Energy Technology Data Exchange (ETDEWEB)

The study was performed for evaluating the risk effect of digital systems on the total plant. Based on risk monitor, a fault tree model for the Korean Standard Nuclear Power Plants (KSNPP), we integrate the fault-tree models for Digital Plant Protection System (DPPS) and Digital Engineered SaFety Actuation System (DESFAS) which are the most important safety-critical I and C systems in the KSNPP. In this study, however, three important factors (the probabilities of manual actuation failure, the software failure probability, and the watchdog timer fault coverage) are treated as the variables of the sensitivity study because quantification methodologies for these factors are not developed yet. Not only the unavailability of digital safety-critical system itself, but also the risk effect of digital ...

Energy Technology Data Exchange (ETDEWEB)

The present research has been made to develop and review critically the functional requirements of the specific safety systems of CANDU such as SDS-1, SDS2, ECCS, and containment. Based on R documents for this, a systematic study was made to develop the domestic regulation statements. Also, the conventional laws are carefully reviewed to see the compatibility to CANDU. Also, the safety assessment method for CANDU was studied by reviewing C documents and recommendation of IAEA. Through the present works, the vague policy in the CANDU safety regulation is cleaning up in a systematic form and a new frame to measure the objective risk of nuclear power plants was developed.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this document is to provide the definition and means of maintaining the Safety Envelope (SE) related to the Criticality Alarm System (CAS). This document provides amplification of the Limiting Condition for Operation (LCO) described in the Plutonium Finishing Plant (PFP) Operational Safety Requirements (OSR), WHC-SD-CP-OSR-010, Rev. 0, 1994, Section 3.1.2, Criticality Detectors and Alarms. This document, with its appendices, provides the following: (1) System functional requirements for determining system operability (Section 3); (2) A list of annotated system block diagrams which indicate the safety envelope boundaries (Appendix C); (3) A list of the Safety Class 1 and 2 Safety Envelope (SC-1/2 SE) equipment for input into the Master Component ...

Energy Technology Data Exchange (ETDEWEB)

This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains-in chronological order-the full-text ...

Energy Technology Data Exchange (ETDEWEB)

This paper described a risk control management tool that has been developed by Petrobras Petroleo, the largest Brazilian oil company and one of the world's leading oil companies. The system covers health, safety and environmental (HSE) issues regarding pipeline construction projects. The limitations of traditional safety management systems for coping with the critical problems related to environmental safety issues were discussed. In particular, this paper described how the HSE tool evaluates the risks resulting from the following aspects of onshore pipeline construction and assembly: establishing right-of-way and route locations, transporting pipe, developing the construction site, opening the trench, pipe laying, pipe bending, concrete external coating, welding, external anticorrosive coatings, pipe placement backfilling, hydrostatic testing, ...

Energy Technology Data Exchange (ETDEWEB)

Monte Carlo neutron transport methods can be used to verify the applicability of point kinetics for safety analysis of nuclear reactors. KENO-NR was used to obtain the transfer function of the Advanced Neutron Source reactor and the time delay between the core power production and the external detectors, a parameter of interest to the safety systems design. The good agreement between the Monte Carlo generated transfer function and the point kinetics transfer function validates that the uncommon ANS geometry does not preclude the use of point kinetics in the frequency range that was investigated. Various features of the power spectral densities also demonstrated the applicability of point kinetics. The time delay was obtained from the cross-power spectral density (CPSD) and is {approximately}15 ms. These analyses show that frequency analysis can be used experimentally to investigate the validity of the use of point kinetics ...

International Nuclear Information System (INIS)

Integrated Leakage Rate Test (ILRT) of containment system plays a very important role in safety of a Nuclear Power Plant. Containment system constitutes the last physical barrier to release of radioactivity from the core and is called upon to mitigate the consequences of not only accidents within the design basis, but also some of the highly unlikely severe accidents. Hence, leak tightness of containment becomes uttermost priority for the safety of plant personnel and public. The containment and associated ESFs are tested before the first criticality and there after periodically during service. The pre-operational integrated leakage rate is carried out at LOCA based design pressure, at periodic test pressure and at some intermediate pressure points to assess the leakage characteristics. This paper summarizes the various requirements and activities relevant to the ILRT of the Indian ...

Energy Technology Data Exchange (ETDEWEB)

Benchmark calculations for SCALE4.4 CSAS6 module have been performed for 31 UO{sub 2} fuel, 15MOX fuel and 10 metal material criticality experiments and then calculation biases of the SCALE 4.4 CSAS6 module have been revealed to be 0.00982, 0.00579 and 0.02347, respectively. When CSAS6 is applied to the criticality safety analysis for the mockup facility in which several kinds of nuclear material components are included, the calculation bias of CSAS6 is conservatively taken to be 0.02347. With the aid of this benchmarked code system, criticality safety analyses for the mockup facility at normal and hypothetical accidental conditions have been carried out. It appears that the maximum K{sub eff} is 0.28356 well below than the critical limit, K{sub eff}=0.95 at normal condition. In a hypothetical accidental condition, the maximum K{sub eff} is ...

Energy Technology Data Exchange (ETDEWEB)

This paper summarizes results of reviews on the safety, critical software performed during the licensing process for the new Wolsung units. Each of these CANDU-type nuclear power plants has two micro-computerized shutdown systems. The SDS No. 1 program is graphically programmed in such a manner that its development process does not essentially differ from the design process of the conventional analog counterpart. This approach is understandable even to a reviewer in the regulatory agency without additional training in software engineering. The confidence in the reliability of this system is strengthened by the reverse verification and increased by extensive testing such as the reliability test. Concerning SDS No. 2, the development process is significantly influenced by the {open_quotes}software cost reduction project{close_quotes} of the U.S. naval research laboratory, and is, as a whole, clear and ...

International Nuclear Information System (INIS)

Emergency Core Cooling System (ECCS) is a safety critical system provided to mitigate the consequence of Loss of Coolant Accident (LOCA) in PHWR. Unlike 220MWe, all header injection has been introduced in 540MWe to simplify the logic. ECCS Integrated Test is schematic approach to establish that ECC system will behave as per design intent during actual LOCA condition. Objective of ECCS Integrated test is to ascertain that various ECC system components operate as intended in design. Additionally, the various system resistances which form the input to LOCA analysis are validated. This test has been carried out by creating actual LOCA during cold and pressurised condition of PHT system to establish all phases of injection with overlap. This paper discusses the results obtained during the Integrated Test and comparison with ...

International Nuclear Information System (INIS)

The use of previously measured mixed-oxide (MOX) fuel systems as benchmarks can be valuable tool in computational analysis and quality assurance efforts. The Fissile Materials Disposition Program (FMDP) has identified these experiments as potential benchmarks, or standards, for VVER's employing MOX fuel. Standards for the analysis of these benchmark experiments were based on those used in the recent compilation International Handbook of Evaluated Criticality Safety Benchmark Experiments begun in 1992 by the U.S. Department of Energy. The Los Alamos National Laboratory's archives were explored for log-book records of these experiments without success. These experiments were the first to use MOX fuel in light water. Three approach-to-critical experiments were performed using fuel rods at various pitches and different plutonium-oxide concentrations. A parallel program verified the prediction of ...

Energy Technology Data Exchange (ETDEWEB)

A study has been conducted on the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. Studies were conducted on three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

Science.gov (United States)

The dynamic response characteristics of the vertical axis wind turbine (VAWT) rotor are important factors governing the safety and fatigue life of VAWT systems. The principal problems are the determination of critical rotor speeds (resonances) and the assessment of forced vibration response amplitudes. The solution to these problems is complicated by centrifugal and Coriolis effects which can have substantial influence on rotor resonant frequencies and mode shapes. The primary tools now in use for rotor analysis are described and discussed. These tools include a lumped spring mass model (VAWTDYN) and also finite-element based approaches. The accuracy and completeness of current capabilities are also discussed.

Energy Technology Data Exchange (ETDEWEB)

To assure quality of safety critical software, software should be developed in accordance with software development procedures and rigorous software verification and validation should be performed. Software verification is the formal act of reviewing, testing of checking, and documenting whether software components comply with the specified requirements for a particular stage of the development phase[1]. New software verification methodology was developed and was applied to the Shutdown System No. 1 and 2 (SDS1,2) for Wolsung 2,3 and 4 nuclear power plants by Korea Atomic Energy Research Institute(KAERI) and Atomic Energy of Canada Limited(AECL) in order to satisfy new regulation requirements of Atomic Energy Control Boars(AECB). Software verification methodology applied to SDS1 for Wolsung 2,3 and 4 project will be described in this paper. Some errors were found by this methodology during the software development for SDS1 ...

Energy Technology Data Exchange (ETDEWEB)

The American National Standard, `Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors` ANSI/ANS-8.1- 1983 provides guidance for the nuclides [sup 233]U, [sup 235]U, and [sup 239]Pu These three nuclides are of primary interest in out-of-reactor criticality safety since they are the most commonly encountered in the vast majority of operations. However, some operations can involve nuclides other than `U, `U, and `Pu in sufficient quantities that their effect on criticality safety could be of concern. The American National Standard, `Nuclear Criticality Control of Special Actinide Elements` ANSI/ANS-8.`15-1983 (Ref 2), provides guidance for fifteen such nuclides.

Energy Technology Data Exchange (ETDEWEB)

This report presents a study on the use of computerised, continuous remote monitoring systems for fire and explosive atmosphere safety in underground coal mines. The effects of these systems on the safety level in mines are investigated, and the relationship between mine safety regulations and computerised, continuous, remote monitoring is analysed.

Science.gov (United States)

The Interim Decay Storage tank (IDS) will be located in a concrete cell in the FFTF reactor building. The tank will have capacity to store 112 driver fuel assemblies and 10 test assemblies in sodium. A criticality safety analysis for the design of the IDS tank was performed. From the analysis, it is concluded that under normal operating conditions and minor abnormal conditions that might shift the fuel, the IDS tank will remain adequately subcritical. (auth)

International Nuclear Information System (INIS)

This article describes the project for the installation of an additional emergency diesel generator in both Asco and Vandellos NPPs. The basic objectives of this project are to improve the availability of the emergency generation system, in order to provide greater ability to address potential contingencies, and also to increase the flexibility of the preventive periodic maintenance of the emergency diesel generators. This maintenance, that is currently a milestone of the critical path of the refueling outage, will be performed on-line. The new diesel generator will be sized to support all the loads considered in the safety case and also the consumption of its own auxiliary systems, and will be tested for operability assessment on the same periodical basis than the existing ones. The solution adopted will also permit that the N diesel generator may be connected to any bus bar class 1E in a station ...

British Library Electronic Table of Contents (United Kingdom)

We show that the HACCP system is not fully applicable at the primary production level, and that food safety is obtained through the careful implementation of good hygiene practice (GHP) at the farm. Guides to GHP intended at primary productions cover one activity, such as cattle rearing or corn production. Yet most farms have more than one activity. Hazards from one activity can be transferred to another activity, and in general this is not considered in one-activity guides. There is a need therefore for farmers to be able to detect and control such transfers. We suggest a horizontal complement to the Guides to GHP that would consider only the application of the Step 6 and Principle 1 of the HACCP system amended as follows: ''List all potential hazards transferred from one activity to anot...

Energy Technology Data Exchange (ETDEWEB)

In order to study nuclear criticality safety related to the development of fast breeder technology, /sup 252/Cf-source-driven neutron noise analysis measurements were performed with a Pu-U nitrate solution in a slab tank of various heights and thickness varying 11.43 cm to 19.05 cm. The results and conclusions of these experiments are (1) a capability to measure the subcriticality of a multiplying system of slab geometry to a k/sub eff/ as low as 0.7 was demonstrated, (2) calculated neutron multiplication factors agreed with those from the experiments within approx.0.02, and (3) the applicability of the method for plutonium solution systems was demonstrated. This paper describes measurements in which the height of the slab was varied for a fixed thickness and the thickness varied for a fixed height, which are the first applications of this measurement method to slab geometry.

International Nuclear Information System (INIS)

The nuclear power industry has experienced four carbon based adsorbent fires in its history, one was of the Monticello Standby Gas Treatment System and other three were in various off-gas delay beds. Although, some of the latter may not be classified as a full fledged fires. There were a number of experiments performed relating to igniting carbon beds and experiments relating to attempts at extinguishing set fires reported in the literature. Review of these experiments indicates that fire resulting from decay heat of adsorbed radioactive iodine is not justified even under the somewhat unrealistic source terms still in effect. At the same time the non-nuclear chemical industry application of carbon base adsorbents for solvent recovery has resulted in numerous fires and significant property losses. Fire control systems installed in nuclear air cleaning systems in the US consists of water deluge. Accidental initiation of these ...

Energy Technology Data Exchange (ETDEWEB)

Development in Instrumentation and Control (I and C) technology provides more convenience and better performance, thus, adopted in many fields. To adopt newly developed technology, nuclear industry requires rigorous V and V procedure and tests to assure reliable operation. Adoption of digital system requires verification and testing of the OS for licensing. Commercial real-time operating system (RTOS) is targeted to apply to various, unpredictable needs, which makes it difficult to verify. For this reason, simple, application-oriented realtime OS is developed for the nuclear application. In this work, we show how to verify the developed RTOS at each development lifecycle. Commercial formal tool is used in specification and verification of the system. Based on the developed model, software in C language is automatically generated. Tests are performed for two purposes; one is to identify consistency between the verified model ...

International Nuclear Information System (INIS)

Full text: The transmutation of nuclear waste to reduce the burden on a geological repository is a relevant topic within the Program of Nuclear Safety Research of the Research Centre Karlsruhe. Several studies have confirmed that a high efficiency of transmutation of actinides is reached in fast neutron spectrum reactor system. Therefore, an important effort is dedicated to the study of transmutation strategies with different fast reactors and their associated technologies. Moreover, in international contexts as Generation IV International Forum (GIF) and Sustainable Nuclear Energy Technology Platform (SNETP), fast reactors are considered in the frame of sustainable development of nuclear energy and reduction of waste. The systems that are currently under investigation, in the frame of the different fuel cycle scenarios, are liquid metal cooled and gas cooled fast reactors as well as Accelerator Driven ...

International Nuclear Information System (INIS)

Application of Programmable Digital Comparator System (PDCS) in NPP is to monitor large number of plant parameters and generate contact outputs for reactor trip, reactor setback, process interlocks etc. when parameters cross their operational bounds. Till NAPS these functions are achieved through individual Indicating Alarm Meters (IAM). PDCS used for the first time in KAPS replaces these IAMs. Since its inception, PDCS has undergone improvements in design, incorporates additional functionalities/enhanced features. Dedicated PDCS is provided in TAPP-3 and 4 for protection function. System re-configurability, on-line inter channel comparison of safety critical process parameters' values, Graphic User Interface etc. are other enhancements. From KAPS to TAPP-4 system has given many years of almost trouble-free operation. Commissioning of TAPP-3 system has been very ...

International Nuclear Information System (INIS)

This report discusses the safety approach of the Advanced Liquid Metal reactor program, sponsored by the US Department of Energy, which relies upon passive reactor responses to off-normal condition to limit power and temperature excursions to levels that allow safety margins. Gas expansion modules (GEM) have included in the design to provide negative reactivity to enhance these margins in the extremely unlikely event that pumping power is lost and the highly reliable scram system fails to operate. The feasibility and beneficial features of these devices were first demonstrated in the core of the Fast Flux Test Facility (FFTF) in 1986. Preapplication safety evaluations by the US Nuclear Regulatory Commission have identified areas that must be addressed if these devices are to be relied on. One of these areas is the response of the reactor when it is critical and the pumps are turned ...

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: The Nuclear Power Plants (NPPs) are always designed for the highest level of safety against postulated accidents which may be initiated due to internal or external causes. One of the external/internal causes, which may lead to accident in the reactor and its associated systems, is fire in certain vital areas of the plant. Conventionally, the fire containment approach and/or the fire confinement approach is used in designing the fire protection systems of NPPs. Indian NPPs (PHWRs) follow the combined approach to ensure plant safety and all newly designed plants are required to comply with the provisions of Atomic Energy Regulatory Board (AERB) fire safety Guide. In respect of older plants, the reassessment of adequacy of fire safety provisions in the light of current advances has becomes essential so as to decide upon the steps ...

Energy Technology Data Exchange (ETDEWEB)

The dynamic response characteristics of the VAWT rotor are important factors governing the safety and fatique life of VAWT systems. The principal problems are the determination of critical rotor speeds (resonances) and the assessment of forced vibration response amplitudes. The solution to these problems is complicated by centrifugal and Coriolis effects which can have substantial influence on rotor resonant frequencies and mode shapes. This paper will describe and discuss the primary tools now in use at Sandia National Laboratories for rotor analysis. These tools include a lumped spring-mass model (VAWTDYN) and also finite-element based approaches. The discussion will center on the accuracy and completeness of current capabilities and plans for future research. As this paper is meant primarily to provide an overview, much of the detail is omitted and will be presented in a follow-on report.

International Nuclear Information System (INIS)

Exposure control at the operating Nuclear Power Station is a major concern. TAPS Unit-4 is the first Pressurized Heavy Water Reactor of 540 MWe electrical capacity. This unit was made critical on March 6, 2005. In-depth review of radiation safety was done to identify the impact of design modification on dose rates at various locations and on the equipment's. Problems encountered in controlling the dose rates in 220 MWe electrical are eliminated by appropriate design modifications. Due to higher capacity of the unit there are design changes in major systems such as reactor core, primer heat transport system, moderator system, reactor regulation and protection systems. Reactor operations and maintenance activities during shut down contributes to exposure of the employees. Based on the experience gained in the operation of 220 MWe, design modifications incorporated ...

Energy Technology Data Exchange (ETDEWEB)

Leakage of CO{sub 2} and displaced brine from geologic carbon sequestration (GCS) sites into potable groundwater or to the near-surface environment is a primary concern for safety and effectiveness of GCS. The focus of this study is on the estimation of the probability of CO{sub 2} leakage along conduits such as faults and fractures. This probability is controlled by (1) the probability that the CO{sub 2} plume encounters a conductive fault that could serve as a conduit for CO{sub 2} to leak through the sealing formation, and (2) the probability that the conductive fault(s) intersected by the CO{sub 2} plume are connected to other conductive faults in such a way that a connected flow path is formed to allow CO{sub 2} to leak to environmental resources that may be impacted by leakage. This work is designed to fit into the certification framework for geological CO{sub 2} storage, which represents vulnerable resources such as potable groundwater, health and ...

International Nuclear Information System (INIS)

Safety indicators play a role in providing information on organizational performance, motivating people to work on safety and increasing organizational potential for safety. The aim of this report is to provide an overview on leading safety indicators in the domain of nuclear safety. The report explains the distinction between lead and lag indicators and proposes a framework of three types of safety performance indicators - feedback, monitor and drive indicators. Finally the report provides guidance for nuclear energy organizations for selecting and interpreting safety indicators. It proposes the use of safety culture as a leading safety performance indicator and offers an example list of potential indicators in all three categories. The report concludes that monitor and drive indicators are so ...

Energy Technology Data Exchange (ETDEWEB)

The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool , i.e. RELAP5/MOD3. This scope of project is a fourth step of the whole project, applying the RELAP5/MOD3/CANDU+ version for the real CANDU plant LOCA Analysis and D2O leakage incident. There are three main models under investigation, i.e. Moody critical flow model, flow regime model of horizontal CANDU bundle, and fuel element heatup model when the stratification occurs, especially when CANDU LOCA is tested. Also, for Wolsung unit 1 D2O leakage incident analysis, the plant behavior is predicted with the newly developed version for the first 1000 seconds after onset of the incident, with the main interest aiming for system pressure, level control system, and thermal hydraulic transient behavior of the secondary system. The model applied for this ...

Science.gov (United States)

This paper presents a systematic study on the stability of a two-dimensional vibration isolation floating raft system with a time-delayed feedback control. Based on the generalized Sturm criterion, the critical control gain for the delay-independent stability region and critical time delays for the stability switches are derived. The critical conditions can provide a theoretical guidance of chaotification design for line spectra reduction. Numerical simulations verify the correctness of the approach. Bifurcation analyses reveal that chaotification is more likely to occur in unstable region defined by these critical conditions, and the stiffness of the floating raft and mass ratio are the sensitive parameters to reduce critical control gain.

International Nuclear Information System (INIS)

During the last years one focus of German PWR safety analysis was boron dilution events with the potential of reactivity transients. Coolant with a low boron concentration could be collected in localized areas of the reactor coolant system e.g. by separation of borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux- condenser heat transfer after a small break loss of coolant accident with a limited availability of the emergency core cooling systems. The TUeV NORD SysTec was charged by German supervisory authorities with the assessment of the safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses shall demonstrate that boron dilution events cannot lead to recriticality of the ...

UK PubMed Central (United Kingdom)

Vulnerable periods during the development of the nervous system are sensitive to environmental insults because they are dependent on the temporal and regional emergence of critical developmental processes...Full Text Available

International Nuclear Information System (INIS)

To be able to carry out review functions regulatory authorities must be able to make critical evaluations of proponent's safety cases. In Sweden the Swedish Radiation Safety Authority aims to have in place its own suite of performance assessment tools. This paper looks at the role and application of a regulator's models to important features of current modelling in a proponent's performance assessment. (authors)

International Nuclear Information System (INIS)

This book deals with organizations that operate in high hazard industries, such as the nuclear power, aviation, oil and chemical industry organisations. The society puts a great strain on these organisations to rigorously manage the risks inherent in the technology they use and the products they produce. In this book, an organisational psychology view is taken to analyse what are the typical challenges of daily work in these environments. The analysis is based on a literature review about human and organisational factors in safety critical industries, and on the interviews of Finnish safety experts and safety managers from four different companies. In addition to this, personnel interviews conducted in the Finnish nuclear power plants are utilised. The authors come up with eight themes that seem to be common organizational challenges cross the industries. These include e.g. how does the personnel ...

Science.gov (United States)

Organic farming (or ecological agriculture) is of growing importance in the agricultural sector worldwide. In the Nordic countries, 1-10% of the arable land was in organic production in 1999. Organic farming can be seen as an approach to agriculture where the aim is to create integrated, humane, environmentally and economically sustainable agricultural production systems. Principles like nutrient recycling, prevention rather than treatment and the precautionary principle are included in aims and standards. Animal welfare is another hallmark of organic livestock production but despite this, several studies have indicated severe health problems e.g. in organic poultry production in Denmark. Also the quality of animal food products in relation to human health, particularly the risk of zoonotic infections, has been debated. For these reasons there is a need for improvement of production methods and animal health status. Vets play an important role in this development ...

International Nuclear Information System (INIS)

The SMART (System-integrated Modular Advanced ReacTor) which is a 330 MWt advanced integral PWR was developed by the KAERI (Korea Atomic Energy Institute) for electricity generation and seawater desalination. A thermal hydraulic evaluation and analysis of the SMART is performed by the TASS /SMR-S (Transient And Setpoint Simulation/System integrated Modular Reactor-Safety). The TASS/SMR-S code has various models reflecting the design features of the SMART such as the drift flux model, the core models (core power and core heat transfer model), the component models, and the specific models. One of the core models is the core heat transfer model. The role of this model is to calculate the heat flux and radial temperature profiles at a fuel rod surface using the relevant heat transfer correlations for all of the heat transfer modes. Also it is modeled to meet the requirements of the 10 CFR 50 appendix K EM model for the CHF ...

International Nuclear Information System (INIS)

This paper explores the current trends in development of technology-neutral safety requirements to be used in the regulation of future nuclear power reactors and the role of the quantitative safety goals in the design of reactor safety systems. Establishing the requirements concerning the reliability of safety functions rather than on particular systems employed to achieve the functions, as well as the use of the recommendations of the International Commission on Radiological Protection (ICRP) on protection against potential exposure could form the basis of a technology-neutral framework for safety requirements on new reactor designs. Also it could contribute to international harmonisation of nuclear safety assessment practices as part of the licensing processes for future nuclear power plants. (author)

Energy Technology Data Exchange (ETDEWEB)

Information is presented concerning new trends in licensing; seismic considerations and system structural behavior; TMI-2 risk assessment and thermal hydraulics; statistical assessment of potential accidents and verification of computational methods; issues with respect to improved safety; human factors in nuclear power plant operation; diagnostics and activities in support of recovery; LOCA transient analysis; unresolved safety issues and other safety considerations; and fission product transport.

International Nuclear Information System (INIS)

The AVR experimental nuclear reactor was Professor Dr. Rudolf Schulten's brainchild. Visionary ideas led to the success of this technology: - Helium coolant because of the particularly high heat transfer coefficients; - an integrated primary system reactor concept as the basis of all safety considerations in the interest of maximum safety; - uranium-235 and thorium-232 fuel allowing new fuel to be bred; - high temperatures for electricity generation at maximum thermodynamic efficiencies, i.e. optimum fuel utilization; - the possibility to run chemical processes economically at high temperatures by means of nuclear fuels; - the inherent safety of the reactor, for a major accident accompanied by a complete loss of cooling cannot occur for nuclear physics reasons, as was tested twice in the AVR. The AVR attained its first criticality on August 28, 1968. It was operated for more than 20 ...

Energy Technology Data Exchange (ETDEWEB)

Mitsubishi is now developing a new Pressurized water reactor (PWR), the Mitsubishi simplified PWR (MS-PWR), which has the innovative features of hybrid safety systems (an optimum combination of passive and active systems) and cooling by horizontal steam generators. In order to confirm the feasibility of the Mitsubishi hybrid safety system, various kinds of safety analyses are performed for loss-of-coolant accident events. In parallel to these safety analysis efforts, the following thermal-hydraulic tests are to be performed: (1) thermal-hydraulic test of a horizontal steam generator; (2) integrated thermal-hydraulic test using a simulation loop for the innovative MS-PWR (SLIM).

Energy Technology Data Exchange (ETDEWEB)

This Safety Analysis Report (SAR) is prepared in compliance with the requirements of DOE Order 5480.23, Nuclear Safety Analysis Reports, and has been written to the format and content guide of DOE-STD-3009-94 Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Safety Analysis Reports. The Hot Cell Facility is a Hazard Category 2 nonreactor nuclear facility, and is operated by Sandia National Laboratories for the Department of Energy. This SAR provides a description of the HCF and its operations, an assessment of the hazards and potential accidents which may occur in the facility. The potential consequences and likelihood of these accidents are analyzed and described. Using the process and criteria described in DOE-STD-3009-94, safety-related structures, systems and components are identified, and the important safety functions of each SSC are ...

Energy Technology Data Exchange (ETDEWEB)

Alpha continuous air monitors (CAMs) will be used at the Waste Isolation Pilot Plant (WIPP) to measure airborne transuranic radioactivity that might be present in air exhaust or in work-place areas. WIPP CAMs are important to health and safety because they are used to alert workers to airborne radioactivity, to actuate air-effluent filtration systems, and to detect airborne radioactivity so that the radioactivity can be confined in a limited area. In 1993, the Environmental Evaluation Group (EEG) reported that CAM operational performance was affected by salt aerosol, and subsequently, the WIPP CAM design and usage were modified. In this report, operational data and current theories on aerosol collection were reviewed to determine CAM quantitative performance limitations. Since 1993, the overall CAM performance appears to have improved, but anomalous alpha spectra are present when sampling-filter salt deposits are at normal to high levels. This ...

International Nuclear Information System (INIS)

Since its creation the nuclear industry has been struggling with the question of how safe is safe enough. Safety is a common goal to all involved in the design, operation and regulation of a nuclear installation. As a concept safety is not easy to define. However, there is a general understanding of what attributes a nuclear power plant should have in order to operate safely. The challenge lies in measuring the attributes. The new competitive open electricity market, in many countries throughout the world, is increasing the economic pressure on operators to lower operating costs without jeopardizing safety. Challenges are occurring at a rate that is unprecedented in the nuclear industry: competitiveness; downsizing; ageing; policy changes; reorganization; restructuring; mergers; globalization; and takeovers demand increasing attention to the management of safety. There are various means to measure ...

Energy Technology Data Exchange (ETDEWEB)

Since August 1984, the MITRE Corporation has been supporting the Naval Sea Systems Command (NAVSEA) and the Naval Medical Command (NAVMEDCOM) in their joint efforts to enhance the Navy Occupational Health Information Management System (NOHIMS). The goal of the enhancement effort was to create a comprehensive occupational health and safety system for Navy industrial facilities by expanding upon the original NOHIMS functions and adding modules for hazard deficiency abatement, hazardous-material control, injury claims and compensation, and safety and health training. To meet this goal, MITRE developed an enhanced industrial subsystem, referred to as the Occupational Safety and Health Record Keeping System (OSHRKS), using a prototyping approach and a public-domain data base-management software package, the Veterans Administration's ...

International Nuclear Information System (INIS)

In the revised GCFR Safety Program Plan a quantitative risk limit line has been adopted to establish requirements for the safety related functions and systems. The risk limit line is derived from an interpretation of NRC established licensing requirements, including those for LMFBR's. Multiple barriers to the progression of accident sequences are defined in the form of six Lines of Protection (LOPs). LOPs-1 to 3 are dedicated to accident prevention and represent the normal operating systems, the dedicated safety systems and the inherent design features, respectively. LOPs-4 to 6 are dedicated to the mitigation of core melt accident consequences and include in-vessel accident containment, secondary containment integrity and radiological attenuation, respectively. Cumulative frequency limits and consequence limits are established for each LOP. Design features ...

International Nuclear Information System (INIS)

Computer based control systems for safety related applications in nuclear power plants have to meet not only the functional, performance and interface requirements, they in addition, have to meet regulatory requirements like enhanced reliability, safety and security and should provide fault tolerance, diagnostics and self-supervision. The control system architecture, hardware design and software design should meet requirements as specified in design code and guides of AERB. The Dual Processor Hot Standby Process Control System (DPHS-PCS) for TAPP-3 and 4 is a safety related (Class- IB) system. DPHS-PCS regulates PHT pressure, Pressuriser pressure, Pressuriser level, Bleed condenser pressure, Bleed condenser level and Steam generator pressure. The performance, reliability and safety requirements of this control ...

International Nuclear Information System (INIS)

The Decree specifies basic quality assurance requirements applicable to machines, their parts and materials, civil engineering structures, means for automated control of technological processes including hardware and software, and electricity supply systems related to nuclear safety of nuclear facilities, and stipulates binding procedures for the implementation of technical and organizational provisions associated with the quality of selected equipment to ensure nuclear safety of nuclear facilities. Safety classes are defined for selected equipment. Requirements laid on safety assurance documentation are specified, and requirements placed on safety assurance programmes, their preparation, finalization and approval are defined. Quality assurance requirements are also specified with respect to the designing, manufacture, construction, operation, repair, ...

CERN Document Server

This paper presents an application of the state of the art and new trends for risk management of safety-related control and monitoring systems, currently applied in the industry. These techniques not only enable to manage safety and reliability issues but they also help in the control of quality and economic factors affected by the availability and maintenance of the system. The method includes an unambiguous definition of the system in terms of functions and a systematic analysis of hazardous situations, undesired events and possible malfunctions. It also includes the identification and quantification of the risk associated to the system. The required risk reduction is specified in terms of safety integrity levels. The safety integrity level results in requirements, preventive measures, possible improvements and ...

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the evolution of the horizontal subsea tree and its utilization in increasingly demanding applications. Initially, the Horizontal Tree was seen as a solution for wells requiring high well maintenance, such as those using electrical downhole pumps. Today, the horizontal tree is being applied to natural drive wells because of attractive whole life economics. This raises concern in a number of areas. Tubing hanger seals are permanently exposed to well fluids, and must provide high integrity sealing. This required the development of a new type of radially energized, all metal sealing system, specifically for horizontal tree applications, suitable for oil or gas service at working pressures to 15,000 psi. In addition, horizontal tree pressure integrity depends on the master valve stem, gate and bonnet seals. The need for high seal integrity also dictates that the first master valves should be integral to the main body of the tree, to maximize ...

UK PubMed Central (United Kingdom)

Though notes in electronic medical record systems (EMRs) have advantages, they are often criticized for their unattractive and unprofessional appearance. We sought to identify notes regarded by physicians...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Biomarkers are biometric measurements that provide critical quantitative information about the biological condition of the animal or individual being tested. In drug safety studies, established toxicity biomarkers are used along with other conventional study data to determine dose-limiting organ toxicity, and to define species sensitivity for new chemical entities intended for possible use as human medicines. A continuing goal of drug safety scientists in the pharmaceutical industry is to discover and develop better trans-species biomarkers that can be used to determine target organ toxicities for preclinical species in short-term studies at dose levels that are some multiple of the intended human dose and again later in full development for monitoring clinical trials at lower therapeutic ...

Energy Technology Data Exchange (ETDEWEB)

Nuclear energy related research in Switzerland is concentrated at PSI's Nuclear Energy and Safety Research Department (NES). The activities of the department are concentrated on three main domains of: Safety and related problems of operating plants; safety features of future reactor and fuel cycles; waste management. Comprehensive assessments of energy systems are carried out in cooperation with PSI's General Energy Research Department. Many of the programs are part of collaborations with universities, industry, or international organisations. Progress in 2000 in these topical areas is described in this report. A list of scientific publications in 2000 is also provided.

Energy Technology Data Exchange (ETDEWEB)

This safety design guide for pipe rupture protection identifies high-energy systems in which pipe ruptures must be postulated to occur, as well as systems that must be protected from the dynamic effects of such ruptures. Dynamic effects considered in this SDG consist of pipe whip (including missiles generated by pipe ruptures, if any) and jet impingement, Requirements for protection against the dynamic effects of a postulated pipe rupture and method of protection of essential structures, systems and components are specified for these effects. The change status for the regulatory requirements, code and standards should be traced and this safety design guide shall be updated accordingly. 2 tabs., 5 refs. (Author) .new.

Science.gov (United States)

The dynamic response characteristics of the VAWT rotor are important factors governing the safety and fatique life of VAWT systems. The principal problems are ...

Energy Technology Data Exchange (ETDEWEB)

Critical properties of a fluid or fluid mixtures are important for describing fluid phase behavior, predicting physical properties, developing equations of state, and designing supercritical-fluid extraction processes, and compression and refrigeration units. The predictive capability of the Peng-Robinson-Styjek-Vera (PRSV-2) equation of state (1986) for critical properties of binary mixtures was investigated. The procedure adopted by Heidemann and Khalil (1980) and discussed by Abu-Eishah et al. (1998) was followed. An optimized value for the binary interaction parameter based on minimization of error between experimental and predicted critical temperatures was used. The standard and the average of the absolute relative deviations in critical properties are included. The predicted critical temperature and pressure for several nonpolar and polar systems agree ...

Energy Technology Data Exchange (ETDEWEB)

The Senior Committee on Environmental, Safety, and Economic Aspects of Magnetic Fusion Energy (ESECOM) has assessed magnetic fusion energy's prospects for providing energy with economic, environmental, and safety characteristics that would be attractive compared with other energy sources (mainly fission) available in the year 2015 and beyond. ESECOM gives particular attention to the interaction of environmental, safety, and economic characteristics of a variety of magnetic fusion reactors, and compares them with a variety of fission cases. Eight fusion cases, two fusion-fission hybrid cases, and four fission cases are examined, using consistent economic and safety models. These models permit exploration of the environmental, safety, and economic potential of fusion concepts using a wide range of possible materials choices, power densities, power conversion schemes, and fuel ...

International Nuclear Information System (INIS)

A variety of critical experiments were constructed of enriched uranium metal during the 1960s and 1970s at the Oak Ridge Critical Experiments Facility (ORCEF) in support of criticality safety operations at the Y-12 Plant. The purposes of these experiments included the evaluation of storage, casting, and handling limits for the Y-12 Plant and providing data for verification of calculation methods and cross-sections for nuclear criticality safety applications. These included solid cylinders of various diameters, annuli of various inner and outer diameters, two and three interacting cylinders of various diameters, and graphite and polyethylene reflected cylinders and annuli. Of the hundreds of delayed critical experiments, one experiment was comprised of a stack of approximately 7-inch-diameter metal discs. The bottom of the stack consisted of ...

International Nuclear Information System (INIS)

The potential public safety impacts from accidents in conceptual fusion power plants were investigated. Fusion was found to have some potential for accidents, as does any energy generating system. Functions of fusion power plants were identified that possess sufficient potential for an accidental release of toxic materials to the environment. An assessment was made of the impact of the potential accidents and recommendations are included for R and D that will allow incorporation of safety concerns in fusion power plant design. This work was based on a review of information available in conceptual design documents of fusion reactor systems.

International Nuclear Information System (INIS)

During the operation of the Fast Flux Test Facility (FFTF), radioactive gases, primarily xenon and krypton, will be produced which will require processing and storing. Two systems have been installed in the FFTF for handling these gases: (1) one to handle, primarily, the reactor cover gas system, and (2) a second to handle the cells and cover gas systems, other than the reactor, whose atmosphere may become contaminated. The system that processes the reactor cover gas, which is argon, is called the Radioactive Argon Processing System (RAPS). The effluent argon from RAPS will normally be sufficiently decontaminated to allow its reuse as the reactor cover gas. If the radioactive level in the RAPS becomes too high, the exhaust stream will be diverted to the Cell Atmosphere Processing System (CAPS), a system which can function as a backup to ...

International Nuclear Information System (INIS)

Perspectives from industry, academe, and the NRC are brought together in this report and used to develop a logical framework that links management and organization factors and safety in nuclear power plant performance. The framework focuses on intermediate outcomes which can be predicted by organizational and management factors, and which are subsequently linked to safety. The intermediate outcomes are efficiency, compliance, quality, and innovation. The organization and management factors can be classified in terms of environment, context, organizational governance, organizational design, and emergent processes. Initial empirical analyses were conducted on a limited set of hypotheses derived from the framework. One set of hypotheses concerned the relationships between one of the intermediate outcome variables, efficiency, as measured by critical hours and outage rate, and safety, as measured by 5 NRC ...

Energy Technology Data Exchange (ETDEWEB)

The paper presents a sequential procedure for coordinated stabilization of a multimachine power system with arbitrary complexity of the system model. The most effective machine to be equipped with a power system stabilizer is identified using eigenvalue analysis. The selection is based on the sensitivity of critical eigenvalues to increases in the coefficient of a damping term which is inserted in each equation of motion, in succession. The method is applied to a three-machine system and simulation studies show appreciable improvements in the small disturbance stability of the system.

Energy Technology Data Exchange (ETDEWEB)

This technical memorandum (TM) documents the 1995 characterization of eight underground radioactive waste tanks at Oak Ridge National Laboratory (ORNL). These tanks belong to the Gunite and Associated Tanks (GAAT) operable unit, and the characterization is part of the ongoing GAAT remedial investigation/feasibility study (RI/FS) process. This TM reports both field observations and analytical results; analytical results are also available from the Oak Ridge Environmental Information System (OREIS) data base under the project name GAAT (PROJ-NAME = GAAT). This characterization effort (Phase II) was a follow-up to the {open_quotes}Phase I{close_quotes} sampling campaign reported in Results of Fall 1994 Sampling of Gunite and Associated Tanks at the Oak Ridge National Laboratory, Oak Ridge, Tennessee, ORNL/ER/Sub/87-99053/74, June 1995. The information contained here should be used in conjunction with that in the previous TM. The sampling plan is documented in ORNL ...

Energy Technology Data Exchange (ETDEWEB)

Monte Carlo methods have been used to compute k{sub eff} and the fundamental mode eigenfunction of critical systems since the 1950s. While such calculations have become routine using standard codes such as MCNP and SCALE/KENO, there still remain 3 concerns that must be addressed to perform calculations correctly: convergence of k{sub eff} and the fission distribution, bias in k{sub eff} and tally results, and bias in statistics on tally results. This paper provides a review of the fundamental problems inherent in Monte Carlo criticality calculations. To provide guidance to practitioners, suggested best practices for avoiding these problems are discussed and illustrated by examples.

Energy Technology Data Exchange (ETDEWEB)

The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the W7-AS stellarator. ...

Science.gov (United States)

This Addendum to the Facility Safety Plan (FSP) 360 Complex describes the safety requirements for the safe conduct of all biohazardous research operations in all buildings within the 360 complex program areas. These requirements include all the responsibilities and authorities of building personnel, operational hazards, and environmental concerns and their controls. In addition, this Addendum prescribes facility-specific training requirements and emergency controls, as well as maintenance and quality assurance requirements for ES&H-related building systems.

Energy Technology Data Exchange (ETDEWEB)

Thermophotovoltaics is the science and technology associated with the direct generation of electricity from high temperature heat. Potential applications include combined heat and power, portable and auxiliary power, radioisotope space power, industrial waste heat recovery and concentrated solar power. This book aims at serving as an introduction to the underlying theory, overview of present day components and system arrangements, and update of the latest developments in the field. The emphasis is placed on the understanding of the critical aspects of efficient thermophotovoltaic system design. The aim is to assist researchers in the field. (orig.)

International Nuclear Information System (INIS)

Power density measurements in the critical facility RA-8 are presented. These measurements were the first systematic use of the reactor. A measurement system was designed, built and proved for this goal. Power profiles are showed and the results are compared with calculated values. (author)

International Nuclear Information System (INIS)

A variety of critical experiments were constructed of enriched uranium metal during the 1960s and 1970s at the Oak Ridge Critical Experiments Facility (ORCEF) in support of criticality safety operations at the Y-12 Plant. The purposes of these experiments included the evaluation of storage, casting, and handling limits for the Y-12 Plant and providing data for verification of calculation methods and cross-sections for nuclear criticality safety applications. These included solid cylinders of various diameters, annuli of various inner and outer diameters, two and three interacting cylinders of various diameters, and graphite and polyethylene reflected cylinders and annuli. Of the hundreds of delayed critical experiments, two were performed that consisted of uranium metal annuli with a solid beryllium metal core. The outer diameter of the ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe the embedded computer systems approach taken at Experimental Breeder Reactor II (EBR-II) for non-safety related systems. The hardware and software structures for typical embedded systems are presented The embedded systems development process is described. Three examples are given which illustrate typical embedded computer applications in EBR-II.

Energy Technology Data Exchange (ETDEWEB)

The {sup 252}Cf-source-driven frequency analysis method can be used for measuring the subcritical neutron multiplication factor of arrays of LWR fuel and as little as a single PWR fuel assembly. These measurements can be used to verify the criticality safety margins of spent LWR fuel configurations and thus could be a means of obtaining the information to justify burnup credit for spent LWR transportation/storage casks. In addition, the data can be used to validate calculational methods for criticality safety. These measurements provide parameters that have a higher sensitivity to changes in fissile mass than neutron multiplication factor and thus serve as a better test of calculational methods. The analysis have also shown that measurement of the cross power spectral density (CPSD) between detectors on one side of a single fuel assembly and an internal or external {sup 252}Cf source driving the fission ...

Energy Technology Data Exchange (ETDEWEB)

Subcritical experiments using californium source-driven noise analysis (CSDNA) and Feynman variance-to-mean methods were performed with an alpha-phase plutonium sphere reflected by nickel shells, up to a maximum thickness of 7.62 cm. Both methods provide means of determining the subcritical multiplication of a system containing nuclear material. A benchmark analysis of the experiments was performed for inclusion in the 2010 edition of the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Benchmark models have been developed that represent these subcritical experiments. An analysis of the computed eigenvalues and the uncertainty in the experiment and methods was performed. The eigenvalues computed using the CSDNA method were very close to those calculated using MCNP5; however, computed eigenvalues are used in the analysis of the CSDNA method. Independent calculations using KENO-VI provided similar ...

Energy Technology Data Exchange (ETDEWEB)

The objective of project is to derive the policy recommendations to improve the efficiency of CANDU plants regulation. These policy recommendations will eventually contribute to the upgrading of Korean nuclear regulatory system and safety enhancement. During the second phase of this 2 years study, following research activities were done. Review the technical basis and framework of the new Canadian Regulation System and IAEA. Analysis on the interview of Wolsung operation staffs to identify important safety issues and regulation problems experienced at operation. Providing a plan of CANDU regulation system enhancement program.

Energy Technology Data Exchange (ETDEWEB)

As a maintenance optimization project to improve the safety of Wolsung NPP (Nuclear Power Plant), reliability of diesel generators are estimated based on the operating experience, and improvement options are suggested. A reliability measure is suggested for the estimation of reliability for standby safety systems to reflect availability. It is assessed that the reliability of diesel generators can be much improved if the suggested improvement options are implemented.

Science.gov (United States)

Background Food additives are an integral part of the modern food system, but opinion polls showing most Europeans have worries about them imply an urgent need for ethical analysis of their use. Sources of data The existing literature on food ethics, safety assessment and animal testing. Areas of agreement Food additives provide certain advantages in terms of many people's lifestyles. Areas of controversy There are disagreements about the appropriate application of the precautionary principle and of the value and ethical validity of animal tests in assessing human safety. Growing points Most consumers have a poor understanding of the relative benefits and risks of additives, but concerns over food safety and animal testing remain high. Areas timely for developing research Examining the impacts of food additives on consumer sovereignty, consumer health and on animals used in safety ...

Science.gov (United States)

The long operating cycle simplified boiling water reactor is a reactor concept that pursues both safety and the economy by employing a natural circulation reactor core without a refueling, a passive decay heat removal, and an integrated building for the reactor and turbine. Throughout the entire spectrum of the design basis accident, the reactor core is kept covered by the passive emergency core cooling system. The decay heat is removed by the conventional active low-pressure residual heat removal system. As for a postulated severe accident, the suppression pool water floods the lower part of the reactor pressure vessel (RPV) in the case when core damage occurs, and the in-vessel retention that keeps the melt inside the RPV is achieved by supplying the coolant. The containment adopts a parallel-double-steel-plate structure similar to a hull structure, which contains coolant between the inner and outer walls to absorb the ...

UK PubMed Central (United Kingdom)

Thyroid hormone is a critical regulator of growth, development and metabolism in virtually all tissues, and altered thyroid status affects many organs and systems. Although for many years testis...Full Text Available

UK PubMed Central (United Kingdom)

The C1 fixation test is widely used for the study of the interaction between immunoglobulins, their fragments and the complement system. Some factors influencing the apparent extent of the C1 fixation...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The verification of the subcriticality is of utmost importance for the safe transportation and storage of nuclear reactor fuels. Transportation containers and storage facilities are designed such that nuclear fuels remain in a subcritical state. Such designs often involve excess conservatism because of the lack of relevant experimental data to verify the accuracy of Monte Carlo codes used in nuclear criticality safety analyses. A joint experimental research program between Oak Ridge National Laboratory, Westinghouse Safety Management Solutions, Inc., and the University of Missouri was initiated to obtain measured quantities that could be directly related to the subcriticality of simple arrays of Missouri University Research Reactor (MURR) fuel elements. A series of measurement were performed to assess the reactivity of materials such as BORAL, stainless steel, aluminum, and lead that are typically used in the construction ...

Energy Technology Data Exchange (ETDEWEB)

The public expects that the Los Alamos National Laboratory (LANL) will operate in a manner that prevents negative impacts to the environment and protects the safety and health of its employees and the public. To achieve this goal within budget, the Department of Energy (DOE) and LANL must develop new and improved environment, safety, and health (ES and H) technologies and implement innovative, more cost-effective ES and H approaches to operations. In FY95, the Environment, Safety, and Health (ESH) Division initiated a Technology Development, Evaluation, and Application (TDEA) program. The purpose of this unique program is to test and develop technologies that solve LANL ES and H problems and improve the safety of LANL operations. This progress report presents the results of 10 projects funded in FY97 by the TDEA Committee of the Environment, Safety, and Health Division. Products ...

CERN Document Server

Denial of service attacks (DoS) can cause significant financial damages. Flooding and Malicious packets are two kinds of DoS attacks. This paper presents a new security approach which stops malicious packets and prevents flooding in the critical systems. New concepts of packet stamp a dynamic-multi-communication-point mechanism has been identified for this proposed approach to make the prevention of flooding attacks easier and the performing of malicious packet attacks harder. In addition, dynamic key encryption technique has been adapted as a part of the proposed approach to enhance its functionality.

UK PubMed Central (United Kingdom)

BackgroundMagnetic Resonance Imaging scanners have become ubiquitous in hospitals and high-field systems (greater than 3 Tesla) are becoming increasingly common. In light of recent...Full Text Available

UK PubMed Central (United Kingdom)

Healthcare-associated infections (HAIs) take a major human toll on society and reduce public confidence in the healthcare system. The current convergence of scientific, public, and legislative...Full Text Available

Science.gov (United States)

At Wolsung NPP, three more CANDU reactors will be operated soon, and the tritium accumulation in the moderator and coolant systems was estimated to be greatly increased. In order to reduce tritium exposure for nuclear safety at Wolsung, a study was carrie...

International Nuclear Information System (INIS)

The symposium covers papers under different sections namely, (i) Core physics and Fuel management, (ii) Commissioning of facilities and systems, (iii) Operational experience and Human resource development, (iv) Fuel handling, Maintenance management and Surveillance, (v) Instrumentation and Control and Power supply systems, (vi) Analysis, modifications and developments for enhancing operational safety, (vii) Chemistry control and Effluent management, (viii) Radiation and industrial safety and (ix) Steam generators, Turbo-generators and other auxiliaries. Papers relevant to INIS are indexed separately. (author)

Energy Technology Data Exchange (ETDEWEB)

This paper describes the safety gas management system utilizing public telephone cables. Buyo Gas Co., Ltd. has installed about 100 governors for exclusive-use or use in the districts to control the gas supply to the consumers. A gas safety management system has been developed. This system consists of a pressure sensor, the terminals of gas leak alarms, and their masters. The features lie in that the system can utilize public cables, is operative at interruption of power service, can correspond to emergency situations, serves to save the cost, and can display the data constantly. For electric facilities in a governor room and the NTT cable service work, sufficient agreement with the possessor is required. In the case of non-utility electric facilities, some restrictions are imposed on the cable work for laying from privately-owned transformers, etc. Insurance ...

International Nuclear Information System (INIS)

Mitsubishi is now developing a next-generation Pressurized Water Reactor (PWR) which has the innovative feature of hybrid safety systems (optimum combination of passive safety system and active safety system) and passive core cooling by horizontal steam generators during Loss of Coolant Accident (LOCA). In order to confirm the capability of this passive core cooling system during LOCAs, the thermal-hydraulic tests of horizontal steam generator and the integral thermal-hydraulic tests simulating the LOCAs were performed. The thermal-hydraulic tests of horizontal steam generator consist of a single tube test and a multi-tubes test. On the basis of these test results, the heat transfer characteristics of steam-water two-phase flow with noncondensable gas along a long horizontal tube is understood and the heat transfer correlation including the ...

Energy Technology Data Exchange (ETDEWEB)

As a candidate of the new concept safety system for the next generation PWR in Japan, the hybrid safety systems, which are combination of the active and the passive safety systems, and passive core cooling system by natural circulation in the reactor coolant loop with horizontal-type steam generators during Loss of Coolant Accidents (LOCAs) are investigated. The passive safety systems are advanced accumulators (ACC), primary-side and secondary-side automatic-depressurization systems (ADS, SADS), and a gravity-driven safety injection system (GDI). The horizontal steam generator design avoids a siphon break caused from the accumulation of non-condensable gases in the tubes by using a vent line in the channel head of the steam generators. ...

International Nuclear Information System (INIS)

As a basic research to consider aging deterioration of the operating nuclear power plant to seismic fragility analysis, aging deteriorations occurring safety related equipment of both Kori unit 1 and Wolsung unit 1, are investigated in this study. First of all, 378 and 152 safety related equipment are selected at Kori unit 1 and Wolsung unit 1 respectively. Seismic review team including seismic capability engineer, is organized and seismic walkdown is carried out using the nondestructive tests. As a results of seismic walkdown, crack is a typical aging deterioration which can reduce the seismic safety of safety related equipment and the other aging deteriorations such as concrete compressive strength, corrosion, and tightness of anchor bolt, have a much smaller influence than crack. In order to manage the aging deterioration data collected through the seismic walkdown in effective and systematic, ...

Science.gov (United States)

Prepared to make housing project managers, maintenance engineering staff, and designers and architects of HUD - assisted and HUD - insured housing projects and mobile home parks aware of their responsibilities under the Natural Gas Pipeline Safety Act, this handbook provides technical guidance for the reduction of gas leaks and the handling of gas leak incidents in residential areas. The hazards of natural gas, concern over gas safety in residential areas, applicable codes and standards, and sources of information and help are reviewed, along with maintenance and engineering considerations relating to gas pipe failures, the detection of gas leaks, appliance servicing, and pipe installation, repair, and replacement. Housing management considerations are also examined, with attention to recordkeeping and reporting, emergency contingency planning, tenant education, staff qualifications and training, and the development and use of a maintenance and ...

Energy Technology Data Exchange (ETDEWEB)

This report, entitled Combustion Engineering Standard Safety Analysis Report -- Design Certification (CESSAR-DC), has been prepared in support of the industry effort to standardize nuclear plant designs. These volumes describe the Combustion Engineering, Inc. System 80{sup +}{trademark} Standard Design. This volume 9 discusses Electric Power and Auxiliary Systems.

Energy Technology Data Exchange (ETDEWEB)

The use of irrigation systems in the proximity of high voltage transmission lines is increasing. This study examines the induced voltages and currents on a pivotal irrigation system operating under a 765 kV line. With a few simple precautions such as a system can be operated in complete safety. 1 ref.

International Nuclear Information System (INIS)

The ROP margin in a CANDU reactor is decreasing over time due to the Primary Heat-Transport System (PHTS) aging effect. Adjustment of the ROP trip setpoint is required to maintain a high trip-probability and ROP trip effectiveness. Especially, for Wolsong-1, which is scheduled to change the old pressure tubes in 2009, the trend of ROPT after the retubing should be reevaluated. Before setting a ROPT, the main thermal characteristics including Critical Channel Power (CCP) should be calculated by the NUCIRC code. In this paper, the thermalhydraulic evaluation for Wolsung-1 was conducted with the updated Wolsung-1 PHTS data. Specifically, for the case of 0 EFPY (Effective Full Power Year) and 11 EFPY after the retubing, the distribution of the channel flow rate, channel exit quality, critical channel power, and critical power ratio (CPR) of the Wolsong-1 aged plant are calculated

Energy Technology Data Exchange (ETDEWEB)

Ternary diagrams or pseudo ternary diagrams are commonly used to provide a graphical representation of equilibrium fluid phase behavior for systems as diverse as distillation columns and miscible gas floods of oil reservoirs. The phase envelope and the position of the critical point on it are important to enhanced oil recovery engineers who are involved with miscible gas flood design. In the past, phase equilibrium data were laboriously plotted on the pseudo ternary diagram and special graphical techniques were utilized to locate the critical point on the phase envelope. Presented in this article is a computerized curve fitting method to, firstly, generate the phase envelope from a given set of phase equilibrium data and then use the 'tie-line slopes' to position the critical point. Experimental data are included and show excellent agreement with this new method.

Energy Technology Data Exchange (ETDEWEB)

It was recognized from the early days of commissioning of Bruce B that Control Maintenance staff would require a level of expertise to be able to maintain Special Safety Systems in proper running order. In the early 80's this was achieved through hands on experience during the original commissioning, troubleshooting and placing of the various systems in service. Control maintenance procedures were developed and implemented as the new systems came available for commissioning, as were operating manuals,training manuals etc. Under the development of the Maintenance Manager, a Conduct of Maintenance section was organized. One of the responsibilities of this section was to develop a series of Maintenance Administrative Procedures (MAPs) that set the standards for maintenance activities including training.

International Nuclear Information System (INIS)

SMART (System integrated Modular Advanced ReacTor) , is under development at the Korea Atomic Energy Research Institute (KAERI). SMART is an integral type pressurized water reactor which contains a pressurizer, 4 reactor coolant pumps (RCPs), and 8 steam generator cassettes(S/Gs) in a single reactor vessel. This reactor has substantially enhanced its safety with an integral layout of its major components, 4 trains of safety injection system (SIS), and an adoption of 4 trains of passive residual heat removal system (PRHRS) instead of an active auxiliary feedwater system . The thermal power is 330 MWth. During the conceptual design stage, a preliminary PSA was performed. PSA results identified that a steam generator tube rupture (SGTR) is one of the most important initiating events which results in a high core damage frequency. Clear understanding of accident ...

Energy Technology Data Exchange (ETDEWEB)

The characteristics of the temperature dependence of the upper critical magnetic field, Hc2(T), of structurally inhomogeneous superconductors (e.g., ternary molybdenum chalcogenides, A-15 compounds, transition metal alloys, and amorphous films) are investigated analytically. The MWGH equation for Hc2(T) is generalized to the case of weakly inhomogeneous systems with a characteristic inhomogeneity scale much smaller than the effective coherence length. It is shown that an increase in the dispersion of the diffusion coefficient leads to an increase in the slope and width of the linear section of the Hc2(T) curve. 11 references.

International Nuclear Information System (INIS)

Taking into consideration India's limited reserves of natural and vast reserves of thorium, the fast reactor route holds a great promise for India's energy supply in future. The fast reactor fueled with "2"3"9Pu/"2"3"8U (unused or depleted) produces (breeds) more fissionable fuel material "2"3"9Pu than it consumes. Calculations show that a fast breeder reactor (FBR) increases energy potential of natural uranium by about 60 times. As the fast reactor can also convert "2"3"2Th into "2"3"3U which is a fissionable material, it can make India's thorium reserves a source of almost inexhaustible energy supply for a long time to come. Significant advantage of FBR plants cooled by sodium and their world-wide operating experience are reviewed. There are two main safety issues of FBR, one nuclear and the other non-nuclear. The nuclear issue concerns core disruptive accident and the non-nuclear one concerns the high chemical energy potential of sodium. These two issues are ...

Energy Technology Data Exchange (ETDEWEB)

The article has three sections. The first discusses the environmental problems the tanker traffic poses to the Norwegian coastal waters and shores. Various precautionary measures and requirements are briefly presented. The size of the present marine transportation and the future Russian marine petroleum activity in the Barents area are briefly mentioned. The second named, conflicting exploration drilling, presents the conflicting interests regarding exploratory drilling in the Barents Sea in Norway. The environmental problems are large and have lead to an on-going reevaluation. Some pollution abatement measures are mentioned. The regional economic development is briefly outlined. The third deals with the Norwegian governmental safety activities and presents a brief survey of the official safety activities in the petroleum sector in Norway and the international cooperation particularly with the Russian Federation. The emphasis is on the maritime ...

International Nuclear Information System (INIS)

A three-dimensional (3D) thermal-hydraulic model and a numerical procedure for the simulation and analysis of a steady-state, as well as transient operation of nuclear power plant components are presented. A two-fluid approach is applied to modelling of two-phase flow. Thermal-hydraulics of a horizontal steam generator in the WWER 1000 nuclear power plant has been simulated at the full load, steady-state operation. A comparison of the numerical results with data measured at the NPP Novovoronjezh shows good agreement. 3D numerical results can be used in plant design or retrofitting, in nuclear power plant operation and safety analysis and as improvement of existing one-dimensional thermal-hydraulics models of the horizontal steam generator which are assessed by system codes used for the nuclear power plant safety analyses. (author)

International Nuclear Information System (INIS)

As part of the Probabilistic Safety Analysis of the Multi Purpose Reactor, MPR, the list of Postulated Initiating Events was analyzed and one of these PIEs corresponds to the Loss of Coolant Flow. It is well known that during the operation life of a research reactor a LOFA could eventually occur and, once this event takes place, in time detection and automatic actions, thanks to the engineering safety features of the system, will mitigate the incident evolution. The postulated event corresponds to a loss of flow due to a total loss of power supply. The goal of the present work is to provide a general description and the engineering safety features of the MPR, as well as describe the sequence of scenarios during a LOFA. Temporal evolution of main parameters is presented, also. During Stage A of the Commissioning Program measurements of the core cooling system pump coast-down were ...

Energy Technology Data Exchange (ETDEWEB)

This guide is intended to provide the necessary guidance to successfully manage the NAVMED Navy Occupational Health Information Management System (NOHIMS) at NAVMED sites and the NAVSEA Occupational Safety and Health Record Keeping System (OSHRKS) at NAVSEA sites. Outlines procedures to manage system operations, procedures to resolve hardware, software and communications problems, and procedures outside the realm of system operations that are required for a successful system. This guide is intended for the System and Functional Managers use. The System Manager is the individual designated to provide overall ADP management to the entire local configuration. Usually responsible for file backup, daily operations of the CPU, security, supplies, equipment, operating software and technical ADP guidance to the local functional ...

International Nuclear Information System (INIS)

The textbook is primarily intended for radiologic staff and radiologic safety officers and gives information on the current regulatory provisions of the German X-ray Ordinance, applications of X-rays, quality assurance, organisational aspects of film processing and quality requirements of X-rays. An annex lists the guidelines of the Bundesaerztekammer (German National Chamber of Physicians) relating to quality assurance aspects, and further useful information on commercially available film-screen systems, the various associations of physicians in Germany, and requirements and performance of radiation surveys. (vhe).

Energy Technology Data Exchange (ETDEWEB)

Equipment Qualification technology for I and C system on nuclear grade have been approved with accurate and safe for verifying and validation. It contributes to acknowledge of reliability and to review of user approval. Also it did not completely satisfied the requirement of Russia, it can be satisfied by bit of modification on design. It is expected to support the export of safety PLC to nuclear power plant. Proven EQ technology is required on the further markets of nuclear. Therefore, comparison test with foreign country is necessary to support the mutual accreditation of EQ for export of domestic products.

International Nuclear Information System (INIS)

KSC-1 (KAERI Shipping Cask-1) was designed and manufactured with a pure domestic technology in 1985 in order to transport a PWR spent fuel assembly from nuclear power plant to PIEF (Post-Irradiation Examination Facility) of KAERI. Since the first transportation of the fuel assembly from Kori-1 NPP was carried out by the cask in 1987, 19 shipments for the PWR spent fuels have been done successfully by now. Maximum discharge burnup of PWR in Korea has been extended from the late 1990s in order to reduce the cost of power generation. From this cause, allowable design values of the initial enrichment and the cooling time for the cask have been changed three times: year 2003, 2007 and 2010. Radiation shielding and criticality of KSC-1 were analyzed for all the PWR fuel type irradiated in Korea NPP to renew the design approval

Energy Technology Data Exchange (ETDEWEB)

One of the supporting elements of the Advanced Turbine Systems (ATS) Program is the materials/manufacturing technologies task. The objective of this element is to address critical materials issues for both industrial and utility gas turbines. DOE Oak Ridge Operations Office (ORO) will manage this element of the program, and a team from DOE-ORO and Oak Ridge National Laboratory is coordinating the planning for the materials/manufacturing effort. This paper describes that planning activity which is in the early stages.

Energy Technology Data Exchange (ETDEWEB)

This paper is focused on TLP and Spar technology as applied to floating production applications. In particular, safety considerations as related to classification and certification requirements are addressed. This covers hull structures, marine systems, production facilities and the relevant mooring systems for each platform type from design approval on through construction, installation and ultimately the ongoing maintenance of the platform to acceptable standards throughout its operating life. The experience of the American Bureau of Shipping with these platforms will be utilized in supporting the practical application of classification and regulatory standards to ensure safe operations and concluding that use of such standards in conjunction with an experienced classification society provides a substantial benefit to companies utilizing these technologies. (author)

International Nuclear Information System (INIS)

The Structural Aging (SAG) Program is carried out by the Oak Ridge National Laboratory (ORNL) under sponsorship of the United States Nuclear Regulatory Commission (USNRC). The Program has evolved from preliminary studies conducted to evaluate the long-term environmental challenges to light-water reactor safety-related concrete civil structures. An important conclusion of these studies was that a damage methodology, which can provide a quantitative measure of a concrete structure's durability with respect to potential future requirements, needs to be developed. Under the SAG Program, this issue is being addressed through: establishment of a structural materials information center, evaluation of structural component assessment and repair technologies, and development of a quantitative methodology for structural aging determinations. Progress to date of each of these activities is presented as well as future plans. 7 refs., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

The ability of the /sup 252/Cf-source-driven neutron noise analysis method to measure subcriticality has been demonstrated in a variety of experimental configurations of fissile materials. Calculations for an approximately 4-m-dia configuration of light water reactor (LWR) fuel elements indicated the feasibility of measuring the subcriticality of large, loosely coupled arrays of LWR fuel elements by this same method. These analysis suggested application to the initial loading of both pressurized and boiling water reactors, zero-power testing of reactors (such as shutdown margin measurements after initial loading), light water reactor refueling, and safe storage of LWR spent fuel. In the fuel storage application, direct measurement of subcriticality in the actual fuel storage facilities provides the parameter which is directly related to criticality safety.

International Nuclear Information System (INIS)

Inherent boron dilution can occur in case of a Small Break LOCA when low borated water is mainly accumulated in the U-legs due to reflux boiling in the Steam Generator tubes after the loss of natural circulation. The restart of the natural circulation may lead to criticality because of the injection of these low borated slugs towards the core. To evaluate this potential risk, the boron concentration at the core inlet has to be known which makes necessary to estimate the mixing phenomena in the cold leg, in the downcomer and in the lower plenum: CFD calculations are required. First of all the validation of CFX5 CFD code on the relevant phenomena of inherent boron dilution has been established (UPTF TRAM C3 test). Then, an application to the 900 MW French Pressurized Water Reactor series has been performed. (authors)

International Nuclear Information System (INIS)

This paper shows how molecular theory paves the way for accelerated aging tests of safety-related equipment in nuclear power plants, as required by NRC qualification programs. Arrhenius' model, based on an equation, provides useful information regarding the extent of molecular change as a function of time and temperature. Critical to determining the aging characteristics and qualified life of organic materials is the activation energy concept, which is derived from information gathered when the molecular reaction of the material is documented over the entire life cycle. In accelerated-aging applications, the importance of the model lies in characterizing the chemical related reactions of materials. The problem with the Arrhenius approach is that, in generating a testing period of reasonable duration, a rather high test temperature must be selected which may lead to an added and unrelated environmental effect.

Energy Technology Data Exchange (ETDEWEB)

Residual plutonium (Pu), with trace quantities of depleted uranium (DU) or weapons grade uranium (WU), exists in surficial soils at the Nevada Test Site (NTS), Nellis Air Force Range (NAFR), and the Tonopah Test Range (TTR) as the result of the above-ground testing of nuclear weapons and special experiments involving the detonation of plutonium-bearing devices. The special experiments (referred to as safety shots) involving plutonium-bearing devices were conducted to study the behavior of Pu as it was being explosively compressed; ensure that the accidental detonation of the chemical explosive in a production weapon would not result in criticality; evaluate the ability of personnel to manage large-scale Pu dispersal accidents; and develop criteria for transportation and storage of nuclear weapons. These sites do not pose a health threat to either workers or the general public because they are under active institutional control. The DOE is ...

Energy Technology Data Exchange (ETDEWEB)

This report, entitled Combustion Engineering Standard Safety Analysis Report -- Design Certification (CESSAR-DC), has been prepared in support of the industry effort to standardize nuclear plant designs. These volumes describe the Combustion Engineering, Inc. System 80{sup +}{trademark} Standard Design. This volume 8 provides a description of instrumentation and controls.

Energy Technology Data Exchange (ETDEWEB)

Experience and technical innovations in power plant engineering have resulted in continuous improvements of operation control, availability and safety of pumped storage plants. Process control is constantly improved as new developments are made in equipment and systems engineering. Plant control concepts with increasingly complex automation hierarchy are described by which pumped storage processes can be controlled optimally, reliably, and automatically.

Energy Technology Data Exchange (ETDEWEB)

Design-for-reliability concepts can be applied to the products of the construction industry, which includes buildings, bridges, transportation systems, dams, and other structures. The application of a systems approach to designing in reliability emphasizes the importance of incorporating uncertainty in the analyses, the benefits of optimization analyses, and the importance of integrating reliability, safety, and security. 4 refs., 3 figs.

Energy Technology Data Exchange (ETDEWEB)

The PIUS reactor utilizes simplified, inherent, passive, or other innovative means to accomplish safety functions. Accordingly, the PIUS reactor is subject to the requirements of 10CFR52.47(b)(2)(i)(A). This regulation requires that the applicant adequately demonstrate the performance of each safety feature, interdependent effects among the safety features, and a sufficient data base on the safety features of the design to assess the analytical tools used for safety analysis. Los Alamos has assessed the quality and completeness of the existing and planned data bases used by Asea Brown Boveri to validate its safety analysis codes and other relevant data bases. Only a limited data base of separate effect and integral tests exist at present. This data base is not adequate to fulfill the requirements of 10CFR52.47(b)(2)(i)(A). Asea Brown Boveri has stated that it ...

International Nuclear Information System (INIS)

In order to achieve the safe core cooling during normal operation and upset conditions, HANARO adopted an upward forced convection cooling system with dual containment arrangements instead of the forced downward flow system popularly used in the majority of forced convection cooling research reactors. This kind of upward flow system was selected by comparing the relative merits of upward and downward flow systems from various points of view such as safety, performance, maintenance. However, several operational matters which were not regarded as serious at design come out during operation. In this paper are presented the design and operational experiences on the unique cooling features of HANARO. (author)

Energy Technology Data Exchange (ETDEWEB)

The feasibility study on conceptual design methodology for accelerator-driven sodium-cooled sub-critical transmutation reactors has been conducted to optimize the design parameters from the scale laws and validates the reactor performance with the integrated code system. A 1000 MWth sodium-cooled sub-critical transmutation reactor has been scaled and verified through the methodology in this paper, which is referred to Advanced Liquid Metal Reactor (ALMR). A Pb-Bi target material and a partitioned fuel are the liquid phases, and they are cooled by the circulation of secondary Pb-Bi coolant and by primary sodium coolant, respectively. Overall key design parameters are generated from the scale laws and they are improved and validated by the integrated code system. Integrated Code System (ICS) consists of LAHET, HMCNP, ORIGEN2, and COMMIX codes and some files. Through ICS the target ...

Energy Technology Data Exchange (ETDEWEB)

Many existing methods of identifying the optimum sites for installing power system stabilizers (PSSs) in multi-machine systems are restricted to the sequential PSS application, which considers the enhancement of damping of just one critical electromechanical mode at a time; the eigenstructure analysis of the open-loop system, which does not take the control matrix (i.e., the B matrix in the linearized model x = Ax + Bu for power systems) into consideration. This paper presents a method of identifying the optimum sites for installing power system stabilizers. The advantages of this method are: it can identify the optimum sites for installing PSSs so that several electrochemical modes are damped out simultaneously; it takes both the eigenstructure of the open-loop system and the control matrix into consideration.

Energy Technology Data Exchange (ETDEWEB)

Inherent safety tests were performed during 1986 in the 400-MW (thermal) Fast Flux Test Facility (FFTF) reactor to demonstrate the effectiveness of an inherent shutdown device called the gas expansion module (GEM). The GEM device provided a strong negative reactivity feedback during loss-of-flow conditions by increasing the neutron leakage as a result of an expanding gas bubble. The best-estimate pretest calculations for these tests were performed using the IANUS plant analysis code (Westinghouse Electric Corporation proprietary code) and the MELT/SIEX3 core analysis code. These two codes were also used to perform the required operational safety analyses for the FFTF reactor and plant. Although it was intended to also use the SASSYS systems (core and plant) analysis code, the calibration of the SASSYS code for FFTF core and plant analysis was not completed in time to perform pretest analyses. The purpose of this paper is to ...

International Nuclear Information System (INIS)

The design boron concentration of the Boron Injection Tank (BIT) in Daya Bay Nuclear Power Station is 21000 #mu#g/g. The BIT should operate under high temperature to avoid boron crystallization, causing higher evaporation, frequent water makeup, higher deposition and pipe blockage to decrease the operability of the safety injection system. The author proposes to decrease the boron concentration in BIT from 21000 #mu#g/g to 7000 #mu#g/g to solve the existing problem. The safety analyses (core DNBR and containment response) are conducted and other impacts are evaluated for the BIT reduction. The analysis results show that the core DNBR meets the safety criterion and the containment pressure is within the design value for the steam line rupture accident after the BIT reduction. The feasibility study report of Daya bay BIT reduction has been approved by NNSA. The site implementation of BIT reduction has ...

International Nuclear Information System (INIS)

ARIES-AT is a 1000 MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under ...

Energy Technology Data Exchange (ETDEWEB)

Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) are promoting construction plan of Material-Life Science Facility, which is consisted of Muon Science Facility and Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutrons generated by the spallation reaction induced by injecting a 1 MW pulsed proton beam onto a mercury target. Design of the spallation mercury target system is in progress to obtain good neutron performance keeping high reliability and safety. The target material is mercury. As a result of the spallation reaction, large amount of radioactive spallation products are to be contained in the mercury. Therefore to establish the safety of the target system, transient behaviors of the ...

Energy Technology Data Exchange (ETDEWEB)

According to biological and chemical control strategy for pest control, we investigate the dynamics of a predator-prey food chain with impulsive effect, periodic releasing natural enemies and spraying pesticide at different fixed times, by using impulsive differential equation. Choose pest birth rate r{sub 2} as control parameter, we show that there exists a stable pest-eradication periodic solution when r{sub 2} is less than some critical value r{sub 2}* and the system is permanence when r{sub 2} is larger than the critical value r{sub 2}*. By use of standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in prey, middle-predator and top predator. Furthermore, bifurcation diagrams have shown that there exists complexity for the pulsed system including periodic doubling cascade.

Energy Technology Data Exchange (ETDEWEB)

This report, which summarizes the result of preliminary conceptual design activities during Phase 1, follows the format of safety analysis report. The purpose of publishing this report is to gather all of the design information developed so far in a systematic way so that KALIMER designers have a common source of the consistent design information necessary for their future design activities. This report will be revised and updated as design changes occur and more detailed design specification is developed during Phase 2. Chapter 1 describes the KALIMER Project. Chapter 2 includes the top level design requirements of KALIMER and general plant description. Chapter 3 summarizes the design of structures, components, equipment and systems. Specific systems and safety analysis results are described in the remaining chapters. Appendix on the HCDA evaluation is attached at the end of this report.

British Library Electronic Table of Contents (United Kingdom)

Sex steroids and thyroid hormones play a key role in the development of the central nervous system. The critical role of these hormonal systems may explain the sensitivity of the hypothalamus, the cerebral cortex, and the hippocampus to endocrine-disrupting chemicals (EDC). This review examines the evidence for endocrine disruption of glial-neuronal functions in the hypothalamus, hippocampus, and cerebral cortex. Focus was placed on two well-studied EDC, the insecticide dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCB). DDT is involved in neuroendocrine disruption of the reproductive axis, whereas polychlorinated biphenyls (PCB) interact with both the thyroid hormone- and sex steroid-dependent systems and disturb the neuroendocrine control of reproduction and develo...

International Nuclear Information System (INIS)

This report presents the results of a systems failure analysis study of the CANDU 3 reactor design; the study was performed for the US Nuclear Regulatory Commission. As part of the study a review of the CANDU 3 design documentation was performed, a plant assessment methodology was developed, representative plant initiating events were identified for detailed analysis, and a plant assessment was performed. The results of the plant assessment included classification of the CANDU 3 event sequences that were analyzed, determination of CANDU 3 systems that are ''significant to safety,'' and identification of key operator actions for the analyzed events.

International Nuclear Information System (INIS)

The second international conference on containment design and operation included sessions on the following topics: performance and regulatory requirements; radionuclide behaviour; severe accident design and analysis; operation, maintenance, leaking and aging of containment systems; thermal hydraulic behaviour of containment systems; hydrogen mixing and mitigation; design methods and concepts; code validation; structural analysis and response tests; passive safety systems; aerosol behaviour; containment reliability, integrity, and risk assessment; hydrogen deflagration and detonation. Due prominence was given to CANDU and other PHWR reactors. The individual papers have been abstracted separately.

Energy Technology Data Exchange (ETDEWEB)

A model system, described by the consistent Vlasov-Poisson equations under periodical boundary conditions, has been studied numerically near the point of a marginal stability. The power laws, typical for a system, undergoing a second-order phase transition, hold in a vicinity of the critical point: (i) A {proportional_to} -{theta}{sup {beta}}, {beta}=1.907{+-}0.006 for {theta} {<=} 0, where A is the saturated amplitude of the marginally-stable mode; (ii) {chi} {proportional_to} {theta}{sup -{gamma}} as {theta} {yields} 0, {gamma}={gamma}{sub -}=1.020{+-}0.008 for {theta} < 0, and {gamma}={gamma}{sub +}=0.995{+-}0.020 for {theta} > 0, where {chi}={partial_derivative}A/{partial_derivative}F{sub 1} at F{sub 1} {yields} 0 is the susceptibility to external drive of the strain F{sub 1}; (iii) at {theta}=0 the system responds to external drive as A {proportional_to} F{sub 1}{sup ...

Energy Technology Data Exchange (ETDEWEB)

Probabilistic assessment methods can be used to identify specific plant vulnerabilities. Application of such methods can also facilitate selection among system design alternatives available for safety enhancements. The quality of assessment results is however strongly dependent on realistic and accurate input data for modelling of system component behaviour and failure modes during conditions to be assessed. Use of conservative input data may not lead to results providing guidance on safety upgrades. Adequate input data for probabilistic assessments seems to be lacking for at least failure modes of some electrical components when exposed to a fire. This report presents an attempt to improve the situation with respect to such input data. In order to take advantage of information in existing documentation of fire incident occurrences some of the lessons learned from the fire at Browns Ferry Nuclear Power ...

Energy Technology Data Exchange (ETDEWEB)

The development of KNGR (Korean Next Generation Reactor) is now in progress. KAERI is developing KNGR which is a advanced active PWR (pressurized water reactor) and 1350 MW electric capacities and is by based on UCN(Ulchin) 3 and 4 nuclear power plant which is a Korean standard PWR. In this report, the PZR (pressurizer) and Related System Design Features for KNGR which include PZR volume, PPCS (pressurizer safety valve)were analyzed. First, the Design Parameters between KNGR compared to UCH 3 and 4 were compared, and second, advanced design features of KNGR compared to UCN 3 and 4 were analyzed. After the present analysis, it has been concluded that the safety margins for the PZR level and pressure of KNGR were more increased by the larger PZR volume than those of UCN 3 and 4, for PZR minimum water level at reactor/turbine trip and PZR maximum pressure at LOCV(loss of condenser vacuum) of KNGR were higher and lower, ...

Science.gov (United States)

The surveillance systems have been widely used in automatic teller machines (ATMs), banks, convenient stores, etc. For example, when a customer uses the ATM, the surveillance systems will record his/her face information. The information will help us understand and trace who withdrew money. However, when criminals use the ATM to withdraw illegal money, they usually block their faces with something (in Taiwan, criminals usually use safety helmets or masks to block their faces). That will degrade the purpose of the surveillance system. In previous work, we already proposed a technology for safety helmet detection. In this paper, we propose a mask detection technology based upon automatic face recognition methods. We use the Gabor filters to generate facial features and utilize geometric analysis algorithms for mask detection. The technology can give an early warning to save-guards when ...

Energy Technology Data Exchange (ETDEWEB)

Certification as applied to existing computer codes includes the verification and validation process, placing the code in configuration control, establishing user qualification standards and training requirements. All software intended for use in critical calculations must be certified. This report is intended to fulfill the requirements for the certification of the SHIELD, SHLDED, GEDIT, GENPRT, FIPROD, FPCALC, and PROCES modules of the SHIELD system built February, 1992, by W.S. Parks. These modules are used for burnup, cooling, separate, and edit calculations.

Energy Technology Data Exchange (ETDEWEB)

Pile foundations are extensively used to support off-shore and on-shore structures. Under dynamic loads, the behavior of single pile is well understood. However the soil-pile-soil interaction studies are confusing, on which account the analyses do not necessarily predict response of the systems which may match satisfactorily with the performances. In this paper, the nature of dynamic loads is described, and solutions for soil-pile and pile-soil-pile interaction solutions by several authors are presented and a critical evaluation is made.

Energy Technology Data Exchange (ETDEWEB)

This heat exchanger is a critical step in the development of the Externally Fired Combined Cycle power system, a direct-coal combustion power plant (gas turbine). SiC is the only material with the needed resistance to creep, thermal shock, and oxidation; however a protective coating is needed. Ten candidate materials were identified: alumina-based materials, materials stable with SiO, and low expansion materials. An initial screening study should be performed.

UK PubMed Central (United Kingdom)

The neocortex plays a critical role in the gradual formation and storage of remote declarative memories. Because the circuitry mechanisms of systems-level consolidation are not well understood, the...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a method that can incorporate system contingencies into power system stabilizer (PSS) design. Selection of critical contingencies is first performed by a ranking of contingencies under a wide range of operating conditions according to a small signal stability index. A multi-objective optimization model is formulated to pursue satisfactory system damping performance under both pre-contingency and post-contingency situations. A recursive Genetic Algorithm is then presented to tune the PSS parameters so that the dynamic security criteria subject to contingencies are met under a wide range of operating conditions. Finally, an eight-machine system is utilized to demonstrate the effectiveness of the proposed approach and a comparison of the proposed method with a pre-contingency tuning scheme is reported. (author)

British Library Electronic Table of Contents (United Kingdom)

This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.

Energy Technology Data Exchange (ETDEWEB)

The book examines current experimental and clinical knowledge concerning the biological and biophysical effects of electromagnetic radiation, particularly that in the microwave range. The biophysical bases of the interaction of electromagnetic radiation with matter are reviewed with emphasis on biological systems, and the effects of radiation on critical biological systems, including the nervous, reproductive, visual and blood-forming systems are compared. Data concerning the lethal effects of nonionizing radiation is presented and characteristics of the effects of electromagnetic radiation on the whole mammalian organisms are examined. Various reactions of the neuroendocrine system to electromagnetic radiation are described, with particular attention given to the adrenal system, and the combined effects of ionizing and microwave radiation in the flight ...

International Nuclear Information System (INIS)

The vortex amplifier controller has no moving parts and therefore it can have extremely high reliability and avoid the maintenance problems associated with contaminated equipment. The vortex amplifier and its application to ventilation control of radioactive enclosures is described. Reverse purge vortex amplifier ventilation system control is also discussed. (U.K.).

Energy Technology Data Exchange (ETDEWEB)

The risk perception of the public consists of two components: the objectively factual component and the subjectively irrational component. The two strategies adopted by the German gas supply industry are the internal and the external communication strategy. Concepts and measures of accident precaution, registration and analysis of accident data (installation and operating errors, defects on flue systems, pipelines and valves, subsequent installation of gas appliances) are discussed. (R.P.)

International Nuclear Information System (INIS)

'Small radioactive source results in big accident' have occurred repeatedly in China and worldwide alike. Radioactive source management is one of the key activities for a nuclear power plant to maintain its good safety record and image to the public. From aspects of establishing the management system, centralized storage, periodic accounting, performing whole process control to the source usage and experience feedback etc., the author reports the practice and experience of radioactive source management in Daya Bay Nuclear Power Plant

International Nuclear Information System (INIS)

Apppendix B of 10 CFR Part 50 establishes quality assurance requirements for the operation of nuclear power plant safety-related structures, systems and components. This Guide describes an acceptable method for complying with these regulations with regard to overall quality assurance program requirements for the operation phase of nuclear power plants. Input to this Guide has been provided by the Advisory Committee on Reactor Safeguards.

International Nuclear Information System (INIS)

Any transport of nuclear material is associated with the risk of contamination after release into working areas or environment. stationary installed safe geometry vessels with pneumatic transfer between them offer unique safety features and reduce operating costs. The article describes the case of HTR fuel spheres, where a specially designed conveying system has been developed and the prototype conveyor has been tested.

Energy Technology Data Exchange (ETDEWEB)

Today, highly frequent radio waves are regarded as undangerous to man. Diseases seen at radar-technicians during the 2nd World War, however, indicated that microwaves applied in radar systems were hazardous to health. The Russian work medicine has been knowing microwave-caused hazards in industry since the beginning of the thirties. Therefore in some East-European countries there are terms of protection and severe norms of safety for the staying of persons in the radiation sphere of microwaves.

International Nuclear Information System (INIS)

The two favourable dry storage concepts being under consideration in the Federal Republic of Germany are presented and the physical behaviour or natural convection cooling with air is explained. With the three examples cask store, vault storage horizontally and vertically arranged the main thermodynamical design parameters and their influence on the efficiency of the cooling system and on the temperature distribution inside the store and of the stored material are discussed. Moreover, the importance of the fulfilment and the harmony of all safety criteria and the difficulties while to do so are carried out especially with the vault store.

Energy Technology Data Exchange (ETDEWEB)

CommAspen is a new agent-based model for simulating the interdependent effects of market decisions and disruptions in the telecommunications infrastructure on other critical infrastructures in the U.S. economy such as banking and finance, and electric power. CommAspen extends and modifies the capabilities of Aspen-EE, an agent-based model previously developed by Sandia National Laboratories to analyze the interdependencies between the electric power system and other critical infrastructures. CommAspen has been tested on a series of scenarios in which the communications network has been disrupted, due to congestion and outages. Analysis of the scenario results indicates that communications networks simulated by the model behave as their counterparts do in the real world. Results also show that the model could be used to analyze the economic impact of communications congestion and outages.

British Library Electronic Table of Contents (United Kingdom)

Actinidia deliciosa endosperm-derived callus culture is stable over a long period of culture. This system was used to investigate the ultrastructure of extracellular matrix occurring in morphogenic tissue. Specimens were prepared by different biological techniques (chemical fixation, liquid nitrogen fixation, glycerol substitution, critical-point drying, lyophilization) and observed by scanning electron microscopy (SEM). Fresh and wet samples were analyzed with the use of environmental scanning electron microscopy (ESEM). Extracellular matrix was observed on the surface of cell clusters as a membranous layer or reticulated network, shrunken or wrinkled, depending on the procedure. Generally, shrunken membranous layers with a globular appearance and fibrils were noted after critical-point d...

International Nuclear Information System (INIS)

Investigatins into the welding of alloy 800 at the Reactor Fuel Element Laboratories, Springfields, commenced about three years ago following an extended development programme on tube to tube plate welding of low alloy and stainless steels for the Prototype Fast Reactor. The techniques and approach developed for critical fuel element welding applications had proved equally suitable for the precision welding requirements on the much heavier sections of heat exchangers. It had been demonstrated that the same control of weld quality and profile could be achieved with consistency and the permissible range of critical parameters could be readily defined. Because of this, development work was continued to include other materials, such as alloy 800, which might be of potential use. The tungsten inert gas (T.I.G.) arc welding process is used, and the equipment, including the control system, is described. Tube to tube-plate welding, ...

Energy Technology Data Exchange (ETDEWEB)

The Authenticated Tracking and Monitoring System (ATMS) has been designed to address the need for global monitoring of the status and location of proliferation-sensitive items. Conceived to utilize the proposed Global Verification and Location System (GVLS) satellite link, ATMS could use the existing International Maritime Satellite commercial communication system until GVLS is operational. The ATMS concept uses sensor packs to monitor items and environmental conditions, collects a variety of events data through a sensor processing unit, and transmits the data to a satellite, which then sends data to ground stations. Authentication and encryption algorithms will be used to secure the data. A typical ATMS application would be to track and monitor the safety and security of a number of items in transit along a scheduled shipping route. This paper also discusses a possible proof-of-concept ...

Energy Technology Data Exchange (ETDEWEB)

Encouragement and incentives ar being given in many counties to the electricity industry and private sector to install, own and operate renewable energy systems. The impact of renewable energy installations connected to the grid or operating independently is an important issue concerning the technical and economic viability of harnessing these emerging energy sources. This paper brings out the need for developing and implementing a strategy for comprehensive and accurate protection and control systems for these dispersed generator installations. It appears that a combination of discrete and fuzzy logic devices on an integrated platform will be a novel technique for the protection and control schemes. This development has the potential to be cost effective and suits the requirements for operating renewable energy systems safety. (author). 2 figs., 16 refs.

International Nuclear Information System (INIS)

Theoretical description of Raman scattering in disordered alloys of Ti and Zr with transition metals of groups 5-8 of the Mendeleev Periodic System in critical range of concentrations (CRC) is given. Results of Raman scattering experiment in the system Ti_1_-_xF_x at 0.0005

International Nuclear Information System (INIS)

The experimental results of the components substitution effect on crystal structure, electronic transport properties, and Eu effective valence in solid solutions based on EuCu_2Si_2 and EuPd_2Si_2 ternary compounds are presented. It is shown, that when the Eu effective valence reaches the critical value #nu#"c"r_e_f_f=2.1, corresponding to degeneration of the 4f"7 and 4f"6 configurations, the condition of the concentrated Kondo system and an essential perturbation of the band electron spectrum near the Fermi level occur. (orig.).

British Library Electronic Table of Contents (United Kingdom)

We discuss the feasibility of a hierarchical protocol whereby the description and prediction of adsorbed fluids in confined systems at the mesoscopic scale is achieved by use of interface potentials that are obtained from raw molecular simulation data. Starting from a microscopic description of a fluid?s interface on a flat substrate, we attempt to extract the minimum information that is required in order to predict the behavior of that fluid at larger length scales from coarse grained surface Hamiltonians. A critical assessment of this procedure hinges on controversial aspects of wetting behavior and more generally on the meaning of metastability and instability of thermodynamic systems.

International Nuclear Information System (INIS)

Commissioning of a Pressurized heavy water reactor (PHWR) plant of NPCIL involves three phases viz phase-A which consist of pre-criticality activities such as hydro test, air hold test, no load test of motors etc., phase-B consist of criticality and post criticality physics experiments. The phase-C, which is considered the major phase, consist of initial power raise to about 10 % , TG rolling, synchronization, going to significant power in steps and performance tests such as load rejection tests from various power levels. In order to have smooth commissioning for the Phase-C, an integrated team consisting of engineers from various design and analysis groups of NPCIL headquarters was formed to participate along with site O and M engineers, closely observe and coordinate phase-C commissioning activities. During this commissioning some major events and observations took place. An attempt is made to bring out the salient ...

Energy Technology Data Exchange (ETDEWEB)

The Savannah River Site is a Department of Energy facility. The facility stores, processes, and works with fissionable material at a number of locations. Technical standards and US Department of Energy orders, require these locations to be monitored by criticality alarm systems under certain circumstances. The Savannah River Site calls such instruments Nuclear Incident Monitors or NIMs. The Sole purpose of the Nuclear Incident Monitor is to provide an immediate evacuation signal in the case of an accidental criticality in order to minimize personnel exposure to radiation. The new unit is the third generation Nuclear Incident Monitor at the Savannah River Site. The second generation unit was developed in 1979. It was designed to eliminate vacuum-tube circuits, and was the first solid state NIM at SRS. The major design objectives of the second generation NIM were to improve reliability and reduce maintenance costs. Ten ...

International Nuclear Information System (INIS)

This document presents the way which the 8th principle of the quality management system 'Process approach' is applied, the principle that is identified and used by international standard ISO 9000. In order to understand the evolution of the management system requirements, as used today in different activities namely, industry, services, and nuclear activities, the authors present an evolution of the quality concept and its traceability to different standards, applicable in time. There are described the requirements of ISO 9001 standard, that represents the most widely spread model for modern organization management and the IAEA concerns related to integration of the above standard requirements into the most recent safety IAEA standard 'The Management System for facilities and activities'. The IAEA Safety Standard GS-R-3 describes a management model considering both the evolution of ...

British Library Electronic Table of Contents (United Kingdom)

Introduction: Patients in underdeveloped nations have limited access to life-saving medical technology including cardiac rhythm management (CRM) devices. We evaluated alternative means to provide such technology to this patient population while assessing the safety and efficacy of such a practice. Methods: Patients in the United States with clinical indications for extraction of CRM devices were consented. Antemortem CRM devices were cleaned and sterilized following a protocol established at our institution. Surveillance in vitro cultures were performed for quality assurance. The functional status of pulse generators was tested with a pacing system analyzer to confirm at least 70% battery life. Most generators were transported, in person, to an implanting institution in Nicaragua. Recipien...

International Nuclear Information System (INIS)

An overview of LOCA analysis in Japanese industry is presented. The BASH-M code, developed for large scale LOCA reflooding analysis, is given as an example of verification and improvement of US computer programs are given. The code's application to the operational safety analysis concerns the following main areas: 1D drift flux model base computer program CANAC; CANAC-based advanced training simulator; emergency operating procedures. The author considers also the code application to the following new PWR safety design concepts: use of steam generators for decay heat removal at LOCA conditions; use of horizontal type steam generator for maintaining two-phase natural circulation under the reactor coolant system submerged. 9 figs.

Energy Technology Data Exchange (ETDEWEB)

Metal machining facilities pose interesting design problems. This article provides an overview of key environmental control considerations and ways to deal with them. Machine shops offer a variety of environmental control challenges to mechanical engineers. Among the design problems that must be considered include: whether to provide space heating only or year-round air conditioning; temperature and relative humidity requirements; air cleanliness; exhaust air requirements; the type of HVAC system to be used; industrial waste and plumbing considerations; compressed air needs; and noise control. In addition, the designer must comply with worker health and safety and environmental protection regulations set forth by the National Institute of Safety and Health (NIOSH), OSHA, and EPA, as well as with any applicable state and local requirements.

International Nuclear Information System (INIS)

Mitsubishi is developing a new type of accumulator incorporating the technology of fluidics as one of the seeds for the improved safety of the newly constructed pressurized water reactor plants. This accumulator employs a vortex flow control device, called a vortex damper, as a fluidic device to simplify the safety systems. A fundamental experimental study with a one-fifth scale model and confirmation tests with a one-third scale model to develop the vortex damper have been carried out, and satisfactory results have been achieved. The results of the confirmation tests under the prototype pressure conditions agree well with the basic tests. The flow rate ratio can be 5 to 6. The pressure loss coefficient in the large flow rate period is 8. A cavitation factor is the main parameter of the flow rate coefficient.

International Nuclear Information System (INIS)

In the safety assessment of a high-level radioactive waste (HLW) disposal system, it is required to estimate radiological impacts on future human beings arising from potential radionuclide releases from a deep repository into the surface environment. In order to estimated the impacts, a biosphere model is developed by reasonably assuming radionuclide migration processes in the surface environment and relevant human lifestyles. It is important to modify the present biosphere models or to develop alternative biosphere models applying the biosphere models according to quality and quantify of the information acquired through the siting process for constructing the repository. In this study, alternative biosphere models were developed taking geosphere-biosphere interface of marine environment into account. Moreover, the flux to dose conversion factors calculated by these alternative biosphere models was compared with those by the present basic ...

Energy Technology Data Exchange (ETDEWEB)

Due to changed operational conditions and because of the increasing age of several hydro power plant components, there is an increasing risk of damages and the control of degradation mechanisms is of increasing significance. Therefore lifetime considerations for safety relevant components in pumped-storage plants become more and more important. The development of a lifetime management system, in conjunction with monitoring systems and specific surveillance for a group of pumped-storage power plants of different ages and in a wide range of power output is presented. The special focus is on the impact of fatigue strength considerations within this framework. The applied procedure will be described for typical mechanical components in pumped-storage plants exemplarily. (orig.)

Science.gov (United States)

This student manual, part of a small-engine repair series on servicing fuel systems, is designed for use by special needs students in Texas. The manual explains in pictures and short sentences, written on a low reading level, the job of replacing carburetor diaphragms. Along with the steps of this repair job, specific safety and caution information is frequently noted. To reinforce consistency in material presented to the slow learners, the pictures and written words correspond exactly with the pictures and wording on a corresponding audiovisual presentation. A progress chart for rating the students is included in the manual. (KC)

International Nuclear Information System (INIS)

A lot of effort has been made to spread the application of RTOS in embedded system development in China. RTOS, #mu#C/OS and #mu#C/OS-II, with its opened source code, is well known in embedded systems. Learning RTOS, Using RTOS, becomes more and more popular. The Book of 'Micro C/OS-II The Real-Time Kennel Second Edition' was published in 2002. Here some new progress of the RTOS, especially the safety certifications, the reliability of software is introduced. (authors)

Energy Technology Data Exchange (ETDEWEB)

Sudden changes in the temperature of flowing liquids can result in transient buoyancy forces which strongly impact the flow hydrodynamics via flow stratification. These effects have been studied for the case of potential flow of stratified liquids to line sinks, but not for moderator flow in SRS reactors. Standard codes, such as TRAC and COMMIX, do not have the capability to capture the stratification effect, due to strong numerical diffusion which smears away the hot/cold fluid interface. A related problem with standard codes is the inability to track plumes injected into the liquid flow, again due to numerical diffusion. The combined effects of buoyant stratification and plume dispersion have been identified as being important in operation the Supplementary Safety System which injects neutron-poison ink into SRS reactors to provide safe shutdown in the event of safety rod failure. The MODFLOW code discussed here provides ...

Science.gov (United States)

Laser devices are currently in widespread use in particular by armed forces for different tasks. Electro-optical sensors as well as unprotected human eyes are extremely sensitive to laser radiation and can be permanently damaged from direct or reflected beams. Laser damage depends on the interaction between the laser beam and the atmosphere in which it traverses. The atmospheric conditions, including the range, terrain features, turbulence, and atmospheric particulates, may alter the laser's effect on different electro-optical devices and systems. When a laser beam passes through the atmosphere the optical turbulence affects the beam. As a result, temporal intensity fluctuations (scintillations) or spatial variations in intensity within a beam cross-section occur. Atmospheric scintillations pose a safety problem because an observer or sensor can be subjected to the risk of a localized irradiance (local focusing effect) much greater than that ...

Energy Technology Data Exchange (ETDEWEB)

Safety in general and harmonization of International Maritime Organization rules on mobile offshore drilling rig operation in particular are discussed. The improvement of the industry's safety record is also discussed.

International Nuclear Information System (INIS)

The FFTF is a 400-MWt sodium-cooled fast neutron flux test reactor located on the US government-owned Hanford Site in southeastern Washington state. The reactor is operated for the US Department of Energy by the Westinghouse Hanford Company. Since FFTF started routine operation in 1982, the commercially fabricated driver fuel has performed flawlessly to well beyond the design goal peak burnup of 80 MWd/kgM. The core average discharge exposure is now some 60% beyond the original design expectations and attests to the ruggedness and reliability of the mixed oxide fuel system. In Cycle 9 sixteen long-life assemblies were installed to begin the irradiation of mixed oxides in the advanced low-swelling alloy HT-9 as the Core Demonstration Experiment (CDE). Operation of the plant from initial startup testing to ten cycles of operation has confirmed that the nuclear characteristics are well within the design predictions, and all parameters have remained inside the ...

Energy Technology Data Exchange (ETDEWEB)

This report provides an assessment of the designs of turret and swivel systems for floating production, storage and offloading (FPSO) vessels and floating storage Units (FSU) which are either purpose built or converted from tankers. Use of FPSO and FSO in the North Sea with the move to subsea and deepwater production is discussed, and the background to FPSO and FSU turret systems is traced. Details are given of general issues relating to ship structure, systems affecting the turret, swivel systems, mooring systems, turret loading, scaffolding and support structure, on-board personnel, and construction standards. Turret system components and types are described, and failure modes, operation and safety relevant components are examined. Inspection and maintenance, examples of good and poor practice, and applicable regulations are considered. ...