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Sample records for criticality safety controls

  1. Review of criteria for nuclear criticality safety control in transportation

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J. T.; Smith, D. R.

    1978-01-01

    Basic elements in the review of criteria for nuclear criticality safety in transportation are the magnitudes of reactivity changes that may occur to a shipment of packages and those inherent in the regulatory procedure of assessment. The generic representation of criticality of reflected arrays of uncontained fissionable materials is used as a basis for comparison of packaged fissionable materials. The reactivities associated with array changes and perturbations representative of credible conditions that may occur in storage or transportation are summarized for air-spaced units of fissionable materials. Calculations of packaged fissionable material determined reactivities associated with similar changes to arrays of packages. Typical thermal insulating materials being studied are Celotex, wood, Foamglas, and a bonded vermiculite. The effect on the array neutron multiplication of these, with and without steel as an inner and outer container material, is examined. The present stage of the study has produced results illustrating the variable margin of subcriticality manifested by the criteria. Depending upon the packaging, mass loading and array reflector condition, the margin of subcriticality can be of the order of 1% in k/sub eff/.

  2. Nuclear criticality safety guide

    Energy Technology Data Exchange (ETDEWEB)

    Pruvost, N.L.; Paxton, H.C. [eds.

    1996-09-01

    This technical reference document cites information related to nuclear criticality safety principles, experience, and practice. The document also provides general guidance for criticality safety personnel and regulators.

  3. Validation of Safety-Critical Systems for Aircraft Loss-of-Control Prevention and Recovery

    Science.gov (United States)

    Belcastro, Christine M.

    2012-01-01

    Validation of technologies developed for loss of control (LOC) prevention and recovery poses significant challenges. Aircraft LOC can result from a wide spectrum of hazards, often occurring in combination, which cannot be fully replicated during evaluation. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of hazardous and uncertain conditions, and the validation framework must provide some measure of assurance that the new vehicle safety technologies do no harm (i.e., that they themselves do not introduce new safety risks). This paper summarizes a proposed validation framework for safety-critical systems, provides an overview of validation methods and tools developed by NASA to date within the Vehicle Systems Safety Project, and develops a preliminary set of test scenarios for the validation of technologies for LOC prevention and recovery

  4. On localization with robust power control for safety critical wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A hybrid methodology is proposed for use in low power, safety critical wireless sensor network applications, where quality-of-service orientated transceiver output power control is required to operate in parallel with radio frequency-based localization. The practical implementation is framed in an experimental procedure designed to track a moving agent in a realistic indoor environment. An adaptive time synchronized approach is employed to ensure the positioning technique can operate effectively in the pres...

  5. The hazard analysis and critical control point system in food safety.

    Science.gov (United States)

    Herrera, Anavella Gaitan

    2004-01-01

    The Hazard Analysis and Critical Control Point (HACCP) system is a preventive method of ensuring food safety. Its objectives are the identification of consumer safety hazards that can occur in the production line and the establishment of a control process to guarantee a safer product for the consumer; it is based on the identification of potential hazards to food safety and on measures aimed at preventing these hazards. HACCP is the system of choice in the management of food safety. The principles of HACCP are applicable to all phases of food production, including basic husbandry practices, food preparation and handling, food processing, food service, distribution systems, and consumer handling and use. The HACCP system is involved in every aspect of food safety production (according to the UN Food and Agriculture Organization [FAO] and the International Commission on Microbiological Specifications for Foods [ICMSF]). The most basic concept underlying the HACCP system is that of prevention rather than inspection. The control of processes and conditions comprises the critical control point (CCP) element. HACCP is simply a methodical, flexible, and systematic application of the appropriate science and technology for planning, controlling, and documenting the safe production of foods. The successful application of HACCP requires the full commitment and involvement of management and the workforce, using a multidisciplinary approach that should include, as appropriate, expertise in agronomy, veterinary health, microbiology, public health, food technology, environmental health, chemistry, engineering, and so on according to the particular situation. Application of the HACCP system is compatible with the implementation of total quality management (TQM) systems such as the ISO 9000 series.

  6. 75 FR 8239 - School Food Safety Program Based on Hazard Analysis and Critical Control Point Principles (HACCP...

    Science.gov (United States)

    2010-02-24

    ... Service 7 CFR Parts 210 and 220 RIN 0584-AD65 School Food Safety Program Based on Hazard Analysis and... rule entitled School Food Safety Program Based on Hazard Analysis and Critical Control Point Principles... Program (SBP) to develop a school food safety program for the preparation and service of school meals...

  7. Nuclear criticality safety: 2-day training course

    Energy Technology Data Exchange (ETDEWEB)

    Schlesser, J.A. [ed.] [comp.

    1997-02-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used as Los Alamos; be able to identify examples of circumstances present during criticality accidents; have participated in conducting two critical experiments; be asked to complete a critique of the nuclear criticality safety training course.

  8. High-confidence software for safety-critical process-control systems

    Energy Technology Data Exchange (ETDEWEB)

    Bastani, F.B. [Univ. of Houston, TX (United States)

    1997-12-01

    Software for safety-critical systems, such as nuclear power plant control systems; avionic systems; and medical, defense, and manufacturing systems, must be highly reliable because failures can have catastrophic consequences. While existing methods, such as formal techniques, testing, and fault-tolerant software, can significantly enhance software reliability, they have some limitations in achieving ultrahigh reliability requirements. Formal methods are not able to cope with specification faults, testing is not cost-effective for high-assurance systems, and fault-tolerant software based on diverse designs is susceptible to common-mode failures.

  9. Criticality safety training

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, S.K. [Los Alamos National Lab., NM (United States)

    1997-06-01

    Criticality safety training is an important element of the Plutonium Facility safety program at Los Alamos National Laboratory. Training consists of student self-study handbooks and hands-on performance-based training in a mock-up laboratory containing gloveboxes, trolley conveyor system, and self-monitoring instruments. A 10-minute video tape and lecture was presented to describe how training in this area is conducted.

  10. An Actuator Control Unit for Safety-Critical Mechatronic Applications with Embedded Energy Storage Backup

    Directory of Open Access Journals (Sweden)

    Sergio Saponara

    2016-03-01

    Full Text Available This paper presents an actuator control unit (ACU with a 450-J embedded energy storage backup to face safety critical mechatronic applications. The idea is to ensure full operation of electric actuators, even in the case of battery failure, by using supercapacitors as a local energy tank. Thanks to integrated switching converter circuitry, the supercapacitors provide the required voltage and current levels for the required time to guarantee actuator operation until the system enters into safety mode. Experimental results are presented for a target application related to the control of servomotors for a robotized prosthetic arm. Mechatronic devices for rehabilitation or assisted living of injured and/or elderly people are available today. In most cases, they are battery powered with lithium-based cells, providing high energy density and low weight, but at the expense of a reduced robustness compared to lead-acid- or nickel-based battery cells. The ACU of this work ensures full operation of the wearable robotized arm, controlled through acceleration and electromyography (EMG sensor signals, even in the case of battery failure, thanks to the embedded energy backup unit. To prove the configurability and scalability of the proposed solution, experimental results related to the electric actuation of the car door latch and of a robotized gearbox in vehicles are also shown. The reliability of the energy backup device has been assessed in a wide temperature range, from −40 to 130 °C, and in a durability test campaign of more than 10,000 cycles. Achieved results prove the suitability of the proposed approach for ACUs requiring a burst of power of hundreds of watts for only a few seconds in safety-critical applications. Alternatively, the aging and temperature characterizations of energy backup units is limited to supercapacitors of thousands of farads for high power applications (e.g., electric/hybrid propulsion and with a temperature range limited to

  11. Multi-core System Architecture for Safety-critical Control Applications

    DEFF Research Database (Denmark)

    Li, Gang

    certification cost. Meanwhile, hardware platforms with improved processing power are required to execute the applications of larger size. To tackle the two issues mentioned above, the state of the art approaches are using more Electronic Control Units (ECU) in a federated architecture or increasing...... cores, low power consumption, on-chip interconnection and natural support to on-chip hardware diversity and redundancy at the inter-core level. The objective of this dissertation is to propose a multi-core system architecture for safety-critical control applications with reduced certification cost...... on partitioning design of both multi-core hardware and software architectures, in order to minimize efforts and cost of system certification at the integration time. Hardware architecture design concentrates on a firmware architecture on SoC platforms, providing separated hardware execution environments...

  12. KAERI software safety guideline for developing safety-critical software in digital instrumentation and control system of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jang Soo; Kim, Jang Yeol; Eum, Heung Seop

    1997-07-01

    Recently, the safety planning for safety-critical software systems is being recognized as the most important phase in the software life cycle, and being developed new regulatory positions and standards by the regulatory and the standardization organization. The requirements for software important to safety of nuclear reactor are described in such positions and standards. Most of them are describing mandatory requirements, what shall be done, for the safety-critical software. The developers of such a software. However, there have been a lot of controversial factors on whether the work practices satisfy the regulatory requirements, and to justify the safety of such a system developed by the work practices, between the licenser and the licensee. We believe it is caused by the reason that there is a gap between the mandatory requirements (What) and the work practices (How). We have developed a guidance to fill such gap, which can be useful for both licenser and licensee to conduct a justification of the safety in the planning phase of developing the software for nuclear reactor protection systems. (author). 67 refs., 13 tabs., 2 figs.

  13. KAERI software safety guideline for developing safety-critical software in digital instrumentation and control system of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jang Soo; Kim, Jang Yeol; Eum, Heung Seop

    1997-07-01

    Recently, the safety planning for safety-critical software systems is being recognized as the most important phase in the software life cycle, and being developed new regulatory positions and standards by the regulatory and the standardization organization. The requirements for software important to safety of nuclear reactor are described in such positions and standards. Most of them are describing mandatory requirements, what shall be done, for the safety-critical software. The developers of such a software. However, there have been a lot of controversial factors on whether the work practices satisfy the regulatory requirements, and to justify the safety of such a system developed by the work practices, between the licenser and the licensee. We believe it is caused by the reason that there is a gap between the mandatory requirements (What) and the work practices (How). We have developed a guidance to fill such gap, which can be useful for both licenser and licensee to conduct a justification of the safety in the planning phase of developing the software for nuclear reactor protection systems. (author). 67 refs., 13 tabs., 2 figs.

  14. Regenerative braking strategies, vehicle safety and stability control systems: critical use-case proposals

    Science.gov (United States)

    Oleksowicz, Selim A.; Burnham, Keith J.; Southgate, Adam; McCoy, Chris; Waite, Gary; Hardwick, Graham; Harrington, Cian; McMurran, Ross

    2013-05-01

    The sustainable development of vehicle propulsion systems that have mainly focused on reduction of fuel consumption (i.e. CO2 emission) has led, not only to the development of systems connected with combustion processes but also to legislation and testing procedures. In recent years, the low carbon policy has made hybrid vehicles and fully electric vehicles (H/EVs) popular. The main virtue of these propulsion systems is their ability to restore some of the expended energy from kinetic movement, e.g. the braking process. Consequently new research and testing methods for H/EVs are currently being developed. This especially concerns the critical 'use-cases' for functionality tests within dynamic events for both virtual simulations, as well as real-time road tests. The use-case for conventional vehicles for numerical simulations and road tests are well established. However, the wide variety of tests and their great number (close to a thousand) creates a need for selection, in the first place, and the creation of critical use-cases suitable for testing H/EVs in both virtual and real-world environments. It is known that a marginal improvement in the regenerative braking ratio can significantly improve the vehicle range and, therefore, the economic cost of its operation. In modern vehicles, vehicle dynamics control systems play the principal role in safety, comfort and economic operation. Unfortunately, however, the existing standard road test scenarios are insufficient for H/EVs. Sector knowledge suggests that there are currently no agreed tests scenarios to fully investigate the effects of brake blending between conventional and regenerative braking as well as the regenerative braking interaction with active driving safety systems (ADSS). The paper presents seven manoeuvres, which are considered to be suitable and highly informative for the development and examination of H/EVs with regenerative braking capability. The critical manoeuvres presented are considered to be

  15. 2011 Annual Criticality Safety Program Performance Summary

    Energy Technology Data Exchange (ETDEWEB)

    Andrea Hoffman

    2011-12-01

    The 2011 review of the INL Criticality Safety Program has determined that the program is robust and effective. The review was prepared for, and fulfills Contract Data Requirements List (CDRL) item H.20, 'Annual Criticality Safety Program performance summary that includes the status of assessments, issues, corrective actions, infractions, requirements management, training, and programmatic support.' This performance summary addresses the status of these important elements of the INL Criticality Safety Program. Assessments - Assessments in 2011 were planned and scheduled. The scheduled assessments included a Criticality Safety Program Effectiveness Review, Criticality Control Area Inspections, a Protection of Controlled Unclassified Information Inspection, an Assessment of Criticality Safety SQA, and this management assessment of the Criticality Safety Program. All of the assessments were completed with the exception of the 'Effectiveness Review' for SSPSF, which was delayed due to emerging work. Although minor issues were identified in the assessments, no issues or combination of issues indicated that the INL Criticality Safety Program was ineffective. The identification of issues demonstrates the importance of an assessment program to the overall health and effectiveness of the INL Criticality Safety Program. Issues and Corrective Actions - There are relatively few criticality safety related issues in the Laboratory ICAMS system. Most were identified by Criticality Safety Program assessments. No issues indicate ineffectiveness in the INL Criticality Safety Program. All of the issues are being worked and there are no imminent criticality concerns. Infractions - There was one criticality safety related violation in 2011. On January 18, 2011, it was discovered that a fuel plate bundle in the Nuclear Materials Inspection and Storage (NMIS) facility exceeded the fissionable mass limit, resulting in a technical safety requirement (TSR) violation. The

  16. Autoclave nuclear criticality safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    D`Aquila, D.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Tayloe, R.W. Jr. [Battelle, Columbus, OH (United States)

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  17. AGING FACILITY CRITICALITY SAFETY CALCULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    C.E. Sanders

    2004-09-10

    The purpose of this design calculation is to revise and update the previous criticality calculation for the Aging Facility (documented in BSC 2004a). This design calculation will also demonstrate and ensure that the storage and aging operations to be performed in the Aging Facility meet the criticality safety design criteria in the ''Project Design Criteria Document'' (Doraswamy 2004, Section 4.9.2.2), and the functional nuclear criticality safety requirement described in the ''SNF Aging System Description Document'' (BSC [Bechtel SAIC Company] 2004f, p. 3-12). The scope of this design calculation covers the systems and processes for aging commercial spent nuclear fuel (SNF) and staging Department of Energy (DOE) SNF/High-Level Waste (HLW) prior to its placement in the final waste package (WP) (BSC 2004f, p. 1-1). Aging commercial SNF is a thermal management strategy, while staging DOE SNF/HLW will make loading of WPs more efficient (note that aging DOE SNF/HLW is not needed since these wastes are not expected to exceed the thermal limits form emplacement) (BSC 2004f, p. 1-2). The description of the changes in this revised document is as follows: (1) Include DOE SNF/HLW in addition to commercial SNF per the current ''SNF Aging System Description Document'' (BSC 2004f). (2) Update the evaluation of Category 1 and 2 event sequences for the Aging Facility as identified in the ''Categorization of Event Sequences for License Application'' (BSC 2004c, Section 7). (3) Further evaluate the design and criticality controls required for a storage/aging cask, referred to as MGR Site-specific Cask (MSC), to accommodate commercial fuel outside the content specification in the Certificate of Compliance for the existing NRC-certified storage casks. In addition, evaluate the design required for the MSC that will accommodate DOE SNF/HLW. This design calculation will achieve the objective of providing the

  18. Nuclear Criticality Safety Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Hollenbach, D. F. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-11-14

    The objective of this document is to support the revision of criticality safety process studies (CSPSs) for the Uranium Processing Facility (UPF) at the Y-12 National Security Complex (Y-12). This design analysis and calculation (DAC) document contains development and justification for generic inputs typically used in Nuclear Criticality Safety (NCS) DACs to model both normal and abnormal conditions of processes at UPF to support CSPSs. This will provide consistency between NCS DACs and efficiency in preparation and review of DACs, as frequently used data are provided in one reference source.

  19. DOE/EM Criticality Safety Needs Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Westfall, Robert Michael [ORNL; Hopper, Calvin Mitchell [ORNL

    2011-02-01

    The issue of nuclear criticality safety (NCS) in Department of Energy Environmental Management (DOE/EM) fissionable material operations presents challenges because of the large quantities of material present in the facilities and equipment that are committed to storage and/or material conditioning and dispositioning processes. Given the uncertainty associated with the material and conditions for many DOE/EM fissionable material operations, ensuring safety while maintaining operational efficiency requires the application of the most-effective criticality safety practices. In turn, more-efficient implementation of these practices can be achieved if the best NCS technologies are utilized. In 2002, DOE/EM-1 commissioned a survey of criticality safety technical needs at the major EM sites. These needs were documented in the report Analysis of Nuclear Criticality Safety Technology Supporting the Environmental Management Program, issued May 2002. Subsequent to this study, EM safety management personnel made a commitment to applying the best and latest criticality safety technology, as described by the DOE Nuclear Criticality Safety Program (NCSP). Over the past 7 years, this commitment has enabled the transfer of several new technologies to EM operations. In 2008, it was decided to broaden the basis of the EM NCS needs assessment to include not only current needs for technologies but also NCS operational areas with potential for improvements in controls, analysis, and regulations. A series of NCS workshops has been conducted over the past years, and needs have been identified and addressed by EM staff and contractor personnel. These workshops were organized and conducted by the EM Criticality Safety Program Manager with administrative and technical support by staff at Oak Ridge National Laboratory (ORNL). This report records the progress made in identifying the needs, determining the approaches for addressing these needs, and assimilating new NCS technologies into EM

  20. Critical points of Brazil nuts: a beginning for food safety, quality control and Amazon sustainability.

    Science.gov (United States)

    Lima, Andriele M; Gonçalves, Evonnildo C; Andrade, Soraya S; Barbosa, Maria S R; Barroso, Karla F P; de Sousa, Mayara B; Borges, Larissa; Vieira, Jozé L F; Teixeira, Francisco M

    2013-03-15

    One difficulty of self-sustainability is the quality assurance of native products. This research was designed to study the risks and critical control points in the collection, handling and marketing of Brazil nuts from native forests and urban fairs in the Brazilian Amazon by characterisation of morphological aspects of fungi and posterior identification by molecular biology and determination of aflatoxins by high-performance liquid chromatography. Several corrective actions to improve product quality were found to be necessary in both sites. Growth of fungi was observed in 95% of fragments of Brazil nuts from both sites during the between-harvest period. Aflatoxin levels indicated that, although fungal growth was observed in both sites, only Brazil nuts from the native forest showed a high risk to human health (total aflatoxin level of 471.69 µg kg(-1)). This study has shown the main issues related to the process design of Brazil nuts, supporting the necessity for research on new strategies to improve the quality of nuts. Also, the habit of eating Brazil nuts stored throughout the year may represent a risk to farmers. © 2012 Society of Chemical Industry.

  1. Lecture notes for criticality safety

    Science.gov (United States)

    Fullwood, R.

    1992-03-01

    These lecture notes for criticality safety are prepared for the training of Department of Energy supervisory, project management, and administrative staff. Technical training and basic mathematics are assumed. The notes are designed for a two-day course, taught by two lecturers. Video tapes may be used at the options of the instructors. The notes provide all the materials that are necessary but outside reading will assist in the fullest understanding. The course begins with a nuclear physics overview. The reader is led from the macroscopic world into the microscopic world of atoms and the elementary particles that constitute atoms. The particles, their masses and sizes and properties associated with radioactive decay and fission are introduced along with Einstein's mass-energy equivalence. Radioactive decay, nuclear reactions, radiation penetration, shielding and health-effects are discussed to understand protection in case of a criticality accident. Fission, the fission products, particles and energy released are presented to appreciate the dangers of criticality. Nuclear cross sections are introduced to understand the effectiveness of slow neutrons to produce fission. Chain reactors are presented as an economy; effective use of the neutrons from fission leads to more fission resulting in a power reactor or a criticality excursion. The six-factor formula is presented for managing the neutron budget. This leads to concepts of material and geometric buckling which are used in simple calculations to assure safety from criticality. Experimental measurements and computer code calculations of criticality are discussed. To emphasize the reality, historical criticality accidents are presented in a table with major ones discussed to provide lessons-learned. Finally, standards, NRC guides and regulations, and DOE orders relating to criticality protection are presented.

  2. Lecture notes for criticality safety

    Energy Technology Data Exchange (ETDEWEB)

    Fullwood, R.

    1992-03-01

    These lecture notes for criticality safety are prepared for the training of Department of Energy supervisory, project management, and administrative staff. Technical training and basic mathematics are assumed. The notes are designed for a two-day course, taught by two lecturers. Video tapes may be used at the options of the instructors. The notes provide all the materials that are necessary but outside reading will assist in the fullest understanding. The course begins with a nuclear physics overview. The reader is led from the macroscopic world into the microscopic world of atoms and the elementary particles that constitute atoms. The particles, their masses and sizes and properties associated with radioactive decay and fission are introduced along with Einstein`s mass-energy equivalence. Radioactive decay, nuclear reactions, radiation penetration, shielding and health-effects are discussed to understand protection in case of a criticality accident. Fission, the fission products, particles and energy released are presented to appreciate the dangers of criticality. Nuclear cross sections are introduced to understand the effectiveness of slow neutrons to produce fission. Chain reactors are presented as an economy; effective use of the neutrons from fission leads to more fission resulting in a power reactor or a criticality excursion. The six-factor formula is presented for managing the neutron budget. This leads to concepts of material and geometric buckling which are used in simple calculations to assure safety from criticality. Experimental measurements and computer code calculations of criticality are discussed. To emphasize the reality, historical criticality accidents are presented in a table with major ones discussed to provide lessons-learned. Finally, standards, NRC guides and regulations, and DOE orders relating to criticality protection are presented.

  3. Lecture notes for criticality safety

    Energy Technology Data Exchange (ETDEWEB)

    Fullwood, R.

    1992-03-01

    These lecture notes for criticality safety are prepared for the training of Department of Energy supervisory, project management, and administrative staff. Technical training and basic mathematics are assumed. The notes are designed for a two-day course, taught by two lecturers. Video tapes may be used at the options of the instructors. The notes provide all the materials that are necessary but outside reading will assist in the fullest understanding. The course begins with a nuclear physics overview. The reader is led from the macroscopic world into the microscopic world of atoms and the elementary particles that constitute atoms. The particles, their masses and sizes and properties associated with radioactive decay and fission are introduced along with Einstein's mass-energy equivalence. Radioactive decay, nuclear reactions, radiation penetration, shielding and health-effects are discussed to understand protection in case of a criticality accident. Fission, the fission products, particles and energy released are presented to appreciate the dangers of criticality. Nuclear cross sections are introduced to understand the effectiveness of slow neutrons to produce fission. Chain reactors are presented as an economy; effective use of the neutrons from fission leads to more fission resulting in a power reactor or a criticality excursion. The six-factor formula is presented for managing the neutron budget. This leads to concepts of material and geometric buckling which are used in simple calculations to assure safety from criticality. Experimental measurements and computer code calculations of criticality are discussed. To emphasize the reality, historical criticality accidents are presented in a table with major ones discussed to provide lessons-learned. Finally, standards, NRC guides and regulations, and DOE orders relating to criticality protection are presented.

  4. LC Oscillator Driver for Safety Critical Applications

    CERN Document Server

    Horsky, Pavel

    2011-01-01

    A CMOS harmonic signal LC oscillator driver for automotive applications working in a harsh environment with high safety critical requirements is described. The driver can be used with a wide range of external components parameters (LC resonance network of a sensor). Quality factor of the external LC network can vary two decades. Amplitude regulation of the driver is digitally controlled and the DAC is constructed as exponential with piece-wise-linear (PWL) approximation. Low current consumption for high quality resonance networks is achieved. Realized oscillator is robust, used in safety critical application and has low EMC emissions.

  5. Metal food packaging design based on hazard analysis critical control point (HACCP system in canned food safety

    Directory of Open Access Journals (Sweden)

    Li Xingyi

    2016-06-01

    Full Text Available This study aims to design metal food packaging with hazard analysis critical control point (HACCP. First, theory of HACCP was introduced in detail. Taking empty cans provided by Wuxi Huapeng Food Packaging Company as an example, we studied migration of bisphenol compounds in coating of food can to food stimulant. Moreover, packaging design of luncheon meat can was taken as an example to confirm whether HACCP system could effectively control migration of phenolic substance. Results demonstrated that, coating of such empty were more likely to contain multiple bisphenol compounds such as bisphenol A (BPA, and bisphenol A diglycidyl ether (BADGE was considered as the leading bisphenol pollutant; food stimulant of different types, storage temperature and time could all impact migration of bisphenol compounds. HACCP system was proved to be effective in controlling hazards of phenolic substance in luncheon meat can and could reduce various phenolic substance indexes to an acceptable range. Therefore, HACCP can control migration of phenolic substance and recontamination of food and thus ensure food safety.

  6. Security for safety critical space borne systems

    Science.gov (United States)

    Legrand, Sue

    1987-01-01

    The Space Station contains safety critical computer software components in systems that can affect life and vital property. These components require a multilevel secure system that provides dynamic access control of the data and processes involved. A study is under way to define requirements for a security model providing access control through level B3 of the Orange Book. The model will be prototyped at NASA-Johnson Space Center.

  7. Final Technical Report on Quantifying Dependability Attributes of Software Based Safety Critical Instrumentation and Control Systems in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Smidts, Carol [The Ohio State Univ., Columbus, OH (United States); Huang, Funqun [The Ohio State Univ., Columbus, OH (United States); Li, Boyuan [The Ohio State Univ., Columbus, OH (United States); Li, Xiang [The Ohio State Univ., Columbus, OH (United States)

    2016-03-25

    With the current transition from analog to digital instrumentation and control systems in nuclear power plants, the number and variety of software-based systems have significantly increased. The sophisticated nature and increasing complexity of software raises trust in these systems as a significant challenge. The trust placed in a software system is typically termed software dependability. Software dependability analysis faces uncommon challenges since software systems’ characteristics differ from those of hardware systems. The lack of systematic science-based methods for quantifying the dependability attributes in software-based instrumentation as well as control systems in safety critical applications has proved itself to be a significant inhibitor to the expanded use of modern digital technology in the nuclear industry. Dependability refers to the ability of a system to deliver a service that can be trusted. Dependability is commonly considered as a general concept that encompasses different attributes, e.g., reliability, safety, security, availability and maintainability. Dependability research has progressed significantly over the last few decades. For example, various assessment models and/or design approaches have been proposed for software reliability, software availability and software maintainability. Advances have also been made to integrate multiple dependability attributes, e.g., integrating security with other dependability attributes, measuring availability and maintainability, modeling reliability and availability, quantifying reliability and security, exploring the dependencies between security and safety and developing integrated analysis models. However, there is still a lack of understanding of the dependencies between various dependability attributes as a whole and of how such dependencies are formed. To address the need for quantification and give a more objective basis to the review process -- therefore reducing regulatory uncertainty

  8. Application of hazard analysis and critical control point methodology and risk-based grading to consumer food safety surveys.

    Science.gov (United States)

    Røssvoll, Elin Halbach; Ueland, Øydis; Hagtvedt, Therese; Jacobsen, Eivind; Lavik, Randi; Langsrud, Solveig

    2012-09-01

    Traditionally, consumer food safety survey responses have been classified as either "right" or "wrong" and food handling practices that are associated with high risk of infection have been treated in the same way as practices with lower risks. In this study, a risk-based method for consumer food safety surveys has been developed, and HACCP (hazard analysis and critical control point) methodology was used for selecting relevant questions. We conducted a nationally representative Web-based survey (n = 2,008), and to fit the self-reported answers we adjusted a risk-based grading system originally developed for observational studies. The results of the survey were analyzed both with the traditional "right" and "wrong" classification and with the risk-based grading system. The results using the two methods were very different. Only 5 of the 10 most frequent food handling violations were among the 10 practices associated with the highest risk. These 10 practices dealt with different aspects of heat treatment (lacking or insufficient), whereas the majority of the most frequent violations involved storing food at room temperature for too long. Use of the risk-based grading system for survey responses gave a more realistic picture of risks associated with domestic food handling practices. The method highlighted important violations and minor errors, which are performed by most people and are not associated with significant risk. Surveys built on a HACCP-based approach with risk-based grading will contribute to a better understanding of domestic food handling practices and will be of great value for targeted information and educational activities.

  9. 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.

  10. Status of criticality safety research at NUCEF

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Ken [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Two critical facilities, named STACY (Static Experiment Critical Facility) and TRACY (Transient Experiment Critical Facility), at the Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF) started their hot operations in 1995. Since then, basic experimental data for criticality safety research have been accumulated using STACY, and supercritical experiments for the study of criticality accident in a reprocessing plant have been performed using TRACY. In this paper, the outline of those critical facilities and the main results of TRACY experiments are presented. (author)

  11. Elements of a nuclear criticality safety program

    Energy Technology Data Exchange (ETDEWEB)

    Hopper, C.M.

    1995-07-01

    Nuclear criticality safety programs throughout the United States are quite successful, as compared with other safety disciplines, at protecting life and property, especially when regarded as a developing safety function with no historical perspective for the cause and effect of process nuclear criticality accidents before 1943. The programs evolved through self-imposed and regulatory-imposed incentives. They are the products of conscientious individuals, supportive corporations, obliged regulators, and intervenors (political, public, and private). The maturing of nuclear criticality safety programs throughout the United States has been spasmodic, with stability provided by the volunteer standards efforts within the American Nuclear Society. This presentation provides the status, relative to current needs, for nuclear criticality safety program elements that address organization of and assignments for nuclear criticality safety program responsibilities; personnel qualifications; and analytical capabilities for the technical definition of critical, subcritical, safety and operating limits, and program quality assurance.

  12. Final Technical Report on Quantifying Dependability Attributes of Software Based Safety Critical Instrumentation and Control Systems in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Smidts, Carol [The Ohio State Univ., Columbus, OH (United States); Huang, Funqun [The Ohio State Univ., Columbus, OH (United States); Li, Boyuan [The Ohio State Univ., Columbus, OH (United States); Li, Xiang [The Ohio State Univ., Columbus, OH (United States)

    2016-03-25

    With the current transition from analog to digital instrumentation and control systems in nuclear power plants, the number and variety of software-based systems have significantly increased. The sophisticated nature and increasing complexity of software raises trust in these systems as a significant challenge. The trust placed in a software system is typically termed software dependability. Software dependability analysis faces uncommon challenges since software systems’ characteristics differ from those of hardware systems. The lack of systematic science-based methods for quantifying the dependability attributes in software-based instrumentation as well as control systems in safety critical applications has proved itself to be a significant inhibitor to the expanded use of modern digital technology in the nuclear industry. Dependability refers to the ability of a system to deliver a service that can be trusted. Dependability is commonly considered as a general concept that encompasses different attributes, e.g., reliability, safety, security, availability and maintainability. Dependability research has progressed significantly over the last few decades. For example, various assessment models and/or design approaches have been proposed for software reliability, software availability and software maintainability. Advances have also been made to integrate multiple dependability attributes, e.g., integrating security with other dependability attributes, measuring availability and maintainability, modeling reliability and availability, quantifying reliability and security, exploring the dependencies between security and safety and developing integrated analysis models. However, there is still a lack of understanding of the dependencies between various dependability attributes as a whole and of how such dependencies are formed. To address the need for quantification and give a more objective basis to the review process -- therefore reducing regulatory uncertainty

  13. Criticality Safety Basics for INL Emergency Responders

    Energy Technology Data Exchange (ETDEWEB)

    Valerie L. Putman

    2012-08-01

    This document is a modular self-study guide about criticality safety principles for Idaho National Laboratory emergency responders. This guide provides basic criticality safety information for people who, in response to an emergency, might enter an area that contains much fissionable (or fissile) material. The information should help responders understand unique factors that might be important in responding to a criticality accident or in preventing a criticality accident while responding to a different emergency.

    This study guide specifically supplements web-based training for firefighters (0INL1226) and includes information for other Idaho National Laboratory first responders. However, the guide audience also includes other first responders such as radiological control personnel.

    For interested readers, this guide includes clearly marked additional information that will not be included on tests. The additional information includes historical examples (Been there. Done that.), as well as facts and more in-depth information (Did you know …).

    INL criticality safety personnel revise this guide as needed to reflect program changes, user requests, and better information. Revision 0, issued May 2007, established the basic text. Revision 1 incorporates operation, program, and training changes implemented since 2007. Revision 1 increases focus on first responders because later responders are more likely to have more assistance and guidance from facility personnel and subject matter experts. Revision 1 also completely reorganized the training to better emphasize physical concepts behind the criticality controls that help keep emergency responders safe. The changes are based on and consistent with changes made to course 0INL1226.

  14. Nuclear criticality safety: 300 Area

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-31

    This Standard applies to the receipt, processing, storage, and shipment of fissionable material in the 300 Area and in any other facility under the control of the Reactor Materials Project Management Team (PMT). The objective is to establish practices and process conditions for the storage and handling of fissionable material that prevent the accidental assembly of a critical mass and that comply with DOE Orders as well as accepted industry practice.

  15. 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...

  16. Criticality safety basics, a study guide

    Energy Technology Data Exchange (ETDEWEB)

    V. L. Putman

    1999-09-01

    This document is a self-study and classroom guide, for criticality safety of activities with fissile materials outside nuclear reactors. This guide provides a basic overview of criticality safety and criticality accident prevention methods divided into three parts: theory, application, and history. Except for topic emphasis, theory and history information is general, while application information is specific to the Idaho National Engineering and Environmental Laboratory (INEEL). Information presented here should be useful to personnel who must know criticality safety basics to perform their assignments safely or to design critically safe equipment or operations. However, the guide's primary target audience is fissile material handler candidates.

  17. Critical view of safety during laparoscopic cholecystectomy.

    Science.gov (United States)

    Vettoretto, Nereo; Saronni, Cristiano; Harbi, Asaf; Balestra, Luca; Taglietti, Lucio; Giovanetti, Maurizio

    2011-01-01

    Laparoscopic cholecystectomy has a 0.3% to 0.5% morbidity rate due to major biliary injuries. The majority of surgeons have routinely performed the so-called "infundibular" technique for gallbladder hilar dissection since the introduction of laparoscopy in the early nineties. The "critical view of safety" approach has only been recently discussed in controlled studies. It is characterized by a blunt dissection of the upper part of Calot's space, which does not usually contain arterial or biliary anomalies and is therefore ideal for a safe dissection, even in less experienced hands. We applied and compared the critical view of safety triangle approach with the infundibular approach in a retrospective cohort study. We divided 174 patients into 2 groups, with a similar case-mix (cholelithiasis, chronic cholecystitis, and acute cholecystitis). Results of operations performed by a young surgeon using critical view of safety dissection were compared to results of the infundibular approach performed by an experienced surgeon. Outcome values and operative times were examined with univariate analysis (Student t test). No difference occurred in terms of morbidity (even though comparison for biliary injuries is inconclusive because of insufficient power) and outcome; significant differences were found in operative time, favoring the critical view of safety approach in every stage of gallbladder disease, with minor significance for acute cases. We suggest this technique as the gold standard for resident teaching, because it has a similar rate of biliary and hemorrhagic complications but has a shorter operative time, builds self-confidence, and is a simple standardized method both for complicated and uncomplicated gallbladder lithiasis.

  18. 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.

  19. Criticality Safety Experimental Investigation of Heterogeneous Fuel

    Institute of Scientific and Technical Information of China (English)

    WANG; Fan; ZHOU; Qi; XIA; Zhao-dong; ZHU; Qing-fu

    2015-01-01

    The spent fuel dissolver is the most important component in the reprocessing plant of the spent fuel dissolver reprocessing steps.The tonnage throughput,criticality safety and economical efficiency of the reprocess or mostly depend on the tonnage throughput,treatment rate and criticality safety of the dissolver.Because of the

  20. A Methodological Framework for Software Safety in Safety Critical Computer Systems

    Directory of Open Access Journals (Sweden)

    P. V. Srinivas Acharyulu

    2012-01-01

    Full Text Available 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 issues for real-time safety-critical embedded systems. At present no standard framework does exist addressing the safety management and safety engineering priniciples for the development of software safety in safety-critical computer systems. Approach: In this study we propose a methodological framework involving safety management practices, safety engineering practices and software development life cycle phases for the development of software safety. In this framework we make use of the safety management practices such as planning, defining priniciples, fixing responsibilities, creteria and targets, risk assessment, design for safety, formulating safety requirements and integrating skills and techniques to address safety issues early with a vision for assurance and so on. In this framework we have also analysed integration of applicability of generic industrial heirarchy and software development heirarchy, with derived cyclical review involving safety professionals generating a nodal point for software safety. Results: This framework is applied to safety-critical software based laboratory prototype Railroad Crossing Control System (RCCS with a limited complexity. The results have shown that all critical operations were safe and risk free. Conclusion: The development of software based on the proposed framework for RCCS have shown a clarified and improved safety-critical operations of the overall system peformance.

  1. HYGIENE PRACTICES IN URBAN RESTAURANTS AND CHALLENGES TO IMPLEMENTING FOOD SAFETY AND HAZARD ANALYSIS CRITICAL CONTROL POINTS (HACCP) PROGRAMMES IN THIKA TOWN, KENYA.

    Science.gov (United States)

    Muinde, R K; Kiinyukia, C; Rombo, G O; Muoki, M A

    2012-12-01

    To determine the microbial load in food, examination of safety measures and possibility of implementing an Hazard Analysis Critical Control Points (HACCP) system. The target population for this study consisted of restaurants owners in Thika. Municipality (n = 30). Simple randomsamples of restaurantswere selected on a systematic sampling method of microbial analysis in cooked, non-cooked, raw food and water sanitation in the selected restaurants. Two hundred and ninety eight restaurants within Thika Municipality were selected. Of these, 30 were sampled for microbiological testing. From the study, 221 (74%) of the restaurants were ready to eat establishments where food was prepared early enough to hold and only 77(26%) of the total restaurants, customers made an order of food they wanted. 118(63%) of the restaurant operators/staff had knowledge on quality control on food safety measures, 24 (8%) of the restaurants applied these knowledge while 256 (86%) of the restaurants staff showed that food contains ingredients that were hazard if poorly handled. 238 (80%) of the resultants used weighing and sorting of food materials, 45 (15%) used preservation methods and the rest used dry foods as critical control points on food safety measures. The study showed that there was need for implementation of Hazard Analysis Critical Control Points (HACCP) system to enhance food safety. Knowledge of HACCP was very low with 89 (30%) of the restaurants applying some of quality measures to the food production process systems. There was contamination with Coliforms, Escherichia coli and Staphylococcus aureus microbial though at very low level. The means of Coliforms, Escherichia coli and Staphylococcus aureas microbial in sampled food were 9.7 x 103CFU/gm, 8.2 x 103 CFU/gm and 5.4 x 103 CFU/gm respectively with Coliforms taking the highest mean.

  2. Reusable libraries for safety-critical Java

    DEFF Research Database (Denmark)

    Rios Rivas, Juan Ricardo; Schoeberl, Martin

    2014-01-01

    The large collection of Java class libraries is a main factor of the success of Java. However, these libraries assume that a garbage-collected heap is used. Safety-critical Java uses scope-based memory areas instead of a garbage-collected heap. Therefore, the Java class libraries are problematic...... to use in safety-critical Java. We have identified common programming patterns in the Java class libraries that make them unsuitable for safety-critical Java. We propose ways to improve the libraries to avoid the impact of the identified problematic patterns. We illustrate these changes by implementing...

  3. A Profile for Safety Critical Java

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Søndergaard, Hans; Thomsen, Bent

    2007-01-01

    We propose a new, minimal specification for real-time Java for safety critical applications. The intention is to provide a profile that supports programming of applications that can be validated against safety critical standards such as DO-178B [15]. The proposed profile is in line with the Java...... specification request JSR-302: Safety Critical Java Technology, which is still under discussion. In contrast to the current direction of the expert group for the JSR-302 we do not subset the rather complex Real-Time Specification for Java (RTSJ). Nevertheless, our profile can be implemented on top of an RTSJ...

  4. A nuclear criticality safety assessment of the loss of moderation control in 2 1/2 and 10-ton cylinders containing enriched UF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Newvahner, R.L. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Pryor, W.A. [PAI Corp., Oak Ridge, TN (United States)

    1991-12-31

    Moderation control for maintaining nuclear criticality safety in 2 {1/2}-ton, 10-ton, and 14-ton cylinders containing enriched uranium hexafluoride (UF{sub 6}) has been used safely within the nuclear industry for over thirty years, and is dependent on cylinder integrity and containment. This assessment evaluates the loss of moderation control by the breaching of containment and entry of water into the cylinders. The first objective of this study was to estimate the required amounts of water entering these large UF{sub 6} cylinders to react with, and to moderate the uranium compounds sufficiently to cause criticality. Hypothetical accident situations were modeled as a uranyl fluoride (UO{sub 2}F{sub 2}) slab above a UF{sub 6} hemicylinder, and a UO{sub 2}F{sub 2} sphere centered within a UF{sub 6} hemicylinder. These situations were investigated by computational analyses utilizing the KENO V.a Monte Carlo Computer Code. The results were used to estimate both the masses of water required for criticality, and the limiting masses of water that could be considered safe. The second objective of the assessment was to calculate the time available for emergency control actions before a criticality would occur, i.e., a {open_quotes}safetime{close_quotes}, for various sources of water and different size openings in a breached cylinder. In the situations considered, except the case for a fire hose, the safetime appears adequate for emergency control actions. The assessment shows that current practices for handling moderation controlled cylinders of low enriched UF{sub 6}, along with the continuation of established personnel training programs, ensure nuclear criticality safety for routine and emergency operations.

  5. Nuclear criticality safety department training implementation

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, K.J.; Taylor, R.G.; Worley, C.A.

    1996-09-06

    The Nuclear Criticality Safety Department (NCSD) is committed to developing and maintaining a staff of qualified personnel to meet the current and anticipated needs in Nuclear Criticality Safety (NCS) at the Oak Ridge Y-12 Plant. The NCSD Qualification Program is described in Y/DD-694, Qualification Program, Nuclear Criticality Safety Department This document provides a listing of the roles and responsibilities of NCSD personnel with respect to training and details of the Training Management System (TMS) programs, Mentoring Checklists and Checksheets, as well as other documentation utilized to implement the program. This document supersedes Y/DD-696, Revision 2, dated 3/27/96, Training Implementation, Nuclear Criticality Safety Department. There are no backfit requirements associated with revisions to this document.

  6. 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...

  7. USING STATISTICAL PROCESS CONTROL AND SIX SIGMA TO CRITICALLY ANALYSE SAFETY OF HELICAL SPRINGS: A RAILWAY CASE STUDY

    Directory of Open Access Journals (Sweden)

    Fulufhelo Ṋemavhola

    2017-09-01

    Full Text Available The paper exhibits the examination of life quality evaluation of helical coil springs in the railway industry as it impacts the safety of the transportation of goods and people. The types of spring considered are: the external spring, internal spring and stabiliser spring. Statistical process control was utilised as the fundamental instrument in the investigation. Measurements were performed using a measuring tape, dynamic actuators and the vernier caliper. The purpose of this research was to examine the usability of old helical springs found in a railway environment. The goal of the experiment was to obtain factual statistical information to determine the life quality of the helical springs used in the railroad transportation environment. Six sigma advocacies were additionally used as a part of this paper. According to six sigma estimation examination only the stabilizers and inner springs for coil bar diameter met the six sigma prerequisites. It is reasoned that the coil springs should be replaced as they do not meet the six sigma requirements.

  8. [Design of a Hazard Analysis and Critical Control Points (HACCP) plan to assure the safety of a bologna product produced by a meat processing plant].

    Science.gov (United States)

    Bou Rached, Lizet; Ascanio, Norelis; Hernández, Pilar

    2004-03-01

    The Hazard Analysis and Critical Control Point (HACCP) is a systematic integral program used to identify and estimate the hazards (microbiological, chemical and physical) and the risks generated during the primary production, processing, storage, distribution, expense and consumption of foods. To establish a program of HACCP has advantages, being some of them: to emphasize more in the prevention than in the detection, to diminish the costs, to minimize the risk of manufacturing faulty products, to allow bigger trust to the management, to strengthen the national and international competitiveness, among others. The present work is a proposal based on the design of an HACCP program to guarantee the safety of the Bologna Special Type elaborated by a meat products industry, through the determination of hazards (microbiological, chemical or physical), the identification of critical control points (CCP), the establishment of critical limits, plan corrective actions and the establishment of documentation and verification procedures. The used methodology was based in the application of the seven basic principles settled down by the Codex Alimentarius, obtaining the design of this program. In view of the fact that recently the meat products are linked with pathogens like E. coli O157:H7 and Listeria monocytogenes, these were contemplated as microbiological hazard for the establishment of the HACCP plan whose application will guarantee the obtaining of a safe product.

  9. Memory Management for Safety-Critical Java

    DEFF Research Database (Denmark)

    Schoeberl, Martin

    2011-01-01

    Safety-Critical Java (SCJ) is based on the Real-Time Specification for Java. To simplify the certification of Java programs, SCJ supports only a restricted scoped memory model. Individual threads share only immortal memory and the newly introduced mission memory. All other scoped memories...

  10. Safety Critical Java for Robotics Programming

    DEFF Research Database (Denmark)

    Thomsen, Bent; Luckow, Kasper Søe; Bøgholm, Thomas

    2015-01-01

    This paper introduces Safety Critical Java (SCJ) and argues its readiness for robotics programming. We give an overview of the work done at Aalborg University and elsewhere on SCJl, some of its implementations in the form of the JOP, FijiVM and HVM and some of the tools, especially WCA, Teta...

  11. Physics Design of Criticality Assembly in Experimental Research About Criticality Safety in Spent Fuel Dissolver

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Qi

    2012-01-01

    <正>In order to meet the experimental demand of criticality safety research in the spent fuel dissolver, we need to design a suitable criticality assembly. The key problem of the design work is the core design because there are many limits for it such as the number of fuel rods loaded, fissile materials existed in the solution, reactivity control, core size and etc.

  12. Food safety and nutritional quality for the prevention of non communicable diseases: the Nutrient, hazard Analysis and Critical Control Point process (NACCP).

    Science.gov (United States)

    Di Renzo, Laura; Colica, Carmen; Carraro, Alberto; Cenci Goga, Beniamino; Marsella, Luigi Tonino; Botta, Roberto; Colombo, Maria Laura; Gratteri, Santo; Chang, Ting Fa Margherita; Droli, Maurizio; Sarlo, Francesca; De Lorenzo, Antonino

    2015-04-23

    The important role of food and nutrition in public health is being increasingly recognized as crucial for its potential impact on health-related quality of life and the economy, both at the societal and individual levels. The prevalence of non-communicable diseases calls for a reformulation of our view of food. The Hazard Analysis and Critical Control Point (HACCP) system, first implemented in the EU with the Directive 43/93/CEE, later replaced by Regulation CE 178/2002 and Regulation CE 852/2004, is the internationally agreed approach for food safety control. Our aim is to develop a new procedure for the assessment of the Nutrient, hazard Analysis and Critical Control Point (NACCP) process, for total quality management (TMQ), and optimize nutritional levels. NACCP was based on four general principles: i) guarantee of health maintenance; ii) evaluate and assure the nutritional quality of food and TMQ; iii) give correct information to the consumers; iv) ensure an ethical profit. There are three stages for the application of the NACCP process: 1) application of NACCP for quality principles; 2) application of NACCP for health principals; 3) implementation of the NACCP process. The actions are: 1) identification of nutritional markers, which must remain intact throughout the food supply chain; 2) identification of critical control points which must monitored in order to minimize the likelihood of a reduction in quality; 3) establishment of critical limits to maintain adequate levels of nutrient; 4) establishment, and implementation of effective monitoring procedures of critical control points; 5) establishment of corrective actions; 6) identification of metabolic biomarkers; 7) evaluation of the effects of food intake, through the application of specific clinical trials; 8) establishment of procedures for consumer information; 9) implementation of the Health claim Regulation EU 1924/2006; 10) starting a training program. We calculate the risk assessment as follows

  13. Radiological safety and control

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Sea Young; Yoo, Y. S.; Lee, J. C.; Lee, T. Y.; Lee, J. L.; Kim, B. W.; Lee, B. J.; Chung, K. K.; Chung, R. I.; Kim, J. S.; Lee, H. S.; Han, Y. D.; Lee, J. I.; Lee, K. C.; Yoon, J. H.; Sul, C. W.; Kim, C. K.; Yoon, K. S.; Seo, K. W.; Yoon, Y. C. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-01-01

    This report describes the annual results of radiological safety and control program of 1995. This program consists of working area monitoring including HANARO, personnel radiation monitoring, education for radiation protection. As a result, the objectives of radiation protection have been achieved satisfactorily through the activities mentioned above. Also, the calibration services were provided to insure accurate radiation measurement in the radiation working places. 21 figs., 39 tabs., 5 refs. (Author) .new.

  14. Allen Denver Russell Memorial Lecture, 2006. The use of microbicides in infection control: a critical look at safety, testing and applications.

    Science.gov (United States)

    Sattar, S A

    2006-10-01

    Microbial pathogens continue as major threats to health. Indeed, many ongoing societal changes are enhancing our vulnerability and exposure to several frank and opportunistic pathogens. This, together with rampant antimicrobial resistance and reduced prospects for newer drugs and vaccines, is forcing a higher reliance on microbiocides in infection prevention and control. That this reliance may not be well-founded becomes apparent from a closer look at current ways of testing and registering microbiocides, their label claims as well as human and environmental safety of certain widely used microbicidal chemicals. Many methods to test microbiocides for registration are flawed and/or entail test conditions irrelevant to field use. Pathogens listed on product labels may not be among those amenable to interruption through microbiocide use. The wide variations and discrepancies in existing national/regional regulations for registering microbiocides for sale stifle innovation. This is a critical look at the above-mentioned issues with emphasis on chemicals meant for use on environmental surfaces and medical devices. It highlights better ways to test microbiocides and to attain global harmonization of testing and product registration. It also details the known and potential dangers of microbiocide use and what to consider in choosing such formulations for optimal safety and effectiveness. End users are advised to be more critical and prudent in the selection and application of microbicidal chemicals, manufacturers are encouraged to explore infection control products and technologies that are safer in the workplace and for the environment, and regulators are urged to review and update the requirements and procedures for premarket review of microbiocide efficacy data and label claims. Independent investigations are also urgently needed to document the proportion of nosocomial infections that would be amenable to prevention through chemical disinfection of environmental

  15. Safety in Serbian animal source food industry and the impact of hazard analysis and critical control points: A review

    Science.gov (United States)

    Tomašević, I.; Đekić, I.

    2017-09-01

    There is a significant lack of HACCP-educated and/or HACCP-highly trained personnel within the Serbian animal source food workforces and veterinary inspectors, and this can present problems, particularly in hazard identification and assessment activities. However, despite obvious difficulties, HACCP benefits to the Serbian dairy industry are widespread and significant. Improving prerequisite programmes on the farms, mainly through infrastructural investments in milk collectors and transportation vehicles on one hand, and increasing hygiene awareness of farmers through training on the other hand has improved the safety of milk. The decline in bacterial numbers on meat contact surfaces, meat handlers’ hands and cooling facilities presents strong evidence of improved process hygiene and justifies the adoption of HACCP in Serbian meat establishments. Apart from the absence of national food poisoning statistics or national foodborne disease databases, the main obstacle to fully recognising the impact of HACCP on the safety of animal source food in Serbia is the lack of research regarding the occurrence of chemical and/or physical hazards interrelated with its production.

  16. Criticality Safety Basics for INL FMHs and CSOs

    Energy Technology Data Exchange (ETDEWEB)

    V. L. Putman

    2012-04-01

    Nuclear power is a valuable and efficient energy alternative in our energy-intensive society. However, material that can generate nuclear power has properties that require this material be handled with caution. If improperly handled, a criticality accident could result, which could severely harm workers. This document is a modular self-study guide about Criticality Safety Principles. This guide's purpose it to help you work safely in areas where fissionable nuclear materials may be present, avoiding the severe radiological and programmatic impacts of a criticality accident. It is designed to stress the fundamental physical concepts behind criticality controls and the importance of criticality safety when handling fissionable materials outside nuclear reactors. This study guide was developed for fissionable-material-handler and criticality-safety-officer candidates to use with related web-based course 00INL189, BEA Criticality Safety Principles, and to help prepare for the course exams. These individuals must understand basic information presented here. This guide may also be useful to other Idaho National Laboratory personnel who must know criticality safety basics to perform their assignments safely or to design critically safe equipment or operations. This guide also includes additional information that will not be included in 00INL189 tests. The additional information is in appendices and paragraphs with headings that begin with 'Did you know,' or with, 'Been there Done that'. Fissionable-material-handler and criticality-safety-officer candidates may review additional information at their own discretion. This guide is revised as needed to reflect program changes, user requests, and better information. Issued in 2006, Revision 0 established the basic text and integrated various programs from former contractors. Revision 1 incorporates operation and program changes implemented since 2006. It also incorporates suggestions, clarifications

  17. Safety-Critical Java for Embedded Systems

    DEFF Research Database (Denmark)

    Rios Rivas, Juan Ricardo

    for Java aims at providing a reduced set of the Java programming language that can be used for systems that need to be certified at the highest levels of criticality. Safety-critical Java (SCJ) restricts how a developer can structure an application by providing a specific programming model...... and by restricting the set of methods and libraries that can be used. Furthermore, its memory model do not use a garbage-collected heap but scoped memories. In this thesis we examine the use of the SCJ specification through an implementation in a time-predictable, FPGA-based Java processor. The specification is now...

  18. A desktop 3D printer in safety-critical Java

    DEFF Research Database (Denmark)

    Strøm, Tórur Biskopstø; Schoeberl, Martin

    2012-01-01

    It is desirable to bring Java technology to safety-critical systems. To this end The Open Group has created the safety-critical Java specification, which will allow Java applications, written according to the specification, to be certifiable in accordance with safety-critical standards. Although...... there exist several safety-critical Java framework implementations, there is a lack of safety-critical use cases implemented according to the specification. In this paper we present a 3D printer and its safety-critical Java level 1 implementation as a use case. With basis in the implementation we evaluate...

  19. CANISTER HANDLING FACILITY CRITICALITY SAFETY CALCULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    C.E. Sanders

    2005-04-07

    This design calculation revises and updates the previous criticality evaluation for the canister handling, transfer and staging operations to be performed in the Canister Handling Facility (CHF) documented in BSC [Bechtel SAIC Company] 2004 [DIRS 167614]. The purpose of the calculation is to demonstrate that the handling operations of canisters performed in the CHF meet the nuclear criticality safety design criteria specified in the ''Project Design Criteria (PDC) Document'' (BSC 2004 [DIRS 171599], Section 4.9.2.2), the nuclear facility safety requirement in ''Project Requirements Document'' (Canori and Leitner 2003 [DIRS 166275], p. 4-206), the functional/operational nuclear safety requirement in the ''Project Functional and Operational Requirements'' document (Curry 2004 [DIRS 170557], p. 75), and the functional nuclear criticality safety requirements described in the ''Canister Handling Facility Description Document'' (BSC 2004 [DIRS 168992], Sections 3.1.1.3.4.13 and 3.2.3). Specific scope of work contained in this activity consists of updating the Category 1 and 2 event sequence evaluations as identified in the ''Categorization of Event Sequences for License Application'' (BSC 2004 [DIRS 167268], Section 7). The CHF is limited in throughput capacity to handling sealed U.S. Department of Energy (DOE) spent nuclear fuel (SNF) and high-level radioactive waste (HLW) canisters, defense high-level radioactive waste (DHLW), naval canisters, multicanister overpacks (MCOs), vertical dual-purpose canisters (DPCs), and multipurpose canisters (MPCs) (if and when they become available) (BSC 2004 [DIRS 168992], p. 1-1). It should be noted that the design and safety analyses of the naval canisters are the responsibility of the U.S. Department of the Navy (Naval Nuclear Propulsion Program) and will not be included in this document. In addition, this calculation is valid for

  20. Critical appraisal of the safety and efficacy of insulin detemir in glycemic control and cardiovascular risk management in diabetics

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Le Floch

    2010-06-01

    Full Text Available Jean-Pierre Le FlochDepartment of Diabetology, Medical Clinic, Villecresnes, FranceAbstract: Insulin detemir is an analog of human insulin designed to provide a long duration of basal insulin action. This is achieved by protracted absorption from the injection depot, which results in part from increased self-association of insulin detemir molecules and in part from reversible albumin binding. Subsequent albumin binding in the circulation is thought to buffer changes in the effects at target tissues that could otherwise arise from variability in absorption rate. In consequence, insulin detemir has shown a less variable pharmacodynamic profile than alternative basal insulins; this manifests as more consistent temporal glucose reduction profiles in repeat-clamp studies. In clinical trials, insulin detemir has been characterized by consistent risk reductions in hypoglycemia, as well as reduced weight gain in comparison with other basal insulins. Given some recent associations that have been made in prospective and epidemiologic studies between glucose variability and/or hypoglycemia and increased cardiovascular risk, and the long-known association between excess weight and cardiovascular risk, it is possible that the clinical profile of insulin detemir may carry prognostic value with regard to cardiovascular safety, although this is yet to be substantiated. There have also been some concerns raised recently over the use of insulin analogs and cancer risk, but available clinical data and the receptor interaction profile of insulin detemir suggest no excess in risk in comparison with human insulin therapy. Optimal approaches for the clinical use of insulin detemir have been emerging through an increasing clinical study base, and the analog is becoming established as a potentially valuable therapy option.Keywords: insulin detemir, type 2 diabetes, glucose variability, hypoglycemia, weight gain

  1. Formal methods in the development of safety critical software systems

    Energy Technology Data Exchange (ETDEWEB)

    Williams, L.G. [Software Engineering Research, Boulder, CO (United States)

    1991-11-15

    As the use of computers in critical control systems such as aircraft controls, medical instruments, defense systems, missile controls, and nuclear power plants has increased, concern for the safety of those systems has also grown. Much of this concern has focused on the software component of those computer-based systems. This is primarily due to historical experience with software systems that often exhibit larger numbers of errors than their hardware counterparts and the fact that the consequences of a software error may endanger human life, property, or the environment. A number of different techniques have been used to address the issue of software safety. Some are standard software engineering techniques aimed at reducing the number of faults in a software protect, such as reviews and walkthroughs. Others, including fault tree analysis, are based on identifying and reducing hazards. This report examines the role of one such technique, formal methods, in the development of software for safety critical systems. The use of formal methods to increase the safety of software systems is based on their role in reducing the possibility of software errors that could lead to hazards. The use of formal methods in the development of software systems is controversial. Proponents claim that the use of formal methods can eliminate errors from the software development process, and produce programs that are probably correct. Opponents claim that they are difficult to learn and that their use increases development costs unacceptably. This report discusses the potential of formal methods for reducing failures in safety critical software systems.

  2. Radiological safety and control

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Kyeong Won; You, Young Soo; Chang, Sea Young; Yoon, Yeo Chang; Yoon, Suk Chul; Kim, Jang Yeol; Lee, Tae Young; Lee, Bong Jae; Kim, Bong Hwan; Lee, Jong Il; Jeong, Juk Yeon; Lee, Sang Yeol; Jeong, Kyung Ki; Jeong, Rae Ik; Kim, Jong Su; Han, Young Dae; Lee, Hyung Sub; Kim, Chang Kyung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-01-01

    This report describes the annual results of radiological safety and control program. This program includes working area monitoring (WAM), personnel radiation monitoring (PRM), education for radiation protection (ERP), preparing for KMRR operation and developing QA program on personal dose evaluation. As a result, the objectives of radiation protection have been achieved satisfactorily through the WAM, PRM and ERP. The QA program on personal dose evaluation has been approved by the MOST according to the Ministerial Ordinance (No. 1992-15). KAERI has also been authorized as a specialized processor for personal dose evaluation. 32 tabs., 20 figs. (Author) .new.

  3. Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients : a randomised, controlled, open-label trial

    NARCIS (Netherlands)

    de Jong, Evelien; van Oers, Jos A; Beishuizen, Albertus; Vos, Piet; Vermeijden, Wytze J; Haas, Lenneke E; Loef, Bert G; Dormans, Tom; van Melsen, Gertrude C; Kluiters, Yvette C; Kemperman, Hans; van den Elsen, Maarten J; Schouten, Jeroen A; Streefkerk, Jörn O; Krabbe, Hans G; Kieft, Hans; Kluge, Georg H; van Dam, Veerle C; van Pelt, Joost; Bormans, Laura; Otten, Martine Bokelman; Reidinga, Auke C; Endeman, Henrik; Twisk, Jos W; van de Garde, Ewoudt M W; de Smet, Anne Marie G A; Kesecioglu, Jozef; Girbes, Armand R; Nijsten, Maarten W; de Lange, Dylan W

    2016-01-01

    BACKGROUND: In critically ill patients, antibiotic therapy is of great importance but long duration of treatment is associated with the development of antimicrobial resistance. Procalcitonin is a marker used to guide antibacterial therapy and reduce its duration, but data about safety of this reduct

  4. Compositional synthesis of safety controllers

    NARCIS (Netherlands)

    Kuijper, Wouter

    2012-01-01

    In my thesis I investigate compositional techniques for synthesis of safety controllers. A safety controller, in this context, is a state machine that gives the set of safe control outputs for every possible sequence of observations from the plant under control. Compositionality, in this context, re

  5. A double blind randomized placebo controlled phase I/II study assessing the safety and efficacy of allogeneic bone marrow derived mesenchymal stem cell in critical limb ischemia

    OpenAIRE

    Gupta, Pawan K; Chullikana, Anoop; Parakh, Rajiv; Desai, Sanjay; Das, Anjan; Gottipamula, Sanjay; Krishnamurthy, Sagar; Anthony, Naveen; Pherwani, Arun; Majumdar, Anish S

    2013-01-01

    Background Peripheral vascular disease of the lower extremities comprises a clinical spectrum that extends from no symptoms to presentation with critical limb ischemia (CLI). Bone marrow derived Mesenchymal Stem Cells (BM- MSCs) may ameliorate the consequences of CLI due to their combinatorial potential for inducing angiogenesis and immunomodulatory environment in situ. The primary objective was to determine the safety of BM- MSCs in patients with CLI. Methods Prospective, double blind random...

  6. Critical View of Safety During Laparoscopic Cholecystectomy

    OpenAIRE

    Vettoretto, Nereo; Saronni, Cristiano; Harbi, Asaf; Balestra, Luca; Taglietti, Lucio; Giovanetti, Maurizio

    2011-01-01

    Background and Objectives: Laparoscopic cholecystectomy has a 0.3% to 0.5% morbidity rate due to major biliary injuries. The majority of surgeons have routinely performed the so-called “infundibular” technique for gallbladder hilar dissection since the introduction of laparoscopy in the early nineties. The “critical view of safety” approach has only been recently discussed in controlled studies. It is characterized by a blunt dissection of the upper part of Calot's space, which does not usual...

  7. FUEL HANDLING FACILITY CRITICALITY SAFETY CALCULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    C.E. Sanders

    2005-06-30

    The purpose of this design calculation is to perform a criticality evaluation of the Fuel Handling Facility (FHF) and the operations and processes performed therein. The current intent of the FHF is to receive transportation casks whose contents will be unloaded and transferred to waste packages (WP) or MGR Specific Casks (MSC) in the fuel transfer bays. Further, the WPs will also be prepared in the FHF for transfer to the sub-surface facility (for disposal). The MSCs will be transferred to the Aging Facility for storage. The criticality evaluation of the FHF features the following: (I) Consider the types of waste to be received in the FHF as specified below: (1) Uncanistered commercial spent nuclear fuel (CSNF); (2) Canistered CSNF (with the exception of horizontal dual-purpose canister (DPC) and/or multi-purpose canisters (MPCs)); (3) Navy canistered SNF (long and short); (4) Department of Energy (DOE) canistered high-level waste (HLW); and (5) DOE canistered SNF (with the exception of MCOs). (II) Evaluate the criticality analyses previously performed for the existing Nuclear Regulatory Commission (NRC)-certified transportation casks (under 10 CFR 71) to be received in the FHF to ensure that these analyses address all FHF conditions including normal operations, and Category 1 and 2 event sequences. (III) Evaluate FHF criticality conditions resulting from various Category 1 and 2 event sequences. Note that there are currently no Category 1 and 2 event sequences identified for FHF. Consequently, potential hazards from a criticality point of view will be considered as identified in the ''Internal Hazards Analysis for License Application'' document (BSC 2004c, Section 6.6.4). (IV) Assess effects of potential moderator intrusion into the fuel transfer bay for defense in depth. The SNF/HLW waste transfer activity (i.e., assembly and canister transfer) that is being carried out in the FHF has been classified as safety category in the &apos

  8. Critical review of oral drug treatments for diabetic neuropathic pain-clinical outcomes based on efficacy and safety data from placebo-controlled and direct comparative studies.

    NARCIS (Netherlands)

    Adriaensen, H.F.M; Plaghki, L.; Mathieu, C.; Joffroy, A.; Vissers, K.C.P.

    2005-01-01

    The present review aims to evaluate the efficacy and safety of a selection of oral treatments for the management of painful diabetic neuropathy. A literature review was conducted retrieving placebo-controlled and direct comparative studies with a selection of oral treatments for painful diabetic neu

  9. The Department of Energy Nuclear Criticality Safety Program

    Science.gov (United States)

    Felty, James R.

    2005-05-01

    This paper broadly covers key events and activities from which the Department of Energy Nuclear Criticality Safety Program (NCSP) evolved. The NCSP maintains fundamental infrastructure that supports operational criticality safety programs. This infrastructure includes continued development and maintenance of key calculational tools, differential and integral data measurements, benchmark compilation, development of training resources, hands-on training, and web-based systems to enhance information preservation and dissemination. The NCSP was initiated in response to Defense Nuclear Facilities Safety Board Recommendation 97-2, Criticality Safety, and evolved from a predecessor program, the Nuclear Criticality Predictability Program, that was initiated in response to Defense Nuclear Facilities Safety Board Recommendation 93-2, The Need for Critical Experiment Capability. This paper also discusses the role Dr. Sol Pearlstein played in helping the Department of Energy lay the foundation for a robust and enduring criticality safety infrastructure.

  10. Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess; J. Blair Briggs; David W. Nigg

    2009-11-01

    One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

  11. Proceedings of the Nuclear Criticality Technology Safety Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Rene G. Sanchez

    1998-04-01

    This document contains summaries of most of the papers presented at the 1995 Nuclear Criticality Technology Safety Project (NCTSP) meeting, which was held May 16 and 17 at San Diego, Ca. The meeting was broken up into seven sessions, which covered the following topics: (1) Criticality Safety of Project Sapphire; (2) Relevant Experiments For Criticality Safety; (3) Interactions with the Former Soviet Union; (4) Misapplications and Limitations of Monte Carlo Methods Directed Toward Criticality Safety Analyses; (5) Monte Carlo Vulnerabilities of Execution and Interpretation; (6) Monte Carlo Vulnerabilities of Representation; and (7) Benchmark Comparisons.

  12. A Critical Perspective on Online Safety Measures

    Directory of Open Access Journals (Sweden)

    Elza Dunkels

    2010-06-01

    Full Text Available The Nordic countries have enjoyed mass use of the Internet at home and in schools since the mid-1990’s. Children have been noted to have rapidly taken the Internet into possession and to have made use of the affordances (Greeno, 1994 of Internet communication. However, media coverage of how children take on, and learn what the Internet has to offer has often been of a negative kind. Blazing headlines portray a generation in bottomless danger where children are defined both as possible victims and perpetrators. Another common attribute of this media coverage is the exoticising of young people’s net cultures – describing the young and their cultures as profoundly different from earlier generations and elevating the “colourful and the bizarre” (Coffey et al., 1999, p. 169 to a level where it appears normal for this particular generation. In this setting safe use guides – tips for parents and children on how to keep safe on the Internet – began to appear. They were often composed by teachers, concerned parents, non-governmental organisations and in some cases governments. The safe use guides were disseminated online in different forums aimed at concerned adults. In this article I will give a brief description of current online safety issues and examine them critically. My earlier research – 104 interviews with 12-year old Swedes conducted in 2004-2005 (Dunkels, 2007 and a study of European safe use guides conducted in 2008 (Lüders et al., 2009 left me with a number of questions. I could see that safe use guides were strikingly similar, despite their origin, and I could see that they rested upon norms and values that were actually neither accounted for nor even declared. This article is a literature review of the area with the aim of critically discussing some of these questions.

  13. SRTC criticality safety technical review: Nuclear Criticality Safety Evaluation 93-04 enriched uranium receipt

    Energy Technology Data Exchange (ETDEWEB)

    Rathbun, R.

    1993-10-13

    Review of NMP-NCS-930087, {open_quotes}Nuclear Criticality Safety Evaluation 93-04 Enriched Uranium Receipt (U), July 30, 1993, {close_quotes} was requested of SRTC (Savannah River Technology Center) Applied Physics Group. The NCSE is a criticality assessment to determine the mass limit for Engineered Low Level Trench (ELLT) waste uranium burial. The intent is to bury uranium in pits that would be separated by a specified amount of undisturbed soil. The scope of the technical review, documented in this report, consisted of (1) an independent check of the methods and models employed, (2) independent HRXN/KENO-V.a calculations of alternate configurations, (3) application of ANSI/ANS 8.1, and (4) verification of WSRC Nuclear Criticality Safety Manual procedures. The NCSE under review concludes that a 500 gram limit per burial position is acceptable to ensure the burial site remains in a critically safe configuration for all normal and single credible abnormal conditions. This reviewer agrees with that conclusion.

  14. Agile Methods for Open Source Safety-Critical Software.

    Science.gov (United States)

    Gary, Kevin; Enquobahrie, Andinet; Ibanez, Luis; Cheng, Patrick; Yaniv, Ziv; Cleary, Kevin; Kokoori, Shylaja; Muffih, Benjamin; Heidenreich, John

    2011-08-01

    The introduction of software technology in a life-dependent environment requires the development team to execute a process that ensures a high level of software reliability and correctness. Despite their popularity, agile methods are generally assumed to be inappropriate as a process family in these environments due to their lack of emphasis on documentation, traceability, and other formal techniques. Agile methods, notably Scrum, favor empirical process control, or small constant adjustments in a tight feedback loop. This paper challenges the assumption that agile methods are inappropriate for safety-critical software development. Agile methods are flexible enough to encourage the rightamount of ceremony; therefore if safety-critical systems require greater emphasis on activities like formal specification and requirements management, then an agile process will include these as necessary activities. Furthermore, agile methods focus more on continuous process management and code-level quality than classic software engineering process models. We present our experiences on the image-guided surgical toolkit (IGSTK) project as a backdrop. IGSTK is an open source software project employing agile practices since 2004. We started with the assumption that a lighter process is better, focused on evolving code, and only adding process elements as the need arose. IGSTK has been adopted by teaching hospitals and research labs, and used for clinical trials. Agile methods have matured since the academic community suggested they are not suitable for safety-critical systems almost a decade ago, we present our experiences as a case study for renewing the discussion.

  15. Nuclear Criticality Safety Handbook, Version 2. English translation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-08-01

    The Nuclear Criticality Safety Handbook, Version 2 essentially includes the description of the Supplement Report to the Nuclear Criticality Safety Handbook, released in 1995, into the first version of the Nuclear Criticality Safety Handbook, published in 1988. The following two points are new: (1) exemplifying safety margins related to modeled dissolution and extraction processes, (2) describing evaluation methods and alarm system for criticality accidents. Revision has been made based on previous studies for the chapter that treats modeling the fuel system: e.g., the fuel grain size that the system can be regarded as homogeneous, non-uniformity effect of fuel solution, an burnup credit. This revision has solved the inconsistencies found in the first version between the evaluation of errors found in JACS code system and the criticality condition data that were calculated based on the evaluation. This report is an English translation of the Nuclear Criticality Safety Handbook, Version 2, originally published in Japanese as JAERI 1340 in 1999. (author)

  16. Criticality safety evaluation report for K Basin filter cartridges

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, D.G., Westinghouse Hanford

    1996-08-28

    A criticality safety evaluation of the K Basin filter cartridge assemblies was completed to support operations without criticality alarm system. The results show that for normal operation, the cartridge assembly is far below the safety limit of K eff = 0.95.

  17. Evaluating safety-critical organizations - emphasis on the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, Teemu; Oedewald, Pia (VTT, Technical Research Centre of Finland (Finland))

    2009-04-15

    - it is understood that safety is a complex phenomenon. Safety is understood as a property of an entire system and not just absence of incidents - people feel personally responsible for the safety of the entire system, they feel they can have an effect on safety - the organizations aims for understanding the hazards and anticipating the risks in their activities - the organization is alert to the possibility of an unanticipated event - good prerequisites for carrying out the daily work exist. An organizational evaluation should aim at reasoning the: - sources of effectiveness in the organizational dimensions - sources of ineffectiveness in the organization dimensions - social processes in the organization - psychological outcomes of the current organization on a personnel level, e.g. motivation, understanding of hazards and sense of control. When drawing inferences from the organizational evaluations and defining development initiatives, it is important to consider actions that will promote and maintain the strengths of the organization as well as actions that will address and develop the weak areas. Issues associated with data collection and choice of methods has been a topic of much discussion in the field of evaluation of safety-critical organizations. We argue that the problem of collecting data is not the most important problem in terms of facilitating valid evaluations. A more important problem concerns the criteria that are used, as well as the operationalization of criteria into something measurable. Too much effort has been spent on methods and too little on contemplating the question of valid evaluation criteria and a valid means of deducing from the data whether the criteria are fulfilled. In order to accomplish this, a valid evaluation framework is needed, which incorporates the idea of organization as a complex sociotechnical system. This report has been an attempt to illustrate the premises and key issues to consider in organizational evaluations. No

  18. Criticality Safety Evaluation of Hanford Site High Level Waste Storage Tanks

    Energy Technology Data Exchange (ETDEWEB)

    ROGERS, C.A.

    2000-02-17

    This criticality safety evaluation covers operations for waste in underground storage tanks at the high-level waste tank farms on the Hanford site. This evaluation provides the bases for criticality safety limits and controls to govern receipt, transfer, and long-term storage of tank waste. Justification is provided that a nuclear criticality accident cannot occur for tank farms operations, based on current fissile material and operating conditions.

  19. Safety and security profiles of industry networks used in safety- critical applications

    Directory of Open Access Journals (Sweden)

    Mária FRANEKOVÁ

    2008-01-01

    Full Text Available The author describes the mechanisms of safety and security profiles of industry and communication networks used within safety – related applications in technological and information levels of process control recommended according to standards IEC 61784-3,4. Nowadays the number of vendors of the safety – related communication technologies who guarantees besides the standard communication, the communication amongst the safety – related equipment according to IEC 61508 is increasing. Also the number of safety – related products is increasing, e. g. safety Fieldbus, safety PLC, safety curtains, safety laser scanners, safety buttons, safety relays and other. According to world survey the safety Fieldbus denoted the highest growth from all manufactured safety products.The main part of this paper is the description of the safety-related Fieldbus communication system, which has to guaranty Safety Integrity Level.

  20. Proceedings of the nuclear criticality technology safety project

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R.G. [comp.

    1997-06-01

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

  1. Glucose control in critical care

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Glycemic control among critically-ill patients has beena topic of considerable attention for the past 15 years.An initial focus on the potentially deleterious effects ofhyperglycemia led to a series of investigations regardingintensive insulin therapy strategies that targeted tightglycemic control. As knowledge accumulated, the pursuitof tight glycemic control among critically-ill patients cameto be seen as counterproductive, and moderate glycemiccontrol came to dominate as the standard practice inintensive care units. In recent years, there has beenincreased focus on the importance of hypoglycemicepisodes, glycemic variability, and premorbid diabeticstatus as factors that contribute to outcomes amongcritically-ill patients. This review provides a survey ofkey studies on glucose control in critical care, and aimsto deliver perspective regarding glycemic managementamong critically-ill patients.

  2. The Qualification Experiences for Safety-critical Software of POSAFE-Q

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Yeol; Son, Kwang Seop; Cheon, Se Woo; Lee, Jang Soo; Kwon, Kee Choon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    Programmable Logic Controllers (PLC) have been applied to the Reactor Protection System (RPS) and the Engineered Safety Feature (ESF)-Component Control System (CCS) as the major safety system components of nuclear power plants. This paper describes experiences on the qualification of the safety-critical software including the pCOS kernel and system tasks related to a safety-grade PLC, i.e. the works done for the Software Verification and Validation, Software Safety Analysis, Software Quality Assurance, and Software Configuration Management etc.

  3. Process control under safety aspects

    Energy Technology Data Exchange (ETDEWEB)

    Vollmer, T. E-mail: theo.vollmer@hvt.fzk.de; Borcherding, K.; Hellriegel, G.; Penzhorn, R.-D

    2000-08-01

    The safety of people and the environment is increasingly important in the operation and, consequently, also in the project design of process equipment. Rules and regulations for safeguarding of industrial process plants (not-nuclear and nuclear) by means of process control engineering are either being developed or expanded. This includes the international harmonization of existing national codes. This article presents an introduction into the philosophy of ensuring plant safety by means of instrumentation and control protection systems. The methods of risk assessment are described, and various potential solutions are shown which are geared to achieving the necessary level of safety and, at the same time, allowing flexible operation to be maintained. Reference is made to the problems existing with respect to integrating people into this process, i.e. man-machine interaction, especially in view of possible interventions in emergencies.

  4. A Test Suite for Safety-Critical Java using JML

    DEFF Research Database (Denmark)

    Ravn, Anders Peter; Søndergaard, Hans

    2013-01-01

    Development techniques are presented for a test suite for the draft specification of the Java profile for Safety-Critical Systems. Distinguishing features are: specification of conformance constraints in the Java Modeling Language, encoding of infrastructure concepts without implementation bias...

  5. Criticality safety benchmark evaluation project: Recovering the past

    Energy Technology Data Exchange (ETDEWEB)

    Trumble, E.F.

    1997-06-01

    A very brief summary of the Criticality Safety Benchmark Evaluation Project of the Westinghouse Savannah River Company is provided in this paper. The purpose of the project is to provide a source of evaluated criticality safety experiments in an easily usable format. Another project goal is to search for any experiments that may have been lost or contain discrepancies, and to determine if they can be used. Results of evaluated experiments are being published as US DOE handbooks.

  6. Explicit Precedence Constraints in Safety-Critical Java

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang; Noulard, Eric; Pagetti, Claire

    2013-01-01

    Safety-critical Java (SCJ) aims at making the amenities of Java available for the development of safety-critical applications. The multi-rate synchronous language Prelude facilitates the specification of the communication and timing requirements of complex real-time systems. This paper combines...... to provide explicit support for precedence constraints. We present the considerations behind the design of this extension and discuss our experiences with a first prototype implementation based on the SCJ implementation of the Java Optimized Processor....

  7. Natural Language Interface for Safety Certification of Safety-Critical Software

    Science.gov (United States)

    Denney, Ewen; Fischer, Bernd

    2011-01-01

    Model-based design and automated code generation are being used increasingly at NASA. The trend is to move beyond simulation and prototyping to actual flight code, particularly in the guidance, navigation, and control domain. However, there are substantial obstacles to more widespread adoption of code generators in such safety-critical domains. Since code generators are typically not qualified, there is no guarantee that their output is correct, and consequently the generated code still needs to be fully tested and certified. The AutoCert generator plug-in supports the certification of automatically generated code by formally verifying that the generated code is free of different safety violations, by constructing an independently verifiable certificate, and by explaining its analysis in a textual form suitable for code reviews.

  8. 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

  9. Proceedings of the Nuclear Criticality Technology and Safety Project Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R.G. [comp.

    1994-01-01

    This report is the proceedings of the annual Nuclear Criticality Technology and Safety Project (NCTSP) Workshop held in Monterey, California, on April 16--28, 1993. The NCTSP was sponsored by the Department of Energy and organized by the Los Alamos Critical Experiments Facility. The report is divided into six sections reflecting the sessions outlined on the workshop agenda.

  10. Towards the Design of Safety-Critical Software

    Directory of Open Access Journals (Sweden)

    R. Rafeh

    2013-10-01

    Full Text Available Safety is the most important factor when developing software for safety-critical systems. Traditional approaches attempted to achieve safety through testing the software. However, there might be some bugs in the software not revealed in the test procedure. Formal verification is a new trend in developing safe software. In this paper, we propose a multi-phase formal approach for safety management in safety-critical software. We use timed transition Petri-net as a formal means to specify the properties of the model and their relations in each component of the software. In addition, we use the Z language to specify textual and mathematical specifications of the model, as a representative model to evaluate the proposed approach; we chose continuous infusion insulin pump (CIIP.

  11. Criticality safety in high explosives dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Troyer, S.D.

    1997-06-01

    In 1992, an incident occurred at the Pantex Plant in which the cladding around a fissile material component (pit) cracked during dismantlement of the high explosives portion of a nuclear weapon. Although the event did not result in any significant contamination or personnel exposures, concerns about the incident led to the conclusion that the current dismantlement process was unacceptable. Options considered for redesign, dissolution tooling design considerations, dissolution tooling design features, and the analysis of the new dissolution tooling are summarized. The final tooling design developed incorporated a number of safety features and provides a simple, self-contained, low-maintenance method of high explosives removal for nuclear explosive dismantlement. Analyses demonstrate that the tooling design will remain subcritical under normal, abnormal, and credible accident scenarios. 1 fig.

  12. Analyzing Software Requirements Errors in Safety-Critical, Embedded Systems

    Science.gov (United States)

    Lutz, Robyn R.

    1993-01-01

    This paper analyzes the root causes of safety-related software errors in safety-critical, embedded systems. The results show that software errors identified as potentially hazardous to the system tend to be produced by different error mechanisms than non- safety-related software errors. Safety-related software errors are shown to arise most commonly from (1) discrepancies between the documented requirements specifications and the requirements needed for correct functioning of the system and (2) misunderstandings of the software's interface with the rest of the system. The paper uses these results to identify methods by which requirements errors can be prevented. The goal is to reduce safety-related software errors and to enhance the safety of complex, embedded systems.

  13. Training of nuclear criticality safety engineers

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.G. [Oak Ridge Y-12 Plant, TN (United States)

    1997-06-01

    The site specific analysis of nuclear criticality training needs is very briefly described. Analysis indicated that the four major components required were analysis, surveillance, business practices or administration, and emergency preparedness. The analysis component was further divided into process analysis, accident analysis, and transportation analysis. Ten subject matter areas for the process analysis component were identified as candidates for class development. Training classes developed from the job content analysis have demonstrated that the specialized information can be successfully delivered to new entrants. 1 fig.

  14. Agility in Development of Safety-Critical Software: A Conceptual Model

    DEFF Research Database (Denmark)

    Tordrup Heeager, Lise; Nielsen, Peter Axel

    2017-01-01

    Safety-critical information systems are being used increasingly as we see applications in new areas such as personal medical devices, traffic control and detection of pathogens. A current research debate is whether safety-critical systems must be developed with traditional waterfall processes...... or agile processes which are faster and will lead to better products. In this paper we review the diverse research literature on agility in safety-critical software development. There are key propositions that we pull from the literature and combine into a framework for understanding the foundational...... challenges and the contingencies of agile development of safety-critical software. The framework consists of four problematic practice areas (which the literature mainly has focused on) and five relationships, which we suggest is even more important than the problematic areas. From this review we suggest...

  15. Criticality Safety Code Validation with LWBR’s SB Cores

    Energy Technology Data Exchange (ETDEWEB)

    Putman, Valerie Lee

    2003-01-01

    The first set of critical experiments from the Shippingport Light Water Breeder Reactor Program included eight, simple geometry critical cores built with 233UO2-ZrO2, 235UO2-ZrO2, ThO2, and ThO2-233UO2 nuclear materials. These cores are evaluated, described, and modeled to provide benchmarks and validation information for INEEL criticality safety calculation methodology. In addition to consistency with INEEL methodology, benchmark development and nuclear data are consistent with International Criticality Safety Benchmark Evaluation Project methodology.Section 1 of this report introduces the experiments and the reason they are useful for validating some INEEL criticality safety calculations. Section 2 provides detailed experiment descriptions based on currently available experiment reports. Section 3 identifies criticality safety validation requirement sources and summarizes requirements that most affect this report. Section 4 identifies relevant hand calculation and computer code calculation methodologies used in the experiment evaluation, benchmark development, and validation calculations. Section 5 provides a detailed experiment evaluation. This section identifies resolutions for currently unavailable and discrepant information. Section 5 also reports calculated experiment uncertainty effects. Section 6 describes the developed benchmarks. Section 6 includes calculated sensitivities to various benchmark features and parameters. Section 7 summarizes validation results. Appendices describe various assumptions and their bases, list experimenter calculations results for items that were independently calculated for this validation work, report other information gathered and developed by SCIENTEC personnel while evaluating these same experiments, and list benchmark sample input and miscellaneous supplementary data.

  16. Aluminum Data Measurements and Evaluation for Criticality Safety Applications

    Science.gov (United States)

    Leal, L. C.; Guber, K. H.; Spencer, R. R.; Derrien, H.; Wright, R. Q.

    2002-12-01

    The Defense Nuclear Facility Safety Board (DNFSB) Recommendation 93-2 motivated the US Department of Energy (DOE) to develop a comprehensive criticality safety program to maintain and to predict the criticality of systems throughout the DOE complex. To implement the response to the DNFSB Recommendation 93-2, a Nuclear Criticality Safety Program (NCSP) was created including the following tasks: Critical Experiments, Criticality Benchmarks, Training, Analytical Methods, and Nuclear Data. The Nuclear Data portion of the NCSP consists of a variety of differential measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) at the Oak Ridge National Laboratory (ORNL), data analysis and evaluation using the generalized least-squares fitting code SAMMY in the resolved, unresolved, and high energy ranges, and the development and benchmark testing of complete evaluations for a nuclide for inclusion into the Evaluated Nuclear Data File (ENDF/B). This paper outlines the work performed at ORNL to measure, evaluate, and test the nuclear data for aluminum for applications in criticality safety problems.

  17. Formalization and Validation of Safety-Critical Requirements

    CERN Document Server

    Cimatti, Alessandro; Susi, Angelo; Tonetta, Stefano

    2010-01-01

    The validation of requirements is a fundamental step in the development process of safety-critical systems. In safety critical applications such as aerospace, avionics and railways, the use of formal methods is of paramount importance both for requirements and for design validation. Nevertheless, while for the verification of the design, many formal techniques have been conceived and applied, the research on formal methods for requirements validation is not yet mature. The main obstacles are that, on the one hand, the correctness of requirements is not formally defined; on the other hand that the formalization and the validation of the requirements usually demands a strong involvement of domain experts. We report on a methodology and a series of techniques that we developed for the formalization and validation of high-level requirements for safety-critical applications. The main ingredients are a very expressive formal language and automatic satisfiability procedures. The language combines first-order, tempor...

  18. Safety Cases for Advanced Control Software: Safety Case Patterns

    Science.gov (United States)

    2007-10-15

    Classification Argument (from [14]) The classification of software failure modes can be useful for adaptive systems. Kurd in [15] shows how HAZOPS ...Safety Cases for Advanced Control Software : Safety Case Patterns Robert Alexander, Tim Kelly, Zeshan Kurd, John...5a. CONTRACT NUMBER FA8655-07-1-3025 5b. GRANT NUMBER 4. TITLE AND SUBTITLE Safety Cases for Advanced Control Software 5c. PROGRAM ELEMENT

  19. Nuclear Criticality Safety Organization training implementation. Revision 4

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, K.J.; Taylor, R.G.; Worley, C.A.

    1997-05-19

    The Nuclear Criticality Safety Organization (NCSO) is committed to developing and maintaining a staff of qualified personnel to meet the current and anticipated needs in Nuclear Criticality Safety (NCS) at the Oak Ridge Y-12 Plant. This document provides a listing of the roles and responsibilities of NCSO personnel with respect to training and details of the Training Management System (TMS) programs, Mentoring Checklists and Checksheets, as well as other documentation utilized to implement the program. This Training Implementation document is applicable to all technical and managerial NCSO personnel, including temporary personnel, sub-contractors and/or LMES employees on loan to the NCSO, who are in a qualification program.

  20. Safety critical systems handbook a straightforward guide to functional safety : IEC 61508 (2010 edition) and related standards

    CERN Document Server

    Smith, David J

    2010-01-01

    Electrical, electronic and programmable electronic systems increasingly carry out safety functions to guard workers and the public against injury or death and the environment against pollution. The international functional safety standard IEC 61508 was revised in 2010, and this is the first comprehensive guide available to the revised standard. As functional safety is applicable to many industries, this book will have a wide readership beyond the chemical and process sector, including oil and gas, power generation, nuclear, aircraft, and automotive industries, plus project, instrumentation, design, and control engineers. * The only comprehensive guide to IEC 61508, updated to cover the 2010 amendments, that will ensure engineers are compliant with the latest process safety systems design and operation standards* Helps readers understand the process required to apply safety critical systems standards* Real-world approach helps users to interpret the standard, with case studies and best practice design examples...

  1. Fission, critical mass and safety-a historical review

    Energy Technology Data Exchange (ETDEWEB)

    Meggitt, Geoff

    2006-06-15

    Since the discovery of fission, the notion of a chain reaction in a critical mass releasing massive amounts of energy has haunted physicists. The possibility of a bomb or a reactor prompted much of the early work on determining a critical mass, but the need to avoid an accidental critical excursion during processing or transport of fissile material drove much that took place subsequently. Because of the variety of possible situations that might arise, it took some time to develop adequate theoretical tools for criticality safety and the early assessments were based on direct experiment. Some extension of these experiments to closely similar situations proved possible, but it was not until the 1960s that theoretical methods (and computers to run them) developed enough for them to become reliable assessment tools. Validating such theoretical methods remained a concern, but by the end of the century they formed the backbone of criticality safety assessment. This paper traces the evolution of these methods, principally in the UK and USA, and summarises some related work concerned with the nature of criticality accidents and their radiological consequences. It also indicates how the results have been communicated and used in ensuring nuclear safety. (review)

  2. Nuclear criticality safety training: guidelines for DOE contractors

    Energy Technology Data Exchange (ETDEWEB)

    Crowell, M.R.

    1983-09-01

    The DOE Order 5480.1A, Chapter V, Safety of Nuclear Facilities, establishes safety procedures and requirements for DOE nuclear facilities. This guide has been developed as an aid to implementing the Chapter V requirements pertaining to nuclear criticality safety training. The guide outlines relevant conceptual knowledge and demonstrated good practices in job performance. It addresses training program operations requirements in the areas of employee evaluations, employee training records, training program evaluations, and training program records. It also suggests appropriate feedback mechanisms for criticality safety training program improvement. The emphasis is on academic rather than hands-on training. This allows a decoupling of these guidelines from specific facilities. It would be unrealistic to dictate a universal program of training because of the wide variation of operations, levels of experience, and work environments among DOE contractors and facilities. Hence, these guidelines do not address the actual implementation of a nuclear criticality safety training program, but rather they outline the general characteristics that should be included.

  3. Private Memory Allocation Analysis for Safety-Critical Java

    DEFF Research Database (Denmark)

    Dalsgaard, Andreas E.; Hansen, René Rydhof; Schoeberl, Martin

    2012-01-01

    Safety-critical Java (SCJ) avoids garbage collection and uses a scope based memory model. This memory model is based on a restricted version of RTSJ [2] style scopes. The scopes form a clear hierarchy with different lifetimes. Therefore, references between objects in different scopes are only...

  4. Chip-Multiprocessor Hardware Locks for Safety-Critical Java

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Puffitsch, Wolfgang; Schoeberl, Martin

    2013-01-01

    and may void a task set's schedulability. In this paper we present a hardware locking mechanism to reduce the synchronization overhead. The solution is implemented for the chip-multiprocessor version of the Java Optimized Processor in the context of safety-critical Java. The implementation is compared...

  5. Criticality safety enhancements for SCALE 6.2 and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Rearden, Bradley T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bekar, Kursat B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Clarno, Kevin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dunn, Michael E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hart, Shane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ibrahim, Ahmad M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Langley, Brandon R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lefebvre, Jordan P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lefebvre, Robert A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Marshall, William J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mertyurek, Ugur [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mueller, Don [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peplow, Douglas E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Perfetti, Christopher M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Petrie Jr, Lester M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thompson, Adam B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wiarda, Dorothea [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Mark L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    SCALE is a widely used suite of tools for nuclear systems modeling and simulation that provides comprehensive, verified and validated, user-friendly capabilities for criticality safety, reactor physics, radiation shielding, and sensitivity and uncertainty analysis. Since 1980, regulators, industry, and research institutions around the world have relied on SCALE for nuclear safety analysis and design. SCALE 6.2 provides several new capabilities and significant improvements in many existing features for criticality safety analysis. Enhancements are realized for nuclear data; multigroup resonance self-shielding; continuous-energy Monte Carlo analysis for sensitivity/uncertainty analysis, radiation shielding, and depletion; and graphical user interfaces. An overview of these capabilities is provided in this paper, and additional details are provided in several companion papers.

  6. Criticality safety enhancements for SCALE 6.2 and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Rearden, Bradley T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bekar, Kursat B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Celik, Cihangir [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Clarno, Kevin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dunn, Michael E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hart, Shane W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ibrahim, Ahmad M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Langley, Brandon R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lefebvre, Jordan P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lefebvre, Robert A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Marshall, William J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mertyurek, Ugur [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mueller, Don [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peplow, Douglas E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Perfetti, Christopher M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Petrie Jr, Lester M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thompson, Adam B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wiarda, Dorothea [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Mark L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    SCALE is a widely used suite of tools for nuclear systems modeling and simulation that provides comprehensive, verified and validated, user-friendly capabilities for criticality safety, reactor physics, radiation shielding, and sensitivity and uncertainty analysis. Since 1980, regulators, industry, and research institutions around the world have relied on SCALE for nuclear safety analysis and design. SCALE 6.2 provides several new capabilities and significant improvements in many existing features for criticality safety analysis. Enhancements are realized for nuclear data; multigroup resonance self-shielding; continuous-energy Monte Carlo analysis for sensitivity/uncertainty analysis, radiation shielding, and depletion; and graphical user interfaces. An overview of these capabilities is provided in this paper, and additional details are provided in several companion papers.

  7. Criticality safety assessment of tank 241-C-106 remediation

    Energy Technology Data Exchange (ETDEWEB)

    Waltar, A.E., Westinghouse Hanford

    1996-07-19

    A criticality safety assessment was performed in support of Project 320 for the retrieval of waste from tank 241-C-106 to tank 241-AY-102. The assessment was performed by a multi-disciplined team consisting of expertise covering the range of nuclear engineering, plutonium and nuclear waste chemistry,and physical mixing hydraulics. Technical analysis was performed to evaluate the physical and chemical behavior of fissile material in neutralized Hanford waste as well as modeling of the fluid dynamics for the retrieval activity. The team has not found evidence of any credible mechanism to attain neutronic criticality in either tank and has concluded that a criticality accident is incredible.

  8. Lecture Notes on Criticality Safety Validation Using MCNP & Whisper

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    Training classes for nuclear criticality safety, MCNP documentation. The need for, and problems surrounding, validation of computer codes and data area considered first. Then some background for MCNP & Whisper is given--best practices for Monte Carlo criticality calculations, neutron spectra, S(α,β) thermal neutron scattering data, nuclear data sensitivities, covariance data, and correlation coefficients. Whisper is computational software designed to assist the nuclear criticality safety analyst with validation studies with the Monte Carlo radiation transport package MCNP. Whisper's methodology (benchmark selection – Ck's, weights; extreme value theory – bias, bias uncertainty; MOS for nuclear data uncertainty – GLLS) and usage are discussed.

  9. Rolls-Royce successful modernization of safety-critical Instrumentation and Control (I and C) equipment at the Dukovany VVER 440/213 Nuclear Power Plant, based on SPINLINE 3 platform

    Energy Technology Data Exchange (ETDEWEB)

    Rebreyend, P.; Burel, J.P. [Rolls-Royce Civil Nuclear SAS (France); Spoc, J. [Skoda JS (Czech republic); Karasek, A. [CEZ a.s.(Czech republic)

    2010-07-01

    Rolls-Royce has provided on-time delivery of a substantial safety-critical I and C overhaul for four Nuclear reactors operated by Czech Republic utility, CEZ a.s. This nine-year project is considered to be one of the largest I and C modernization projects in the world. The Dukovany VVER 440 I and C modernization project and its key success factors are profiled in this paper. The project is in the final stages with the last unit to be completed in 2009. Beginning in September 2000, the project is in compliance with the initial schedule. Rolls-Royce has been designing and manufacturing I and C solutions dedicated to the implementation of safety and safety-related functions in nuclear power plants (NPPs) for more than 30 years. Though the early solutions were non-software-based, since 1984 software-based solutions for safety I and C functions have been deployed in operating NPPs across France and 15 other countries. The Rolls-Royce platform is suitable for implementation of safety I and C functions in new NPPs, as well as in the modernization of safety equipment in existing plants. CEZ a.s. is a major electricity supplier for the national grid. At Dukovany, CEZ a.s. operates four units of VVER-440/213-type reactors producing one quarter of CEZ a.s. electricity production. The first of these units was connected to the grid in 1985. Since the year 2000, the nine-year modernization program has been underway at Dukovany, at a cost of more than 200 million Euros. The equipment replacement was implemented during regular, planned outages of the original equipment and systems. After an international bidding phase, CEZ a.s. awarded a contract to Skoda JS for general engineering and project management. Individual subcontracts were then signed between Skoda JS and a consortium between Rolls-Royce and Areva for modernization of the safety systems, including the Reactor Protection System (RPS), the Reactor Control System (RCS), and the Post-Accident Monitoring System (PAMS). Two

  10. Bioprotective agents in safety control

    Directory of Open Access Journals (Sweden)

    Dimitrijević-Branković Suzana I.

    2003-01-01

    Full Text Available Food poisoning is the one of the main health hazards even today. More than 200 known diseases are transmitted through food. The causes of foodborne illness include viruses, bacteria, parasites, toxins, metals, and prions and the symptoms of foodborne illness range from mild gastroenteritis to life-threatening neurological, hepatic and renal syndromes.The prevention of food poisonings represents very serious task for food manufacturers. Beside food control according to the concept "from the farm to the table" there is increased need for the development of new technology for longer shelf lifes of food. Food fermented by lactic acid bacteria (LAB and traditionally considered to be safe. There are many substances produced by LAB that affect the shelf life of fermented food, by active suppression of poisoning microorganisms growth. Because of that, the LAB is recently considered as bioprotective agents that have important role in food safety.

  11. 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.

  12. Implications of Monte Carlo Statistical Errors in Criticality Safety Assessments

    Energy Technology Data Exchange (ETDEWEB)

    Pevey, Ronald E.

    2005-09-15

    Most criticality safety calculations are performed using Monte Carlo techniques because of Monte Carlo's ability to handle complex three-dimensional geometries. For Monte Carlo calculations, the more histories sampled, the lower the standard deviation of the resulting estimates. The common intuition is, therefore, that the more histories, the better; as a result, analysts tend to run Monte Carlo analyses as long as possible (or at least to a minimum acceptable uncertainty). For Monte Carlo criticality safety analyses, however, the optimization situation is complicated by the fact that procedures usually require that an extra margin of safety be added because of the statistical uncertainty of the Monte Carlo calculations. This additional safety margin affects the impact of the choice of the calculational standard deviation, both on production and on safety. This paper shows that, under the assumptions of normally distributed benchmarking calculational errors and exact compliance with the upper subcritical limit (USL), the standard deviation that optimizes production is zero, but there is a non-zero value of the calculational standard deviation that minimizes the risk of inadvertently labeling a supercritical configuration as subcritical. Furthermore, this value is shown to be a simple function of the typical benchmarking step outcomes--the bias, the standard deviation of the bias, the upper subcritical limit, and the number of standard deviations added to calculated k-effectives before comparison to the USL.

  13. A software engineering process for safety-critical software application.

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Heon; Kim, Hang Bae; Chang, Hoon Seon; Jeon, Jong Sun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    Application of computer software to safety-critical systems in on the increase. To be successful, the software must be designed and constructed to meet the functional and performance requirements of the system. For safety reason, the software must be demonstrated not only to meet these requirements, but also to operate safely as a component within the system. For longer-term cost consideration, the software must be designed and structured to ease future maintenance and modifications. This paper presents a software engineering process for the production of safety-critical software for a nuclear power plant. The presentation is expository in nature of a viable high quality safety-critical software development. It is based on the ideas of a rational design process and on the experience of the adaptation of such process in the production of the safety-critical software for the shutdown system number two of Wolsung 2, 3 and 4 nuclear power generation plants. This process is significantly different from a conventional process in terms of rigorous software development phases and software design techniques, The process covers documentation, design, verification and testing using mathematically precise notations and highly reviewable tabular format to specify software requirements and software requirements and software requirements and code against software design using static analysis. The software engineering process described in this paper applies the principle of information-hiding decomposition in software design using a modular design technique so that when a change is required or an error is detected, the affected scope can be readily and confidently located. it also facilitates a sense of high degree of confidence in the `correctness` of the software production, and provides a relatively simple and straightforward code implementation effort. 1 figs., 10 refs. (Author).

  14. Lithium safety and tolerability in mood disorders: a critical review

    Directory of Open Access Journals (Sweden)

    Ivan Aprahamian

    2014-04-01

    Full Text Available Background : Lithium is a first-line treatment for bipolar disorder in all phases, also indicated as add-on drug for unipolar depression and suicide prevention. This study encompasses a broad critical review on the safety and tolerability of lithium for mood disorders. Methods : A computerized search for English written human studies was made in MEDLINE, using the keywords “lithium” and “mood disorders”, starting from July 1993 through July 2013 (n = 416. This initial search aimed to select clinical trials, prospective data, and controlled design studies of lithium treatment for mood disorders reporting adverse effects (n = 36. The final selection yielded 91 studies. Results : The most common general side effects in patients on lithium treatment were thirst, frequent urination, dry mouth, weight gain, fatigue and cognitive complaints. Lithium users showed a high prevalence of hypothyroidism, hyperparathyroidism, and decrease in urinary concentration ability. Reduction of glomerular filtration rate in patients using lithium was also observed, but in a lesser extent. The evidence of teratogenicity associated with lithium use is not well established. Anti-inflammatory non-steroidal drugs, thiazide diuretics, angiotensin-converting enzyme inhibitors, and alprazolam may increase serum lithium and the consequent risk for intoxication. Discussion : Short-term lithium treatment is associated with mild side effects. Medium and long-term lithium treatment, however, might have effects on target organs which may be prevented by periodical monitoring. Overall, lithium is still a safe option for the treatment of mood disorders.

  15. Criticality safety research at the University of Tennessee-Knoxville

    Energy Technology Data Exchange (ETDEWEB)

    Dodds, H.L. [Univ. of Tennessee, Knoxville, TN (United States)

    1997-06-01

    A list of seven research projects in nuclear criticality safety being conducted at the University of Tennessee is given. One of the projects is very briefly described. The study of space-dependent kinetics analysis of a hypothetical criticality accident involving an array of bottles containing UO{sub 2}F{sub 2} is being conducted for the US DOE, Oak Ridge National Laboratory, K-25 plant. Preliminary results for power versus time are presented, which indicate that space-time effects are significant after approximately 70 seconds. 2 refs., 1 fig.

  16. Critical Ethnography, Cultural Safety, and International Nursing Research

    Directory of Open Access Journals (Sweden)

    Jean N. Harrowing PhD

    2010-09-01

    Full Text Available Critical qualitative methodology provides a strategy to examine the human experience and its relationship to power and truth. Cultural safety is a concept that has been applied to nursing education and practice and refers to interactions that acknowledge and respect the unique cultural background of patients. It recognizes power inequities between caregivers who belong to dominant cultures and patients who may belong to oppressed groups. Culture is interpreted from a critical constructivist perspective as a fluid relational process that is enacted contextually. The purpose of this paper is to examine the congruence between and

  17. Criticality safety calculations of the Soreq research reactor storage pool

    Energy Technology Data Exchange (ETDEWEB)

    Caner, M.; Hirshfeld, H.; Nagler, A.; Silverman, I.; Bettan, M. [Soreq Nuclear Research Center, Yavne 81800 (Israel); Levine, S.H. [Penn State University, University Park 16802 (United States)

    2001-07-01

    The IRR-l spent fuel is to be relocated in a storage pool. The present paper describes the actual facility and summarizes the Monte Carlo criticality safety calculations. The fuel elements are to be placed inside cadmium boxes to reduce their reactivity. The fuel element is 7.6 cm by 8.0 cm in the horizontal plane. The cadmium box is effectively 9.7 cm by 9.7 cm, providing significant water between the cadmium and the fuel element. The present calculations show that the spent fuel storage pool is criticality safe even for fresh fuel elements. (author)

  18. Criticality safety at Zircatec - past present and future - part II

    Energy Technology Data Exchange (ETDEWEB)

    Horton, R.; Longinov, M.; Pant, A. [Zircatec Precision Industries, Port Hope, Ontario (Canada)

    2005-07-01

    In response to the Power Uprate program at Bruce Power, Zircatec has committed to introduce, by Spring 2006 a new manufacturing line for the production of 43 element CANFLEX bundles containing Slightly Enriched Uranium (SEU) with a centre pin of blended dysprosia/urania (BDU). This is a new fuel design and is the first change in fuel design since the introduction of the current 37 element fuel over 20 years ago. This move to LVRF fuel manufacture has prompted the change to a plant wide implementation of criticality safety methods. The major aspects of this change will be discussed from the viewpoint of the end user of the facility. Some of the methods used in the design of the unit processes and in the conducting of the criticality safety evaluations will be elaborated. (author)

  19. From Safety Critical Java Programs to Timed Process Models

    DEFF Research Database (Denmark)

    Thomsen, Bent; Luckow, Kasper Søe; Thomsen, Lone Leth

    2015-01-01

    built and the tools have been used to analyse a number of systems for properties such as worst case execution time, schedulability and energy optimization [12–14,19,34,36,38]. In this paper we will elaborate on the theoretical underpinning of the translation from Java programs to timed automata models...... frameworks, we have in recent years pursued an agenda of translating hard-real-time embedded safety critical programs written in the Safety Critical Java Profile [33] into networks of timed automata [4] and subjecting those to automated analysis using the UPPAAL model checker [10]. Several tools have been...... and briefly summarize some of the results based on this translation. Furthermore, we discuss future work, especially relations to the work in [16,24] as Java recently has adopted first class higher order functions in the form of lambda abstractions....

  20. Healthcare hazard control and safety management

    CERN Document Server

    Tweedy, James T

    2014-01-01

    Comprehensive in scope, this totally revamped edition of a bestseller is the ideal desk reference for anyone tasked with hazard control and safety management in the healthcare industry. Presented in an easy-to-read format, Healthcare Hazard Control and Safety Management, Third Edition examines hazard control and safety management as proactive functions of an organization. Like its popular predecessors, the book supplies a complete overview of hazard control, safety management, compliance, standards, and accreditation in the healthcare industry. This edition includes new information on leadersh

  1. Criticality safety evaluation of disposing of K Basin sludge in double-shell tank AW-105

    Energy Technology Data Exchange (ETDEWEB)

    ROGERS, C.A.

    1999-06-04

    A criticality safety evaluation is made of the disposal of K Basin sludge in double-shell tank (DST) AW-105 located in the 200 east area of Hanford Site. The technical basis is provided for limits and controls to be used in the development of a criticality prevention specification (CPS). A model of K Basin sludge is developed to account for fuel burnup. The iron/uranium mass ration required to ensure an acceptable magrin of subcriticality is determined.

  2. Multiprocessor Priority Ceiling Emulation for Safety-Critical Java

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Schoeberl, Martin

    2015-01-01

    Priority ceiling emulation has preferable properties on uniprocessor systems, such as avoiding priority inversion and being deadlock free. This has made it a popular locking protocol. According to the safety-critical Java specication, priority ceiling emulation is a requirement for implementations....... However, implementing the protocol for multiprocessor systemsis more complex so implementations might perform worse than non-preemptive implementations. In this paper we compare two multiprocessor lock implementations with hardware support for the Java optimized processor: non-preemptive locking...

  3. A Test Suite for Safety-Critical Java using JML

    DEFF Research Database (Denmark)

    Ravn, Anders P.; Søndergaard, Hans

    2013-01-01

    Development techniques are presented for a test suite for the draft specification of the Java profile for Safety-Critical Systems. Distinguishing features are: specification of conformance constraints in the Java Modeling Language, encoding of infrastructure concepts without implementation bias......, and corresponding specifications of implicitly stated behavioral and real-time properties. The test programs are auto-generated from the specification, while concrete values for test parameters are selected manually. The suite is open source and publicly accessible....

  4. A Test Suite for Safety-Critical Java using JML

    DEFF Research Database (Denmark)

    Ravn, Anders P.; Søndergaard, Hans

    2013-01-01

    Development techniques are presented for a test suite for the draft specification of the Java profile for Safety-Critical Systems. Distinguishing features are: specification of conformance constraints in the Java Modeling Language, encoding of infrastructure concepts without implementation bias, ......, and corresponding specifications of implicitly stated behavioral and real-time properties. The test programs are auto-generated from the specification, while concrete values for test parameters are selected manually. The suite is open source and publicly accessible....

  5. Safety-Critical Software: Status Report and Annotated Bibliography

    Science.gov (United States)

    1993-06-01

    software in place of hardware in safety-critical sys- tems are the Therac 25 (a therapeutic linear accelerator) and nuclear reactor shutdown sys- tems...Leveson and Turner [141], is the Therac 25 radiation treatment machine. A predecessor to the Therac 25, the Therac 20, had a number of hardware Interlocks...to stop an undesirable behavior. Much of the software in the Therac 25 was similar to that of the Therac 20 and the software in both cases contained

  6. Improved analysis of bias in Monte Carlo criticality safety

    Science.gov (United States)

    Haley, Thomas C.

    2000-08-01

    Criticality safety, the prevention of nuclear chain reactions, depends on Monte Carlo computer codes for most commercial applications. One major shortcoming of these codes is the limited accuracy of the atomic and nuclear data files they depend on. In order to apply a code and its data files to a given criticality safety problem, the code must first be benchmarked against similar problems for which the answer is known. The difference between a code prediction and the known solution is termed the "bias" of the code. Traditional calculations of the bias for application to commercial criticality problems are generally full of assumptions and lead to large uncertainties which must be conservatively factored into the bias as statistical tolerances. Recent trends in storing commercial nuclear fuel---narrowed regulatory margins of safety, degradation of neutron absorbers, the desire to use higher enrichment fuel, etc.---push the envelope of criticality safety. They make it desirable to minimize uncertainty in the bias to accommodate these changes, and they make it vital to understand what assumptions are safe to make under what conditions. A set of improved procedures is proposed for (1) developing multivariate regression bias models, and (2) applying multivariate regression bias models. These improved procedures lead to more accurate estimates of the bias and much smaller uncertainties about this estimate, while also generally providing more conservative results. The drawback is that the procedures are not trivial and are highly labor intensive to implement. The payback in savings in margin to criticality and conservatism for calculations near regulatory and safety limits may be worth this cost. To develop these procedures, a bias model using the statistical technique of weighted least squares multivariate regression is developed in detail. Problems that can occur from a weak statistical analysis are highlighted, and a solid statistical method for developing the bias

  7. Formalization and Validation of Safety-Critical Requirements

    Directory of Open Access Journals (Sweden)

    Alessandro Cimatti

    2010-03-01

    Full Text Available The validation of requirements is a fundamental step in the development process of safety-critical systems. In safety critical applications such as aerospace, avionics and railways, the use of formal methods is of paramount importance both for requirements and for design validation. Nevertheless, while for the verification of the design, many formal techniques have been conceived and applied, the research on formal methods for requirements validation is not yet mature. The main obstacles are that, on the one hand, the correctness of requirements is not formally defined; on the other hand that the formalization and the validation of the requirements usually demands a strong involvement of domain experts. We report on a methodology and a series of techniques that we developed for the formalization and validation of high-level requirements for safety-critical applications. The main ingredients are a very expressive formal language and automatic satisfiability procedures. The language combines first-order, temporal, and hybrid logic. The satisfiability procedures are based on model checking and satisfiability modulo theory. We applied this technology within an industrial project to the validation of railways requirements.

  8. Diversity for security: case assessment for FPGA-based safety-critical systems

    Directory of Open Access Journals (Sweden)

    Kharchenko Vyacheslav

    2016-01-01

    Full Text Available Industrial safety critical instrumentation and control systems (I&Cs are facing more with information (in general and cyber, in particular security threats and attacks. The application of programmable logic, first of all, field programmable gate arrays (FPGA in critical systems causes specific safety deficits. Security assessment techniques for such systems are based on heuristic knowledges and the expert judgment. Main challenge is how to take into account features of FPGA technology for safety critical I&Cs including systems in which are applied diversity approach to minimize risks of common cause failure. Such systems are called multi-version (MV systems. The goal of the paper is in description of the technique and tool for case-based security assessment of MV FPGA-based I&Cs.

  9. Plutonium Finishing Plant (PFP) Safety Class and Safety Significant Commercial Grade Items (CGI) Critical Characteristic

    Energy Technology Data Exchange (ETDEWEB)

    THOMAS, R.J.

    2000-04-24

    This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for use in the Plutonium Finishing Plant as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics of any one item.

  10. Towards the certification of non-deterministic control systems for safety-critical applications: analysing aviation analogies for possible certification strategies

    CSIR Research Space (South Africa)

    Burger, CR

    2011-11-01

    Full Text Available . A further definition required is the principle of a Standard Operating Procedure (SOP). SOPs dictate speed and altitude profiles, power settings, crew interaction protocols, terminology, callouts (verbal cues used during crew interaction... conscious effort was made to observe and discuss the thinking patterns of the pilots involved in a wide variety of roles. The outcome is indispensable for robotic controllers in all regulated industries and for autonomous robots. Many applications...

  11. The Integration of On-Line Monitoring and Reconfiguration Functions using EDAA - European design and Automation Association1149.4 Into a Safety Critical Automotive Electronic Control Unit

    CERN Document Server

    Jeffrey, C; Prosser, S; Lickess, M; Richardson, A; Riches, S

    2011-01-01

    This paper presents an innovative application of EDAA - European design and Automation Association 1149.4 and the Integrated Diagnostic Reconfiguration (IDR) as tools for the implementation of an embedded test solution for an Automotive Electronic Control Unit implemented as a fully integrated mixed signal system. The paper described how the test architecture can be used for fault avoidance with results from a hardware prototype presented. The paper concludes that fault avoidance can be integrated into mixed signal electronic systems to handle key failure modes.

  12. Criticality safety evaluation report for the multi-canister overpack

    Energy Technology Data Exchange (ETDEWEB)

    KESSLER, S.F.

    1999-05-21

    This criticality evaluation is for Spent N Reactor fuel unloaded from the existing canisters in both KE and KW Basins, and loaded into multiple canister overpack (MCO) containers with specially built baskets containing a maximum of either 54 Mark 1V or 48 Mark IA fuel assemblies. The criticality evaluations include loading baskets into the cask-MCO, operations at the Cold Vacuum Drying Facility, and storage in the Canister Storage Building. Many conservatisms have been built into this analysis, the primary one being the selection of the k{sub eff} = 0.95 criticality safety limit. Additional analyses in this revision include partial fuel basket loadings, loading 26.1 inch Mark IA fuel assemblies into Mark IV fuel baskets, and the revised fuel and scrap basket designs. The MCO MCNP model was revised to include the shield plug assembly.

  13. Computer-assisted glucose control in critically ill patients

    NARCIS (Netherlands)

    Vogelzang, Mathijs; Loef, Bert G.; Regtien, Joost G.; van der Horst, Iwan C. C.; van Assen, Hein; Zijlstra, Felix; Nijsten, Maarten W. N.

    2008-01-01

    Objective: Intensive insulin therapy is associated with the risk of hypoglycemia and increased costs of material and personnel. We therefore evaluated the safety and efficiency of a computer-assisted glucose control protocol in a large population of critically ill patients. Design and setting: Obser

  14. Computer-assisted glucose control in critically ill patients

    NARCIS (Netherlands)

    Vogelzang, Mathijs; Loef, Bert G.; Regtien, Joost G.; van der Horst, Iwan C. C.; van Assen, Hein; Zijlstra, Felix; Nijsten, Maarten W. N.

    Objective: Intensive insulin therapy is associated with the risk of hypoglycemia and increased costs of material and personnel. We therefore evaluated the safety and efficiency of a computer-assisted glucose control protocol in a large population of critically ill patients. Design and setting:

  15. RESILIENT INTERFACE DESIGN FOR SAFETY-CRITICAL EMBEDDED AUTOMOTIVE SOFTWARE

    Directory of Open Access Journals (Sweden)

    Harald Sporer

    2016-01-01

    Full Text Available The replacement of the former, purely mechanical, functionality with mechatronics-based solutions, the introduction of new propulsion technologies, and the connection of cars to their environment are just a few reasons for the continuously increasing electrical and/or electronic system (E/E system complexity in modern passenger cars. Smart methodologies and techniques have been introduced in system development to cope with these new challenges. A topic that is often neglected is the definition of the interface between the hardware and software subsystems. However, during the development of safety-critical E/E systems, according to the automotive functional safety standard ISO 26262, an unambiguous definition of the hardware-software interface (HSI has become vital. This paper presents a domain-specific modelling approach for mechatronic systems with an integrated hardware-software interface definition feature. The newly developed model-based domain-specific language is tailored to the needs of mechatronic system engineers and supports the system’s architectural design including the interface definition, with a special focus on safety-criticality.

  16. Patterns for Safety-Critical Java Memory Usage

    DEFF Research Database (Denmark)

    Rios Rivas, Juan Ricardo; Nilsen, Kelvin; Schoeberl, Martin

    2012-01-01

    Scoped memories are introduced in real-time Java profiles in order to make object allocation and deallocation time and space predictable. However, explicit scoping requires care from programmers when dealing with temporary objects, passing scope-allocated objects as arguments to methods, and retu......Scoped memories are introduced in real-time Java profiles in order to make object allocation and deallocation time and space predictable. However, explicit scoping requires care from programmers when dealing with temporary objects, passing scope-allocated objects as arguments to methods...... are illustrated by implementations in the safety-critical Java profile....

  17. A safety-critical java technology compatibility kit

    DEFF Research Database (Denmark)

    Søndergaard, Hans; Korsholm, Stephan E.; Ravn, Anders Peter

    2014-01-01

    In order to claim conformance with a given Java Specification Request (JSR), a Java implementation has to pass all tests in an associated Technology Compatibility Kit (TCK). This paper presents development of test cases and tools for the draft Safety-Critical Java (SCJ) specification. In previous...... work we have shown how the Java Modeling Language (JML) is applied to specify conformance constraints for SCJ, and how JML-related tools may assist in generating and executing tests. Here we extend this work with a layout for concrete test cases including checking of results in a simplified version...

  18. Safety-critical Java on a Java processor

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Rios Rivas, Juan Ricardo

    2012-01-01

    The safety-critical Java (SCJ) specification is developed within the Java Community Process under specification request number JSR 302. The specification is available as public draft, but details are still discussed by the expert group. In this stage of the specification we need prototype...... implementations of SCJ and first test applications that are written with SCJ, even when the specification is not finalized. The feedback from those prototype implementations is needed for final decisions. To help the SCJ expert group, a prototype implementation of SCJ on top of the Java optimized processor...

  19. Safety-Critical Java for Low-End Embedded Platforms

    DEFF Research Database (Denmark)

    Søndergaard, Hans; Korsholm, Stephan E.; Ravn, Anders P.

    2012-01-01

    We present an implementation of the Safety-Critical Java profile (SCJ), targeted for low-end embedded platforms with as little as 16 kB RAM and 256 kB flash. The distinctive features of the implementation are a combination of a lean Java virtual machine (HVM), with a bare metal kernel implementing...... hardware objects, first level interrupt handlers, and native variables, and an infrastructure written in Java which is minimized through program specialization. The HVM allows the implementation to be easily ported to embedded platforms which have a C compiler as part of the development environment...

  20. Safety-critical Java for low-end embedded platforms

    DEFF Research Database (Denmark)

    Søndergaard, Hans; Korsholm, Stephan E.; Ravn, Anders Peter

    2012-01-01

    We present an implementation of the Safety-Critical Java profile (SCJ), targeted for low-end embedded platforms with as little as 16 kB RAM and 256 kB flash. The distinctive features of the implementation are a combination of a lean Java virtual machine (HVM), with a bare metal kernel implementing...... hardware objects, first level interrupt handlers, and native variables, and an infrastructure written in Java which is minimized through program specialization. The HVM allows the implementation to be easily ported to embedded platforms which have a C compiler as part of the development environment...

  1. A Safety-Critical Java Technology Compatibility Kit

    DEFF Research Database (Denmark)

    Søndergaard, Hans; Korsholm, Stephan Erbs; Ravn, Anders P.

    2014-01-01

    In order to claim conformance with a given Java Specification Request (JSR), a Java implementation has to pass all tests in an associated Technology Compatibility Kit (TCK). This paper presents development of test cases and tools for the draft Safety-Critical Java (SCJ) specification. In previous...... work we have shown how the Java Modeling Language (JML) is applied to specify conformance constraints for SCJ, and how JML-related tools may assist in generating and executing tests. Here we extend this work with a layout for concrete test cases including checking of results in a simplified version...

  2. Safety-Critical Java for Low-End Embedded Platforms

    DEFF Research Database (Denmark)

    Søndergaard, Hans; Korsholm, Stephan E.; Ravn, Anders P.

    2012-01-01

    We present an implementation of the Safety-Critical Java profile (SCJ), targeted for low-end embedded platforms with as little as 16 kB RAM and 256 kB flash. The distinctive features of the implementation are a combination of a lean Java virtual machine (HVM), with a bare metal kernel implementing...... hardware objects, first level interrupt handlers, and native variables, and an infrastructure written in Java which is minimized through program specialization. The HVM allows the implementation to be easily ported to embedded platforms which have a C compiler as part of the development environment...

  3. Galileo Safety-of-Life Service Utilization for Railway Non-Safety and Safety Critical Applications

    Science.gov (United States)

    Mocek, Hynek; Filip, Aleš; Bazant, Lubor

    Global Navigation Satellite System (GNSS) Galileo is expected to play an essential role in railway transport with view to reduce operational, investment and maintenance costs. However, quality requirements of the GNSS originate mainly from the aviation suggestions. Different safety philosophies used in aviation domain and in railway signaling complicate direct employment of the GNSS quality measures to the railway telematic applications. The objective of this paper is to outline the conception of railway requirements specification for the GNSS in order to cover a large amount of the appropriate applications in the non-safety and safety related domains. The elaborated methodology enables to provide specification of minimal quantitative requirements for GNSS system by means of railway attributes RAMS. This process generally represents contribution for GNSS system certification, when it is necessary to demonstrate that the GNSS system meets requirements, and the system outputs are correct. In the second level, certification of the specific GNSS application must follow subsequently.

  4. China's Feed Companies Eye Safety Control

    Institute of Scientific and Technical Information of China (English)

    Richard Zhu

    2011-01-01

    @@ China's feed companies in China are looking to strengthen safety control substantially according to the highest international standard.The first step will be improving the feed safety control in the pre-mixture and compound feed production.The next step will be extending this control to the whole feed supply chain, covering feed ingredients and services like transport and storage.Besides, a joint program will be defined in cooperation with GMP+ International.

  5. Criticality Safety Validation of Scale 6.1

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, William BJ J [ORNL; Rearden, Bradley T [ORNL

    2011-11-01

    The computational bias of criticality safety computer codes must be established through the validation of the codes to critical experiments. A large collection of suitable experiments has been vetted by the International Criticality Safety Benchmark Experiment Program (ICSBEP) and made available in the International Handbook of Evaluated Criticality Safety Benchmark Experiments (IHECSBE). A total of more than 350 cases from this reference have been prepared and reviewed within the Verified, Archived Library of Inputs and Data (VALID) maintained by the Reactor and Nuclear Systems Division at Oak Ridge National Laboratory. The performance of the KENO V.a and KENO-VI Monte Carlo codes within the Scale 6.1 code system with ENDF/B-VII.0 cross-section data in 238-group and continuous energy is assessed using the VALID models of benchmark experiments. The TSUNAMI tools for sensitivity and uncertainty analysis are utilized to examine some systems further in an attempt to identify potential causes of unexpected results. The critical experiments available for validation of the KENO V.a code cover eight different broad categories of systems. These systems use a range of fissile materials including a range of uranium enrichments, various plutonium isotopic vectors, and mixed uranium-plutonium oxides. The physical form of the fissile material also varies and is represented as metal, solutions, or arrays of rods or plates in a water moderator. The neutron energy spectra of the systems also vary and cover both fast and thermal spectra. Over 300 of the total cases used utilize the KENO V.a code. The critical experiments available for the validation of the KENO-VI code cover three broad categories of systems. The fissile materials in the systems vary and include high and intermediate-enrichment uranium and mixed uranium/plutonium oxides. The physical form of the fissile material is either metal or rod arrays in water. As with KENO V.a, both fast and thermal neutron energy spectra

  6. Licensing process for safety-critical software-based systems

    Energy Technology Data Exchange (ETDEWEB)

    Haapanen, P. [VTT Automation, Espoo (Finland); Korhonen, J. [VTT Electronics, Espoo (Finland); Pulkkinen, U. [VTT Automation, Espoo (Finland)

    2000-12-01

    System vendors nowadays propose software-based technology even for the most critical safety functions in nuclear power plants. Due to the nature of software faults and the way they cause system failures new methods are needed for the safety and reliability evaluation of these systems. In the research project 'Programmable automation systems in nuclear power plants (OHA)', financed together by the Radiation and Nuclear Safety Authority (STUK), the Ministry of Trade and Industry (KTM) and the Technical Research Centre of Finland (VTT), various safety assessment methods and tools for software based systems are developed and evaluated. As a part of the OHA-work a reference model for the licensing process for software-based safety automation systems is defined. The licensing process is defined as the set of interrelated activities whose purpose is to produce and assess evidence concerning the safety and reliability of the system/application to be licensed and to make the decision about the granting the construction and operation permissions based on this evidence. The parties of the licensing process are the authority, the licensee (the utility company), system vendors and their subcontractors and possible external independent assessors. The responsibility about the production of the evidence in first place lies at the licensee who in most cases rests heavily on the vendor expertise. The evaluation and gauging of the evidence is carried out by the authority (possibly using external experts), who also can acquire additional evidence by using their own (independent) methods and tools. Central issue in the licensing process is to combine the quality evidence about the system development process with the information acquired through tests, analyses and operational experience. The purpose of the licensing process described in this report is to act as a reference model both for the authority and the licensee when planning the licensing of individual applications

  7. Automatic Control System for Neutron Laboratory Safety

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Xiao; ZHANG; Guo-guang; FENG; Shu-qiang; SU; Dan; YANG; Guo-zhao; ZHANG; Shuai

    2015-01-01

    In order to cooperate with the experiment of neutron generator,and realize the automatic control in the experiment,a set of automatic control system for the safety of the neutron laboratory is designed.The system block diagram is shown as Fig.1.Automatic control device is for processing switch signal,so PLC is selected as the core component

  8. Critical incident stress debriefing after adverse patient safety events.

    Science.gov (United States)

    Harrison, Reema; Wu, Albert

    2017-05-01

    Adverse events (AEs) are common, estimated to occur in around 10% internationally. Although preventable harm can be minimized, when AEs occur it is important that they be managed appropriately. AEs can be traumatic not only for patients, their friends, and relatives, but also for the involved clinicians, who have been referred to as "second victims" in a growing body of international research. Despite the frequency with which AEs occur, organizational mechanisms for supporting staff in these circumstances are not routinely embedded in healthcare settings. Critical Incident Stress Debriefing (CISD) has long been provided for professionals, such as disaster workers, who are exposed to traumatic and high-stress events. CISD is considered an effective strategy to promote resilience and recovery. We explore the potential value of providing CISD for health professionals involved in patient safety-related AEs and discuss the instances in which this could be routinely implemented.

  9. Safety-critical Java on a time-predictable processor

    DEFF Research Database (Denmark)

    Korsholm, Stephan E.; Schoeberl, Martin; Puffitsch, Wolfgang

    2015-01-01

    For real-time systems the whole execution stack needs to be time-predictable and analyzable for the worst-case execution time (WCET). This paper presents a time-predictable platform for safety-critical Java. The platform consists of (1) the Patmos processor, which is a time-predictable processor......; (2) a C compiler for Patmos with support for WCET analysis; (3) the HVM, which is a Java-to-C compiler; (4) the HVM-SCJ implementation which supports SCJ Level 0, 1, and 2 (for both single and multicore platforms); and (5) a WCET analysis tool. We show that real-time Java programs translated to C...... and compiled to a Patmos binary can be analyzed by the AbsInt aiT WCET analysis tool. To the best of our knowledge the presented system is the second WCET analyzable real-time Java system; and the first one on top of a RISC processor....

  10. Hardware Support for Safety-critical Java Scope Checks

    DEFF Research Database (Denmark)

    Rios Rivas, Juan Ricardo; Schoeberl, Martin

    2012-01-01

    Memory management in Safety-Critical Java (SCJ) is based on time bounded, non garbage collected scoped memory regions used to store temporary objects. Scoped memory regions may have different life times during the execution of a program and hence, to avoid leaving dangling pointers, it is necessary...... between threads and any other scoped region is thread private. In this paper we present how, due to this simplified model, a single scope nesting level can be used to check the legality of every reference assignment. We also show that with simple hardware extensions a processor can see some improvement...... in terms of execution time for applications where cross-scope references are frequent. Our proposal was implemented and tested on the Java Optimized Processor (JOP)....

  11. Safety-Critical Java on a Time-predictable Processor

    DEFF Research Database (Denmark)

    Korsholm, Stephan Erbs; Schoeberl, Martin; Puffitsch, Wolfgang

    2015-01-01

    For real-time systems the whole execution stack needs to be time-predictable and analyzable for the worst-case execution time (WCET). This paper presents a time-predictable platform for safety-critical Java. The platform consists of (1) the Patmos processor, which is a time-predictable processor......; (2) a C compiler for Patmos with support for WCET analysis; (3) the HVM, which is a Java-to-C compiler; (4) the HVM-SCJ implementation which supports SCJ Level 0, 1, and 2 (for both single and multicore platforms); and (5) a WCET analysis tool. We show that real-time Java programs translated to C...... and compiled to a Patmos binary can be analyzed by the AbsInt aiT WCET analysis tool. To the best of our knowledge the presented system is the second WCET analyzable real-time Java system; and the first one on top of a RISC processor....

  12. Collegiate Aviation Research and Education Solutions to Critical Safety Issues. UNO Aviation Monograph Series. UNOAI Report.

    Science.gov (United States)

    Bowen, Brent, Ed.

    This document contains four papers concerning collegiate aviation research and education solutions to critical safety issues. "Panel Proposal Titled Collegiate Aviation Research and Education Solutions to Critical Safety Issues for the Tim Forte Collegiate Aviation Safety Symposium" (Brent Bowen) presents proposals for panels on the…

  13. Use of Opioid Medications for Employees in Critical Safety or Security Positions and Positions with Safety Sensitive Duties

    Science.gov (United States)

    2017-01-30

    Employees in Critical Safety or Security Positions and Positions with Safety Sensitive Duties . 1. REFERENCES. A. Army Regulation 40-5, Preventive... duties . C. The employee is considered unfit for safety sensitive duties until such a time when he or she is no longer taking opioid pain...Aeromedical Policy Letters, Medication Waivers, January 2002 Revision. 2. BACKGROUND. Employees who work in safety-sensitive occupations or handle

  14. Process Control Systems in the Chemical Industry: Safety vs. Security

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Hahn; Thomas Anderson

    2005-04-01

    Traditionally, the primary focus of the chemical industry has been safety and productivity. However, recent threats to our nation’s critical infrastructure have prompted a tightening of security measures across many different industry sectors. Reducing vulnerabilities of control systems against physical and cyber attack is necessary to ensure the safety, security and effective functioning of these systems. The U.S. Department of Homeland Security has developed a strategy to secure these vulnerabilities. Crucial to this strategy is the Control Systems Security and Test Center (CSSTC) established to test and analyze control systems equipment. In addition, the CSSTC promotes a proactive, collaborative approach to increase industry's awareness of standards, products and processes that can enhance the security of control systems. This paper outlines measures that can be taken to enhance the cybersecurity of process control systems in the chemical sector.

  15. Concepts and techniques: Active electronics and computers in safety-critical accelerator operation

    Energy Technology Data Exchange (ETDEWEB)

    Frankel, R.S.

    1995-12-31

    The Relativistic Heavy Ion Collider (RHIC) under construction at Brookhaven National Laboratory, requires an extensive Access Control System to protect personnel from Radiation, Oxygen Deficiency and Electrical hazards. In addition, the complicated nature of operation of the Collider as part of a complex of other Accelerators necessitates the use of active electronic measurement circuitry to ensure compliance with established Operational Safety Limits. Solutions were devised which permit the use of modern computer and interconnections technology for Safety-Critical applications, while preserving and enhancing, tried and proven protection methods. In addition a set of Guidelines, regarding required performance for Accelerator Safety Systems and a Handbook of design criteria and rules were developed to assist future system designers and to provide a framework for internal review and regulation.

  16. Criticality safety of the ET-RR-1 new spent fuel storage pool

    Energy Technology Data Exchange (ETDEWEB)

    Massoud, E.; Sallam, O.H.; Amin, E

    2001-03-01

    A new ET-RR-1 spent fuel storage pool is now under construction on the reactor site at Inshass. In addition, the pool is designed to accommodate spent fuel of MTR type as well. Criticality safety of this pool for the different fuel types has been evaluated as a function of U{sup 235} loading. The effect of fuel element separation (rows and columns) on the eigenvalue has been studied. As a conservative assumption, the pool is assumed to be filled with fresh fuel. The eigenvalue considering a realistic degree of fuel burn-up was determined in order to determine the safety margin. The calculations have been carried out using the code packages of the National Center for Nuclear Safety and Radiation Control.

  17. Handbook on criticality. Vol. 1. Criticality and nuclear safety; Handbuch zur Kritikalitaet. Bd. 1. Kritikalitaet und nukleare Sicherheit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-04-15

    This handbook was prepared primarily with the aim to provide information to experts in industry, authorities or research facilities engaged in criticality-safety-related problems that will allow an adequate and rapid assessment of criticality safety issues already in the planning and preparation of nuclear facilities. However, it is not the intention of the authors of the handbook to offer ready solutions to complex problems of nuclear safety. Such questions have to remain subject to an in-depth analysis and assessment to be carried out by dedicated criticality safety experts. Compared with the previous edition dated December 1998, this handbook has been further revised and supplemented. The proven basic structure of the handbook remains unchanged. The handbook follows in some ways similar criticality handbooks or instructions published in the USA, UK, France, Japan and the former Soviet Union. The expedient use of the information given in this handbook requires a fundamental understanding of criticality and the terminology of nuclear safety. In Vol. 1, ''Criticality and Nuclear Safety'', therefore, first the most important terms and fundamentals are introduced and explained. Subsequently, experimental techniques and calculation methods for evaluating criticality problems are presented. The following chapters of Vol. 1 deal i. a. with the effect of neutron reflectors and absorbers, neutron interaction, measuring methods for criticality, and organisational safety measures and provide an overview of criticality-relevant operational experience and of criticality accidents and their potential hazardous impact. Vol. 2 parts 1 and 2 finally compile criticality parameters in graphical and tabular form. The individual graph sheets are provided with an initially explained set of identifiers, to allow the quick finding of the information of current interest. Part 1 includes criticality parameters for systems with {sup 235}U as fissile material, while part

  18. Safety issues in cultural heritage management and critical infrastructures management

    Science.gov (United States)

    Soldovieri, Francesco; Masini, Nicola; Alvarez de Buergo, Monica; Dumoulin, Jean

    2013-12-01

    This special issue is the fourth of its kind in Journal of Geophysics and Engineering , containing studies and applications of geophysical methodologies and sensing technologies for the knowledge, conservation and security of products of human activity ranging from civil infrastructures to built and cultural heritage. The first discussed the application of novel instrumentation, surface and airborne remote sensing techniques, as well as data processing oriented to both detection and characterization of archaeological buried remains and conservation of cultural heritage (Eppelbaum et al 2010). The second stressed the importance of an integrated and multiscale approach for the study and conservation of architectural, archaeological and artistic heritage, from SAR to GPR to imaging based diagnostic techniques (Masini and Soldovieri 2011). The third enlarged the field of analysis to civil engineering structures and infrastructures, providing an overview of the effectiveness and the limitations of single diagnostic techniques, which can be overcome through the integration of different methods and technologies and/or the use of robust and novel data processing techniques (Masini et al 2012). As a whole, the special issue put in evidence the factors that affect the choice of diagnostic strategy, such as the material, the spatial characteristics of the objects or sites, the value of the objects to be investigated (cultural or not), the aim of the investigation (knowledge, conservation, restoration) and the issues to be addressed (monitoring, decay assessment). In order to complete the overview of the application fields of sensing technologies this issue has been dedicated to monitoring of cultural heritage and critical infrastructures to address safety and security issues. Particular attention has been paid to the data processing methods of different sensing techniques, from infrared thermography through GPR to SAR. Cascini et al (2013) present the effectiveness of a

  19. Integrated Design and Analysis Environment for Safety Critical Human-Automation Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flight deck systems, like many safety critical systems, often involve complex interactions between multiple human operators, automated subsystems, and physical...

  20. Segmentation Scheme for Safety Enhancement of Engineered Safety Features Component Control System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangseok; Sohn, Kwangyoung [Korea Reliability Technology and System, Daejeon (Korea, Republic of); Lee, Junku; Park, Geunok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    Common Caused Failure (CCF) or undetectable failure would adversely impact safety functions of ESF-CCS in the existing nuclear power plants. We propose the segmentation scheme to solve these problems. Main function assignment to segments in the proposed segmentation scheme is based on functional dependency and critical function success path by using the dependency depth matrix. The segment has functional independence and physical isolation. The segmentation structure is that prohibit failure propagation to others from undetectable failures. Therefore, the segmentation system structure has robustness to undetectable failures. The segmentation system structure has functional diversity. The specific function in the segment defected by CCF, the specific function could be maintained by diverse control function that assigned to other segments. Device level control signals and system level control signals are separated and also control signal and status signals are separated due to signal transmission paths are allocated independently based on signal type. In this kind of design, single device failure or failures on signal path in the channel couldn't result in the loss of all segmented functions simultaneously. Thus the proposed segmentation function is the design scheme that improves availability of safety functions. In conventional ESF-CCS, the single controller generates the signal to control the multiple safety functions, and the reliability is achieved by multiplication within the channel. This design has a drawback causing the loss of multiple functions due to the CCF (Common Cause Failure) and single failure Heterogeneous controller guarantees the diversity ensuring the execution of safety functions against the CCF and single failure, but requiring a lot of resources like manpower and cost. The segmentation technology based on the compartmentalization and functional diversification decreases the CCF and single failure nonetheless the identical types of

  1. Sensitivity-Uncertainty Based Nuclear Criticality Safety Validation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States). Nuclear Engineering Dept.

    2016-09-20

    These are slides from a seminar given to the University of Mexico Nuclear Engineering Department. Whisper is a statistical analysis package developed to support nuclear criticality safety validation. It uses the sensitivity profile data for an application as computed by MCNP6 along with covariance files for the nuclear data to determine a baseline upper-subcritical-limit for the application. Whisper and its associated benchmark files are developed and maintained as part of MCNP6, and will be distributed with all future releases of MCNP6. Although sensitivity-uncertainty methods for NCS validation have been under development for 20 years, continuous-energy Monte Carlo codes such as MCNP could not determine the required adjoint-weighted tallies for sensitivity profiles. The recent introduction of the iterated fission probability method into MCNP led to the rapid development of sensitivity analysis capabilities for MCNP6 and the development of Whisper. Sensitivity-uncertainty based methods represent the future for NCS validation – making full use of today’s computer power to codify past approaches based largely on expert judgment. Validation results are defensible, auditable, and repeatable as needed with different assumptions and process models. The new methods can supplement, support, and extend traditional validation approaches.

  2. Pre-Orbital Criticality Safety for the Proposed NEPSTP Mission

    Science.gov (United States)

    Sapir, Joseph; Pelowitz, Denise; Streetman, J. Robert; Glushkov, Yevgeny S.; Ponomarev-Stepnoi, Nikolai N.; Kompanietz, Georgiy V.; Lobynstev, Vyacheslav A.

    1994-07-01

    In December 1991, the Strategic Defense Initiative Organization (SDIO) proposed investigating whether launching a Russian Topaz-II space nuclear power system could be done safely and within budget constraints. Functional safety requirements developed for the potential US space application of the Topaz-II mandated that the reactor remain subcritical when immersed in water. Topaz-II is an epithermal, enriched-uranium-fueled, NaK-(liquid metal alloy with 22% sodium and 78% potassium) cooled, and zirconium hydride-moderated reactor. A radial beryllium reflector containing 12 rotatable control drums surrounds the core. We prepared a computer model of the Topaz reactor that explicitly represented all major reactor components. Initial analyses indicated that in several water-immersion scenarios, the reactor would not remain subcritical. After additional calculations, modifications were proposed that would assure subcriticality under such conditions. This paper describes the analyses and the proposed modifications.

  3. Testing of Safety-Critical Software Embedded in an Artificial Heart

    Science.gov (United States)

    Cha, Sungdeok; Jeong, Sehun; Yoo, Junbeom; Kim, Young-Gab

    Software is being used more frequently to control medical devices such as artificial heart or robotic surgery system. While much of software safety issues in such systems are similar to other safety-critical systems (e.g., nuclear power plants), domain-specific properties may warrant development of customized techniques to demonstrate fitness of the system on patients. In this paper, we report results of a preliminary analysis done on software controlling a Hybrid Ventricular Assist Device (H-VAD) developed by Korea Artificial Organ Centre (KAOC). It is a state-of-the-art artificial heart which completed animal testing phase. We performed software testing in in-vitro experiments and animal experiments. An abnormal behaviour, never detected during extensive in-vitro analysis and animal testing, was found.

  4. Automated safety control by video cameras

    NARCIS (Netherlands)

    Lefter, I.; Rothkrantz, L.; Somhorst, M.

    2012-01-01

    At this moment many surveillance systems are installed in public domains to control the safety of people and properties. They are constantly watched by human operators who are easily overloaded. To support the human operators, a surveillance system model is designed that detects suspicious behaviour

  5. Validation and Verification of Future Integrated Safety-Critical Systems Operating under Off-Nominal Conditions

    Science.gov (United States)

    Belcastro, Christine M.

    2010-01-01

    Loss of control remains one of the largest contributors to aircraft fatal accidents worldwide. Aircraft loss-of-control accidents are highly complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence, there is no single intervention strategy to prevent these accidents and reducing them will require a holistic integrated intervention capability. Future onboard integrated system technologies developed for preventing loss of vehicle control accidents must be able to assure safe operation under the associated off-nominal conditions. The transition of these technologies into the commercial fleet will require their extensive validation and verification (V and V) and ultimate certification. The V and V of complex integrated systems poses major nontrivial technical challenges particularly for safety-critical operation under highly off-nominal conditions associated with aircraft loss-of-control events. This paper summarizes the V and V problem and presents a proposed process that could be applied to complex integrated safety-critical systems developed for preventing aircraft loss-of-control accidents. A summary of recent research accomplishments in this effort is also provided.

  6. Technical safety requirements control level verification

    Energy Technology Data Exchange (ETDEWEB)

    STEWART, J.L.

    1999-05-21

    A Technical Safety Requirement (TSR) control level verification process was developed for the Tank Waste Remediation System (TWRS) TSRs at the Hanford Site in Richland, WA, at the direction of the US. Department of Energy, Richland Operations Office (RL). The objective of the effort was to develop a process to ensure that the TWRS TSR controls are designated and managed at the appropriate levels as Safety Limits (SLs), Limiting Control Settings (LCSs), Limiting Conditions for Operation (LCOs), Administrative Controls (ACs), or Design Features. The TSR control level verification process was developed and implemented by a team of contractor personnel with the participation of Fluor Daniel Hanford, Inc. (FDH), the Project Hanford Management Contract (PHMC) integrating contractor, and RL representatives. The team was composed of individuals with the following experience base: nuclear safety analysis; licensing; nuclear industry and DOE-complex TSR preparation/review experience; tank farm operations; FDH policy and compliance; and RL-TWRS oversight. Each TSR control level designation was completed utilizing TSR control logic diagrams and TSR criteria checklists based on DOE Orders, Standards, Contractor TSR policy, and other guidance. The control logic diagrams and criteria checklists were reviewed and modified by team members during team meetings. The TSR control level verification process was used to systematically evaluate 12 LCOs, 22 AC programs, and approximately 100 program key elements identified in the TWRS TSR document. The verification of each TSR control required a team consensus. Based on the results of the process, refinements were identified and the TWRS TSRs were modified as appropriate. A final report documenting key assumptions and the control level designation for each TSR control was prepared and is maintained on file for future reference. The results of the process were used as a reference in the RL review of the final TWRS TSRs and control suite. RL

  7. Taking ownership of safety. What are the active ingredients of safety coaching and how do they impact safety outcomes in critical offshore working environments?

    Science.gov (United States)

    Krauesslar, Victoria; Avery, Rachel E; Passmore, Jonathan

    2015-01-01

    Safety coaching interventions have become a common feature in the safety critical offshore working environments of the North Sea. Whilst the beneficial impact of coaching as an organizational tool has been evidenced, there remains a question specifically over the use of safety coaching and its impact on behavioural change and producing safe working practices. A series of 24 semi-structured interviews were conducted with three groups of experts in the offshore industry: safety coaches, offshore managers and HSE directors. Using a thematic analysis approach, several significant themes were identified across the three expert groups including connecting with and creating safety ownership in the individual, personal significance and humanisation, ingraining safety and assessing and measuring a safety coach's competence. Results suggest clear utility of safety coaching when applied by safety coaches with appropriate coach training and understanding of safety issues in an offshore environment. The current work has found that the use of safety coaching in the safety critical offshore oil and gas industry is a powerful tool in managing and promoting a culture of safety and care.

  8. Criticality Safety Evaluation of the LLNL Inherently Safe Subcritical Assembly (ISSA)

    Energy Technology Data Exchange (ETDEWEB)

    Percher, Catherine [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-06-19

    The LLNL Nuclear Criticality Safety Division has developed a training center to illustrate criticality safety and reactor physics concepts through hands-on experimental training. The experimental assembly, the Inherently Safe Subcritical Assembly (ISSA), uses surplus highly enriched research reactor fuel configured in a water tank. The training activities will be conducted by LLNL following the requirements of an Integration Work Sheet (IWS) and associated Safety Plan. Students will be allowed to handle the fissile material under the supervision of LLNL instructors. This report provides the technical criticality safety basis for instructional operations with the ISSA experimental assembly.

  9. Criticality safety evaluation for the Advanced Test Reactor enhanced low enriched uranium fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Montierth, Leland M. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-07-19

    The Global Threat Reduction Initiative (GTRI) convert program is developing a high uranium density fuel based on a low enriched uranium (LEU) uranium-molybdenum alloy. Testing of prototypic GTRI fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. GTRI Enhanced LEU Fuel (ELF) elements based on the ATR-Standard Size elements (all plates fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). While a specific ELF element design will eventually be provided for detailed analyses and in-core testing, this criticality safety evaluation (CSE) is intended to evaluate a hypothetical ELF element design for criticality safety purposes. Existing criticality analyses have analyzed Standard (HEU) ATR elements from which controls have been derived. This CSE documents analysis that determines the reactivity of the hypothetical ELF fuel elements relative to HEU ATR elements and whether the existing HEU ATR element controls bound the ELF element. The initial calculations presented in this CSE analyzed the original ELF design, now referred to as Mod 0.1. In addition as part of a fuel meat thickness optimization effort for reactor performance other designs have been evaluated. As of early 2014 the most current conceptual designs are Mk1A and Mk1B that were previously referred to as conceptual designs Mod 0.10 and Mod 0.11, respectively. Revision 1 evaluates the reactivity of the ATR HEU Mark IV elements for a comparison with the Mark VII elements.

  10. Criticality safety evaluation for the Advanced Test Reactor enhanced low enriched uranium fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Montierth, Leland M. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-07-19

    The Global Threat Reduction Initiative (GTRI) convert program is developing a high uranium density fuel based on a low enriched uranium (LEU) uranium-molybdenum alloy. Testing of prototypic GTRI fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. GTRI Enhanced LEU Fuel (ELF) elements based on the ATR-Standard Size elements (all plates fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). While a specific ELF element design will eventually be provided for detailed analyses and in-core testing, this criticality safety evaluation (CSE) is intended to evaluate a hypothetical ELF element design for criticality safety purposes. Existing criticality analyses have analyzed Standard (HEU) ATR elements from which controls have been derived. This CSE documents analysis that determines the reactivity of the hypothetical ELF fuel elements relative to HEU ATR elements and whether the existing HEU ATR element controls bound the ELF element. The initial calculations presented in this CSE analyzed the original ELF design, now referred to as Mod 0.1. In addition, as part of a fuel meat thickness optimization effort for reactor performance, other designs have been evaluated. As of early 2014 the most current conceptual designs are Mk1A and Mk1B, that were previously referred to as conceptual designs Mod 0.10 and Mod 0.11, respectively. Revision 1 evaluates the reactivity of the ATR HEU Mark IV elements for a comparison with the Mark VII elements.

  11. Analysis using formal method and testing technique for the processor module for safety-critical application

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J. Y.; Choi, B. J.; Song, H. J.; Hwang, D. Y.; Song, G. H.; Lee, H. [Korea University, Seoul (Korea, Republic of)

    2008-06-15

    This research is on help develop nuclear power plant control system, through the requirement specification and verification method development. As the result of applying the test method, a test standard was obtain through test documentation writing support and a test document reflecting the standard test activities based on the test standard. The specification and verification of the pCOS system and the unified testing documentation and execution helps the entire project to progress and enable us to achieve necessary documents and technology to develop a safety critical system.

  12. Enhancing Safety at Airline Operations Control Centre

    Directory of Open Access Journals (Sweden)

    Lukáš Řasa

    2015-04-01

    Full Text Available In recent years a new term of Safety Management System (SMS has been introduced into aviation legislation. This system is being adopted by airline operators. One of the groundbased actors of everyday operations is Operations Control Centre (OCC. The goal of this article has been to identify and assess risks and dangers which occur at OCC and create a template for OCC implementation into SMS.

  13. Controlling superconductivity by tunable quantum critical points.

    Science.gov (United States)

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-03-04

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.

  14. Analyzing Software Errors in Safety-Critical Embedded Systems

    Science.gov (United States)

    Lutz, Robyn R.

    1994-01-01

    This paper analyzes the root causes of safty-related software faults identified as potentially hazardous to the system are distributed somewhat differently over the set of possible error causes than non-safety-related software faults.

  15. Operator's Influence on the Safety of the Controlled Process

    Directory of Open Access Journals (Sweden)

    Peter Nagy

    2015-01-01

    Full Text Available An analysis of risks related to controlled process and related hazards identification is an important activity during the development of the safety related control system (SRCS. The mistake of the operational staff during the execution of the safety relevant operations related to controlled process can be the cause of hazard. Influence of the operator on controlled process safety depends on operation mode of the SRCS and on technical safety of the SRCS. This contribution deals with the issue of the safety assessment of the operator effect on the safety of the controlled process.

  16. Overview of Risk Mitigation for Safety-Critical Computer-Based Systems

    Science.gov (United States)

    Torres-Pomales, Wilfredo

    2015-01-01

    This report presents a high-level overview of a general strategy to mitigate the risks from threats to safety-critical computer-based systems. In this context, a safety threat is a process or phenomenon that can cause operational safety hazards in the form of computational system failures. This report is intended to provide insight into the safety-risk mitigation problem and the characteristics of potential solutions. The limitations of the general risk mitigation strategy are discussed and some options to overcome these limitations are provided. This work is part of an ongoing effort to enable well-founded assurance of safety-related properties of complex safety-critical computer-based aircraft systems by developing an effective capability to model and reason about the safety implications of system requirements and design.

  17. Critical issues of alcohol safety in the region

    Directory of Open Access Journals (Sweden)

    Svetlana Vasil’evna Aksyutina

    2015-03-01

    Full Text Available The paper presents results of the research into the economic and socio-demographic indicators associated with the production and consumption of alcoholic beverages. It discloses the analysis of the alcoholic beverage market structure in the Vologda Oblast. The authors have identified the threshold of the safe alcohol production volume in the region taking into account the World Health Organization standards of alcohol consumption and the share of illegally produced goods. The article states that the increased alcohol production contributes to the rise in tax revenues, but the state fiscal policy to regulate the alcoholic beverage market leads to an increase in the share of shadow turnover. The authors have calculated the economic loss connected with the illegal production of alcoholic beverages in the Vologda Oblast. The alcohol consumption is a destructive socio-demographic process and one of the threats to the health of the nation. Excessive alcohol consumption leads to alcohol dependence, regression of the society and increases the threat to national and economic security. The study reveals a direct correlation between the consumption of alcoholic beverages per capita and mortality rates in men and women of working age from the causes related to the consumption of alcoholic beverages. The study of the international experience to regulate alcohol consumption has showed the need to tighten state control in the sphere of production and turnover of alcoholic products. The conduct of the unified state alcohol policy substantiates the selection of the alcohol industry in the all-Russian classifier of economic activity types. The authors have elaborated the concept and conditions of alcoholic security from the point of view of economic growth and social development. The article substantiates the necessity to monitor alcohol safety indicators when considering the regional development. It presents the complex system of socio-economic and demographic

  18. RECENT ADDITIONS OF CRITICALITY SAFETY RELATED INTEGRAL BENCHMARK DATA TO THE ICSBEP AND IRPHEP HANDBOOKS

    Energy Technology Data Exchange (ETDEWEB)

    J. Blair Briggs; Lori Scott; Yolanda Rugama; Enrico Sartori

    2009-09-01

    High-quality integral benchmark experiments have always been a priority for criticality safety. However, interest in integral benchmark data is increasing as efforts to quantify and reduce calculational uncertainties accelerate to meet the demands of future criticality safety needs to support next generation reactor and advanced fuel cycle concepts. The importance of drawing upon existing benchmark data is becoming more apparent because of dwindling availability of critical facilities worldwide and the high cost of performing new experiments. Integral benchmark data from the International Handbook of Evaluated Criticality Safety Benchmark Experiments and the International Handbook of Reactor Physics Benchmark Experiments are widely used. Benchmark data have been added to these two handbooks since the last Nuclear Criticality Safety Division Topical Meeting in Knoxville, Tennessee (September 2005). This paper highlights these additions.

  19. Safety Metrics for Human-Computer Controlled Systems

    Science.gov (United States)

    Leveson, Nancy G; Hatanaka, Iwao

    2000-01-01

    The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems.This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

  20. A Method to Select Test Input Cases for Safety-critical Software

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heeeun; Kang, Hyungook [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Son, Hanseong [Joongbu Univ., Geumsan (Korea, Republic of)

    2013-05-15

    This paper proposes a new testing methodology for effective and realistic quantification of RPS software failure probability. Software failure probability quantification is important factor in digital system safety assessment. In this study, the method for software test case generation is briefly described. The test cases generated by this method reflect the characteristics of safety-critical software and past inputs. Furthermore, the number of test cases can be reduced, but it is possible to perform exhaustive test. Aspect of software also can be reflected as failure data, so the final failure data can include the failure of software itself and external influences. Software reliability is generally accepted as the key factor in software quality since it quantifies software failures which can make a powerful system inoperative. In the KNITS (Korea Nuclear Instrumentation and Control Systems) project, the software for the fully digitalized reactor protection system (RPS) was developed under a strict procedure including unit testing and coverage measurement. Black box testing is one type of Verification and validation (V and V), in which given input values are entered and the resulting output values are compared against the expected output values. Programmable logic controllers (PLCs) were used in implementing critical systems and function block diagram (FBD) is a commonly used implementation language for PLC.

  1. Who is in control of road safety? A STAMP control structure analysis of the road transport system in Queensland, Australia.

    Science.gov (United States)

    Salmon, Paul M; Read, Gemma J M; Stevens, Nicholas J

    2016-11-01

    Despite significant progress, road trauma continues to represent a global safety issue. In Queensland (Qld), Australia, there is currently a focus on preventing the 'fatal five' behaviours underpinning road trauma (drug and drink driving, distraction, seat belt wearing, speeding, and fatigue), along with an emphasis on a shared responsibility for road safety that spans road users, vehicle manufacturers, designers, policy makers etc. The aim of this article is to clarify who shares the responsibility for road safety in Qld and to determine what control measures are enacted to prevent the fatal five behaviours. This is achieved through the presentation of a control structure model that depicts the actors and organisations within the Qld road transport system along with the control and feedback relationships that exist between them. Validated through a Delphi study, the model shows a diverse set of actors and organisations who share the responsibility for road safety that goes beyond those discussed in road safety policies and strategies. The analysis also shows that, compared to other safety critical domains, there are less formal control structures in road transport and that opportunities exist to add new controls and strengthen existing ones. Relationships that influence rather than control are also prominent. Finally, when compared to other safety critical domains, the strength of road safety controls is brought into question.

  2. Controlling traffic jams by time modulating the safety distance

    DEFF Research Database (Denmark)

    Gaididei, Yu B.; Gorria, C.; Berkemer, R.

    2013-01-01

    in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well......The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case....... This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance...

  3. 46 CFR 62.25-15 - Safety control systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Safety control systems. 62.25-15 Section 62.25-15... AUTOMATION General Requirements for All Automated Vital Systems § 62.25-15 Safety control systems. (a) Minimum safety trip controls required for specific types of automated vital systems are listed in Table...

  4. Nuclear Data Activities in Support of the DOE Nuclear Criticality Safety Program

    Science.gov (United States)

    Westfall, R. M.; McKnight, R. D.

    2005-05-01

    The DOE Nuclear Criticality Safety Program (NCSP) provides the technical infrastructure maintenance for those technologies applied in the evaluation and performance of safe fissionable-material operations in the DOE complex. These technologies include an Analytical Methods element for neutron transport as well as the development of sensitivity/uncertainty methods, the performance of Critical Experiments, evaluation and qualification of experiments as Benchmarks, and a comprehensive Nuclear Data program coordinated by the NCSP Nuclear Data Advisory Group (NDAG). The NDAG gathers and evaluates differential and integral nuclear data, identifies deficiencies, and recommends priorities on meeting DOE criticality safety needs to the NCSP Criticality Safety Support Group (CSSG). Then the NDAG identifies the required resources and unique capabilities for meeting these needs, not only for performing measurements but also for data evaluation with nuclear model codes as well as for data processing for criticality safety applications. The NDAG coordinates effort with the leadership of the National Nuclear Data Center, the Cross Section Evaluation Working Group (CSEWG), and the Working Party on International Evaluation Cooperation (WPEC) of the OECD/NEA Nuclear Science Committee. The overall objective is to expedite the issuance of new data and methods to the DOE criticality safety user. This paper describes these activities in detail, with examples based upon special studies being performed in support of criticality safety for a variety of DOE operations.

  5. An overview of criticality safety research at the All-Russian Research Institute of Experimental Physics

    Energy Technology Data Exchange (ETDEWEB)

    Kuvshinov, M.I.; Voinov, A.M.; Yuferev, V.I. [All-Russian Research Institute of Experimental Physics, Arzamas (Russian Federation)] [and others

    1997-06-01

    This paper presents a summary of experimental and calculational activities conducted at VNIIEF from the late 1940s to now to study the critical conditions of systems as part of a nuclear safety program. 9 refs., 1 tab.

  6. Model-based schedulability analysis of safety critical hard real-time Java programs

    DEFF Research Database (Denmark)

    Bøgholm, Thomas; Kragh-Hansen, Henrik; Olsen, Petur

    2008-01-01

    In this paper, we present a novel approach to schedulability analysis of Safety Critical Hard Real-Time Java programs. The approach is based on a translation of programs, written in the Safety Critical Java profile introduced in [21] for the Java Optimized Processor [18], to timed automata models...... has been implemented in a tool, named SARTS, successfully used to verify the schedulability of a real-time sorting machine consisting of two periodic and two sporadic tasks. SARTS has also been applied on a number of smaller examples to investigate properties of our approach.......In this paper, we present a novel approach to schedulability analysis of Safety Critical Hard Real-Time Java programs. The approach is based on a translation of programs, written in the Safety Critical Java profile introduced in [21] for the Java Optimized Processor [18], to timed automata models...

  7. Analytical Methods for Verification and Validation of Adaptive Systems in Safety-Critical Aerospace Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A major challenge of the use of adaptive systems in safety-critical applications is the software life-cycle: requirement engineering through verification and...

  8. Testing Result Statistics-Based Rapid Testing Method for Safety-Critical System

    Institute of Scientific and Technical Information of China (English)

    Zhi-Yao Deng; Nan Sang

    2008-01-01

    Safety-critical system (SCS) has highly demand for dependability, which requires plenty of resource to ensure that the system under test (SUT) satisfies the dependability requirement. In this paper, a new SCS rapid testing method is proposed to improve SCS adaptive dependability testing. The result of each test execution is saved in calculation memory unit and evaluated as an algorithm model. Then the least quantity of scenario test case for next test execution will be calculated according to the promised SUT's confidence level. The feedback data are generated to weight controller as the guideline for the further testing. Finally, a compre- hensive experiment study demonstrates that this adaptive testing method can really work in practice. This rapid testing method, testing result statistics-based adaptive control, makes the SCS dependability testing much more effective.

  9. A validation metrics framework for safety-critical software-intensive systems

    OpenAIRE

    Cruickshank, Kristian John.

    2009-01-01

    Approved for public release, distribution unlimited Validation of safety-critical software requirements is a difficult and frequently misunderstood task. It answers the question of "are we building the right product?" and is essential to Software Engineering. However, validation is often confused with verification activities, or simply left as a final tick-in-the-box just prior to delivery. Current models for validation cannot satisfy the unique aspects of safety-critical software where "b...

  10. Classification for Safety-Critical Car-Cyclist Scenarios Using Machine Learning

    NARCIS (Netherlands)

    Cara, I.; Gelder, E.D.

    2015-01-01

    The number of fatal car-cyclist accidents is increasing. Advanced Driver Assistance Systems (ADAS) can improve the safety of cyclists, but they need to be tested with realistic safety-critical car-cyclist scenarios. In order to store only relevant scenarios, an online classification algorithm is nee

  11. Using Machine Learning for Risky Module Estimation of Safety-Critical Software

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Mi; Jeong, Choong Heui [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2009-05-15

    With the rapid development of digital computer and information processing technologies, nuclear I and C (Instrument and Control) system which needs safety critical function has adopted digital technologies. Software used in safety-critical system must have high dependability. Highly dependable software needs strict software testing and V and V activities. These days, regulatory demands for nuclear power plants are more and more increasing. But, human resources and time for regulation are limited. So, early software risky module prediction is very useful for software testing and regulation activities. Early estimation can be built from a collection of internal metrics during early development phase. Internal metrics are measures of a product derived from assessment of the product itself, and external metrics are measures of a product derived from assessment of the behavior of the systems. Internal metrics can be collected more easily and early than external metrics. In addition, internal metrics can be useful for estimating fault-prone software modules using machine learning. In this paper, we introduce current research status and techniques related to estimating risky software module using machine learning techniques. Section 2 describes the overview of the estimation model using machine learning and section 3 describes processes of the estimation model. Section 4 describes several estimation models using machine leanings. Section 5 concludes the paper.

  12. Using the Job Demands-Resources model to investigate risk perception, safety climate and job satisfaction in safety critical organizations.

    Science.gov (United States)

    Nielsen, Morten Birkeland; Mearns, Kathryn; Matthiesen, Stig Berge; Eid, Jarle

    2011-10-01

    Using the Job Demands-Resources model (JD-R) as a theoretical framework, this study investigated the relationship between risk perception as a job demand and psychological safety climate as a job resource with regard to job satisfaction in safety critical organizations. In line with the JD-R model, it was hypothesized that high levels of risk perception is related to low job satisfaction and that a positive perception of safety climate is related to high job satisfaction. In addition, it was hypothesized that safety climate moderates the relationship between risk perception and job satisfaction. Using a sample of Norwegian offshore workers (N = 986), all three hypotheses were supported. In summary, workers who perceived high levels of risk reported lower levels of job satisfaction, whereas this effect diminished when workers perceived their safety climate as positive. Follow-up analyses revealed that this interaction was dependent on the type of risks in question. The results of this study supports the JD-R model, and provides further evidence for relationships between safety-related concepts and work-related outcomes indicating that organizations should not only develop and implement sound safety procedures to reduce the effects of risks and hazards on workers, but can also enhance other areas of organizational life through a focus on safety.

  13. Incorporating Traffic Control and Safety Hardware Performance Functions into Risk-based Highway Safety Analysis

    National Research Council Canada - National Science Library

    Zongzhi Li; Hoang Dao; Harshingar Patel; Yi Liu; Bei Zhou

    2017-01-01

    .... This study introduces a refined method for computing the Safety Index (SI) as a means of crash predictions for a highway segment that incorporates traffic control and safety hardware performance functions into the analysis...

  14. An assessment of criticality safety at the Department of Energy Rocky Flats Plant, Golden, Colorado, July--September 1989

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, Roger J.

    1989-09-01

    This is a report on the 1989 independent Criticality Safety Assessment of the Rocky Flats Plant, primarily in response to public concerns that nuclear criticality accidents involving plutonium may have occurred at this nuclear weapon component fabrication and processing plant. The report evaluates environmental issues, fissile material storage practices, ventilation system problem areas, and criticality safety practices. While no evidence of a criticality accident was found, several recommendations are made for criticality safety improvements. 9 tabs.

  15. An assessment of criticality safety at the Department of Energy Rocky Flats Plant, Golden, Colorado, July--September 1989

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, Roger J.

    1989-09-01

    This is a report on the 1989 independent Criticality Safety Assessment of the Rocky Flats Plant, primarily in response to public concerns that nuclear criticality accidents involving plutonium may have occurred at this nuclear weapon component fabrication and processing plant. The report evaluates environmental issues, fissile material storage practices, ventilation system problem areas, and criticality safety practices. While no evidence of a criticality accident was found, several recommendations are made for criticality safety improvements. 9 tabs.

  16. CSER 98-003: criticality safety evaluation report for PFP glovebox HC-21A with button can opening

    Energy Technology Data Exchange (ETDEWEB)

    ERICKSON, D.G.

    1999-02-25

    Glovebox HC-21A is an enclosure where cans containing plutonium metal buttons or other plutonium bearing materials are prepared for thermal stabilization in the muffle furnaces. The Inert Atmosphere Confinement (IAC), a new feature added to Glovebox HC-21 A, allows the opening of containers suspected of containing hydrided plutonium metal. The argon atmosphere in the IAC prevents an adverse reaction between oxygen and the hydride. The hydride is then stabilized in a controlled manner to prevent glovebox over pressurization. After removal from the containers, the plutonium metal buttons or plutonium bearing materials will be placed into muffle furnace boats and then be sent to one of the muffle furnace gloveboxes for stabilization. The materials allowed to be brought into Glovebox HC-21A are limited to those with a hydrogen to fissile atom ratio (H/X) {le} 20. Glovebox HC-21A is classified as a DRY glovebox, meaning it has no internal liquid lines, and no free liquids or solutions are allowed to be introduced. The double contingency principle states that designs shall incorporate sufficient factors of safety to require at least two unlikely, independent, and concurrent changes in process conditions before a criticality accident is possible. This criticality safety evaluation report (CSER) shows that the operations to be performed in this glovebox are safe from a criticality standpoint. No single identified event that causes criticality controls to be lost exceeded the criticality safety limit of k{sub eff} = 0.95 (including uncertainties). Therefore, this CSER meets the requirements for a criticality analysis contained in the Hanford Site Nuclear Criticality Safety Manual, HNF-PRO-334, and meets the double contingency principle.

  17. CSER 98-003: criticality safety evaluation report for PFP glovebox HC-21A with button can opening

    Energy Technology Data Exchange (ETDEWEB)

    ERICKSON, D.G.

    1999-02-25

    Glovebox HC-21A is an enclosure where cans containing plutonium metal buttons or other plutonium bearing materials are prepared for thermal stabilization in the muffle furnaces. The Inert Atmosphere Confinement (IAC), a new feature added to Glovebox HC-21 A, allows the opening of containers suspected of containing hydrided plutonium metal. The argon atmosphere in the IAC prevents an adverse reaction between oxygen and the hydride. The hydride is then stabilized in a controlled manner to prevent glovebox over pressurization. After removal from the containers, the plutonium metal buttons or plutonium bearing materials will be placed into muffle furnace boats and then be sent to one of the muffle furnace gloveboxes for stabilization. The materials allowed to be brought into Glovebox HC-21A are limited to those with a hydrogen to fissile atom ratio (H/X) {le} 20. Glovebox HC-21A is classified as a DRY glovebox, meaning it has no internal liquid lines, and no free liquids or solutions are allowed to be introduced. The double contingency principle states that designs shall incorporate sufficient factors of safety to require at least two unlikely, independent, and concurrent changes in process conditions before a criticality accident is possible. This criticality safety evaluation report (CSER) shows that the operations to be performed in this glovebox are safe from a criticality standpoint. No single identified event that causes criticality controls to be lost exceeded the criticality safety limit of k{sub eff} = 0.95 (including uncertainties). Therefore, this CSER meets the requirements for a criticality analysis contained in the Hanford Site Nuclear Criticality Safety Manual, HNF-PRO-334, and meets the double contingency principle.

  18. Safety factor profile control in a tokamak

    CERN Document Server

    Bribiesca Argomedo, Federico; Prieur, Christophe

    2014-01-01

    Control of the Safety Factor Profile in a Tokamak uses Lyapunov techniques to address a challenging problem for which even the simplest physically relevant models are represented by nonlinear, time-dependent, partial differential equations (PDEs). This is because of the  spatiotemporal dynamics of transport phenomena (magnetic flux, heat, densities, etc.) in the anisotropic plasma medium. Robustness considerations are ubiquitous in the analysis and control design since direct measurements on the magnetic flux are impossible (its estimation relies on virtual sensors) and large uncertainties remain in the coupling between the plasma particles and the radio-frequency waves (distributed inputs). The Brief begins with a presentation of the reference dynamical model and continues by developing a Lyapunov function for the discretized system (in a polytopic linear-parameter-varying formulation). The limitations of this finite-dimensional approach motivate new developments in the infinite-dimensional framework. The t...

  19. Ending on a positive: Examining the role of safety leadership decisions, behaviours and actions in a safety critical situation.

    Science.gov (United States)

    Donovan, Sarah-Louise; Salmon, Paul M; Horberry, Timothy; Lenné, Michael G

    2018-01-01

    Safety leadership is an important factor in supporting safe performance in the workplace. The present case study examined the role of safety leadership during the Bingham Canyon Mine high-wall failure, a significant mining incident in which no fatalities or injuries were incurred. The Critical Decision Method (CDM) was used in conjunction with a self-reporting approach to examine safety leadership in terms of decisions, behaviours and actions that contributed to the incidents' safe outcome. Mapping the analysis onto Rasmussen's Risk Management Framework (Rasmussen, 1997), the findings demonstrate clear links between safety leadership decisions, and emergent behaviours and actions across the work system. Communication and engagement based decisions featured most prominently, and were linked to different leadership practices across the work system. Further, a core sub-set of CDM decision elements were linked to the open flow and exchange of information across the work system, which was critical to supporting the safe outcome. The findings provide practical implications for the development of safety leadership capability to support safety within the mining industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. 30 CFR 7.103 - Safety system control test.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Safety system control test. 7.103 Section 7.103.... Temporarily disable the reserve water supply, if applicable, and any safety shutdown system control that might... and attempt to restart the engine. (b) Acceptable performance. Tests of the safety system...

  1. Brazed Joints Design and Allowables: Discuss Margins of Safety in Critical Brazed Structures

    Science.gov (United States)

    FLom, Yury

    2009-01-01

    This slide presentation tutorial discusses margins of safety in critical brazed structures. It reviews: (1) the present situation (2) definition of strength (3) margins of safety (4) design allowables (5) mechanical testing (6) failure criteria (7) design flowchart (8) braze gap (9) residual stresses and (10) delayed failures. This presentation addresses the strength of the brazed joints, the methods of mechanical testing, and our ability to evaluate the margins of safety of the brazed joints as it applies to the design of critical and expensive brazed assemblies.

  2. A Study on Methodologies for Assessing Safety Critical Network's Risk Impact on Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lim, T. J.; Park, S. K.; Seo, S. J. [Soongsil Univ., Seoul (Korea, Republic of)

    2007-04-15

    The objectives of this project is to establish methodologies for assessing safety-critical network's risk impact on nuclear power plant by developing reliability analysis models for the safety-critical network. It is essential to develop reliability analysis models for safety-critical network, and it is very important to adapt the model to the current methodologies for assessing risk impact on nuclear power plants. Major outputs of the first year study are preliminary models for assessing reliability of safety-critical communication networks and those of the second year study are methodologies for assessing safety-critical network's risk impact on nuclear power plant.

  3. Electronics system design techniques for safety critical applications

    CERN Document Server

    Sterpone, Luca

    2008-01-01

    Addresses the development of techniques for the evaluation and the hardening of designs implemented on SRAM-based Field Programmable Gate Arrays. This title presents a design methodology solving industrial designer''s needs for implementing electronic systems using SRAM-based FPGAs in critical environments, like the space or avionic ones.

  4. Perceived versus Observed Patient Safety Measures in a Critical Care Unit from a Teaching Hospital in Southern Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Hernan Montenegro

    2016-01-01

    Full Text Available Introduction. Patient safety is an important topic. The purpose of this study is to evaluate the perceived versus observed patient safety measures (PSM in critically ill patients in a teaching hospital in Latin America. Materials and Methods. The level of perceived patient safety was evaluated with the patient safety hospital survey. Three months later, a qualitative study was conducted, including video recording of procedures, graded according to adherence to PSM. Levels of adherence were scored during patient mobilization (PM, placement of central catheters (PCC, other invasive procedures (OIP, infection control (IC, and endotracheal intubation (ETI. Results. The perceived adherence of PSM in the prestudy survey was considered fair by 89.1% of the ICU staff. After the survey, 829 ICU procedures were video-recorded. Mean observed adherence for fair patient safety measures was 20.8%. Perceived adherence was higher than the real patient safety protocol measures observed in the videos. Conclusion. Perception of PSM was higher than observed in the management of critically ill patients in a teaching hospital in southern Colombia.

  5. Software safety analysis techniques for developing safety critical software in the digital protection system of the LMR

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jang Soo; Cheon, Se Woo; Kim, Chang Hoi; Sim, Yun Sub

    2001-02-01

    This report has described the software safety analysis techniques and the engineering guidelines for developing safety critical software to identify the state of the art in this field and to give the software safety engineer a trail map between the code and standards layer and the design methodology and documents layer. We have surveyed the management aspects of software safety activities during the software lifecycle in order to improve the safety. After identifying the conventional safety analysis techniques for systems, we have surveyed in details the software safety analysis techniques, software FMEA(Failure Mode and Effects Analysis), software HAZOP(Hazard and Operability Analysis), and software FTA(Fault Tree Analysis). We have also surveyed the state of the art in the software reliability assessment techniques. The most important results from the reliability techniques are not the specific probability numbers generated, but the insights into the risk importance of software features. To defend against potential common-mode failures, high quality, defense-in-depth, and diversity are considered to be key elements in digital I and C system design. To minimize the possibility of CMFs and thus increase the plant reliability, we have provided D-in-D and D analysis guidelines.

  6. SAFETY: STRICTER CONTROLS IN CONTROLLED AREAS IN THE PS

    CERN Document Server

    G. Daems

    2001-01-01

    The PS accelerators will soon stop for several months. Work will take place in controlled areas in the PS and will involve many people who are not always aware of the risks associated with the work sites. To guarentee the safety of these workers, the following two measures will be applied: everyone working in a controlled zone - Linacs, PSB, and PS machines tunnels, and transfer lines - must wear, visibly, his CERN access card and his film badge. the CERN access card and the film badge will only be issued after following a basic safety course. Regular checks will be carried out during the shutdown. Anyone without these two items on their person will be obliged to leave the area immediately.

  7. METHODS OF CONTROL DIPHTHERIA VACCINE SAFETY

    Directory of Open Access Journals (Sweden)

    Isayenko Ye. Yu

    2016-12-01

    Full Text Available Vaccination success depends not only on the timely coverage of threatened contingents, but also on the quality of vaccines. Every day, the requirements for security guarantees vaccines and their use guarantees of security increases. For the fast, reliable and independent scientific assessment of vaccine safety issues, WHO in 1999 created the Global Advisory Committee on Vaccine Safety. To enhance the capacity of pharmaceutical supervision in relation to vaccines in 2012 it was developed the Global Vaccine Safety Initiative. The main directions of the Global Vaccine Safety programs are considered in this review. It’s noted more strict requirements of Ukrainian pharmaceutical industry to produce public immunization drugs regulated Supplements to the State Pharmacopoeia of Ukraine, in comparison with other countries. This review considered diphtheria vaccine safety monitoring in the process of production according to the recommendations of the World Health Organization (WHO, described a subcutaneous method for determining the specific toxicity of the combined purified toxoid, characterized an intracutaneous method of determining of the presence of diphtheria toxin in each sample of the combined purified toxoid, that additionally used by some manufacturers. The definition of diphtheria toxin in dilutions of purified toxoid is presented. This review considered diphtheria vaccine safety monitoring in the process of production according to the recommendations of the World Health Organization (WHO, described a subcutaneous method for determining the specific toxicity of the combined purified toxoid, characterized an intracutaneous method of determining of the presence of diphtheria toxin in each sample of the combined purified toxoid, that additionally used by some manufacturers. The definition of diphtheria toxin in dilutions of purified toxoid is presented. As methods for determination of diphtheria toxin must be able to detect even a small amount

  8. Safety physics inter-comparison of advanced concepts of critical reactors and ADS

    Energy Technology Data Exchange (ETDEWEB)

    Slessarev, I. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d' Etudes des Reacteurs

    2001-07-01

    Enhanced safety based on the principle of the natural ''self-defence'' is one of the most desirable features of innovative nuclear systems (critical or sub-critical) regarding both TRU transmutation and ''clean'' energy producer concepts. For the evaluation of the ''self-defence'' domain, the method of the asymptotic reactivity balance has been generalised. The promising option of Hybrids systems (that use a symbiosis of fission and spallation in sub-critical cores) which could benefit the advantages of both Accelerated Driven Systems of the traditional type and regular critical systems, has been advocated. General features of Hybrid dynamics have been presented and analysed. It was demonstrated that an external neutron source of Hybrids can expand the inherent safety potential significantly. This analysis has been applied to assess the safety physics potential of innovative concepts for prospective nuclear power both for energy producers and for transmutation. It has been found, that safety enhancement goal defines a choice of sub-criticality of Hybrids. As for energy producers with Th-fuel cycle, a significant sub-criticality level is required due to a necessity of an improvement of neutronics together with safety enhancement task. (author)

  9. Student research in criticality safety at the University of Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Hetrick, D.L.

    1997-06-01

    A very brief progress report on four University of Arizona student projects is given. Improvements were made in simulations of power pulses in aqueous solutions, including the TWODANT model. TWODANT calculations were performed to investigate the effect of assembly shape on the expansion coefficient of reactivity for solutions. Preliminary calculations were made of critical heights for the Los Alamos SHEBA assembly. Calculations to support French experiments to measure temperature coefficients of dilute plutonium solutions confirmed feasibility.

  10. Sensitivity-Uncertainty Techniques for Nuclear Criticality Safety

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-07

    The sensitivity and uncertainty analysis course will introduce students to keff sensitivity data, cross-section uncertainty data, how keff sensitivity data and keff uncertainty data are generated and how they can be used. Discussion will include how sensitivity/uncertainty data can be used to select applicable critical experiments, to quantify a defensible margin to cover validation gaps and weaknesses, and in development of upper subcritical limits.

  11. Critical incidents related to cardiac arrests reported to the Danish Patient Safety Database

    DEFF Research Database (Denmark)

    Andersen, Peter Oluf; Maaløe, Rikke; Andersen, Henning Boje

    2010-01-01

    Background Critical incident reports can identify areas for improvement in resuscitation practice. The Danish Patient Safety Database is a mandatory reporting system and receives critical incident reports submitted by hospital personnel. The aim of this study is to identify, analyse and categorize...... critical incidents related to cardiac arrests reported to the Danish Patient Safety Database. Methods The search terms “cardiac arrest” and “resuscitation” were used to identify reports in the Danish Patient Safety Database. Identified critical incidents were then classified into categories. Results One...... hundred and seven reports describing 122 separate incidents were identified and classified into incidents related to: alerting the resuscitation team (n = 32; 26%), human performance (n = 22; 18%), equipment failure (n = 19; 16%), resuscitation equipment not available (n = 13; 11%), physical environment...

  12. Repository criticality control for {sup 233}U using depleted uranium

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Elam, K.R.; Hopper, C.M.

    1999-07-01

    The US is evaluating methods for the disposition of excess weapons-usable {sup 233}U, including disposal in a repository. Isotopic dilution studies were undertaken to determine how much depleted uranium (DU) would need to be added to the {sup 233}U to minimize the potential for nuclear criticality in a repository. Numerical evaluations were conducted to determine the nuclear equivalence of different {sup 235}U enrichments to {sup 233}U isotopically diluted with DU containing 0.2 wt% {sup 235}U. A homogeneous system of silicon dioxide, water, {sup 233}U, and DU, in which the ratio of each component was varied, was used to determine the conditions of maximum nuclear reactivity. In terms of preventing nuclear criticality in a repository, there are three important limits from these calculations. 1. Criticality safe in any nonnuclear system: The required isotopic dilution to ensure criticality under all conditions, except in the presence of man-made nuclear materials (beryllium, etc.), is {approximately}1.0% {sup 235}U in {sup 238}U. The equivalent {sup 233}U enrichment level is 0.53 wt% {sup 233}U in DU. 2. Critically safe in natural systems: The lowest {sup 235}U enrichment found in a natural reactor at shutdown was {approximately}1.3%. French studies, based on the characteristics of natural uranium ore bodies, indicate that a minimum enrichment of {approximately}1.28% {sup 235}U is required for criticality. These data suggest that nuclear criticality from migrating uranium is not realistic unless the {sup 235}U enrichments exceed {approximately}1.3%, which is a result that is equivalent to 0.72% {sup 233}U in DU. 3. Criticality safety equivalent to light water reactor (LWR) spent nuclear fuel (SNF): The {sup 233}U can be diluted with DU so that the uranium criticality characteristics match SNF uranium. Whatever repository criticality controls are used for SNF can then be used for {sup 233}U. The average LWR SNF assay (after decay of plutonium isotopes to uranium

  13. A Comparison of Bus Architectures for Safety-Critical Embedded Systems

    Science.gov (United States)

    Rushby, John; Miner, Paul S. (Technical Monitor)

    2003-01-01

    We describe and compare the architectures of four fault-tolerant, safety-critical buses with a view to deducing principles common to all of them, the main differences in their design choices, and the tradeoffs made. Two of the buses come from an avionics heritage, and two from automobiles, though all four strive for similar levels of reliability and assurance. The avionics buses considered are the Honeywell SAFEbus (the backplane data bus used in the Boeing 777 Airplane Information Management System) and the NASA SPIDER (an architecture being developed as a demonstrator for certification under the new DO-254 guidelines); the automobile buses considered are the TTTech Time-Triggered Architecture (TTA), recently adopted by Audi for automobile applications, and by Honeywell for avionics and aircraft control functions, and FlexRay, which is being developed by a consortium of BMW, DaimlerChrysler, Motorola, and Philips.

  14. Measurement of Fresh Fuel Rods to Demonstrate Compliance with Criticality Safety Limits

    Energy Technology Data Exchange (ETDEWEB)

    Miko, David K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Desimone, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-03

    In order to operate TA-66 as a radiological facility with the quantity of nuclear material required to fulfil its mission, a criticality safety evaluation was required. This evaluation defined the control parameters for operations at the facility. The resulting evaluation for TA-66 placed limits on the amount of SNM, as well as other materials such as beryllium. In addition, there is a limit on the number of uranium fuel rods allowed subject to enrichment, outer diameter, and overall length restrictions. The enrichments for the rods to be shipped to TA-66 were documented in LA-UR-13-23581, but the outer diameter and length were not documented. This report provides this information.

  15. Testing Result Statistics-Based Rapid Testing Method for Safety-Critical System

    Institute of Scientific and Technical Information of China (English)

    Zhi-Yao Deng; Nan Sang

    2008-01-01

    Safety-critical system (SCS) has highlydemand for dependability, which requires plenty ofresource to ensure that the system under test (SUT)satisfies the dependability requirement. In this paper, anew SCS rapid testing method is proposed to improveSCS adaptive dependability testing. The result of each testexecution is saved in calculation memory unit andevaluated as an algorithm model. Then the least quantityof scenario test case for next test execution will becalculated according to the promised SUT's confidencelevel. The feedback data are generated to weightcontroller as the guideline for the further testing. Finally,a compre- hensive experiment study demonstrates thatthis adaptive testing method can really work in practice.This rapid testing method, testing result statistics-basedadaptive control, makes the SCS dependability testingmuch more effective.

  16. Criticality Safety Evaluation for the Advanced Test Reactor U-Mo Demonstration Elements

    Energy Technology Data Exchange (ETDEWEB)

    Leland M. Montierth

    2010-12-01

    The Reduced Enrichment Research Test Reactors (RERTR) fuel development program is developing a high uranium density fuel based on a (LEU) uranium-molybdenum alloy. Testing of prototypic RERTR fuel elements is necessary to demonstrate integrated fuel performance behavior and scale-up of fabrication techniques. Two RERTR-Full Size Demonstration fuel elements based on the ATR-Reduced YA elements (all but one plate fueled) are to be fabricated for testing in the Advanced Test Reactor (ATR). The two fuel elements will be irradiated in alternating cycles such that only one element is loaded in the reactor at a time. Existing criticality analyses have analyzed Standard (HEU) ATR elements (all plates fueled) from which controls have been derived. This criticality safety evaluation (CSE) documents analysis that determines the reactivity of the Demonstration fuel elements relative to HEU ATR elements and shows that the Demonstration elements are bound by the Standard HEU ATR elements and existing HEU ATR element controls are applicable to the Demonstration elements.

  17. Incorporating Traffic Control and Safety Hardware Performance Functions into Risk-based Highway Safety Analysis

    Directory of Open Access Journals (Sweden)

    Zongzhi Li

    2017-04-01

    Full Text Available Traffic control and safety hardware such as traffic signs, lighting, signals, pavement markings, guardrails, barriers, and crash cushions form an important and inseparable part of highway infrastructure affecting safety performance. Significant progress has been made in recent decades to develop safety performance functions and crash modification factors for site-specific crash predictions. However, the existing models and methods lack rigorous treatments of safety impacts of time-deteriorating conditions of traffic control and safety hardware. This study introduces a refined method for computing the Safety Index (SI as a means of crash predictions for a highway segment that incorporates traffic control and safety hardware performance functions into the analysis. The proposed method is applied in a computation experiment using five-year data on nearly two hundred rural and urban highway segments. The root-mean square error (RMSE, Chi-square, Spearman’s rank correlation, and Mann-Whitney U tests are employed for validation.

  18. Energy Neutral Wireless Bolt for Safety Critical Fastening.

    Science.gov (United States)

    Seyoum, Biruk B; Rossi, Maurizio; Brunelli, Davide

    2017-09-26

    Thermoelectric generators (TEGs) are now capable of powering the abundant low power electronics from very small (just a few degrees Celsius) temperature gradients. This factor along with the continuously lowering cost and size of TEGs, has contributed to the growing number of miniaturized battery-free sensor modules powered by TEGs. In this article, we present the design of an ambient-powered wireless bolt for high-end electro-mechanical systems. The bolt is equipped with a temperature sensor and a low power RF chip powered from a TEG. A DC-DC converter interfacing the TEG with the RF chip is used to step-up the low TEG voltage. The work includes the characterizations of different TEGs and DC-DC converters to determine the optimal design based on the amount of power that can be generated from a TEG under different loads and at temperature gradients typical of industrial environments. A prototype system was implemented and the power consumption of this system under different conditions was also measured. Results demonstrate that the power generated by the TEG at very low temperature gradients is sufficient to guarantee continuous wireless monitoring of the critical fasteners in critical systems such as avionics, motorsport and aerospace.

  19. Covariance matrices for use in criticality safety predictability studies

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H.; Larson, N.M.; Leal, L.C.

    1997-09-01

    Criticality predictability applications require as input the best available information on fissile and other nuclides. In recent years important work has been performed in the analysis of neutron transmission and cross-section data for fissile nuclei in the resonance region by using the computer code SAMMY. The code uses Bayes method (a form of generalized least squares) for sequential analyses of several sets of experimental data. Values for Reich-Moore resonance parameters, their covariances, and the derivatives with respect to the adjusted parameters (data sensitivities) are obtained. In general, the parameter file contains several thousand values and the dimension of the covariance matrices is correspondingly large. These matrices are not reported in the current evaluated data files due to their large dimensions and to the inadequacy of the file formats. The present work has two goals: the first is to calculate the covariances of group-averaged cross sections from the covariance files generated by SAMMY, because these can be more readily utilized in criticality predictability calculations. The second goal is to propose a more practical interface between SAMMY and the evaluated files. Examples are given for {sup 235}U in the popular 199- and 238-group structures, using the latest ORNL evaluation of the {sup 235}U resonance parameters.

  20. A critical review on toxicological safety of 2-alkylcyclobutanones

    Science.gov (United States)

    Song, Beom-Seok; Choi, Soo-Jeong; Jin, Young-Bae; Park, Jong-Heum; Kim, Jae-Kyung; Byun, Eui-Baek; Kim, Jae-Hun; Lee, Ju-Woon; Kim, Gang-Sung; Marchioni, Eric

    2014-10-01

    2-Alkylcyclobutanones (2-ACBs) are known as unique radiolytic products generated from the major fatty acids and triglycerides in food through only irradiation. Since 1990, studies on the toxicological safety of 2-ACBs have been conducted extensively with synthetic compounds. Mutagenicity tests of 2-ACBs on the microorganisms reviewed in this study clearly indicate that no evidence was observed, while several in vitro studies demonstrated the cytotoxicity of 2-ACBs through cell death. Moreover, the genotoxicity of 2-ACBs was suggested as DNA strand breaks were observed. However, these findings should be interpreted with caution because genotoxicity may result from cytotoxicity, which causes DNA damage or from cell membrane destruction and indirect oxidative DNA damage. Therefore, elucidation of the mechanism of genotoxic effects is needed. With regards to the suggestion of Raul et al. (2002) who showed the promoting effect of colon cancer by the administration of 2-ACBs, further studies are needed to correct some experimental design errors. Moreover, an in-vivo experiment that evaluated the metabolism of 2-ACBs has revealed that 2-dDCB was metabolized into cyclic alcohol and excreted through fecal discharge. In conclusion, it is considered that the ingestion of 2-ACBs through irradiated foods is unlikely to affect the human health. However, more specific studies are required to identify the fate of 2-ACBs in body and the LD50 values. The determination of chronic toxicity by long-term exposure to low concentrations of 2-ACBs has to be evaluated more clearly to determine if these compounds are safe to human.

  1. Glucose control in critically ill patients in 2009: no alarms and no surprises.

    Science.gov (United States)

    Pitrowsky, Melissa; Shinotsuka, Cassia Righy; Soares, Márcio; Salluh, Jorge Ibrain Figueira

    2009-08-01

    Glucose control is a major issue in critical care since landmark publications from the last decade leading to widespread use of strict glucose control in the clinical practice. Subsequent trials showed discordant results that lead to several questions and concerns about benefits and risks of implementing an intensive glucose control protocol. In the midst of all recent controversy, we propose that a new glycemic target -150mg/dl) should be aimed. This target glucose level could offer protection against the deleterious effects of hyperglycemia and at the same time keep patient's safety avoiding hypoglicemia. The article presents a critical review of the current literature on intensive insulin therapy in critically ill patients.

  2. Laboratory quality control and patient safety

    CERN Document Server

    Gras, Jeremie M

    2017-01-01

    Patient Safety emphasizes the reporting, analysis and prevention of medical errors that very often leads to adverse healthcare situations.1 in 10 patients are impacted by medical errors.The WHO calls the patient safety issue an endemic concern. A number of well-known experts of all areas in the medical field have collectedvery valuable information for a better patient treatment and higher safety culture in all medical disciplines.

  3. Direct and indirect effects of mood on risk decision making in safety-critical workers.

    Science.gov (United States)

    Morgan, James I; Jones, Fiona A; Harris, Peter R

    2013-01-01

    The study aimed to examine the direct influence of specific moods (fatigue, anxiety, happiness) on risk in safety-critical decision making. It further aimed to explore indirect effects, specifically, the potential mediating effects of information processing assessed using a goodness-of-simulation task. Trait fatigue and anxiety were associated with an increase in risk taking on the Safety-Critical Personal Risk Inventory (S-CPRI), however the effect of fatigue was partialled out by anxiety. Trait happiness, in contrast was related to less risky decision making. Findings concerning the ability to simulate suggest that better simulators made less risky decisions. Anxious workers were generally less able to simulate. It is suggested that in this safety-critical environment happiness had a direct effect on risk decision making while the effect of trait anxiety was mediated by goodness-of-simulation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Supporting Multiprocessors in the Icecap Safety-Critical Java Run-Time Environment

    DEFF Research Database (Denmark)

    Zhao, Shuai; Wellings, Andy; Korsholm, Stephan Erbs

    2015-01-01

    The current version of the Safety Critical Java (SCJ) specification defines three compliance levels. Level 0 targets single processor programs while Level 1 and 2 can support multiprocessor platforms. Level 1 programs must be fully partitioned but Level 2 programs can also be more globally...... scheduled. As of yet, there is no official Reference Implementation for SCJ. However, the icecap project has produced a Safety-Critical Java Run-time Environment based on the Hardware-near Virtual Machine (HVM). This supports SCJ at all compliance levels and provides an implementation of the safety......-critical Java (javax.safetycritical) package. This is still work-in-progress and lacks certain key features. Among these is the ability to support multiprocessor platforms. In this paper, we explore two possible options to adding multiprocessor support to this environment: the “green thread” and the “native...

  5. A software cost model with maintenance and risk costs for safety-critical systems

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-wei; YANG Xiao-zong; QU Feng; DONG Jian

    2006-01-01

    According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets: common faults and fatal faults. Common faults cause slight loss when they are activated. A fatal fault can lead to significant loss, and even damage the safety-critical system entirely when it is activated. A software reliability growth model for safety-critical systems is developed based on G-O model. And a software cost model is proposed too. The cost model considers maintenance and risk costs due to software failures. The optimal release policies are discussed to minimize the total software cost. A numerical example is provided to illustrate how to use the results we obtained.

  6. 食品安全关键控制点在餐饮业重大活动管理中的应用探讨%Discussion on the Application of Food Safety Critical Control Point in the Management of Major Events in the Catering Industry

    Institute of Scientific and Technical Information of China (English)

    于建焕

    2016-01-01

    On previous catering industry major activities in health supervision work to conduct a comprehensive analysis summary,combined with the characteristics of the catering industry,to develop a set of effective food safety critical control point. Through the implementation of the supervision to ensure that major activities of food hygiene and safety. And promotion to the daily food and beverage health supervision and management work,the formation of self inspection and self-discipline,and it can effectively prevent the occurrence of food safety incidents.%对以往餐饮业重大活动卫生监督工作进行全面分析总结,结合餐饮行业特点,制定出一套有效的食品安全关键控制点,通过监督实施,确保重大活动食品卫生安全。并推广到日常餐饮卫生监督管理工作中,形成自检自律,有效预防食品安全事件的发生。

  7. Application of a Comprehensive Unit-based Safety Program in critical care: the royal exchange.

    Science.gov (United States)

    Smith, Lauren E; Flanders, Sonya A

    2014-12-01

    This article discusses the history of the Comprehensive Unit-based Safety Program (CUSP) and how it is used to foster a culture of safety. CUSP involves interdisciplinary teamwork and empowers nurses at all levels to pioneer changes and develop leadership skills. A case study is presented to show how CUSP was used effectively in critical care to create a standardized handover of patients from the operating room to the intensive care unit.

  8. Planning the Unplanned Experiment: Assessing the Efficacy of Standards for Safety Critical Software

    Science.gov (United States)

    Graydon, Patrick J.; Holloway, C. Michael

    2015-01-01

    We need well-founded means of determining whether software is t for use in safety-critical applications. While software in industries such as aviation has an excellent safety record, the fact that software aws have contributed to deaths illustrates the need for justi ably high con dence in software. It is often argued that software is t for safety-critical use because it conforms to a standard for software in safety-critical systems. But little is known about whether such standards `work.' Reliance upon a standard without knowing whether it works is an experiment; without collecting data to assess the standard, this experiment is unplanned. This paper reports on a workshop intended to explore how standards could practicably be assessed. Planning the Unplanned Experiment: Assessing the Ecacy of Standards for Safety Critical Software (AESSCS) was held on 13 May 2014 in conjunction with the European Dependable Computing Conference (EDCC). We summarize and elaborate on the workshop's discussion of the topic, including both the presented positions and the dialogue that ensued.

  9. Application of Hazard Analysis and Critical Control Points in Cherry Juice Processing Enterprises

    Directory of Open Access Journals (Sweden)

    Peilong Xu

    2015-09-01

    Full Text Available Qingdao is one of the homelands for Cherry in China and in recent years, deep processing industry of cherry is developing rapidly. In this study, Hazard Analysis and Critical Control Points (HACCP quality control system is introduced into production process of cherry juice, which has effectively controlled food safety risks in food production processes. The practices have proved that application of HACCP system reduced probability of pollution in cherry juice production process effectively. The application of risk control system in cherry juice production provides benefits for standardization of the production process and helps in food safety supervision in production processes.

  10. Criticality safety issues in the disposition of BN-350 spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, R. W.; Klann, R. T.; Koltyshev, S. M.; Krechetov, S.

    2000-02-28

    A criticality safety analysis has been performed as part of the BN-350 spent fuel disposition project being conducted jointly by the DOE and Kazakhstan. The Kazakhstan regulations are reasonably consistent with those of the DOE. The high enrichment and severe undermoderation of this fast reactor fuel has significant criticality safety consequences. A detailed modeling approach was used that showed some configurations to be safe that otherwise would be rejected. Reasonable requirements for design and operations were needed, and with them, all operations were found to be safe.

  11. Nuclear criticality safety experiments, calculations, and analyses: 1958 to 1982. Volume 1. Lookup tables

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, B.L.; Hampel, V.E.

    1982-10-21

    This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains - in chronological order - the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41.

  12. Safety control program for complex system based on behavior science

    Institute of Scientific and Technical Information of China (English)

    LIANG Mei-jian; YANG Guang; CHEN Da-wei

    2008-01-01

    To control complex system's safety effectively,safety control program was supported based on the principles of behavioral science that shapes organizational behavior,and organizational behavior produced individual behavior.The program can be structured into a model that consists of three modules including individual behavior rectification,organization behavior diagnosis and model of safety culture.The research result not only reveals the deep cause of complex system accidents but also provides structural descriptions with the accidents cause.

  13. Safety control program for complex system based on behavior science

    Institute of Scientific and Technical Information of China (English)

    LIANG Mei-jian; YANG Guang; CHEN Da-wei

    2008-01-01

    To control complex system's safety effectively, safety control program was supported based on the principles of behavioral science that shapes organizational be-havior, and organizational behavior produced individual behavior. The program can be structured into a model that consists of three modules including individual behavior rectifi-cation, organization behavior diagnosis and model of safety culture. The research result not only reveals the deep cause of complex system accidents but also provides structural descriptions with the accidents cause.

  14. Glycemic control in critically ill patients

    OpenAIRE

    2012-01-01

    Hyperglycemia is common in critically ill patients and can be caused by various mechanisms, including nutrition, medications, and insufficient insulin. In the past, hyperglycemia was thought to be an adaptive response to stress, but hyperglycemia is no longer considered a benign condition in patients with critical illnesses. Indeed, hyperglycemia can increase morbidity and mortality in critically ill patients. Correction of hyperglycemia may improve clinical outcomes. To date, a definite answ...

  15. Trends in Control Area of PLC Reliability and Safety Parameters

    Directory of Open Access Journals (Sweden)

    Juraj Zdansky

    2008-01-01

    Full Text Available Extension of the PLC application possibilities is closely related to increase of reliability and safety parameters. If the requirement of reliability and safety parameters will be suitable, the PLC could by implemented to specific applications such the safety-related processes control. The goal of this article is to show the way which producers are approaching to increase PLC`s reliability and safety parameters. The second goal is to analyze these parameters for range of present choice and describe the possibility how the reliability and safety parameters can be affected.

  16. Validation of acid washes as critical control points in hazard analysis and critical control point systems.

    Science.gov (United States)

    Dormedy, E S; Brashears, M M; Cutter, C N; Burson, D E

    2000-12-01

    A 2% lactic acid wash used in a large meat-processing facility was validated as an effective critical control point (CCP) in a hazard analysis and critical control point (HACCP) plan. We examined the microbial profiles of beef carcasses before the acid wash, beef carcasses immediately after the acid wash, beef carcasses 24 h after the acid wash, beef subprimal cuts from the acid-washed carcasses, and on ground beef made from acid-washed carcasses. Total mesophilic, psychrotrophic, coliforms, generic Escherichia coli, lactic acid bacteria, pseudomonads, and acid-tolerant microorganisms were enumerated on all samples. The presence of Salmonella spp. was also determined. Acid washing significantly reduced all counts except for pseudomonads that were present at very low numbers before acid washing. All other counts continued to stay significantly lower (P HACCP plans and can significantly reduce the total number of microorganisms present on the carcass and during further processing.

  17. Safety Evalution of Cryptography Modules within Safety Related Control Systems for Railway Applications

    Directory of Open Access Journals (Sweden)

    Maria Franekova

    2011-01-01

    Full Text Available The paper deals with the problem of safety evaluation of cryptographic modules used within safety-related control system for applications with increasing safety integrity level. The requirements to cryptographic techniques in safety-related communication for railway application are describe. The mainly part is oriented to description of mathematical apparatus for an error probability of cryptography code with a safety code, used in an additional safety communication layer. The practical results are related with the quantitative evaluation of an average error probability of code word for Euroradio protocol recommended for communication in European Train Control System.

  18. A Randomized, Controlled Clinical Trial Comparing Efficacy, Safety ...

    African Journals Online (AJOL)

    A Randomized, Controlled Clinical Trial Comparing Efficacy, Safety and Cost Effectiveness of ... Log in or Register to get access to full text downloads. ... Pharmacological control of pain is the mainstay of management of osteoarthritis.

  19. Planning the Unplanned Experiment: Towards Assessing the Efficacy of Standards for Safety-Critical Software

    Science.gov (United States)

    Graydon, Patrick J.; Holloway, C. M.

    2015-01-01

    Safe use of software in safety-critical applications requires well-founded means of determining whether software is fit for such use. While software in industries such as aviation has a good safety record, little is known about whether standards for software in safety-critical applications 'work' (or even what that means). It is often (implicitly) argued that software is fit for safety-critical use because it conforms to an appropriate standard. Without knowing whether a standard works, such reliance is an experiment; without carefully collecting assessment data, that experiment is unplanned. To help plan the experiment, we organized a workshop to develop practical ideas for assessing software safety standards. In this paper, we relate and elaborate on the workshop discussion, which revealed subtle but important study design considerations and practical barriers to collecting appropriate historical data and recruiting appropriate experimental subjects. We discuss assessing standards as written and as applied, several candidate definitions for what it means for a standard to 'work,' and key assessment strategies and study techniques and the pros and cons of each. Finally, we conclude with thoughts about the kinds of research that will be required and how academia, industry, and regulators might collaborate to overcome the noted barriers.

  20. Controlling traffic jams by time modulating the safety distance

    Science.gov (United States)

    Gaididei, Yu. B.; Gorria, C.; Berkemer, R.; Kawamoto, A.; Shiga, T.; Christiansen, P. L.; Sørensen, M. P.; Starke, J.

    2013-10-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case. This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well separated. A link between a microscopic description and the macroscopic fundamental diagram is established.

  1. Cyclic executive for safety-critical Java on chip-multiprocessors

    DEFF Research Database (Denmark)

    Ravn, Anders P.; Schoeberl, Martin

    2010-01-01

    , that uses model checking to find a static schedule, if one exists at all, which gives an implementation of a table driven multiprocessor scheduler. To evaluate the proposed cyclic executive for multiprocessors we have implemented it in the context of safety-critical Java on a Java processor....

  2. Criticality safety and sensitivity analyses of PWR spent nuclear fuel repository facilities

    NARCIS (Netherlands)

    Maucec, M; Glumac, B

    2005-01-01

    Monte Carlo criticality safety and sensitivity calculations of pressurized water reactor (PWR) spent nuclear fuel repository facilities for the Slovenian nuclear power plant Krsko are presented. The MCNP4C code was deployed to model and assess the neutron multiplication parameters of pool-based stor

  3. Criticality safety and sensitivity analyses of PWR spent nuclear fuel repository facilities

    NARCIS (Netherlands)

    Maucec, M; Glumac, B

    2005-01-01

    Monte Carlo criticality safety and sensitivity calculations of pressurized water reactor (PWR) spent nuclear fuel repository facilities for the Slovenian nuclear power plant Krsko are presented. The MCNP4C code was deployed to model and assess the neutron multiplication parameters of pool-based stor

  4. Safety analysis of the Los Alamos critical experiments facility: burst operation of Skua

    Energy Technology Data Exchange (ETDEWEB)

    Orndoff, J.D.; Paxton, H.C.; Wimett, T.F.

    1980-12-01

    Detailed consideration of the Skua burst assembly is provided, thereby supplementing the facility Safety Analysis Report covering the operation of other critical assemblies at the Los Alamos Scientific Laboratory. As with these assemblies the small fission-product inventory, ambient pressure, and moderate temperatures in Skua are amenable to straightforward measures to ensure the protection of the public.

  5. Safety out of control: dopamine and defence.

    Science.gov (United States)

    Lloyd, Kevin; Dayan, Peter

    2016-05-23

    We enjoy a sophisticated understanding of how animals learn to predict appetitive outcomes and direct their behaviour accordingly. This encompasses well-defined learning algorithms and details of how these might be implemented in the brain. Dopamine has played an important part in this unfolding story, appearing to embody a learning signal for predicting rewards and stamping in useful actions, while also being a modulator of behavioural vigour. By contrast, although choosing correct actions and executing them vigorously in the face of adversity is at least as important, our understanding of learning and behaviour in aversive settings is less well developed. We examine aversive processing through the medium of the role of dopamine and targets such as D2 receptors in the striatum. We consider critical factors such as the degree of control that an animal believes it exerts over key aspects of its environment, the distinction between 'better' and 'good' actual or predicted future states, and the potential requirement for a particular form of opponent to dopamine to ensure proper calibration of state values.

  6. Application of Hazard Analysis and Critical Control Points in Cherry Juice Processing Enterprises

    OpenAIRE

    Peilong Xu; Na Na

    2015-01-01

    Qingdao is one of the homelands for Cherry in China and in recent years, deep processing industry of cherry is developing rapidly. In this study, Hazard Analysis and Critical Control Points (HACCP) quality control system is introduced into production process of cherry juice, which has effectively controlled food safety risks in food production processes. The practices have proved that application of HACCP system reduced probability of pollution in cherry juice production process effectively. ...

  7. CONTROL COMMAND SYSTEMS IMPACT ON THE RAILWAY OPERATIONAL SAFETY

    Directory of Open Access Journals (Sweden)

    Marek Pawlik

    2015-04-01

    Full Text Available Purpose. Safety is seen as a must, for railway transport market. However it is not so obvious what does safety exactly mean as it means different things for different experts. Showing safety ensured by control command systems as a component of the railway operational safety and pointing associated challenges especially those arising from subdivision of the national railway system into different entities. Methodology. To achieve this purpose control command and signalling systems keeping safe distances between trains, preventing setting conflicting train routs, locking of the mobile elements of the switches, protecting the level crossings, enabling safe incorporation of additional trains were analyzed. Findings. Article analyses how control command system influence operational safety taking into account safety of the control-command system itself, interfaces on one side between signalling systems and control command system and on the other side between control command system and vehicle control systems, transmission, maintenance, and operation in degraded modes of running. Originality. New and high-effective scope of tests which are necessary for putting new control command installation into service both track-side and on-board are proposed. Practical value. Control command implementations will significantly improve operational safety, however it is possible only when recommendations defined in this article are taken into account. This means that all the components including interfaces have to meet acceptable hazard rate 10E-9 and have to be properly design, constructed, assembled and maintained, all taking into account whole chain of functions performed and supervised by different railway entities.

  8. Automated Translation of Safety Critical Application Software Specifications into PLC Ladder Logic

    Science.gov (United States)

    Leucht, Kurt W.; Semmel, Glenn S.

    2008-01-01

    The numerous benefits of automatic application code generation are widely accepted within the software engineering community. A few of these benefits include raising the abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at the NASA Kennedy Space Center (KSC) recognized the need for PLC code generation while developing their new ground checkout and launch processing system. They developed a process and a prototype software tool that automatically translates a high-level representation or specification of safety critical application software into ladder logic that executes on a PLC. This process and tool are expected to increase the reliability of the PLC code over that which is written manually, and may even lower life-cycle costs and shorten the development schedule of the new control system at KSC. This paper examines the problem domain and discusses the process and software tool that were prototyped by the KSC software engineers.

  9. Nuclear criticality safety assessment of the low level radioactive waste disposal facility trenches

    Energy Technology Data Exchange (ETDEWEB)

    Kahook, S.D.

    1994-04-01

    Results of the analyses performed to evaluate the possibility of nuclear criticality in the Low Level Radioactive Waste Disposal Facility (LLRWDF) trenches are documented in this report. The studies presented in this document are limited to assessment of the possibility of criticality due to existing conditions in the LLRWDF. This document does not propose nor set limits for enriched uranium (EU) burial in the LLRWDF and is not a nuclear criticality safety evaluation nor analysis. The calculations presented in the report are Level 2 calculations as defined by the E7 Procedure 2.31, Engineering Calculations.

  10. Controlled versus automatic processes: which is dominant to safety? The moderating effect of inhibitory control.

    Directory of Open Access Journals (Sweden)

    Yaoshan Xu

    Full Text Available This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end.

  11. Controlled versus automatic processes: which is dominant to safety? The moderating effect of inhibitory control.

    Science.gov (United States)

    Xu, Yaoshan; Li, Yongjuan; Ding, Weidong; Lu, Fan

    2014-01-01

    This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT) reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end.

  12. Shielding calculation and criticality safety analysis of spent fuel transportation cask in research reactors.

    Science.gov (United States)

    Mohammadi, A; Hassanzadeh, M; Gharib, M

    2016-02-01

    In this study, shielding calculation and criticality safety analysis were carried out for general material testing reactor (MTR) research reactors interim storage and relevant transportation cask. During these processes, three major terms were considered: source term, shielding, and criticality calculations. The Monte Carlo transport code MCNP5 was used for shielding calculation and criticality safety analysis and ORIGEN2.1 code for source term calculation. According to the results obtained, a cylindrical cask with body, top, and bottom thicknesses of 18, 13, and 13 cm, respectively, was accepted as the dual-purpose cask. Furthermore, it is shown that the total dose rates are below the normal transport criteria that meet the standards specified.

  13. Proceedings of the workshop on integral experiment covariance data for critical safety validation

    Energy Technology Data Exchange (ETDEWEB)

    Stuke, Maik (ed.)

    2016-04-15

    For some time, attempts to quantify the statistical dependencies of critical experiments and to account for them properly in validation procedures were discussed in the literature by various groups. Besides the development of suitable methods especially the quality and modeling issues of the freely available experimental data are in the focus of current discussions, carried out for example in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECD-NEA Nuclear Science Committee. The same committee compiles and publishes also the freely available experimental data in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Most of these experiments were performed as series and might share parts of experimental setups leading to correlated results. The quality of the determination of these correlations and the underlying covariance data depend strongly on the quality of the documentation of experiments.

  14. GROWTH OF THE INTERNATIONAL CRITICALITY SAFETY AND REACTOR PHYSICS EXPERIMENT EVALUATION PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    J. Blair Briggs; John D. Bess; Jim Gulliford

    2011-09-01

    Since the International Conference on Nuclear Criticality Safety (ICNC) 2007, the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPhEP) have continued to expand their efforts and broaden their scope. Eighteen countries participated on the ICSBEP in 2007. Now, there are 20, with recent contributions from Sweden and Argentina. The IRPhEP has also expanded from eight contributing countries in 2007 to 16 in 2011. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments1' have increased from 442 evaluations (38000 pages), containing benchmark specifications for 3955 critical or subcritical configurations to 516 evaluations (nearly 55000 pages), containing benchmark specifications for 4405 critical or subcritical configurations in the 2010 Edition of the ICSBEP Handbook. The contents of the Handbook have also increased from 21 to 24 criticality-alarm-placement/shielding configurations with multiple dose points for each, and from 20 to 200 configurations categorized as fundamental physics measurements relevant to criticality safety applications. Approximately 25 new evaluations and 150 additional configurations are expected to be added to the 2011 edition of the Handbook. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Reactor Physics Benchmark Experiments2' have increased from 16 different experimental series that were performed at 12 different reactor facilities to 53 experimental series that were performed at 30 different reactor facilities in the 2011 edition of the Handbook. Considerable effort has also been made to improve the functionality of the searchable database, DICE (Database for the International Criticality Benchmark Evaluation Project) and verify the accuracy of the data contained therein. DICE will be discussed in separate papers at ICNC 2011. The status of the

  15. Discussion on software aging management of nuclear power plant safety digital control system.

    Science.gov (United States)

    Liang, Huihui; Gu, Pengfei; Tang, Jianzhong; Chen, Weihua; Gao, Feng

    2016-01-01

    Managing the aging of digital control systems ensures that nuclear power plant systems are in adequate safety margins during their life cycles. Software is a core component in the execution of control logic and differs between digital and analog control systems. The hardware aging management for the digital control system is similar to that for the analog system, which has matured over decades of study. However, software aging management is still in the exploratory stage. Software aging evaluation is critical given the higher reliability and safety requirements of nuclear power plants. To ensure effective inputs for reliability assessment, this paper provides the required software aging information during the life cycle. Moreover, the software aging management scheme for safety digital control system is proposed on the basis of collected aging information.

  16. Some Challenges in the Design of Human-Automation Interaction for Safety-Critical Systems

    Science.gov (United States)

    Feary, Michael S.; Roth, Emilie

    2014-01-01

    Increasing amounts of automation are being introduced to safety-critical domains. While the introduction of automation has led to an overall increase in reliability and improved safety, it has also introduced a class of failure modes, and new challenges in risk assessment for the new systems, particularly in the assessment of rare events resulting from complex inter-related factors. Designing successful human-automation systems is challenging, and the challenges go beyond good interface development (e.g., Roth, Malin, & Schreckenghost 1997; Christoffersen & Woods, 2002). Human-automation design is particularly challenging when the underlying automation technology generates behavior that is difficult for the user to anticipate or understand. These challenges have been recognized in several safety-critical domains, and have resulted in increased efforts to develop training, procedures, regulations and guidance material (CAST, 2008, IAEA, 2001, FAA, 2013, ICAO, 2012). This paper points to the continuing need for new methods to describe and characterize the operational environment within which new automation concepts are being presented. We will describe challenges to the successful development and evaluation of human-automation systems in safety-critical domains, and describe some approaches that could be used to address these challenges. We will draw from experience with the aviation, spaceflight and nuclear power domains.

  17. Critical Period of Weed Control in Aerobic Rice

    OpenAIRE

    Anwar, M. P.; A. S. Juraimi; Samedani, B.; Puteh, A.; Man, A.

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined th...

  18. Quality and safety: reflection on the implications for critical care nursing education.

    Science.gov (United States)

    Baid, Heather; Hargreaves, Jessica

    2015-07-01

    Safe and high quality health care is underpinned by health care professionals possessing the knowledge, skills and professional attributes which are necessary for their specific clinical speciality and area of practice. Education is crucial as it enables clinicians to learn and put into practice their specialist knowledge, skills and attributes. These elements will be based on clinical standards, which set the agenda for quality and safety in health care. The purpose of this paper is to reflect upon how a post-registration, degree-level critical care nursing course provided by an English university facilitates nurses to deliver high quality, safe nursing care for critically ill patients and their families. As a reflective analysis, the process of reflection will be guided and structured according to Rolfe's framework for reflective practice. The reflection is based upon the personal observations and teaching experiences of two university lecturers involved in the delivery of the critical care course. Critical care nursing education can incorporate informed practice, simulation and non-technical skills into post-registration critical-care nursing courses as a way of promoting high-quality, safe clinical practice in the critical care setting. This article provides examples from one course's experience with doing this and ends with specific recommendations for how critical care nursing courses can enhance further the promotion of quality and safety. Educators, mentors and students of post-registration critical care nursing courses are encouraged to explore the relevance of nursing education in promoting safe and high-quality clinical practice. © 2015 British Association of Critical Care Nurses.

  19. Bias and Uncertainty of Critical Experiment Models with CSAS25 from SCALE4.4a for Criticality Safety Analyses On the HP J-5600 (CMODB) Workstation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.H.; Keener, H.J.; DeClue, J.F.; Krass, A.W.; Cain, V.R.

    2001-02-01

    This report documents establishment of bias, bias trends and uncertainty for validation of the CSAS25 control module from the SCALE 4.4a computer code system for use in evaluating criticality safety of uranium systems. The 27-group ENDF/B-IV, 44-group ENDF/B-V, and 238-group ENDF/B-V cross-section libraries were used. The criticality validation calculations were performed using over 500 benchmark cases from Volumes II and IV of the ''International Handbook of Evaluated Criticality Safety Benchmark Experiments,'' published by the Nuclear Energy Agency Organization for Economic Cooperation and Development (NEA/OECD). Based on statistical analysis of the calculation results, the bias, bias trends and uncertainty of the benchmark calculations have been established for these benchmark experiments. Numerical methods for applying margins are briefly described, but the determination of appropriate correlating parameter and values for additional margin, applicable to a particular analysis, must be determined as part of process analysis. As such, this document does not specify upper subcritical limits as has been done in the past. A follow-on report will be written to assess the methods for determination of an upper safety limit in more detail, provide comparisons, and recommend a preferred method. Analysts using these results are responsible for exercising sound engineering judgment using strong technical arguments to develop a margin in k{sub eff} or other correlating parameter that is sufficiently large to ensure that conditions (calculated by this method to be subcritical by this margin) will actually be subcritical. Documentation of determination and justification of the appropriate margin in the analyst's evaluation, in conjunction with this report, will constitute the complete Validation Report in accordance with ANSI/ANS-8.1-1998, Section 4.3.6(4).

  20. Guide to verification and validation of the SCALE-4 criticality safety software

    Energy Technology Data Exchange (ETDEWEB)

    Emmett, M.B.; Jordan, W.C.

    1996-12-01

    Whenever a decision is made to newly install the SCALE nuclear criticality safety software on a computer system, the user should run a set of verification and validation (V&V) test cases to demonstrate that the software is properly installed and functioning correctly. This report is intended to serve as a guide for this V&V in that it specifies test cases to run and gives expected results. The report describes the V&V that has been performed for the nuclear criticality safety software in a version of SCALE-4. The verification problems specified by the code developers have been run, and the results compare favorably with those in the SCALE 4.2 baseline. The results reported in this document are from the SCALE 4.2P version which was run on an IBM RS/6000 workstation. These results verify that the SCALE-4 nuclear criticality safety software has been correctly installed and is functioning properly. A validation has been performed for KENO V.a utilizing the CSAS25 criticality sequence and the SCALE 27-group cross-section library for {sup 233}U, {sup 235}U, and {sup 239}Pu fissile, systems in a broad range of geometries and fissile fuel forms. The experimental models used for the validation were taken from three previous validations of KENO V.a. A statistical analysis of the calculated results was used to determine the average calculational bias and a subcritical k{sub eff} criteria for each class of systems validated. Included the statistical analysis is a means of estimating the margin of subcriticality in k{sub eff}. This validation demonstrates that KENO V.a and the 27-group library may be used for nuclear criticality safety computations provided the system being analyzed falls within the range of the experiments used in the validation.

  1. Nuclear criticality safety and time reactivity enhancement aspects of energy amplifier system devices

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, F. [ENEA, Centro Ricerche Trisaia, Rotondelle, Matera (Italy). Direzione INFO

    1995-12-01

    As far as the Rubbia`s and colleagues proposal of innovating Energy Amplifier system (E.A.s.) device driven by a particle beam accelerator is concerned, four basic topics are comprised in the present paper: (1) A short outline of the nuclear aspects of Th-U and U-Pu fuel cycles regarding their general breeding and efficiency features. (2) The needed nuclear criticality control requirements have been studied in terms of safety regulating parameters on the basis of the ThO2 mixed oxides selected as fuel kind for the E.A.s. device technology development. Particular attention is devoted to time evolution of neutron multiplication factor since delayed development of the 233U buildup and so system reactivity are expected in the Th-U cycle. (3) Code E.A.s. device irradiation and post-irradiation modelling for determining higher actinides buildup, fission products formation and fuel consumption trends as function of time, system enrichment degree and flux level parameters. (4) The confirmation, on the basis of the same specific power irradiation, of expected actinides waste obtainment cleaner than the one deriving from the U-Pu cycle utilization. For this end, a model comparison of equivalent enriched fissile nuclides in both cycles has been devised as having, within the range of 0-700 days, ten irradiation periods of about 53 MW/ton specific power and equivalent cooling time post-irradiation periods.

  2. KAERI software verification and validation guideline for developing safety-critical software in digital I and C system of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Yeol; Lee, Jang Soo; Eom, Heung Seop

    1997-07-01

    This technical report is to present V and V guideline development methodology for safety-critical software in NPP safety system. Therefore it is to present V and V guideline of planning phase for the NPP safety system in addition to critical safety items, for example, independence philosophy, software safety analysis concept, commercial off the shelf (COTS) software evaluation criteria, inter-relationships between other safety assurance organizations, including the concepts of existing industrial standard, IEEE Std-1012, IEEE Std-1059. This technical report includes scope of V and V guideline, guideline framework as part of acceptance criteria, V and V activities and task entrance as part of V and V activity and exit criteria, review and audit, testing and QA records of V and V material and configuration management, software verification and validation plan production etc., and safety-critical software V and V methodology. (author). 11 refs.

  3. Criticality Safety Scoping Study for the Transport of Weapons-Grade Mixed-Oxide Fuel Using the MO-1 Shipping Package

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, M.E.; Fox, P.B.

    1999-05-01

    This report provides the criticality safety information needed for obtaining certification of the shipment of mixed-oxide (MOX) fuel using the MO-1 [USA/9069/B()F] shipping package. Specifically, this report addresses the shipment of non-weapons-grade MOX fuel as certified under Certificate of Compliance 9069, Revision 10. The report further addresses the shipment of weapons-grade MOX fuel using a possible Westinghouse fuel design. Criticality safety analysis information is provided to demonstrate that the requirements of 10 CFR S 71.55 and 71.59 are satisfied for the MO-1 package. Using NUREG/CR-5661 as a guide, a transport index (TI) for criticality control is determined for the shipment of non-weapons-grade MOX fuel as specified in Certificate of Compliance 9069, Revision 10. A TI for criticality control is also determined for the shipment of weapons-grade MOX fuel. Since the possible weapons-grade fuel design is preliminary in nature, this report is considered to be a scoping evaluation and is not intended as a substitute for the final criticality safety analysis of the MO-1 shipping package. However, the criticality safety evaluation information that is presented in this report does demonstrate the feasibility of obtaining certification for the transport of weapons-grade MOX lead test fuel using the MO-1 shipping package.

  4. Computerization upgrade project for the Rocky Flats Plant Critical Mass Laboratory Reactor Control Console

    Energy Technology Data Exchange (ETDEWEB)

    Bachman, H.C.; Miles, R.E.; Sachs, R.D.

    1987-01-01

    This report discusses present and planned future work on computerization of the Rocky Flats Plant (RFP) Critical Mass Laboratory (CML) Nuclear Reactor Control Console. No computerized control functions are planned or anticipated at this time. The scope of this computerization effort is limited to Data Acquisition and Analysis. In this work an IBM-PC will be connected to four (4) Nuclear Safety channels, and two (2) nonnuclear safety channels. Programming is being done in interpretive advanced BASIC. At the present time only two channels, Linear Picoammeters 1 and 2, are having their signals processed by the IBM-PC.

  5. Propagation of Isotopic Bias and Uncertainty to Criticality Safety Analyses of PWR Waste Packages

    Energy Technology Data Exchange (ETDEWEB)

    Radulescu, Georgeta [ORNL

    2010-06-01

    Burnup credit methodology is economically advantageous because significantly higher loading capacity may be achieved for spent nuclear fuel (SNF) casks based on this methodology as compared to the loading capacity based on a fresh fuel assumption. However, the criticality safety analysis for establishing the loading curve based on burnup credit becomes increasingly complex as more parameters accounting for spent fuel isotopic compositions are introduced to the safety analysis. The safety analysis requires validation of both depletion and criticality calculation methods. Validation of a neutronic-depletion code consists of quantifying the bias and the uncertainty associated with the bias in predicted SNF compositions caused by cross-section data uncertainty and by approximations in the calculational method. The validation is based on comparison between radiochemical assay (RCA) data and calculated isotopic concentrations for fuel samples representative of SNF inventory. The criticality analysis methodology for commercial SNF disposal allows burnup credit for 14 actinides and 15 fission product isotopes in SNF compositions. The neutronic-depletion method for disposal criticality analysis employing burnup credit is the two-dimensional (2-D) depletion sequence TRITON (Transport Rigor Implemented with Time-dependent Operation for Neutronic depletion)/NEWT (New ESC-based Weighting Transport code) and the 44GROUPNDF5 crosssection library in the Standardized Computer Analysis for Licensing Evaluation (SCALE 5.1) code system. The SCALE 44GROUPNDF5 cross section library is based on the Evaluated Nuclear Data File/B Version V (ENDF/B-V) library. The criticality calculation code for disposal criticality analysis employing burnup credit is General Monte Carlo N-Particle (MCNP) Transport Code. The purpose of this calculation report is to determine the bias on the calculated effective neutron multiplication factor, k{sub eff}, due to the bias and bias uncertainty associated with

  6. A Novel Hybrid Safety-control Strategy for a Manipulator

    Directory of Open Access Journals (Sweden)

    Jing Xia

    2014-04-01

    Full Text Available As robots tend to work cooperatively with humans in shared workplaces, safety as regards robot- human interactions has caused a great deal of concern in the robot community, and control strategies have become a hot topic in robotics research. In order to guarantee the robot’s safety and continuous motions, this paper proposes a novel safety-control strategy, which is strictly conservative and which consists of a pre-contact and post-contact safety strategy. We adopt an optimal motion trajectory-planning method, by use of which the jerk, acceleration and velocity of the robot’s motion can be limited and a time-optimal motion can be obtained as a post-contact safety strategy for a position-controlled manipulator. The optimal motion trajectory planning not only reduces the impact forces during the collision period, but also maintains the efficiency of the manipulator and preserves continuous motions. Next, we describe a novel collision detection method as a pre-contact safety strategy to avoid collisions. The method proposed here can compute security warning region to handle the effect of robot motion on collision detection and detect collisions between non-convex polygon soups. Finally, the control strategy is implemented for a 7-DOF humanoid manipulator and the experimental results demonstrate the validity of this novel hybrid safety-control strategy.

  7. Feasibility and safety of virtual-reality-based early neurocognitive stimulation in critically ill patients.

    Science.gov (United States)

    Turon, Marc; Fernandez-Gonzalo, Sol; Jodar, Mercè; Gomà, Gemma; Montanya, Jaume; Hernando, David; Bailón, Raquel; de Haro, Candelaria; Gomez-Simon, Victor; Lopez-Aguilar, Josefina; Magrans, Rudys; Martinez-Perez, Melcior; Oliva, Joan Carles; Blanch, Lluís

    2017-12-01

    Growing evidence suggests that critical illness often results in significant long-term neurocognitive impairments in one-third of survivors. Although these neurocognitive impairments are long-lasting and devastating for survivors, rehabilitation rarely occurs during or after critical illness. Our aim is to describe an early neurocognitive stimulation intervention based on virtual reality for patients who are critically ill and to present the results of a proof-of-concept study testing the feasibility, safety, and suitability of this intervention. Twenty critically ill adult patients undergoing or having undergone mechanical ventilation for ≥24 h received daily 20-min neurocognitive stimulation sessions when awake and alert during their ICU stay. The difficulty of the exercises included in the sessions progressively increased over successive sessions. Physiological data were recorded before, during, and after each session. Safety was assessed through heart rate, peripheral oxygen saturation, and respiratory rate. Heart rate variability analysis, an indirect measure of autonomic activity sensitive to cognitive demands, was used to assess the efficacy of the exercises in stimulating attention and working memory. Patients successfully completed the sessions on most days. No sessions were stopped early for safety concerns, and no adverse events occurred. Heart rate variability analysis showed that the exercises stimulated attention and working memory. Critically ill patients considered the sessions enjoyable and relaxing without being overly fatiguing. The results in this proof-of-concept study suggest that a virtual-reality-based neurocognitive intervention is feasible, safe, and tolerable, stimulating cognitive functions and satisfying critically ill patients. Future studies will evaluate the impact of interventions on neurocognitive outcomes. Trial registration Clinical trials.gov identifier: NCT02078206.

  8. Agricultural pest control programmes, food security and safety | Eze ...

    African Journals Online (AJOL)

    Agricultural pest control programmes, food security and safety. ... of some of the pests to the chemical pesticides, coupled with potential health hazards on the ... or post harvest treatments and basic information regarding the individual farmer or ...

  9. Supporting Multiprocessors in the Icecap Safety-Critical Java Run-Time Environment

    DEFF Research Database (Denmark)

    Zhao, Shuai; Wellings, Andy; Korsholm, Stephan Erbs

    2015-01-01

    scheduled. As of yet, there is no official Reference Implementation for SCJ. However, the icecap project has produced a Safety-Critical Java Run-time Environment based on the Hardware-near Virtual Machine (HVM). This supports SCJ at all compliance levels and provides an implementation of the safety......-critical Java (javax.safetycritical) package. This is still work-in-progress and lacks certain key features. Among these is the ability to support multiprocessor platforms. In this paper, we explore two possible options to adding multiprocessor support to this environment: the “green thread” and the “native...... thread” approaches. The “native thread” approach is adopted and the design and implementation of a revised icecap SCJ run-time environment is discussed....

  10. Trustworthy Variant Derivation with Translation Validation for Safety Critical Product Lines

    DEFF Research Database (Denmark)

    Iosif-Lazăr, Alexandru Florin; Wasowski, Andrzej

    2016-01-01

    Software product line (SPL) engineering facilitates development of entire families of software products with systematic reuse. Model driven SPLs use models in the design and development process. In the safety critical domain, validation of models and testing of code increases the quality of the p......Software product line (SPL) engineering facilitates development of entire families of software products with systematic reuse. Model driven SPLs use models in the design and development process. In the safety critical domain, validation of models and testing of code increases the quality...... translation validation. We demonstrate it using Featherweight VML—a core language for separate variability modeling relying on a single kind of variation point to define transformations of artifacts seen as object models. We use Featherweight VML with its semantics as a correctness specification...

  11. System Guidelines for EMC Safety-Critical Circuits: Design, Selection, and Margin Demonstration

    Science.gov (United States)

    Lawton, R. M.

    1996-01-01

    Demonstration of required safety margins on critical electrical/electronic circuits in large complex systems has become an implementation and cost problem. These margins are the difference between the activation level of the circuit and the electrical noise on the circuit in the actual operating environment. This document discusses the origin of the requirement and gives a detailed process flow for the identification of the system electromagnetic compatibility (EMC) critical circuit list. The process flow discusses the roles of engineering disciplines such as systems engineering, safety, and EMC. Design and analysis guidelines are provided to assist the designer in assuring the system design has a high probability of meeting the margin requirements. Examples of approaches used on actual programs (Skylab and Space Shuttle Solid Rocket Booster) are provided to show how variations of the approach can be used successfully.

  12. Distributed Measuring System for Predictive Diagnosis of Uninterruptible Power Supplies in Safety-Critical Applications

    Directory of Open Access Journals (Sweden)

    Sergio Saponara

    2016-04-01

    Full Text Available This work proposes a scalable architecture of an Uninterruptible Power Supply (UPS system, with predictive diagnosis capabilities, for safety critical applications. A Failure Mode and Effect Analysis (FMEA has identified the faults occurring in the energy storage unit, based on Valve Regulated Lead-Acid batteries, and in the 3-phase high power transformers, used in switching converters and for power isolation, as the main bottlenecks for power system reliability. To address these issues, a distributed network of measuring nodes is proposed, where vibration-based mechanical stress diagnosis is implemented together with electrical (voltage, current, impedance and thermal degradation analysis. Power system degradation is tracked through multi-channel measuring nodes with integrated digital signal processing in the transformed frequency domain, from 0.1 Hz to 1 kHz. Experimental measurements on real power systems for safety-critical applications validate the diagnostic unit.

  13. Road safety management by objectives: a critical analysis of the Norwegian approach.

    Science.gov (United States)

    Elvik, Rune

    2008-05-01

    The Norwegian Public Roads Administration has developed a comprehensive system of road safety management by objectives. A broad set of objectives regarding road user behaviour, vehicle safety standards and the safety of roads has been formulated as part of the National Transport Plan for the term 2010--2019. These objectives have been derived from an overall objective of reducing the number of killed or seriously injured road users by 50% before the year 2020. This paper describes the system and provides a critical analysis of it. Factors that influence the effectiveness of management by objectives are identified. It is concluded that while the system of management by objectives developed in Norway has a number of attractive characteristics it also has a number of weak points that may limit its effectiveness. It is therefore by no means certain that the objective of reducing fatalities and serious injuries by 50% will be realised.

  14. Safety-critical Java with cyclic executives on chip-multiprocessors

    DEFF Research Database (Denmark)

    Ravn, Anders P.; Schoeberl, Martin

    2012-01-01

    Chip-multiprocessors offer increased processing power at a low cost. However, in order to use them for real-time systems, tasks have to be scheduled efficiently and predictably. It is well known that finding optimal schedules is a computationally hard problem. In this paper we present a solution ...... for multiprocessors, we have implemented it in the context of safety-critical Java on a Java processor....

  15. Application of the SCALE TSUNAMI Tools for the Validation of Criticality Safety Calculations Involving 233U

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Rearden, Bradley T [ORNL; Hollenbach, Daniel F [ORNL

    2009-02-01

    The Radiochemical Development Facility at Oak Ridge National Laboratory has been storing solid materials containing 233U for decades. Preparations are under way to process these materials into a form that is inherently safe from a nuclear criticality safety perspective. This will be accomplished by down-blending the {sup 233}U materials with depleted or natural uranium. At the request of the U.S. Department of Energy, a study has been performed using the SCALE sensitivity and uncertainty analysis tools to demonstrate how these tools could be used to validate nuclear criticality safety calculations of selected process and storage configurations. ISOTEK nuclear criticality safety staff provided four models that are representative of the criticality safety calculations for which validation will be needed. The SCALE TSUNAMI-1D and TSUNAMI-3D sequences were used to generate energy-dependent k{sub eff} sensitivity profiles for each nuclide and reaction present in the four safety analysis models, also referred to as the applications, and in a large set of critical experiments. The SCALE TSUNAMI-IP module was used together with the sensitivity profiles and the cross-section uncertainty data contained in the SCALE covariance data files to propagate the cross-section uncertainties ({Delta}{sigma}/{sigma}) to k{sub eff} uncertainties ({Delta}k/k) for each application model. The SCALE TSUNAMI-IP module was also used to evaluate the similarity of each of the 672 critical experiments with each application. Results of the uncertainty analysis and similarity assessment are presented in this report. A total of 142 experiments were judged to be similar to application 1, and 68 experiments were judged to be similar to application 2. None of the 672 experiments were judged to be adequately similar to applications 3 and 4. Discussion of the uncertainty analysis and similarity assessment is provided for each of the four applications. Example upper subcritical limits (USLs) were

  16. Starting up unstable multivariable controllers safety

    DEFF Research Database (Denmark)

    Stoustrup, J.; Niemann, Hans Henrik

    The problem of superimposing a multivariable controller on a running plant is considered. A simple but effective controller architecture is suggested which allows the transition from a conventional controller to a full multivariable controller to take place in a continuous way. This architecture...... allows for unstable controllers to be handled in a reliable way. Moreover, bandwidth properties can be tuned separately. It is shown how this architecture can be extended to provide a useful tool to implement gain scheduled controllers in the same fashion....

  17. Cyber Security Threats to Safety-Critical, Space-Based Infrastructures

    Science.gov (United States)

    Johnson, C. W.; Atencia Yepez, A.

    2012-01-01

    Space-based systems play an important role within national critical infrastructures. They are being integrated into advanced air-traffic management applications, rail signalling systems, energy distribution software etc. Unfortunately, the end users of communications, location sensing and timing applications often fail to understand that these infrastructures are vulnerable to a wide range of security threats. The following pages focus on concerns associated with potential cyber-attacks. These are important because future attacks may invalidate many of the safety assumptions that support the provision of critical space-based services. These safety assumptions are based on standard forms of hazard analysis that ignore cyber-security considerations This is a significant limitation when, for instance, security attacks can simultaneously exploit multiple vulnerabilities in a manner that would never occur without a deliberate enemy seeking to damage space based systems and ground infrastructures. We address this concern through the development of a combined safety and security risk assessment methodology. The aim is to identify attack scenarios that justify the allocation of additional design resources so that safety barriers can be strengthened to increase our resilience against security threats.

  18. Deadlock-free traffic control with geometrical critical sections

    NARCIS (Netherlands)

    Schoute, Albert L.; Bouwens, Peter J.; Backer, E.

    1994-01-01

    Traffic control of vehicles on pre-planned paths may be based on critical sections where vehicles have to control their velocity mutually in order to avoid collisions. By analysing the geometry of critical sections carefully deadlock situations can be recognised and situations where vehicles may sha

  19. Safety Impact of Average Speed Control in the UK

    DEFF Research Database (Denmark)

    Lahrmann, Harry Spaabæk; Brassøe, Bo; Johansen, Jonas Wibert

    2016-01-01

    in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control....

  20. Safety Impacts of the Actuated Signal Control at Urban Intersections

    Directory of Open Access Journals (Sweden)

    Sang Hyuk Lee

    2016-02-01

    Full Text Available To reduce travel time, the actuated signal controls have been implemented at urban intersections. However, the safety impacts of actuated signal controls thus far have rarely been examined. In this assessment of the safety impact of urban intersections with semi-actuated signal controls, the safety performance functions and EB approaches were applied. The semi-actuated signal controls have increased injuries and total crashes in all crash types by around 5.9% and 3.8%, respectively. Regarding the most common crash types, such as angle, sideswipe & rear-end, and head-on crashes, semi-actuated signal controls have been seen to decrease injuries by 7.7%. Total crashes have been reduced by over 9.2% through the use of semi-actuated signal controls. This may be result of optimal signal timings considering traffic conditions during peak time periods. In conclusion, safety impact factors which have been established in this study can be used to improve safety and minimize travel times using semi-actuated signal controls.

  1. Parametric Analysis of PWR Spent Fuel Depletion Parameters for Long-Term-Disposal Criticality Safety

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, M.D.

    1999-08-01

    Utilization of burnup credit in criticality safety analysis for long-term disposal of spent nuclear fuel allows improved design efficiency and reduced cost due to the large mass of fissile material that will be present in the repository. Burnup-credit calculations are based on depletion calculations that provide a conservative estimate of spent fuel contents (in terms of criticality potential), followed by criticality calculations to assess the value of the effective neutron multiplication factor (k(sub)eff) for the a spent fuel cask or a fuel configuration under a variety of probabilistically derived events. In order to ensure that the depletion calculation is conservative, it is necessary to both qualify and quantify assumptions that can be made in depletion models.

  2. Packaging Strategies for Criticality Safety for "Other" DOE Fuels in a Repository

    Energy Technology Data Exchange (ETDEWEB)

    Larry L Taylor

    2004-06-01

    Since 1998, there has been an ongoing effort to gain acceptance of U.S. Department of Energy (DOE)-owned spent nuclear fuel (SNF) in the national repository. To accomplish this goal, the fuel matrix was used as a discriminating feature to segregate fuels into nine distinct groups. From each of those groups, a characteristic fuel was selected and analyzed for criticality safety based on a proposed packaging strategy. This report identifies and quantifies the important criticality parameters for the canisterized fuels within each criticality group to: (1) demonstrate how the “other” fuels in the group are bounded by the baseline calculations or (2) allow identification of individual type fuels that might require special analysis and packaging.

  3. Building capacity for quality and safety in critical care: A roundtable discussion from the second international patient safety conference in April 9-11, 2013, Riyadh, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Yaseen M Arabi

    2013-01-01

    Full Text Available This paper summarizes the roundtable discussion from the Second International Patient Safety Conference held in April 9-11, 2013, Riyadh, Saudi Arabia. The objectives of the roundtable discussion were to: (1 review the conceptual framework for building capacity in quality and safety in critical care. (2 examine examples of leading international experiences in building capacity. (3 review the experience in Saudi Arabia in this area. (4 discuss the role of building capacity in simulation for patient safety in critical care and (5 review the experience in building capacity in an ongoing improvement project for severe sepsis and septic shock.

  4. Educating Next Generation Nuclear Criticality Safety Engineers at the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    J. D. Bess; J. B. Briggs; A. S. Garcia

    2011-09-01

    One of the challenges in educating our next generation of nuclear safety engineers is the limitation of opportunities to receive significant experience or hands-on training prior to graduation. Such training is generally restricted to on-the-job-training before this new engineering workforce can adequately provide assessment of nuclear systems and establish safety guidelines. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPhEP) can provide students and young professionals the opportunity to gain experience and enhance critical engineering skills. The ICSBEP and IRPhEP publish annual handbooks that contain evaluations of experiments along with summarized experimental data and peer-reviewed benchmark specifications to support the validation of neutronics codes, nuclear cross-section data, and the validation of reactor designs. Participation in the benchmark process not only benefits those who use these Handbooks within the international community, but provides the individual with opportunities for professional development, networking with an international community of experts, and valuable experience to be used in future employment. Traditionally students have participated in benchmarking activities via internships at national laboratories, universities, or companies involved with the ICSBEP and IRPhEP programs. Additional programs have been developed to facilitate the nuclear education of students while participating in the benchmark projects. These programs include coordination with the Center for Space Nuclear Research (CSNR) Next Degree Program, the Collaboration with the Department of Energy Idaho Operations Office to train nuclear and criticality safety engineers, and student evaluations as the basis for their Master's thesis in nuclear engineering.

  5. Criticality Safety Analysis Of As-loaded Spent Nuclear Fuel Casks

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Kaushik [ORNL; Scaglione, John M [ORNL

    2015-01-01

    The final safety analysis report (FSAR) or the safety analysis report (SAR) for a particular spent nuclear fuel (SNF) cask system documents models and calculations used to demonstrate that a system meets the regulatory requirements under all normal, off-normal, and accident conditions of spent fuel storage, and normal and accident conditions of transportation. FSAR/SAR calculations and approved content specifications are intended to be bounding in nature to certify cask systems for a variety of fuel characteristics with simplified SNF loading requirements. Therefore, in general, loaded cask systems possess excess and uncredited criticality margins (i.e., the difference between the licensing basis and the as-loaded calculations). This uncredited margin could be quantified by employing more detailed cask-specific evaluations that credit the actual as-loaded cask inventory, and taking into account full (actinide and fission product) burnup credit. This uncredited criticality margin could be potentially used to offset (1) uncertainties in the safety basis that needs to account for the effects of system aging during extended dry storage prior to transportation, and (2) increases in SNF system reactivity over a repository performance period (e.g., 10,000 years or more) as the system undergoes degradation and internal geometry changes. This paper summarizes an assessment of cask-specific, as-loaded criticality margins for SNF stored at eight reactor sites (215 loaded casks were analyzed) under fully flooded conditions to assess the margins available during transportation after extended storage. It is observed that the calculated keff margin varies from 0.05 to almost 0.3 Δkeff for the eight selected reactor sites, demonstrating that significant uncredited safety margins are present. In addition, this paper evaluates the sufficiency of this excess margin in applications involving direct disposal of currently loaded SNF casks.

  6. Criticality Safety Analysis Of As-loaded Spent Nuclear Fuel Casks

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Kaushik [ORNL; Scaglione, John M [ORNL

    2015-01-01

    The final safety analysis report (FSAR) or the safety analysis report (SAR) for a particular spent nuclear fuel (SNF) cask system documents models and calculations used to demonstrate that a system meets the regulatory requirements under all normal, off-normal, and accident conditions of spent fuel storage, and normal and accident conditions of transportation. FSAR/SAR calculations and approved content specifications are intended to be bounding in nature to certify cask systems for a variety of fuel characteristics with simplified SNF loading requirements. Therefore, in general, loaded cask systems possess excess and uncredited criticality margins (i.e., the difference between the licensing basis and the as-loaded calculations). This uncredited margin could be quantified by employing more detailed cask-specific evaluations that credit the actual as-loaded cask inventory, and taking into account full (actinide and fission product) burnup credit. This uncredited criticality margin could be potentially used to offset (1) uncertainties in the safety basis that needs to account for the effects of system aging during extended dry storage prior to transportation, and (2) increases in SNF system reactivity over a repository performance period (e.g., 10,000 years or more) as the system undergoes degradation and internal geometry changes. This paper summarizes an assessment of cask-specific, as-loaded criticality margins for SNF stored at eight reactor sites (215 loaded casks were analyzed) under fully flooded conditions to assess the margins available during transportation after extended storage. It is observed that the calculated keff margin varies from 0.05 to almost 0.3 Δkeff for the eight selected reactor sites, demonstrating that significant uncredited safety margins are present. In addition, this paper evaluates the sufficiency of this excess margin in applications involving direct disposal of currently loaded SNF casks.

  7. A comparative study between transport and criticality safety indexes for fissile uranium nuclearly pure

    Energy Technology Data Exchange (ETDEWEB)

    Moraes da Silva, T. de; Sordi, G.M.A.A. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN (Brazil)]. e-mail: tmsilva@ipen.br

    2006-07-01

    The international and national standards determine that during the transport of radioactive materials the package to be sent should be identified by labels of risks specifying content, activity and the transport index. The result of the monitoring of the package to 1 meter identifies the transport index, TI, which represents the dose rate to 1 meter of this. The transport index is, by definition, a number that represents a gamma radiation that crosses the superficial layer the radioactive material of the package to 1 meter of distance. For the fissile radioactive material that is the one in which a neutron causes the division of the atom, the international standards specify criticality safety index CSI, which is related with the safe mass of the fissile element. In this work it was determined the respective safe mass for each considered enrichment for the compounds of uranium oxides UO{sub 2}, U{sub 3}O{sub 8} and U{sub 3}Si{sub 2}. In the study of CSI it was observed that the value 50 of the expression 50/N being N the number of packages be transported in subcriticality conditions it represents a fifth part of the safe mass of the element uranium or 9% of the smallest mass critical for a transport not under exclusive use. As conclusion of the accomplished study was observed that the transport index starting from 7% of enrichment doesn't present contribution and that criticality safety index is always greater than the transport index. Therefore what the standards demand to specify, the largest value between both indexes, was clearly identified in this study as being the criticality safety index. (Author)

  8. Congestion Control Algorithm for Non-Safety Messages in Vehicular Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Shamsul Jamel Elias

    2014-03-01

    Full Text Available Recent development in Congestion control mechanism on non-safety applications in Vehicular Ad Hoc Networks (VANETs have heightened the need for sustainable and reliable networks. However, the key challenges with this kind of applications are in the events of intermittent connectivity and data collisions. Comparatively, the event-driven effect on both safety and non-safety applications have critically are rely on delay and reliability. To date, the WAVE protocol in VANETs is derived from the IEEE 802.11pMAC protocol section. However, far to little attention has been given to non-safety applications for instance twitter, SMS services, internet services etc. Hence, Infotainment applications are not applying inter-vehicle communications (IVC provide services such as comfort and driving assistance. In spite of that, Roadside-Vehicle Communications (RVC caters for information concerning repair notifications, remote diagnostics, context information, navigation information, and alerts system. In this paper, we show design model for existing congestion control algorithms problems. The impact of the strategy are evaluated as opposed to the performance of non-safety applications. Furthermore, researches are centered on investigation the advantages and drawbacks of congestion control algorithms. In final analysis, we proposed non-safety applications approaches as our future research domain for solving the congestion problems

  9. Cyber Security: Critical Infrastructure Controls Assessment Framework

    Science.gov (United States)

    2011-05-01

    recoverability Storm and Lightning Fire Chemical Leakage Nuclear Leakage n ercep on & Spoofing, Hacking Sabotage or Vandalism 4 capability 5...Action  10. ICS – Infrastructure Control System 11. IEC  – International Electrochemical  Commission 12. IED – Intelligent Electronic Devices 13 IEEE

  10. Control, Operator Support and Safety System of PVC-reactors

    Directory of Open Access Journals (Sweden)

    Jens I. Ytreeide

    1997-01-01

    Full Text Available In modern petrochemical plants the corporate and societal demands to plant safety and minimum environmental effects are high. These demands rise high performance requirements to the technical systems, specially the process control and safety systems including an effective operator support system with fault detection capability. The systems must have high reliability also against erroneous operations which may cause shutdown situations or quality deviations.

  11. Surveying Wearable Human Assistive Technology for Life and Safety Critical Applications: Standards, Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Muhammad Mahtab Alam

    2014-05-01

    Full Text Available In this survey a new application paradigm life and safety for critical operations and missions using wearable Wireless Body Area Networks (WBANs technology is introduced. This paradigm has a vast scope of applications, including disaster management, worker safety in harsh environments such as roadside and building workers, mobile health monitoring, ambient assisted living and many more. It is often the case that during the critical operations and the target conditions, the existing infrastructure is either absent, damaged or overcrowded. In this context, it is envisioned that WBANs will enable the quick deployment of ad-hoc/on-the-fly communication networks to help save many lives and ensuring people’s safety. However, to understand the applications more deeply and their specific characteristics and requirements, this survey presents a comprehensive study on the applications scenarios, their context and specific requirements. It explores details of the key enabling standards, existing state-of-the-art research studies, and projects to understand their limitations before realizing aforementioned applications. Application-specific challenges and issues are discussed comprehensively from various perspectives and future research and development directions are highlighted as an inspiration for new innovative solutions. To conclude, this survey opens up a good opportunity for companies and research centers to investigate old but still new problems, in the realm of wearable technologies, which are increasingly evolving and getting more and more attention recently.

  12. Surveying wearable human assistive technology for life and safety critical applications: standards, challenges and opportunities.

    Science.gov (United States)

    Alam, Muhammad Mahtab; Ben Hamida, Elyes

    2014-05-23

    In this survey a new application paradigm life and safety for critical operations and missions using wearable Wireless Body Area Networks (WBANs) technology is introduced. This paradigm has a vast scope of applications, including disaster management, worker safety in harsh environments such as roadside and building workers, mobile health monitoring, ambient assisted living and many more. It is often the case that during the critical operations and the target conditions, the existing infrastructure is either absent, damaged or overcrowded. In this context, it is envisioned that WBANs will enable the quick deployment of ad-hoc/on-the-fly communication networks to help save many lives and ensuring people's safety. However, to understand the applications more deeply and their specific characteristics and requirements, this survey presents a comprehensive study on the applications scenarios, their context and specific requirements. It explores details of the key enabling standards, existing state-of-the-art research studies, and projects to understand their limitations before realizing aforementioned applications. Application-specific challenges and issues are discussed comprehensively from various perspectives and future research and development directions are highlighted as an inspiration for new innovative solutions. To conclude, this survey opens up a good opportunity for companies and research centers to investigate old but still new problems, in the realm of wearable technologies, which are increasingly evolving and getting more and more attention recently.

  13. The Designing Bus for Nuclear Safety Class Controller

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongil; Lee, Myeongkyun; Yun, Donghwa [PONUTech Co,. Ltd., Research Institute, Ulsan (Korea, Republic of); Ryoo, Kwangki [Hanbat National Univ., Daejeon (Korea, Republic of)

    2013-10-15

    EtherCAT (Ethernet for Control Automation Technology) is based on the IEEE 802.3 standard as one of the communication which is the I/O (Input/Output), sensors and communication function of PLC (Programmable Logic Controller) in industry and factory environment use is increasing. The Nuclear Safety Class Controller implemented by the EtherCAT applied bus can be shown the improving performance of data transmission in the controller.

  14. Remote control as an aid to safety in underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Noel, M.; Carbonel, P.

    1987-04-01

    Discusses the general concepts of safety and reliability on coal shearers, both with manual and remote control steering, including how the remote-control equipment is protected from electromagnetic disturbance, etc. Describes equipment developed by Cerchar: Telsafe carrier-cable remote control, Telsafe TV remote control, Telsafe CA data transmission system. Concludes by emphasising the need for equipment reliability in order to achieve marketing success.

  15. Safety of timber: An analysis of quality control options

    NARCIS (Netherlands)

    Kovryga, A.; Stapel, P.; Van de Kuilen, J.W.G.

    2014-01-01

    The quality assurance of timber properties is important for the safety of timber structures. In the current study, the quality control options of timber are analysed under the prism of the different growth regions. Therefore, these options - machine and output control - are simulated in accordance w

  16. Structural safety: Study into critical factors in the design and construction process

    NARCIS (Netherlands)

    Terwel, K.C.

    2014-01-01

    Failure investigations show that 80-85% of the structural failures are caused by inadequacies in the design and construction process, related to human and organizational factors. This study showed that safety culture, allocation of responsibilities control, communication and collaboration and knowl

  17. Safety in the Chemical Laboratory: Flood Control.

    Science.gov (United States)

    Pollard, Bruce D.

    1983-01-01

    Describes events leading to a flood in the Wehr Chemistry Laboratory at Marquette University, discussing steps taken to minimize damage upon discovery. Analyzes the problem of flooding in the chemical laboratory and outlines seven steps of flood control: prevention; minimization; early detection; stopping the flood; evaluation; clean-up; and…

  18. Blood transfusions in critical care: improving safety through technology & process analysis.

    Science.gov (United States)

    Aulbach, Rebecca K; Brient, Kathy; Clark, Marie; Custard, Kristi; Davis, Carolyn; Gecomo, Jonathan; Ho, Judy Ong

    2010-06-01

    A multidisciplinary safety initiative transformed blood transfusion practices at St. Luke's Episcopal Hospital in Houston, Texas. An intense analysis of a mistransfusion using the principles of a Just Culture and the process of Cause Mapping identified system and human performance factors that led to the transfusion error. Multiple initiatives were implemented including technology, education and human behaviour change. The wireless technology of Pyxis Transfusion Verification by CareFusion is effective with the rapid infusion module efficient for use in critical care. Improvements in blood transfusion safety were accomplished by thoroughly evaluating the process of transfusions and by implementing wireless electronic transfusion verification technology. During the 27 months following implementation of the CareFusion Transfusion Verification there have been zero cases of transfusing mismatched blood.

  19. The Inquiry into the Waterfall train crash: implications for medical examinations of safety-critical workers.

    Science.gov (United States)

    Hocking, Bruce

    2006-02-06

    The implications arising from the Inquiry into the Waterfall train crash for medical examinations of safety-critical workers are discussed. Examinations need to be appropriate for the level of risk in the job and apply current medical thinking. A careful balance is required between the various legal obligations, including duty of care, disability discrimination and privacy. The frequency of examinations depends on a combination of medical, economic and logistical factors. Health professionals who conduct examinations should be familiar with the occupation of the person being examined. Ethical relationships with the worker's general practitioner or specialist(s) must be observed. The procedures associated with the examinations are as important in achieving safety as the actual examinations. These include complying with relevant standards; providing all relevant documentation with a referral for an examination; acting on the doctor's report appropriately; and auditing the process.

  20. The implementation of a Hazard Analysis and Critical Control Point management system in a peanut butter ice cream plant

    OpenAIRE

    2015-01-01

    To ensure the safety of the peanut butter ice cream manufacture, a Hazard Analysis and Critical Control Point (HACCP) plan has been designed and applied to the production process. Potential biological, chemical, and physical hazards in each manufacturing procedure were identified. Critical control points for the peanut butter ice cream were then determined as the pasteurization and freezing process. The establishment of a monitoring system, corrective actions, verification procedures, and doc...

  1. HFE safety reviews of advanced nuclear power plant control rooms

    Science.gov (United States)

    Ohara, John

    1994-01-01

    Advanced control rooms (ACR's) will utilize human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator's overall role and means of interacting with the system. The Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) aspects of HSI's to ensure that they are designed to good HFE principles and support performance and reliability in order to protect public health and safety. However, the only available NRC guidance was developed more than ten years ago, and does not adequately address the human performance issues and technology changes associated with ACR's. Accordingly, a new approach to ACR safety reviews was developed based upon the concept of 'convergent validity'. This approach to ACR safety reviews is described.

  2. Critical period of weed control In cumin (Cuminum cyminum)

    OpenAIRE

    azade hoseyni; alireza koochaki; mehdi nassiri mahalati

    2009-01-01

    In order to evaluate the critical period of weed control in Cumin, an experiment with Complete Randomized Block Design and three replications was conducted in experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, During 2004-2005 growing season. Treatments included different combinations of weed free and weed infested periods (20, 30, 40 and 80 days after germination) plus weedy check and weed free check. Critical period weed control was evaluated with Gompertz and Log...

  3. An evaluation of safety-critical Java on a Java processor

    DEFF Research Database (Denmark)

    Rios Rivas, Juan Ricardo; Schoeberl, Martin

    2014-01-01

    The safety-critical Java (SCJ) specification provides a restricted set of the Java language intended for applications that require certification. In order to test the specification, implementations are emerging and the need to evaluate those implementations in a systematic way is becoming important....... In this paper we evaluate our SCJ implementation which is based on the Java Optimized Processor JOP and we measure different performance and timeliness criteria relevant to hard real-time systems. Our implementation targets Level 0 and Level1 of the specification and to test it we use a series of micro...

  4. Water Resistant Container Technical Basis Document for the TA-55 Criticality Safety Program

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul Herrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Teague, Jonathan Gayle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-30

    Criticality safety at TA-55 relies on nuclear material containers that are water resistant to prevent significant amounts of water from coming into contact with fissile material in the event of a fire that causes a breach of glovevbox confinement and subsequent fire water ingress. A “water tight container” is a container that will not allow more than 50ml of water ingress when fully submerged, except when under sufficient pressure to produce structural discontinuity. There are many types of containers, welded containers, hermetically sealed containers, filtered containers, etc.

  5. Multi-hypothesis GPS and electronic fence data fusion for safety-critical positioning in railway worksites

    DEFF Research Database (Denmark)

    Figueiras, Joao; Gronbaek, Jesper; Schwefel, Hans-Peter

    2013-01-01

    Safety-critical applications often use position information as a mean of assessing the safety level of people. For this reason, such information is required to be precise in terms of accuracy and timeliness. This paper regards position mechanisms for personalized warning systems for railway worke...

  6. Nuclear electric power safety, operation, and control aspects

    CERN Document Server

    Knowles, J Brian

    2013-01-01

    Assesses the engineering of renewable sources for commercial power generation and discusses the safety, operation, and control aspects of nuclear electric power From an expert who advised the European Commission and UK government in the aftermath of Three Mile Island and Chernobyl comes a book that contains experienced engineering assessments of the options for replacing the existing, aged, fossil-fired power stations with renewable, gas-fired, or nuclear plants. From geothermal, solar, and wind to tidal and hydro generation, Nuclear Electric Power: Safety, Operation, and Control Aspects ass

  7. Implementation of hazard analysis critical control point in jameed production.

    Science.gov (United States)

    Al-Saed, A K; Al-Groum, R M; Al-Dabbas, M M

    2012-06-01

    The average of standard plate count and coliforms, Staphylococcus aureus and Salmonella counts for three home-made jameed samples, a traditional fermented dairy product, before applying hazard analysis critical control point system were 2.1 × 10(3), 8.9 × 10(1), 4 × 10(1) and less than 10 cfu/g, respectively. The developed hazard analysis critical control point plan resulted in identifying ten critical control points in the flow chart of jameed production. The critical control points included fresh milk receiving, pasteurization, addition of starter, water and salt, straining, personnel hygiene, drying and packaging. After applying hazard analysis critical control point system, there was significant improvement in the microbiological quality of the home-made jameed. The standard plate count was reduced to 3.1 × 10(2) cfu/g whereas coliform and Staphylococcus aureus counts were less than 10 cfu/g and Salmonella was not detected. Sensory evaluation results of color and flavor of sauce prepared from jameed showed a significant increase in the average scores given after hazard analysis critical control point application.

  8. Failure mode and effect analysis on safety critical components of space travel

    Directory of Open Access Journals (Sweden)

    Kouroush Jenab

    2015-07-01

    Full Text Available Sending men to space has never been an ordinary activity, it requires years of planning and preparation in order to have a chance of success. The payoffs of reliable and repeatable space flight are many, including both Commercial and Military opportunities. In order for reliable and repeatable space flight to become a reality, catastrophic failures need to be detected and mitigated before they occur. It can be shown that small pieces of a design which seem ordinary can create devastating impacts if not designed and tested properly. This paper will address the use of a Failure Mode, Effects, and Criticality Analysis (FMECA with modified Risk Priority Number (RPN and its application to safety critical design components of shuttle liftoff. An example will be presented here which specifically focuses on the Solid Rocket Boosters (SRBs to illustrate the FMECA approach to reliable space travel.

  9. The implementation of a Hazard Analysis and Critical Control Point management system in a peanut butter ice cream plant

    Directory of Open Access Journals (Sweden)

    Yu-Ting Hung

    2015-09-01

    Full Text Available To ensure the safety of the peanut butter ice cream manufacture, a Hazard Analysis and Critical Control Point (HACCP plan has been designed and applied to the production process. Potential biological, chemical, and physical hazards in each manufacturing procedure were identified. Critical control points for the peanut butter ice cream were then determined as the pasteurization and freezing process. The establishment of a monitoring system, corrective actions, verification procedures, and documentation and record keeping were followed to complete the HACCP program. The results of this study indicate that implementing the HACCP system in food industries can effectively enhance food safety and quality while improving the production management.

  10. A systems perspective of managing error recovery and tactical re-planning of operating teams in safety critical domains.

    Science.gov (United States)

    Kontogiannis, Tom

    2011-04-01

    Research in human error has provided useful tools for designing procedures, training, and intelligent interfaces that trap errors at an early stage. However, this "error prevention" policy may not be entirely successful because human errors will inevitably occur. This requires that the error management process (e.g., detection, diagnosis and correction) must also be supported. Research has focused almost exclusively on error detection; little is known about error recovery, especially in the context of safety critical systems. The aim of this paper is to develop a research framework that integrates error recovery strategies employed by experienced practitioners in handling their own errors. A control theoretic model of human performance was used to integrate error recovery strategies assembled from reviews of the literature, analyses of near misses from aviation and command & control domains, and observations of abnormal situations training at air traffic control facilities. The method of system dynamics has been used to analyze and compare error recovery strategies in terms of patterns of interaction, system affordances, and types of recovery plans. System dynamics offer a promising basis for studying the nature of error recovery management in the context of team interactions and system characteristics. The proposed taxonomy of error recovery strategies can help human factors and safety experts to develop resilient system designs and training solutions for managing human errors in unforeseen situations; it may also help incident investigators to explore why people's actions and assessments were not corrected at the time. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. The effects of safety behaviors during exposure therapy for anxiety: Critical analysis from an inhibitory learning perspective.

    Science.gov (United States)

    Blakey, Shannon M; Abramowitz, Jonathan S

    2016-11-01

    In the context of clinical anxiety, safety behaviors are actions performed to prevent, escape, or minimize feared catastrophes and/or associated distress. Research consistently implicates safety behaviors in the development and maintenance of anxiety disorders; accordingly, safety behaviors are traditionally eliminated during exposure treatments for pathological anxiety. The notion that safety behaviors are ubiquitously deleterious in the context of exposure has recently been challenged, yet findings regarding safety behaviors' effects on exposure outcomes are limited, mixed, and controversial. Furthermore, developments in explanatory models for exposure's effectiveness (e.g., inhibitory learning theory) highlight other possible consequences of safety behaviors performed during exposure. Unfortunately, these theoretical advances are neglected in experimental research. The present review critically examines the literature addressing the role of safety behaviors in exposure therapy from an inhibitory learning perspective. Limitations, future directions, and clinical recommendations are also discussed.

  12. Safety Management in an Oil Company through Failure Mode Effects and Critical Analysis

    Directory of Open Access Journals (Sweden)

    Benedictus Rahardjo

    2016-06-01

    Full Text Available This study attempts to apply Failure Mode Effects and Criticality Analysis (FMECA to improve the safety of a production system, specifically the production process of an oil company. Since food processing is a worldwide issue and self-management of a food company is more important than relying on government regulations, therefore this study focused on that matter. The initial step of this study is to identify and analyze the criticality of the potential failure modes of the production process. Furthermore, take corrective action to minimize the probability of repeating the same failure mode, followed by a re-analysis of its criticality. The results of corrective actions were compared with those before improvement conditions by testing the significance of the difference using two sample t-test. The final measured result is the Criticality Priority Number (CPN, which refers to the severity category of the failure mode and the probability of occurrence of the same failure mode. The recommended actions proposed by the FMECA significantly reduce the CPN compared with the value before improvement, with increases of 38.46% for the palm olein case study.

  13. Ontario Hydro experience in the identification and mitigation of potential failures in safety critical software systems

    Energy Technology Data Exchange (ETDEWEB)

    Huget, R.G.; Viola, M.; Froebel, P.A. [Ontario Hydro, Toronto, Ontario (Canada)

    1995-08-01

    Ontario Hydro has had experience in designing and qualifying safety critical software used in the reactor shutdown systems of its nuclear generating stations. During software design, an analysis of system level hazards and potential hardware failure effects provide input to determining what safeguards will be needed. One form of safeguard, called software self checks, continually monitor the health of the computer on line. The design of self checks usually is a trade off between the amount of computing resources required, the software complexity, and the level of safeguarding provided. As part of the software verification activity, a software hazards analysis is performed, which identifiers any failure modes that could lead to the software causing an unsafe state, and which recommends changes to mitigate that potential. These recommendations may involve a re-structuring of the software to be more resistant to failure, or the introduction of other safeguarding measures. This paper discusses how Ontario Hydro has implemented these aspects of software design and verification into safety critical software used in reactor shutdown systems.

  14. Verification of MCNP6.2 for Nuclear Criticality Safety Applications

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-10

    Several suites of verification/validation benchmark problems were run in early 2017 to verify that the new production release of MCNP6.2 performs correctly for nuclear criticality safety applications (NCS). MCNP6.2 results for several NCS validation suites were compared to the results from MCNP6.1 [1] and MCNP6.1.1 [2]. MCNP6.1 is the production version of MCNP® released in 2013, and MCNP6.1.1 is the update released in 2014. MCNP6.2 includes all of the standard features for NCS calculations that have been available for the past 15 years, along with new features for sensitivity-uncertainty based methods for NCS validation [3]. Results from the benchmark suites were compared with results from previous verification testing [4-8]. Criticality safety analysts should consider testing MCNP6.2 on their particular problems and validation suites. No further development of MCNP5 is planned. MCNP6.1 is now 4 years old, and MCNP6.1.1 is now 3 years old. In general, released versions of MCNP are supported only for about 5 years, due to resource limitations. All future MCNP improvements, bug fixes, user support, and new capabilities are targeted only to MCNP6.2 and beyond.

  15. The automatic programming for safety-critical software in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Yeol; Eom, Heung Seop; Choi, You Rark

    1998-06-01

    We defined the Korean unique safety-critical software development methodology by modifying Dr. Harel`s statechart-based on formal methods in order to digitalized the reactor protection system. It is suggested software requirement specification guideline to specify design specification which is basis for requirement specification and automatic programming by the caused by shutdown parameter logic of the steam generator water level for Wolsung 2/3/4 unit SDS no.1 and simulated it by binding the Graphic User Interface (GUI). We generated the K and R C code automatically by utilizing the Statemate MAGNUM Sharpshooter/C code generator. Auto-generated K and R C code is machine independent code and has high productivity, quality and provability. The following are the summaries of major research and development. - Set up the Korean unique safety-critical software development methodology - Developed software requirement specification guidelines - Developed software design specification guidelines - Reactor trip modeling for steam generator waster level Wolsung 2/3/4 SDS no. 1 shutdown parameter logic - Graphic panel binding with GUI. (author). 20 refs., 12 tabs., 15 figs

  16. SCJ-Circus: a refinement-oriented formal notation for Safety-Critical Java

    Directory of Open Access Journals (Sweden)

    Alvaro Miyazawa

    2016-06-01

    Full Text Available Safety-Critical Java (SCJ is a version of Java whose goal is to support the development of real-time, embedded, safety-critical software. In particular, SCJ supports certification of such software by introducing abstractions that enforce a simpler architecture, and simpler concurrency and memory models. In this paper, we present SCJ-Circus, a refinement-oriented formal notation that supports the specification and verification of low-level programming models that include the new abstractions introduced by SCJ. SCJ-Circus is part of the family of state-rich process algebra Circus, as such, SCJ-Circus includes the Circus constructs for modelling sequential and concurrent behaviour, real-time and object orientation. We present here the syntax and semantics of SCJ-Circus, which is defined by mapping SCJ-Circus constructs to those of standard Circus. This is based on an existing approach for modelling SCJ programs. We also extend an existing Circus-based refinement strategy that targets SCJ programs to account for the generation of SCJ-Circus models close to implementations in SCJ.

  17. Modeling the critical safety functions status tree of a NPP using FPGA

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Marcos Santana; Oliveira, Mauro Vitor de; Jaime, Guilherme Dutra Gonzaga; Almeida, Jose Carlos Soares de; Augusto, Silas Cordeiro, E-mail: msantana@ien.gov.br, E-mail: mvitor@ien.gov.br, E-mail: gdjaime@ien.gov.br, E-mail: jcsa@ien.gov.br, E-mail: silas@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisao de Engenharia Nuclear

    2013-07-01

    Field Programmable Gate Arrays (FPGAs) based systems and equipment are beginning to appear in new plants I and C applications, as well as in retrofits for operating plants, in particular for safety applications due to their capability to face the systems obsolescence since they are circuit independent. The circuits implemented can be portable to different FPGAs architectures. Moreover, they reduce complexity for regulatory approval as compared to conventional microprocessor-based systems. Critical safety function (CSF) is the most significant design concept for prioritize operator actions for NPP based on the potential threat to the three barriers (fuel cladding, primary coolant system boundary, and containment) and allows the operator to respond to these threats prior to event diagnosis. CSF has a hierarchical information structure that organizes the system variables affecting the plant safety in terms of goal-means relations. This paper describes the application of FPGA in the implementation of the CSFs status tree logic for a Westinghouse 3-loops NPP simulator. (author)

  18. Minimum Safety Factor for Evaluation of Critical Buckling Pressure of Zirconium Alloy Tube

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kyu; Kim, Jae Yong; Yoon, Kyung Ho; Lee, Young Ho; Lee, Kang Hee; Kang, Heung Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-03-15

    We consider the uncertainty in the elastic buckling formula for a thin tube. We take into account the measurement uncertainty of Young's modulus and Poisson's ratio and the tolerance of the tube thickness and diameter. Elastic buckling must be prohibited for a thin tube such as a nuclear fuel rod that must satisfy a self-stand criterion. Since the predicted critical buckling pressure overestimated that found in the experiment, the determination of the minimum safety factor is crucial. The uncertainty in each parameter (i.e., Young's modulus, Poisson's ratio, thickness, and diameter) is mutually independent, so the safety factor is evaluated as the sum of the inverse of each uncertainty. We found that the thickness variation greatly affects the uncertainty. The minimum safety factor of a thin tube of Zirconium alloy is evaluated as 1.547 for a thickness of 0.87 mm and 3.487 for a thickness of 0.254 mm.

  19. Communication in Change - Voice over IP in Safety and Security Critical Communication Networks

    Science.gov (United States)

    Zeilinger, Heimo; Sevcik, Berndt; Turek, Thomas; Zucker, Gerhard

    During the last decade communication technology has changed rapidly. Due to its decreasing costs and rising expansion, IP (Internet Protocol) technology has found its way to areas that have long been the domain of public-switched telephone networks (PSTN). Voice over IP (VoIP) applications are widely used not only for phone calls or common Internet conferences, but also tend to be used for safety critical communication applications. Hence security and safety topics arise, which pose new challenges in this area of research. The authors are convinced that new issues on the network layer as well as on the application layer require detailed analysis. Hence this paper gives an overview on latest developments in this area, and states the authors’ view on this topic. Thereby safety and security issues are faced from different abstraction layers. On the one hand the network layer and on the other hand the application layer focusing on middleware systems in the area of service oriented architectures (SOAs).

  20. Towards the Verification of Safety-critical Autonomous Systems in Dynamic Environments

    Directory of Open Access Journals (Sweden)

    Adina Aniculaesei

    2016-12-01

    Full Text Available There is an increasing necessity to deploy autonomous systems in highly heterogeneous, dynamic environments, e.g. service robots in hospitals or autonomous cars on highways. Due to the uncertainty in these environments, the verification results obtained with respect to the system and environment models at design-time might not be transferable to the system behavior at run time. For autonomous systems operating in dynamic environments, safety of motion and collision avoidance are critical requirements. With regard to these requirements, Macek et al. [6] define the passive safety property, which requires that no collision can occur while the autonomous system is moving. To verify this property, we adopt a two phase process which combines static verification methods, used at design time, with dynamic ones, used at run time. In the design phase, we exploit UPPAAL to formalize the autonomous system and its environment as timed automata and the safety property as TCTL formula and to verify the correctness of these models with respect to this property. For the runtime phase, we build a monitor to check whether the assumptions made at design time are also correct at run time. If the current system observations of the environment do not correspond to the initial system assumptions, the monitor sends feedback to the system and the system enters a passive safe state.

  1. Supplemental studies for cardiovascular risk assessment in safety pharmacology: a critical overview.

    Science.gov (United States)

    Picard, Sandra; Goineau, Sonia; Guillaume, Philippe; Henry, Joël; Hanouz, Jean-Luc; Rouet, René

    2011-12-01

    Safety Pharmacology studies for the cardiovascular risk assessment, as described in the ICH S7A and S7B guidelines, appear as being far from sufficient. The fact that almost all medicines withdrawn from the market because of life-threatening tachyarrhythmias (torsades-de-pointes) were shown as hERG blockers and QT interval delayers led the authorities to focus mainly on these markers. However, other surrogate biomarkers, e.g., TRIaD (triangulation, reverse-use-dependence, instability and dispersion of ventricular repolarization), have been identified to more accurately estimate the drug-related torsadogenic risk. In addition, more attention should be paid to other arrhythmias, not related to long QT and nevertheless severe and/or not self-extinguishing, e.g., atrial or ventricular fibrillation, resulting from altered electrical conduction or heterogeneous shortening of cardiac repolarization. Moreover, despite numerous clinical cases of drug-induced pulmonary hypertension, orthostatic hypotension, or heart valvular failure, few safety investigations are still conducted on drug interaction with cardiac and regional hemodynamics other than changes in aortic blood pressure evaluated in conscious large animals during the core battery mandatory studies. This critical review aims at discussing the usefulness, relevance, advantages, and limitations of some preclinical in vivo, in vitro, and in silico models, with high predictive values and currently used in supplemental safety studies.

  2. Pathogen Reduction and Hazard Analysis and Critical Control Point (HACCP) systems for meat and poultry. USDA.

    Science.gov (United States)

    Hogue, A T; White, P L; Heminover, J A

    1998-03-01

    The United States Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) adopted Hazard Analysis and Critical Control Point Systems and established finished product standards for Salmonella in slaughter plants to improve food safety for meat and poultry. In order to make significant improvements in food safety, measures must be taken at all points in the farm-to-table chain including production, transportation, slaughter, processing, storage, retail, and food preparation. Since pathogens can be introduced or multiplied anywhere along the continuum, success depends on consideration and comparison of intervention measures throughout the continuum. Food animal and public health veterinarians can create the necessary preventative environment that mitigates risks for food borne pathogen contamination.

  3. Prioritization and selection of parameters for control chart implementation based on technical criticality and cost criticality

    Directory of Open Access Journals (Sweden)

    Sirintra Tan-intara-art

    2013-07-01

    Full Text Available An important problem in control chart implementation is the availability of resources to collect and analyze data for control charts implementation. This paper proposes a method to prioritize and select final product parameters to control. The prioritization is based on cost of quality and technical criticality of those parameters. The prioritization method is demonstrated by a case study of flexible printed circuit manufacturing.

  4. Additional Studies of the Criticality Safety of Failed Used Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, William BJ J [ORNL; Wagner, John C [ORNL

    2013-01-01

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for periods potentially greater than 40 years. Extended storage (ES) time and irradiation to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, could result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. Criticality analyses are conducted considering representative UNF designs covering a range of enrichments and burnups in multiple cask systems. Prior work developed a set of failed fuel configuration categories and specific configurations were evaluated to understand trends and quantify the consequences of worst-case potential reconfiguration progressions. These results will be summarized here and indicate that the potential impacts on subcriticality can be rather significant for certain configurations (e.g., >20% keff). It can be concluded that the consequences of credible fuel failure configurations from ES or transportation following ES are manageable (e.g., <5% keff). The current work expands on these efforts and examines some modified scenarios and modified approaches to investigate the effectiveness of some techniques for reducing the calculated increase in keff. The areas included here are more realistic modeling of some assembly types and the effect of reconfiguration of some assemblies in the storage and transportation canister.

  5. Simple Expressions for Safety Factors in Inventory Control

    NARCIS (Netherlands)

    Strijbosch, L.W.G.; Moors, J.J.A.

    1999-01-01

    The literature on inventory control discusses many methods to establish the level of decision parameters -like reorder levels or safety factors-, necessary to attain a prescribed service level. In general, however, these methods are not easy applicable: they often use time-consuming iterations, requ

  6. Controlling self-organized criticality in sandpile models

    CERN Document Server

    Cajueiro, Daniel O

    2013-01-01

    We introduce an external control to reduce the size of avalanches in some sandpile models exhibiting self organized criticality. This rather intuitive approach seems to be missing in the vast literature on such systems. The control action, which amounts to triggering avalanches in sites that are near to be come critical, reduces the probability of very large events, so that energy dissipation occurs most locally. The control is applied to a directed Abelian sandpile model driven by both uncorrelated and correlated deposition. The latter is essential to design an efficient and simple control heuristic, but has only small influence in the uncontrolled avalanche probability distribution. The proposed control seeks a tradeoff between control cost and large event risk. Preliminary results hint that the proposed control works also for an undirected sandpile model.

  7. Generation of integral experiment covariance data and their impact on criticality safety validation

    Energy Technology Data Exchange (ETDEWEB)

    Stuke, Maik; Peters, Elisabeth; Sommer, Fabian

    2016-11-15

    The quantification of statistical dependencies in data of critical experiments and how to account for them properly in validation procedures has been discussed in the literature by various groups. However, these subjects are still an active topic in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECDNEA Nuclear Science Committee. The latter compiles and publishes the freely available experimental data collection, the International Handbook of Evaluated Criticality Safety Benchmark Experiments, ICSBEP. Most of the experiments were performed as series and share parts of experimental setups, consequently leading to correlation effects in the results. The correct consideration of correlated data seems to be inevitable if the experimental data in a validation procedure is limited or one cannot rely on a sufficient number of uncorrelated data sets, e.g. from different laboratories using different setups. The general determination of correlations and the underlying covariance data as well as the consideration of them in a validation procedure is the focus of the following work. We discuss and demonstrate possible effects on calculated k{sub eff}'s, their uncertainties, and the corresponding covariance matrices due to interpretation of evaluated experimental data and its translation into calculation models. The work shows effects of various modeling approaches, varying distribution functions of parameters and compares and discusses results from the applied Monte-Carlo sampling method with available data on correlations. Our findings indicate that for the reliable determination of integral experimental covariance matrices or the correlation coefficients a detailed study of the underlying experimental data, the modeling approach and assumptions made, and the resulting sensitivity analysis seems to be inevitable. Further, a Bayesian method is discussed to include integral experimental covariance data when estimating an

  8. DASHBOARDS & CONTROL CHARTS EXPERIENCES IN IMPROVING SAFETY AT HANFORD WASHINGTON

    Energy Technology Data Exchange (ETDEWEB)

    PREVETTE, S.S.

    2006-02-27

    The aim of this paper is to demonstrate the integration of safety methodology, quality tools, leadership, and teamwork at Hanford and their significant positive impact on safe performance of work. Dashboards, Leading Indicators, Control charts, Pareto Charts, Dr. W. Edward Deming's Red Bead Experiment, and Dr. Deming's System of Profound Knowledge have been the principal tools and theory of an integrated management system. Coupled with involved leadership and teamwork, they have led to significant improvements in worker safety and protection, and environmental restoration at one of the nation's largest nuclear cleanup sites.

  9. Practice of strict glycemic control in critically ill patients.

    Science.gov (United States)

    Schultz, Marcus J; de Graaff, Mart J; Royakkers, Annic A N M; van Braam Houckgeest, Floris; van der Sluijs, Johannes P; Kieft, Hans; Spronk, Peter E

    2008-11-01

    Blood glucose control aiming at normoglycemia, frequently referred to as "strict glycemic control", decreases mortality and morbidity of critically ill patients. We searched the medical literature for export opinions, surveys, and clinical reports on blood glucose control in intensive care medicine. While strict glycemic control has been recommended standard of care for critically ill patients, the risk of severe hypoglycemia with strict glycemic control is frequently mentioned by experts. Some rationalize this risk, though others strongly point out the high incidence of hypoglycemia to be (one) reason not to perform strict glycemic control. Implementation of strict glycemic control is far from complete in intensive care units across the world. Frequently local guidelines accept higher blood glucose levels than those with strict glycemic control. Only a minority of retrieved manuscripts are on blood glucose regimens with the lower targets as with strict glycemic control. Hypoglycemia certainly is encountered with blood glucose control, in particular with strict glycemic control. Reports show intensive care-nurses can adequately and safely perform strict glycemic control. Implementation of strict glycemic control is far from complete, at least in part because of the feared risks of hypoglycemia. The preference for hyperglycemia over intermittent hypoglycemia is irrational, however, because there is causal evidence of harm for the former but only associative evidence of harm for the latter. For several reasons it is wise to have strict glycemic control being a nurse-based strategy.

  10. Physics related to control and safety of hybrid systems; Physique associee au controle et a la surete des systemes hybrides

    Energy Technology Data Exchange (ETDEWEB)

    Gueton, O

    2001-12-01

    Regarding nuclear waste management, ADS can be considered as large minor actinides burners. In a first part, a critical analysis of different reactor types shows that fast spectrum, helium coolant and nitride fuel, containing 100% minor actinides, agree perfectly with the high transmutation requirements of ADS. The control and safety demonstration of this system represents the main purpose of this study. Understanding spatial and dynamic behaviour of ADS flux is absolutely necessary. For this purpose, we have defined an indicator to quantify spatial decoupling. It shows, on the one hand, point kinetic deficiency to study local transients, and on the other hand, perturbations propagation differences between ADS and critical cores. Then, in a more concrete approach, accidental sequences (source transient, beam de-focalization, reactivity insertions, loss of flow, depressurization) are evaluated for this core, strongly loaded with minor actinides. It is shown that the automatic beam shutdown leads to preserve large safety margins for all studied transients. The accelerator emergency stop is induced by an unexpected evolution of the core control parameters. These parameters, except reactivity, can be directly measured in subcritical systems like in critical ones. Concerning reactivity, we suggest a new method for its absolute determination in ADS: at the time of reactor start-up, the reactivity must be calibrated by coupling two methods of relative reactivity measurements (pulsed source and Approached Source Multiplication) for successive subcritical levels. After that, the on-line follow-up of reactivity is obtained from this calibration like in a critical core. (authors)

  11. Critical period of weed control in aerobic rice.

    Science.gov (United States)

    Anwar, M P; Juraimi, A S; Samedani, B; Puteh, A; Man, A

    2012-01-01

    Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a) increasing duration of weed interference and (b) increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7-49 days after seeding in off-season and 7-53 days in main season to achieve 95% of weed-free yield, and 23-40 days in off-season and 21-43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21-43 days for better yield and higher economic return.

  12. Critical Period of Weed Control in Aerobic Rice

    Directory of Open Access Journals (Sweden)

    M. P. Anwar

    2012-01-01

    Full Text Available Critical period of weed control is the foundation of integrated weed management and, hence, can be considered the first step to design weed control strategy. To determine critical period of weed control of aerobic rice, field trials were conducted during 2010/2011 at Universiti Putra Malaysia. A quantitative series of treatments comprising two components, (a increasing duration of weed interference and (b increasing length of weed-free period, were imposed. Critical period was determined through Logistic and Gompertz equations. Critical period varied between seasons; in main season, it started earlier and lasted longer, as compared to off-season. The onset of the critical period was found relatively stable between seasons, while the end was more variable. Critical period was determined as 7–49 days after seeding in off-season and 7–53 days in main season to achieve 95% of weed-free yield, and 23–40 days in off-season and 21–43 days in main season to achieve 90% of weed-free yield. Since 5% yield loss level is not practical from economic view point, a 10% yield loss may be considered excellent from economic view point. Therefore, aerobic rice should be kept weed-free during 21–43 days for better yield and higher economic return.

  13. Criticality safety validation: Simple geometry, single unit {sup 233}U systems

    Energy Technology Data Exchange (ETDEWEB)

    Putman, V.L.

    1997-06-01

    Typically used LMITCO criticality safety computational methods are evaluated for suitability when applied to INEEL {sup 233}U systems which reasonably can be modeled as simple-geometry, single-unit systems. Sixty-seven critical experiments of uranium highly enriched in {sup 233}U, including 57 aqueous solution, thermal-energy systems and 10 metal, fast-energy systems, were modeled. These experiments include 41 cylindrical and 26 spherical cores, and 41 reflected and 26 unreflected systems. No experiments were found for intermediate-neutron-energy ranges, or with interstitial non-hydrogenous materials typical of waste systems, mixed {sup 233}U and plutonium, or reflectors such as steel, lead, or concrete. No simple geometry experiments were found with cubic or annular cores, or approximating infinite sea systems. Calculations were performed with various tools and methodologies. Nine cross-section libraries, based on ENDF/B-IV, -V, or -VI.2, or on Hansen-Roach source data, were used with cross-section processing methods of MCNP or SCALE. The k{sub eff} calculations were performed with neutral-particle transport and Monte Carlo methods of criticality codes DANT, MCNP 4A, and KENO Va.

  14. Regulatory control of nuclear safety in Finland. Annual report 1997

    Energy Technology Data Exchange (ETDEWEB)

    Tossavainen, K. [ed.

    1998-08-01

    The report describes regulatory control of the use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in Finland in 1997. Nuclear regulatory control ascertained that the operation of Finnish NPPs was in compliance with the conditions set out in operating licences and current regulations. In addition to NPP normal operation, STUK oversaw projects at the plant units relating to power uprating and safety improvements. STUK prepared statements for the Ministry of Trade and Industry about the applications for renewing the operating licenses of Loviisa and Olkiluoto NPPs. The most important items of supervision in nuclear waste management were studies relating to the final disposal of spent fuel from NPPs and the review of the licence application for a repository for low- and intermediate-level reactor waste from Loviisa NPP. Preparation of general safety regulations for the final disposal of spent nuclear fuel, to be published in the form of a Council of State Decision, was started. By safeguards control, the use of nuclear materials was verified to be in compliance with current regulations and that the whereabouts of every batch of nuclear material were always known. Nuclear material safeguards were stepped up to prevent illicit trafficking of nuclear materials and other radioactive materials. In co-operation with the Ministry for Foreign Affairs and the Institute of Seismology (University of Helsinki), preparations were undertaken to implement the Comprehensive Nuclear Test Ban Treaty (CTBT). For enforcement of the Treaty and as part of the international regulatory approach, STUK is currently developing laboratory analyses relating to airborne radioactivity measurements. The focus of co-operation funded by external sources was as follows: improvement of the safety of Kola and Leningrad NPPs, improvement of nuclear waste management in North-West Russia, development of the organizations of nuclear safety authorities in Eastern Europe and development

  15. Regulatory control of nuclear safety in Finland. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    Tossavainen, K. [ed.

    1999-10-01

    The report describes regulatory control of the safe use of nuclear energy by the Radiation and Nuclear Safety Authority (STUK) in 1998. STUK is the Finnish nuclear safety authority. The submission of this report to the Ministry of Trade and Industry is stipulated in Section 121 of the Nuclear Energy Decree. It was verified by regulatory control that the operation of Finnish NPPs was in compliance with conditions set out in the operating licences of the plants and with regulations currently in force. In addition to supervising the normal operation of the plants, STUK oversaw projects carried out at the plant units, which related to the uprating of their power and the improvement of their safety. STUK issued to the Ministry of Trade and Industry a statement about applications for the renewal of the operating licences of Loviisa and Olkiluoto NPPs, which had been submitted by Imatran Voima Oy and Teollisuuden Voima Oy. Regulatory activities in the field of nuclear waste management were focused on the storage and final disposal of spent fuel as well as the treatment, storage and final disposal of reactor waste. STUK issued a statement to the Ministry of Trade and Industry about an environmental impact assessment programme pertaining to a spent fuel repository project, which had been submitted by Posiva Oy, as well as on Imatran Voima Oy's application concerning the operation of a repository for medium- and low-level reactor waste from Loviisa NPP. The use of nuclear materials was in compliance with the regulations currently in force and also the whereabouts of every batch of nuclear material were ensured by safeguards control. In international safeguards, important changes took place, which were reflected also in safeguards activities at national level. International co-operation continued based on financing both from STUK's budget and from additional sources. The focus of co-operation funded from outside sources was as follows: improvement of the safety of

  16. Control, operator support and safety system of PVC reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ytreeide, J.I.; Aaker, O.; Kristoffersen, V.; Moe, G.; Naustdal, C.

    1997-06-01

    In modern petrochemical plants the corporate and societal demands to plant safety and minimum environmental effects are high. These demands rise high performance requirements to the technical systems, specially the process control and safety systems including an effective operator support system with fault detection capability. PVC producing plants have high inherent hazard potentials, and the studied reaction in this publication is exothermic and non-linear and open-loop unstable, and the plant is equipped with two independent cooling systems to keep the reaction under control. A system to solve the stability problem of parallel control is suggested, showing the simulation of real process data. The publication describes an operator support system for monitoring the heat of reaction in the autoclave consisting of a model based estimator. The system is tested on-line, and the results of simulations and on-line estimates are presented. 6 refs., 13 figs.

  17. [Healthcare-Associated Infection Control with Awareness of Patient Safety].

    Science.gov (United States)

    Murakami, Nobuo

    2016-03-01

    In order to provide safe and secure medical care for patients, health care-associated infections (HAI) must not occur. HAI should be considered as incidents, and countermeasures should be viewed as a patient safety management itself. Healthcare-associated infection control (HAIC) is practiced by the infection control team (ICT), which is based on multidisciplinary cooperation. Team members have to recognize that it is the most important to make use of the expertise of each discipline. In addition, all members must try to respond quickly, to help the clinic staff. Visualized rapid information provision and sharing, environmental improvement, outbreak factor analysis, hand hygiene compliance rate improvement, proper antibiotic use (Antimicrobial Stewardship Program: ASP), and regional cooperation & leadership comprise the role of the ICT in the flagship hospital. Regarding this role, we present our hospital's efforts and the outcomes. In conclusion, for medical practice quality improvement, healthcare-associated infection control should be conducted thoroughly along with an awareness of patient safety.

  18. Distributed Air Traffic Control : A Human Safety Perspective

    CERN Document Server

    Nikumbh, Sarvesh; Vartak, Rahul

    2011-01-01

    The issues in air traffic control have so far been addressed with the intent to improve resource utilization and achieve an optimized solution with respect to fuel comsumption of aircrafts, efficient usage of the available airspace with minimal congestion related losses under various dynamic constraints. So the focus has almost always been more on smarter management of traffic to increase profits while human safety, though achieved in the process, we believe, has remained less seriously attended. This has become all the more important given that we have overburdened and overstressed air traffic controllers managing hundreds of airports and thousands of aircrafts per day. We propose a multiagent system based distributed approach to handle air traffic ensuring complete human (passenger) safety without removing any humans (ground controllers) from the loop thereby also retaining the earlier advantages in the new solution. The detailed design of the agent system, which will be easily interfacable with the existin...

  19. Readiness to implement Hazard Analysis and Critical Control Point (HACCP) systems in Iowa schools.

    Science.gov (United States)

    Henroid, Daniel; Sneed, Jeannie

    2004-02-01

    To evaluate current food-handling practices, food safety prerequisite programs, and employee knowledge and food safety attitudes and provide baseline data for implementing Hazard Analysis and Critical Control Point (HACCP) systems in school foodservice. One member of the research team visited each school to observe food-handling practices and assess prerequisite programs using a structured observation form. A questionnaire was used to determine employees' attitudes, knowledge, and demographic information. A convenience sample of 40 Iowa schools was recruited with input from the Iowa Department of Education. Descriptive statistics were used to summarize data. One-way analysis of variance was used to assess differences in attitudes and food safety knowledge among managers, cooks, and other foodservice employees. Multiple linear regression assessed the relationship between manager and school district demographics and the food safety practice score. Proper food-handling practices were not being followed in many schools and prerequisite food safety programs for HACCP were found to be inadequate for many school foodservice operations. School foodservice employees were found to have a significant amount of food safety knowledge (15.9+/-2.4 out of 20 possible points). School districts with managers (P=.019) and employees (P=.030) who had a food handler certificate were found to have higher food safety practice scores. Emphasis on implementing prerequisite programs in preparation for HACCP is needed in school foodservice. Training programs, both basic food safety such as ServSafe and HACCP, will support improvement of food-handling practices and implementation of prerequisite programs and HACCP.

  20. Hazard analysis and critical control points among Chinese food business operators

    Directory of Open Access Journals (Sweden)

    Stefano Saccares

    2014-09-01

    Full Text Available The purpose of the present paper is to highlight some critical situations emerged during the implementation of long-term projects locally managed by Prevention Services, to control some manufacturing companies in Rome and Prato, Central Italy. In particular, some critical issues on the application of selfcontrol in marketing and catering held by Chinese operators are underlined. The study showed serious flaws in preparing and controlling of manuals for good hygiene practice, participating of the consultants among food business operators (FBOs to the control of the procedures. Only after regular actions by the Prevention Services, there have been satisfying results. This confirms the need to have qualified and expert partners able to promptly act among FBOs and to give adequate support to authorities in charge in order to guarantee food safety.

  1. Lasershot(sm) marking system: high-volume labeling for safety-critical parts

    Energy Technology Data Exchange (ETDEWEB)

    Dane, C B; Hackel, L; Honig, J; Halpin, J; Chen, H-L; Mendieta, F; Harris, F; Lane, L; Daly, J; Harrison, J

    2001-02-16

    The Lasershot Marking System uses laser pulses to safely and permanently impress identification markings on metal components. This process does not remove material or change surface chemistry and actually increases the marked area's resistance to fatigue and corrosion failure. Lasershot marking is ideally suited for marking parts used in situations where safety is critical--from hip-joint replacements to commercial airliner components. The minimum size of the mark is limited only by the resolution of the reading system, allowing manufacturers to mark parts which, up to now, have been too small to label with mechanical peening techniques. The high resolution of the Lasershot marks makes them difficult to reproduce, providing a solution to the ongoing problem of inferior, counterfeited parts. The high marking rate of up to six marks per second makes this system practical and cost-effective for marking high-volume components.

  2. Identification of safety-critical events using kinematic vehicle data and the discrete fourier transform.

    Science.gov (United States)

    Kluger, Robert; Smith, Brian L; Park, Hyungjun; Dailey, Daniel J

    2016-11-01

    Recent technological advances have made it both feasible and practical to identify unsafe driving behaviors using second-by-second trajectory data. Presented in this paper is a unique approach to detecting safety-critical events using vehicles' longitudinal accelerations. A Discrete Fourier Transform is used in combination with K-means clustering to flag patterns in the vehicles' accelerations in time-series that are likely to be crashes or near-crashes. The algorithm was able to detect roughly 78% of crasjavascript:void(0)hes and near-crashes (71 out of 91 validated events in the Naturalistic Driving Study data used), while generating about 1 false positive every 2.7h. In addition to presenting the promising results, an implementation strategy is discussed and further research topics that can improve this method are suggested in the paper.

  3. Understanding safety-critical interactions with a home medical device through Distributed Cognition.

    Science.gov (United States)

    Rajkomar, Atish; Mayer, Astrid; Blandford, Ann

    2015-08-01

    As healthcare shifts from the hospital to the home, it is becoming increasingly important to understand how patients interact with home medical devices, to inform the safe and patient-friendly design of these devices. Distributed Cognition (DCog) has been a useful theoretical framework for understanding situated interactions in the healthcare domain. However, it has not previously been applied to study interactions with home medical devices. In this study, DCog was applied to understand renal patients' interactions with Home Hemodialysis Technology (HHT), as an example of a home medical device. Data was gathered through ethnographic observations and interviews with 19 renal patients and interviews with seven professionals. Data was analyzed through the principles summarized in the Distributed Cognition for Teamwork methodology. In this paper we focus on the analysis of system activities, information flows, social structures, physical layouts, and artefacts. By explicitly considering different ways in which cognitive processes are distributed, the DCog approach helped to understand patients' interaction strategies, and pointed to design opportunities that could improve patients' experiences of using HHT. The findings highlight the need to design HHT taking into consideration likely scenarios of use in the home and of the broader home context. A setting such as home hemodialysis has the characteristics of a complex and safety-critical socio-technical system, and a DCog approach effectively helps to understand how safety is achieved or compromised in such a system.

  4. [Analysis of adverse events associated with interhospital transfer of critically ill patients. Safety checklist].

    Science.gov (United States)

    Melgarejo Urendez, A; Bernat Adell, M D; Lorente García, P

    2014-01-01

    Mobilization entails a risk for critically ill patients. It is therefore important to design and apply the tools to detect any safety lapses and to improve the quality of patient healthcare. To identify which adverse events (AE) are related to interhospital transfer of assisted patients and how enabling a protocol may prevent potential risks. Descriptive, observational study. We analyzed 110 transfers during morning shift in an Intensive Care Unit at a reference hospital between January and March 2011. Variables related to underlying security factors were collected. The average transfer time was 37.16 minutes. 61.82% of the transfers were carried out on a scheduled basis. An 18.18% of AE were detected. In both cases, desaturation and hemodynamic instability made up to 2.7% of the cases. 5.5% of the cases were underlying factors related to monitoring during transfer, and those related to ventilation during transfer accounted for 2.7%. Not having all materials by the stretcher constituted 1.8%. We detected 31 AE for non-compliance with the protocol, that being a 27.15% of all transfers. Before each hospital transfer, a risk-benefit assessment is recommended in order to avoid potential alterations in the patient's pathophysiologic condition. Both the protocol and the safety checklist are key to detect underlying factors and improve security during interhospital transfers. Copyright © 2012 Elsevier España, S.L. y SEEIUC. All rights reserved.

  5. Understanding the application of knowledge management to the safety critical facilities

    Energy Technology Data Exchange (ETDEWEB)

    Ilina, Elena

    2010-07-01

    Challenges to the operating nuclear power plants and transport infrastructures are outlined. It is concluded that most aggravating factors are related to knowledge. Thus, of necessity, effective knowledge management is required. Knowledge management theories are reviewed in their historical perspective as a natural extension and unification of information theories and theories about learning. The first line is identified with names as Wiener, Ashby, Shannon, Jaynes, Dretske, Harkevich. The second line - with Vygotsky, Engestroem, Carayannis. The recent developments of knowledge management theorists as Davenport, Prusak, Drew, Wiig, Zack are considered stressing learning, retaining of knowledge, approaching the state awareness of awareness, and alignment of knowledge management with the strategy of the concerned organizations. Further, some of the details and results are presented of what is achieved so far. More specifically, knowledge management tools are applied to the practical work activities as event reporting, data collection, condition assessment, verification of safety functions and incident investigation. Obstacles are identified and improvements are proposed. Finally, it is advised to continue to implement and further develop knowledge management tools in the organizations involved in various aspects of safety critical facilities

  6. Cadmium and lead residue control in a hazard analysis and critical control point (HACCP) environment.

    Science.gov (United States)

    Pagan-Rodríguez, Doritza; O'Keefe, Margaret; Deyrup, Cindy; Zervos, Penny; Walker, Harry; Thaler, Alice

    2007-02-21

    In 2003-2004, the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) conducted an exploratory assessment to determine the occurrence and levels of cadmium and lead in randomly collected samples of kidney, liver, and muscle tissues of mature chickens, boars/stags, dairy cows, and heifers. The data generated in the study were qualitatively compared to data that FSIS gathered in a 1985-1986 study in order to identify trends in the levels of cadmium and lead in meat and poultry products. The exploratory assessment was necessary to verify that Hazard Analysis and Critical Control Point plans and efforts to control exposure to these heavy metals are effective and result in products that meet U.S. export requirements. A comparison of data from the two FSIS studies suggests that the incidence and levels of cadmium and lead in different slaughter classes have remained stable since the first study was conducted in 1985-1986. This study was conducted to fulfill FSIS mandate to ensure that meat, poultry, and egg products entering commerce in the United States are free of adulterants, including elevated levels of environmental contaminants such as cadmium and lead.

  7. B190 computer controlled radiation monitoring and safety interlock system

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa, D L; Fields, W F; Gittins, D E; Roberts, M L

    1998-08-01

    The Center for Accelerator Mass Spectrometry (CAMS) in the Earth and Environmental Sciences Directorate at Lawrence Livermore National Laboratory (LLNL) operates two accelerators and is in the process of installing two new additional accelerators in support of a variety of basic and applied measurement programs. To monitor the radiation environment in the facility in which these accelerators are located and to terminate accelerator operations if predetermined radiation levels are exceeded, an updated computer controlled radiation monitoring system has been installed. This new system also monitors various machine safety interlocks and again terminates accelerator operations if machine interlocks are broken. This new system replaces an older system that was originally installed in 1988. This paper describes the updated B190 computer controlled radiation monitoring and safety interlock system.

  8. Criticality Safety Evaluation for Small Sample Preparation and Non-Destructive Assay (NDA) Operations in Wing 7 Basement of the CMR Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kunkle, Paige Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zhang, Ning [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-02

    Nuclear Criticality Safety (NCS) has reviewed the fissionable material small sample preparation and NDA operations in Wing 7 Basement of the CMR Facility. This is a Level-1 evaluation conducted in accordance with NCS-AP-004 [Reference 1], formerly NCS-GUIDE-01, and the guidance set forth on use of the Standard Criticality Safety Requirements (SCSRs) [Reference 2]. As stated in Reference 2, the criticality safety evaluation consists of both the SCSR CSED and the SCSR Application CSED. The SCSR CSED is a Level-3 CSED [Reference 3]. This Level-1 CSED is the SCSR Application CSED. This SCSR Application (Level-1) evaluation does not derive controls, it simply applies controls derived from the SCSR CSED (Level-3) for the application of operations conducted here. The controls derived in the SCSR CSED (Level-3) were evaluated via the process described in Section 6.6.5 of SD-130 (also reproduced in Section 4.3.5 of NCS-AP-004 [Reference 1]) and were determined to not meet the requirements for consideration of elevation into the safety basis documentation for CMR. According to the guidance set forth on use of the SCSRs [Reference 2], the SCSR CSED (Level-3) is also applicable to the CMR Facility because the process and the normal and credible abnormal conditions in question are bounded by those that are described in the SCSR CSED. The controls derived in the SCSR CSED include allowances for solid materials and solution operations. Based on the operations conducted at this location, there are less-than-accountable (LTA) amounts of 233U. Based on the evaluation documented herein, the normal and credible abnormal conditions that might arise during the execution of this process will remain subcritical with the following recommended controls.

  9. Sensitivity analysis of parameters important to nuclear criticality safety of Castor X/28F spent nuclear fuel cask

    Energy Technology Data Exchange (ETDEWEB)

    Leotlela, Mosebetsi J. [Witwatersrand Univ., Johannesburg (South Africa). School of Physics; Koeberg Operating Unit, Johannesburg (South Africa). Regulations and Licensing; Malgas, Isaac [Koeberg Nuclear Power Station, Duinefontein (South Africa). Nuclear Engineering Analysis; Taviv, Eugene [ASARA consultants (PTY) LTD, Johannesburg (South Africa)

    2015-11-15

    In nuclear criticality safety analysis it is essential to ascertain how various components of the nuclear system will perform under certain conditions they may be subjected to, particularly if the components of the system are likely to be affected by environmental factors such as temperature, radiation or material composition. It is therefore prudent that a sensitivity analysis is performed to determine and quantify the response of the output to variation in any of the input parameters. In a fissile system, the output parameter of importance is the k{sub eff}. Therefore, in attempting to prevent reactivity-induced accidents, it is important for the criticality safety analyst to have a quantified degree of response for the neutron multiplication factor to perturbation in a given input parameter. This article will present the results of the perturbation of the parameters that are important to nuclear criticality safety analysis and their respective correlation equations for deriving the sensitivity coefficients.

  10. Hazard Analysis and Critical Control Point Program for Foodservice Establishments.

    Science.gov (United States)

    Control Point ( HACCP ) inspections in foodservice operations throughout the state. The HACCP system , which first emerged in the late 1960s, is a rational...has been adopted for use in the foodservice industry. The HACCP system consists of three main components which are the: (1) Assessment of the hazards...to monitor critical control points. This system has shown promise as a tool to reduce the frequency of foodborne disease outbreaks in foodservice

  11. Safety systems and access control in the National Ignition Facility.

    Science.gov (United States)

    Reed, Robert K; Bell, Jayce C

    2013-06-01

    The National Ignition Facility (NIF) is the world's largest and most energetic laser system. The facility has the potential to generate ionizing radiation due to the interaction between the laser beams and target material, with neutrons and gamma rays being produced during deuterium-tritium fusion reactions. To perform these experiments, several types of hazards must be mitigated and controlled to ensure personnel safety. NIF uses a real-time safety system to monitor and mitigate the hazards presented by the facility. The NIF facility Safety Interlock System (SIS) monitors for oxygen deficiency and controls access to the facility preventing exposure to laser light and radiation from the Radiation Generating Devices. It also interfaces to radiation monitoring and other radiological monitoring and alarm systems. The SIS controls permissives to the hazard-generating equipment and annunciates hazard levels in the facility. To do this reliably and safely, the SIS has been designed as a fail-safe system with a proven performance record now spanning over 10 y. This paper discusses the SIS, its design, implementation, operator interfaces, validation/verification, and the hazard mitigation approaches employed in the NIF. A brief discussion of the Failure Modes and Effect Analysis supporting the SIS will also be presented. The paper ends with a general discussion of SIS do's and don'ts and common design flaws that should be avoided in SIS design.

  12. Use of feedback control to address flight safety issues

    Science.gov (United States)

    Ganguli, Subhabrata

    This thesis addresses three control problems related to flight safety. The first problem relates to the scope of improvement in performance of conventional flight control laws. In particular, aircraft longitudinal axis control based on the Total Energy Control System (TECS) is studied. The research draws attention to a potentially sluggish and undesirable aircraft response when the engine dynamics is slow (typically the case). The proposed design method uses a theoretically well-developed modern design method based on Hinfinity optimization to improve the aircraft dynamic behavior in spite of slow engine characteristics. At the same time, the proposed design method achieves other desirable performance goals such as insensitivity to sensor noise and wind gust rejection: all addressed in one unified framework. The second problem is based on a system level analysis of control structure hierarchy for aircraft flight control. The objective of the analysis problem is to translate outer-loop stability and performance specifications into a comprehensive inner-loop metric. The prime motivation is to make the flight control design process more systematic and the system-integration reliable and independent of design methodology. The analysis problem is posed within the robust control analysis framework. Structured singular value techniques and free controller parameterization ideas are used to impose a hierarchical structure for flight control architecture. The third problem involves development and demonstration of a new reconfiguration strategy in the flight control architecture that has the potential of improving flight safety while keeping cost and complexity low. This research proposes a fault tolerant feature based on active robust reconfiguration. The fault tolerant control problem is formulated in the Linear Parameter Varying (LPV) design framework. A prime advantage of this approach is that the synthesis results in a single nonlinear controller (as opposed to a bank

  13. The ORSphere Benchmark Evaluation and Its Potential Impact on Nuclear Criticality Safety

    Energy Technology Data Exchange (ETDEWEB)

    John D. Bess; Margaret A. Marshall; J. Blair Briggs

    2013-10-01

    In the early 1970’s, critical experiments using an unreflected metal sphere of highly enriched uranium (HEU) were performed with the focus to provide a “very accurate description…as an ideal benchmark for calculational methods and cross-section data files.” Two near-critical configurations of the Oak Ridge Sphere (ORSphere) were evaluated as acceptable benchmark experiments for inclusion in the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP Handbook). The results from those benchmark experiments were then compared with additional unmoderated and unreflected HEU metal benchmark experiment configurations currently found in the ICSBEP Handbook. For basic geometries (spheres, cylinders, and slabs) the eigenvalues calculated using MCNP5 and ENDF/B-VII.0 were within 3 of their respective benchmark values. There appears to be generally a good agreement between calculated and benchmark values for spherical and slab geometry systems. Cylindrical geometry configurations tended to calculate low, including more complex bare HEU metal systems containing cylinders. The ORSphere experiments do not calculate within their 1s uncertainty and there is a possibility that the effect of the measured uncertainties for the GODIVA I benchmark may need reevaluated. There is significant scatter in the calculations for the highly-correlated ORCEF cylinder experiments, which are constructed from close-fitting HEU discs and annuli. Selection of a nuclear data library can have a larger impact on calculated eigenvalue results than the variation found within calculations of a given experimental series, such as the ORCEF cylinders, using a single nuclear data set.

  14. Burn-up credit in criticality safety of PWR spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoud, Rowayda F., E-mail: Rowayda_mahmoud@yahoo.com [Metallurgy Department, Nuclear Research Center, Atomic Energy Authority (Egypt); Shaat, Mohamed K. [Nuclear Engineering, Reactors Department, Nuclear Research Center, Atomic Energy Authority (Egypt); Nagy, M.E.; Agamy, S.A. [Professor of Nuclear Engineering, Nuclear and Radiation Department, Alexandria University (Egypt); Abdelrahman, Adel A. [Metallurgy Department, Nuclear Research Center, Atomic Energy Authority (Egypt)

    2014-12-15

    Highlights: • Designing spent fuel wet storage using WIMS-5D and MCNP-5 code. • Studying fresh and burned fuel with/out absorber like “B{sub 4}C and Ag–In–Cd” in racks. • Sub-criticality was confirmed for fresh and burned fuel under specific cases. • Studies for BU credit recommend increasing fuel burn-up to 60.0 GWD/MTU. • Those studies require new core structure materials, fuel composition and cladding. - Abstract: The criticality safety calculations were performed for a proposed design of a wet spent fuel storage pool. This pool will be used for the storage of spent fuel discharged from a typical pressurized water reactor (PWR). The mathematical model based on the international validated codes, WIMS-5 and MCNP-5 were used for calculating the effective multiplication factor, k{sub eff}, for the spent fuel stored in the pool. The data library for the multi-group neutron microscopic cross-sections was used for the cell calculations. The k{sub eff} was calculated for several changes in water density, water level, assembly pitch and burn-up with different initial fuel enrichment and new types and amounts of fixed absorbers. Also, k{sub eff} was calculated for the conservative fresh fuel case. The results of the calculations confirmed that the effective multiplication factor for the spent fuel storage is sub-critical for all normal and abnormal states. The future strategy for the burn-up credit recommends increasing the fuel burn-up to a value >60.0 GWD/MTU, which requires new fuel composition and new fuel cladding material with the assessment of the effects of negative reactivity build up.

  15. Effectiveness and safety of a protocol for promotion of early intragastric feeding in critically ill children.

    Science.gov (United States)

    Briassoulis, G C; Zavras, N J; Hatzis MD, T D

    2001-04-01

    OBJECTIVES: To investigate the feasibility, adequacy, and efficacy of early poststress intragastric feeding (EPIGF) in critically ill children. DESIGN: A prospective clinical study. SETTING: Pediatric intensive care unit in a tertiary care children's hospital. PATIENTS: Seventy-one consecutively enrolled critically ill children requiring prolonged mechanical ventilation. INTERVENTIONS: Full-strength intragastric tube feedings (Nutrison Pediatric, Standard) were initiated within 12 hrs of the study-entry event. Enteral feedings were advanced to a target volume of energy intake = 1/2, 1, 5/4, 6/4, and 6/4 of the predicted basal metabolic rate (PBMR) on days 1-5, respectively. MEASUREMENTS AND MAIN RESULTS: Nutritional status by the caloric intake, recommended dietary allowances, PBMR, predicted energy expenditure (PEE), anthropometry, and clinical indices were evaluated on days 1 and 5. Safety was assessed by the clinical course of disease, laboratory findings, and occurrence of complications. Success was determined by accomplishment of the PEE target. The early success rate was 94.4% and predicted late enteral feeding success accurately (p =.0001). Caloric intake approached PBMR the second day (43 +/- 1.7 kcal/kg/day vs. 43.2 +/- 1.1 kcal/kg/day) and PEE the fifth day (66.2 +/- 2.7 kcal/kg/day vs. 67.7 +/- 6.4 kcal/kg/day). Multivariate stepwise regression analysis showed that poor outcome and a high Therapeutic Intervention Scoring System score correlated with failure of EPIGF (p PBMR by the second day and PEE by the fourth day in critically ill children. Caloric intake lower than PBMR is associated with higher mortality and morbidity rates.

  16. 77 FR 22602 - Information Collection Activities: Well Control and Production Safety Training, Submitted for...

    Science.gov (United States)

    2012-04-16

    ... paperwork requirements in the regulations under Subpart O, ``Well Control and Production Safety Training... Control and Production Safety Training. OMB Control Number: 1014-0008. Abstract: The Outer Continental... Bureau of Safety and Environmental Enforcement (BSEE) Information Collection Activities: Well Control...

  17. [Incorporation of the Hazard Analysis and Critical Control Point system (HACCP) in food legislation].

    Science.gov (United States)

    Castellanos Rey, Liliana C; Villamil Jiménez, Luis C; Romero Prada, Jaime R

    2004-01-01

    The Hazard Analysis and Critical Control Point system (HACCP), recommended by different international organizations as the Codex Alimentarius Commission, the World Trade Organization (WTO), the International Office of Epizootics (OIE) and the International Convention for Vegetables Protection (ICPV) amongst others, contributes to ensuring the innocuity of food along the agro-alimentary chain and requires of Good Manufacturing Practices (GMP) for its implementation, GMP's which are legislated in most countries. Since 1997, Colombia has set rules and legislation for application of HACCP system in agreement with international standards. This paper discusses the potential and difficulties of the legislation enforcement and suggests some policy implications towards food safety.

  18. Safety Message Power Transmission Control for Vehicular Ad hoc Networks

    CERN Document Server

    Samara, Ghassan; Al-Salihy, Wafaa A H

    2010-01-01

    Vehicular Ad hoc Networks (VANET) is one of the most challenging research area in the field of Mobile Ad Hoc Networks. In this research we proposed a dynamic power adjustment protocol that will be used for sending the periodical safety message. (Beacon)based on the analysis of the channel status depending on the channel congestion and the power used for transmission. The Beacon Power Control (BPC) protocol first sensed and examined the percentage of the channel congestion, the result obtained was used to adjust the transmission power for the safety message to reach the optimal power. This will lead to decrease the congestion in the channel and achieve good channel performance and beacon dissemination.

  19. Pasteurised milk and implementation of HACCP (Hazard Analysis Critical Control Point

    Directory of Open Access Journals (Sweden)

    T.B Murdiati

    2004-10-01

    Full Text Available The purpose of pasteurisation is to destroy pathogen bacteria without affecting the taste, flavor, and nutritional value. A study on the implementation of HACCP (Hazard Analysis Critical Control Point in producing pasteurized milk was carried out in four processing unit of pasteurised milk, one in Jakarta, two in Bandung and one in Bogor. The critical control points in the production line were identified. Milk samples were collected from the critical points and were analysed for the total number of microbes. Antibiotic residues were detected on raw milks. The study indicated that one unit in Bandung dan one unit in Jakarta produced pasteurized milk with lower number of microbes than the other units, due to better management and control applied along the chain of production. Penisilin residues was detected in raw milk used by unit in Bogor. Six critical points and the hazard might arise in those points were identified, as well as how to prevent the hazards. Quality assurance system such as HACCP would be able to produce high quality and safety of pasteurised milk, and should be implemented gradually.

  20. Is Model-Based Development a Favorable Approach for Complex and Safety-Critical Computer Systems on Commercial Aircraft?

    Science.gov (United States)

    Torres-Pomales, Wilfredo

    2014-01-01

    A system is safety-critical if its failure can endanger human life or cause significant damage to property or the environment. State-of-the-art computer systems on commercial aircraft are highly complex, software-intensive, functionally integrated, and network-centric systems of systems. Ensuring that such systems are safe and comply with existing safety regulations is costly and time-consuming as the level of rigor in the development process, especially the validation and verification activities, is determined by considerations of system complexity and safety criticality. A significant degree of care and deep insight into the operational principles of these systems is required to ensure adequate coverage of all design implications relevant to system safety. Model-based development methodologies, methods, tools, and techniques facilitate collaboration and enable the use of common design artifacts among groups dealing with different aspects of the development of a system. This paper examines the application of model-based development to complex and safety-critical aircraft computer systems. Benefits and detriments are identified and an overall assessment of the approach is given.

  1. 77 FR 30765 - Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for Heavy Vehicles

    Science.gov (United States)

    2012-05-23

    ... CFR Part 571 Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for Heavy... 571 RIN 2127-AK97 Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for... a new Federal Motor Vehicle Safety Standard No. 136 to require electronic stability control (ESC...

  2. 76 FR 49532 - Federal Motor Vehicle Safety Standards; Electronic Stability Control; Technical Report on the...

    Science.gov (United States)

    2011-08-10

    ... National Highway Traffic Safety Administration Federal Motor Vehicle Safety Standards; Electronic Stability Control; Technical Report on the Effectiveness of Electronic Stability Control Systems for Cars and LTVs... Technical Report on its existing Safety Standard 126, Electronic Stability Control Systems. The report's...

  3. Comprehensive analysis and differentiated assessment of food safety control systems: a diagnostic instrument

    NARCIS (Netherlands)

    Luning, P.A.; Bango, L.; Kussaga, J.; Rovira, J.; Marcelis, W.J.

    2008-01-01

    In this article, an instrument is presented to diagnose microbial safety control activities in a food safety management system. The need of such a tool is derived from the importance of microbial safety control and the need for improvement of existing control systems. Careful diagnosis of these syst

  4. 75 FR 5536 - Pipeline Safety: Control Room Management/Human Factors, Correction

    Science.gov (United States)

    2010-02-03

    ... Safety: Control Room Management/Human Factors, Correction AGENCY: Pipeline and Hazardous Materials Safety... Regulations to address human factors and other aspects of control room management for pipelines where... 63310) entitled ``Pipeline Safety: Control Room Management/Human Factors.'' This final rule...

  5. SCOPE safety-controls optimization by performance evaluation: A systematic approach for safety-related decisions at the Hanford Tank Remediation System. Phase 1, final report

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, K.D.; Williams, D.C.; Slezak, S.E.; Young, M.L. [and others

    1996-12-01

    The Department of Energy`s Hanford Tank Waste Remediation system poses a significant challenge for hazard management because of the uncertainty that surrounds many of the variables that must be considered in decisions on safety and control strategies. As a result, site managers must often operate under excessively conservative and expensive assumptions. This report describes a systematic approach to quantifying the uncertainties surrounding the critical parameters in control decisions (e.g., condition of the tanks, kinds of wastes, types of possible accidents) through the use of expert elicitation methods. The results of the elicitations would then be used to build a decision support system and accident analysis model that would allow managers to see how different control strategies would affect the cost and safety of a facility configuration.

  6. A critical assessment of vector control for dengue prevention.

    Science.gov (United States)

    Achee, Nicole L; Gould, Fred; Perkins, T Alex; Reiner, Robert C; Morrison, Amy C; Ritchie, Scott A; Gubler, Duane J; Teyssou, Remy; Scott, Thomas W

    2015-05-01

    Recently, the Vaccines to Vaccinate (v2V) initiative was reconfigured into the Partnership for Dengue Control (PDC), a multi-sponsored and independent initiative. This redirection is consistent with the growing consensus among the dengue-prevention community that no single intervention will be sufficient to control dengue disease. The PDC's expectation is that when an effective dengue virus (DENV) vaccine is commercially available, the public health community will continue to rely on vector control because the two strategies complement and enhance one another. Although the concept of integrated intervention for dengue prevention is gaining increasingly broader acceptance, to date, no consensus has been reached regarding the details of how and what combination of approaches can be most effectively implemented to manage disease. To fill that gap, the PDC proposed a three step process: (1) a critical assessment of current vector control tools and those under development, (2) outlining a research agenda for determining, in a definitive way, what existing tools work best, and (3) determining how to combine the best vector control options, which have systematically been defined in this process, with DENV vaccines. To address the first step, the PDC convened a meeting of international experts during November 2013 in Washington, DC, to critically assess existing vector control interventions and tools under development. This report summarizes those deliberations.

  7. A critical assessment of vector control for dengue prevention.

    Directory of Open Access Journals (Sweden)

    Nicole L Achee

    2015-05-01

    Full Text Available Recently, the Vaccines to Vaccinate (v2V initiative was reconfigured into the Partnership for Dengue Control (PDC, a multi-sponsored and independent initiative. This redirection is consistent with the growing consensus among the dengue-prevention community that no single intervention will be sufficient to control dengue disease. The PDC's expectation is that when an effective dengue virus (DENV vaccine is commercially available, the public health community will continue to rely on vector control because the two strategies complement and enhance one another. Although the concept of integrated intervention for dengue prevention is gaining increasingly broader acceptance, to date, no consensus has been reached regarding the details of how and what combination of approaches can be most effectively implemented to manage disease. To fill that gap, the PDC proposed a three step process: (1 a critical assessment of current vector control tools and those under development, (2 outlining a research agenda for determining, in a definitive way, what existing tools work best, and (3 determining how to combine the best vector control options, which have systematically been defined in this process, with DENV vaccines. To address the first step, the PDC convened a meeting of international experts during November 2013 in Washington, DC, to critically assess existing vector control interventions and tools under development. This report summarizes those deliberations.

  8. Validation and Verification (V&V) of Safety-Critical Systems Operating Under Off-Nominal Conditions

    Science.gov (United States)

    Belcastro, Christine M.

    2012-01-01

    Loss of control (LOC) remains one of the largest contributors to aircraft fatal accidents worldwide. Aircraft LOC accidents are highly complex in that they can result from numerous causal and contributing factors acting alone or more often in combination. Hence, there is no single intervention strategy to prevent these accidents. Research is underway at the National Aeronautics and Space Administration (NASA) in the development of advanced onboard system technologies for preventing or recovering from loss of vehicle control and for assuring safe operation under off-nominal conditions associated with aircraft LOC accidents. The transition of these technologies into the commercial fleet will require their extensive validation and verification (V&V) and ultimate certification. The V&V of complex integrated systems poses highly significant technical challenges and is the subject of a parallel research effort at NASA. This chapter summarizes the V&V problem and presents a proposed process that could be applied to complex integrated safety-critical systems developed for preventing aircraft LOC accidents. A summary of recent research accomplishments in this effort is referenced.

  9. Criticality safety evaluation report for the Cold Vacuum Drying Facility`s process water handling system

    Energy Technology Data Exchange (ETDEWEB)

    Roblyer, S.D.

    1998-02-12

    This report addresses the criticality concerns associated with process water handling in the Cold Vacuum Drying Facility (CVDF). The controls and limitations on equipment design and operations to control potential criticality occurrences are identified. The effectiveness of equipment design and operation controls in preventing criticality occurrences during normal and abnormal conditions is evaluated and documented in this report. Spent nuclear fuel (SNF) is removed from existing canisters in both the K East and K West Basins and loaded into a multicanister overpack (MCO) in the K Basin pool. The MCO is housed in a shipping cask surrounded by clean water in the annulus between the exterior of the MCO and the interior of the shipping cask. The fuel consists of spent N Reactor and some single pass reactor fuel. The MCO is transported to the CVDF near the K Basins to remove process water from the MCO interior and from the shipping cask annulus. After the bulk water is removed from the MCO, any remaining free liquid is removed by drawing a vacuum on the MCO`s interior. After cold vacuum drying is completed, the MCO is filled with an inert cover gas, the lid is replaced on the shipping cask, and the MCO is transported to the Canister Storage Building. The process water removed from the MCO contains fissionable materials from metallic uranium corrosion. The process water from the MCO is first collected in a geometrically safe process water conditioning receiver tank. The process water in the process water conditioning receiver tank is tested, then filtered, demineralized, and collected in the storage tank. The process water is finally removed from the storage tank and transported from the CVDF by truck.

  10. 76 FR 55829 - Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems

    Science.gov (United States)

    2011-09-09

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL02 Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems AGENCY: National Highway Traffic Safety Administration... changes to a new Federal motor vehicle safety standard requiring light vehicles to be equipped with...

  11. Uranium-233 waste definition: Disposal options, safeguards, criticality control, and arms control

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Storch, S.N. [Oak Ridge National Lab., TN (United States); Lewis, L.C. [Lockheed Martin Idaho Technology Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.

    1998-07-07

    The US investigated the use of {sup 233}U for weapons, reactors, and other purposes from the 1950s into the 1970s. Based on the results of these investigations, it was decided not to use {sup 233}U on a large scale. Most of the {sup 233}U-containing materials were placed in long-term storage. At the end of the cold war, the US initiated, as part of its arms control policies, a disposition program for excess fissile materials. Other programs were accelerated for disposal of radioactive wastes placed in storage during the cold war. Last, potential safety issues were identified related to the storage of some {sup 233}U-containing materials. Because of these changes, significant activities associated with {sup 233}U-containing materials are expected. This report is one of a series of reports to provide the technical bases for future decisions on how to manage this material. A basis for defining when {sup 233}U-containing materials can be managed as waste and when they must be managed as concentrated fissile materials has been developed. The requirements for storage, transport, and disposal of radioactive wastes are significantly different than those for fissile materials. Because of these differences, it is important to classify material in its appropriate category. The establishment of a definition of what is waste and what is fissile material will provide the guidance for appropriate management of these materials. Wastes are defined in this report as materials containing sufficiently small masses or low concentrations of fissile materials such that they can be managed as typical radioactive waste. Concentrated fissile materials are defined herein as materials containing sufficient fissile content such as to warrant special handling to address nuclear criticality, safeguards, and arms control concerns.

  12. Glycemic control in critically ill: A moving target

    Directory of Open Access Journals (Sweden)

    Subhash Todi

    2014-01-01

    Full Text Available Glycemic control targets in intensive care units (ICUs have three distinct domains. Firstly, excessive hyperglycemia needs to be avoided. The upper limit of this varies depending on the patient population studied and diabetic status of the patients. Surgical patients particularly cardiac surgery patients tend to benefit from a lower upper limit of glycemic control, which is not evident in medically ill patient. Patient with premorbid diabetic status tends to tolerate higher blood sugar level better than normoglycemics. Secondly, hypoglycemia is clearly detrimental in all groups of critically ill patient and all measures to avoid this catastrophe need to be a part of any glycemic control protocol. Thirdly, glycemic variability has increasingly been shown to be detrimental in this patient population. Glycemic control protocols need to take this into consideration and target to reduce any of the available metrics of glycemic variability. Newer technologies including continuous glucose monitoring techniques will help in titrating all these three domains within a desirable range.

  13. Work Practice Simulation of Complex Human-Automation Systems in Safety Critical Situations: The Brahms Generalized berlingen Model

    Science.gov (United States)

    Clancey, William J.; Linde, Charlotte; Seah, Chin; Shafto, Michael

    2013-01-01

    The transition from the current air traffic system to the next generation air traffic system will require the introduction of new automated systems, including transferring some functions from air traffic controllers to on­-board automation. This report describes a new design verification and validation (V&V) methodology for assessing aviation safety. The approach involves a detailed computer simulation of work practices that includes people interacting with flight-critical systems. The research is part of an effort to develop new modeling and verification methodologies that can assess the safety of flight-critical systems, system configurations, and operational concepts. The 2002 Ueberlingen mid-air collision was chosen for analysis and modeling because one of the main causes of the accident was one crew's response to a conflict between the instructions of the air traffic controller and the instructions of TCAS, an automated Traffic Alert and Collision Avoidance System on-board warning system. It thus furnishes an example of the problem of authority versus autonomy. It provides a starting point for exploring authority/autonomy conflict in the larger system of organization, tools, and practices in which the participants' moment-by-moment actions take place. We have developed a general air traffic system model (not a specific simulation of Überlingen events), called the Brahms Generalized Ueberlingen Model (Brahms-GUeM). Brahms is a multi-agent simulation system that models people, tools, facilities/vehicles, and geography to simulate the current air transportation system as a collection of distributed, interactive subsystems (e.g., airports, air-traffic control towers and personnel, aircraft, automated flight systems and air-traffic tools, instruments, crew). Brahms-GUeM can be configured in different ways, called scenarios, such that anomalous events that contributed to the Überlingen accident can be modeled as functioning according to requirements or in an

  14. Critical period of weed control In cumin (Cuminum cyminum

    Directory of Open Access Journals (Sweden)

    azade hoseyni

    2009-06-01

    Full Text Available In order to evaluate the critical period of weed control in Cumin, an experiment with Complete Randomized Block Design and three replications was conducted in experimental field of Faculty of Agriculture, Ferdowsi University of Mashhad, During 2004-2005 growing season. Treatments included different combinations of weed free and weed infested periods (20, 30, 40 and 80 days after germination plus weedy check and weed free check. Critical period weed control was evaluated with Gompertz and Logestic functions. Traits measured were yield and yield components, harvest index of cumin and also number and weight of weed species. Results showed the critical period was between 24-38 days after germination. With increasing interfereing period at early or late growth stages of cumin, the economic yield was reduced. By extending weeding periods at early stage of growth or during the growth period, dry weight of weeds were reduced, while extending weeding period at the end of growth stage and also weed free during growth period, early or late stages of growth had no significant effects on yield components except on number of umbels per plant. Harvest index was positively affected by early weeding. It appears that early weeding was somehow more effective on yield components for cumin.

  15. Regulatory control of nuclear safety in Finland. Annual report 1999

    Energy Technology Data Exchange (ETDEWEB)

    Tossavainen, K. [ed.

    2000-06-01

    This report concerns the regulatory control of nuclear energy in Finland in 1999. Its submission to the Ministry of Trade and Industry by the Finnish Radiation and Nuclear Safety Authority (STUK) is stipulated in section 121 of the Nuclear Energy Decree. STUK's regulatory work was focused on the operation of the Finnish nuclear power plants as well as on nuclear waste management and safeguards of nuclear materials. The operation of the Finnish nuclear power plants was in compliance with the conditions set out in their operating licences and with current regulations, with the exception of some inadvertent deviations from the Technical Specifications. No plant events endangering the safe use of nuclear energy occurred. The individual doses of all nuclear power plant workers remained below the dose threshold. The collective dose of the workers was low, compared internationally, and did not exceed STUK's guidelines at either nuclear power plant. The radioactive releases were minor and the dose calculated on their basis for the most exposed individual in the vicinity of the plant was well below the limit established in a decision of the Council of State at both Loviisa and Olkiluoto nuclear power plants. STUK issued statements to the Ministry of Trade and Industry about the environmental impact assessment programme reports on the possible nuclear power plant projects at Olkiluoto and Loviisa and about the continued operation of the research reactor in Otaniemi, Espoo. A Y2k-related safety assessment of the Finnish nuclear power plants was completed in December. In nuclear waste management STUK's regulatory work was focused on spent fuel storage and final disposal plans as well as on the treatment, storage and final disposal of reactor waste. No events occurred in nuclear waste management that would have endangered safety. A statement was issued to the Ministry of Trade and Industry about an environmental impact assessment report on a proposed final

  16. Use of hazard analysis critical control point and alternative treatments in the production of apple cider.

    Science.gov (United States)

    Senkel, I A; Henderson, R A; Jolbitado, B; Meng, J

    1999-07-01

    The purpose of this study was to evaluate the practices of Maryland cider producers and determine whether implementing hazard analysis critical control point (HACCP) would reduce the microbial contamination of cider. Cider producers (n = 11) were surveyed to determine existing manufacturing practices and sanitation. A training program was then conducted to inform operators of safety issues, including contamination with Escherichia coli O157:H7, and teach HACCP concepts and principles, sanitation procedures, and good manufacturing practice (GMP). Although all operators used a control strategy from one of the model HACCP plans provided, only one developed a written HACCP plan. None developed specific GMP, sanitation standard operating procedures, or sanitation monitoring records. Six operators changed or added production controls, including the exclusion of windfall apples, sanitizing apples chemically and by hot dip, and cider treatment with UV light or pasteurization. Facility inspections indicated improved sanitation and hazard control but identified ongoing problems. Microbiological evaluation of bottled cider before and after training, in-line apples, pomace, cider, and inoculated apples was conducted. E. coli O157:H7, Salmonella, or Staphylococcus aureus were not found in samples of in-line apple, pomace, and cider, or bottled cider. Generic E. coli was not isolated on in-coming apples but was found in 4 of 32 (13%) in-line samples and 3 of 17 (18%) bottled fresh cider samples, suggesting that E. coli was introduced during in-plant processing. To produce pathogen-free cider, operators must strictly conform to GMP and sanitation procedures in addition to HACCP controls. Controls aimed at preventing or eliminating pathogens on source apples are critical but alone may not be sufficient for product safety.

  17. Pedestrian safety under permissive left-turn signal control

    Directory of Open Access Journals (Sweden)

    Yi Qi

    2017-06-01

    Full Text Available At intersections with permissive only signal control, pedestrians will move at the phase with the parallel through vehicular movement and the permissive left-turn movement. The left-turn vehicles have to yield to both opposing vehicles and pedestrians at the crosswalk. Under such complicated driving conditions, collision risks rise if left-turn vehicles make misjudgments and fail to yield to the pedestrians. In this research, driving-simulation based experiments were conducted for identifying and assessing the impacts of the factors that contribute to the collision between the left-turn vehicles and the pedestrians during the permissive left-turn phase. The results of this study showed that the percentage of left-turn trucks and the pedestrian volume has significant impacts on the pedestrian safety under permissive left-turn signal control.

  18. Validation of nuclear criticality safety software and 27 energy group ENDF/B-IV cross sections. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.L. Jr. [Battelle, Columbus, OH (United States); D`Aquila, D.M. [Lockheed Martin Utility Services, Inc., Oak Ridge, TN (United States)

    1996-01-01

    The original validation report, POEF-T-3636, was documented in August 1994. The document was based on calculations that were executed during June through August 1992. The statistical analyses in Appendix C and Appendix D were completed in October 1993. This revision is written to clarify the margin of safety being used at Portsmouth for nuclear criticality safety calculations. This validation gives Portsmouth NCS personnel a basis for performing computerized KENO V.a calculations using the Lockheed Martin Nuclear Criticality Safety Software. The first portion of the document outlines basic information in regard to validation of NCSS using ENDF/B-IV 27-group cross sections on the IBM3090 at ORNL. A basic discussion of the NCSS system is provided, some discussion on the validation database and validation in general. Then follows a detailed description of the statistical analysis which was applied. The results of this validation indicate that the NCSS software may be used with confidence for criticality calculations at the Portsmouth Gaseous Diffusion Plant. For calculations of Portsmouth systems using the specified codes and systems covered by this validation, a maximum k{sub eff} including 2{sigma} of 0.9605 or lower shall be considered as subcritical to ensure a calculational margin of safety of 0.02. The validation of NCSS on the IBM 3090 at ORNL was extended to include NCSS on the IBM 3090 at K-25.

  19. SAFETY

    CERN Document Server

    Niels Dupont

    2013-01-01

    CERN Safety rules and Radiation Protection at CMS The CERN Safety rules are defined by the Occupational Health & Safety and Environmental Protection Unit (HSE Unit), CERN’s institutional authority and central Safety organ attached to the Director General. In particular the Radiation Protection group (DGS-RP1) ensures that personnel on the CERN sites and the public are protected from potentially harmful effects of ionising radiation linked to CERN activities. The RP Group fulfils its mandate in collaboration with the CERN departments owning or operating sources of ionising radiation and having the responsibility for Radiation Safety of these sources. The specific responsibilities concerning "Radiation Safety" and "Radiation Protection" are delegated as follows: Radiation Safety is the responsibility of every CERN Department owning radiation sources or using radiation sources put at its disposition. These Departments are in charge of implementing the requi...

  20. Temporal Logic Motion Control using Actor-Critic Methods

    CERN Document Server

    Ding, Xu Chu; Lahijanian, Morteza; Paschalidis, Ioannis Ch; Belta, Calin A

    2012-01-01

    In this paper, we consider the problem of deploying a robot from a specification given as a temporal logic statement about some properties satisfied by the regions of a large, partitioned environment. We assume that the robot has noisy sensors and actuators and model its motion through the regions of the environment as a Markov Decision Process (MDP). The robot control problem becomes finding the control policy maximizing the probability of satisfying the temporal logic task on the MDP. For a large environment, obtaining transition probabilities for each state-action pair, as well as solving the necessary optimization problem for the optimal policy are usually not computationally feasible. To address these issues, we propose an approximate dynamic programming framework based on a least-square temporal difference learning method of the actor-critic type. This framework operates on sample paths of the robot and optimizes a randomized control policy with respect to a small set of parameters. The transition proba...

  1. 76 FR 20588 - FDA Food Safety Modernization Act: Focus on Preventive Controls for Facilities; Public Meeting

    Science.gov (United States)

    2011-04-13

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Chapter I FDA Food Safety Modernization Act: Focus on... a public meeting entitled ``FDA Food Safety Modernization Act: Focus on Preventive Controls for... implementation of the preventive controls for facilities provisions of the recently enacted FDA Food Safety...

  2. Control core of safety management: the reasonable distribution of safety resources

    Institute of Scientific and Technical Information of China (English)

    YAO Qing-guo; ZHANG Xue-mu

    2009-01-01

    The distribution of resources is the basis of safety management. Based on the systematic analysis of a resource distribution system affecting the level of safety, the best distribution proportion between safety activities and production and best resources distri-bution proportion among the various links of security activities are presented. Moreover, it is stated that the distribution of resources law needs to be researched deeply in practical work to achieve optimization of safety management practice.

  3. Testing of LWR fuel rods to support criticality safety analysis of transport accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Purcell, P.C. [BNFL International Transport, Spent Fuel Services (United Kingdom); Dallongeville, M. [COGEMA Logistics (AREVA Group) (France)

    2004-07-01

    For the transport of low enriched materials, criticality safety may be demonstrated by applying pessimistic modelling assumptions that bound any realistic case. Where Light Water Reactor (LWR) fuel is being transported, enrichment levels are usually too high to permit this approach and more realistic data is needed. This requires a method by which the response of LWR fuel under impact accident conditions can be approximated or bounded. In 2000, BNFL and COGEMA LOGISTICS jointly commenced the Fuel Integrity Project (FIP) whose objective was to develop such methods. COGEMA LOGISTICS were well advanced with a method for determining the impact response of unirradiated fuel, but required further test data before acceptance by the Transport Regulators. The joint project team extensively discussed the required inputs to the FIP, from which it was agreed that BNFL would organise new tests on both unirradiated and irradiated fuel samples and COGEMA LOGISTICS would take major responsibility for evaluating the test results. Tests on unirradiated fuel rod samples involved both dynamic and quasi-static loading on fuel samples. PWR fuel rods loaded with uranium pellets were dropped vertically from 9m onto a rigid target and this was repeated on BWR fuel rods, similar tests on empty fuel rods were also conducted. Quasi-static tests were conducted on 530 mm long PWR and BWR fuel specimens under axial loading. Tests on irradiated fuel samples were conducted on high burn-up fuel rods of both PWR and BWR types. These were believed original to the FIP project and involved applying bending loads to simply supported pressurised rod specimens. In one test the fuel rod was heated to nearly 500oC during loading, all specimens were subject to axial impact before testing. Considerable experience of fuel rod testing and new data was gained from this test programme.

  4. Impact of critical care environment on burnout, perceived quality of care and safety attitude of the nursing team.

    Science.gov (United States)

    Guirardello, Edinêis de Brito

    2017-06-05

    assess the perception of the nursing team about the environment of practice in critical care services and its relation with the safety attitude, perceived quality of care and burnout level. cross-sectional study involving 114 nursing professionals from the intensive care unit of a teaching hospital. The following instruments were used: Nursing Work Index-Revised, Maslach Burnout Inventory and the Safety Attitude Questionnaire. the professionals who perceived greater autonomy, good relationships with the medical team and better control over the work environment presented lower levels of burnout, assessed the quality of care as good and reported a positive perception on the safety attitude for the domain job satisfaction. the findings evidenced that environments favorable to these professionals' practice result in lower levels of burnout, a better perceived quality of care and attitudes favorable to patient safety. avaliar a percepção da equipe de enfermagem sobre o ambiente da prática em unidades de cuidados críticos e sua relação com atitude de segurança, percepção da qualidade do cuidado e nível de burnout. estudo transversal com a participação de 114 profissionais de enfermagem da unidade de terapia intensiva de um hospital de ensino. Foram utilizados os instrumentos: Nursing Work Index-Revised, Inventário de Burnout de Maslach e o Questionário de Atitudes de Segurança. os profissionais que perceberam maior autonomia, boas relações com a equipe médica e melhor controle sobre o ambiente de trabalho, apresentaram menores níveis de burnout, avaliaram como boa a qualidade do cuidado e relataram uma percepção positiva da atitude de segurança para o domínio satisfação no trabalho. os achados evidenciaram que ambientes favoráveis à prática desses profissionais resultam em menores níveis de burnout, melhor percepção da qualidade do cuidado e atitudes favoráveis à segurança do paciente. evaluar la percepción del equipo de enfermer

  5. Coherent optical control of polarization with a critical metasurface

    CERN Document Server

    Kang, Ming

    2015-01-01

    We describe the mechanism by which a metamaterial surface can act as an ideal phase-controlled rotatable linear polarizer. With equal-power linearly polarized beams incident on each side of the surface, varying the relative phase rotates the polarization angles of the output beams, while keeping the polarization exactly linear. The explanation is based on coupled-mode theory and the idea of coherent perfect absorption into auxiliary polarization channels. The polarization-rotating behavior occurs at a critical point of the coupled-mode theory, which can be associated with the exceptional point of a parity-time (PT) symmetric effective Hamiltonian.

  6. Investigation of critical parameters controlling the efficiency of associative ionization

    Science.gov (United States)

    Le Padellec, A.; Launoy, T.; Dochain, A.; Urbain, X.

    2017-05-01

    This paper compiles our merged-beam experimental findings for the associative ionization (AI) process from charged reactants, with the aim of guiding future investigations with e.g. the double electrostatic ion storage ring DESIREE in Stockholm. A reinvestigation of the isotopic effect in H-(D-) + He+ collisions is presented, along with a review of {{{H}}}3+ and NO+ production by AI involving ion pairs or excited neutrals, and put in perspective with the mutual neutralization and radiative association reactions. Critical parameters are identified and evaluated for their systematic role in controlling the magnitude of the cross section: isotopic substitution, exothermicity, electronic state density, and spin statistics.

  7. System modeling with the DISC framework: evidence from safety-critical domains.

    Science.gov (United States)

    Reiman, Teemu; Pietikäinen, Elina; Oedewald, Pia; Gotcheva, Nadezhda

    2012-01-01

    The objective of this paper is to illustrate the development and application of the Design for Integrated Safety Culture (DISC) framework for system modeling by evaluating organizational potential for safety in nuclear and healthcare domains. The DISC framework includes criteria for good safety culture and a description of functions that the organization needs to implement in order to orient the organization toward the criteria. Three case studies will be used to illustrate the utilization of the DISC framework in practice.

  8. Applications of near-infrared spectroscopy in food safety evaluation and control: a review of recent research advances.

    Science.gov (United States)

    Qu, Jia-Huan; Liu, Dan; Cheng, Jun-Hu; Sun, Da-Wen; Ma, Ji; Pu, Hongbin; Zeng, Xin-An

    2015-01-01

    Food safety is a critical public concern, and has drawn great attention in society. Consequently, developments of rapid, robust, and accurate methods and techniques for food safety evaluation and control are required. As a nondestructive and convenient tool, near-infrared spectroscopy (NIRS) has been widely shown to be a promising technique for food safety inspection and control due to its huge advantages of speed, noninvasive measurement, ease of use, and minimal sample preparation requirement. This review presents the fundamentals of NIRS and focuses on recent advances in its applications, during the last 10 years of food safety control, in meat, fish and fishery products, edible oils, milk and dairy products, grains and grain products, fruits and vegetables, and others. Based upon these applications, it can be demonstrated that NIRS, combined with chemometric methods, is a powerful tool for food safety surveillance and for the elimination of the occurrence of food safety problems. Some disadvantages that need to be solved or investigated with regard to the further development of NIRS are also discussed.

  9. Critical Period of Weed Control in Corn (Zea mays L.

    Directory of Open Access Journals (Sweden)

    R Alizadeh

    2012-06-01

    Full Text Available In order to determine the critical peroid of weed control (CPWC in grain maize, a field study was conducted in 2008 in Agricultural Research Station of Esfahan province using a randomized complete block design with 12 treatments and three replications. The treatments consisted of two different periods of weed interference, a critical weed-free period and a critical time of weed removal were imposed at V3, V6, V9, V12, and R1 (based on phenological stages of corn development with a weedy check and a weed-free check. The CPWC was determined by fitting non-linear regression models of logistic and gompertz equations to the data in range of 2.5, 5, 10 and 15% of acceptable yield loss levels. The CPWC was from 1- to 13-leaf stage (2-54 DAE, 3- to 11-leaf stage (10-46 DAE, 5- to 8-leaf stage (20-35 DAE and 6-leaf stage (27 DAE in Esfahan condition to prevent yield losses of 2.5%, 5% , 10% and 15% respectively.

  10. The implementation of a Hazard Analysis and Critical Control Point management system in a peanut butter ice cream plant.

    Science.gov (United States)

    Hung, Yu-Ting; Liu, Chi-Te; Peng, I-Chen; Hsu, Chin; Yu, Roch-Chui; Cheng, Kuan-Chen

    2015-09-01

    To ensure the safety of the peanut butter ice cream manufacture, a Hazard Analysis and Critical Control Point (HACCP) plan has been designed and applied to the production process. Potential biological, chemical, and physical hazards in each manufacturing procedure were identified. Critical control points for the peanut butter ice cream were then determined as the pasteurization and freezing process. The establishment of a monitoring system, corrective actions, verification procedures, and documentation and record keeping were followed to complete the HACCP program. The results of this study indicate that implementing the HACCP system in food industries can effectively enhance food safety and quality while improving the production management. Copyright © 2015. Published by Elsevier B.V.

  11. Expressed breast milk on a neonatal unit: a hazard analysis and critical control points approach.

    Science.gov (United States)

    Cossey, Veerle; Jeurissen, Axel; Thelissen, Marie-José; Vanhole, Chris; Schuermans, Annette

    2011-12-01

    With the increasing use of human milk and growing evidence of the benefits of mother's milk for preterm and ill newborns, guidelines to ensure its quality and safety are an important part of daily practice in neonatal intensive care units. Operating procedures based on hazard analysis and critical control points can standardize the handling of mother's expressed milk, thereby improving nutrition and minimizing the risk of breast milk-induced infection in susceptible newborns. Because breast milk is not sterile, microorganisms can multiply when the milk is not handled properly. Additional exogenous contamination should be prevented. Strict hygiene and careful temperature and time control are important during the expression, collection, transport, storage, and feeding of maternal milk. In contrast to formula milk, no legal standards exist for the use of expressed maternal milk. The need for additional measures, such as bacteriological screening or heat treatment, remains unresolved.

  12. [The Hazard Analysis Critical Control Point approach (HACCP) in meat production].

    Science.gov (United States)

    Berends, B R; Snijders, J M

    1994-06-15

    The Hazard Analysis Critical Control Point (HACCP) approach is a method that could transform the current system of safety and quality assurance of meat into a really effective and flexible integrated control system. This article discusses the origin and the basic principles of the HACCP approach. It also discusses why the implementation of the approach is not as widespread as might be expected. It is concluded that a future implementation of the approach in the entire chain of meat production, i.e. from conception to consumption, is possible. Prerequisites are, however, that scientifically validated risk analyses become available, that future legislation forms a framework that actively supports the approach, and that all parties involved in meat production not only become convinced of the advantages, but also are trained to implement the HACCP approach with insight.

  13. Safety

    CERN Multimedia

    2003-01-01

    Please note that the safety codes A9, A10 AND A11 (ex annexes of SAPOCO/42) entitled respectively "Safety responsibilities in the divisions" "The safety policy committee (SAPOCO) and safety officers' committees" and "Administrative procedure following a serious accident or incident" are available on the web at the following URLs: Code A9: http://edms.cern.ch/document/337016/LAST_RELEASED Code A10: http://edms.cern.ch/document/337019/LAST_RELEASED Code A11: http://edms.cern.ch/document/337026/LAST_RELEASED Paper copies can also be obtained from the TIS divisional secretariat, e-mail: tis.secretariat@cern.ch. TIS Secretariat

  14. Recent development of plasma pollution control technology: a critical review

    Directory of Open Access Journals (Sweden)

    Jen-Shih Chang

    2001-01-01

    Full Text Available Gaseous pollution control, solid and liquid waste treatments have been commercialized based on incineration, catalysis, adsorption, disposal with landfill, etc. More recently technology based on plasmas has become significant due to the advantages such as lower costs, higher treatment and energy efficiencies, smaller space volume, etc. In order to commercialize this new technology, the treatment rate, energy efficiency of treatment, pressure drop of reactor, reusable by-products production rate, must be improved, based on the identifications of major fundamental mechanism of processes, optimizations of reactor, and power supply for an integrated system. In this work, recent development of plasma pollution control technology was critically reviewed and the principle of processes and reactor technologies were outlined. Special attention will be focused on material processing generated pollutants.

  15. SRAM-Based FPGA Systems for Safety-Critical Applications:A Survey on Design Standards and Proposed Methodologies

    Institute of Scientific and Technical Information of China (English)

    Cinzia Bernardeschi; Luca Cassano; Andrea Domenici

    2015-01-01

    As the ASIC design cost becomes affordable only for very large-scale productions, the FPGA technology is currently becoming the leading technology for those applications that require a small-scale production. FPGAs can be considered as a technology crossing between hardware and software. Only a small-number of standards for the design of safety-critical systems give guidelines and recommendations that take the peculiarities of the FPGA technology into consideration. The main contribution of this paper is an overview of the existing design standards that regulate the design and verification of FPGA-based systems in safety-critical application fields. Moreover, the paper proposes a survey of significant published research proposals and existing industrial guidelines about the topic, and collects and reports about some lessons learned from industrial and research pro jects involving the use of FPGA devices.

  16. 77 FR 58567 - Information Collection Activities: Well Control and Production Safety Training, Submitted for...

    Science.gov (United States)

    2012-09-21

    ... of the paperwork requirements in the regulations under Subpart O, ``Well Control and Production... 250, Subpart O, Well Control and Production Safety Training. OMB Control Number: 1014-0008. Abstract... 30 CFR part 250, subpart O, Well Control and Production Safety Training. Responses are mandatory...

  17. Inventory of possible emerging hazards to food safety and an analysis of critical factors

    NARCIS (Netherlands)

    Kleter, G.A.; Poelman, M.; Groot, M.J.; Marvin, H.J.P.

    2006-01-01

    Various recent incidents around food safety issues have led to the establishment of the European Food Safety Authority and its national counterparts in the member states of the European Union. Besides these measures, it is desirable to identify food risks while they are still emerging, i.e. when

  18. Implementation of the Hazard Analysis Critical Control Point (HACCP system to UF white cheese production line

    Directory of Open Access Journals (Sweden)

    Mahmoud El-Hofi

    2010-09-01

    Full Text Available Background. HACCP, or the Hazard Analysis and Critical Control Point System has been recognised as an effective and rational means of assuring food safety from primary production through to final consumption, using a “farm to table” methodology. The application of this preventive oriented approach would give the food producer better control over operation, better manufacturing practices and greater efficiencies, including reduced wastes. Material and methods. The steps taken to put HACCP in place are described and the process was monitored to assess its impact. Assessment of the hygiene quality of the UF white cheese products line before and after HACCP showed an improvement in quality and an overall improvement in the conditions at the company. Results. HACCP was introduced for the in UF White Cheese line at Misr Milk and Food, Mansoura, Egypt, for safe and good quality foods products. All necessary quality control procedures were verified for completeness and to determine if they are being implemented to required standards. A hazard analysis was conducted to identify hazards that may occur in the product cycle, Critical Control Points (CCPs were determined to control the identified hazards. CCP signs were then posted on the factory floor. Critical limits were established at each CCP, corrective actions to be taken when monitoring indicates deviation or loss of control were established. Verification procedures were established to confirm that the HACCP system is working effectively. Documentation concerning all procedures and records was established and integrating HACCP with ISO 9000 under one management system was applied. Conclusions. The HACCP system in this study for UF White Cheese line manufacture is developed step-by-step based on the twelve steps mentioned in the literature review. The prerequisite program was provided to deal with some hazards before the production to simplify the HACCP plan.

  19. Trichinella diagnostics and control: Mandatory and best practices for ensuring food safety

    DEFF Research Database (Denmark)

    Gajadhar, A. A.; Pozio, E.; Gamble, H. R.

    2009-01-01

    in all aspects of a Trichinella diagnostic system is emphasized. It includes the use of international quality standards, test validation and standardization, critical control points, laboratory accreditation, certification of analysts and proficiency testing. Also described, are the roles and locations......Because of its role in human disease, there are increasing global requirements for reliable diagnostic and control methods for Trichinella in food animals to ensure meat safety and to facilitate trade. Consequently, there is a need for standardization of methods, programs, and best practices used...... in various porcine and equine pre- and post-slaughter programs, including farm or herd certification programs is also discussed. A brief review of the effectiveness of meat processing methods, such as freezing, cooking and preserving is provided. The importance of proper quality assurance and its application...

  20. Application of Integrated Verification Approach to FPGA-based Safety-Critical I and C System of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ibrahim; Heo, Gyunyoung [Kyunghee Univ., Yongin (Korea, Republic of); Jung, Jaecheon [KEPCO, Ulsan (Korea, Republic of)

    2016-10-15

    Safety-critical instrumentation and control (I and C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. Generally in FPGA design verification, the designers make use of verification techniques by writing the test benches which involved various stages of verification activities of register-transfer level (RTL), gate-level, and place and route. Writing the test benches is considerably time consuming and require a lot of efforts to achieve a satisfied desire results. Furthermore, performing the verification at each stage is a major bottleneck and demanded much activities and time. In addition, verification is conceivably, the most difficult and complicated aspect of any design. Therefore, in view of these, this work applied an integrated verification approach to the verification of FPGA-based I and C system in NPP that simultaneously verified the whole design modules using MATLAB/Simulink HDL Co-simulation models. Verification is conceivably, the most difficult and complicated aspect of any design, and an FPGA design is not an exception. Therefore, in this work, we introduced and discussed how an application of integrated verification technique to the verification and testing of FPGA-based I and C system design in NPP can facilitate the verification processes, and verify the entire design modules of the system simultaneously using MATLAB/Simulink HDL co-simulation models. In conclusion, the results showed that, the integrated verification approach through MATLAB/Simulink models, if applied to any design to be verified, could speed up the design verification and reduce the V and V tasks.

  1. Stability, Transient Response, Control, and Safety of a High-Power Electric Grid for Turboelectric Propulsion of Aircraft

    Science.gov (United States)

    Armstrong, Michael; Ross, Christine; Phillips, Danny; Blackwelder, Mark

    2013-01-01

    This document contains the deliverables for the NASA Research and Technology for Aerospace Propulsion Systems (RTAPS) regarding the stability, transient response, control, and safety study for a high power cryogenic turboelectric distributed propulsion (TeDP) system. The objective of this research effort is to enumerate, characterize, and evaluate the critical issues facing the development of the N3-X concept aircraft. This includes the proposal of electrical grid architecture concepts and an evaluation of any needs for energy storage.

  2. Devices for the control of electrical safety; Appareils de controle de la securite electrique

    Energy Technology Data Exchange (ETDEWEB)

    Leconte, A.; Kantorowski, B. [Societe Chauvin-Arnoux, 75 - Paris (France)

    2005-02-01

    After a recall of the risks linked with electric currents and of the equipments used to avoid electrical hazards, this article makes a review of the different devices used to control the electrical safety of equipments: ohmmeters for the measurement of the insulation conductivity; ohmmeters for the checking of grounding continuity; ohmmeters for the measurement of loop conductivities; devices for the control of dielectric resistance; devices for the control of the characteristics of differential circuit breakers; permanent controllers of insulation; and multi-purpose testing devices. (J.S.)

  3. Closed-loop prevention and control research of coal mine safety management

    Institute of Scientific and Technical Information of China (English)

    LI Xing-dong; ZHAO Yun-xia; ZHAO Xing-qiang; LU Ying

    2009-01-01

    According to the current problems of safety management processes in coal mine enterprises, we introduced barrel theory to coal mine safety management, con-structed the closed-loop structure of a coal mine safety management system, and pointed out that efficient safety management lies in three factors: safety quality of all of the staff in coal mine enterprises, weak links in security management systems, and co-operation among departments. After conducting detailed analysis of these three factors, we proposed concrete ways of preventing and controlling potential safety hazards during the process of coal mine production.

  4. Critical control points of complementary food preparation and handling in eastern Nigeria.

    Science.gov (United States)

    Ehiri, J. E.; Azubuike, M. C.; Ubbaonu, C. N.; Anyanwu, E. C.; Ibe, K. M.; Ogbonna, M. O.

    2001-01-01

    OBJECTIVE: To investigate microbial contamination and critical control points (CCPs) in the preparation and handling of complementary foods in 120 households in Imo state, Nigeria. METHODS: The Hazard Analysis Critical Control Point (HACCP) approach was used to investigate processes and procedures that contributed to microbial contamination, growth and survival, and to identify points where controls could be applied to prevent or eliminate these microbiological hazards or reduce them to acceptable levels. Food samples were collected and tested microbiologically at different stages of preparation and handling. FINDINGS: During cooking, all foods attained temperatures capable of destroying vegetative forms of food-borne pathogens. However, the risk of contamination increased by storage of food at ambient temperature, by using insufficiently high temperatures to reheat the food, and by adding contaminated ingredients such as dried ground crayfish and soybean powder at stages where no further heat treatment was applied. The purchasing of contaminated raw foodstuffs and ingredients, particularly raw akamu, from vendors in open markets is also a CCP. CONCLUSION: Although an unsafe environment poses many hazards for children's food, the hygienic quality of prepared food can be assured if basic food safety principles are observed. When many factors contribute to food contamination, identification of CCPs becomes particularly important and can facilitate appropriate targeting of resources and prevention efforts. PMID:11417038

  5. Near Critical Catalyst Reactant Branching Processes with Controlled Immigration

    CERN Document Server

    Budhiraja, Amarjit

    2012-01-01

    Near critical catalyst-reactant branching processes with controlled immigration are studied. The reactant population evolves according to a branching process whose branching rate is proportional to the total mass of the catalyst. The bulk catalyst evolution is that of a classical continuous time branching process; in addition there is a specific form of immigration. Immigration takes place exactly when the catalyst population falls below a certain threshold, in which case the population is instantaneously replenished to the threshold. Such models are motivated by problems in chemical kinetics where one wants to keep the level of a catalyst above a certain threshold in order to maintain a desired level of reaction activity. A diffusion limit theorem for the scaled processes is presented, in which the catalyst limit is described through a reflected diffusion, while the reactant limit is a diffusion with coefficients that are functions of both the reactant and the catalyst. Stochastic averaging principles under ...

  6. Control of critical coupling in a coiled coaxial cable resonator.

    Science.gov (United States)

    Huang, Jie; Wei, Tao; Wang, Tao; Fan, Jun; Xiao, Hai

    2014-05-01

    This paper reports a coiled coaxial cable resonator fabricated by cutting a slot in a spring-like coiled coaxial cable to produce a periodic perturbation. Electromagnetic coupling between two neighboring slots was observed. By manipulating the number of slots, critical coupling of the coiled coaxial cable resonator can be well controlled. An ultrahigh signal-to-noise ratio (over 50 dB) at the resonant frequency band was experimentally achieved from a coiled coaxial cable resonator with 38 turns. A theoretic model is developed to understand the device physics. The proposed device can be potentially used as a high quality and flexibly designed band-stop filter or a sensor in structural health monitoring.

  7. Coherent optical control of polarization with a critical metasurface

    Science.gov (United States)

    Kang, Ming; Chong, Y. D.

    2015-10-01

    We present a mechanism by which a metamaterial surface, or metasurface, can act as an ideal phase-controlled rotatable linear polarizer. Using coupled-mode theory and the idea of coherent perfect absorption into auxiliary polarization channels, we show how the losses and near-field couplings on the metasurface can be balanced so that, with equal-power linearly polarized beams incident on each side, varying the relative phase rotates the polarization angles of the output beams while maintaining zero ellipticity. The system can be described by a non-Hermitian effective Hamiltonian which is parity-time (P T ) symmetric, although there is no actual gain present; perfect polarization conversion occurs at the eigenfrequencies of this Hamiltonian, and the polarization rotating behavior occurs at the critical point of its P T -breaking transition.

  8. Formulation of a strategy for monitoring control integrity in critical digital control systems

    Science.gov (United States)

    Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

    1991-01-01

    Advanced aircraft will require flight critical computer systems for stability augmentation as well as guidance and control that must perform reliably in adverse, as well as nominal, operating environments. Digital system upset is a functional error mode that can occur in electromagnetically harsh environments, involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. A strategy is presented for dynamic upset detection to be used in the evaluation of critical digital controllers during the design and/or validation phases of development. Critical controllers must be able to be used in adverse environments that result from disturbances caused by an electromagnetic source such as lightning, high intensity radiated field (HIRF), and nuclear electromagnetic pulses (NEMP). The upset detection strategy presented provides dynamic monitoring of a given control computer for degraded functional integrity that can result from redundancy management errors and control command calculation error that could occur in an electromagnetically harsh operating environment. The use is discussed of Kalman filtering, data fusion, and decision theory in monitoring a given digital controller for control calculation errors, redundancy management errors, and control effectiveness.

  9. 75 FR 69912 - Pipeline Safety: Control Room Management/Human Factors

    Science.gov (United States)

    2010-11-16

    ... Safety: Control Room Management/Human Factors AGENCY: Pipeline and Hazardous Materials Safety..., 2010, PHMSA published a Control Room Management/Human Factors notice of proposed rulemaking (NPRM... to expedite the program implementation deadlines of the Control Room Management/Human Factors rule...

  10. Liquefied Gaseous Fuels Safety and Environmental Control Assessment Program: second status report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-01

    This document is arranged in three volumes and reports on progress in the Liquefied Gaseous Fuels (LGF) Safety and Environmental Control Assessment Program made in fiscal Year (FY)-1979 and early FY-1980. Volume 3 contains reports from 6 government contractors on LPG, anhydrous ammonia, and hydrogen energy systems. Report subjects include: simultaneous boiling and spreading of liquefied petroleum gas (LPG) on water; LPG safety research; state-of-the-art of release prevention and control technology in the LPG industry; ammonia: an introductory assessment of safety and environmental control information; ammonia as a fuel, and hydrogen safety and environmental control assessment.

  11. Safety precautions in atomic pile control (1962); Securite dans le controle des piles atomiques (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1962-07-01

    We have been led to study the problem of safety in atomic pile control as a result of our participation on the one hand in the planning of C.E.A. atomic piles, and on the other hand in the pile safety sub omission considering atomic pile safety of operational or planned C.E.A. piles. We have thus had to consider the wishes occurring in piles during their operation and also their behaviour in the dynamic state The present work deals mainly with the importance of intrinsic safety devices, with the influence of reactivity variations on the power fluctuations during accidental operation, and with the development of robust and reliable safety appliances. The starting p accident has been especially studied both for low-flux piles where a compromise is necessary between the response time of the safety appliances and the statistical fluctuations and for high lux piles where xenon poisoning has an effect on the lower limit of the velocity of reactivity liberation. The desirability has been stressed of automation as a safety factor in atomic pile control. The details required for an understanding of the diagrams of the apparatus are given. (author) [French] Nous avons aborde le probleme de la securite dans le controle des piles atomiques a la suite de notre participation d'une part aux avant rojets de piles atomiques du CE.A. et d'autre part a l'examen au sein de la sous ommission de surete des piles, de la securite des piles du CE.A. en fonctionnement ou en projet. Nous avons ete amenes a nous interesser alors aux risques encourus par les piles pendant leur fonctionnement et par la meme a leur comportement en regime dynamique. Ce travail traite principalement de l'importance des securites intrinseques, de l'influence des variations de reactivite sur les evolutions de puissance en regime d'accident et du developpement d'appareillages de securite robustes et de fonctionnement tres sur. L'accident de demarrage a ete particulierement

  12. Assessment of hygiene standards and Hazard Analysis Critical Control Points implementation on passenger ships.

    Science.gov (United States)

    Mouchtouri, Varavara; Malissiova, Eleni; Zisis, Panagiotis; Paparizou, Evina; Hadjichristodoulou, Christos

    2013-01-01

    The level of hygiene on ferries can have impact on travellers' health. The aim of this study was to assess the hygiene standards of ferries in Greece and to investigate whether Hazard Analysis Critical Control Points (HACCP) implementation contributes to the hygiene status and particularly food safety aboard passenger ships. Hygiene inspections on 17 ferries in Greece were performed using a standardized inspection form, with a 135-point scale. Thirty-four water and 17 food samples were collected and analysed. About 65% (11/17) of ferries were scored with >100 points. Ferries with HACCP received higher scores during inspection compared to those without HACCP (p value hygiene aboard passenger ships.

  13. PENERAPAN SISTEM HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP PADA PROSES PEMBUATAN KERIPIK TEMPE

    Directory of Open Access Journals (Sweden)

    Rahmi Yuniarti

    2015-06-01

    Full Text Available Malang is one of the industrial centers of tempe chips. To maintain the quality and food safety, analysis is required to identify the hazards during the production process. This study was conducted to identify the hazards during the production process of tempe chips and provide recommendations for developing a HACCP system. The phases of production process of tempe chips are started from slice the tempe, move it to the kitchen, coat it with flour dough, fry it in the pan, drain it, package it, and then storage it. There are 3 types of potential hazards in terms of biological, physical, and chemical during the production process. With the CCP identification, there are three processes that have Critical Control Point. There are the process of slicing tempe, immersion of tempe into the flour mixture and draining. Recommendations for the development of HACCP systems include recommendations related to employee hygiene, supporting equipment, 5-S analysis, and the production layout.

  14. 21 CFR 120.8 - Hazard Analysis and Critical Control Point (HACCP) plan.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Hazard Analysis and Critical Control Point (HACCP... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP) SYSTEMS General Provisions § 120.8 Hazard Analysis and Critical Control Point (HACCP) plan. (a) HACCP plan....

  15. Critical Review of Commercial Secondary Lithium-Ion Battery Safety Standards

    Science.gov (United States)

    Jones, Harry P.; Chapin, Thomas, J.; Tabaddor, Mahmod

    2010-09-01

    The development of Li-ion cells with greater energy density has lead to safety concerns that must be carefully assessed as Li-ion cells power a wide range of products from consumer electronics to electric vehicles to space applications. Documented field failures and product recalls for Li-ion cells, mostly for consumer electronic products, highlight the risk of fire, smoke, and even explosion. These failures have been attributed to the occurrence of internal short circuits and the subsequent thermal runaway that can lead to fire and explosion. As packaging for some applications include a large number of cells, the risk of failure is likely to be magnified. To address concerns about the safety of battery powered products, safety standards have been developed. This paper provides a review of various international safety standards specific to lithium-ion cells. This paper shows that though the standards are harmonized on a host of abuse conditions, most lack a test simulating internal short circuits. This paper describes some efforts to introduce internal short circuit tests into safety standards.

  16. Estimation of Remained defects in a Safety-Critical Software using Bayesian Belief Network of Software Development Life Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Jun; Jung, Wondea Jung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Some researchers recognized Bayesian belief network (BBN) method to be a promising method of quantifying software reliability. Brookhaven National Laboratory (BNL) comprehensively reviewed various quantitative software reliability methods to identify the most promising methods for use in probabilistic safety assessments (PSAs) of digital systems of NPPs against a set of the most desirable characteristics developed therein. BBNs are recognized as a promising way of quantifying software reliability and are useful for integrating many aspects of software engineering and quality assurance. The method explicitly incorporates important factors relevant to reliability, such as the quality of the developer, the development process, problem complexity, testing effort, and the operation environment. In this work, a BBN model was developed to estimate the number of remained defects in a safety-critical software based on the quality evaluation of software development life cycle (SDLC). Even though a number of software reliability evaluation methods exist, none of them can be applicable to the safety-critical software in an NPP because software quality in terms of PDF is required for the PSA.

  17. Strategies to control odours in livestock facilities: a critical review

    Directory of Open Access Journals (Sweden)

    Y. Ubeda

    2013-11-01

    Full Text Available Odours generated in livestock buildings constitute one of the most relevant air quality issues of intensive livestock production. Reducing nuisance episodes related to odour exposure is therefore essential for a sustainable livestock production. In this study, the state-of-the-art on odour mitigation techniques in livestock housing is critically reviewed. Scientific advances in the last decade are revised and research needs are also identified. The complex nature of livestock odours is firstly reviewed and examined. Then, the most relevant odour control strategies are analyzed in terms of present knowledge and future needs. The strategies considered are: nutritional strategies, manure additives, building design, air filtration, manure covers, manure treatment systems and windbreaks. Finally, future research needs and priorities when establishing mitigation techniques are identified. Despite important recent advances, there are still some challenges for scientists, producers and regulators, particularly related to field evaluation of odours. Therefore, to control livestock odours effectively, using standardized field assessment techniques will be required. Also, investigating measurement and model errors may be useful to better understand the limitations of the current methods, as well as to identify research priorities.

  18. Machine learning of verifiable classifiers for autonomous control of safety-related systems; Maschinelles Lernen von validierbaren Klassifikatoren zur autonomen Steuerung sicherheitsrelevanter Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Nusser, Sebastian; Kruse, Rudolf [Magdeburg Univ. (Germany). Fakultaet fuer Informatik; Otte, Clemens; Hauptmann, Werner [Siemens AG, Muenchen (Germany). Corporate Technology, Information and Communications, Learning Systems; Leirich, Oskar; Kraetschmer, Manfred [Continental Automotive GmbH, Regensburg (Germany)

    2009-07-01

    In the area of safety-related applications, it is particularly important to make sure that the learned solution is correct within the complete input space. A method for learning classification models is introduced which can also be used for safety-critical control functions. An ensemble of low dimensional submodels is built where each submodel can be interpreted and validated by a domain expert. (orig.)

  19. Postharvest intervention technologies for safety enhancement of meat and meat based products; a critical review.

    Science.gov (United States)

    Sohaib, Muhammad; Anjum, Faqir Muhammad; Arshad, Muhammad Sajid; Rahman, Ubaid Ur

    2016-01-01

    Globally, the demand for safe, healthy and nutritious meat and allied products possesses improved taste with extended shelf life is mounting. Microbial safety is among the imperative challenges that prevails in meat products because they provide an ideal medium for the growth of microorganisms particularly pathogenic bacteria. The incidence of these microbes can result quality deterioration of products leading towards food borne diseases when consumed by peoples. Several preservation technologies like chemical and biological interventions are effective to retard or inactivate the growth of micro-organisms most commonly related to food-borne diseases. Despite these, innovative approaches like hydrostatic pressure processing, active packaging, pulse electric field, hurdle approach and use of natural antimicrobials can be deployed to enhance the safety of meat and meat products. The objective of review is to describe the current approaches and developing technologies for enhancing safety of meat and allied meat products.

  20. Safety Considerations in the Design of Riot-Control Grenades

    Science.gov (United States)

    1982-08-01

    fuze design resulted in injuries to the user, because the user would not maintain the required pressure after removing the safety pin . The grenade...of the M25A2 grenade was the accidental functioning of the grenade with the safety pin intact. If the ferenade was dropped onto a hard surface

  1. Process management - critical safety issues with focus on risk management; Processtyrning - kritiska saekerhetsfraagor med inriktning paa riskhantering

    Energy Technology Data Exchange (ETDEWEB)

    Sanne, Johan M. [Linkoeping Univ. (Sweden). The Tema Inst. - Technology and Social Change

    2005-12-15

    Organizational changes focused on process orientation are taking place among Swedish nuclear power plants, aiming at improving the operation. The Swedish Nuclear Power Inspectorate has identified a need for increased knowledge within the area for its regulatory activities. In order to analyze what process orientation imply for nuclear power plant safety a number of questions must be asked: 1. How is safety in nuclear power production created currently? What significance does the functional organization play? 2. How can organizational forms be analysed? What consequences does quality management have for work and for the enterprise? 3. Why should nuclear power plants be process oriented? Who are the customers and what are their customer values? Which customers are expected to contribute from process orientation? 4. What can one learn from process orientation in other safety critical systems? What is the effect on those features that currently create safety? 5. Could customer values increase for one customer without decreasing for other customers? What is the relationship between economic and safety interests from an increased process orientation? The deregulation of the electricity market have caused an interest in increased economic efficiency, which is the motivation for the interest in process orientation. among other means. It is the nuclear power plants' owners and the distributors (often the same corporations) that have the strongest interest in process orientation. If the functional organization and associated practices are decomposed, the prerequisites of the risk management regime changes, perhaps deteriorating its functionality. When nuclear power operators consider the introduction of process orientation, the Nuclear Power Inspectorate should require that 1. The operators perform a risk analysis beforehand concerning the potential consequences that process orientation might convey: the analysis should contain a model specifying how safety is currently

  2. Controlling Factors of Cell Design on Large-format Li-ion Battery Safety During Nail Penetration

    Directory of Open Access Journals (Sweden)

    Qing eWang

    2015-08-01

    Full Text Available In this paper we investigate the controlling design parameters of large-format Li-ion batteries on safety while undergoing nail penetration. We have identified three critical design parameters that control the safety during the nail penetration process: nail diameter, single sheet foil area, and cell capacity.Using commercial AutoLion software, we have investigated two typical design problems related to the selection of cell thickness and aspect ratio, namely: (1 the safety ramifications of increasing cell capacity via greater cell thickness for a fixed footprint, and (2 the effect of aspect ratio, or single sheet foil size, on safety at a given capacity. For a fixed footprint, our results indicate that the safety of the cell can be predicted by (Qcell Dnail^-0.5. For a given cell capacity, our results indicate that typically a larger single sheet foil area leads to a greater likelihood for thermal runaway due to its effect of making the heating more local in nature; however, for small cells (~ 5Ah and large nails (~ 20mm, the greater aspect ratio can lead to a safer cell, as the greater surface area strongly cools the global heating of the cell.

  3. Design optimization for security-and safety-critical distributed real-time applications

    DEFF Research Database (Denmark)

    Jiang, Wei; Pop, Paul; Jiang, Ke

    2016-01-01

    In this paper, we are interested in the design of real-time applications with security, safety, timing, and energy requirements. The applications are scheduled with cyclic scheduling, and are mapped on distributed heterogeneous architectures. Cryptographic services are deployed to satisfy securit...

  4. Reaping the Benefits of Task Conflict in Teams: The Critical Role of Team Psychological Safety Climate

    Science.gov (United States)

    Bradley, Bret H.; Postlethwaite, Bennett E.; Klotz, Anthony C.; Hamdani, Maria R.; Brown, Kenneth G.

    2012-01-01

    Past research suggests that task conflict may improve team performance under certain conditions; however, we know little about these specific conditions. On the basis of prior theory and research on conflict in teams, we argue that a climate of psychological safety is one specific context under which task conflict will improve team performance.…

  5. Public Safety Transmitter Towers, Public safety towers controlled by the FCC and combined with all other types of towers., Published in 2006, Johnson County AIMS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Public Safety Transmitter Towers dataset, was produced all or in part from Other information as of 2006. It is described as 'Public safety towers controlled by...

  6. Design verification enhancement of field programmable gate array-based safety-critical I&C system of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ibrahim [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of); Jung, Jaecheon, E-mail: jcjung@kings.ac.kr [Department of Nuclear Power Plant Engineering, KEPCO International Nuclear Graduate School, 658-91 Haemaji-ro, Seosang-myeon, Ulju-gun, Ulsan 45014 (Korea, Republic of); Heo, Gyunyoung [Department of Nuclear Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of)

    2017-06-15

    Highlights: • An enhanced, systematic and integrated design verification approach is proposed for V&V of FPGA-based I&C system of NPP. • RPS bistable fixed setpoint trip algorithm is designed, analyzed, verified and discussed using the proposed approaches. • The application of integrated verification approach simultaneously verified the entire design modules. • The applicability of the proposed V&V facilitated the design verification processes. - Abstract: Safety-critical instrumentation and control (I&C) system in nuclear power plant (NPP) implemented on programmable logic controllers (PLCs) plays a vital role in safe operation of the plant. The challenges such as fast obsolescence, the vulnerability to cyber-attack, and other related issues of software systems have currently led to the consideration of field programmable gate arrays (FPGAs) as an alternative to PLCs because of their advantages and hardware related benefits. However, safety analysis for FPGA-based I&C systems, and verification and validation (V&V) assessments still remain important issues to be resolved, which are now become a global research point of interests. In this work, we proposed a systematic design and verification strategies from start to ready-to-use in form of model-based approaches for FPGA-based reactor protection system (RPS) that can lead to the enhancement of the design verification and validation processes. The proposed methodology stages are requirement analysis, enhanced functional flow block diagram (EFFBD) models, finite state machine with data path (FSMD) models, hardware description language (HDL) code development, and design verifications. The design verification stage includes unit test – Very high speed integrated circuit Hardware Description Language (VHDL) test and modified condition decision coverage (MC/DC) test, module test – MATLAB/Simulink Co-simulation test, and integration test – FPGA hardware test beds. To prove the adequacy of the proposed

  7. 76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

    Science.gov (United States)

    2011-01-03

    ... posted speed limit of 55 mph that was in effect in 1991. \\2\\ Comercial Motor Vehicle Speed Control... improved truck designs. \\3\\ Comercial Motor Vehicle Speed Control Devices (1991), DOT HS 807 725. TCA... National Highway Traffic Safety Administration 49 CFR Part 571 Federal Motor Vehicle Safety Standard...

  8. Selecting an Architecture for a Safety-Critical Distributed Computer System with Power, Weight and Cost Considerations

    Science.gov (United States)

    Torres-Pomales, Wilfredo

    2014-01-01

    This report presents an example of the application of multi-criteria decision analysis to the selection of an architecture for a safety-critical distributed computer system. The design problem includes constraints on minimum system availability and integrity, and the decision is based on the optimal balance of power, weight and cost. The analysis process includes the generation of alternative architectures, evaluation of individual decision criteria, and the selection of an alternative based on overall value. In this example presented here, iterative application of the quantitative evaluation process made it possible to deliberately generate an alternative architecture that is superior to all others regardless of the relative importance of cost.

  9. Safety Margins in Older Adults Increase with Improved Control of a Dynamic Object

    Directory of Open Access Journals (Sweden)

    Christopher James Hasson

    2014-07-01

    Full Text Available Older adults face decreasing motor capabilities due to pervasive neuromuscular degradations. As a consequence errors in movement control increase. Thus, older individuals should maintain larger safety margins than younger adults. While this has been shown for object manipulation tasks, several reports on whole-body activities, such as posture and locomotion, however demonstrate age-related reductions in safety margins. This is despite increased costs for control errors, such as a fall. We posit that this paradox could be explained by the dynamic challenge presented by the body or an external object, and that age-related reductions in safety margins are in part due to a decreased ability to control dynamics. To test this conjecture we used a virtual ball-in-cup task that had challenging dynamics, yet afforded an explicit rendering of the physics and safety margin. The hypotheses were: 1 When manipulating an object with challenging dynamics, older adults have smaller safety margins than younger adults. 2 Older adults increase their safety margins with practice. Nine young and 10 healthy older adults practiced moving the virtual ball-in-cup to a target location in exactly two seconds. The accuracy and precision of the timing error quantified skill and the ball energy relative to an escape threshold quantified the safety margin. Compared to the young adults, older adults had increased timing errors, greater variability, and decreased safety margins. With practice, both young and older adults improved their ability to control the object with decreased timing errors and variability, and increased their safety margins. These results suggest that safety margins are related to the ability to control dynamics, and may explain why in tasks with simple dynamics older adults use adequate safety margins, but in more complex tasks, safety margins may be inadequate. Further, the results indicate that task-specific training may improve safety margins in older

  10. [A regular internal auditing and registration of critical incidents regarded as safety maintenance elements within the anesthetic management of patients].

    Science.gov (United States)

    Vinogradov, V L; Likhvantsev, V V; Alekseev, A A

    2004-01-01

    The paper summarizes a 5-year experience of evaluating the safety of anesthetic management of patients with thermal lesions treated at the department of thermal lesions of Vishnevsky's Institute of Surgery, Russia's Academy of Medical Sciences. Regular internal auditings, based on the principles of registering the critical incidents, the course of 1473 general anesthesia managements was analyzed in 168 patients. The conclusion is that the introduction of protocols of anesthetic management as well as a regular monitoring over meeting the fixed targets cut the total frequency of critical incidents from 2.85 to 1.19 as estimated per one general anesthesia. Finally the authors suggest a concept whose essence in that the operation of the modern anesthesiology department must be based on a scientifically substantiated technology of anesthetic management.

  11. The efficacy and safety of bromacil based herbicide for the control of ...

    African Journals Online (AJOL)

    The efficacy and safety of bromacil based herbicide for the control of the invasive bush species ... rangelands and reduce cost and drudgery associated with other methods of bush control. ... DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT ...

  12. Risk-Based Predictive Maintenance for Safety-Critical Systems by Using Probabilistic Inference

    Directory of Open Access Journals (Sweden)

    Tianhua Xu

    2013-01-01

    Full Text Available Risk-based maintenance (RBM aims to improve maintenance planning and decision making by reducing the probability and consequences of failure of equipment. A new predictive maintenance strategy that integrates dynamic evolution model and risk assessment is proposed which can be used to calculate the optimal maintenance time with minimal cost and safety constraints. The dynamic evolution model provides qualified risks by using probabilistic inference with bucket elimination and gives the prospective degradation trend of a complex system. Based on the degradation trend, an optimal maintenance time can be determined by minimizing the expected maintenance cost per time unit. The effectiveness of the proposed method is validated and demonstrated by a collision accident of high-speed trains with obstacles in the presence of safety and cost constrains.

  13. An Introduction to Formal Methods for the Development of Safety-critical Applications

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth

    2010-01-01

    is assumed to have some knowledge about software development, but not on formal methods. The background for the railway authorities’ interest in formal methods is the fact that during the next decade a total renewal of the Danish signalling infrastructure is going to take place. Central parts of the new......This report is a delivery to The Danish Government’s railway authority, Trafikstyrelsen, as a part of the Public Sector Consultancy service offered by the Technical University of Denmark. The purpose of the report is to give the reader an insight into the stateof-the-art of formal methods. The reader...... systems will be software components that must fulfill strong safety requirements: in order to get the software certified at the highest Safety Integrity Levels of the European CENELEC standards for railway applications, the software providers are expected to use formal methods....

  14. Does assisted driving behavior lead to safety-critical encounters with unequipped vehicles' drivers?

    Science.gov (United States)

    Preuk, Katharina; Stemmler, Eric; Schießl, Caroline; Jipp, Meike

    2016-10-01

    With Intelligent Transport Systems (e.g., traffic light assistance systems) assisted drivers are able to show driving behavior in anticipation of upcoming traffic situations. In the years to come, the penetration rate of such systems will be low. Therefore, the majority of vehicles will not be equipped with these systems. Unequipped vehicles' drivers may not expect the driving behavior of assisted drivers. However, drivers' predictions and expectations can play a significant role in their reaction times. Thus, safety issues could arise when unequipped vehicles' drivers encounter driving behavior of assisted drivers. This is why we tested how unequipped vehicles' drivers (N=60) interpreted and reacted to the driving behavior of an assisted driver. We used a multi-driver simulator with three drivers. The three drivers were driving in a line. The lead driver in the line was a confederate who was followed by two unequipped vehicles' drivers. We varied the equipment of the confederate with an Intelligent Transport System: The confederate was equipped either with or without a traffic light assistance system. The traffic light assistance system provided a start-up maneuver before a light turned green. Therefore, the assisted confederate seemed to show unusual deceleration behavior by coming to a halt at an unusual distance from the stop line at the red traffic light. The unusual distance was varied as we tested a moderate (4m distance from the stop line) and an extreme (10m distance from the stop line) parameterization of the system. Our results showed that the extreme parametrization resulted in shorter minimal time-to-collision of the unequipped vehicles' drivers. One rear-end crash was observed. These results provided initial evidence that safety issues can arise when unequipped vehicles' drivers encounter assisted driving behavior. We recommend that future research identifies counteractions to prevent these safety issues. Moreover, we recommend that system developers

  15. Four Pillars for Improving the Quality of Safety-Critical Software-Reliant Systems

    Science.gov (United States)

    2013-04-01

    the use of ISO 9001 /CMMI®,1 the suite of ISO -IEC SC 7 process standards, and standards and practices specific to the certification of safety...Carnegie Mellon University. 2 ISO , International Organization for Standardization; ISO -IEC SC 7, ISO -International Electro technical Commission...Ellison 2008]). International Standards Organization ( ISO ) stand- ard (15026-2) for assurance cases is now under development. The U.S. Food and Drug

  16. An Economic Evaluation of Food Safety Education Interventions: Estimates and Critical Data Gaps.

    Science.gov (United States)

    Zan, Hua; Lambea, Maria; McDowell, Joyce; Scharff, Robert L

    2017-08-01

    The economic evaluation of food safety interventions is an important tool that practitioners and policy makers use to assess the efficacy of their efforts. These evaluations are built on models that are dependent on accurate estimation of numerous input variables. In many cases, however, there is no data available to determine input values and expert opinion is used to generate estimates. This study uses a benefit-cost analysis of the food safety component of the adult Expanded Food and Nutrition Education Program (EFNEP) in Ohio as a vehicle for demonstrating how results based on variable values that are not objectively determined may be sensitive to alternative assumptions. In particular, the focus here is on how reported behavioral change is translated into economic benefits. Current gaps in the literature make it impossible to know with certainty how many people are protected by the education (what are the spillover effects?), the length of time education remains effective, and the level of risk reduction from change in behavior. Based on EFNEP survey data, food safety education led 37.4% of participants to improve their food safety behaviors. Under reasonable default assumptions, benefits from this improvement significantly outweigh costs, yielding a benefit-cost ratio of between 6.2 and 10.0. Incorporation of a sensitivity analysis using alternative estimates yields a greater range of estimates (0.2 to 56.3), which highlights the importance of future research aimed at filling these research gaps. Nevertheless, most reasonable assumptions lead to estimates of benefits that justify their costs.

  17. Food safety controls in different governance structures in China’s vegetable and fruit industry

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie-hong; LI Kai; LIANG Qiao

    2015-01-01

    Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by ifrms with different governance structures in China. Food safety control is expressed by the folowing aspects, i.e., polution-free, green, organic, and/or geographical indication prod-ucts certiifcation, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most ifrms, folowed by products certiifcation, and production records are adopted by the fewest ifrms, and (2) agricul-tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.

  18. Quality and Safety in Orthopaedics: Learning and Teaching at the Same Time: AOA Critical Issues.

    Science.gov (United States)

    Black, Kevin P; Armstrong, April D; Hutzler, Lorraine; Egol, Kenneth A

    2015-11-04

    Increasing attention has been placed on providing higher quality and safer patient care. This requires the development of a new set of competencies to better understand and navigate the system and lead the orthopaedic team. While still trying to learn and develop these competencies, the academic orthopaedist is also expected to model and teach them.The orthopaedic surgeon must understand what is being measured and why, both for purposes of providing better care and to eliminate unnecessary expense in the system. Metrics currently include hospital-acquired conditions, "never events," and thirty-day readmission rates. More will undoubtedly follow.Although commitment and excellence at the individual level are essential, the orthopaedist must think at the systems level to provide the highest value of care. A work culture characterized by respect and trust is essential to improved communication, teamwork, and confidential peer review. An increasing number of resources, both in print and electronic format, are available for us to understand what we can do now to improve quality and safety.Resident education in quality and safety is a fundamental component of the systems-based practice competency, the Next Accreditation System, and the Clinical Learning Environment Review. This needs to be longitudinally integrated into the curriculum and applied parallel to the development of resident knowledge and skill, and will be best learned if resident learning is experiential and taught within a genuine culture of quality and safety. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

  19. Efficient integration of secure and safety critical industrial wireless sensor networks

    Directory of Open Access Journals (Sweden)

    Björkman Mats

    2011-01-01

    Full Text Available Abstract Wireless communication has gained more interest in industrial automation due to flexibility, mobility, and cost reduction. Wireless systems, in general, require additional and different engineering and maintenance tasks, for example cryptographic key management. This is an important aspect that needs to be addressed before wireless systems can be deployed and maintained efficiently in the industry. In this paper, we take an holistic approach that addresses safety and security regardless of the underlying media. In our proposed framework we introduce security modules which can be retrofitted to provide end-to-end integrity and authentication measures by utilizing the black channel concept. With the proposed approach, we can extend and provide end-to-end security as well as functional safety using existing automation equipment and standards, such as Profisafe, Profinet IO, and WirelessHART. Furthermore, we improve the WirelessHART standard with periodic and deterministic downlink transmissions to enable efficient usage of wireless actuators, as well as improving the performance of functional safety protocols.

  20. Can the Hazard Assessment and Critical Control Points (HACCP) system be used to design process-based hygiene concepts?

    Science.gov (United States)

    Hübner, N-O; Fleßa, S; Haak, J; Wilke, F; Hübner, C; Dahms, C; Hoffmann, W; Kramer, A

    2011-01-01

    Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible and will probably not readily yield the intended results, the underlying principles of process-orientation, in-process safety control and hazard analysis based counter measures are transferable to clinical settings. In model projects the proposed concepts should be implemented, monitored, and evaluated under real world conditions.

  1. A critical appraisal of the misoprostol removable, controlled-release vaginal delivery system of labor induction

    Directory of Open Access Journals (Sweden)

    Patte C

    2015-11-01

    Full Text Available Charlotte Patte,1 Philippe Deruelle1,21Lille University Hospital, Jeanne De Flandre Maternity, 2UPRES EA 4489, Environnement périnatal et santé, Faculté de médecine Henri Warembourg, Université Lille 2, Lille, France Background: Induction of labor is a major issue in pregnancy management. Finding strategies to increase rate and decrease time to vaginal delivery is an important goal, but maternal or neonatal safety must remain the primary objective. Misoprostol is a synthetic analogue of prostaglandin used off label to ripen the cervix and induce labor. The misoprostol vaginal insert (MVI was designed to allow a controlled-release delivery of misoprostol (from 50 to 200 µg with a removal tape. The objective of this review was to make a critical appraisal of this device referring to the literature.Methods: A literature search was performed in the PubMed and Cochrane databases using the keywords “vaginal misoprostol insert”.Results: Several studies compared different doses of MVI (50, 100, 150, and 200 µg with the 10 mg dinoprostone insert. The 100 µg MVI compared with the dinoprostone vaginal insert (DVI showed similar efficacy and no significant differences in cesarean delivery rate. MVI 200 µg compared with DVI showed a reduced time to vaginal delivery and oxytocin need but had an increased risk of uterine hyperstimulation. The rate of hyperstimulation syndrome was two to three times more frequent with the 200 µg MVI than the 100 µg.Conclusion: Current data suggest that the 100 µg MVI would provide the best balance between efficacy and safety. Further studies should be performed to evaluate this dose, especially in high-risk situations needing induction of labor. Keywords: prostaglandins, efficacy, safety, pregnancy 

  2. Challenging Popular Media's Control by Teaching Critical Viewing.

    Science.gov (United States)

    Couch, Richard A.

    The purpose of this paper is to express the importance of visual/media literacy and the teaching of critical television viewing. An awareness of the properties and characteristics of television--including camera angles and placement, editing, and emotionally involving subject matter--aids viewers in the critical viewing process. The knowledge of…

  3. Safety of Animal Fats for Biodiesel Production: A Critical Review of Literature

    Energy Technology Data Exchange (ETDEWEB)

    Greene, A.; Dawson, P.; Nixon, D.; Atkins, J.; Pearl, G. [Clemson University, SC (United States)

    2007-05-15

    An in-depth review of available literature was conducted on the safety of using animal fats for biodiesel. The review indicated little or no known risk to human and animal health and to the environment relative to inherent microbial, organic or inorganic agents in animal fats destined for biodiesel production. Animal by-products are generated from the inedible tissues derived from meat, poultry and fish production. This material is thermally processed by the rendering industry to generate a number of industrial materials including use of the fat portion to produce biodiesel. As the biodiesel industry continues to develop, questions have emerged about the safety of animal versus vegetable fats for biodiesel production and utilization. The following report is the result of a detailed literature search into the potential microbial, organic, and inorganic contaminants that may be present in animal fats and the potential for human or environmental safety issues associated with each. The potential safety risks associated with prions are discussed in a separate report, 'Biodiesel from Specified Risk Material Tallow: An Appraisal of TSE Risks and their Reduction'. In certain instances, very little was reported about the potential contaminating moiety and its fate in biodiesel production and usage. Establishing an absolute zero risk assessment is impossible on any fat utilized for biodiesel production. Among the potential microbial contaminants, bacteria, viruses, fungi, yeast, parasites, and microbial toxins were considered. In each instance, the nature of the production process and usage of biodiesel via combustion reduce the possibility that microbial contaminants would be a cause for concern to humans, animals, or the environment. Potential organic moieties contaminating the fat should meet a similar fate. Current evidence suggests that metals and metalloids within animal fats will not cause significant safety issues in the production and use of rendered fat

  4. Applicability of the SCALE code system to MOX fuel transport systems for criticality safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Toshihiro; Naito, Yoshitaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Hayashi, Toshiaki; Takasugi, Masahiro; Natsume, Toshihiro; Tsuda, Kazuaki

    1996-11-01

    In order to ascertain feasibilities of the SCALE code system for MOX fuel transport systems, criticality analyses were performed for MOX fuel (Pu enrichment; 3.0 wt.%) criticality experiments at JAERI`s TCA and for infinite fuel rod arrays as parameters of Pu enrichment and lattice pitch. The comparison with a combination of the continuous energy Monte Carlo code MCNP and JENDL-3.2 indicated that the SCALE code system with GAM-THERMOS 123-group library can produce feasible results. Though HANSEN-ROACH 16-group library gives poorer results for MOS fuel transport systems, the errors are conservative except for high enriched fuels. (author)

  5. Second pilot trials of the STAR-Liege protocol for tight glycemic control in critically ill patients

    Directory of Open Access Journals (Sweden)

    Penning Sophie

    2012-08-01

    Full Text Available Abstract Background Critically ill patients often present increased insulin resistance and stress-induced hyperglycemia. Tight glycemic control aims to reduce blood glucose (BG levels and variability while ensuring safety from hypoglycemia. This paper presents the results of the second Belgian clinical trial using the customizable STAR framework in a target-to-range control approach. The main objective is reducing measurement frequency while maintaining performance and safety of the glycemic control. Methods The STAR-Liege 2 (SL2 protocol targeted the 100–140 mg/dL glycemic band and offered 2-hourly and 3-hourly interventions. Only insulin rates were adjusted, and nutrition inputs were left to the attending clinicians. This protocol restricted the forecasted risk of BG  Results During the SL2 trial, 91 measurements were taken over 194 hours. BG levels were tightly distributed: 54.9% of BG within 100–140 mg/dL, 40.7% were ≥ 140 mg/dL and 4.4% were  0.05 with significantly reduced measurement frequency for SL2 (p  Conclusions The SL2 protocol succeeded in reducing clinical workload while maintaining safety and effectiveness of the glycemic control. SL2 was also shown to be safer and tighter than hospital control. Overall results validate the efficacy of significantly customizing the STAR framework.

  6. INTEGRAL BENCHMARKS AVAILABLE THROUGH THE INTERNATIONAL REACTOR PHYSICS EXPERIMENT EVALUATION PROJECT AND THE INTERNATIONAL CRITICALITY SAFETY BENCHMARK EVALUATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    J. Blair Briggs; Lori Scott; Enrico Sartori; Yolanda Rugama

    2008-09-01

    Interest in high-quality integral benchmark data is increasing as efforts to quantify and reduce calculational uncertainties accelerate to meet the demands of next generation reactor and advanced fuel cycle concepts. The International Reactor Physics Experiment Evaluation Project (IRPhEP) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) continue to expand their efforts and broaden their scope to identify, evaluate, and provide integral benchmark data for method and data validation. Benchmark model specifications provided by these two projects are used heavily by the international reactor physics, nuclear data, and criticality safety communities. Thus far, 14 countries have contributed to the IRPhEP, and 20 have contributed to the ICSBEP. The status of the IRPhEP and ICSBEP is discussed in this paper, and the future of the two projects is outlined and discussed. Selected benchmarks that have been added to the IRPhEP and ICSBEP handbooks since PHYSOR’06 are highlighted, and the future of the two projects is discussed.

  7. Determination of the critical period of weed control in corn using a thermal basis.

    OpenAIRE

    BEDMAR,FRANCISCO; Manetti,Pablo; MONTERUBBIANESI,GLORIA

    1999-01-01

    Field studies were conducted over 3 years in southeast Buenos Aires, Argentina, to determine the critical period of weed control in maize (Zea mays L.). The treatments consisted of two different periods of weed interference, a critical weed-free period, and a critical time of weed removal. The Gompertz and logistic equations were fitted to relative yields representing the critical weed-free and the critical time of weed removal, respectively. Accumulated thermal units were used to describe ea...

  8. In-Situ Radiological Surveys to Address Nuclear Criticality Safety Requirements During Remediation Activities at the Shallow Land Disposal Area, Armstrong County, Pennsylvania - 12268

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Phillip; Mihalo, Mark; Eberlin, John; Lambert, Mike [Cabrera Services (United States); Matthews, Brian [Nuclear Safety Associates (United States)

    2012-07-01

    Cabrera Services Inc. (CABRERA) is the remedial contractor for the Shallow Land Disposal Area (SLDA) Site in Armstrong County Pennsylvania, a United States (US) Army Corps of Engineers - Buffalo District (USACE) contract. The remediation is being completed under the USACE's Formerly Utilized Sites Remedial Action Program (FUSRAP) which was established to identify, investigate, and clean up or control sites previously used by the Atomic Energy Commission (AEC) and its predecessor, the Manhattan Engineer District (MED). As part of the management of the FUSRAP, the USACE is overseeing investigation and remediation of radiological contamination at the SLDA Site in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 US Code (USC), Section 9601 et. seq, as amended and, the National Oil and Hazardous Substance Pollution Contingency Plan (NCP), Title 40 of the Code of Federal Regulations (CFR) Section 300.430(f) (2). The objective of this project is to clean up radioactive waste at SLDA. The radioactive waste contains special nuclear material (SNM), primarily U-235, in 10 burial trenches, Cabrera duties include processing, packaging and transporting the waste to an offsite disposal facility in accordance with the selected remedial alternative as defined in the Final Record of Decision (USACE, 2007). Of particular importance during the remediation is the need to address nuclear criticality safety (NCS) controls for the safe exhumation and management of waste containing fissile materials. The partnership between Cabrera Services, Inc. and Measutronics Corporation led to the development of a valuable survey tool and operating procedure that are essential components of the SLDA Criticality Safety and Material Control and Accountability programs. Using proven existing technologies in the design and manufacture of the Mobile Survey Cart, the continued deployment of the Cart will allow for an efficient and reliable

  9. Critical review of the reactor-safety study radiological health effects model. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, D.W.; Evans, J.S.; Jacob, N.; Kase, K.R.; Maletskos, C.J.; Robertson, J.B.; Smith, D.G.

    1983-03-01

    This review of the radiological health effects models originally presented in the Reactor Safety Study (RSS) and currently used by the US Nuclear Regulatory Commission (NRC) was undertaken to assist the NRC in determining whether or not to revise the models and to aid in the revision, if undertaken. The models as presented in the RSS and as implemented in the CRAC (Calculations of Reactor Accident Consequences) Code are described and critiqued. The major elements analyzed are those concerning dosimetry, early effects, and late effects. The published comments on the models are summarized, as are the important findings since the publication of the RSS.

  10. Nuclear Safety Functions of ITER Gas Injection System Instrumentation and Control and the Concept Design

    Science.gov (United States)

    Yang, Yu; Maruyama, S.; Fossen, A.; Villers, F.; Kiss, G.; Zhang, Bo; Li, Bo; Jiang, Tao; Huang, Xiangmei

    2016-08-01

    The ITER Gas Injection System (GIS) plays an important role on fueling, wall conditioning and distribution for plasma operation. Besides that, to support the safety function of ITER, GIS needs to implement three nuclear safety Instrumentation and Control (I&C) functions. In this paper, these three functions are introduced with the emphasis on their latest safety classifications. The nuclear I&C design concept is briefly discussed at the end.

  11. Risk-Informed Safety Assurance and Probabilistic Assessment of Mission-Critical Software-Intensive Systems

    Science.gov (United States)

    Guarro, Sergio B.

    2010-01-01

    This report validates and documents the detailed features and practical application of the framework for software intensive digital systems risk assessment and risk-informed safety assurance presented in the NASA PRA Procedures Guide for Managers and Practitioner. This framework, called herein the "Context-based Software Risk Model" (CSRM), enables the assessment of the contribution of software and software-intensive digital systems to overall system risk, in a manner which is entirely compatible and integrated with the format of a "standard" Probabilistic Risk Assessment (PRA), as currently documented and applied for NASA missions and applications. The CSRM also provides a risk-informed path and criteria for conducting organized and systematic digital system and software testing so that, within this risk-informed paradigm, the achievement of a quantitatively defined level of safety and mission success assurance may be targeted and demonstrated. The framework is based on the concept of context-dependent software risk scenarios and on the modeling of such scenarios via the use of traditional PRA techniques - i.e., event trees and fault trees - in combination with more advanced modeling devices such as the Dynamic Flowgraph Methodology (DFM) or other dynamic logic-modeling representations. The scenarios can be synthesized and quantified in a conditional logic and probabilistic formulation. The application of the CSRM method documented in this report refers to the MiniAERCam system designed and developed by the NASA Johnson Space Center.

  12. Control of Listeria species food safety at a poultry food production facility.

    Science.gov (United States)

    Fox, Edward M; Wall, Patrick G; Fanning, Séamus

    2015-10-01

    Surveillance and control of food-borne human pathogens, such as Listeria monocytogenes, is a critical aspect of modern food safety programs at food production facilities. This study evaluated contamination patterns of Listeria species at a poultry food production facility, and evaluated the efficacy of procedures to control the contamination and transfer of the bacteria throughout the plant. The presence of Listeria species was studied along the production chain, including raw ingredients, food-contact, non-food-contact surfaces, and finished product. All isolates were sub-typed by pulsed-field gel electrophoresis (PFGE) to identify possible entry points for Listeria species into the production chain, as well as identifying possible transfer routes through the facility. The efficacy of selected in-house sanitizers against a sub-set of the isolates was evaluated. Of the 77 different PFGE-types identified, 10 were found among two or more of the five categories/areas (ingredients, food preparation, cooking and packing, bulk packing, and product), indicating potential transfer routes at the facility. One of the six sanitizers used was identified as unsuitable for control of Listeria species. Combining PFGE data, together with information on isolate location and timeframe, facilitated identification of a persistent Listeria species contamination that had colonized the facility, along with others that were transient.

  13. Dependability analysis of a safety critical system the LHC beam dumping system at CERN

    CERN Document Server

    Filippini, R

    2006-01-01

    This thesis presents the dependability study of the Beam Dumping System of the Large Hadron Collider (LHC), the high energy particle accelerator to be commissioned at CERN in summer 2007. There are two identical, independent LHC Beam Dumping Systems (LBDS), one per LHC beam, each consisting of a series of magnets that extract the particle beam from the LHC ring into the extraction line leading to the absorbing block. The consequences of a failure within the LBDS can be very severe. This risk is reduced by applying redundancy to the design of the most critical components and on-line surveillance that, in case of a detected failure, issues a safe operation abort, called false beam dump. The system has been studied applying Failure Modes Effects and Criticality Analysis (FMECA) and reliability prediction. The system failure processes have been represented with a state transition diagram, governed by a Markov regenerative stochastic process, and analysed for different operational scenarios for one year of operati...

  14. SAFETY

    CERN Multimedia

    M. Plagge, C. Schaefer and N. Dupont

    2013-01-01

    Fire Safety – Essential for a particle detector The CMS detector is a marvel of high technology, one of the most precise particle measurement devices we have built until now. Of course it has to be protected from external and internal incidents like the ones that can occur from fires. Due to the fire load, the permanent availability of oxygen and the presence of various ignition sources mostly based on electricity this has to be addressed. Starting from the beam pipe towards the magnet coil, the detector is protected by flooding it with pure gaseous nitrogen during operation. The outer shell of CMS, namely the yoke and the muon chambers are then covered by an emergency inertion system also based on nitrogen. To ensure maximum fire safety, all materials used comply with the CERN regulations IS 23 and IS 41 with only a few exceptions. Every piece of the 30-tonne polyethylene shielding is high-density material, borated, boxed within steel and coated with intumescent (a paint that creates a thick co...

  15. SAFETY

    CERN Multimedia

    C. Schaefer and N. Dupont

    2013-01-01

      “Safety is the highest priority”: this statement from CERN is endorsed by the CMS management. An interpretation of this statement may bring you to the conclusion that you should stop working in order to avoid risks. If the safety is the priority, work is not! This would be a misunderstanding and misinterpretation. One should understand that “working safely” or “operating safely” is the priority at CERN. CERN personnel are exposed to different hazards on many levels on a daily basis. However, risk analyses and assessments are done in order to limit the number and the gravity of accidents. For example, this process takes place each time you cross the road. The hazard is the moving vehicle, the stake is you and the risk might be the risk of collision between both. The same principle has to be applied during our daily work. In particular, keeping in mind the general principles of prevention defined in the late 1980s. These principles wer...

  16. Finite-horizon control-constrained nonlinear optimal control using single network adaptive critics.

    Science.gov (United States)

    Heydari, Ali; Balakrishnan, Sivasubramanya N

    2013-01-01

    To synthesize fixed-final-time control-constrained optimal controllers for discrete-time nonlinear control-affine systems, a single neural network (NN)-based controller called the Finite-horizon Single Network Adaptive Critic is developed in this paper. Inputs to the NN are the current system states and the time-to-go, and the network outputs are the costates that are used to compute optimal feedback control. Control constraints are handled through a nonquadratic cost function. Convergence proofs of: 1) the reinforcement learning-based training method to the optimal solution; 2) the training error; and 3) the network weights are provided. The resulting controller is shown to solve the associated time-varying Hamilton-Jacobi-Bellman equation and provide the fixed-final-time optimal solution. Performance of the new synthesis technique is demonstrated through different examples including an attitude control problem wherein a rigid spacecraft performs a finite-time attitude maneuver subject to control bounds. The new formulation has great potential for implementation since it consists of only one NN with single set of weights and it provides comprehensive feedback solutions online, though it is trained offline.

  17. Digital System Reliability Test for the Evaluation of safety Critical Software of Digital Reactor Protection System

    Directory of Open Access Journals (Sweden)

    Hyun-Kook Shin

    2006-08-01

    Full Text Available A new Digital Reactor Protection System (DRPS based on VME bus Single Board Computer has been developed by KOPEC to prevent software Common Mode Failure(CMF inside digital system. The new DRPS has been proved to be an effective digital safety system to prevent CMF by Defense-in-Depth and Diversity (DID&D analysis. However, for practical use in Nuclear Power Plants, the performance test and the reliability test are essential for the digital system qualification. In this study, a single channel of DRPS prototype has been manufactured for the evaluation of DRPS capabilities. The integrated functional tests are performed and the system reliability is analyzed and tested. The results of reliability test show that the application software of DRPS has a very high reliability compared with the analog reactor protection systems.

  18. Towards a decision support system for control of multiple food safety hazards in raw milk production

    NARCIS (Netherlands)

    Spiegel, van der M.; Sterrenburg, P.; Haasnoot, W.; Fels-Klerx, van der H.J.

    2013-01-01

    Decision support systems (DSS) for controlling multiple food safety hazards in raw milk production have not yet been developed, but the underlying components are fragmentarily available. This article presents the state-of-the-art of essential DSS elements for judging food safety compliance of raw mi

  19. Antisideslip and Antirollover Safety Speed Controller Design for Vehicle on Curved Road

    Directory of Open Access Journals (Sweden)

    Guo Lie

    2014-01-01

    Full Text Available When the drivers cannot be aware of the existing of forthcoming curved roads and fail to regulate their safety speeds accordingly, sideslip or rollover may occur with high probability. The antisideslip and antirollover control of vehicle on curved road in automatic highway systems is studied. The safety speed warning system is set before entering the curved road firstly. The speed adhesion control is adopted to shorten the braking distance while decelerating and to guarantee the safety speed. The velocity controller when decelerating on the straight path and the posture controller when driving on curved road are designed, respectively, utilizing integral backstepping technology. Simulation results demonstrate that this control system is characterized by quick and precise tracking and global stability. Consequently, it is able to avoid the dangerous operating conditions, such as sideslip and rollover, and guarantee the safety and directional stability when driving on curved road.

  20. Testing and qualification of Control and Safety Rod and its drive mechanism of Fast Breeder Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Rajan Babu, V., E-mail: vrb@igcar.gov.i [Indira Gandhi Centre for Atomic Research, Department of Atomic Energy, Kalpakkam 603 102 (India); Veerasamy, R.; Patri, Sudheer; Ignatius Sundar Raj, S.; Kumar Krovvidi, S.C.S.P.; Dash, S.K.; Meikandamurthy, C.; Rajan, K.K.; Puthiyavinayagam, P.; Chellapandi, P.; Vaidyanathan, G.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Department of Atomic Energy, Kalpakkam 603 102 (India)

    2010-07-15

    Prototype Fast Breeder Reactor (PFBR) has two independent fast acting diverse shutdown systems. The absorber rod of the first system is called Control and Safety Rod (CSR). CSR and its Drive Mechanism (CSRDM) are used for reactor control and for safe shutdown of the reactor by scram action. In view of the safety role, the qualification of CSRDM is one of the important requirements. CSR and CSRDM were qualified in two stages by extensive testing. In the first stage, the critical subassemblies of the mechanism, such as scram release electromagnet, hydraulic dashpot and dynamic seals and CSR subassembly, were tested and qualified individually simulating the operating conditions of the reactor. Experiments were also carried out on sodium vapour deposition in the annular gaps between the stationary and mobile parts of the mechanism. In the second stage, full-scale CSRDM and CSR were subjected to all the integrated functional tests in air, hot argon and subsequently in sodium simulating the operating conditions of the reactor and finally subjected to endurance tests. Since the damage occurring in CSRDM and CSR is mainly due to fatigue cycles during scram actions, the number of test cycles was decided based on the guidelines given in ASME, Section III, Div. 1. The results show that the performance of CSRDM and CSR is satisfactory. Subsequent to the testing in sodium, the assemblies having contact with liquid sodium/sodium vapour were cleaned using CO{sub 2} process and the total cleaning process has been established, so that the mechanism can be reused in sodium. The various stages of qualification programmes have raised the confidence level on the performance of the system as a whole for the intended and reliable operation in the reactor.

  1. Intelligent monitoring, control, and security of critical infrastructure systems

    CERN Document Server

    Polycarpou, Marios

    2015-01-01

    This book describes the challenges that critical infrastructure systems face, and presents state of the art solutions to address them. How can we design intelligent systems or intelligent agents that can make appropriate real-time decisions in the management of such large-scale, complex systems? What are the primary challenges for critical infrastructure systems? The book also provides readers with the relevant information to recognize how important infrastructures are, and their role in connection with a society’s economy, security and prosperity. It goes on to describe state-of-the-art solutions to address these points, including new methodologies and instrumentation tools (e.g. embedded software and intelligent algorithms) for transforming and optimizing target infrastructures. The book is the most comprehensive resource to date for professionals in both the private and public sectors, while also offering an essential guide for students and researchers in the areas of modeling and analysis of critical in...

  2. Controlling avalanche criticality in 2D nano arrays.

    Science.gov (United States)

    Zohar, Y C; Yochelis, S; Dahmen, K A; Jung, G; Paltiel, Y

    2013-01-01

    Many physical systems respond to slowly changing external force through avalanches spanning broad range of sizes. Some systems crackle even without apparent external force, such as bursts of neuronal activity or charge transfer avalanches in 2D molecular layers. Advanced development of theoretical models describing disorder-induced critical phenomena calls for experiments probing the dynamics upon tuneable disorder. Here we show that isomeric structural transitions in 2D organic self-assembled monolayer (SAM) exhibit critical dynamics with experimentally tuneable disorder. The system consists of field effect transistor coupled through SAM to illuminated semiconducting nanocrystals (NCs). Charges photoinduced in NCs are transferred through SAM to the transistor surface and modulate its conductivity. Avalanches of isomeric structural transitions are revealed by measuring the current noise I(t) of the transistor. Accumulated surface traps charges reduce dipole moments of the molecules, decrease their coupling, and thus decrease the critical disorder of the SAM enabling its tuning during experiments.

  3. [The critical incident reporting system as an instrument of risk management for better patient safety].

    Science.gov (United States)

    Panzica, M; Krettek, C; Cartes, M

    2011-09-01

    The probability that an inpatient will be harmed by a medical procedure is at least 3% of all patients. As a consequence, hospital risk management has become a central management task in the health care sector. The critical incident reporting system (CIRS) as a voluntary instrument for reporting (near) incidents plays a key role in the implementation of a risk management system. The goal of the CIRS is to register system errors without assigning guilt or meting out punishment and at the same time increasing the number of voluntary reports.

  4. Criticality Safety Evaluation for TRU Waste In Storage at the RWMC

    Energy Technology Data Exchange (ETDEWEB)

    M. E. Shaw; J. B. Briggs; C. A. Atkinson; G. J. Briscoe

    1994-04-01

    Stored containers (drums, boxes, and bins) of transuranic waste at the Radioactive Waste Management Complex (RWMC) facility located at the Idaho National Engineering Laboratory (INEL) were evaluated based on inherent neutron absorption characteristics of the waste materials. It was demonstrated that these properties are sufficient to preclude a criticality accident at the actual fissile levels present in the waste stored at the RWMC. Based on the database information available, the results reported herein confirm that the waste drums, boxes, and bins currently stored at the RWMC will remain safely subcritical if rearranged, restacked, or otherwise handled. Acceptance criteria for receiving future drum shipments were established based on fully infinite systems.

  5. Metals in wheat flour; comparative study and safety control.

    Science.gov (United States)

    Tejera, Raquel L; Luis, G; González-Weller, Dailos; Caballero, José M; Gutiérrez, Angel J; Rubio, Carmen; Hardisson, Arturo

    2013-01-01

    Cereal industry and its derived products have a big economic and social importance worldwide. Therefore, as wheat flour is a commodity for all bread and bakery industry, it is safety is of high nutrition and toxicological interest. In this investigation we intend to study and determine the content of twelve metals in 50 samples of wheat flour coming from a wheat flour industry. Macro elements sodium, potassium magnesium and calcium, micro elements manganese, iron, copper, zinc, chrome and nickel as well as toxic trace elements cadmium and lead have been analysed. The estimated diary intake of each metal and their contribution in percentage terms to the RDI (macro and micro elements) and to the PTWI (toxic elements) has been determined. Contribution of Cd and Pb to the PTWI was very low, a fact that shows safety in this wheat flour concerning toxic metals. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

  6. Metals in wheat flour: comparative study and safety control

    Directory of Open Access Journals (Sweden)

    Raquel L. Tejera

    2013-04-01

    Full Text Available Cereal industry and its derived products have a big economic and social importance worldwide. Therefore, as wheat flour is a commodity for all bread and bakery industry, it is safety is of high nutrition and toxicological interest. In this investigation we intend to study and determine the content of twelve metals in 50 samples of wheat flour coming from a wheat flour industry. Macro elements sodium, potassium magnesium and calcium, micro elements manganese, iron, copper, zinc, chrome and nickel as well as toxic trace elements cadmium and lead have been analysed. The estimated diary intake of each metal and their contribution in percentage terms to the RDI (macro and micro elements and to the PTWI (toxic elements has been determined. Contribution of Cd and Pb to the PTWI was very low, a fact that shows safety in this wheat flour concerning toxic metals.

  7. MODSARE-V: Validation of Dependability and Safety Critical Software Components with Model Based Requirements

    Science.gov (United States)

    Silveira, Daniel T. de M. M.; Schoofs, Tobias; Alana Salazar, Elena; Rodriguez Rodriguez, Ana Isabel; Devic, Marie-Odile

    2010-08-01

    The wide use of RAMS methods and techniques [1] (e.g. SFMECA, SFTA, HAZOP, HA...) in critical software development resulted in the specification of new software requirements, design constraints and other issues such as mandatory coding rules. Given the large variety of RAMS Requirements and Techniques, different types of Verification and Validation (V&V) [14] are spread over the phases of the software engineering process. As a result, the V&V process becomes complex and the cost and time required for a complete and consistent V&V process is increased. By introducing the concept of a model based approach to facilitate the RAMS requirements definition process, the V&V may be reduce in time and effort. MODSARE-V is demonstrates the feasibility of this concept based on case studies applied to ground or on-board software space projects with critical functions/components. This paper describes the approach adopted at MODSARE-V to realize the concept into a prototype and summarizes the results and conclusions met after the prototype application on the case studies.

  8. Integrated Design and Analysis Environment for Safety Critical Human-Automation Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Numerous advances have been made in recent years in the areas of flight deck design, aircraft modeling, resilient control, and vehicle health management. The...

  9. Control of finite critical behaviour in a small-scale social system

    Science.gov (United States)

    Daniels, Bryan C.; Krakauer, David C.; Flack, Jessica C.

    2017-01-01

    Many adaptive systems sit near a tipping or critical point. For systems near a critical point small changes to component behaviour can induce large-scale changes in aggregate structure and function. Criticality can be adaptive when the environment is changing, but entails reduced robustness through sensitivity. This tradeoff can be resolved when criticality can be tuned. We address the control of finite measures of criticality using data on fight sizes from an animal society model system (Macaca nemestrina, n=48). We find that a heterogeneous, socially organized system, like homogeneous, spatial systems (flocks and schools), sits near a critical point; the contributions individuals make to collective phenomena can be quantified; there is heterogeneity in these contributions; and distance from the critical point (DFC) can be controlled through biologically plausible mechanisms exploiting heterogeneity. We propose two alternative hypotheses for why a system decreases the distance from the critical point. PMID:28186194

  10. The importance of safety, agency and control during involuntary mental health admissions.

    Science.gov (United States)

    Wyder, Marianne; Bland, Robert; Crompton, David

    2016-08-01

    Constructs such as personal recovery, patient engagement and consumer involvement are central in mental health care delivery. These approaches emphasise the importance of empowerment and choice. Under some circumstances Involuntary Treatment Orders (ITO) allow a person to be treated for a mental illness without their consent. This study explores the tensions between the principles of empowerment and control and involuntary treatment. Twenty-five involuntary inpatients of a major teaching hospital were interviewed about their experiences of being placed under an ITO. The interviews were analysed thematically. Being able to have some sense of agency and re-asserting personal control are critical components of an involuntary mental health admission. Participants wanted information about their treatment, the ITO process and their environment. They also spoke about the importance of a space where they felt safe from themselves and others to make sense of the experience. This study suggests that for coercive treatment to aid, rather than disrupt recovery, treatment services need to focus on: the provision of rights; the creation of a sense of safety; establishing supportive relationships; carrying hope and finding ways to foster a strong sense of agency and empowerment.

  11. Human factors engineering suitability verification of APR1400 soft control and safety console

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S. G.; Kim, Y. K.; Shin, Y. C.; Jeo, S. J. [Nuclear Environment Technology Institute, Taejon (Korea, Republic of)

    2003-10-01

    At first, standard design of APR1400 is designed to support the operation of the EOP using soft control of safety and non-safety like the control room of N4 and AP600. However, KINS required that the design of the soft control for the operation of the EOP is safety grade. According to the comment of the KINS, the concept of the soft control is changed into the concept of the separation of the safety and non-safety for the design of the soft control. KINS required that the result of the HFE suitability verification for changed design is submitted to obtain the approval of the design certification. It was assessed that channelized soft controller is advantageous at the side of operator's mistake prevention and convenience. But non-channelized soft control was assessed that it was the most advantageous considering human factor. Safety console operation strategy is assessed that it is properly without problem during experiment period.

  12. Experimental study of neutron noise with criticality safety applications in mind

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, C.S.

    1985-11-01

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

  13. Active Flow Control with Adaptive Design Techniques for Improved Aircraft Safety Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The increased aircraft safety potential of active flow control using synthetic jets - specifically, using synthetic jets on the leading edge of the wing to delay...

  14. Safety of Temporary Discontinuation of Antihypertensive Medication in Patients with Difficult-to-Control Hypertension

    NARCIS (Netherlands)

    Beeftink, Martine M.A.; Van Der Sande, Nicolette G.C.; Bots, Michiel L.; Doevendans, Pieter A.; Blankestijn, Peter J.; Visseren, Frank L.J.; Voskuil, Michiel; Spiering, Wilko

    2017-01-01

    Successful control of blood pressure relies on identification of secondary causes and contributing factors of hypertension. As antihypertensive medication can interfere with diagnostic investigations, temporary discontinuation of medication is advised. However, there are concerns about the safety of

  15. Open-access technique and "critical view of safety" as the safest way to perform laparoscopic cholecystectomy.

    Science.gov (United States)

    Tsalis, Konstantinos; Antoniou, Nikolaos; Koukouritaki, Zambia; Patridas, Dimitrios; Christoforidis, Emmanuel; Lazaridis, Charalampos

    2015-04-01

    The 2 main challenges of laparoscopic cholecystectomy are primary peritoneal access and safe identification, ligation, and division of the cystic duct and cystic artery. This is a 13-year period retrospective study from January 2000 to December 2012. All the operations were performed by 1 surgeon and all the data were collected from the hospitals archive. A total of 929 laparoscopic cholecystectomies were performed for symptomatic cholelithiasis. The first author was involved in all the operations either by performing or assisting in them. The open access (OA) technique was used in all cases for the creation of pneumoperitoneum. After establishing the pneumoperitoneum, the "critical view of safety" (CVS) technique was used to ligate and divide the cystic duct and cystic artery. When the OA was not possible or CVS was not feasible, the operation was converted to open. Successful establishment of pneumoperitoneum with OA was possible in 911 of 929 (98.06%) patients and CVS was achieved in 873 patients (95.82%). In 18 patients the operation was converted to open because of dense adhesions not permitting the establishment of the pneumoperitoneum. No intraoperative or postoperative complications occurred in these patients. No bile duct injury occurred in this series. Postoperative complications were recorded in 19 patients (2.04%). Five patients had bleeding from port sites, 12 patients had wound infection at the umbilical incision, and 2 patients developed subhepatic collections, which were drained percutaneously under computed tomographic guidance. In this series of laparoscopic cholecystectomies, we used the "open access" technique to create pneumoperitoneum and we obtained the "critical view of safety" for the identification of the cystic duct. Our results show that this approach is the safest way to perform and teach laparoscopic cholecystectomy.

  16. Workload control concepts in job shops : A critical assessment

    NARCIS (Netherlands)

    Land, M.J.; Gaalman, G.J.C.

    1996-01-01

    In the case of production environments with job shop characteristics, much research has been done on partial control such as priority dispatching. The development of comprehensive control concepts lags behind. However, the principles of workload control (WLC) have been elaborated to more comprehensi

  17. Workload control concepts in job shops - A critical assessment

    NARCIS (Netherlands)

    Land, M; Gaalman, G

    1996-01-01

    In the case of production environments with job shop characteristics, much research has been done on partial control such as priority dispatching. The development of comprehensive control concepts lags behind. However, the principles of workload control (WLC) have been elaborated to more comprehensi

  18. Critical appraisal of efficacy and safety of abatacept in the treatment of refractory rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Augustine JM

    2012-02-01

    Full Text Available Lisa M Lundquist1, Sabrina W Cole2, Jill M Augustine11Mercer University College of Pharmacy and Health Sciences, Atlanta, GA, 2Wingate University School of Pharmacy, Wingate, NC, USAAbstract: Rheumatoid arthritis is a chronic, progressive, autoimmune disease that leads to significant disability and premature mortality. Various treatment options are available, but the foundation of treatment includes nonbiologic and biologic disease-modifying antirheumatic drugs. The incidence of patients with rheumatoid arthritis refractory to first-line agents is estimated to be at least 20%. Abatacept, a T cell costimulation modulator, is the first agent to interfere with full T cell activation by competing with CD28 for binding of CD80 and CD86, which results in decreased secretion of proinflammatory cytokines and autoantibody production. Current American College of Rheumatology treatment guidelines recommend abatacept for patients with at least moderate disease activity and a poor prognosis demonstrating an inadequate response to other agents. Several key Phase III trials have been conducted to evaluate the efficacy and safety of abatacept in patients with an inadequate response to methotrexate or anti-tumor necrosis factor alpha therapy. Response rates in all trials showed statistically significant improvements compared with placebo according to American College of Rheumatology criteria for disease improvement. The most common adverse event report in patients receiving abatacept was infection; however, the frequency of adverse events was similar to placebo. Abatacept is a safe and effective rheumatoid arthritis treatment for patients with an inadequate response to methotrexate or anti-tumor necrosis factor alpha therapy.Keywords: abatacept, rheumatoid arthritis, treatment refractory, biologic, disease-modifying antirheumatic drugs

  19. Emplacement Guidance for Criticality Safety in Low-Level-Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Elam, K.R.

    2001-06-23

    The disposal of low-level radioactive waste (LLW) containing special nuclear material (SNM) presents some unusual challenges for LLW disposal site operators and regulators. Radiological concerns associated with the radioactive decay of the SNM are combined with concerns associated with the avoidance of a nuclear criticality both during handling and after disposal of the waste. Currently, there are three operating LLW disposal facilities: Envirocare, Barnwell, and Richland. All these facilities are located in U.S. Nuclear Regulatory Commission (NRC) Agreement States and are regulated by their respective state: Utah, South Carolina, and Washington. As such, the amount of SNM that can be possessed by each of these facilities is limited to the 10 CFR Part 150 limits (i.e., 350 g of uranium-235, 200 g of uranium-233, and 200 g of Pu, with the sum-of-fractions rule applying), unless an exemption is issued. NRC has applied these SNM possession limits to above-ground possession. The purpose of this report is to provide data which could demonstrate that SNM waste at emplacement will not cause a nuclear criticality accident. Five different SNM isotopic compositions were studied: 100 wt% enriched uranium, 10 wt% enriched uranium, uranium-233, plutonium-239, and an isotopic mixture of plutonium (76 wt% plutonium-239, 12 wt% plutonium-240, and 12 wt% plutonium-241). Three different graded-approach methods are presented. The first graded-approach method is the most conservative and may be applicable to facilities that dispose of very low areal densities of SNM, or dispose of material with a low average enrichment. It relies on the calculation of average areal density or on the average enrichment of SNM. The area over which averaging may be performed is also specified, but the emplacement depth is not constrained. The second graded-approach method relies on limiting the average concentration by weight of SNM in the waste, and on limiting the depth of the emplacement. This method

  20. Nuclear safety enhancement of the Instrumentation and Control System at TRIGA SSR 14 MW-Romania

    Energy Technology Data Exchange (ETDEWEB)

    Preda, Marin; Ciocanescu, Marin; Mugurel Ana, Emil; Barbalata, Eugenia [Institute for Nuclear Research, Pitesti (Romania)

    2008-10-29

    In order to comply with the IAEA safety standards and national regulations and to enhance the nuclear safety at TRIGA SSR 14 MW Romanian reactor in 2006 has began a process of instrumentation and control system modifications. By taking account of the operation experience and IAEA guides, the basic requirement for instrumentation and control system modification is the separation between safety and operating components in order to decrease the human error consequences and avoid the common cause failures. Beside that system modernization consists in TRIGA 14 MW console replacement. New instrumentation and control system consists in: - a new reactor operation console, that contains all the necessary modules for reactor operation and parameter display, - three racks for control system that contains all the necessary modules for safety parameter measurement and in scram logic the required redundancy, data acquisition, annunciators, - a terminal boundary rack for connections between field transducers and control room equipments. Modernization did not cover any sensor replacement but keep the actual scram logic and enhance the reactor safety features. The instrumentation and control system is designed, manufactured by INVAP Argentina and will be delivered, installed and tested by the end of 2008. Following to these activities safety documentation will be completed and issued to National Regulatory Body in order to obtain the operation license. Financially the Project is supported by IAEA Vienna and Romanian Government in the framework of a technical cooperation program. (authors)

  1. Nuclear Criticality Safety of the DOT 9975 Container for237NpO2Storage, Handling, and Transport

    Energy Technology Data Exchange (ETDEWEB)

    Reed, D.A.

    2003-08-29

    Nuclear criticality safety considerations are presented to address use of the DOT 9975 shipping container for {sup 237}NpO{sub 2}. The DOT 9975 container will be used by multiple DOE sites and contractors. Various of site- and activity-specific NCS and facility safety documents are yet to be developed. For these reasons, an overall assessment of criticality safety of {sup 237}NpO{sub 2}-loaded DOT 9975 containers is considered useful to personnel involved in generating, reviewing, or approving these various documents. It is concluded that inherent container features, the loading per container (maximum of 6 kg {sup 237}Np), and the nuclear physics properties of {sup 237}NpO{sub 2} combine to preclude the potential for a nuclear criticality accident. This conclusion applies to storage, handling, and transport operations involving closed DOT 9975 packages, including credible off-normal conditions that may result in damage to packages during those operations.

  2. Criticality safety aspects of spent fuel arrays from emerging nuclear fuel cycles

    Energy Technology Data Exchange (ETDEWEB)

    Nicolaou, G. [University of Thrace, Department of Electrical and Computer Engineering, Laboratory of Nuclear Technology, Kimmerria Campus, 67100 Xanthi (Greece)

    2010-07-01

    Emerging nuclear fuel cycles: fuels with Pu or minor actinides (MA) for their self-generated recycling or transmutation in PWR or FR {yields} reduction of radiotoxicity of HLW. The aim of work is to assess criticality (k{sub {infinity}}) of arrays of spent nuclear fuels from these emerging fuel cycles. Procedures: Calculations of - k{sub {infinity}}, using MCNP5 based on fresh and spent fuel compositions (infinite arrays), - spent fuel compositions using ORIGEN. Fuels considered: - commercial PWR-UO{sub 2} (R1) and -MOX (R2), [45 GWd/t] and fast reactor [100 GWd/t] (R3), - PWR self-generated Pu recycling (S1) and MA recycling (S2), FR self-generated MA recycling (S3), FR with 2% {sup 237}Np for transmutation purposes (T). Results: k{sub {infinity}} based on fresh and spent fuel compositions is shown. Fuels are clustered in two distinct families: - fast reactor fuels, - thermal reactor fuels; k{sub {infinity}} decreases when calculated on the basis of actinide and fission product inventory. In conclusions: - Emerging fuels considered resemble their corresponding commercial fuels; - k{sub {infinity}} decreases in all cases when calculated on the basis of spent fuel compositions (reactivity worth {approx}-20%{Delta}k/k), hence improving the effectiveness of packaging. (author)

  3. Robust Propulsion Control for Improved Aircraft Safety Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Scientific Monitoring, Inc. proposes to develop a robust propulsion control approach to facilitate control law design and simulation-based validation. The proposed...

  4. Citizen's Guide to Pest Control and Pesticide Safety

    Science.gov (United States)

    Teaches consumers how to control pests, choose, use, store, and dispose pesticides safely, reduce exposure when others use pesticides, prevent pesticide poisoning, handle an emergency, and how to choose a pest control company.

  5. Validation of MCNP6.1 for Criticality Safety of Pu-Metal, -Solution, and -Oxide Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kiedrowski, Brian C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Conlin, Jeremy Lloyd [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Favorite, Jeffrey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kahler, III, Albert C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kersting, Alyssa R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parsons, Donald K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Walker, Jessie L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-05-13

    Guidance is offered to the Los Alamos National Laboratory Nuclear Criticality Safety division towards developing an Upper Subcritical Limit (USL) for MCNP6.1 calculations with ENDF/B-VII.1 nuclear data for three classes of problems: Pu-metal, -solution, and -oxide systems. A benchmark suite containing 1,086 benchmarks is prepared, and a sensitivity/uncertainty (S/U) method with a generalized linear least squares (GLLS) data adjustment is used to reject outliers, bringing the total to 959 usable benchmarks. For each class of problem, S/U methods are used to select relevant experimental benchmarks, and the calculational margin is computed using extreme value theory. A portion of the margin of sub criticality is defined considering both a detection limit for errors in codes and data and uncertainty/variability in the nuclear data library. The latter employs S/U methods with a GLLS data adjustment to find representative nuclear data covariances constrained by integral experiments, which are then used to compute uncertainties in keff from nuclear data. The USLs for the classes of problems are as follows: Pu metal, 0.980; Pu solutions, 0.973; dry Pu oxides, 0.978; dilute Pu oxide-water mixes, 0.970; and intermediate-spectrum Pu oxide-water mixes, 0.953.

  6. 46 CFR 62.35-50 - Tabulated monitoring and safety control requirements for specific systems.

    Science.gov (United States)

    2010-10-01

    ...) ......ditto (3) Manual trip (3) Burner valve Open/closed Low fire interlock Status Program control interlock... lubrication Pressure Low Main propulsion, controllable pitch propeller Hydraulic oil Pressure High, Low.... See § 62.35-20(a). 4. Loss of forced lubrication safety trip controls must be provided, as...

  7. Health Monitor for Multitasking, Safety-Critical, Real-Time Software

    Science.gov (United States)

    Zoerner, Roger

    2011-01-01

    Health Manager can detect Bad Health prior to a failure occurring by periodically monitoring the application software by looking for code corruption errors, and sanity-checking each critical data value prior to use. A processor s memory can fail and corrupt the software, or the software can accidentally write to the wrong address and overwrite the executing software. This innovation will continuously calculate a checksum of the software load to detect corrupted code. This will allow a system to detect a failure before it happens. This innovation monitors each software task (thread) so that if any task reports "bad health," or does not report to the Health Manager, the system is declared bad. The Health Manager reports overall system health to the outside world by outputting a square wave signal. If the square wave stops, this indicates that system health is bad or hung and cannot report. Either way, "bad health" can be detected, whether caused by an error, corrupted data, or a hung processor. A separate Health Monitor Task is started and run periodically in a loop that starts and stops pending on a semaphore. Each monitored task registers with the Health Manager, which maintains a count for the task. The registering task must indicate if it will run more or less often than the Health Manager. If the task runs more often than the Health Manager, the monitored task calls a health function that increments the count and verifies it did not go over max-count. When the periodic Health Manager runs, it verifies that the count did not go over the max-count and zeroes it. If the task runs less often than the Health Manager, the periodic Health Manager will increment the count. The monitored task zeroes the count, and both the Health Manager and monitored task verify that the count did not go over the max-count.

  8. Study of neutron noise from reflected, metal assemblies with criticality safety applications in mind

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, C.S.

    1985-08-20

    The author studied the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. The calculated multiplication factors of the assemblies are 0.59, 0.74, 0.82, and 0.92. The author studied three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. They are: (1) variance-to-mean ratio of the counts in a time bin (V/M); (2) covariance-to-mean ratio of the counts in a common time bin from two different detectors (C/M); and (3) covariance-to-mean ratio of the counts from a single detector in two adjacent time bins of equal length, which the author calls the serial-covariance-to-mean ratio (SC/M). The performances of the three discriminators were not greatly different, but a hierarchy did emerge: SC/M greater than or equal to V/M greater than or equal to C/M. An example of some results: in the neighborhood of k = 0.6 the ..delta..k required for satisfactory discrimination varies from about 3% to 7% as detector solid angle varies from 19% to 5%. In the neighborhood of k = 0.8 the corresponding ..delta..ks are 1% and 2%. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

  9. [Monitoring of a HACCP (Hazard Analysis Critical Control Point) plan for Listeria monocytogenes control].

    Science.gov (United States)

    Mengoni, G B; Apraiz, P M

    2003-01-01

    The monitoring of a HACCP (Hazard Analysis Critical Control Point) plan for the Listeria monocytogenes control in the cooked and frozen meat section of a thermo-processing meat plant was evaluated. Seventy "non-product-contact" surface samples and fourteen finished product samples were examined. Thirty eight positive sites for the presence of Listeria sp. were obtained. Twenty-two isolates were identified as L. monocytogenes, two as L. seeligeri and fourteen as L. innocua. Non isolates were obtained from finished product samples. The detection of L. monocytogenes in cooked and frozen meat section environment showed the need for the HACCP plan to eliminate or prevent product contamination in the post-thermal step.

  10. Very early passive cycling exercise in mechanically ventilated critically ill patients: physiological and safety aspects--a case series.

    Directory of Open Access Journals (Sweden)

    Ruy Camargo Pires-Neto

    Full Text Available INTRODUCTION: Early mobilization can be performed in critically ill patients and improves outcomes. A daily cycling exercise started from day 5 after ICU admission is feasible and can enhance functional capacity after hospital discharge. In the present study we verified the physiological changes and safety of an earlier cycling intervention (< 72 hrs of mechanical ventilation in critical ill patients. METHODS: Nineteen hemodynamically stable and deeply sedated patients within the first 72 hrs of mechanical ventilation were enrolled in a single 20 minute passive leg cycling exercise using an electric cycle ergometer. A minute-by-minute evaluation of hemodynamic, respiratory and metabolic variables was undertaken before, during and after the exercise. Analyzed variables included the following: cardiac output, systemic vascular resistance, central venous blood oxygen saturation, respiratory rate and tidal volume, oxygen consumption, carbon dioxide production and blood lactate levels. RESULTS: We enrolled 19 patients (42% male, age 55 ± 17 years, SOFA = 6 ± 3, SAPS3 score = 58 ± 13, PaO2/FIO2 = 223 ± 75. The median time of mechanical ventilation was 1 day (02, and 68% (n=13 of our patients required norepinephrine (maximum concentration = 0.47 µg.kg(-1.min(-1. There were no clinically relevant changes in any of the analyzed variables during the exercise, and two minor adverse events unrelated to hemodynamic instability were observed. CONCLUSIONS: In our study, this very early passive cycling exercise in sedated, critically ill, mechanically ventilated patients was considered safe and was not associated with significant alterations in hemodynamic, respiratory or metabolic variables even in those requiring vasoactive agents.

  11. Control of critical behavior in a small-scale social system

    CERN Document Server

    Daniels, Bryan C; Flack, Jessica C

    2016-01-01

    Over the last decade new technologies for making large numbers of fine-grained measurements have led to the surprising discovery that many biological systems sit near a critical point. These systems are potentially more adaptive in that small changes to component behavior can induce large-scale changes in aggregate structure and function. Accounting for criticality remains a challenge as sensitivity to perturbation suggests a lack of robustness. Furthermore, change induced by perturbation may not be adaptive. Complicating matters further critical phenomena can result from history-dependent stochastic processes. A question central to distinguishing among these conflicting views of criticality is to what degree criticality can be controlled by the components of the system. We address the control of criticality using data on conflict dynamics and fight sizes from an animal society model system (Macaca nemestrina, n=48). The system is fundamentally finite so we operationalize criticality in information theoretic ...

  12. Online Model Learning Algorithms for Actor-Critic Control

    NARCIS (Netherlands)

    Grondman, I.

    2015-01-01

    Classical control theory requires a model to be derived for a system, before any control design can take place. This can be a hard, time-consuming process if the system is complex. Moreover, there is no way of escaping modelling errors. As an alternative approach, there is the possibility of having

  13. Generating Safety-Critical PLC Code From a High-Level Application Software Specification

    Science.gov (United States)

    2008-01-01

    The benefits of automatic-application code generation are widely accepted within the software engineering community. These benefits include raised abstraction level of application programming, shorter product development time, lower maintenance costs, and increased code quality and consistency. Surprisingly, code generation concepts have not yet found wide acceptance and use in the field of programmable logic controller (PLC) software development. Software engineers at Kennedy Space Center recognized the need for PLC code generation while developing the new ground checkout and launch processing system, called the Launch Control System (LCS). Engineers developed a process and a prototype software tool that automatically translates a high-level representation or specification of application software into ladder logic that executes on a PLC. All the computer hardware in the LCS is planned to be commercial off the shelf (COTS), including industrial controllers or PLCs that are connected to the sensors and end items out in the field. Most of the software in LCS is also planned to be COTS, with only small adapter software modules that must be developed in order to interface between the various COTS software products. A domain-specific language (DSL) is a programming language designed to perform tasks and to solve problems in a particular domain, such as ground processing of launch vehicles. The LCS engineers created a DSL for developing test sequences of ground checkout and launch operations of future launch vehicle and spacecraft elements, and they are developing a tabular specification format that uses the DSL keywords and functions familiar to the ground and flight system users. The tabular specification format, or tabular spec, allows most ground and flight system users to document how the application software is intended to function and requires little or no software programming knowledge or experience. A small sample from a prototype tabular spec application is

  14. Safety Verification of a Fault Tolerant Reconfigurable Autonomous Goal-Based Robotic Control System

    Science.gov (United States)

    Braman, Julia M. B.; Murray, Richard M; Wagner, David A.

    2007-01-01

    Fault tolerance and safety verification of control systems are essential for the success of autonomous robotic systems. A control architecture called Mission Data System (MDS), developed at the Jet Propulsion Laboratory, takes a goal-based control approach. In this paper, a method for converting goal network control programs into linear hybrid systems is developed. The linear hybrid system can then be verified for safety in the presence of failures using existing symbolic model checkers. An example task is simulated in MDS and successfully verified using HyTech, a symbolic model checking software for linear hybrid systems.

  15. Using Botnets to provide security for safety critical embedded systems - a case study focused on UAVs

    Science.gov (United States)

    Garcia Muzzi, Fernando Augusto; Rogério de Mello Cardoso, Paulo; Pigatto, Daniel Fernando; Jaquie Castelo Branco, Kalinka Regina Lucas

    2015-09-01

    The use of unmanned aerial vehicles (UAV s) has been growing not only in military applications, but also in civilian. UAVs have enormous potential for use, which mostly still are unexplored. For the use of UAV s in the airspace, not only Brazilian new studies on methods of analysis and technologies should be incorporated into navigation systems, control among others, promoting security mechanisms for these aircraft. Implement security mechanisms using a platform with operating systems and botnet to simulate such attack Distributed Denial of Service (DDoS) in UAVs is an important task when it is aimed at containment and mitigation of attacks on this type of platform.

  16. Safety System for Controlling Fluid Flow into a Suction Line

    Science.gov (United States)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

    2015-01-01

    A safety system includes a sleeve fitted within a pool's suction line at the inlet thereof. An open end of the sleeve is approximately aligned with the suction line's inlet. The sleeve terminates with a plate that resides within the suction line. The plate has holes formed therethrough. A housing defining a plurality of distinct channels is fitted in the sleeve so that the distinct channels lie within the sleeve. Each of the distinct channels has a first opening on one end thereof and a second opening on another end thereof. The second openings reside in the sleeve. Each of the distinct channels is at least approximately three feet in length. The first openings are in fluid communication with the water in the pool, and are distributed around a periphery of an area of the housing that prevents coverage of all the first openings when a human interacts therewith.

  17. Using model-driven engineering to support the certification of safety-critical systems

    Energy Technology Data Exchange (ETDEWEB)

    Panesar-Walawege, Rajwinder Kaur

    2012-07-15

    Iron (Fe) is an important impurity in solar-grade silicon which contributes substantially in degrading the efficiency of solar cells. The degradation is mainly caused by the Fe atoms situating at an unperturbed tetrahedral interstitial sites (Fei) in the silicon crystal, consequently acting as a recombination center. By altering the position and the neighbouring environment at which the Fe atoms reside, there are opportunities in minimizing or neutralizing the electrical activity of Fe. Furthermore, utilizing the high mobility of Fe, one can increase the performance of a device by accumulating the Fe atoms from critical regions into regions where Fe can be tolerated. These approaches can help in realizing high efficient solar cells based on cheap and highly Fe-contaminated silicon. In this work, we have investigated the interaction between Fe and defects relevant to solar cells, using mainly electrical characterization methods such as capacitance-voltage measurement, deep level transient spectroscopy and admittance spectroscopy. From the study of potential hydrogen passivation of Fe, hydrogen was introduced through wet chemical etching and further driven to a defined region. Using depth profiles, it is found that incorporation of hydrogen stimulates the dissociation of the iron-boron (Fe-B) pair, releasing and resulting in the unwanted Fei. At the same time, no passivation of Fe by hydrogen has been observed. On the investigation of the mechanism of phosphorus gettering of metal impurities, vacancies have been generated through proton-irradiation. The resulting irradiation-induced defects were examined for reactions with Fe after heat treatments. Based on the evolution of defect concentrations by isochronal annealings, it is found that Fe interacts with the divacancy and the vacancy-oxygen complexes, forming deep levels of 0.28 eV and 0.34 eV above the valence band edge (EV), respectively. In the search for substitutional Fe to investigate its electrical activity

  18. Determination of the Critical Parameters for Remote Microscope Control

    Science.gov (United States)

    Hahn, R. C.; Herbach, B. A.; Johnston, J. C.; Bethea, M.

    1991-01-01

    As part of a program to determine the capabilities of Telescience as applied to Microgravity Materials Science the need for a remotely controlled microscope was recognized. For this purpose we equipped a microscope with an X-Y-Z positioning device and motors on the zoom and focus controls. Computer control of these devices allowed remote operation. A standard TV camera was mounted to the computer controlled video board which could compress the image in resolution and grey scale. The operator control console was programmed to display three still video pictures as well as provide command access. A standard data transfer network was used to transmit the video data files and the command interaction was via a high speed phone modem. This system, with the microscope in the Microgravity Materials Science Laboratory (MMSL) at LeRC and the control at RPI, was used to determine the accuracy of setting, time required to achieve setting and the operator ease factor. It was found that the focus setting could be established well within the resolution limit of the TV system and that each motion took about 50 seconds and approximately 12 minutes was required to reach ?best? focus. These times could be reduced significantly with operator experience. The operators were provided with ancillary equipment which provided assistance in making the necessary decisions and they reported satisfaction with the control.

  19. Use of the self-controlled case-series method in vaccine safety studies: review and recommendations for best practice.

    Science.gov (United States)

    Weldeselassie, Y G; Whitaker, H J; Farrington, C P

    2011-12-01

    The self-controlled case-series method was originally developed to investigate potential associations between vaccines and adverse events, and is now commonly used for this purpose. This study reviews applications of the method to vaccine safety investigations in the period 1995-2010. In total, 40 studies were reviewed. The application of the self-controlled case-series method in these studies is critically examined, with particular reference to the definition of observation and risk periods, control of confounders, assumptions and potential biases, methodological and presentation issues, power and sample size, and software. Comparisons with other study designs undertaken in the papers reviewed are also highlighted. Some recommendations are presented, with the emphasis on promoting good practice.

  20. Nuclear criticality safety experiments, calculations, and analyses - 1958 to 1982. Volume 2. Summaries. Complilation of papers from the Transactions of the American Nuclear Society

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, B.L.; Hampel, V.E.

    1982-10-21

    This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains-in chronological order-the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41.