setting. The multi-kanban mechanism relies on dynamic routing of kanbans according to the state of the system. We investigate the multi-kanban mechanism using simulation and demonstrate that this mechanism is superior to the traditional push system in terms of controlling the system"s inventory while maintaining a decent customer service level.

On the optimal design of the disassembly and recovery processes.

Science.gov (United States)

Xanthopoulos, A; Iakovou, E

2009-05-01

This paper tackles the problem of the optimal design of the recovery processes of the end-of-life (EOL) electric and electronic products, with a special focus on the disassembly issues. The objective is to recover as much ecological and economic value as possible, and to reduce the overall produced quantities of waste. In this context, a medium-range tactical problem is defined and a novel two-phased algorithm is presented for a remanufacturing-driven reverse supply chain. In the first phase, we propose a multicriteria/goal-programming analysis for the identification and the optimal selection of the most 'desirable' subassemblies and components to be disassembled for recovery, from a set of different types of EOL products. In the second phase, a multi-product, multi-period mixed-integer linear programming (MILP) model is presented, which addresses the optimization of the recovery processes, while taking into account explicitly the lead times of the disassembly and recovery processes. Moreover, a simulation-based solution approach is proposed for capturing the uncertainties in reverse logistics. The overall approach leads to an easy-to-use methodology that could support effectively middle level management decisions. Finally, the applicability of the developed methodology is illustrated by its application on a specific case study.

On the optimal design of the disassembly and recovery processes

International Nuclear Information System (INIS)

Xanthopoulos, A.; Iakovou, E.

2009-01-01

This paper tackles the problem of the optimal design of the recovery processes of the end-of-life (EOL) electric and electronic products, with a special focus on the disassembly issues. The objective is to recover as much ecological and economic value as possible, and to reduce the overall produced quantities of waste. In this context, a medium-range tactical problem is defined and a novel two-phased algorithm is presented for a remanufacturing-driven reverse supply chain. In the first phase, we propose a multicriteria/goal-programming analysis for the identification and the optimal selection of the most 'desirable' subassemblies and components to be disassembled for recovery, from a set of different types of EOL products. In the second phase, a multi-product, multi-period mixed-integer linear programming (MILP) model is presented, which addresses the optimization of the recovery processes, while taking into account explicitly the lead times of the disassembly and recovery processes. Moreover, a simulation-based solution approach is proposed for capturing the uncertainties in reverse logistics. The overall approach leads to an easy-to-use methodology that could support effectively middle level management decisions. Finally, the applicability of the developed methodology is illustrated by its application on a specific case study

Assessment of the impacts of spent fuel disassembly alternatives on the Nuclear Waste Isolation System

International Nuclear Information System (INIS)

1984-07-01

The objective of this report was to evaluate four possible alternative methods of preparing and packaging spent fuel assemblies for geologic disposal against the Reference Process of unmodified spent fuel. The four alternative processes were: (1) End fitting removal, (2) Fission gas venting and resealing, (3) Fuel bundle disassembly and close packing of fuel pins, and (4) Fuel shearing and immobilization. Systems analysis was used to develop a basis of comparison of the alternatives. Conceptual processes and facility layouts were devised for each of the alternatives, based on technology deemed feasible for the purpose. Assessments were made of 15 principal attributes from the technical, operational, safety/risk, and economic considerations related to each of the alternatives, including both the surface packaging and underground repository operations. Specific attributes of the alternative processes were evaluated by assigning a number for each that expressed its merit relative to the corresponding attribute of the Reference Process. Each alternative process was then ranked by summing the numbers for attributes in each of the four assessment areas and collectively. Fuel bundle disassembly and close packing of fuel pins was ranked the preferred method of disposal of spent fuel. 63 references, 46 figures, 46 tables

Accomplishment of JT-60U disassembly work dealing with radioactive components

International Nuclear Information System (INIS)

Ikeda, Yoshitaka

2015-01-01

The upgrade of the JT-60U to the superconducting tokamak 'JT-60SA' has been carried out to contribute the early realization of fusion energy by addressing key physics issues relevant for ITER and DEMO. Disassembly of the JT-60U tokamak was required so as to newly install the JT-60SA torus at the same position in the torus hall. The JT-60U tokamak was featured by the complicated and welded structure against the strong electromagnetic force, and by the radioactivation due to deuterium-deuterium (D-D) reactions of 1.5x10"2"0 (n) in total. Since this work was the first experience of disassembling a large radioactivated fusion device in Japan, careful preparations of disassembly activities, including treatment of the radioactivated materials and safety work, have been made. About 13,000 components with a total weight of more than 5,400 tonnes were removed from the torus hall and stored safely in storage facilities. All disassembly components were stored with recording the data such as dose rate, weight and kind of material, so as to apply the clearance level regulation in future. It was confirmed that the main radioactive material of the disassembly components was the stainless steel and that its dose rate was almost background level (∼0.1 μSv/h) at ∼10 m far from the vacuum vessel. It seems that the disassembly components with background dose level are in the clearance level. The assembly of JT-60SA tokamak has started in January 2013 after this disassembly of the JT-60U tokamak. (author)

An Entropy-Based Adaptive Hybrid Particle Swarm Optimization for Disassembly Line Balancing Problems

Directory of Open Access Journals (Sweden)

Shanli Xiao

2017-11-01

Full Text Available In order to improve the product disassembly efficiency, the disassembly line balancing problem (DLBP is transformed into a problem of searching for the optimum path in the directed and weighted graph by constructing the disassembly hierarchy information graph (DHIG. Then, combining the characteristic of the disassembly sequence, an entropy-based adaptive hybrid particle swarm optimization algorithm (AHPSO is presented. In this algorithm, entropy is introduced to measure the changing tendency of population diversity, and the dimension learning, crossover and mutation operator are used to increase the probability of producing feasible disassembly solutions (FDS. Performance of the proposed methodology is tested on the primary problem instances available in the literature, and the results are compared with other evolutionary algorithms. The results show that the proposed algorithm is efficient to solve the complex DLBP.

A methodological approach for designing and sequencing product families in Reconfigurable Disassembly Systems

Directory of Open Access Journals (Sweden)

Ignacio Eguia

2011-10-01

Full Text Available Purpose: A Reconfigurable Disassembly System (RDS represents a new paradigm of automated disassembly system that uses reconfigurable manufacturing technology for fast adaptation to changes in the quantity and mix of products to disassemble. This paper deals with a methodology for designing and sequencing product families in RDS. Design/methodology/approach: The methodology is developed in a two-phase approach, where products are first grouped into families and then families are sequenced through the RDS, computing the required machines and modules configuration for each family. Products are grouped into families based on their common features using a Hierarchical Clustering Algorithm. The optimal sequence of the product families is calculated using a Mixed-Integer Linear Programming model minimizing reconfigurability and operational costs. Findings: This paper is focused to enable reconfigurable manufacturing technologies to attain some degree of adaptability during disassembly automation design using modular machine tools. Research limitations/implications: The MILP model proposed for the second phase is similar to the well-known Travelling Salesman Problem (TSP and therefore its complexity grows exponentially with the number of products to disassemble. In real-world problems, which a higher number of products, it may be advisable to solve the model approximately with heuristics. Practical implications: The importance of industrial recycling and remanufacturing is growing due to increasing environmental and economic pressures. Disassembly is an important part of remanufacturing systems for reuse and recycling purposes. Automatic disassembly techniques have a growing number of applications in the area of electronics, aerospace, construction and industrial equipment. In this paper, a design and scheduling approach is proposed to apply in this area. Originality/value: This paper presents a new concept called Reconfigurable Disassembly System

Design for Disassembly

DEFF Research Database (Denmark)

Beim, Anne

2018-01-01

‘Design for Disassembly’ is becoming a familiar part of discourses on environmental strategies for construction and sustainable design. The concept originates in industrial design and pertains to a wide range of strategies for reuse and recycling, all of which highlight a whole-of-life approach t...... to materials and buildings. Design for Disassembly is particularly relevant to prefabricated and industrialized construction; as such methodologies already contain within them the possibility for easy deconstruction, whether for maintenance, refurbishment or reuse....

Application of industrial robots in automatic disassembly line of waste LCD displays

Science.gov (United States)

Wang, Sujuan

2017-11-01

In the automatic disassembly line of waste LCD displays, LCD displays are disassembled into plastic shells, metal shields, circuit boards, and LCD panels. Two industrial robots are used to cut metal shields and remove circuit boards in this automatic disassembly line. The functions of these two industrial robots, and the solutions to the critical issues of model selection, the interfaces with PLCs and the workflows were described in detail in this paper.

Cleaning, disassembly, and requalification of the FFTF in vessel handling machine

International Nuclear Information System (INIS)

Coops, W.J.

1977-10-01

The Engineering Model In Vessel Handling Machine (IVHM) was successfully removed, cleaned, disassembled, inspected, reassembled and reinstalled into the sodium test vessel at Richland, Washington. This was the first time in the United States a full size operational sodium wetted machine has been cleaned by the water vapor nitrogen process and requalified for operation. The work utilized an atmospheric control system during removal, a tank type water vapor nitrogen cleaning system and an open ''hands on'' disassembly and assembly stand. Results of the work indicate the tools, process and equipment are adequate for the non-radioactive maintenance sequence. Additionally, the work proves that a machine of this complexity can be successfully cleaned, maintained and re-used without the need to replace a large percentage of the sodium wetted parts

Low cytoplasmic pH reduces ER-Golgi trafficking and induces disassembly of the Golgi apparatus

Energy Technology Data Exchange (ETDEWEB)

Soonthornsit, Jeerawat [Laboratory for Cell and Developmental Biology, Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita, Kyoto 603-8555 (Japan); Yamaguchi, Yoko; Tamura, Daisuke [Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan); Ishida, Ryuichi; Nakakoji, Yoko; Osako, Shiho [Laboratory for Cell and Developmental Biology, Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita, Kyoto 603-8555 (Japan); Yamamoto, Akitsugu [Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, 266 Tamura, Nagahama, Shiga, 526‐0829 (Japan); Nakamura, Nobuhiro, E-mail: osaru3@cc.kyoto-su.ac.jp [Laboratory for Cell and Developmental Biology, Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita, Kyoto 603-8555 (Japan); Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192 (Japan)

2014-11-01

The Golgi apparatus was dramatically disassembled when cells were incubated in a low pH medium. The cis-Golgi disassembled quickly, extended tubules and spread to the periphery of cells within 30 min. In contrast, medial- and trans-Golgi were fragmented in significantly larger structures of smaller numbers at a slower rate and remained largely in structures distinct from the cis-Golgi. Electron microscopy revealed the complete disassembly of the Golgi stack in low pH treated cells. The effect of low pH was reversible; the Golgi apparatus reassembled to form a normal ribbon-like structure within 1–2 h after the addition of a control medium. The anterograde ER to Golgi transport and retrograde Golgi to ER transport were both reduced under low pH. Phospholipase A{sub 2} inhibitors (ONO, BEL) effectively suppressed the Golgi disassembly, suggesting that the phospholipase A{sub 2} was involved in the Golgi disassembly. Over-expression of Rab1, 2, 30, 33 and 41 also suppressed the Golgi disassembly under low pH, suggesting that they have protective role against Golgi disassembly. Low pH treatment reduced cytoplasmic pH, but not the luminal pH of the Golgi apparatus, strongly suggesting that reduction of the cytoplasmic pH triggered the Golgi disassembly. Because a lower cytoplasmic pH is induced in physiological or pathological conditions, disassembly of the Golgi apparatus and reduction of vesicular transport through the Golgi apparatus may play important roles in cell physiology and pathology. Furthermore, our findings indicated that low pH treatment can serve as an important tool to analyze the molecular mechanisms that support the structure and function of the Golgi apparatus. - Highlights: • The Golgi apparatus reversibly disassembles by low pH treatment. • The cis-Golgi disassembles quickly generating tubular structures. • Both anterograde and retrograde transport between the ER and the Golgi apparatus are reduced. • Phospholipase A{sub 2} inhibitors (ONO

Development of remote disassembly technology for liquid-metal reactor (LMR) fuel

International Nuclear Information System (INIS)

Bradley, E.C.; Evans, J.H.; Metz, C.F. III; Weil, B.S.

1990-01-01

A major objective of the Consolidated Fuel Reprocessing Program (CFRP) is to develop equipment and demonstrate technology to reprocess fast breeder reactor fuel. Experimental work on fuel disassembly cutting methods began in the 1970s. High-power laser cutting was selected as the preferred cutting method for fuel disassembly. Remotely operated development equipment was designed, fabricated, installed, and tested at Oak Ridge National Laboratory (ORNL). Development testing included remote automatic operation, remote maintenance testing, and laser cutting process development. This paper summarizes the development work performed at ORNL on remote fuel disassembly. 2 refs., 1 fig

Disassembly Properties of Cementitious Finish Joints Using an Induction Heating Method

Science.gov (United States)

Ahn, Jaecheol; Noguchi, Takafumi; Kitagaki, Ryoma

2015-01-01

Efficient maintenance and upgrading of a building during its lifecycle are difficult because a cementitious finish uses materials and parts with low disassembly properties. Additionally, the reuse and recycling processes during building demolition also present numerous problems from the perspective of environmental technology. In this study, an induction heating (IH) method was used to disassemble cementitious finish joints, which are widely used to join building members and materials. The IH rapidly and selectively heated and weakened these joints. The temperature elevation characteristics of the cementitious joint materials were measured as a function of several resistor types, including wire meshes and punching metals, which are usually used for cementitious finishing. The disassembly properties were evaluated through various tests using conductive resistors in cementitious joints such as mortar. When steel fiber, punching metal, and wire mesh were used as conductive resistors, the cementitious modifiers could be weakened within 30 s. Cementitious joints with conductive resistors also showed complete disassembly with little residual bond strength.

Corrosion of aluminum alloys in a reactor disassembly basin

International Nuclear Information System (INIS)

Howell, J.P.; Zapp, P.E.; Nelson, D.Z.

1992-01-01

This document discusses storage of aluminum clad fuel and target tubes of the Mark 22 assembly takes place in the concrete-lined, light-water-filled, disassembly basins located within each reactor area at the Savannah River Site (SRS). A corrosion test program has been conducted in the K-Reactor disassembly basin to assess the storage performance of the assemblies and other aluminum clad components in the current basin environment. Aluminum clad alloys cut from the ends of actual fuel and target tubes were originally placed in the disassembly water basin in December 1991. After time intervals varying from 45--182 days, the components were removed from the basin, photographed, and evaluated metallographically for corrosion performance. Results indicated that pitting of the 8001 aluminum fuel clad alloy exceeded the 30-mil (0.076 cm) cladding thickness within the 45-day exposure period. Pitting of the 1100 aluminum target clad alloy exceeded the 30-mil (0.076 cm) clad thickness in 107--182 days exposure. The existing basin water chemistry is within limits established during early site operations. Impurities such as Cl - , NO 3 - and SO 4 - are controlled to the parts per million level and basin water conductivity is currently 170--190 μmho/cm. The test program has demonstrated that the basin water is aggressive to the aluminum components at these levels. Other storage basins at SRS and around the US have successfully stored aluminum components for greater than ten years without pitting corrosion. These basins have impurity levels controlled to the parts per billion level (1000X lower) and conductivity less than 1.0 μmho/cm

Low cytoplasmic pH reduces ER-Golgi trafficking and induces disassembly of the Golgi apparatus.

Science.gov (United States)

Soonthornsit, Jeerawat; Yamaguchi, Yoko; Tamura, Daisuke; Ishida, Ryuichi; Nakakoji, Yoko; Osako, Shiho; Yamamoto, Akitsugu; Nakamura, Nobuhiro

2014-11-01

The Golgi apparatus was dramatically disassembled when cells were incubated in a low pH medium. The cis-Golgi disassembled quickly, extended tubules and spread to the periphery of cells within 30 min. In contrast, medial- and trans-Golgi were fragmented in significantly larger structures of smaller numbers at a slower rate and remained largely in structures distinct from the cis-Golgi. Electron microscopy revealed the complete disassembly of the Golgi stack in low pH treated cells. The effect of low pH was reversible; the Golgi apparatus reassembled to form a normal ribbon-like structure within 1-2h after the addition of a control medium. The anterograde ER to Golgi transport and retrograde Golgi to ER transport were both reduced under low pH. Phospholipase A2 inhibitors (ONO, BEL) effectively suppressed the Golgi disassembly, suggesting that the phospholipase A2 was involved in the Golgi disassembly. Over-expression of Rab1, 2, 30, 33 and 41 also suppressed the Golgi disassembly under low pH, suggesting that they have protective role against Golgi disassembly. Low pH treatment reduced cytoplasmic pH, but not the luminal pH of the Golgi apparatus, strongly suggesting that reduction of the cytoplasmic pH triggered the Golgi disassembly. Because a lower cytoplasmic pH is induced in physiological or pathological conditions, disassembly of the Golgi apparatus and reduction of vesicular transport through the Golgi apparatus may play important roles in cell physiology and pathology. Furthermore, our findings indicated that low pH treatment can serve as an important tool to analyze the molecular mechanisms that support the structure and function of the Golgi apparatus. Copyright © 2014 Elsevier Inc. All rights reserved.

pH-Sensitive Reversible Programmed Targeting Strategy by the Self-Assembly/Disassembly of Gold Nanoparticles.

Science.gov (United States)

Ma, Jinlong; Hu, Zhenpeng; Wang, Wei; Wang, Xinyu; Wu, Qiang; Yuan, Zhi

2017-05-24

A reversible programmed targeting strategy could achieve high tumor accumulation due to its long blood circulation time and high cellular internalization. Here, targeting ligand-modified poly(ethylene glycol) (PEG-ligand), dibutylamines (Bu), and pyrrolidinamines (Py) were introduced on the surface of gold nanoparticles (Au NPs) for reversible shielding/deshielding of the targeting ligands by pH-responsive self-assembly. Hydrophobic interaction and steric repulsion are the main driving forces for the self-assembly/disassembly of Au NPs. The precise self-assembly (pH ≥ 7.2) and disassembly (pH ≤ 6.8) of Au NPs with different ligands could be achieved by fine-tuning the modifying molar ratio of Bu and Py (R m ), which followed the formula R m = 1/(-0.0013X 2 + 0.0323X + 1), in which X is the logarithm of the partition coefficient of the targeting ligand. The assembled/disassembled behavior of Au NPs at pH 7.2 and 6.8 was confirmed by transmission electron microscopy and dynamic light scattering. Enzyme-linked immunosorbent assays and cellular uptake studies showed that the ligands could be buried inside the assembly and exposed when disassembled. More importantly, this process was reversible, which provides the possibility of prolonging blood circulation by shielding ligands associated with the NPs that were effused from tumor tissue.

Disassembly and Sanitization of Classified Matter

International Nuclear Information System (INIS)

Stockham, Dwight J.; Saad, Max P.

2008-01-01

The Disassembly Sanitization Operation (DSO) process was implemented to support weapon disassembly and disposition by using recycling and waste minimization measures. This process was initiated by treaty agreements and reconfigurations within both the DOD and DOE Complexes. The DOE is faced with disassembling and disposing of a huge inventory of retired weapons, components, training equipment, spare parts, weapon maintenance equipment, and associated material. In addition, regulations have caused a dramatic increase in the need for information required to support the handling and disposition of these parts and materials. In the past, huge inventories of classified weapon components were required to have long-term storage at Sandia and at many other locations throughout the DoE Complex. These materials are placed in onsite storage unit due to classification issues and they may also contain radiological and/or hazardous components. Since no disposal options exist for this material, the only choice was long-term storage. Long-term storage is costly and somewhat problematic, requiring a secured storage area, monitoring, auditing, and presenting the potential for loss or theft of the material. Overall recycling rates for materials sent through the DSO process have enabled 70 to 80% of these components to be recycled. These components are made of high quality materials and once this material has been sanitized, the demand for the component metals for recycling efforts is very high. The DSO process for NGPF, classified components established the credibility of this technique for addressing the long-term storage requirements of the classified weapons component inventory. The success of this application has generated interest from other Sandia organizations and other locations throughout the complex. Other organizations are requesting the help of the DSO team and the DSO is responding to these requests by expanding its scope to include Work-for- Other projects. For example

Effects of reactive oxygen species on cellular wall disassembly of banana fruit during ripening.

Science.gov (United States)

Cheng, Guiping; Duan, Xuewu; Shi, John; Lu, Wangjin; Luo, Yunbo; Jiang, Weibo; Jiang, Yueming

2008-07-15

Fruit softening is generally attributed to cell wall disassembly. Experiments were conducted to investigate effects of various reactive oxygen species (ROS) on in vitro cellular wall disassembly of harvested banana fruit. The alcohol-extracted insoluble residue (AEIR) was obtained from the pulp tissues of banana fruit at various ripening stages and then used to examine the disassembly of cellular wall polysaccharides in the presence of superoxide anion (O2(-)), hydrogen peroxide (H2O2) or hydroxyl radical (OH) and their scavengers. The presence of OH accelerated significantly disassembly of cellular wall polysaccharides in terms of the increase in contents of total sugars released and uronic acid, and the decrease in molecular mass of soluble polysaccharides, using gel permeation chromatography. However, the treatment with H2O2 or O2(-) showed no significant effect on the disassembly of cellular wall polysaccharides. Furthermore, the degradation of the de-esterified AEIR was more susceptible to OH attack than the esterified AEIR. In addition, the effect of OH could be inhibited in the presence of OH scavenger. This study suggests that disassembly of cellular wall polysaccharides could be initiated by OH as the solublisation of the polysaccharides increased, which, in turn, accelerated fruit softening. Copyright © 2008 Elsevier Ltd. All rights reserved.

Meiotic Clade AAA ATPases: Protein Polymer Disassembly Machines.

Science.gov (United States)

Monroe, Nicole; Hill, Christopher P

2016-05-08

Meiotic clade AAA ATPases (ATPases associated with diverse cellular activities), which were initially grouped on the basis of phylogenetic classification of their AAA ATPase cassette, include four relatively well characterized family members, Vps4, spastin, katanin and fidgetin. These enzymes all function to disassemble specific polymeric protein structures, with Vps4 disassembling the ESCRT-III polymers that are central to the many membrane-remodeling activities of the ESCRT (endosomal sorting complexes required for transport) pathway and spastin, katanin p60 and fidgetin affecting multiple aspects of cellular dynamics by severing microtubules. They share a common domain architecture that features an N-terminal MIT (microtubule interacting and trafficking) domain followed by a single AAA ATPase cassette. Meiotic clade AAA ATPases function as hexamers that can cycle between the active assembly and inactive monomers/dimers in a regulated process, and they appear to disassemble their polymeric substrates by translocating subunits through the central pore of their hexameric ring. Recent studies with Vps4 have shown that nucleotide-induced asymmetry is a requirement for substrate binding to the pore loops and that recruitment to the protein lattice via MIT domains also relieves autoinhibition and primes the AAA ATPase cassettes for substrate binding. The most striking, unifying feature of meiotic clade AAA ATPases may be their MIT domain, which is a module that is found in a wide variety of proteins that localize to ESCRT-III polymers. Spastin also displays an adjacent microtubule binding sequence, and the presence of both ESCRT-III and microtubule binding elements may underlie the recent findings that the ESCRT-III disassembly function of Vps4 and the microtubule-severing function of spastin, as well as potentially katanin and fidgetin, are highly coordinated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Capillarity-induced disassembly of virions in carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Fan Xiaobin; Peng Wenchao; Li Yang; Li Xianyu; Zhang Guoliang; Zhang Fengbao [School of Chemical Engineering and Technology, Tianjin University, Tianjin (China); Barclay, J Elaine; Evans, David J [Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH (United Kingdom)], E-mail: fbzhang@tju.edu.cn

2008-04-23

Studying the transport and fate of viruses through nanochannels is of great importance. By using the nanochannel of a carbon nanotube (CNT) as an ideal model, we evaluated the possibility of capillarity-induced viral transport through a closely fitting nanochannel and explored the mechanisms involved. It is shown both experimentally and theoretically that Cowpea mosaic virus can enter CNTs by capillarity. However, when introduced into a nanotube the protein capsid may disassemble. During the initial capillary filling stage, anomalous needle-shaped high pressure exists in the centre of the nanotube's entrance. This high pressure, combining with the significant negative pressure within the nanotube, may account for the disassembly of the virions.

Dismantling the activated annular water tank of the Rheinsberg nuclear power plant

International Nuclear Information System (INIS)

Klietz, Maik; Konitzer, Arnold; Luedeke, Michael

2010-01-01

Acting on behalf of Energiewerke Nord GmbH Lubmin, Anlagen- und Kraftwerksrohrleitungsbau Greifswald GmbH (AKB) planned and built a station for disassembly of the activated annular water tank (RWB) of the decommissioned Rheinsberg nuclear power plant. As part of this demolition step, the annular water tank must be conditioned and disposed of as a component of the reactor facility. This required planning, manufacturing, testing and construction on site of suitable disassembly and handling techniques and the necessary plant and equipment. The client opted for disassembly by means of a diamond cable saw for conditioning the annular water tank into segments fit for shipping, and defined the basic components for the disassembly station in a specification of deliveries and services. The disassembly station serves to divide the annular water tank by means of diamond cable saws into 2 sections in such a way that segment pieces for transport are produced. The existing activation of the annular water tank also entailed the need to plan for the shortest possible time to be spent on handling near the annular water tank, providing radiological protection to the personnel, and performing the sawing steps from a separate operating console assisted by camera surveillance. After works acceptance tests at the manufacturer's, AKB, in October 2009 and February 2010, the disassembly station was delivered to the customer at Rheinsberg KKR free from defects in June 2010. (orig.)

Characterization of spent fuel disassembly hardware and nonfuel bearing components and their relationship to 10 CFR 61

International Nuclear Information System (INIS)

Luksic, A.T.

1987-02-01

There are a variety of wastes that will be disposed of by the federal waste management system under the Nuclear Waste Policy Act of 1982. The primary waste form is spent nuclear fuel. Currently, this is in the form of fuel assemblies. If the fuel pins are removed from the fuel assembly, as in consolidation, then the fuel pins and the structural portion of the fuel assembly must be considered as separate waste streams. The structural hardware consists of end fittings, grid spacers, water rods (BWR 8 x 8 only), control rod guide tubes (PWR only) and various nuts, washers, springs, etc. These are referred to as spent fuel disassembly (SFD) hardware. There will also be a number of other components which are defined in Appendix E of 10 CFR 961, the standard utility contract. These are referred to as nonfuel-bearing (NFB) components, and include fuel channels (BWR), control rods, fission chambers, neutron sources, thimble plugs, and other components. This paper characterizes spent fuel disassembly (SFD) hardware, and nonfuel-bearing (NFB) components for the most abundant fuel types. The descriptions and figures given are representative for the items described. Many subvariants exist due to design evaluation, which are not covered. This paper also discusses the relationship of these wastes to 10 CFR 61 waste classification

The Effect of Uncertain End-of-Life Product Quality and Consumer Incentives on Partial Disassembly Sequencing in Value Recovery Operations

OpenAIRE

Rickli, Jeremy Lewis

2013-01-01

This dissertation addresses gaps in the interaction between End-of-Life (EoL) product acquisition systems and disassembly sequencing. The research focuses on two remanufacturing research problems; 1) modeling uncertain EoL product quality, quantity, and timing in regards to EoL product acquisition and disassembly sequencing and 2) designing EoL product acquisition schemes considering EoL product uncertainty. The main research objectives within these areas are; analyzing, predicting, and contr...

Digital mock-up for the spent fuel disassembly processes

International Nuclear Information System (INIS)

Lee, J. Y.; Kim, S. H.; Song, T. G.; Kim, Y. H.; Hong, D. H.; Yoon, J. S.

2000-12-01

In this study, the graphical design system is developed and the digital mock-up is implemented for designing the spent fuel handling and disassembly processes. The system consists of a 3D graphical modeling system, a devices assembling system, and a motion simulation system. This system is used throughout the design stages from the conceptual design to the motion analysis. By using this system, all the process involved in the spent fuel handling and disassembly processes are analyzed and optimized. Also, this system is used in developing the on-line graphic simulator which synchronously simulates the motion of the equipment in a real time basis by connecting the device controllers with the graphic server through the TCP/IP network. This simulator can be effectively used for detecting the malfunctions of the process equipment which is remotely operated. Thus, the simulator enhances the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process. The graphical design system and the digital mock-up system can be effectively used for designing the process equipment, as well as the optimized process and maintenance process. And the on-line graphic simulator can be an alternative of the conventional process monitoring system which is a hardware based system

Preliminary topical report on comparison reactor disassembly calculations

International Nuclear Information System (INIS)

McLaughlin, T.P.

1975-11-01

Preliminary results of comparison disassembly calculations for a representative LMFBR model (2100-l voided core) and arbitrary accident conditions are described. The analytical methods employed were the computer programs: FX2-POOL, PAD, and VENUS-II. The calculated fission energy depositions are in good agreement, as are measures of the destructive potential of the excursions, kinetic energy, and work. However, in some cases the resulting fuel temperatures are substantially divergent. Differences in the fission energy deposition appear to be attributable to residual inconsistencies in specifying the comparison cases. In contrast, temperature discrepancies probably stem from basic differences in the energy partition models inherent in the codes. Although explanations of the discrepancies are being pursued, the preliminary results indicate that all three computational methods provide a consistent, global characterization of the contrived disassembly accident

Systems impacts of spent fuel disassembly alternatives

International Nuclear Information System (INIS)

1984-07-01

Three studies were completed to evaluate four alternatives to the disposal of intact spent fuel assemblies in a geologic repository. A preferred spent fuel waste form for disposal was recommended on consideration of (1) package design and fuel/package interaction, (2) long-term, in-repository performance of the waste form, and (3) overall process performance and costs for packaging, handling, and emplacement. The four basic alternative waste forms considered were (1) end fitting removal, (2) fission gas venting, (3) disassembly and close packing, and (4) shearing/immobilization. None of the findings ruled out any alternative on the basis of waste package considerations or long-term performance of the waste form. The third alternative offers flexibility in loading that may prove attractive in the various geologic media under consideration, greatly reduces the number of packages, and has the lowest unit cost. These studies were completed in October, 1981. Since then Westinghouse Electric Corporation and the Office of Nuclear Waste Isolation have completed studies in related fields. This report is now being published to provide publicly the background material that is contained within. 47 references, 28 figures, 31 tables

Technical considerations in nuclear terrorism

International Nuclear Information System (INIS)

Velardo, G.

2007-01-01

Nuclear terrorism is an evil application of nuclear energy, in the same way that chemical and biological terrorism could be considered as the evil side of chemistry and biology. This paper presents two effects of nuclear terrorism. First, dirty bombs or radioactive bombs or radiological dispersion devices (RDDs), and second, crude atom bombs or improvised nuclear devices (INDs). The paper analyses as well the probabilities of an attack, its biological effects and nuclear risk. Experiments carried out so far indicate that the lethal effects produced by RDDs are likely the same that the effects produced by the chemical explosive used in the bomb. These type of bombs are rather bounded to generate panic and have implicit a high cost of decontamination. It will be described the measures to be adopted. INDs will be also considered. Uranium INDs by gun-method are more feasible to be made. They can be disassembled and their components transported to the target place. Plutonium INDs by the implosion-method are complex and required high precision technology. Their disassembly is very difficult

Centralized disassembly and packaging of spent fuel in the DOE spent fuel management system

International Nuclear Information System (INIS)

Johnson, E.R.

1986-01-01

In October 1984, E.R. Johnson Associates, Inc. (JAI) initiated a study of the prospective use of a centralized facility for the disassembly and packaging of spent fuel to support the various elements of the US Dept. of Energy (DOE) spent fuel management system, including facilities for monitored retrievable storage (MRS) and repositories. It was DOE's original plan to receive spent fuel at each repository where it would be disassembled and packaged (overpacked) for disposal purposes. Subsequently, DOE considered the prospective use of MRS of spent fuel as an option for providing safe and reliable management of spent fuel. This study was designed to consider possible advantages of the use of centralized facilities for disassembly and packaging of spent fuel at whose location storage facilities could be added as required. The study was divided into three principal technical tasks that covered: (a) development of requirements and criteria for the central disassembly and packaging facility and associated systems. (2) Development of conceptual designs for the central disassembly and packaging facility and associated systems. (3) Estimation of capital and operating costs involved for all system facilities and determination of life cycle costs for various scenarios of operation - for comparison with the reference system

Phosphatase PP2A and microtubule-mediated pulling forces disassemble centrosomes during mitotic exit

Directory of Open Access Journals (Sweden)

Stephen J. Enos

2018-01-01

Full Text Available Centrosomes are microtubule-nucleating organelles that facilitate chromosome segregation and cell division in metazoans. Centrosomes comprise centrioles that organize a micron-scale mass of protein called pericentriolar material (PCM from which microtubules nucleate. During each cell cycle, PCM accumulates around centrioles through phosphorylation-mediated assembly of PCM scaffold proteins. During mitotic exit, PCM swiftly disassembles by an unknown mechanism. Here, we used Caenorhabditis elegans embryos to determine the mechanism and importance of PCM disassembly in dividing cells. We found that the phosphatase PP2A and its regulatory subunit SUR-6 (PP2ASUR-6, together with cortically directed microtubule pulling forces, actively disassemble PCM. In embryos depleted of these activities, ∼25% of PCM persisted from one cell cycle into the next. Purified PP2ASUR-6 could dephosphorylate the major PCM scaffold protein SPD-5 in vitro. Our data suggest that PCM disassembly occurs through a combination of dephosphorylation of PCM components and force-driven fragmentation of the PCM scaffold.

Direct measurement of conformational strain energy in protofilaments curling outward from disassembling microtubule tips.

Science.gov (United States)

Driver, Jonathan W; Geyer, Elisabeth A; Bailey, Megan E; Rice, Luke M; Asbury, Charles L

2017-06-19

Disassembling microtubules can generate movement independently of motor enzymes, especially at kinetochores where they drive chromosome motility. A popular explanation is the 'conformational wave' model, in which protofilaments pull on the kinetochore as they curl outward from a disassembling tip. But whether protofilaments can work efficiently via this spring-like mechanism has been unclear. By modifying a previous assay to use recombinant tubulin and feedback-controlled laser trapping, we directly demonstrate the spring-like elasticity of curling protofilaments. Measuring their mechanical work output suggests they carry ~25% of the energy of GTP hydrolysis as bending strain, enabling them to drive movement with efficiency similar to conventional motors. Surprisingly, a β-tubulin mutant that dramatically slows disassembly has no effect on work output, indicating an uncoupling of disassembly speed from protofilament strain. These results show the wave mechanism can make a major contribution to kinetochore motility and establish a direct approach for measuring tubulin mechano-chemistry.

Improved Nondestructive Disassembly Process using Augmented Reality and RFID Product/Part Tracking

Directory of Open Access Journals (Sweden)

Ile Mircheski

2017-11-01

Full Text Available The waste from electric and electronic equipment and discarded automobiles in the past grew rapidly and resulted with waste in billions of tones. The aim of this paper is to present an improved non-destructive disassembly process of electromechanical products using augmented reality based devices, such as glasses, tablets or mobile phones, and RFID technology for valuable product/part tracking. The proposed method includes tagging of components of interest in the product assembly by using a RFID tag. The valuable product is marked with specific ID number written in the RFID tag, in order to declare the product. The relevant data such as material and weight of components, guidelines for non-destructive disassembly for the valuable product and removing of component of interest will be obtained with the assistance of RFID tag and a centralized database. This modular system offers guidelines for the non-destructive disassembly process for obtaining valuable component of interest intended for easy repairs, remanufacture, reuse or recycling. The guidelines are in video presentation format using augmented reality for easy visualization of non-destructive disassembly process. The benefits of proposed modular system includes biggest percentage of reuse of the valuable components, easy maintaining, improved material recycling, environmental protection and greater total return form end of life products.

The assembly and disassembly of ecological networks.

Science.gov (United States)

Bascompte, Jordi; Stouffer, Daniel B

2009-06-27

Global change has created a severe biodiversity crisis. Species are driven extinct at an increasing rate, and this has the potential to cause further coextinction cascades. The rate and shape of these coextinction cascades depend very much on the structure of the networks of interactions across species. Understanding network structure and how it relates to network disassembly, therefore, is a priority for system-level conservation biology. This process of network collapse may indeed be related to the process of network build-up, although very little is known about both processes and even less about their relationship. Here we review recent work that provides some preliminary answers to these questions. First, we focus on network assembly by emphasizing temporal processes at the species level, as well as the structural building blocks of complex ecological networks. Second, we focus on network disassembly as a consequence of species extinctions or habitat loss. We conclude by emphasizing some general rules of thumb that can help in building a comprehensive framework to understand the responses of ecological networks to global change.

Statistical calculation of complete events in medium-energy nuclear collisions

International Nuclear Information System (INIS)

Randrup, J.

1984-01-01

Several heavy-ion accelerators throughout the world are presently able to deliver beams of heavy nuclei with kinetic energies in the range from tens to hundreds of MeV per nucleon, the so-called medium or intermediate energy range. At such energies a large number of final channels are open, each consisting of many nuclear fragments. The disassembly of the collision system is expected to be a very complicated process and a detailed dynamical description is beyond their present capability. However, by virtue of the complexity of the process, statistical considerations may be useful. A statistical description of the disassembly yields the least biased expectations about the outcome of a collision process and provides a meaningful reference against which more specific dynamical models, as well as the data, can be discussed. This lecture presents the essential tools for formulating a statistical model for the nuclear disassembly process. The authors consider the quick disassembly (explosion) of a hot nuclear system, a so-called source, into multifragment final states, which complete according to their statistical weight. First some useful notation is introduced. Then the expressions for exclusive and inclusive distributions are given and the factorization of an exclusive distribution into inclusive ones is carried out. In turn, the grand canonical approximation for one-fragment inclusive distributions is introduced. Finally, it is outlined how to generate a statistical sample of complete final states. On this basis, a model for statistical simulation of complete events in medium-energy nuclear collisions has been developed

Advanced disassembling technique of irradiated driver fuel assembly for continuous irradiation of fuel pins

International Nuclear Information System (INIS)

Ichikawa, Shoichi; Haga, Hiroyuki; Katsuyama, Kozo; Maeda, Koji; Nishinoiri, Kenji

2012-01-01

It was necessary to carry out continuous irradiation tests in order to obtain the irradiation data of high burn-up fuel and high neutron dose material for FaCT (Fast Reactor Cycle Technology Development) project. There, the disassembling technique of an irradiated fuel assembly was advanced in order to realize further continuous irradiation tests. Although the conventional disassembling technique had been cutting a lower end-plug of a fuel pin needed to fix fuel pins to an irradiation vehicle, the advanced disassembling technique did not need cutting a lower end-plug. As a result, it was possible to supply many irradiated fuel pins to various continuous irradiation tests for FaCT project. (author)

Substantiation of the admissable concentration of radionuclides in the utilization of concrete from disassembled reactors

International Nuclear Information System (INIS)

Engovatov, I.A.; Mashkovich, V.P.; Morev, M.N.

1995-01-01

The complete or partial disassembly of the buildings and systems of a modern nuclear power plant results in the formation of hundreds of thousands of tons of wastes. More than 90% of this mass consists of reinforced concrete. Only a small fraction of these materials is contaminated and/or activated up to high level and must be treated as radioactive wastes that must be buried. For this reason, it is helpful to consider a variant of recycling of some of the wastes and secondary utilization of these wastes in different industrial production processes. In this paper, we analyze the concrete that is freed when a nuclear power plant is decommissioned, and in particular, we examine three scenarios: (1) stockpiling and long-term storage of concrete at an industrial site, (2) highway construction, and (3) industrial building construction. Admissable radionuclide concentrations of several isotopes are tabulated for each scenario, and the results provide the basic information for the development of standards for the utilization of the concrete wastes produced during the decommissioning of nuclear power plants

SAVANNAH RIVER SITE R REACTOR DISASSEMBLY BASIN IN SITU DECOMMISSIONING

Energy Technology Data Exchange (ETDEWEB)

Langton, C.; Blankenship, J.; Griffin, W.; Serrato, M.

2009-12-03

The US DOE concept for facility in-situ decommissioning (ISD) is to physically stabilize and isolate in tact, structurally sound facilities that are no longer needed for their original purpose of, i.e., generating (reactor facilities), processing(isotope separation facilities) or storing radioactive materials. The 105-R Disassembly Basin is the first SRS reactor facility to undergo the in-situ decommissioning (ISD) process. This ISD process complies with the105-R Disassembly Basin project strategy as outlined in the Engineering Evaluation/Cost Analysis for the Grouting of the R-Reactor Disassembly Basin at the Savannah River Site and includes: (1) Managing residual water by solidification in-place or evaporation at another facility; (2) Filling the below grade portion of the basin with cementitious materials to physically stabilize the basin and prevent collapse of the final cap - Sludge and debris in the bottom few feet of the basin will be encapsulated between the basin floor and overlying fill material to isolate if from the environment; (3) Demolishing the above grade portion of the structure and relocating the resulting debris to another location or disposing of the debris in-place; and (4) Capping the basin area with a concrete slab which is part of an engineered cap to prevent inadvertent intrusion. The estimated total grout volume to fill the 105-R Reactor Disassembly Basin is 24,424 cubic meters or 31,945 cubic yards. Portland cement-based structural fill materials were design and tested for the reactor ISD project and a placement strategy for stabilizing the basin was developed. Based on structural engineering analyses and work flow considerations, the recommended maximum lift height is 5 feet with 24 hours between lifts. Pertinent data and information related to the SRS 105-R-Reactor Disassembly Basin in-situ decommissioning include: regulatory documentation, residual water management, area preparation activities, technology needs, fill material designs

A Taxonomy and Comparison of Haptic Actions for Disassembly Tasks

National Research Council Canada - National Science Library

Bloomfield, Aaron; Deng, Yu; Wampler, Jeff; Rondot, Pascale; Harth, Dina; McManus, Mary; Badler, Norman

2003-01-01

.... We conducted a series of human subject experiments to compare user performance and preference on a disassembly task with and without haptic feedback using CyberGlove, Phantom, and SpaceMouse interfaces...

Optimization of Two-Level Disassembly/Remanufacturing/Assembly System with an Integrated Maintenance Strategy

Directory of Open Access Journals (Sweden)

Zouhour Guiras

2018-04-01

Full Text Available With an increase of environmental pressure on economic activities, reverse flow is increasingly important. It seeks to save resources, eliminate waste, and improve productivity. This paper investigates the optimization of the disassembly, remanufacturing and assembly system, taking into account assembly-disassembly system degradation. An analytical model is developed to consider disassembly, remanufacturing of used/end-of-life product and assembly of the finished product. The finished product is composed of remanufactured and new components. A maintenance policy is sequentially integrated to reduce the system unavailability. The aim of this study is to help decision-makers, under certain conditions, choose the most cost-effective process for them to satisfy the customer as well as to adapt to the potential risk that can perturb the disassembly-assembly system. A heuristic is developed to determine the optimal ordered date of the used end-of-life product as well as the optimum release dates of new external components. The results reveal that considering some remanufacturing and purchase components costs, the proposed model is more economical in comparison with a model without remanufactured parts. Numerical results are provided to illustrate the impact of the variation of the ordering cost and quality of the used end-of-life product on the system profitability. Finally, the risk due to system repair periods is discussed, which has an impact on managerial decision-making.

DISA- a computer code for accident analysis of fast reactor during disassembly phase

International Nuclear Information System (INIS)

Yadav, R.D.S.; Gupta, H.P.

2005-01-01

Analysis of the hypothetical transients in fast rectors that result in the disassembly of the reactor generally consists of three phases. In the phase-l, some initiating event like control rod ejection, coolant pump failure etc. is assumed to have taken place which leads the reactor to prompt critical state where fuel melting, sodium voiding etc. take place. In fast reactor normally the fuel is not in the optimum shape and further positive reactivity may be introduced into the system due to fuel melting. Fuel slumping is assumed to take place in this phase. If prompt criticality is reached as a result of the first phase, then disassembly phase is assumed to start. In this phase the neutron transient is followed till it is terminated by the disassembly of the core which takes place due to generation of high pressure gradients and which lead the core material to move from more worth region to less worth region. Doppler feed back is taken into account and reactivity feedback due to material movement is calculated by solving the hydrodynamics equations. The third phase will calculate the effect of this transient on the reactor vessel and containment. A computer code DISA for fast reactor DISAssembly phase, which is similar to the well known code VENUS has been developed. (author)

What if the hand piece spring disassembles during robotic radical prostatectomy?

Science.gov (United States)

Akbulut, Ziya; Canda, Abdullah Erdem; Atmaca, Ali Fuat; Asil, Erem; Isgoren, Egemen; Balbay, Mevlana Derya

2011-01-01

Robot-assisted laparoscopic radical prostatectomy (RALRP) is successfully being performed for treating prostate cancer (PCa). However, instrumentation failure associated with robotic procedures represents a unique new problem. We report the successful completion of RALRP in spite of a disassembled hand piece spring during the procedure. A PubMed/Medline search was made concerning robotic malfunction and robot-assisted laparoscopic radical prostatectomy to discuss our experience. We performed RALRP in a 60-year-old male patient with localized PCa. During the procedure, the spring of the hand piece disassembled, and we were not able to reassemble it. We completed the procedure successfully however without fixing the disassembled hand piece spring. We were able to grasp tissue and needles when we brought our fingers together. The only movement we needed to do was to move fingers apart to release tissue or needles caught by robotic instrument. Although malfunction risk related to the da Vinci Surgical System seems to be very low, it might still occur. Sometimes, simple maneuvers may compensate for the failed function as occurred in our case. However, patients should be informed before the operation about the possibility of converting their procedure to laparoscopic or open due to robotic malfunction.

Phosphorylation of p37 is important for Golgi disassembly at mitosis

International Nuclear Information System (INIS)

Kaneko, Yayoi; Tamura, Kaori; Totsukawa, Go; Kondo, Hisao

2010-01-01

Research highlights: → p37 is phosphorylated on Serine-56 and Threonine-59 by Cdc2 at mitosis. → Phosphorylated p37 does not bind to Golgi membranes. → p37 phosphorylation inhibits p97/p37-mediated Golgi membrane fusion. -- Abstract: In mammals, the Golgi apparatus is disassembled at early mitosis and reassembled at the end of mitosis. For Golgi disassembly, membrane fusion needs to be blocked. Golgi biogenesis requires two distinct p97ATPase-mediated membrane fusion, the p97/p47 and p97/p37 pathways. We previously reported that p47 phosphorylation on Serine-140 by Cdc2 results in mitotic inhibition of the p97/p47 pathway . In this study, we demonstrate that p37 is phosphorylated on Serine-56 and Threonine-59 by Cdc2 at mitosis, and this phosphorylated p37 does not bind to Golgi membranes. Using an in vitro Golgi reassembly assay, we show that mutated p37(S56D, T59D), which mimics mitotic phosphorylation, does not cause any cisternal regrowth, indicating that p37 phosphorylation inhibits the p97/p37 pathway. Our results demonstrate that p37 phosphorylation on Serine-56 and Threonine-59 is important for Golgi disassembly at mitosis.

AGR-2 Irradiated Test Train Preliminary Inspection and Disassembly First Look

Energy Technology Data Exchange (ETDEWEB)

Ploger, Scott [Idaho National Lab. (INL), Idaho Falls, ID (United States); Demkowciz, Paul [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-05-01

The AGR 2 irradiation experiment began in June 2010 and was completed in October 2013. The test train was shipped to the Materials and Fuels Complex in July 2014 for post-irradiation examination (PIE). The first PIE activities included nondestructive examination of the test train, followed by disassembly of the test train and individual capsules and detailed inspection of the capsule contents, including the fuel compacts and their graphite fuel holders. Dimensional metrology was then performed on the compacts, graphite holders, and steel capsule shells. AGR 2 disassembly and metrology were performed with the same equipment used successfully on AGR 1 test train components. Gamma spectrometry of the intact test train gave a preliminary look at the condition of the interior components. No evidence of damage to compacts or graphite components was evident from the isotopic and gross gamma scans. Disassembly of the AGR 2 test train and its capsules was conducted rapidly and efficiently by employing techniques refined during the AGR 1 disassembly campaign. Only one major difficulty was encountered while separating the test train into capsules when thermocouples (of larger diameter than used in AGR 1) and gas lines jammed inside the through tubes of the upper capsules, which required new tooling for extraction. Disassembly of individual capsules was straightforward with only a few minor complications. On the whole, AGR 2 capsule structural components appeared less embrittled than their AGR 1 counterparts. Compacts from AGR 2 Capsules 2, 3, 5, and 6 were in very good condition upon removal. Only relatively minor damage or markings were visible using high resolution photographic inspection. Compact dimensional measurements indicated radial shrinkage between 0.8 to 1.7%, with the greatest shrinkage observed on Capsule 2 compacts that were irradiated at higher temperature. Length shrinkage ranged from 0.1 to 0.9%, with by far the lowest axial shrinkage on Capsule 3 compacts�

SAVANNAH RIVER SITE R-REACTOR DISASSEMBLY BASIN IN-SITU DECOMMISSIONING -10499

Energy Technology Data Exchange (ETDEWEB)

Langton, C.; Serrato, M.; Blankenship, J.; Griffin, W.

2010-01-04

The US DOE concept for facility in-situ decommissioning (ISD) is to physically stabilize and isolate intact, structurally sound facilities that are no longer needed for their original purpose, i.e., generating (reactor facilities), processing(isotope separation facilities) or storing radioactive materials. The 105-R Disassembly Basin is the first SRS reactor facility to undergo the in-situ decommissioning (ISD) process. This ISD process complies with the 105-R Disassembly Basin project strategy as outlined in the Engineering Evaluation/Cost Analysis for the Grouting of the R-Reactor Disassembly Basin at the Savannah River Site and includes: (1) Managing residual water by solidification in-place or evaporation at another facility; (2) Filling the below grade portion of the basin with cementitious materials to physically stabilize the basin and prevent collapse of the final cap - Sludge and debris in the bottom few feet of the basin will be encapsulated between the basin floor and overlying fill material to isolate it from the environment; (3) Demolishing the above grade portion of the structure and relocating the resulting debris to another location or disposing of the debris in-place; and (4) Capping the basin area with a concrete slab which is part of an engineered cap to prevent inadvertent intrusion. The estimated total grout volume to fill the 105-R Reactor Disassembly Basin is 24,384 cubic meters or 31,894 cubic yards. Portland cement-based structural fill materials were designed and tested for the reactor ISD project, and a placement strategy for stabilizing the basin was developed. Based on structural engineering analyses and material flow considerations, maximum lift heights and differential height requirements were determined. Pertinent data and information related to the SRS 105-R Reactor Disassembly Basin in-situ decommissioning include: regulatory documentation, residual water management, area preparation activities, technology needs, fill material

Disassembly and physical separation of electric/electronic components layered in printed circuit boards (PCB).

Science.gov (United States)

Lee, Jaeryeong; Kim, Youngjin; Lee, Jae-chun

2012-11-30

Although printed circuit boards (PCBs) contain various elements, only the major elements (i.e., those with content levels in wt% or over grade) of and precious metals (e.g., Ag, Au, and platinum groups) contained within PCBs can be recycled. To recover other elements from PCBs, the PCBs should be properly disassembled as the first step of the recycling process. The recovery of these other elements would be beneficial for efforts to conserve scarce resources, reuse electric/electronic components (EECs), and eliminate environmental problems. This paper examines the disassembly of EECs from wasted PCBs (WPCBs) and the physical separation of these EECs using a self-designed disassembling apparatus and a 3-step separation process of sieving, magnetic separation, and dense medium separation. The disassembling efficiencies were evaluated by using the ratio of grinding area (E(area)) and the weight ratio of the detached EECs (E(weight)). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (E(area)) and 98% (E(weight)) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5mm. Through a series of physical separations, most groups of the EECs (except for the diode, transistor, and IC chip groups) could be sorted at a relatively high separation efficiency of about 75% or more. To evaluate the separation efficiency with regard to the elemental composition, the distribution ratio (R(dis)) and the concentration ratio (R(conc)) were used. 15 elements could be separated with the highest R(dis) and R(conc) in the same separated division. This result implies that the recyclability of the elements is highly feasible, even though the initial content in EECs is lower than several tens of mg/kg. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of the spent fuel disassembling process by utilizing the 3D graphic design technology

International Nuclear Information System (INIS)

Song, T. K.; Lee, J. Y.; Kim, S. H.; Yun, J. S.

2001-01-01

For developing the spent fuel disassembling process, the 3D graphic simulation has been established by utilizing the 3D graphic design technology which is widely used in the industry. The spent fuel disassembling process consists of a downender, a rod extraction device, a rod cutting device, a pellet extracting device and a skeleton compaction device. In this study, the 3D graphical design model of these devices is implemented by conceptual design and established the virtual workcell within kinematics to motion of each device. By implementing this graphic simulation, all the unit process involved in the spent fuel disassembling processes are analyzed and optimized. The 3D graphical model and the 3D graphic simulation can be effectively used for designing the process equipment, as well as the optimized process and maintenance process

Dismantling the activated annular water tank of the Rheinsberg nuclear power plant; Zerlegung des aktivierten Ringwasserbehaelters des Kernkraftwerks Rheinsberg

Energy Technology Data Exchange (ETDEWEB)

Klietz, Maik; Konitzer, Arnold; Luedeke, Michael [Anlagen- und Kraftwerksrohrleitungsbau GmbH, Greifswald (Germany)

2010-10-15

Acting on behalf of Energiewerke Nord GmbH Lubmin, Anlagen- und Kraftwerksrohrleitungsbau Greifswald GmbH (AKB) planned and built a station for disassembly of the activated annular water tank (RWB) of the decommissioned Rheinsberg nuclear power plant. As part of this demolition step, the annular water tank must be conditioned and disposed of as a component of the reactor facility. This required planning, manufacturing, testing and construction on site of suitable disassembly and handling techniques and the necessary plant and equipment. The client opted for disassembly by means of a diamond cable saw for conditioning the annular water tank into segments fit for shipping, and defined the basic components for the disassembly station in a specification of deliveries and services. The disassembly station serves to divide the annular water tank by means of diamond cable saws into 2 sections in such a way that segment pieces for transport are produced. The existing activation of the annular water tank also entailed the need to plan for the shortest possible time to be spent on handling near the annular water tank, providing radiological protection to the personnel, and performing the sawing steps from a separate operating console assisted by camera surveillance. After works acceptance tests at the manufacturer's, AKB, in October 2009 and February 2010, the disassembly station was delivered to the customer at Rheinsberg KKR free from defects in June 2010. (orig.)

Phosphorylation and disassembly of intermediate filaments in mitotic cells

International Nuclear Information System (INIS)

Chou, Yinghao; Rosevear, E.; Goldman, R.D.

1989-01-01

As baby hamster kidney (BHK-21) cells enter mitosis, networks of intermediate filaments (IFs) are transformed into cytoplasmic aggregates of protofilaments. Coincident with this morphological change, the phosphate content of vimentin increases from 0.3 mol of P i per mol of protein in interphase to 1.9 mol of P i per mol of protein in mitosis. A similar increase in phosphate content is observed with desmin, from 0.5 mol of P i per mol of protein to 1.5 mol of P i per mol of protein. Fractionation of mitotic cell lysates by hydroxylapatite column chromatography reveals the presence of two IF protein kinase activities, designated as IF protein kinase I and IF protein kinase II. Comparison of two-dimensional 32 P-labeled phosphopeptide maps of vimentin and desmin phosphorylated in vivo in mitosis, and in vitro using partially purified kinase fractions, reveals extensive similarity in the two sets of phosphorylation sites. Phosphorylation of in vitro polymerized IFs by IF protein kinase II induces complete disassembly as determined by negative-stain electron microscopy. The results support the idea that the disassembly of IFs in mitosis is regulated by the phosphorylation of its subunit proteins

Montmorillonite-induced Bacteriophage φ6 Disassembly

Science.gov (United States)

Trusiak, A.; Gottlieb, P.; Katz, A.; Alimova, A.; Steiner, J. C.; Block, K. A.

2012-12-01

It is estimated that there are 1031 virus particles on Earth making viruses an order of magnitude more prevalent in number than prokaryotes with the vast majority of viruses being bacteriophages. Clays are a major component of soils and aquatic sediments and can react with RNA, proteins and bacterial biofilms. The clays in soils serve as an important moderator between phage and their host bacteria, helping to preserve the evolutionary balance. Studies on the effects of clays on viral infectivity have given somewhat contradictory results; possibly a consequence of clay-virus interactions being dependent on the unique structure of particular viruses. In this work, the interaction between montmorillonite and the bacteriophage φ6 is investigated. φ6 is a member of the cystovirus family that infects Pseudomonas syringe, a common plant pathogen. As a member of the cystovirus family with an enveloped structure, φ6 serves as a model for reoviruses, a human pathogen. Experiments were conducted with φ6 suspended in dilute, purified homoionic commercial-grade montmorillonite over a range of virus:clay ratios. At a 1:100000 virus:clay ratio, the clay reduced viral infectivity by 99%. The minimum clay to virus ratio which results in a measurable reduction of P. syringae infection is 1:1. Electron microscopy demonstrates that mixed suspensions of smectite and virus co-aggregate to form flocs encompassing virions within the smectite. Both free viral particles as well as those imbedded in the flocs are seen in the micrographs to be missing the envelope- leaving only the nucleocapsid (NC) intact; indicating that smectite inactivates the virus by envelope disassembly. These results have strong implications in the evolution of both the φ6 virus and its P. syringae host cells. TEM of aggregate showing several disassembled NCs.

Remote-automated inspection and maintenance of nuclear power plant equipment

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Masayoshi; Nakano, Yoshiyuki

1984-12-01

Employing remote-control inspection and maintenance equipment in nuclear power plants increases the plant availability by decreasing the annual shutdown time (outage), as well as radiation exposure and man-power. This paper presents an outline of the latest designs for an automatic refueling machine, a control rod drive handling machine, a fuel preparation machine, and a main steam line plug, which were supplied to the Fukushima Dai-Ni No. 2 Plant of the Tokyo Electric Power Co., Inc. (Fukushima 2-2). Also, the up-to-date developments of other new automatic machines, such as a CRD disassembly and cleaning system, spent fuel channel box volume reduction equipment, and robotics for nuclear plant use are presented.

Old foes, new understandings: nuclear entry of small non-enveloped DNA viruses.

Science.gov (United States)

Fay, Nikta; Panté, Nelly

2015-06-01

The nuclear import of viral genomes is an important step of the infectious cycle for viruses that replicate in the nucleus of their host cells. Although most viruses use the cellular nuclear import machinery or some components of this machinery, others have developed sophisticated ways to reach the nucleus. Some of these have been known for some time; however, recent studies have changed our understanding of how some non-enveloped DNA viruses access the nucleus. For example, parvoviruses enter the nucleus through small disruptions of the nuclear membranes and nuclear lamina, and adenovirus tugs at the nuclear pore complex, using kinesin-1, to disassemble their capsids and deliver viral proteins and genomes into the nucleus. Here we review recent findings of the nuclear import strategies of three small non-enveloped DNA viruses, including adenovirus, parvovirus, and the polyomavirus simian virus 40. Copyright © 2015 Elsevier B.V. All rights reserved.

Asymmetric ring structure of Vps4 required for ESCRT-III disassembly

Science.gov (United States)

Caillat, Christophe; Macheboeuf, Pauline; Wu, Yuanfei; McCarthy, Andrew A.; Boeri-Erba, Elisabetta; Effantin, Gregory; Göttlinger, Heinrich G.; Weissenhorn, Winfried; Renesto, Patricia

2015-12-01

The vacuolar protein sorting 4 AAA-ATPase (Vps4) recycles endosomal sorting complexes required for transport (ESCRT-III) polymers from cellular membranes. Here we present a 3.6-Å X-ray structure of ring-shaped Vps4 from Metallosphera sedula (MsVps4), seen as an asymmetric pseudohexamer. Conserved key interface residues are shown to be important for MsVps4 assembly, ATPase activity in vitro, ESCRT-III disassembly in vitro and HIV-1 budding. ADP binding leads to conformational changes within the protomer, which might propagate within the ring structure. All ATP-binding sites are accessible and the pseudohexamer binds six ATP with micromolar affinity in vitro. In contrast, ADP occupies one high-affinity and five low-affinity binding sites in vitro, consistent with conformational asymmetry induced on ATP hydrolysis. The structure represents a snapshot of an assembled Vps4 conformation and provides insight into the molecular motions the ring structure undergoes in a concerted action to couple ATP hydrolysis to ESCRT-III substrate disassembly.

A Trio-Rac1-PAK1 signaling axis drives invadopodia disassembly

Science.gov (United States)

Moshfegh, Yasmin; Bravo-Cordero, Jose Javier; Miskolci, Veronika; Condeelis, John; Hodgson, Louis

2014-01-01

Rho family GTPases control cell migration and participate in the regulation of cancer metastasis. Invadopodia, associated with invasive tumor cells, are crucial for cellular invasion and metastasis. To study Rac1 GTPase in invadopodia dynamics, we developed a genetically-encoded, single-chain Rac1 Fluorescence Resonance Energy Transfer (FRET) biosensor. The biosensor shows Rac1 activity exclusion from the core of invadopodia, and higher activity when invadopodia disappear, suggesting that reduced Rac1 activity is necessary for their stability, and Rac1 activation is involved in disassembly. Photoactivating Rac1 at invadopodia confirmed this previously-unknown Rac1 function. We built an invadopodia disassembly model, where a signaling axis involving TrioGEF, Rac1, PAK1, and phosphorylation of cortactin, causing invadopodia dissolution. This mechanism is critical for the proper turnover of invasive structures during tumor cell invasion, where a balance of proteolytic activity and locomotory protrusions must be carefully coordinated to achieve a maximally invasive phenotype. PMID:24859002

Assembly, operation and disassembly manual for the Battelle Large Volume Water Sampler (BLVWS)

International Nuclear Information System (INIS)

Thomas, V.W.; Campbell, R.M.

1984-12-01

Assembly, operation and disassembly of the Battelle Large Volume Water Sampler (BLVWS) are described in detail. Step by step instructions of assembly, general operation and disassembly are provided to allow an operator completely unfamiliar with the sampler to successfully apply the BLVWS to his research sampling needs. The sampler permits concentration of both particulate and dissolved radionuclides from large volumes of ocean and fresh water. The water sample passes through a filtration section for particle removal then through sorption or ion exchange beds where species of interest are removed. The sampler components which contact the water being sampled are constructed of polyvinylchloride (PVC). The sampler has been successfully applied to many sampling needs over the past fifteen years. 9 references, 8 figures

Ufd1-Npl4 Recruit Cdc48 for Disassembly of Ubiquitylated CMG Helicase at the End of Chromosome Replication

Directory of Open Access Journals (Sweden)

Marija Maric

2017-03-01

Full Text Available Disassembly of the Cdc45-MCM-GINS (CMG DNA helicase is the key regulated step during DNA replication termination in eukaryotes, involving ubiquitylation of the Mcm7 helicase subunit, leading to a disassembly process that requires the Cdc48 “segregase”. Here, we employ a screen to identify partners of budding yeast Cdc48 that are important for disassembly of ubiquitylated CMG helicase at the end of chromosome replication. We demonstrate that the ubiquitin-binding Ufd1-Npl4 complex recruits Cdc48 to ubiquitylated CMG. Ubiquitylation of CMG in yeast cell extracts is dependent upon lysine 29 of Mcm7, which is the only detectable site of ubiquitylation both in vitro and in vivo (though in vivo other sites can be modified when K29 is mutated. Mutation of K29 abrogates in vitro recruitment of Ufd1-Npl4-Cdc48 to the CMG helicase, supporting a model whereby Ufd1-Npl4 recruits Cdc48 to ubiquitylated CMG at the end of chromosome replication, thereby driving the disassembly reaction.

Evaluation of nuclear facility decommissioning projects. Three Mile Island Unit 2 reactor defueling and disassembly. Summary status report. Volume 3

International Nuclear Information System (INIS)

Doerge, D.H.; Miller, R.L.; Scotti, K.S.

1986-05-01

This document summarizes information relating to the preparations for defueling the Three Mile Island Unit 2 (TMI-2) reactor and disassembly activities being performed concurrently with decontamination of the facility. Data have been collected from activity reports, reactor containment entry records, and other sources and entered in a computerized data sysem which permits extraction/manipulation of specific data which can be used in planning for recovery from a loss of coolant event similar to that experienced at TMI-2 on March 28, 1979. This report contains summaries of man-hours, manpower, and radiation exposures incurred during the period of April 23, 1979 to April 16, 1985, in the completion of activities related to preparation for reactor defueling. Support activities conducted outside of radiation areas are not included within the scope of this report. Computerized reports included in this document are: A chronological summary listing work performed for the period; and summary reports for each major task undertaken in connection with the specific scope of this report. Presented in chronological order for the referenced time period. Manually-assembled table summaries are included for: Labor and exposures by department; and labor and exposures by major activity

Nuclear reactor fuel element with a cluster of parallel fuel pins

International Nuclear Information System (INIS)

Macfall, D.; Butterfield, C.E.; Butterfield, R.S.

1977-01-01

An improvement of the design of nuclear reactor fuel elements is described and illustrated by the example of a gas-cooled, graphite-moderated nuclear reactor. The fuel element has a cluster of parallel fuel pins with an outer can of structure material and an inner sleeve, as well as tie bars and spacing devices for all of these parts. The fuel element designed according to the invention allows lasy assembling and disassembling before and after use. During use, no relative axial motions are possible; nevertheless, the graphite sleeve is at no time subject to tensile stress: the individual parts are held in position from below by a single holding device. (UWI) [de

Cdk1 and okadaic acid-sensitive phosphatases control assembly of nuclear pore complexes in Drosophila embryos.

Science.gov (United States)

Onischenko, Evgeny A; Gubanova, Natalia V; Kiseleva, Elena V; Hallberg, Einar

2005-11-01

Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat germ agglutinin (WGA) or in fixed embryos using electron microscopy and immunostaining techniques. We found that in live embryos Cdk1 activity was necessary and sufficient to induce disassembly of NPCs as well as their cytoplasmic mimics: annulate lamellae pore complexes (ALPCs). Cdk1 activity was also required for keeping NPCs and ALPCs disassembled during mitosis. In agreement recombinant Cdk1/cyclin B was able to induce phosphorylation and dissociation of nucleoporins from the NPCs in vitro. Conversely, reassembly of NPCs and ALPCs was dependent on the activity of protein phosphatases, sensitive to okadaic acid (OA). Our findings suggest a model where mitotic disassembly/reassembly of the NPCs is regulated by a dynamic equilibrium of Cdk1 and OA-sensitive phosphatase activities and provide evidence that mitotic phosphorylation mediates disassembly of the NPC.

Nucleolus disassembly in mitosis and apoptosis: dynamic redistribution of phosphorylated-c-Myc, fibrillarin and Ki-67

Directory of Open Access Journals (Sweden)

C Soldani

2009-06-01

Full Text Available The nucleolus may undergo disassembly either reversibly during mitosis, or irreversibly in apoptosis, thus allowing the redistribution of the nucleolar proteins.We investigated here by immunocytochemistry the fate of three representative proteins, namely phosphorylated c-Myc, fibrillarin and Ki-67, and found that they behave independently in both processes: they relocate in distinct compartments during mitosis, whereas during apoptosis they may either be cleaved (Ki-67 or be extruded into the cytoplasm with a different kinetics and following an ordered, non chaotic program. The separation of these nucleolar proteins which occurs in early apoptotic nuclei continues also in the cytoplasm, and culminates in the final formation of apoptotic blebs containing different nucleolar proteins: this evidence confirms that the apoptotic bodies may be variable in size, content and surface reactivity, and include heterogeneous aggregates of nuclear proteins and/or nucleic acids.

Cdk1 and Okadaic Acid-sensitive Phosphatases Control Assembly of Nuclear Pore Complexes in Drosophila EmbryosV⃞

OpenAIRE

Onischenko, Evgeny A.; Gubanova, Natalia V.; Kiseleva, Elena V.; Hallberg, Einar

2005-01-01

Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat...

Charge correlations as a probe of nuclear disassembly

International Nuclear Information System (INIS)

Kreutz, P.; Pochodzalla, J.; Schuettauf, A.; Tucholski, A.; Bouissou, P.; Leray, S.; Seidel, W.; Begemann-Blaich, M.; Hubele, J.; Kunde, G.J.; Lindenstruth, V.; Liu, Z.; Lynen, U.; Meijer, R.J.; Milkau, U.; Mueller, W.F.J.; Ogilvie, C.A.; Sann, H.; Trautmann, W.

1992-03-01

We have studied multi-fragment decays of Au projectiles after collision with C, Al, Cu and Pb targets at a bombarding energy of 600 MeV/nucleon. We examine the correlations between the charges emitted in these reactions. These correlations are given as a function of the total charge in bound fragments, Z bound , at forward angles, which is a measure of the violence of the collision and can be related to the impact parameter. The charge distributions have been fit by a power law and the extracted τ parameter exhibits a minimum as a function of Z bound . We observe a strong reduction in the maximum charge, Z max , of the event with decreasing Z bound . For those events where Z max is less than half Z bound , the relative sizes of the two largest charges within the event cover the full spectrum of possibilities. The charge-Dalitz plots indicate that the multi-fragmentation events are not an extension of symmetric fission reactions. The event-by-event charge moments are examined to measure the size of the charge fluctuations. All of the charge correlations are independent of the target when plotted as a function of Z bound . The results are compared to both nuclear statistical and percolation calculations. The model predictions differ from each other, establishing that the observables are sensitive to how the available phase space is populated. The sequential nuclear model predicts too asymmetric a decay, while the simultaneous model predicts too symmetrical a break-up. The percolation model, which was adjusted to reproduce the mean multiplicity of fragments and the size of Z max , correctly predicts the charge fluctuations. (orig.)

Artificial biofilms establish the role of matrix interactions in staphylococcal biofilm assembly and disassembly

Science.gov (United States)

Stewart, Elizabeth J.; Ganesan, Mahesh; Younger, John G.; Solomon, Michael J.

2015-01-01

We demonstrate that the microstructural and mechanical properties of bacterial biofilms can be created through colloidal self-assembly of cells and polymers, and thereby link the complex material properties of biofilms to well understood colloidal and polymeric behaviors. This finding is applied to soften and disassemble staphylococcal biofilms through pH changes. Bacterial biofilms are viscoelastic, structured communities of cells encapsulated in an extracellular polymeric substance (EPS) comprised of polysaccharides, proteins, and DNA. Although the identity and abundance of EPS macromolecules are known, how these matrix materials interact with themselves and bacterial cells to generate biofilm morphology and mechanics is not understood. Here, we find that the colloidal self-assembly of Staphylococcus epidermidis RP62A cells and polysaccharides into viscoelastic biofilms is driven by thermodynamic phase instability of EPS. pH conditions that induce phase instability of chitosan produce artificial S. epidermidis biofilms whose mechanics match natural S. epidermidis biofilms. Furthermore, pH-induced solubilization of the matrix triggers disassembly in both artificial and natural S. epidermidis biofilms. This pH-induced disassembly occurs in biofilms formed by five additional staphylococcal strains, including three clinical isolates. Our findings suggest that colloidal self-assembly of cells and matrix polymers produces biofilm viscoelasticity and that biofilm control strategies can exploit this mechanism. PMID:26272750

AGR-3/4 Irradiation Test Train Disassembly and Component Metrology First Look Report

Energy Technology Data Exchange (ETDEWEB)

Stempien, John Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rice, Francine Joyce [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Philip Lon [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-09-01

The AGR-3/4 experiment was designed to study fission product transport within graphitic matrix material and nuclear-grade graphite. To this end, this experiment consisted of 12 capsules, each fueled with 4 compacts containing UCO TRISO particles as driver fuel and 20 UCO designed-to-fail (DTF) fuel particles in each compact. The DTF fuel was fabricated with a thin pyrocarbon layer which was intended to fail during irradiation and provide a source of fission products. These fission products could then migrate through the compact and into the surrounding concentric rings of graphitic matrix material and/or nuclear graphite. Through post-irradiation examination (PIE) of the rings (including physical sampling and gamma scanning) fission product concentration profiles within the rings can be determined. These data can be used to elucidate fission product transport parameters (e.g. diffusion coefficients within the test materials) which will be used to inform and refine models of fission product transport. After irradiation in the Advanced Test Reactor (ATR) had been completed in April 2014, the AGR-3/4 experiment was shipped to the Hot Fuel Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) for inspection, disassembly, and metrology. The AGR-3/4 test train was received at MFC in two separate shipments between February and April 2015. Visual examinations of the test train exterior did not indicate dimensional distortion, and only two small discolored areas were observed at the bottom of Capsules 8 and 9. No corresponding discoloration was found on the inside of these capsules, however. Prior to disassembly, the two test train sections were subject to analysis via the Precision Gamma Scanner (PGS), which did not indicate that any gross fuel relocation had occurred. A series of specialized tools (including clamps, cutters, and drills) had been designed and fabricated in order to carry out test train disassembly and recovery of capsule components (graphite

AGR-3/4 Irradiation Test Train Disassembly and Component Metrology First Look Report

Energy Technology Data Exchange (ETDEWEB)

Stempien, John Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rice, Francine Joyce [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Philip Lon [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-03-01

The AGR-3/4 experiment was designed to study fission product transport within graphitic matrix material and nuclear-grade graphite. To this end, this experiment consisted of 12 capsules, each fueled with 4 compacts containing UCO TRISO particles as driver fuel and 20 UCO designed-to-fail (DTF) fuel particles in each compact. The DTF fuel was fabricated with a thin pyrocarbon layer which was intended to fail during irradiation and provide a source of fission products. These fission products could then migrate through the compact and into the surrounding concentric rings of graphitic matrix material and/or nuclear graphite. Through post-irradiation examination (PIE) of the rings (including physical sampling and gamma scanning) fission product concentration profiles within the rings can be determined. These data can be used to elucidate fission product transport parameters (e.g. diffusion coefficients within the test materials) which will be used to inform and refine models of fission product transport. After irradiation in the Advanced Test Reactor (ATR) had been completed in April 2014, the AGR-3/4 experiment was shipped to the Hot Fuel Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) for inspection, disassembly, and metrology. The AGR-3/4 test train was received at MFC in two separate shipments between February and April 2015. Visual examinations of the test train exterior did not indicate dimensional distortion, and only two small discolored areas were observed at the bottom of Capsules 8 and 9. No corresponding discoloration was found on the inside of these capsules, however. Prior to disassembly, the two test train sections were subject to analysis via the Precision Gamma Scanner (PGS), which did not indicate that any gross fuel relocation had occurred. A series of specialized tools (including clamps, cutters, and drills) had been designed and fabricated in order to carry out test train disassembly and recovery of capsule components (graphite

Structure of nuclear transition matrix elements for neutrinoless ...

Indian Academy of Sciences (India)

Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double- decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...

Nuclear installations: decommissioning and dismantling

International Nuclear Information System (INIS)

Anon.

1995-01-01

This document is a compilation of seven talks given during the 1995 EUROFORUM conference about decommissioning and dismantling of Nuclear installations in the European Community. The first two papers give a detailed description of the legal, financial and regulatory framework of decommissioning and dismantling of nuclear facilities in the European Union and a review of the currently available decommissioning techniques for inventory, disassembly, decontamination, remote operations and management of wastes. Other papers describe some legal and technical aspects of reactor and plants dismantling in UK, Germany, Spain and France. (J.S.)

Spiropyran-Decorated SiO₂-Pt Janus Micromotor: Preparation and Light-Induced Dynamic Self-Assembly and Disassembly.

Science.gov (United States)

Zhang, Qilu; Dong, Renfeng; Chang, Xueyi; Ren, Biye; Tong, Zhen

2015-11-11

The controlled self-assembly of self-propelled Janus micromotors may give the micromotors some potential applications in many fields. In this work, we design a kind of SiO2-Pt Janus catalytic micromotor functionalized by spiropyran (SP) moieties on the surface of the SiO2 hemisphere. The spiropyran-modified SiO2-Pt Janus micromotor exhibits autonomous self-propulsion in the presence of hydrogen peroxide fuel in N,N-dimethylformamide (DMF)/H2O (1:1 in volume) mixture. We demonstrate that the self-propelled Janus micromotors can dynamically assemble into multiple motors because of the electrostatic attractions and π-π stacking between MC molecules induced by UV light irradiation (λ = 365 nm) and also quickly disassemble into mono motors when the light is switched to green light (λ = 520 nm) for the first time. Furthermore, the assembled Janus motors can move together automatically with different motion patterns propelled by the hydrogen peroxide fuels upon UV irradiation. The work provides a new approach not only to the development of the potential application of Janus motors but also to the fundamental science of reversible self-assembly and disassembly of Janus micromotors.

Nano-functionalized filamentous fungus hyphae with fast reversible macroscopic assembly & disassembly features.

Science.gov (United States)

Wang, Haiying; Li, Xiaorui; Chai, Liyuan; Zhang, Liyuan

2015-05-18

A uniform decoration of hyphae by polyaniline nanoparticles (PANI NPs) was achieved here. This novel hybrid structure can be effectively assembled into a film by filtration and disassembled in water by shaking. This reversible process is very fast, which promises applications in nanomaterials including adsorption.

Structure of nuclear transition matrix elements for neutrinoless ...

Indian Academy of Sciences (India)

Abstract. The structure of nuclear transition matrix elements (NTMEs) required for the study of neutrinoless double-β decay within light Majorana neutrino mass mechanism is disassembled in the PHFB model. The NTMEs are calculated using a set of HFB intrinsic wave functions, the reliability of which has been previously ...

Actin-interacting Protein 1 Promotes Disassembly of Actin-depolymerizing Factor/Cofilin-bound Actin Filaments in a pH-dependent Manner.

Science.gov (United States)

Nomura, Kazumi; Hayakawa, Kimihide; Tatsumi, Hitoshi; Ono, Shoichiro

2016-03-04

Actin-interacting protein 1 (AIP1) is a conserved WD repeat protein that promotes disassembly of actin filaments when actin-depolymerizing factor (ADF)/cofilin is present. Although AIP1 is known to be essential for a number of cellular events involving dynamic rearrangement of the actin cytoskeleton, the regulatory mechanism of the function of AIP1 is unknown. In this study, we report that two AIP1 isoforms from the nematode Caenorhabditis elegans, known as UNC-78 and AIPL-1, are pH-sensitive in enhancement of actin filament disassembly. Both AIP1 isoforms only weakly enhance disassembly of ADF/cofilin-bound actin filaments at an acidic pH but show stronger disassembly activity at neutral and basic pH values. However, a severing-defective mutant of UNC-78 shows pH-insensitive binding to ADF/cofilin-decorated actin filaments, suggesting that the process of filament severing or disassembly, but not filament binding, is pH-dependent. His-60 of AIP1 is located near the predicted binding surface for the ADF/cofilin-actin complex, and an H60K mutation of AIP1 partially impairs its pH sensitivity, suggesting that His-60 is involved in the pH sensor for AIP1. These biochemical results suggest that pH-dependent changes in AIP1 activity might be a novel regulatory mechanism of actin filament dynamics. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Evidence of the Disassembly of α-Cyclodextrin-octylamine Inclusion Compounds Conjugated to Gold Nanoparticles via Thermal and Photothermal Effects

Directory of Open Access Journals (Sweden)

Nataly Silva

2016-10-01

Full Text Available Cyclodextrin (CD molecules form inclusion compounds (ICs, generating dimers that are capable of encapsulating molecules derived from long-chain hydrocarbons. The aim of this study is to evaluate the structural changes experienced by ICs in solution with increasing temperatures. For this, a nuclear magnetic resonance (1H-NMR titration was performed to determinate the stoichiometric α-cyclodextrin (α-CD:octylamine (OA 2:1 and binding constant (k = 2.16 M−2 of ICs. Solution samples of α-CD-OA ICs conjugated with gold nanoparticles (AuNPs were prepared, and 1H-NMR spectra at different temperatures were recorded. Comparatively, 1H-NMR spectra of the sample irradiated with a laser with tunable wavelengths, with plasmons of conjugated AuNPs, were recorded. In this work, we present evidence of the disassembly of ICs conjugated with AuNPs. Thermal studies demonstrated that, at 114 °C, there are reversible rearrangements of the host and guests in the ICs in a solid state. Migration movements of the guest molecules from the CD cavity were monitored via temperature-dependent 1H-NMR, and were verified comparing the chemical shifts of octylamine dissolved in deuterated dimethylsulfoxide (DMSO-d6 with the OA molecule included in α-CD dissolved in the same solvent. It was observed that, at 117 °C, OA exited the α-CD cavity. CD IC dimer disassembly was also observed when the sample was irradiated with green laser light.

Early cysteine-dependent inactivation of 26S proteasomes does not involve particle disassembly

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Martín Hugo

2018-06-01

Full Text Available Under oxidative stress 26S proteasomes suffer reversible disassembly into its 20S and 19S subunits, a process mediated by HSP70. This inhibits the degradation of polyubiquitinated proteins by the 26S proteasome and allows the degradation of oxidized proteins by a free 20S proteasome. Low fluxes of antimycin A-stimulated ROS production caused dimerization of mitochondrial peroxiredoxin 3 and cytosolic peroxiredoxin 2, but not peroxiredoxin overoxidation and overall oxidation of cellular protein thiols. This moderate redox imbalance was sufficient to inhibit the ATP stimulation of 26S proteasome activity. This process was dependent on reversible cysteine oxidation. Moreover, our results show that this early inhibition of ATP stimulation occurs previous to particle disassembly, indicating an intermediate step during the redox regulation of the 26S proteasome with special relevance under redox signaling rather than oxidative stress conditions.

Protoparvovirus Knocking at the Nuclear Door.

Science.gov (United States)

Mäntylä, Elina; Kann, Michael; Vihinen-Ranta, Maija

2017-10-02

Protoparvoviruses target the nucleus due to their dependence on the cellular reproduction machinery during the replication and expression of their single-stranded DNA genome. In recent years, our understanding of the multistep process of the capsid nuclear import has improved, and led to the discovery of unique viral nuclear entry strategies. Preceded by endosomal transport, endosomal escape and microtubule-mediated movement to the vicinity of the nuclear envelope, the protoparvoviruses interact with the nuclear pore complexes. The capsids are transported actively across the nuclear pore complexes using nuclear import receptors. The nuclear import is sometimes accompanied by structural changes in the nuclear envelope, and is completed by intranuclear disassembly of capsids and chromatinization of the viral genome. This review discusses the nuclear import strategies of protoparvoviruses and describes its dynamics comprising active and passive movement, and directed and diffusive motion of capsids in the molecularly crowded environment of the cell.

Phosphomimetic mutation of the mitotically phosphorylated serine 1880 compromises the interaction of the transmembrane nucleoporin gp210 with the nuclear pore complex

International Nuclear Information System (INIS)

Onischenko, Evgeny A.; Crafoord, Ellinor; Hallberg, Einar

2007-01-01

The nuclear pore complexes (NPCs) reversibly disassemble and reassemble during mitosis. Disassembly of the NPC is accompanied by phosphorylation of many nucleoporins although the function of this is not clear. It was previously shown that in the transmembrane nucleoporin gp210 a single serine residue at position 1880 is specifically phosphorylated during mitosis. Using amino acid substitution combined with live cell imaging, time-lapse microscopy and FRAP, we investigated the role of serine 1880 in binding of gp210 to the NPC in vivo. An alanine substitution mutant (S1880A) was significantly more dynamic at the NPC compared to the wild-type protein, suggesting that serine 1880 is important for binding of gp210 to the NPC. Moreover a glutamate substitution (S1880E) closely mimicking phosphorylated serine specifically interfered with incorporation of gp210 into the NPC and compromised its post-mitotic recruitment to the nuclear envelope of daughter nuclei. Our findings are consistent with the idea that mitotic phosphorylation acts to dissociate gp210 from the structural elements of the NPC

Pilot scale, alpha disassembly and decontamination facility at the Savannah River Laboratory

International Nuclear Information System (INIS)

Cadieux, J.R.; Becker, G.W. Jr.; Richardson, G.W.; Coogler, A.L.

1982-01-01

An alpha-contained pilot facility is being built at the Savannah River Laboratory (SRL) for research into the disassembly and dcontamination of noncombustible, Transuranic (TRU) waste. The design and program objectives for the facility are presented along with the initial test results from laboratory scale decontamination experiments with Pu-238 and Cm-244

Disassembled DJ-1 high molecular weight complex in cortex mitochondria from Parkinson's disease patients

Directory of Open Access Journals (Sweden)

Adler Charles

2009-07-01

Full Text Available Abstract Correction to Nural H, He P, Beach T, Sue L, Xia W, Shen Y. Disassembled DJ-1 high molecular weight complex in cortex mitochondria from Parkinson's disease patients Molecular Neurodegeneration 2009, 4:23.

Rab5 GTPase controls chromosome alignment through Lamin disassembly and relocation of the NuMA-like protein Mud to the poles during mitosis

Science.gov (United States)

Capalbo, Luisa; D'Avino, Pier Paolo; Archambault, Vincent; Glover, David M.

2011-01-01

The small GTPase Rab5 is a conserved regulator of membrane trafficking; it regulates the formation of early endosomes, their transport along microtubules, and the fusion to the target organelles. Although several members of the endocytic pathway were recently implicated in spindle organization, it is unclear whether Rab5 has any role during mitosis. Here, we describe that Rab5 is required for proper chromosome alignment during Drosophila mitoses. We also found that Rab5 associated in vivo with nuclear Lamin and mushroom body defect (Mud), the Drosophila counterpart of nuclear mitotic apparatus protein (NuMA). Consistent with this finding, Rab5 was required for the disassembly of the nuclear envelope at mitotic entry and the accumulation of Mud at the spindle poles. Furthermore, Mud depletion caused chromosome misalignment defects that resembled the defects of Rab5 RNAi cells, and double-knockdown experiments indicated that the two proteins function in a linear pathway. Our results indicate a role for Rab5 in mitosis and reinforce the emerging view of the contributions made by cell membrane dynamics to spindle function. PMID:21987826

Development of disassembly and pin chopping technology for FBR spent fuels

International Nuclear Information System (INIS)

Kobayashi, Tsuguyuki; Namba, Takashi; Kawabe, Yukinari; Washiya, Tadahiro

2008-01-01

Japan Atomic Power Company (JAPC) and Japan Atomic Energy Agency (JAEA) have been developing fuel disassembly and fuel pin chopping systems for a future Japanese commercial FBR. At first, the wrapper tube is cut by the slit-cut to pull it out, then the fuel pins are cut by the crop-cut at their end-plugs to separate them from the entrance nozzle. The pins are transferred to the magazine of the chopping machine. A series of tests were performed to develop this procedure. As the result of mechanical cutting tests, the CBN wheel was selected. The slit-cut tests were carried out to evaluated the cutting performance of the wheel. The wrapper tube is normally slit-cut in the circumferential direction. One CBN wheel could cut more than 5 fuel assemblies in this direction. The slit-cut in the axial direction is prepared as provision when the tube is difficult to put out. More work is needed to cut 5mm thick PNC-FMS plate in this direction without damaging the pins beneath it. As the result of the crop-cut tests of end-plugs made of ODS steel, the CBN wheel could cut the 61 pin bundle by two strokes. More work is needed to cut the 217 pin bundle. Fuel pin handling tests were performed to transfer them from the disassembly machine to the chopping machine. The Saucer tray was selected to receive the disassembled pins. All the pins were transferred and loaded into a magazine of the chopping machine. Fuel pin loading tests were conducted to optimize the magazine configuration to make the chopping length within 1.0±0.5 cm. In order to decrease the disturbance during chopping, the width of the magazine was adjusted to be 12 cm and installation of a height adjuster is favourable to control the free space above the pins. (author)

Workshop on instrumentation of the disassembled BER II

International Nuclear Information System (INIS)

Jauch, W.; Steiner, M.

1982-01-01

A workshop on the instrumentation of a disassembled BER II-reactor took place in the Hahn-Meitner-Institute in Berlin on April 19 and 20, 1982. Invited were all groups that are promoted by the associations 'Neutron Scattering for Investigation of Condensed Substance' and 'Neutron Scattering and Complementary Methods in Chemistry and Biology', along with experts for neutron spectrometers. 40 foreign scientists from 22 different institutes had accepted the invitation. The actual questions were treated in 13 presentations and a certain number of posters, with the latter also comprising activation analysis. The present report contains the presentations submitted, the final discussion minutes and a summary from HMI-view. (orig./RW) [de

Trend of development of robots for nuclear facilities

International Nuclear Information System (INIS)

Maki, Hideo; Sasaki, Masayoshi

1984-01-01

Robot technology becomes more and more important in the field of atomic energy industries. Hitachi Ltd. has energetically engaged in the development of the robot technology for nuclear facilities, recognizing these situations. The course of the development of robot technology and the robots for nuclear facilities is described. As the practical examples of the robots for nuclear facilities, there have been automatic fuel exchangers, the remotely operated automatic exchangers for control rod driving mechanism, automatic and semi-automatic ultrasonic flaw detectors and so on. As the robots for nuclear facilities under development, control rod driving mechanism disassembling and cleaning system, the volume reduction device for spent fuel channel boxes and control rods and others are reported. (Kako, I.)

Prey and mound disassembly, manipulation and transport by fire ant collectives

Science.gov (United States)

Dutta, Bahnisikha; Monaenkova, Daria; Goodisman, Michael A.; Goldman, Daniel

Fire ants inhabit subterranean nests covered by a hemispherical mound of soil permeated by narrow ( 1 body length diameter) tunnels. Fire ants can use their mound for long-term food storage [Gayahan &Tschinkel, J. Insect Sci.,2008]. Since mound tunnels are narrow, we expect that in addition to prey manipulation, mound reconfiguration could also be an important aspect of the food storage strategy. Ant colonies collected from wild were allowed to build nests in containers filled with clay soil in the laboratory. These colonies were offered diverse prey embedded with lead markers, including mealworms, crickets and shrimp. Ant-prey-soil interactions on the nest surface were recorded using overhead video and subsurface using x-ray imaging. Individual ants involved in prey storage exhibited three distinct behaviors: prey maneuvering, prey dissection and mound reconfiguration. Small prey (e.g. mealworms) were collectively carried intact into the mound through a tunnel, and then disassembled within the mound. Larger prey (e.g. shrimp) were dismantled into small pieces above the surface and carried to mound tunnels. The bodies of hard medium-sized prey (e.g. crickets) were buried after limb removal and then disassembled and moved into tunnels. Soil reconfiguration occurred in all cases.

Studies and research concerning BNFP design and construction of a spent-fuel disassembly/encapsulation system

International Nuclear Information System (INIS)

Dabolt, R.J.

1981-04-01

Commercial light water power reactor operation in the United States is developing a cumbersome inventory of spent fuel. Systems for interim storage and handling of this fuel are being developed by the Federal Government and industry. Disassembly and canning of the spent fuel elements is one of these systems. It has the potential to double the storage capacity of a prereprocessing storage facility or to triple the capacity of conventional shipping casks. Prototype equipment and controls required to perform this operation in a dry environment have been primarily designed and fabricated at the Barnwell Nuclear Fuel Plant (BNFP). Ridihalgh, Eggers, and Associates have provided design support and fabrication of the control system. This system is capable of extracting and canning the fuel pins and compacting the nonfuel-bearing components of spent fuel assemblies at processing rates of 10 to 12 assemblies per day. The process also provides the potential for enhanced inspection and assay of spent fuel by reducing the interference encountered from the high gamma fields of the nonfuel bearing hardware

Cofilin phosphorylation is elevated after F-actin disassembly induced by Rac1 depletion.

Science.gov (United States)

Liu, Linna; Li, Jing; Zhang, Liwang; Zhang, Feng; Zhang, Rong; Chen, Xiang; Brakebusch, Cord; Wang, Zhipeng; Liu, Xinyou

2015-01-01

Cytoskeletal reorganization is essential to keratinocyte function. Rac1 regulates cytoskeletal reorganization through signaling pathways such as the cofilin cascade. Cofilin severs actin filaments after activation by dephosphorylation. Rac1 was knocked out in mouse keratinocytes and it was found that actin filaments disassembled. In the epidermis of mice in which Rac1 was knocked out only in keratinocytes, cofilin phosphorylation was aberrantly elevated, corresponding to repression of the phosphatase slingshot1 (SSH1). These effects were independent of the signaling pathways for p21-activated kinase/LIM kinase (Pak/LIMK), protein kinase C, or protein kinase D or generation of reactive oxygen species. Similarly, when actin polymerization was specifically inhibited or Rac1 was knocked down, cofilin phosphorylation was enhanced and SSH1 was repressed. Repression of SSH1 partially blocked actin depolymerization induced by Rac1 depletion. Therefore, aberrant cofilin phosphorylation that induces actin polymerization might be a consequence of actin disassembly induced by the absence of Rac1. © 2015 International Union of Biochemistry and Molecular Biology.

Engineering multifunctional protein nanoparticles by in vitro disassembling and reassembling of heterologous building blocks

Science.gov (United States)

Unzueta, Ugutz; Serna, Naroa; Sánchez-García, Laura; Roldán, Mónica; Sánchez-Chardi, Alejandro; Mangues, Ramón; Villaverde, Antonio; Vázquez, Esther

2017-12-01

The engineering of protein self-assembling at the nanoscale allows the generation of functional and biocompatible materials, which can be produced by easy biological fabrication. The combination of cationic and histidine-rich stretches in fusion proteins promotes oligomerization as stable protein-only regular nanoparticles that are composed by a moderate number of building blocks. Among other applications, these materials are highly appealing as tools in targeted drug delivery once empowered with peptidic ligands of cell surface receptors. In this context, we have dissected here this simple technological platform regarding the controlled disassembling and reassembling of the composing building blocks. By applying high salt and imidazole in combination, nanoparticles are disassembled in a process that is fully reversible upon removal of the disrupting agents. By taking this approach, we accomplish here the in vitro generation of hybrid nanoparticles formed by heterologous building blocks. This fact demonstrates the capability to generate multifunctional and/or multiparatopic or multispecific materials usable in nanomedical applications.

Spent fuel disassembly hardware and other non-fuel bearing components: characterization, disposal cost estimates, and proposed repository acceptance requirements

Energy Technology Data Exchange (ETDEWEB)

Luksic, A.T.; McKee, R.W.; Daling, P.M.; Konzek, G.J.; Ludwick, J.D.; Purcell, W.L.

1986-10-01

There are two categories of waste considered in this report. The first is the spent fuel disassembly (SFD) hardware. This consists of the hardware remaining after the fuel pins have been removed from the fuel assembly. This includes end fittings, spacer grids, water rods (BWR) or guide tubes (PWR) as appropriate, and assorted springs, fasteners, etc. The second category is other non-fuel-bearing (NFB) components the DOE has agreed to accept for disposal, such as control rods, fuel channels, etc., under Appendix E of the standard utiltiy contract (10 CFR 961). It is estimated that there will be approximately 150 kg of SFD and NFB waste per average metric ton of uranium (MTU) of spent uranium. PWR fuel accounts for approximately two-thirds of the average spent-fuel mass but only 50 kg of the SFD and NFB waste, with most of that being spent fuel disassembly hardware. BWR fuel accounts for one-third of the average spent-fuel mass and the remaining 100 kg of the waste. The relatively large contribution of waste hardware in BWR fuel, will be non-fuel-bearing components, primarily consisting of the fuel channels. Chapters are devoted to a description of spent fuel disassembly hardware and non-fuel assembly components, characterization of activated components, disposal considerations (regulatory requirements, economic analysis, and projected annual waste quantities), and proposed acceptance requirements for spent fuel disassembly hardware and other non-fuel assembly components at a geologic repository. The economic analysis indicates that there is a large incentive for volume reduction.

Sequential phosphorylation of GRASP65 during mitotic Golgi disassembly

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Danming Tang

2012-09-01

GRASP65 phosphorylation during mitosis and dephosphorylation after mitosis are required for Golgi disassembly and reassembly during the cell cycle. At least eight phosphorylation sites on GRASP65 have been identified, but whether they are modified in a coordinated fashion during mitosis is so far unknown. In this study, we raised phospho-specific antibodies that recognize phosphorylated T220/T224, S277 and S376 residues of GRASP65, respectively. Biochemical analysis showed that cdc2 phosphorylates all three sites, while plk1 enhances the phosphorylation. Microscopic studies using these antibodies for double and triple labeling demonstrate sequential phosphorylation and dephosphorylation during the cell cycle. S277 and S376 are phosphorylated from late G2 phase through metaphase until telophase when the new Golgi is reassembled. T220/224 is not modified until prophase, but is highly modified from prometaphase to anaphase. In metaphase, phospho-T220/224 signal localizes on both Golgi haze and mitotic Golgi clusters that represent dispersed Golgi vesicles and Golgi remnants, respectively, while phospho-S277 and S376 labeling is more concentrated on mitotic Golgi clusters. Expression of a phosphorylation-resistant GRASP65 mutant T220A/T224A inhibited mitotic Golgi fragmentation to a much larger extent than the expression of the S277A and S376A mutants. In cytokinesis, T220/224 dephosphorylation occurs prior to that of S277, but after S376. This study provides evidence that GRASP65 is sequentially phosphorylated and dephosphorylated during mitosis at different sites to orchestrate Golgi disassembly and reassembly during cell division, with phosphorylation of the T220/224 site being most critical in the process.

Engineering scale tests of mechanical disassembly and short stroke shearing systems for FBR fuel assembly

International Nuclear Information System (INIS)

Higuchi, Hidetoshi; Kitagaki, Toru; Koizumi, Kenji; Hirano, Hiroyasu; Takeuchi, Masayuki; Washiya, Tadahiro; Kawabe, Yukinari; Kobayashi, Tsuguyuki

2011-01-01

Japan Atomic Energy Agency (JAEA) and The Japan Atomic Power Company (JAPC) have been developing an advanced head-end process based on mechanical disassembly and short stroke shearing systems as a part of Fast Reactor Cycle Technology Development (FaCT). Fuel pins for a fast reactor are installed within a hexagonal shaped wrapper tube made of stainless steel. In order to reprocess the fast reactor fuel pins, they must be removed from the wrapper tube and transported to the shearing system without failure. In addition, the advanced aqueous reprocessing process, called 'NEXT' (New Extraction System for TRU Recovery) process requires a solution of the spent fuel with relatively high concentration (500g/L). JAEA and JAPC have developed the mechanical disassembly and the short stroke shearing technology which is expected to make fragmented fuel to satisfy these requirements. This paper reports the results of engineering scale tests on the mechanical disassembly and short stroke shearing systems. These tests were carried out with simulated FBR fuel assembly and removed pins. The mechanical cutting method has been developed to avoid fuel pin failure during disassembly operation. The cutting process is divided into two modes, so called 'slit-cut' for cutting the wrapper tube and 'crop-cut' for the end plug region of the fuel pin bundle. In the slit-cut mode, the depth of cutting was automatically controlled based on the calculated wastage of the cutting tool and deformation of the wrapper tube which had been measured before the cutting. This procedure was confirmed to minimize the fuel pin failure which was hard to prevent in the case of laser cutting. The cutting speed was also controlled automatically by the electric current of the cutting motor to lower the load of the cutting tool. The removed fuel pins were transported to the shearing machine, whose fuel shearing magazine width was set to be narrow to realize the suitable configuration for the short stroke shearing

A Parameter Study of Large Fast Reactor Nuclear Explosion Accidents

Energy Technology Data Exchange (ETDEWEB)

Wiesel, J R

1969-02-15

An IBM-code EEM (Explosive Excursion Model) has been developed for calculating the energy releases associated with the explosive disassembly of a large fast reactor following a superprompt critical condition. The assumed failure chain of events and the possible core collapse following a fuel meltdown give the input data and initial conditions, the most important of which is the reactivity insertion rate at the moment of the explosive core disassembly. The dependence of the energy releases on the reactivity insertion rate, the Doppler reactivity feedback, the power form factor and the core size have been studied. The model enables a quick estimation of conservative values of the destructive mechanical energy releases following a nuclear explosion and gives suggestions as to how to reduce or even avoid such excursions.

A Parameter Study of Large Fast Reactor Nuclear Explosion Accidents

International Nuclear Information System (INIS)

Wiesel, J.R.

1969-02-01

An IBM-code EEM (Explosive Excursion Model) has been developed for calculating the energy releases associated with the explosive disassembly of a large fast reactor following a superprompt critical condition. The assumed failure chain of events and the possible core collapse following a fuel meltdown give the input data and initial conditions, the most important of which is the reactivity insertion rate at the moment of the explosive core disassembly. The dependence of the energy releases on the reactivity insertion rate, the Doppler reactivity feedback, the power form factor and the core size have been studied. The model enables a quick estimation of conservative values of the destructive mechanical energy releases following a nuclear explosion and gives suggestions as to how to reduce or even avoid such excursions

VENUS-2, Reactor Kinetics with Feedback, 2-D LMFBR Disassembly Excursions

International Nuclear Information System (INIS)

Jackson, J.F.; Nicholson, R.B.; Weber, D.P.

1980-01-01

1 - Description of problem or function: VENUS-2 is an improved edition of the VENUS fast-reactor disassembly program. It is a two- dimensional (r-z) coupled neutronics-hydrodynamics code that calculates the dynamic behavior of an LMFBR during a prompt-critical disassembly excursion. It calculates the power history and fission energy release as well as the space-time histories of the fuel temperatures, core material pressures, and core material motions. Reactivity feedback effects due to Doppler broadening and reactor material motion are taken into account. 2 - Method of solution: The power and energy release are calculated using a point-kinetics formulation with up to six delayed neutron groups. The reactivity is a combination of an input driving function and feedback effects due to Doppler broadening and material motion. An adiabatic model is used to calculate the temperature increase throughout the reactor based on an initial temperature distribution and power profile provided as input data. These temperatures are, in turn, converted to fuel pressures through one of several equation of state options provided. The material motion that results from the pressure buildup is calculated by a direct finite difference solution of a set of two-dimensional (r-z) hydrodynamics equations. This is done in Lagrangian coordinates. The reactivity change associated with this motion is calculated by first-order perturbation theory. The displacements are also used to adjust the fuel densities as required for the density dependent equation-of- state option. An automatic time-step-size selection scheme is provided. 3 - Restrictions on the complexity of the problem: VENUS-2 is written so that the dimensions of the storage arrays can be readily changed to accommodate a broad range of problem sizes. In the base version, the total number of mesh intervals is restricted such that (NR+3)*(NZ+3) is less than 700, where NR and NZ are the total number of mesh intervals in the r and z

Dismantling of nuclear facilities

International Nuclear Information System (INIS)

Tallec, M.; Kus, J.P.

2009-01-01

Nuclear facilities have a long estimable lifetime but necessarily limited in time. At the end of their operation period, basic nuclear installations are the object of cleansing operations and transformations that will lead to their definitive decommissioning and then to their dismantling. Because each facility is somewhere unique, cleansing and dismantling require specific techniques. The dismantlement consists in the disassembly and disposing off of big equipments, in the elimination of radioactivity in all rooms of the facility, in the demolition of buildings and eventually in the reconversion of all or part of the facility. This article describes these different steps: 1 - dismantling strategy: main de-construction guidelines, expected final state; 2 - industries and sites: cleansing and dismantling at the CEA, EDF's sites under de-construction; 3 - de-construction: main steps, definitive shutdown, preparation of dismantling, electromechanical dismantling, cleansing/decommissioning, demolition, dismantling taken into account at the design stage, management of polluted soils; 4 - waste management: dismantlement wastes, national policy of radioactive waste management, management of dismantlement wastes; 5 - mastery of risks: risk analysis, conformability of risk management with reference documents, main risks encountered at de-construction works; 6 - regulatory procedures; 7 - international overview; 8 - conclusion. (J.S.)

Artificial intelligence: the future in nuclear plant maintenance

International Nuclear Information System (INIS)

Norgate, G.

1984-01-01

The role of robotics and remote handling equipment in future nuclear power plant maintenance activities is discussed in the context of artificial intelligence applications. Special requirements manipulators, control systems, and man-machine interfaces for nuclear applications are noted. Tasks might include inspection with cameras, eddy current probes, and leak detectors; the collection of material samples; radiation monitoring; and the disassembly, repair and reassembly of a variety of system components. A robot with vision and force sensing and an intelligent control system that can access a knowledge base is schematically described. Recent advances in image interpretation systems are also discussed

Investigations of nuclear structure and nuclear reactions induced by complex projectiles

International Nuclear Information System (INIS)

Sarantites, D.G.

1993-01-01

This is a progress report on activities of the Washington University group in nuclear reaction studies for the period Sept 1, 1992 to Aug 31, 1993. This group has a research program which touches five areas of nuclear physics: nuclear structure studies at high spin; studies at the interface between structure and reactions; production and study of hot nuclei; reaction mechanism studies; development and use of novel techniques and instrumentation in the above areas of research. Specific activities of the group include in part: superdeformation in 82 Sr; structure of and identical bands in 182 Hg and 178 Pt; a highly deformed band in 136 Pm; particle decay of the 164 Yb compound nucleus; fusion reactions; proton evaporation; two-proton decay of 12 O; modeling and theoretical studies; excited 16 O disassembly into four alpha particles; 209 Bi + 136 Xe collisions at 28.2 MeV/amu; and development work on 4π solid angle gamma detectors, and x-ray detectors

[Study on the liver-protective and choleretic effect of zhizi baipi soup and its disassembled prescription].

Science.gov (United States)

Xiao, Xu; Zhu, Ji-Xiao; Luo, Guang-Ming; Li, Lei; Zhu, Yu-Ye; Zeng, Jin-Xiang; Wang, Xiao-Yun; Wu, Bo

2013-07-01

To investigate the effect of Zhizi Baipi soup and its disassembled prescription on protecting liver and improving choleresis and explore the regularity of Zhizi Baipi soup composition. The model of mouse liver injury induced by carbon tetraehlofide (CCl4) was used to observe the effects of Zhizi Baipi soup and its disassembled prescription by oral adminstration, the bile volume was determinied by common bile duct drainage. Zhizi Baipi soup and each treatment group with gardenia could significantly inhibit the increased serum ATL and AST activities, reduce liver MDA level, and significantly promote the bile flow and bilirubin in bile in normal rats. Zhizi Baipi soup has effects on protecting liver and increasing bile secretion, its monarch drug, gardenia plays an important role in the decoction, the effect of eliminating dampness and heat are mainly ascribed to the synergic effect of gardenia and phellodendron.

Remote disassembly of radioactively contaminated vessels by means of an arc saw

International Nuclear Information System (INIS)

Beitel, G.A.

1977-01-01

The arc saw, a newly developed tool, is a toothless circular saw which cuts by means of an electric arc. Cutting speeds between 20 to 30 cm 2 /S and depths up to 45 cm are possible. There is no mechanical contact between blade and work piece, no binding, and no blade breakage. The arc saw will be applied to the rapid and remote disassembly of multiple ton, contaminated stainless steel vessels

Pyrolysis and its potential use in nuclear graphite disposal

International Nuclear Information System (INIS)

Mason, J.B.; Bradbury, D.

2001-01-01

Graphite is used as a moderator material in a number of nuclear reactor designs, such as MAGNOX and AGR gas cooled reactors in the United Kingdom and the RBMK design in Russia. During construction the moderator of the reactor is usually installed as an interlocking structure of graphite bricks. At the end of reactor life the graphite moderator, weighing typically 2,000 tonnes, is a radioactive waste which requires eventual management. Radioactive graphite disposal options conventionally include: In-situ SAFESTORE for extended periods to permit manual disassembly of the graphite moderator through decay of short-lived radionuclides. Robotic or manual disassembly of the reactor core followed by disposal of the graphite blocks. Robotic or manual disassembly of the reactor core followed by incineration of the graphite and release of the resulting carbon dioxide Studsvik, Inc. is a nuclear waste management and waste processing company organised to serve the US nuclear utility and government facilities. Studsvik's management and technical staff have a wealth of experience in processing liquid, slurry and solid low level radioactive waste using (amongst others) pyrolysis and steam reforming techniques. Bradtec is a UK company specialising in decontamination and waste management. This paper describes the use of pyrolysis and steam reforming techniques to gasify graphite leading to a low volume off-gas product. This allows the following options/advantages. Safe release of any stored Wigner energy in the graphite. The process can accept small pieces or a water-slurry of graphite, which enables the graphite to be removed from the reactor core by mechanical machining or water cutting techniques, applied remotely in the reactor fuel channels. In certain situations the process could be used to gasify the reactor moderator in-situ. The low volume of the off-gas product enables non-carbon radioactive impurities to be efficiently separated from the off-gas. The off-gas product can

Conceptual design report for the mechanical disassembly of Fort St. Vrain fuel elements

International Nuclear Information System (INIS)

Lord, D.L.; Wadsworth, D.C.; Sekot, J.P.; Skinner, K.L.

1993-04-01

A conceptual design study was prepared that: (1) reviewed the operations necessary to perform the mechanical disassembly of Fort St. Vrain fuel elements; (2) contained a description and survey of equipment capable of performing the necessary functions; and (3) performed a tradeoff study for determining the preferred concepts and equipment specifications. A preferred system was recommended and engineering specifications for this system were developed

Conceptual design report for the mechanical disassembly of Fort St. Vrain fuel elements

Energy Technology Data Exchange (ETDEWEB)

Lord, D.L. [Westinghouse Idaho Nuclear Co., Inc., Idaho Falls, ID (United States); Wadsworth, D.C.; Sekot, J.P.; Skinner, K.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1993-04-01

A conceptual design study was prepared that: (1) reviewed the operations necessary to perform the mechanical disassembly of Fort St. Vrain fuel elements; (2) contained a description and survey of equipment capable of performing the necessary functions; and (3) performed a tradeoff study for determining the preferred concepts and equipment specifications. A preferred system was recommended and engineering specifications for this system were developed.

[PHAHs levels in soil samples from the E-waste disassembly sites and their sources allocation].

Science.gov (United States)

Zhao, Gao-Feng; Wang, Zi-Jian

2009-06-15

Soil samples (each with 3 replicates of - 1 kg, at the top 0-5 cm layer) were collected from each of the e-waste disassembly sites and the control site. Also obtained from each disassembly site were samples (each weighing - 0.2 kg) of cable coating,stuffing powder, and circuit boards chipping. The contents of 23 PBB congeners, 12 PBDE congeners, and 27 PCB congeners in soil and in their potential sources, including e-waste residues, were measured using the GC-MS5975B technique. The highest level of PBBs was found in the cable coating among the three e-waste residues, with a concentration of 35.25 ng x g(-1). The contents of low-brominated PBBs (including monobromobiphenyls and dibromobiphenyls) accounted for 38% of the total PBBs concentration observed in cable coating sample. The highest levels of PBDEs and PBDE209 were found in the stuffing powder for electronic component among the collected e-waste residues, with a concentration of 29.71 and 4.19 x 10(3) ng x g(-1). PBDE153 and PBDE183 were the most predominant PBDE congeners, with their concentration accounting for 43% and 24% of the total PBDEs concentration observed in the stuffing powder sample, respectively. Levels of PCBs in cable coating were the highest in these e-waste residues, with a concentration of 680.02 ngx g(-1). The observed values of the three PHAHs in soils from the disassembly site were considerably higher than their corresponding values observed in the control site (p < 0.05), which indicates that these PHAHs from e-waste is the pollution source of local environment.

Connexin43 hemichannels contributes to the disassembly of cell junctions through modulation of intracellular oxidative status

Directory of Open Access Journals (Sweden)

Yuan Chi

2016-10-01

Full Text Available Connexin (Cx hemichannels regulate many cellular processes with little information available regarding their mechanisms. Given that many pathological factors that activate hemichannels also disrupts the integrity of cellular junctions, we speculated a potential participation of hemichannels in the regulation of cell junctions. Here we tested this hypothesis. Exposure of renal tubular epithelial cells to Ca2+-free medium led to disassembly of tight and adherens junctions, as indicated by the reduced level of ZO-1 and cadherin, disorganization of F-actin, and severe drop in transepithelial electric resistance. These changes were preceded by an activation of Cx43 hemichannels, as revealed by extracellular efflux of ATP and intracellular influx of Lucifer Yellow. Inhibition of hemichannels with chemical inhibitors or Cx43 siRNA greatly attenuated the disassembly of cell junctions. Further analysis using fetal fibroblasts derived from Cx43 wide-type (Cx43+/+, heterozygous (Cx43+/- and knockout (Cx43-/- littermates showed that Cx43-positive cells (Cx43+/+ exhibited more dramatic changes in cell shape, F-actin, and cadherin in response to Ca2+ depletion, as compared to Cx43-null cells (Cx43-/-. Consistently, these cells had higher level of protein carbonyl modification and phosphorylation, and much stronger activation of P38 and JNK. Hemichannel opening led to extracellular loss of the major antioxidant glutathione (GSH. Supplement of cells with exogenous GSH or inhibition of oxidative sensitive kinases largely prevented the above-mentioned changes. Taken together, our study indicates that Cx43 hemichannels promote the disassembly of cell junctions through regulation of intracellular oxidative status.

Robotic control architecture development for automated nuclear material handling systems

International Nuclear Information System (INIS)

Merrill, R.D.; Hurd, R.; Couture, S.; Wilhelmsen, K.

1995-02-01

Lawrence Livermore National Laboratory (LLNL) is engaged in developing automated systems for handling materials for mixed waste treatment, nuclear pyrochemical processing, and weapon components disassembly. In support of these application areas there is an extensive robotic development program. This paper will describe the portion of this effort at LLNL devoted to control system architecture development, and review two applications currently being implemented which incorporate these technologies

Isotope identification as a part of the decommissioning of San Diego State University's Texas Nuclear neutron generator

International Nuclear Information System (INIS)

Taylor, D.

1997-07-01

The Department of Physics at San Diego State University has maintained a Neutron Generator facility in room P-32C since the mid 1960's. This facility has provided students and faculty with a resource for the study of neutron interactions with matter, such as activation analysis, flux determinations, cross section determinations and shielding studies. The model 9500 was built by Texas Nuclear Research in the early 1960's, and could be used for either photon or neutron generation, depending on the source ions introduced into the accelerator's plasma bottle and the target material. In February of 1988, the Texas Nuclear Research neutron generator was replaced by a unit manufactured by Kaman Sciences Corporation. The Texas Nuclear unit was then removed and stored for later disassembly and disposal. In the summer of 1993, the neutron generator was disassembled into three large sections consisting of the titanium-tritide target, the oil diffusion pump and the corona shield/accelerator tube assembly. The target was packaged and stored in room P-33A and the other 2 assemblies were wrapped in plastic for storage. In June of 1995 the neutron generator was further disassembled to enable storage in 55 gallon drums and thoroughly surveyed for loose surface contamination. Openings on the disassembled hardware components were closed off using either duct tape or bolted stainless steel flanges to prevent the possible spread of contamination. Significant levels of removable surface contamination could be found on system internal and some external surfaces, up to five hundred thousand disintegrations per minute. Initial analysis of the removable contamination using aluminum absorbers and a Geiger-Meuller tube indicated beta particle or possibly photon emitters with an energy of approximately 180 keV. This apparent radiation energy conflicted with what one would be expected to find, given knowledge of the source material and the possible neutron activated products that would be

A probabilistic model for US nuclear power construction times

International Nuclear Information System (INIS)

Shash, A.A.H.

1988-01-01

Construction time for nuclear power plants is an important element in planning for resources to meet future load demands. Analysis of actual versus estimated construction times for past US nuclear power plants indicates that utilities have continuously underestimated their power plants' construction durations. The analysis also indicates that the actual average construction time has been increasing upward, and the actual durations of power plants permitted to construct in the same year varied substantially. This study presents two probabilistic models for nuclear power construction time for use by the nuclear industry as estimating tool. The study also presents a detailed explanation of the factors that are responsible for increasing and varying nuclear power construction times. Observations on 91 complete nuclear units were involved in three interdependent analyses in the process of explanation and derivation of the probabilistic models. The historical data was first utilized in the data envelopment analysis (DEA) for the purpose of obtaining frontier index measures for project management achievement in building nuclear power plants

Knowledge of damage identification about tensegrities via flexibility disassembly

Science.gov (United States)

Jiang, Ge; Feng, Xiaodong; Du, Shigui

2017-12-01

Tensegrity structures composing of continuous cables and discrete struts are under tension and compression, respectively. In order to determine the damage extents of tensegrity structures, a new method for tensegrity structural damage identification is presented based on flexibility disassembly. To decompose a tensegrity structural flexibility matrix into the matrix represention of the connectivity between degress-of-freedoms and the diagonal matrix comprising of magnitude informations. Step 1: Calculate perturbation flexibility; Step 2: Compute the flexibility connectivity matrix and perturbation flexibility parameters; Step 3: Calculate the perturbation stiffness parameters. The efficiency of the proposed method is demonstrated by a numeical example comprising of 12 cables and 4 struts with pretensioned. Accurate identification of local damage depends on the availability of good measured data, an accurate and reasonable algorithm.

Nuclear power: time to start again

International Nuclear Information System (INIS)

Rezak, W.D.

2004-01-01

This paper presents data which support the construction and operating successes enjoyed by energy companies that operate nuclear power plants in the US. The result is that the US nuclear industry is alive and well. Perhaps it's time to start anew the building of nuclear power plants. Over 20% of the electricity generated in the United States comes from nuclear power plants. An adequate, reliable supply of reasonably priced electric energy is not a consequence of an expanding economy and gross national product; it is an absolute necessity before such expansion can occur. It is hard to imagine any aspect of our business or personal lives not, in some way, dependent upon electricity. All over the world (in over 30 countries) nuclear power is a low-cost, secure, safe, dependable, and environmentally friendly form of electric power generation. Nuclear plants in these countries are built in six to eight years using technology developed in the US, with good performance and safety records. This treatise addresses the success experienced by the US nuclear industry over the last 40 years, and makes the case that this reliable, cost-competitive source of electric power can help support the economic engine of the country and help prevent experiences like the recent crises in California and the Northeast. Successful operation of nuclear facilities is determined by examining capacity or load factors. Load factor is the percentage of design generating capacity that a power plant actually produces over the course of a year's operation. This paper makes the case that these operating performance indicators warrant renewed consideration of the nuclear option. Usage of electricity in the US now approaches total generating capacity. The Nuclear Regulatory Commission has pre-approved construction and operating licenses for several nuclear plant designs. State public service commissions are beginning to understand that dramatic reform is required. The economy is recovering and inflation

Interactive domains in the molecular chaperone human alphaB crystallin modulate microtubule assembly and disassembly.

Directory of Open Access Journals (Sweden)

Joy G Ghosh

2007-06-01

Full Text Available Small heat shock proteins regulate microtubule assembly during cell proliferation and in response to stress through interactions that are poorly understood.Novel functions for five interactive sequences in the small heat shock protein and molecular chaperone, human alphaB crystallin, were investigated in the assembly/disassembly of microtubules and aggregation of tubulin using synthetic peptides and mutants of human alphaB crystallin.The interactive sequence (113FISREFHR(120 exposed on the surface of alphaB crystallin decreased microtubule assembly by approximately 45%. In contrast, the interactive sequences, (131LTITSSLSSDGV(142 and (156ERTIPITRE(164, corresponding to the beta8 strand and the C-terminal extension respectively, which are involved in complex formation, increased microtubule assembly by approximately 34-45%. The alphaB crystallin peptides, (113FISREFHR(120 and (156ERTIPITRE(164, inhibited microtubule disassembly by approximately 26-36%, and the peptides (113FISREFHR(120 and (131LTITSSLSSDGV(142 decreased the thermal aggregation of tubulin by approximately 42-44%. The (131LTITSSLSSDGV(142 and (156ERTIPITRE(164 peptides were more effective than the widely used anti-cancer drug, Paclitaxel, in modulating tubulinmicrotubule dynamics. Mutagenesis of these interactive sequences in wt human alphaB crystallin confirmed the effects of the alphaB crystallin peptides on microtubule assembly/disassembly and tubulin aggregation. The regulation of microtubule assembly by alphaB crystallin varied over a narrow range of concentrations. The assembly of microtubules was maximal at alphaB crystallin to tubulin molar ratios between 1:4 and 2:1, while molar ratios >2:1 inhibited microtubule assembly.Interactive sequences on the surface of human alphaB crystallin collectively modulate microtubule assembly through a dynamic subunit exchange mechanism that depends on the concentration and ratio of alphaB crystallin to tubulin. These are the first

Development of decontamination technology for the decommissioned Bohunice A-1 nuclear power plant

International Nuclear Information System (INIS)

Krejci, F.; Majersky, D.; Solcanyi, M.; Sekely, S.; Kucharik, D.

1991-01-01

The main results of investigation into the decontamination technology for the equipment and buildings of the decommissioned A-1 nuclear power plant, achieved by the Nuclear Power Plants Research Institute in Trnava over the 1988-1990 period, are summarized. Mobile decontamination and recirculation equipment has been developed for pre-disassembling decontamination. A solution containing formic acid (19 g/l), EDTA-Na 4 (6 g/l) and thiourea (0.5 g/l) was used for decontamination of low-alloy steels; for materials from the steam generators and turbo-compressors, the decontamination factor (DF) of this solution was 30 to 150 per decontamination cycle. For high-alloy steels, a two-stage process comprising the use of an oxidation solution and a reduction solution appeared suitable. The oxidation solution contained potassium permanganate (0.6 g/l) and nitric acid (0.4 g/l), whereas the reduction solution, viz. Citrox 21, contained citric acid (0.5 g/l), oxalic acid (1.0 g/l) and EDTA-NA 4 (2.5 g/l). The DF is 10 to 50 in one oxidation-reduction cycle and 50-100 in two cycles. For the post-disassembling chemical decontamination, the contaminated material was cut into pieces 70 to 80 cm long, freed from grease and decontaminated chemically by submerging in the solution while applying treatment by ultrasound. A technology of electrochemical decontamination has also been developed. It appeared particularly suitable for structural materials of the primary coolant circuit comprising austenitic stainless steels and low-alloy steels after pre-disassembling chemical decontamination with remainders of the corrosion layer, and for structural materials of the secondary coolant circuit after chemical post-disassembling decontamination. Research in the field of decontamination of the building parts and of the outer surfaces of the structural materials concentrated mainly on the use of decontamination foams. Foaming solutions have been developed for the decontamination of PESL floors and

Confirmation of the seismic resistance of nuclear power plant equipment after assembly

International Nuclear Information System (INIS)

Kaznovsky, P. S.; Kaznovsky, A. P.; Saakov, E. S.; Ryasnyj, S. I.

2013-01-01

It is shown that the natural frequencies and damping decrements of nuclear power plant equipment can only be determined experimentally and directly at the power generation units (reactors) of nuclear power plants under real disassembly conditions for the equipment, piping network, thermal insulation, etc. A computational experimental method is described in which the natural frequencies and damping decrements are determined in the field and the seismic resistance is reevaluated using these values. This method is the basis of the standards document “Methods for confirming the dynamic characteristics of systems and components of the generating units of nuclear power plants which are important for safety” prepared and introduced in 2012.

Explosion-evaporation model for fragment production in intermediate-energy nuclear collisions

International Nuclear Information System (INIS)

Fai, G.; Randrup, J.

1981-01-01

Nuclear collisions at intermediate energies may create transient systems of hot nuclear matter that decay into many nuclear fragments. The disassembly of such a nuclear fireball is described as a two-stage process. In the primary explosion stage the system quickly fragments into nucleons and composite nuclei according to the available phase space. The explosion produces excited nuclei with half-lives longer than the time associated with the breakup. In the secondary evaporation stage, these nuclei decay, first by sequential emission of light particles (neutrons, protons, alphas), later by electromagnetic radiation. The secondary stage in general changes the relative abundancies of the various fragment species. This general feature makes it essential to take account of the composite fragments before using d/p as a measure of the entropy of the initial source. The formation of unbound nuclei at the explosion stage also has the desirable effect of enhancing the final abundancies of particularly stable nuclei, e.g., 4 He. For neutron-excessive sources the presence of composite nuclei amplifies the ratio of observed neutrons and protons; this effect persists for heavier mirror systems. Predictions of the model are qualitatively compared to available experimental data. The model offers a convenient way to augment existing dynamical models, such as intra-nuclear cascade and nuclear fluid dynamics, to yield actual nuclear fragments rather than merely matter distributions

Polygons and adhesion plaques and the disassembly and assembly of myofibrils in cardiac myocytes.

Science.gov (United States)

Lin, Z X; Holtzer, S; Schultheiss, T; Murray, J; Masaki, T; Fischman, D A; Holtzer, H

1989-06-01

Successive stages in the disassembly of myofibrils and the subsequent assembly of new myofibrils have been studied in cultures of dissociated chick cardiac myocytes. The myofibrils in trypsinized and dispersed myocytes are sequentially disassembled during the first 3 d of culture. They split longitudinally and then assemble into transitory polygons. Multiples of single sarcomeres, the cardiac polygons, are analogous to the transitory polygonal configurations assumed by stress fibers in spreading fibroblasts. They differ from their counterparts in fibroblasts in that they consist of muscle alpha-actinin vertices and muscle myosin heavy chain struts, rather than of the nonmuscle contractile protein isoforms of stress fiber polygons. EM sections reveal the vertices and struts in cardiac polygons to be typical Z and A bands. Most cardiac polygons are eliminated by day 5 of culture. Concurrent with the disassembly and elimination of the original myofibrils new myofibrils are rapidly assembled elsewhere in the same myocyte. Without exception both distal tips of each nascent myofibril terminate in adhesion plaques. The morphology and composition of the adhesion plaques capping each end of each myofibril are similar to those of the termini of stress fibers in fibroblasts. However, whereas the adhesion complexes involving stress fibers in fibroblasts consist of vinculin/nonmuscle alpha-actinin/beta- and gamma-actins, the analogous structures in myocytes involving myofibrils consist of vinculin/muscle alpha-actinin/alpha-actin. The addition of 1.7-2.0 microns sarcomeres to the distal tips of an elongating myofibril, irrespective of whether the myofibril consists of 1, 10, or several hundred tandem sarcomeres, occurs while the myofibril appears to remain linked to its respective adhesion plaques. The adhesion plaques in vitro are the equivalent of the in vivo intercalated discs, both in terms of their molecular composition and with respect to their functioning as initiating

Organization of the lamin scaffold in the internal nuclear matrix of normal and transformed hepatocytes

International Nuclear Information System (INIS)

Barboro, Paola; D'Arrigo, Cristina; Repaci, Erica; Patrone, Eligio; Balbi, Cecilia

2010-01-01

Nuclear lamins are among the more abundant proteins making up the internal nuclear matrix, but very little is known about their structure in the nucleoplasm. Using immunoelectron microscopy, we demonstrate the organization of lamins in the nuclear matrix isolated from rat hepatocytes for the first time. Lamin epitopes are arrayed both in locally ordered clusters and in quasi-regular rows. Fourier filtering of the images demonstrates that the epitopes are placed at the nodes and halfway between the nodes of square or rhombic lattices that are about 50 nm on each side, as well as along rows at regular ∼25-nm intervals. In addition, we have compared this structure with that of the internal nuclear matrix isolated from persistent hepatocyte nodules. In transformed hepatocytes, the islands of lamin lattice are lost, and only a partial regularity in the rows of gold particles remains. We suggest that orthogonal lattice assembly might be an intrinsic property of lamin molecules, and that the disassembly may be triggered by simple molecular events such as phosphorylation.

Program for upgrading nuclear materials protection, control, and accounting at all facilities within the All-Russian Institute of Experimental Physics (VNIIEF)

International Nuclear Information System (INIS)

Yuferev, V.; Zhikharev, S.; Yakimov, Y.

1998-01-01

As part of the Department of Energy-Russian program for strengthening nuclear material protection, control, and accounting (MPC and A), plans have now been formulated to install an integrated MPC and A system at all facilities containing large quantities of weapons-usable nuclear material within the All-Russian Institute of Experimental Physics (VNIIEF, Arzamas-16) complex. In addition to storage facilities, the complex houses a number of critical facilities used to conduct nuclear physics research and facilities for developing procedures for disassembly of nuclear weapons

Exploiting nuclear plants in time

International Nuclear Information System (INIS)

Tran, Lionel

2011-02-01

This document outlines that the French fleet of 58 reactors is only 25 year old in average, and that nuclear safety is strongly regulated, and notably relies on improved indicators and on a decennial re-assessment. It outlines that nuclear energy is a response to energy challenges and that it is therefore relevant to operate the nuclear fleet beyond the initially foreseen lifetime (40 years). Due to maintenance and renewal activities, plants are supposed to be safer and more efficient. To guarantee an always safer and more efficient operation in time, five actions are highlighted: decennial controls, installation and equipment modifications, control and anticipation of installation and equipment wear, competencies and ability renewal, better knowledge of techniques and technologies

Method for inspecting nuclear reactor fuel elements

International Nuclear Information System (INIS)

Jabsen, F.S.

1979-01-01

A technique for disassembling a nuclear reactor fuel element without destroying the individual fuel pins and other structural components from which the element is assembled is described. A traveling bridge and trolley span a water-filled spent fuel storage pool and support a strongback. The strongback is under water and provides a working surface on which the spent fuel element is placed for inspection and for the manipulation that is associated with disassembly and assembly. To remove, in a non-destructive manner, the grids that hold the fuel pins in the proper relative positions within the element, bars are inserted through apertures in the grids with the aid of special tools. These bars are rotated to flex the adjacent grid walls and, in this way relax the physical engagement between protruding portions of the grid walls and the associated fuel pins. With the grid structure so flexed to relax the physical grip on the individual fuel pins, these pins can be withdrawn for inspection or replacement as necessary without imposing a need to destroy fuel element components

History and current status of nuclear fuel reprocessing technology

International Nuclear Information System (INIS)

Funasaka, Hideyuki; Nagai, Toshihisa; Washiya, Tadahiro

2008-01-01

History and present state of fast breeder reactor was reviewed in series. As a history and current status of nuclear fuel reprocessing technology, this ninth lecture presented the progress of the FBR fuel reprocessing technology and advanced reprocessing processes. FBR fuel reprocessing technology had been developed to construct the reprocessing equipment test facilities (RETF) based on PUREX process technologies. With economics, reduction of environmental burdens and proliferation resistance taken into consideration, advanced aqueous method for nuclear fuel cycle activities has been promoted as the government's basic policy. Innovative technologies on mechanical disassembly, continuous rotary dissolver, crystallizer, solvent extraction and actinides recovery have been mainly studied. (T. Tanaka)

Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform

International Nuclear Information System (INIS)

Gallagher, John R.; Torian, Udana; McCraw, Dustin M.; Harris, Audray K.

2017-01-01

While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

Characterization of the disassembly and reassembly of the HBV glycoprotein surface antigen, a pliable nanoparticle vaccine platform

Energy Technology Data Exchange (ETDEWEB)

Gallagher, John R.; Torian, Udana; McCraw, Dustin M.; Harris, Audray K., E-mail: harrisau@mail.nih.gov

2017-02-15

While nanoparticle vaccine technology is gaining interest due to the success of vaccines like those for the human papillomavirus that is based on viral capsid nanoparticles, little information is available on the disassembly and reassembly of viral surface glycoprotein-based nanoparticles. One such particle is the hepatitis B virus surface antigen (sAg) that exists as nanoparticles. Here we show, using biochemical analysis coupled with electron microscopy, that sAg nanoparticle disassembly requires both reducing agent to disrupt intermolecular disulfide bonds, and detergent to disrupt hydrophobic interactions that stabilize the nanoparticle. Particles were otherwise resistant to salt and urea, suggesting the driving mechanism of particle formation involves hydrophobic interactions. We reassembled isolated sAg protein into nanoparticles by detergent removal and reassembly resulted in a wider distribution of particle diameters. Knowledge of these driving forces of nanoparticle assembly and stability should facilitate construction of epitope-displaying nanoparticles that can be used as immunogens in vaccines.

Authorized Limits for the Release of a 25 Ton Locomotive, Serial Number 21547, at the Area 25 Engine Maintenance, Assembly, and Disassembly Facility, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

Gwin, Jeremy; Frenette, Douglas

2010-01-01

This document contains process knowledge and radiological data and analysis to support approval for release of the 25-ton locomotive, Serial Number 21547, at the Area 25 Engine Maintenance, Assembly, and Disassembly (EMAD) Facility, located on the Nevada Test Site (NTS). The 25-ton locomotive is a small, one-of-a-kind locomotive used to move railcars in support of the Nuclear Engine for Rocket Vehicle Application project. This locomotive was identified as having significant historical value by the Nevada State Railroad Museum in Boulder City, Nevada, where it will be used as a display piece. A substantial effort to characterize the radiological conditions of the locomotive was undertaken by the NTS Management and Operations Contractor, National Security Technologies, LLC (NSTec). During this characterization process, seven small areas on the locomotive had contamination levels that exceeded the NTS release criteria (limits consistent with U.S. Department of Energy (DOE) Order DOE O 5400.5, 'Radiation Protection of the Public and the Environment'). The decision was made to perform radiological decontamination of these known accessible impacted areas to further the release process. On February 9, 2010, NSTec personnel completed decontamination of these seven areas to within the NTS release criteria. Although all accessible areas of the locomotive had been successfully decontaminated to within NTS release criteria, it was plausible that inaccessible areas of the locomotive (i.e., those areas on the locomotive where it was not possible to perform radiological surveys) could potentially have contamination above unrestricted release limits. To access the majority of these inaccessible areas, the locomotive would have to be disassembled. A complete disassembly for a full radiological survey could have permanently destroyed parts and would have ruined the historical value of the locomotive. Complete disassembly would also add an unreasonable financial burden for the

New findings on the onset of thermal disassembly in spallation reactions

International Nuclear Information System (INIS)

Napolitani, P.

2004-09-01

Thermal multifragmentation is the process of multi body disassembly of a hot nucleus when the excitation is almost purely thermal i.e. dynamical effects like compression (characteristic of ion-ion collisions at Fermi energy) are negligible. Suited reactions are proton induced collision or ion-ion abrasion at relativistic incident energy. Thus we measured four systems at FRS (Fragment separator, GSI, Darmstadt) in inverse kinematics: Fe 56 +p, Fe 56 +Ti(nat), Xe 136 +p, Xe 136 +Ti(nat) a 1 A*GeV. The inverse kinematics allows to observe all particles without any threshold in energy. This is a great advantage compared to experiments in direct kinematics, because only in inverse kinematics it is possible to obtain complete velocity spectra (without a hole for low velocities) for fully identified isotopes. The complex shape of the velocity spectra allows to identify the different deexcitation channels and it clearly shows the transition from a chaotic-dominated process (Gaussian cloud in velocity space) to a direct Coulomb- (or eventually expansion-) dominated process (shell of a sphere in velocity space). Different possible descriptions of the reaction process are discussed, based either on asymmetric fission or multifragmentation. The resulting physical picture is especially interesting for the Fe 56 +p, and Xe 136 +p systems: proton induced collisions could result in the split of the system in two or more fragments due to a fast break-up process. In this case, the configuration of the break-up partition is very asymmetric. The discussion will be extended to other characteristics, like the restoring of nuclear structure features in the isotopic production and the temperature dependence of the isotopic composition of the residues. (author)

Innovation and employee injury risk in automotive disassembly operations

DEFF Research Database (Denmark)

Neumann, W. Patrick; Winkel, Jørgen; Palmerud, Gunnar

2018-01-01

to control injury hazards as part of the development and design process. These cases suggest how failure to manage RSI hazards in the innovation process may allow increases of injury risks that can compromise operational performance. This ‘innovation pitfall’ has implications for operator health...... increased movement speeds and reduced muscular recovery opportunities, implying increased RSI risk. This case study reveals a mechanism by which innovation may increase RSI risks for operators. Managers responsible for engineering innovation should ensure their teams have the tools and mandate necessary......Engineering innovations in car disassembly systems are studied for affects on system operators’ risk of repetitive strain injury (RSI). Objective instrumented measures of injury risk factors with synchronised video-based task analyses were used to examine changes in operators’ RSI risk during...

Disassembly Control of Saccharide-Based Amphiphiles Driven by Electrostatic Repulsion.

Science.gov (United States)

Yamada, Taihei; Kokado, Kenta; Sada, Kazuki

2017-03-14

According to the design of disassembly using electrostatic repulsion, novel amphiphiles consisting of a lipophilic ion part and a hydrophilic saccharide part were synthesized via the facile copper-catalyzed click reaction, and their molecular assemblies in water and chloroform were studied. The amphiphiles exhibited a molecular orientation opposite to that of the conventional amphiphiles in each case. ζ Potential measurements indicated that the lipophilic ion part is exposed outside in chloroform. The size of a solvophobic part in the amphiphiles dominates the size of an assembling structure; that is, in water, these amphiphiles tethering different lengths of the saccharide part exhibited almost identical assembling size, whereas in chloroform, the size depends on the length of the saccharide part in the amphiphiles.

Application of laser processing for disassembly of nuclear power plants

Science.gov (United States)

Baranov, Gennady A.; Zinchenko, A. V.; Arutyunyan, R. B.

1998-12-01

Provision of safety and drop of ecological risk at salvaging of nuclear submarines (NSM) of Russia Navy Forces represents one of the most actual problems of nowadays. It is necessary to remove from services of Russian Navy Forces 170 - 180 nuclear submarines by 2000. At salvaging of Russian Navy Forces NSM it should be necessary to cut out reactor compartments with more than 150 thousand tons of gross weight and to fragment terminal carcasses of submarines with gross weight of 2 million tons. Taking into account overall dimensions of salvaging objects and Euro-standard requirement on the sizes of carcass fragments, for salvaging of one NSM it is necessary to execute more than 10 km of cuts. Using of conventional methods of gas and plasma cutting of ship constructions and equipment polluted with radioactive oxides and bedding of insulation and paint and varnish materials causes contamination of working zones and environment by a mix of radioactive substances and highly toxic combustion products, nomenclature of which includes up to 50 names. Calculations carried out in the Institute of industrial and Marine Medicine have shown that salvage of just one NSM with using of gas and plasma cutting are accompanied by discharge into an environment of up to 11.5 kg of chromium oxides, up to 22.5 kg of manganese oxides, up to 97 kg of carbon oxides and up to 650 kg of nitrogen oxides. Fragmentation of such equipment by a method of directional explosion or hydraulic jet is problematic because of complexity of treated constructions and necessity to create special protective facilities, which will accumulate a bulk of radioactive and toxic discharges, as a consequence of the explosion and spreaded by shock waves and water deluges. In a number of new technological processes the cutting with using of high-power industrial lasers radiation stands out. As compared with other technological processes, laser cutting has many advantages determined by such unique properties of laser

Testing of different data libraries in activation analysis of concrete and graphite from nuclear installations

International Nuclear Information System (INIS)

Cometto, M.; Ancius, D.; Ridikas, D.

2003-01-01

With the aging of the nuclear park, decommissioning and dismantling of nuclear installations after their service life is becoming an important issue for the nuclear industry. The radiological characterisation of the equipment and structures present in the reactor and its environment is an essential stage in a decommissioning project since it permits to define and optimize the decommissioning strategy and the disassembling operations. In addition, correct activation estimates are essential for determining the quantity and the nature of the radiological waste generated during decommissioning. The adoption of efficient dismantling procedures and the optimization of the mass flow going to different waste repositories might reduce substantially the total cost of decommissioning. The present work has been done in the framework of the decommissioning and dismantling of the experimental reactor of the University of Strasbourg (RUS). A methodology that combines theoretical calculations and direct measurements has been developed for determining the long-term induced activity in the graphite, concrete and materials present in the reactor. After characterisation of the different elements present in the reactor, it is then possible to plan efficiently the disassembling and dismantling of the system and to optimise the mass flow going to different waste repositories. From a scientific perspective, the comparison of theoretical predictions with experimental values validates the approach and the methodology used in the present study and tests the consistency and the reliability of the nuclear data used for activation analysis. (orig.)

T1R3 homomeric sweet taste receptor regulates adipogenesis through Gαs-mediated microtubules disassembly and Rho activation in 3T3-L1 cells.

Directory of Open Access Journals (Sweden)

Yosuke Masubuchi

Full Text Available We previously reported that 3T3-L1 cells express a functional sweet taste receptor possibly as a T1R3 homomer that is coupled to Gs and negatively regulates adipogenesis by a Gαs-mediated but cAMP-independent mechanism. Here, we show that stimulation of this receptor with sucralose or saccharin induced disassembly of the microtubules in 3T3-L1 preadipocytes, which was attenuated by overexpression of the dominant-negative mutant of Gαs (Gαs-G226A. In contrast, overexpression of the constitutively active mutant of Gαs (Gαs-Q227L as well as treatment with cholera toxin or isoproterenol but not with forskolin caused disassembly of the microtubules. Sweetener-induced microtubule disassembly was accompanied by activation of RhoA and Rho-associated kinase (ROCK. This was attenuated with by knockdown of GEF-H1, a microtubule-localized guanine nucleotide exchange factor for Rho GTPase. Furthermore, overexpression of the dominant-negative mutant of RhoA (RhoA-T19N blocked sweetener-induced dephosphorylation of Akt and repression of PPARγ and C/EBPα in the early phase of adipogenic differentiation. These results suggest that the T1R3 homomeric sweet taste receptor negatively regulates adipogenesis through Gαs-mediated microtubule disassembly and consequent activation of the Rho/ROCK pathway.

Time of glory and cultivating : 30 years with nuclear energy

International Nuclear Information System (INIS)

Cha, Jong Hui

1994-09-01

This autobiography describes the time of studying on nuclear energy. It tells us the story of dedicated life for research on nuclear energy for 30 years. It includes his studying abroad and studying, solar heat age, the first safety test of nuclear reactor, time of glory and trial another beginning, a speech in Malaysia and remembrance of nuclear energy for 50 years.

Time of glory and cultivating : 30 years with nuclear energy

Energy Technology Data Exchange (ETDEWEB)

Cha, Jong Hui

1994-09-15

This autobiography describes the time of studying on nuclear energy. It tells us the story of dedicated life for research on nuclear energy for 30 years. It includes his studying abroad and studying, solar heat age, the first safety test of nuclear reactor, time of glory and trial another beginning, a speech in Malaysia and remembrance of nuclear energy for 50 years.

The development of underwater remote cutting method for the disassembling of rotary specimen rack KRR-1 and 2

Energy Technology Data Exchange (ETDEWEB)

Lee, D. K.; Jung, K. H.; Lee, K. W.; Oh, W. J. [KAERI, Taejon (Korea, Republic of); Lee, K. Y. [Korea Institute of Industrial Technology, Kwangju (Korea, Republic of)

2004-07-01

The Rotary Specimen Racks (RSRs) were highly activated and then classified intermediate level radioactive waste for the decommissioning of KRR-1anel2. The RSR can be treated as low level radioactive waste after removing stainless steel parts. To reduce the volume of intermediate level radioactive waste, underwater cutting is required to separate stainless steel parts from RSR because of high radioactivity. In this study, the automatic remote cutting method was developed to disassemble RSR under water. For automatic remote cutting processes, a CAM (Computer Aided Manufacturing) system is employed. A computer inputs NC (Numerical Control) codes to the controller, which are based on CAM model, and the controller instructs the equipment to process according to NC codes automatically. And the cutting force model was improved to cut RSR stably. The automatic cutting was conducted using imitation of RSR and then it was resulted that the developed automatic cutting method can be safely disassemble stainless steel parts of RSR under water.

Maintenance and disassembly considerations for the Technology Demonstration Facility

International Nuclear Information System (INIS)

Spampinato, P.T.

1983-01-01

The Technology Demonstration Facility (TDF) is a tandem-mirror design concept carried out under the direction of Lawrence Livermore National Laboratory. It was conceived as a near-term device with a mission of developing engineering technology in a D-T fusion environment. Overall maintenance and component disassembly were among the responsibilities of the Fusion Engineering Design Center (FEDC). A configuration evolved that was based on the operational requirements of the components, as well as the requirements for their replacements. Component lifetime estimates were used to estimate the frequency and the number of replacements. In addition, it was determined that the need for remote handling equipment followed within 1.5 years after initial start-up, emphasizing the direct relationship between developing maintenance scenarios/equipment and the device configuration. Many of the scheduled maintenance operations were investigated to first order, and preliminary handling equipment concepts were developed

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

Science.gov (United States)

Rios, Pedro; Stuart, Julie Ann; Grant, Ed

2003-12-01

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

Stimuli-disassembling gold nanoclusters for diagnosis of early stage oral cancer by optical coherence tomography

Science.gov (United States)

Kim, Chang Soo; Ingato, Dominique; Wilder-Smith, Petra; Chen, Zhongping; Kwon, Young Jik

2018-01-01

A key design consideration in developing contrast agents is obtaining distinct, multiple signal changes in diseased tissue. Plasmonic gold nanoparticles (Au NPs) have been developed as contrast agents due to their strong surface plasmon resonance (SPR). This study aims to demonstrate that stimuli-responsive plasmonic Au nanoclusters (Au NCs) can be used as a contrast agent for optical coherence tomography (OCT) in detecting early-stage cancer. Au NPs were clustered via acid-cleavable linkers to synthesize Au NCs that disassemble under mildly acidic conditions into individual Au NPs, simultaneously diminishing SPR effect (quantified by scattering intensity) and increasing Brownian motion (quantified by Doppler variance). The acid-triggered morphological and accompanying optico-physical property changes of the acid-disassembling Au NCs were confirmed by TEM, DLS, UV/Vis, and OCT. Stimuli-responsive Au NCs were applied in a hamster check pouch model carrying early-stage squamous carcinoma tissue. The tissue was visualized by OCT imaging, which showed reduced scattering intensity and increased Doppler variance in the dysplastic tissue. This study demonstrates the promise of diagnosing early-stage cancer using molecularly programmable, inorganic nanomaterial-based contrast agents that are capable of generating multiple, stimuli-triggered diagnostic signals in early-stage cancer.[Figure not available: see fulltext.

Technical review of WSRC-TR-93-614 criticality safety evaluation for disassembly basin sand filter

International Nuclear Information System (INIS)

Reed, R.L.

1994-01-01

The study documented in WSRC-TR-93-614 performed an evaluation of the criticality potential associated with the Disassembly Basin Sand Filter for K and L Areas. The document reviewed incorporated results of calculations documented in the engineering calculation N-CLC-K-00151. Analyses of the contents of disassembly basin sludge has indicated that the sludge contains fissile material in excess of subcritical mass limits as specified in ANSI/ANS standards. Previous studies had determined that the fissile material can not collect into a critical configuration in the basin. Since the sand filter is intended to remove suspended particles from the basin water and could serve as a mechanism to collect the fissile material into a critical configuration, the study examined conditions under which criticality could occur in the sand filter. The study shows that criticality is not considered possible in the sand filter. This review emphasized the technical accuracy and presentation of the evaluation. The evaluation was also examined for the elements required for NCSEs. The review was performed in accordance with the NRTSC technical review requirements and procedures and the E7 Manual technical review requirements. The technical review (per the E7 manual) of the engineering calculation (N-CLC-K-0 1 5 1) was previously performed by this reviewer

Alpha Decontamination and Disassembly Pilot Facility. Final report

International Nuclear Information System (INIS)

Daugherty, B.A.; Clark, H.E.

1985-04-01

The Alpha Decontamination and Disassembly (AD and D) Pilot Facility was built to develop and demonstrate a reference process for the decontamination and size reduction of noncombustible transuranic (TRU) waste. The goals of the reference process were to remove >99% of the surface contamination to the high-level waste tanks, and to achieve volume reduction factors greater than 15:1. Preliminary bench-scale decontamination work was accomplished at Savannah River Laboratory (SRL), establishing a reference decontamination process. Initially, the pilot facility did not achieve the decontamination goals. As the program continued, and modifications to the process were made, coupon analysis idicated that 99% of the surface contamination was removed to the high-level drain system. Prior to the AD and D Pilot Facility, no size reduction work had been done at SRL. Several other Department of Energy (DOE) facilities were experimenting with plasma arc torches for size reduction work. Their methods were employed in the AD and D hot cell with moderate success. The experimental work concluded with recommendations for further testing of other size reduction techniques. 11 figs., 6 tabs

Cesium removal from the fuel storage water at the Savannah River Site R-Building Disassembly Basin using 3M Empore reg-sign-membrane filter technology

International Nuclear Information System (INIS)

Oji, L.N.; Thompson, M.C.; Peterson, K.; May, C.; Kafka, T.M.

1998-01-01

This report describes results from a seven-day demonstration of the use of 3M Empore membrane filter loaded with ion exchange material (potassium cobalt hexacynoferrate (CoHex)) for cesium uptake from the R-Disassembly Basin at the Savannah River Site. The goal of the demonstration was to evaluate the ability of the Process Absorber Development unit (PADU), a water pre-filtration /CoHex configuration on a skid, to remove cesium from R-Disassembly Basin at a linear processing flow rate of 22.7 liters per minute (1,195.8 liters/minute/m 2 or 29.35 gallons/minute/ft 2 ). Over 210,000 liters (> 55,500 gallons) of R-Disassembly Basin water was processed through the PADU without a cesium breakthrough, that is, the effluent after treatment with CoHex, contained less than detectable amounts of radioactive cesium. Some of the observed advantages of the Empore membrane filter technology over conventional packed column ion exchange systems includes rapid flow rates without channeling effects, low volume secondary waste and fast extraction or rapid kinetics per unit of flow

Nuclear physics at Ganil. A compilation 1989-1991

International Nuclear Information System (INIS)

1991-01-01

This compilation deals with experimental and theoretical work performed at GANIL for the 1989-1991 years about the nuclear structure and nuclear reactions. During this period, the accelerator performances have been strongly increased, as well for the delivered energies and intensities as for the span of accelerated ions. In the experimental areas, a totally new data acquisition system has been set up, and the adding of a Wien filter to the Lise spectrometer results now in a versatile and efficient isotope separator, called LISE III. The time structure and the large intensity of the beam were decisive in identifying, for the first time, kaon production in heavy ions collisions at the GANIL subthreshold energies. Nucleons have to undergo several collisions before inducing such a process, and the strange particle emission should be very sensitive to the physical conditions of the hot and compressed interacting zone. Lead and Uranium beams now available at the Fermi energy, have been used to study the nuclear disassembly of very large and heavy systems. New results have been obtained on the collective flow in heavy ion reactions, giving new insights on the Equation of State problematics. In the field of nuclear structure, the magnetic spectrometer SPEG, coupled with large particle or gamma detectors shed light on new aspects of the giant resonance excitations. Exotic nuclei are extensively studied, with a particular emphasis on the 11Li nucleus. A new method of mass measurement, using the CSS2 as a mass separator, has been successfully tested; it will greatly improve the accuracy achieved on intermediate and heavy nuclei. Last but not least, the theory group is actively working to include fluctuations in the description of the nuclear dynamics and to characterise the onset of the multifragmentation process in heavy ion collisions. Author index and publication list are added

Practice and prospects of creation of equipment for reprocessing and utilization of contaminated metal wastes of plants of nuclear industry in Russia

International Nuclear Information System (INIS)

Popov, G.P.

2005-01-01

Program of reprocessing and utilization of metallic radioactive wastes exists in Russia. In the framework of this program in nuclear industry it is accumulated forty years experience on taking-off-service, disassembly, decontamination and reprocessing of technological facilities. Some technical characteristics of the units used for these operations are represented [ru

Time-series-analysis techniques applied to nuclear-material accounting

International Nuclear Information System (INIS)

Pike, D.H.; Morrison, G.W.; Downing, D.J.

1982-05-01

This document is designed to introduce the reader to the applications of Time Series Analysis techniques to Nuclear Material Accountability data. Time series analysis techniques are designed to extract information from a collection of random variables ordered by time by seeking to identify any trends, patterns, or other structure in the series. Since nuclear material accountability data is a time series, one can extract more information using time series analysis techniques than by using other statistical techniques. Specifically, the objective of this document is to examine the applicability of time series analysis techniques to enhance loss detection of special nuclear materials. An introductory section examines the current industry approach which utilizes inventory differences. The error structure of inventory differences is presented. Time series analysis techniques discussed include the Shewhart Control Chart, the Cumulative Summation of Inventory Differences Statistics (CUSUM) and the Kalman Filter and Linear Smoother

Instability in nuclear dynamics: loss of collectivity and multifragmentation

International Nuclear Information System (INIS)

Colonna, M.; Di Toro, M.; Guarnera, A.; Latora, V.; Smerzi, A.

1995-01-01

Two limiting cases of nuclear dynamics are analysed: the disappearing of giant collective motions in hot nuclei and the nuclear disassembly in violent heavy ion collisions. For collective vibration build on excited states we get a dramatic increase of the widths of hot Giant Dipole Resonances (GDR). As a consequence of the competition with particle evaporation we get a sharp quenching of giant photon emission. Pre-equilibrium effects on the GDR formation are also accounted for. At high temperature and low density the collective motions can become unstable leading to multifragmentation events in heavy ion collisions. We present a general procedure to identify instability regions and to get informations on the instability point. Some hints towards fully dynamical picture of multi-fragmentation processes are finally suggested. (author)

Introductory Education for Mechanical Engineering by Exercise in Mechanical Disassembly

Science.gov (United States)

Matsui, Yoshio; Asakawa, Naoki; Iwamori, Satoru

An introductory program “Exercise for engineers in mechanical disassembly” is an exercise that ten students of every team disassemble a motor scooter to the components and then assemble again to the initial form in 15 weeks. The purpose of this program is to introduce mechanical engineering by touching the real machine and learning how it is composed from various mechanical parts to the students at the early period after the entrance into the university. Additional short lectures by young teachers and a special lecture by a top engineer in the industry encourage the students to combine the actual machine and the mechanical engineering subjects. Furthermore, various educations such as group leader system, hazard prediction training, parts filing are included in this program. As a result, students recognize the importance of the mechanical engineering study and the way of group working.

Support of nuclear fusion apparatus

International Nuclear Information System (INIS)

Watarai, Tetsuo; Ito, Yutaka.

1975-01-01

Object: To integrally form a bed for a body for supporting a vacuum container, coil and the like and a bed for a current transformer for supporting the current transformer prior to installation thereof on the floor thereby facilitating assembly and installation. Structure: To provide a base common to a current transformer bed and a body bed without direct installation thereof on the floor. Prior to installation of the current transformer bed and body bed, they are fastened to the base by means of bolts and welded integrally, and the thus formed base is fixed to the floor by means of anchor bolts. Since the current transformer bed and the body bed are formed integrally through the common base, apparatus may easily be carried in and disassembling and re-assembling of apparatus become unnecessary when installed. Further, since the positional relation of the current transformer bed and body bed does not depend on accuracy at the time of installation but depends on accuracy when apparatus manufactured, the toroidal type nuclear fusion apparatus of good accuracy may be obtained. (Yoshihara, H.)

The impact of project management on nuclear construction lead times

International Nuclear Information System (INIS)

Radlaver, M.A.; Bauman, D.S.; Chapel, S.W.

1985-01-01

A two-year study of lead times for nuclear power plants found that construction time is affected by six fundamental influences. One of the six is project management. An analysis of construction management teams at 26 nuclear units found that many of the most successful shared five general characteristics: nuclear power experience, skill in project control, adaptability and initiative, commitment to success, and communication and coordination skill

Interactive real-time nuclear plant simulations on a UNIX based supercomputer

International Nuclear Information System (INIS)

Behling, S.R.

1990-01-01

Interactive real-time nuclear plant simulations are critically important to train nuclear power plant engineers and operators. In addition, real-time simulations can be used to test the validity and timing of plant technical specifications and operational procedures. To accurately and confidently simulate a nuclear power plant transient in real-time, sufficient computer resources must be available. Since some important transients cannot be simulated using preprogrammed responses or non-physical models, commonly used simulation techniques may not be adequate. However, the power of a supercomputer allows one to accurately calculate the behavior of nuclear power plants even during very complex transients. Many of these transients can be calculated in real-time or quicker on the fastest supercomputers. The concept of running interactive real-time nuclear power plant transients on a supercomputer has been tested. This paper describes the architecture of the simulation program, the techniques used to establish real-time synchronization, and other issues related to the use of supercomputers in a new and potentially very important area. (author)

Time-space structure of nuclear safety

International Nuclear Information System (INIS)

Miya, Kenzo

2003-01-01

New idea to analyze the structure of nuclear safety and to investigate functioning property of hierarchical principle is applied to nuclear safety in this paper. The nuclear safety is expressed by three principles such as 1) the action and subject are partitioned and classified by time and space, 2) introduction of hierarchy with three strata to the closed object and hierarchy with many strata to the open object and 3) application of 'element, relation and abstraction' to the engineering system as a framework of intellectual activity. For example, prevention of core melt is the closed object and it is obtained by acting hierarchies with three strata (operation stop, cooling and closing radiation) as the safety functions. Prevention of increase of accident is open object, so that, space hierarchy with many strata of prevention is used for the safety security of reactor. The safety security method of reactor consists of three processes, that is 1) the basic process to make clear the continuous operating time on the basis of regular inspection, 2) the action process of operating ECCS to prevent core damage accident, when a large leakage happens and 3) many strata prevention process of stopping a leak in the environment. (S.Y.)

KADIS: a program to analyse the disassembly phase of hypothetical accidents in LMFBRs

International Nuclear Information System (INIS)

Schmuck, P.; Jacobs, G.; Arnecke, G.

1977-11-01

The program KADIS models the disassembly phase during power excursions in LMFBR hypothetical accidents. KADIS is based on point kinetics in the neutronics part and on a 2-dimensional representation of the reactor core in the hydrodynamics part. The core is modeled as an ideal, compressible fluid which is heated up adiabatically during the excursion. KADIS was built up with the help of the VENUS program of Argonne National Laboratory. Several important features were added to the basic VENUS model. Therefore we give first a complete description of the mathematical models used. Secondly we provide the user with the necessary information to handle the input/output of KADIS. (orig.) [de

A Study on Dismantling of Westinghouse Type Nuclear Reactor

International Nuclear Information System (INIS)

Jeong, Woo-Tae; Lee, Sang-Guk

2014-01-01

KHNP started a research project this year to develop a methodology to dismantle nuclear reactors and internals. In this paper, we reviewed 3D design model of the reactor and suggested feasible cutting scheme.. Using 3-D CAD model of Westinghouse type nuclear reactor and its internals, we reviewed possible options for disposal. Among various options of dismantling the nuclear reactor, plasma cutting was selected to be the best feasible and economical method. The upper internals could be segmented by using a band saw. It is relatively fast, and easily maintained. For cutting the lower internals, plasma torch was chosen to be the best efficient tool. Disassembling the baffle and the former plate by removing the baffle former bolts was also recommended for minimizing storage volume. When using plasma torch for cutting the reactor vessel and its internal, installation of a ventilation system for preventing pollution of atmosphere was recommended. For minimizing radiation exposure during the cutting operation, remotely controlled robotic tool was recommended to be used

FaCT phase-I evaluation on the advanced aqueous reprocessing process (2). Development of mechanical disassembly and short stroke shearing systems for FBR fuel reprocessing

International Nuclear Information System (INIS)

Takeuchi, Masayuki; Kitagaki, Toru; Higuchi, Hidetoshi; Fukushima, Mineo; Washiya, Tadahiro; Kobayashi, Tsuguyuki

2011-01-01

JAEA promotes a development of an advanced head-end process in FaCT project. We selected mechanical cutting method for disassembly process and short stroke method for shearing process. In the FaCT phase-I, the criteria was set for decision about the innovative technology and some fundamental performances of the innovative technology such as precision, speed, durability, operation performance and system concept were discussed by the engineering test and design work. We designed and fabricated an engineering-scale test device for mechanical disassembly and short stroke shearing and have carried out the engineering tests using simulated fuel assemblies. As a part of the engineering test results, the effects of cutting conditions on the durability of cutting tool and cutting stability were discussed. Also, the reduction of magazine width is effective to improve the precision of sheared pin length, and the bundle of simulated fuel pins were successfully sheared to 10 ± 5mm, which is a target for the sheared pin length. The criteria for the mechanical disassembly technology and the short stroke shearing technology were satisfied, so we judged that the development of innovative technologies has worth going on for the next phase in the FaCT project. (author)

Caring for disused nuclear power plants

International Nuclear Information System (INIS)

Francioni, W.M.

1981-10-01

EIR studies are being made among other things of the break-down of the biological shield of light water reactors and in particular the break-down of the reactor island of the former research reactor DIORIT. In selecting a method for disassembly of the concrete structures the use of a wire saw has also been examined. To gain experience two concrete test pieces - representing respectively the concrete and reinforcement of the DIORIT biological shield and the biological shield of the Beznau nuclear plants - have undergone cutting trials. The results show that the wire saw can be economically used to cut not only Baryte concrete and cast iron (thermal shield of DIORIT) but also the reinforced concrete of Beznau. (Auth.)

A perspective on relativistic nuclear collisions

International Nuclear Information System (INIS)

Glendenning, N.K.; Paris-11 Univ., 91 - Orsay

1979-01-01

A quasi-dynamical model for the disassembly of a high energy hadronic fireball has been developed. It is fund that some signals from the early high density stage are expected to survive the expansion stage. Indeed cetain signals, the π /N and K / N ratio at high kinetic energy, are so qualitatively unique in their dependance on target projectile mass, that we believe they will survive a refinement of the collision dynamics. Therefore a determination of the assymptotic form of the hadron spectrum can be made by studying nuclear collisions. The required energies are high (approximately 10 GeV/ nucleon in C.M.), but they are within the reach of present technology

Present state and subjects for hereafter of technical development for decommissioning

International Nuclear Information System (INIS)

Ishikura, Takeshi; Onozawa, Teruo; Saishu, Sadanori

1997-01-01

As to the decommissioning of nuclear power facilities, it was confirmed that there is no technical problem which makes decommissioning impossible in the report of the nuclear power subcommittee of Advisory Committee for Energy. In OECD/NEA, the international joint research for exchanging the information and experience of the decommissioning projects has been carried out. In foreign countries, the decommissioning has been executed practically. As the disassembling techniques for structures, laser cutting, plasma are cutting, arc gouging and gas cutting, arc saw cutting, gas cutting and powder gas cutting, mechanical cutting and molded explosive cutting are described. As the disassembling techniques for concrete structures, diamond wire saw method, mechanical cutting, water jet cutting and the method of using disk cutter and mechanical wedge are described. As to decontamination techniques, decontamination before disassembling, decontamination of large equipment, and decontamination after disassembling by blast, electrolysis and chemical immersion are described. The technology for measuring the radiation before disassembling and the radiation of buildings and disassembled waste is reported. (K.I.)

Expert System analysis of non-fuel assembly hardware and spent fuel disassembly hardware: Its generation and recommended disposal

International Nuclear Information System (INIS)

Williamson, D.A.

1991-01-01

Almost all of the effort being expended on radioactive waste disposal in the United States is being focused on the disposal of spent Nuclear Fuel, with little consideration for other areas that will have to be disposed of in the same facilities. one area of radioactive waste that has not been addressed adequately because it is considered a secondary part of the waste issue is the disposal of the various Non-Fuel Bearing Components of the reactor core. These hardware components fall somewhat arbitrarily into two categories: Non-Fuel Assembly (NFA) hardware and Spent Fuel Disassembly (SFD) hardware. This work provides a detailed examination of the generation and disposal of NFA hardware and SFD hardware by the nuclear utilities of the United States as it relates to the Civilian Radioactive Waste Management Program. All available sources of data on NFA and SFD hardware are analyzed with particular emphasis given to the Characteristics Data Base developed by Oak Ridge National Laboratory and the characterization work performed by Pacific Northwest Laboratories and Rochester Gas ampersand Electric. An Expert System developed as a portion of this work is used to assist in the prediction of quantities of NFA hardware and SFD hardware that will be generated by the United States' utilities. Finally, the hardware waste management practices of the United Kingdom, France, Germany, Sweden, and Japan are studied for possible application to the disposal of domestic hardware wastes. As a result of this work, a general classification scheme for NFA and SFD hardware was developed. Only NFA and SFD hardware constructed of zircaloy and experiencing a burnup of less than 70,000 MWD/MTIHM and PWR control rods constructed of stainless steel are considered Low-Level Waste. All other hardware is classified as Greater-ThanClass-C waste

Studies and research concerning BNFP: evaluation of spent-fuel-examination techniques for the Barnwell Nuclear Fuel Plant

International Nuclear Information System (INIS)

Anderson, R.T.; Gray, J.H.; Rogell, M.L.

1982-09-01

A study was made of various examinations which could be remotely performed on a production basis with spent fuel at the Barnwell Nuclear Fuel Plant (BNFP). These techniques could form an integral portion of fuel disassembly and canning operations. Their benefits accrue to either improved fuel storage, reprocessing, or both. In conjunctoin with these studies, evaluations have been made of the operational impact of receiving failed or canned fuel at the BNFP

Electrostatic assembly/disassembly of nanoscaled colloidosomes for light-triggered cargo release

KAUST Repository

Li, Song

2015-04-27

Colloidosome capsules possess the potential for the encapsulation and release of molecular and macromolecular cargos. However, the stabilization of the colloidosome shell usually requires an additional covalent crosslinking which irreversibly seals the capsules, and greatly limits their applications in large-cargos release. Herein we report nanoscaled colloidosomes designed by the electrostatic assembly of organosilica nanoparticles (NPs) with oppositely charged surfaces (rather than covalent bonds), arising from different contents of a bridged nitrophenylene-alkoxysilane [NB; 3-nitro-N-(3-(triethoxysilyl)propyl)-4-(((3-(triethoxysilyl)propyl)-amino)methyl)benzamid] derivative in the silica. The surface charge of the positively charged NPs was reversed by light irradiation because of a photoreaction in the NB moieties, which impacted the electrostatic interactions between NPs and disassembled the colloidosome nanosystems. This design was successfully applied for the encapsulation and light-triggered release of cargos. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of Melatonin in Cell-Wall Disassembly and Chilling Tolerance in Cold-Stored Peach Fruit.

Science.gov (United States)

Cao, Shifeng; Bian, Kun; Shi, Liyu; Chung, Hsiao-Hang; Chen, Wei; Yang, Zhenfeng

2018-06-06

Melatonin reportedly increases chilling tolerance in postharvest peach fruit during cold storage, but information on its effects on cell-wall disassembly in chilling-injured peaches is limited. In this study, we investigated the role of cell-wall depolymerization in chilling-tolerance induction in melatonin-treated peaches. Treatment with 100 μM melatonin alleviated chilling symptoms (mealiness) characterized by a decrease in fruit firmness and increase in juice extractability in treated peaches during storage. The loss of neutral sugars, such as arabinose and galactose, in both the 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA)- and Na 2 CO 3 -soluble fractions was observed at 7 days in treated peaches, but the contents increased after 28 days of storage. Atomic-force-microscopy (AFM) analysis revealed that the polysaccharide widths in the CDTA- and Na 2 CO 3 -soluble fractions in the treated fruit were mainly distributed in a shorter range, as compared with those in the control fruit. In addition, the expression profiles of a series of cell-wall-related genes showed that melatonin treatment maintained the balance between transcripts of PpPME and PpPG, which accompany the up-regulation of several other genes involved in cell-wall disassembly. Taken together, our results suggested that the reduced mealiness by melatonin was probably associated with its positive regulation of numerous cell-wall-modifying enzymes and proteins; thus, the depolymerization of the cell-wall polysaccharides in the peaches treated with melatonin was maintained, and the treated fruit could soften gradually during cold storage.

Exclusive observables from a statistical simulation of energetic nuclear collisions

International Nuclear Information System (INIS)

Fai, G.

1983-01-01

Exclusive observables are calculated in the framework of a statistical model for medium-energy nuclear collisions. The collision system is divided into a few (participant/spectator) sources, that are assumed to disassemble independently. Sufficiently excited sources explode into pions, nucleons, and composite, possibly particle unstable, nuclei. The different final states compete according to their microcanonical weight. Less excited sources, and the unstable explosion products, deexcite via light-particle evaporation. The model has been implemented as a Monte Carlo computer code that is sufficiently efficient to permit generation of large event samples. Some illustrative applications are discussed. (author)

Nuclear fuel assemblies and fuel pins usable in such assemblies

International Nuclear Information System (INIS)

Jolly, R.

1982-01-01

A novel end cap for a nuclear fuel assembly is described in detail. It consists of a trisection arrangement which is received within a cell of a cellular grid. The cell contains abutment means with which the trisection comes into abutment. The grid also contains an abutment means for preventing the trisections from being inserted into the cell in an incorrect orientation. The present design allows fuel pins to be securely held in a hold-down grid of a sub-assembly. The design also allows easier dis-assembly of the swollen and embrittled fuel pins prior to reprocessing. (U.K.)

Fieldable Nuclear Material Identification System

International Nuclear Information System (INIS)

Radle, James E.; Archer, Daniel E.; Carter, Robert J.; Mullens, James Allen; Mihalczo, John T.; Britton, Charles L. Jr.; Lind, Randall F.; Wright, Michael C.

2010-01-01

The Fieldable Nuclear Material Identification System (FNMIS), funded by the NA-241 Office of Dismantlement and Transparency, provides information to determine the material attributes and identity of heavily shielded nuclear objects. This information will provide future treaty participants with verifiable information required by the treaty regime. The neutron interrogation technology uses a combination of information from induced fission neutron radiation and transmitted neutron imaging information to provide high confidence that the shielded item is consistent with the host's declaration. The combination of material identification information and the shape and configuration of the item are very difficult to spoof. When used at various points in the warhead dismantlement sequence, the information complimented by tags and seals can be used to track subassembly and piece part information as the disassembly occurs. The neutron transmission imaging has been developed during the last seven years and the signature analysis over the last several decades. The FNMIS is the culmination of the effort to put the technology in a usable configuration for potential treaty verification purposes.

Nuclear fuel, mass balances, conversion ratio, doubling time, and uncertainty

International Nuclear Information System (INIS)

Vondy, D.R.

1976-11-01

Information on the performance aspects of nuclear power plants is presented concerning conversion ratio, criticality, primitive economic analysis, stable breeder-converter industry, doubling time, breeder industry economic benefit, defining nuclear fuel, recommendations, and uncertainty

Nuclear Dissipation from Fission Time

International Nuclear Information System (INIS)

Gontchar, I.; Morjean, M.; Basnary, S.

2000-01-01

Fission times, pre-scission neutron multiplicities and GDR pre-scission γ-ray multiplicities measured for uranium or thorium nuclei formed with temperatures T ∼ 1.8 MeV have been compared with calculations performed with CDSM2, a two-dimensional dynamical model combined with a statistical one. Among the three experimental approaches considered, fission times give access to the most precise pieces of information on nuclear dissipation at high excitation energy. For the temperature range under consideration, an agreement between the model and data is achieved if one-body dissipation is used with a strength factor k red ∼ 0.45 ± 0.10 applied to the wall term for the mononuclear configuration. (authors)

The pedagogical value of Disassemble/Analyze/Assemble (DAA) activities: Assessing the potential for motivation and transfer

Science.gov (United States)

Dalrymple, Odesma Onika

Undergraduate engineering institutions are currently seeking to improve recruiting practices and to retain engineering majors particularly by addressing what many studies document as a major challenge of poor instruction. There is an undisputed need for instructional practices that motivate students in addition to facilitating the transfer of learning beyond the classroom. Reverse engineering and product dissection, more broadly termed Disassemble/Analyze/Assemble (DAA) activities, have shown potential to address these concerns, based on the reviews of students and professors alike. DAA activities involve the systematic deconstruction of an artifact, the subsequent analysis and possible reconstruction of its components for the purpose of understanding the embodied fundamental concepts, design principles and developmental processes. These activities have been part of regular industry practice for some time; however, the systematic analysis of their benefits for learning and instruction is a relatively recent phenomenon. A number of studies have provided highly descriptive accounts of curricula and possible outcomes of DAA activities; but, relatively few have compared participants doing DAA activities to a control group doing more traditional activities. In this respect, two quasi-experiments were conducted as part of a first-year engineering laboratory, and it was hypothesized that students who engaged in the DAA activity would be more motivated and would demonstrate higher frequencies of transfer than the control. A DAA activity that required students to disassemble a single-use camera and analyze its components to discover how it works was compared to a step-by-step laboratory activity in the first experiment and a lecture method of instruction in the second experiment. In both experiments, over forty percent of the students that engaged in the DAA activity demonstrated the ability to transfer the knowledge gained about the functions of the camera's components and

Life time estimation of SSCs for decommissioning safety of nuclear facilities

International Nuclear Information System (INIS)

Jeong, Kwan-Seong; Lee, Kune-Woo; Moon, Jei-Kwon; Jeong, Seong-Young; Lee, Jung-Jun; Kim, Geun-Ho; Choi, Byung-Seon

2012-01-01

Highlights: ► This paper suggests the expectation algorithm of SSCs life time for decommissioning safety of nuclear facilities. ► The life time of SSCs can be estimated by using fuzzy theory. ► The estimated results depend on the membership functions and performance characteristic functions. - Abstract: This paper suggests the estimation algorithm for life time of structure, system and components (SSCs) for decommissioning safety of nuclear facilities using the performance data of linguistic languages and fuzzy theory. The fuzzy estimation algorithm of life time can be easily applicable but the estimated results depend on the relevant membership functions and performance characteristic functions. This method will be expected to be very useful for maintenance and decommissioning of nuclear facilities’ SSCs as a safety assessment tool.

Environmental Impact Assessment following a Nuclear Accident to a Candu NPP

International Nuclear Information System (INIS)

Margeanu, C.A.; Margeanu, S.; Olteanu, Gh.

2009-01-01

The paper presents calculations of nuclear accident consequences to public and environment, for a Candu NPP using advanced fuel in two hypothetical accident scenarios: (1) large LOCA followed by partial core melting with early containment failure; (2) late core disassembly and containment bypass through ECCS. During both accidents a release occurs, radioactive contaminants being dispersed into atmosphere. As reference, estimations for Candu standard UO 2 fuel were used. The radioactive core inventory was obtained by using ORIGEN-S computer code included in ORNL,SCALE 5 programs package. Radiological consequences assessment to public and environment was performed by means of PC COSYMA computer code

Cofilin phosphorylation is elevated after F-actin disassembly induced by Rac1 depletion

DEFF Research Database (Denmark)

Liu, Linna; Li, Jing; Zhang, Liwang

2015-01-01

Cytoskeletal reorganization is essential to keratinocyte function. Rac1 regulates cytoskeletal reorganization through signaling pathways such as the cofilin cascade. Cofilin severs actin filaments after activation by dephosphorylation. Rac1 was knocked out in mouse keratinocytes and it was found...... that actin filaments disassembled. In the epidermis of mice in which Rac1 was knocked out only in keratinocytes, cofilin phosphorylation was aberrantly elevated, corresponding to repression of the phosphatase slingshot1 (SSH1). These effects were independent of the signaling pathways for p21-activated kinase....../LIM kinase (Pak/LIMK), protein kinase C, or protein kinase D or generation of reactive oxygen species. Similarly, when actin polymerization was specifically inhibited or Rac1 was knocked down, cofilin phosphorylation was enhanced and SSH1 was repressed. Repression of SSH1 partially blocked actin...

Assembly/disassembly of a complex icosahedral virus to incorporate heterologous nucleic acids

Science.gov (United States)

Pascual, Elena; Mata, Carlos P.; Carrascosa, José L.; Castón, José R.

2017-12-01

Hollow protein containers are widespread in nature, and include virus capsids as well as eukaryotic and bacterial complexes. Protein cages are studied extensively for applications in nanotechnology, nanomedicine and materials science. Their inner and outer surfaces can be modified chemically or genetically, and the internal cavity can be used to template, store and/or arrange molecular cargos. Virus capsids and virus-like particles (VLP, noninfectious particles) provide versatile platforms for nanoscale bioengineering. Study of capsid protein self-assembly into monodispersed particles, and of VLP structure and biophysics is necessary not only to understand natural processes, but also to infer how these platforms can be redesigned to furnish novel functional VLP. Here we address the assembly dynamics of infectious bursal disease virus (IBDV), a complex icosahedral virus. IBDV has a ~70 nm-diameter T  =  13 capsid with VP2 trimers as the only structural subunits. During capsid assembly, VP2 is synthesized as a precursor (pVP2) whose C terminus is cleaved. The pVP2 C terminus has an amphipathic helix that controls VP2 polymorphism. In the absence of the VP3 scaffolding protein, necessary for control of assembly, 466/456-residue pVP2 intermediates bearing this helix assemble into VLP only when expressed with an N-terminal His6 tag (the HT-VP2-466 protein). HT-VP2-466 capsids are optimal for genetic insertion of proteins (cargo space ~78 000 nm3). We established an in vitro assembly/disassembly system of HT-VP2-466-based VLP for heterologous nucleic acid packaging and/or encapsulation of drugs and other molecules. HT-VP2-466 (empty) capsids were disassembled and reassembled by dialysis against low-salt/basic pH and high-salt/acid pH buffers, respectively, thus illustrating the reversibility in vitro of IBDV capsid assembly. HT-VP2-466 VLP also packed heterologous DNA by non-specific confinement during assembly. These and previous results establish the bases

The dynamics of the nuclear disassembly in a field-theoretical model at finite entropies

International Nuclear Information System (INIS)

Knoll, J.; Strack, B.

1984-10-01

The expansion phase of a hot nuclear system as created in an energetic heavy-ion collision is calculated and discussed by a selfconsistent field-theoretical model. Dynamical instabilities arising during the expansion from strong fluctuations of the one-body density are included explicitely. First multiplicity distributions and mass spectra resulting from a series of numerical runs in a 2+1 dimensional model world are presented. The dependence of break-up dynamics both on the properties of the binding force and possible correlations in the initially compressed hot state are discussed. (orig.)

Methods of assembling and disassembling spider and burnable poison rod structures for nuclear reactors

International Nuclear Information System (INIS)

Edwards, G.T.; Schluderberg, D.C.

1981-01-01

A technique is provided for engaging and disengaging burnable poison rods from a spider in a nuclear reactor fuel assembly. A cap on the end of each of the burnable poison rods is provided with a shank or stem that is received in a respective bore formed in the spider. A frangible flange secures the shank and rod to the spider. Pressing the shank in the direction of the bore axis by means, e.g., of a plate ruptures the frangible flange to release the rod from the spider. (author)

Radionuclide inventories for short run-time space nuclear reactor systems

International Nuclear Information System (INIS)

Coats, R.L.

1993-01-01

Space Nuclear Reactor Systems, especially those used for propulsion, often have expected operation run times much shorter than those for land-based nuclear power plants. This produces substantially different radionuclide inventories to be considered in the safety analyses of space nuclear systems. This presentation describes an analysis utilizing ORIGEN2 and DKPOWER to provide comparisons among representative land-based and space systems. These comparisons enable early, conceptual considerations of safety issues and features in the preliminary design phases of operational systems, test facilities, and operations by identifying differences between the requirements for space systems and the established practice for land-based power systems. Early indications are that separation distance is much more effective as a safety measure for space nuclear systems than for power reactors because greater decay of the radionuclide activity occurs during the time to transport the inventory a given distance. In addition, the inventories of long-lived actinides are very low for space reactor systems

Crunch time for nuclear power

International Nuclear Information System (INIS)

Edwards, Rob.

1994-01-01

The Federal Republic of Germany, one of the most advanced nations, technically has a thriving nuclear power industry. However there is stiff opposition to nuclear power from political parties and environmental groups. General elections due to be held in mid October hold the future of the nuclear industry in the balance. If the present opposition party comes to power, it is committed to a policy of phasing out nuclear power completely. At the centre of the political uproar is the Gorleben ''interim store'' which is intended to house Germany's spent fuel for at least the next forty years. The nuclear industry must resolve the issue of nuclear waste disposal to the voters' satisfaction if it is to have a viable future. (UK)

Time stamp technique using a nuclear emulsion multi-stage shifter for gamma-ray telescope

International Nuclear Information System (INIS)

Takahashi, Satoru; Aoki, Shigeki; Rokujo, Hiroki; Hamada, Kaname; Komatsu, Masahiro; Morishima, Kunihiro; Nakamura, Mitsuhiro; Nakano, Toshiyuki; Niwa, Kimio; Sato, Osamu; Yoshioka, Teppei; Kodama, Koichi

2010-01-01

Nuclear emulsion has a potential use as a gamma-ray telescope with high angular resolution. For this application it is necessary to know the time when each track was recorded in the emulsion. In previous experiments using nuclear emulsion, various efforts were used to associate time to nuclear emulsion tracks and to improve the time resolution. Using a high speed readout system for nuclear emulsion together with a clock-based multi-stage emulsion shifter, we invented a technique to give a time-stamp to emulsion tracks and greatly improve the time resolution. A test experiment with a 2-stage shifter was used to demonstrate the principle of multi-stage shifting, and we achieved a time resolution 1.5 s for 12.1 h (about 1 part in 29 000) with the time stamp reliability 97% and the time stamp efficiency 98%. This multi-stage shifter can achieve the time resolution required for a gamma-ray telescope and can also be applied to another cosmic ray observations and accelerator experiments using nuclear emulsion.

Real-time simulation of ex-core nuclear instrumentation system

International Nuclear Information System (INIS)

Zhao Qiang; Zhang Zhijian; Cao Xinrong

2005-01-01

Real-time simulation of ex-core nuclear instrumentation system is an indispensable part of nuclear power plant (NPP) full-scope training simulator. The simulation method, which is based upon the theory of measurement, is introduced in the paper. The fitting formula between the measured data and the three-dimensional neutron flux distribution in the core is established. The fitting parameter is adjusted according to the reactor physical calculation or the experiment of power calibration. The simulation result shows that the method can simulate the ex-core neutron instrumentation system accurately in real-time and meets the needs of NPP full-scope training simulator. (authors)

Safety provision for nuclear power plants during remaining running time

International Nuclear Information System (INIS)

Rossnagel, Alexander; Hentschel, Anja

2012-01-01

With the phasing-out of the industrial use of nuclear energy for the power generation, the risk of the nuclear power plants has not been eliminated in principle, but only for a limited period of time. Therefore, the remaining nine nuclear power plants must also be used for the remaining ten years according to the state of science and technology. Regulatory authorities must substantiate the safety requirements for each nuclear power plant and enforce these requirements by means of various regulatory measures. The consequences of Fukushima must be included in the assessment of the safety level of nuclear power plants in Germany. In this respect, the regulatory authorities have the important tasks to investigate and assess the security risks as well as to develop instructions and orders.

The role of nuclear energy in times of energy transition

International Nuclear Information System (INIS)

2012-01-01

Since the reactor catastrophe in Fukushima, the risk of nuclear power has once again become more evident to the public and has also led to a rethinking of politics in Europe. Slogans like ''Nuclear Power, No Thanks!'', ''Get Out of Euratom'' are making more and more the rounds. The phase-out of nuclear energy is the topic that is increasingly provoking people to think. But how should one handle this? What role will nuclear energy play in a distant future? Central factors such as the economic viability of renewable energy sources and the environmental and social compatibility of production and distribution must be taken into account, while at the same time the reduction of pollutants and greenhouse gases must continue. If this is done without nuclear energy, is the rapid abandonment of nuclear energy even necessary or does nuclear energy generation have to be used as a temporary solution? (roessner)

A basic framework for managing time of nuclear plant projects

International Nuclear Information System (INIS)

Beck, J.R.

1987-01-01

One of the crucial problems that faces managers of nuclear power plant projects is how to obtain more effective and efficient utilization of their company's resources. Analysis of this problem showed that improvement was necessary in the time management area. Time management is one of the primary functions of project groups. Much has been written about planning and scheduling, and there are many modern techniques (CPM, PERT, etc.) available to a project group to manage time. So, why is time management still a problem? One reason is that nuclear projects are generally very complex and involve many organizations requiring the same resources. It is the intent of this paper to present a comprehensive and basic framework on which to either build a time management system or use as a basis to assess an existing system

Nuclear: Water-testing time?

International Nuclear Information System (INIS)

Anon.

1990-01-01

With Florida Power and Light Co reporting that five unnamed independent power producers specified nuclear powerplants in response to the utility's Request for Proposal for 800 MW (EW, January 1990, p 15), along with a report in McGraw-Hill's Nucleonics Week that Florida Public Service Commission (PSC) Chairman Michael Wilson told Westinghouse Electric Corp - developer of the AP-600 reactor - he did not have a knee-jerk reaction against nuclear power if it's done right, speculation increases that the state of Florida is one of the top locations in the US for the next nuclear order

Sodium removal disassembly and examination of the Fermi secondary sodium pump

International Nuclear Information System (INIS)

Maffei, H.P.; Funk, C.W.; Ballif, J.L.

1974-01-01

The Fermi secondary pump is a centrifugal single stage design. The pump had been operated more than 42,000 hours between 450 and 800 0 F. Sodium was drained from the pump in 1973 and the system was back filled with carbon dioxide. The pump was fabricated for 2.25 Cr-1 Mo Croloy steel. Prior to cleaning the pump was inerted and heated with 150 0 F nitrogen using the pump casing as the containment vessel. The water-vapor-nitrogen process was used in three increasing stages of water concentration. The hydrogen concentration in the discharge line was followed as an indicator of the sodium-water reaction rate. Upon completion of the hydrogen evolution, the pump was rinsed several times with hot water. Six pounds of sodium were removed from the pump during a process cycle of 79 hours including rinsing. The maximum pump temperature recorded was 175 0 F with no variation exceeding 10 0 F. The hydrogen concentration in the effluent provided a very satisfactory index for control of the reaction by adjustment of the water-vapor concentration feed to the system. Rinsing effectiveness was limited by a pool of water in the volute that was not drainable with the available system hook up. Sodium and its compounds were removed from all internal surfaces that could be observed by the first stage of disassembly. All such surfaces were coated with a black deposit. Areas above the sodium liquid level were coated with a vermillion colored oxide. Sodium was found on the (1) threads of the impeller nut lock screw, (2) impeller nut-tapered shaft interface, and (3) vapor deposited sodium was found in the oil seal

Present status of design, research and development of nuclear fusion reactors and problems

International Nuclear Information System (INIS)

1983-04-01

Seven years have elapsed since the publication of ''Progress of nuclear fusion research and perspective toward the development of power reactors'' by the Atomic Energy Society of Japan in August, 1976. During this period, the research and development of nuclear fusion have changed from plasma physics to reactor technology, being conscious of the realization of fusion reactors. There are the R project in the Institute of Plasma Physics, Nagoya University, and the design and construction of JT-60 in Japan Atomic Energy Research Institute, to put it concretely. Now the research and development taking the economical efficiency into account are adopted. However, the type of fusion reactors is not reduced to tokamak type, accordingly the research and development to meet the diverse possibilities are forwarded. The progress of tokamak reactor research, core plasma design, nuclear design and shielding design, thermal structure design, the design of superconducting magnets, disassembling and repair, safety, economical efficiency, the conceptual design of other types than tokamak and others are reported. (Kako, I.)

Reduced order for nuclear reactor model in frequency and time domain

International Nuclear Information System (INIS)

Nugroho, D.H.

1997-01-01

In control system theory, a model can be represented by frequency or time domain. In frequency domain, the model was represented by transfer function. in time domain, the model was represented by state space. for the sake of simplification in computation, it is necessary to reduce the model order. the main aim of this research is to find the best in nuclear reactor model. Model order reduction in frequency domain can be done utilizing pole-zero cancellation method; while in time domain utilizing balanced aggregation method the balanced aggregation method was developed by moore (1981). In this paper, the two kinds of method were applied to reduce a nuclear reactor model which was constructed by neutron dynamics and heat transfer equations. to validate that the model characteristics were not change when model order reduction applied, the response was utilized for full and reduced order. it was shown that the nuclear reactor order model can be reduced from order 8 to 2 order 2 is the best order for nuclear reactor model

Addressing the long time horizon for managing used nuclear fuel

International Nuclear Information System (INIS)

Hodge, R.A.

2006-01-01

The time horizon that must be considered in developing an approach to managing used nuclear fuel extends many thousands of years. Such a time horizon is without precedent in environmental, economic, social, technical and public policy terms. As a first step in addressing this issue, the Nuclear Waste Management Organization convened a team of 33 individuals to undertake a formal scenarios exercise. Such an exercise is a way of framing potential futures that might occur. There is no intent to predict the future. This exercise represents the first time that the scenarios technique has been used for such a long time horizon. The approach involved identifying two principle axes of potential change: (1) social - political - environmental well-being; and (2) magnitude of the used nuclear fuel challenge. Using this organizing template, four scenarios were developed reaching out 25 years, and an additional twelve were developed at 175 years branching out from the original four. In addition, a series of sixteen possible 'end-points' were identified to span conditions 500 years out and for 10,000 years a large number of 'what- ifs' were developed. The scenarios, end-points, and what- ifs were then used to identify a number of criteria that could be used for testing proposed management options and their capacity to deal with future conditions. This paper describes this work and the role that it has played in the deliberations of the Nuclear Waste Management Organization. (author)

Development of an advanced, continuous mild-gasification process for the production of coproducts. Report for Task 4.8, Decontamination and disassembly of the mild-gasification and char-to-carbon PRUs and disposal of products from testing

Energy Technology Data Exchange (ETDEWEB)

Merriam, N.W. [Western Research Inst., Laramie, WY (United States); Jha, Mahesh C. [AMAX Research and Development Center, Golden, CO (United States)

1991-11-01

This report contains descriptions of mild-gasification and char-to-carbon process research units (PRUS) used by WRI and AMAX R&D Center to conduct tests under contract AC21-87MC24268. Descriptions of materials produced during those tests are also contained herein. Western Research Institute proposes to dispose of remaining fines and dried coal by combustion and remaining coal liquids by incineration during mid-1992. The mild-gasification PRU will be used for additional tests until 1993, at which time WRI proposes to decontaminate and disassemble the PRU. AMAX R&D Center intends to return the spent char, any remaining feed char, and unusable product carbon to the Eagle Butte Mine near Gillette, Wyoming, from where the coal originally came. The solid products will be added to the mine`s coal product stream. Coal liquids collected from condensers will be concentrated and sent to a local oil and solvent recycling company where the liquids will be burned as fuel. The char-to-carbon PRU will be operated periodically until 1993 when the plant will be decontaminated and disassembled.

Dry spent-fuel consolidation demonstration at the Barnwell Nuclear Fuel Plant (BNFP)

International Nuclear Information System (INIS)

Townes, G.A.

1982-08-01

Equipment for disassembling and canning (or encapsulating) spent fuel to allow more efficient storage is being developed and demonstrated at the BNFP. The program is aimed at dry disassembly of fuel to allow storage and shipment of fuel pins rather than full fuel assemblies. Results indicate that doubling the existing storage capacity or tripling the carrying capacity of existing transportation equipment is achievable. Disassembly has been demonstrated in the BNFP hot cells at rates of approx. 10 to 12 assemblies per day. 3 figures

Time reversal violating nuclear polarizability and atomic electric dipole moment

International Nuclear Information System (INIS)

Ginges, J.S.M.; Flambaum, V.V.; Mititelu, G.

2000-01-01

Full text: We propose a nuclear mechanism which can induce an atomic electric dipole moment (EDM). The interaction of external electric E and magnetic H fields with nuclear electric and magnetic dipole moments, d and ,u, gives rise to an energy shift, U= -β ik E i H k , where β ik is the nuclear polarizability. Parity and time invariance violating (P,T-odd) nuclear forces generate a mixed P,T-odd nuclear polarizability, whereψ 0 and ψ n are P,T-odd perturbed ground and excited nuclear states, respectively. In the case of a heavy spherical nucleus with a single unpaired nucleon, the perturbed wavefunctions are U = -β ik E i H k , where ξis a constant proportional to the strength of the nuclear P,T-odd interaction, σ is the nuclear spin operator, and ψ n is an unperturbed wavefunction. There are both scalar and tensor contributions to the nuclear P,T-odd polarizability. An atomic EDM is induced by the interaction of the fields of an unpaired electron in an atom with the P,T-odd perturbed atomic nucleus. An estimate for the value of this EDM has been made. The measurements of atomic EDMs can provide information about P,T-odd nuclear forces and test models of CP-violation

Decommissioning considerations at a time of nuclear renaissance

International Nuclear Information System (INIS)

Devgun, Jas S.

2007-01-01

At a time of renaissance in the nuclear power industry, when it is estimated that anywhere between 60 to 130 new power reactors may be built worldwide over the next 15 years, why should we focus on decommissioning? Yet it is precisely the time to examine what decommissioning considerations should be taken into account as the industry proceeds with developing final designs for new reactors and the construction on the new build begins. One of the lessons learned from decommissioning of existing reactors has been that decommissioning was not given much thought when these reactors were designed three or four decades ago. Even though decommissioning may be sixty years down the road from the time they go on line, eventually all reactors will be decommissioned. It is only prudent that new designs be optimized for eventual decommissioning, along with the other major considerations. The overall objective in this regard is that when the time comes for decommissioning, it can be completed in shorter time frames, with minimum generation of radioactive waste, and with better radiological safety. This will ensure that the tail end costs of the power reactors are manageable and that the public confidence in the nuclear power is sustained through the renaissance and beyond. (author)

Problems of space-time behaviour of nuclear reactors

International Nuclear Information System (INIS)

Obradovic, D.

1966-01-01

This paper covers a review of literature and mathematical methods applied for space-time behaviour of nuclear reactors. The review of literature is limited to unresolved problems and trends of actual research in the field of reactor physics [sr

LRRK2 phosphorylates pre-synaptic N-ethylmaleimide sensitive fusion (NSF) protein enhancing its ATPase activity and SNARE complex disassembling rate.

Science.gov (United States)

Belluzzi, Elisa; Gonnelli, Adriano; Cirnaru, Maria-Daniela; Marte, Antonella; Plotegher, Nicoletta; Russo, Isabella; Civiero, Laura; Cogo, Susanna; Carrion, Maria Perèz; Franchin, Cinzia; Arrigoni, Giorgio; Beltramini, Mariano; Bubacco, Luigi; Onofri, Franco; Piccoli, Giovanni; Greggio, Elisa

2016-01-13

Lrrk2, a gene linked to Parkinson's disease, encodes a large scaffolding protein with kinase and GTPase activities implicated in vesicle and cytoskeletal-related processes. At the presynaptic site, LRRK2 associates with synaptic vesicles through interaction with a panel of presynaptic proteins. Here, we show that LRRK2 kinase activity influences the dynamics of synaptic vesicle fusion. We therefore investigated whether LRRK2 phosphorylates component(s) of the exo/endocytosis machinery. We have previously observed that LRRK2 interacts with NSF, a hexameric AAA+ ATPase that couples ATP hydrolysis to the disassembling of SNARE proteins allowing them to enter another fusion cycle during synaptic exocytosis. Here, we demonstrate that NSF is a substrate of LRRK2 kinase activity. LRRK2 phosphorylates full-length NSF at threonine 645 in the ATP binding pocket of D2 domain. Functionally, NSF phosphorylated by LRRK2 displays enhanced ATPase activity and increased rate of SNARE complex disassembling. Substitution of threonine 645 with alanine abrogates LRRK2-mediated increased ATPase activity. Given that the most common Parkinson's disease LRRK2 G2019S mutation displays increased kinase activity, our results suggest that mutant LRRK2 may impair synaptic vesicle dynamics via aberrant phosphorylation of NSF.

TRIM15 is a focal adhesion protein that regulates focal adhesion disassembly

Science.gov (United States)

Uchil, Pradeep D.; Pawliczek, Tobias; Reynolds, Tracy D.; Ding, Siyuan; Hinz, Angelika; Munro, James B.; Huang, Fang; Floyd, Robert W.; Yang, Haitao; Hamilton, William L.; Bewersdorf, Joerg; Xiong, Yong; Calderwood, David A.; Mothes, Walther

2014-01-01

ABSTRACT Focal adhesions are macromolecular complexes that connect the actin cytoskeleton to the extracellular matrix. Dynamic turnover of focal adhesions is crucial for cell migration. Paxillin is a multi-adaptor protein that plays an important role in regulating focal adhesion dynamics. Here, we identify TRIM15, a member of the tripartite motif protein family, as a paxillin-interacting factor and a component of focal adhesions. TRIM15 localizes to focal contacts in a myosin-II-independent manner by an interaction between its coiled-coil domain and the LD2 motif of paxillin. Unlike other focal adhesion proteins, TRIM15 is a stable focal adhesion component with restricted mobility due to its ability to form oligomers. TRIM15-depleted cells display impaired cell migration and reduced focal adhesion disassembly rates, in addition to enlarged focal adhesions. Thus, our studies demonstrate a cellular function for TRIM15 as a regulatory component of focal adhesion turnover and cell migration. PMID:25015296

The analysis of energy-time sequences in the nuclear power plants construction

International Nuclear Information System (INIS)

Milivojevic, S.; Jovanovic, V.; Riznic, J.

1983-01-01

The current nuclear energy development pose many problems; one of them is nuclear power plant construction. They are evaluated energy and time features of the construction and their relative ratios by the analysis of available data. The results point at the reached efficiency of the construction and, in the same time, they are the basis for real estimation of energy-time sequences of the construction in the future. (author)

Timely Endocytosis of Cytokinetic Enzymes Prevents Premature Spindle Breakage during Mitotic Exit.

Directory of Open Access Journals (Sweden)

Cheen Fei Chin

2016-07-01

Full Text Available Cytokinesis requires the spatio-temporal coordination of membrane deposition and primary septum (PS formation at the division site to drive acto-myosin ring (AMR constriction. It has been demonstrated that AMR constriction invariably occurs only after the mitotic spindle disassembly. It has also been established that Chitin Synthase II (Chs2p neck localization precedes mitotic spindle disassembly during mitotic exit. As AMR constriction depends upon PS formation, the question arises as to how chitin deposition is regulated so as to prevent premature AMR constriction and mitotic spindle breakage. In this study, we propose that cells regulate the coordination between spindle disassembly and AMR constriction via timely endocytosis of cytokinetic enzymes, Chs2p, Chs3p, and Fks1p. Inhibition of endocytosis leads to over accumulation of cytokinetic enzymes during mitotic exit, which accelerates the constriction of the AMR, and causes spindle breakage that eventually could contribute to monopolar spindle formation in the subsequent round of cell division. Intriguingly, the mitotic spindle breakage observed in endocytosis mutants can be rescued either by deleting or inhibiting the activities of, CHS2, CHS3 and FKS1, which are involved in septum formation. The findings from our study highlight the importance of timely endocytosis of cytokinetic enzymes at the division site in safeguarding mitotic spindle integrity during mitotic exit.

Assembly mechanism for nuclear fuel bundles

International Nuclear Information System (INIS)

Long, J.W.; Flora, B.S.

1977-01-01

A method of securing a fuel bundle to permit easy remote disassembly is described. Fuel rods are held loosely between end plates, each end of the rods fitting into holes in the end plates. At the upper end of each fuel rod there is a spring pressing against the end plate. Tie rods are used to hold the end plates together securely. The lower end of each tie rod is screwed into the lower end plate; the upper end of each tie rod is attached to the upper end plate by means of a locking assembly described in the patent. In order to remove the upper tie plate during the disassembly process, it is necessary only to depress the tie plate against the pressure of the springs surrounding the fuel rods and then to rotate each locking sleeve on the tie rods from its locked to its unlocked position. It is then possible to remove the tie plate without disassembling the locking assembly. (LL)

Time-domain soil-structure interaction analysis of nuclear facilities

International Nuclear Information System (INIS)

Coleman, Justin L.; Bolisetti, Chandrakanth; Whittaker, Andrew S.

2016-01-01

The Nuclear Regulatory Commission (NRC) regulation 10 CFR Part 50 Appendix S requires consideration of soil-structure interaction (SSI) in nuclear power plant (NPP) analysis and design. Soil-structure interaction analysis for NPPs is routinely carried out using guidance provided in the ASCE Standard 4-98 titled “Seismic Analysis of Safety-Related Nuclear Structures and Commentary”. This Standard, which is currently under revision, provides guidance on linear seismic soil-structure-interaction (SSI) analysis of nuclear facilities using deterministic and probabilistic methods. A new appendix has been added to the forthcoming edition of ASCE Standard 4 to provide guidance for time-domain, nonlinear SSI (NLSSI) analysis. Nonlinear SSI analysis will be needed to simulate material nonlinearity in soil and/or structure, static and dynamic soil pressure effects on deeply embedded structures, local soil failure at the foundation-soil interface, nonlinear coupling of soil and pore fluid, uplift or sliding of the foundation, nonlinear effects of gaps between the surrounding soil and the embedded structure and seismic isolation systems, none of which can be addressed explicitly at present. Appendix B of ASCE Standard 4 provides general guidance for NLSSI analysis but will not provide a methodology for performing the analysis. This paper provides a description of an NLSSI methodology developed for application to nuclear facilities, including NPPs. This methodology is described as series of sequential steps to produce reasonable results using any time-domain numerical code. These steps require some numerical capabilities, such as nonlinear soil constitutive models, which are also described in the paper.

Time for final disposal of nuclear waste - society, technology and nature

International Nuclear Information System (INIS)

Forsling, Willis; Andersson-Skog, Lena; Haenninen, Hannu; Knutsson, Gert; Ma ttsson, Soeren; Stigh, Jimmy; Soederberg, Olof; Bolin, Bert; Nordlund, Erling

2007-05-01

This report consists of a number of independent contribution that treat different aspects of the nuclear waste complex, with the time perspective as a common starting point. The review does not pretend to cover the entire area, but the selected issues addressed are those of large general interest. First a general overview is given of how the nuclear waste issue has been treated in Sweden since the plans to use nuclear power begun be planned in the middle of the 1940s. The complex of problem around the nuclear waste issue is linked to our natural aversion against the development of nuclear weapons during they last 60-70 years, but also to the controversies around the peaceful use of the nuclear power that has happened during the latest 30-40 years. In chapters 3 the time perspective is considerably shorter, approximately 20 years. Here, construction and operation of an underground repository for nuclear waste is discussed. Such an undertaking has many resemblances with establishing an underground mine and there is much experience to learn from. In chapters 4 questions about the technical barriers are treated, the copper container, bentonite buffer and the backfilling. The copper container and bentonite buffer both have key roles to prevent ground water to come in contact with the spent fuel and that radioactivity is transported out into the environment. They must both fulfil their functions during the period when the fuel is dangerous, i.e. over 100,000 years. Different processes affects the repository, some during short periods, some during several 10,000 years. Specific intervals (from 10 years and up to 100,000 years) are indicated for the different processes, almost all with the starting point at the deposition of the waste. The possibility to gain experiences from natural analogies is treated in chapters 5. They can be seen as a prolonged experiment in natural systems where one reactor zone has been active for more than 100,000 years. The time perspective

Neuroprotective Effects against POCD by Photobiomodulation: Evidence from Assembly/Disassembly of the Cytoskeleton

Directory of Open Access Journals (Sweden)

Ann D. Liebert

2016-01-01

Full Text Available Postoperative cognitive dysfunction (POCD is a decline in memory following anaesthesia and surgery in elderly patients. While often reversible, it consumes medical resources, compromises patient well-being, and possibly accelerates progression into Alzheimer's disease. Anesthetics have been implicated in POCD, as has neuroinflammation, as indicated by cytokine inflammatory markers. Photobiomodulation (PBM is an effective treatment for a number of conditions, including inflammation. PBM also has a direct effect on microtubule disassembly in neurons with the formation of small, reversible varicosities, which cause neural blockade and alleviation of pain symptoms. This mimics endogenously formed varicosities that are neuroprotective against damage, toxins, and the formation of larger, destructive varicosities and focal swellings. It is proposed that PBM may be effective as a preconditioning treatment against POCD; similar to the PBM treatment, protective and abscopal effects that have been demonstrated in experimental models of macular degeneration, neurological, and cardiac conditions.

Real-time advanced nuclear reactor core model

International Nuclear Information System (INIS)

Koclas, J.; Friedman, F.; Paquette, C.; Vivier, P.

1990-01-01

The paper describes a multi-nodal advanced nuclear reactor core model. The model is based on application of modern equivalence theory to the solution of neutron diffusion equation in real time employing the finite differences method. The use of equivalence theory allows the application of the finite differences method to cores divided into hundreds of nodes, as opposed to the much finer divisions (in the order of ten thousands of nodes) where the unmodified method is currently applied. As a result the model can be used for modelling of the core kinetics for real time full scope training simulators. Results of benchmarks, validate the basic assumptions of the model and its applicability to real-time simulation. (orig./HP)

Development of spent fuel remote handling technology

International Nuclear Information System (INIS)

Yoon, Ji Sup; Park, B. S.; Park, Y. S.; Oh, S. C.; Kim, S. H.; Cho, M. W.; Hong, D. H.

1997-12-01

Since the nation's policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

MgATP hydrolysis destabilizes the interaction between subunit H and yeast V1-ATPase, highlighting H's role in V-ATPase regulation by reversible disassembly.

Science.gov (United States)

Sharma, Stuti; Oot, Rebecca A; Wilkens, Stephan

2018-05-12

Vacuolar H+-ATPases (V-ATPases; V1Vo-ATPases) are rotary motor proton pumps that acidify intracellular compartments and in some tissues, the extracellular space. V-ATPase is regulated by reversible disassembly into autoinhibited V1-ATPase and Vo proton channel sectors. An important player in V-ATPase regulation is subunit H, which binds at the interface of V1 and Vo. H is required for MgATPase activity in holo V-ATPase, but also for stabilizing the MgADP inhibited state in membrane detached V1. However, how H fulfills these two functions is poorly understood. To characterize the H-V1 interaction and its role in reversible disassembly, we determined binding affinities of full length H and its N-terminal domain (HNT) for an isolated heterodimer of subunits E and G (EG), the N-terminal domain of subunit a (aNT), and V1 lacking subunit H (V1ΔH). Using isothermal titration calorimetry (ITC) and biolayer interferometry (BLI), we show that HNT binds EG with moderate affinity, that full length H binds aNT weakly, and that both H and HNT bind V1ΔH with high affinity. We also found that only one molecule of HNT binds V1ΔH with high affinity, suggesting conformational asymmetry of the three EG heterodimers in V1ΔH. Moreover, MgATP hydrolysis-driven conformational changes in V1 destabilized the interaction of H, or HNT, with V1ΔH, suggesting an interplay between MgADP inhibition and subunit H. Our observation that H binding is affected by MgATP hydrolysis in V1 points to H's role in the mechanism of reversible disassembly. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

International Nuclear Information System (INIS)

Berthelemy, Michel; Escobar Rangel, Lina

2013-01-01

This paper provides the first comparative analysis of nuclear reactor construction costs in France and the United States. Studying the cost of nuclear power has often been a challenge, owing to the lack of reliable data sources and heterogeneity between countries, as well as the long time horizon which requires controlling for input prices and structural changes. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using expected demand variation as an instrument. We argue that benefits from nuclear reactor program standardization can arise through short term coordination gains, when the diversity of nuclear reactors' technologies under construction is low, or through long term benefits from learning spillovers from past reactor construction experience, if those spillovers are limited to similar reactors. We find that overnight construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect-Engineer (A- E). In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. (authors)

The Chloroplast Division Protein ARC6 Acts to Inhibit Disassembly of GDP-bound FtsZ2.

Science.gov (United States)

Sung, Min Woo; Shaik, Rahamthulla; TerBush, Allan D; Osteryoung, Katherine W; Vitha, Stanislav; Holzenburg, Andreas

2018-05-16

Chloroplasts host photosynthesis and fulfill other metabolic functions that are essential to plant life. They have to divide by binary fission to maintain their numbers throughout cycles of cell division. Chloroplast division is achieved by a complex ring-shaped division machinery located on both the inner (stromal) and the outer (cytosolic) side of the chloroplast envelope. The inner division ring (termed the Z ring) is formed by the assembly of tubulin-like FtsZ1 and FtsZ2 proteins. ARC6 is a key chloroplast division protein that interacts with the Z ring. ARC6 spans the inner envelope membrane, is known to stabilize or maintain the Z ring, and anchors the Z ring to the inner membrane through interaction with FtsZ2. The underlying mechanism of Z-ring stabilization is not well understood. Here, biochemical and structural characterization of ARC6 was conducted using light scattering, sedimentation, and light and transmission electron microscopy. The recombinant protein was purified as a dimer. The results indicated that a truncated form of ARC6 (tARC6), representing the stromal portion of ARC6, affects FtsZ2 assembly without forming higher-order structures, and exerts its effect via FtsZ2 dynamics. tARC6 prevented GDP-induced FtsZ2 disassembly and caused a significant net increase in FtsZ2 assembly when GDP was present. Single particle analysis and 3D reconstruction were performed to elucidate the structural basis of ARC6 activity. Together, the data reveal that a dimeric form of tARC6 binds to FtsZ2 filaments and does not increase FtsZ polymerization rates but rather inhibits GDP-associated FtsZ2 disassembly. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Requirements for near-real-time accounting of strategic nuclear materials in nuclear fuel reprocessing

International Nuclear Information System (INIS)

Hakkila, E.A.; Cobb, D.D.; Dietz, R.J.; Shipley, J.P.; Smith, D.B.

1978-01-01

A Purex-based nuclear fuel reprocessing plant has been studied for possible incorporation of near-real-time accounting to supplement conventional accounting procedures. Near-real-time accounting of special nuclear materials relies on in-line or at-line flow measurements and plutonium assay of product and waste streams, complemented by conventional analytical chemistry for daily instrument calibrations. In-line alpha monitors could be used for waste stream measurements of plutonium, even in the presence of high beta-gamma fluxes from fission products. X-ray absorption edge densitometry using either K- or L-absorption edges could be used for plutonium concentration measurements in main product streams. Some problem areas identified in waste stream measurements include measurements of leached hulls and of centrifuge sludge. Conventional analytical chemical methods for measuring plutonium in weapons grade material can be modified for reprocessed plutonium. Analytical techniques requiring special precautions will be reviewed

Deep Time Iterations: Familiarity, Horizons, and Pattern among Finland's Nuclear Waste Safety Experts

Science.gov (United States)

Ialenti, Vincent Francis

This ethnography reconsiders nuclear waste risk's deep time horizons' often-sensationalized aesthetics of horror, sublimity, and awe. It does so by tracking how Finland's nuclear energy and waste experts made visions of distant future Finlands appear more intelligible through mundane corporate, regulatory, financial, and technoscientific practices. Each chapter unpacks how informants iterated and reiterated traces of the very familiar to establish shared grounds of continuity for moving forward in time. Chapter 1 explores how Finland's energy sector's "mankala" cooperative corporate form was iterated and reiterated to give shape to political and financial time horizons. Chapter 2 explores how workplace role distinctions between recruit/retiree and junior/senior were iterated and reiterated to reckon nuclear personnel successions' intergenerational horizons. Chapter 3 explores how input/output and part/whole distinctions were iterated and reiterated to help model distant future worlds in a portfolio of "Safety Case" evidence made to demonstrate the Olkiluoto repository's safety to Finnish nuclear regulator STUK. Chapter 4 explores how Safety Case experts iterated and reiterated memories of a deceased predecessor figure in everyday engagements with deep time. What emerges are three insights about how futures attain discernible features--insights about the "continuity," "thinkability," and "extensibility" of expert thought--that, I argue, can help twenty-first century experts better navigate not only deep time, but also unknown futures of nuclear technologies, planetary environment, and expertise itself.

Final environmental impact statement for the continued operation of the Pantex Plant and associated storage of nuclear weapon components. Volume 3 -- Comment response

International Nuclear Information System (INIS)

1996-11-01

The Draft Environmental Impact Statement (EIS) for the continued operation of Pantex Plant was published in March 1996. The document assessed the alternatives of no action, relocation of the storage of plutonium components resulting from nuclear weapon disassemble activities at Pantex Plant to another site, and the proposed action (preferred alternative) of continuing operations and increasing the quantity of pits in interim storage at Pantex Plant. This report contains the comments and responses received on the Draft EIS

Neutron mean annihilation time and inverse of the mean annihilation rate in nuclear reactor

International Nuclear Information System (INIS)

Hayashi, Masatoshi

1999-01-01

There is a dogma in nuclear reactor theory that in a critical reactor the mean annihilation time of neutron is equal to the mean generation time. The author insists that this is a dogma from the basic reexamination of the mean annihilation time of neutron. There are two kinds of neutrons, one participating in chain reactions and the other not participating in chain reactions. The mean annihilation time of neutron is the mean time of the time to annihilation of all neutrons generated in the reactor. The 'prompt neutron life' as a dynamic characteristic parameter proper to nuclear reactor can not be understood as the mean time of neutron to annihilation. The author explains the logic quantitatively with two kinds of nuclear reactors, a bare reactor and an infinite reactor, for which two different mean neutron annihilation times can be defined. Thus, (1) the inverse of the annihilation rate can not simply be considered as the mean annihilation time, (2) the mean annihilation time of a critical reactor is not necessarily equal to the mean generation time, and (3) the prompt neutron life used as a dynamic characteristic parameter of a nuclear reactor can not be understood as the mean time of neutron to annihilation. (M.M.)

Approach to a generalized real-time nuclear materials control system

International Nuclear Information System (INIS)

Jarsch, V.; Onnen, S.; Polster, F.J.; Woit, J.

1978-01-01

Untrained users and a large amount of--at first glance incompatible--processes and materials are the environment of computer-aided nuclear materials control systems. To find an efficient model of the real processes and materials descriptions and to allow the operating personnel to communicate with the system in his everyday symbolism are goals in the development of the concept presented in this paper. According to this concept a real-time minicomputer-based materials control system is being implemented in the Nuclear Research Center of Karlsruhe. The chosen approach satisfies the heterogeneous requirements of the various institutes of the Center and is also applicable to other nuclear plants

Radiation shield ring assembly and method of disassembling components of a nuclear steam generator using such assembly

International Nuclear Information System (INIS)

Meuschke, R.E.; Wolfe, D.L.

1982-01-01

This invention relates to an apparatus and a method for cutting, within a shielding confinement, the irradiated components of a nuclear steam generator to reduce such components to a size to permit their subsequent removal from the containment structure of the generator

Remote-automation of nuclear power plant equipment inspection and maintenance

International Nuclear Information System (INIS)

Sasaki, Masayoshi; Kawamura, Hironobu; Nakano, Yoshiyuki; Izumi, Shigeru.

1984-01-01

The remotely operated automation of the checkup and maintenance of nuclear power generation facilities has largely contributed to the rise of capacity ratio of plants due to the shortening of regular inspection period and to the reduction of radiation exposure dose during working, the labor saving in working and so on. In this paper, the new technologies adopted in an automatic fuel exchanger, a remotely operated automatic CRD exchanger, a new type channel handling machine, pressure-withstanding main steam line plugs and so on for No.2 plant in the Fukushima No.2 Nuclear Power Station, Tokyo Electric Power Co., Inc., are reported. Besides, the state of development of new remotely operated automatic machines for nuclear power use, such as CRD disassembling and cleaning device, volume reduction equipment for spent fuel channel boxes and control rods, multi-functional robots for use under high radiation and so on is described. Also the trend of development of latest robot technology which will be put in practical use in near future is outlined, such as a running manipulator for checkup and inspection, a variable form crawler vehicle and a five-leg movable manipulator. (Kako, I.)

Development of spent fuel remote handling technology

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ji Sup; Park, B S; Park, Y S; Oh, S C; Kim, S H; Cho, M W; Hong, D H

1997-12-01

Since the nation`s policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

Evaluation issues on real-time operating system in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. M.; Jeong, C. H.; Koh, J. S. [Regulatory Research Div., Korea Inst. of Nuclear Safety (Korea, Republic of)

2006-07-01

In the recent few years, using the hard real-time operating system (RTOS) of safety-critical applications has gained increased acceptance in the nuclear safety system. Failure of this software could cause catastrophic consequences for human life. The digital I and C systems of nuclear power plants also have used hard RTOSs which are executing a required mission completely within its deadline. Because the nuclear power plants have to maintain a very high level of safety, the hard RTOS software should be reliable and safe. The RTOS used in safety-critical I and C systems is the base software used for the purpose of satisfying the real-time constraints, So, careful evaluation of its safety and functionality is very important, So far, the nuclear power plants of Korea have adopted commercial off-the-shelf (COTS) RTOS software. But, these days the RTOS embedded in safety grade PLC has been developed by KNICS project controlled by Ministry of Commerce, Industry and Energy of Korea. Whether COTS RTOS or newly developed RTOS, it must be evaluated its safety and reliability. (authors)

Evaluation issues on real-time operating system in nuclear power plants

International Nuclear Information System (INIS)

Kim, Y. M.; Jeong, C. H.; Koh, J. S.

2006-01-01

In the recent few years, using the hard real-time operating system (RTOS) of safety-critical applications has gained increased acceptance in the nuclear safety system. Failure of this software could cause catastrophic consequences for human life. The digital I and C systems of nuclear power plants also have used hard RTOSs which are executing a required mission completely within its deadline. Because the nuclear power plants have to maintain a very high level of safety, the hard RTOS software should be reliable and safe. The RTOS used in safety-critical I and C systems is the base software used for the purpose of satisfying the real-time constraints, So, careful evaluation of its safety and functionality is very important, So far, the nuclear power plants of Korea have adopted commercial off-the-shelf (COTS) RTOS software. But, these days the RTOS embedded in safety grade PLC has been developed by KNICS project controlled by Ministry of Commerce, Industry and Energy of Korea. Whether COTS RTOS or newly developed RTOS, it must be evaluated its safety and reliability. (authors)

Chain Assembly and Disassembly Processes Differently Affect the Conformational Space of Ubiquitin Chains.

Science.gov (United States)

Kniss, Andreas; Schuetz, Denise; Kazemi, Sina; Pluska, Lukas; Spindler, Philipp E; Rogov, Vladimir V; Husnjak, Koraljka; Dikic, Ivan; Güntert, Peter; Sommer, Thomas; Prisner, Thomas F; Dötsch, Volker

2018-02-06

Ubiquitination is the most versatile posttranslational modification. The information is encoded by linkage type as well as chain length, which are translated by ubiquitin binding domains into specific signaling events. Chain topology determines the conformational space of a ubiquitin chain and adds an additional regulatory layer to this ubiquitin code. In particular, processes that modify chain length will be affected by chain conformations as they require access to the elongation or cleavage sites. We investigated conformational distributions in the context of chain elongation and disassembly using pulsed electron-electron double resonance spectroscopy in combination with molecular modeling. Analysis of the conformational space of diubiquitin revealed conformational selection or remodeling as mechanisms for chain recognition during elongation or hydrolysis, respectively. Chain elongation to tetraubiquitin increases the sampled conformational space, suggesting that a high intrinsic flexibility of K48-linked chains may contribute to efficient proteasomal degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuclear power plant monitoring using real-time learning neural network

International Nuclear Information System (INIS)

Nabeshima, Kunihiko; Tuerkcan, E.; Ciftcioglu, O.

1994-01-01

In the present research, artificial neural network (ANN) with real-time adaptive learning is developed for the plant wide monitoring of Borssele Nuclear Power Plant (NPP). Adaptive ANN learning capability is integrated to the monitoring system so that robust and sensitive on-line monitoring is achieved in real-time environment. The major advantages provided by ANN are that system modelling is formed by means of measurement information obtained from a multi-output process system, explicit modelling is not required and the modelling is not restricted to linear systems. Also ANN can respond very fast to anomalous operational conditions. The real-time ANN learning methodology with adaptive real-time monitoring capability is described below for the wide-range and plant-wide data from an operating nuclear power plant. The layered neural network with error backpropagation algorithm for learning has three layers. The network type is auto-associative, inputs and outputs are exactly the same, using 12 plant signals. (author)

Disassembly of an arch bridge deformed due to landslide activity and the replacement of a new bridge in the same site. Jisuberi ni yori henkei shita arch bashi no kaitai to shinbashi no kakekae

Energy Technology Data Exchange (ETDEWEB)

Sano, S; Morimoto, C; Tomoda, T; Mizukawa, Y; Onushi, M; Ito, T [Kawasaki Heavy Industries, Ltd., Tokyo (Japan)

1991-10-20

This report describes the replacement process of an arch bridge deformed due to landslide activity, selection and contents of the disassembly method, and configuration of the new bridge and its design method. The Ryugu Bridge had been damaged by landslides over an extended period. It was a deck arch bridge having originally a span of 74 meters, but it had shortened by 424 mm due to landslide activity during 14 years since its completion. Then it was decided to be replaced by a new bridge having an adjustable structure to support the movement of its abutments. As disassembly of the deformed arch bridge could be dangerous, the best methodology was studied, and the disassembly was carried out by the cable method. The new bridge had box-girder parts in both side of the main truss, so as to be adjustable to the change of the span length, and the bridge was designed for a working life of 50 years if the bearing supports and expansion joints were reset every 10 years. Concerning the connecting parts between the box-girder and the main truss, appropriateness of the sectional configuration was verified by FEM analysis. 9 refs., 18 figs., 2 tab.

Time to increase momentum in bridging the nuclear skills gap

Energy Technology Data Exchange (ETDEWEB)

Shepherd, John [nuclear 24, London (United Kingdom)

2014-07-15

A international conference hosted by the International Atomic Energy Agency (IAEA) in May 2014 highlighted the difficult balancing act that countries have in making sure that a pool of talent continues to be available to the nuclear sector into the future. The International Conference on Human Resource Development for Nuclear Power Programmes noted the huge task of maintaining a skilled workforce with the ability to cover nuclear in its widest sense: everything from fuel manufacturing, nuclear power plant operations, decommissioning, waste management and of course nurturing those who may become future regulators or captains of industry. The conference also correctly identified the different requirements of countries depending on their individual circumstances. There can certainly be no delay in this task. Even if no new nuclear power plants were to be built again - which is certainly not the case - highly-skilled individuals would still be required to manage existing plants, work in decommissioning, waste management and so on. The nuclear industry should continue and expand its support for academies, training establishments and other such institutions with the goal of training the next generation of nuclear professionals. At the same time, knowledge transfer programmes should be stepped up, so that professionals who are approaching retirement can pass on their invaluable expertise to those who will follow them. (orig.)

Time to increase momentum in bridging the nuclear skills gap

International Nuclear Information System (INIS)

Shepherd, John

2014-01-01

A international conference hosted by the International Atomic Energy Agency (IAEA) in May 2014 highlighted the difficult balancing act that countries have in making sure that a pool of talent continues to be available to the nuclear sector into the future. The International Conference on Human Resource Development for Nuclear Power Programmes noted the huge task of maintaining a skilled workforce with the ability to cover nuclear in its widest sense: everything from fuel manufacturing, nuclear power plant operations, decommissioning, waste management and of course nurturing those who may become future regulators or captains of industry. The conference also correctly identified the different requirements of countries depending on their individual circumstances. There can certainly be no delay in this task. Even if no new nuclear power plants were to be built again - which is certainly not the case - highly-skilled individuals would still be required to manage existing plants, work in decommissioning, waste management and so on. The nuclear industry should continue and expand its support for academies, training establishments and other such institutions with the goal of training the next generation of nuclear professionals. At the same time, knowledge transfer programmes should be stepped up, so that professionals who are approaching retirement can pass on their invaluable expertise to those who will follow them. (orig.)

Nuclear matter saturation in a U(1) circle-times chiral model

International Nuclear Information System (INIS)

Lin, Wei

1989-01-01

The mean-field approximation in the U(1) circle-times chiral model for nuclear matter maturation is reviewed. Results show that it cannot be the correct saturation mechanism. It is argued that in this chiral model, other than the fact the ω mass can depend on the density of nuclear matter, saturation is still quite like the Walecka picture. 16 refs., 3 figs

A study on constructing a machine-maintenance training system based on virtual reality technology

International Nuclear Information System (INIS)

Ishii, H.; Kashiwa, K.; Tezuka, T.; Yoshikawa, H.

1997-01-01

The development of a VR based training system are presented for teaching disassembling procedures of mechanical machines used in nuclear power plant. The methods of Petri net model for describing trainees' plausible actions in the disassembling process and reduce a right sequence of action sequence are developed as well as realization of the related Petri net editor and the demonstration of the developed VR based training system was demonstrated by example practice of disassembly simulation of check valve. Moreover, the needed future works are also discussed

Acoustically Triggered Disassembly of Multilayered Polyelectrolyte Thin Films through Gigahertz Resonators for Controlled Drug Release Applications

Directory of Open Access Journals (Sweden)

Zhixin Zhang

2016-11-01

Full Text Available Controlled drug release has a high priority for the development of modern medicine and biochemistry. To develop a versatile method for controlled release, a miniaturized acoustic gigahertz (GHz resonator is designed and fabricated which can transfer electric supply to mechanical vibrations. By contacting with liquid, the GHz resonator directly excites streaming flows and induces physical shear stress to tear the multilayered polyelectrolyte (PET thin films. Due to the ultra-high working frequency, the shear stress is greatly intensified, which results in a controlled disassembling of the PET thin films. This technique is demonstrated as an effective method to trigger and control the drug release. Both theory analysis and controlled release experiments prove the thin film destruction and the drug release.

Time characteristics for the spinodal decomposition in nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Idier, D.; Farine, M.; Benhassine, B.; Remaud, B.; Sebille, F.

1992-12-31

Dynamics of the fluctuation growth are studied. Time characteristics are key quantities to determine the conditions under which spinodal decomposition could be observed. Dynamical instabilities arising from fluctuations in spinodal zone for nuclear matter are studied using Skyrme type interactions within a pseudo-particle model. Typical times for cluster formation are extracted. The numerical treatment is based on the Vlasov phase space transport equation. (K.A.) 11 refs.; 7 figs.

Time characteristics for the spinodal decomposition in nuclear matter

International Nuclear Information System (INIS)

Idier, D.; Farine, M.; Benhassine, B.; Remaud, B.; Sebille, F.

1992-01-01

Dynamics of the fluctuation growth are studied. Time characteristics are key quantities to determine the conditions under which spinodal decomposition could be observed. Dynamical instabilities arising from fluctuations in spinodal zone for nuclear matter are studied using Skyrme type interactions within a pseudo-particle model. Typical times for cluster formation are extracted. The numerical treatment is based on the Vlasov phase space transport equation. (K.A.) 11 refs.; 7 figs

Modeling and simulation of nuclear fuel in scenarios with long time scales

Energy Technology Data Exchange (ETDEWEB)

Espinosa, Carlos E.; Bodmann, Bardo E.J., E-mail: eduardo.espinosa@ufrgs.br, E-mail: bardo.bodmann@ufrgs.br [Universidade Federal do Rio Grande do Sul (DENUC/PROMEC/UFRGS), Porto Alegre, RS (Brazil). Departamento de Engenharia Nuclear. Programa de Pos Graduacao em Engenharia Mecanica

2015-07-01

Nuclear reactors play a key role in defining the energy matrix. A study by the Fraunhofer Society shows in different time scales for long periods of time the distribution of energy sources. Regardless of scale, the use of nuclear energy is practically constant. In these scenarios, the nuclear fuel behavior over time is of interest. For kinetics of long-term scales, changing the chemical composition of fuel is significant. Thus, it is appropriate to consider fission products called neutron poisons. Such products are of interest in the nuclear reactor, since they become parasitic neutron absorbers and result in long thermal heat sources. The objective of this work is to solve the kinetics system coupled to neutron poison products. To solve this system, we use similar ideas to the method of Adomian decomposition. Initially, one separates the system of equations as the sum of a linear part and a non-linear part in order to solve a recursive system. The nonlinearity is treated as Adomian polynomial. We present numerical results of the effects of changing the power of a reactor, scenarios such as start-up and shut-down. For these results we consider time dependent reactivity, such as linear reactivity, quadratic polynomial and oscillatory. With these results one can simulate the chemical composition of the fuel due to the reuse of the spent fuel in subsequent cycles. (author)

Modeling and simulation of nuclear fuel in scenarios with long time scales

International Nuclear Information System (INIS)

Espinosa, Carlos E.; Bodmann, Bardo E.J.

2015-01-01

Nuclear reactors play a key role in defining the energy matrix. A study by the Fraunhofer Society shows in different time scales for long periods of time the distribution of energy sources. Regardless of scale, the use of nuclear energy is practically constant. In these scenarios, the nuclear fuel behavior over time is of interest. For kinetics of long-term scales, changing the chemical composition of fuel is significant. Thus, it is appropriate to consider fission products called neutron poisons. Such products are of interest in the nuclear reactor, since they become parasitic neutron absorbers and result in long thermal heat sources. The objective of this work is to solve the kinetics system coupled to neutron poison products. To solve this system, we use similar ideas to the method of Adomian decomposition. Initially, one separates the system of equations as the sum of a linear part and a non-linear part in order to solve a recursive system. The nonlinearity is treated as Adomian polynomial. We present numerical results of the effects of changing the power of a reactor, scenarios such as start-up and shut-down. For these results we consider time dependent reactivity, such as linear reactivity, quadratic polynomial and oscillatory. With these results one can simulate the chemical composition of the fuel due to the reuse of the spent fuel in subsequent cycles. (author)

Software for the nuclear reactor dynamics study using time series processing

International Nuclear Information System (INIS)

Valero, Esbel T.; Montesino, Maria E.

1997-01-01

The parametric monitoring in Nuclear Power Plant (NPP) permits the operational surveillance of nuclear reactor. The methods employed in order to process this information such as FFT, autoregressive models and other, have some limitations when those regimens in which appear strongly non-linear behaviors are analyzed. In last years the chaos theory has offered new ways in order to explain complex dynamic behaviors. This paper describes a software (ECASET) that allow, by time series processing from NPP's acquisition system, to characterize the nuclear reactor dynamic as a complex dynamical system. Here we show using ECASET's results the possibility of classifying the different regimens appearing in nuclear reactors. The results of several temporal series processing from real systems are introduced. This type of analysis complements the results obtained with traditional methods and can constitute a new tool for monitoring nuclear reactors. (author). 13 refs., 3 figs

Improvement of the in vivo cellular repopulation of decellularized cardiovascular tissues by a detergent-free, non-proteolytic, actin-disassembling regimen.

Science.gov (United States)

Assmann, Alexander; Struß, Marc; Schiffer, Franziska; Heidelberg, Friederike; Munakata, Hiroshi; Timchenko, Elena V; Timchenko, Pavel E; Kaufmann, Tim; Huynh, Khon; Sugimura, Yukiharu; Leidl, Quentin; Pinto, Antonio; Stoldt, Volker R; Lichtenberg, Artur; Akhyari, Payam

2017-12-01

Low immunogenicity and high repopulation capacity are crucial determinants for the functional and structural performance of acellular cardiovascular implants. The present study evaluates a detergent-free, non-proteolytic, actin-disassembling regimen (BIO) for decellularization of heart valve and vessel grafts, particularly focusing on their bio-functionality. Rat aortic conduits (rAoC; n = 89) and porcine aortic valve samples (n = 106) are decellularized using detergents (group DET) or the BIO regimen. BIO decellularization results in effective elimination of cellular proteins and significantly improves removal of DNA as compared with group DET, while the extracellular matrix (ECM) structure as well as mechanical properties are preserved. The architecture of rAoC in group BIO allows for improved bio-functionalization with fibronectin (FN) in a standardized rat implantation model: BIO treatment significantly increases speed and amount of autologous medial cellular repopulation in vivo (p < 0.001) and decreases the formation of hyperplastic intima (p < 0.001) as compared with FN-coated DET-decellularized grafts. Moreover, there are no signs of infiltration with inflammatory cells. The present biological, detergent-free, non-proteolytic regimen balances effective decellularization and ECM preservation in cardiovascular grafts, and provides optimized bio-functionality. Additionally, this study implies that the actin-disassembling regimen may be a promising approach for bioengineering of acellular scaffolds from other muscular tissues, as for example myocardium or intestine. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

International Nuclear Information System (INIS)

Berthélemy, Michel; Escobar Rangel, Lina

2015-01-01

This paper provides an econometric analysis of nuclear reactor construction costs in France and the United States based on overnight costs data. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using change in expected electricity demand as instrument. We argue that the construction of nuclear reactors can benefit from standardization gains through two channels. First, short term coordination benefits can arise when the diversity of nuclear reactors' designs under construction is low. Second, long term benefits can occur due to learning spillovers from past constructions of similar reactors. We find that construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect–Engineer. In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. -- Highlights: •This paper analyses the determinants of nuclear reactors construction costs and lead-time. •We study short term (coordination gains) and long term (learning by doing) benefits of standardization in France and the US. •Results show that standardization of nuclear programs is a key factor for reducing construction costs. •We also suggest that technological progress has contributed to construction costs escalation

Nucleolus disassembly and distribution of segregated nucleolar material in prophase of root-tip meristematic cells in Triticum aestivum L.

Directory of Open Access Journals (Sweden)

Wang Jianyue

2015-01-01

Full Text Available This paper presents details of the process of nucleolar disassembly, studied by conventional transmission electron microscopy (TEM in wheat root cells. In early prophase, chromatin condensation and irregular nucleolar morphology are observed, with many small particles appearing around the nucleolus. In middle prophase, the nucleolus radiates outwards; in late prophase, the fine structure of the nucleolus disappears and nucleolar material diffuses away. Using “en bloc” silver-staining to distinguish between nucleoli and chromatin, we observed that the dispersed nucleolar material aggregates around the chromatin, forming a sheath-like perichromosomal structure that coats the chromosomes in late prophase.

Role of a reducing environment in disassembly of the herpesvirus tegument

Energy Technology Data Exchange (ETDEWEB)

Newcomb, William W. [Department of Microbiology Immunology and Cancer Biology, University of Virginia Health System, Box 800734, University of Virginia Health System, 1300 Jefferson Park Ave. Charlottesville, VA 22908 (United States); Jones, Lisa M. [Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130 (United States); Dee, Alexander [Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030 (United States); Chaudhry, Farid [Department of Microbiology Immunology and Cancer Biology, University of Virginia Health System, Box 800734, University of Virginia Health System, 1300 Jefferson Park Ave. Charlottesville, VA 22908 (United States); Brown, Jay C., E-mail: JCB2G@VIRGINIA.EDU [Department of Microbiology Immunology and Cancer Biology, University of Virginia Health System, Box 800734, University of Virginia Health System, 1300 Jefferson Park Ave. Charlottesville, VA 22908 (United States)

2012-09-15

Initiation of infection by herpes family viruses involves a step in which most of the virus tegument becomes detached from the capsid. Detachment takes place in the host cell cytosol near the virus entry site and it is followed by dispersal of tegument proteins and disappearance of the tegument as a distinct entity. Here we describe the results of experiments designed to test the idea that the reducing environment of the cytosol may contribute to tegument detachment and disassembly. Non-ionic detergent was used to remove the membrane of purified herpes simplex virus under control and reducing conditions. The effects on the tegument were then examined by SDS-PAGE and electron microscopy. Protein analysis demonstrated that most major tegument proteins were removed under both oxidizing and reducing conditions except for UL49 which required a reducing environment. It is proposed therefore that the reducing conditions in the cytosol are involved in removal of UL49 protein. Electron microscopic analysis revealed that capsids produced under oxidizing conditions contained a coating of protein that was absent in reduced virions and which correlated uniquely with the presence of UL49. This capsid-associated layer is suggested to be the location of UL49 in the extracted virion.

Stress analysis and collapse time prediction of nuclear fuel cladding tube with wear scar

International Nuclear Information System (INIS)

Lee, J. S.; Kim, O. H.; Kim, H. K.; Hu, Y. H.; Kim, J. I.; Kim, K. T.

2004-01-01

In this analysis, the stress and collapse time analysis models for nuclear fuel rod with the fretting wear scar were developed in order to evaluate the effects of the wear depth on the integrity of nuclear fuel rod. The stress analysis result shows that the nuclear fuel rod with approximately 60% deep wear scar of the clad wall thickness, meets the allowable stress criteria and the collapse time analysis indicates that the fuel rod with less than roughly 56% deep wear scar of the clad wall thickness has longer collapse time than the expected fuel life-time. The both stress and collapse time results are evaluated to be very reasonable on considering the comparison with the outputs of existing design code for the simple model. However, the developed analysis models and the results will be confirmed by the tests

Proceedings of the nuclear criticality technology safety project

Energy Technology Data Exchange (ETDEWEB)

Sanchez, R.G. [comp.

1997-06-01

This document contains summaries of the most of the papers presented at the 1994 Nuclear Criticality Technology Safety Project (NCTSP) meeting, which was held May 10 and 11 at Williamsburg, Va. The meeting was broken up into seven sessions, which covered the following topics: (1) Validation and Application of Calculations; (2) Relevant Experiments for Criticality Safety; (3) Experimental Facilities and Capabilities; (4) Rad-Waste and Weapons Disassembly; (5) Criticality Safety Software and Development; (6) Criticality Safety Studies at Universities; and (7) Training. The minutes and list of participants of the Critical Experiment Needs Identification Workgroup meeting, which was held on May 9 at the same venue, has been included as an appendix. A second appendix contains the names and addresses of all NCTSP meeting participants. Separate abstracts have been indexed to the database for contributions to this proceedings.

Proceedings of the nuclear criticality technology safety project

International Nuclear Information System (INIS)

Sanchez, R.G.

1997-06-01

This document contains summaries of the most of the papers presented at the 1994 Nuclear Criticality Technology Safety Project (NCTSP) meeting, which was held May 10 and 11 at Williamsburg, Va. The meeting was broken up into seven sessions, which covered the following topics: (1) Validation and Application of Calculations; (2) Relevant Experiments for Criticality Safety; (3) Experimental Facilities and Capabilities; (4) Rad-Waste and Weapons Disassembly; (5) Criticality Safety Software and Development; (6) Criticality Safety Studies at Universities; and (7) Training. The minutes and list of participants of the Critical Experiment Needs Identification Workgroup meeting, which was held on May 9 at the same venue, has been included as an appendix. A second appendix contains the names and addresses of all NCTSP meeting participants. Separate abstracts have been indexed to the database for contributions to this proceedings

National project : advanced robot for nuclear power plant

International Nuclear Information System (INIS)

Tsunemi, T.; Takehara, K.; Hayashi, T.; Okano, H.; Sugiyama, S.

1993-01-01

The national project 'Advanced Robot' has been promoted by the Agency of Industrial science and Technology, MITI for eight years since 1983. The robot for a nuclear plant is one of the projects, and is a prototype intelligent one that also has a three dimensional vision system to generate an environmental model, a quadrupedal walking mechanism to work on stairs and four fingered manipulators to disassemble a valve with a hand tool. Many basic technologies such as an actuator, a tactile sensor, autonomous control and so on progress to high level. The prototype robot succeeded functionally in official demonstration in 1990. More refining such as downsizing and higher intelligence is necessary to realize a commercial robot, while basic technologies are useful to improve conventional robots and systems. This paper presents application studies on the advanced robot technologies. (author)

Integrating complex functions: coordination of nuclear pore complex assembly and membrane expansion of the nuclear envelope requires a family of integral membrane proteins.

Science.gov (United States)

Schneiter, Roger; Cole, Charles N

2010-01-01

The nuclear envelope harbors numerous large proteinaceous channels, the nuclear pore complexes (NPCs), through which macromolecular exchange between the cytosol and the nucleoplasm occurs. This double-membrane nuclear envelope is continuous with the endoplasmic reticulum and thus functionally connected to such diverse processes as vesicular transport, protein maturation and lipid synthesis. Recent results obtained from studies in Saccharomyces cerevisiae indicate that assembly of the nuclear pore complex is functionally dependent upon maintenance of lipid homeostasis of the ER membrane. Previous work from one of our laboratories has revealed that an integral membrane protein Apq12 is important for the assembly of functional nuclear pores. Cells lacking APQ12 are viable but cannot grow at low temperatures, have aberrant NPCs and a defect in mRNA export. Remarkably, these defects in NPC assembly can be overcome by supplementing cells with a membrane fluidizing agent, benzyl alcohol, suggesting that Apq12 impacts the flexibility of the nuclear membrane, possibly by adjusting its lipid composition when cells are shifted to a reduced temperature. Our new study now expands these findings and reveals that an essential membrane protein, Brr6, shares at least partially overlapping functions with Apq12 and is also required for assembly of functional NPCs. A third nuclear envelope membrane protein, Brl1, is related to Brr6, and is also required for NPC assembly. Because maintenance of membrane homeostasis is essential for cellular survival, the fact that these three proteins are conserved in fungi that undergo closed mitoses, but are not found in metazoans or plants, may indicate that their functions are performed by proteins unrelated at the primary sequence level to Brr6, Brl1 and Apq12 in cells that disassemble their nuclear envelopes during mitosis.

Analysis of several digital network technologies for hard real-time communications in nuclear plant

International Nuclear Information System (INIS)

Song, Ki Sang; No, Hee Chun

1999-01-01

Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Tiken Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity form electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant. (author). 11 refs., 3 figs., 4 tabs

The Oncogenic Fusion Proteins SET-Nup214 and Sequestosome-1 (SQSTM1)-Nup214 Form Dynamic Nuclear Bodies and Differentially Affect Nuclear Protein and Poly(A)+ RNA Export*

Science.gov (United States)

Port, Sarah A.; Mendes, Adélia; Valkova, Christina; Spillner, Christiane; Fahrenkrog, Birthe; Kaether, Christoph; Kehlenbach, Ralph H.

2016-01-01

Genetic rearrangements are a hallmark of several forms of leukemia and can lead to oncogenic fusion proteins. One example of an affected chromosomal region is the gene coding for Nup214, a nucleoporin that localizes to the cytoplasmic side of the nuclear pore complex (NPC). We investigated two such fusion proteins, SET-Nup214 and SQSTM1 (sequestosome)-Nup214, both containing C-terminal portions of Nup214. SET-Nup214 nuclear bodies containing the nuclear export receptor CRM1 were observed in the leukemia cell lines LOUCY and MEGAL. Overexpression of SET-Nup214 in HeLa cells leads to the formation of similar nuclear bodies that recruit CRM1, export cargo proteins, and certain nucleoporins and concomitantly affect nuclear protein and poly(A)+ RNA export. SQSTM1-Nup214, although mostly cytoplasmic, also forms nuclear bodies and inhibits nuclear protein but not poly(A)+ RNA export. The interaction of the fusion proteins with CRM1 is RanGTP-dependent, as shown in co-immunoprecipitation experiments and binding assays. Further analysis revealed that the Nup214 parts mediate the inhibition of nuclear export, whereas the SET or SQSTM1 part determines the localization of the fusion protein and therefore the extent of the effect. SET-Nup214 nuclear bodies are highly mobile structures, which are in equilibrium with the nucleoplasm in interphase and disassemble during mitosis or upon treatment of cells with the CRM1-inhibitor leptomycin B. Strikingly, we found that nucleoporins can be released from nuclear bodies and reintegrated into existing NPC. Our results point to nuclear bodies as a means of preventing the formation of potentially insoluble and harmful protein aggregates that also may serve as storage compartments for nuclear transport factors. PMID:27613868

The Oncogenic Fusion Proteins SET-Nup214 and Sequestosome-1 (SQSTM1)-Nup214 Form Dynamic Nuclear Bodies and Differentially Affect Nuclear Protein and Poly(A)+ RNA Export.

Science.gov (United States)

Port, Sarah A; Mendes, Adélia; Valkova, Christina; Spillner, Christiane; Fahrenkrog, Birthe; Kaether, Christoph; Kehlenbach, Ralph H

2016-10-28

Genetic rearrangements are a hallmark of several forms of leukemia and can lead to oncogenic fusion proteins. One example of an affected chromosomal region is the gene coding for Nup214, a nucleoporin that localizes to the cytoplasmic side of the nuclear pore complex (NPC). We investigated two such fusion proteins, SET-Nup214 and SQSTM1 (sequestosome)-Nup214, both containing C-terminal portions of Nup214. SET-Nup214 nuclear bodies containing the nuclear export receptor CRM1 were observed in the leukemia cell lines LOUCY and MEGAL. Overexpression of SET-Nup214 in HeLa cells leads to the formation of similar nuclear bodies that recruit CRM1, export cargo proteins, and certain nucleoporins and concomitantly affect nuclear protein and poly(A) + RNA export. SQSTM1-Nup214, although mostly cytoplasmic, also forms nuclear bodies and inhibits nuclear protein but not poly(A) + RNA export. The interaction of the fusion proteins with CRM1 is RanGTP-dependent, as shown in co-immunoprecipitation experiments and binding assays. Further analysis revealed that the Nup214 parts mediate the inhibition of nuclear export, whereas the SET or SQSTM1 part determines the localization of the fusion protein and therefore the extent of the effect. SET-Nup214 nuclear bodies are highly mobile structures, which are in equilibrium with the nucleoplasm in interphase and disassemble during mitosis or upon treatment of cells with the CRM1-inhibitor leptomycin B. Strikingly, we found that nucleoporins can be released from nuclear bodies and reintegrated into existing NPC. Our results point to nuclear bodies as a means of preventing the formation of potentially insoluble and harmful protein aggregates that also may serve as storage compartments for nuclear transport factors. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Recommendations relating to safety-critical real-time software in nuclear power plants

International Nuclear Information System (INIS)

1992-01-01

The Advisory Committee on Nuclear Safety (ACNS) has reviewed safety issues associated with the software for the digital computers in the safety shutdown systems for the Darlington NGS. From this review the ACNS has developed four recommendations for safety-critical real-time software in nuclear power plants. These recommendations cover: the completion of the present efforts to develop an overall standard and sub-tier standards for safety-critical real-time software; the preparation of schedules and lists of responsibilities for this development; the concentration of AECB efforts on ensuring the scrutability of safety-critical real-time software; and, the collection of data on reliability and causes of failure (error) of safety-critical real-time software systems and on the probability and causes of common-mode failures (errors). (9 refs.)

Time-dependent Thomas-Fermi approach to nuclear monopole oscillations

International Nuclear Information System (INIS)

Pi, M.; Barranco, M.; Nemeth, J.; Ngo, C.; Tomasi, E.

1985-10-01

A Time-dependent Thomas-Fermi (TDTF) method has been used to study nuclear monopole oscillations and in particular, the semiclassical strength function S(E). An analysis of the S(E) moments, obtained by suitable integrations, shows that these results are in good agreement with data previously obtained from static Thomas-Fermi calculations

Optimization of time and location dependent spent nuclear fuel storage capacity

International Nuclear Information System (INIS)

Macek, V.

1977-01-01

A linear spent fuel storage model is developed to identify cost-effective spent nuclear fuel storage strategies. The purpose of this model is to provide guidelines for the implementation of the optimal time-dependent spent fuel storage capacity expansion in view of the current economic and regulatory environment which has resulted in phase-out of the closed nuclear fuel cycle. Management alternatives of the spent fuel storage backlog, which is created by mismatch between spent fuel generation rate and spent fuel disposition capability, are represented by aggregate decision variables which describe the time dependent on-reactor-site and off-site spent fuel storage capacity additions, and the amount of spent fuel transferred to off-site storage facilities. Principal constraints of the model assure determination of cost optimal spent fuel storage expansion strategies, while spent fuel storage requirements are met at all times. A detailed physical and economic analysis of the essential components of the spent fuel storage problem, which precedes the model development, assures its realism. The effects of technological limitations on the on-site spent fuel storage expansion and timing of reinitiation of the spent fuel reprocessing on optimal spent fuel storage capacity expansion are investigated. The principal results of the study indicate that (a) expansion of storage capacity beyond that of currently planned facilities is necessary, and (b) economics of the post-reactor fuel cycle is extremely sensitive to the timing of reinitiation of spent fuel reprocessing. Postponement of reprocessing beyond mid-1982 may result in net negative economic liability of the back end of the nuclear fuel cycle

Design and implementation of real-time diagnostic expert system in nuclear power plant

International Nuclear Information System (INIS)

Zhang Yan; Zhou Zhiwei; Dong Xiuchen

2006-01-01

In order to decrease the probability of malfunctions in nuclear power plant, a real-time expert system to be applied to malfunction diagnosis was designed. Based on the expert system theory the system converts the expert knowledge for diagnosing failures into the rules stored in database, and it can display real-time information of the abnormal symptoms, perform real-time diagnosis of malfunctions and suggest the operation actions related to malfunctions, etc. The results indicate that several typical malfunctions in nuclear power plant are diagnosed automatically and the corresponding operation schedules are given out by present expert system. (authors)

Advance on the technology of assembly and disassembly of a head frame with four legs and the machine-assembled head frame

Energy Technology Data Exchange (ETDEWEB)

Zhou Youzong; Cao Baozhen [Ministry of Coal Industry (China). Geological Exploration Machinery Factory

1996-12-31

According to the meditation of assembling headframes from upper to lower instead of that from lower to upper, the authors created successfully a new type of machine for assembling and disassembling headframes as well as a type of machine-assembled headframe. The new type of headframe not only has the merits of old type of headframe with four legs, but also can keep people away from dangers of working in high space and save the workers much labour. The new technology has good effect on raising productive efficiency. 2 figs.

Life time of nuclear power plants and new types of reactors

International Nuclear Information System (INIS)

2003-05-01

This report, realized by the Evaluation Parliamentary Office of scientific and technological choices, aims to answer simple but fundamental questions for the french electric power production. What are the phenomena which may limit the exploitation time of nuclear power plants? How can we fight against the aging, at which cost and with which safety? The first chapter presents the management of the nuclear power plants life time, an essential element of the park optimization but not a sufficient element. The second chapter details the EPR and the other reactors for 2015 as a bond between the today and tomorrow parks. The last chapter deals with the necessity of efforts in the research and development to succeed in 2035 and presents other reactors in project. (A.L.B.)

Gamma-ray imaging system for real-time measurements in nuclear waste characterisation

Science.gov (United States)

Caballero, L.; Albiol Colomer, F.; Corbi Bellot, A.; Domingo-Pardo, C.; Leganés Nieto, J. L.; Agramunt Ros, J.; Contreras, P.; Monserrate, M.; Olleros Rodríguez, P.; Pérez Magán, D. L.

2018-03-01

A compact, portable and large field-of-view gamma camera that is able to identify, locate and quantify gamma-ray emitting radioisotopes in real-time has been developed. The device delivers spectroscopic and imaging capabilities that enable its use it in a variety of nuclear waste characterisation scenarios, such as radioactivity monitoring in nuclear power plants and more specifically for the decommissioning of nuclear facilities. The technical development of this apparatus and some examples of its application in field measurements are reported in this article. The performance of the presented gamma-camera is also benchmarked against other conventional techniques.

Analysis of the stress-deformed condition of the disassembly parabolic antenna

Science.gov (United States)

Odinets, M. N.; Kaygorodtseva, N. V.; Krysova, I. V.

2018-01-01

Active development of satellite communications and computer-aided design systems raises the problem of designing parabolic antennas on a new round of development. The aim of the work was to investigate the influence of the design of the mirror of a parabolic antenna on its endurance under wind load. The research task was an automated analysis of the stress-deformed condition of various designs of computer models of a paraboloid mirror (segmented or holistic) at modeling the exploitation conditions. The peculiarity of the research was that the assembly model of the antenna’s mirror was subjected to rigid connections on the contacting surfaces of the segments and only then the finite element grid was generated. The analysis showed the advantage of the design of the demountable antenna, which consists of cyclic segments, in front of the construction of the holistic antenna. Calculation of the stress-deformed condition of the antennas allows us to conclude that dividing the design of the antenna’s mirror on parabolic and cyclic segments increases it strength and rigidity. In the future, this can be used to minimize the mass of antenna and the dimensions of the disassembled antenna. The presented way of modeling a mirror of a parabolic antenna using to the method of the finite-element analysis can be used in the production of antennas.

A multi-particle model applicable to social issues--time-evolution of Japanese public opinion on nuclear energy

International Nuclear Information System (INIS)

Ohnishi, Teruaki

2002-01-01

The characteristics of an interacting multi-particle system in natural sciences can form a useful model for the evolution of public attitudes and opinions, provided that each particle corresponds to one individual. A simulation model which uses a multi-particle system to represent society was developed. By using this model, the time evolution of the public attitudes to nuclear energy were investigated. The nuclear attitude of an individual was assumed to be influenced by three factors: a uniform information environment, mutual interactions between members of the public, and spontaneous recovery of the original attitude with time. Also the time-evolution of the socio-psychological position of members of the public was assumed to be given by a Langevin-type equation. Various attributes of individuals obtained by public opinion surveys together with data on the secular variation of availability of nuclear information were used as the input. By numerically solving the simultaneous differential equations for the system of a 1000 particles, the time behavior of Japanese public opinion regarding the promotion of nuclear generation was investigated. It was found from this calculation that the public aversion to nuclear energy is catastrophically aggravated with every large-scale nuclear accident, that the opinions of individual members of the public as to the value of nuclear energy were gradually attracted to a few views with time, and that the unification of such views occurred with the Chernobyl accident as a promoter. It also became clear that the public attitude at a particular time is governed by the information environment over several years immediately prior to that time

Zero Time of Transitory Nuclear Events Derived by Parent-Daughter Systems

International Nuclear Information System (INIS)

Nir-El, Y.

2014-01-01

The detection and identification of a nuclear event that results in the dissemination of radioactive products into the environment can be realized by dating the age of the event. In order to correct observed activities for the decay since the occurrence of the event, the age must be known to a high level of confidence. Previous papers. described the method to date the age of a nuclear event by measuring the activity of two fission products, which constitute the clock in this application. Within the proficiency test programme for radionuclide laboratories supporting the CTBT, a simulated gamma spectrum with the characteristics of an atmospheric test of a Chinese thermonuclear device, was used to determine the zero time by calculating the theoretical peak area ratio of 95Nb/95Zr. Their approach used only the main gamma lines at 766 and 757 keV and assigned the same detection efficiency to both these close lines. Their methodology of calculating the uncertainty of zero time is subject to comments because it takes the sum of two components (nuclide ratio and activity ratio as function of time) in quadrature. In another paper, the activity of 95Nb as a function of time was presented without any development or expression for the zero time. Analytical equations for zero time and the associated uncertainty calculations were derived in a recent paper using a measured activity ratio of two nuclides and illustrating the procedure by data from the Chinese test. The evaluation of the zero time uncertainty was performed by a very large set of very complicated analytical equations. The present paper aims at developing a procedure to determine the zero time and its uncertainty in a transitory nuclear event by treating a parent-daughter system of 3 nuclides, where one daughter feeds the other one, in addition to its direct feeding by the decay of the parent

Reviewing real-time performance of nuclear reactor safety systems

International Nuclear Information System (INIS)

Preckshot, G.G.

1993-08-01

The purpose of this paper is to recommend regulatory guidance for reviewers examining real-time performance of computer-based safety systems used in nuclear power plants. Three areas of guidance are covered in this report. The first area covers how to determine if, when, and what prototypes should be required of developers to make a convincing demonstration that specific problems have been solved or that performance goals have been met. The second area has recommendations for timing analyses that will prove that the real-time system will meet its safety-imposed deadlines. The third area has description of means for assessing expected or actual real-time performance before, during, and after development is completed. To ensure that the delivered real-time software product meets performance goals, the paper recommends certain types of code-execution and communications scheduling. Technical background is provided in the appendix on methods of timing analysis, scheduling real-time computations, prototyping, real-time software development approaches, modeling and measurement, and real-time operating systems

Reviewing real-time performance of nuclear reactor safety systems

Energy Technology Data Exchange (ETDEWEB)

Preckshot, G.G. [Lawrence Livermore National Lab., CA (United States)

1993-08-01

The purpose of this paper is to recommend regulatory guidance for reviewers examining real-time performance of computer-based safety systems used in nuclear power plants. Three areas of guidance are covered in this report. The first area covers how to determine if, when, and what prototypes should be required of developers to make a convincing demonstration that specific problems have been solved or that performance goals have been met. The second area has recommendations for timing analyses that will prove that the real-time system will meet its safety-imposed deadlines. The third area has description of means for assessing expected or actual real-time performance before, during, and after development is completed. To ensure that the delivered real-time software product meets performance goals, the paper recommends certain types of code-execution and communications scheduling. Technical background is provided in the appendix on methods of timing analysis, scheduling real-time computations, prototyping, real-time software development approaches, modeling and measurement, and real-time operating systems.

US nuclear power - has its time passed

International Nuclear Information System (INIS)

Price, K.A.; Ahearne, J.F.

1984-01-01

An interview with former Nuclear Regulatory Commission (NRC) member John F. Ahearne inquires into the future for commercial nuclear power. Ahearne thinks the role played by intervenors is exaggerated, and that the NRC, despite its inefficiencies, has not been a major factor in the slowdown of nuclear industry growth. He does credit the AEC and subsequent regulators for enhancing the industry's safety record and improving the quality of construction. Complex technology more than regulation is responsible for the delays and added costs of construction and licensing. A high degree of government involvement and standardized design have helped France build nuclear plants faster than the US, but Germany and Japan have had comparable problems. Three Mile Island was a financial and psychological disaster, but safety improvements since should reduce the probability of a similar accident. Other questions touch on public confidence, nuclear waste handling and storage, and breeder programs, Ahearne concludes that a substantial change in management is needed before the nuclear industry can proceed

The crucial role of nomothetic and idiographic conceptions of time: interdisciplinary collaboration in nuclear waste management.

Science.gov (United States)

Moser, Corinne; Stauffacher, Michael; Krütli, Pius; Scholz, Roland W

2012-01-01

The disposal of nuclear waste involves extensive time scales. Technical experts consider up to 1 million years for the disposal of spent fuel and high-level waste in their safety assessment. Yet nuclear waste is not only a technical but also a so-called sociotechnical problem and, therefore, requires interdisciplinary collaboration between technical, natural, social sciences, and the humanities in its management. Given that these disciplines differ in their language, epistemics, and interests, such collaboration might be problematic. Based on evidence from cognitive psychology, we suggest that, in particular, a concept like time is presumably critical and can be understood differently. This study explores how different scientific disciplines understand extensive time scales in general and then focuses on nuclear waste. Eighteen qualitative exploratory interviews were conducted with experts for time-related phenomena of different disciplines, among them experts working in nuclear waste management. Analyses revealed two distinct conceptions of time corresponding to idiographic and nomothetic research approaches: scientists from the humanities and social sciences tend to have a more open, undetermined conception of time, whereas natural scientists tend to focus on a more determined conception that includes some undetermined aspects. Our analyses lead to reflections on potential difficulties for interdisciplinary teams in nuclear waste management. We focus on the understanding of the safety assessment, on potential implications for communication between experts from different disciplines (e.g., between experts from the humanities and engineering for risk assessment and risk communication), and we reflect on the roles of different disciplines in nuclear waste management. © 2011 Society for Risk Analysis.

Fuzzy controller for real time supervision of nuclear power reactor

International Nuclear Information System (INIS)

Bala Subramanian, R.

2012-01-01

Generally nuclear energy provides about 60% of the whole electricity production. A modulation of the nuclear power plants must be able to respond to the demand on the network. The pressurized water nuclear reactor has to yield correctly a load set point. Fundamentally, two parameters are concerned in leading this task to a successful conclusion: the power axial-offset and the control rods position. The focus of this study is the automation of the control of the power axial-offset by adding soluble boron and by minimizing the volume flows through the water pump. It is also important to take into consideration the liquid waste volume. Water or boron is injected into the reactor primary circuit. At the present time this task is still performed manually by an operator, for all previous attempts to automate it failed. That device, sketchily described in the paper, gave rise to the development of a real-time fuzzy controller for the power axial-offset and the control rods insertion in a pressurized water reactor (PWR). The fuzzy controller, which is the main subject of the paper, expresses more naturally the human expertise, thus avoiding the previous issue of empirical tunings. It was implemented in simulation using Matlab-Simulink on a Sun workstation. Two realistic tests discussed show that the fuzzy controller runs as efficiently as an expert operator does

Manipulator and materials handling systems for reactor decommissioning -Cooperation between the university and the plant operator

International Nuclear Information System (INIS)

Schreck, G.; Bach, F. W.; Haferkamp, H.

1995-01-01

Nuclear reactor dismantling requires suitable handling systems for tools and disassembled components, as well as qualified and reliable disassembly and cutting techniques. From the angle of radiation protection, remote-controlled handling techniques and underwater techniques are the methods of choice, the latter particularly in continuation of plant operating conditions, and this all the more the more disassembly work proceeds towards the reactor core. With the experience accumulated for 20 years now by the Institut fuer Werkstoffkunde (materials science) of Hannover University by basic research and application-oriented development work in the field of thermal cutting technology, especially plasma arc cutting techniques, as well as development work in the field of remote-controlled materials handling systems, the institute is the cut-out partner for disassembly tasks in reactor decommissioning. (Orig./DG) [de

Studies of Fluctuation Processes in Nuclear Collisions

Energy Technology Data Exchange (ETDEWEB)

Ayik, Sakir [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Physics

2016-04-14

The standard one-body transport approaches have been extensively applied to investigate heavy-ion collision dynamics at low and intermediate energies. At low energies the approach is the mean-field description of the time-dependent Hartree-Fock (TDHF) theory. At intermediate energies the approach is extended by including a collision term, and its application has been carried out mostly in the semi-classical framework of the Boltzmann-Uhling-Uhlenbeck (BUU) model. The standard transport models provide a good understanding of the average properties of the collision dynamics in terms of the effective interactions in both low and intermediate energies. However, the standard models are inadequate for describing the fluctuation dynamics of collective motion at low energies and disassembling of the nuclear system into fragments at intermediate energies resulting from the growth of density fluctuations in the spinodal region. Our tasks have been to improve the standard transport approaches by incorporating fluctuation mechanisms into the description. There are mainly two different mechanisms for fluctuations: (i) Collisional fluctuations generated by binary nucleon collisions, which provide the dominant mechanism at intermediate energies, and (ii) One-body mechanism or mean-field fluctuations, which is the dominant mechanism at low energies. In the first part of our project, the PI extended the standard transport model at intermediate energies by incorporating collisional mechanism according to the “Generalized Langevin Description” of Mori formalism. The PI and his collaborators carried out a number of applications for describing dynamical mechanism of nuclear multi fragmentations, and nuclear collective response in the semi-classical framework of the approach, which is known as the Boltzmann-Langevin model. In the second part of the project, we considered dynamical description at low energies. Because of the effective Pauli blocking, the collisional dissipation and

Significance of host cell kinases in herpes simplex virus type 1 egress and lamin-associated protein disassembly from the nuclear lamina

International Nuclear Information System (INIS)

Leach, Natalie R.; Roller, Richard J.

2010-01-01

The nuclear lamina is thought to be a steric barrier to the herpesvirus capsid. Disruption of the lamina accompanied by phosphorylation of lamina proteins is a conserved feature of herpesvirus infection. In HSV-1-infected cells, protein kinase C (PKC) alpha and delta isoforms are recruited to the nuclear membrane and PKC delta has been implicated in phosphorylation of emerin and lamin B. We tested two critical hypotheses about the mechanism and significance of lamina disruption. First, we show that chemical inhibition of all PKC isoforms reduced viral growth five-fold and inhibited capsid egress from the nucleus. However, specific inhibition of either conventional PKCs or PKC delta does not inhibit viral growth. Second, we show hyperphosphorylation of emerin by viral and cellular kinases is required for its disassociation from the lamina. These data support hypothesis that phosphorylation of lamina components mediates lamina disruption during HSV nuclear egress.

Modeling and control of a large nuclear reactor. A three-time-scale approach

Energy Technology Data Exchange (ETDEWEB)

Shimjith, S.R. [Indian Institute of Technology Bombay, Mumbai (India); Bhabha Atomic Research Centre, Mumbai (India); Tiwari, A.P. [Bhabha Atomic Research Centre, Mumbai (India); Bandyopadhyay, B. [Indian Institute of Technology Bombay, Mumbai (India). IDP in Systems and Control Engineering

2013-07-01

Recent research on Modeling and Control of a Large Nuclear Reactor. Presents a three-time-scale approach. Written by leading experts in the field. Control analysis and design of large nuclear reactors requires a suitable mathematical model representing the steady state and dynamic behavior of the reactor with reasonable accuracy. This task is, however, quite challenging because of several complex dynamic phenomena existing in a reactor. Quite often, the models developed would be of prohibitively large order, non-linear and of complex structure not readily amenable for control studies. Moreover, the existence of simultaneously occurring dynamic variations at different speeds makes the mathematical model susceptible to numerical ill-conditioning, inhibiting direct application of standard control techniques. This monograph introduces a technique for mathematical modeling of large nuclear reactors in the framework of multi-point kinetics, to obtain a comparatively smaller order model in standard state space form thus overcoming these difficulties. It further brings in innovative methods for controller design for systems exhibiting multi-time-scale property, with emphasis on three-time-scale systems.

Key technology research of nuclear signal digitized pulse shaping in real time

International Nuclear Information System (INIS)

Zhou Jianbin; Wang Min; Zhou Wei; Zhu Xing; Liu Yi; Chen Bao; Lu Baoping; Yue Aizhong; Qin Li; He Xuxin

2014-01-01

The computer simulation and analysis were carried out for the ideal nuclear pulse signal and the actual detector output signals, and the determination method of digital trapezoidal shape parameter for different nuclear pulse shaping time was summarized. At high count rate measurement occasion, the effective count rate is increased, some pile-up pulses are eliminated and the accumulation of dead time of the system is reduced. Meanwhile, Si-PIN semiconductor detector performance was tested by 256 points and 512 points digital triangle forming methods and the analog circuit forming methods for comparative tests. Test results show that the pulse forming treatment method increases the count rate performance and the resolution of detector. (authors)

Nuclear: time to decide. Report June 2016

International Nuclear Information System (INIS)

Tran Thiet, Jean-Paul; Albernhe, Stephane; Therond Koos, Corinne; Castel, Charles; Fouco, Laurent; Martiniere, Raphaele de la; Aubouin, Pierre; Chaudat, David; Fremaux, Benjamin; Geoffron, Patrice; Jaouen, Claude; Kottmann, Gerard; Puyfaucher, Laetitia; Stricker, Laurent; Authier, Marc-Antoine; Gerault, Jacques; Maignant, Anne-Sophie

2016-06-01

This document proposes reflections and thoughts about the future of nuclear energy in a changing context, notably in terms of climate challenges and of restructuring of the nuclear sector. The authors first outline and discusses that nuclear energy is today indispensable to face climate challenge, but must still overcome many difficulties regarding cooperation, standards and waste management. They outline that the European Union must integrate nuclear energy into a more ambitious energetic strategy aimed at securing energy supply, economic competitiveness and its contribution to the struggle against climate change, and should be based on an actual value of carbon, and an easier financing of low carbon energy production infrastructures, whatever the chosen technology be. In a third part, the authors outline that the French State must take its responsibilities in order nuclear industry to remain an asset for France: the nuclear fleet renewal must be prepared (renovation of existing reactors and construction of new ones), renewable energies must be developed to reach an energy mix which would be one of the lowest carbonated one. In this respect, objectives defined by the law on energy transition should be reviewed to optimize economic and environmental costs. Finally, the authors state that the French nuclear industry should perform a competitiveness leap at the occasion of the current restructuring of activities between EDF and Areva. A set of recommendations is proposed to address these issues

Nuclear Winter Revisited: can it Make a Difference This Time?

Science.gov (United States)

Schneider, S.

2006-12-01

news. Therefore, the re- examination in this AGU session of the entire subject of environmental and social after-effects of any nuclear weapons use is, unfortunately, once again timely. Hopefully it will convince anyone not already convinced based on conventional damages from nuclear weapons use of the urgent need to abate proliferation and monitor and control access to and potential capabilities of those who might contemplate using such weapons for some Strangelove-like strategic or ideological objective. The extent to which a scientific re-examination of the broader horrendous implications of any scale of use of nuclear weapons will deter those contemplating their use is questionable. However, it seems likely such research would increase the resolve of the large number of countries and institutions already pressing to prevent nuclear weapons use.

CSN-associated USP48 confers stability to nuclear NF-κB/RelA by trimming K48-linked Ub-chains.

Science.gov (United States)

Schweitzer, Katrin; Naumann, Michael

2015-02-01

Diligent balance of nuclear factor kappa B (NF-κB) activity is essential owing to NF-κB's decisive role in cellular processes including inflammation, immunity and cell survival. Ubiquitin/proteasome-system (UPS)-dependent degradation of activated NF-κB/RelA involves the cullin-RING-ubiquitin-ligase (CRL) ECS(SOCS1). The COP9 signalosome (CSN) controls ubiquitin (Ub) ligation by CRLs through the removal of the CRL-activating Ub-like modifier NEDD8 from their cullin subunits and through deubiquitinase (DUB) activity of associated DUBs. However, knowledge about DUBs involved in the regulation of NF-κB activity within the nucleus is scarce. In this study we observed that USP48, a DUB of hitherto ill-defined function identified through a siRNA screen, associates with the CSN and RelA in the nucleus. We show that USP48 trims rather than completely disassembles long K48-linked free and substrate-anchored Ub-chains, a catalytic property only shared with ataxin-3 (Atx3) and otubain-1 (OTU1), and that USP48 Ub-chain-trimming activity is regulated by casein-kinase-2 (CK2)-mediated phosphorylation in response to cytokine-stimulation. Functionally, we demonstrate for the first time the CSN and USP48 to cooperatively stabilize the nuclear pool of RelA, thereby facilitating timely induction and shutoff of NF-κB target genes. In summary, this study demonstrates that USP48, a nuclear DUB regulated by CK2, controls the UPS-dependent turnover of activated NF-κB/RelA in the nucleus together with the CSN. Thereby USP48 contributes to a timely control of immune responses. Copyright © 2014 Elsevier B.V. All rights reserved.

Rough order of magnitude cost estimate for immobilization of 50 MT of plutonium sharing existing facilities at Hanford with pit disassembly and conversion facility: alternative 11

International Nuclear Information System (INIS)

DiSabatino, A.

1998-01-01

The purpose of this Cost Estimate Report is to identify preliminary capital and operating costs for a facility to immobilize 50 metric tons (nominal) of plutonium as a ceramic in an existing facility at Hanford, the Fuels and Materials Examination Facility (FMEF). The Pit Disassembly and Conversion Facility (PDCF), which is being costed in a separate report by LANL, will also be located in the FMEF in this co-location option

Simple nuclear norm based algorithms for imputing missing data and forecasting in time series

OpenAIRE

Butcher, Holly Louise; Gillard, Jonathan William

2017-01-01

There has been much recent progress on the use of the nuclear norm for the so-called matrix completion problem (the problem of imputing missing values of a matrix). In this paper we investigate the use of the nuclear norm for modelling time series, with particular attention to imputing missing data and forecasting. We introduce a simple alternating projections type algorithm based on the nuclear norm for these tasks, and consider a number of practical examples.

Summary of the CDFE nuclear data activity for 2011 - 2012 period of time, Progress report

International Nuclear Information System (INIS)

Varlamov, V.V.; Komarov, S.Yu.; Peskov, N.N.; Stepanov, M.E.

2012-01-01

This report contains the short review of the main fields of nuclear data activity of the Centre for Photonuclear Experiments Data (Centr Dannykh Fotoyadernykh Eksperimentov - CDFE) of Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University and main results obtained. All works were carried out in close co-operation with the Nuclear Science Section in the frame of the IAEA Nuclear Reaction Data Centres Network for the period of time from the IAEA Technical Meeting on the International Network of Nuclear Reaction Data Centers' (23 - 24 May 2011, IAEA, Vienna, Austria) till the spring of 2012. (author)

Selenide isotope generator for the Galileo mission. GDS disassembly report

International Nuclear Information System (INIS)

1978-11-01

The GDS-1 was disassembled to determine the cause for the rapid degradation of the output power. Unfortunately, it was not possible to relate the observations to direct causes for the degradation. However, some positive statements can be made which have an impact on the flight program. First, the outgassing and gas management techniques were shown to be adequate to maintain clean conditions within the generator. Second, the non-modular components within the generator including the receptacles on the housing were not affected by the thermal environment during operation of GDS-1. Third, a significant amount of sublimation of the P-legs has occurred during the relatively short life of 2000 + hours as shown by the bullet nosing of the legs and deposits on the cold end hardware. The fact that the generator atmosphere was not 100% xenon may have some bearing on this observation but the statement is still accurate. Fourth, all exposed N-legs display cracks and/or chips. Fifth, a great deal of misalignment of both N and P-legs was seen both visually and with radiographs. Although no definite conclusions can be made concerning the cause for the rapid degradation of performance, several of the observed conditions within the module could possibly contribute to that fact. They are: cracks in N-legs (increased resistance); deposits on edges of BeO discs (shorting of thermoelectric circuit); and bullet nosing of P-legs (increased resistance). It remains to be shown if any of these effects or the follower hangup described earlier contributed to the poor performance of GDS-1 or if another effect as yet unknown was the important factor

Time differentiated nuclear resonance spectroscopy coupled with pulsed laser heating in diamond anvil cells

Energy Technology Data Exchange (ETDEWEB)

Kupenko, I., E-mail: kupenko@esrf.fr; Strohm, C. [Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth (Germany); ESRF-The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9 (France); McCammon, C.; Cerantola, V.; Petitgirard, S.; Dubrovinsky, L. [Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth (Germany); Glazyrin, K. [Photon Science, DESY, D-22607 Hamburg (Germany); Vasiukov, D.; Aprilis, G. [Laboratory of Crystallography, Material Physics and Technology at Extreme Conditions, Universität Bayreuth, D-95440 Bayreuth (Germany); Chumakov, A. I.; Rüffer, R. [ESRF-The European Synchrotron, CS 40220, 38043 Grenoble Cedex 9 (France)

2015-11-15

Developments in pulsed laser heating applied to nuclear resonance techniques are presented together with their applications to studies of geophysically relevant materials. Continuous laser heating in diamond anvil cells is a widely used method to generate extreme temperatures at static high pressure conditions in order to study the structure and properties of materials found in deep planetary interiors. The pulsed laser heating technique has advantages over continuous heating, including prevention of the spreading of heated sample and/or the pressure medium and, thus, a better stability of the heating process. Time differentiated data acquisition coupled with pulsed laser heating in diamond anvil cells was successfully tested at the Nuclear Resonance beamline (ID18) of the European Synchrotron Radiation Facility. We show examples applying the method to investigation of an assemblage containing ε-Fe, FeO, and Fe{sub 3}C using synchrotron Mössbauer source spectroscopy, FeCO{sub 3} using nuclear inelastic scattering, and Fe{sub 2}O{sub 3} using nuclear forward scattering. These examples demonstrate the applicability of pulsed laser heating in diamond anvil cells to spectroscopic techniques with long data acquisition times, because it enables stable pulsed heating with data collection at specific time intervals that are synchronized with laser pulses.

An international contribution to decommissioning of nuclear facilities

International Nuclear Information System (INIS)

Lazo, T.

1995-01-01

Nuclear power plants and fuel cycle facilities must be retired from service when they have completed their design objective, become obsolete or when they no longer fulfill current safety, technical or economic requirements. Decommissioning is defined as the set of technical and administrative operations that provides adequate protection of workers and public against radiation risks, minimizes impact on the environment and involves manageable costs. A traditional definition of the stages of decommissioning has been proposed by the IAEA and is largely used worldwide. A number of factors have to be considered when selecting the optimum strategy, which include the national nuclear policy, characteristics of the facility, health and safety, environmental protection, radioactive waste management, future use of the site, improvements of the technology that may be achieved in the future, costs and availability of funds and various social considerations. The paper describes the current situation of nuclear facilities and the associated forthcoming requirements and problems of decommissioning. This task requires a complete radionuclide inventory, decontamination methods, disassembly techniques and remote operations. Radiation safety presents three aspects: nuclear safety, protection of workers and protection of the public. An appropriate delay to initiate decommissioning after shutdown of a facility may considerably reduce workers exposures and costs. Decommissioning also generates significant quantities of neutron-activated and surface contaminated materials which require a specific management. A vigorous international cooperation and coordinated research programs have been encouraged by the NEA for a minimization of costs and efforts and to provide a basis for consensus of opinions on policies, strategies and criteria. (J.S.). 19 refs., 5 figs., 3 tabs

A real-time computer simulation of nuclear simulator software using standard PC hardware and linux environments

International Nuclear Information System (INIS)

Cha, K. H.; Kweon, K. C.

2001-01-01

A feasibility study, which standard PC hardware and Real-Time Linux are applied to real-time computer simulation of software for a nuclear simulator, is presented in this paper. The feasibility prototype was established with the existing software in the Compact Nuclear Simulator (CNS). Throughout the real-time implementation in the feasibility prototype, we has identified that the approach can enable the computer-based predictive simulation to be approached, due to both the remarkable improvement in real-time performance and the less efforts for real-time implementation under standard PC hardware and Real-Time Linux envrionments

Identification of a novel nuclear localization signal and speckle-targeting sequence of tuftelin-interacting protein 11, a splicing factor involved in spliceosome disassembly

Energy Technology Data Exchange (ETDEWEB)

Tannukit, Sissada [Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, CSA Rm103, Los Angeles, CA 90033-1004 (United States); Crabb, Tara L.; Hertel, Klemens J. [Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, CA 92697-4025 (United States); Wen, Xin [Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, CSA Rm103, Los Angeles, CA 90033-1004 (United States); Jans, David A. [Department of Biochemistry and Molecular Biology, Nuclear Signalling Laboratory, Monash University, Clayton, Victoria 3800 (Australia); Paine, Michael L., E-mail: paine@usc.edu [Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, CSA Rm103, Los Angeles, CA 90033-1004 (United States)

2009-12-18

Tuftelin-interacting protein 11 (TFIP11) is a protein component of the spliceosome complex that promotes the release of the lariat-intron during late-stage splicing through a direct recruitment and interaction with DHX15/PRP43. Expression of TFIP11 is essential for cell and organismal survival. TFIP11 contains a G-patch domain, a signature motif of RNA-processing proteins that is responsible for TFIP11-DHX15 interactions. No other functional domains within TFIP11 have been described. TFIP11 is localized to distinct speckled regions within the cell nucleus, although excluded from the nucleolus. In this study sequential C-terminal deletions and mutational analyses have identified two novel protein elements in mouse TFIP11. The first domain covers amino acids 701-706 (VKDKFN) and is an atypical nuclear localization signal (NLS). The second domain is contained within amino acids 711-735 and defines TFIP11's distinct speckled nuclear localization. The identification of a novel TFIP11 nuclear speckle-targeting sequence (TFIP11-STS) suggests that this domain directly interacts with additional spliceosomal components. These data help define the mechanism of nuclear/nuclear speckle localization of the splicing factor TFIP11, with implications for it's function.

Technological forecasting a long time of the scientific-technological development of the nuclear fusion

International Nuclear Information System (INIS)

Schettert, Plinio G.; Oliveira, Wagner S.; Aquino, Afonso R.

2009-01-01

With base in the introduction in long time of the nuclear fusion inside of a system of viable energy, taking in consideration economic factors, would imply on investment in a long period. The objective of this project utilizing the method of the Delphi technique is the technological forecast a long time of the scientific-technological development of the nuclear fusion and its impact. This research project will be carried through different stages of improvement of variables. A questionnaire based on information and analysis of the literature validated for specialists in nuclear fusion becomes this project a tool in the elaboration future of a database contends variables on the theme nuclear fusion and its perspectives. The database will be composed for the answers and suggestions obtained, with exploratory and extrapolatory elements, on the theme a great number of specialists involving in the nuclear fusion area. The database is analyzed for the configuration of variables that represent elements as scientific-technological factors, economical, political, social and environmental among others. As final result of the research with the Delphi technique, different scenes obtained with the variables will be indicated by convergent factors or not on the approached perspectives. The analysis of the data will be possible through of improve of statistical analysis tools. This is the first analyzes of the answers. The questionnaire was validated with nuclear fusion specialists from the Institute of Physics of the University of Sao Paulo in Brazil and the Center of Nuclear Fusion of the Technical University of Lisbon in Portugal. (author)

An approach to evaluate the cutting time for the nuclear dismantling simulation

Energy Technology Data Exchange (ETDEWEB)

Lee, Jonghwan; Hyun, Dongjun; Kang, Sinyoung; Kim, Ikjune; Jeong, Kwan-Seong; Choi, Byung-Seon; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Nuclear power plant (NPP) decommissioning involves various processes and technologies. Decommissioning should be performed after a comprehensive review of the information related to these processes and technologies. There are various means of prior examination and evaluation to ensure the feasibility and safety of the decommissioning process plan. Our dismantling simulation system aims to simulate and evaluate whole processes related to the dismantlement of core equipment of NPP such as the device preparation, cutting operation, waste transfer, and so on. This paper introduces the estimation methodology of the time required for the cutting processes based on real cutting conditions in order to provide effective economic evaluation functionalities used for the system. The methodology to estimate the time required for the remote cutting process in the nuclear dismantling simulation system was proposed. Among the factors which mainly determine the time, the cutting trace was directly calculated from the simulation system and the continuous cutting speed was obtained by proper order of the spline fitting with constraint conditions.

Disassembly of Bacterial Biofilms by the Self-Assembled Glycolipids Derived from Renewable Resources.

Science.gov (United States)

Prasad, Yadavali Siva; Miryala, Sandeep; Lalitha, Krishnamoorthy; Ranjitha, K; Barbhaiwala, Shehnaz; Sridharan, Vellaisamy; Maheswari, C Uma; Srinandan, C S; Nagarajan, Subbiah

2017-11-22

More than 80% of chronic infections of bacteria are caused by biofilms. It is also a long-term survival strategy of the pathogens in a nonhost environment. Several amphiphilic molecules have been used in the past to potentially disrupt biofilms; however, the involvement of multistep synthesis, complicated purification and poor yield still remains a major problem. Herein, we report a facile synthesis of glycolipid based surfactant from renewable feedstocks in good yield. The nature of carbohydrate unit present in glycolipid influence the ring chain tautomerism, which resulted in the existence of either cyclic structure or both cyclic and acyclic structures. Interestingly, these glycolipids self-assemble into gel in highly hydrophobic solvents and vegetable oils, and displayed foam formation in water. The potential application of these self-assembled glycolipids to disrupt preformed biofilm was examined against various pathogens. It was observed that glycolipid 6a disrupts Staphylococcus aureus and Listeria monocytogenes biofilm, while the compound 6c was effective in disassembling uropathogenic E. coli and Salmonella enterica Typhimurium biofilms. Altogether, the supramolecular self-assembled materials, either as gel or as surfactant solution could be potentially used for surface cleansing in hospital environments or the food processing industries to effectively reduce pathogenic biofilms.

A CAMAC based real-time noise analysis system for nuclear reactors

International Nuclear Information System (INIS)

Ciftcioglu, O.

1987-01-01

A CAMAC based real-time noise analysis system was designed for the TRIGA MARK II nuclear reactor at the Institute for Nuclear Energy, Istanbul. The input analog signals obtained from the radiation detectors are introduced to the system through CAMAC interface. The signals coverted into digital form are processed by a PDP-11 computer. The fast data processing based on auto/cross power spectral density computations is carried out by means of assembly written FFT algorithms in real-time and the spectra obtained are displayed on a CAMAC driven display system as an additional monitoring device. The system has the advantage of being software programmable and controlled by a CAMAC system so that it is operated under porgram control for reactor surveillance, anomaly detection and diagnosis. The system can also be used for the identification of nonstationary operational characteristics of the reactor in long term by comparing the noise power spectra with the corresponding reference noise patterns prepared in advance. (orig.)

Affordable Development and Qualification Strategy for Nuclear Thermal Propulsion

Science.gov (United States)

Gerrish, Harold P., Jr.; Doughty, Glen E.; Bhattacharyya, Samit K.

2013-01-01

Nuclear Thermal Propulsion (NTP) is a concept which uses a nuclear reactor to heat a propellant to high temperatures without combustion and can achieve significantly greater specific impulse than chemical engines. NTP has been considered many times for human and cargo missions beyond low earth orbit. A lot of development and technical maturation of NTP components took place during the Rover/NERVA program of the 60's and early 70's. Other NTP programs and studies followed attempting to further mature the NTP concept and identify a champion customer willing to devote the funds and support the development schedule to a demonstration mission. Budgetary constraints require the use of an affordable development and qualification strategy that takes into account all the previous work performed on NTP to construct an existing database, and include lessons learned and past guidelines followed. Current guidelines and standards NASA uses for human rating chemical rocket engines is referenced. The long lead items for NTP development involve the fuel elements of the reactor and ground testing the engine system, subsystem, and components. Other considerations which greatly impact the development plans includes the National Space Policy, National Environmental Policy Act, Presidential Directive/National Security Council Memorandum #25 (Scientific or Technological Experiments with Possible Large-Scale Adverse Environmental Effects and Launch of Nuclear Systems into Space), and Safeguards and Security. Ground testing will utilize non-nuclear test capabilities to help down select components and subsystems before testing in a nuclear environment to save time and cost. Existing test facilities with minor modifications will be considered to the maximum extent practical. New facilities will be designed to meet minimum requirements. Engine and test facility requirements are based on the driving mission requirements with added factors of safety for better assurance and reliability

An interface between the nuclear physics and the atomic physics; how to measure nuclear times observing atomic transitions

International Nuclear Information System (INIS)

Pinho, A.G. de

1985-01-01

Recent observations are related in which processes resulting from the ionization in ion-atom collisions are observed in coincidence with nuclear processes (where the incidence ion nucleus hits the target atom nucleus). The delay introduced by the nuclear reaction contaminates the results of the atomic collision and manifest itself either in the X rays (positrons) emitted in the joined atom system or in the X rays (Auger electrons) emitted by separeted atoms, after the collision. Both effects serve to obtain information on the reaction times (in general much less then 10 -16 sec). Following this line, other experimental possibilities are discussed. (L.C.) [pt

Time scales for spinodal decomposition in nuclear matter with pseudoparticle models

International Nuclear Information System (INIS)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

1993-01-01

Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudoparticle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed

Time scales for spinodal decomposition in nuclear matter with pseudoparticle models

Energy Technology Data Exchange (ETDEWEB)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F. (Laboratoire de Physique Nucleaire CNRS/IN2P3, Universite de Nantes, 2, rue de la Houssiniere, 44072 Nantes (France))

1993-08-01

Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudoparticle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed.

Ageing and life-time management in nuclear power stations - concept and examples

International Nuclear Information System (INIS)

Erve, M.; Tenckhoff, E.

1999-01-01

Knowledge, assessment and understanding of phenomena caused by ageing, together with systematic utilization and extension of the technical life-time of components and systems, are of critical importance to the safety and economy of electricity generation in nuclear power stations. Economic use can be optimized by integrated ageing and life-time management; it can also be used to improve performance characteristics. (orig.) [de

Effect of construction time, interest rate, and inflation on the capital cost of nuclear power plants

International Nuclear Information System (INIS)

Abel, P.S.; Greybeck, E.M.; Omberg, R.P.

1981-09-01

Cost estimates for nuclear power plants currently under construction are on the order of four billion dollars. It will be shown, in this paper, that this is a direct consequence of relatively high inflation rates and relatively long construction times. If either inflation rates or construction times, or a combination thereof, should decrease significantly, cost estimates for nuclear power plants could return to approximately two billion dollars

A Study on the Safety Evaluation of Real-Time Operating System in Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Hyung Tae; Jeong, Choong Heui; Kim, Dail Il

2008-01-01

Along with the digitalisation of the nuclear Instrumentation and Control (I and C) system, Real-Time Operating System (RTOS) is being widely used. The RTOS used in nuclear I and C system should satisfy strict performance requirements and resolve various technical issues under complicated conditions. In this regard a careful safety evaluation of RTOS is important for the safety of Nuclear Power Plants. The objective of this study is to provide a guideline for safety evaluation of RTOS appropriate to the nuclear I and C system. In this paper, we suggest evaluation approach for the RTOS

A Study on the Safety Evaluation of Real-Time Operating System in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Tae; Jeong, Choong Heui; Kim, Dail Il [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2008-10-15

Along with the digitalisation of the nuclear Instrumentation and Control (I and C) system, Real-Time Operating System (RTOS) is being widely used. The RTOS used in nuclear I and C system should satisfy strict performance requirements and resolve various technical issues under complicated conditions. In this regard a careful safety evaluation of RTOS is important for the safety of Nuclear Power Plants. The objective of this study is to provide a guideline for safety evaluation of RTOS appropriate to the nuclear I and C system. In this paper, we suggest evaluation approach for the RTOS.

Real-time variables dictionary (RTVD), and expert system for development of real-time applications in nuclear power plants

International Nuclear Information System (INIS)

Senra Martinez, A.; Schirru, R.; Dutra Thome Filho, Z.

1990-01-01

It is presented in this paper a computerized methodology based on a data dictionary managed by an expert system called Real-Time Variables Dictionary (RTVD). This system is very usefull for development of real-time applications in nuclear power plants. It is described in details the RTVD functions and its implantation in a VAX 8600 computer. It is also pointed out the concepts of artificial intelligence used in teh RTVD

CDKL5 influences RNA splicing activity by its association to the nuclear speckle molecular machinery.

Science.gov (United States)

Ricciardi, Sara; Kilstrup-Nielsen, Charlotte; Bienvenu, Thierry; Jacquette, Aurélia; Landsberger, Nicoletta; Broccoli, Vania

2009-12-01

Mutations in the human X-linked cyclin-dependent kinase-like 5 (CDKL5) gene have been shown to cause severe neurodevelopmental disorders including infantile spasms, encephalopathy, West-syndrome and an early-onset variant of Rett syndrome. CDKL5 is a serine/threonine kinase whose involvement in Rett syndrome can be inferred by its ability to directly bind and mediate phosphorylation of MeCP2. However, it remains to be elucidated how CDKL5 exerts its function. Here, we report that CDKL5 localizes to specific nuclear foci referred to as nuclear speckles in both cell lines and tissues. These sub-nuclear structures are traditionally considered as storage/modification sites of pre-mRNA splicing factors. Interestingly, we provide evidence that CDKL5 regulates the dynamic behaviour of nuclear speckles. Indeed, CDKL5 overexpression leads to nuclear speckle disassembly, and this event is strictly dependent on its kinase activity. Conversely, its down-regulation affects nuclear speckle morphology leading to abnormally large and uneven speckles. Similar results were obtained for primary adult fibroblasts isolated from CDKL5-mutated patients. Altogether, these findings indicate that CDKL5 controls nuclear speckle morphology probably by regulating the phosphorylation state of splicing regulatory proteins. Nuclear speckles are dynamic sites that can continuously supply splicing factors to active transcription sites, where splicing occurs. Notably, we proved that CDKL5 influences alternative splicing, at least as proved in heterologous minigene assays. In conclusion, we provide evidence that CDKL5 is involved indirectly in pre-mRNA processing, by controlling splicing factor dynamics. These findings identify a biological process whose disregulation might affect neuronal maturation and activity in CDKL5-related disorders.

Time to rethink nuclear waste storage

International Nuclear Information System (INIS)

Flynn, J.; Kasperson, R.; Kunreuther, H.; Slovic, P.

1992-01-01

The authors feel that given the levels of public opposition and distrust, congress should scrap the current nuclear waste storage program and reconsider the options. They observe that no compelling reason currently exists for siting a permanent repository at an early date. Technology developed in the past decade, especially dry-cask storage, provides assurance that wastes from commercial reactors can be stored safely for a lengthy period at current sites. In the longer term, reprocessing may reduce the volume of high-level wastes; storage elsewhere than in a geological repository may prove attractive; and experimental techniques such as transmutation - aimed at radically reducing the amount of time that wastes remain highly radioactive - could help solve the problem. In the meantime, the authors suggest that the US must begin a long-term effort to engage the public in a process of active collaboration. In doing so, the US has much to learn from other countries, where innovative approaches and techniques have began to establish public confidence

Nuclear reaction studies

International Nuclear Information System (INIS)

Alexander, J.M.; Lacey, R.A.

1994-01-01

Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

Hydrogen from nuclear plus wind using real-time electricity prices. Abstract 154

International Nuclear Information System (INIS)

Miller, A.I.; Duffey, R.B.; Fairlie, M.

2004-01-01

'Full text:' During the early years of hydrogen's use as a vehicle fuel, penetration of the market will be small. This favours distributed production by electrolysis, which avoids the scale-dependent costs of distribution from centralized plants. For electrolysis actually to be the preferred option, capital equipment for electrolysis must be reasonably cheap but the dominant cost component is the electricity price. By about 2006, advanced designs of nuclear reactors should be available to produce electricity at around 30 US$/MW.h. The best approach to producing low-cost electrolytic hydrogen is shown to be use of such reactors to supply electricity to the grid at times of peak price and demand and to make hydrogen at other times. This model has been analysed using the actual prices of electricity paid by the Alberta Power Pool in 2002 and 2003 and by the Ontario Grid for 2003. The analysis shows clearly that this route electrolytic hydrogen can comfortably meet the US Department of Energy's hydrogen production-cost target of 2000$/t. Because of its low availability wind-produced electricity cannot meet this cost target. However, if wind availability can reach 35% availability, an intermittent supplementary current of wind-generated electricity may economically be fed to an electrolytic plant primarily supplied by nuclear power. Additional current raises the voltage for electrolysis but there would be only small additional capital costs. The two non-CO 2 -emitting sources, nuclear and wind (or other intermittent renewables with costs comparable to advanced nuclear) could become complementary, providing an affordable way of storing wind-generated electricity. (author)

Safety at the End of a Nuclear Facility's Life

International Nuclear Information System (INIS)

Geis, John A.; McEahern, Patrice; Evans, Brad

2004-01-01

The objective of this paper is to capture the changes that are caused by the transition from nuclear operation through closure of defense nuclear facilities and convey lessons learned from their deactivation, decontamination and demolition. The specific area of discussion is focused on the planned reduction of safety equipment and consequent shift in hazard controls and safety management programs as the facility moves toward closure. The premise of the paper is that as the dominant hazards transition from nuclear to radiological and/or industrial, the facility control of the hazards and response to the potential upset conditions must transition as well to ensure safe and efficient operations. Using recent experience of the accelerated closure mission for U. S. Department of Energy (DOE) defense nuclear facilities at Rocky Flats Environmental Technology Site, the current culture with respect to developing and implementing hazard controls and response to upset conditions is illustrated. Several events have been documented that provide insight into the challenges facing line managers and safety professionals at the end of a facility's life cycle. Replacing permanent systems with temporary equipment challenges the traditional concept of reliability. Workers disassemble safety systems daily, but must rely on some of these components or redundant systems as work continues. Decisions governing upkeep of systems that await demolition balance the risk of running to failure against the cost benefit of maintenance and repair. This is further complicated as regulators and safety professionals are often unfamiliar with these new conditions and continue to view facility work activities and potential upset conditions from a nuclear operations perspective. The results of this paper evaluate the differences in how regulatory, safety basis, and operational practices must adapt to the dynamic environment of decontamination and decommissioning in contrast to the relatively constant

ISC origin times for announced and presumed underground nuclear explosions at several test sites

International Nuclear Information System (INIS)

Rodean, H.C.

1979-01-01

Announced data for US and French underground nuclear explosions indicate that nearly all detonations have occurred within one or two tenths of a second after the minute. This report contains ISC origin-time data for announced explosions at two US test sites and one French test site, and includes similar data for presumed underground nuclear explosions at five Soviet sites. Origin-time distributions for these sites are analyzed for those events that appeared to be detonated very close to the minute. Particular attention is given to the origin times for the principal US and Soviet test sites in Nevada and Eastern Kazakhstan. The mean origin times for events at the several test sites range from 0.4 s to 2.8 s before the minute, with the earlier mean times associated with the Soviet sites and the later times with the US and French sites. These times indicate lower seismic velocities beneath the US and French sites, and higher velocities beneath the sites in the USSR 9 figures, 8 tables

Time-resolved laser-induced fluorescence in the nuclear fuel cycle

International Nuclear Information System (INIS)

Moulin, C.; Decambox, P.; Mauchien, P.; Petit, A.

1995-01-01

Time-Resolved Laser-Induced Fluorescence (TRLIF) is a very sensitive and selective method that has been used for actinides and lanthanides analysis in the nuclear fuel cycle. This technique has been used in different fields such as in geology, in the Purex process, in the environment, in the medical and in waste storage assessment. Spectroscopic data, limits of detection and results obtained in previously quoted fields are presented. (author)

Preliminary research on time degradation of mechanical characteristics of concretes used in nuclear power plant buildings

International Nuclear Information System (INIS)

Ciornei, R.

1991-01-01

To provide severe safety rules governing the operation of nuclear power plants, reinforced and concrete elements and structures should preserve the quality and time-constant parameters throughout the life-time of the buildings. Some important design parameters are concrete strength and elasticity modulus. Preliminary research on concrete specimens made in laboratory whose strength and static and dynamic elasticity modulus have been determined after an ageing test, has aimed at nuclear power design and building. (author)

The timing system of the RFX Nuclear Fusion Experiment

International Nuclear Information System (INIS)

Schmidt, V.; Flor, G.; Manduchi, G.; Piacentini, I.

1992-01-01

The REX Nuclear Fusion Experiment [1] in Padova, Italy, employs a distributed system to produce precision trigger signals for the fast control of the experiment and for the experiment-wide synchronization of data acquisition channels. The hardware of the system is based on a set of CAMAC modules. The modules have been integrated into a hardware/software system which provides the following features: 1) generation of pre-programmed timing events, 2) distribution of asynchronous (not pre-programmed) timing events, 3) gating of timing event generation by Machine Protection System, 4) automatic stop of timing sequence in case of highway damage, 5) dual-speed time base for transient recorders, 6) system-wide precision of ≤ 3 μs, time resolution ≥ 10 μs. The operation of the timing system is fully integrated into the RFX data acquisition system software. The Timing System Software consists of three layers: the lowest one corresponds directly to the CAMAC modules, the intermediate one provides pseudo-devices which essentially correspond to specific features for the modules (e.g. a dual frequency clock source for transient recorders), the highest level provides system set-up support. The system is fully operational and was first used during the commissioning of the RFX Power Supplies in spring '91. (author)

A Study on Evaluation Issues of Real-Time Operating System in Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Y. M.; Jeong, C. H.; Koh, J. S.

2006-01-01

Control applications such as aircraft, robotics and nuclear power plant have to maintain a very high level of safety, typically defined as the avoidance of unplanned events resulting in hazard. These applications usually operate with hard real-time operating system (RTOS). In this case, hard RTOS software should be reliable and safe. RTOS used in safety-critical I and C system is the base software for the purpose of satisfying the real-time constraints. So, careful evaluation of its safety and functionality is very important. In this paper, we present the case study for RTOSs used in real nuclear power plants (NPP), and suggest the evaluation approach for the RTOS

A Study on Evaluation Issues of Real-Time Operating System in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. M.; Jeong, C. H.; Koh, J. S. [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

2006-07-01

Control applications such as aircraft, robotics and nuclear power plant have to maintain a very high level of safety, typically defined as the avoidance of unplanned events resulting in hazard. These applications usually operate with hard real-time operating system (RTOS). In this case, hard RTOS software should be reliable and safe. RTOS used in safety-critical I and C system is the base software for the purpose of satisfying the real-time constraints. So, careful evaluation of its safety and functionality is very important. In this paper, we present the case study for RTOSs used in real nuclear power plants (NPP), and suggest the evaluation approach for the RTOS.

Study on neutron diffusion and time dependence heat ina fluidized bed nuclear reactor

International Nuclear Information System (INIS)

Vilhena, M.T. de.

1988-01-01

The purpose of this work is to model the neutron diffusion and heat transfer for a Fluidized Bed Nuclear Reactor and its solution by Laplace Transform Technique with numerical inversion using Fourier Series. Also Gaussian quadrature and residues techniques were applied for numerical inversion. The neutron transport, diffusion, and point Kinetic equation for this nuclear reactor concept are developed. A matricial and Taylor Series methods are proposed for the solution of the point Kinetic equation which is a time scale problem of Stiff type

Final environmental impact statement for the continued operation of the Pantex Plant and associated storage of nuclear weapon components. Volume 1 -- Main report

International Nuclear Information System (INIS)

1996-11-01

This document assesses the potential environmental impacts over approximately 10 years of continued operation of Pantex Plant, including foreseeable projects and activities. For Pantex Plant, this document assesses the alternatives of No Action, Relocation of the storage of plutonium components (pits) resulting from nuclear weapon disassembly activities at Pantex Plant to another site, and the Proposed Action (Preferred Alternative) of continuing operations and increasing the quantity of pits in interim storage at Pantex Plant. For the Pit Storage Relocation Alternative, this document also assesses the potential environmental impacts to three DOE candidate sites and one Department of Defense candidate site that could be selected for the relocation of the nuclear component storage activities from Pantex Plant. Evaluations of site infrastructure, land resources, geology and soils, water resources, air quality, acoustics, biotic resources, cultural resources, socio-economic resources, intrasite transportation, waste management, human health, aircraft accidents, and environmental justice for Pantex Plant and the candidate sites are included in the assessment. The intersite transportation of nuclear and hazardous materials is also assessed

Time-stamping system for nuclear physics experiments at RIKEN RIBF

International Nuclear Information System (INIS)

Baba, H.; Ichihara, T.; Ohnishi, T.; Takeuchi, S.; Yoshida, K.; Watanabe, Y.; Ota, S.; Shimoura, S.; Yoshinaga, K.

2015-01-01

A time-stamping system for nuclear physics experiments has been introduced at the RIKEN Radioactive Isotope Beam Factory. Individual trigger signals can be applied for separate data acquisition (DAQ) systems. After the measurements are complete, separately taken data are merged based on the time-stamp information. In a typical experiment, coincidence trigger signals are formed from multiple detectors to take desired events only. The time-stamping system allows the use of minimum bias triggers. Since coincidence conditions are given by software, a variety of physics events can be flexibly identified. The live time for a DAQ system is important when attempting to determine reaction cross-sections. However, the combined live time for separate DAQ systems is not clearly known because it depends not only on the DAQ dead time but also on the coincidence conditions. Using the proposed time-stamping system, all trigger timings can be acquired, so that the combined live time can be easily determined. The combined live time is also estimated using Monte Carlo simulations, and the results are compared with the directly measured values in order to assess the accuracy of the simulation

Time series analysis of nuclear instrumentation in EBR-II

International Nuclear Information System (INIS)

Imel, G.R.

1996-01-01

Results of a time series analysis of the scaler count data from the 3 wide range nuclear detectors in the Experimental Breeder Reactor-II are presented. One of the channels was replaced, and it was desired to determine if there was any statistically significant change (ie, improvement) in the channel's response after the replacement. Data were collected from all 3 channels for 16-day periods before and after detector replacement. Time series analysis and statistical tests showed that there was no significant change after the detector replacement. Also, there were no statistically significant differences among the 3 channels, either before or after the replacement. Finally, it was determined that errors in the reactivity change inferred from subcritical count monitoring during fuel handling would be on the other of 20-30 cents for single count intervals

The time-reversal- and parity-violating nuclear potential in chiral effective theory

NARCIS (Netherlands)

Maekawa, C. M.; Mereghetti, E.; de Vries, J.; van Kolck, U.

2011-01-01

We derive the parity- and time-reversal-violating nuclear interactions stemming from the QCD (theta) over bar term and quark/gluon operators of effective dimension 6: quark electric dipole moments, quark and gluon chromo-electric dipole moments, and two four-quark operators. We work in the framework

Caenorhabditis elegans polo-like kinase PLK-1 is required for merging parental genomes into a single nucleus.

Science.gov (United States)

Rahman, Mohammad M; Munzig, Mandy; Kaneshiro, Kiyomi; Lee, Brandon; Strome, Susan; Müller-Reichert, Thomas; Cohen-Fix, Orna

2015-12-15

Before the first zygotic division, the nuclear envelopes of the maternal and paternal pronuclei disassemble, allowing both sets of chromosomes to be incorporated into a single nucleus in daughter cells after mitosis. We found that in Caenorhabditis elegans, partial inactivation of the polo-like kinase PLK-1 causes the formation of two nuclei, containing either the maternal or paternal chromosomes, in each daughter cell. These two nuclei gave rise to paired nuclei in all subsequent cell divisions. The paired-nuclei phenotype was caused by a defect in forming a gap in the nuclear envelopes at the interface between the two pronuclei during the first mitotic division. This was accompanied by defects in chromosome congression and alignment of the maternal and paternal metaphase plates relative to each other. Perturbing chromosome congression by other means also resulted in failure to disassemble the nuclear envelope between the two pronuclei. Our data further show that PLK-1 is needed for nuclear envelope breakdown during early embryogenesis. We propose that during the first zygotic division, PLK-1-dependent chromosome congression and metaphase plate alignment are necessary for the disassembly of the nuclear envelope between the two pronuclei, ultimately allowing intermingling of the maternal and paternal chromosomes. © 2015 Rahman et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Reinforcement course 2013. Challenges at the operation end of nuclear power plants

International Nuclear Information System (INIS)

Rey, Matthias

2014-01-01

The reinforcement course 2013 of the Nuclear Forum in Switzerland dedicated itself to the question, of which challenges are implicated by decommissioning and dismantling nuclear power plants. The course has been divided into 4 blocks, discussing concepts regarding decommissioning, special points such as organisational or psychological aspects as well as juridical and practical questions. Around 140 persons accepted the invitation of the committee for educational questions under the patronage of Urs Weidmann, head of the nuclear power plant Beznau. Altogether 17 presentations dealt with the following topics: 'Strategies and Steps of Decommissioning' by Roger Lundmark, 'Decommissioning from the Perspective of the Swiss Regulatory Authority' by Hannes Haenggi, 'Operating Period Management Using the Example of the Nuclear Power Plant Leibstadt' by Johannis Noeggerath, 'Questions and Concepts from the Perspective of a Nuclear Power Plant Operator' by Roland Schmidiger, 'Decommissioning of nuclear facilities in the UK' by Andrew Munro, 'Practical experiences of transferring nuclear power plants from operating to out of operation' by Gerd Reinstrom, 'Dismantling of Nuclear Facilities: From the Pilot Scheme to Industrialized Disassembling' by Anke Traichel and Thomas Seipolt, 'Organisational challenges: From Decommissioning Strategy to Decommissioning Targets' by Michael Kruse, Anton von Gunten, Julia Heizinger, Joerg Sokoll, 'Knowing That and Knowing How - Motivational Aspects of Safety-Related Knowledge Management for the Post-Operational phase and dismantling' by Frank Ritz, 'The Juridical Frame of Decommissioning' by Peter Koch, 'The Path to the Decommissioning Order and its Guidelines Ensi-G17' by Torsten Krietsch, 'Requirements for a Safe and Economical Decommissioning From the Perspective of the Operator' by Anton Von Gunten, Michael Kruse, Thomas Herren, Erwin Neukaeter, Mario Radke and Anton Schegg, 'Evaluation of Activation Distribution in a Nuclear Power Plant

Application of near real time accountancy to nuclear material balance data

International Nuclear Information System (INIS)

Seifert, R.

1990-02-01

The application of near real time accountancy to nuclear material balance data can be performed effectively only with the help of computerised nuclear material accounting and information systems. Two computer programmes are introduced: DIDI, a programme for computing the MUF series and the measurement model of a reprocessing plant which is assumed to be a one-block model from data resulting from the routine operation of the facility, and PROSA, a programme for statistical analysis of NRTA data, which evaluates the MUF series on the basis of the measurement model. After the presentation of the two computer programmes two examples with realistic balance data will demonstrate the application of NRTA measures. Furthermore, some new remarks on the precision of Monte-Carlo simulations are mentioned which provide a substantial better estimation. (orig.) [de

Study on deterministic response time design for a class of nuclear Instrumentation and Control systems

International Nuclear Information System (INIS)

Chen, Chang-Kuo; Hou, Yi-You; Luo, Cheng-Long

2012-01-01

Highlights: ► An efficient design procedure for deterministic response time design of nuclear I and C system. ► We model the concurrent operations based on sequence diagrams and Petri nets. ► The model can achieve the deterministic behavior by using symbolic time representation. ► An illustrative example of the bistable processor logic is given. - Abstract: This study is concerned with a deterministic response time design for computer-based systems in the nuclear industry. In current approach, Petri nets are used to model the requirement of a system specified with sequence diagrams. Also, the linear logic is proposed to characterize the state of changes in the Petri net model accurately by using symbolic time representation for the purpose of acquiring deterministic behavior. An illustrative example of the bistable processor logic is provided to demonstrate the practicability of the proposed approach.

Nuclear Energy: It is Time to Revitalize the Peaceful Atom

Science.gov (United States)

2011-03-16

difficulties of obtaining NRC licensing approval since the NRC had to evaluate each individual design.26 Nuclear Waste James Lovelock , an...OfNuclearPower (accessed December 26, 2010). 25 Ibid. 26 Ibid. 27 James Lovelock , “Nuclear Energy: The Safe Choice for Now,” Environmentalists for Nuclear...Energy, July 2005, http://www.ecolo.org/ lovelock /nuclear-safe-choice-05.htm (accessed 27 December 2010). 28 Caldicott, Nuclear Power is Not the Answer

Studies on the radioactive contamination due to nuclear detonations III. On the method of estimating the probable time of nuclear detonation from the measurements of gross-activity

Energy Technology Data Exchange (ETDEWEB)

Nishiwaki, Yasushi [Nuclear Reactor Laboratory, Tokyo Institute of Technology, Tokyo (Japan); Nuclear Reactor Laboratoroy, Kinki University, Fuse City, Osaka Precture (Japan)

1961-11-25

Since it has been observed in Spring of 1954 that a considerable amount of fission products mixture fell with the rain following a large scale nuclear detonation conducted in Bikini area in the South Pacific by the United States Atomic Energy Commission, it has become important, especially from the health physics standpoint, to estimate the effective average age of the fission products mixture after the nuclear detonation. If the energy transferred to the atmospheric air at the time of nuclear detonation is large enough (order of megaton at the distance of about 4000 km), the probable time and test site of nuclear detonation may be estimated with considerable accuracy, from the records of the pressure wave caused by the detonation in the microbarographs at different meteorological stations. Even in this case, in order to estimate the possible correlation between the artificial radioactivity observed in the rain and the probable detonation, it is often times desirable to estimate the effective age of the fission products mixture in the rain from the decay measurement of the radioactivity.

Studies on the radioactive contamination due to nuclear detonations III. On the method of estimating the probable time of nuclear detonation from the measurements of gross-activity

International Nuclear Information System (INIS)

Nishiwaki, Yasushi

1961-01-01

Since it has been observed in Spring of 1954 that a considerable amount of fission products mixture fell with the rain following a large scale nuclear detonation conducted in Bikini area in the South Pacific by the United States Atomic Energy Commission, it has become important, especially from the health physics standpoint, to estimate the effective average age of the fission products mixture after the nuclear detonation. If the energy transferred to the atmospheric air at the time of nuclear detonation is large enough (order of megaton at the distance of about 4000 km), the probable time and test site of nuclear detonation may be estimated with considerable accuracy, from the records of the pressure wave caused by the detonation in the microbarographs at different meteorological stations. Even in this case, in order to estimate the possible correlation between the artificial radioactivity observed in the rain and the probable detonation, it is often times desirable to estimate the effective age of the fission products mixture in the rain from the decay measurement of the radioactivity

Fuel elements handling device and method

International Nuclear Information System (INIS)

Jabsen, F.S.

1976-01-01

This invention relates to nuclear equipment and more particularly to methods and apparatus for the non-destructive inspection, manipulation, disassembly and assembly of reactor fuel elements and the like. (author)

Time response prediction of Brazilian Nuclear Power Plant temperature sensors using neural networks

Energy Technology Data Exchange (ETDEWEB)

Santos, Roberto Carlos dos; Pereira, Iraci Martinez, E-mail: rcsantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2011-07-01

This work presents the results of the time constants values predicted from ANN using Angra I Brazilian nuclear power plant data. The signals obtained from LCSR loop current step response test sensors installed in the process presents noise end fluctuations that are inherent of operational conditions. Angra I nuclear power plant has 20 RTDs as part of the protection reactor system. The results were compared with those obtained from traditional way. Primary coolant RTDs (Resistance Temperature Detector) typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. An in-situ test method called LCSR - loop current step response test was developed to measure remotely the response time of RTDs. In the LCSR method, the response time of the sensor is identified by means of the LCSR transformation that involves the dynamic response modal time constants determination using a nodal heat transfer model. For this reason, this calculation is not simple and requires specialized personnel. This work combines the two methodologies, Plunge test and LCSR test, using neural networks. With the use of neural networks it will not be necessary to use the LCSR transformation to determine sensor's time constant and this leads to more robust results. (author)

Time response prediction of Brazilian Nuclear Power Plant temperature sensors using neural networks

International Nuclear Information System (INIS)

Santos, Roberto Carlos dos; Pereira, Iraci Martinez

2011-01-01

This work presents the results of the time constants values predicted from ANN using Angra I Brazilian nuclear power plant data. The signals obtained from LCSR loop current step response test sensors installed in the process presents noise end fluctuations that are inherent of operational conditions. Angra I nuclear power plant has 20 RTDs as part of the protection reactor system. The results were compared with those obtained from traditional way. Primary coolant RTDs (Resistance Temperature Detector) typically feed the plant's control and safety systems and must, therefore, be very accurate and have good dynamic performance. An in-situ test method called LCSR - loop current step response test was developed to measure remotely the response time of RTDs. In the LCSR method, the response time of the sensor is identified by means of the LCSR transformation that involves the dynamic response modal time constants determination using a nodal heat transfer model. For this reason, this calculation is not simple and requires specialized personnel. This work combines the two methodologies, Plunge test and LCSR test, using neural networks. With the use of neural networks it will not be necessary to use the LCSR transformation to determine sensor's time constant and this leads to more robust results. (author)

State of the art in evacuation time estimate studies for nuclear power plants

International Nuclear Information System (INIS)

Urbanik, T.E.; Jamison, J.D.

1992-03-01

In the event of a major accident at a commercial nuclear power station, exposure of the public to airborne radioactive materials can be prevented or greatly reduced by evacuating the area immediately surrounding the reactor site. Reactor licensees are required to conduct studies to estimate the time needed to evacuate the public from the area surrounding each nuclear power station. The results of such studies are used by regulatory personnel and emergency planners to assess the potential effectiveness of protective responses for the public. The time required to evacuate the public from a 10-mile emergency planning radius is estimated by analyzing the available transportation facilities and other relevant conditions within this radius. To support the analysis, data must be collected and assumptions must be made regarding the transportation facilities, the size and characteristics of the population and other conditions in the planning zone. This report describes standard approaches and provides recommendations regarding the relevant information, assumptions and methods to be used in performing evacuation time estimate studies

Time-dependent reliability analysis of nuclear reactor operators using probabilistic network models

International Nuclear Information System (INIS)

Oka, Y.; Miyata, K.; Kodaira, H.; Murakami, S.; Kondo, S.; Togo, Y.

1987-01-01

Human factors are very important for the reliability of a nuclear power plant. Human behavior has essentially a time-dependent nature. The details of thinking and decision making processes are important for detailed analysis of human reliability. They have, however, not been well considered by the conventional methods of human reliability analysis. The present paper describes the models for the time-dependent and detailed human reliability analysis. Recovery by an operator is taken into account and two-operators models are also presented

Operating experience with a near-real-time inventory balance in a nuclear-fuel-cycle plant

International Nuclear Information System (INIS)

Armento, W.J.; Box, W.D.; Kitts, F.G.; Krichinsky, A.M.; Morrison, G.W.; Pike, D.H.

1981-01-01

The principal objective of the ORNL Integrated Safeguards Program (ISP) is to provide enhanced material accountability, improved process control, and greater security for nuclear fuel cycle facilities. With the improved instrumentation and computer interfacing currently installed, the ORNL 233 U Pilot Plant has demonstrated capability of a near-real-time liquid-volume balance in both the solvent-extraction and ion-exchange systems. Future developments should include the near-real-time mass balancing of special nuclear materials as both a static, in-tank summation and a dynamic, in-line determination. In addition, the aspects of site security and physical protection can be incorporated into the computer monitoring

Operating experience with a near-real-time inventory balance in a nuclear fuel cycle plant

International Nuclear Information System (INIS)

Armento, W.J.; Box, W.D.; Kitts, F.G.; Krichinsky, A.M.; Morrison, G.W.; Pike, D.H.

1981-01-01

The principal objective of the ORNL Integrated Safeguards Program (ISP) is to provide enhanced material accountability, improved process control, and greater security for nuclear fuel cycle facilities. With the improved instrumentation and computer interfacing currently installed, the ORNL 233 U Pilot Plant has demonstrated capability of a near-real-time liquid-volume balance in both the solvent-extraction and ion-exchange systems. Future developments should include the near-real-time mass balancing of special nuclear materials as both a static, in-tank summation and a dynamic, in-line determination. In addition, the aspects of site security and physical protection can be incorporated into the computer monitoring

Nuclear disarmament and peaceful nuclear technology

International Nuclear Information System (INIS)

Taylor, T.B.

1989-01-01

According to the author, it remains to be seen whether nuclear disarmament can reduce the risks of nuclear war sufficiently for the residual risks to be acceptable to a majority of the world's population, while at the same time vigorous growth in the world's dependence on nuclear energy for peaceful purposes continues. This paper discusses how use of nuclear materials from dismantled weapons as fuel for peaceful purposes may help progress to be made towards that goal, by stimulating considerable improvements in the effectiveness of arrangements for preventing diversion of the materials from peaceful to military purposes, while at the same time eliminating large numbers of nuclear weapons

Flight-time spread of uniform field sector magnet system for use in nuclear life-time measurements

International Nuclear Information System (INIS)

Sakata, Akihiko; Mamei, Masayuki; Yamada, Yoshihiro; Ohira, Kyozo

1984-01-01

A nuclear life-time measurement apparatus incorporating a deflecting β-ray spectrometer with electron pre-accelerator has been constructed. A new arrangement consisting of two double angular focusing sector magnets based on the principle of symmetry has been devised so as to reduce the time spread in the spectrometer, which up till now has been the weak point of such systems. The time spread in the spectrometer was estimated to be asymptotically equals 0.1 ns by a simulation method, and good agreement was obtained between this estimated value and the experimental value. A prompt time resolution of 1.25 ns (FWHM) was obtained. The half-lives of the 199 and 401 keV levels in 75 As were measured with an acceleration voltage up to 30 kV to check the reliability of the apparatus. The values were found to be 0.87+-0.04 ns and 1.74+-0.05 ns, respectively, in good agreement with previous measurements. (author)

Framing the Fukushima Daiichi nuclear accident: An international, comparative study of news frames in Der Spiegel, the Japan Times and the Los Angeles Times

International Nuclear Information System (INIS)

Giannakopoulos, Thanos

2013-01-01

This study investigated into the news frames employed in reporting on the Fukushima Daiichi nuclear accident, explored the maintenance of the radiation reporting standard, and assessed the overall tone for the local government, the Japanese Government, and the IAEA. Based on content from Der Spiegel, the Japan Times and the Los Angeles Times (n=60), it was found that media evoked 'conflict', 'responsibility attribution', and 'human interest' frames, radiation reporting standard was marginally maintained, and the overall tone was neutral (local government, IAEA) or negative (Japanese Government). Variances across countries were observed, but results coincided with the country's nuclear energy policy. (author)

Time scales for spinodal decomposition in nuclear matter with pseudo-particle model

Energy Technology Data Exchange (ETDEWEB)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

1993-12-31

Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab.

Time scales for spinodal decomposition in nuclear matter with pseudo-particle model

International Nuclear Information System (INIS)

Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.

1993-01-01

Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab

A nuclear decision support system built with a real-time process control AI shell

International Nuclear Information System (INIS)

Nevins, M.A.

1990-01-01

Managing large nuclear power plants is generally approached by creating separate management teams to handle major functional areas such as operations, maintenance, training and engineering. While this approach facilitates a general understanding of the specific functions and problem areas of a nuclear plant, such broad definitions diminish the integration of information needed to understand the overall problem domain. One solution utilizes a decision support system that integrates a real-time process control AI shell, relational database manager, graphic depiction of the real-time events, and distributed knowledge bases that reside within each of the departments. The goal is to create a living model between plant components, procedures, tech specs, specific functions, maintenance and training requirements. This paper describes such a model, called Engineering Model and Simulation System (EMASS)

Just In-Time Maintenance of Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

DR. Alexander G. Parlos

2002-01-22

The goal of this project has been to develop and demonstrate the feasibility of a new technology for maintenance engineering: a Just-In-Time Maintenance (JITM) system for rotating machines. The JITM system is based on several key developments at Texas A and M over the past ten years in emerging intelligent information technologies, which if integrated into a single system could provide a revolutionary approach in the way maintenance is performed. Rotating machines, such as induction motors, range from a few horse power (hp) to several thousand hp in size, and they are widely used in nuclear power plants and in other industries. Forced outages caused by induction motor failures are the reason for as much as 15% - 40% of production costs to be attributable to maintenance, whereas plant shutdowns caused by induction motor failures result in daily financial losses to the utility and process industries of $1 M or more. The basic components of the JITM system are the available machine sensors, that is electric current sensors and accelerometers, and the computational algorithms used in the analysis and interpretation of the occurring incipient failures. The JITM system can reduce the costs attributable to maintenance by about 40% and it can lower the maintenance budgets of power and process plants by about 35%, while requiring no additional sensor installation. As a result, the JITM system can improve the competitiveness of US nuclear utilities at minimal additional cost.

Just In-Time Maintenance of Nuclear Power Plants

International Nuclear Information System (INIS)

Parlos, Alexander G.

2002-01-01

The goal of this project has been to develop and demonstrate the feasibility of a new technology for maintenance engineering: a Just-In-Time Maintenance (JITM) system for rotating machines. The JITM system is based on several key developments at Texas A and M over the past ten years in emerging intelligent information technologies, which if integrated into a single system could provide a revolutionary approach in the way maintenance is performed. Rotating machines, such as induction motors, range from a few horse power (hp) to several thousand hp in size, and they are widely used in nuclear power plants and in other industries. Forced outages caused by induction motor failures are the reason for as much as 15% - 40% of production costs to be attributable to maintenance, whereas plant shutdowns caused by induction motor failures result in daily financial losses to the utility and process industries of $1 M or more. The basic components of the JITM system are the available machine sensors, that is electric current sensors and accelerometers, and the computational algorithms used in the analysis and interpretation of the occurring incipient failures. The JITM system can reduce the costs attributable to maintenance by about 40% and it can lower the maintenance budgets of power and process plants by about 35%, while requiring no additional sensor installation. As a result, the JITM system can improve the competitiveness of US nuclear utilities at minimal additional cost

Remotely controlled cutting techniques in the field of nuclear decommissioning. Overview of effectively applied thermal and non thermal cutting methods

International Nuclear Information System (INIS)

Bienia, H.

2008-01-01

Remote disassembly of radiologically burdened large components is among the most sophisticated and complex activities in the dismantling of nuclear installations. The required space for the technical equipment during the dismantling operations, especially for the removal of larger components is often an additional problem. Conventional cutting technologies like sawing with a disk saw or band saw require large and heavy frameworks as well as guiding systems with high rigidity. These solutions are expensive and sometimes not applicable. The essential question of all cutting and dismantling tasks is the physiological constitution of the component which will be dismantled. That means size, material and structure of the component. All these points are primarily technological questions. The last question is about the estimated costs of the used dismantling technology. Therefore following questions must be answered. How much are the investments for the cutting equipment itself and how much are the investments for the supporting equipment (e.g. necessary handling equipment)? Can I use this cutting equipment only for one special task or is it applicable for many tasks and therefore saves money because other cutting or dismantling technologies are dispensable? How long is the cutting time and what is the to control this technique required personnel? Four different cutting and dismantling technologies will be introduced and described. These four technologies differ in their principle of operation but all of them are used by cutting and dismantling tasks in nuclear power plants. (author)

Development of containment system for application to decommissioning of nuclear facilities. 2

International Nuclear Information System (INIS)

Mizuno, Oichi; Iwasaki, Yukio; Miyao, Hidehiko; Uchikoshi, Tadaaki; Furuya, Hirotaka; Kamata, Hirofumi

1998-01-01

New greenhouse/containment was developed to apply for confining the radioactive materials and preventing the dispersion of radioactive contamination during the maintenance and dismantling of the nuclear facility. The pressed-air tubes for columns and beams of the structure frame were applied and the vinyl chloride sheet reinforced with the polyester fiber was used as a canvas of wall and ceiling. This canvas is possible to use repeatedly and has high efficiency of safe enclosing. The containment can be easily assembled and disassembled by charge and discharge of the pressed air in the tubes of columns and beams. Two standard units (2.5mL x 2.5mW x 2.5mH, 5mL x 5mW x 2.5mH) are prepared, and lateral connection of these standard units makes it applicable to the wide working area. Expansion model up to 5m in height is also available. (author)

Experience with RTD response time testing in nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.; Kerlin, T.W.

1985-01-01

The reactor coolant temperatures in pressurized water reactors are measured with platinum resistance temperature detectors (RTDs). The information furnished by these RTDs is used for plant protection as well as control. As a part of the plant protection system, the RTDs must respond to temperature changes in a timely fashion. The RTD response time requirements are different for the various plant types. These requirements are specified in the plant technical specifications in terms of an RTd time constant. The current time constant requirements for nuclear plant RTDs varies from 0.5 seconds to 13.0 seconds depending on the type of the plant. Therefore, different types of RTDs are used in different plants to achieve the required time constants. In addition, in-situ response time tests are periodically performed on protective system RTDs to ensure that the in-service time constants are within acceptable limits as the plant is operating. The periodic testing is important because response time degradation may occur while the RTD ages in the process. Recent response time tests in operating plants revealed unacceptable time constants for several protection system RTDs. As a result, these plants had to be shut down to resolve the problem which in one case was due to improper installation and in another case was because of degradation of a thermal compound used in the thermowell

Longer operating times of nuclear power plants. Options for compensating public utility advantages

International Nuclear Information System (INIS)

Bode, Sven; Kondziella, Hendrik; Bruckner, Thomas

2010-01-01

The current German government of CDU/CSU and FDP intends to prolong the operating time of existing nuclear power plants in Germany. The advantages resulting for public utilities are to be compensated. The authors discuss how compensation may be achieved and outline the available instruments. (orig.)

Time domain-nuclear magnetic resonance study of chars from southern hardwoods

International Nuclear Information System (INIS)

Elder, Thomas; Labbe, Nicole; Harper, David; Rials, Timothy

2006-01-01

Chars from the thermal degradation of silver maple (Acer saccharinum), red maple (Acer rubrum), sugar maple (Acer saccharum), and white oak (Quercus spp.), performed at temperatures from 250 to 350 o C, were examined using time domain-nuclear magnetic resonance spectroscopy. Prior to analysis, the chars were equilibrated under conditions insuring the presence of bound water only and both bound water and free water. Transverse relaxation times were found to be related to the moisture content of the chars, which varied with temperature. At elevated temperatures the number of signals assigned to free water decreased, indicative of an increase in pore size within the chars

The database system of the real-time dose appreciation for Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Jiang Li; Chai Luquan

1993-01-01

The paper is about the data base system of the real-time dose appreciation for Qinshan Nuclear Power Plant and describes in detail the design of the system, the data structure, the programming and the characteristics

Determination of C0-60 in Cobalt Slugs and Slabs and Radionuclides in Curium Sampler Slugs L-Reactor Disassembly Basin

International Nuclear Information System (INIS)

Casella, V.R.

2004-01-01

Co-60 was historically produced in the SRS reactors. Cobalt slugs were irradiated in the early 1970s. Post-production, remaining cobalt slugs (including slab form) were consolidated for storage. There are approximately nine hundred cobalt slugs currently stored awaiting final disposition. These slugs had historically incomplete documentation for activity rates; therefore, assaying was required in order to determine their activity levels. Since the gamma dose rate from these slugs is extremely high, the most cost effective way to shield a source of this magnitude from personnel and the radiation detector was to use the basin water in which the slugs are stored as the shield. A sodium iodide gamma detector was placed above a specially designed air collimator assembly, so that slug was at least eight feet from the detector and was shielded by the basin water. Using a sodium iodide detector and multichannel analyzer system and an underwater collimator assembly, Co-60 concentrations we re determined for Disassembly Basin cobalt slugs and slabs and 18 curium sampler slugs. The total activity of all of the assayed slugs summed to 31,783 curies. From the Co-60 concentrations of the curium sampler slugs, the irradiation flux was determined for the known irradiation time. The amounts of Pu-238, 239, 240, 241, 242; Am-241, 243; and Cm-242, 244 produced were then obtained based on the original amount of Pu-239 irradiated

Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses.

Science.gov (United States)

Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

2015-12-01

Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.

Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses

Science.gov (United States)

Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

2015-01-01

Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it. PMID:26630202

Head-end reprocessing equipment remote maintenance demonstration

International Nuclear Information System (INIS)

Evans, J.H.; Metz, C.F. III.

1989-01-01

Prototype equipment for reprocessing breeder reactor nuclear fuel was installed in the Remote Operation and Maintenance Demonstration (ROMD) area of the Consolidated Fuel Reprocessing Program (CFRP) facility at the Oak Ridge National Laboratory (ORNL) in order to evaluate the design of this equipment in a cold mock-up of a remotely maintained hot cell. This equipment included the Remote Disassembly System (RDS) and the Remote Shear System (RSS). These systems were disassembled and reassembled remotely by using the extensive remote handling systems that are installed in this simulated hot-cell environment. 5 refs., 5 figs

Optimal testing input sets for reduced diagnosis time of nuclear power plant digital electronic circuits

International Nuclear Information System (INIS)

Kim, D.S.; Seong, P.H.

1994-01-01

This paper describes the optimal testing input sets required for the fault diagnosis of the nuclear power plant digital electronic circuits. With the complicated systems such as very large scale integration (VLSI), nuclear power plant (NPP), and aircraft, testing is the major factor of the maintenance of the system. Particularly, diagnosis time grows quickly with the complexity of the component. In this research, for reduce diagnosis time the authors derived the optimal testing sets that are the minimal testing sets required for detecting the failure and for locating of the failed component. For reduced diagnosis time, the technique presented by Hayes fits best for the approach to testing sets generation among many conventional methods. However, this method has the following disadvantages: (a) it considers only the simple network (b) it concerns only whether the system is in failed state or not and does not provide the way to locate the failed component. Therefore the authors have derived the optimal testing input sets that resolve these problems by Hayes while preserving its advantages. When they applied the optimal testing sets to the automatic fault diagnosis system (AFDS) which incorporates the advanced fault diagnosis method of artificial intelligence technique, they found that the fault diagnosis using the optimal testing sets makes testing the digital electronic circuits much faster than that using exhaustive testing input sets; when they applied them to test the Universal (UV) Card which is a nuclear power plant digital input/output solid state protection system card, they reduced the testing time up to about 100 times

Real-time assessment of radiation burden of the population in the vicinity of nuclear power plants during radiation accidents

International Nuclear Information System (INIS)

Stubna, M.

1986-01-01

The method is presented of real-time calculation of the radiation situation (dose equivalents) in the environs of a nuclear power plant in case of an accident involving the release of radioactive substances into the atmosphere, this for the potentially most significant exposure paths in the initial and medium stages of the accident. The method allows to take into consideration the time dependence of the rate of radioactive substance release from the nuclear power plant and to assess the development in space and time of the radiation situation in the environs of the nuclear power plant. The use of the method is illustrated by an example of the calculation of the development of the radiation situation for model accidents of a hypothetical PWR with containment. (author)

Time for final disposal of nuclear waste - society, technology and nature; Tid foer slutfoervaring. Samhaelle, teknik och natur

Energy Technology Data Exchange (ETDEWEB)

Forsling, Willis; Andersson-Skog, Lena; Haenninen, Hannu; Knutsson, Gert; Ma ttsson, Soeren; Stigh, Jimmy; Soederberg, Olof; Bolin, Bert; Nordlund, Erling

2007-05-15

This report consists of a number of independent contribution that treat different aspects of the nuclear waste complex, with the time perspective as a common starting point. The review does not pretend to cover the entire area, but the selected issues addressed are those of large general interest. First a general overview is given of how the nuclear waste issue has been treated in Sweden since the plans to use nuclear power begun be planned in the middle of the 1940s. The complex of problem around the nuclear waste issue is linked to our natural aversion against the development of nuclear weapons during they last 60-70 years, but also to the controversies around the peaceful use of the nuclear power that has happened during the latest 30-40 years. In chapters 3 the time perspective is considerably shorter, approximately 20 years. Here, construction and operation of an underground repository for nuclear waste is discussed. Such an undertaking has many resemblances with establishing an underground mine and there is much experience to learn from. In chapters 4 questions about the technical barriers are treated, the copper container, bentonite buffer and the backfilling. The copper container and bentonite buffer both have key roles to prevent ground water to come in contact with the spent fuel and that radioactivity is transported out into the environment. They must both fulfil their functions during the period when the fuel is dangerous, i.e. over 100,000 years. Different processes affects the repository, some during short periods, some during several 10,000 years. Specific intervals (from 10 years and up to 100,000 years) are indicated for the different processes, almost all with the starting point at the deposition of the waste. The possibility to gain experiences from natural analogies is treated in chapters 5. They can be seen as a prolonged experiment in natural systems where one reactor zone has been active for more than 100,000 years. The time perspective

Time-correlated pulse-height measurements of low-multiplying nuclear materials

Energy Technology Data Exchange (ETDEWEB)

Miller, E.C., E-mail: ericcm@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI (United States); Dolan, J.L.; Clarke, S.D.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI (United States); Tomanin, A.; Peerani, P. [European Commission EC-JRC-IPSC, Ispra (Italy); Marleau, P. [Sandia National Laboratories, Livermore, CA (United States); Mattingly, J.K. [North Carolina State University, Raleigh, NC (United States)

2013-11-21

Methods for the determination of the subcritical neutron multiplication of nuclear materials are of interest in the field of nuclear nonproliferation and safeguards. A series of measurements were performed at the Joint Research Center facility in Ispra, Italy to investigate the possibility of using a time-correlated pulse-height (TCPH) analysis to estimate the sub-critical multiplication of nuclear material. The objective of the measurements was to evaluate the effectiveness of this technique, and to benchmark the simulation capabilities of MCNPX-PoliMi/MPPost. In this campaign, two low-multiplication samples were measured: a 1-kg mixed oxide (MOX) powder sample and several low-mass plutonium–gallium (PuGa) disks. The measured results demonstrated that the sensitivity of the TCPH technique could not clearly distinguish samples with very-low levels of multiplication. However, the simulated TCPH distributions agree well with the measured data, within 12% for all cases, validating the simulation capabilities of MCNPX-PoliMi/MPPost. To investigate the potential of the TCPH method for identifying high-multiplication samples, the validated MCNPX-PoliMi/MPPost codes were used to simulate sources of higher multiplications. Lastly, a characterization metric, the cumulative region integral (CRI), was introduced to estimate the level of multiplication in a source. However, this response was shown to be insensitive over the range of multiplications of interest. -- Highlights: •Present results of measurements of MOX fuel and PuGa disks. •Compared measurement results to simulations performed using MCNPX-Polimi and MPPost. •Investigated using correlated γ–n pairs to determine the multiplication of a system.

Nuclear fuel reprocessing: A time for decision

International Nuclear Information System (INIS)

O'Donnell, A.J.; Sandbery, R.O.

1983-01-01

Availability of adequate supplies of energy at an affordable cost is essential to continued growth of the world's economics. The tie between economic growth and electricity usage is particularly strong and the pervasive wordwide trend toward increasing electrification shows no signs of abating. Very few viable alternatives are available for supplying the projected increase in baseload electric generating capacity in the next several decades, and most industrialized nations have chosen nuclear power to play a major role. Sustained growth of nuclear power can only be achieved, however, by reprocessing spent fuel to recover and utilize the residual uranium and plutonium energy values

A nuclear insect appears

International Nuclear Information System (INIS)

Shin, Gi Hwal

1989-06-01

This book is dairy of a nuclear insect in A. F. era. It consists of 6 parts, which have fun pictures and titles. The contents are the letter that is sent the Homo sapiens by insect, exodus of nuclear insect F 100 years latter. The time that a nuclear insect is attacked in F 101, the time that a nuclear dinosaur is beat in AF 102, the time that a nuclear insect struggles in AF 104 and the time that a nuclear insect drifts in AF 104.

Dynamical suppression of nuclear-spin decoherence time in Si and GaAs using inversion pulses

International Nuclear Information System (INIS)

Watanabe, S.; Harada, J.; Sasaki, S.; Hirayama, Y.

2007-01-01

We found that nuclear-spin decoherence is suppressed by applying inversion pulses such as alternating phase Carr-Purcell (APCP) and Carr-Purcell-Meiboom-Gill (CPMG) sequences in silicon and GaAs. The decoherence time reaches ∼1.3s by applying inversion pulses, which is ∼200 times as long as the characteristic decay time obtained from the Hahn echo sequence (∼6ms) in silicon

The time is ripe to introduce nuclear power plants in Asia

International Nuclear Information System (INIS)

Machi, Sueo; Odera, Mitsutoshi; Ishii, Noriyuki; Nakasugi, Hideo; Mukaiyama, Takehiko; Nagasaki, Takao; Ake, Yutaka

2010-01-01

While the ambitious growth in nuclear power generation is expected in China and India, a number of countries in East and South Asia such as Vietnam and Indonesia are planning to construct new nuclear power plants to meet their increasing demands for electricity. In this feature article, eight experts described the state of introduction of nuclear power plants in such countries. These were titled as 'Trends of Deployment of Nuclear Energy in Asia-FNCA Ministerial Level Meeting', 'Vietnam- National Assembly Approval of Pre-feasibility Study and its Implementation', 'Present State of Nuclear Power Introduction in Indonesia-Awaiting the Decision of the President-', 'Present Status of Volcanic Hazard Assessment for Nuclear Facilities and Case of Bataan Nuclear Power Plant in Philippines', 'State of Nuclear Power Introduction in Thailand', 'Slow Start of Nuclear Power Introduction in Malaysia', 'Nuclear Energy Development in China in the View of Asian Market' and 'Is the Rollback in the Asian Market of Japan Group Possible?' It is highly expected Japan's high level of technology and safety with nuclear power generation would lead to promote international activities and cooperation of Japan group in the Asian Market. (T. Tanaka)

On the long standing question of nuclear track etch induction time: Surface-cap model

International Nuclear Information System (INIS)

Rana, Mukhtar Ahmed

2008-01-01

Using a systematic set of experiments, nuclear track etch induction time measurements in a widely used CR-39 detector were completed for accessible track-forming particles (fission fragments, 5.2 MeV alpha particles and 5.9 MeV antiprotons). Results of the present work are compared with appropriately selected published results. The possibility of the use of etch induction time for charged particle identification is evaluated. Analysis of experimental results along with the use of well-established theoretical concepts yielded a model about delay in the start of chemical etching of nuclear tracks. The suggested model proposes the formation of a surface-cap (top segment) in each nuclear track consisting of chemically modified material with almost same or even higher resistance to chemical etching compared with bulk material of the track detector. Existing track formation models are reviewed very briefly, which provide one of the two bases of the proposed model. The other basis of the model is the general behavior of hot or energised material having a connection with an environment containing a number of species like ordinary air. Another reason for the delay in the start of etching is suggested as the absence of localization of etching atoms/molecules, which is present during etching at depth along the latent track

Response Time Test for The Application of the Data Communication Network to Nuclear Power Plant

International Nuclear Information System (INIS)

Shin, Y.C.; Lee, J.Y.; Park, H.Y.; Seong, S.H.; Chung, H.Y.

2002-01-01

This paper discusses the response time test for the application of the Data Communication Network (DCN) to Nuclear Power Plant (NPP). Conventional Instrumentation and Control (I and C) Systems using the analog technology in NPP have raised many problems regarding the lack of spare parts, maintenance burden, inaccuracy, etc.. In order to solve the problems, the Korean Next Generation Reactor (KNGR) I and C system has adopted the digital technology and new design features of using the data communication networks. It is essential to prove the response time requirements that arise from the introduction of digital I and C technology and data communication networks to nuclear power plant design. For the response time test, a high reliable data communication network structure has been developed to meet the requirements of redundancy, diversity, and segmentation. This paper presents the results of network load analysis and response time test for the KNGR DCN prototype. The test has been focused on the response time from the field components to the gateway because the response times from the gateway to the specific systems are similar to those of the existing design. It is verified that the response time requirements are met through the prototype test for KNGR I and C systems. (authors)

Innovative real time simulation training and nuclear probabilistic risk assessment

International Nuclear Information System (INIS)

Reisinger, M.F.

1991-01-01

Operator errors have been an area of public concern for the safe operation of nuclear power plants since the TMI2 incident. Simply stated, nuclear plants are very complex systems and the public is skeptical of the operators' ability to comprehend and deal with the vast indications and complexities of potential nuclear power plant events. Prior to the TMI2 incident, operator errors and human factors were not included as contributing factors in the Probabilistic Risk Assessment (PRA) studies of nuclear power plant accidents. More recent efforts in nuclear risk assessment have addressed some of the human factors affecting safe nuclear plant operations. One study found four major factors having significant impact on operator effectiveness. This paper discusses human factor PRAs, new applications in simulation training and the specific potential benefits from simulation in promoting safer operation of future power plants as well as current operating power plants

Hydrogen from nuclear plus wind using real-time electricity prices

International Nuclear Information System (INIS)

Miller, A.I.; Duffey, R.B.; Fairlie, M.; Anders, P.

2004-01-01

During the early years of hydrogen's use as a vehicle fuel, penetration of the market will be small. This favours distributed production by electrolysis, which avoids the scale-dependent costs of distribution from centralized plants. For electrolysis actually to be the preferred option, capital equipment for electrolysis must be reasonably cheap but the dominant cost component is the electricity price. By about 2006, advanced designs of nuclear reactors should be available to produce electricity at around 30 US$/MW.h at the plant gate. The best approach to producing low-cost electrolytic hydrogen is shown to be use of such reactors to supply electricity to the grid at times of peak price and demand and to make hydrogen at other times In this paper, this model has been used to calculate the production costs for electrolytic hydrogen at the location where the electricity is generated, using the actual prices of electricity paid by the Alberta Power Pool in 2002 and 2003 and by the Ontario Grid for 2003. The analysis shows clearly that by optimizing the co-production of hydrogen and electricity (referred to as the H 2 /e process) the cost for hydrogen produced can comfortably meet the US Department of Energy's target of 2000 US$/tonne. Because of its lower availability factor, wind-produced electricity cannot meet this cost target. However, if wind power availability can reach 35%, an intermittent supplementary current of wind-generated electricity may economically be fed to an electrolytic plant primarily supplied by nuclear power. Additional current raises the voltage for electrolysis but there would be only small additional capital costs. The two non-CO 2 -emitting sources, nuclear and wind could become complementary, providing an affordable way of storing wind-generated electricity when the supply exceeds demand in electricity markets The analyses presented in this paper looks at the case of bulk production of H 2 /e in a 'wholesale' energy market and does not

New findings on the onset of thermal disassembly in spallation reactions; Nouvelles approches pour l'etude de la multifragmentation thermique dans la spallation

Energy Technology Data Exchange (ETDEWEB)

Napolitani, P

2004-09-15

Thermal multifragmentation is the process of multi body disassembly of a hot nucleus when the excitation is almost purely thermal i.e. dynamical effects like compression (characteristic of ion-ion collisions at Fermi energy) are negligible. Suited reactions are proton induced collision or ion-ion abrasion at relativistic incident energy. Thus we measured four systems at FRS (Fragment separator, GSI, Darmstadt) in inverse kinematics: Fe{sup 56}+p, Fe{sup 56}+Ti(nat), Xe{sup 136}+p, Xe{sup 136}+Ti(nat) a 1 A*GeV. The inverse kinematics allows to observe all particles without any threshold in energy. This is a great advantage compared to experiments in direct kinematics, because only in inverse kinematics it is possible to obtain complete velocity spectra (without a hole for low velocities) for fully identified isotopes. The complex shape of the velocity spectra allows to identify the different deexcitation channels and it clearly shows the transition from a chaotic-dominated process (Gaussian cloud in velocity space) to a direct Coulomb- (or eventually expansion-) dominated process (shell of a sphere in velocity space). Different possible descriptions of the reaction process are discussed, based either on asymmetric fission or multifragmentation. The resulting physical picture is especially interesting for the Fe{sup 56}+p, and Xe{sup 136}+p systems: proton induced collisions could result in the split of the system in two or more fragments due to a fast break-up process. In this case, the configuration of the break-up partition is very asymmetric. The discussion will be extended to other characteristics, like the restoring of nuclear structure features in the isotopic production and the temperature dependence of the isotopic composition of the residues. (author)

Electromagnetic nuclear life time - theoretical context

International Nuclear Information System (INIS)

Niez, J.J.

2000-01-01

One describes here the theoretical tools which are needed for evaluating the nuclear lifetime of a nucleus dipped into electromagnetic surroundings which are composed of electrons and photons. The case where this environment is a material or a cavity will be treated in a following report. (Author)

Double-arm time-of-flight mass-spectrometer of nuclear fragments

International Nuclear Information System (INIS)

Ajvazian, G.M.; Astabatyan, R.A.

1995-01-01

A double-arm time-of-flight spectrometer of nuclear fragments for the investigation of heavy nuclei photofission in the intermediate energy range is described. The calibration results and working characteristics of the spectrometer, obtained using 252 Cf as a source of spontaneous fission, are presented. A mass resolution of σ m ∼2-3 a.m.u. was obtained within the registered fragments mass range of 80-160 a.m.u. The spectrometer was tested in the experiment on the investigation of 238 U nuclei fission by Bremsstahlung photons with Eγ max=1.75 GeV

Real-time detection and characterization of nuclear explosion using broadband analyses of regional seismic stations

Science.gov (United States)

Prastowo, T.; Madlazim

2018-01-01

This preliminary study aims to propose a new method of real-time detection and characterization of nuclear explosions by analyzing broadband seismic waveforms acquired from a network of regional seismic stations. Signal identification generated by a nuclear test was differentiated from natural sources of either earthquakes or other natural seismo-tectonic events by verifying crucial parameters, namely source depth, type of first motion, and P-wave domination of the broadband seismic wavesunder consideration. We examined and analyzed a recently hypothetical nuclear test performed by the North Koreangovernment that occurred on September 3, 2017 as a vital point to study. From spectral analyses, we found that the source of corresponding signals associated with detonations of the latest underground nuclear test was at a much shallower depth below the surface relatively compared with that of natural earthquakes, the suspected nuclear explosions produced compressional waves with radially directed outward from the source for their first motions, and the waves were only dominated by P-components. The results are then discussed in the context of potential uses of the proposed methodology for human-induced disaster early warning system and/or the need of rapid response purposes for minimizing the disaster risks.

First records of thermal neutrons with the spectrometer for time of flight (TOF) in the RP-10 Nuclear Reactor

International Nuclear Information System (INIS)

Munive, M.; Baltuano, O; Soto, C; Ravello, Y

2002-01-01

To obtain the first spectrum of an emergent beam of neutrons of a nuclear reactor is the main parameter of the characterization in the use of this reactor; one of ways to get this spectrum is for the technique of time of flight, TOF, which registers the time that a neutron need to cover a certain distance, associating this time then to the kinetic energy of the neutron. The kinetic study of the beam of neutrons is carried out on neutron pulses that are generated by a revolving choke called Chopper; and the analysis in the time of the detected pulses is carried out for a system MCS. Using this technique it is achieved the record of the spectra in energy, or in wavelength , of the irradiation facilities No 2 and 4, and of the exit N o 5 of the thermal column of the Nuclear Reactor RP-10 of the Nuclear Center Oscar de la Guerra RACSO, Peru (au)

Valuing modular nuclear power plants in finite time decision horizon

International Nuclear Information System (INIS)

Jain, Shashi; Roelofs, Ferry; Oosterlee, Cornelis W.

2013-01-01

Small and medium sized reactors, SMRs, (according to IAEA, ‘small’ refers to reactors with power less than 300 MWe, and ‘medium’ with power less than 700 MWe) are considered as an attractive option for investment in nuclear power plants. SMRs may benefit from flexibility of investment, reduced upfront expenditure, enhanced safety, and easy integration with small sized grids. Large reactors on the other hand have been an attractive option due to the economy of scale. In this paper we focus on the economic impact of flexibility due to modular construction of SMRs. We demonstrate, using real option analysis, the value of sequential modular SMRs. Numerical results under different considerations of decision time, uncertainty in electricity prices, and constraints on the construction of units, are reported for a single large unit and for modular SMRs. - Highlights: ► Real option value of modular construction in finite time decision horizon. ► Stochastic grid method is used to value the real option. ► Decisions in finite time can differ significantly from infinite decision time. ► Decisions depend on length of decision horizon and price volatilities

Sensor response time calculation with no stationary signals from a Nuclear Power Plant

International Nuclear Information System (INIS)

Vela, O.; Vallejo, I.

1998-01-01

Protection systems in a Nuclear Power Plant have to response in a specific time fixed by design requirements. This time includes the event detection (sensor delay) and the actuation time system. This time is obtained in refuel simulating the physics event, which trigger the protection system, with an electric signal and measuring the protection system actuation time. Nowadays sensor delay is calculated with noise analysis techniques. The signals are measured in Control Room during the normal operation of the Plant, decreasing both the cost in time and personal radioactive exposure. The noise analysis techniques require stationary signals but normally the data collected are mixed with process signals that are no stationary. This work shows the signals processing to avoid no-stationary components using conventional filters and new wavelets analysis. (Author) 2 refs

Tests of Micro-Pattern Gaseous Detectors for active target time projection chambers in nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Pancin, J., E-mail: pancin@ganil.fr [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Damoy, S.; Perez Loureiro, D. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Chambert, V.; Dorangeville, F. [IPNO, CNRS/IN2P3, Orsay (France); Druillole, F. [CEA, DSM/Irfu/SEDI, Gif-Sur-Yvette (France); Grinyer, G.F. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Lermitage, A.; Maroni, A.; Noël, G. [IPNO, CNRS/IN2P3, Orsay (France); Porte, C.; Roger, T. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Rosier, P. [IPNO, CNRS/IN2P3, Orsay (France); Suen, L. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France)

2014-01-21

Active target detection systems, where the gas used as the detection medium is also a target for nuclear reactions, have been used for a wide variety of nuclear physics applications since the eighties. Improvements in Micro-Pattern Gaseous Detectors (MPGDs) and in micro-electronics achieved in the last decade permit the development of a new generation of active targets with higher granularity pad planes that allow spatial and time information to be determined with unprecedented accuracy. A novel active target and time projection chamber (ACTAR TPC), that will be used to study reactions and decays of exotic nuclei at facilities such as SPIRAL2, is presently under development and will be based on MPGD technology. Several MPGDs (Micromegas and Thick GEM) coupled to a 2×2 mm{sup 2} pixelated pad plane have been tested and their performances have been determined with different gases over a wide range of pressures. Of particular interest for nuclear physics experiments are the angular and energy resolutions. The angular resolution has been determined to be better than 1° FWHM for short traces of about 4 cm in length and the energy resolution deduced from the particle range was found to be better than 5% for 5.5 MeV α particles. These performances have been compared to Geant4 simulations. These experimental results validate the use of these detectors for several applications in nuclear physics.

Tests of Micro-Pattern Gaseous Detectors for active target time projection chambers in nuclear physics

International Nuclear Information System (INIS)

Pancin, J.; Damoy, S.; Perez Loureiro, D.; Chambert, V.; Dorangeville, F.; Druillole, F.; Grinyer, G.F.; Lermitage, A.; Maroni, A.; Noël, G.; Porte, C.; Roger, T.; Rosier, P.; Suen, L.

2014-01-01

Active target detection systems, where the gas used as the detection medium is also a target for nuclear reactions, have been used for a wide variety of nuclear physics applications since the eighties. Improvements in Micro-Pattern Gaseous Detectors (MPGDs) and in micro-electronics achieved in the last decade permit the development of a new generation of active targets with higher granularity pad planes that allow spatial and time information to be determined with unprecedented accuracy. A novel active target and time projection chamber (ACTAR TPC), that will be used to study reactions and decays of exotic nuclei at facilities such as SPIRAL2, is presently under development and will be based on MPGD technology. Several MPGDs (Micromegas and Thick GEM) coupled to a 2×2 mm 2 pixelated pad plane have been tested and their performances have been determined with different gases over a wide range of pressures. Of particular interest for nuclear physics experiments are the angular and energy resolutions. The angular resolution has been determined to be better than 1° FWHM for short traces of about 4 cm in length and the energy resolution deduced from the particle range was found to be better than 5% for 5.5 MeV α particles. These performances have been compared to Geant4 simulations. These experimental results validate the use of these detectors for several applications in nuclear physics

COPI-mediated retrograde trafficking from the Golgi to the ER regulates EGFR nuclear transport

International Nuclear Information System (INIS)

Wang, Ying-Nai; Wang, Hongmei; Yamaguchi, Hirohito; Lee, Hong-Jen; Lee, Heng-Huan; Hung, Mien-Chie

2010-01-01

Research highlights: → ARF1 activation is involved in the EGFR transport to the ER and the nucleus. → Assembly of γ-COP coatomer mediates EGFR transport to the ER and the nucleus. → Golgi-to-ER retrograde trafficking regulates nuclear transport of EGFR. -- Abstract: Emerging evidence indicates that cell surface receptors, such as the entire epidermal growth factor receptor (EGFR) family, have been shown to localize in the nucleus. A retrograde route from the Golgi to the endoplasmic reticulum (ER) is postulated to be involved in the EGFR trafficking to the nucleus; however, the molecular mechanism in this proposed model remains unexplored. Here, we demonstrate that membrane-embedded vesicular trafficking is involved in the nuclear transport of EGFR. Confocal immunofluorescence reveals that in response to EGF, a portion of EGFR redistributes to the Golgi and the ER, where its NH 2 -terminus resides within the lumen of Golgi/ER and COOH-terminus is exposed to the cytoplasm. Blockage of the Golgi-to-ER retrograde trafficking by brefeldin A or dominant mutants of the small GTPase ADP-ribosylation factor, which both resulted in the disassembly of the coat protein complex I (COPI) coat to the Golgi, inhibit EGFR transport to the ER and the nucleus. We further find that EGF-dependent nuclear transport of EGFR is regulated by retrograde trafficking from the Golgi to the ER involving an association of EGFR with γ-COP, one of the subunits of the COPI coatomer. Our findings experimentally provide a comprehensive pathway that nuclear transport of EGFR is regulated by COPI-mediated vesicular trafficking from the Golgi to the ER, and may serve as a general mechanism in regulating the nuclear transport of other cell surface receptors.

Predicting linear and nonlinear time series with applications in nuclear safeguards and nonproliferation

International Nuclear Information System (INIS)

Burr, T.L.

1994-04-01

This report is a primer on the analysis of both linear and nonlinear time series with applications in nuclear safeguards and nonproliferation. We analyze eight simulated and two real time series using both linear and nonlinear modeling techniques. The theoretical treatment is brief but references to pertinent theory are provided. Forecasting is our main goal. However, because our most common approach is to fit models to the data, we also emphasize checking model adequacy by analyzing forecast errors for serial correlation or nonconstant variance

Verification tests for remote controlled inspection system in nuclear power plants

International Nuclear Information System (INIS)

Kohno, Tadaaki

1986-01-01

Following the increase of nuclear power plants, the total radiation exposure dose accompanying inspection and maintenance works tended to increase. Japan Power Engineering and Inspection Corp. carried out the verification test of a practical power reactor automatic inspection system from November, 1981, to March, 1986, and in this report, the state of having carried out this verification test is described. The objects of the verification test were the equipment which is urgently required for reducing radiation exposure dose, the possibility of realization of which is high, and which is important for ensuring the safety and reliability of plants, that is, an automatic ultrasonic flaw detector for the welded parts of bend pipes, an automatic disassembling and inspection system for control rod driving mechanism, a fuel automatic inspection system, and automatic decontaminating equipments for steam generator water chambers, primary system crud and radioactive gas in coolant. The results of the verification test of these equipments were judged as satisfactory, therefore, the application to actual plants is possible. (Kako, I.)

Scenarios for dealing with large components in the process of decommissioning nuclear power plants and the possibility of their implementation in the Slovak Republic

International Nuclear Information System (INIS)

Hornacek, M.; Necas, V.

2014-01-01

The subject of this presentation is a general assessment of the strategies of dismantling of large components in view of the experience gained from projects implemented as well as the identification of the factors determining the choice of the appropriate disassembly procedure. The paper also deals with the possibilities of removing the steam generator used in nuclear power plant Bohunice V1, which is currently in the process of decommissioning. Different scenarios for dismantling, storage respectively storing into the repository are analyzed. The is also studied the impact of declining of the activity of natural decay and application of decontamination technologies (before or dismantling decontamination) on quantities of materials releasable into the environment respectively leviable in the corresponding storage system. (authors)

Crystal structure of the Xpo1p nuclear export complex bound to the SxFG/PxFG repeats of the nucleoporin Nup42p.

Science.gov (United States)

Koyama, Masako; Hirano, Hidemi; Shirai, Natsuki; Matsuura, Yoshiyuki

2017-10-01

Xpo1p (yeast CRM1) is the major nuclear export receptor that carries a plethora of proteins and ribonucleoproteins from the nucleus to cytoplasm. The passage of the Xpo1p nuclear export complex through nuclear pore complexes (NPCs) is facilitated by interactions with nucleoporins (Nups) containing extensive repeats of phenylalanine-glycine (so-called FG repeats), although the precise role of each Nup in the nuclear export reaction remains incompletely understood. Here we report structural and biochemical characterization of the interactions between the Xpo1p nuclear export complex and the FG repeats of Nup42p, a nucleoporin localized at the cytoplasmic face of yeast NPCs and has characteristic SxFG/PxFG sequence repeat motif. The crystal structure of Xpo1p-PKI-Nup42p-Gsp1p-GTP complex identified three binding sites for the SxFG/PxFG repeats on HEAT repeats 14-20 of Xpo1p. Mutational analyses of Nup42p showed that the conserved serines and prolines in the SxFG/PxFG repeats contribute to Xpo1p-Nup42p binding. Our structural and biochemical data suggest that SxFG/PxFG-Nups such as Nup42p and Nup159p at the cytoplasmic face of NPCs provide high-affinity docking sites for the Xpo1p nuclear export complex in the terminal stage of NPC passage and that subsequent disassembly of the nuclear export complex facilitates recycling of free Xpo1p back to the nucleus. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Software for the nuclear reactor dynamics study using time series processing; Software para el estudio de la dinamica de reactores nucleares mediante el procesamiento de series temporales

Energy Technology Data Exchange (ETDEWEB)

Valero, Esbel T.; Montesino, Maria E. [Instituto Superior de Ciencia y Tecnologia Nuclear (ISCTN), La Habana (Cuba)

1997-12-01

The parametric monitoring in Nuclear Power Plant (NPP) permits the operational surveillance of nuclear reactor. The methods employed in order to process this information such as FFT, autoregressive models and other, have some limitations when those regimens in which appear strongly non-linear behaviors are analyzed. In last years the chaos theory has offered new ways in order to explain complex dynamic behaviors. This paper describes a software (ECASET) that allow, by time series processing from NPP`s acquisition system, to characterize the nuclear reactor dynamic as a complex dynamical system. Here we show using ECASET`s results the possibility of classifying the different regimens appearing in nuclear reactors. The results of several temporal series processing from real systems are introduced. This type of analysis complements the results obtained with traditional methods and can constitute a new tool for monitoring nuclear reactors. (author). 13 refs., 3 figs.

Fuzzy operation and real time surveillance of a nuclear reactor

International Nuclear Information System (INIS)

Si-Fodil, M.; Guely, F.; Siarry, P.; Tyran, J.L.

1997-01-01

The operating power of nuclear power plants needs to be modulated according to the thin evolutions of electric power demand. Two parameters are concerned by load following operations: the power axial disequilibrium and the position of control rods. This paper deals with the automation of the control of power axial disequilibrium using boration-dilution. An automatic system based on fuzzy logic is proposed which can be substituted to the expert operator who is in charge of this fastidious manual task. The management of water and boron flow rates are studied in details. A Graphic interface was designed for the real-time surveillance of the reactor. (J.S.)

Nuclear grade cable thermal life model by time temperature superposition algorithm based on Matlab GUI

International Nuclear Information System (INIS)

Lu Yanyun; Gu Shenjie; Lou Tianyang

2014-01-01

Background: As nuclear grade cable must endure harsh environment within design life, it is critical to predict cable thermal life accurately owing to thermal aging, which is one of dominant factors of aging mechanism. Purpose: Using time temperature superposition (TTS) method, the aim is to construct nuclear grade cable thermal life model, predict cable residual life and develop life model interactive interface under Matlab GUI. Methods: According to TTS, nuclear grade cable thermal life model can be constructed by shifting data groups at various temperatures to preset reference temperature with translation factor which is determined by non linear programming optimization. Interactive interface of cable thermal life model developed under Matlab GUI consists of superposition mode and standard mode which include features such as optimization of translation factor, calculation of activation energy, construction of thermal aging curve and analysis of aging mechanism., Results: With calculation result comparison between superposition and standard method, the result with TTS has better accuracy than that with standard method. Furthermore, confidence level of nuclear grade cable thermal life with TTS is higher than that with standard method. Conclusion: The results show that TTS methodology is applicable to thermal life prediction of nuclear grade cable. Interactive Interface under Matlab GUI achieves anticipated functionalities. (authors)

Real-Time Characterization of Special Nuclear Materials

Energy Technology Data Exchange (ETDEWEB)

Walston, Sean [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Candy, Jim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chambers, Dave [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chandrasekaran, Hema [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyderman, Neal [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-09-04

When confronting an item that may contain nuclear material, it is urgently necessary to determine its characteristics. Our goal is to provide accurate information with high-con dence as rapidly as possible.

Study of Real Time Location System For Worker in Containment Building at Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Lee, S. Y.; Kim, G. S. [Samchang Enterprise Company, Ulsan (Korea, Republic of); Kim, H. S. [Ulsan Univ., Ulsan (Korea, Republic of)

2012-03-15

Workers are required special management to minimize radiation exposure in nuclear power plant. Especially, there are many limitation in their activities at containment building in nuclear power plant. Test personnel shall administer the workers by tracing the location of them inside containment building in nuclear power plant. They may be exposed to the unnecessary radiation due to a complex and high radiation area in the building. Test personnel needs to manage efficiently for worker's safety and work hours at containment building. Therefore, it is critical for the test personnel to notice the risk to the workers by identifying the location when the workers are facing the dangerous situation on the high area. In this paper, we introduce requirements and design method to develop the one and two dimensional RTLS(Real Time Locating System) by using CSS(Chirp Spread Spectrum) which enables precise location measurement and robust data communication even indoor environment with serious electromagnetic interference caused by complicated structure such as the inside of containment building in the nuclear power plant. In the algorithm to compute the distance, it is suggested to use SDS-TWR(Symmetrical Double-Sided Two-Way Ranging) to solve the issue of indirect routes, and develop the power circuit with 10mW of designing gain for output power to meet the KCC standard in order to increase the raging distance, in addition, communication between Anchor and distance measuring computer shall be designed to increase energy using time of Tags(nodes) by using CAN(Controller Area Network) communication.

Nuclear criticality safety and time reactivity enhancement aspects of energy amplifier system devices

Energy Technology Data Exchange (ETDEWEB)

Siciliano, F [ENEA, Centro Ricerche Trisaia, Rotondelle, Matera (Italy). Direzione INFO

1995-12-01

As far as the Rubbia`s and colleagues proposal of innovating Energy Amplifier system (E.A.s.) device driven by a particle beam accelerator is concerned, four basic topics are comprised in the present paper: (1) A short outline of the nuclear aspects of Th-U and U-Pu fuel cycles regarding their general breeding and efficiency features. (2) The needed nuclear criticality control requirements have been studied in terms of safety regulating parameters on the basis of the ThO2 mixed oxides selected as fuel kind for the E.A.s. device technology development. Particular attention is devoted to time evolution of neutron multiplication factor since delayed development of the 233U buildup and so system reactivity are expected in the Th-U cycle. (3) Code E.A.s. device irradiation and post-irradiation modelling for determining higher actinides buildup, fission products formation and fuel consumption trends as function of time, system enrichment degree and flux level parameters. (4) The confirmation, on the basis of the same specific power irradiation, of expected actinides waste obtainment cleaner than the one deriving from the U-Pu cycle utilization. For this end, a model comparison of equivalent enriched fissile nuclides in both cycles has been devised as having, within the range of 0-700 days, ten irradiation periods of about 53 MW/ton specific power and equivalent cooling time post-irradiation periods.

A comparison of availability and outage time of nuclear power plants

International Nuclear Information System (INIS)

Nagatomi, Yu; Matsuo, Yuhji; Murakami, Tomoko

2011-01-01

Japan has recently been urged to implement measures to increase availability for nuclear power plants in order to address energy security and greenhouse gas emission cuts. The average availability for Japan's nuclear power plants in 2009 rose from 58.0% in 2008 to 64.7%, still below levels in other major nuclear power generation countries including South Korea and the United States. Some major foreign nuclear power generation countries have kept their availability for nuclear plants at high levels at or above 90% since 1990, while others including the United States and South Korea have raised their respective factors since 2000 following the 1990s when their factors were close to the Japanese level. The latter group made ambitious efforts to raise these factors. In considering specific measures to effectively utilize existing nuclear reactors, Japan should take full account of these overseas efforts and promote discussions on overall Japanese nuclear energy and safety approaches. (author)

Time-reversal-noninvariant, parity-conserving nuclear interactions

International Nuclear Information System (INIS)

Haxton, W.C.; Hoering, A.; Washington Univ., Seattle, WA; Melbourne Univ., Parkville, VIC

1993-01-01

In this paper the authors quantify the relationship between compound nucleus (CN) and electric dipole moment (edm) constraints on long-ranged time-reversal-noninvariant (TRNI), parity-conserving (PC) interactions. It begins by reviewing the work that has been done in compound nuclei. In the second section, it considers the general form of the TRNI PC interaction in meson exchange models. In the third section discusses one mechanism for generating an atomic edm, a TRNI PC nuclear interaction mediate by ρ exchange coupled with Z exchange between atomic electrons and the nucleus. While a variety of other mechanisms can similarly generate edms from TRNI PC interactions this example has some interesting experimental consequences. The limits extracted are then translated into a constraint on α, the ratio of typical TRNI and TRI N N matrix elements. It is concluded that such atomic edm limits on TRNI PC interactions are at least comparable to those obtained in the best CN studies. These limits from long-distance contributions to edms are then compared to the stringent bounds obtained recently by Conti and Khriplovich from studies of short-ranged mechanisms. 37 refs., 2 figs

TFG facilitates outer coat disassembly on COPII transport carriers to promote tethering and fusion with ER-Golgi intermediate compartments.

Science.gov (United States)

Hanna, Michael G; Block, Samuel; Frankel, E B; Hou, Feng; Johnson, Adam; Yuan, Lin; Knight, Gavin; Moresco, James J; Yates, John R; Ashton, Randolph; Schekman, Randy; Tong, Yufeng; Audhya, Anjon

2017-09-12

The conserved coat protein complex II (COPII) mediates the initial steps of secretory protein trafficking by assembling onto subdomains of the endoplasmic reticulum (ER) in two layers to generate cargo-laden transport carriers that ultimately fuse with an adjacent ER-Golgi intermediate compartment (ERGIC). Here, we demonstrate that Trk-fused gene (TFG) binds directly to the inner layer of the COPII coat. Specifically, the TFG C terminus interacts with Sec23 through a shared interface with the outer COPII coat and the cargo receptor Tango1/cTAGE5. Our findings indicate that TFG binding to Sec23 outcompetes these other associations in a concentration-dependent manner and ultimately promotes outer coat dissociation. Additionally, we demonstrate that TFG tethers vesicles harboring the inner COPII coat, which contributes to their clustering between the ER and ERGIC in cells. Together, our studies define a mechanism by which COPII transport carriers are retained locally at the ER/ERGIC interface after outer coat disassembly, which is a prerequisite for fusion with ERGIC membranes.

HUWE1 Ubiquitylates and Degrades the RAC Activator TIAM1 Promoting Cell-Cell Adhesion Disassembly, Migration, and Invasion

Directory of Open Access Journals (Sweden)

Lynsey Vaughan

2015-01-01

Full Text Available The E3 ubiquitin ligase HUWE1, deregulated in carcinoma, has been implicated in tumor formation. Here, we uncover a role for HUWE1 in cell migration and invasion through degrading the RAC activator TIAM1, implying an additional function in malignant progression. In MDCKII cells in response to HGF, HUWE1 catalyzes TIAM1 ubiquitylation and degradation predominantly at cell-cell adhesions, facilitating junction disassembly, migration, and invasion. Depleting HUWE1 or mutating the TIAM1 ubiquitylation site prevents TIAM1 degradation, antagonizing scattering, and invasion. Moreover, simultaneous depletion of TIAM1 restores migration and invasion in HUWE1-depleted cells. Significantly, we show that HUWE1 stimulates human lung cancer cell invasion through regulating TIAM1 stability. Finally, we demonstrate that HUWE1 and TIAM1 protein levels are inversely correlated in human lung carcinomas. Thus, we elucidate a critical role for HUWE1 in regulating epithelial cell-cell adhesion and provide additional evidence that ubiquitylation contributes to spatiotemporal control of RAC.

Nuclear reaction data and nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Paver, N [University of Trieste (Italy); Herman, M [International Atomic Energy Agency, Vienna (Austria); Gandini, A [ENEA, Rome (Italy)

2001-12-15

These two volumes contain the lecture notes of the workshop 'Nuclear Reaction Data and Nuclear Reactors: Physics, Design and Safety', which was held at the Abdus Salam ICTP in the Spring of 2000. The workshop consisted of five weeks of lecture courses followed by practical computer exercises on nuclear data treatment and design of nuclear power systems. The spectrum of topics is wide enough to timely cover the state-of-the-art and the perspectives of this broad field. The first two weeks were devoted to nuclear reaction models and nuclear data evaluation. Nuclear data processing for applications to reactor calculations was the subject of the third week. On the last two weeks reactor physics and on-going projects in nuclear power generation, waste disposal and safety were presented.

Karyopherin alpha7 (KPNA7), a divergent member of the importin alpha family of nuclear import receptors.

Science.gov (United States)

Kelley, Joshua B; Talley, Ashley M; Spencer, Adam; Gioeli, Daniel; Paschal, Bryce M

2010-08-11

Classical nuclear localization signal (NLS) dependent nuclear import is carried out by a heterodimer of importin alpha and importin beta. NLS cargo is recognized by importin alpha, which is bound by importin beta. Importin beta mediates translocation of the complex through the central channel of the nuclear pore, and upon reaching the nucleus, RanGTP binding to importin beta triggers disassembly of the complex. To date, six importin alpha family members, encoded by separate genes, have been described in humans. We sequenced and characterized a seventh member of the importin alpha family of transport factors, karyopherin alpha 7 (KPNA7), which is most closely related to KPNA2. The domain of KPNA7 that binds Importin beta (IBB) is divergent, and shows stronger binding to importin beta than the IBB domains from of other importin alpha family members. With regard to NLS recognition, KPNA7 binds to the retinoblastoma (RB) NLS to a similar degree as KPNA2, but it fails to bind the SV40-NLS and the human nucleoplasmin (NPM) NLS. KPNA7 shows a predominantly nuclear distribution under steady state conditions, which contrasts with KPNA2 which is primarily cytoplasmic. KPNA7 is a novel importin alpha family member in humans that belongs to the importin alpha2 subfamily. KPNA7 shows different subcellular localization and NLS binding characteristics compared to other members of the importin alpha family. These properties suggest that KPNA7 could be specialized for interactions with select NLS-containing proteins, potentially impacting developmental regulation.

Hot nuclei: high temperatures, high angular momenta

International Nuclear Information System (INIS)

Guerreau, D.

1991-01-01

A review is made of the present status concerning the production of hot nuclei above 5 MeV temperature, concentrating mainly on the possible experimental evidences for the attainment of a critical temperature, on the existence of dynamical limitations to the energy deposition and on the experimental signatures for the formation of hot spinning nuclei. The data strongly suggest a nuclear disassembly in collisions involving very heavy ions at moderate incident velocities. Furthermore, hot nuclei seem to be quite stable against rotation on a short time scale. (author) 26 refs.; 12 figs

Time-domain, nuclear-resonant, forward scattering: the classical approach

International Nuclear Information System (INIS)

Hoy, G.R.

1997-01-01

This paper deals with the interaction of electromagnetic radiation with matter assuming the matter to have nuclear transitions in resonance with incident electromagnetic radiation. The source of the radiation is taken to be of two types; natural radioactive gamma decay and synchrotron radiation. Numerical examples using 57 Fe are given for the two types of source radiation. Calculated results are contrasted for the two cases. Electromagnetic radiation produced by recoil-free gamma-ray emission has essentially the natural linewidth. Electromagnetic radiation from a synchrotron, even with the best monochromators available, has a relatively broad-band spectrum, essentially constant for these considerations. Polarization effects are considered. In general, the nuclear-resonant medium changes the polarization of the input radiation on traversing the medium. Calculations are presented to illustrate that synchrotron radiation studies using nuclear-resonant forward scattering have the potential for making high-precision measurements of hyperfine fields and recoilless fractions. An interesting aspect of nuclear-resonant forward scattering, relative to possible gamma-ray laser development, is the so-called 'speed-up' effect

SP-100 reactor disassembly remote handling test program

International Nuclear Information System (INIS)

Wilson, C.E.; Potter, J.D.; Maiden, G.E.; Vader, D.P.

1991-01-01

This paper is presented as an overview of the remote handling equipment validation testing, which will be conducted before installation and use in the ground engineering test facility. This equipment will be used to defuel the SP-100 reactor core after removing it from the Test Assembly following nuclear testing. A series of full scale mock-up operational tests will be conducted at a Hanford Site facility to verify equipment design, operation, and capabilities

On the use of time resolved laser-induced spectrofluorometry in the nuclear fuel cycle

International Nuclear Information System (INIS)

Moulin, C.; Decambox, P.; Mauchien, P.; Davin, T.; Pradel, B.

1991-01-01

Time Resolved Laser-Induced Spectrofluorometry (TRLIS) has been used for actinides trace analysis and complexation analysis in the nuclear fuel cycle. Results obtained in the different fields such as in geology, in the Purex process, in the environment, in the medical and in waste storage assessment are presented. 4 figs., 6 refs

Study of time-critical diagnostic method for emergency operation of nuclear power plant

International Nuclear Information System (INIS)

Gofuku, A.; Yoshikawa, H.; Itoh, K.; Wakabayashi, J.

1986-01-01

In order to support the emergency operation of nuclear power plant, the method of time-critical diagnostic plant analyzer has been investigated. The conception of the emergency operation support center is proposed and two types of plant analyzer may be installed in this center. One analyzer is a real-time tracking simulation code using the observed signals and another is a fast trend-prediction code. A real-time tracking code, TOKRAC, has been developed for analyzing the PWR primary loop thermo-hydraulics at SBLOCA, and the applicability of this code was examined by the numerical experiments for the initial phase transient of both TMI-2 accident and 6% coldleg SBLOCA of a Westinghouse-type PWR plant. The results showed that fairly good tracking was carried out by TOKRAC. The CPU time of TOKRAC was about 12-14 percent of real-time

CPU time reduction strategies for the Lambda modes calculation of a nuclear power reactor

Energy Technology Data Exchange (ETDEWEB)

Vidal, V.; Garayoa, J.; Hernandez, V. [Universidad Politecnica de Valencia (Spain). Dept. de Sistemas Informaticos y Computacion; Navarro, J.; Verdu, G.; Munoz-Cobo, J.L. [Universidad Politecnica de Valencia (Spain). Dept. de Ingenieria Quimica y Nuclear; Ginestar, D. [Universidad Politecnica de Valencia (Spain). Dept. de Matematica Aplicada

1997-12-01

In this paper, we present two strategies to reduce the CPU time spent in the lambda modes calculation for a realistic nuclear power reactor.The discretization of the multigroup neutron diffusion equation has been made using a nodal collocation method, solving the associated eigenvalue problem with two different techniques: the Subspace Iteration Method and Arnoldi`s Method. CPU time reduction is based on a coarse grain parallelization approach together with a multistep algorithm to initialize adequately the solution. (author). 9 refs., 6 tabs.

Just in Time DSA-The Hanford Nuclear Safety Basis Strategy

Energy Technology Data Exchange (ETDEWEB)

Olinger, S. J.; Buhl, A. R.

2002-02-26

The U.S. Department of Energy, Richland Operations Office (RL) is responsible for 30 hazard category 2 and 3 nuclear facilities that are operated by its prime contractors, Fluor Hanford Incorporated (FHI), Bechtel Hanford, Incorporated (BHI) and Pacific Northwest National Laboratory (PNNL). The publication of Title 10, Code of Federal Regulations, Part 830, Subpart B, Safety Basis Requirements (the Rule) in January 2001 imposed the requirement that the Documented Safety Analyses (DSA) for these facilities be reviewed against the requirements of the Rule. Those DSA that do not meet the requirements must either be upgraded to satisfy the Rule, or an exemption must be obtained. RL and its prime contractors have developed a Nuclear Safety Strategy that provides a comprehensive approach for supporting RL's efforts to meet its long term objectives for hazard category 2 and 3 facilities while also meeting the requirements of the Rule. This approach will result in a reduction of the total number of safety basis documents that must be developed and maintained to support the remaining mission and closure of the Hanford Site and ensure that the documentation that must be developed will support: compliance with the Rule; a ''Just-In-Time'' approach to development of Rule-compliant safety bases supported by temporary exemptions; and consolidation of safety basis documents that support multiple facilities with a common mission (e.g. decontamination, decommissioning and demolition [DD&D], waste management, surveillance and maintenance). This strategy provides a clear path to transition the safety bases for the various Hanford facilities from support of operation and stabilization missions through DD&D to accelerate closure. This ''Just-In-Time'' Strategy can also be tailored for other DOE Sites, creating the potential for large cost savings and schedule reductions throughout the DOE complex.

Just in Time DSA the Hanford Nuclear Safety Basis Strategy

Energy Technology Data Exchange (ETDEWEB)

JACKSON, M.W.

2002-06-01

The U.S. Department of Energy, Richland Operations Office (RL) is responsible for 30 hazard category 2 and 3 nuclear facilities that are operated by its prime contractors, Fluor Hanford, Incorporated (FHI), Bechtel Hanford, Incorporated (BHI) and Pacific Northwest National Laboratory (PNNL). The publication of Title 10, Code of Federal Regulations, Part 830, Subpart B, Safely Basis Requirements (the Rule) in January 2001 requires that the Documented Safety Analyses (DSA) for these facilities be reviewed against the requirements of the Rule. Those DSAs that do not meet the requirements must either be upgraded to satisfy the Rule, or an exemption must be obtained. RL and its prime contractors have developed a Nuclear Safety Strategy that provides a comprehensive approach for supporting RL's efforts to meet its long-term objectives for hazard category 2 and 3 facilities while also meeting the requirements of the Rule. This approach will result in a reduction of the total number of safety basis documents that must be developed and maintained to support the remaining mission and closure of the Hanford Site and ensure that the documentation that must be developed will support: Compliance with the Rule; A ''Just-In-Time'' approach to development of Rule-compliant safety bases supported by temporary exemptions; and Consolidation of safety basis documents that support multiple facilities with a common mission (e.g. decontamination, decommissioning and demolition [DD&D], waste management, surveillance and maintenance). This strategy provides a clear path to transition the safety bases for the various Hanford facilities from support of operation and stabilization missions through DD&D to accelerate closure. This ''Just-In-Time'' Strategy can also be tailored for other DOE Sites, creating the potential for large cost savings and schedule reductions throughout the DOE complex.

Just in Time DSA the Hanford Nuclear Safety Basis Strategy

International Nuclear Information System (INIS)

JACKSON, M.W.

2002-01-01

The U.S. Department of Energy, Richland Operations Office (RL) is responsible for 30 hazard category 2 and 3 nuclear facilities that are operated by its prime contractors, Fluor Hanford, Incorporated (FHI), Bechtel Hanford, Incorporated (BHI) and Pacific Northwest National Laboratory (PNNL). The publication of Title 10, Code of Federal Regulations, Part 830, Subpart B, Safely Basis Requirements (the Rule) in January 2001 requires that the Documented Safety Analyses (DSA) for these facilities be reviewed against the requirements of the Rule. Those DSAs that do not meet the requirements must either be upgraded to satisfy the Rule, or an exemption must be obtained. RL and its prime contractors have developed a Nuclear Safety Strategy that provides a comprehensive approach for supporting RL's efforts to meet its long-term objectives for hazard category 2 and 3 facilities while also meeting the requirements of the Rule. This approach will result in a reduction of the total number of safety basis documents that must be developed and maintained to support the remaining mission and closure of the Hanford Site and ensure that the documentation that must be developed will support: Compliance with the Rule; A ''Just-In-Time'' approach to development of Rule-compliant safety bases supported by temporary exemptions; and Consolidation of safety basis documents that support multiple facilities with a common mission (e.g. decontamination, decommissioning and demolition [DD and D], waste management, surveillance and maintenance). This strategy provides a clear path to transition the safety bases for the various Hanford facilities from support of operation and stabilization missions through DD and D to accelerate closure. This ''Just-In-Time'' Strategy can also be tailored for other DOE Sites, creating the potential for large cost savings and schedule reductions throughout the DOE complex

Just in Time DSA-The Hanford Nuclear Safety Basis Strategy

International Nuclear Information System (INIS)

Olinger, S. J.; Buhl, A. R.

2002-01-01

The U.S. Department of Energy, Richland Operations Office (RL) is responsible for 30 hazard category 2 and 3 nuclear facilities that are operated by its prime contractors, Fluor Hanford Incorporated (FHI), Bechtel Hanford, Incorporated (BHI) and Pacific Northwest National Laboratory (PNNL). The publication of Title 10, Code of Federal Regulations, Part 830, Subpart B, Safety Basis Requirements (the Rule) in January 2001 imposed the requirement that the Documented Safety Analyses (DSA) for these facilities be reviewed against the requirements of the Rule. Those DSA that do not meet the requirements must either be upgraded to satisfy the Rule, or an exemption must be obtained. RL and its prime contractors have developed a Nuclear Safety Strategy that provides a comprehensive approach for supporting RL's efforts to meet its long term objectives for hazard category 2 and 3 facilities while also meeting the requirements of the Rule. This approach will result in a reduction of the total number of safety basis documents that must be developed and maintained to support the remaining mission and closure of the Hanford Site and ensure that the documentation that must be developed will support: compliance with the Rule; a ''Just-In-Time'' approach to development of Rule-compliant safety bases supported by temporary exemptions; and consolidation of safety basis documents that support multiple facilities with a common mission (e.g. decontamination, decommissioning and demolition [DD and D], waste management, surveillance and maintenance). This strategy provides a clear path to transition the safety bases for the various Hanford facilities from support of operation and stabilization missions through DD and D to accelerate closure. This ''Just-In-Time'' Strategy can also be tailored for other DOE Sites, creating the potential for large cost savings and schedule reductions throughout the DOE complex

Interrelationship between nuclear safety, safeguards and nuclear security

International Nuclear Information System (INIS)

Irie, Kazutomo

2007-01-01

As preventive activities against danger within nuclear systems, three major areas exist; nuclear safety, safeguards and nuclear security. Considering the purpose of these activities, to prevent non-peaceful use is common in nuclear security in general and safeguards. At the same time, measures against sabotage, one of the subcategory in nuclear security, is similar to nuclear safety in aiming at preventing nuclear accidents. When taking into account the insider issues in nuclear security, the distinction between measures against sabotage and nuclear safety becomes ambiguous. Similarly, the distinction between measures against theft, another subcategory in nuclear security, and safeguards also becomes vague. These distinctions are influenced by psychological conditions of members in nuclear systems. Members who have the intention to make nuclear systems dangerous to human society shall be the 'enemy' to nuclear systems and thus be the target for nuclear security. (author)

Time for nuclear to hold its nerve at this pivotal time for the industry

International Nuclear Information System (INIS)

Shepherd, John

2017-01-01

Recent weeks have been tough for the world's nuclear energy industry. The nuclear industry has seen setbacks before. And it is the nature of this inter-connected global industry to find itself in the international media spotlight when ''bad news'' strikes. The task for the industry now is to pick itself up and face the economic challenges head-on. As one English proverb notes, ''fortune favours the brave''.

In-situ measurement of response time of RTDs and pressure transmitters in nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.; Riner, J.L.

1993-01-01

Response time measurements are performed once every fuel cycle on most safety-related temperature and pressure sensors in a majority of nuclear power plants in the US. This paper provides a review of the methods that are used for these measurements. The methods are referred to as the Loop Current Step Response (LCSR) test, which is used for response time testing of temperature sensors, and noise analysis and power interrupt (PI) tests, which are used for response time testing of pressure, level, and flow transmitters

Modeling and Control of a Large Nuclear Reactor A Three-Time-Scale Approach

CERN Document Server

Shimjith, S R; Bandyopadhyay, B

2013-01-01

Control analysis and design of large nuclear reactors requires a suitable mathematical model representing the steady state and dynamic behavior of the reactor with reasonable accuracy. This task is, however, quite challenging because of several complex dynamic phenomena existing in a reactor. Quite often, the models developed would be of prohibitively large order, non-linear and of complex structure not readily amenable for control studies. Moreover, the existence of simultaneously occurring dynamic variations at different speeds makes the mathematical model susceptible to numerical ill-conditioning, inhibiting direct application of standard control techniques. This monograph introduces a technique for mathematical modeling of large nuclear reactors in the framework of multi-point kinetics, to obtain a comparatively smaller order model in standard state space form thus overcoming these difficulties. It further brings in innovative methods for controller design for systems exhibiting multi-time-scale property,...

Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 113: Reactor Maintenance, Assembly, and Disassembly Building Nevada Test Site, Nevada

Energy Technology Data Exchange (ETDEWEB)

J. L. Smith

2001-01-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure in place of Corrective Action Unit (CAU) 113 Area 25 Reactor Maintenance, Assembly, and Disassembly Facility (R-MAD). CAU 113 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (NDEP, 1996). The CAU is located in Area 25 of the Nevada Test Site (NTS) and consists of Corrective Action Site (CAS) 25-04-01, R-MAD Facility (Figures 1-2). This plan provides the methodology for closure in place of CAU 113. The site contains radiologically impacted and hazardous material. Based on preassessment field work, there is sufficient process knowledge to close in place CAU 113 using the SAFER process. At a future date when funding becomes available, the R-MAD Building (25-3110) will be demolished and inaccessible radiologic waste will be properly disposed in the Area 3 Radiological Waste Management Site (RWMS).

Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 113: Reactor Maintenance, Assembly, and Disassembly Building Nevada Test Site, Nevada

International Nuclear Information System (INIS)

Smith, J. L.

2001-01-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure in place of Corrective Action Unit (CAU) 113 Area 25 Reactor Maintenance, Assembly, and Disassembly Facility (R-MAD). CAU 113 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (NDEP, 1996). The CAU is located in Area 25 of the Nevada Test Site (NTS) and consists of Corrective Action Site (CAS) 25-04-01, R-MAD Facility (Figures 1-2). This plan provides the methodology for closure in place of CAU 113. The site contains radiologically impacted and hazardous material. Based on preassessment field work, there is sufficient process knowledge to close in place CAU 113 using the SAFER process. At a future date when funding becomes available, the R-MAD Building (25-3110) will be demolished and inaccessible radiologic waste will be properly disposed in the Area 3 Radiological Waste Management Site (RWMS)

Wood cell-wall structure requires local 2D-microtubule disassembly by a novel plasma membrane-anchored protein.

Science.gov (United States)

Oda, Yoshihisa; Iida, Yuki; Kondo, Yuki; Fukuda, Hiroo

2010-07-13

Plant cells have evolved cortical microtubules, in a two-dimensional space beneath the plasma membrane, that regulate patterning of cellulose deposition. Although recent studies have revealed that several microtubule-associated proteins facilitate self-organization of transverse cortical microtubules, it is still unknown how diverse patterns of cortical microtubules are organized in different xylem cells, which are the major components of wood. Using our newly established in vitro xylem cell differentiation system, we found that a novel microtubule end-tracking protein, microtubule depletion domain 1 (MIDD1), was anchored to distinct plasma membrane domains and promoted local microtubule disassembly, resulting in pits on xylem cell walls. The introduction of RNA interference for MIDD1 resulted in the failure of local microtubule depletion and the formation of secondary walls without pits. Conversely, the overexpression of MIDD1 reduced microtubule density. MIDD1 has two coiled-coil domains for the binding to microtubules and for the anchorage to plasma membrane domains, respectively. Combination of the two coils caused end tracking of microtubules during shrinkage and suppressed their rescue events. Our results indicate that MIDD1 integrates spatial information in the plasma membrane with cortical microtubule dynamics for determining xylem cell wall pattern. Copyright 2010 Elsevier Ltd. All rights reserved.

High-Frequency Dynamic Nuclear Polarization in the Nuclear Rotating Frame

DEFF Research Database (Denmark)

Farrar, C. T.; Hall, D. A.; Gerfen, G. J.

2000-01-01

A proton dynamic nuclear polarization (DNP) NMR signal enhancement (ϵ) close to thermal equilibrium, ϵ = 0.89, has been obtained at high field (B0 = 5 T, νepr = 139.5 GHz) using 15 mM trityl radical in a 40:60 water/glycerol frozen solution at 11 K. The electron-nuclear polarization transfer...... is performed in the nuclear rotating frame with microwave irradiation during a nuclear spin-lock pulse. The growth of the signal enhancement is governed by the rotating frame nuclear spin–lattice relaxation time (T1ρ), which is four orders of magnitude shorter than the nuclear spin–lattice relaxation time (T1n......). Due to the rapid polarization transfer in the nuclear rotating frame the experiment can be recycled at a rate of 1/T1ρ and is not limited by the much slower lab frame nuclear spin–lattice relaxation rate (1/T1n). The increased repetition rate allowed in the nuclear rotating frame provides an effective...

Disassembly of actin structures by nanosecond pulsed electric field is a downstream effect of cell swelling.

Science.gov (United States)

Pakhomov, Andrei G; Xiao, Shu; Pakhomova, Olga N; Semenov, Iurii; Kuipers, Marjorie A; Ibey, Bennett L

2014-12-01

Disruption of the actin cytoskeleton structures was reported as one of the characteristic effects of nanosecond-duration pulsed electric field (nsPEF) in both mammalian and plant cells. We utilized CHO cells that expressed the monomeric fluorescent protein (mApple) tagged to actin to test if nsPEF modifies the cell actin directly or as a consequence of cell membrane permeabilization. A train of four 600-ns pulses at 19.2 kV/cm (2 Hz) caused immediate cell membrane poration manifested by YO-PRO-1 dye uptake, gradual cell rounding and swelling. Concurrently, bright actin features were replaced by dimmer and uniform fluorescence of diffuse actin. To block the nsPEF-induced swelling, the bath buffer was isoosmotically supplemented with an electropore-impermeable solute (sucrose). A similar addition of a smaller, electropore-permeable solute (adonitol) served as a control. We demonstrated that sucrose efficiently blocked disassembly of actin features by nsPEF, whereas adonitol did not. Sucrose also attenuated bleaching of mApple-tagged actin in nsPEF-treated cells (as integrated over the cell volume), although did not fully prevent it. We conclude that disintegration of the actin cytoskeleton was a result of cell swelling, which, in turn, was caused by cell permeabilization by nsPEF and transmembrane diffusion of solutes which led to the osmotic imbalance. Copyright © 2014 Elsevier B.V. All rights reserved.

Real-time computing in environmental monitoring of a nuclear power plant

International Nuclear Information System (INIS)

Deme, S.; Lang, E.; Nagy, Gy.

1987-06-01

A real-time computing method is described for calculating the environmental radiation exposure due to a nuclear power plant both at normal operation and at accident. The effects of the Gaussian plume are recalculated in every ten minutes based on meteorological parameters measured at a height of 20 and 120 m as well as on emission data. At normal operation the quantity of radioactive materials released through the stacks is measured and registered while, at an accident, the source strength is unknown and the calculated relative data are normalized to the values measured at the eight environmental monitoring stations. The doses due to noble gases and to dry and wet deposition as well as the time integral of 131 I concentration are calculated and stored by a professional personal computer for 720 points of the environment of 11 km radius. (author)

Dismantling and removal of the Niederaichbach nuclear power plant (KKN) to the 'Green Field'. Final report

International Nuclear Information System (INIS)

Valencia, L.; Prechtl, E.

1998-04-01

The major objective of the present project consisted in the complete dismantling and removal of the Niederaichbach nuclear power plant (KKN), ranging from the state of safe enclosure to re-establishing the original state of vegetation of the site (so-called 'green field'). By reaching this objective, principle feasibility of the complete removal of a power reactor was demonstrated. In addition, considerable experience has been gained with regard to the execution of all phases of such a complex project and project optimization. The following phases of the project can be distinguished: - Licensing procedure - dismantling of the inactive, contaminated and activated plant sections - disassembly of the activated building structures and decontamination of the buildings - demolition (conventional) of the buildings and recultivation of the site. Moreover, the project included the work performed under the direct supervision of the licensing authority, comprehensive radiation protection activities, the solution of waste management problems and the respective public relations work. (orig./MM) [de

Time-dependent, many-body scattering theory and nuclear reaction applications

International Nuclear Information System (INIS)

Levin, F.S.

1977-01-01

The channel component state form of the channel coupling array theory of many-body scattering is briefly reviewed. These states obey a non-hermitian matrix equation whose exact solution yields the Schroedinger eigenstates, eigenvalues and scattering amplitudes. A time-dependent formulation of the theory is introduced in analogy to the time-dependent Schrodinger equation and several consequences of the development are noted. These include an interaction picture, a single (matrix) S operator, and the usual connection between the t = 0 time-dependent and the time-independent scattering states. Finally, the channel component states (psi/sub j/) are shown to have the useful property that only psi/sub j/ has (two-body) outgoing waves in channel j: psi/sub m/, m not equal to j, is asymptotically zero in two-body channel j. This formalism is then considered as a means for direct nuclear reaction analysis. Typical bound state approximations are introduced and it is shown that a DWBA amplitude occurs in only one channel. The non-time-reversal invariance of the approximate theory is noted. Results of calculations based on a realistic model for two sets of light-ion induced, one-particle transfer reactions are discussed and compared with the coupled reaction channel (CRC) results using the CRC procedure of Cotanch and Vincent. Angular distributions for the two calculational methods are found to be similar in shape and magnitude. Higher ordercorrections are small as are time-reversal non-invariant effects. Post- and prior-type CRC calculations are seen to differ; the latter are closer to the full CRC results

Safeguards and nuclear forensics

International Nuclear Information System (INIS)

Gangotra, Suresh

2016-01-01

Nuclear Safeguards is the detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons, or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by early detection. Safeguards implementation involves nuclear material accounting and containment and surveillance measures. The safeguards are implemented in nuclear facilities by the states, or agencies and International Atomic Energy Agency (IAEA). The measures for the safeguards include nuclear material Accounting (NUMAC) and Containment and surveillance systems. In recent times, there have been advances in safeguards like Near Real Time Monitoring (NRTM), Dynamic Nuclear Material Accounting (DNMA), Safeguards-by-Design (SBD), satellite imagery, information from open sources, remote monitoring etc

Time for nuclear to hold its nerve at this pivotal time for the industry

Energy Technology Data Exchange (ETDEWEB)

Shepherd, John [nuclear 24, Redditch (United Kingdom)

2017-05-15

Recent weeks have been tough for the world's nuclear energy industry. The nuclear industry has seen setbacks before. And it is the nature of this inter-connected global industry to find itself in the international media spotlight when ''bad news'' strikes. The task for the industry now is to pick itself up and face the economic challenges head-on. As one English proverb notes, ''fortune favours the brave''.

Research on real-time simulation test for upgrades of digital I and C system in nuclear power plant

International Nuclear Information System (INIS)

Shi Ji; Jiang Mingyu; Ma Yunqin

2005-01-01

The developing trend that digital instrument and control (I and C) system will supplant traditional analog I and C system in nuclear power plant is emphasized. This paper introduces mathematical model of steam generator of full scope simulator for nuclear power plant. The independent real-time simulation system, which forms the interactive closed loop together with the steam generator control system, can be applied to provide a simulation target for upgrades of instrument and control system and the research of control schemes. At the same time, a simulation method for this purpose is presented in this paper. In this method all of the hardware and software are composed of real distributed control system except the model of controlled object. This will not only create favorable conditions for commissioning on site in the future, but also give a theoretical analysis for upgrades of digital I and C system in nuclear power plant. (authors)

Russian Federal nuclear center facilities for nuclear spectroscopy investigations

International Nuclear Information System (INIS)

Ilkaev, R.I.; Punin, V.T.; Abramovich, S.N.

2001-01-01

Russian Federal Nuclear Center facilities for Spectroscopy investigation in the field of nuclear spectroscopy are described. Here are discussed basic properties of used radiation sources, facilities and technologies for target material production and manufacture of targets from rare, high-toxic or radioactive materials. Here are also reported basic features of complex detector systems and technologies for manufacture of scintillation detectors with special properties VNIIEF was founded as a weapons laboratory. The development of nuclear and thermonuclear bombs was followed by a wide complex of nuclear-physics investigations. Naturally, data on nuclear-physics properties of active and structure materials being part of nuclear weapons were of greatest interest.At the initial stage of work on the development of nuclear weapons the information on nuclear constants of materials including the most important neutron ones was rather scant. Data published in scientific literature had low exactness and were insecure. Results of measurements sometimes differed greatly by various groups of investigators. At the same time it was clear that, for example, a 1,5-times mistake in the fission cross-section could cause a several times mistake in the choice of uranium or plutonium mass, which is necessary for the bomb development. These circumstances determined importance of the nuclear-physics investigations. Demands on knowledge of process details occurring inside the nuclei conditioned by a problem of developing and improving of nuclear weapons and atomic power are rather limited. However, the further development of nuclear industry has proved a well-known point that this knowledge being accumulated forms a critical mass that leads to an explosive situation in the elaboration both of ideological and technological aspects of these problems. It is the tendency of inside development of nuclear science that has conditioned preparedness of knowledge about intranuclear processes for

Delay consequencies in the construction time-schedule of nuclear power plants in relation to its safety and quality

International Nuclear Information System (INIS)

Recalde, J.A.

1991-01-01

An important delay in the construction time-schedule of a Nuclear Power Plant affects its safety and quality. This mainly occurs as a consequence of four reasons: discontinuity of the personnel working for the project; discontinuities of project suppliers; new safety and quality concepts; long-term storage. This work analyses each of the above reasons so as to foresee countermeasures to garantee the non deterioration of a Nuclear Power Plant. (author)

A scheme for the evaluation of dominant time-eigenvalues of a nuclear reactor

International Nuclear Information System (INIS)

Modak, R.S.; Gupta, Anurag

2007-01-01

This paper presents a scheme to obtain the fundamental and few dominant solutions of the prompt time eigenvalue problem (referred to as α-eigenvalue problem) for a nuclear reactor using multi-group neutron diffusion theory. The scheme is based on the use of an algorithm called Orthomin(1). This algorithm was originally proposed by Suetomi and Sekimoto [Suetomi, E., Sekimoto, H., 1991. Conjugate gradient like methods and their application to eigenvalue problems for neutron diffusion equations. Ann. Nucl. Energy 18 (4), 205-227] to obtain the fundamental K-eigenvalue (K-effective) of nuclear reactors. Recently, it has been shown that the algorithm can be used to obtain the further dominant K-modes also. Since α-eigenvalue problem is usually more difficult to solve than the K-eigenvalue problem, an attempt has been made here to use Orthomin(1) for its solution. Numerical results are given for realistic 3-D test case

Treatment of spent nuclear fuel L-basin sludge

International Nuclear Information System (INIS)

Westover, B.L.; Oji, L.N.; Martin, H.L.; Nichols, D.M.

1997-01-01

Each production reactor at the DOE Savannah River Site (SRS) has a disassembly basin whose primary purpose is to cool irradiated production fuel and target. The disassembly basins also provide a shielded environment for personnel. Material has historically resided in the basins for 6 to 12 months. Increases in basin storage time have occurred, and have caused the buildup of a sludge layer on the basin floors to be greater than historical levels. The sludge is composed primarily of inorganic oxide and hydroxide corrosion products. The sludge layer has increased the turbidity and conductivity of the basin water, contributed to fuel corrosion, and has impacted fuel handling operations. Initial characterization of the sludge indicates that it is a low-level radioactive aqueous waste. This evaluation looked at methods to separate the sludge into its liquid and solid phases. The experimental data obtained during this evaluation clearly shows that a filtration-based approach to dewatering using an Oberlin pressure filtration unit at SRS is possible. This research task was to identify and optimize filtration and settling parameters pursuant sludge processing. The research specifically addressed: choice of filter aid, filter aid to sludge ratio, choice and dosage of polymer flocculation and settling agents, and the determination of Kynch curve settling parameters. Two commercial perlite filter-aids were identified as the most suitable. Of 11 water soluble flocculating polymers evaluated, 3 cationic commercial types formed stable flocs in the screening tests. In low doses, the flocculating polymers also enhanced sludge particle settling and decreased filtrate turbidity. The filtration cake from the sludge can be solidified to meet waste acceptance and storage criteria. However, the conductivity of the remaining filtrate does not meet Reactor Area Return Water criteria and may require a secondary filtration process. 2 refs., 14 figs., 5 tabs

Nuclear morphometry in histological specimens of canine prostate cancer: Correlation with histological subtypes, Gleason score, methods of collection and survival time.

Science.gov (United States)

Di Donato, Guido; Laufer-Amorim, Renée; Palmieri, Chiara

2017-10-01

Ten normal prostates, 22 benign prostatic hyperplasia (BPH) and 29 prostate cancer (PC) were morphometrically analyzed with regard to mean nuclear area (MNA), mean nuclear perimeter (MNP), mean nuclear diameter (MND), coefficient of variation of the nuclear area (NACV), mean nuclear diameter maximum (MDx), mean nuclear diameter minimum (MDm), mean nuclear form ellipse (MNFe) and form factor (FF). The relationship between nuclear morphometric parameters and histological type, Gleason score, methods of sample collection, presence of metastases and survival time of canine PC were also investigated. Overall, nuclei from neoplastic cells were larger, with greater variation in nuclear size and shape compared to normal and hyperplastic cells. Significant differences were found between more (small acinar/ductal) and less (cribriform, solid) differentiated PCs with regard to FF (pnuclear morphometric analysis in combination with Gleason score can help in canine prostate cancer grading, thus contributing to the establishment of a more precise prognosis and patient's management. Copyright © 2017 Elsevier Ltd. All rights reserved.

75 FR 41850 - Amended Notice of Intent to Modify the Scope of the Surplus Plutonium Disposition Supplemental...

Science.gov (United States)

2010-07-19

... and packaging capabilities, including direct metal oxidation, to fulfill plutonium storage..., disassemble nuclear weapons pits (a weapons component) and convert the plutonium metal to an oxide form for fabrication into mixed uranium-plutonium oxide (MOX) reactor fuel in the Mixed Oxide Fuel Fabrication Facility...

Application of an expert system for real time diagnosis of the limiting conditions for operation in nuclear power plants

International Nuclear Information System (INIS)

Paiva, Gustavo Varanda; Schirru, Roberto

2015-01-01

In the history of nuclear power plants operation safety is an important factor to be considered and for this, the use of resistant materials and the application of redundant systems are used to make a plant with high reliability. Through the acquisition of experience with time and accidents that happened in the area, it was observed that the importance of creating methods that simplify the operator work in making decisions in accidents scenarios is an important factor in ensuring the safety of nuclear power plants. This work aims to create a program made with the Python language, which with the use of an expert systems be able to apply, in real time, the rules contained in the Limiting Conditions for Operation (LCO) and tell to the operator the occurrence of any limiting conditions and the occurrence of failure to perform the require actions in the time to completion. The generic structure used to represent the knowledge of the expert system was a fault tree where the events of this tree are objects in program. To test the accuracy of the program a simplified model of a fault tree was used that represents the LCO of the nuclear power station named Central Nuclear Almirante Alvaro Alberto 1. With the results obtained in the analysis of the simplified model it was observed a significant reduction in the time to identify the LCO, showing that the implementation of this program to more complex models of fault tree would be viable.(author)

Application of an expert system for real time diagnosis of the limiting conditions for operation in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Paiva, Gustavo Varanda; Schirru, Roberto, E-mail: gustavopaiva@poli.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (brazil). Programa de Engenharia Nuclear

2015-07-01

In the history of nuclear power plants operation safety is an important factor to be considered and for this, the use of resistant materials and the application of redundant systems are used to make a plant with high reliability. Through the acquisition of experience with time and accidents that happened in the area, it was observed that the importance of creating methods that simplify the operator work in making decisions in accidents scenarios is an important factor in ensuring the safety of nuclear power plants. This work aims to create a program made with the Python language, which with the use of an expert systems be able to apply, in real time, the rules contained in the Limiting Conditions for Operation (LCO) and tell to the operator the occurrence of any limiting conditions and the occurrence of failure to perform the require actions in the time to completion. The generic structure used to represent the knowledge of the expert system was a fault tree where the events of this tree are objects in program. To test the accuracy of the program a simplified model of a fault tree was used that represents the LCO of the nuclear power station named Central Nuclear Almirante Alvaro Alberto 1. With the results obtained in the analysis of the simplified model it was observed a significant reduction in the time to identify the LCO, showing that the implementation of this program to more complex models of fault tree would be viable.(author)

Nuclear Waste Facing the Test of Time: The Case of the French Deep Geological Repository Project.

Science.gov (United States)

Poirot-Delpech, Sophie; Raineau, Laurence

2016-12-01

The purpose of this article is to consider the socio-anthropological issues raised by the deep geological repository project for high-level, long-lived nuclear waste. It is based on fieldwork at a candidate site for a deep storage project in eastern France, where an underground laboratory has been studying the feasibility of the project since 1999. A project of this nature, based on the possibility of very long containment (hundreds of thousands of years, if not longer), involves a singular form of time. By linking project performance to geology's very long timescale, the project attempts "jump" in time, focusing on a far distant future, without understanding it in terms of generations. But these future generations remain measurements of time on the surface, where the issue of remembering or forgetting the repository comes to the fore. The nuclear waste geological storage project raises questions that neither politicians nor scientists, nor civil society, have ever confronted before. This project attempts to address a problem that exists on a very long timescale, which involves our responsibility toward generations in the far future.

High reliable and Real-time Data Communication Network Technology for Nuclear Power Plant

International Nuclear Information System (INIS)

Jeong, K. I.; Lee, J. K.; Choi, Y. R.; Lee, J. C.; Choi, Y. S.; Cho, J. W.; Hong, S. B.; Jung, J. E.; Koo, I. S.

2008-03-01

As advanced digital Instrumentation and Control (I and C) system of NPP(Nuclear Power Plant) are being introduced to replace analog systems, a Data Communication Network(DCN) is becoming the important system for transmitting the data generated by I and C systems in NPP. In order to apply the DCNs to NPP I and C design, DCNs should conform to applicable acceptance criteria and meet the reliability and safety goals of the system. As response time is impacted by the selected protocol, network topology, network performance, and the network configuration of I and C system, DCNs should transmit a data within time constraints and response time required by I and C systems to satisfy response time requirements of I and C system. To meet these requirements, the DCNs of NPP I and C should be a high reliable and real-time system. With respect to high reliable and real-time system, several reports and techniques having influences upon the reliability and real-time requirements of DCNs are surveyed and analyzed

Construction of overseas nuclear power plants for first time by Japanese industry

International Nuclear Information System (INIS)

Maruyama, Tohru; Naruse, Yoshihiro; Yabuta, Hitoshi

2010-01-01

In response to the worldwide demand for stable energy supplies and the reduction of greenhouse gas emissions, nuclear power plant construction projects have been expanding on a global scale. Even in the United States, where no nuclear power plants have been constructed over the past 30 years, there are plans for the construction of more than 30 plants. Toshiba has been awarded a contract for a nuclear power plant construction project in the U.S., the first case of overseas nuclear power plant construction by Japanese industry. Toshiba America Nuclear Energy Corporation (TANE), the first U.S. subsidiary in our nuclear business, located in Charlotte, North Carolina, is engaged in this globally prominent project, applying various technologies and know-how that we have cultivated over many years of experience in developing and constructing nuclear power plants in Japan and adapting them to U.S. business practices, laws, and regulations. (author)

Regulatory assembly of the vacuolar proton pump VoV1-ATPase in yeast cells by FLIM-FRET

Science.gov (United States)

Ernst, Stefan; Batisse, Claire; Zarrabi, Nawid; Böttcher, Bettina; Börsch, Michael

2010-02-01

We investigate the reversible disassembly of VOV1-ATPase in life yeast cells by time resolved confocal FRET imaging. VOV1-ATPase in the vacuolar membrane pumps protons from the cytosol into the vacuole. VOV1-ATPase is a rotary biological nanomotor driven by ATP hydrolysis. The emerging proton gradient is used for secondary transport processes as well as for pH and Ca2+ homoeostasis in the cell. The activity of the VOV1-ATPase is regulated through assembly / disassembly processes. During starvation the two parts of VOV1-ATPase start to disassemble. This process is reversed after addition of glucose. The exact mechanisms are unknown. To follow the disassembly / reassembly in vivo we tagged two subunits C and E with different fluorescent proteins. Cellular distributions of C and E were monitored using a duty cycle-optimized alternating laser excitation scheme (DCO-ALEX) for time resolved confocal FRET-FLIM measurements.

Disassembly of microtubules and inhibition of neurite outgrowth, neuroblastoma cell proliferation, and MAP kinase tyrosine dephosphorylation by dibenzyl trisulphide.

Science.gov (United States)

Rösner, H; Williams, L A; Jung, A; Kraus, W

2001-08-22

Dibenzyl trisulphide (DTS), a main lipophilic compound in Petiveria alliacea L. (Phytolaccaceae), was identified as one of the active immunomodulatory compounds in extracts of the plant. To learn more about its biological activities and molecular mechanisms, we conducted one-dimensional NMR interaction studies with bovine serum albumin (BSA) and tested DTS and related compounds in two well-established neuronal cell-and-tissue culture systems. We found that DTS preferentially binds to an aromatic region of BSA which is rich in tyrosyl residues. In SH-SY5Y neuroblastoma cells, DTS attenuates the dephosphorylation of tyrosyl residues of MAP kinase (erk1/erk2). In the same neuroblastoma cell line and in Wistar 38 human lung fibroblasts, DTS causes a reversible disassembly of microtubules, but it did not affect actin dynamics. Probably due to the disruption of the microtubule dynamics, DTS also inhibits neuroblastoma cell proliferation and neurite outgrowth from spinal cord explants. Related dibenzyl compounds with none, one, or two sulphur atoms were found to be significantly less effective. These data confirmed that the natural compound DTS has a diverse spectrum of biological properties, including cytostatic and neurotoxic actions in addition to immunomodulatory activities.

The development of the time dependence of the nuclear EMP electric field

International Nuclear Information System (INIS)

Eng, C.

2009-01-01

The nuclear electromagnetic pulse (EMP) electric field calculated with the legacy code CHAP is compared with the field given by an integral solution of Maxwell's equations, also known as the Jefimenko equation, to aid our current understanding on the factors that affect the time dependence of the EMP. For a fair comparison the CHAP current density is used as a source in the Jefimenko equation. At first, the comparison is simplified by neglecting the conduction current and replacing the standard atmosphere with a constant density air slab. The simplicity of the resultant current density aids in determining the factors that affect the rise, peak and tail of the EMP electric field versus time. The three dimensional nature of the radiating source, i.e. sources off the line-of-sight, and the time dependence of the derivative of the current density with respect to time are found to play significant roles in shaping the EMP electric field time dependence. These results are found to hold even when the conduction current and the standard atmosphere are properly accounted for. Comparison of the CHAP electric field with the Jefimenko electric field offers a direct validation of the high-frequency/outgoing wave approximation.

Real-time graphic display utility for nuclear safety applications

International Nuclear Information System (INIS)

Yang, S.; Huang, X.; Taylor, J.; Stevens, J.; Gerardis, T.; Hsu, A.; McCreary, T.

2006-01-01

With the increasing interests in the nuclear energy, new nuclear power plants will be constructed and licensed, and older generation ones will be upgraded for assuring continuing operation. The tendency of adopting the latest proven technology and the fact of older parts becoming obsolete have made the upgrades imperative. One of the areas for upgrades is the older CRT display being replaced by the latest graphics displays running under modern real time operating system (RTOS) with safety graded modern computer. HFC has developed a graphic display utility (GDU) under the QNX RTOS. A standard off-the-shelf software with a long history of performance in industrial applications, QNX RTOS used for safety applications has been examined via a commercial dedication process that is consistent with the regulatory guidelines. Through a commercial survey, a design life cycle and an operating history evaluation, and necessary tests dictated by the dedication plan, it is reasonably confirmed that the QNX RTOS was essentially equivalent to what would be expected in the nuclear industry. The developed GDU operates and communicates with the existing equipment through a dedicated serial channel of a flat panel controller (FPC) module. The FPC module drives a flat panel display (FPD) monitor. A touch screen mounted on the FPD serves as the normal operator interface with the FPC/FPD monitor system. The GDU can be used not only for replacing older CRTs but also in new applications. The replacement of the older CRT does not disturb the function of the existing equipment. It not only provides modern proven technology upgrade but also improves human ergonomics. The FPC, which can be used as a standalone controller running with the GDU, is an integrated hardware and software module. It operates as a single board computer within a control system, and applies primarily to the graphics display, targeting, keyboard and mouse. During normal system operation, the GDU has two sources of data

Through the Time Tunnel - Clausewitz on Nuclear Deterrence

National Research Council Canada - National Science Library

Studenka, John M

1990-01-01

This essay presents the presumed thoughts and ruminations of Carl von Clausewitz, the great Prussian military strategist, on an article by Bernard Brodie entitled "On Nuclear Weapons: Utility in Nonuse...

Generation of floor spectra compatible time histories for equipment seismic qualification in nuclear power plants

International Nuclear Information System (INIS)

Shyu, Y.-S.; Luh, Gary G.; Blum, Arie

2004-01-01

This paper proposes a procedure for generating floor response spectra compatible time histories used for equipment seismic qualification in nuclear power plants. From the 84th percentile power spectrum density function of an earthquake ensemble of four randomly generated time history motions, a statistically equivalent time history can be obtained by converting the power spectrum density function from the frequency domain into the time domain. With minor modification, if needed, the converted time history will satisfy both the spectral and the power spectrum density enveloping criteria, as required by the USNRC per Revision 2 of the Standard Review Plan, Section 3.7.1. Step-by-step generating procedures and two numerical examples are presented to illustrate the applications of the methodology. (author)

China's nuclear safety regulatory body: The national nuclear safety administration

International Nuclear Information System (INIS)

Zhang Shiguan

1991-04-01

The establishment of an independent nuclear safety regulatory body is necessary for ensuring the safety of nuclear installations and nuclear fuel. Therefore the National Nuclear Safety Administration was established by the state. The aim, purpose, organization structure and main tasks of the Administration are presented. At the same time the practical examples, such as nuclear safety regulation on the Qinshan Nuclear Power Plant, safety review and inspections for the Daya Bay Nuclear Power Plant during the construction, and nuclear material accounting and management system in the nuclear fuel fabrication plant in China, are given in order to demonstrate the important roles having been played on nuclear safety by the Administration after its founding

High-Fidelity Space-Time Adaptive Multiphysics Simulations in Nuclear Engineering

Energy Technology Data Exchange (ETDEWEB)

Solin, Pavel [Univ. of Reno, NV (United States); Ragusa, Jean [Texas A & M Univ., College Station, TX (United States)

2014-03-09

We delivered a series of fundamentally new computational technologies that have the potential to significantly advance the state-of-the-art of computer simulations of transient multiphysics nuclear reactor processes. These methods were implemented in the form of a C++ library, and applied to a number of multiphysics coupled problems relevant to nuclear reactor simulations.

High-Fidelity Space-Time Adaptive Multiphysics Simulations in Nuclear Engineering

International Nuclear Information System (INIS)

Solin, Pavel; Ragusa, Jean

2014-01-01

We delivered a series of fundamentally new computational technologies that have the potential to significantly advance the state-of-the-art of computer simulations of transient multiphysics nuclear reactor processes. These methods were implemented in the form of a C++ library, and applied to a number of multiphysics coupled problems relevant to nuclear reactor simulations.

The Japanese attitude towards nuclear power generation. Changes as seen through time series

International Nuclear Information System (INIS)

Kitada, Atsuko; Hayashi, Chikio

1999-01-01

This study is intended to determine people's attitudes toward nuclear power generation, shedding light on the changed and unchanged structures of attitudes by comparing data on nuclear power generation for 1993 and 1998. Although some nuclear facility accidents occurred during the last five years, public attitudes toward nuclear power generation remain almost the same. For the utilization of nuclear power generation, there was a slight increase in passive affirmation. The percentage of active affirmation was less than 10 percent, but if passive affirmation is included a high percentage exceeding 70 percent acknowledged the utilization of nuclear power. It was found that people's attitudes toward the utilization of nuclear power became slightly more positive in 1998 than in 1993. The difference was found in the general measure of attitudes based on many questions about nuclear power generation, and in the importance and the utility of nuclear power generation including the purpose of nuclear power generation. People are not conscious of the anxiety about nuclear power generation in ordinary life. However, when people were made to think about nuclear power generation, the degree of anxiety increases even if provided with data that prove its safety. On the other hand, it was revealed that the degree of anxiety about nuclear facility accidents remains the same in the last five years, that is, it has not increased, although a growing interest in the disposal and treatment of radioactive wastes was seen. As a result of a comparison of the structure of attitudes, based on the study by Hayashi 1994, it was found that the group that had no interest in nuclear power generation offered the most noticeable features in answering pattern in both 1993 and 1998. Moreover, it was found also that the latter group of respondents were characterized by a little opportunity to have information. A similarity in the relationship between people's attitudes toward nuclear power generation

Development of Real Time Operating System for Safety Grade PLC (POSAFE-Q) for Nuclear Power Plants

International Nuclear Information System (INIS)

Son, Han Seong; Hwang, Sung Jae; Lee, Young Joon; Kim, Chang Hwoi; Lee, Dong Young

2006-01-01

POSAFE-Q is a newly developed programmable logic controller (PLC) in order to apply to digital safety system of nuclear power plants (NPP) according to Nuclear Power Plant safety requirements. POSAFE-Q hardware and software development process, including design, review, verification and validation, and configuration control and quality assurance, satisfies the requirements imposed by 10CFR50, Appendix B. This article introduces a real time operating system pCOS, which is the core of POSAFE-Q. Section 2 describes the structure of pCOS. Section 3 describes a few important features of pCOS, which are necessary to the application for the digital safety system of NPP

Development of Real Time Operating System for Safety Grade PLC (POSAFE-Q) for Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Son, Han Seong [ENESYS, Taejon (Korea, Republic of); Hwang, Sung Jae [POSCON, Seoul (Korea, Republic of); Lee, Young Joon; Kim, Chang Hwoi; Lee, Dong Young [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2006-07-01

POSAFE-Q is a newly developed programmable logic controller (PLC) in order to apply to digital safety system of nuclear power plants (NPP) according to Nuclear Power Plant safety requirements. POSAFE-Q hardware and software development process, including design, review, verification and validation, and configuration control and quality assurance, satisfies the requirements imposed by 10CFR50, Appendix B. This article introduces a real time operating system pCOS, which is the core of POSAFE-Q. Section 2 describes the structure of pCOS. Section 3 describes a few important features of pCOS, which are necessary to the application for the digital safety system of NPP.0.

Real-time neutron radiography at the Iea-R1 m nuclear research reactor

International Nuclear Information System (INIS)

Menezes, M.O. de; Pugliesi, R.; Pereira, M.A.S.; Andrade, M.L.G.

2003-01-01

A LIXI (Light Intensifier X-ray Image) device has been employed in a real-time neutron radiography system. The LIXI is coupled to a video camera and the real-time images can be observed in a TV monitor, and processed in a computer. In order to get the real-time system operational, the neutron radiography facility installed at the IEA-R1 m nuclear research reactor of the IPEN-CNEN/S P has been optimized. The most important improvements were the neutron/gamma ratio, the effective energy of the neutron beam, decrease of the scattered radiation at the irradiation position, and the additional shielding of the video camera. Several one-frame as well as computer processed images are presented. The overall Modulation Transfer Function for the real-time system was obtained from the resolution parameter p = 0:44 +- 0:04 mm; the system sensitivity, evaluated for a Perspex step wedge, was determined and the average value is 0:70 +- 0:09 mm. (author)

K X-rays and nuclear reaction times in the deep inelastic reactions U+U and U+Pb at 7.5 MeV/amu

International Nuclear Information System (INIS)

Stoller, C.

1985-01-01

The K-shell ionisation probability of the heavy reaction products emerging from binary deep inelastic collisions of U + U and U + Pb at 7.5 MeV/amu has been measured as a function of the total kinetic energy loss - Q. After subtraction of the ionisation probability due to internal conversion of γ-rays, a strongly Q-dependent Psub(K) is found, in agreement with theoretical predictions relating the change in ionisation probability to the nuclear sticking time. The deduced nuclear reaction times are in qualitative agreement with predictions from nuclear models of deep inelastic reactions. (orig.)

Nuclear disarmament and the elimination of nuclear dangers

International Nuclear Information System (INIS)

Daerr, Hans-Joachim

2002-01-01

... today's threats to security and stability have become less predictable and require at the same time a joint response. They illustrate the need for a new international order organized around shared values, common norms of behaviour and the rule of law. Disarmament, arms control, and non-proliferation are indispensable elements of this cooperative international order... We have to make sure that the functions that are today attributed to nuclear weapons become dispensable ... Nuclear disarmament is the counterpart of the renunciation of nuclear weapons by non-nuclear-weapons states. This bargain must not be undermined ... The NPT is no licence to perpetuate the status of the nuclear 'haves' versus the nuclear 'have nots.' (author)

Nuclear material control systems for nuclear power plants

International Nuclear Information System (INIS)

1975-06-01

Paragraph 70.51(c) of 10 CFR Part 70 requires each licensee who is authorized to possess at any one time special nuclear material in a quantity exceeding one effective kilogram to establish, maintain, and follow written material control and accounting procedures that are sufficient to enable the licensee to account for the special nuclear material in his possession under license. While other paragraphs and sections of Part 70 provide specific requirements for nuclear material control systems for fuel cycle plants, such detailed requirements are not included for nuclear power reactors. This guide identifies elements acceptable to the NRC staff for a nuclear material control system for nuclear power reactors. (U.S.)

The nuclear in debate: don't we have time to develop acceptable solutions?

International Nuclear Information System (INIS)

1999-01-01

The contributions discuss different issues related to the future of nuclear energy: the nuclear energy in the long term, the possible new options for the fuel cycle, the relationship between nuclear energy and greenhouse effect according to scenarios for the period 2010-2020, how to avoid the nuclear energy technology decline, the way out from nuclear in Germany, and the world electricity production market trends

Gamma spectrometric characterization of short cooling time nuclear spent fuels using hemispheric CdZnTe detectors

CERN Document Server

Lebrun, A; Szabó, J L; Arenas-Carrasco, J; Arlt, R; Dubreuil, A; Esmailpur-Kazerouni, K

2000-01-01

After years of cooling, nuclear spent fuel gamma emissions are mainly due to caesium isotopes which are emitters at 605, 662 and 796-801 keV. Extensive work has been done on such fuels using various CdTe or CdZnTe probes. When fuels have to be measured after short cooling time (during NPP outage) the spectrum is much more complex due to the important contributions of niobium and zirconium in the 700 keV range. For the first time in a nuclear power plant, four spent fuels of the Kozloduy VVER reactor no 4 were measured during outage, 37 days after shutdown of the reactor. In such conditions, good resolution is of particular interest, so a 20 mm sup 3 hemispheric crystal was used with a resolution better than 7 keV at 662 keV. This paper presents the experimental device and analyzes the results which show that CdZnTe commercially available detectors enabled us to perform a semi-quantitative determination of the burn-up after a short cooling time. In addition, it is discussed how a burn-up evolution code (CESAR)...

Survey of methods and measurements of nuclear reactor time and frequency responses

International Nuclear Information System (INIS)

Cummins, J.D.

1961-11-01

Methods of measuring reactivity effects in nuclear reactors are described and the main control engineering analytical problems in nuclear reactors are detailed. A description of the use of reactor models and adaptive control in improving the economy of power producing nuclear reactors is included. (author)

Nuclear energy and the nuclear energy industry

International Nuclear Information System (INIS)

Bromova, E.; Vargoncik, D.; Sovadina, M.

2013-01-01

A popular interactive multimedia publication on nuclear energy in Slovak. 'Nuclear energy and energy' is a modern electronic publication that through engaging interpretation, combined with a number of interactive elements, explains the basic principles and facts of the peaceful uses of nuclear energy. Operation of nuclear power plants, an important part of the energy resources of developed countries, is frequently discussed topic in different social groups. Especially important is truthful knowledgeability of the general public about the benefits of technical solutions, but also on the risks and safety measures throughout the nuclear industry. According to an online survey 'Nuclear energy and energy' is the most comprehensive electronic multimedia publication worldwide, dedicated to the popularization of nuclear energy. With easy to understand texts, interactive and rich collection of accessories stock it belongs to modern educational and informational titles of the present time. The basic explanatory text of the publication is accompanied by history and the present time of all Slovak nuclear installations, including stock photos. For readers are presented the various attractions legible for the interpretation, which help them in a visual way to make a more complete picture of the concerned issue. Each chapter ends with a test pad where the readers can test their knowledge. Whole explanatory text (72 multimedia pages, 81,000 words) is accompanied by a lot of stock of graphic materials. The publication also includes 336 photos in 60 thematic photo galleries, 45 stock charts and drawings, diagrams and interactive 31 videos and 3D models.