Application software for new BEPC interlock system

International Nuclear Information System (INIS)

Tang Shuming; Na Xiangyin; Chen Jiansong; Yu Yulan

1997-01-01

New BEPC (Beijing electron Positron collider) interlock system has been built in order to improve the reliability of personnel safety and interlock functions. Moreover, the system updates BEPC operation message once every 6 seconds, which are displayed on TV screens at the major entrances. Since March of 1996, new BEPC interlock system has been operating reliably. The hardware of the system is based on Programmable Logic Controllers (PLC). A multimedia IBM/PC-586 as the host computer of the PLCs, monitors the PLC system via serial port COM2. The PC communicates with the central computer VAX-4500 of BEPC control system and gets operating massage of the accelerator through serial port COM3. The application software on the host computer has been developed. Visual C++ for MS-Windows 3.2 TM is selected as the work bench. It provides nice tools for building programs, such as APP STUDIO, CLASS WIZARD, APP WIZARD and debugger tool. The author describes the design idea and the structure of the application software. Error tolerance is taken into consideration. The author also presents a small database and its data structure for the application

Availability Analysis of the Ventilation Stack CAM Interlock System

CERN Document Server

Young, J

2000-01-01

Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability.

Compositional Model Checking of Interlocking Systems for Lines with Multiple Stations

DEFF Research Database (Denmark)

Macedo, Hugo Daniel dos Santos; Fantechi, Alessandro; Haxthausen, Anne Elisabeth

2017-01-01

In the railway domain safety is guaranteed by an interlocking system which translates operational decisions into commands leading to field operations. Such a system is safety critical and demands thorough formal verification during its development process. Within this context, our work has focused...

Formal Modeling and Verification of Interlocking Systems Featuring Sequential Release

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2015-01-01

In this paper, we present a method and an associated tool suite for formal verification of the new ETCS level 2 based Danish railway interlocking systems. We have made a generic and reconfigurable model of the system behavior and generic high-level safety properties. This model accommodates seque...... SMT based bounded model checking (BMC) and inductive reasoning, we are able to verify the properties for model instances corresponding to railway networks of industrial size. Experiments also show that BMC is efficient for finding bugs in the railway interlocking designs....

Formal Modeling and Verification of Interlocking Systems Featuring Sequential Release

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2014-01-01

In this paper, we present a method and an associated tool suite for formal verification of the new ETCS level 2 based Danish railway interlocking systems. We have made a generic and reconfigurable model of the system behavior and generic high-level safety properties. This model accommodates seque...... SMT based bounded model checking (BMC) and inductive reasoning, we are able to verify the properties for model instances corresponding to railway networks of industrial size. Experiments also show that BMC is efficient for finding bugs in the railway interlocking designs....

Distributed Supervisory Protection Interlock System

International Nuclear Information System (INIS)

Walz, H.V.; Agostini, R.C.; Barker, L.; Cherkassky, R.; Constant, T.; Matheson, R.

1989-03-01

The Distributed Supervisory Protection Interlock System, DSPI, is under development at the Stanford Linear Accelerator Center for requirements in the areas of personnel protection, beam containment and equipment protection interlocks. The DSPI system, distributed over the application site, consists of segments with microprocessor-based controller and I/O modules, local area networks for communication, and a global supervisor computer. Segments are implemented with commercially available controller and I/O modules arranged in local interlock clusters, and associated software. Segments provide local interlock data acquisition, processing and control. Local area networks provide the communication backbone between segments and a global supervisor processor. The supervisor processor monitors the overall system, reports detail status and provides human interfaces. Details of an R and D test system, which will implement the requirements for personnel protection of 4 typical linear accelerator sectors, will be described. 4 refs., 2 figs

Modular safety interlock system for high energy physics experiments

International Nuclear Information System (INIS)

Kieffer, J.; Golceff, B.V.

1980-10-01

A frequent problem in electronics systems for high energy physics experiments is to provide protection for personnel and equipment. Interlock systems are typically designed as an afterthought and as a result, the working environment around complex experiments with many independent high voltages or hazardous gas subsystems, and many different kinds of people involved, can be particularly dangerous. A set of modular hardware has been designed which makes possible a standardized, intergrated, hierarchical system's approach and which can be easily tailored to custom requirements

Survey of electronic safety systems in accelerator applications

International Nuclear Information System (INIS)

Mahoney, K.

1997-01-01

This paper presents the preliminary results and analysis of a comprehensive survey of the implementation of accelerator safety interlock systems from over 30 international labs. At the present time there is not a self consistent means to evaluate both the experiences and level of protection provided by electronic safety interlock systems. This research is intended to analyze the strength and weaknesses of several different types of interlock system implementation methodologies. Research, medical, and industrial accelerators are compared. Thomas Jefferson National Accelerator Facility (TJNAF) was one of the first large particle accelerators to implement a safety interlock system using programmable logic controllers. Since that time all of the major new U.S. accelerator construction projects plan to use some form of programmable electronics as part of a safety interlock system in some capacity

Interlocked systems in nanomedicine.

Science.gov (United States)

Ornelas-Megiatto, Catia; Becher, Tiago B; Megiatto, Jackson D

2015-01-01

The concept of Nanomedicine emerged along with the new millennium, and it is expected to provide solutions to some of modern medicine's unsolved problems. Nanomedicine offers new hopes in several critical areas such as cancer treatment, viral and bacterial infections, medical imaging, tissue regeneration, and theranostics. To explore all these applications, a wide variety of nanomaterials have been developed which include liposomes, dendrimers, nanohydrogels and polymeric, metallic and inorganic nanoparticles. Recently, interlocked systems, namely rotaxanes and catenanes, have been incorporated into some of these chemical platforms in an attempt to improve their performance. This review focus on the nanomedicine applications of nanomaterials containing interlocked structures. The introduction gives an overview on the significance of interdisciplinary science in the progress of the nanomedicine field, and it explains the evolution of interlocked molecules until their application in nanomedicine. The following sections are organized by the type of interlocked structure, and it comprises details of the in vitro and/or in vivo experiments involving each material: rotaxanes as imaging agents, rotaxanes as cytotoxic agents, rotaxanes as peptide transporters, mechanized silica nanoparticles as stimuli responsive drug delivery systems, and polyrotaxanes as drug and gene delivery systems.

Residual Heat Removal System qualitative probabilistic safety analysis before and after auto closure interlock removal

International Nuclear Information System (INIS)

Mikulicic, V.; Simic, Z.

1992-01-01

The analysis evaluates the consequences of the removal of the auto closure interlock (ACI) on the Residual Heat Removal System (RHRS) suction/isolation valves at the nuclear power plant. The deletion of the RHRS ACI is in part based on a probabilistic safety analysis (PSA) which justifies the removal based on a criterion of increased availability and reliability. Three different areas to be examined in PSA: the likelihood of an interfacing system LOCA; RHRS availability and reliability; and low temperature overpressurization control. The paper emphasizes particularly the RHRS unavailability and reliability evaluation utilizing the current control circuitry configuration and then with the proposed modification to the control circuitry. (author)

Definition and means of maintaining the process vacuum liquid detection interlock systems portion of the PFP safety envelope

International Nuclear Information System (INIS)

LINTHO, J.E.

2003-01-01

The purpose of this document is to record the technical evaluation of the Technical Safety Requirements described in the Plutonium Finishing Plant (PFP) Safety Technical Requirements, HNF-SD-CP-OSR-010/Rev.1, Section 3.1.1, ''Criticality Prevention System.'' This document also defines the Safety Envelope (SE) for the liquid detection interlock system in the Process Vacuum System. The SE is derived FR-om information in the Plutonium Finishing Plant Final Safety Analysis Report (PFP FSAR), HNF-SD-CP-SAR-021, Rev 4, and the Criticality Safety Analysis Report (CSAR) for the 26-inch Hg Vacuum System, WHC-SD-SQA-CSA-20159, Rev 0-A. This document, with its appendices, provides the following: (1) The system functional requirements for determining system operability (Section 3). (2) Evaluations of equipment to determine the safety envelope boundary for the system (Section 4 list of SE boundary drawings). (3) A list of the safety envelope equipment (Appendix B). (4) Functional requirements for the individual safety envelope equipment, including appropriate set points and process parameters (Section 4). (5) A list of the operational and surveillance procedures necessary to operate and maintain the system equipment within the safety envelope (Sections 5 and 6 and Appendix A)

Central system of Interlock of ITER, high integrity architecture

International Nuclear Information System (INIS)

Prieto, I.; Martinez, G.; Lopez, C.

2014-01-01

The CIS (Central Interlock System), along with the CODAC system and CSS (Central Safety System), form the central I and C systems of ITER. The CIS is responsible for implementing the core functions of protection (Central Interlock Functions) through different systems of plant (Plant Systems) within the overall strategy of investment protection for ITER. IBERDROLA supports engineering to define and develop the control architecture of CIS according to the stringent requirements of integrity, availability and response time. For functions with response times of the order of half a second is selected PLC High availability of industrial range. However, due to the nature of the machine itself, certain functions must be able to act under the millisecond, so it has had to develop a solution based on FPGA (Field Programmable Gate Array) capable of meeting the requirements architecture. In this article CIS architecture is described, as well as the process for the development and validation of the selected platforms. (Author)

The use of microprocessors at TRIUMF in the control of radiation safety interlock systems

International Nuclear Information System (INIS)

King, L.

1988-01-01

At TRIUMF the cyclotron vault, all primary beam lines, and each experimental area has a dedicated control unit to manage the safety interlock control of the area lockup sequence, beam blocker drive and area access. Typically each area has 24 devices which are monitored to control 16 outputs. These control units (Area Safety Units) were first implemented through the use of relay logic. The relay logic was reliable but difficult to modify to incorporate changes to the areas. In 1979 it was decided to use microprocessors in the form of single board computers to control the Area Safety Units. The details of the hardware and software is discussed as well as the advantages of microprocessor control

The vacuum interlock system for the PETRA III beamlines

Energy Technology Data Exchange (ETDEWEB)

Degenhardt, Markus; Hahn, Ulrich; Hesse, Mathias; Schulte-Schrepping, Horst [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2008-07-01

The storage ring PETRA at DESY in Hamburg is being reconstructed into the third generation source for synchrotron radiation, PETRA III. The up to 100 m long beamlines are large UHV-systems that guide the synchrotron radiation from the storage ring to the experiments. Each beamline will be equipped with a vacuum interlock system to ensure the safe operation of the vacuum components. In particular the task of the vacuum interlock is to prevent faulty operations that can cause a ventilation of the vacuum system or a damage of vacuum components by the high power synchrotron radiation beam. The interlock system will be implemented as a PLC that is connected to a distributed input/output layer via a field bus system. As a specialty, the PLC will be realised as a soft-PLC running on a PC with a real time windows operating system. Another specialty is the visualisation and remote control of the vacuum interlock system by means of a website. At the beamline the interlock will be operated via a touch panel that displays the visualisation website. Additionally, the interlock can be remotely operated from any location by opening the visualisation website with a browser. The interlock is protected against unauthorised operation by a login page. All relevant interlock data will be fed into the existing network-based archive system.

Interlocks for the LEP Radio-Frequency System

CERN Document Server

Livesley, S

2000-01-01

Interlocks for the LEP RF system totalled more than 7000. They provided protection for the personnel and a wide range of equipment: copper cavities, superconducting cavities, klystrons and high voltage equipment. The interlock system layout, functionality and components are described.

Definition and means of maintaining the process vacuum liquid detection interlock systems portion of the PFP safety envelope

International Nuclear Information System (INIS)

THOMAS, R.J.

1999-01-01

The Process Vacuum Liquid Detection interlock systems prevent intrusion of process liquids into the HEPA filters downstream of demisters No.6 and No.7 during Process Vacuum System operation. This prevents liquid intrusion into the filters, which could cause a criticality. The Safety Envelope (SE) includes the equipment, which detects the presence of liquids in the vacuum headers; isolates the filters; shuts down the vacuum pumps; and alarms the condition. This report identifies the equipment in the SE operating, maintenance, and surveillance procedures needed to maintain the SE equipment; and rationale for exclusion of some equipment and testing from the SE

Control and Interlocking System for Bending Magnet Front-end at Indus-2

Science.gov (United States)

Kane, Sanjeev R.; Garg, Chander Kant; Nandedkar, R. V.

2007-01-01

We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ˜ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0.

Control and Interlocking System for Bending Magnet Front-end at Indus-2

International Nuclear Information System (INIS)

Kane, Sanjeev R.; Garg, Chander Kant; Nandedkar, R. V.

2007-01-01

We present control and interlock system developed for Indus-2 bending magnet front-end. The paper describes in detail the control of various signals associated with the front-end and the interlocking scheme implemented for the installed front-end. The number of signals associated with each front-end is ∼ 75. A control system is designed for monitoring temperature, pressure, airflow, water flow and control of vacuum gauges, fast shutter, water cooled shutter, safety shutter, pneumatic gate valves, sputter ion pump power supplies, beam position monitor etc. Two independent signals are generated for critical components that are used for software interlock and hard-wired interlock. The front-end control system is VME based and window 2000/XP workstation as an operator console. The CPU used is Motorola 68000-processor board of the VME bus having OS-9 real time operating system. One VME crate serves a cluster of 2-3 front ends. The communication between the VME and the workstation is linked over RS232 serial communication. The sputter ion power supplies are connected over isolated RS485 network. Critical protection features are implemented so that no single failure can render the system unsafe. This is implemented by providing two independent chains of protection (1) Hard wired in which relay logic is used and (2) Software. A Graphical User Interface (GUI) is developed using Lab view Version 7.0

Availability Analysis of the Ventilation Stack CAM Interlock System

International Nuclear Information System (INIS)

YOUNG, J.

2000-01-01

Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

Evaluation of a fast PLC module in prospect of the LHC beam interlock system

CERN Document Server

Zaera-Sanz, Manuel

2005-01-01

The LHC Beam Interlock system requires a controller performing a simple matrix function to collect the different beam dump requests. To satisfy the expected safety level of the Interlock, the system should be robust and reliable. The PLC is a promising candidate to fulfil both aspects but too slow to meet the expected response time which is of the order of mseconds. Siemens has introduced a “so called” fast module (FM352-5 Boolean Processor) that provides independent and extremely fast control of a process within a larger control system using an onboard processor, a Field Programmable Gate Array (FPGA), to execute code in parallel which results in extremely fast scan times. It is interesting to investigate its features and to evaluate it as a possible candidate for the beam interlock system. This note publishes the results of this study. As well, this note could be useful for other applications requiring fast processing using a PLC.

A Domain-Specific Language for Railway Interlocking Systems

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2014-01-01

). Furthermore, the paper describes an interlocking table generator (ITG) that generates automatically a well-formed interlocking table from a well-formed railway network layout. Experiments with the DSL and ITG using the RAISE tools and the C++ implementation show that the use of the DSL and ITG can increase...... the productivity and significantly reduce errors in the specifications of railway interlocking systems....

PLC-based interlock system for superconducting magnets

International Nuclear Information System (INIS)

Agostini, R.C.; Barker, L.; Hodgers, J.; Reagan, D.; Walz, H.V.

1989-01-01

Conventional interlock systems rely heavily on hard-wired electromagnetic relays. Although this approach is well understood and has proven to be reliable, several drawbacks plague the designer as well as the repairman. If larger systems have to be implemented in relay logic, the complexity limit is soon reached; the systems become too bulky, and wiring expenses sky-rocket; moreover, the intelligence of those designs is limited in such a way that desirable features such as self-tests have to be left out. Additionally, relay interlocks are inherently inflexible: if the configuration of the system they protect has to change, a disproportional amount of time, work and money has to be invested in order to adapt the hard-wiring of the interlock system to the new requirements. Repair work is often unnecessarily delayed due to the lack of adequate documentation

A new interlock design for the TESLA RF system

International Nuclear Information System (INIS)

Leich, H.; Kahl, J.; Choroba, S.; Grevsmuehl, T.; Heidbrook, N.

2001-01-01

The RF system for TESLA requires a comprehensive interlock system. Usually interlock systems are organized in a hierarchical way. In order to react to different fault conditions in a fast and flexible manner a nonhierarchical organization seems to be the better solution. At the TESLA Test Facility (TTF) at DESY the authors will install a nonhierarchical interlock system that is based on user designed reprogrammable gate-arrays (FPGA's) which incorporate an embedded microcontroller system. This system could be used later for the TESLA linear collider replacing a strictly hierarchical design

The multi-interlock and check of logical system for 5 MW low power reactor automatic rod

International Nuclear Information System (INIS)

Li Guangjian; Zhao Zengqiao

1992-01-01

The safety and reliability of the logical system for 5 MW LPR automatic rod are improved, because of using multi-interlock and manual check on line. The design character and function of the logical system are introduced

Evaluation and application of a fast module in a PLC based interlock and control system

International Nuclear Information System (INIS)

Zaera-Sanz, M

2009-01-01

The LHC Beam Interlock system requires a controller performing a simple matrix function to collect the different beam dump requests. To satisfy the expected safety level of the Interlock, the system should be robust and reliable. The PLC is a promising candidate to fulfil both aspects but too slow to meet the expected response time which is of the order of μseconds. Siemens has introduced a 'so called' fast module (FM352-5 Boolean Processor). It provides independent and extremely fast control of a process within a larger control system using an onboard processor, a Field Programmable Gate Array (FPGA), to execute code in parallel which results in extremely fast scan times. It is interesting to investigate its features and to evaluate it as a possible candidate for the beam interlock system. This paper publishes the results of this study. As well, this paper could be useful for other applications requiring fast processing using a PLC.

Applied Bounded Model Checking for Interlocking System Designs

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf

2014-01-01

In this paper the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification o...

Applied Bounded Model Checking for Interlocking System Designs

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf

2013-01-01

In this article the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification...

National Synchrotron Light Source angiography personnel protection interlock

International Nuclear Information System (INIS)

Gmuer, N.; Larson, R.; Thomlinson, W.

1992-06-01

This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system

National Synchrotron Light Source angiography personnel protection interlock

Energy Technology Data Exchange (ETDEWEB)

Gmuer, N.; Larson, R.; Thomlinson, W.

1992-06-01

This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system.

Hardwired interlock system with fault latchability and annunciation panel for electron accelerators

International Nuclear Information System (INIS)

Mukesh Kumar; Roychoudhury, P.; Nimje, V.T.

2011-01-01

A hard-wired interlock system is designed, developed, installed and tested to ensure healthy status for interlock signals, coming from the various sub-systems of electron accelerators as digital inputs. Each electron accelerator has approximately ninety-six interlock signals. Hardwired Interlock system consists of twelve-channel 19 inches rack mountable hard-wired interlock module of 4U height. Digital inputs are fed to the hard-wired interlock module in the form of 24V dc for logic 'TRUE' and 0V for logic 'FALSE'. These signals are flow signals to ensure cooling of the various sub-systems, signals from the klystron modulator system in RF Linac to ensure its healthy state to start, signals from high voltage system of DC accelerator, vacuum signals from vacuum system to ensure proper vacuum in the electron accelerator, door interlock signals, air flow signals, and area search and secure signals. This hard-wired interlock system ensures the safe start-up, fault annunciation and alarm, fault latchablity, and fail-safe operation of the electron accelerators. Safe start-up feature ensures that beam generation system can be made ON only when cooling of all the electron accelerator sub-systems are confirmed, all the fault signals of high voltage generation system are attended, proper vacuum is achieved inside the beam transport system, all the doors are closed and various areas have been searched and secured manually. Fault annunciation and alarm feature ensures that during the start up and operation of the electron accelerators, if any fault is there, that fault signal window keeps on flashing with red colour and alarm is sounded till the operator acknowledges the fault. Once acknowledged, flashing and alarm stops but display of the window in red colour remains till the operator clears the fault. Fault latchability feature ensures that if any fault has happened, accelerator cannot be started again till the operator resets that interlock signal. Fail-safe feature ensures

Radiation interlocks - The choice between conventional hard-wired logic and computer-based systems

International Nuclear Information System (INIS)

Crook, K.F.

1987-01-01

During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system? Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy (DOE) has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper reviews the status of the committee's recommendations, and describes radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional (relay) approach and designs using computers

Radiation interlocks: The choice between conventional hard-wired logic and computer-based systems

International Nuclear Information System (INIS)

Crook, K.F.

1986-11-01

During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system. Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper will review the status of the committee's recommendations, and describe radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional relay approach and designs using computers. 6 refs., 6 figs

Enhancing the Use of Vehicle Alcohol Interlocks With Emerging Technology.

Science.gov (United States)

Voas, Robert B

2014-01-01

Among the earliest applications of health technologies to a safety program was the development of blood alcohol content (BAC) tests for use in impaired-driving enforcement. This led to the development of miniature, highly accurate devices that officers could carry in their pockets. A natural extension of this technology was the vehicle alcohol interlock, which is used to reduce recidivism among drivers convicted of driving under the influence (DUI) by requiring them to install the devices (which will not allow someone with a positive BAC to drive) on their vehicles. While on the vehicle, interlocks have been shown to reduce recidivism by two-thirds. Use of these devices has been growing at the rate of 10 to 15 percent a year, and there currently are more than 300,000 units in use. This expansion in the application of interlocks has benefited from the integration of other emerging technologies into interlock systems. Such technologies include data systems that record both driver actions and vehicle responses, miniature cameras and face recognition to identify the user, Wi-Fi systems to provide rapid reporting on offender performance and any attempt to circumvent the device, GPS tracking of the vehicle, and more rapid means for monitoring the integrity of the interlock system. This article describes how these health technologies are being applied in interlock programs and the outlook for new technologies and new court sanctioning programs that may influence the growth in the use of interlocks in the future.

National synchrotron light source medical personnel protection interlock

International Nuclear Information System (INIS)

Buda, S.; Gmur, N.F.; Larson, R.; Thomlinson, W.

1998-01-01

This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated

NATIONAL SYNCHROTRON LIGHT SOURCE MEDICAL PERSONNEL PROTECTION INTERLOCK

Energy Technology Data Exchange (ETDEWEB)

BUDA,S.; GMUR,N.F.; LARSON,R.; THOMLINSON,W.

1998-11-03

This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated.

Design of the interlock and protection system for the SPIDER experiment

International Nuclear Information System (INIS)

Pomaro, N.; Grando, L.; Luchetta, A.; Paolucci, F.; Sartori, F.

2013-01-01

Highlights: •A custom designed interlock and protection system for SPIDER experiment is described. •It includes two subsystems implementing slow and fast protection functions. •High reliability PLCs are adopted for slow protection. •Fiber-optic based, custom designed fast logic circuitry is proposed for fast protection. •Accelerators breakdown events are also managed by the fast subsystem. -- Abstract: Unprecedented levels of beam energy and power are required for ITER Neutral Beam Heating systems. SPIDER experiment is an experimental device aimed to test and optimize a full size beam source satisfying ITER requirements. SPIDER experiment operation involves high power, voltage, temperature, and gas pressure. All these critical conditions are present simultaneously, so that any failure if not properly detected and managed is likely to cause severe damage. The Interlock and Protection System is a high-reliability system devoted to the investment protection of SPIDER. Its main purpose is to manage abnormal events occurring in one or more plants in order to minimize adverse consequences. The Interlock System also manages the SPIDER Operating Modes, defining the set and status of the Plants used in the various possible experimental configurations. In addition, the Interlock and Protection System takes care of particular events occurring during normal SPIDER operation, i.e. electrical arcs between accelerator grids, named breakdowns. Their treatment is committed to the Interlock and Protection System, as they need to be managed timely and with absolute reliability like actual faults. To perform the required functions, the Interlock and Protection System is interfaced with most SPIDER plants and with the SPIDER Control and Data Acquisition System. The paper describes the rationale of the protection functions, their implementation in the design and the technical specifications of the system

Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Bliguet, Marie Le; Kjær, Andreas

2010-01-01

This paper describes how relay interlocking systems as used by the Danish railways can be formally modelled and verified. Such systems are documented by circuit diagrams describing their static layout. It is explained how to derive a state transition system model for the dynamic behaviour...

The Use of UML to Development of a Railway Interlocking System

Directory of Open Access Journals (Sweden)

Karol Rastocny

2003-01-01

Full Text Available The paper deals with problems of using the Unifield Modeling Lanfuage (UML in developmentt of new railway interlocking and signalling systems. A simplifield example of the control circuit of a point machine is used to demonstrate an object-oriented approach to specifying the functional safety requirements. An informal specification given by the relevant technical standart is used as a starting point and results in semi-formal specification based on UML model. Advantages of the presented approach are discussed and new trends of increasing formality of UML models are indicated within conclusions.

Efficacy and Safety of Interlocked Intramedullary Nailing for Open Fracture Shaft of Tibia

International Nuclear Information System (INIS)

Ahmad, N.; Awan, A. S.; Sultan, S.; Saifullah, K.; Afridi, S. A.; Afridi, S. K.; Lodhi, F. S.

2016-01-01

Background: Due to increasing population and changing human habits the number of accidents and high energy trauma is rising. Management of open fracture tibia is a complex problem and is a challenge for both orthopaedic and plastic surgeons. The study was carried out to ascertain the efficacy and safety of interlocked intra-medullary nailing for open shaft tibial fractures in patients presenting at or after 24 hr of injury. Methods: In this descriptive case series, over a period of 6 moths, 163 consecutive cases of open fracture of tibial shaft were reviewed in terms of clinical profile, time of presentation, and gender distribution. Results: In this study mean age was 30±0.02 years. Males comprised 85 percent of study population while 15 percent were females. Gustilo-I type fracture and Gustilo-II type fracture was diagnosed in 90 percent and 10 percent patients respectively. Thirty three percent patients had wound infection while fracture union was found in 15 percent cases. Moreover interlocked intramedullary nailing for open fracture shaft of tibia was safe in 80 percent patients while this procedure was effective in 85 percent. Conclusion: Un-reamed, interlocked intra-medullary nailing may be considered as a suitable option for treatment of open fractures of tibia. (author)

A formal safety analysis for PLC software-based safety critical system using Z

International Nuclear Information System (INIS)

Koh, Jung Soo

1997-02-01

This paper describes a formal safety analysis technique which is demonstrated by performing empirical formal safety analysis with the case study of beamline hutch door Interlock system that is developed by using PLC (Programmable Logic Controller) systems at the Pohang Accelerator Laboratory. In order to perform formal safety analysis, we have built the Z formal specifications representation from user requirement written in ambiguous natural language and target PLC ladder logic, respectively. We have also studied the effective method to express typical PLC timer component by using specific Z formal notation which is supported by temporal history. We present a formal proof technique specifying and verifying that the hazardous states are not introduced into ladder logic in the PLC-based safety critical system. And also, we have found that some errors or mismatches in user requirement and final implemented PLC ladder logic while analyzing the process of the consistency and completeness of Z translated formal specifications. In the case of relatively small systems like Beamline hutch door interlock system, a formal safety analysis including explicit proof is highly recommended so that the safety of PLC-based critical system may be enhanced and guaranteed. It also provides a helpful benefits enough to comprehend user requirement expressed by ambiguous natural language

Some aspects of operational reliability of the JET central interlock and safety system (CISS) in the period March 1984 to December 1986

International Nuclear Information System (INIS)

Montfoort, Joop van.

1987-01-01

The Central Interlock and Safety System (CISS) provides basic safety functions for the JET plant. It monitors the status of emergency push buttons, access doors and plant equipment and takes corrective shutdown actions in the case that plant conditions are not compatible with safe operation. CISS consists of a hierarchical network of PLCs (programmable logic controllers) paralleling the CODAS architecture. It has been successfully in operation since June 1983 and has intervened many times and halted operation to protect JET from (further) damage or personnel against danger. The note will analyse genuine CISS failures only, and as will be shown, these failures are all due to malfunctioning of PLC hardware. All CISS failures have failed-safe and resulted in the expected shutdown action. Hence CISS failures have never resulted in a dangerous situation but they have restricted operational availability of JET. (author)

COMPRESS - a computerized reactor safety system

International Nuclear Information System (INIS)

Vegh, E.

1986-01-01

The computerized reactor safety system, called COMPRESS, provides the following services: scram initiation; safety interlockings; event recording. The paper describes the architecture of the system and deals with reliability problems. A self-testing unit checks permanently the correct operation of the independent decision units. Moreover the decision units are tested by short pulses whether they can initiate a scram. The self-testing is described in detail

Control interlock and monitoring system for 80 KW IOT based RF power amplifier system at 505.812 MHz for Indus-2

International Nuclear Information System (INIS)

Kumar, Gautam; Deo, R.K.; Jain, M.K.; Bagre, Sunil; Hannurkar, P.R.

2013-01-01

For 80 kW inductive output tube (IOT) based RF power amplifier system at 505.812 MHz for Indus-2, a control, interlock and monitoring system is realized. This is to facilitate proper start-up and shutdown of the amplifier system, monitor various parameters to detect any malfunction during its operation and to bring the system in a safe stage, thereby assuring reliable operation of the amplifier system. This high power amplifier system incorporates interlocks such as cooling interlocks, various voltage and current interlocks and time critical RF interlocks. Processing of operation sequence, cooling interlocks and various voltage and current interlocks have been realized by using Siemens make S7-CPU-315-2DP (CPU) based programmable logic controller (PLC) system. While time critical or fast interlocks have been realized by using Siemens make FPGA based Boolean Co-processor FM-352-5 which operates in standalone mode. Siemens make operating panel OP277 6'' is being used as a human machine interface (HMI) device for command, data, alarm generation and process parameter monitoring. (author)

Emerging standards with application to accelerator safety systems

International Nuclear Information System (INIS)

Mahoney, K.L.; Robertson, H.P.

1997-01-01

This paper addresses international standards which can be applied to the requirements for accelerator personnel safety systems. Particular emphasis is given to standards which specify requirements for safety interlock systems which employ programmable electronic subsystems. The work draws on methodologies currently under development for the medical, process control, and nuclear industries

Analysis of operator support method based on intelligent dynamic interlock in lead-cooled fast reactor simulator

International Nuclear Information System (INIS)

Xu, Peng; Wang, Jianye; Yang, Minghan; Wang, Weitian; Bai, Yunqing; Song, Yong

2017-01-01

Highlights: • We development an operator support method based on intelligent dynamic interlock. • We offer an integrated aid system to reduce the working strength of operators. • The method can help operators avoid dangerous, irreversible operation. • This method can be used in the fusion research reactor in the further. - Abstract: In nuclear systems, operators have to carry out corrective actions when abnormal situations occur. However, operators might make mistakes under pressure. In order to avoid serious consequences of the human errors, a new method for operators support based on intelligent dynamic interlock was proposed. The new method based on full digital instrumentation and control system, contains real-time alarm analysis process, decision support process and automatic safety interlock process. Once abnormal conditions occur, necessary safety interlock parameter based on analysis of real-time alarm and decision support process can be loaded into human-machine interfaces and controllers automatically, and avoid human errors effectively. Furthermore, the new method can make recommendations for further use and development of this technique in nuclear power plant or fusion research reactor.

NSTX Protection And Interlock Systems For Coil And Powers Supply Systems

International Nuclear Information System (INIS)

Zhao, X.; Ramakrishnan, S.; Lawson, J.; Neumeyer, C.; Marsala, R.; Schneider, H.

2009-01-01

NSTX at Princeton Plasma Physics Laboratory (PPPL) requires sophisticated plasma positioning control system for stable plasma operation. TF magnetic coils and PF magnetic coils provide electromagnetic fields to position and shape the plasma vertically and horizontally respectively. NSTX utilizes twenty six coil power supplies to establish and initiate electromagnetic fields through the coil system for plasma control. A power protection and interlock system is utilized to detect power system faults and protect the TF coils and PF coils against excessive electromechanical forces, overheating, and over current. Upon detecting any fault condition the power system is restricted, and it is either prevented from initializing or suppressed to de-energize coil power during pulsing. Power fault status is immediately reported to the computer system. This paper describes the design and operation of NSTX's protection and interlocking system and possible future expansion.

The vacuum interlock system for the CELSIUS ring

International Nuclear Information System (INIS)

Gajewski, K.

1990-01-01

A vacuum interlock system has been designed and built for the CELSIUS storage ring. The ultrahigh-vacuum system of CELSIUS has a design pressure of 10 -11 mbar. This is achieved by using vacuum-fired stainless-steel chambers, baking the whole ring to 300degC and running some 50 sputter ion and titanium sublimation pumps. The turbopumps, combined with roughing pumps, are used during the pump-down and the bake-out. The pressure is monitored by Penning vacuum gauges. There is a number of programmable pressure thresholds set to trigger various events (like closing the sector valves, disabling the bake-out, etc.). The interlock system is based on the Mitsubishi programmable logic controller (PLC). An IBM PC is used as an operator's console. The operation and performance of the system is described. On the basis of present experience an upgrading of the system is suggested. (orig.)

Automatic generation and verification of railway interlocking control tables using FSM and NuSMV

Directory of Open Access Journals (Sweden)

Mohammad B. YAZDI

2009-01-01

Full Text Available Due to their important role in providing safe conditions for train movements, railway interlocking systems are considered as safety critical systems. The reliability, safety and integrity of these systems, relies on reliability and integrity of all stages in their lifecycle including the design, verification, manufacture, test, operation and maintenance.In this paper, the Automatic generation and verification of interlocking control tables, as one of the most important stages in the interlocking design process has been focused on, by the safety critical research group in the School of Railway Engineering, SRE. Three different subsystems including a graphical signalling layout planner, a Control table generator and a Control table verifier, have been introduced. Using NuSMV model checker, the control table verifier analyses the contents of control table besides the safe train movement conditions and checks for any conflicting settings in the table. This includes settings for conflicting routes, signals, points and also settings for route isolation and single and multiple overlap situations. The latest two settings, as route isolation and multiple overlap situations are from new outcomes of the work comparing to works represented on the subject recently.

National Synchrotron Light Source medical personnel protection interlock

Energy Technology Data Exchange (ETDEWEB)

Buda, S.; Gmuer, N.F.; Larson, R.; Thomlinson, W.

1998-11-01

This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated. This MPPI report is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system. The general overview is presented in Section 1.0, MPPI Operational Mode and Procedures. The various MPPI components are described in detail in Section 2.0. Section 3.0 presents some simplified logic diagrams and accompanying text. This section was written to allow readers to become familiar with the logic system without having to work through the entire set of detailed engineering drawings listed in the Appendix. Detailed logic specifications are given in Section 4.0. The Appendix also contains copies of the current MPPI interlock test procedures for Setup and Patient Modes.

A Retrospective View to the Magnet Interlock Systems at CERN

CERN Document Server

Romera, I; Mompo, R; Puccio, B; Zerlauth, M

2014-01-01

Several thousands of both, superconducting and normal conducting magnets are in charge of guiding the particle beams in CERN’s accelerator complex. In order to protect the magnet and powering equipment from damage, dedicated magnet interlock and protection systems are deployed throughout the various accelerators and transfer lines. These systems have worked extremely well during the first years of LHC operation, providing highly dependable interlocking of magnet powering based on industrial COTS components. This paper reviews the performance and experience with more than 70 individual installations during the first LHC running period and compares the operational experience with the initial expectations of dependability. Additional improvements required to address specific operational needs and observed shortcomings are presented. Finally, we review the existing magnet interlock infrastructure in the LHC injector complex and the ongoing renovation works during the first long shutdown.

Comparing formal verification approaches of interlocking systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Nguyen, Hoang Nga; Roggenbach, Markus

2016-01-01

these approaches. As a first step towards this, in this paper we suggest a way to compare different formal approaches for verifying designs of route-based interlocking systems and we demonstrate it on modelling and verification approaches developed within the research groups at DTU/Bremen and at Surrey......The verification of railway interlocking systems is a challenging task, and therefore several research groups have suggested to improve this task by using formal methods, but they use different modelling and verification approaches. To advance this research, there is a need to compare....../Swansea. The focus is on designs that are specified by so-called control tables. The paper can serve as a starting point for further comparative studies. The DTU/Bremen research has been funded by the RobustRailS project granted by Innovation Fund Denmark. The Surrey/Swansea research has been funded by the Safe...

SaRDIn - A Safe Reconfigurable Distributed Interlocking

DEFF Research Database (Denmark)

Fantechi, Alessandro; Gnesi, S.; Haxthausen, Anne Elisabeth

2016-01-01

Current computer-based interlocking systems most often have a centralized design, with all logic residing in a single computer. Centralized interlockings are complex to design. Following the general trend in Cyber-Physical Systems, the SaRDIn (Safe Reconfigurable Distributed Interlockings) concept...

Beam-limiting and radiation-limiting interlocks

International Nuclear Information System (INIS)

Macek, R.J.

1996-01-01

This paper reviews several aspects of beam-limiting and radiation- limiting interlocks used for personnel protection at high-intensity accelerators. It is based heavily on the experience at the Los Alamos Neutron Science Center (LANSCE) where instrumentation-based protection is used extensively. Topics include the need for ''active'' protection systems, system requirements, design criteria, and means of achieving and assessing acceptable reliability. The experience with several specific devices (ion chamber-based beam loss interlock, beam current limiter interlock, and neutron radiation interlock) designed and/or deployed to these requirements and criteria is evaluated

Advanced interlocking systems to improve heavy-load-bearing characteristics of flexible intramedullary nailing

Energy Technology Data Exchange (ETDEWEB)

Berger, Leopold, E-mail: leopold.berger@tuwien.ac.at [Institute of Building Construction and Technology, TU Wien, Karlsplatz 13/206-4, 1040 Vienna (Austria); Eichler, Johannes [Department of Orthopedics and Orthopedic Surgery, Medical University of Graz, Auenbruggerplatz 5/6, 8036 Graz (Austria); Ryll, E. Jonathan S. [Department of Trauma-, Hand- and Reconstructive Surgery, University Hospital Muenster, Westphalian-Wilhelms University, Muenster (Germany); Fischerauer, Stefan [Department of Traumatology, Medical University of Graz, Auenbruggerplatz 5/6, 8036 Graz (Austria); Raschke, Michael J. [Department of Trauma-, Hand- and Reconstructive Surgery, University Hospital Muenster, Westphalian-Wilhelms University, Muenster (Germany); Kolbitsch, Andreas [Institute of Building Construction and Technology, TU Wien, Karlsplatz 13/206-4, 1040 Vienna (Austria); Castellani, Christoph [Department of Pediatric and Adolescence Surgery, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria); Weinberg, Annelie-Martina [Department of Orthopedics and Orthopedic Surgery, Medical University of Graz, Auenbruggerplatz 5/6, 8036 Graz (Austria)

2016-11-01

Flexible intramedullary nailing (FIN) is a minimally invasive and widespread standard method for osteosynthesis of pediatric long bone fractures. In the case of unstable fractures of the lower extremity, interlocking systems need to be used to prevent axial shortening and subsequent perforation of the nail at its insertion site. In the present study, four different screw-fixed interlocking systems for FINs (Hofer TwinPlug with two 3-mm titanium interlocking screws, Hofer FixPlug with 3-mm titanium interlocking screw, Hofer Plug with 3.5-mm titanium interlocking screw, and Hofer Plug with 3-mm titanium interlocking screw) in comparison with the commonly used Ender stainless steel nails (locked with 3.5-mm screw) were experimentally investigated in cadaveric lamb tibiae, regarding their load characteristics and failure modes in the case of heavy loading. The specimens were subjected to sequential axial cyclic loading of 5000cycles with stepwise increase of the load amplitude until failure. Migration of locking screws and internal damage of bone tissue was quantified by micro-computed tomography (CT) imaging. Ender nails failed on average at a peak load of 800 N, TwinPlugs at 1367 N, FixPlugs at 1222 N, Plugs 3.5mm at 1225 N and Plugs 3.0mm at 971 N. TwinPlugs, FixPlugs, and Plugs 3.5mm failed in a slow manner over several hundred loading cycles, whereas Ender nails and Plugs 3.0mm exhibited abrupt failure without any prior indication. Our results confirm that axial stability of FIN can be further improved by screw-fixed plugs by simultaneously avoiding shortcomings of an eye-locked system, which the Ender nails are. Considering biomechanical results, plug interlocking systems with 3.5-mm screws should be favored over conventional Ender nails and plugs with 3-mm screws. - Highlights: • Locked flexible intramedullary nails in lamb tibiae were cyclically loaded. • Strongly different failure modes of locking systems were detected. • Novel screw-fixed plugs are

Formal Development of a Tool for Automated Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Kjær, Andreas A.; Le Bliguet, Marie

2011-01-01

This paper describes a tool for formal modelling relay interlocking systems and explains how it has been stepwise, formally developed using the RAISE method. The developed tool takes the circuit diagrams of a relay interlocking system as input and gives as result a state transition system modelling...

The Daresbury personnel safety system

International Nuclear Information System (INIS)

Poole, D.E.; Ring, T.

1989-01-01

The personnel safety system designed for the SRS at Daresbury is a unified system covering the three accelerators of the source itself, the beamlines and the experimental stations. The system has also been applied to the experimental areas of the Nuclear Structure Facility, and is therefore established as a site standard. A dual guardline interlock module forms a building block for a relay based interlock system completely independent of the machine control system, although comprehensive monitoring of the system status via the control system computer is a feature. An outline of the design criteria adopted for the system is presented together with a more detailed description of the philosophy of the guardline logic and the way this is implemented in a standard modular form. The emphasis is on the design features of a modern microprocessor based variant of the original SRS system. Experience with the original system during build-up and operation of the SRS facility is described. 2 refs., 4 figs

Coastal protection using topological interlocking blocks

Science.gov (United States)

Pasternak, Elena; Dyskin, Arcady; Pattiaratchi, Charitha; Pelinovsky, Efim

2013-04-01

The coastal protection systems mainly rely on the self-weight of armour blocks to ensure its stability. We propose a system of interlocking armour blocks, which form plate-shape assemblies. The shape and the position of the blocks are chosen in such a way as to impose kinematic constraints that prevent the blocks from being removed from the assembly. The topological interlocking shapes include simple convex blocks such as platonic solids, the most practical being tetrahedra, cubes and octahedra. Another class of topological interlocking blocks is so-called osteomorphic blocks, which form plate-like assemblies tolerant to random block removal (almost 25% of blocks need to be removed for the assembly to loose integrity). Both classes require peripheral constraint, which can be provided either by the weight of the blocks or post-tensioned internal cables. The interlocking assemblies provide increased stability because lifting one block involves lifting (and bending) the whole assembly. We model the effect of interlocking by introducing an equivalent additional self-weight of the armour blocks. This additional self-weight is proportional to the critical pressure needed to cause bending of the interlocking assembly when it loses stability. Using beam approximation we find an equivalent stability coefficient for interlocking. It is found to be greater than the stability coefficient of a structure with similar blocks without interlocking. In the case when the peripheral constraint is provided by the weight of the blocks and for the slope angle of 45o, the effective stability coefficient for a structure of 100 blocks is 33% higher than the one for a similar structure without interlocking. Further increase in the stability coefficient can be reached by a specially constructed peripheral constraint system, for instance by using post-tension cables.

Economic aspects of interlocking hollow brick system designed for industrialized building system

Science.gov (United States)

Tahir, Mahmood Md.; Saggaff, Anis; Ngian, Shek Poi; Sulaiman, Arizu

2017-11-01

Construction industry has moved forward into a technology driven where a transition is in progress from conventional method to a more advanced and mechanised system known as the Industrialised Building System (IBS). However, the need to implement the IBS should be well understood by all construction players such as designer, architect, contraction, erectors and construction workers. Therefore, there is a need to educate all these construction players which should be spearheaded by authorities such as Construction Industrial Development Board where enforcement trough building by laws as well as initiative to those that adopt the IBS in their construction. This paper reports on economic aspects of using interlocking hollow brick system in construction as an alternative method offered for Industrialized Building System. The main objective is to address the economic aspects of using interlocking block system in terms of time, costs, and utilization of manpower and to present some of the experimental tests results related to Interlocking Hollow Brick System (IHBS). Example of savings from the use of IHBS is presented in this paper by comparing the construction of two storey terrace house with build-up area of about 200 square meter with conventional construction method of typical reinforced concrete construction (RCC) compared to IHBS. The comparison shows that the implementation of IHBS can reduce construction time, cost, and utilization of man power up to 26.6% compared to the conventional method. Moreover, the construction time using IHBS can also be reduced by up to 50% as compared to the conventional construction.

The New Control and Interlock System for the SPS Main Power Converters

CERN Document Server

Denis, B; Mugnier, C; Varas, J

1999-01-01

The Control and Interlock System (CIS) of the SPS main power converters was designed in the mid-70s and became increasingly difficult to maintain. A new system based on Programmable Logic Controllers has been developed by an external contractor in close collaboration with CERN. The system is now operational and fully integrated in the SPS/LEP control infrastructure. The CIS is the first major contracted industrial solution used to control accelerator equipment directly involved in the production of particle beams at CERN. This paper gives an overview of the SPS main power converter installation and describes both the contractual and technical solution adopted for the CIS. It first explains how the system was specified and how the contractual relationship was defined to respect CERN’s purchasing rules and the operational requirements of the SPS accelerator. The architectural design of the new system is presented with special emphasis on how the conflict between safety and availability has been addressed.

Control Logic for the Interlock system of the ATLAS Insertable B-Layer

CERN Document Server

Riegel, Christian

Part of the first upgrade program of the ATLAS detector is the installation of the Insertable B-Layer (IBL) as a fourth and innermost detector layer of the ATLAS pixel detector to prepare the tracking system for the expected increase of pile-up events. As with every sub-detector, the IBL and its components have to be monitored and controlled via a Detector Control System (DCS). A hardware-based interlock system is installed on-site to prevent detector and people working at the detector from serious harm and damage. For the IBL, the logical processing of interlock signals is realised in Interlock Matrix Crates (IMCs) using Complex Programmable Logic Devices (CPLD). One part of this master thesis is the automatic implementation of the logical assignments from database information. A script was developed to generate the needed file to program the CPLD. The second part of this thesis is the design of a test setup to verify the functionality of the electrical components of each IMC and to confirm the correct proce...

Interlock system for the COMPASS tokamak

Czech Academy of Sciences Publication Activity Database

Hron, Martin; Sova, J.; Šíba, J.; Kovář, J.; Adámek, Jiří; Pánek, Radomír; Havlíček, Josef; Písačka, Jan; Mlynář, Jan; Stöckel, Jan

2010-01-01

Roč. 85, 3-4 (2010), s. 505-508 ISSN 0920-3796. [IAEA Technical Meeting on Control, Data Acquisition and Remote Participation for Fusion Research/7th./. Aix – en – Provence, 15.06.2009-19.06.2009] R&D Projects: GA MŠk 7G09042; GA ČR GD202/08/H057 Institutional research plan: CEZ:AV0Z20430508 Keywords : Tokamak operation * Interlock * Personnel safety Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.143, year: 2010 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3C-5003BXW-1&_user=6542793&_coverDate=07%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000070123&_version=1&_urlVersion=0&_userid=6542793&md5=ef5794d05cc6530a905d1de43aa0ac6a&searchtype=a

From the LHC Reference Database to the Powering Interlock System

CERN Document Server

Dehavay, C; Schmidt, R; Veyrunes, E; Zerlauth, M

2003-01-01

The protection of the magnet powering system for the Large Hadron Collider (LHC) currently being built at CERN is a major challenge due to the unprecedented complexity of the accelerator. The Powering Interlock System of the LHC will have to manage more than 1600 DC circuits for magnet powering, different in their structure, complexity and importance to the accelerator. For the coherent description of such complex system, a Reference Database as unique source of the parameters of the electrical circuits has been developed. The information, introduced via a generic circuit description language, is first used for installing the accelerator and making all electrical connections. The data is then used for tests and commissioning. During operation, the Powering Interlock System manages all critical functions. It consists of 36 PLC based controllers dis tributed around the machine and requires a flexible and transparent way of configuration, since each controller manages different numbers and types of electrical ci...

A formal safety analysis for PLC software-based safety critical system using Z

International Nuclear Information System (INIS)

Koh, Jung Soo; Seong, Poong Hyun

1997-01-01

This paper describes a formal safety analysis technique which is demonstrated by performing empirical formal safety analysis with the case study of beamline hutch door Interlock system that is developed by using PLC (Programmable Logic Controller) systems at the Pohang Accelerator Laboratory. In order to perform formed safety analysis, we have built the Z formal specifications representation from user requirement written in ambiguous natural language and target PLC ladder logic, respectively. We have also studied the effective method to express typical PLC timer component by using specific Z formal notation which is supported by temporal history. We present a formal proof technique specifying and verifying that the hazardous states are not introduced into ladder logic in the PLC-based safety critical system

Automatic Verification of Railway Interlocking Systems: A Case Study

DEFF Research Database (Denmark)

Petersen, Jakob Lyng

1998-01-01

This paper presents experiences in applying formal verification to a large industrial piece of software. The are of application is railway interlocking systems. We try to prove requirements of the program controlling the Swedish railway Station Alingsås by using the decision procedure which...... express thoughts on what is needed in order to be able to successfully verify large real-life systems....

PcInterlock: Implementation and Operational Experience with the Optics Interlock

CERN Document Server

Schaumann, Michaela; Fuchsberger, Kajetan; Wenninger, Jorg

2018-01-01

In 2016 the luminosity reach of the LHC was increased by reducing the β-function in the main collision points below the design value to β∗ = 40 cm. This was possible due to a review of the margins in the collimation hierarchy followed by the implementation of additional measures to ensure the phase advance in defined ranges around the circumference. The risk of damaging the triplet or the tertiary collimators (TCTs) close to the interaction points in the event of an asynchronous beam dump is minimized by including margins in the collimation hierarchy, which define the β∗-reach. By guaranteeing the phase advance within an acceptable tolerance between the beam dump kicker and the TCTs, those margins can be reduced and operation at lower β∗ becomes possible. A new interlock system on the quadrupole magnet currents was put in place to safeguard the stability of the phase advance. This note describes the technical implementation of this power-converter interlock (PcInterlock) and the strategies used to...

Towards a Framework for Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth

2011-01-01

This paper describes a framework currently under development for modelling, simulation, and verification of relay interlocking systems as used by the Danish railways. The framework is centred around a domain-specific language (DSL) for describing such systems, and provides (1) a graphical editor...

Towards a Framework for Modelling and Verification of Relay Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth

2010-01-01

This paper describes a framework currently under development for modelling, simulation, and verification of relay interlocking systems as used by the Danish railways. The framework is centred around a domain-specific language (DSL) for describing such systems, and provides (1) a graphical editor ...

Cold Vacuum Drying Safety Class Instrumentation and Control System Design Description

International Nuclear Information System (INIS)

WHITEHURST, R.

1999-01-01

This document describes the Cold Vacuum Drying Facility (CVDF) Safety Class Instrumentation and Control system (SCIC). The SCIC provides safety functions and features to protect the environment, off-site and on-site personnel and equipment. The function of the SCIC is to provide automatic trip features, valve interlocks, alarms, indication and control for the cold vacuum drying process

49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

Science.gov (United States)

2010-10-01

... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic... 49 Transportation 4 2010-10-01 2010-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations...

Beam interlock system and safe machine parameters system 2010 and beyond

CERN Document Server

Todd, B

2010-01-01

The Beam Interlock System (BIS) and Safe Machine Parameters (SMP) system are central to the protection of the Large Hadron Collider (LHC) machine. The BIS has been critical for the safe operation of LHC from the first day of operation. It has been installed and commissioned, only minor enhancements are required in order to accommodate all future LHC machine protection requirements. At reduced intensity, the SMP system is less critical for LHC operation. As such, the current system satisfies the 2010 operational requirements. Further developments are required, both at the SMP Controller level, and at the system level, in order to accommodate the requirements of the LHC beyond 2010.

Interlock System for the COMPASS Tokamak

Energy Technology Data Exchange (ETDEWEB)

Hron, M.; Adamek, J.; Pisacka, J.; Panek, R. [Institute of Plasma Physics AS CR, Association EURATOM/IPP.CR, Prague (Czech Republic); Sova, J.; Siba, J.; Kovarj, J. [Department of Control Engineering, Faculty of Electrical Engineering, Prague (Czech Republic)

2009-07-01

Full text of publication follows: The COMPASS tokamak (R=0.56 m, a=0.18 - 0.23 m) is starting operation presently at Institute of Plasma Physics AS CR in Prague. An important issue of the operation is the safety of the personnel and machine protection against faults, presented in this contribution. The personnel protection is based on a restricted access into the experimental hall during the operation of potentially dangerous systems. A tokamak hall access system, based on Honeywell WIN-PAK (tm) 2005, allows to set the status of the experimental area (open/closed) and to control the in and out movement of persons using access cards. On top of this, a check of the whole experimental area by the operator is enforced before the hall enclosure. A hardware interlock then interprets the experimental hall status and controls the operation of key systems accordingly. The permit for operation is granted and the real status of the systems is reported by hard wired potential less contacts. The control procedure is based on a PLC MicroPEL M66. This PLC provides HW interface between Actuators (Relays and switches) and it is connected on PESNET bus. Its programming is done using language Simple v.2 in Winstudio IDE. Second site of personnel protection system is created on PC where runs a .NET application on MSWindows XP or 2000. This PC is connected with PLC via PESNET bus (on RS485 layer) and it generates all control signals to PLC from the operator. Simultaneously, the PC receives all warning and alarm signals from the PLC. This signals are displayed on a screen of the PC in real-time, this way the GUI provides visualization of the controlled process. Except for this fact the operator is informed about the status of the system and individual subsystems on a PC via an operator's panel. Further we will describe the machine protection which uses similar system for checking conditions for the start of a shot. Fast key processes which have to be checked during the shot are

CAMAC-based interlock system for power-supply-hardware protection on MFTF

International Nuclear Information System (INIS)

Strauch, M.S.

1981-01-01

This interlock module accepts 16 inputs and generates, in conjunction with an internal PROM map, 8 outputs. This decision process is autonomous of the CAMAC dataway and host computer. The map is generated, burned and verified by a user interactive program written to accept input/output equations in Boolean algebra. The interlock module requires the host computer to periodically interrogate it to verify proper operation of the module, host computer and date link; otherwise, permissives are dropped. An internal mask register may be used to override interlock inputs. This mask is perishable and must be constantly refreshed. Output drivers may be operated in a latch/no latch mode. This prevents outputs, once dropped, from being reasserted even if the proper input sequence is reestablished. A first-out register may be utilized to determine which input has dropped first in the event that chain reactions are developed among the interlock inputs

Cold Vacuum Drying Safety Class Instrumentation and Control System Design Description SYS 93-2

International Nuclear Information System (INIS)

WHITEHURST, R.

1999-01-01

This document describes the Cold Vacuum Drying Facility (CVDF) Safety Class Instrumentation and Control system (SCIC). The SCIC provides safety functions and features to protect the environment, off-site and on-site personnel and equipment. The function of the SCIC is to provide automatic trip features, valve interlocks, alarms, indication and control for the cold vacuum drying process

Compositional Verification of Multi-Station Interlocking Systems

DEFF Research Database (Denmark)

Macedo, Hugo Daniel dos Santos; Fantechi, Alessandro; Haxthausen, Anne Elisabeth

2016-01-01

pose a big challenge to current verification methodologies, due to the explosion of state space size as soon as large, if not medium sized, multi-station systems have to be controlled. For these reasons, verification techniques that exploit locality principles related to the topological layout...... of the controlled system to split in different ways the state space have been investigated. In particular, compositional approaches divide the controlled track network in regions that can be verified separately, once proper assumptions are considered on the way the pieces are glued together. Basing on a successful...... method to verify the size of rather large networks, we propose a compositional approach that is particularly suitable to address multi-station interlocking systems which control a whole line composed of stations linked by mainline tracks. Indeed, it turns out that for such networks, and for the adopted...

JET neutral beam duct Optical Interlock

Energy Technology Data Exchange (ETDEWEB)

Ash, A.D.; Jones, T.T.C.; Surrey, E.; Ćirić, D.; Hall, S.I.; Young, D.; Afzal, M.; Hackett, L.; Day, I.E.; King, R.

2015-10-15

Highlights: • Optical Interlocks were installed on the JET NBI system as part of the EP2 upgrade. • The system protects the JET tokamak and NBI systems from thermal load damage. • Balmer-α beam emission is used to monitor the neutral beam-line pressure. • We demonstrate an improved trip delay of 2 ms compared to 50 ms before EP2. - Abstract: The JET Neutral Beam Injection (NBI) system is the most powerful neutral beam plasma heating system currently operating. Optical Interlocks were installed on the beam lines in 2011 for the JET Enhancement Project 2 (EP2), when the heating power was increased from 23 MW to 34 MW. JET NBI has two beam lines. Each has eight positive ion injectors operating in deuterium at 80 kV–125 kV (accelerator voltage) and up to 65 A (beam current). Heating power is delivered through two ducts where the central power density can be more than 100 MW/m{sup 2}. In order to deliver this safely, the beam line pressure should be below 2 × 10{sup −5} mbar otherwise the power load on the duct from the re-ionised fraction of the beam is excessive. The new Optical Interlock monitors the duct pressure by measuring the Balmer-α beam emission (656 nm). This is proportional to the instantaneous beam flux and the duct pressure. Light is collected from a diagnostic window and focused into 1-mm diameter fibres. The Doppler shifted signal is selected using an angle-tuned interference filter. The light is measured by a photo-multiplier module with a logarithmic amplifier. The interlock activation time of 2 ms is sufficient to protect the system from a fully re-ionised beam—a significant improvement on the previous interlock. The dynamic range is sufficient to see bremsstrahlung emission from JET plasma and not saturate during plasma disruptions. For high neutron flux operations the optical fibres within the biological shield can be annealed to 350 °C. A self-test is possible by illuminating the diagnostic window with a test lamp and measuring

Software Development for Auto-Generation of Interlocking Knowledge base using Artificial Intelligence Approach

Energy Technology Data Exchange (ETDEWEB)

Ko, Yun Seok [Nanseoul University (Korea); Kim, JOng Sun [Kwangwoon University (Korea)

1999-06-01

This paper proposes IIKBAG (Intelligent Interlocking Knowledge Base Generator) which can build automatically the interlocking knowledge base utilized as the real-time interlocking strategy of the electronic interlocking system in order to enhance it's reliability and expansion. The IIKBAG consists of the inference engine and the knowledge base. The former has an auto-learning function which searches all the train routes for the given station model based on heuristic search technique while dynamically searching the model, and then generates automatically the interlocking patterns obtained from the interlocking relations of signal facilities on the routes. The latter is designed as the structure which the real-time expert system embedded on IS (Interlocking System) can use directly in order to enhances the reliability and accuracy. The IIKBAG is implemented in C computer language for the purpose of the build and interface of the station structure database. And, a typical station model is simulated to prove the validity of the proposed IIKBAG. (author). 13 refs., 5 figs., 2 tabs.

Safety Evaluation of Kartini Reactor Based on Instrumentation System Design

International Nuclear Information System (INIS)

Tjipta Suhaemi; Djen Djen Dj; Itjeu K; Johnny S; Setyono

2003-01-01

The safety of Kartini reactor has been evaluated based on instrumentation system aspect. The Kartini reactor is designed by BATAN. Design power of the reactor is 250 kW, but it is currently operated at 100 kW. Instrumentation and control system function is to monitor and control the reactor operation. Instrumentation and control system consists of safety system, start-up and automatic power control, and process information system. The linear power channel and logarithmic power channel are used for measuring power. There are 3 types of control rod for controlling the power, i.e. safety rod, shim rod, and regulating rod. The trip and interlock system are used for safety. There are instrumentation equipment used for measuring radiation exposure, flow rate, temperature and conductivity of fluid The system of Kartini reactor has been developed by introducing a process information system, start-up system, and automatic power control. It is concluded that the instrumentation of Kartini reactor has followed the requirement and standard of IAEA. (author)

Controls and interlocks for a prototype 1MHz beam chopper

International Nuclear Information System (INIS)

Waters, G.; Bishop, D.; Barnes, M.J.; Wait, G.D.

1991-05-01

A prototype 1 MHz beam chopper for the proposed KAON Factory at TRIUMF has been constructed. The chopper is an electric field device, driven by a tetrode based pulser, for deflecting a charged particle beam. Associated with the tetrode used in the prototype design are high voltage power supplies for the electrodes. We use an FET based grid pulser and a sequencer capable of accurate digital control of pulse timing to 0.4 ns. A safety interlock and control system using a programmable controller with fibre optic links has been built. This has given us the versatility required in a prototype system. (Author) 4 refs., 5 figs

The RF-Station Interlock for the European X-ray laser

CERN Document Server

Grevsmühl, T; Duval, P; Hensler, O; Kahl, J; Kaiser, F R; Kretzschmann, A; Rehlich, K; Schwendicke, U; Simrock, S; Weisse, S

2004-01-01

The RF-station interlock for the European X-ray laser will be based on a 19"- 3U crate incorporating a controller with the 32-bit RISC NIOS-processor (ALTERA). The main task of the interlock system is to prevent any damage from the components of the RF station and connected cavities. The interlock system must also guarantee a maximum time of operation of the RF stations which implies the implementation of self diagnostics and repair strategies on a module basis. Additional tasks are: collection and temporary storage of status information of the individual channels of the interlock system, transfer of this information to the control system, slow control functions (e.g. HV setting and monitoring) and control of inputs and outputs from and to other subsystems. In this paper we present the implementation using an ALTERA-FPGA running a 32-bit RISC NIOS-processor. Connection to the accelerator main control is provided by Ethernet using BSD-style socket routines based on ALTERA's plugs-library. The layout o...

Access control and interlock system at the Advanced Photon Source

International Nuclear Information System (INIS)

Forrestal, J.; Hogrefe, R.; Knott, M.; McDowell, W.; Reigle, D.; Solita, L.; Koldenhoven, R.; Haid, D.

1997-01-01

The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel from prompt radiation generated by the linac, PAR, synchrotron, and storage ring. This paper describes the ACIS's design philosophy, configuration, hardware, functionality, validation requirements, and operational experience

49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of signal...

A review on past and present development on the interlocking loadbearing hollow block (ILHB) system

Science.gov (United States)

Bosro, M. Z. M.; Samad, A. A. A.; Mohamad, N.; Goh, W. I.; Tambichik, M. A.; Iman, M. A.

2018-04-01

Massive migration and increasing population in Malaysia has contributed to the increasing demand of quality and affordable housing. Over the past 50 years, the Malaysian housing industry has seen the growth of using conventional construction system such as reinforced concrete frame structures and bricks. The conventional system, as agreed by many researchers, causes delays and other disadvantages in some of the construction projects. Thus, the utilization of interlocking loadbearing hollow block (ILHB) system is needed to address these issues. This system has been identified as an alternative and sustainable building system for the construction industry in Malaysia which the PUTRA block system is the latest example of the ILHB developed. The system offers various advantages in terms of speed and cost in construction, strength, environmentally friendly and aesthetic qualities. Despite these advantages, this system has not been practically applied and develop in Malaysia. Therefore, this paper aims to review the past and present development of the interlocking loadbearing hollow block (ILHB) system that available locally and globally.

Modular reliability modeling of the TJNAF personnel safety system

International Nuclear Information System (INIS)

Cinnamon, J.; Mahoney, K.

1997-01-01

A reliability model for the Thomas Jefferson National Accelerator Facility (formerly CEBAF) personnel safety system has been developed. The model, which was implemented using an Excel spreadsheet, allows simulation of all or parts of the system. Modularity os the model's implementation allows rapid open-quotes what if open-quotes case studies to simulate change in safety system parameters such as redundancy, diversity, and failure rates. Particular emphasis is given to the prediction of failure modes which would result in the failure of both of the redundant safety interlock systems. In addition to the calculation of the predicted reliability of the safety system, the model also calculates availability of the same system. Such calculations allow the user to make tradeoff studies between reliability and availability, and to target resources to improving those parts of the system which would most benefit from redesign or upgrade. The model includes calculated, manufacturer's data, and Jefferson Lab field data. This paper describes the model, methods used, and comparison of calculated to actual data for the Jefferson Lab personnel safety system. Examples are given to illustrate the model's utility and ease of use

Machine interlock and protection system based on PLC for the SSRF linac

International Nuclear Information System (INIS)

Chou Wenjun; Zhou Dayong; Chen Jianfeng; Shen Liren; Liu Yajuan

2008-01-01

This paper describes a machine interlock and protection system used for accelerators based on EPICS (Experimental physics and industrial control system). The system is composed of a front-end computer and an FM-3R logic controller PLC. The alarm signal is passed by the hardware directly, and would be deal with PLC. The reporting, recording and analyst of the event are accomplished by EPICS control software. And PLC is linked to the EPICS by Internet. (authors)

The LHC personnel safety system

International Nuclear Information System (INIS)

Ninin, P.; Valentini, F.; Ladzinski, T.

2011-01-01

Large particle physics installations such as the CERN Large Hadron Collider require specific Personnel Safety Systems (PSS) to protect the personnel against the radiological and industrial hazards. In order to fulfill the French regulation in matter of nuclear installations, the principles of IEC 61508 and IEC 61513 standard are used as a methodology framework to evaluate the criticality of the installation, to design and to implement the PSS.The LHC PSS deals with the implementation of all physical barriers, access controls and interlock devices around the 27 km of underground tunnel, service zones and experimental caverns of the LHC. The system shall guarantee the absence of personnel in the LHC controlled areas during the machine operations and, on the other hand, ensure the automatic accelerator shutdown in case of any safety condition violation, such as an intrusion during beam circulation. The LHC PSS has been conceived as two separate and independent systems: the LHC Access Control System (LACS) and the LHC Access Safety System (LASS). The LACS, using off the shelf technologies, realizes all physical barriers and regulates all accesses to the underground areas by identifying users and checking their authorizations.The LASS has been designed according to the principles of the IEC 61508 and 61513 standards, starting from a risk analysis conducted on the LHC facility equipped with a standard access control system. It consists in a set of safety functions realized by a dedicated fail-safe and redundant hardware guaranteed to be of SIL3 class. The integration of various technologies combining electronics, sensors, video and operational procedures adopted to establish an efficient personnel safety system for the CERN LHC accelerator is presented in this paper. (authors)

Implementation of a Direct Link between the LHC Beam Interlock System and the LHC Beam Dumping System Re-Triggering Lines

CERN Document Server

Gabourin, S; Denz, R; Magnin, N; Uythoven, J; Wollmann, D; Zerlauth, M; Vatansever, V; Bartholdt, M; Bertsche, B; Zeiler, P

2014-01-01

To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump blocks must be guaranteed at all times. When a beam dump is demanded, the Beam Interlock System communicates this request to the Trigger Synchronisation and Distribution System of the LHC Beam Dumping System. Both systems were built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the Trigger Synchronisation and Distribution System, a new direct link from the Beam Interlock System to the re-triggering lines of the LHC Beam Dumping System will be implemented for the start-up with beam in 2015. The link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called asynchronous beam dumps nor compromise machine availability. This paper describes the implementation choices of this link. Furthermore the results of a rel...

Development of Interlocking Masonry Bricks and its’ Structural Behaviour: A Review Paper

Science.gov (United States)

Al-Fakih, Amin; Mohammed, Bashar S.; Nuruddin, Fadhil; Nikbakht, Ehsan

2018-04-01

Conventional bricks are the most elementary building materials for houses construction. However, the rapid growth in today’s construction industry has obliged the civil engineers in searching for a new building technique that may result in even greater economy, more efficient and durable as an alternative for the conventional brick. Moreover, the high demands for having a speedy and less labour and cost building systems is one of the factor that cause the changes of the masonry conventional systems. These changes have led to improved constructability, performance, and cost as well. Several interlocking bricks has been developed and implemented in building constructions and a number of researches had studied the manufacturing of interlocking brick and its structural behaviour as load bearing and non-load bearing element. This technical paper aims to review the development of interlocking brick and its structural behaviour. In conclusion, the concept of interlocking system has been widely used as a replacement of the conventional system where it has been utilized either as load bearing or non-load bearing masonry system.

21 CFR 876.4590 - Interlocking urethral sound.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Interlocking urethral sound. 876.4590 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An interlocking urethral sound is a device that consists of two metal sounds...

Shutdown channels and fitted interlocks in atomic reactors

International Nuclear Information System (INIS)

Furet, J.; Landauer, C.

1968-01-01

This catalogue consists of tables (one per reactor) giving the following information: number and type of detectors, range of the shutdown channels, nature of the associated electronics, thresholds setting off the alarms, fitted interlocks. These cards have been drawn up with a view to an examination of the reactors safety by the 'Reactor Safety Sub-Commission', they take into account the latest decisions. The reactors involved in this review are: Azur, Cabri, Castor-Pollux, Cesar-Marius-2, Edf-2, EL3, EL4, Eole, G1, G2-G3, Harmonie, Isis, Masurca, Melusine, Minerve, Osiris, Pegase, Peggy, PAT, Rapsodie, SENA, Siloe, Siloette, Triton-Nereide, and Ulysse. (authors) [fr

INTERFIRM COOPERATION AND INFORMATION SHARING THROUGH INTERLOCKING DIRECTORATES

Directory of Open Access Journals (Sweden)

Mohammed Belal UDDIN

2012-01-01

Full Text Available When firms engage in cooperative efforts, interfirm relations get particular interest to be studied. A direct interlock occurs when an executive or director of one firm sits on the board of another firm, and an indirect interlock occurs when two firms have directors or executives who sit on the board of a third firm. The three commonly used theoretical models such as social network theory, learning theory, and theory of strategic choice are more relevant for the formation and management of interlocking directorates. Uncertainty, resource scarcity, mutual trust, dependency, etc. influence the formation of interlocking directorates. Consequently, interlocking directorates allow sharing of information and overall cooperation between partners through learning, collaboration, networking, and effective relationship, etc. Proper management of interlocking directorates requires communication and collaboration among partners that enhance exchange of knowledge and cooperation.

PLC based development of control, monitoring and interlock for 100 kW, 45.6 MHz ICRH system

International Nuclear Information System (INIS)

Jadav, Hiralal; Joshi, Rameshkumar; Mali, Aniruddh K.; Kadia; Bhavesh; Parmar; Maganbhai, Kiritkumar; Kulkarni, S.V.

2015-01-01

This paper presents details of PLC based system development for 100KW at the rate 45.6 MHz. Presently in ICRH RF DAC (Data acquisition and control) system existing based on real time VME and linux operating system. The ICRH system consists of 1.5 MW RF generator operating at 22- 40MHz which is used for second harmonic heating and pre-ionization experiments on SST-1 Tokamak at 1.5T and 3T magnetic field operation respectively. The task of PLC system in RF ICRH is to control, monitoring and interlocks HVDC power supply signal. Voltage and current signal of 2 kW, 20 kW, tetrode for 100 kW RF tube electrode like Filament, Control grid, Plate, Screen grid, signal monitor and voltage set raised by PLC analog IO module. Acknowledgement of the HVDC supply Filament, Control grid, Plate, Screen grid power supply is monitor and interlocks by PLC Digital IO module to interlocks stop the RF pulse and off HV power supply. The RF pulse(shot) to trigger signal generator (5mw) RF power output feed to LPA then chain of 2 KW, 20 KW, 100 KW at the rate 45.6 MHz. The programming logic controller (PLC) software is written in ladder language for AH500 Delta make using ISP Soft 2.04 and GUI is in the table form to control and monitor the parameters. Communication of PLC to PC by ethernet LAN network. (author)

Access Safety Systems – New Concepts from the LHC Experience

CERN Document Server

Ladzinski, T; di Luca, S; Hakulinen, T; Hammouti, L; Riesco, T; Nunes, R; Ninin, P; Juget, J-F; Havart, F; Valentini, F; Sanchez-Corral Mena, E

2011-01-01

The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hardwired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and th...

RF generator interlock by plasma grid bias current - An alternate to Hα interlock

Science.gov (United States)

Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

2017-08-01

ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma

Software Verification and Validation Test Report for the HEPA filter Differential Pressure Fan Interlock System

International Nuclear Information System (INIS)

ERMI, A.M.

2000-01-01

The HEPA Filter Differential Pressure Fan Interlock System PLC ladder logic software was tested using a Software Verification and Validation (VandV) Test Plan as required by the ''Computer Software Quality Assurance Requirements''. The purpose of his document is to report on the results of the software qualification

Homodyne reflectometer for NBI interlock on Large Helical Device

International Nuclear Information System (INIS)

Tanaka, Kenji; Ito, Yasuhiko; Kawahata, Kazuo; Tokuzawa, Tokihiko; Osakabe, Masaki; Takeiri, Yasuhiko; Ejiri, Akira

2001-01-01

Neutral Beam Injection (NBI) under low density causes serious damage on vacuum vessel wall. It is necessary to stop NBI when electron density becomes lower than 1x10 19 m -3 . This needs reliable density monitor for NBI interlock. A three-channel homodyne reflectometer was installed on Large Helical Device (LHD) and was used for NBI interlock. 28.5, 34.9 and 40.2 GHz Gunn oscillators were used with O mode injection. Their O mode cut off density correspond to 1x10 19 , 1.5x10 19 and 2x10 19 m -3 respectively. The simple homodyne detection is presently used. When the density reaches to the cutoff density, the reflected signals are detected. The reflected signal consists of DC signal due to local and reflected power, and AC signal due to position of cut off layer and density fluctuation. Since the change of DC signal at lower and higher than cut off density was very small, root mean square (RMS) value of AC signal were used for interlock signal. This interlock system is successfully working from the beginning of the NBI experiments campaign on LHD. (author)

Access safety systems - New concepts from the LHC experience

International Nuclear Information System (INIS)

Ladzinski, T.; Delamare, C.; Luca, S. di; Hakulinen, T.; Hammouti, L.; Havart, F.; Juget, J.F.; Ninin, P.; Nunes, R.; Riesco, T.; Sanchez-Corral Mena, E.; Valentini, F.

2012-01-01

The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hard wired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and the access control includes a state of the art bio-metry check. Building on the LHC experience, new projects targeting the refurbishment of the existing access safety infrastructure in the injector chain have started. This paper summarises the new concepts introduced in the LHC access control and safety systems, discusses the return of experience and outlines the main guiding principles for the renewal stage of the personnel protection systems in the LHC injector chain in a homogeneous manner. (authors)

Design review report for the hydrogen interlock preliminary design

International Nuclear Information System (INIS)

Corbett, J.E.

1996-01-01

This report documents the completion of a preliminary design review for the hydrogen interlock. The hydrogen interlock, a proposed addition to the Rotary Mode Core Sampling (RMCS) system portable exhauster, is intended to support core sampling operations in waste tanks requiring flammable gas controls. The objective of this review was to validate basic design assumptions and concepts to support a path forward leading to a final design. The conclusion reached by the review committee was that the design was acceptable and efforts should continue toward a final design review

Safety Aspects of EPS-3000 Electron Beam Machine

International Nuclear Information System (INIS)

Siti Aiasah Hashim; Shari Jahar; Ayub Muhamad; Sarada Idris

2011-01-01

The EPS-3000 electron beam machine was installed and commission in 1991 at the Alurtron Electron Beam Irradiation Centre. It is utilized as a tool to enhance finished products through electron beam irradiation. The machine and its auxiliary systems were built with highest safety in mind due to the possible dangers that it can cause during the irradiation activities. Automatic stops may be activated via various interlocks to protect the integrity of the machine. This type of interlocks are controlled by the set upper and lower limits, mostly related to the machine high voltage (and beam) generation and cooling systems. Radiation safety is also taken care of by provision of shielding and area monitoring. Other potential hazards include ozone poisoning and electromagnetic field (EMF) could be generated by the high voltage. This paper describes the safety and security systems installed within the facility as measures to protect the workers and general public from radiation and other physical threats. (author)

An active interlock system for the NSLS x-ray ring insertion devices

International Nuclear Information System (INIS)

Nawrocky, R.J.; Biscardi, R.; Dabrowski, J.; Flannigan, J.; Ramamoorthy, S.; Rothman, J.; Smith, J.; So, I.; Thomas, M.; Decker, G.

1991-01-01

This paper describes the design and operation of an active interlock system which has been installed in the NSLS X-ray electron storage ing to protect the vacuum chamber from thermal damage by mis-steered high power photon beams from insertion devices (IDs). the system employs active beam position detectors to monitor beam motion in the ID straight sections and solid state logic circuitry to ''dump'' the stored beam in the event of a fault condition by interrupting the rf. To ensure a high degree of reliability, redundancy and continuous automatic checking has been incorporated into the design. Overall system integrity is checked periodically with beam at safe levels of beam current. 2 refs., 3 figs

Design of test JIG for centralized interlock and protection module of ITER-India Gyrotron Test Facility

International Nuclear Information System (INIS)

Rathod, Vipal; Rao, S.L.; Edappala, Praveenlal; Rajpal, Rachana

2017-01-01

Fast Interlock and protection system plays very crucial role in ensuring the safe and reliable operation of high power RF sources such as a Gyrotron system. Critical Protection Interlocks are generally implemented using hardwired components and are required to have a response time as fast as < 10 μs. In this context, an Industrial grade prototype Centralized Interlock and Protection Module (CIM) based on ITER-India design has been developed successfully with the help of local industry. This paper presents the complete requirements, approach, detailed design concept and current status of Test JIG in detail

Analysis of interlocking performances on non-oriented electrical steels

Science.gov (United States)

Liu, Li-Hsiang; Liu, Lee-Cheng

2018-05-01

In order to reduce energy loss in motor, applications of high-efficiency non-oriented electrical steel sheets and optimal laminating process are both important elements. The motor core loss deterioration is influenced by a number of factors, such as flux distribution, stress and strain, space harmonics, temperature, and short circuits between lamination. In conventional clamping method, steel sheets are laminated via interlocking or welding in general manner. The measured energy loss by welding was much larger than that by interlocking. Therefore, interlocking is well known and usually employed with benefit of easy conducting. The protuberance shapes affected the fastening strength. Generally, the intensity of rectangular type is stronger than the circular counterparts. However, the circular interlocking has better magnetic characteristics. To clarify the method effectiveness, interlocking performances regarding fastened strength and magnetic deterioration by lamination were investigated. The key parameters of protuberance shape and forming depth were designed. Precisely manufacturing operation was applied to avoid interlocking failure. Magnetic properties largely influenced by clamping method are crucial to minimizing the magnetic deterioration during laminating procedure. Several experiments for various processing conditions were undertaken, and the quantification results showed the rectangular interlocking had better fastened strength but worsened iron loss comparing with the circular arrangement. To acquire the comprehensive mechanical and electrical identities for electrical steel lamination, deliberate producing conditions regarding minimizing the magnetic deterioration should be adopted prudently.

Binding of anions in triply interlocked coordination catenanes and dynamic allostery for dehalogenation reactions.

Science.gov (United States)

Yang, Linlin; Jing, Xu; An, Bowen; He, Cheng; Yang, Yang; Duan, Chunying

2018-01-28

By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds. The presence of several kinds of individual pocket that were attributed to the triply interlocked patterns enabled the possibility of encapsulating different anions, allowing the dynamic allostery between the unlocked/locked conformers to promote the dehalogenation reaction of 3-bromo-cyclohexene efficiently, as with the use of dehalogenase enzymes. The interlocked structures could be unlocked into two individual tetrahedrons through removal of the well-matched anion templates. The stability and reversibility of the locked/unlocked structures were further confirmed by the catching/releasing process that accompanied emission switching, providing opportunities for the system to be a dynamic molecular logic system.

Experimental Investigation About Stamping Behaviour of 3D Warp Interlock Composite Preforms

Science.gov (United States)

Dufour, Clément; Wang, Peng; Boussu, François; Soulat, Damien

2014-10-01

Forming of continuous fibre reinforcements and thermoplastic resin commingled prepregs can be performed at room temperature due to its similar textile structure. The "cool" forming stage is better controlled and more economical. The increase of temperature and the resin consolidation phases after the forming can be carried out under the isothermal condition thanks to a closed system. It can avoid the manufacturing defects easily experienced in the non-isothermal thermoforming, in particular the wrinkling [1]. Glass/Polypropylene commingled yarns have been woven inside different three-dimensional (3D) warp interlock fabrics and then formed using a double-curved shape stamping tool. The present study investigates the in-plane and through-thickness behaviour of the 3D warp interlock fibrous reinforcements during forming with a hemispherical punch. Experimental data allow analysing the forming behaviour in the warp and weft directions and on the influence of warp interlock architectures. The results point out that the layer to layer warp interlock preform has a better stamping behaviour, in particular no forming defects and good homogeneity in thickness.

COUNTERMEASURE FOR MINIMIZE UNWANTED ALARM OF AUTOMATIC FIRE NOTIFICATION SYSTEM IN THE REPUBLIC OF KOREA

Directory of Open Access Journals (Sweden)

Hasung Kong

2015-01-01

Full Text Available In this article investigated the cause of error through survey to building officials for minimizing the unwanted alarm of automatic fire notification and suggested countermeasure for minimizing the unwanted alarm. The main cause of the unwanted alarm is defective fire detector, interlocking with automatic fire detection system, lack in fire safety warden’s ability, worn-out fire detect receiving system. The countermeasure for minimizing unwanted alarm is firstly, tightening up the standard of model approval, Secondly, interlocking with cross-section circuit method fire extinguishing system or realizing automatic fire notification system interlocking with home network, thirdly, tightening up licensing examination of fire safety warden, lastly, it suggested term of use rule of fire detect receiving system.

Development of rubberized geopolymer interlocking bricks

Directory of Open Access Journals (Sweden)

Bashar S Mohammed

2018-06-01

Full Text Available Waste tires contribute badly to the environment on a huge scale as they are bulky, non-biodegradable, and prone to fire and being a shelter for mosquitos and other insects. This paper reports on a novel approach towards the development of rubberized brick by utilizing crumb rubber as the sole fine aggregate in the production of geopolymer interlocking bricks. The response surface methodology (RSM from Design Experts software has been used to determine the numbers of trial mixes and their corresponding ingredients. A total of thirteen trial mixes were carried out and tested for compressive strength and the RSM model was developed to predict the design mix based on the targeted compressive strength. The mix design was obtained to be an 18 M for NaOH and 0.8 solution to fly ash ratio. The geopolymer interlocking rubberized bricks were then produced and tested for compressive strength, dimension, modulus of rupture, water absorption, initial rate of absorption, and efflorescence. The geopolymer interlocking rubberised bricks presented a low compressive and flexural strength and a high-water absorption capacity. The bricks were rated as non-effloresced and classified as 3rd class bricks which can be used as non-load bearing material. It is recommended to utilize nano silica in order to increase the strength of the brick. Keywords: Rubberized bricks, Crumb rubber, Interlocking bricks, Geopolymer, Response surface methodology

Reliability Analysis of the new Link between the Beam Interlock System and the LHC Beam Dumping System Zuverlässigkeitsanalyse der neuen Verbindung zwischen dem Beam Interlock System und dem LHC Beam Dumping System

CERN Document Server

Vatansever, Volkan

The nominal stored energy in each LHC beam is 360 MJ, surpassing the beam energy of other accelerators by orders of magnitude. This energy threatens to damage accelerator components in case of uncontrolled beam losses To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump block must be guaranteed at all times. Therefore, the LHC Beam Dumping System was built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the redundant system, a new direct link from the LHC Beam Interlock System to the Re-triggering Lines of the LHC Beam Dumping System will be implemented for the startup with beam in 2015. This link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called Asynchronous Beam Dumps nor compromise machine availability. Therefore, a reliability analysis down to the co...

[The monorail system--bone segment transport over unreamed interlocking nails].

Science.gov (United States)

Oedekoven, G; Jansen, D; Raschke, M; Claudi, B F

1996-11-01

A treatment protocol is demonstrated, consisting of an osteotomy, either proximal or distal, of the bone defect with subsequent segmental transport via an anteromedially (tibia) or laterally (femur) mounted AO external fixation over an unreamed interlocking nail (monorail system). Twenty patients were treated by this method with indications as follows: 13 had a segmental bone defect of the tibia, 3 of the femur. Three patients showed post-traumatic and postinfectious leg-length discrepancies and one was treated for hypertrophic non-union of the femur. Defect distance varied between 5 and 18.5 cm and average time for transport was 19,42 days/ cm for the tibial shaft, 15,93 days/cm for the femur. Two patients developed deep infection, which required change of treatment, removing the monorail system and application of an Ilizarov apparatus. Despite complications using the monorail system, all patients healed and no amputations were required. The monorail system can be used as an alternative to the Ilizarov method under certain criteria of patient selection; these criteria are shown by an algorithm for segmental bone defects without infection, respecting the soft-tissue status with or without neurovascular compromise.

COUNTERMEASURE FOR MINIMIZE UNWANTED ALARM OF AUTOMATIC FIRE NOTIFICATION SYSTEM IN THE REPUBLIC OF KOREA

Directory of Open Access Journals (Sweden)

Hasung Kong

2015-01-01

Full Text Available In this article investigated the cause of error through survey to building officials for minimizing the unwanted alarm of automatic fire notification and suggested countermeasure for minimizing the unwanted alarm. The main cause of the unwanted alarm is defective fire detector, interlocking with automatic fire detection system, lack in fire safety warden’s ability, worn-out fire detect receiving system. The countermeasure for minimizing unwanted alarm is firstly, tightening up the standard of model approval, Secondly, interlocking with cross-section circuit method fire extinguishing system or realizing automatic fire notification system interlocking with home network, thirdly, tightening up licensing examination of fire safety warden, lastly, it suggested term of use rule of fire detect receiving system. 

Nitric Acid Revamp and Upgrading of the Alarm & Protection Safety System at Petrokemija, Croatia

Directory of Open Access Journals (Sweden)

Hoško, I.

2012-04-01

Full Text Available Every industrial production, particularly chemical processing, demands special attention in conducting the technological process with regard to the security requirements. For this reason, production processes should be continuously monitored by means of control and alarm safety instrumented systems. In the production of nitric acid at Petrokemija d. d., the original alarm safety system was designed as a combination of an electrical relay safety system and transistorized alarm module system. In order to increase safety requirements and modernize the technological process of nitric acid production, revamping and upgrading of the existing alarm safety system was initiated with a new microprocessor system. The newly derived alarm safety system, Simatic PCS 7, links the function of "classically" distributed control (DCS and logical systems in a common hardware and software platform with integrated engineering tools and operator interface to meet the minimum safety standards with safety integrity level 2 (SIL2 up to level 3 (SIL3, according to IEC 61508 and IEC 61511. This professional paper demonstrates the methodology of upgrading the logic of the alarm safety system in the production of nitric acid in the form of a logical diagram, which was the basis for a further step in its design and construction. Based on the mentioned logical diagram and defined security requirements, the project was implemented in three phases: analysis and testing, installation of the safety equipment and system, and commissioning. Developed also was a verification system of all safety conditions, which could be applied to other facilities for production of nitric acid. With the revamped and upgraded interlock alarm safety system, a new and improved safety boundary in the production of nitric acid was set, which created the foundation for further improvement of the production process in terms of improved analysis.

On the Use of Static Checking in the Verification of Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Østergaard, Peter H.

2016-01-01

In the formal methods community, the correctness of interlocking tables is typically verified by model checking. This paper suggests to use a static checker for this purpose and it demonstrates for the RobustRailS verification tool set that the execution time and memory usage of its static checker...

Development of Remote Control and Interlock System for the PEFP Microwave Ion Source

International Nuclear Information System (INIS)

Song, Young Gi; Seol, Kyung Tae; Kwon, Hyeok Jung; Jang, Ji Ho; Cho, Yong Sub

2011-01-01

The control system for a microwave ion source as an isolated high voltage device is a main part of the PEFP distributed control system. The system is used to control two sets of microwave ion sources, the remote control and the interlock system. A VME system with an embedded Power PC CPU is used as main computer. The VME system is dedicated to control and monitoring of the ion source operation. An isolated control system has been designed and developed for remote control and monitoring of a microwave generator and various power supplies. As the source is placed on high voltage platform, optical fiber isolation has been used between the serial to optical fiber VME I/O board and the control system on the high voltage platform. These are connected through RS232 serial interface. A fast Ethernet is used to communicate between the microwave ion source control system and other control stations in the PEFP control system. EPICS toolkit is adopted to provide network programming and user interface by using EPICS Channel Access (CA)

Generic FPGA-Based Platform for Distributed IO in Proton Therapy Patient Safety Interlock System

Science.gov (United States)

Eichin, Michael; Carmona, Pablo Fernandez; Johansen, Ernst; Grossmann, Martin; Mayor, Alexandre; Erhardt, Daniel; Gomperts, Alexander; Regele, Harald; Bula, Christian; Sidler, Christof

2017-06-01

At the Paul Scherrer Institute (PSI) in Switzerland, cancer patients are treated with protons. Proton therapy at PSI has a long history and started in the 1980s. More than 30 years later, a new gantry has recently been installed in the existing facility. This new machine has been delivered by an industry partner. A big challenge is the integration of the vendor's safety system into the existing PSI environment. Different interface standards and the complexity of the system made it necessary to find a technical solution connecting an industry system to the existing PSI infrastructure. A novel very flexible distributed IO system based on field-programmable gate array (FPGA) technology was developed, supporting many different IO interface standards and high-speed communication links connecting the device to a PSI standard versa module eurocard-bus input output controller. This paper summarizes the features of the hardware technology, the FPGA framework with its high-speed communication link protocol, and presents our first measurement results.

49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

Science.gov (United States)

2010-10-01

... Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that mechanical... 49 Transportation 4 2010-10-01 2010-10-01 false Electromechanical interlocking machine; locking...

The personnel protection system for a Synchrotron Radiation Accelerator Facility: Radiation safety perspective

International Nuclear Information System (INIS)

Liu, J.C.

1993-05-01

The Personnel Protection System (PPS) at the Stanford Synchrotron Radiation Laboratory is summarized and reviewed from the radiation safety point of view. The PPS, which is designed to protect people from radiation exposure to beam operation, consists of the Access Control System (ACS) and the Beam Containment System (BCS), The ACS prevents people from being exposed to the very high radiation level inside the shielding housing (also called a PPS area). The ACS for a PPS area consists of the shielding housing and a standard entry module at every entrance. The BCS prevents people from being exposed to the radiation outside a PPS area due to normal and abnormal beam losses. The BCS consists of the shielding (shielding housing and metal shielding in local areas), beam stoppers, active current limiting devices, and an active radiation monitor system. The system elements for the ACS and BCS and the associated interlock network are described. The policies and practices in setting up the PPS are compared with some requirements in the US Department of Energy draft Order of Safety of Accelerator Facilities

Novel Repair Concept for Composite Materials by Repetitive Geometrical Interlock Elements

Directory of Open Access Journals (Sweden)

David Zaremba

2011-12-01

Full Text Available Material adapted repair technologies for fiber-reinforced polymers with thermosetting matrix systems are currently characterized by requiring major efforts for repair preparation and accomplishment in all industrial areas of application. In order to allow for a uniform distribution of material and geometrical parameters over the repair zone, a novel composite interlock repair concept is introduced, which is based on a repair zone with undercuts prepared by water-jet technology. The presented numerical and experimental sensitivity analyses make a contribution to the systematic development of the interlock repair technology with respect to material and geometrical factors of influence. The results show the ability of the novel concept for a reproducible and automatable composite repair.

Poly[n]catenanes: Synthesis of molecular interlocked chains

Science.gov (United States)

Wu, Qiong; Rauscher, Phillip M.; Lang, Xiaolong; Wojtecki, Rudy J.; de Pablo, Juan J.; Hore, Michael J. A.; Rowan, Stuart J.

2017-12-01

As the macromolecular version of mechanically interlocked molecules, mechanically interlocked polymers are promising candidates for the creation of sophisticated molecular machines and smart soft materials. Poly[n]catenanes, where the molecular chains consist solely of interlocked macrocycles, contain one of the highest concentrations of topological bonds. We report, herein, a synthetic approach toward this distinctive polymer architecture in high yield (~75%) via efficient ring closing of rationally designed metallosupramolecular polymers. Light-scattering, mass spectrometric, and nuclear magnetic resonance characterization of fractionated samples support assignment of the high-molar mass product (number-average molar mass ~21.4 kilograms per mole) to a mixture of linear poly[7-26]catenanes, branched poly[13-130]catenanes, and cyclic poly[4-7]catenanes. Increased hydrodynamic radius (in solution) and glass transition temperature (in bulk materials) were observed upon metallation with Zn2+.

Verifying therapy safety interlock system with spin

CSIR Research Space (South Africa)

Seotsanyana, M

2009-11-01

Full Text Available signal is sent to the SIS. 2.6 Accelerator control system There are two types of beam stop devices: a Faraday cup, which is a cup shaped piece of copper and a neutron shutter, which is a steel cylinder for shielding radiation. Both kinds of devices... have two micro-switches, associated with each extreme movement of the device, which are used to detect whether the device is in the beam line or not. There are five of these beam-stop devices: (1) Faraday Cup 1: can be in or out of the beam line...

30 CFR 75.819 - Motor-starter enclosures; barriers and interlocks.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motor-starter enclosures; barriers and...-Voltage Distribution High-Voltage Longwalls § 75.819 Motor-starter enclosures; barriers and interlocks. Compartment separation and cover interlock switches for motor-starter enclosures must be maintained in...

The LHC access system LACS and LASS

CERN Document Server

Ninin, P

2005-01-01

The LHC complex is divided into a number of zones with different levels of access controls.Inside the interlocked areas, the personnel protection is ensured by the LHC Access System.The system is made of two parts:the LHC Access Safety System and the LHC Access Control System. During machine operation,the LHC Access Safety System ensures the collective protection of the personnel against the radiation hazards arising from the operation of the accelerator by interlocking the LHC key safety elements. When the beams are off, the LHC Access Control System regulates the access to the accelerator and its many subsystems.It allows a remote, local or automatic operation of the access control equipment which verifies and identifies all users entering the controlled areas.The global architecture of the LHC Access System is now designed and is being validated to ensure that it meets the safety requirements for operation of the LHC.A pilot installation will be tested in the summer 2005 to validate the concept with the us...

Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture

International Nuclear Information System (INIS)

Khan, I.; Javed, S.; Khan, G.N.; Aziz, A.

2013-01-01

Objective: To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Study Design: Case series. Place and Duration of Study: Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Methodology: Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Results: Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Conclusion: Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function. (author)

Outcome of intramedullary interlocking SIGN nail in tibial diaphyseal fracture.

Science.gov (United States)

Khan, Irfanullah; Javed, Shahzad; Khan, Gauhar Nawaz; Aziz, Amer

2013-03-01

To determine the outcome of intramedullary interlocking surgical implant generation network (SIGN) nail in diaphyseal tibial fractures in terms of union and failure of implant (breakage of nail or interlocking screws). Case series. Orthopaedics and Spinal Surgery, Ghurki Trust Teaching Hospital, Lahore Medical and Dental College, Lahore, from September 2008 to August 2009. Fifty patients aged 14 - 60 years, of either gender were included, who had closed and Gustilo type I and II open fractures reported in 2 weeks, whose closed reduction was not possible or was unsatisfactory and fracture was located 7 cm below knee joint to 7 cm above ankle joint. Fractures previously treated with external fixator, infected fractures and unfit patients were excluded. All fractures were fixed with intramedullary interlocking SIGN nail and were followed clinically and radiographically for union and for any implant failure. Forty one (88%) patients had united fracture within 6 months, 5 (10%) patients had delayed union while 4 (8%) patients had non-union. Mean duration for achieving union was 163 + 30.6 days. Interlocking screws were broken in 2 patients while no nail was broken in any patient. Intramedullary interlocking nailing is an effective measure in treating closed and grade I and II open tibial fractures. It provides a high rate of union less complications and early return to function.

The laser Megajoule facility personnel security and safety interlocks

International Nuclear Information System (INIS)

Chapuis, J.C.; Arnoul, J.P.; Hurst, A.; Manson, M.

2012-01-01

The LMJ (Laser Megajoule) is designed to deliver about 1.4 MJ of 0.35 μm light to targets for high energy density physics experiments. Such an installation entails specific hazards related to the presence of intense laser beams, and high voltage power laser amplifiers. Furthermore, the thermonuclear fusion reactions induced by the experiment also produce different radiations and neutrons burst, and also activate various materials in the chamber environment. All these hazards could be lethal. The SSP (Personnel Safety System) was designed to prevent accidents and protect personnel working in the LMJ. To satisfy at the lowest cost the requirements of safety regulations and those of the operation management, the choice was made to implement a functional architecture built around two independent technological barriers when required by the risk level. Each technical barrier is composed of two subsets, one dedicated to hazard sources management, and the other one dedicated to worker presence management. The two completely independent barriers, even at the sensor or actuator level, are designed with different technologies adapted to the required Safety Integrity Level. The combination of these 2 barriers is equivalent to a unique barrier with a rate of dangerous failure of about 10 -6 per year

NGSLR Safety Handbook

Science.gov (United States)

McGarry, Jan

2015-01-01

NASA's Next Generation Satellite Laser Ranging (NGSLR) station is the prototype for NASA's Satellite Laser Ranging (SLR) systems which will be deployed around the world in the coming decade. The NGSLR system will be an autonomous, photon-counting SLR station with an expected absolute range accuracy of better than one centimeter and a normal point (time-averaged) range precision better than one millimeter. The system provides continuous (weather permitting), 24 hour tracking coverage to an existing constellation of approximately two dozen artificial satellites equipped with passive retroreflector arrays, using pulsed, 532 nm, class IV laser systems. Current details on the approved laser systems can be found in the Appendix 1 of this document. This safety plan addresses the potential hazards to emitted laser radiation, which can occur both inside and outside the shelter. Hazards within the shelter are mitigated through posted warning signs, activated warning lights, procedural controls, personal protective equipment (PPE), laser curtains, beam blocking systems, interlock controls, pre-configured laser control settings, and other controls discussed in this document. Since the NGSLR is a satellite tracking system, laser hazards exist outside the shelter to personnel on the shelter roof and to passing aircraft. Potential exposure to personnel outside the system is mitigated through the use of posted warning signs, access control, procedural controls, a stairwell interlock, beam attenuation/blocking devices, and a radar based aircraft detection system.

FRACTURE SHAFT HUMERUS: INTERLOCKING

Directory of Open Access Journals (Sweden)

Deepak Kaladagi

2014-12-01

Full Text Available BACKGROUND: The incidence of humeral fracture has significantly increased during the present years due to the population growth and road traffic, domestic, industrial, automobile accidents & disasters like tsunami, earthquakes, head-on collisions, polytrauma etc. In order to achieve a stable fixation followed by early mobilization, numerous surgical implants have been devised. PURPOSE: The purpose of this study is to analyze the results of intramedullary fixation of proximal 2/3rd humeral shaft fractures using an unreamed interlocking intramedullary nail. INTRODUCTION: In 40 skeletally matured patients with fracture shaft of humerus admitted in our hospital, we used unreamed antegrade interlocking nails. MATERIAL: We carried out a prospective analysis of 40 patients randomly selected between 2001 to 2014 who were operated at JNMC Belgaum, MMC Mysore & Navodaya Medical College, Raichur. All cases were either RTAs, Domestic, Industrial, automobile accidents & also other modes of injury. METHOD: Routine investigations with pre-anaesthetic check-up & good quality X-rays of both sides of humerus was taken. Time of surgery ranged from 5-10 days from the time of admission. Only upper 1/3rd & middle 1/3rd humeral shaft fractures were included in the study. In all the cases antegrade locked unreamed humeral nails were inserted under C-arm. Patient was placed in supine position & the shoulder was kept elevated by placing a sandbag under the scapula. In all patients incision taken from tip of acromion to 3cm over deltoid longitudinally. Postoperatively sling applied with wrist & shoulder movements started after 24 hours. All the patients ranged between the age of 21-50 years. RESULTS: Total 40 patients were operated. Maximum fracture site were in the middle third- 76%, 14% upper 1/3rd. All 40 patients achieved union. The average time of union was 8-10 weeks. All patients regained full range of movements except in few cases, where there was shoulder

Interlocking Boards and Firm Performance: Evidence from a New Panel Database

NARCIS (Netherlands)

M.C. Non (Marielle); Ph.H.B.F. Franses (Philip Hans)

2007-01-01

textabstractAn interlock between two firms occurs if the firms share one or more directors in their boards of directors. We explore the effect of interlocks on firm performance for 101 large Dutch firms using a large and new panel database. We use five different performance measures, and for each

Design and development of embedded control system for high power RF test facility

International Nuclear Information System (INIS)

Nageswara Rao, J.; Badapanda, M.K.; Upadhyay, Rinki; Tripathi, Akhilesh; Hannurkar, P.R.

2013-01-01

Design and development of an embedded control system for the control, interlock and operation of 1MW, 352.2 MHz TH2089 klystron based RF test facility. The key components of the control system are NI compact Re configurable Input Output (cRIO) system and Windows based PC. The cRIO system's rugged hardware architecture includes a 1.06 GHz Dual-Core embedded controller with Real Time (RT) Operating System, a reconfigurable Field Programmable Gate Array (FPGA) chassis for custom I/O timing, control and processing; and I/O modules. Windows based Graphical User Interface (GUI) has been developed to guide the user through start-up procedure, to set the operating parameters and also to display the status information of all the signals. The application software for data logging and publishing of the acquired data namely set, read back and status signals of auxiliary power supplies and machine safety interlocks has been developed in LabVIEW RT module and is running on embedded controller. Machine safety interlock logic has been implemented in FPGA to meet the time criticality. (author)

Composites reinforced via mechanical interlocking of surface-roughened microplatelets within ductile and brittle matrices.

Science.gov (United States)

Libanori, R; Carnelli, D; Rothfuchs, N; Binelli, M R; Zanini, M; Nicoleau, L; Feichtenschlager, B; Albrecht, G; Studart, A R

2016-04-12

Load-bearing reinforcing elements in a continuous matrix allow for improved mechanical properties and can reduce the weight of structural composites. As the mechanical performance of composite systems are heavily affected by the interfacial properties, tailoring the interactions between matrices and reinforcing elements is a crucial problem. Recently, several studies using bio-inspired model systems suggested that interfacial mechanical interlocking is an efficient mechanism for energy dissipation in platelet-reinforced composites. While cheap and effective solutions are available at the macroscale, the modification of surface topography in micron-sized reinforcing elements still represents a challenging task. Here, we report a simple method to create nanoasperities with tailored sizes and densities on the surface of alumina platelets and investigate their micromechanical effect on the energy dissipation mechanisms of nacre-like materials. Composites reinforced with roughened platelets exhibit improved mechanical properties for both organic ductile epoxy and inorganic brittle cement matrices. Mechanical interlocking increases the modulus of toughness (area under the stress-strain curve) by 110% and 56% in epoxy and cement matrices, respectively, as compared to those reinforced with flat platelets. This interlocking mechanism can potentially lead to a significant reduction in the weight of mechanical components while retaining the structural performance required in the application field.

242-A evaporator vacuum condenser system

International Nuclear Information System (INIS)

Smith, V.A.

1994-01-01

This document is written for the 242-A evaporator vacuum condenser system (VCS), describing its purpose and operation within the evaporator. The document establishes the operating parameters specifying pressure, temperature, flow rates, interlock safety features and interfacing sub-systems to support its operation

A Focus on Triazolium as a Multipurpose Molecular Station for pH-Sensitive Interlocked Crown-Ether-Based Molecular Machines.

Science.gov (United States)

Coutrot, Frédéric

2015-10-01

The control of motion of one element with respect to others in an interlocked architecture allows for different co-conformational states of a molecule. This can result in variations of physical or chemical properties. The increase of knowledge in the field of molecular interactions led to the design, the synthesis, and the study of various systems of molecular machinery in a wide range of interlocked architectures. In this field, the discovery of new molecular stations for macrocycles is an attractive way to conceive original molecular machines. In the very recent past, the triazolium moiety proved to interact with crown ethers in interlocked molecules, so that it could be used as an ideal molecular station. It also served as a molecular barrier in order to lock interlaced structures or to compartmentalize interlocked molecular machines. This review describes the recently reported examples of pH-sensitive triazolium-containing molecular machines and their peculiar features.

Dynamically variable spot size laser system

Science.gov (United States)

Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

2012-01-01

A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

Supervision Software for the Integration of the Beam Interlock System with the CERN Accelerator Complex

CERN Document Server

Audrain, M; Dragu, M; Fuchsberger, K; Garnier, JC; Gorzawski, AA; Koza, M; Krol, K; Moscatelli, A; Puccio, B; Stamos, K; Zerlauth, M

2014-01-01

The Accelerator complex at the European Organisation for Nuclear Research (CERN) is composed of many systems which are required to function in a valid state to ensure safe beam operation. One key component of machine protection, the Beam Interlock System (BIS), was designed to interface critical systems around the accelerator chain, provide fast and reliable transmission of beam dump requests and trigger beam extraction in case of malfunctioning of equipment systems or beam losses. Numerous upgrades of accelerator and controls components during the Long Shutdown 1 (LS1) are followed by subsequent software updates that need to be thoroughly validated before the restart of beam operation in 2015. In parallel, the ongoing deployments of the BIS hardware in the PS booster (PSB) and the future LINAC4 give rise to new requirements for the related controls and monitoring software due to their fast cycle times. This paper describes the current status and ongoing work as well as the long-term vision for the integratio...

Poly[ n ]catenanes: Synthesis of molecular interlocked chains

Energy Technology Data Exchange (ETDEWEB)

Wu, Qiong; Rauscher, Phillip M.; Lang, Xiaolong; Wojtecki, Rudy J.; de Pablo, Juan J.; Hore, Michael J. A.; Rowan, Stuart J.

2017-11-30

As the macromolecular version of mechanically interlocked molecules, mechanically interlocked polymers are promising candidates for the creation of sophisticated molecular machines and smart soft materials. Poly[n]catenanes, where the molecular chains consist solely of interlocked macrocycles, contain one of the highest concentrations of topological bonds. We report, herein, a synthetic approach toward this distinctive polymer architecture in high yield (similar to 75%) via efficient ring closing of rationally designed metallosupramolecular polymers. Light-scattering, mass spectrometric, and nuclear magnetic resonance characterization of fractionated samples support assignment of the high-molar mass product (number-average molar mass similar to 21.4 kilograms per mole) to a mixture of linear poly[7-26]catenanes, branched poly[13-130]catenanes, and cyclic poly[4-7]catenanes. Increased hydrodynamic radius (in solution) and glass transition temperature (in bulk materials) were observed upon metallation with Zn2+.

Safety procedures for the MFTF sustaining-neutral-beam power supply

International Nuclear Information System (INIS)

Wilson, J.H.

1981-01-01

The MFTF SNBPSS comprises a number of sources of potentially hazardous electrical energy in a small physical area. Power is handled at 80 kV dc, 80 A; 70 V dc, 4000 A; 25 V dc, 5500 A; 3 kV dc, 10 A; and 2 kV dc, 10 A. Power for these systems is furnished from two separate 480 V distribution systems and a 13.8 kV distribution system. A defense in depth approach is used; interlocks are provided in the hardware to make it difficult to gain access to an energized circuit, and the operating procedure includes precautions which would protect personnel even if no interlocks were working. The complexity of the system implies a complex operating procedure, and this potential complexity is controlled by presenting the procedure in a modular form using 37 separate checklists for specific operations. The checklists are presented in flowchart form, so contingencies can be handled at the lowest possible level without compromising safety

Influence of interlocked transactions on gum arabic production and marketing in Senegal

NARCIS (Netherlands)

Mujawamariya, G.; Haese, D' M.F.C.; Burger, C.P.J.

2010-01-01

Interlocked relationships are characterised by traders’ supply of inputs and cash to producers on credit, to be reimbursed at sale time based on a pre-defined price which is often lower than the prevailing market price. The study analyses determinants of choice of interlocking in the gum sector in

Engineering Task Plan for Hepa Filter Differential Pressure (DP) Fan Interlock Upgrades

International Nuclear Information System (INIS)

SIMONS, S.R.

2000-01-01

This document provides a plan for installation of Differential Pressure (DP) fan interlocks on the primary ventilation systems in selected Tank Farm facilities. This plan contains the engineering tasks required for installation and is summarized by the Acceptance for Beneficial Use list. Individuals responsible for each task are identified and scheduled accordingly

Vertical interlocks of executives and performance of affiliated firms in state owned Chinese business groups

DEFF Research Database (Denmark)

Arnoldi, Jakob; Chen, Xin; Na, Chaohong

. Further, the positive effects of vertically interlocking chairmen decrease as the number of pyramidal layers increases or regional marketization index improves. Such positive effects of interlocks, however, become greater as the divergence between cash flow rights and control rights of business groups...... increases. Our findings are consistent with the hypotheses that vertically interlocking executives can increase firm value by providing better protection against political interference and expropriation by the ultimate controllers of business groups. Our study sheds new light in the role and function...... of interlocks and adds to a small body of literature on the dynamics of state owned business groups in emerging markets generally and China particularly....

AC Initiation System.

Science.gov (United States)

An ac initiation system is described which uses three ac transmission signals interlocked for safety by frequency, phase, and power discrimination...The ac initiation system is pre-armed by the application of two ac signals have the proper phases, and activates a load when an ac power signal of the proper frequency and power level is applied. (Author)

D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Operating Procedures

International Nuclear Information System (INIS)

Hance, R.

1998-01-01

This procedure is used when it is necessary to operate the solenoid energization, controls, interlocks and quench detection system. Note that a separate procedure exists for operating the solenoid 'cryogenic' systems. Only D0 Control Room Operators or the Project Electrical Engineer are qualified to execute these procedures or operate the solenoid system. This procedure assumes that the operator is familiar with using the Distributed Manufacturing Automation and Control Software (DMACS).

ROLES OF INTERLOCKING DIRECTORATES IN AN EMERGING COUNTRY: CONTROL AND COORDINATION IN FAMILY BUSINESS GROUPS

Directory of Open Access Journals (Sweden)

Aylin Ataay

2016-04-01

Full Text Available Maman (1999 proposed that, in countries in which business groups are dominant forms for organizing economic activities, the interlocking directorate is a managerial tool that can be prioritized to control and coordinate activities of their affiliated firms within the same groups and align their business objectives. This organizational connection appears to be an intentional strategy on the part of the groups‟ headquarters. In order to study the interlocking ties in Turkish family business groups (FBG, this study focused on interlocking directorates among listed firms in Turkey. The findings of preliminary study reveal that almost all of the interlocking ties were within the business groups (BG in our sample. This is the result of assignment of familyaffiliated and/or professional inside directors to the various boards of companies in the BG. We also found that compare to vertical ties; business groups are using more horizontal interlocking connections to bond their affiliated companies together.

ATR/OTR-SY Tank Camera Purge System and in Tank Color Video Imaging System

International Nuclear Information System (INIS)

Werry, S.M.

1995-01-01

This procedure will document the satisfactory operation of the 101-SY tank Camera Purge System (CPS) and 101-SY in tank Color Camera Video Imaging System (CCVIS). Included in the CPRS is the nitrogen purging system safety interlock which shuts down all the color video imaging system electronics within the 101-SY tank vapor space during loss of nitrogen purge pressure

Radiation safety training for industrial irradiators: What are we trying to accomplish?

International Nuclear Information System (INIS)

Smith, M.A.

1998-01-01

Radiation safety training at an industrial irradiator facility takes a different approach than the traditional methods and topics used at other facilities. Where the more routine industrial radiation users focus on standard training topics of contamination control, area surveys, and the traditional dogma of time, distance, and shielding, radiation safety in an industrial irradiation facility must be centered on preventing accidents. Because the primary methods for accomplishing that goal are engineering approaches such as safety system interlocks, training provided to facility personnel should address system operation and emergency actions. This presents challenges in delivering radiation safety training to an audience of varied educational and technical background where little to no commercially available training material specific to this type of operation exists

Experience of safety and performance improvement for fuel handling equipment

International Nuclear Information System (INIS)

Gyoon Chang, Sang; Hee Lee, Dae

2014-01-01

The purpose of this study is to provide experience of safety and performance improvement of fuel handling equipment for nuclear power plants in Korea. The fuel handling equipment, which is used as an important part of critical processes during the refueling outage, has been improved to enhance safety and to optimize fuel handling procedures. Results of data measured during the fuel reloading are incorporated into design changes. The safety and performance improvement for fuel handling equipment could be achieved by simply modifying the components and improving the interlock system. The experience provided in this study can be useful lessons for further improvement of the fuel handling equipment. (authors)

Extending DIII-D Neutral Beam Modulated Operations with a Camac Based Total on Time Interlock

International Nuclear Information System (INIS)

Baggest, D.S.; Broesch, J.D.; Phillips, J.C.

1999-01-01

A new total-on-time interlock has increased the operational time limits of the Neutral Beam systems at DIII-D. The interlock, called the Neutral Beam On-Time-Limiter (NBOTL), is a custom built CAMAC module utilizing a Xilinx 9572 Complex Programmable Logic Device (CPLD) as its primary circuit. The Neutral Beam Injection Systems are the primary source of auxiliary heating for DIII-D plasma discharges and contain eight sources capable of delivering 20MW of power. The delivered power is typically limited to 3.5 s per source to protect beam-line components, while a DIII-D plasma discharge usually exceeds 5 s. Implemented as a hardware interlock within the neutral beam power supplies, the NBOTL limits the beam injection time. With a continuing emphasis on modulated beam injections, the NBOTL guards against command faults and allows the beam injection to be safely spread over a longer plasma discharge time. The NBOTL design is an example of incorporating modern circuit design techniques (CPLD) within an established format (CAMAC). The CPLD is the heart of the NBOTL and contains 90% of the circuitry, including a loadable, 1 MHz, 28 bit, BCD count down timer, buffers, and CAMAC communication circuitry. This paper discusses the circuit design and implementation. Of particular interest is the melding of flexible modern programmable logic devices with the CAMAC format

El prestigi empresarial: Anàlisi a través de les conselleries creuades The business prestige: A preliminary study based on interlocks within companies The business prestige: A preliminary study based on interlocks within companies

Directory of Open Access Journals (Sweden)

David Gonzalez-Prieto

2011-11-01

Full Text Available Purpose: The literature on interlocked directorate or interlocks has proposed the presence of cross-directors as an influential factor in the prestige of a firm (Mizruchi, 1996. This theory is based on the fact that, by having multiple companies with interlocks within them, major stakeholders of the company ought to have a higher perception of prestige. The aim of this preliminary study is to present an exploratory study and suggest future research lines on this issue. Design/methodology/approach: In a first preliminary study, we evaluate the interlocks network comprising companies belonging to the ranking established by the MERCO report in Spain for the year 2010. This is a well-known ranking of corporate reputation in Spain used in recent articles (Luna & Fernandez, 2010. For further analysis, other variables are considered as being quoted in the Spanish market benchmark index, IBEX 35, and the location of the headquarters.Findings: Significant positive relationship was obtained between the number of directorships shared with other public companies and the perceived prestige that stakeholders perceive from the firm. Similarly, we obtain significant positive correlation between the prestige and being listed on the IBEX 35. Finally, we identified banking, construction and energy sectors as the ones that use interlocking directorates more intensively.Research limitations: The results of this preliminary study show the viability of future studies about prestige and interlocks (Mizruchi, 1996. For the validation of the theory described in this study, it should be replicated in different regions and, with larger samples, to observe the effect that interlocks have on the perception of prestige of the company.Practical implications / Originality/value: This is among the first studies showing the existence of a relationship between interlocks and business prestige. It highlights the importance of the composition of the boards for the perceived prestige

Lattice modeling of aggregate interlocking in concrete

DEFF Research Database (Denmark)

Eliáš, Jan; Stang, Henrik

2012-01-01

roughness, i.e.what is termed aggregate interlocking. We demonstrate this enhancement via the simulation of mixed-mode experiments on concrete performed at a laboratory at the Technical University of Denmark. Double notched concrete specimens were initially pre-cracked in tension. Then, various combinations...

Winter Performance of Inter-Locking Pavers—Stormwater Quantity and Quality

Directory of Open Access Journals (Sweden)

Angus Chu

2012-12-01

Full Text Available This study examined the effectiveness of open-joint inter-locking pavers in a permeable pavement in cold (winter conditions. A field-scale inter-locking paver cell (UNI Eco-Optiloc® was built to evaluate the hydraulic performance and water quality improvements experienced during freeze-thaw and frozen conditions in Calgary, Alberta, Canada. Hydraulic performance was assessed using stormwater runoff reduction (peaks and volumes and surface infiltration capacity. Water quality performance for removal of total suspended solids (TSS, total nitrogen (TN, total phosphorous (TP and three heavy metals: copper, lead and zinc, was assessed. Results from the study demonstrated that the inter-locking pavers were effective in attenuating stormwater runoff peak volumes. The surface infiltration capacity decreased significantly due to the deposition of sanding and de-icing materials on the pavement surface during winter operation. Infiltrated stormwater was stored and treated within the pavement structure, which showed removal rates of 91% for TSS, 78% for TP, 6% for TN, 68% for zinc, 69% for copper and 55% for lead.

Septum magnet MNP-23 for the CERN PS experimental area and its fast interlock system

CERN Document Server

Borburgh, J; Prost, A; Zickler, T

2004-01-01

Two MNP-23 septum-like magnets are installed at CERN in the transfer line from the Proton Synchrotron (PS) to the East Hall Experimental Area. They are exposed to extremely high doses of ionizing radiation. In the past, the magnets experienced two catastrophic failures due to overheating of its coils and cannot be repaired. The magnets of improved design which is subject of this article are built as replacements for the magnets presently installed. The MNP-23 is a resistive C shaped iron-dominated magnet made of solid low carbon steel blocks. The excitation windings consist of two water-cooled coils wound from hollow copper conductor. The septum design of these magnets implies a high current density which requires an efficient water cooling system. The newly designed cooling circuit provides better cooling performance and more reliability. To avoid failures due to coil overheating, an elaborate interlock system was developed and installed. It consists of two parts: firstly a slow, more classic sensor, to dete...

Metal-organic frameworks with dynamic interlocked components

Science.gov (United States)

Vukotic, V. Nicholas; Harris, Kristopher J.; Zhu, Kelong; Schurko, Robert W.; Loeb, Stephen J.

2012-06-01

The dynamics of mechanically interlocked molecules such as rotaxanes and catenanes have been studied in solution as examples of rudimentary molecular switches and machines, but in this medium, the molecules are randomly dispersed and their motion incoherent. As a strategy for achieving a higher level of molecular organization, we have constructed a metal-organic framework material using a [2]rotaxane as the organic linker and binuclear Cu(II) units as the nodes. Activation of the as-synthesized material creates a void space inside the rigid framework that allows the soft macrocyclic ring of the [2]rotaxane to rotate rapidly, unimpeded by neighbouring molecular components. Variable-temperature 13C and 2H solid-state NMR experiments are used to characterize the nature and rate of the dynamic processes occurring inside this unique material. These results provide a blueprint for the future creation of solid-state molecular switches and molecular machines based on mechanically interlocked molecules.

Determinants of Board Interlocking in the Brazilian Capital Market

Directory of Open Access Journals (Sweden)

Flávio Ribeiro

2016-10-01

Full Text Available The objective in this article was to identify the main determinants of Board Interlocking in the Brazilian capital market. As the theoretical structure, the Agency theory and Corporate Governance, the Resource Dependence theory and the Board of Administrators and the Characteristics of Board Interlocking. The sample consists of 58 Brazilian companies that participate in the Bovespa Index (Ibovespa. An empirical analytic study was undertaken. With regard to the objectives, it is characterized as exploratory and, with regard to the procedures, a documentary research was undertaken. The data on the Boards of Administrators were collected from the Reference Forms available on the website of the São Paulo Stock Exchange (BM&FBOVESPA. The results found demonstrate the generalized presence of Board Interlocking in these companies, normally associated with four factors: (1 economic group formation; (2 governmental control; (3 formation of pension funds; and (4 presence of professionals with acknowledged market experience. The results also suggest that the first three factors give rise to long-lasting links and that these connections are hard to break. On the other hand, the links established through professionals with market experience tend to be more unstable because the presence of these professionals is highly demanded to serve on the board of different companies.

The Utilisation of Shredded PET as Aggregate Replacement for Interlocking Concrete Block

Science.gov (United States)

Mokhtar, M.; Kaamin, M.; Sahat, S.; Hamid, N. B.

2018-03-01

The consumption of plastic has grown substantially all over the world in recent years and this has created huge quantities of plastic-based waste. Plastic waste is now a serious environmental threat to the modern way of living, although steps were taken to reduce its consumption. This creates substantial garbage every day, which is much unhealthy. Plastic bottles such as Polyethylene terephthalate (PET) was use as the partially component in this making of interlocking blocks concrete. This project investigates the strength and workability of the interlocking block concrete by replacing course aggregate with % PET. The suitability of recycled plastics (PET) as course aggregate in interlocking block concrete and its advantages are discussed here. Moreover, there were more benefits when using interlocking block than using conventional block such as it easy for construction because they are aligning, easy to place, high speed stacking and they offer more resistance to shear and buildings would be even stronger. Based on the test perform, the failure parameter were discussed .From the compressive strength test result, it shows that the strength of concrete block decreased with increased of PET used. From the results, it shows that higher compressive strength was found with 5% natural course aggregate replaced with PET compared to other percentages.

Influence of Sawdust as an Aggregate in the Production of Interlocking Pavers

Directory of Open Access Journals (Sweden)

Olayiwola Olaleye AJALA

2017-03-01

Full Text Available The study was conducted to determine the effect of incorporating sawdust into the production of interlocking pavers. Sawdust, stone dust, cement and sharp-sand were combined in different mixing ratios of 2:4:2:0, 2:3:2:1, 2:2:2:2, 3:1:2:2 and 0:3:2:3 respectively with five replicates of each treatment. The interlocking pavers produced were tested for weight, density, hardness, compressive and impact strength. The Analysis of Variance was conducted to test the significance of the strength properties of the pavers produced. The results showed that pavers produced with mixing ratio 0:3:2:3 has the highest mean density and mean compressive strength at 1.58kg/m3 and 4.72N/mm2 respectively, closely followed by ratio 2:2:2:2 which has the highest mean impact strength at 4.39J, compressive strength of 3.26N/mm2 , hardness of 1.70kg and mean density of 1.20kg/m3 . However there is no significant difference in the interlocking pavers’ degree of resistance to abrasion (hardness. It can be concluded that optimum replacement of aggregates exists in ratio 2:2:2:2 where 25% of sawdust can be utilized in each unit of interlocking paver.

Achieving interlocking nails without using an image intensifier.

Science.gov (United States)

Ikem, Innocent C; Ogunlusi, Johnson D; Ine, Henry R

2007-08-01

Interlocking nails are commonly performed using an image intensifier. These are expensive and are not readily available in most resource-poor countries of the world. The aim of this study was to achieve interlocking nailing without the use of an image intensifier. This is a prospective descriptive analysis of 40 consecutive cases seen with shaft fractures of the humerus, femur, and tibia. Fracture fixation was done using Surgical Implant Generation Network (SIGN) nails. Forty limbs in 34 patients were studied. There were 12 females and 22 males, giving a ratio of 1:2. The mean age (years) was 35.75+/-13.16 and the range was 17-70 years. The studied bones were: humerus 10%, femur 65%, and tibia 25%. The fracture lines were: transverse 40%, oblique 15%, and communited 45%. Fracture grades were: closed 90%, grade I, 5%, grade II, 2.5%, and grade IIIA, 2.5%. Surgical approaches were: antegrade 62.5% and retrograde 37.5%. Indications for fixation were: recent fracture 92.5%, non-union 5%, and malunion 3%. Methods of reductions were: open 85% and closed 15%. The mean follow-up period (years) was 1.50+/-0.78. The union time averaged 3 months. Complication was mainly screw loosening due to severe osteoporoses in one case. It is, therefore, concluded that, with the aid of external jigs and slot finders, interlocking can be achieved without an image intensifier.

Radiation safety in welding and testing

International Nuclear Information System (INIS)

King, B.E.; Malaxos, M.; Hartley, B.M.

1985-01-01

There are a number of ways of achieving radiation safety in the workplace. The first is by engineering radiation safety into the equipment, providing shielded rooms and safety interlocks. The second is by following safe working procedures. The National Health and Medical Research Council's Code of practice for the control and safe handling of sealed radioactive sources used in industrial radiography (1968) sets out the standards which must be met by equipment to be used in industrial radiography

Communities detection as a tool to assess a reform of the Italian interlocking directorship network

Science.gov (United States)

Drago, Carlo; Ricciuti, Roberto

2017-01-01

Interlocking directorships are important communication channels among companies and may have anticompetitive effect. A corporate governance reform was introduced in 2011 to prevent interlocking directorships in the financial sector. We apply community detection techniques to the analysis of the networks in 2009 and 2012 to ascertain the effect of such reform on the Italian directorship network. We find that, although the number of interlocking directorships decreases in 2012, the reduction takes place mainly at the periphery of the network. The network core is stable, allowing the most connected companies to keep their strategic position.

Radiation safety aspects at Indus accelerator complex

International Nuclear Information System (INIS)

Marathe, R.G.

2011-01-01

Indus Accelerator Complex at Raja Ramanna Center for Advanced Technology houses two synchrotron radiation sources Indus-1 and Indus-2 that are being operated round-the-clock to cater to the needs of the research community. Indus-1 is a 450 MeV electron storage ring and Indus-2 is presently being operated with electrons stored at 2 GeV. Bremsstrahlung radiation and photo-neutrons form the major radiation environment in Indus Accelerator Complex. They are produced due to loss of electron-beam occurring at different stages of operation of various accelerators located in the complex. The synchrotron radiation (SR) also contributes as a potential hazard. In order to ensure safety of synchrotron radiation users and operation and maintenance staff working in the complex from this radiation, an elaborate radiation safety system is in place. The system comprises a Personnel Protection System (PPS) and a Radiation Monitoring System (RMS). The PPS includes zoning, radiation shielding, door interlocks, a search and scram system and machine operation trip-interlocks. The RMS consists of area radiation monitors and beam loss monitors, whose data is available online in the Indus control room. Historical data of radiation levels is also available for data analysis. Synchrotron radiation beamlines at Indus-2 are handled in a special manner owing to the possibility of exposure to synchrotron radiation. Shielding hutches with SR monitors are installed at each beamline of Indus-2. Health Physics Unit also carries out regular radiological surveillance for photons and neutrons during various modes of operation and data is logged shift wise. The operation staff is appropriately trained and qualified as per the recommendations of Atomic Energy Regulatory Board (AERB). Safety training is also imparted to the beamline users. Safe operation procedures and operation checklists are being followed strictly. A radiation instrument calibration facility is also being set-up at RRCAT. The radiation

Governance of pension funds: interlocking and compensation of Australian superannuation fund boards

OpenAIRE

Ooi, Elizabeth Meishan

2017-01-01

This thesis documents the incidence and determinants of board interlocking (where directors simultaneously sit on multiple boards) in pension funds and examines its effect on fund performance. It also investigates the determinants of pension fund director compensation. The motivation to examine these issues stems from the distinctive interlocking and compensation practices in pension funds. Data on a sample of 249 Australian pension funds from 2004 to 2011 is collected from fund documents ...

76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems

Science.gov (United States)

2011-09-09

... during road tests for the braking system, a vehicle equipped with an interlocking axle system or a front... vehicle braking systems, tire characteristics related to lateral force and longitudinal force generation... stopping distance without activating the ABS system by braking the vehicle so that the brake pressure is...

Bio-inspired design of geometrically interlocked 3D printed joints

Science.gov (United States)

Kumar, S.; Oliva, Noel; Kumar's Lab Team

The morphology of the adhesive-adherend interface significantly affects the mechanical behavior of adhesive joints. As seen in some biocomposites like human skull, or the nacre of some bivalve molluscs' shells, a geometrically interlocking architecture of interfaces creates toughening and strengthening mechanisms enhancing the mechanical properties of the joint. In an attempt to characterize this mechanical interlocking mechanism, this study is focused on computational and experimental investigation of a single-lap joint with a very simple geometrically interlocked interface design in which both adherends have a square waveform configuration of the joining surfaces. This square waveform configuration contains a positive and a negative rectangular teeth per cycle in such a way that the joint is symmetric about the mid-bondlength. Both physical tests performed on 3D printed prototypes of joints and computational results indicate that the joints with square waveform design have higher strength and damage tolerance than those of joints with flat interface. In order to identify an optimal design configuration of this interface, a systematic parametric study is conducted by varying the geometric and material properties of the non-flat interface. This work was supported by Lockheed Martin (Award No: 12NZZ1).

Macro-Micro Interlocked Simulator

International Nuclear Information System (INIS)

Sato, Tetsuya

2005-01-01

Simulation Science is now standing on a turning point. After the appearance of the Earth Simulator, HEC is struggling with several severe difficulties due to the physical limit of LSI technologies and the so-called latency problem. In this paper I would like to propose one clever way to overcome these difficulties from the simulation algorithm viewpoint. Nature and artificial products are usually organized with several nearly autonomously working internal systems (organizations, or layers). The Earth Simulator has gifted us with a really useful scientific tool that can deal with the entire evolution of one internal system with a sufficient soundness. In order to make a leap jump of Simulation Science, therefore, it is desired to design an innovative simulator that enables us to deal with simultaneously and as consistently as possible a real system that evolves cooperatively with several internal autonomous systems. Three years experience of the Earth Simulator Project has stimulated to come up with one innovative simulation algorithm to get rid of the technological barrier standing in front of us, which I would like to call 'Macro-Micro Interlocked Algorithm', or 'Macro-Micro Multiplying Algorithm', and present a couple of such examples to validate the proposed algorithm. The first example is an aurora-arc formation as a result of the mutual interaction between the macroscopic magnetosphere-ionosphere system and the microscopic field-aligned electron and ion system. The second example is the local heavy rain fall resulting from the interaction between the global climate evolution and the microscopic raindrop growth process. Based on this innovative feasible algorithm, I came up with a Macro-Micro Multiplying Simulator

The Impact of Board Interlocks on Auditor Choice and Audit Fees

DEFF Research Database (Denmark)

Riise Johansen, Thomas; Pettersson, Kim

2013-01-01

Research Question/Issue This paper uses unique Danish data to examine whether non-executive directors draw on both direct and indirect ties in the network of interlocking directorates to impact auditor choice, and whether this impact has consequences for audit fees. Research Findings/Insight The ......Research Question/Issue This paper uses unique Danish data to examine whether non-executive directors draw on both direct and indirect ties in the network of interlocking directorates to impact auditor choice, and whether this impact has consequences for audit fees. Research Findings....../Insight The paper finds clear evidence that non-executive directors draw on their networks to impact auditor choice, and evidence that clients pay an audit fee premium when non-executive directors are connected to audit firms outside the focal company. The relationship between non-executive directors and auditors...... of the non-executive director–auditor relationship and the role that board networks have in governing auditor choice decisions. The study identifies interlocks as an infrastructure for differentiation in the audit market and determines that such differentiation is associated with an audit fee premium...

Safety aspects and shield design of a Poton irradiator

International Nuclear Information System (INIS)

Mehta, S.K.; Nayak, A.R.; Bongirwar, D.R.; Modi, R.K.; Ramkumar, M.S.

1998-01-01

An irradiation plant, POTON, for irradiation of potatoes and onions is being set up at Nashik. Shield design and safety features of this plant incorporate some novel and innovative features like a compact cell, curved cell boundaries for smooth conveyor movement though the cell labyrinth and conform to ICRP and AERB design safety requirements. The safety features include multiple safety interlocks, audio-visual alarms, scram switches and trip wire for avoiding accidental exposures. (author)

Structural damage monitoring of harbor caissons with interlocking condition

Energy Technology Data Exchange (ETDEWEB)

Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae [Pukyong National Univ., Busan (Korea, Republic of)

2012-12-15

The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons.

Structural damage monitoring of harbor caissons with interlocking condition

International Nuclear Information System (INIS)

Huynh, Thanh Canh; Lee, So Young; Nauyen, Khac Duy; Kim, Jeong Tae

2012-01-01

The objective of this study is to monitor the health status of harbor caissons which have potential foundation damage. To obtain the objective, the following approaches are performed. Firstly, a structural damage monitoring(SDM) method is designed for interlocked multiple caisson structures. The SDM method utilizes the change in modal strain energy to monitor the foundation damage in a target caisson unit. Secondly, a finite element model of a caisson system which consists of three caisson units is established to verify the feasibility of the proposed method. In the finite element simulation, the caisson units are constrained each other by shear key connections. The health status of the caisson system against various levels of foundation damage is monitored by measuring relative modal displacements between the adjacent caissons

An analytical hierarchical model explaining the robustness and flaw-tolerance of the interlocking barb-barbule structure of bird feathers

Science.gov (United States)

Chen, Qiang; Gorb, Stanislav; Kovalev, Alexander; Li, Zhiyong; Pugno, Nicola

2016-10-01

Feathers can fulfill their aerodynamic function only if the pennaceous vane forms an airfoil stabilized by robust interlocking between barbules. Thus, revealing the robustness of the interlocking mechanical behavior of the barbules is very important to understand the function and long-term resilience of bird feathers. This paper, basing on the small- and large-beam deflection solutions, presents a hierarchical mechanical model for deriving the critical delamination conditions of the interlocking barbules between two adjacent barbs in bird feathers. The results indicate a high robustness and flaw-tolerant design of the structure. This work contributes to the understanding of the mechanical behavior of the robust interlocking barb-barbule structure of the bird feather, and provides a basis for design of feather-inspired materials with robust interlocking mechanism, such as advanced bio-inspired micro-zipping devices.

Innovative monitoring of 3D warp interlock fabric during forming process

Science.gov (United States)

Dufour, C.; Jerkovic, I.; Wang, P.; Boussu, F.; Koncar, V.; Soulat, D.; Grancaric, A. M.; Pineau, P.

2017-10-01

The final geometry of 3D warp interlock fabric needs to be check during the 3D forming step to ensure the right locations of warp and weft yarns inside the final structure. Thus, a new monitoring approach has been proposed based on sensor yarns located in the fabric thickness. To ensure the accuracy of measurements, the observation of the surface deformation of the 3D warp interlock fabric has been joined to the sensor yarns measurements. At the end, it has been revealed a good correlation between strain measurement done globally by camera and locally performed by sensor yarns.

Refining the maintenance techniques for Interlocking Concrete Paver GIs

Science.gov (United States)

Surface clogging adversely affects the performance of Interlocking Concrete Pavements (ICP) by reducing their ability to infiltrate stormwater runoff. The clogging rate is a function of pavement type, traffic loading, surrounding physical environment and maintenance treatments. ...

Design of responsive materials using topologically interlocked elements

International Nuclear Information System (INIS)

Molotnikov, A; Gerbrand, R; Qi, Y; Simon, G P; Estrin, Y

2015-01-01

In this work we present a novel approach to designing responsive structures by segmentation of monolithic plates into an assembly of topologically interlocked building blocks. The particular example considered is an assembly of interlocking osteomorphic blocks. The results of this study demonstrate that the constraining force, which is required to hold the blocks together, can be viewed as a design parameter that governs the bending stiffness and the load bearing capacity of the segmented structure. In the case where the constraining forces are provided laterally using an external frame, the maximum load the assembly can sustain and its stiffness increase linearly with the magnitude of the lateral load applied. Furthermore, we show that the segmented plate with integrated shape memory wires employed as tensioning cables can act as a smart structure that changes its flexural stiffness and load bearing capacity in response to external stimuli, such as heat generated by the switching on and off an electric current. (paper)

The health physics system at the Bonn 2.3 GeV electron synchrotron with the ELSA storage ring

International Nuclear Information System (INIS)

Doeing, R.; Giese, R.; Husmann, D.; Ewen, K.

1992-01-01

The health physics system installed and operated for providing radiological safety to the personnal consists of an interlock system monitoring access to the controlled areas, alarm and signaling systems, and a radiation measuring equipment for the controlled and monitored areas. (DG) [de

Discontinuous Residue and Theme in Higher-Order Semiotic: A Case for Interlocking Systems

Directory of Open Access Journals (Sweden)

Ali Akbar Farahani

2008-11-01

Full Text Available The fallacy persists in discourse analysis research to explore lexicogrammatical phenomena detached from any adjacent plane of the meaning potential. In an attempt to dispel this and toss out some preconceived notions about what a modern SFG vantage point should involve, this study homes in on one aspect of SFG within prose fiction in particular, which is very revealing in terms of how separate system networks are actually in synergistic simultaneity, and how SFG allows one , phenomenally well, to bring such synergies out, getting to the heart of the fact that language pervasively operates on multiple planes of textuality simultaneously. Thus, building upon Halliday’s 2004 work, the quest is if it is interpersonally significant when the Residue is split into two parts; more importantly, if it is also laced with some lexicogrammatical quality on the textual plane, in light of the fairly well-entrenched assumption that there is always Theme at work when the Residue is split. Halliday is the only scholar to touch upon the topic of Discontinuous Residue and its relationship to Marked Theme in the culmination of his groundbreaking career, i.e. his 2004 work. Having driven home the proposal to make into a watchword the ubiquity of interlocking macro-semantic system networks, some pedagogical and research implications and suggestions flowing from this are brought up.

Active interlock system for high power insertion devices in the x-ray ring

International Nuclear Information System (INIS)

Anon.

1991-01-01

In modern synchrotron radiation rings photon beams generated by high power insertion devices (IDs) may be sufficiently intense to cause severe thermal damage to the machine vacuum chamber if mis-steered. Thus when operating a storage ring with the IDs, great care must be exercised to prevent mis-steering of the electron beam orbit. At present, the X-ray ring operates with three IDs, namely two hybrid wigglers (HBW) at X-21 and X-25,a nd a 5-Tesla superconducting wiggler at X-17. All wigglers are located in low-beta straight sections. In the straight sections. In the straight sections, beam orbit may be deflected by as much as ±8 mrad without scraping the chamber wall. For various reasons it was not possible to design the X-ray ring vacuum chamber to be safe under all possible operating conditions, however, the chamber is safe for i < 7 mA, all horizontal beam deflection angles and for vertical angles < ± 2.5 mrad. To protect the machine vacuum chamber from damage due to mis-steered beams, and interlock system has been developed and installed. This system utilizes active beam position detectors which continuously monitor beam motion in each of the ID straight sections and logic circuitry which interrupts the RF and dumps the stored beam in the case of a fault

49 CFR 1242.17 - Signals and interlockers (accounts XX-17-19 and XX-18-19).

Science.gov (United States)

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Signals and interlockers (accounts XX-17-19 and XX... RAILROADS 1 Operating Expenses-Way and Structures § 1242.17 Signals and interlockers (accounts XX-17-19 and XX-18-19). Separate common expenses on the basis of the total train-hours in running service, and/or...

Effects of Interlocking and Supporting Conditions on Concrete Block Pavements

Science.gov (United States)

Mahapatra, Geetimukta; Kalita, Kuldeep

2018-02-01

Concrete Block Paving (CBP) is widely used as wearing course in flexible pavements, preferably under light and medium vehicular loadings. Construction of CBP at site is quick and easy in quality control. Usually, flexible pavement design philosophy is followed in CBP construction, though it is structurally different in terms of small block elements with high strength concrete and their interlocking aspects, frequent joints and discontinuity, restrained edge etc. Analytical solution for such group action of concrete blocks under loading in a three dimensional multilayer structure is complex and thus, the need of conducting experimental studies is necessitated for extensive understanding of the load—deformation characteristics and behavior of concrete blocks in pavement. The present paper focuses on the experimental studies for load transfer characteristics of CBP under different interlocking and supporting conditions. It is observed that both interlocking and supporting conditions affect significantly on the load transfer behavior in CBP structures. Coro-lock block exhibits better performance in terms of load carrying capacity and distortion behavior under static loads. Plate load tests are performed over subgrade, granular sub-base (GSB), CBP with and without GSB using different block shapes. For an example case, the comparison of CBP with conventional flexible pavement section is also presented and it is found that CBP provides considerable benefit in terms of construction cost of the road structure.

COMPARATIVE STUDY OF KUNTSCHER’S NAIL VS. INTERLOCKING NAILING FOR FEMORAL ISTHMUS FRACTURES

Directory of Open Access Journals (Sweden)

Rajeev Kumar Roy

2017-05-01

Full Text Available BACKGROUND Interlocking intramedullary nailing is suitable for comminuted femoral isthmus fractures, but for non-comminuted fractures its benefit over unlocked nailing is debatable. This study was undertaken to compare outcomes of interlocking nailing versus k-nail in such fractures. MATERIALS AND METHODS 40 cases of noncomminuted femoral isthmus fractures treated with interlocking nailing and K-nail from April 1, 2015, to December 1, 2016, were reviewed. Radiological and clinical union rates, bony alignment, complication and knee function were investigated. RESULTS There was no statistical significant difference with regard to union rate, implant failure, infection and fracture alignment in both study groups. Open fixation with K-nail is technically less demanding and requires less operating time; additionally, there is no exposure to radiation and cost of the implant is cheaper. CONCLUSION We therefore conclude that unlocked nailing is still useful for the management of noncomminuted isthmus fractures of the femur.

Safety considerations of new critical assembly for the Research Reactor Institute, Kyoto University

International Nuclear Information System (INIS)

Umeda, Iwao; Matsuoka, Naomi; Harada, Yoshihiko; Miyamoto, Keiji; Kanazawa, Takashi

1975-01-01

The new critical assembly type of nuclear reactor having three cores for the first time in the world was completed successfully at the Research Reactor Institute of Kyoto University in autumn of 1974. It is called KUCA (Kyoto University Critical Assembly). Safety of the critical assembly was considered sufficiently in consequence of discussions between the researchers of the institute and the design group of our company, and then many bright ideas were created through the discussions. This paper is described the new safety design of main equipments - oil pressure type center core drive mechanism, removable water overflow mechanism, core division mechanism, control rod drive mechansim, protection instrumentation system and interlock key system - for the critical assembly. (author)

Fracture Union in Closed Interlocking Nail in Humeral Shaft Fractures

Directory of Open Access Journals (Sweden)

Ramji Lal Sahu

2015-01-01

Conclusions: The results of the present study indicates that in the presence of proper indications, reamed antegrade intramedullary interlocked nailing appears to be a method of choice for internal fixation of osteoporotic and pathologic fractures.

A control system of radiation protection at HESYRL

International Nuclear Information System (INIS)

Li Yuxiong; Li Juexin; Ning Xinquan

1990-01-01

A control system for radiation protection at Hefei National Synchrotron Radiation Laboratory (HESYRL) consists of three parts. They are a personal radiation safety interlock system, an automatic environmental radiation monitoring system and a data logging and management system for area radiation monitoring. Two-year operating experiments have shown that this system is reasonably designed, reliable, high-sensitive and automatic. The design principle, construction and operating status of each part of the system are introduced

Research to connect the ozone monitor into irradiation system at Hanoi Irradiation Centre

International Nuclear Information System (INIS)

Le Van Huy; Pham Duy Duong; Nguyen Dinh Hung; Vu Quoc Dat

2013-01-01

Since 2006, in order to develop radiation technology, Vietnam Atomic Energy Institute has supported Hanoi Irradiation Centre a Project titled: Upgrading the irradiation facility. According to the Project, equipment have been replaced by a new one so that the facility could be suitable for treatment of products. The facility was designed and produced by the former Russia experts. Under normal operating conditions, we are protected by shielding, detection systems, and safety procedures. A system of interlocks prevents unauthorized entry into the radiation chamber when the source is exposed. However, interlocks system have not been warning and preventing ozone gas that can affect human health. So we are having an upgrade as connecting the ozone monitor into irradiation system at Hanoi Irradiation Centre. (author)

Cloning Nacre's 3D Interlocking Skeleton in Engineering Composites to Achieve Exceptional Mechanical Properties.

Science.gov (United States)

Zhao, Hewei; Yue, Yonghai; Guo, Lin; Wu, Juntao; Zhang, Youwei; Li, Xiaodong; Mao, Shengcheng; Han, Xiaodong

2016-07-01

Ceramic/polymer composite equipped with 3D interlocking skeleton (3D IL) is developed through a simple freeze-casting method, exhibiting exceptionally light weight, high strength, toughness, and shock resistance. Long-range crack energy dissipation enabled by 3D interlocking structure is considered as the primary reinforcing mechanism for such superior properties. The smart composite design strategy should hold a place in developing future structural engineering materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental and numerical analysis of interlocking rib formation at sheet metal blanking

Science.gov (United States)

Bolka, Špela; Bratuš, Vitoslav; Starman, Bojan; Mole, Nikolaj

2018-05-01

Cores for electrical motors are typically produced by blanking of laminations and then stacking them together, with, for instance, interlocking ribs or welding. Strict geometrical tolerances, both on the lamination and on the stack, combined with complex part geometry and harder steel strip material, call for use of predictive methods to optimize the process before actual blanking to reduce the costs and speed up the process. One of the major influences on the final stack geometry is the quality of the interlocking ribs. A rib is formed in one step and joined with the rib of the preceding lamination in the next. The quality of the joint determines the firmness of the stack and also influences its. The geometrical and positional accuracy is thus crucial in rib formation process. In this study, a complex experimental and numerical analysis of interlocking rib formation has been performed. The aim of the analysis is to numerically predict the shape of the rib in order to perform a numerical simulation of the stack formation in the next step of the process. A detailed experimental research has been performed in order to characterize influential parameters on the rib formation and the geometry of the ribs itself, using classical and 3D laser microscopy. The formation of the interlocking rib is then simulated using Abaqus Explicit. The Hilll 48 constitutive material model is based on extensive and novel material characterization process, combining data from in-plane and out-of-plane material tests to perform a 3D analysis of both, rib formation and rib joining. The study shows good correlation between the experimental and numerical results.

A comparative study of interlocking directorates at the end of the import-substituting industrialization period in Argentina and Chile

Directory of Open Access Journals (Sweden)

Erica Salvaj, Andrea Lluch

2012-12-01

Full Text Available Research on interlocking directorates has been conducted primarily in the United States and European countries. Little work of either theoretical or empirical nature has been done to study the characteristics and the factors that affect this important business network in peripheral and turbulent economies. In this comparative and historical study, we focus on the effect of the political and economic turbulence and the ownership composition of the largest firms on shaping the structure of interlocking directorates in Argentina and Chile by the end of the sixties. Four main findings result from this analysis: 1 the interlocking directorate in Argentina is more fragmented than in Chile; 2 most relevant actors in the directorship interlock in Argentina are firms in industries considered strategic by the government; 3 multinational subsidiaries occupy a central position in Argentina; 4 banks and firms owned by local business groups played a central role in the interlocking directorates in Chile. This study shows how the institutional and economic factors shape the structure of relations between companies.

Synthesis of interlocked molecules by olefin metathesis

Science.gov (United States)

Clark, Paul Gregory

polyammonium scaffold. Diolefin polyether fragments were coordinated and "clipped" around the ammonium sites within the polymer backbone using ring-closing olefin metathesis, giving the molecular "charm bracelet". Confirmation of the interlocked nature of the product was achieved via 1H NMR spectroscopy and two-dimensional diffusion ordered NMR spectroscopy. A simple strategy for a one-pot, multi-component synthesis of polyrotaxanes using acyclic diene metathesis polymerization was developed. The polyrotaxanes were characterized by traditional 1H NMR spectroscopy as well as size exclusion chromatography, and the interlocked topology was confirmed using two-dimension diffusion-ordered NMR spectroscopy. The dynamic, self-correcting nature of the ADMET polymerization was also explored through the equilibration of a capped polyammonium polymer in the presence of dibenzo-24-crown-8 ether and olefin metathesis catalysts. The efficiency and ease with which these mechanically interlocked macromolecules can be assembled should facilitate rapid modulation to achieve versatile polyrotaxane architectures. Flexible, switchable [c2]daisy-chain dimers (DCDs) were synthesized, where the macromer ammonium binding site was adjacent to the crown-type recognition structure and separated from the cap by an alkyl chain. A DCD of this topology is expected to have an extended structure in the bound conformation (when the ammonium was coordinated to the crown). Several different macromer candidates were designed to allow access to DCDs with flexible alkyl chains between the ammonium binding site and the cap, and a number of synthetic routes were explored in an effort to access these challenging materials. While the first generation DCD structure proved to be unstable due to a labile ester linkage, work is continuing toward the development of several cap structures in an effort to replace the ester linkage with an ether linkage, which, in the second generation model systems, has proven much more stable

Radiation safety analysis and action plans for NSRRC top-up operation

International Nuclear Information System (INIS)

Wang, J.-P.; Sheu, R.-J.; Liu, Joseph C.; Chen, C.-R.; Chang, F.-D.; Kao, S.-P.

2006-01-01

This paper summarizes the radiation safety analysis and action plans for the upcoming top-up operation at the National Synchrotron Radiation Research Center (NSRRC). Electron beam loss scenarios and consequence of beam lifetime and injection efficiency have been studied. Dose assessment was conducted based on measurement and Monte Carlo simulation results. Radiation safety action plans such as upgrading the shielding of the injection section, enlarging the exclusion zones of the straight section beamlines, installing new interlock system for top-up operation and most importantly improving the injection efficiency have been scheduled. The goal is to keep present dose limit of 2 mSv/y and make top-up operation feasible at normal user's run of year 2006

Safety protection and technical improvement of 60Co irradiation facilities

International Nuclear Information System (INIS)

Zhou Yongxing; Liang Cannan

1993-01-01

To ensure personal safety, some improvements has been made in the design of 60 Co irradiation compartment. The shielding door was interlocked while the 60 Co source to be lifted to the irradiation position or lowered to the shielded position. A universal change-over switch was used to cut the power supply when the source moved beyond the limits. Both γ-ray alarm and a closed-TV system were adopted. The electromagnetic attraction method was employed to shift the 60 Co source from the Pb container to the source pipe

Comparative Study on the Cost of Building Public House Construction Using Red Brick and Interlock Brick Building Material in the City of Banda Aceh

Science.gov (United States)

Malahayati, Nurul; Hayati, Yulia; Nursaniah, Cut; Firsa, T.; Fachrurrazi; Munandar, Aris

2018-05-01

Red brick and interlocking brick are the building materials that are often used for wall installation work on houses construction. In the development of building materials technology and cost savings, interlocking brick can be alternative to replace red bricks. In Aceh Province, the use of interlocking bricks is less popular compared to other big cities in Indonesia. Interlocking brick is made from a mixture of clay, concrete sand and compacted cement and one of the environmentally friendly materials because it does not burn the process like red brick material. It is named interlocking brick because the installation method is locked together and it serves as a structural and partition wall of residential buildings. The aims of this study are to compare the cost of building a house in Banda Aceh City using red brick and interlock brick building materials. The data were obtained from interviews and questionnaires distributed to respondents who had built houses in Banda Aceh City. The results concluded that the house construction cost using interlock brick offer lower construction cost at comparable quality rather than using red brick.

The Diamond machine protection system

International Nuclear Information System (INIS)

Heron, M.T.; Lay, S.; Chernousko, Y.; Hamadyk, P.; Rotolo, N.

2012-01-01

The Diamond Light Source Machine Protection System (MPS) manages the hazards from high power photon beams and other hazards to ensure equipment protection on the booster synchrotron and storage ring. The system has a shutdown requirement, on a beam mis-steer of under 1 msec and has to manage in excess of a thousand interlocks. This is realised using a combination of bespoke hardware and programmable logic controllers. The MPS monitors a large number of interlock signals from diagnostics instrumentation, vacuum instrumentation, photon front ends and plant monitoring subsystems. Based on logic it can then remove the source of the energy to ensure protection of equipment. Depending on requirements, interlocks are managed on a Local or a Global basis. The Global system is structured as two layers, and supports fast- and slow-response-time interlock requirements. A Global MPS module takes the interlock permits for a given interlock circuit from each of the cells of the accelerator, and, subject to all interlocks being good, produces a permit to operate the source of energy: the RF amplifier for vessel protection and the PSU for magnet protection. The Local MPS module takes fast Interlock inputs from one cell of the Storage Ring or one quadrant of the Booster. Fast interlocks are those that must drop the beam in under 400 μsec (the maximum speed of the interlock) in the event of failure. EPIC provides the user interface to the MPS system

A protection system for picosecond accelerator

International Nuclear Information System (INIS)

Cao Hongping; Chinese Academy of Sciences, Beijing; Chen Huanguang; Xu Ruinian; Tang Junlong; Li Deming

2006-01-01

A personnel and machine protection system for the picosecond accelerator has been built. The key of the system is to send on/off of three triggering signals which are those of electron gun, 2856 MHz and 476 MHz, respectively, to ensure the safety of users and the accelerator. This paper describes the emergencies interlocked by ADAM5511 and timing trigger processor, and some secondary functions which improve the efficiency of the protection system completed in upper layer software. (authors)

Board interlocking in Brazil: Director participation in multiple companies and its effect on the value of firms

Directory of Open Access Journals (Sweden)

Alexandre Di Miceli da Silveira

2007-12-01

Full Text Available This paper investigates the simultaneous participation of directors in different companies from 320 Brazilian listed firms in 2003 and 2005. We identify which firms are connected through a network of directors, which corporate characteristics contribute to this phenomenon, and if board interlocking influences firm value and operational performance. The results show that interlocking directorates are a common practice in Brazil. Besides, larger boards, more dispersed ownership structures, and larger firm size are factors associated with a high level of board interlocking. Moreover, we find that firm value is, on average, negatively impacted by higher levels of board interlocking, especially on firms with board of directors considered too busy (those in which a majority of directors hold three or more directorships or on firms where their CEO hold directorships in other companies. Besides being a pioneer work on this field in Latin America, the paper provides subsides for the preparation of good corporate governance practices from regulators regarding the effectiveness of multiple directorships and its consequences for corporate value.

WALS: A sensor-based robotic system for handling nuclear materials

International Nuclear Information System (INIS)

Drotning, W.; Kimberly, H.; Wapman, W.

1997-01-01

An automated system is being developed for handling large payloads of radioactive nuclear materials in an analytical laboratory. The system uses machine vision and force/torque sensing to provide sensor-based control of the automation system to enhance system safety, flexibility, and robustness and achieve easy remote operation. The automation system also controls the operation of the laboratory measurement systems and the coordination of them with the robotic system. Particular attention has been given to system design features and analytical methods that provide an enhanced level of operational safety. Independent mechanical gripper interlock and too release mechanisms were designed to prevent payload mishandling. An extensive failure modes and effects analysis (FMEA) of the automation system was developed as a safety design analysis tool

Bunker door interlock limit issues of K-130 cyclotron, VECC

International Nuclear Information System (INIS)

Srihari, K.; Ravishankar, R.; Mitra, M.S.; Mishra, S.K.; Bandyopadhyay, T.; Sarkar, P.K.

2011-01-01

The K-130 cyclotron is in operation at VECC, Kolkata. Recently modernization of the cyclotron has taken place. Central region modification has increased reasonable internal beam current. During the tuning of the projectiles, loss of beam is unavoidable and projectiles hitting different parts of the machine inside the vacuum chamber . These interactions produce prompt radiation comprising neutron and gamma. However machine bunker is not accessible during the operation of the machine. The induced activity produced because of interactions of the primary and secondary radiation a radiation hazardous environment during the shut down for the related maintenance work. Area radiation monitors placed at machine bunker room have the interlock with massive shield door of the bunker. Area radiation monitors are set to specified limiting value, lower than that will allow to open the shield door in normal condition. As, the internal beam current being increased and the probability of beam spread being more. Consequently generation of induced activity is also high leading to delay in machine bunker door opening because of the interlock settings. Radiation dose mapping after a long operation of the machine was done for the different strategic points (The locations mainly people access immediate after shut down). Different consequences and remedial measures being presented in paper to raise the dose rate limit level for the interlocks between the area radiation monitors with machine bunker door, keeping in mind of the regulatory requirements. Raising the limit of dose rate limiting value will minimize the waiting time to access the machine bunker which will increase the duty factor of the machine. (author)

System safety education focused on flight safety

Science.gov (United States)

Holt, E.

1971-01-01

The measures necessary for achieving higher levels of system safety are analyzed with an eye toward maintaining the combat capability of the Air Force. Several education courses were provided for personnel involved in safety management. Data include: (1) Flight Safety Officer Course, (2) Advanced Safety Program Management, (3) Fundamentals of System Safety, and (4) Quantitative Methods of Safety Analysis.

Board and auditor interlocks and voluntary disclosure in annual reports

NARCIS (Netherlands)

Braam, G.J.M.; Borghans, L.

2014-01-01

Purpose – The purpose of this study is to explore whether interlock ties between the board of directors and the external auditors facilitate the cross-firm diffusion of voluntary disclosures in annual reports. Design/methodology/approach – Using a sample of 149 non-financial companies publicly

Breath Alcohol Ignition Interlock Devices : Policy and Implementing Implications [Mobile .MP4 (480x320/29.97fps/13.9MB)

Science.gov (United States)

2011-01-01

The goal of this project is to perform a systematic review of breath alcohol ignition interlock devices (BAIID or IID) to understand how other states have integrated such systems into administrative and judicial practice and to make recommendations f...

Breath Alcohol Ignition Interlock Devices : Policy and Implementing Implications [SD .MP4 (640x424/29.97fps/22.6MB)

Science.gov (United States)

2011-01-01

The goal of this project is to perform a systematic review of breath alcohol ignition interlock devices (BAIID or IID) to understand how other states have integrated such systems into administrative and judicial practice and to make recommendations f...

A DUAL NETWORK MODEL OF INTERLOCKING DIRECTORATES

Directory of Open Access Journals (Sweden)

Humphry Hung

2003-01-01

Full Text Available The article proposes an integrative framework for the study of interlocking directorates by using an approach that encompasses the concepts of multiple networks and resource endowment. This serves to integrate the traditional views of interorganizational linkages and intra-class cohesion. Through appropriate strategic analysis of relevant resource endowment of internal environment and external networks of organizations and corporate elites, this article argues that the selection of directors, if used effectively, can be adopted as a strategic device to enhance the corporation's overall performance.

PC based manual and safety logic card test setup for 235 MWe PHWRs

International Nuclear Information System (INIS)

Chandgadkar, G.M.; Kohli, A.K.; Agarwal, R.G.; Chandra, Rajesh

1992-01-01

Fuel handling controls for 235 MWe PHWR make use of Manual and Logic cards (MLCs) for providing safety interlocks. These cards consist of various type of logic blocks. By connecting these logic blocks all the safety interlocks required for fuel handling controls have been provided. Previously trouble shooting of these cards was done by means of logic probe. Since the method was manual, it was laborious and time consuming. PC based test setup has overcome this drawback and detects the fault at the component level within few seconds. It also gives printout of status of faulty MLC cards. Here motherboard has been designed having slots for insertion of MLC cards. The input/output connection of these cards are coming to two 50 pin FRC connectors. PC communicates through 144 line digital input/output card with MLC card under test. Software is user friendly and outputs suitable input patterns to the card under test and checks for output pattern. It compares this output pattern with compare pattern and detects the fault and displays the symptoms. This system is currently in use at test facility for fuelling machine for 235 MWe PHWR reactor at Refuelling Technology Division, Hall-7. This test setup has been proposed for use at NAPP and future reactors. (author). 4 figs., 1 annexure

Outcomes in closed reamed interlocking nail in fractures of shaft of femur

International Nuclear Information System (INIS)

Mohammad, T.; Sawati, A.; Ahmed, A.

2015-01-01

Femoral shaft fracture is one of the common fractures seen in accident and emergency department of our hospital. Violent forces are required to break this and strongest of human bones. There are various treatment modalities for femoral shaft fractures in adults like traction, brace, platting, intramedullary nail (IMN), external fixators and inter locking nails. The study was done with an objective to evaluate the results of closed reamed interlocking nail in fractures of shaft of femur. Methods: A prospective study of 114 cases of femoral shaft fractures was carried out at orthopaedic unit of Ayub Teaching Hospital Abbottabad during 1 year. All these cases were treated with statically locked nails under spinal or general anaesthesia. These cases were followed up for up to one year and Results of the interlocking nail were observed in terms of union and complications. Results: Out of 114 patients, 95 underwent union in 90-150 days with a mean of 110.68 days. Ten patients had dynamization within six weeks because of obvious fracture gap in radiograph. There were 3 patients who had non-union, and 6 patients had delayed union which was treated with dynamization. Conclusion: Close reamed interlocking intramedullary nail in femoral shaft fractures is the treatment of choice. Patient rehabilitation is early, hospitalization is short, and fracture healing response is good. (author)

Elaboration of the configuration and programming of the interlocks system of the TRIGA Mark III reactor

International Nuclear Information System (INIS)

Mejia C, M. A.

2016-01-01

The modernization of the TRIGA Mark III reactor interlock system requires a system that provides high reliability, flexibility and ease of operation during reactor operation. With this modernization of the system, is intended to prevent, control and mitigate the causes of probable accidents reported in the reactor accident analysis. On the other hand, is foreseen the ease reactor operation in a simple, safe and efficient way. The programmable logic controller can be programmed by programming instructions using simple language and easy to develop, these can be modified from a computer using the programming software. In addition, another of the advantages offered by the controller is that can be modified from a touch screen (human-machine interface) that allows adjustment, without the need to use programming software and diagnostic functions during the process. As a result of the present work, a situation of improvement in the reactor operation was generated, facilitating the handling of the bridge and increasing the efficiency of the system in the execution of the operating conditions of the installations external to the reactor. A modern, more reliable and much less expensive system was achieved than the previous one, avoiding that the maintenance to the system generates high expenses. With respect to the development of the application programming, a control was implemented that allows to select a zone of the five that have inside the pool to carry out the displacement of automatic way and later to be located in that zone, having in this way a greater efficiency and ease in bridge control. (Author)

Software Safety Risk in Legacy Safety-Critical Computer Systems

Science.gov (United States)

Hill, Janice L.; Baggs, Rhoda

2007-01-01

Safety Standards contain technical and process-oriented safety requirements. Technical requirements are those such as "must work" and "must not work" functions in the system. Process-Oriented requirements are software engineering and safety management process requirements. Address the system perspective and some cover just software in the system > NASA-STD-8719.13B Software Safety Standard is the current standard of interest. NASA programs/projects will have their own set of safety requirements derived from the standard. Safety Cases: a) Documented demonstration that a system complies with the specified safety requirements. b) Evidence is gathered on the integrity of the system and put forward as an argued case. [Gardener (ed.)] c) Problems occur when trying to meet safety standards, and thus make retrospective safety cases, in legacy safety-critical computer systems.

The Layer of Kevlar Angle-interlock Woven Fabric Effect on the Tensile Properties of Composite Materials

Science.gov (United States)

Xie, Wan-Chen; Guo, Xu-Yi; Yan, Tao; Zhang, Shang-Yong

2017-09-01

This article is based on the structure of three-dimensional angle-interlock longitudinal.The 3-layer, 5-layer, 7-layer and 9-layer of angle-interlock 3D fabrics are woven on sample weaving machine respectively with the 1500D Kevlar fiber twist filament produced by United States DuPont. At the same time, Kevlar plain weave fabric is woven, and three, five, seven and nine layers’ fabric are to be compared. In the process of VARTM composite technology, epoxy resin is matrix material, acetone is diluent, triethylene tetramine is curing agent and the five different fabrics are the reinforced materials respectively. Finally, eight different three-dimensional woven fabric composites were prepared. In this paper, the tensile properties of eight kinds of three-dimensional woven fabric composites were tested respectively.Finally, it is concluded that the five-layer angle-interlock woven fabric prepared by Kevlar fiber shows the best tensile property.

Outsourcing the development of specific application software using the ESA software engineering standards the SPS software Interlock System

CERN Document Server

Denis, B

1995-01-01

CERN is considering outsourcing as a solution to the reduction of staff. To need to re-engineer the SPS Software Interlock System provided an opportunity to explore the applicability of outsourcing to our specific controls environment and the ESA PSS-05 standards were selected for the requirements specification, the development, the control and monitoring and the project management. The software produced by the contractor is now fully operational. After outlining the scope and the complexity of the project, a discussion on the ESA PSS-05 will be presented: the choice, the way these standards improve the outsourcing process, the quality induced but also the need to adapt them and their limitation in the definition of the customer-supplier relationship. The success factors and the difficulties of development under contract will also be discussed. The maintenance aspect and the impact on in-house developments will finally be addressed.

A study on design of the trip computer for ECCS based on dynamic safety system

International Nuclear Information System (INIS)

Kim, Seog Nam

2000-02-01

The Emergency Core Cooling system in current nuclear power plants typically has a considerable number of complex functions and largely cumbersome operator interfaces. Functions for initiation, switch-over between various phases of operation, interlocks, monitoring, and alarming are usually performed by relay and analog comparator logic which is difficult to maintain and test. To improve problems of an analog based ECC (Emergency Core Cooling) System, the trip computer for ECCS based on Dynamic Safety System is implemented. The Dynamic Safety System (DSS) is a computer based reactor protection system that has fail-safe nature and performs a dynamic self-testing. The most important feature of the DSS is the introduction of test signal that send the system into a tripped state. The test signals are interleaved between the plant signals to produce an output which switches between a tripped and health state. The dynamic operation is a key feature of the failsafe design of the system. In this thesis, a possible implementation of the DSS using PLC is presented for a CANDU reactor. ECC System of the CANDU Reactor is selected as the reference system. The function of the DSS is implemented In PLC with the CONCEPT language. CONCEPT was developed by GROUPE SCHNEIDER as a graphic user interface programming tool for the Quantum PLC. A MMI display for ECCS based on DSS is implemented with LOOKOUT as an object driven programming tool. The Validation test has been performed by S/W Input Simulator as per Validation Test Procedure. The result of the test was checked and displayed on the MMI display. From the test results, it is shown that the DSS based ECC System operates correctly in all conditions

Radiation safety aspects of new X-ray free electron laser facility, SACLA

International Nuclear Information System (INIS)

Asano, Yoshihiro

2013-01-01

In the safety point of view, X-ray free electron laser facilities have some characteristics in comparison with 3 rd generation synchrotron radiation facilities. One is that the high energy electrons are always injected into the beam dump and the beamlines must be constructed in the direction of the movements of electrons, and another is that the total number of accelerated electrons of X-ray free electron laser facilities is much larger than that of synchrotron radiation facilities. In addition to the importance of safety interlock systems, therefore, it is important that high energy electrons never invade into X-ray free electron laser beamlines and the amount of accelerated electron beam losses must be reduced as much as possible. At SACLA, a safety permanent magnet was installed into the X-ray light beam axis, and a beam halo monitor and beam loss monitors were installed within and around the electron transport pipes, respectively. In comparison with the SPring-8 synchrotron radiation facility, shielding design of SACLA, outline of the radiation safety systems including the monitors will be presented

Fracture Union in Closed Interlocking Nail in Femoral Fracture

Directory of Open Access Journals (Sweden)

R L Sahu

2010-09-01

Full Text Available INTRODUCTION: Fractures shaft femur is a major cause of morbidity and mortality in patients with lower extremity injuries. The objective of this study was to find out the outcome of Interlocking nail in fracture femur. METHODS: This study was conducted in the Department of Orthopaedic surgery in M. M. Medical College from July 2006 to November 2008. Seventy eight patients were recruited from Emergency and out patient department having closed fracture of femoral shaft. All patients were operated under general or spinal anesthesia. All patients were followed for nine months. RESULTS: Out of seventy eight patients, sixty nine patients underwent union in 90 to 150 days with a mean of 110.68 days. Touch down weight bearing was started on 2nd post-operative day. Complications found in four patients who had non-union, and five patients had delayed union which was treated with dynamization and bone graft. The results were excellent in 88.46% and good in 6.41% patients. CONCLUSIONS: We concluded that this technique is advantageous because of early mobilization (early weight bearing, less complication with good results and is economical. Keywords: close reamed interlocking nail, dynamization, femoral shaft fractures, union

Control/interlock/display system for EBT-P using commercially-available hardware and firmware

International Nuclear Information System (INIS)

Schmitt, R.J.

1983-01-01

For the EBT-P project, alternative commercially-available hardware, software and firmware have been employed for control, interlock and data display functions. This paper describes the criteria and rationale used to select that commercial equipment and discusses the important features of the equipment chosen, especially programmable controllers. Additional discussion is centered on interface problems which are encountered upon attempts to integrate equipment from several vendors. Some solutions to these problems are discussed. Details of software and hardware performance during tests are presented. The extent to which the EBT-P hardware and software configuration addresses and resolves various issues is discussed. Several areas have been uncovered in which relatively slight improvements/modifications of commercial programmable controller firmware would significantly improve the capability of this type of hardware in fusion control applications. These improvements are discussed in detail

NASA System Safety Handbook. Volume 2: System Safety Concepts, Guidelines, and Implementation Examples

Science.gov (United States)

Dezfuli, Homayoon; Benjamin, Allan; Everett, Christopher; Feather, Martin; Rutledge, Peter; Sen, Dev; Youngblood, Robert

2015-01-01

This is the second of two volumes that collectively comprise the NASA System Safety Handbook. Volume 1 (NASASP-210-580) was prepared for the purpose of presenting the overall framework for System Safety and for providing the general concepts needed to implement the framework. Volume 2 provides guidance for implementing these concepts as an integral part of systems engineering and risk management. This guidance addresses the following functional areas: 1.The development of objectives that collectively define adequate safety for a system, and the safety requirements derived from these objectives that are levied on the system. 2.The conduct of system safety activities, performed to meet the safety requirements, with specific emphasis on the conduct of integrated safety analysis (ISA) as a fundamental means by which systems engineering and risk management decisions are risk-informed. 3.The development of a risk-informed safety case (RISC) at major milestone reviews to argue that the systems safety objectives are satisfied (and therefore that the system is adequately safe). 4.The evaluation of the RISC (including supporting evidence) using a defined set of evaluation criteria, to assess the veracity of the claims made therein in order to support risk acceptance decisions.

D0 Central Tracking Solenoid Energization, Controls, Interlocks and Quench Protection Initial Validation Procedures

International Nuclear Information System (INIS)

Jaskierny, W.; Hance, R.

1998-01-01

This note presents the inspection and tests to be performed on the DZERO solenoid energization, controls, interlocks and quench protection system before it is energized for the first time. This test is to be performed with a 5000A jumper at the end of the bus instead of the solenoid. This system is based in DZERO room 511. A copy of this note shall be annotated, signed and dated by the person coordinating the procedure; and filed with the system maintenance records. Annotations shall include comments about any aspect of the procedure that is abnormal or unsuccessful. The following inspections and tests shall be performed by persons knowledgeable about the system. Each individual test step should be reviewed and understood before proceeding with that step.

[Clinical application of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nail].

Science.gov (United States)

Zhu, Hai-Bing; Wu, Li-Guo; Fang, Zhi-Song; Luo, Cong-Feng; Wang, Qing-Feng; Ma, Yi-Ping; Gao, Hong; Fu, Guo-Hai; Hu, Cheng-Ting

2012-07-01

To introduce the clinical method of blocking screws and rooting technique in the treatment of distal tibial fracture with interlocking intramedullary nails. From June 2006 to March 2011, 26 patients with distal tibial fracture were treated with interlocking intramedullary nails using blocking screws and rooting technique, included 18 males and 8 females with an average age of 46.2 years old ranging from 24 to 64 years. According to AO classification: 10 cases of type A1, 4 cases of type A2, 8 cases of type B1, 4 cases of type B2. The average distance of the fractures end to the ankle joint was 85 mm ranging from 55 to 125 mm, the mean time between injured and operation was 4.5 days. The patients were evaluated with pain, range of motion, walking. All cases were followed-up for 6 to 22 months (averaged 15 months). According to Iowa ankle joint grading system,the score was improved from preoperative (66.8 +/- 8.2) to postoperative (94.6 +/- 4.8). All fractures had united, and got satisfactory reduction and stable fixation with no complications had happen such as breakage of screw. Fixation with interlocking intramedullary nail using blocking screws and rooting technique in treating distal tibial fracture, is a safe and effective technique for the improvement of stability.

Fuel rod fixing system

International Nuclear Information System (INIS)

Christiansen, D.W.

1982-01-01

This is a reusable system for fixing a nuclear reactor fuel rod to a support. An interlock cap is fixed to the fuel rod and an interlock strip is fixed to the support. The interlock cap has two opposed fingers, which are shaped so that a base is formed with a body part. The interlock strip has an extension, which is shaped so that this is rigidly fixed to the body part of the base. The fingers of the interlock cap are elastic in bending. To fix it, the interlock cap is pushed longitudinally on to the interlock strip, which causes the extension to bend the fingers open in order to engage with the body part of the base. To remove it, the procedure is reversed. (orig.) [de

External jig in the placement of distal interlocking screws | Ikem ...

African Journals Online (AJOL)

Retrograde (52.2%) was the commonest surgical approach used for femur. The main indication for SIGN interlocking surgery was recent fracture 77.8%. Open reduction 97.8% was the commonest method of reduction used. The mean±SD bone union time was 3.58±0.56 months and range 3-5 months. Distal screw insertion ...

Reactor safety systems

International Nuclear Information System (INIS)

Kafka, P.

1975-01-01

The spectrum of possible accidents may become characterized by the 'maximum credible accident', which will/will not happen. Similary, the performance of safety systems in a multitude of situations is sometimes simplified to 'the emergency system will/will not work' or even 'reactors are/ are not safe'. In assessing safety, one must avoid this fallacy of reducing a complicated situation to the simple black-and-white picture of yes/no. Similarly, there is a natural tendency continually to improve the safety of a system to assure that it is 'safe enough'. Any system can be made safer and there is usually some additional cost. It is important to balance the increased safety against the increased costs. (orig.) [de

General distributed control system for fusion experiments

International Nuclear Information System (INIS)

Klingner, P.L.; Levings, S.J.; Wilkins, R.W.

1986-01-01

A general control system using distributed LSI-11 microprocessors is being developed. Common software residues in each LSI-11 and is tailored to an application by control specifications downloaded from a host computer. The microprocessors, their control interfaces, and the micro-to-host communications are CAMAC based. The host computer also supports an operator interface, coordination of multiple microprocessors, and utilities to create and maintain the control specifications. Typical applications include monitoring safety interlocks as well as controlling vacuum systems, high voltage charging systems, and diagnostics

Online visual inspection of self-piercing riveting to determine the quality of the mechanical interlock

International Nuclear Information System (INIS)

Johnson, P; Cullen, J D; Al-Shamma'a, A I; Shaw, A

2007-01-01

Self-piercing riveting (SPR) has become a significant joining technique for the automotive applications of aluminium sheets. Quality control in this locale has progressed at an altogether more leisurely rate than other areas of mechanical joining (e.g. spotweld) and is underdeveloped. Testing the quality mechanical interlock is often achieved by destructive testing, which results in material and time wastage. The solution is online monitoring of the self-piercing riveting process to provide non-destructive testing of the mechanical interlock. Introducing sensors into the process facilitates real time data acquisition, which can be used to determine the quality of the joint

Reactor system safety assurance

International Nuclear Information System (INIS)

Mattson, R.J.

1984-01-01

The philosophy of reactor safety is that design should follow established and conservative engineering practices, there should be safety margins in all modes of plant operation, special systems should be provided for accidents, and safety systems should have redundant components. This philosophy provides ''defense in depth.'' Additionally, the safety of nuclear power plants relies on ''safety systems'' to assure acceptable response to design basis events. Operating experience has shown the need to study plant response to more frequent upset conditions and to account for the influence of operators and non-safety systems on overall performance. Defense in depth is being supplemented by risk and reliability assessment

Custom sectional impression trays with interlocking type handle for microstomia patients

Directory of Open Access Journals (Sweden)

Fernandes Aquaviva

2009-01-01

Full Text Available Making impressions in microstomia patients is often cumbersome. A modification of standard impression procedure is often necessary while treating such patients. This article describes the fabrication of a custom sectional impression tray with interlocking type of a handle for definitive impression procedures in a microstomia patient.

Design of Data Acquisition and Control System for Indian Test Facility of Diagnostics Neutral Beam

International Nuclear Information System (INIS)

Soni, Jignesh; Tyagi, Himanshu; Yadav, Ratnakar; Rotti, Chandramouli; Bandyopadhyay, Mainak; Bansal, Gourab; Gahluat, Agrajit; Sudhir, Dass; Joshi, Jaydeep; Prasad, Rambilas; Pandya, Kaushal; Shah, Sejal; Parmar, Deepak; Chakraborty, Arun

2015-01-01

Highlights: • More than 900 channels Data Acquisition and Control System. • INTF DACS has been designed based on ITER-PCDH guidelines. • Separate Interlock and Safety system designed based on IEC 61508 standard. • Hardware selected from ITER slow controller and fast controller catalog. • Software framework based on ITER CODAC Core System and LabVIEW software. - Abstract: The Indian Test Facility (INTF) – a negative hydrogen ion based 100 kV, 60 A, 5 Hz modulated NBI system having 3 s ON/20 s OFF duty cycle. Prime objective of the facility is to install a full-scale test bed for the qualification of all Diagnostic Neutral Beam (DNB) parameters, prior to installation in ITER. The automated and safe operation of the INTF will require a reliable and rugged instrumentation and control system which provide control, data acquisition (DAQ), interlock and safety functions, referred as INTF-DACS. The INTF-DACS has been decided to be design based on the ITER CODAC architecture and ITER-PCDH guidelines since the technical understanding of CODAC technology gained from this will later be helpful in development of plant system I&C for DNB. For complete operation of the INTF, approximately 900 numbers of signals are required to be superintending by the DACS. In INTF conventional control loop time required is within the range of 5–100 ms and for DAQ except high-end diagnostics, required sampling rates in range of 5 sample per second (Sps) to 10 kSps; to fulfill these requirements hardware components have been selected from the ITER slow and fast controller catalogs. For high-end diagnostics required sampling rates up to 100 MSps normally in case of certain events, therefore event and burst based DAQ hardware has been finalized. Combined use of CODAC core software (CCS) and NI-LabVIEW has been finalized due to the fact that full required DAQ support is not available in present version of CCS. Interlock system for investment protection of facility and Safety system for

Design of Data Acquisition and Control System for Indian Test Facility of Diagnostics Neutral Beam

Energy Technology Data Exchange (ETDEWEB)

Soni, Jignesh, E-mail: jsoni@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Tyagi, Himanshu; Yadav, Ratnakar; Rotti, Chandramouli; Bandyopadhyay, Mainak [ITER-India, Institute for Plasma Research, Gandhinagar 380 025, Gujarat (India); Bansal, Gourab; Gahluat, Agrajit [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Sudhir, Dass; Joshi, Jaydeep; Prasad, Rambilas [ITER-India, Institute for Plasma Research, Gandhinagar 380 025, Gujarat (India); Pandya, Kaushal [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India); Shah, Sejal; Parmar, Deepak [ITER-India, Institute for Plasma Research, Gandhinagar 380 025, Gujarat (India); Chakraborty, Arun [Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India)

2015-10-15

Highlights: • More than 900 channels Data Acquisition and Control System. • INTF DACS has been designed based on ITER-PCDH guidelines. • Separate Interlock and Safety system designed based on IEC 61508 standard. • Hardware selected from ITER slow controller and fast controller catalog. • Software framework based on ITER CODAC Core System and LabVIEW software. - Abstract: The Indian Test Facility (INTF) – a negative hydrogen ion based 100 kV, 60 A, 5 Hz modulated NBI system having 3 s ON/20 s OFF duty cycle. Prime objective of the facility is to install a full-scale test bed for the qualification of all Diagnostic Neutral Beam (DNB) parameters, prior to installation in ITER. The automated and safe operation of the INTF will require a reliable and rugged instrumentation and control system which provide control, data acquisition (DAQ), interlock and safety functions, referred as INTF-DACS. The INTF-DACS has been decided to be design based on the ITER CODAC architecture and ITER-PCDH guidelines since the technical understanding of CODAC technology gained from this will later be helpful in development of plant system I&C for DNB. For complete operation of the INTF, approximately 900 numbers of signals are required to be superintending by the DACS. In INTF conventional control loop time required is within the range of 5–100 ms and for DAQ except high-end diagnostics, required sampling rates in range of 5 sample per second (Sps) to 10 kSps; to fulfill these requirements hardware components have been selected from the ITER slow and fast controller catalogs. For high-end diagnostics required sampling rates up to 100 MSps normally in case of certain events, therefore event and burst based DAQ hardware has been finalized. Combined use of CODAC core software (CCS) and NI-LabVIEW has been finalized due to the fact that full required DAQ support is not available in present version of CCS. Interlock system for investment protection of facility and Safety system for

78 FR 26849 - Model Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs)

Science.gov (United States)

2013-05-08

... requirements, and asked whether the Model Specifications should limit sensor technology to alcohol-specific sensors (such as fuel cell technology based on electrochemical oxidation of alcohol) or other emerging... have demanded alcohol- specific sensor technology. [Interlocks that] are not alcohol-specific...

A sensor-based automation system for handling nuclear materials

International Nuclear Information System (INIS)

Drotning, W.; Kimberly, H.; Wapman, W.; Darras, D.

1997-01-01

An automated system is being developed for handling large payloads of radioactive nuclear materials in an analytical laboratory. The automation system performs unpacking and repacking of payloads from shipping and storage containers, and delivery of the payloads to the stations in the laboratory. The system uses machine vision and force/torque sensing to provide sensor-based control of the automation system in order to enhance system safety, flexibility, and robustness, and achieve easy remote operation. The automation system also controls the operation of the laboratory measurement systems and the coordination of them with the robotic system. Particular attention has been given to system design features and analytical methods that provide an enhanced level of operational safety. Independent mechanical gripper interlock and tool release mechanisms were designed to prevent payload mishandling. An extensive Failure Modes and Effects Analysis of the automation system was developed as a safety design analysis tool

Design progress of cryogenic hydrogen system for China Spallation Neutron Source

Energy Technology Data Exchange (ETDEWEB)

Wang, G. P.; Zhang, Y.; Xiao, J.; He, C. C.; Ding, M. Y.; Wang, Y. Q.; Li, N.; He, K. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P.R. (China)

2014-01-29

China Spallation Neutron Source (CSNS) is a large proton accelerator research facility with 100 kW beam power. Construction started in October 2011 and is expected to last 6.5 years. The cryogenic hydrogen circulation is cooled by a helium refrigerator with cooling capacity of 2200 W at 20 K and provides supercritical hydrogen to neutron moderating system. Important progresses of CSNS cryogenic system were concluded as follows. Firstly, process design of cryogenic system has been completed including helium refrigerator, hydrogen loop, gas distribution, and safety interlock. Secondly, an accumulator prototype was designed to mitigate pressure fluctuation caused by dynamic heat load from neutron moderation. Performance test of the accumulator has been carried out at room and liquid nitrogen temperature. Results show the accumulator with welding bellows regulates hydrogen pressure well. Parameters of key equipment have been identified. The contract for the helium refrigerator has been signed. Mechanical design of the hydrogen cold box has been completed, and the hydrogen pump, ortho-para hydrogen convertor, helium-hydrogen heat exchanger, hydrogen heater, and cryogenic valves are in procurement. Finally, Hydrogen safety interlock has been finished as well, including the logic of gas distribution, vacuum, hydrogen leakage and ventilation. Generally, design and construction of CSNS cryogenic system is conducted as expected.

Safety system status monitoring

International Nuclear Information System (INIS)

Lewis, J.R.; Morgenstern, M.H.; Rideout, T.H.; Cowley, P.J.

1984-03-01

The Pacific Northwest Laboratory has studied the safety aspects of monitoring the preoperational status of safety systems in nuclear power plants. The goals of the study were to assess for the NRC the effectiveness of current monitoring systems and procedures, to develop near-term guidelines for reducing human errors associated with monitoring safety system status, and to recommend a regulatory position on this issue. A review of safety system status monitoring practices indicated that current systems and procedures do not adequately aid control room operators in monitoring safety system status. This is true even of some systems and procedures installed to meet existing regulatory guidelines (Regulatory Guide 1.47). In consequence, this report suggests acceptance criteria for meeting the functional requirements of an adequate system for monitoring safety system status. Also suggested are near-term guidelines that could reduce the likelihood of human errors in specific, high-priority status monitoring tasks. It is recommended that (1) Regulatory Guide 1.47 be revised to address these acceptance criteria, and (2) the revised Regulatory Guide 1.47 be applied to all plants, including those built since the issuance of the original Regulatory Guide

Safety system status monitoring

Energy Technology Data Exchange (ETDEWEB)

Lewis, J.R.; Morgenstern, M.H.; Rideout, T.H.; Cowley, P.J.

1984-03-01

The Pacific Northwest Laboratory has studied the safety aspects of monitoring the preoperational status of safety systems in nuclear power plants. The goals of the study were to assess for the NRC the effectiveness of current monitoring systems and procedures, to develop near-term guidelines for reducing human errors associated with monitoring safety system status, and to recommend a regulatory position on this issue. A review of safety system status monitoring practices indicated that current systems and procedures do not adequately aid control room operators in monitoring safety system status. This is true even of some systems and procedures installed to meet existing regulatory guidelines (Regulatory Guide 1.47). In consequence, this report suggests acceptance criteria for meeting the functional requirements of an adequate system for monitoring safety system status. Also suggested are near-term guidelines that could reduce the likelihood of human errors in specific, high-priority status monitoring tasks. It is recommended that (1) Regulatory Guide 1.47 be revised to address these acceptance criteria, and (2) the revised Regulatory Guide 1.47 be applied to all plants, including those built since the issuance of the original Regulatory Guide.

Safety aspects of pulsed YAYOI and Japan Linac Booster

International Nuclear Information System (INIS)

An, S.; Oka, Y.; Wakabayashi, J.

1976-01-01

The paper consists of two parts. The first part is concerned with safety aspects of pulsed YAYOI. Reactivity pulsed operation of YAYOI is performed with reactivity oscillating devices. Inherent safety characteristics due to dilation of metal fuel, a small amount of f.p. build up, reactor operation preserving fuel integrity and experience on transient experiments are the principal basis for safety assurance. Conditions for pulsed operation, namely, maximum allowable temperature, maximum number of repetition of pulsed operation and so on are derived from the consideration on the integrity of fuel. Instrumentation and control systems are reinforced by displacement meter in the core, interlock system, special timer for pulsed operation, additional scram conditions and reactivity meter. Accident analysis and safety evaluation indicate the conservative safety features of the facility. Concerning pulsed operation of YAYOI combined with Linac, special attention must be given to the design of Linac target placed in the core. In the second part are described the principal guide-lines and basic ideas for safety design of Japan Linac Booster (JLB). JLB is a U-Mo fueled and sodium cooled fast reactor with rotating reflector and Linac target in the core. The pulsed neutrons are injected into the core coincidentally with repetitive peaks of reactivity. Design of rotating reflector and Linac target system are the new and important safety problems not yet encountered in the usual sodium fast reactor design. The axis of the rotating reflector is horizontal, which avoids the collision of reflector block with core in the case of failure of rotating reflector. The separate cooling channels for target and the Linac electron beam control system are provided. Reactor shut down and power control systems must be carefully designed. Core meltdown and disassembly accident is considered as a hypothetical accident which is a basis for containment system design. (auth.)

System design for safe robotic handling of nuclear materials

International Nuclear Information System (INIS)

Drotning, W.; Wapman, W.; Fahrenholtz, J.; Kimberly, H.; Kuhlmann, J.

1996-01-01

Robotic systems are being developed by the Intelligent Systems and Robotics Center at Sandia National Laboratories to perform automated handling tasks with radioactive nuclear materials. These systems will reduce the occupational radiation exposure to workers by automating operations which are currently performed manually. Because the robotic systems will handle material that is both hazardous and valuable, the safety of the operations is of utmost importance; assurance must be given that personnel will not be harmed and that the materials and environment will be protected. These safety requirements are met by designing safety features into the system using a layered approach. Several levels of mechanical, electrical and software safety prevent unsafe conditions from generating a hazard, and bring the system to a safe state should an unexpected situation arise. The system safety features include the use of industrial robot standards, commercial robot systems, commercial and custom tooling, mechanical safety interlocks, advanced sensor systems, control and configuration checks, and redundant control schemes. The effectiveness of the safety features in satisfying the safety requirements is verified using a Failure Modes and Effects Analysis. This technique can point out areas of weakness in the safety design as well as areas where unnecessary redundancy may reduce the system reliability

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2014-09-02

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

Traceability of Software Safety Requirements in Legacy Safety Critical Systems

Science.gov (United States)

Hill, Janice L.

2007-01-01

How can traceability of software safety requirements be created for legacy safety critical systems? Requirements in safety standards are imposed most times during contract negotiations. On the other hand, there are instances where safety standards are levied on legacy safety critical systems, some of which may be considered for reuse for new applications. Safety standards often specify that software development documentation include process-oriented and technical safety requirements, and also require that system and software safety analyses are performed supporting technical safety requirements implementation. So what can be done if the requisite documents for establishing and maintaining safety requirements traceability are not available?

Concept design of multipurpose gamma irradiator ISG-500 instrumentation and control system

International Nuclear Information System (INIS)

Dian F Atmoko; Sutomo B; Ikhsan S; A Suntoro

2010-01-01

Has been concept designed of multipurpose 2 x 250 kCi gamma irradiator instrumentation and control system (ICS). The problem in ICS of irradiator is How to get similar of dose rate and start-up/shut down mechanism with highest safety factor. The concept designed of ICS had of tree parameter such as safety, operation and security. The tree of parameter used to start-up and shut-down in irradiator installation with interlock system connection to guarantee of safety. Similar of dose rate obtained by controlled of exposure time witch stopped of carrier conveyor in point of stopped carrier and for delay time, with speed of moved motor carrier to set in constant speed. (author)

Integrated cooling system for the Mirror Fusion Test Facility

International Nuclear Information System (INIS)

Johnson, B.; Chang, Y.

1979-01-01

The MFTF components that require water cooling include the neutral beam dumps, ion dumps, plasma dumps, baffle plates, magnet liners, gas boxes, streaming guns, and the neutral beam injectors. A total heat load of nearly 500 MW for 0.5 s dissipates over 4-min intervals. A steady-flow, closed-loop system is utilized. The design of the cooling system assumes that all components require cooling simultaneously. The cooling system contains process instrumentation for loop control. Alarms and safety interlocks are incorporated for the safe operation of the system

Safety design guide for safety related systems for CANDU 9

International Nuclear Information System (INIS)

Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young; A. C. D. Wright

1996-03-01

In general, two types of safety related systems and structures exist in the nuclear plant; The one is a systems and structures which perform safety functions during the normal operation of the plant, and the other is a systems and structures which perform safety functions to mitigate events caused by failure of the normally operating systems or by naturally occurring phenomena. In this safety design guide, these systems are identified in detail, and the major events for which the safety functions are required and the major safety requirements are identified in the list. As the probabilistic safety assessments are completed during the course of the project, additions or deletions to the list may be justified. 3 tabs. (Author) .new

Safety design guide for safety related systems for CANDU 9

Energy Technology Data Exchange (ETDEWEB)

Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of); Wright, A.C.D. [Atomic Energy of Canada Ltd., Toronto (Canada)

1996-03-01

In general, two types of safety related systems and structures exist in the nuclear plant; The one is a systems and structures which perform safety functions during the normal operation of the plant, and the other is a systems and structures which perform safety functions to mitigate events caused by failure of the normally operating systems or by naturally occurring phenomena. In this safety design guide, these systems are identified in detail, and the major events for which the safety functions are required and the major safety requirements are identified in the list. As the probabilistic safety assessments are completed during the course of the project, additions or deletions to the list may be justified. 3 tabs. (Author) .new.

American National Standards Institute ANSI N 43.1 Radiological Safety in the Design and Operation of Particle Accelerators

International Nuclear Information System (INIS)

Scott Walker, L.; Liu, J.

2004-01-01

The ANSI N43 committee established a writing committee to re-write the ANSI N43.1 accelerator safety standard in 1994. James Liu and Scott Walker were appointed as co-chairman. Compared to the old standard, the new standard is aimed to have a broader application, up-to-date requirements, and recommendations for best practices. The new standard uses a hazard based graded approach to address radiation safety programs for accelerators with various energies, beam currents and applications (excluding medical accelerators which are covered by another standard). Thus, the standard fulfills the goal of the committee to prepare a standard with unlimited application to industrial and research accelerators. The standard is largely complete with chapters as follows: 1) Scope. 2) Definitions. 3) Radiation Safety Program (facility safety program, radiation safety planning, organizational considerations, safety assessment, review and performance evaluation). 4) Radiation Safety System (prompt radiation, safety system features, reliability and fail-safety, tamper resistance, quality control, configuration control, adventitious production of radiation, and induced radioactivity). 5) Personnel Access Control System (including graded approach, postings, barriers, beam inhibiting devices and interlocks). 6) Radiation Control System, (passive shielding, and active systems). 7) Accelerator Operation (including readiness reviews, maintenance and testing, bypasses and deviation from procedure, operating practices, emergencies). 8) Operational Health Physics, and 9) Training. The document also has appendices regarding how to determine the Safety and Operations Envelope, Guidance for Computer Based Access Control Systems, and Radiation Measurements at Accelerators. (Author)

Safety system function trends

International Nuclear Information System (INIS)

Johnson, C.

1989-01-01

This paper describes research to develop risk-based indicators of plant safety performance. One measure of the safety-performance of operating nuclear power plants is the unavailability of important safety systems. Brookhaven National Laboratory and Science Applications International Corporation are evaluating ways to aggregate train-level or component-level data to provide such an indicator. This type of indicator would respond to changes in plant safety margins faster than the currently used indicator of safety system unavailability (i.e., safety system failures reported in licensee event reports). Trends in the proposed indicator would be one indication of trends in plant safety performance and maintenance effectiveness. This paper summarizes the basis for such an indicator, identifies technical issues to be resolved, and illustrates the potential usefullness of such indicators by means of computer simulations and case studies

A STUDY OF THE MANAGEMENT OF OPEN FRACTURES OF TIBIA BY UNREAMED INTERLOCKING NAIL

Directory of Open Access Journals (Sweden)

Kuppa Srinivas

2015-01-01

Full Text Available AIMS AND OBJECTIVES: To evaluate the results of closed interlocking intramedullary nailing without reaming in the treatment of open fractures of t he tibial shaft and study the difficulties (complications encountered during the operative study. To compare the efficacy of interlocking intramedullary nailing without reaming in treating open fractures of tibia, Time required for the union of fracture, Range of motion of ankle and knee joint, Rate of malunion and mal rotation and Pain at the knee joint. RESULTS: The average age of patient is 32 years,83.33% are males, road traffic accidents account for majority(79.16%,right side involved in 58.33%,gustillo type II and type I compound fractures are common, full range of movements is seen in 66.67% by 12 weeks and union occurred in 95.83% by 9 months. Thirteen (54.17% patients had excellent results, six (25% patients had good results, four (1 6.67% patients had fair results and one (4.16 patient had poor result. CONCLUSION: Unreamed interlocking intramedullary nailing with the help of image intensifier seems feasible in open diaphyseal fractures of tibia with the advantages of minimal blood l oss, low risk of infection, early mobilisation , earlier soft tissue coverage , Promotes early union , minimal hospital stay and early returns to activities

Bio-inspired ``jigsaw''-like interlocking sutures: Modeling, optimization, 3D printing and testing

Science.gov (United States)

Malik, I. A.; Mirkhalaf, M.; Barthelat, F.

2017-05-01

Structural biological materials such as bone, teeth or mollusk shells draw their remarkable performance from a sophisticated interplay of architectures and weak interfaces. Pushed to the extreme, this concept leads to sutured materials, which contain thin lines with complex geometries. Sutured materials are prominent in nature, and have recently served as bioinspiration for toughened ceramics and glasses. Sutures can generate large deformations, toughness and damping in otherwise all brittle systems and materials. In this study we examine the design and optimization of sutures with a jigsaw puzzle-like geometry, focusing on the non-linear traction behavior generated by the frictional pullout of the jigsaw tabs. We present analytical models which accurately predict the entire pullout response. Pullout strength and energy absorption increase with higher interlocking angles and for higher coefficients of friction, but the associated high stresses in the solid may fracture the tabs. Systematic optimization reveals a counter-intuitive result: the best pullout performance is achieved with interfaces with low coefficient of friction and high interlocking angle. We finally use 3D printing and mechanical testing to verify the accuracy of the models and of the optimization. The models and guidelines we present here can be extended to other types of geometries and sutured materials subjected to other loading/boundary conditions. The nonlinear responses of sutures are particularly attractive to augment the properties and functionalities of inherently brittle materials such as ceramics and glasses.

IAEA Safety Standards on Management Systems and Safety Culture

International Nuclear Information System (INIS)

Persson, Kerstin Dahlgren

2007-01-01

The IAEA has developed a new set of Safety Standard for applying an integrated Management System for facilities and activities. The objective of the new Safety Standards is to define requirements and provide guidance for establishing, implementing, assessing and continually improving a Management System that integrates safety, health, environmental, security, quality and economic related elements to ensure that safety is properly taken into account in all the activities of an organization. With an integrated approach to management system it is also necessary to include the aspect of culture, where the organizational culture and safety culture is seen as crucial elements of the successful implementation of this management system and the attainment of all the goals and particularly the safety goals of the organization. The IAEA has developed a set of service aimed at assisting it's Member States in establishing. Implementing, assessing and continually improving an integrated management system. (author)

Acceptance/operational test procedure 101-AW tank camera purge system and 101-AW video camera system

International Nuclear Information System (INIS)

Castleberry, J.L.

1994-01-01

This procedure will document the satisfactory operation of the 101-AW Tank Camera Purge System (CPS) and the 101-AW Video Camera System. The safety interlock which shuts down all the electronics inside the 101-AW vapor space, during loss of purge pressure, will be in place and tested to ensure reliable performance. This procedure is separated into four sections. Section 6.1 is performed in the 306 building prior to delivery to the 200 East Tank Farms and involves leak checking all fittings on the 101-AW Purge Panel for leakage using a Snoop solution and resolving the leakage. Section 7.1 verifies that PR-1, the regulator which maintains a positive pressure within the volume (cameras and pneumatic lines), is properly set. In addition the green light (PRESSURIZED) (located on the Purge Control Panel) is verified to turn on above 10 in. w.g. and after the time delay (TDR) has timed out. Section 7.2 verifies that the purge cycle functions properly, the red light (PURGE ON) comes on, and that the correct flowrate is obtained to meet the requirements of the National Fire Protection Association. Section 7.3 verifies that the pan and tilt, camera, associated controls and components operate correctly. This section also verifies that the safety interlock system operates correctly during loss of purge pressure. During the loss of purge operation the illumination of the amber light (PURGE FAILED) will be verified

Reinforcing the role of the conventional C-arm - a novel method for simplified distal interlocking

Directory of Open Access Journals (Sweden)

Windolf Markus

2012-01-01

Full Text Available Abstract Background The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR like setting on human cadaveric lower legs in terms of operating time and radiation exposure. Methods The proposed concept (guided freehand, generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required. Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland. The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. Results A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4 (mean ± SD compared to the freehand technique (17.6 ± 10.3 (p p = 0.001. Operating time per screw (from first shot to screw tightened was on average 22% reduced by guided freehand (p = 0

Reinforcing the role of the conventional C-arm--a novel method for simplified distal interlocking.

Science.gov (United States)

Windolf, Markus; Schroeder, Josh; Fliri, Ladina; Dicht, Benno; Liebergall, Meir; Richards, R Geoff

2012-01-25

The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR) like setting on human cadaveric lower legs in terms of operating time and radiation exposure. The proposed concept (guided freehand), generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required.Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland). The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4) (mean ± SD) compared to the freehand technique (17.6 ± 10.3) (p < 0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique compared to conventional freehand (p = 0.001). Operating time per screw (from first

Safety logic systems of PFBR

International Nuclear Information System (INIS)

Sambasivan, S. Ilango

2004-01-01

Full text : PFBR is provided with two independent, fast acting and diverse shutdown systems to detect any abnormalities and to initiate safety action. Each system consists of sensors, signal processing systems, logics, drive mechanisms and absorber rods. The absorber rods of the first system are Control and Safety Rods (CSR) and that of the second are called as Diverse Safety Rods (DSR). There are nine CSR and three DSR. While CSR are used for startup, control of reactor power, controlled shutdown and SCRAM, the DSR are used only for SCRAM. The respective drive mechanisms are called as CSRDM and DSRDM. Each of these two systems is capable of executing the shutdown satisfactorily with single failure criteria. Two independent safety logic systems based on diverse principles have been designed for the two shut down systems. The analog outputs of the sensors of Core Monitoring Systems comprising of reactor flux monitoring, core temperature monitoring, failed fuel detection and core flow monitoring systems are processed and converted into binary signals depending on their instantaneous values. Safety logic systems receive the binary signals from these core-monitoring systems and process them logically to protect the reactor against postulated initiating events. Neutronic and power to flow (P/Q) signals form the inputs to safety logic system-I and temperature signals are inputs to the safety logic system II. Failed fuel detection signals are processed by both the shut down systems. The two logic systems to actuate the safety rods are also based on two diverse designs and implemented with solid-state devices to meet all the requirements of safety systems. Safety logic system I that caters to neutronic and P/Q signals is designed around combinational logic and has an on-line test facility to detect struck at faults. The second logic system is based on dynamic logic and hence is inherently safe. This paper gives an overview of the two logic systems that have been

Patología de pavimentos articulados Pathology of interlocking pavements

Directory of Open Access Journals (Sweden)

Carlos Hernando Higuera Sandoval

2010-07-01

Full Text Available Este artículo presenta los resultados de un proyecto de grado sobre patología de pavimentos articulados, el cual fue elaborado con el propósito de hacer una recolección de los deterioros típicos de los pavimentos articulados construidos con adoquines de concreto o de ladrillo; y de esta forma, elaborar un catálogo de deterioros para este tipo de estructuras que facilitará la identificación y cuantificación de los deterioros en una inspección visual. El segundo propósito de este proyecto, es la formulación para Colombia de una metodología que permita determinar el Índice de Condición de las estructuras de pavimentos articulados.This article presents the results of a thesis on pathology of interlocking pavements, which objective was to make a compilation of typical damages of interlocking pavements constructed with concrete or brick pavers and, in this way, to elaborate a catalogue of damages for this kind of structures which will make the identification and quantification of deteriorations possible in a visual inspection. The second purpose of this project is the formulation of a methodology which allows determining the Index of pavement conditions for Colombia.

Safety of mechanical devices. Safety of automation systems

International Nuclear Information System (INIS)

Pahl, G.; Schweizer, G.; Kapp, K.

1985-01-01

The paper deals with the classic procedures of safety engineering in the sectors mechanical engineering, electrical and energy engineering, construction and transport, medicine technology and process technology. Particular stress is laid on the safety of automation systems, control technology, protection of mechanical devices, reactor safety, mechanical constructions, transport systems, railway signalling devices, road traffic and protection at work in chemical plans. (DG) [de

First operation of the wide-area remote experiment system

International Nuclear Information System (INIS)

Furukawa, Y.; Hasegawa, K.; Ueno, G.

2012-01-01

The Wide-area Remote Experiment System (WRES) at Spring-8 has been successfully developed. The system communicates with remote users on the basis of SSL/TLS with bi-directional authentication to avoid interference from unauthorized access to the system. The system has a message-filtering system to allow remote users access only to the corresponding beamline equipment and safety interlock system. This is to protect persons inside the experimental station from injury from any accidental motion of heavy equipment. The system also has a video streaming system to monitor samples or experimental equipment. We have tested the system from the point of view of safety, stability, reliability etc. and successfully performed the first experiment from a remote site, i.e., RIKEN's Wako campus, which is 480 km away from Spring-8, at the end of October 2010. (authors)

Evaluating safety management system implementation

International Nuclear Information System (INIS)

Preuss, M.

2009-01-01

Canada is committed to not only maintaining, but also improving upon our record of having one of the safest aviation systems in the world. The development, implementation and maintenance of safety management systems is a significant step towards improving safety performance. Canada is considered a world leader in this area and we are fully engaged in implementation. By integrating risk management systems and business practices, the aviation industry stands to gain better safety performance with less regulatory intervention. These are important steps towards improving safety and enhancing the public's confidence in the safety of Canada's aviation system. (author)

System Design and the Safety Basis

International Nuclear Information System (INIS)

Ellingson, Darrel

2008-01-01

The objective of this paper is to present the Bechtel Jacobs Company, LLC (BJC) Lessons Learned for system design as it relates to safety basis documentation. BJC has had to reconcile incomplete or outdated system description information with current facility safety basis for a number of situations in recent months. This paper has relevance in multiple topical areas including documented safety analysis, decontamination and decommissioning (D and D), safety basis (SB) implementation, safety and design integration, potential inadequacy of the safety analysis (PISA), technical safety requirements (TSR), and unreviewed safety questions. BJC learned that nuclear safety compliance relies on adequate and well documented system design information. A number of PIS As and TSR violations occurred due to inadequate or erroneous system design information. As a corrective action, BJC assessed the occurrences caused by systems design-safety basis interface problems. Safety systems reviewed included the Molten Salt Reactor Experiment (MSRE) Fluorination System, K-1065 fire alarm system, and the K-25 Radiation Criticality Accident Alarm System. The conclusion was that an inadequate knowledge of system design could result in continuous non-compliance issues relating to nuclear safety. This was especially true with older facilities that lacked current as-built drawings coupled with the loss of 'historical knowledge' as personnel retired or moved on in their careers. Walkdown of systems and the updating of drawings are imperative for nuclear safety compliance. System design integration with safety basis has relevance in the Department of Energy (DOE) complex. This paper presents the BJC Lessons Learned in this area. It will be of benefit to DOE contractors that manage and operate an aging population of nuclear facilities

Safety Information System Guide

International Nuclear Information System (INIS)

Bullock, M.G.

1977-03-01

This Guide provides guidelines for the design and evaluation of a working safety information system. For the relatively few safety professionals who have already adopted computer-based programs, this Guide may aid them in the evaluation of their present system. To those who intend to develop an information system, it will, hopefully, inspire new thinking and encourage steps towards systems safety management. For the line manager who is working where the action is, this Guide may provide insight on the importance of accident facts as a tool for moving ideas up the communication ladder where they will be heard and acted upon; where what he has to say will influence beneficial changes among those who plan and control his operations. In the design of a safety information system, it is suggested that the safety manager make friends with a computer expert or someone on the management team who has some feeling for, and understanding of, the art of information storage and retrieval as a new and better means for communication

Three-dimensional Interlocking Professional Management Mechanism of Agricultural Family-Owned Enterprise

OpenAIRE

Zhong-ming, Shen; Cheng-jun, Zhang

2010-01-01

The establishment of the three-dimensional interlocking professional management mechanism of agricultural family-owned enterprise was studied through the following three mechanisms; the stimulation and restriction mechanism within the agricultural family-owned enterprises, the credit mechanism of professional manager and the social environment mechanism. The relationship between the agricultural family-owned enterprise, professional manager and the society was studied. In the first place, the...

Implementing and measuring safety goals and safety culture. 4. Utility's Activities for Better Safety Culture After the JCO Accident

International Nuclear Information System (INIS)

Omoto, Akira

2001-01-01

depended heavily on operators strictly abiding by the prescribed procedures. This would become a design fault if operators are not well educated in background procedures and do not take the procedures seriously. Although NPSs are designed in such a way that an appropriate combination of operational rules and electromechanical interlocks would prevent plant systems from going wrong, areas still exist where safety is mostly dependent on human actions and on operators strictly following the procedures. We have initiated research into such possibilities using semi-probabilistic analysis and are implementing modifications to the interlocks to augment safety and reliability. Review of lessons learned has resulted in activities to augment safety and reliability: (a) self-diagnosis of safety culture, (b) improvement of on-site education and training, and (c) review of plant safety from the viewpoint of interface between design and operation. (author)

Architecture Level Safety Analyses for Safety-Critical Systems

Directory of Open Access Journals (Sweden)

K. S. Kushal

2017-01-01

Full Text Available The dependency of complex embedded Safety-Critical Systems across Avionics and Aerospace domains on their underlying software and hardware components has gradually increased with progression in time. Such application domain systems are developed based on a complex integrated architecture, which is modular in nature. Engineering practices assured with system safety standards to manage the failure, faulty, and unsafe operational conditions are very much necessary. System safety analyses involve the analysis of complex software architecture of the system, a major aspect in leading to fatal consequences in the behaviour of Safety-Critical Systems, and provide high reliability and dependability factors during their development. In this paper, we propose an architecture fault modeling and the safety analyses approach that will aid in identifying and eliminating the design flaws. The formal foundations of SAE Architecture Analysis & Design Language (AADL augmented with the Error Model Annex (EMV are discussed. The fault propagation, failure behaviour, and the composite behaviour of the design flaws/failures are considered for architecture safety analysis. The illustration of the proposed approach is validated by implementing the Speed Control Unit of Power-Boat Autopilot (PBA system. The Error Model Annex (EMV is guided with the pattern of consideration and inclusion of probable failure scenarios and propagation of fault conditions in the Speed Control Unit of Power-Boat Autopilot (PBA. This helps in validating the system architecture with the detection of the error event in the model and its impact in the operational environment. This also provides an insight of the certification impact that these exceptional conditions pose at various criticality levels and design assurance levels and its implications in verifying and validating the designs.

Photovoltaic module and interlocked stack of photovoltaic modules

Science.gov (United States)

Wares, Brian S.

2012-09-04

One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame having at least a top member and a bottom member. A plurality of alignment features are included on the top member of each frame, and a plurality of alignment features are included on the bottom member of each frame. Adjacent photovoltaic modules are interlocked by the alignment features on the top member of a lower module fitting together with the alignment features on the bottom member of an upper module. Other embodiments, features and aspects are also disclosed.

FOOD SAFETY CONTROL SYSTEM IN CHINA

Institute of Scientific and Technical Information of China (English)

Liu Wei-jun; Wei Yi-min; Han Jun; Luo Dan; Pan Jia-rong

2007-01-01

Most countries have expended much effort to develop food safety control systems to ensure safe food supplies within their borders. China, as one of the world's largest food producers and consumers,pays a lot of attention to food safety issues. In recent years, China has taken actions and implemented a series of plans in respect to food safety. Food safety control systems including regulatory, supervisory,and science and technology systems, have begun to be established in China. Using, as a base, an analysis of the current Chinese food safety control system as measured against international standards, this paper discusses the need for China to standardize its food safety control system. We then suggest some policies and measures to improve the Chinese food safety control system.

Ground-state kinetics of bistable redox-active donor-acceptor mechanically interlocked molecules.

Science.gov (United States)

Fahrenbach, Albert C; Bruns, Carson J; Li, Hao; Trabolsi, Ali; Coskun, Ali; Stoddart, J Fraser

2014-02-18

The ability to design and confer control over the kinetics of theprocesses involved in the mechanisms of artificial molecular machines is at the heart of the challenge to create ones that can carry out useful work on their environment, just as Nature is wont to do. As one of the more promising forerunners of prototypical artificial molecular machines, chemists have developed bistable redox-active donor-acceptor mechanically interlocked molecules (MIMs) over the past couple of decades. These bistable MIMs generally come in the form of [2]rotaxanes, molecular compounds that constitute a ring mechanically interlocked around a dumbbell-shaped component, or [2]catenanes, which are composed of two mechanically interlocked rings. As a result of their interlocked nature, bistable MIMs possess the inherent propensity to express controllable intramolecular, large-amplitude, and reversible motions in response to redox stimuli. In this Account, we rationalize the kinetic behavior in the ground state for a large assortment of these types of bistable MIMs, including both rotaxanes and catenanes. These structures have proven useful in a variety of applications ranging from drug delivery to molecular electronic devices. These bistable donor-acceptor MIMs can switch between two different isomeric states. The favored isomer, known as the ground-state co-conformation (GSCC) is in equilibrium with the less favored metastable state co-conformation (MSCC). The forward (kf) and backward (kb) rate constants associated with this ground-state equilibrium are intimately connected to each other through the ground-state distribution constant, KGS. Knowing the rate constants that govern the kinetics and bring about the equilibration between the MSCC and GSCC, allows researchers to understand the operation of these bistable MIMs in a device setting and apply them toward the construction of artificial molecular machines. The three biggest influences on the ground-state rate constants arise from

Safety analysis of the CSTR-1 bench-scale coal liquefaction unit

Energy Technology Data Exchange (ETDEWEB)

Hulburt, D.A.

1981-05-01

The objective of the program reported herein was to provide a Safety Analysis of the CSTR-1 bench scale unit located in Building 167 at the Pittsburgh Energy Technology Center. It was apparent that considerable effort was expended in the design and construction of the unit, and in the development of operating procedures, with regard to safety. Exhaust ventilation, H/sub 2/ and H/sub 2/S monitoring, overpressure protection, overtemperature protection, and interlock systems have been provided. Present settings on the pressure and temperature safety systems are too high, however, to insure prevention of vessel deformation or damage in all cases. While the occurrence of catastrophic rupture of a system pressure vessel (e.g., reactor, high pressure separators) is unlikely, the potential consequences to personnel are severe. Feasibility of providing shielding for these components should be considered. A more probable mode of vessel failure in the event of overpressure or overtemperature and failure of the safety system is yielding of the closure bolts followed by high pressure flow across the mating surfaces. As a minimum, shielding should be designed to restrict travel of resultant spray. The requirements for personal protective equipment are presently stated in rather broad and general terms in the operating procedures. Safe practices and procedures would be more assured if specific requirements were stated and included for each operational step. Recommendations were developed for all hazards triggered by the guidelines.

NASA System Safety Handbook. Volume 1; System Safety Framework and Concepts for Implementation

Science.gov (United States)

Dezfuli, Homayoon; Benjamin, Allan; Everett, Christopher; Smith, Curtis; Stamatelatos, Michael; Youngblood, Robert

2011-01-01

System safety assessment is defined in NPR 8715.3C, NASA General Safety Program Requirements as a disciplined, systematic approach to the analysis of risks resulting from hazards that can affect humans, the environment, and mission assets. Achievement of the highest practicable degree of system safety is one of NASA's highest priorities. Traditionally, system safety assessment at NASA and elsewhere has focused on the application of a set of safety analysis tools to identify safety risks and formulate effective controls.1 Familiar tools used for this purpose include various forms of hazard analyses, failure modes and effects analyses, and probabilistic safety assessment (commonly also referred to as probabilistic risk assessment (PRA)). In the past, it has been assumed that to show that a system is safe, it is sufficient to provide assurance that the process for identifying the hazards has been as comprehensive as possible and that each identified hazard has one or more associated controls. The NASA Aerospace Safety Advisory Panel (ASAP) has made several statements in its annual reports supporting a more holistic approach. In 2006, it recommended that "... a comprehensive risk assessment, communication and acceptance process be implemented to ensure that overall launch risk is considered in an integrated and consistent manner." In 2009, it advocated for "... a process for using a risk-informed design approach to produce a design that is optimally and sufficiently safe." As a rationale for the latter advocacy, it stated that "... the ASAP applauds switching to a performance-based approach because it emphasizes early risk identification to guide designs, thus enabling creative design approaches that might be more efficient, safer, or both." For purposes of this preface, it is worth mentioning three areas where the handbook emphasizes a more holistic type of thinking. First, the handbook takes the position that it is important to not just focus on risk on an individual

Design and development of an automated D.C. ground fault detection and location system for Cirus

International Nuclear Information System (INIS)

Marik, S.K.; Ramesh, N.; Jain, J.K.; Srivastava, A.P.

2002-01-01

Full text: The original design of Cirus safety system provided for automatic detection of ground fault in class I D.C. power supply system and its annunciation followed by delayed reactor trip. Identification of a faulty section was required to be done manually by switching off various sections one at a time thus requiring a lot of shutdown time to identify the faulty section. Since class I power supply is provided for safety control system, quick detection and location of ground faults in this supply is necessary as these faults have potential to bypass safety interlocks and hence the need for a new system for automatic location of a faulty section. Since such systems are not readily available in the market, in-house efforts were made to design and develop a plant-specific system, which has been installed and commissioned

Early Conversion of External Fixation to Interlocked Nailing in Open Fractures of Both Bone Leg Assisted with Vacuum Closure (VAC) - Final Outcome.

Science.gov (United States)

Gill, Simrat Pal Singh; Raj, Manish; Kumar, Sunil; Singh, Pulkesh; Kumar, Dinesh; Singh, Jasveer; Deep, Akash

2016-02-01

Management of compound grade III fractures of both bone leg includes external stabilization for long period, followed by various soft tissue coverage procedures. Primary interlocking of tibia had been also done with variable results. External fixation for long time without any bone loss often leads to infected nonunion, loss of reduction, pin tract infection and failure of fixation, primary interlocking in compound grade III fractures had shown high medullary infection rate. We managed all cases of compound grade III A/B fractures with primary external fixation, simultaneous wound management using vacuum assisted closure (VAC) followed by early conversion to interlocking within 2 weeks of fixator application. To determine the effectiveness of vacuum assisted closure (VAC) for the early conversion of external fixator to definitive interlocking in open fractures of the both bone leg. In current study we selected 84 cases of compound grade IIIA/B diaphyseal fractures of both bone leg during period of May 2010 to September 2013. We managed these cases by immediate debridement and application of external fixation followed by repeated debridement, application of vacuum assisted closure (VAC) and conversion to interlocking within two weeks. Out of 84 cases union was achieved in 80(95%) of cases with definitive tibial interlocking. Excellent to good result were obtained in 77(91.8%) of cases and fair to poor result seen in rest of 7(8.2%) of cases according to modified Ketenjian's criteria. 5 out of these 7 poor result group cases were from Compound Grade III B group to start with. Deep infection rate in our series were 7% i.e. total 6 cases and 4 out of these were from compound Grade III B group to start with. Vacuum assisted closure (VAC) give a good help for rapid closure of the wound and help in early conversion to definitive intramedullary nailing. Reamed nail could well be used in compound grade IIIA/B fractures without increasing the risk of infection. It gives

Three-dimensional iron sulfide-carbon interlocked graphene composites for high-performance sodium-ion storage

DEFF Research Database (Denmark)

Huang, Wei; Sun, Hongyu; Shangguan, Huihui

2018-01-01

Three-dimensional (3D) carbon-wrapped iron sulfide interlocked graphene (Fe7S8@C-G) composites for high-performance sodium-ion storage are designed and produced through electrostatic interactions and subsequent sulfurization. The iron-based metal–organic frameworks (MOFs, MIL-88-Fe) interact with...

Instrumentation and control systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared under the IAEA programme for establishing safety standards for nuclear power plants. It supplements Safety Standards Series No. NS-R-1: Safety of Nuclear Power Plants: Design (the Requirements for Design), which establishes the design requirements for ensuring the safety of nuclear power plants. This Safety Guide describes how the requirements should be met for instrumentation and control (I and C) systems important to safety. This publication is a revision and combination of two previous Safety Guides: Safety Series Nos 50-SG-D3 and 50-SG-D8, which are superseded by this new Safety Guide. The revision takes account of developments in I and C systems important to safety since the earlier Safety Guides were published in 1980 and 1984, respectively. The objective of this Safety Guide is to provide guidance on the design of I and C systems important to safety in nuclear power plants, including all I and C components, from the sensors allocated to the mechanical systems to the actuated equipment, operator interfaces and auxiliary equipment. This Safety Guide deals mainly with design requirements for those I and C systems that are important to safety. It expands on paragraphs of Ref in the area of I and C systems important to safety. This publication is intended for use primarily by designers of nuclear power plants and also by owners and/or operators and regulators of nuclear power plants. This Safety Guide provides general guidance on I and C systems important to safety which is broadly applicable to many nuclear power plants. More detailed requirements and limitations for safe operation specific to a particular plant type should be established as part of the design process. The present guidance is focused on the design principles for systems important to safety that warrant particular attention, and should be applied to both the design of new I and C systems and the modernization of existing systems. Guidance is provided on how design

How could intelligent safety transport systems enhance safety ?

NARCIS (Netherlands)

Wiethoff, M. Heijer, T. & Bekiaris, E.

2017-01-01

In Europe, many deaths and injured each years are the cost of today's road traffic. Therefore, it is wise to look for possible solutions for enhancing traffic safety. Some Advanced Driver Assistance Systems (ADAS) are expected to increase safety, but they may also evoke new safety hazards. Only

Safety Review related to Commercial Grade Digital Equipment in Safety System

International Nuclear Information System (INIS)

Yu, Yeongjin; Park, Hyunshin; Yu, Yeongjin; Lee, Jaeheung

2013-01-01

The upgrades or replacement of I and C systems on safety system typically involve digital equipment developed in accordance with non-nuclear standards. However, the use of commercial grade digital equipment could include the vulnerability for software common-mode failure, electromagnetic interference and unanticipated problems. Although guidelines and standards for dedication methods of commercial grade digital equipment are provided, there are some difficulties to apply the methods to commercial grade digital equipment for safety system. This paper focuses on regulatory guidelines and relevant documents for commercial grade digital equipment and presents safety review experiences related to commercial grade digital equipment in safety system. This paper focuses on KINS regulatory guides and relevant documents for dedication of commercial grade digital equipment and presents safety review experiences related to commercial grade digital equipment in safety system. Dedication including critical characteristics is required to use the commercial grade digital equipment on safety system in accordance with KEPIC ENB 6370 and EPRI TR-106439. The dedication process should be controlled in a configuration management process. Appropriate methods, criteria and evaluation result should be provided to verify acceptability of the commercial digital equipment used for safety function

Safety parameter display system: an operator support system for enhancement of safety in Indian PHWRs

International Nuclear Information System (INIS)

Subramaniam, K.; Biswas, T.

1994-01-01

Ensuring operational safety in nuclear power plants is important as operator errors are observed to contribute significantly to the occurrence of accidents. Computerized operator support systems, which process and structure information, can help operators during both normal and transient conditions, and thereby enhance safety and aid effective response to emergency conditions. An important operator aid being developed and described in this paper, is the safety parameter display system (SPDS). The SPDS is an event-independent, symptom-based operator aid for safety monitoring. Knowledge-based systems can provide operators with an improved quality of information. An information processing model of a knowledge based operator support system (KBOSS) developed for emergency conditions using an expert system shell is also presented. The paper concludes with a discussion of the design issues involved in the use of a knowledge based systems for real time safety monitoring and fault diagnosis. (author). 8 refs., 4 figs., 1 tab

Safety evaluation for communication network software modifications of PCS in Ulchin NPP unit 3

International Nuclear Information System (INIS)

Ji, S. H.; Koh, J. S.; Kim, B. R.; Oh, S. H.

1999-01-01

On February 2, 1999, an incident occurred at the Ulchin Nuclear Power Plant Unit 3 which resulted in the corruption of data on Perform Net of Plant Control System. This incident was caused by the ASIC (Application Specific Integrated Circuit) chip on the Rehostable Module which is a part of Network Interface Module. Regarding this incident, we required that the utility should propose new algorithms to detect the hardware failure of ASIC chip and evaluated the appropriateness of network software modifications. As a result of this evaluation process, we required that the safety related interlock signals using data communication path be hardwired to make up for the vulnerability of the system architecture. In this paper, we will discuss the system architecture of PCS and fault analysis and evaluation findings

Feasibility of a fast optical pressure interlock for the ITER neutral beam injectors

International Nuclear Information System (INIS)

Ash, Andrew; Surrey, Elizabeth

2009-01-01

The feasibility of using Balmer-α emission for a high-speed pressure diagnostic and beam interlock for the ITER neutral beam heating system is investigated. An interlock is needed to prevent excessive re-ionisation of the neutral beam when rapid excursions of pressure occur in either the electrostatic residual ion dump (ERID), or the neutral beam duct (NBD). The re-ionised fraction of the beam, will be deflected by stray tokamak fields, potentially causing excessive thermal loads on beam line components. Experience from JET indicates that a response time of order 100 μs is required in order to prevent fast pressure excursions. Fast penning gauges have a time response of around 30-50 ms, however, a faster response (around 1 μs) is possible by monitoring the H α (656.3 nm)/D α (656.1 nm) emission from collisional excitation of the background gas and neutral beam. Published total cross-sections are used to calculate a signal of 3.5x10 13 -3.0x10 17 photons s -1 m -2 sr -1 for normal conditions. This signal must be distinguished from the background light of the tokamak plasma (line emission and bremsstrahlung). The beam emission is Doppler shifted by up to 21 nm (D operation) and up to 27 nm (H operation) depending on angle of observation and this can be used to help distinguish against background line emission. The distribution of background light along the beam line is calculated with a two-dimensional radiosity code, solving the equilibrium energy balance within the beam line enclosure. The Balmer-α signal and background signal due to bremsstrahlung are compared for a 500-MW reference plasma.

Comprehensive Lifecycle for Assuring System Safety

Science.gov (United States)

Knight, John C.; Rowanhill, Jonathan C.

2017-01-01

CLASS is a novel approach to the enhancement of system safety in which the system safety case becomes the focus of safety engineering throughout the system lifecycle. CLASS also expands the role of the safety case across all phases of the system's lifetime, from concept formation to decommissioning. As CLASS has been developed, the concept has been generalized to a more comprehensive notion of assurance becoming the driving goal, where safety is an important special case. This report summarizes major aspects of CLASS and contains a bibliography of papers that provide additional details.

Safety-related control air systems

International Nuclear Information System (INIS)

Anon.

1977-01-01

This Standard applies to those portions of the control air system that furnish air required to support, control, or operate systems or portions of systems that are safety related in nuclear power plants. This Standard relates only to the air supply system(s) for safety-related air operated devices and does not apply to the safety-related air operated device or to air operated actuators for such devices. The objectives of this Standard are to provide (1) minimum system design requirements for equipment, piping, instruments, controls, and wiring that constitute the air supply system; and (2) the system and component testing and maintenance requirements

The use of interlocking prostheses for both temporary and definitive management of infected periprosthetic femoral fractures.

Science.gov (United States)

Konan, Sujith; Rayan, Faizal; Manketelow, Andrew R J; Haddad, Fares S

2011-12-01

Infected periprosthetic fractures around total hip arthroplasties are an extremely challenging problem. We describe our experience of managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants. The Cannulock (Orthodesign, Christchurch, United Kingdom) uncoated stem was used in 12 cases, and the Kent hip prosthesis (Biomet Merck, Bridgend, United Kingdom), in 5 cases. Satisfactory outcome was noted in all cases, and in 11 cases, revision to a definitive stem has been undertaken after successful control of infection and fracture union. The use of interlocking stems offers a relatively appealing solution for a complex problem and avoids the complications that would be associated with resection of the entire femur or the use of large quantities of bone cement. Copyright © 2011 Elsevier Inc. All rights reserved.

A Methodological Framework for Software Safety in Safety Critical Computer Systems

OpenAIRE

P. V. Srinivas Acharyulu; P. Seetharamaiah

2012-01-01

Software safety must deal with the principles of safety management, safety engineering and software engineering for developing safety-critical computer systems, with the target of making the system safe, risk-free and fail-safe in addition to provide a clarified differentaition for assessing and evaluating the risk, with the principles of software risk management. Problem statement: Prevailing software quality models, standards were not subsisting in adequately addressing the software safety ...

Interlocked graphene-Prussian blue hybrid composites enable multifunctional electrochemical applications

DEFF Research Database (Denmark)

Zhang, Minwei; Hou, Chengyi; Halder, Arnab

2017-01-01

There has been increasing interest recently in mixed-valence inorganic nanostructure functionalized graphene composites, represented by Prussian blue, because they can cost-effectively apply to biosensors and energy devices. In this work, we present a one-pot green method to synthesize interlocked...... graphene-Prussian Blue hybrid composites as high-performance materials for biosensors and supercapacitor electrodes. Given the fact that graphene oxide (GO) can act as an electron acceptor, we used iron(II) and glucose as co-reducing agents to reduce GO under mild reaction conditions without introducing...

Finite Element Analysis of Absorbable Sheath to Prevent Stress Shielding of Tibial Interlocking Intramedullary Nail

Science.gov (United States)

Dong, Yansheng; Wang, Yongqing; Dong, Limin; Jia, Peng; Lu, Fengcheng

2017-07-01

The nail with absorbable sheath (AS nail) is designed to reduce the stress shielding effect of internal fixation with interlocking intramedullary nail. In order to verify its feasibility, two types of the finite element models of internal fixation of tibia with the AS nail and the common metal nail (CM nail) are established using the Softwares of Mimics, Geomagic, SolidWorks and ANSYS according to the CT scanning data of tibia. The result of the finite element analysis shows that the AS nail has great advantages compared with the CM nail in reducing the stress shielding effect in different periods of fracture healing. The conclusion is that the AS nail can realize the static fixation to the dynamic fixation from the early to the later automatically to shorten the time of fracture healing, which also provides a new technique to the interlocking intramedullary nail.

Study of system safety evaluation on LTO of national project. NISA safety research project on system safety of nuclear power plants

International Nuclear Information System (INIS)

Takizawa, Masayuki; Sekimura, Naoto; Miyano, Hiroshi; Aoyama, Katsunobu

2012-01-01

Japanese safety regulatory body, that is, Nuclear and Industrial Safety Agency (NISA) started a 5-year national safety research project as 'the first stage' from 2006 FY to 2010 FY whose objective is 'Improve the technical information basis in order to utilize knowledge as well as information related to ageing management and maintenance of NPPs. Fukushima disaster happened in March 2011, and the priority of research needs for ageing management dramatically changed in Japan. The second-stage national project started in October 2011 with the concept of 'system safety' of NNPs where not only ageing management on degradation phenomena of important components but also safety management on total plant systems are paid attention to. The second-stage project is so called 'Japanese Ageing Management Program for System Safety (JAMPSS)'. (author)

Preliminary safety evaluation for CSR1000 with passive safety system

International Nuclear Information System (INIS)

Wu, Pan; Gou, Junli; Shan, Jianqiang; Zhang, Bo; Li, Xiang

2014-01-01

Highlights: • The basic information of a Chinese SCWR concept CSR1000 is introduced. • An innovative passive safety system is proposed for CSR1000. • 6 Transients and 3 accidents are analysed with system code SCTRAN. • The passive safety systems greatly mitigate the consequences of these incidents. • The inherent safety of CSR1000 is enhanced. - Abstract: This paper describes the preliminary safety analysis of the Chinese Supercritical water cooled Reactor (CSR1000), which is proposed by Nuclear Power Institute of China (NPIC). The two-pass core design applied to CSR1000 decreases the fuel cladding temperature and flattens the power distribution of the core at normal operation condition. Each fuel assembly is made up of four sub-assemblies with downward-flow water rods, which is favorable to the core cooling during abnormal conditions due to the large water inventory of the water rods. Additionally, a passive safety system is proposed for CSR1000 to increase the safety reliability at abnormal conditions. In this paper, accidents of “pump seizure”, “loss of coolant flow accidents (LOFA)”, “core depressurization”, as well as some typical transients are analysed with code SCTRAN, which is a one-dimensional safety analysis code for SCWRs. The results indicate that the maximum cladding surface temperatures (MCST), which is the most important safety criterion, of the both passes in the mentioned incidents are all below the safety criterion by a large margin. The sensitivity analyses of the delay time of RCPs trip in “loss of offsite power” and the delay time of RMT actuation in “loss of coolant flowrate” were also included in this paper. The analyses have shown that the core design of CSR1000 is feasible and the proposed passive safety system is capable of mitigating the consequences of the selected abnormalities

Peri-Implant Distribution of Polyethylene Debris in Postmortem-Retrieved Knee Arthroplasties: Can Polyethylene Debris Explain Loss of Cement-Bone Interlock in Successful Total Knee Arthroplasties?

Science.gov (United States)

Cyndari, Karen I; Goodheart, Jacklyn R; Miller, Mark A; Oest, Megan E; Damron, Timothy A; Mann, Kenneth A

2017-07-01

Loss of mechanical interlock between cement and bone with in vivo service has been recently quantified for functioning, nonrevised, cemented total knee arthroplasties (TKAs). The cause of interlocking trabecular resorption is not known. The goal of this study is to quantify the distribution of PE debris at the cement-bone interface and determine if polyethylene (PE) debris is locally associated with loss of interlock. Fresh, nonrevised, postmortem-retrieved TKAs (n = 8) were obtained en bloc. Laboratory-prepared constructs (n = 2) served as negative controls. The intact cement-bone interface of each proximal tibia was embedded in Spurr's resin, sectioned, and imaged under polarized light to identify birefringent PE particles. PE wear particle number density was quantified at the cement-bone interface and distal to the interface, and then compared with local loss of cement-bone interlock. The average PE particle number density for postmortem-retrieved TKAs ranged from 8.6 (1.3) to 24.9 (3.1) particles/mm 2 (standard error) but was weakly correlated with years in service. The average particle number density was twice as high as distal (>5mm) to the interface compared to at the interface. The local loss of interlock at the interface was not related to the presence, absence, or particle density of PE. PE debris can migrate extensively along the cement-bone interface of well-fixed tibial components. However, the amount of local bone loss at the cement-bone interface was not correlated with the amount of PE debris at the interface, suggesting that the observed loss of trabecular interlock in these well-fixed TKAs may be due to alternative factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Metacarpophalangeal joint of the thumb arthrodesis using intramedullary interlocking screws XMCP™.

Science.gov (United States)

Novoa-Parra, C N; Montaner-Alonso, D; Morales-Rodríguez, J

2017-09-04

The study objective was to assess the results of a thumb metacarpophalangeal joint (MCPJ) arthrodesis using intramedullary interlocking screws at 25°, XMCP ™ (Extremity Medical, Parsippany, NJ). Radiographs evaluated the angle of arthrodesis, time of fusion and fixation of the implant. Clinical and functional outcomes were assessed using the DASH questionnaire and the VAS scale. Any complications found during surgery or the follow-up period were noted. We studied 9 patients. The mean follow-up was 27.6 months. Patients showed clinical and radiological evidence of fusion in an average of 8 weeks, the angle of fusion was 25°. There were no complications and no implant had to be removed. The XMCP™ system provides a reliable method for MCPJ arthrodesis for several indications and can be used with other procedures in the complex hand. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Formal modelling and verification of interlocking systems featuring sequential release

DEFF Research Database (Denmark)

Vu, Linh Hong; Haxthausen, Anne Elisabeth; Peleska, Jan

2017-01-01

checking (BMC) and inductive reasoning, it is verified that the generated model instance satisfies the generated safety properties. Using this method, we are able to verify the safety properties for model instances corresponding to railway networks of industrial size. Experiments show that BMC is also...

Model Checking Geographically Distributed Interlocking Systems Using UMC

DEFF Research Database (Denmark)

Fantechi, Alessandro; Haxthausen, Anne Elisabeth; Nielsen, Michel Bøje Randahl

2017-01-01

the relevant distributed protocols. By doing that we obey the safety guidelines of the railway signalling domain, that require formal methods to support the certification of such products. We also show how formal modelling can help designing alternative distributed solutions, while maintaining adherence...

Survey and evaluation of inherent safety characteristics and passive safety systems for use in probabilistic safety analyses

International Nuclear Information System (INIS)

Wetzel, N.; Scharfe, A.

1998-01-01

The present report examines the possibilities and limits of a probabilistic safety analysis to evaluate passive safety systems and inherent safety characteristics. The inherent safety characteristics are based on physical principles, that together with the safety system lead to no damage. A probabilistic evaluation of the inherent safety characteristic is not made. An inventory of passive safety systems of accomplished nuclear power plant types in the Federal Republic of Germany was drawn up. The evaluation of the passive safety system in the analysis of the accomplished nuclear power plant types was examined. The analysis showed that the passive manner of working was always assumed to be successful. A probabilistic evaluation was not performed. The unavailability of the passive safety system was determined by the failure of active components which are necessary in order to activate the passive safety system. To evaluate the passive safety features in new concepts of nuclear power plants the AP600 from Westinghouse, the SBWR from General Electric and the SWR 600 from Siemens, were selected. Under these three reactor concepts, the SWR 600 is specially attractive because the safety features need no energy sources and instrumentation in this concept. First approaches for the assessment of the reliability of passively operating systems are summarized. Generally it can be established that the core melt frequency for the passive concepts AP600 and SBWR is advantageous in comparison to the probabilistic objectives from the European Pressurized Water Reactor (EPR). Under the passive concepts is the SWR 600 particularly interesting. In this concept the passive systems need no energy sources and instrumentation, and has active operational systems and active safety equipment. Siemens argues that with this concept the frequency of a core melt will be two orders of magnitude lower than for the conventional reactors. (orig.) [de

Reliability Analysis of the CERN Radiation Monitoring Electronic System CROME

CERN Document Server

AUTHOR|(CDS)2126870

For the new in-house developed CERN Radiation Monitoring Electronic System (CROME) a reliability analysis is necessary to ensure compliance with the statu-tory requirements regarding the Safety Integrity Level. The required Safety Integrity Level by IEC 60532 standard is SIL 2 (for the Safety Integrated Functions Measurement, Alarm Triggering and Interlock Triggering). The first step of the reliability analysis was a system and functional analysis which served as basis for the implementation of the CROME system in the software “Iso-graph”. In the “Prediction” module of Isograph the failure rates of all components were calculated. Failure rates for passive components were calculated by the Military Standard 217 and failure rates for active components were obtained from lifetime tests by the manufacturers. The FMEA was carried out together with the board designers and implemented in the “FMECA” module of Isograph. The FMEA served as basis for the Fault Tree Analysis and the detection of weak points...

Does the concept of safety culture help or hinder systems thinking in safety?

Science.gov (United States)

Reiman, Teemu; Rollenhagen, Carl

2014-07-01

The concept of safety culture has become established in safety management applications in all major safety-critical domains. The idea that safety culture somehow represents a "systemic view" on safety is seldom explicitly spoken out, but nevertheless seem to linger behind many safety culture discourses. However, in this paper we argue that the "new" contribution to safety management from safety culture never really became integrated with classical engineering principles and concepts. This integration would have been necessary for the development of a more genuine systems-oriented view on safety; e.g. a conception of safety in which human, technological, organisational and cultural factors are understood as mutually interacting elements. Without of this integration, researchers and the users of the various tools and methods associated with safety culture have sometimes fostered a belief that "safety culture" in fact represents such a systemic view about safety. This belief is, however, not backed up by theoretical or empirical evidence. It is true that safety culture, at least in some sense, represents a holistic term-a totality of factors that include human, organisational and technological aspects. However, the departure for such safety culture models is still human and organisational factors rather than technology (or safety) itself. The aim of this paper is to critically review the various uses of the concept of safety culture as representing a systemic view on safety. The article will take a look at the concepts of culture and safety culture based on previous studies, and outlines in more detail the theoretical challenges in safety culture as a systems concept. The paper also presents recommendations on how to make safety culture more systemic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ground-state thermodynamics of bistable redox-active donor-acceptor mechanically interlocked molecules.

Science.gov (United States)

Fahrenbach, Albert C; Bruns, Carson J; Cao, Dennis; Stoddart, J Fraser

2012-09-18

Fashioned through billions of years of evolution, biological molecular machines, such as ATP synthase, myosin, and kinesin, use the intricate relative motions of their components to drive some of life's most essential processes. Having control over the motions in molecules is imperative for life to function, and many chemists have designed, synthesized, and investigated artificial molecular systems that also express controllable motions within molecules. Using bistable mechanically interlocked molecules (MIMs), based on donor-acceptor recognition motifs, we have sought to imitate the sophisticated nanoscale machines present in living systems. In this Account, we analyze the thermodynamic characteristics of a series of redox-switchable [2]rotaxanes and [2]catenanes. Control and understanding of the relative intramolecular movements of components in MIMs have been vital in the development of a variety of applications of these compounds ranging from molecular electronic devices to drug delivery systems. These bistable donor-acceptor MIMs undergo redox-activated switching between two isomeric states. Under ambient conditions, the dominant translational isomer, the ground-state coconformation (GSCC), is in equilibrium with the less favored translational isomer, the metastable-state coconformation (MSCC). By manipulating the redox state of the recognition site associated with the GSCC, we can stimulate the relative movements of the components in these bistable MIMs. The thermodynamic parameters of model host-guest complexes provide a good starting point to rationalize the ratio of GSCC to MSCC at equilibrium. The bistable [2]rotaxanes show a strong correlation between the relative free energies of model complexes and the ground-state distribution constants (K(GS)). This relationship does not always hold for bistable [2]catenanes, most likely because of the additional steric and electronic constraints present when the two rings are mechanically interlocked with each other

The aviation safety reporting system

Science.gov (United States)

Reynard, W. D.

1984-01-01

The aviation safety reporting system, an accident reporting system, is presented. The system identifies deficiencies and discrepancies and the data it provides are used for long term identification of problems. Data for planning and policy making are provided. The system offers training in safety education to pilots. Data and information are drawn from the available data bases.

Bacterial carbonate precipitation improves water absorption of interlocking compressed earth block (ICEB)

Science.gov (United States)

Zamer, M. M.; Irwan, J. M.; Othman, N.; Faisal, S. K.; Anneza, L. H.; Alshalif, A. F.; Teddy, T.

2017-11-01

Interlocking compressed earth blocks (ICEB) are soil based blocks that allows for mortarless construction. The addition of many alternative materials into interlocking block in order to improve the durability has been reported. However there are currently lack of report and evidence on the application of biocalcification or microbiologically induced calcite precipitation (MICP) in improving the engineering properties of ICEB. This paper evaluate the effect of UB in improving the water absorption properties of ICEB. This paper also provide the results on SEM analysis of addition of 1%, 3% and 5% UB in ICEB. The bacteria were added as partial replacement of limestone water in ICEB. The results showed the reduction of 14.72% with 5% UB on initial water absorption followed by the results for water absorption by 24-hour soaking which also indicates reduction of 14.68% with 5% UB on 28th days of testing compared to control specimen. It was expected that the reduction of water absorption was due to the plugging of pores by the bacterial calcite which prevent ingression of water in ICEB samples. Therefore this study hopes that the positive results from the UB as improving in water absorption of ICEB will lead to improve others ICEB properties and others construction materials.

NASA Aviation Safety Reporting System (ASRS)

Science.gov (United States)

Connell, Linda J.

2017-01-01

The NASA Aviation Safety Reporting System (ASRS) collects, analyzes, and distributes de-identified safety information provided through confidentially submitted reports from frontline aviation personnel. Since its inception in 1976, the ASRS has collected over 1.4 million reports and has never breached the identity of the people sharing their information about events or safety issues. From this volume of data, the ASRS has released over 6,000 aviation safety alerts concerning potential hazards and safety concerns. The ASRS processes these reports, evaluates the information, and provides selected de-identified report information through the online ASRS Database at http:asrs.arc.nasa.gov. The NASA ASRS is also a founding member of the International Confidential Aviation Safety Systems (ICASS) group which is a collection of other national aviation reporting systems throughout the world. The ASRS model has also been replicated for application to improving safety in railroad, medical, fire fighting, and other domains. This presentation will discuss confidential, voluntary, and non-punitive reporting systems and their advantages in providing information for safety improvements.

Software for computer based systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

Computer based systems are of increasing importance to safety in nuclear power plants as their use in both new and older plants is rapidly increasing. They are used both in safety related applications, such as some functions of the process control and monitoring systems, as well as in safety critical applications, such as reactor protection or actuation of safety features. The dependability of computer based systems important to safety is therefore of prime interest and should be ensured. With current technology, it is possible in principle to develop computer based instrumentation and control systems for systems important to safety that have the potential for improving the level of safety and reliability with sufficient dependability. However, their dependability can be predicted and demonstrated only if a systematic, fully documented and reviewable engineering process is followed. Although a number of national and international standards dealing with quality assurance for computer based systems important to safety have been or are being prepared, internationally agreed criteria for demonstrating the safety of such systems are not generally available. It is recognized that there may be other ways of providing the necessary safety demonstration than those recommended here. The basic requirements for the design of safety systems for nuclear power plants are provided in the Requirements for Design issued in the IAEA Safety Standards Series.The IAEA has issued a Technical Report to assist Member States in ensuring that computer based systems important to safety in nuclear power plants are safe and properly licensed. The report provides information on current software engineering practices and, together with relevant standards, forms a technical basis for this Safety Guide. The objective of this Safety Guide is to provide guidance on the collection of evidence and preparation of documentation to be used in the safety demonstration for the software for computer based

Software for computer based systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

Computer based systems are of increasing importance to safety in nuclear power plants as their use in both new and older plants is rapidly increasing. They are used both in safety related applications, such as some functions of the process control and monitoring systems, as well as in safety critical applications, such as reactor protection or actuation of safety features. The dependability of computer based systems important to safety is therefore of prime interest and should be ensured. With current technology, it is possible in principle to develop computer based instrumentation and control systems for systems important to safety that have the potential for improving the level of safety and reliability with sufficient dependability. However, their dependability can be predicted and demonstrated only if a systematic, fully documented and reviewable engineering process is followed. Although a number of national and international standards dealing with quality assurance for computer based systems important to safety have been or are being prepared, internationally agreed criteria for demonstrating the safety of such systems are not generally available. It is recognized that there may be other ways of providing the necessary safety demonstration than those recommended here. The basic requirements for the design of safety systems for nuclear power plants are provided in the Requirements for Design issued in the IAEA Safety Standards Series.The IAEA has issued a Technical Report to assist Member States in ensuring that computer based systems important to safety in nuclear power plants are safe and properly licensed. The report provides information on current software engineering practices and, together with relevant standards, forms a technical basis for this Safety Guide. The objective of this Safety Guide is to provide guidance on the collection of evidence and preparation of documentation to be used in the safety demonstration for the software for computer based

Software for computer based systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2000-01-01

Computer based systems are of increasing importance to safety in nuclear power plants as their use in both new and older plants is rapidly increasing. They are used both in safety related applications, such as some functions of the process control and monitoring systems, as well as in safety critical applications, such as reactor protection or actuation of safety features. The dependability of computer based systems important to safety is therefore of prime interest and should be ensured. With current technology, it is possible in principle to develop computer based instrumentation and control systems for systems important to safety that have the potential for improving the level of safety and reliability with sufficient dependability. However, their dependability can be predicted and demonstrated only if a systematic, fully documented and reviewable engineering process is followed. Although a number of national and international standards dealing with quality assurance for computer based systems important to safety have been or are being prepared, internationally agreed criteria for demonstrating the safety of such systems are not generally available. It is recognized that there may be other ways of providing the necessary safety demonstration than those recommended here. The basic requirements for the design of safety systems for nuclear power plants are provided in the Requirements for Design issued in the IAEA Safety Standards Series.The IAEA has issued a Technical Report to assist Member States in ensuring that computer based systems important to safety in nuclear power plants are safe and properly licensed. The report provides information on current software engineering practices and, together with relevant standards, forms a technical basis for this Safety Guide. The objective of this Safety Guide is to provide guidance on the collection of evidence and preparation of documentation to be used in the safety demonstration for the software for computer based

Jefferson Lab IEC 61508/61511 Safety PLC Based Safety System

International Nuclear Information System (INIS)

Mahoney, Kelly; Robertson, Henry

2009-01-01

This paper describes the design of the new 12 GeV Upgrade Personnel Safety System (PSS) at the Thomas Jefferson National Accelerator Facility (TJNAF). The new PSS design is based on the implementation of systems designed to meet international standards IEC61508 and IEC 61511 for programmable safety systems. In order to meet the IEC standards, TJNAF engineers evaluated several SIL 3 Safety PLCs before deciding on an optimal architecture. In addition to hardware considerations, software quality standards and practices must also be considered. Finally, we will discuss R and D that may lead to both high safety reliability and high machine availability that may be applicable to future accelerators such as the ILC.

Intermediate probabilistic safety assessment approach for safety critical digital systems

International Nuclear Information System (INIS)

Taeyong, Sung; Hyun Gook, Kang

2001-01-01

Even though the conventional probabilistic safety assessment methods are immature for applying to microprocessor-based digital systems, practical needs force to apply it. In the Korea, UCN 5 and 6 units are being constructed and Korean Next Generation Reactor is being designed using the digital instrumentation and control equipment for the safety related functions. Korean regulatory body requires probabilistic safety assessment. This paper analyzes the difficulties on the assessment of digital systems and suggests an intermediate framework for evaluating their safety using fault tree models. The framework deals with several important characteristics of digital systems including software modules and fault-tolerant features. We expect that the analysis result will provide valuable design feedback. (authors)

Technical self reliance of digital safety systems

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kee Choon; Lee, Dong Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Kook Hun [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Choi, Seung Gap [POSCON, Pohang (Korea, Republic of)

2009-04-15

This paper summarizes the development results of the Korea Nuclear Instrumentation and Control System (KNICS) project sponsored by the Korean government. In this project, Man Machine Interface System (MMIS) architecture, two digital platforms, and several control systems are developed. One platform is a programmable Logic Controller (PLC) for a safety system and another platform is a Distributed Control System (DCS) for a non safety system. With the POSAFE Q PLC, a Reactor Protection System (RPS) and an Engineered Safety Feature Component Control System (ESF CCS) are developed. A Power Control System (PCS) is developed based on the DCS. The safety grade platform and the digital safety systems obtained approval for the Topical Report from the Korean regulatory body in February of 2009. Also a Korean utility and a vendor company determined KNICS results to apply them to the planned Nuclear Power Plant (NPP) in March 2009. This paper introduces the technical self reliance experiences of the safety grade platform and the digital safety systems developed in the KNICS R and D project.

Integrating system safety into the basic systems engineering process

Science.gov (United States)

Griswold, J. W.

1971-01-01

The basic elements of a systems engineering process are given along with a detailed description of what the safety system requires from the systems engineering process. Also discussed is the safety that the system provides to other subfunctions of systems engineering.

Tasks and structure of the WENDELSTEIN 7-X control system

International Nuclear Information System (INIS)

Schacht, Joerg; Niedermeyer, Helmut; Laqua, Heike; Spring, Anett; Mueller, Ina; Pingel, Steffen; Woelk, Andreas

2006-01-01

The super conducting stellarator WENDELSTEIN 7-X will run pulses of up to 30 min duration with full heating power. Short pulses with arbitrary intervals, steady state long discharges and arbitrary sequences of short phases with different characteristics in one discharge will be supported by the control system. Each technical component and each diagnostic system including its data acquisition will have its own control system permitting autonomous operation for commissioning and testing. During the experimental sessions the activity of these devices will be coordinated by a central control system and the machine runs more or less automatically with predefined programs. A session leader program allows the leader of the experiment to choose and chain predefined segments, to start or stop a segment chain as a discharge. The progress of the discharge is shown by a sequence monitor attached to the central sequence controller and the session leader program. W7-X has to be prepared for the experiment and monitored by means of the PLC based operational management system. A safety system working independently of the operational management consists of local units responsible for the safety of each component and a central unit ensuring the safety of the whole W7-X system. This safety system provides interlocks and controls the human access to the device. A safety analysis is the basis for the development of the safety system

Binding of anions in triply interlocked coordination catenanes and dynamic allostery for dehalogenation reactions† †Electronic supplementary information (ESI) available: Characterization data and additional tables and figures. CCDC 1515722 and 1515723. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc04070a

Science.gov (United States)

Yang, Linlin; Jing, Xu; An, Bowen; Yang, Yang

2017-01-01

By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds. The presence of several kinds of individual pocket that were attributed to the triply interlocked patterns enabled the possibility of encapsulating different anions, allowing the dynamic allostery between the unlocked/locked conformers to promote the dehalogenation reaction of 3-bromo-cyclohexene efficiently, as with the use of dehalogenase enzymes. The interlocked structures could be unlocked into two individual tetrahedrons through removal of the well-matched anion templates. The stability and reversibility of the locked/unlocked structures were further confirmed by the catching/releasing process that accompanied emission switching, providing opportunities for the system to be a dynamic molecular logic system. PMID:29675152

Programmable Electronic Safety Systems

International Nuclear Information System (INIS)

Parry, R.

1993-05-01

Traditionally safety systems intended for protecting personnel from electrical and radiation hazards at particle accelerator laboratories have made extensive use of electromechanical relays. These systems have the advantage of high reliability and allow the designer to easily implement failsafe circuits. Relay based systems are also typically simple to design, implement, and test. As systems, such as those presently under development at the Superconducting Super Collider Laboratory (SSCL), increase in size, and the number of monitored points escalates, relay based systems become cumbersome and inadequate. The move toward Programmable Electronic Safety Systems is becoming more widespread and accepted. In developing these systems there are numerous precautions the designer must be concerned with. Designing fail-safe electronic systems with predictable failure states is difficult at best. Redundancy and self-testing are prime examples of features that should be implemented to circumvent and/or detect failures. Programmable systems also require software which is yet another point of failure and a matter of great concern. Therefore the designer must be concerned with both hardware and software failures and build in the means to assure safe operation or shutdown during failures. This paper describes features that should be considered in developing safety systems and describes a system recently installed at the Accelerator Systems String Test (ASST) facility of the SSCL

Advanced Containment System

Science.gov (United States)

Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru

2004-10-12

An advanced containment system for containing buried waste and associated leachate. A trench is dug on either side of the zone of interest containing the buried waste so as to accommodate a micro tunnel boring machine. A series of small diameter tunnels are serially excavated underneath the buried waste. The tunnels are excavated by the micro tunnel boring machine at a consistent depth and are substantially parallel to each other. As tunneling progresses, steel casing sections are connected end to end in the excavated portion of the tunnel so that a steel tube is formed. Each casing section has complementary interlocking structure running its length that interlocks with complementary interlocking structure on the adjacent casing section. Thus, once the first tube is emplaced, placement of subsequent tubes is facilitated by the complementary interlocking structure on the adjacent, previously placed, casing sections.

Abating coal tar seepage into surface water bodies using sheet piles with sealed interlocks

International Nuclear Information System (INIS)

Collingwood, B.I.; Boscardin, M.D.; Murdock, R.F.

1995-01-01

A former coal tar processing facility processed crude coal tar supplied from manufactured gas plants in the area. Coal-tar-contaminated ground water from the site was observed seeping through an existing timber bulkhead along a tidal river and producing a multicolored sheen on the surface of the river. As part of a short-term measure to abate the seepage into the river, 64-m long anchored sheet pile wall with sheet pile wing walls at each end was constructed inland of the of the timber bulkhead. The sheet piles extended to low-permeability soils at depth and the interlocks of the sheet piles were provided with polyurethane rubber seals. Based on postconstruction observations for leakage and sheens related to leakage, the steel sheet piles with polyurethane rubber interlock seals appeared to provide a successful seal and abate coal-tar-contaminated ground water seepage into the river. The tie rod penetration sealing proved to be a more problematic detail, but through several postconstruction grouting episodes, an effective seal was produced

Production and Testing of Kiln-cast Glass Components for an Interlocking, Dry-assembled Transparent Bridge

NARCIS (Netherlands)

Bristogianni, T.; Oikonomopoulou, F.; Veer, F.A.; Snijder, A.H.; Nijsse, R.

A pedestrian glass bridge, located at the TU Delft campus site, is being designed by the TU Delft Glass & Transparency Lab. Specifically, the arch-formed bridge consists of cast glass, dry-assembled, interlocking components. To validate the shape of the components, glass mock-ups in 1:2 scale

Considerations on nuclear reactor passive safety systems

International Nuclear Information System (INIS)

2016-01-01

After having indicated some passive safety systems present in electronuclear reactors (control bars, safety injection system accumulators, reactor cooling after stoppage, hydrogen recombination systems), this report recalls the main characteristics of passive safety systems, and discusses the main issues associated with the assessment of new passive systems (notably to face a sustained loss of electric supply systems or of cold water source) and research axis to be developed in this respect. More precisely, the report comments the classification of safety passive systems as it is proposed by the IAEA, outlines and comments specific aspects of these systems regarding their operation and performance. The next part discusses the safety approach, the control of performance of safety passive systems, issues related to their reliability, and the expected contribution of R and D (for example: understanding of physical phenomena which have an influence of these systems, capacities of simulation of these phenomena, needs of experimentations to validate simulation codes)

System safety engineering analysis handbook

Science.gov (United States)

Ijams, T. E.

1972-01-01

The basic requirements and guidelines for the preparation of System Safety Engineering Analysis are presented. The philosophy of System Safety and the various analytic methods available to the engineering profession are discussed. A text-book description of each of the methods is included.

Safety performance monitoring of autonomous marine systems

International Nuclear Information System (INIS)

Thieme, Christoph A.; Utne, Ingrid B.

2017-01-01

The marine environment is vast, harsh, and challenging. Unanticipated faults and events might lead to loss of vessels, transported goods, collected scientific data, and business reputation. Hence, systems have to be in place that monitor the safety performance of operation and indicate if it drifts into an intolerable safety level. This article proposes a process for developing safety indicators for the operation of autonomous marine systems (AMS). The condition of safety barriers and resilience engineering form the basis for the development of safety indicators, synthesizing and further adjusting the dual assurance and the resilience based early warning indicator (REWI) approaches. The article locates the process for developing safety indicators in the system life cycle emphasizing a timely implementation of the safety indicators. The resulting safety indicators reflect safety in AMS operation and can assist in planning of operations, in daily operational decision-making, and identification of improvements. Operation of an autonomous underwater vehicle (AUV) exemplifies the process for developing safety indicators and their implementation. The case study shows that the proposed process leads to a comprehensive set of safety indicators. It is expected that application of the resulting safety indicators consequently will contribute to safer operation of current and future AMS. - Highlights: • Process for developing safety indicators for autonomous marine systems. • Safety indicators based on safety barriers and resilience thinking. • Location of the development process in the system lifecycle. • Case study on AUV demonstrating applicability of the process.

78 FR 29392 - Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied...

Science.gov (United States)

2013-05-20

... NUCLEAR REGULATORY COMMISSION [NRC-2013-0098] Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied on for Safety AGENCY: Nuclear Regulatory Commission. ACTION... (NRC) is issuing for public comment Draft Regulatory Issue Summary (RIS) 2013-XX, ``Embedded Digital...

The Evolution of System Safety at NASA

Science.gov (United States)

Dezfuli, Homayoon; Everett, Chris; Groen, Frank

2014-01-01

The NASA system safety framework is in the process of change, motivated by the desire to promote an objectives-driven approach to system safety that explicitly focuses system safety efforts on system-level safety performance, and serves to unify, in a purposeful manner, safety-related activities that otherwise might be done in a way that results in gaps, redundancies, or unnecessary work. An objectives-driven approach to system safety affords more flexibility to determine, on a system-specific basis, the means by which adequate safety is achieved and verified. Such flexibility and efficiency is becoming increasingly important in the face of evolving engineering modalities and acquisition models, where, for example, NASA will increasingly rely on commercial providers for transportation services to low-earth orbit. A key element of this objectives-driven approach is the use of the risk-informed safety case (RISC): a structured argument, supported by a body of evidence, that provides a compelling, comprehensible and valid case that a system is or will be adequately safe for a given application in a given environment. The RISC addresses each of the objectives defined for the system, providing a rational basis for making informed risk acceptance decisions at relevant decision points in the system life cycle.

Current status of electron beam processing system and its applications

International Nuclear Information System (INIS)

Taniguchi, S.

2005-01-01

The feature and application fields of electron beam processing systems (EPS), the selection of machine ratings and safety measures for EPS are described. EPS has the various features: a) Chemical reactions occurs independent of the temperature, b) it occurs without any added substances such as catalysts, c) mass productivity, d) easy operation, as is exemplified by switch ON and OFF, and e) easy maintenance, compared with radioisotope sources. After briefly explaining acceleration type (DC or AC), power supply (Van-de-Graaf or Cockcroft-walton and others), beam scanning to be used for large area irradiation, and some typical applications (cross-linking, radical polymerization, the paper describes necessary safety measures such as X-ray shielding, ozone control including ozone generation and its disposal, interlock system, warning buzzer, and monitoring and measuring. (S. Ohno)

Software Quality Assurance for Nuclear Safety Systems

International Nuclear Information System (INIS)

Sparkman, D R; Lagdon, R

2004-01-01

The US Department of Energy has undertaken an initiative to improve the quality of software used to design and operate their nuclear facilities across the United States. One aspect of this initiative is to revise or create new directives and guides associated with quality practices for the safety software in its nuclear facilities. Safety software includes the safety structures, systems, and components software and firmware, support software and design and analysis software used to ensure the safety of the facility. DOE nuclear facilities are unique when compared to commercial nuclear or other industrial activities in terms of the types and quantities of hazards that must be controlled to protect workers, public and the environment. Because of these differences, DOE must develop an approach to software quality assurance that ensures appropriate risk mitigation by developing a framework of requirements that accomplishes the following goals: (sm b ullet) Ensures the software processes developed to address nuclear safety in design, operation, construction and maintenance of its facilities are safe (sm b ullet) Considers the larger system that uses the software and its impacts (sm b ullet) Ensures that the software failures do not create unsafe conditions Software designers for nuclear systems and processes must reduce risks in software applications by incorporating processes that recognize, detect, and mitigate software failure in safety related systems. It must also ensure that fail safe modes and component testing are incorporated into software design. For nuclear facilities, the consideration of risk is not necessarily sufficient to ensure safety. Systematic evaluation, independent verification and system safety analysis must be considered for software design, implementation, and operation. The software industry primarily uses risk analysis to determine the appropriate level of rigor applied to software practices. This risk-based approach distinguishes safety

77 FR 70409 - System Safety Program

Science.gov (United States)

2012-11-26

...-0060, Notice No. 2] 2130-AC31 System Safety Program AGENCY: Federal Railroad Administration (FRA... rulemaking (NPRM) published on September 7, 2012, FRA proposed regulations to require commuter and intercity passenger railroads to develop and implement a system safety program (SSP) to improve the safety of their...

Modelling safety of multistate systems with ageing components

Energy Technology Data Exchange (ETDEWEB)

Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna [Gdynia Maritime University, Department of Mathematics ul. Morska 81-87, Gdynia 81-225 Poland (Poland)

2016-06-08

An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the consecutive “m out of n: F” is presented as well.

Modelling safety of multistate systems with ageing components

International Nuclear Information System (INIS)

Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna

2016-01-01

An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the consecutive “m out of n: F” is presented as well.

Programmable electronic safety systems

International Nuclear Information System (INIS)

Parry, R.R.

1993-01-01

Traditionally safety systems intended for protecting personnel from electrical and radiation hazards at particle accelerator laboratories have made extensive use of electromechanical relays. These systems have the advantage of high reliability and allow the designer to easily implement fail-safe circuits. Relay based systems are also typically simple to design, implement, and test. As systems, such as those presently under development at the Superconducting Super Collider Laboratory (SSCL), increase in size, and the number of monitored points escalates, relay based systems become cumbersome and inadequate. The move toward Programmable Electronic Safety Systems is becoming more widespread and accepted. In developing these systems there are numerous precautions the designer must be concerned with. Designing fail-safe electronic systems with predictable failure states is difficult at best. Redundancy and self-testing are prime examples of features that should be implemented to circumvent and/or detect failures. Programmable systems also require software which is yet another point of failure and a matter of great concern. Therefore the designer must be concerned with both hardware and software failures and build in the means to assure safe operation or shutdown during failures. This paper describes features that should be considered in developing safety systems and describes a system recently installed at the Accelerator Systems String Test (ASST) facility of the SSCL

System safety education focused on industrial engineering

Science.gov (United States)

Johnston, W. L.; Morris, R. S.

1971-01-01

An educational program, designed to train students with the specific skills needed to become safety specialists, is described. The discussion concentrates on application, selection, and utilization of various system safety analytical approaches. Emphasis is also placed on the management of a system safety program, its relationship with other disciplines, and new developments and applications of system safety techniques.

The application of PLC in 60Co container inspection system

International Nuclear Information System (INIS)

Huang Yibin; Xiang Xincheng

2001-01-01

The author discusses the interlock technique of 60 Co container inspection system, and introduces the hardware structure and program of interlock control system using PLC. Due to adopting PLC distributed control, the system works stably and reliably. The successful application of PLC in 60 Co container inspection system has some use for reference in nuclear technology field

Circuits design of action logics of the protection system of nuclear reactor IAN-R1 of Colombia

International Nuclear Information System (INIS)

Gonzalez M, J. L.; Rivero G, T.; Sainz M, E.

2014-10-01

Due to the obsolescence of the instrumentation and control system of the nuclear research reactor IAN-R1, the Institute of Geology and Mining of Colombia, IngeoMinas, launched an international convoking for renewal it which was won by the Instituto Nacional de Investigaciones Nucleares (ININ). Within systems to design, the reactor protection system is described as important for safety, because this carried out, among others two primary functions: 1) ensuring the reactor shutdown safely, and 2) controlling the interlocks to protect against operational errors if defined conditions have not been met. To fulfill these functions, the various subsystems related to the safety report the state in which they are using binary signals and are connected to the inputs of two redundant logic wiring circuits called action logics (Al) that are part of the reactor protection system. These Al also serve as logical interface to indicate at all times the status of subsystems, both the operator and other systems. In the event that any of the subsystems indicates a state of insecurity in the reactor, the Al generate signals off (or scram) of the reactor, maintaining the interlock until the operator sends a reset signal. In this paper the design, implementation, verification and testing of circuits that make up the Al 1 and 2 of IAN-R1 reactor is described, considering the fulfillment of the requirements that the different international standards imposed on this type of design. (Author)

Radiation safety systems at the NSLS

International Nuclear Information System (INIS)

Dickinson, T.

1987-04-01

This report describes design principles that were used to establish the radiation safety systems at the National Synchrotron Light Source. The author described existing safety systems and the history of partial system failures. 1 fig

Shutdown channels and fitted interlocks in atomic reactors; Chaines de securite et verrouillages installes sur les piles atomiques

Energy Technology Data Exchange (ETDEWEB)

Furet, J; Landauer, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

This catalogue consists of tables (one per reactor) giving the following information: number and type of detectors, range of the shutdown channels, nature of the associated electronics, thresholds setting off the alarms, fitted interlocks. These cards have been drawn up with a view to an examination of the reactors safety by the 'Reactor Safety Sub-Commission', they take into account the latest decisions. The reactors involved in this review are: Azur, Cabri, Castor-Pollux, Cesar-Marius-2, Edf-2, EL3, EL4, Eole, G1, G2-G3, Harmonie, Isis, Masurca, Melusine, Minerve, Osiris, Pegase, Peggy, PAT, Rapsodie, SENA, Siloe, Siloette, Triton-Nereide, and Ulysse. (authors) [French] Ce catalogue est compose d'un ensemble de tableaux (a raison de un tableau par pile) donnant les renseignements suivants: nombre et nature des detecteurs, dynamique des chaines, nature de l'electronique associee, seuils provoquant des actions de securite, verrouillages installes. Ces fiches ont ete etablies en vue de l'examen de la securite des piles par la 'Sous-Commission de Surete des Piles', et tiennent compte des decisions de celle-ci. Les reacteurs concernes sont: Azur, Cabri, Cator-Pollux, Cesar-Marius-2, Edf-2, EL3, EL4, Eole, G1, G2-G3, Harmonie, Isis, Masurca, Melusine, Minerve, Osiris, Pegase, Peggy, PAT, Rapsodie, SENA, Siloe, Siloette, Triton-Nereide, et Ulysse. (auteurs)

The NSC 16 MV tandem accelerator control system

International Nuclear Information System (INIS)

Ajith Kumar, B.P.; Kannaiyan, J.; Sugathan, P.; Bhowmik, R.K.

1994-01-01

The computerized control system for the 16 MV Pelletron accelerator at the Nuclear Science Centre runs on a PC-AT 386 computer. Devices in the accelerator are interfaced to the computer by using a CAMAC Serial Highway. The software, written in C, is Database oriented and supports many features useful for the accelerator operation. The control console consists of an EGA monitor, keyboard, assignable control knobs and meters, a diagrammatic display showing the overall status of the machine and a similar panel for showing the status of radiation safety interlocks. The system has been operational for the past three years and is discussed below. (orig.)

Role of systems safety in maintaining affordable safety in the 1980's

International Nuclear Information System (INIS)

Hollister, H.; Trauth, C.A. Jr.

1979-01-01

Historically, the Department of Energy and its predecessors have used and supported the development of systems safety programs, practices, and principles, finding them by and large adequate, effective, and managerially efficient. Today, attempts are bing made to resolve increasingly complex environmental, safety, and health problems by turning to increasingly complex and detailed regulation as the primary governmental answer. It is increasingly doubtful that such an approach will provide management of these issues and problems that is either effective or efficient. Challenge is issued to those in systems safety to develop and apply systems safety principles and practices more broadly to total operational systems and not just to hardware and to environmental and health protection and not just to safety, so that the total universe of environmental, safety, and health can be managed effectively and efficiently with encouragement of innovation and creativity, using a relatively brief and concise, but adequate, regulatory base

Systems Safety and Engineering Division

Data.gov (United States)

Federal Laboratory Consortium — Volpe's Systems Safety and Engineering Division conducts engineering, research, and analysis to improve transportation safety, capacity, and resiliency. We provide...

Design for safety: theoretical framework of the safety aspect of BIM system to determine the safety index

Directory of Open Access Journals (Sweden)

Ai Lin Evelyn Teo

2016-12-01

Full Text Available Despite the safety improvement drive that has been implemented in the construction industry in Singapore for many years, the industry continues to report the highest number of workplace fatalities, compared to other industries. The purpose of this paper is to discuss the theoretical framework of the safety aspect of a proposed BIM System to determine a Safety Index. An online questionnaire survey was conducted to ascertain the current workplace safety and health situation in the construction industry and explore how BIM can be used to improve safety performance in the industry. A safety hazard library was developed based on the main contributors to fatal accidents in the construction industry, determined from the formal records and existing literature, and a series of discussions with representatives from the Workplace Safety and Health Institute (WSH Institute in Singapore. The results from the survey suggested that the majority of the firms have implemented the necessary policies, programmes and procedures on Workplace Safety and Health (WSH practices. However, BIM is still not widely applied or explored beyond the mandatory requirement that building plans should be submitted to the authorities for approval in BIM format. This paper presents a discussion of the safety aspect of the Intelligent Productivity and Safety System (IPASS developed in the study. IPASS is an intelligent system incorporating the buildable design concept, theory on the detection, prevention and control of hazards, and the Construction Safety Audit Scoring System (ConSASS. The system is based on the premise that safety should be considered at the design stage, and BIM can be an effective tool to facilitate the efforts to enhance safety performance. IPASS allows users to analyse and monitor key aspects of the safety performance of the project before the project starts and as the project progresses.

Improved safety of the system 80+TM standard plants design through increased diversity and redundancy of safety systems

International Nuclear Information System (INIS)

Matzie, Regis A.; Carpentino, Frederick L.; Robertson, James E.

1996-01-01

Safely systems in the System 80+ TM Standard Plant are designed with more redundancy, diversity and simplicity than earlier nuclear power plant designs. These gains were accomplished by an evolutionary process that preserved the desirable and proven features in currently operating nuclear plants, while improving reliability and defense-in-depth. The System 80+ safety systems are the primary contributors to a core damage frequency that is more than 100 times lower than 1980's vintage U. S. designs, including the predecessor System 80 R standard nuclear steam supply system (NSSS) design. The System 80+ design includes significant improvements to the safety injection system, emergency feedwater system, shutdown cooling system, containment spray system, reactor coolant gas vent system, and to their vital support systems. These improvements enhance performance for traditional design basis events and significantly reduce the probability of a severe accident. The System 80+ design also incorporates safety systems to mitigate a severe accident. The added systems include the rapid depressurization system, the in-containment refueling water storage tank, the cavity flooding system. These systems fully address the U. S. Nuclear Regulatory Commission's (US NRC) severe accident policy. The System 80+ safety systems are integrated with the System 80+ Nuclear Island (NI) design. The NI general arrangement provides quadrant separation of the safety systems for protection from fire and flooding, and large equipment pull spaces and lay down areas for maintenance. This paper will describe the System 80+ safety systems advanced design features, the improved accident prevention and mitigation capabilities, and startup, operating and maintenance benefits

Product Engineering Class in the Software Safety Risk Taxonomy for Building Safety-Critical Systems

Science.gov (United States)

Hill, Janice; Victor, Daniel

2008-01-01

When software safety requirements are imposed on legacy safety-critical systems, retrospective safety cases need to be formulated as part of recertifying the systems for further use and risks must be documented and managed to give confidence for reusing the systems. The SEJ Software Development Risk Taxonomy [4] focuses on general software development issues. It does not, however, cover all the safety risks. The Software Safety Risk Taxonomy [8] was developed which provides a construct for eliciting and categorizing software safety risks in a straightforward manner. In this paper, we present extended work on the taxonomy for safety that incorporates the additional issues inherent in the development and maintenance of safety-critical systems with software. An instrument called a Software Safety Risk Taxonomy Based Questionnaire (TBQ) is generated containing questions addressing each safety attribute in the Software Safety Risk Taxonomy. Software safety risks are surfaced using the new TBQ and then analyzed. In this paper we give the definitions for the specialized Product Engineering Class within the Software Safety Risk Taxonomy. At the end of the paper, we present the tool known as the 'Legacy Systems Risk Database Tool' that is used to collect and analyze the data required to show traceability to a particular safety standard

Software system safety

Science.gov (United States)

Uber, James G.

1988-01-01

Software itself is not hazardous, but since software and hardware share common interfaces there is an opportunity for software to create hazards. Further, these software systems are complex, and proven methods for the design, analysis, and measurement of software safety are not yet available. Some past software failures, future NASA software trends, software engineering methods, and tools and techniques for various software safety analyses are reviewed. Recommendations to NASA are made based on this review.

Probabilistic safety criteria at the safety function/system level

International Nuclear Information System (INIS)

1989-09-01

A Technical Committee Meeting was held in Vienna, Austria, from 26-30 January 1987. The objectives of the meeting were: to review the national developments of PSC at the level of safety functions/systems including future trends; to analyse basic principles, assumptions, and objectives; to compare numerical values and the rationale for choosing them; to compile the experience with use of such PSC; to analyse the role of uncertainties in particular regarding procedures for showing compliance. The general objective of establishing PSC at the level of safety functions/systems is to provide a pragmatic tool to evaluate plant safety which is placing emphasis on the prevention principle. Such criteria could thus lead to a better understanding of the importance to safety of the various functions which have to be performed to ensure the safety of the plant, and the engineering means of performing these functions. They would reflect the state-of-the-art in modern PSAs and could contribute to a balance in system design. This report, prepared by the participants of the meeting, reviews the current status and future trends in the field and should assist Member States in developing their national approaches. The draft of this document was also submitted to INSAG to be considered in its work to prepare a document on safety principles for nuclear power plants. Five papers presented at the meeting are also included in this publication. A separate abstract was prepared for each of these papers. Refs, figs and tabs

Reactor Safety Assessment System

International Nuclear Information System (INIS)

Sebo, D.E.; Bray, M.A.; King, M.A.

1987-01-01

The Reactor Safety Assessment System (RSAS) is an expert system under development for the United States Nuclear Regulatory Commission (USNRC). RSAS is designed for use at the USNRC Operations Center in the event of a serious incident at a licensed nuclear power plant. RSAS is a situation assessment expert system which uses plant parametric data to generate conclusions for use by the NRC Reactor Safety Team. RSAS uses multiple rule bases and plant specific setpoint files to be applicable to all licensed nuclear power plants in the United States. RSAS currently covers several generic reactor categories and multiple plants within each category

Reactor safety assessment system

International Nuclear Information System (INIS)

Sebo, D.E.; Bray, M.A.; King, M.A.

1987-01-01

The Reactor Safety Assessment System (RSAS) is an expert system under development for the United States Nuclear Regulatory Commission (USNRC). RSA is designed for use at the USNRC Operations Center in the event of a serious incident at a licensed nuclear power plant. RSAS is a situation assessment expert system which uses plant parametric data to generate conclusions for use by the NRC Reactor Safety Team. RSAS uses multiple rule bases and plant specific setpoint files to be applicable to all licensed nuclear power plants in the United States. RSAS currently covers several generic reactor categories and multiple plants within each category

Safety systems and safety analysis of the Qinshan phase III CANDU nuclear power plant

International Nuclear Information System (INIS)

Cai Jianping; Shen Sen; Barkman, N.

1999-01-01

The author introduces the Canadian nuclear reactor safety philosophy and the Qinshan Phase III CANDU NPP safety systems and safety analysis, which are designed and performed according to this philosophy. The concept of 'defence-in-depth' is a key element of the Canadian nuclear reactor safety philosophy. The design concepts of redundancy, diversity, separation, equipment qualification, quality assurance, and use of appropriate design codes and standards are adopted in the design. Four special safety systems as well as a set of reliable safety support systems are incorporated in the design of Qinshan phase III CANDU for accident mitigation. The assessment results for safety systems performance show that the fundamental safety criteria for public dose, and integrity of fuel, channels and the reactor building, are satisfied

South Ukraine NPP: Safety improvements through Plant Computer upgrade

International Nuclear Information System (INIS)

Brenman, O.; Chernyshov, M. A.; Denning, R. S.; Kolesov, S. A.; Balakan, H. H.; Bilyk, B. I.; Kuznetsov, V. I.; Trosman, G.

2006-01-01

This paper summarizes some results of the Plant Computer upgrade at the Units 2 and 3 of South Ukraine Nuclear Power Plant (NPP). A Plant Computer, which is also called the Computer Information System (CIS), is one of the key safety-related systems at VVER-1000 nuclear plants. The main function of the CIS is information support for the plant operators during normal and emergency operational modes. Before this upgrade, South Ukraine NPP operated out-of-date and obsolete systems. This upgrade project wax founded by the U.S. DOE in the framework of the International Nuclear Safety Program (INSP). The most efficient way to improve the quality and reliability of information provided to the plant operator is to upgrade the Human-System Interface (HSI), which is the Upper Level (UL) CIS. The upgrade of the CIS data-acquisition system (DAS), which is the Lower Level (LL) CIS, would have less effect on the unit safety. Generally speaking, the lifetime of the LL CIS is much higher than one of the UL CIS. Unlike Plant Computers at the Western-designed plants, the functionality of the WER-1000 CISs includes a control function (Centralized Protection Testing) and a number of the plant equipment monitoring functions, for example, Protection and Interlock Monitoring and Turbo-Generator Temperature Monitoring. The new system is consistent with a historical migration of the format by which information is presented to the operator away from the traditional graphic displays, for example, Piping and Instrument Diagrams (P and ID's), toward Integral Data displays. The cognitive approach to information presentation is currently limited by some licensing issues, but is adapted to a greater degree with each new system. The paper provides some lessons learned on the management of the international team. (authors)

Coalescence of 3-phenyl-propynenitrile on Cu(111) into interlocking pinwheel chains

Science.gov (United States)

Luo, Miaomiao; Lu, Wenhao; Kim, Daeho; Chu, Eric; Wyrick, Jon; Holzke, Connor; Salib, Daniel; Cohen, Kamelia D.; Cheng, Zhihai; Sun, Dezheng; Zhu, Yeming; Einstein, T. L.; Bartels, Ludwig

2011-10-01

3-phenyl-propynenitrile (PPN) adsorbs on Cu(111) in a hexagonal network of molecular trimers formed through intermolecular interaction of the cyano group of one molecule with the aromatic ring of its neighbor. Heptamers of trimers coalesce into interlocking pinwheel-shaped structures that, by percolating across islands of the original trimer coverage, create the appearance of gear chains. Density functional theory aids in identifying substrate stress associated with the chemisorption of PPN's acetylene group as the cause of this transition.

Food safety performance indicators to benchmark food safety output of food safety management systems.

Science.gov (United States)

Jacxsens, L; Uyttendaele, M; Devlieghere, F; Rovira, J; Gomez, S Oses; Luning, P A

2010-07-31

There is a need to measure the food safety performance in the agri-food chain without performing actual microbiological analysis. A food safety performance diagnosis, based on seven indicators and corresponding assessment grids have been developed and validated in nine European food businesses. Validation was conducted on the basis of an extensive microbiological assessment scheme (MAS). The assumption behind the food safety performance diagnosis is that food businesses which evaluate the performance of their food safety management system in a more structured way and according to very strict and specific criteria will have a better insight in their actual microbiological food safety performance, because food safety problems will be more systematically detected. The diagnosis can be a useful tool to have a first indication about the microbiological performance of a food safety management system present in a food business. Moreover, the diagnosis can be used in quantitative studies to get insight in the effect of interventions on sector or governmental level. Copyright 2010 Elsevier B.V. All rights reserved.

40 CFR Appendix D to Subpart S of... - Steady-State Short Test Equipment

Science.gov (United States)

2010-07-01

... contaminate or change the character of the gases to be analyzed, including gases from alcohol fueled vehicles... resolution and accuracy of at least 1 mph. (7) Safety interlock. A roll speed sensor and safety interlock...

Safety-critical Java for embedded systems

DEFF Research Database (Denmark)

Schoeberl, Martin; Dalsgaard, Andreas Engelbredt; Hansen, René Rydhof

2016-01-01

This paper presents the motivation for and outcomes of an engineering research project on certifiable Javafor embedded systems. The project supports the upcoming standard for safety-critical Java, which defines asubset of Java and libraries aiming for development of high criticality systems....... The outcome of this projectinclude prototype safety-critical Java implementations, a time-predictable Java processor, analysis tools formemory safety, and example applications to explore the usability of safety-critical Java for this applicationarea. The text summarizes developments and key contributions...

A study of software safety analysis system for safety-critical software

International Nuclear Information System (INIS)

Chang, H. S.; Shin, H. K.; Chang, Y. W.; Jung, J. C.; Kim, J. H.; Han, H. H.; Son, H. S.

2004-01-01

The core factors and requirements for the safety-critical software traced and the methodology adopted in each stage of software life cycle are presented. In concept phase, Failure Modes and Effects Analysis (FMEA) for the system has been performed. The feasibility evaluation of selected safety parameter was performed and Preliminary Hazards Analysis list was prepared using HAZOP(Hazard and Operability) technique. And the check list for management control has been produced via walk-through technique. Based on the evaluation of the check list, activities to be performed in requirement phase have been determined. In the design phase, hazard analysis has been performed to check the safety capability of the system with regard to safety software algorithm using Fault Tree Analysis (FTA). In the test phase, the test items based on FMEA have been checked for fitness guided by an accident scenario. The pressurizer low pressure trip algorithm has been selected to apply FTA method to software safety analysis as a sample. By applying CASE tool, the requirements traceability of safety critical system has been enhanced during all of software life cycle phases

Event notification system with a PLC

International Nuclear Information System (INIS)

Kawase, M.; Yoshikawa, Hiroshi; Sakaki, Hironao; Takahashi, Hiroki; Sako, Hiroyuki; Kamiya, Junichiro; Takayanagi, Tomohiro

2004-01-01

When an interlock occurs in the equipment, it is required to notify the upper rank control system of the Interlock and receive information for apparatus information in the upper rank control system as at high speed as possible. In the apparatus using FA-M3, it can respond to this by using the notice function of an event. This report shows the event notification system with a PLC based Kicker electromagnet power supply for 3GeV RCS. (author)

Safety assessment for Generation IV nuclear systems

International Nuclear Information System (INIS)

Leahy, T.J.

2012-01-01

The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Recent RSWG work has focused on the definition of an integrated safety assessment methodology (ISAM) for evaluating the safety of Generation IV systems. ISAM is an integrated 'tool-kit' consisting of 5 analytical techniques that are available and matched to appropriate stages of Generation IV system concept development: 1) qualitative safety features review - QSR, 2) phenomena identification and ranking table - PIRT, 3) objective provision tree - OPT, 4) deterministic and phenomenological analyses - DPA, and 5) probabilistic safety analysis - PSA. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time

OBTAINING FOOD SAFETY BY APPLYING HACCP SYSTEM

Directory of Open Access Journals (Sweden)

ION CRIVEANU

2012-01-01

Full Text Available In order to increase the confidence of the trading partners and consumers in the products which are sold on the market, enterprises producing food are required to implement the food safety system HACCP,a particularly useful system because the manufacturer is not able to fully control finished products . SR EN ISO 22000:2005 establishes requirements for a food safety management system where an organization in the food chain needs to proove its ability to control food safety hazards in order to ensure that food is safe at the time of human consumption. This paper presents the main steps which ensure food safety using the HACCP system, and SR EN ISO 20000:2005 requirements for food safety.

Industrial Personal Computer based Display for Nuclear Safety System

International Nuclear Information System (INIS)

Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min

2014-01-01

The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view

Industrial Personal Computer based Display for Nuclear Safety System

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min [KEPCO, Youngin (Korea, Republic of)

2014-08-15

The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view.

Artificial nanomachines based on interlocked molecules

International Nuclear Information System (INIS)

Credi, Alberto

2006-01-01

The extension of the concept of machine to the molecular level is of great interest for the growth of nanoscience and the development of nanotechnology. A molecular machine can be defined as an assembly of a discrete number of molecular components (that is, a supramolecular structure) designed to perform a function through the mechanical movements of its components, which occur under appropriate external stimulation. Hence, molecular machines contain a motor part, that is a device capable of converting energy into mechanical work. Molecular motors and machines operate via nuclear rearrangements and, like their macroscopic counterparts, are characterized by the kind of energy input supplied to make them work, the manner in which their operation can be monitored, the possibility to repeat the operation at will, i.e., establishing a cyclic process, the timescale needed to complete a cycle of operation, and the performed function. Owing to the progresses made in several branches of chemistry, and to the better understanding of the operation mechanisms of molecular machines of the biological world, it has become possible to design and construct simple prototypes of artificial molecular motors and machines. Some examples based on rotaxanes, catenanes, and related interlocked molecules will be described

Cost benefit analysis of reactor safety systems

International Nuclear Information System (INIS)

Maurer, H.A.

1984-01-01

Cost/benefit analysis of reactor safety systems is a possibility appropriate to deal with reactor safety. The Commission of the European Communities supported a study on the cost-benefit or cost effectiveness of safety systems installed in modern PWR nuclear power plants. The following systems and their cooperation in emergency cases were in particular investigated in this study: the containment system (double containment), the leakage exhaust and control system, the annulus release exhaust system and the containment spray system. The benefit of a safety system is defined according to its contribution to the reduction of the radiological consequences for the environment after a LOCA. The analysis is so far performed in two different steps: the emergency core cooling system is considered to function properly, failure of the emergency core cooling system is assumed (with the possible consequence of core melt-down) and the results may demonstrate the evidence that striving for cost-effectiveness can produce a safer end result than the philosophy of safety at any cost. (orig.)

Safer Systems: A NextGen Aviation Safety Strategic Goal

Science.gov (United States)

Darr, Stephen T.; Ricks, Wendell R.; Lemos, Katherine A.

2008-01-01

The Joint Planning and Development Office (JPDO), is charged by Congress with developing the concepts and plans for the Next Generation Air Transportation System (NextGen). The National Aviation Safety Strategic Plan (NASSP), developed by the Safety Working Group of the JPDO, focuses on establishing the goals, objectives, and strategies needed to realize the safety objectives of the NextGen Integrated Plan. The three goal areas of the NASSP are Safer Practices, Safer Systems, and Safer Worldwide. Safer Practices emphasizes an integrated, systematic approach to safety risk management through implementation of formalized Safety Management Systems (SMS) that incorporate safety data analysis processes, and the enhancement of methods for ensuring safety is an inherent characteristic of NextGen. Safer Systems emphasizes implementation of safety-enhancing technologies, which will improve safety for human-centered interfaces and enhance the safety of airborne and ground-based systems. Safer Worldwide encourages coordinating the adoption of the safer practices and safer systems technologies, policies and procedures worldwide, such that the maximum level of safety is achieved across air transportation system boundaries. This paper introduces the NASSP and its development, and focuses on the Safer Systems elements of the NASSP, which incorporates three objectives for NextGen systems: 1) provide risk reducing system interfaces, 2) provide safety enhancements for airborne systems, and 3) provide safety enhancements for ground-based systems. The goal of this paper is to expose avionics and air traffic management system developers to NASSP objectives and Safer Systems strategies.

Interlocking Toy Building Blocks as Hands-On Learning Modules for Blind and Visually Impaired Chemistry Students

Science.gov (United States)

Melaku, Samuel; Schreck, James O.; Griffin, Kameron; Dabke, Rajeev B.

2016-01-01

Interlocking toy building blocks (e.g., Lego) as chemistry learning modules for blind and visually impaired (BVI) students in high school and undergraduate introductory or general chemistry courses are presented. Building blocks were assembled on a baseplate to depict the relative changes in the periodic properties of elements. Modules depicting…

An elevator for cobalt-60 source

International Nuclear Information System (INIS)

Tang Zaimin; Liang Donghu

1990-07-01

The elevator used for cobalt-60 source is a key device in the irradiation industry. It plays an important role in the safety and control of irradiation operation as well as the utilization rate of radiation source. From 1983 to 1986, Beijing Institute of Nuclear Engineering undertook designing of various size irradiation projects for different uses. Since then a kind of cobalt-60 source elevator suited for the irradiator of wet-source-storage has been chosen. It is reliable in the operation and complete in the function. An automatic control circuit brings the systems of cobalt-60 source elevator into an interlock system which ensures the irradiation operation safety. Besides introducing the structural features and performance of this elevator, the conditions of safety interlocking in raising or lowering the cobalt-60 source is also discussed. The discussion is from the safety viewpoint of operating an irradiator and irradiation technology

Development of digital safety system logic and control

International Nuclear Information System (INIS)

Nishikawa, H.; Sakamoto, H.

1995-01-01

Advanced-BWR (ABWR) uses total digital control and instrumentation (C and I) system. In particular, ABWR adopts a newly developed safety system using advanced digital technology. In the presentation the digital safety system design, manufacturing and factory validation test method are shortly overviewed. The digital safety system consists of micro-processor based digital controllers, data and information transmission by optical fibers and human-machine interface using color flat displays. This new developed safety system meet the nuclear safety requirements such as high reliability, independence of divisions, operability and maintainability. (2 refs., 4 figs., 1 tab.)

Six sigma tools for a patient safety-oriented, quality-checklist driven radiation medicine department.

Science.gov (United States)

Kapur, Ajay; Potters, Louis

2012-01-01

The purpose of this work was to develop and implement six sigma practices toward the enhancement of patient safety in an electronic, quality checklist-driven, multicenter, paperless radiation medicine department. A quality checklist process map (QPM), stratified into consultation through treatment-completion stages was incorporated into an oncology information systems platform. A cross-functional quality management team conducted quality-function-deployment and define-measure-analyze-improve-control (DMAIC) six sigma exercises with a focus on patient safety. QPM procedures were Pareto-sorted in order of decreasing patient safety risk with failure mode and effects analysis (FMEA). Quantitative metrics for a grouped set of highest risk procedures were established. These included procedural delays, associated standard deviations and six sigma Z scores. Baseline performance of the QPM was established over the previous year of usage. Data-driven analysis led to simplification, standardization, and refinement of the QPM with standard deviation, slip-day reduction, and Z-score enhancement goals. A no-fly policy (NFP) for patient safety was introduced at the improve-control DMAIC phase, with a process map interlock imposed on treatment initiation in the event of FMEA-identified high-risk tasks being delayed or not completed. The NFP was introduced in a pilot phase with specific stopping rules and the same metrics used for performance assessments. A custom root-cause analysis database was deployed to monitor patient safety events. Relative to the baseline period, average slip days and standard deviations for the risk-enhanced QPM procedures improved by over threefold factors in the NFP period. The Z scores improved by approximately 20%. A trend for proactive delays instead of reactive hard stops was observed with no adverse effects of the NFP. The number of computed potential no-fly delays per month dropped from 60 to 20 over a total of 520 cases. The fraction of computed

A comparative study of intramedullary interlocking nailing and minimally invasive plate osteosynthesis in extra articular distal tibial fractures.

Science.gov (United States)

Daolagupu, Arup K; Mudgal, Ashwani; Agarwala, Vikash; Dutta, Kaushik K

2017-01-01

Extraarticular distal tibial fractures are among the most challenging fractures encountered by an orthopedician for treatment because of its subcutaneous location, poor blood supply and decreased muscular cover anteriorly, complications such as delayed union, nonunion, wound infection, and wound dehiscence are often seen as a great challenge to the surgeon. Minimally invasive plate osteosynthesis (MIPO) and intramedullary interlocking nail (IMLN) are two well-accepted and effective methods, but each has been historically related to complications. This study compares clinical and radiological outcome in extraarticular distal tibia fractures treated by intramedullary interlocking nail (IMLN) and minimally invasive plate osteosynthesis (MIPO). 42 patients included in this study, 21 underwent IMLN and 21 were treated with MIPO who met the inclusion criteria and operated between June 2014 and May 2015. Patients were followed up for clinical and radiological evaluation. In IMLN group, average union time was 18.26 weeks compared to 21.70 weeks in plating group which was significant ( P ankle stiffness, and infection, were seen in interlocking group as compared to plating group. Average functional outcome according to American Orthopedic Foot and Ankle Society score was measured which came out to be 96.67. IMLN group was associated with lesser duration of surgery, earlier weight bearing and union rate, lesser incidence of infection and implant irritation which makes it a preferable choice for fixation of extra-articular distal tibial fractures. However, larger randomized controlled trials are required for confirming the results.

Safety features of subcritical fluid fueled systems

International Nuclear Information System (INIS)

Bell, C.R.

1995-01-01

Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible

Safety features of subcritical fluid fueled systems

International Nuclear Information System (INIS)

Bell, C.R.

1994-01-01

Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved in very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible

Safety features of subcritical fluid fueled systems

Energy Technology Data Exchange (ETDEWEB)

Bell, C.R. [Los Alamos National Laboratory, NM (United States)

1995-10-01

Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible.

77 FR 11120 - Patient Safety Organizations: Voluntary Relinquishment From UAB Health System Patient Safety...

Science.gov (United States)

2012-02-24

... Organizations: Voluntary Relinquishment From UAB Health System Patient Safety Organization AGENCY: Agency for... notification of voluntary relinquishment from the UAB Health System Patient Safety Organization of its status as a Patient Safety Organization (PSO). The Patient Safety and Quality Improvement Act of 2005...

Safety Justification and Safety Case for Safety-critical Software in Digital Reactor Protection System

International Nuclear Information System (INIS)

Kwon, Kee-Choon; Lee, Jang-Soo; Jee, Eunkyoung

2016-01-01

Nuclear safety-critical software is under strict regulatory requirements and these regulatory requirements are essential for ensuring the safety of nuclear power plants. The verification & validation (V and V) and hazard analysis of the safety-critical software are required to follow regulatory requirements through the entire software life cycle. In order to obtain a license from the regulatory body through the development and validation of safety-critical software, it is essential to meet the standards which are required by the regulatory body throughout the software development process. Generally, large amounts of documents, which demonstrate safety justification including standard compliance, V and V, hazard analysis, and vulnerability assessment activities, are submitted to the regulatory body during the licensing process. It is not easy to accurately read and evaluate the whole documentation for the development activities, implementation technology, and validation activities. The safety case methodology has been kwon a promising approach to evaluate the level and depth of the development and validation results. A safety case is a structured argument, supported by a body of evidence that provides a compelling, comprehensible, and valid case that a system is safe for a given application in a given operating environment. It is suggested to evaluate the level and depth of the results of development and validation by applying safety case methodology to achieve software safety demonstration. A lot of documents provided as evidence are connected to claim that corresponds to the topic for safety demonstration. We demonstrated a case study in which more systematic safety demonstration for the target system software is performed via safety case construction than simply listing the documents

Safety Justification and Safety Case for Safety-critical Software in Digital Reactor Protection System

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kee-Choon; Lee, Jang-Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jee, Eunkyoung [KAIST, Daejeon (Korea, Republic of)

2016-10-15

Nuclear safety-critical software is under strict regulatory requirements and these regulatory requirements are essential for ensuring the safety of nuclear power plants. The verification & validation (V and V) and hazard analysis of the safety-critical software are required to follow regulatory requirements through the entire software life cycle. In order to obtain a license from the regulatory body through the development and validation of safety-critical software, it is essential to meet the standards which are required by the regulatory body throughout the software development process. Generally, large amounts of documents, which demonstrate safety justification including standard compliance, V and V, hazard analysis, and vulnerability assessment activities, are submitted to the regulatory body during the licensing process. It is not easy to accurately read and evaluate the whole documentation for the development activities, implementation technology, and validation activities. The safety case methodology has been kwon a promising approach to evaluate the level and depth of the development and validation results. A safety case is a structured argument, supported by a body of evidence that provides a compelling, comprehensible, and valid case that a system is safe for a given application in a given operating environment. It is suggested to evaluate the level and depth of the results of development and validation by applying safety case methodology to achieve software safety demonstration. A lot of documents provided as evidence are connected to claim that corresponds to the topic for safety demonstration. We demonstrated a case study in which more systematic safety demonstration for the target system software is performed via safety case construction than simply listing the documents.

Radiological and the other safety aspects in the operation of electron beam facility

International Nuclear Information System (INIS)

Loterina, Roel Alamares

2003-01-01

The radiological safety aspects of the operation of an electron beam facility in general and the 3 MeV ALURTRON electron beam facility of the Malaysian Institute of Nuclear Technology Research (MINT) in particular were reviewed and evaluated. Evaluation was made based on existing records as well as actual monitoring around facility. Area monitoring results using TLDs are within permissible levels. The maximum reading of 7.29 mSv measured in year 2000 is very low as compared to the annual dose limit of 50 mSv/year. In general, the shielding for the installation is adequate and no significant radiation leakage were detected based on radiation survey results. However, measured radiation levels with a maximum of 1.9 mSv/h at the sampling ports easily exceed the limit of 25μSv/h. The facility is equipped with safety features, such as interlocked system, adequate shielding, engineered safety design of irradiation and accelerator rooms, and accessories such as conveyor system and product handling system. Warning lights and signals are adequately installed around the facility. Other identified hazards that may affect the operator, workers, and personnel were also evaluated based on previous records of monitoring. The ozone concentration levels with a maximum reading of 0.05 ppm measured in the environment of the facility are within the threshold limit value of 0.1 ppm. The measured noise levels at all locations around facility are generally below the maximum permissible level of 80dB. The ALURTRON has achieved a minimum safety requirement to warrant its full operation without relying on administrative controls and procedures to ensure safety in operation. (Auth.)

INTEGRATED SAFETY MANAGEMENT SYSTEM IN AIR TRAFFIC SERVICES

Directory of Open Access Journals (Sweden)

Volodymyr Kharchenko

2014-06-01

Full Text Available The article deals with the analysis of the researches conducted in the field of safety management systems.Safety management system framework, methods and tools for safety analysis in Air Traffic Control have been reviewed.Principles of development of Integrated safety management system in Air Traffic Services have been proposed.

Analysis and design on airport safety information management system

Directory of Open Access Journals (Sweden)

Yan Lin

2017-01-01

Full Text Available Airport safety information management system is the foundation of implementing safety operation, risk control, safety performance monitor, and safety management decision for the airport. The paper puts forward the architecture of airport safety information management system based on B/S model, focuses on safety information processing flow, designs the functional modules and proposes the supporting conditions for system operation. The system construction is helpful to perfecting the long effect mechanism driven by safety information, continually increasing airport safety management level and control proficiency．

Development of an access control system for the LHD experimental hall

International Nuclear Information System (INIS)

Kawano, T.; Inoue, N.; Sakuma, Y.; Uda, T.; Yamanishi, H.; Miyake, H.; Tanahashi, S.; Motozima, O.

2000-01-01

An access control system for the LHD (Large Helical Device) experimental hall had been constructed and its practical operation started in March 1998. Continuously, the system has been improved. The present system keeps watch on involved entrance and exit for the use of persons at four entrances by using five turnstile gates while watching on eight shielding doors at eight positions (four entrances, three carriage entrances and a hall overview) and a stairway connecting the LHD main hall with the LHD basement. Besides, for the security of safety operation of the LHD, fifteen kinds of interlock signals are exchanged between the access control system and the LHD control system. Seven of the interlock signals are properly sent as the occasional demands from the access control system to the LHD control system, in which three staple signals are B Personnel Access to Controlled Area, D Shielding Door Closed, and E No Entrance. It is important that any plasma experiments of the LHD are not permitted while the signal B being sent or D being not sent. The signal E is sent to inform the LHD control system that the turnstile gates are locked. All the plasma experiments should not be done unless the lock procedure of the turnstile is confirmed. When the turnstile gates are locked, any persons cannot enter into the LHD controlled area, but are permissible to exit only. Six of the interlock signals are used to send the information of the working at that time in the LHD controlled area to the access control system. When one signal of the operation mode is sent to the access control system from the LHD, the access control system sets the turnstile gate in situation corresponding to the operation mode, A Equipment Operation, B Vacuum Pumping, C Coil Cooling, D Coil Excitation, and E Plasma Experiment. If the access control system receives, for example, the signal B, this system sets the turnstile gate in the condition of control such that only persons assigned to the work of vacuum

System theory and safety models in Swedish, UK, Dutch and Australian road safety strategies.

Science.gov (United States)

Hughes, B P; Anund, A; Falkmer, T

2015-01-01

Road safety strategies represent interventions on a complex social technical system level. An understanding of a theoretical basis and description is required for strategies to be structured and developed. Road safety strategies are described as systems, but have not been related to the theory, principles and basis by which systems have been developed and analysed. Recently, road safety strategies, which have been employed for many years in different countries, have moved to a 'vision zero', or 'safe system' style. The aim of this study was to analyse the successful Swedish, United Kingdom and Dutch road safety strategies against the older, and newer, Australian road safety strategies, with respect to their foundations in system theory and safety models. Analysis of the strategies against these foundations could indicate potential improvements. The content of four modern cases of road safety strategy was compared against each other, reviewed against scientific systems theory and reviewed against types of safety model. The strategies contained substantial similarities, but were different in terms of fundamental constructs and principles, with limited theoretical basis. The results indicate that the modern strategies do not include essential aspects of systems theory that describe relationships and interdependencies between key components. The description of these strategies as systems is therefore not well founded and deserves further development. Copyright © 2014 Elsevier Ltd. All rights reserved.

Study on 'Safety qualification of process computers used in safety systems of nuclear power plants'

International Nuclear Information System (INIS)

Bertsche, K.; Hoermann, E.

1991-01-01

The study aims at developing safety standards for hardware and software of computer systems which are increasingly used also for important safety systems in nuclear power plants. The survey of the present state-of-the-art of safety requirements and specifications for safety-relevant systems and, additionally, for process computer systems has been compiled from national and foreign rules. In the Federal Republic of Germany the KTA safety guides and the BMI/BMU safety criteria have to be observed. For the design of future computer-aided systems in nuclear power plants it will be necessary to apply the guidelines in [DIN-880] and [DKE-714] together with [DIN-192]. With the aid of a risk graph the various functions of a system, or of a subsystem, can be evaluated with regard to their significance for safety engineering. (orig./HP) [de

Design an optimum safety policy for personnel safety management - A system dynamic approach

International Nuclear Information System (INIS)

Balaji, P.

2014-01-01

Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making

Design an optimum safety policy for personnel safety management - A system dynamic approach

Energy Technology Data Exchange (ETDEWEB)

Balaji, P. [The Glocal University, Mirzapur Pole, Delhi- Yamuntori Highway, Saharanpur 2470001 (India)

2014-10-06

Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making.

Design an optimum safety policy for personnel safety management - A system dynamic approach

Science.gov (United States)

Balaji, P.

2014-10-01

Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making.

Prospect, Practices and Safety for Quality Management of the Gamma Greenhouse, a Novel Facility for Chronic Gamma Radiation

International Nuclear Information System (INIS)

Azhar Mohamad; Sobri Hussein; Abdul Rahim Harun; Ahsanulkhaliqin Abdul Wahab

2012-01-01

Malaysia has a special facility for chronic irradiation, known as the Gamma Greenhouse (GGH), located at MINT-Tech Park in Jalan Dengkil, Malaysian Nuclear Agency (Nuclear Malaysia). The Gamma Greenhouse source of chronic irradiation comes from a 137 Cs double encapsulated 800 Ci Cesium-137 pencil, producing a low dose rate, which is considered to be more effective in recovering and producing useful mutants in comparison to acute irradiation at higher dose. The irradiation facility comprises an open-topped irradiation area, 30 m in diameter, protected by a partial concrete wall, with entrance maze and site topography. High safety features are in place, where the facility is protected by a sophisticated interlock system that only allows the source to be exposed when all the prerequisite safety conditions are met, and automatically returns the source to the safe storage position if any safety device is compromised. The main irradiation area is further protected by a 300 m diameter exclusion zone that is also protected by the safety interlock circuit. The facility can accommodate a wide range of plant materials such as seeds, seedlings in pots, cuttings, calluses, somatic embryos and suspension cell cultures. In practice, plant samples will be exposed to low dose gamma radiation over long periods of time (hours, weeks, months), depending on their nature and sensitivity. All procedures generate data for evaluation, which require accuracy; quality management is essential in irradiation service. The prospect of the gamma greenhouse is in research and services on induced mutation techniques for the improvement of plant varieties and microbe strains. Services are provided to academicians, planters, students and researchers working with plants and microorganisms. In addition, it is also useful in the teaching and training on breeding, nuclear and radiation technology. The activities in utilization the gamma greenhouse cover mainly Research and Development, Research

"Fabrication of arbitrarily shaped carbonate apatite foam based on the interlocking process of dicalcium hydrogen phosphate dihydrate".

Science.gov (United States)

Sugiura, Yuki; Tsuru, Kanji; Ishikawa, Kunio

2017-08-01

Carbonate apatite (CO 3 Ap) foam with an interconnected porous structure is highly attractive as a scaffold for bone replacement. In this study, arbitrarily shaped CO 3 Ap foam was formed from α-tricalcium phosphate (α-TCP) foam granules via a two-step process involving treatment with acidic calcium phosphate solution followed by hydrothermal treatment with NaHCO 3 . The treatment with acidic calcium phosphate solution, which is key to fabricating arbitrarily shaped CO 3 Ap foam, enables dicalcium hydrogen phosphate dihydrate (DCPD) crystals to form on the α-TCP foam granules. The generated DCPD crystals cause the α-TCP granules to interlock with each other, inducing an α-TCP/DCPD foam. The interlocking structure containing DCPD crystals can survive hydrothermal treatment with NaHCO 3 . The arbitrarily shaped CO 3 Ap foam was fabricated from the α-TCP/DCPD foam via hydrothermal treatment at 200 °C for 24 h in the presence of a large amount of NaHCO 3 .

Meeting the maglev system's safety requirements

Energy Technology Data Exchange (ETDEWEB)

Pierick, K

1983-12-01

The author shows how the safety requirements of the maglev track system derive from the general legal conditions for the safety of tracked transport. It is described how their compliance beyond the so-called ''development-accompanying'' and ''acceptance-preparatory'' safety work can be assured for the Transrapid test layout (TVE) now building in Emsland and also for later application as public transport system in Germany within the meaning of the General Railway Act.

Changes to the LHC Beam Dumping System for LHC Run 2

CERN Document Server

Uythoven, Jan; Borburgh, Jan; Carlier, Etienne; Gabourin, Stéphane; Goddard, Brennan; Magnin, Nicolas; Senaj, Viliam; Voumard, Nicolas; Weterings, Wim

2014-01-01

The LHC beam dumping system performed according to expectations during Run 1 of the LHC (2009 – 2013). A brief overview of the experience is given, including a summary of the observed performance by comparison to expectations. An important number of changes are applied to the beam dumping system during the present Long Shutdown in order to further improve its safety and performance. They include the addition of a direct link between the Beam Interlock System and the re-triggering system of the dump kickers, the modification of the uninterrupted electrical power distribution architecture, the upgrade of the HV generators, the consolidation of the trigger synchronisation system, the modifications to the triggering system of the power switches and the changes to the dump absorbers TCDQ.

Strategy to safety grade systems replacements

International Nuclear Information System (INIS)

Stimler, M.; Sullivan, K.E.; Trebincevic, I.

1993-01-01

The introduction of digital instrumentation and control systems in nuclear power plants is characterized by the need to satisfy the requirements of safety, reliability and man-machine ergonomics. Today digital instrumentation and control systems meet these requirements and the trend in Europe is towards full digital based nuclear power plant control systems. This paper describes Siemens (KWU) experience in nuclear power plants and development in trends within Europe. Topics which are the subject of major concern to NPP operators addressed in this paper are: human performance factors - man-machine interface; operating philosophy; safety, availability and reliability. Other aspects addressed are: Siemens open-quotes defense in depthclose quotes concept, description of Siemens digital I ampersand C systems, safety requirements and systems, I ampersand C qualification, control room ergonomics, information systems and retrofitting experience

System safety education focused on system management

Science.gov (United States)

Grose, V. L.

1971-01-01

System safety is defined and characteristics of the system are outlined. Some of the principle characteristics include role of humans in hazard analysis, clear language for input and output, system interdependence, self containment, and parallel analysis of elements.

Safety Management System in Croatia Control Ltd.

OpenAIRE

Pavlin, Stanislav; Sorić, Vedran; Bilać, Dragan; Dimnik, Igor; Galić, Daniel

2009-01-01

International Civil Aviation Organization and other international aviation organizations regulate the safety in civil aviation. In the recent years the International Civil Aviation Organization has introduced the concept of the safety management system through several documents among which the most important is the 2006 Safety Management Manual. It treats the safety management system in all the segments of civil aviation, from carriers, aerodromes and air traffic control to design, constructi...

Safety Evaluation Approach with Security Controls for Safety I and C Systems on Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, D. H.; Jeong, S. Y.; Kim, Y. M.; Park, H. S.; Lee, M. S.; Kim, T. H.

2016-01-01

This paper addresses concepts of safety and security and relations between them for assessing effects of security features in safety systems. Also, evaluation approach for avoiding confliction with safety requirements and cyber security features which may be adopted in safety-related digital I and C system will be described. In this paper, safety-security life cycle model based confliction avoidance method was proposed to evaluate the effects when the cyber security control features are implemented in the safety I and C system. Also, safety effect evaluation results using the proposed evaluation method were described. In case of technical security controls, many of them are expected to conflict with safety requirements, otherwise operational and managerial controls are not relatively. Safety measures and cyber security measures for nuclear power plants should be implemented not to conflict with one another. Where safety function and security features are both required within the systems, and also where security features are implemented within safety systems, they should be justified

Safety Evaluation Approach with Security Controls for Safety I and C Systems on Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, D. H.; Jeong, S. Y.; Kim, Y. M.; Park, H. S. [KINS, Daejeon (Korea, Republic of); Lee, M. S.; Kim, T. H. [Formal Works Inc., Seoul (Korea, Republic of)

2016-05-15

This paper addresses concepts of safety and security and relations between them for assessing effects of security features in safety systems. Also, evaluation approach for avoiding confliction with safety requirements and cyber security features which may be adopted in safety-related digital I and C system will be described. In this paper, safety-security life cycle model based confliction avoidance method was proposed to evaluate the effects when the cyber security control features are implemented in the safety I and C system. Also, safety effect evaluation results using the proposed evaluation method were described. In case of technical security controls, many of them are expected to conflict with safety requirements, otherwise operational and managerial controls are not relatively. Safety measures and cyber security measures for nuclear power plants should be implemented not to conflict with one another. Where safety function and security features are both required within the systems, and also where security features are implemented within safety systems, they should be justified.

Safety-related control air systems - approved 1977

International Nuclear Information System (INIS)

Anon.

1978-01-01

This standard applies to those portions of the control air system that furnish air required to support, control, or operate systems or portions of systems that are safety related in nuclear power plants. This standard relates only to the air supply system(s) for safety-related air operated devices and does not apply to the safety-related air operated device or to air operated actuators for such devices. The objectives of this standard are to provide (1) minimum system design requirements for equipment, piping, instruments, controls, and wiring that constitute the air supply system; and (2) the system and component testing and maintenance requirements

Removal torque of nail interlocking screws is related to screw proximity to the fracture and screw breakage.

Science.gov (United States)

White, Alexander A; Kubacki, Meghan R; Samona, Jason; Telehowski, Paul; Atkinson, Patrick J

2016-06-01

Studies have shown that titanium implants can be challenging to explant due to the material's excellent biocompatibility and resulting osseointegration. Clinically, titanium alloy nail interlocking screws may require removal to dynamize a construct or revise the nail due to nonunion, infection, pain, or periprosthetic fracture. This study was designed to determine what variables influence the removal torque for titanium alloy interlocking screws. An intramedullary nail with four interlocking screws was used to stabilize a 1-cm segmental femoral defect in a canine model for 16 weeks. The animals were observed to be active following a several-day recovery after surgery. In six animals, the femora and implanted nail/screws were first tested to failure in torsion to simulate periprosthetic fracture of an implant after which the screws were then removed. In four additional animals, the screws were removed without mechanical testing. Both intraoperative insertional and extraction torques were recorded for all screws. Mechanical testing to failure broke 10/24 screws. On average, the intact screws required 70% of the insertional torque during removal while broken screws only required 16% of the insertional torque (p torque than the outboard distal screw (p torque was ∼80°. The peak axial load did not significantly correlate with the torque required to remove the screws. On average, the removal torque was lower than at the time of insertion, and less torque was required to remove broken screws and screws remote to the fracture. However, broken screws will require additional time to retrieve the remaining screw fragment. This study suggests that broken screws and screws in prematurely active patients will require less torque to remove. © IMechE 2016.

Qualification of FPGA-Based Safety-Related PRM System

International Nuclear Information System (INIS)

Miyazaki, Tadashi; Oda, Naotaka; Goto, Yasushi; Hayashi, Toshifumi

2011-01-01

Toshiba has developed Non-rewritable (NRW) Field Programmable Gate Array (FPGA)-based safety-related Instrumentation and Control (I and C) system. Considering application to safety-related systems, nonvolatile and non-rewritable FPGA which is impossible to be changed after once manufactured has been adopted in Toshiba FPGA-based system. FPGA is a device which consists only of basic logic circuits, and FPGA performs defined processing which is configured by connecting the basic logic circuit inside the FPGA. FPGA-based system solves issues existing both in the conventional systems operated by analog circuits (analog-based system) and the systems operated by central processing unit (CPU-based system). The advantages of applying FPGA are to keep the long-life supply of products, improving testability (verification), and to reduce the drift which may occur in analog-based system. The system which Toshiba developed this time is Power Range Neutron Monitor (PRM). Toshiba is planning to expand application of FPGA-based technology by adopting this development process to the other safety-related systems such as RPS from now on. Toshiba developed a special design process for NRW-FPGA-based safety-related I and C systems. The design process resolves issues for many years regarding testability of the digital system for nuclear safety application. Thus, Toshiba NRW-FPGA-based safety-related I and C systems has much advantage to be a would standard of the digital systems for nuclear safety application. (author)