Integral fast reactor concept inherent safety features

International Nuclear Information System (INIS)

Marchaterre, J.F.; Sevy, R.H.; Cahalan, J.E.

1987-01-01

The Integral Fast Reactor (IFR) is an innovative liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The two major goals of the IFT development effort are improved economics and enhanced safety. The design features that together fulfill these goals are: 1) a liquid metal (sodium) coolant, 2) a pool-type reactor primary system configuration, 3) an advanced ternary alloy metallic fuel, and 4) an integral fuel cycle. This paper reviews the design features that contribute to the safety margins inherent to the IFR concept. Special emphasis is placed on the ability of the IFR design to accommodate anticipated transients without scram (ATWS)

Integral Fast Reactor concept inherent safety features

International Nuclear Information System (INIS)

Marchaterre, J.F.; Sevy, R.H.; Cahalan, J.E.

1986-01-01

The Integral Fast Reactor (IFR) is an innovative liquid-metal-cooled reactor concept being developed at Argonne National Laboratory. The two major goals of the IFR development effort are improved economics and enhanced safety. The design features that together fulfill these goals are: (1) a liquid metal (sodium) coolant, (2) a pool-type reactor primary system configuration, (3) an advanced ternary alloy metallic fuel, and (4) an integral fuel cycle. This paper reviews the design features that contribute to the safety margins inherent to the IFR concept. Special emphasis is placed on the ability of the IFR design to accommodate anticipated transients without scram (ATWS)

Role of FFTF in assessing structural feedbacks and inherent safety of LMR's

International Nuclear Information System (INIS)

Padilla, A.; Omberg, R.P.; O'Dell, L.D.; Harris, R.A.; Nguyen, D.H.; Waltar, A.E.

1985-03-01

The possibility of developing reactor designs with inherent safety characteristics sufficient to provide ''walk away'' safety is receiving additional emphasis in the LMR program. A key element in this effort is the recognition that LMR's possess safety characteristics above and beyond those employed in past safety review processes. Some of these additional safety characteristics are due to reactivity feedback effects caused by small structural movements during hypothetical severe design transients. The effect of these characteristics upon the behavior of the FFTF under such transients has been assessed and is discussed in this paper. The paper also presents a preliminary test matrix which might allow experimental verification of the structural reactivity feedback effects. Such experimental verification should be very useful to innovative designers seeking to optimize inherent safety. 8 refs., 1 fig., 2 tabs

Problems in the assessment of inherent safety characteristics of nuclear reactors

International Nuclear Information System (INIS)

Garribba, S.F.; Vivante, C.

1988-01-01

A number of proposals are being made for an increased RD and D effort on advanced nuclear power reactors that would display outstanding safety performance. A common characteristic of the different reactor concepts would be their limited reliance upon active engineered systems under major accident conditions. However, when submitted to a more close scrutiny reactor concept options may reveal diverging safety behaviors and also development opportunities. In this respect, three issues are explored in this paper. A first question is the meaning of non-active, i.e. inherent and passive safety features. Next, is the ranking of advanced and new reactor concepts from the viewpoint of inherent and passive safety. Multiple correspondence analysis may provide a simple tool, whose use is shown for the case of HTR-500, AP600 and PRISM. Conversely, probabilistic risk assessment would allow quantitative comparisons, although lack of information and data is an obstacle. Finally, is demonstration of safety performances as a step toward market deployment of the new reactor systems

Inherent and passive safety measures in accelerator driven systems: a safety strategy for ADS

International Nuclear Information System (INIS)

Maschek, W.; Rineiski, A.; Morita, K.; Flad, M.

2001-01-01

The efficiency of Accelerator Driven Systems (ADSs) for the transmutation and incineration of nuclear waste is strongly related to the utilization of so-called dedicated fuels. In the ideal case these fuels should consist of pure TRUs without fertile materials as 238 U or 232 Th to achieve highest incineration/transmutation rates. Dedicated fuels still have to be developed and programs are under way for their fabrication, irradiation and testing. These fertile-free fuels may suffer from deteriorated thermal or thermo-mechanical properties, as a reduced melting point, reduced thermal conductivity or even thermal instability. First analyses have shown that the use of dedicated fuels may lead to a strong deterioration of the safety parameters of the reactor core as e.g. the void worth, the Doppler or the kinetics quantities as neutron generation time and β eff . In addition, a dedicated core may contain multiple ''critical'' fuel masses, resulting in a considerable recriticality potential. Current knowledge on these dedicated fuels suggests that ''critical'' reactors may not be feasible, because of safety reasons. However, for ADSs, the salient hope has been promoted that due to the subcriticality of the system the poor safety features of such fuels could be coped with. Analyses are presented which show potential safety problems for such dedicated cores. Respecting the results of these analyses a safety strategy is proposed along the lines of defense approach in analogy with ideas formerly developed for fast reactors. Inherent and passive safety measures are integrated into the various defense lines. (author)

Multi-objective optimization of a cascade refrigeration system: Exergetic, economic, environmental, and inherent safety analysis

International Nuclear Information System (INIS)

Eini, Saeed; Shahhosseini, Hamidreza; Delgarm, Navid; Lee, Moonyong; Bahadori, Alireza

2016-01-01

Highlights: • A multi-objective optimization is performed for a cascade refrigeration cycle. • The optimization problem considers inherently safe design as well as 3E analysis. • As a measure of inherent safety level a quantitative risk analysis is utilized. • A CO 2 /NH 3 cascade refrigeration system is compared with a CO 2 /C 3 H 8 system. - Abstract: Inherently safer design is the new approach to maximize the overall safety of a process plant. This approach suggests some risk reduction strategies to be implemented in the early stages of design. In this paper a multi-objective optimization was performed considering economic, exergetic, and environmental aspects besides evaluation of the inherent safety level of a cascade refrigeration system. The capital costs, the processing costs, and the social cost due to CO 2 emission were considered to be included in the economic objective function. Exergetic efficiency of the plant was considered as the second objective function. As a measure of inherent safety level, Quantitative Risk Assessment (QRA) was performed to calculate total risk level of the cascade as the third objective function. Two cases (ammonia and propane) were considered to be compared as the refrigerant of the high temperature circuit. The achieved optimum solutions from the multi–objective optimization process were given as Pareto frontier. The ultimate optimal solution from available solutions on the Pareto optimal curve was selected using Decision-Makings approaches. NSGA-II algorithm was used to obtain Pareto optimal frontiers. Also, three decision-making approaches (TOPSIS, LINMAP, and Shannon’s entropy methods) were utilized to select the final optimum point. Considering continuous material release from the major equipment in the plant, flash and jet fire scenarios were considered for the CO 2 /C 3 H 8 cycle and toxic hazards were considered for the CO 2 /NH 3 cycle. The results showed no significant differences between CO 2 /NH 3 and

Inherently safe reactors

International Nuclear Information System (INIS)

Maartensson, Anders

1992-01-01

A rethinking of nuclear reactor safety has created proposals for new designs based on inherent and passive safety principles. Diverging interpretations of these concepts can be found. This article reviews the key features of proposed advanced power reactors. An evaluation is made of the degree of inherent safety for four different designs: the AP-600, the PIUS, the MHTGR and the PRISM. The inherent hazards of today's most common reactor principles are used as reference for the evaluation. It is concluded that claims for the new designs being inherently, naturally or passively safe are not substantiated by experience. (author)

Results and implications of the EBR-II inherent safety demonstration tests

International Nuclear Information System (INIS)

Planchon, H.P.; Golden, G.H.; Sackett, J.I.; Mohr, D.; Chang, L.K.; Feldman, E.E.; Betten, P.R.

1987-01-01

On April 3, 1986 two milestone tests were conducted in Experimental Breeder Reactor-2 (EBR-II). The first test was a loss of flow without scram and the second was a loss of heat sink without scram. Both tests were initiated from 100% power and in both tests the reactor was shut down by natural processes, principally thermal expansion, without automatic scram, operator intervention or the help of special in-core devices. The temperature transients during the tests were mild, as predicted, and there was no damage to the core or reactor plant structures. In a general sense, therefore, the tests plus supporting analysis demonstrated the feasibility of inherent passive shutdown for undercooling accidents in metal-fueled LMRs. The results provide a technical basis for future experiments in EBR-II to demonstrate inherent safety for overpower accidents and provide data for validation of computer codes used for design and safety analysis of inherently safe reactor plants

Cost-competitive, inherently safe LFMBR pool plant

International Nuclear Information System (INIS)

McDonald, J.S.; Brunings, J.E.; Chang, Y.I.; Hren, R.R.; Seidensticker, R.W.

1984-01-01

The Cost-Competitive, Inherently Safe LMFBR Pool Plant design was prepared in GFY 1983 under a DOE-sponsored program. This plant design was developed as a joint effort by Rockwell International and the Argonne National Laboratory with major contributions from the Bechtel Group, Inc.; Combustion engineering, Inc.; the Chicago Bridge and Iron Company; and the General Electric Company. Using current LMFBR technology, many innovative features were developed and incorporated into the design to meet the ultimate objectives of the Breeder Program, i.e., energy costs competitive with LWRs and inherent safety features to maintain the plant in a safe condition following assumed accidents without requiring operator action. This paper provides a description of the principal features that were incorporated into the design to achieve low cost and inherent safety

Transient behaviour and inherent safety research of LMFBR power plants

International Nuclear Information System (INIS)

Zhu Jizhou; Wang Ping; Yu Baoan

1995-06-01

Fast Breeder Reactor will be the next generation reactor for nuclear electricity production, the development of FBR will give the profits of efficient utilization of nuclear resources. The fast reactor safety analysis is the foundation and key of FBR research work. Therefore, a block-oriented mathematical model for the primary system of LMFBRs was constructed, and the dynamic simulating results which have been carried out on micro-computer are presented for various transients, i.e. TOP, LOFS, LOHS. The results agree well with the corresponding results of the code NATDEMO and experiment results of EBR-II. Based on previous analysis, various methods are discussed to confirm the inherent safety of LMFBR

Safety assessment in plant layout design using indexing approach: implementing inherent safety perspective. Part 2-Domino Hazard Index and case study.

Science.gov (United States)

Tugnoli, Alessandro; Khan, Faisal; Amyotte, Paul; Cozzani, Valerio

2008-12-15

The design of layout plans requires adequate assessment tools for the quantification of safety performance. The general focus of the present work is to introduce an inherent safety perspective at different points of the layout design process. In particular, index approaches for safety assessment and decision-making in the early stages of layout design are developed and discussed in this two-part contribution. Part 1 (accompanying paper) of the current work presents an integrated index approach for safety assessment of early plant layout. In the present paper (Part 2), an index for evaluation of the hazard related to the potential of domino effects is developed. The index considers the actual consequences of possible escalation scenarios and scores or ranks the subsequent accident propagation potential. The effects of inherent and passive protection measures are also assessed. The result is a rapid quantification of domino hazard potential that can provide substantial support for choices in the early stages of layout design. Additionally, a case study concerning selection among various layout options is presented and analyzed. The case study demonstrates the use and applicability of the indices developed in both parts of the current work and highlights the value of introducing inherent safety features early in layout design.

On the fundamentals of nuclear reactor safety assessment. Inherent threats and their implications

Energy Technology Data Exchange (ETDEWEB)

Hyvaerinen, J. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland). Nuclear Safety Dept.

1996-12-01

The thesis addresses some fundamental questions related to implementation and assessment of nuclear safety. The safety principles and assessment methods are described, followed by descriptions of selected novel technical challenges to nuclear safety. The novel challenges encompass a wide variety of technical issues, thus providing insights on the limitations of conventional safety assessment methods. Study of the limitations suggests means to improve nuclear reactor design criteria and safety assessment practices. The novel safety challenges discussed are (1) inherent boron dilution in PWRs, (2) metallic insulation performance with respect to total loss of emergency cooling systems in a loss-of-coolant accident, and (3) horizontal steam generator heat transfer performance at natural circulation conditions. (50 refs.).

On the fundamentals of nuclear reactor safety assessment. Inherent threats and their implications

International Nuclear Information System (INIS)

Hyvaerinen, J.

1996-12-01

The thesis addresses some fundamental questions related to implementation and assessment of nuclear safety. The safety principles and assessment methods are described, followed by descriptions of selected novel technical challenges to nuclear safety. The novel challenges encompass a wide variety of technical issues, thus providing insights on the limitations of conventional safety assessment methods. Study of the limitations suggests means to improve nuclear reactor design criteria and safety assessment practices. The novel safety challenges discussed are (1) inherent boron dilution in PWRs, (2) metallic insulation performance with respect to total loss of emergency cooling systems in a loss-of-coolant accident, and (3) horizontal steam generator heat transfer performance at natural circulation conditions. (50 refs.)

Results of the 1986 FFTF inherent safety tests

International Nuclear Information System (INIS)

Burke, T.M.; Campbell, L.R.; Franz, G.R.; Knecht, W.L.

1987-01-01

A series of tests was recently completed at the 400-MW (thermal) Fast Flux Test Facility (FFTF) to further demonstrate the passive safety characteristics of liquid-metal-cooled fast reactors. Earlier FFTF testing of decay heat removal by sodium natural circulation was reported in 1981. The main purpose of the 1986 test series was to demonstrate passive reactor shutdown during a loss-of-flow event when several inherent shutdown devices called gas expansion modules (GEMs) were installed in the reactor. However, these tests also provide further data on the natural circulation performance of the primary system, in particular the reactor core, and thus add to the data base available for checking the validity of available analytical tools

Project of a binary breeder reactor and its inherent safety

International Nuclear Information System (INIS)

Nascimento, J.A. do; Dias, A.F.; Ishiguro, Y.

1983-01-01

A core layout for the binary breeder reactor (BBR) is developed based on the results of preliminary burnup calculations. The apparent breeding ratio, in the U 233 /Th fueled inner core, is low due to the accumulation of Pa-233 in the first few months of operation. The loss of reactivity during this time is around 3%. The BBR requires more reactivity control than Pu/U-fueled LMFBRs and the core layout developed has 19 control rod assemblies in the inner core. Three aspects related to the inherent safety of the Binary Breeder Reactor have been studied: the radial distribution of the sodium-void reactivity zone-wise Doppler reactivity and the fractions of delayed neutrons. The results show excellent characteristics for the BRB safety. (Author) [pt

Project of a binary breeder reactor and its inherent safety

International Nuclear Information System (INIS)

Nascimento, J.A. do; Dias, A.F.; Ishiguro, Y.

1983-01-01

A core layout for the binary breeder reactor (BBR) is developed based on the results of preliminary burnup calculations. In the U 233 /TH fueled inner core, the apparent breeding ratio is low due to the accumulation of Pa-233 in the first few months of operation. The loss of reactivity during this time is approximatelly 3%. The BBR requires more reactivity control than Pu/U-fueled LMFBRs and the core layout developed has 19 control rod assemblies in the inner core. Three aspects related to the inherent safety of the BBR have been studied: radial distribution of the sodium-void reactivity, zone-wise Doppler reactivity, and the delayed neutron fractions. Results show excellent safety characteristics of the BBR. (Author) [pt

Dynamics and inherent safety features of small modular high temperature gas-cooled reactors

International Nuclear Information System (INIS)

Harrington, R.M.; Ball, S.J.; Cleveland, J.C.

1986-01-01

Investigations were made at Oak Ridge National Laboratory to characterize the dynamics and inherent safety features of various modular high temperature gas-cooled reactor (HTGR) designs. This work was sponsored by the US Nuclear Regulatory Commission's HTGR Safety Research program. The US Department of Energy (DOE) and the Gas Cooled Reactor Associates (GCRA) have sponsored studies of several modular HTGR concepts, each having it own unique advantageous economic and inherent safety features. The DOE design team has recently choses a 350-MW(t) annular core with prismatic, graphite matrix fuel for its reference plant. The various safety features of this plant and of the pebble-bed core designs similar to those currently being developed and operated in the Federal Republic of Germany (FRG) are described. A varity of postulated accident sequences involving combinations of loss of forced circulation of the helium primary coolant, loss of primary coolant pressurization, and loss of normal and backup heat sinks were studied and are discussed. Results demonstrate that each concept can withstand an uncontrolled heatup accident without reaching excessive peak fuel temperatures. Comparisons of calculated and measured response for a loss of forced circulation test on the FRG reactor, AVR, are also presented. 10 refs

Inherent safety, ethics and human error.

Science.gov (United States)

Papadaki, Maria

2008-02-11

stated. The reason this article is presented here is that I believe that often, complex accidents, similarly to insignificant ones, often demonstrate an attitude which can be characterized as "inherently unsafe". I take the view that the enormous human potential and the human ability to minimize accidents needs to become a focal point towards inherent safety. Restricting ourselves to human limitations and how we could "treat" or prevent humans from not making accidents needs to be re-addressed. The purpose of this presentation is to highlight observations and provoke a discussion on how we could possibly improve the understanding of safety related issues. I do not intent to reject or criticize existing methodologies. (The entire presentation is strongly influenced by Trevor Kletz's work although our views are often different.).

Inherent safety features of the HTTR revealed in the accident condition

International Nuclear Information System (INIS)

Kunitomi, K.; Shinozaki, M.; Baba, O.; Saito, S.

1992-01-01

The High Temperature Engineering Test Reactor (HTTR) being constructed by JAERI (Japan Atomic Energy Research Institute) is a graphite-moderated and helium-cooled reactor with an outlet gas temperature of 950degC. The inherent safety characteristics in the HTTR prevent temperature increase of reactor fuels and fission product release from the reactor core in postulated accident conditions. The reactor core can be cooled by a Vessel Cooling System (VCS) indirectly, even in the case that no forced cooling is expected during the accident such as primary pipe break. The VCS consists of independent water cooling loop and cooling panel around the reactor pressure vessel. The cooling panel whose temperature of 60-90degC cools the reactor pressure vessel by radiation and removes the decay heat from the core indirectly. Furthermore, even if failure of VCS is assumed during this accident as a severe accident, the reactor core is remained safe despite the temperature increase of biological concrete shield around the reactor pressure vessel. This paper describes the inherent safety features of the HTTR specially focused on the accident condition without forced cooling. The detailed analytical results of such an accident are described together with clarifying the role of the VCS. (author)

Improvement of inherent safety features in CSR (Coupled Spectrum Reactor) for treating MA

International Nuclear Information System (INIS)

Aziz, F.; Kitamoto, Asashi.

1996-01-01

Burning and/or transmutation (B/T) of MA is proposed here using a CSR (Coupled Spectrum Reactor) concept. CSR was based on a modified conventional 1150 MWe-PWR system, and consisted of two core regions for thermal and fast neutrons, respectively. The B/T fuel used was supposed such that MA discharged from 1 GWe-LWR were mixed homogeneously in LWR fuel. The geometry of B/T fuel in the outer region was left the same with that of PWR, while in the inner region the B/T fuel was arranged in a tight-lattice geometry that allowed a higher fuel to coolant volume ratio, (V m /V f ). In order to improve its inherent safety features, several cases of CSR were studied and compared, each case used different fuel type in the inner region. The result of the calculations showed that safety features can be improved by using composite fuel of ( 235 U-Pu- 238 U) in the inner region. The equilibrium of main isotopes in CSR can be achieved after about 5 recycle stages. This study also showed that the CSR can burn and transmute MA up to 808 kg/stage in a single reactor operated with a reactivity swing of 2.8 % Δk/kk'. (author)

Concept of an inherently-safe high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Ohashi, Hirofumi; Sato, Hiroyuki; Tachibana, Yukio; Kunitomi, Kazuhiko; Ogawa, Masuro

2012-01-01

As the challenge to ensure no harmful release of radioactive materials at the accidents by deterministic approach instead to satisfy acceptance criteria or safety goal for risk by probabilistic approach, new concept of advanced reactor, an inherently-safe high temperature gas-cooled reactor, is proposed based on the experience of the operation of the actual High Temperature Gas-cooled Reactor (HTGR) in Japan, High Temperature Engineering Test Reactor (HTTR), and the design of the commercial plant (GTHTR300), utilizing the inherent safety features of the HTGR (i.e., safety features based on physical phenomena). The safety design philosophy of the inherently-safe HTGR for the safety analysis of the radiological consequences is determined as the confinement of radioactive materials is assured by only inherent safety features without engineered safety features, AC power or prompt actions by plant personnel if the design extension conditions occur. Inherent safety features to prevent the loss or degradation of the confinement function are identified. It is proposed not to apply the probabilistic approach for the evaluation of the radiological consequences of the accidents in the safety analysis because no inherent safety features fail for the mitigation of the consequences of the accidents. Consequently, there are no event sequences to harmful release of radioactive materials if the design extension conditions occur in the inherently-safe HTGR concept. The concept and future R and D items for the inherently-safe HTGR are described in this paper.

Demonstration of inherent safety features of HTGRs using the HTTR

International Nuclear Information System (INIS)

Tachibana, Yukio; Nakagawa, Shigeaki; Nakazawa, Toshio; Iyoku, Tatsuo

2004-01-01

Safety demonstration tests using the High Temperature Engineering Test Reactor (HTTR) are conducted for the purpose of demonstrating inherent safety features of High Temperature Gas-cooled Reactors (HTGRs) quantitatively as well as providing the core and plant transient data for validation of HTGR analysis codes for safety evaluation. The safety demonstration test are divided to the first phase and second phase tests. In the first phase tests, simulation tests of anticipated operational occurrences and anticipated transients without scram (ATWS) are conducted. The second phase tests will simulate accidents such as a depressurization accident (loss of coolant accident). The first phase test simulating reactivity insertion events and coolant flow reduction events stared in FY 2002. Post-test analyses have been conducted to reproduced the test results by using the core and plant dynamics analysis code, ACCORD and Monte Carlo code, MVP. The analysis results agreed fairly well with the test results of a control rod withdrawal test simulating reactivity insertion, and gas circulators trip test simulating coolant flow reduction, at power levels of 50% and 30% of the rated power, respectively. It is shown that improvement of the ACCORD code by taking into consideration vertical and horizontal temperature distribution gives better analysis results in the control rod withdrawal test. The fist phase safety demonstration tests will continue until FY 2005, and the second phase tests are planned to be started in FY 2006. (author)

The development of an inherent safety approach to the prevention of domino accidents.

Science.gov (United States)

Cozzani, Valerio; Tugnoli, Alessandro; Salzano, Ernesto

2009-11-01

The severity of industrial accidents in which a domino effect takes place is well known in the chemical and process industry. The application of an inherent safety approach for the prevention of escalation events leading to domino accidents was explored in the present study. Reference primary scenarios were analyzed and escalation vectors were defined. Inherent safety distances were defined and proposed as a metric to express the intensity of the escalation vectors. Simple rules of thumb were presented for a preliminary screening of these distances. Swift reference indices for layout screening with respect to escalation hazard were also defined. Two case studies derived from existing layouts of oil refineries were selected to understand the potentialities coming from the application in the methodology. The results evidenced that the approach allows a first comparative assessment of the actual domino hazard in a layout, and the identification of critical primary units with respect to escalation events. The methodology developed also represents a useful screening tool to identify were to dedicate major efforts in the design of add-on measures, optimizing conventional passive and active measures for the prevention of severe domino accidents.

Worldwide advanced nuclear power reactors with passive and inherent safety: What, why, how, and who

International Nuclear Information System (INIS)

Forsberg, C.W.; Reich, W.J.

1991-09-01

The political controversy over nuclear power, the accidents at Three Mile Island (TMI) and Chernobyl, international competition, concerns about the carbon dioxide greenhouse effect and technical breakthroughs have resulted in a segment of the nuclear industry examining power reactor concepts with PRIME safety characteristics. PRIME is an acronym for Passive safety, Resilience, Inherent safety, Malevolence resistance, and Extended time after initiation of an accident for external help. The basic ideal of PRIME is to develop power reactors in which operator error, internal sabotage, or external assault do not cause a significant release of radioactivity to the environment. Several PRIME reactor concepts are being considered. In each case, an existing, proven power reactor technology is combined with radical innovations in selected plant components and in the safety philosophy. The Process Inherent Ultimate Safety (PIUS) reactor is a modified pressurized-water reactor, the Modular High Temperature Gas-Cooled Reactor (MHTGR) is a modified gas-cooled reactor, and the Advanced CANDU Project is a modified heavy-water reactor. In addition to the reactor concepts, there is parallel work on super containments. The objective is the development of a passive ''box'' that can contain radioactivity in the event of any type of accident. This report briefly examines: why a segment of the nuclear power community is taking this new direction, how it differs from earlier directions, and what technical options are being considered. A more detailed description of which countries and reactor vendors have undertaken activities follows. 41 refs

Inherently safe high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Yamada, Masao; Hayakawa, Hitoshi

1987-01-01

It is recognized in general that High Temperature Gas-cooled Reactors have remarkable characteristics in inherent safety and it is well known that credits of the time margin have been admitted for accident evaluation in the licensing of the currently operating prototype HTGRs (300 MWe class). Recently, more inherently safe HTGRs are being developed in various countries and drawing attention on their possibility for urban siting. The inherent safety characteristics of these HTRs differ each other depending on their design philosophy and on the features of the components/structures which constitute the plant. At first, the specific features/characteristics of the elemental components/structures of the HTRs are explained one by one and then the overall safety features/characteristics of these HTR plants are explained in connection with their design philosophy and combination of the elemental features. Taking the KWU/Interatom Modular Reactor System as an example, the particular design philosophy and safety characteristics of the inherently safe HTR are explained with a result of preliminary evaluation on the possibility of siting close to densely populated area. (author)

Inherently safe light water reactors

International Nuclear Information System (INIS)

Ise, Takeharu

1987-01-01

Today's large nuclear power reactors of world-wise use have been designed based on the philosophy. It seems that recent less electricity demand rates, higher capital cost and the TMI accident let us acknowledge relative small and simplified nuclear plants with safer features, and that Chernobyl accident in 1983 underlines the needs of intrinsic and passive safety characteristics. In such background, several inherently safe reactor concepts have been presented abroad and domestically. First describing 'Can inherently safe reactors be designed,' then I introduce representative reactor concepts of inherently safe LWRs advocated abroad so far. All of these innovative reactors employ intrinsic and passive features in their design, as follows: (1) PIUS, an acronym for Process Inherent Ultimate Safety, or an integral PWR with passive heat sink and passive shutdown mechanism, advocated by ASEA-ATOM of Sweden. (2) MAP(Minimum Attention Plant), or a self-pressurized, natural circulation integral PWR, promoted by CE Inc. of the U.S. (3) TPS(TRIGA Power System), or a compact PWR with passive heat sink and inherent fuel characteristics of large prompt temperature coefficient, prompted by GA Technologies Inc. of the U.S. (4) PIUS-BWR, or an inherently safe BWR employing passively actuated fluid valves, in competition with PIUS, prompted by ORNL of the U.S. Then, I will describe the domestic trends in Japan and the innovative inherently safe LWRs presented domestically so far. (author)

Technology which led to the westinghouse inherently safe liquid metal reactor

International Nuclear Information System (INIS)

Schmidt, J.E.; Coffield, R.D.; Doncals, R.A.; Kalinowski, J.E.; Markley, R.A.

1985-01-01

The Fast Flux Test Facility (FFTF) and the Clinch River Breeder Reactor programs resulted in an understanding of liquid metal reactor behavior that is being used to design inherent safety capability into liquid metal reactors. Technological advances give the same beneficial operating characteristics of conventional liquid metal reactors, however, the addition of inherently safe design features precludes the initiation of hypothetical core disruptive accidents. These innovative features permit inherent safety capability to be demonstrated with more than adequate margins. Also, the variety of inherent safety features provides the designers with options in selecting inherent design features for a specific reactor application

Probabilities of inherent shutdown of unprotected events in innovative liquid metal reactors

International Nuclear Information System (INIS)

Mueller, C.J.; Wade, D.C.

1988-01-01

The uncertainty in predicting the effectiveness of inherent shutdown in innovative liquid metal cooled reactors with metallic fuel results from three broad contributing areas of uncertainty: (1) the inability to exactly predict the frequency of ATWS events with potential to challenge the safety systems and require inherent shutdown; (2) the approximation of representing all such events by a selected set of ''generic scenarios''; and (3) the inability to exactly calculate the core response to the selected generic scenarios. This paper discusses the work being done to address each of these contributing areas, identifies the design and research approaches being used at Argonne National Laboratory to reducing the key contributions to uncertainties in inherent shutdown, and presents results. The conditional probabilities (given ATWS initiation) of achieving temperatures capable of defeating inherent shutdown are shown to range from /approximately/0.1% to negligible for current designs

Improved inherent safety in liquid fuel reactors

International Nuclear Information System (INIS)

Taube, M.

1982-01-01

The molten salt reactor system divided into core (thermal and fast) and breeding zone (fission breeder reactor, fusion hybrid system, accelerator-spallation system) has some unique inherent safety properties: a) reduced inventory of fission products during normal operation due to on-line chemical reprocessing and in-core gas purging; b) fast removal of freshly bred fissile nuclides and fission products from the breeding zone (the so called suppressed fission system); c) pressureless fuel and primary coolant system; d) elimination of the possibility of a violent exoenergetic chemical reaction with air, water or metals; e) elimination of the possibility of gaseous hydrogen production during an accident; f) provides a non-engineered feature of dumping of fuel from the core and heat exchanger to a safe drain tank; g) presence of a large heat sink in the form of an inactive diluent salt; h) possibility of natural convection heat removal during an accident and even normal operation (by means of gas lifting); i) dissipation of the remaining decayheat by spraying water on the containment from outside, which allows to manage the worst accident; i) Even in the case of the destruction in the war by conventional or nuclear weapon the contaminated land is significantly reduced. The world-wide present activity in the field of molten salt technology is reviewed. (orig.)

Molten salt reactor as asymptotic safety nuclear system

International Nuclear Information System (INIS)

Novikov, V.M.; Ignatyev, V.V.

1989-01-01

Safety is becoming the main and priority problem of the nuclear power development. An increase of the active safety measures could hardly be considered as the proper way to achieve the asymptotically high level of nuclear safety. It seem that the more realistic way to achieve such a goal is to minimize risk factors and to maximize the use of inherent and passive safety properties. The passive inherent safety features of the liquid fuel molten salt reactor (MSR) technology are making it attractive for future energy generation. The achievement of the asymptotic safety in MSR is being connected with the minimization of such risk factors as a reactivity excess, radioactivity stored, decay heat, non nuclear energy stored in core. In this paper safety peculiarities of the different MSR concepts are discussed

Mitigation of Severe Accident Consequences Using Inherent Safety Principles

International Nuclear Information System (INIS)

Wigeland, R.A.; Cahalan, J.E.

2009-01-01

Sodium-cooled fast reactors are designed to have a high level of safety. Events of high probability of occurrence are typically handled without consequence through reliable engineering systems and good design practices. For accidents of lower probability, the initiating events are characterized by larger and more numerous challenges to the reactor system, such as failure of one or more major engineered systems and can also include a failure to scram the reactor in response. As the initiating conditions become more severe, they have the potential for creating serious consequences of potential safety significance, including fuel melting, fuel pin disruption and recriticality. If the progression of such accidents is not mitigated by design features of the reactor, energetic events and dispersal of radioactive materials may result. For severe accidents, there are several approaches that can be used to mitigate the consequences of such severe accident initiators, which typically include fuel pin failures and core disruption. One approach is to increase the reliability of the reactor protection system so that the probability of an ATWS event is reduced to less than 1 x 10-6 per reactor year, where larger accident consequences are allowed, meeting the U.S. NRC goal of relegating such accident consequences as core disruption to these extremely low probabilities. The main difficulty with this approach is to convincingly test and guarantee such increased reliability. Another approach is to increase the redundancy of the reactor scram system, which can also reduce the probability of an ATWS event to a frequency of less than 1 x 10-6 per reactor year or lower. The issues with this approach are more related to reactor core design, with the need for a greater number of control rod positions in the reactor core and the associated increase in complexity of the reactor protection system. A third approach is to use the inherent reactivity feedback that occurs in a fast reactor to

MHTGR inherent heat transfer capability

International Nuclear Information System (INIS)

Berkoe, J.M.

1992-01-01

This paper reports on the Commercial Modular High Temperature Gas-Cooled Reactor (MHTGR) which achieves improved reactor safety performance and reliability by utilizing a completely passive natural convection cooling system called the RCCS to remove decay heat in the event that all active cooling systems fail to operate. For the highly improbable condition that the RCCS were to become non-functional following a reactor depressurization event, the plant would be forced to rely upon its inherent thermo-physical characteristics to reject decay heat to the surrounding earth and ambient environment. A computational heat transfer model was created to simulate such a scenario. Plant component temperature histories were computed over a period of 20 days into the event. The results clearly demonstrate the capability of the MHTGR to maintain core integrity and provide substantial lead time for taking corrective measures

Prospects for inherently safe reactors

International Nuclear Information System (INIS)

Barkenbus, J.N.

1988-01-01

Public fears over nuclear safety have led some within the nuclear community to investigate the possibility of producing inherently safe nuclear reactors; that is, reactors that are transparently incapable of producing a core melt. While several promising designs of such reactors have been produced, support for large-scale research and development efforts has not been forthcoming. The prospects for commercialization of inherently safe reactors, therefore, are problematic; possible events such as further nuclear reactor accidents and superpower summits, could alter the present situation significantly. (author)

Demonstrated operational and inherent safety of the prototype fast reactor (PFR)

International Nuclear Information System (INIS)

Smedley, J.A.; Gregory, C.V.; Judd, A.M.

1983-01-01

The Prototype Fast Reactor (PFR) is sited at Dounreay, on the north coast of Scotland in the United Kingdom, and has been in operation since 1974. Three aspects of the safety of the reactor are described, including the all-important practical consideration of operational safety, a demonstration of the limited consequences of a sodium/water reaction in a steam generator and the ability of the reactor to protect itself against highly improbable incidents. Attention is drawn to the low radiation levels in the plant and the correspondingly low dose rate to personnel. A feature of PFR operation has been the stable and predictable behaviour of its core together with the high degree of reliability exhibited by the engineered safety system. No failures have occurred within the standard driver charge but two experimental fuel pins suffered cladding failure, which was detected easily by the fission gas and delayed neutron detection systems. In the steam generating units sodium and water are separated by the single steel wall of the steam tubes. Although no under-sodium leak has occurred, an experimental programme is continuing and demonstrates that were any such leak to occur its consequences would be containable and would not result in the release of sodium to the environment or any breach of the reactor containment. The final section describes the inherent safety features of the reactor which enable it to survive a range of very improbable incidents even when the engineered safeguards fail. The features considered are natural circulation, which has been demonstrated by reactor experiment; the reactor's negative power coefficient, which, for example, enables the reactor to survive a complete loss of heat sink; and the durability of the fuel pins, demonstrated by a series of boiling experiments in the Dounreay Fast Reactor (DFR). (author)

Process Inherent Ultimate Safety (PIUS) reactor evaluation study: Final report

International Nuclear Information System (INIS)

1987-02-01

This report presents the results of an independent study by United Engineers and Constructors (UNITED) of the SECURE-P Process Inherent Ultimate Safety (PIUS) Reactor Concept which is presently under development by the Swedish light water reactor vendor ASEA-ATOM of Vasteras, Sweden. This study was performed to investigate whether there is any realistic basis for believing that the PIUS reactor could be a viable competitor in the US energy market in the future. Assessments were limited to the technical, economic and licensing aspects of PIUS. Socio-political issues, while certainly important in answering this question, are so broad and elusive that it was considered that addressing them with the limited perspective of one small group from one company would be of questionable value and likely be misleading. Socio-political issues aside, the key issue is economics. For this reason, the specific objectives of this study were to determine if the estimated PIUS plant cost will be competitive in the US market and to identify and evaluate the technical and licensing risks that might make PIUS uneconomical or otherwise unacceptable

Preliminary risk assessment of the Integral Inherently-Safe Light Water Reactor

International Nuclear Information System (INIS)

McCarroll, Kellen R.; Lee, John C.; Manera, Annalisa; Memmott, Matthew J.; Ferroni, Paolo

2017-01-01

The Integral, Inherently Safe Light Water Reactor (I 2 S-LWR) concept seeks to significantly increase nuclear power plant safety. The project implements a safety-by-design philosophy, eliminating several initiating events and providing novel, passive safety systems at the conceptual phase. Pursuit of unparalleled safety employs an integrated development process linking design with deterministic and probabilistic safety analyses. Unique aspects of the I 2 S-LWR concept and design process present challenges to the probabilistic risk assessment (PRA), particularly regarding overall flexibility, auditability and resolution of results. Useful approaches to initiating events and conditional failures are presented. To exemplify the risk-informed design process using PRA, a trade-off study of two safety system configurations is presented. Although further optimization is required, preliminary results indicate that the I 2 S-LWR can achieve a core damage frequency (CDF) from internal events less than 1.01 × 10 −8 /ry, including reactor vessel ruptures. Containment bypass frequency due to primary heat exchanger rupture is found to be comparable to non-vessel rupture CDF.

An inherently safe power reactor module

International Nuclear Information System (INIS)

Salerno, L.N.

1985-01-01

General Electric's long participation in liquid metal reactor technology has led to a Power Reactor Inherently Safe Module (PRISM) concept supported by DOE contract DE-AC06-85NE37937. The reactor module is sized to maximize inherent safety features. The small size allows factory fabrication, reducing field construction and field QA/QC labor, and allows safety to be demonstrated in full scale, to support a pre-licensed standard commercial product. The module is small enough to be placed underground, and can be combined with steam and electrical generating equipment to provide a complete electrical power producing plant in the range of 400-1200 MWe. Initial assessments are that the concept has the potential to be economically competitive with existing methods of power production used by the utility industry

Toxic release consequence analysis tool (TORCAT) for inherently safer design plant

International Nuclear Information System (INIS)

Shariff, Azmi Mohd; Zaini, Dzulkarnain

2010-01-01

Many major accidents due to toxic release in the past have caused many fatalities such as the tragedy of MIC release in Bhopal, India (1984). One of the approaches is to use inherently safer design technique that utilizes inherent safety principle to eliminate or minimize accidents rather than to control the hazard. This technique is best implemented in preliminary design stage where the consequence of toxic release can be evaluated and necessary design improvements can be implemented to eliminate or minimize the accidents to as low as reasonably practicable (ALARP) without resorting to costly protective system. However, currently there is no commercial tool available that has such capability. This paper reports on the preliminary findings on the development of a prototype tool for consequence analysis and design improvement via inherent safety principle by utilizing an integrated process design simulator with toxic release consequence analysis model. The consequence analysis based on the worst-case scenarios during process flowsheeting stage were conducted as case studies. The preliminary finding shows that toxic release consequences analysis tool (TORCAT) has capability to eliminate or minimize the potential toxic release accidents by adopting the inherent safety principle early in preliminary design stage.

Safety characteristics of small heat producing reactors

International Nuclear Information System (INIS)

Seifritz, W.

1987-10-01

The primary objectives of protection in nuclear power plants are the possibility to shut the reactor down in case of emergency and keep it subcritical in the long run, the existence of a heat sink for post-decay heat removal in order to avoid overheating, let alone core meltdown, and the containment of radioactivity within the barriers designed for this purpose, thus preventing significant activity release. In principle, these objectives can be met in various ways, namely by active, passive or inherent technical safeguards systems. In practice, a mixture of these approaches is employed in almost all cases. What matters in the end is the assessment of the overall concept, not of some outstanding feature. Inherent characteristics are easier to achieve in small reactors. However, also in this case, inherent safety does not mean absolute safety. If inherent safety characteristics were all encompassing, they would have to include self-healing effects. However, inanimate matter is incapable of such self-organization. Consequently, inherent characteristics in nuclear technology by definition should include the increased use of dissipative processes in the thermal part of the plant. (author)

Safety objectives for next generation reactors: proving their achievement

International Nuclear Information System (INIS)

Tanguy, P.Y.

1996-01-01

Assuming that there is a consensus between regulatory bodies and nuclear operating organizations on safety objectives for future plants, how are we going to demonstrate that they have been achieved, with a reasonable certainty? Right from the beginning, I would like to underline the importance of convincing the public that high level safety objectives will be effectively achieved in future nuclear power plants. The mere fulfillment of administrative requirements might not be sufficient to obtain public acceptance. One has to take into account the changes that have occurred in the public preception of nuclear risks in the wake of the Chernobyl accident. Today public opinion rules out the possibility not only that such a catastrophic accident could recur, but also that any accident with detrimental health consequences off-site could occur. The nuclear industry has to reflect this concern in its safety demonstration, independently of proving the achievement of technical safety goals. The public opinion issue will be readdressed at the end of this paper. (orig.)

Licensing issues for inherently safe fast reactors

International Nuclear Information System (INIS)

Kastenberg, W.E.; Lee, S.; Okrent, D.

1986-01-01

There has been considerable interest recently in a new generation of liquid metal reactor (LMR) concepts in the US. Some significant changes in regulatory philosophy will be required if the anticipated cost advantages of inherently safe designs are to be achieved. The defense in depth philosophy will need to be significantly re-evaluated in the context of inherently safe reactors. It is the purpose of this paper to begin such a re-evaluation of this regulatory philosophy

Implications of inherent safe nuclear power system

International Nuclear Information System (INIS)

Song, Yo-Taik

1987-01-01

The safety of present day nuclear power reactors and research reactors depends on a combination of design features of passive and active systems, and the alert judgement of their operators. A few inherently safe designs of nuclear reactors for power plants are currently under development. In these designs, the passive systems are emphasized, and the active systems are minimized. Also efforts are made to eliminate the potential for human failures that initiate the series of accidents. If a major system fails in these designs, the core is flooded automatically with coolants that flow by gravity, not by mechanical pumps or electromagnetic actuators. Depending on the choice of the coolants--water, liquid metal and helium gas--there are three principal types of inherently safe reactors. In this paper, these inherently safe reactor designs are reviewed and their implications are discussed. Further, future perspectives of their acceptance by nuclear industries are discussed. (author)

Key asset - inherent safety of LMFBR Pool Plant

International Nuclear Information System (INIS)

Marchaterre, J.F.; Sevy, R.H.; Lancet, R.T.; Mills, J.C.

1984-04-01

The safety approach used in the design of the Large Pool Plant emphasizes use of the intrinsic characteristics of Liquid Metal Fast Breeder Reactors to incorporate a high degree of safety in the design and reduce cost by providing simpler (more reliable) dedicated safety systems. Correspondingly, a goal was not to require the action of active systems to prevent significant core damage and/or provide large grace periods for all anticipated transients. The key safety features of the plant are presented and the analysis of representative flow and power transients are presented to show that the design goal has been satisfied

Key asset--Inherent safety of LFMBR pool plant

International Nuclear Information System (INIS)

Marchaterre, J.F.; Lancet, R.T.; Mills, J.C.; Sevy, R.H.

1984-01-01

The safety approach used in the design of the Large Pool Plant emphasizes use of the intrinsic characteristics of Liquid Metal Fast Breeder Reactors to incorporate a high degree of safety in the design and reduce cost by providing simpler (more reliable) dedicated safety systems. Correspondingly, a goal was not to require the action of active systems to prevent significant core damage and/or provide large grace periods for all anticipated transients. The key safety features of the plant are presented and the analysis of representative flow and power transients are presented to show that the design goal has been satisfied

Ordeals of Chernobyl and the rejustification of the inherently safe reactors

International Nuclear Information System (INIS)

Lu, Y.

1989-01-01

This paper presents the necessity of developing inherently safe economic reactors (ISERs). Two characteristics which define inherent safety are discussed on the basis of various applications of such a principle in practice. Different design concepts of ISERs are then evaluated and their possible role in the future nuclear program of PRC discussed. A three-stage development strategy of ISERs in PRC is proposed

Safety performance of preliminary KALIMER conceptual design

Energy Technology Data Exchange (ETDEWEB)

Hahn Dohee; Kim Kyoungdoo; Kwon Youngmin; Chang Wonpyo; Suk Soodong [Korea atomic Energy Resarch Inst., Taejon (Korea)

1999-07-01

The Korea Atomic Energy Research Institute (KAERI) is developing KALIMER (Korea Advanced Liquid Metal Reactor), which is a sodium cooled, 150 MWe pool-type reactor. The safety design of KALIMER emphasizes accident prevention by using passive processes, which can be accomplished by the safety design objectives including the utilization of inherent safety features. In order to assess the effectiveness of the inherent safety features in achieving the safety design objectives, a preliminary evaluation of ATWS performance for the KALIMER design has been performed with SSC-K code, which is a modified version of SSC-L code. KAERI's modification of the code includes development of reactivity feedback models for the core and a pool model for KALIMER reactor vessel. This paper describes the models for control rod driveline expansion, gas expansion module and the thermal hydraulic model for reactor pool and the results of preliminary analyses for unprotected loss of flow and loss o heat sink. (author)

Safety performance of preliminary KALIMER conceptual design

International Nuclear Information System (INIS)

Hahn Dohee; Kim Kyoungdoo; Kwon Youngmin; Chang Wonpyo; Suk Soodong

1999-01-01

The Korea Atomic Energy Research Institute (KAERI) is developing KALIMER (Korea Advanced Liquid Metal Reactor), which is a sodium cooled, 150 MWe pool-type reactor. The safety design of KALIMER emphasizes accident prevention by using passive processes, which can be accomplished by the safety design objectives including the utilization of inherent safety features. In order to assess the effectiveness of the inherent safety features in achieving the safety design objectives, a preliminary evaluation of ATWS performance for the KALIMER design has been performed with SSC-K code, which is a modified version of SSC-L code. KAERI's modification of the code includes development of reactivity feedback models for the core and a pool model for KALIMER reactor vessel. This paper describes the models for control rod driveline expansion, gas expansion module and the thermal hydraulic model for reactor pool and the results of preliminary analyses for unprotected loss of flow and loss o heat sink. (author)

The inherently-safe power reactor DYONISOS (Dynamic Nuclear Inherently-Safe Reactor Operating with Spheres)

International Nuclear Information System (INIS)

Taube, M.; Lanfranchi, M.; Weissenfluh, Th. von; Ligou, J.; Yadigaroglu, G.; Taube, P.

1986-01-01

A philosophy of inherent safety is formulated and an inherently-safe thermal power reactor is presented. Solid fuel in the form of spheres a few centimetres in diameter is suspended under the hydro-dynamic pressure of molten lead coolant in vertical channels within the graphite moderator. Loss of main pump pressure, or a loss-of-coolant accident (LOCA), results in immediate removal of the fuel to rigid sieves below the core, with consequent subcriticality. Residual and decay heat are carried away by thermal conduction through the coolant or, in the case of a LOCA, by a combination of radiation and natural convection of cover gas or incoming air from the fuel to the reactor vessel and convection of air between the vessel and steel containment wall. All decay heat removal systems are passive, though actively initiated external spray cooling of the containment can be used to reduce wall temperature. This, however, is only necessary in the case of a LOCA and after a period of 24 h. (author)

Integral Inherently Safe Light Water Reactor (I2S-LWR)

International Nuclear Information System (INIS)

Petrovic, Bojan; Memmott, Matthew; Boy, Guy; Charit, Indrajit; Manera, Annalisa; Downar, Thomas; Lee, John; Muldrow, Lycurgus; Upadhyaya, Belle; Hines, Wesley; Haghighat, Alierza

2017-01-01

This final report summarizes results of the multi-year effort performed during the period 2/2013- 12/2016 under the DOE NEUP IRP Project ''Integral Inherently Safe Light Water Reactors (I 2 S-LWR)''. The goal of the project was to develop a concept of a 1 GWe PWR with integral configuration and inherent safety features, at the same time accounting for lessons learned from the Fukushima accident, and keeping in mind the economic viability of the new concept. Essentially (see Figure 1-1) the project aimed to implement attractive safety features, typically found only in SMRs, to a larger power (1 GWe) reactor, to address the preference of some utilities in the US power market for unit power level on the order of 1 GWe.

SVBR-75/100 multi-purpose modular inherent-safety fast reactor

International Nuclear Information System (INIS)

Dragunov, Yu.G.; Stepanov, V.S.; Klimov, N.N.; Dedul, A.V.; Zrodnokov, A.V.; Toshinsky, G.I.; Komlev, O.G.; Krushelnitsky, V.N.; Takh, S.M.

2006-01-01

In this century energy consumption, including electric power, will continue growing on a large scale especially in developing countries. Significant changes in electric power market needs are to be expected in the direction of decreasing and varying the capacity of power sources. To satisfy the expected growth of demand for electric power and to take a decision concerning the ways of further development of global power, including nuclear engineering, it is very important to continue the development of innovative concepts of nuclear power sources, which might successfully compete with alternative power technologies at the future power markets. The proposed nuclear power source (or in other words - reactor plant) of new generation is supposed: - to have small power capacity in the range of 10 - 100 MW (electric) and possibility of its multi-purpose application (independent nuclear power source for desalination installations and electricity supply, nuclear power plants (NPP) of various capacity and purpose; - to use modular principle of construction of NPP of various capacity on the basis of unified 'typical' reactor plants; - to have qualitatively new level of passive safety and possess properties of inherent safety, deterministically excluding any opportunity of severe accidents; - to have an opportunity to use different kinds of fuel and to work in various fuel cycles at various stages of development of nuclear power without change in the design. And also to have long (7-10 years, and in the long term 15-20 years) core life time and enrichment on U-235 not higher than 20 % (which is in compliance with recommendations of IAEA under non-proliferation condition); - to be completely factory-manufactured, and an opportunity of its safe transportation to and from the NPP site shall be provided. Unified multi-purpose reactor plant SVBR-75/100 (Lead-Bismuth Fast Reactor with equivalent electric power of 75 - 100 MW-e depending on the steam parameters) meets the set of the

The application of probabilistic risk assessment to inherently safe reactors

International Nuclear Information System (INIS)

Cave, L.; Kastenberg, W.E.

1987-01-01

In the development of safety goals and design criteria for 'inherently safe' reactors a question which arises is 'To what extent is PRA relevant.' To answer this question it is necessary to consider both the risk to the public and the investment risk to the utility. In this paper the factors which are likely to determine safety objectives and their allocation are presented. (orig.)

Inherently safe technologies-chemical and nuclear

International Nuclear Information System (INIS)

Weinberg, A.M.

1984-01-01

Probabilistic risk assessments show an inverse relationship between the likelihood and the consequences of nuclear and chemical plant accidents, but the Bhopal accident has change public complacency about the safety of chemical plants to such an extent that public confidence is now at the same low level as with nuclear plants. The nuclear industry's response was to strengthen its institutions and improve its technologies, but the public may not be convinced. One solution is to develop reactors which do not depend upon the active intervention of humans of electromechanical devices to deal with emergencies, but which have physical properties that limit the possible temperature and power of a reactor. The Process Inherent Ultimately Safe and the modular High-Temperature Gas-Cooled reactors are two possibilities. the chemical industry needs to develop its own inherently safe design precepts that incorporate smallness, safe processes, and hardening against sabotage. 5 references

Efficiency of inherent protection mechanisms for an improved HTR safety concept

Energy Technology Data Exchange (ETDEWEB)

Petersen, K.; Buescher, R.; Gerwin, H.; Schenk, W. [Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Reaktorentwicklung

1981-01-15

For a preliminary design of a 350 MWsub(th) annular core derived from AVR-reactor the efficiency of inherent protection mechanisms is discussed. After-heat removal and auto-shut down potential are demonstrated for intact and complete failure of core heat sinks.

The near boiling reactor: Conceptual design of a small inherently safe nuclear reactor to extend the operational capability of the Victoria Class submarine

Science.gov (United States)

Cole, Christopher J. P.

Nuclear power has several unique advantages over other air independent energy sources for nuclear combat submarines. An inherently safe, small nuclear reactor, capable of supply the hotel load of the Victoria Class submarines, has been conceptually developed. The reactor is designed to complement the existing diesel electric power generation plant presently onboard the submarine. The reactor, rated at greater than 1 MW thermal, will supply electricity to the submarine's batteries through an organic Rankine cycle energy conversion plant at 200 kW. This load will increase the operational envelope of the submarine by providing up to 28 continuous days submerged, allowing for an enhanced indiscretion ratio (ratio of time spent on the surface versus time submerged) and a limited under ice capability. The power plant can be fitted into the existing submarine by inserting a 6 m hull plug. With its simplistic design and inherent safety features, the reactor plant will require a minimal addition to the crew. The reactor employs TRISO fuel particles for increased safety. The light water coolant remains at atmospheric pressure, exiting the core at 96°C. Burn-up control and limiting excess reactivity is achieved through movable reflector plates. Shut down and regulatory control is achieved through the thirteen hafnium control rods. Inherent safety is achieved through the negative prompt and delayed temperature coefficients, as well as the negative void coefficient. During a transient, the boiling of the moderator results in a sudden drop in reactivity, essentially shutting down the reactor. It is this characteristic after which the reactor has been named. The design of the reactor was achieved through modelling using computer codes such as MCNP5, WIMS-AECL, FEMLAB, and MicroShield5, in addition to specially written software for kinetics, heat transfer and fission product poisoning calculations. The work has covered a broad area of research and has highlighted additional areas

The near boiling reactor : conceptual design of a small inherently safe nuclear reactor to extend the operational capability of the Victoria Class submarine

International Nuclear Information System (INIS)

Cole, C.J.P.

2005-01-01

Nuclear power has several unique advantages over other air independent energy sources for nuclear combat submarines. An inherently safe, small nuclear reactor, capable of supply the hotel load of the 'Victoria' Class submarines, has been conceptually developed. The reactor is designed to complement the existing diesel electric power generation plant presently onboard the submarine. The reactor, rated at greater than 1 MW thermal, will supply electricity to the submarine's batteries through an organic Rankine cycle energy conversion plant at 200 kW. This load will increase the operational envelope of the submarine by providing up to 28 continuous days submerged, allowing for an enhanced indiscretion ratio (ratio of time spent on the surface versus time submerged) and a limited under ice capability. The power plant can be fitted into the existing submarine by inserting a 6 m hull plug. With its simplistic design and inherent safety features, the reactor plant will require a minimal addition to the crew. The reactor employs TRISO fuel particles for increased safety. The light water coolant remains at atmospheric pressure, exiting the core at 96 o C. Burn-up control and limiting excess reactivity is achieved through movable reflector plates. Shut down and regulatory control is achieved through the thirteen hafnium control rods. Inherent safety is achieved through the negative prompt and delayed temperature coefficients, as well as the negative void coefficient. During a transient, the boiling of the moderator results in a sudden drop in reactivity, essentially shutting down the reactor. It is this characteristic after which the reactor has been named. The design of the reactor was achieved through modelling using computer codes such as MCNP5, WIMS-AECL, FEMLAB, and MicroShield5, in addition to specially written software for kinetics, heat transfer and fission product poisoning calculations. The work has covered a broad area of research and has highlighted additional

Inherent safe design of advanced high temperature reactors - concepts for future nuclear power plants

International Nuclear Information System (INIS)

Hodzic, A.; Kugeler, K.

1997-01-01

This paper discusses the applicable solutions for a commercial size High Temperature Reactor (HTR) with inherent safety features. It describes the possible realization using an advanced concept which combines newly proposed design characteristics with some well known and proven HTR inherent safety features. The use of the HTR technology offers the conceivably best solution to meet the legal criteria, recently stated in Germany, for the future reactor generation. Both systems, block and pebble bed ,reactor, could be under certain design conditions self regulating in terms of core nuclear heat, mechanical stability and the environmental transfer. 23 refs., 7 figs

Food plant toxicants and safety - Risk assessment and regulation of inherent toxicants in plant foods

DEFF Research Database (Denmark)

Essers, A.J.A.; Alink, G.M.; Speijers, G.J.A.

1998-01-01

The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI...... values, particularly when extrapolating from animal data, would prohibit the utilisation of the food, which may have an overall beneficial health effect. Levels of inherent toxicants are difficult to control; their complete removal is not always wanted, due to their function for the plant or for human...... health. The health impact of the inherent toxicant is often modified by factors in the food, e.g. the bioavailability from the matrix and interaction with other inherent constituents. Risk-benefit analysis should be made for different consumption scenarios, without the use of uncertainty factors. Crucial...

Nuclear desalination in the Arab world - Part II: Advanced inherent and passive safe nuclear reactors

International Nuclear Information System (INIS)

Karameldin, A.; Samer S. Mekhemar

2004-01-01

Rapid increases in population levels have led to greater demands for fresh water and electricity in the Arab World. Different types of energies are needed to contribute to bridging the gap between increased demand and production. Increased levels of safeguards in nuclear power plants have became reliable due to their large operational experience, which now exceeds 11,000 years of operation. Thus, the nuclear power industry should be attracting greater attention. World electricity production from nuclear power has risen from 1.7% in 1970 to 17%-20% today. This ratio had increased in June 2002 to reach more than 30%, 33% and 42% in Europe, Japan, and South Korea respectively. In the Arab World, both the public acceptance and economic viability of nuclear power as a major source of energy are greatly dependent on the achievement of a high level of safety and environmental protection. An assessment of the recent generation of advanced reactor safety criteria requirements has been carried out. The promising reactor designs adapted for the Arab world and other similar developing countries are those that profit from the enhanced and passive safety features of the new generation of reactors, with a stronger focus on the effective use of intrinsic characteristics, simplified plant design, and easy construction, operation and maintenance. In addition, selected advanced reactors with a full spectrum from small to large capacities, and from evolutionary to radical types, which have inherent and passive safety features, are discussed. The relevant economic assessment of these reactors adapted for water/electricity cogeneration have been carried out and compared with non-nuclear desalination methods. This assessment indicates that, water/electricity cogeneration by the nuclear method with advanced inherent and passive safe nuclear power plants, is viable and competitive. (author)

Impacts of reactivity feedback uncertainties on inherent shutdown in innovative designs

International Nuclear Information System (INIS)

Mueller, C.J.

1986-01-01

The concept of inherent shutdown is emphasized in the approach to the design of innovative, small pool-type liquid-metal reactors (LMRs). This paper reports an evaluation of reactivity feedback uncertainties used in the analyses of anticipated transients without scram for innovative LMRs, and the associated impacts on safety margins and inherent shutdown success probabilities on unprotected loss-of-flow (LOF) events. It then assesses the ultimate importance of these uncertainties on LOF and transient overpower events in evolving metal and oxide innovative designs

Impacts of reactivity feedback uncertainties on inherent shutdown in innovative designs

International Nuclear Information System (INIS)

Mueller, C.J.

1986-01-01

The concept of ''inherent shutdown'' is emphasized in the approach to the design of innovative, small pool-type liquid metal reactors (LMRs). This paper reports an evaluation of reactivity feedback uncertainties used in the analyses of anticipated transients without scram (ATWS) for innovative LMRs, and the associated impacts on safety margins and inherent shutdown success probabilities on unprotected loss-of-flow (LOF) events. It then assesses the ultimate importance of these uncertainties on LOF and transient overpower (TOP) events in evolving metal and oxide innovative designs

Inherent work suit buoyancy distribution: effects on lifejacket self-righting performance.

Science.gov (United States)

Barwood, Martin J; Long, Geoffrey M; Lunt, Heather; Tipton, Michael J

2014-09-01

Accidental immersion in cold water is an occupational risk. Work suits and life jackets (LJ) should work effectively in combination to keep the airway clear of the water (freeboard) and enable self-righting. We hypothesized that inherent buoyancy, in the suit or LJ, would be beneficial for enabling freeboard, but its distribution may influence LJ self-righting. Six participants consented to complete nine immersions. Suits and LJ tested were: flotation suit (FLOAT; 85 N inherent buoyancy); oilskins 1 (OS-1) and 2 (OS-2), both with no inherent buoyancy; LJs (inherent buoyancy/buoyancy after inflation/total buoyancy), LJ-1 50/150/200 N, LJ-2 0/290/290 N, LJ-3 80/190/270 N. Once dressed, the subject entered an immersion pool where uninflated freeboard, self-righting performance, and inflated freeboard were measured. Data were compared using Friedman's test to the 0.05 alpha level. All suits and LJs enabled uninflated and inflated freeboard, but differences were seen between the suits and LJs. Self-righting was achieved on 43 of 54 occasions, irrespective of suit or LJ. On all occasions that self-righting was not achieved, this occurred in an LJ that included inherent buoyancy (11/54 occasions). Of these 11 failures, 8 occurred (73% of occasions) when the FLOAT suit was being worn. LJs that included inherent buoyancy, that are certified as effective on their own, worked less effectively from the perspective of self-righting in combination with a work suit that also included inherent buoyancy. Equipment that is approved for use in the workplace should be tested in combination to ensure adequate performance in an emergency scenario.

Inherent Conservatism in Deterministic Quasi-Static Structural Analysis

Science.gov (United States)

Verderaime, V.

1997-01-01

The cause of the long-suspected excessive conservatism in the prevailing structural deterministic safety factor has been identified as an inherent violation of the error propagation laws when reducing statistical data to deterministic values and then combining them algebraically through successive structural computational processes. These errors are restricted to the applied stress computations, and because mean and variations of the tolerance limit format are added, the errors are positive, serially cumulative, and excessively conservative. Reliability methods circumvent these errors and provide more efficient and uniform safe structures. The document is a tutorial on the deficiencies and nature of the current safety factor and of its improvement and transition to absolute reliability.

HTGR safety philosophy

Energy Technology Data Exchange (ETDEWEB)

Joksimovic, V.; Fisher, C. R. [General Atomic Co., San Diego, CA (USA)

1981-01-15

The accident at the Three Mile Island has focused public attention on reactor safety. Many public figures advocate a safer method of generating nuclear electricity for the second nuclear era in the U.S. The paper discusses the safety philosophy of a concept deemed suitable for this second nuclear era. The HTGR, in the course of its evolution, included safety as a significant determinant in design philosophy. This is particularly evident in the design features which provide inherent safety. Inherent features cause releases from a wide spectrum of accident conditions to be low. Engineered features supplement inherent features. The significance of HTGR safety features is quantified and order-of-magnitude type of comparisons are made with alternative ways of generating electricity.

HTGR safety philosophy

International Nuclear Information System (INIS)

Joksimovic, V.; Fisher, C.R.

1981-01-01

The accident at the Three Mile Island has focused public attention on reactor safety. Many public figures advocate a safer method of generating nuclear electricity for the second nuclear era in the U.S. The paper discusses the safety philosophy of a concept deemed suitable for this second nuclear era. The HTGR, in the course of its evolution, included safety as a significant determinant in design philosophy. This is particularly evident in the design features which provide inherent safety. Inherent features cause releases from a wide spectrum of accident conditions to be low. Engineered features supplement inherent features. The significance of HTGR safety features is quantified and order-of-magnitude type of comparisons are made with alternative ways of generating electricity. (author)

HTGR safety philosophy

International Nuclear Information System (INIS)

Joskimovic, V.; Fisher, C.R.

1980-08-01

The accident at the Three Mile Island has focused public attention on reactor safety. Many public figures advocate a safer method of generating nuclear electricity for the second nuclear era in the US. The paper discusses the safety philosophy of a concept deemed suitable for this second nuclear era. The HTGR, in the course of its evolution, included safety as a significant determinant in design philosophy. This is particularly evident in the design features which provide inherent safety. Inherent features cause releases from a wide spectrum of accident conditions to be low. Engineered features supplement inherent features. The significance of HTGR safety features is quantified and order-of-magnitude type of comparisons are made with alternative ways of generating electricity

Progress on PRISM, an inherently safe, economic, and testable advanced liquid metal reactor

International Nuclear Information System (INIS)

Tippets, F.E.; Salerno, L.N.; Boardman, C.E.; Kwant, W.; Murata, R.E.; Snyder, C.R.

1987-01-01

This paper reports progress on the design of PRISM (Power Reactor Inherently Safe Module) under the DOE-sponsored innovative reactor program now in its third year at General Electric. The purpose of this program is to develop a design for an inherently safe, reliable, and marketable liquid metal fast reactor power plant. The PRISM design approach includes the following key elements: Compact sodium-cooled pool-type reactor modules that are sized to enable factory fabrication, economical shipment to inland as well as water-side sites, and economical full-scale prototype testing for design certification; Nuclear safety-related envelope limited to the reactor modules and their service systems; Inherent, passive shutdown heat removal for loss-of-cooling events; Inherent, passive reactivity shutdown for failure-to-scram events

Integral Inherently Safe Light Water Reactor (I²S-LWR)

Energy Technology Data Exchange (ETDEWEB)

Petrovic, Bojan [Georgia Inst. of Technology, Atlanta, GA (United States); Memmott, Matthew [Brigham Young Univ., Provo, UT (United States); Boy, Guy [Florida Inst. of Technology, Melbourne, FL (United States); Charit, Indrajit [Univ. of Idaho, Moscow, ID (United States); Manera, Annalisa [Univ. of Michigan, Ann Arbor, MI (United States); Downar, Thomas [Univ. of Michigan, Ann Arbor, MI (United States); Lee, John [Univ. of Michigan, Ann Arbor, MI (United States); Muldrow, Lycurgus [Morehouse College, Atlanta, GA (United States); Upadhyaya, Belle [Univ. of Tennessee, Knoxville, TN (United States); Hines, Wesley [Univ. of Tennessee, Knoxville, TN (United States); Haghighat, Alierza [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

2017-10-02

This final report summarizes results of the multi-year effort performed during the period 2/2013- 12/2016 under the DOE NEUP IRP Project “Integral Inherently Safe Light Water Reactors (I²S-LWR)”. The goal of the project was to develop a concept of a 1 GWe PWR with integral configuration and inherent safety features, at the same time accounting for lessons learned from the Fukushima accident, and keeping in mind the economic viability of the new concept. Essentially (see Figure 1-1) the project aimed to implement attractive safety features, typically found only in SMRs, to a larger power (1 GWe) reactor, to address the preference of some utilities in the US power market for unit power level on the order of 1 GWe.

Design strategy for control of inherently safe reactors

International Nuclear Information System (INIS)

Chisholm, G.H.

1984-01-01

Reactor power plant safety is assured through a combination of engineered barriers to radiation release (e.g., reactor containment) in combination with active reactor safety systems to shut the reactor down and remove decay heat. While not specifically identified as safety systems, the control systems responsible for continuous operation of plant subsystems are the first line of defense for mitigating radiation releases and for plant protection. Inherently safe reactors take advantage of passive system features for decay-heat removal and reactor shutdown functions normally ascribed to active reactor safety systems. The advent of these reactors may permit restructuring of the present control system design strategy. This restructuring is based on the fact that authority for protection against unlikely accidents is, as much as practical, placed upon the passive features of the system instead of the traditional placement upon the PPS. Consequently, reactor control may be simplified, allowing the reliability of control systems to be improved and more easily defended

Development status of PIUS/ISER - a inherently safe reactor for the international use

International Nuclear Information System (INIS)

Wakabayashi, Hiroaki

1987-01-01

It is just in early 1980s that LWR-based nuclear power has become a substantial power source. Though the safety level of nuclear power is always claimed to be sufficiently high by the industry, it rests on the idea of defense in depth, the calculation by probabilistic risk assessment (PRA) or probabilistic safety assessment (PSA). The TMI-2 and Chernobyl-4 accidents occurred in the industrially most advanced countries. In this paper, an alternative way to safe nuclear power is sought in so-called inherently safe reactors (ISR) including the LWR type PIUS/ISER. With proper consideration into the design of nuclear reactor plants, those can be made basically safe through the use of passive safe mechanism for their design. In short, an ISR is a nuclear power reactor which has passive and intrinsic core cooling capability and automatic shutdown capability. As the nuclear power reactors which are currently claimed to be inherently safe, there are the process inherent and ultimately safe reactor (PIUS) of ASEA-ATOM Sweden and the inherently safe and economical reactor (ISER) of the University of Tokyo, Japan, of LWR type. The current status of the development, the reliability, and some technical problems of ISER/PIUS and the attitude of various countries toward ISER/PIUS are described. (Kako, I.)

16 CFR 1211.13 - Inherent force activated secondary door sensors.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Inherent force activated secondary door sensors. 1211.13 Section 1211.13 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT... across the door so that the axis is perpendicular to the plane of the door. See Figure 6 of this part...

Nuclear safety as applied to space power reactor systems

International Nuclear Information System (INIS)

Cummings, G.E.

1987-01-01

To develop a strategy for incorporating and demonstrating safety, it is necessary to enumerate the unique aspects of space power reactor systems from a safety standpoint. These features must be differentiated from terrestrial nuclear power plants so that our experience can be applied properly. Some ideas can then be developed on how safe designs can be achieved so that they are safe and perceived to be safe by the public. These ideas include operating only after achieving a stable orbit, developing an inherently safe design, ''designing'' in safety from the start and managing the system development (design) so that it is perceived safe. These and other ideas are explored further in this paper

Safety management systems and their role in achieving high standards of operational safety

International Nuclear Information System (INIS)

Coulston, D.J.; Baylis, C.C.

2000-01-01

Achieving high standards of operational safety requires a robust management framework that is visible to all personnel with responsibility for its implementation. The structure of the management framework must ensure that all processes used to manage safety interlink in a logical and coherent manner, that is, they form a management system that leads to continuous improvement in safety performance. This Paper describes BNFL's safety management system (SMS). The SMS has management processes grouped within 5 main elements: 1. Policy, 2. Organisation, 3. Planning and Implementation, 4. Measuring and Reviewing Performance, 5. Audit. These elements reflect the overall process of setting safety objective (from Policy), measuring success and reviewing the performance. Effective implementation of the SMS requires senior managers to demonstrate leadership through their commitment and accountability. However, the SMS as a whole reflects that every employee at every level within BNFL is responsible for safety of operations under their control. The SMS therefore promotes a proactive safety culture and safe operations. The system is formally documented in the Company's Environmental, Health and Safety (EHS) Manual. Within in BNFL Group, the Company structures enables the Manual to provide overall SMS guidance and co-ordination to its range of nuclear businesses. Each business develops the SMS to be appropriate at all levels of its organisation, but ensuring that each level is consistent with the higher level. The Paper concludes with a summary of BNFL's safety performance. (author)

Proposed and existing passive and inherent safety-related structures, systems, and components (building blocks) for advanced light-water reactors

International Nuclear Information System (INIS)

Forsberg, C.W.; Moses, D.L.; Lewis, E.B.; Gibson, R.; Pearson, R.; Reich, W.J.; Murphy, G.A.; Staunton, R.H.; Kohn, W.E.

1989-10-01

A nuclear power plant is composed of many structures, systems, and components (SSCs). Examples include emergency core cooling systems, feedwater systems, and electrical systems. The design of a reactor consists of combining various SSCs (building blocks) into an integrated plant design. A new reactor design is the result of combining old SSCs in new ways or use of new SSCs. This report identifies, describes, and characterizes SSCs with passive and inherent features that can be used to assure safety in light-water reactors. Existing, proposed, and speculative technologies are described. The following approaches were used to identify the technologies: world technical literature searches, world patent searches, and discussions with universities, national laboratories and industrial vendors. 214 refs., 105 figs., 26 tabs

Proposed and existing passive and inherent safety-related structures, systems, and components (building blocks) for advanced light-water reactors

Energy Technology Data Exchange (ETDEWEB)

Forsberg, C.W.; Moses, D.L.; Lewis, E.B.; Gibson, R.; Pearson, R.; Reich, W.J.; Murphy, G.A.; Staunton, R.H.; Kohn, W.E.

1989-10-01

A nuclear power plant is composed of many structures, systems, and components (SSCs). Examples include emergency core cooling systems, feedwater systems, and electrical systems. The design of a reactor consists of combining various SSCs (building blocks) into an integrated plant design. A new reactor design is the result of combining old SSCs in new ways or use of new SSCs. This report identifies, describes, and characterizes SSCs with passive and inherent features that can be used to assure safety in light-water reactors. Existing, proposed, and speculative technologies are described. The following approaches were used to identify the technologies: world technical literature searches, world patent searches, and discussions with universities, national laboratories and industrial vendors. 214 refs., 105 figs., 26 tabs.

Perceived School and Neighborhood Safety, Neighborhood Violence and Academic Achievement in Urban School Children

Science.gov (United States)

AJ, Milam; CDM, Furr-Holden; PJ, Leaf

2010-01-01

Community and school violence continue to be a major public health problem, especially among urban children and adolescents. Little research has focused on the effect of school safety and neighborhood violence on academic performance. This study examines the effect of the school and neighborhood climate on academic achievement among a population of 3rd-5th grade students in an urban public school system. Community and school safety were assessed using the School Climate Survey, an annual city-wide assessment of student’s perception of school and community safety. Community violence was measured using the Neighborhood Inventory for Environmental Typology, an objective observational assessment of neighborhood characteristics. Academic achievement was measured using the Maryland State Assessment (MSA), a standardized exam given to all Maryland 3rd-8th graders. School Climate Data and MSA data were aggregated by school and grade. Objective assessments of neighborhood environment and students’ self-reported school and neighborhood safety were both strongly associated with academic performance. Increasing neighborhood violence was associated with statistically significant decreases from 4.2%-8.7% in math and reading achievement; increasing perceived safety was associated with significant increases in achievement from 16%-22%. These preliminary findings highlight the adverse impact of perceived safety and community violence exposure on primary school children’s academic performance. PMID:21197388

Laboratory safety handbook

Science.gov (United States)

Skinner, E.L.; Watterson, C.A.; Chemerys, J.C.

1983-01-01

Safety, defined as 'freedom from danger, risk, or injury,' is difficult to achieve in a laboratory environment. Inherent dangers, associated with water analysis and research laboratories where hazardous samples, materials, and equipment are used, must be minimized to protect workers, buildings, and equipment. Managers, supervisors, analysts, and laboratory support personnel each have specific responsibilities to reduce hazards by maintaining a safe work environment. General rules of conduct and safety practices that involve personal protection, laboratory practices, chemical handling, compressed gases handling, use of equipment, and overall security must be practiced by everyone at all levels. Routine and extensive inspections of all laboratories must be made regularly by qualified people. Personnel should be trained thoroughly and repetitively. Special hazards that may involve exposure to carcinogens, cryogenics, or radiation must be given special attention, and specific rules and operational procedures must be established to deal with them. Safety data, reference materials, and texts must be kept available if prudent safety is to be practiced and accidents prevented or minimized.

Inherently safe nuclear-driven internal combustion engines

International Nuclear Information System (INIS)

Alesso, P.; Chow, Tze-Show; Condit, R.; Heidrich, J.; Pettibone, J.; Streit, R.

1991-01-01

A family of nuclear driven engines is described in which nuclear energy released by fissioning of uranium or plutonium in a prompt critical assembly is used to heat a working gas. Engine performance is modeled using a code that calculates hydrodynamics, fission energy production, and neutron transport self-consistently. Results are given demonstrating a large negative temperature coefficient that produces self-shutoff of energy production. Reduced fission product inventory and the self-shutoff provide inherent nuclear safety. It is expected that nuclear engine reactor units could be scaled from 100 MW on up. 7 refs., 3 figs

Development of inherent core technologies for advanced reactor

International Nuclear Information System (INIS)

Kim, Keung Koo; Noh, J.M.; Hwang, D.H.

1999-03-01

Recently, the developed countries made their effort on developing the advanced reactor which will result in significantly enhanced safety and economy. However, they will protect the advanced reactor and its design technology with patent and proprietary right. Therefore, it is very important to develop our own key core concepts and inherent core design technologies which can form a foundation of indigenous technologies for development of the domestic advanced reactor in order to keep the superiority in the nuclear plant building market among the developing countries. In order to provide the basic technology for the core design of advanced reactor, this project is for developing the inherent core design concepts with enhanced safety and economy, and associated methodologies and technologies for core analyses. The feasibility study of constructing domestic critical facilities are performed by surveying the status and utilization of foreign facilities and by investigating the demand for domestic facilities. The research results developed in this project, such as core analysis methodologies for hexagonal core, conceptual core design based on hexagonal fuel assemblies and soluble boron core design and control strategies, will provide a technical foundation in developing core design of domestic advanced reactor. Furthermore, they will strengthen the competitiveness of Korean nuclear technology. We also expect that some of the design concepts developed in this project to improve the reactor safety and economy can be applicable to the design of advanced reactor. This will significantly reduce the public anxiety on the nuclear power plant, and will contribute to the economy of construction and operation for the future domestic reactors. Even though the critical facility will not be constructed right now, the investigation of the status and utilization of foreign critical facility will contribute to the future critical facility construction. (author). 150 refs., 34 tabs., 103

Development of inherent core technologies for advanced reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Keung Koo; Noh, J.M.; Hwang, D.H. [and others

1999-03-01

Recently, the developed countries made their effort on developing the advanced reactor which will result in significantly enhanced safety and economy. However, they will protect the advanced reactor and its design technology with patent and proprietary right. Therefore, it is very important to develop our own key core concepts and inherent core design technologies which can form a foundation of indigenous technologies for development of the domestic advanced reactor in order to keep the superiority in the nuclear plant building market among the developing countries. In order to provide the basic technology for the core design of advanced reactor, this project is for developing the inherent core design concepts with enhanced safety and economy, and associated methodologies and technologies for core analyses. The feasibility study of constructing domestic critical facilities are performed by surveying the status and utilization of foreign facilities and by investigating the demand for domestic facilities. The research results developed in this project, such as core analysis methodologies for hexagonal core, conceptual core design based on hexagonal fuel assemblies and soluble boron core design and control strategies, will provide a technical foundation in developing core design of domestic advanced reactor. Furthermore, they will strengthen the competitiveness of Korean nuclear technology. We also expect that some of the design concepts developed in this project to improve the reactor safety and economy can be applicable to the design of advanced reactor. This will significantly reduce the public anxiety on the nuclear power plant, and will contribute to the economy of construction and operation for the future domestic reactors. Even though the critical facility will not be constructed right now, the investigation of the status and utilization of foreign critical facility will contribute to the future critical facility construction. (author). 150 refs., 34 tabs., 103

Probabilities of inherent shutdown of unprotected events in innovative liquid metal reactors

International Nuclear Information System (INIS)

Mueller, C.J.

1987-01-01

The uncertainty in predicting the effectiveness of inherent shutdown (ISD) in innovative designs results from three broad contributing areas of uncertainty: (1) the inability to exactly predict the frequency of ATWS events with potential to challenge the safety systems and require ISD; (2) the approximation of representing all such ATWS events by a selected set of ''generic scenarios''; and (3) the inability to exactly calculate the core response to the selected generic scenarios. In this summary, the methodology and associated results of work used to establish probabilities of failure of inherent shutdown of innovative LMRs to the unprotected loss-of-flow (LOF) accident are discussed

Japan's ISER plant aims at inherent safety plus economy

International Nuclear Information System (INIS)

Kejv, L.

1987-01-01

Japan's ISER reactor concept, combining features of the sweden safety PIUS reactor with possibility of sufficient cost decrease, is briefly described. Comparative characteristics of two reactor concepts are presented

Perspectives on Understanding and Verifying the Safety Terrain of Modular High Temperature Gas-Cooled Reactors

International Nuclear Information System (INIS)

Carlson, Donald E.

2014-01-01

The inherent safety characteristics of modular high temperature gas-cooled reactors (HTGRs) are conceptually well known and are largely supported by insights from past and ongoing research. This paper offers perspectives on selected issues in areas where further analysis and testing achievable within existing research and demonstration programs could help address residual uncertainties and better support the analysis of safety performance and the regulatory assessment of defense in depth. Areas considered include the evaluation of normal and anomalous core operating conditions and the analysis of accidents involving coolant depressurization, air ingress, moisture ingress, and reactivity insertion. In addition to discussing associated uncertainties and potential measures to address them, the paper also proposes supplemental “safety terrain” studies that would use realistic assessments of postulated extreme event sequences to establish a more comprehensive understanding of the inherent behaviors and ultimate safety capabilities of modular HTGRs. (author)

Safety design

International Nuclear Information System (INIS)

Kunitomi, Kazuhiko; Shiozawa, Shusaku

2004-01-01

JAERI established the safety design philosophy of the HTTR based on that of current reactors such as LWR in Japan, considering inherent safety features of the HTTR. The strategy of defense in depth was implemented so that the safety engineering functions such as control of reactivity, removal of residual heat and confinement of fission products shall be well performed to ensure safety. However, unlike the LWR, the inherent design features of the high-temperature gas-cooled reactor (HTGR) enables the HTTR meet stringent regulatory criteria without much dependence on active safety systems. On the other hand, the safety in an accident typical to the HTGR such as the depressurization accident initiated by a primary pipe rupture shall be ensured. The safety design philosophy of the HTTR considers these unique features appropriately and is expected to be the basis for future Japanese HTGRs. This paper describes the safety design philosophy and safety evaluation procedure of the HTTR especially focusing on unique considerations to the HTTR. Also, experiences obtained from an HTTR safety review and R and D needs for establishing the safety philosophy for the future HTGRs are reported

The likelihood of achieving quantified road safety targets: a binary logistic regression model for possible factors.

Science.gov (United States)

Sze, N N; Wong, S C; Lee, C Y

2014-12-01

In past several decades, many countries have set quantified road safety targets to motivate transport authorities to develop systematic road safety strategies and measures and facilitate the achievement of continuous road safety improvement. Studies have been conducted to evaluate the association between the setting of quantified road safety targets and road fatality reduction, in both the short and long run, by comparing road fatalities before and after the implementation of a quantified road safety target. However, not much work has been done to evaluate whether the quantified road safety targets are actually achieved. In this study, we used a binary logistic regression model to examine the factors - including vehicle ownership, fatality rate, and national income, in addition to level of ambition and duration of target - that contribute to a target's success. We analyzed 55 quantified road safety targets set by 29 countries from 1981 to 2009, and the results indicate that targets that are in progress and with lower level of ambitions had a higher likelihood of eventually being achieved. Moreover, possible interaction effects on the association between level of ambition and the likelihood of success are also revealed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Charged-particle beam: a safety mandate

International Nuclear Information System (INIS)

Young, K.C.

1983-01-01

The Advanced Test Accelerator (ATA) is a recent development in the field of charged particle beam research at Lawrence Livermore National Laboratory. With this experimental apparatus, researchers will characterize intense pulses of electron beams propagated through air. Inherent with the ATA concept was the potential for exposure to hazards, such as high radiation levels and hostile breathing atmospheres. The need for a comprehensive safety program was mandated; a formal system safety program was implemented during the project's conceptual phase. A project staff position was created for a safety analyst who would act as a liaison between the project staff and the safety department. Additionally, the safety analyst would be responsible for compiling various hazards analyses reports, which formed the basis of th project's Safety Analysis Report. Recommendations for safety features from the hazards analysis reports were incorporated as necessary at appropriate phases in project development rather than adding features afterwards. The safety program established for the ATA project faciliated in controlling losses and in achieving a low-level of acceptable risk

A compact, inherently safe liquid metal reactor plant concept for terrestrial defense power applications

International Nuclear Information System (INIS)

Magee, P.M.; Dubberley, A.E.; Lutz, D.E.; Palmer, R.S.

1987-01-01

A compact, inherently safe, liquid metal reactor concept based on the GE PRISM innovative LMR design has been developed for terrestrial defense power applications in the 2-50 MWe range. The concept uses a small, sodium-cooled, U-5%Zr metal fueled reactor contained within two redundant steel vessels. The core is designed to operate at a low power density and temperature (925 F) and can operate 30 years without refueling. One two primary coolant loops, depending upon the plant size, transport heat from the core to sodium-to-air, double-wall heat exchangers. Power is produced by a gas turbine operated in a closed ''bottoming'' cycle that employs intercoolers between the compressor stages and a recuperator. Inherent safety is provided by passive means only; operator action is not required to ensure plant safety even for events normally considered Beyond Design Basis Accidents. In addition to normal shutdown heat removal via the sodium-to-air heat exchangers, the design utilizes an inherently passive radiant vessel auxiliary cooling system similar to that designed for PRISM. The use of an air cycle gas turbine eliminates the cost and complexity of the sodium-water reactor pressure relief system required for a steam cycle sodium-cooled reactor

The inherent limits of predicting school violence.

Science.gov (United States)

Mulvey, E P; Cauffman, E

2001-10-01

The recent media hype over school shootings has led to demands for methods of identifying school shooters before they act. Despite the fact that schools remain one of the safest places for youths to be, schools are beginning to adopt identification systems to determine which students could be future killers. The methods used to accomplish this not only are unproven but are inherently limited in usefulness and often do more harm than good for both the children and the school setting. The authors' goals in the present article are to place school shootings in perspective relative to other risks of violence that children face and to provide a reasonable and scientifically defensible approach to improving the safety of schools.

Regulatory requirements for demonstration of the achieved safety level at the Mochovce NPP before commissioning

International Nuclear Information System (INIS)

Lipar, M.

1997-01-01

A review of regulatory requirements for demonstration of the achieved safety level at the Mochovce NPP before commissioning is given. It contains licensing steps in Slovakia during commissioning; Status and methodology of Mochovce safety analysis report; Mochovce NPP safety enhancement program; Regulatory body policy towards Mochovce NPP safety enhancement; Recent development in Mochovce pre-operational safety enhancement program review and assessment process; Licensing steps in Slovakia during commissioning

Innovation in the Safety of nuclear systems: fundamental aspects

International Nuclear Information System (INIS)

Herranz, L. E.

2009-01-01

Safety commercial nuclear reactors has been an indispensable condition for future enlargement of power generation based on nuclear technology. Its fundamental principle, defence in depth, far from being outdated, is still adopted as a key foundation in the advanced nuclear system (generations III and IV). Nevertheless, the cumulative experience gained in the operation and maintenance of nuclear reactors, the development of methodologies like the probabilistic safety analysis, the use of passive safety systems and, even, the inherent characteristics of some new design (which exclude accident scenarios), allow estimating safety figures of merit even more outstanding that those achieved in the second generation of nuclear reactors. This safety innovation of upcoming nuclear reactors has entailed a huge investigation program (generation III) that will be focused on optimizing and demonstrating the postulated safety of future nuclear systems (Generation IV). (Author)

Safety and excellence--is regulation ensuring their achievement

International Nuclear Information System (INIS)

Levesque, R.J.A.

1992-01-01

Canada has a large, vigorous nuclear industry staffed by competent people, and a vigourous, independent regulatory agency similarly staffed. Nevertheless, there have been many signs over the last few years that the level of operating and engineering excellence needed to ensure a high level of safety was not being achieved in some key sections of the industry. Years of successful, accident-free operation - a hallmark of Canadian nuclear generating stations - are not by themselves a proof of adequate safety. Signs that the level of excellence is not being met in the nuclear reactor business have been seen, for example, in reviews of significant events, in the standard of generating documentation, and in the time taken to implement necessary design modifications. In the radioisotope business, the number of violations of licence conditions has been growing steadily, and there are an unacceptable number of workers exceeding regulatory dose limits. While many of these violations are minor in themselves, their prevalence suggests a degree of complacency has been developing which will be an enemy of excellence. Equally, the level of review, assessment, inspection and confirmatory research carried out in the past by the Atomic Energy Control Board (AECB) has been clearly inadequate. The paper discusses these and other examples of a lack of excellence, particularly in organization and management within its licensees and its effect on safety,. and identifies some of the performance indicators used. The paper also identifies some of the actions that are being taken by the AECB and the licensees to ensure an adequate level of safety is being maintained. The AECB is increasing, for example, its frequency of inspections in several industrial sectors and increasing its depth of safety review of nuclear generating stations

An Innovative Hybrid Loop-Pool SFR Design and Safety Analysis Methods: Today and Tomorrow

International Nuclear Information System (INIS)

Hongbin Zhang; Haihua Zhao; Vincent Mousseau

2008-01-01

Investment in commercial sodium cooled fast reactor (SFR) power plants will become possible only if SFRs achieve economic competitiveness as compared to light water reactors and other Generation IV reactors. Toward that end, we have launched efforts to improve the economics and safety of SFRs from the thermal design and safety analyses perspectives at Idaho National Laboratory. From the thermal design perspective, an innovative hybrid loop-pool SFR design has been proposed. This design takes advantage of the inherent safety of a pool design and the compactness of a loop design to further improve economics and safety. From the safety analyses perspective, we have initiated an effort to develop a high fidelity reactor system safety code

An assessment of the low seismic risk of the inherently safe sodium advanced fast reactor (SAFR)

International Nuclear Information System (INIS)

Rutherford, P.D.

1988-01-01

A recent probabilistic risk assessment (PRA) of the sodium advanced fast reactor (SAFR) demonstrated the inherently low risk of advanced liquid-metal, pool-type fast reactors with inherent safety systems. As a result, it was recognized that external events, especially seismic events, may not only be a major contributor to risk (as shown in several LWR PRAs) but also may completely dominate the risk. Accordingly, a seismic risk assessment has been completed for SAFR, which resulted in a core damage frequency of 2 x 10 -7 /year and a large release frequency of 4 x 10 -9 /year. This paper reports that public health risk in terms of early fatality risk and latent fatality risk were also several orders of magnitude below the NRC safety goals and below recent LWR risks reported in NUREB/CR1150

Achievements and Perspectives of the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management

International Nuclear Information System (INIS)

Louvat, D.; Lacoste, A.C.

2006-01-01

The Joint Convention on the Safety of Spent Fuel management and on the Safety of Radioactive Waste Management is the first legal instrument to directly address the safety of spent fuel and radioactive waste management on a global scale. The Joint Convention entered into force in 2001. This paper describes its process and its main achievements to date. The perspectives to establish of a Global Waste Safety Regime based on the Joint Convention are also discussed. (authors)

Standardized safety management of AP1000 nuclear power plant

International Nuclear Information System (INIS)

Li Xingwen; Cao Zhiqiang; Cong Jiuyuan

2011-01-01

In 2002, China published and implemented the Law of the People's Republic of China on Work Safety and promulgated a series of guidelines and policies, which strengthened the safety management supervision. Standardization of safety, as another important step on safety supervision, comes after safety assesment and safety production licensing system, is also a permanent solution. Standardization of safety is a strategic, long term and fundamental work, which is also the basic access to achieving scientific safety management and increasing the inherent safety of an enterprise. Haiyang AP1000 nuclear power plant, adopting the modularized, 'open-top' and parallel construction means, overturned the traditional construction theory of installation work comes after the civil work and greatly shorten the construction period. At the same time, the notable increase of oversize module transportation and lifting and parallel construction raises higher demands for safety management. This article combines the characteristics and difficulties of safety management for Haiyang AP1000 nuclear power plant, puts forward ideas and methods for standardized safety management, and could also serve as reference to the safety management for other AP1000 projects. (authors)

The Limits of Logic-Based Inherent Safety of Social Robots

DEFF Research Database (Denmark)

Bentzen, Martin Mose

2017-01-01

Social robots can reason and act while taking into accountsocial and cultural structures, for instance by complying withsocial or ethical norms or values. As social robots are likely to becomemore common and advanced and thus likely to interact withhuman beings in increasingly complex situations......-based safety for ethical robots is shown. Afterwards,an empirical study is used to show that there is a clash betweendeontic reasoning and most formal deontic logics. I give anexample as to how this clash can cause problems in human-robot interaction.I conclude that deontic logics closer to natural...... languagereasoning are needed and that logic only should play a limited partin the overall safety architecture of a social robot, which should alsobe based on other principles of safe design....

Safety of nuclear power in the decades ahead

International Nuclear Information System (INIS)

Niehaus, F.

1991-01-01

Technological advances and the implementation of a safety culture will achieve a safety level in future reactors of the present generation of a core melt probability of less than 10 -5 per year, and less than 10 -6 per year for large releases of radioactive materials. There are older reactors which do not comply with present safety thinking. The paper reviews findings of a recent design review of WWER 440/230 plants. Advanced evolutionary designs might be capable of reducing the probability of significant off-site releases to less than 10 -7 per year. For such reactors, there are inherent limitations to further increases in safety, due to the human element, complexity of design, and capability of the containment function. Therefore, revolutionary designs are being explored to eliminate the potential for off-site releases. In this context, it seems to be advisable to examine concepts in which the fuel is the ultimate safety barrier. (orig./HP) [de

Dealing with uncertainty and pursuing superior technology options in risk management-The inherency risk analysis

International Nuclear Information System (INIS)

Helland, Aasgeir

2009-01-01

Current regulatory systems focus on the state of scientific evidence as the predominant factor for how to handle risks to human health and the environment. However, production and assessment of risk information are costly and time-consuming, and firms have an intrinsic disincentive to produce and distribute information about risks of their products as this could endanger their production opportunities and sales. An emphasis on more or better science may result in insufficient thought and attention going into the exploration of technology alternatives, and that risk management policies miss out on the possible achievement of a more favorable set of consequences. In this article, a method is proposed that combines risk assessment with the search for alternative technological options as a part of the risk management procedure. The method proposed is the inherency risk analysis where the first stage focuses on the original agent subject to investigation, the second stage focuses on identifying technological options whereas the third stage reviews the different alternatives, searching for the most attractive tradeoffs between costs and inherent safety. This is then used as a fundament for deciding which technology option to pursue. This method aims at providing a solution-focused, systematic technology-based approach for addressing and setting priorities for environmental problems. By combining risk assessment with a structured approach to identify superior technology options within a risk management system, the result could very well be a win-win situation for both company and the environment.

Food plant toxicants and safety: risk assessment and regulation of inherent toxicants in plant foods.

NARCIS (Netherlands)

Essers, A.J.; Alink, G.M.; Speijers, G.J.A.; Alexander, J.; Bouwmeister, P.J.; Brandt, van den P.A.; Ciere, S.; Gry, J.; Herrman, J.; Kuiper, H.A.; Mortby, E.; Renwickn, A.G.

1998-01-01

The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI

Feasibility study of a dedicate nuclear desalination system: Low-pressure inherent heat sink nuclear desalination plant (LIND)

Energy Technology Data Exchange (ETDEWEB)

Kim, Ho Sik; No, Hee Cheon; Jo, Yu Gwan; Wivisono, Andhika Feri; Park, Byung Ha; Choi, Jin Young; Lee, Jeong Ik; Jeong, Yong Hoon; Cho, Nam Zin [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2015-04-15

In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND) that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal-hydraulic and neutronic design requirements. In a thermal-hydraulic analysis using an analytical method based on the Wooton-Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 MW{sub th} and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

Feasibility study of a dedicated nuclear desalination system: Low-pressure Inherent heat sink Nuclear Desalination plant (LIND

Directory of Open Access Journals (Sweden)

Ho Sik Kim

2015-04-01

Full Text Available In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal–hydraulic and neutronic design requirements. In a thermal–hydraulic analysis using an analytical method based on the Wooton–Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 MWth and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

Transient safety performance of the PRISM innovative liquid metal reactor

International Nuclear Information System (INIS)

Magee, P.M.; Dubberley, A.E.; Rhow, S.K.; Wu, T.

1988-01-01

The PRISM sodium-cooled reactor concept utilizes passive safety characteristics and modularity to increase performance margins, improve licensability, reduce owner's risk and reduce costs. The relatively small size of each reactor module (471 MWt) facilitates the use of passive self-shutdown and shutdown heat removal features, which permit design simplification and reduction of safety-related systems. Key to the transient performance is the inherent negative reactivity feedback characteristics of the core design resulting from the use of metal (U-Pu-Zr) swing, and very low control rod runout worth. Selected beyond design basis events relying only on these core design features are analyzed and the design margins summarized to demonstrate the advancement in reactor safety achieved with the PRISM design concept

Safety of intrinsically safe and economical reactor (ISER)

International Nuclear Information System (INIS)

Asahi, Y.; Sugawara, I.; Yamanaka, K.

1988-01-01

Inherent safety of a reactor may be quantified by the grace period at various safety levels such as maintenance of fuel integrity, maintenance of fuel coolability and avoidance of core-melt. It is important to find out the grace period especially at the safety level of maintenance of fuel integrity. It has been conducted to design the ISER, which is characterized by the steel-made reactor pressure vessel. In addition to the passive nature of the safety design of the reactor itself, the ISER is equipped in the secondary system with a subsystem called the passive safety and shutdown system (PSSS), which will help to increase the grace period. It was found by the null transient analysis that check valves are needed at the top hot/cold interface. The analysis of the station blackout, which is one of the severest accident conceivable for the ISER, was made to examine inherent safety of the ISER with and without the PSSS. This paper reports that found out that the PSSS enhances inherent safety of the ISER

Safety related requirements on future nuclear power plants

International Nuclear Information System (INIS)

Niehaus, F.

1991-01-01

Nuclear power has the potential to significantly contribute to the future energy supply. However, this requires continuous improvements in nuclear safety. Technological advancements and implementation of safety culture will achieve a safety level for future reactors of the present generation of a probability of core-melt of less than 10 -5 per year, and less than 10 -6 per year for large releases of radioactive materials. There are older reactors which do not comply with present safety thinking. The paper reviews findings of a recent design review of WWER 440/230 plants. Advanced evolutionary designs might be capable of reducing the probability of significant off-site releases to less than 10 -7 per year. For such reactors there are inherent limitations to increase safety further due to the human element, complexity of design and capability of the containment function. Therefore, revolutionary designs are being explored with the aim of eliminating the potential for off-site releases. In this context it seems to be advisable to explore concepts where the ultimate safety barrier is the fuel itself. (orig.) [de

Design-related inherent safety characteristics in large LMFBR power plants

International Nuclear Information System (INIS)

Tzanos, C.P.; Barthold, W.P.; Bowers, C.H.; Ferguson, D.R.; Prohammer, F.G.; van Erp, J.B.

1976-01-01

Design-related safety-enhancing features such as (1) extended pump coastdown, (2) increased negative reactivity feedbacks, (3) reduced sodium void reactivity, and (4) self-actuated shutdown systems are evaluated. Primary emphasis is placed on preventing or limiting core damage. Attention is also given to features aimed at mitigation of the energetics potential of hypothetical core-disruptive accidents

Colonising Safety : creating risk through the enforcement of biomedical constructions of safety.

NARCIS (Netherlands)

Kadetz, P.

2013-01-01

In the normative health care discourse, safety is represented as a concept that is at once universal, irrefutable, and inherently beneficent. Yet, research at local levels in the Philippines challenges these assumptions embedded in the biomedical construction of safety. This article examines how the

Operation: Inherent Resolve

DEFF Research Database (Denmark)

Cramer-Larsen, Lars

2015-01-01

Kapitlet giver læseren indsigt i den internationale koalitions engagement mod IS igennem Operaton Inherent Resolve; herunder koalitionens strategi i forhold til IS strategi, ligesom det belyser kampagnens legalitet og folkeretlige grundlag, ligesom det giver et bud på overvejelser om kampagnens...

Application of system safety engineering techniques for hazard prevention at the Superconducting Super Collider

International Nuclear Information System (INIS)

Hendrix, B.L.

1991-01-01

A primary goal of the Superconducting Super Collider Laboratory (SSCL) is to establish an exemplary safety program. Achieving this goal requires leadership, planning, coordination, and technical know-how. To ensure that safety is an inherent part of the design, the Environment, Safety and Health Office employs a systems engineering discipline and process known as System Safety. The goal of System Safety - hazard prevention - is accomplished by analyzing systems to identify hazards and to evaluate design and procedural options and countermeasures to prevent, eliminate, mitigate, or control hazards and risks. Establishment of safety and human factors design criteria at the outset of the project prevents unsafe designs and safety violations, reduces risks, and helps in avoiding costly design changes later. This process requires a considerable amount of coordination with a variety of technical disciplines and safety professionals to integrate methods of hazard prevention, mitigation, and risk reduction throughout the system life-cycle

A concept of passive safety pressurized water reactor system with inherent matching nature of core heat generation and heat removal

International Nuclear Information System (INIS)

Murao, Yoshio; Araya, Fumimasa; Iwamura, Takamichi; Okumura, Keisuke

1995-01-01

The reduction of manpower in operation and maintenance by simplification of the system are essential to improve the safety and the economy of future light water reactors. At the Japan Atomic Energy Research Institute (JAERI), a concept of a simplified passive safety reactor system JPSR was developed for this purpose and in the concept minimization of developing work and conservation of scale-up capability in design were considered. The inherent matching nature of core heat generation and heat removal rate is introduced by the core with high reactivity coefficient for moderator density and low reactivity coefficient for fuel temperature (Doppler effect) and once-through steam generators (SGs). This nature makes the nuclear steam supply system physically-slave for the steam and energy conversion system by controlling feed water mass flow rate. The nature can be obtained by eliminating chemical shim and adopting in-vessel control rod drive mechanism (CRDM) units and a low power density core. In order to simplify the system, a large pressurizer, canned pumps, passive residual heat removal systems with air coolers as a final heat sink and passive coolant injection system are adopted and the functions of volume and boron concentration control and seal water supply are eliminated from the chemical and volume control system (CVCS). The emergency diesel generators and auxiliary component cooling system of 'safety class' for transferring heat to sea water as a final heat sink in emergency are also eliminated. All of systems are built in the containment except for the air coolers of the passive residual heat removal system. The analysis of the system revealed that the primary coolant expansion in 100% load reduction in 60 s can be mitigated in the pressurizer without actuating the pressure relief valves and the pressure in 50% load change in 30 s does not exceed the maximum allowable pressure in accidental conditions in regardless of pressure regulation. (author)

GT-MHR design, performance, and safety

International Nuclear Information System (INIS)

Neylan, A.J.; Shenoy, A.; Silady, F.A.; Dunn, T.D.

1994-11-01

The Gas Turbine-Modular Helium Reactor (GT-MHR) is the result of coupling the evolution of a low power density passively safe modular reactor with key technology developments in the U.S. during the last decade: large industrial gas turbines; large active magnetic bearings; and compact, highly effective plate-fin heat exchangers. This is accomplished through the unique use of the Brayton cycle to produce electricity with the helium as primary coolant from the reactor directly driving the gas turbine electrical generator. This cycle can achieve a high net efficiency in the range of 45% to 48%. In the design of the GT-MHR the desirable inherent characteristics of the inert helium coolant, graphite core, and the coated fuel particles are supplemented with specific design features such as passive heat removal to achieve the safety objective of not disturbing the normal day-to-day activities of the public even for beyond design basis rare accidents. Each GT-MHR plant consists of four modules. The GT-MHR module components are contained within steel pressure vessels: a reactor vessel, a power conversion vessel, and a connecting cross vessel. All vessels are sited underground in a concrete silo, which serves as an independent vented low pressure containment structure. By capitalizing on industrial and aerospace gas turbine development, highly effective heat exchanger designs, and inherent gas cooled reactor temperature characteristics, the passively safe GT-MHR provides a sound technical, monetary, and environmental basis for new nuclear power generating capacity. This paper provides an update on the status of the design, which has been under development on the US-DOE program since February 1993. An assessment of plant performance and safety is also included

The inherent catastrophic traps in retrograde CTO PCI.

Science.gov (United States)

Wu, Eugene B; Tsuchikane, Etsuo

2018-05-01

When we learn to drive, our driving instructor tells us how to check the side mirror and turn your head to check the blind spot before changing lanes. He tells us how to stop at stop signs, how to drive in slippery conditions, the safe stopping distances, and these all make our driving safe. Similarly, when we learn PCI, our mentors teach us to seat the guiding catheter co-axially, to wire the vessel safely, to deliver balloon and stents over the wire, to watch the pressure of the guiding, in order that we perform PCI safely and evade complications. In retrograde CTO PCI, there is no such published teaching. Also many individual mentors have not had the wide experience to see all the possible complications of retrograde CTO PCI and, therefore, may not be able to warn their apprentice. As the number of retrograde procedures increase worldwide, there is a corresponding increase in catastrophic complications, many of which, we as experts, can see are easily avoidable. To breach this gap in knowledge, this article describes 12 commonly met inherent traps in retrograde CTO PCI. They are inherent because by arranging our equipment in the manner to perform retrograde CTO PCI, these complications are either induced directly or happen easily. We hope this work will enhance safety of retrograde CTO PCI and avoid many catastrophic complications for our readers and operators. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The achievement and assessment of safety in systems containing software

International Nuclear Information System (INIS)

Ball, A.; Dale, C.J.; Butterfield, M.H.

1986-01-01

In order to establish confidence in the safe operation of a reactor protection system, there is a need to establish, as far as it is possible, that: (i) the algorithms used are correct; (ii) the system is a correct implementation of the algorithms; and (iii) the hardware is sufficiently reliable. This paper concentrates principally on the second of these, as it applies to the software aspect of the more accurate and complex trip functions to be performed by modern reactor protection systems. In order to engineer safety into software, there is a need to use a development strategy which will stand a high chance of achieving a correct implementation of the trip algorithms. This paper describes three broad methodologies by which it is possible to enhance the integrity of software: fault avoidance, fault tolerance and fault removal. Fault avoidance is concerned with making the software as fault free as possible by appropriate choice of specification, design and implementation methods. A fault tolerant strategy may be advisable in many safety critical applications, in order to guard against residual faults present in the software of the installed system. Fault detection and removal techniques are used to remove as many faults as possible of those introduced during software development. The paper also discusses safety and reliability assessment as it applies to software, outlining the various approaches available. Finally, there is an outline of a research project underway in the UKAEA which is intended to assess methods for developing and testing safety and protection systems involving software. (author)

Safety flywheel

Energy Technology Data Exchange (ETDEWEB)

Schneider, R.T.

1977-01-17

The patent application relates to an inertial energy storage device employing a safety flywheel which is made of flexible material such as a twisted rope ring. The rigidity required for such a device is achieved through centrifugal forces inherent in such a device when it is operating. A small number of the strands of the rope ring have a tensile strength that is lower than the vast majority of the strands of the rope ring whereby should any of these strands fail, they will begin to whiplash allowing such a failure to be detected and braked before a catastrophic failure occurs. This is accomplished by the inclusion of glass tubes located around the periphery of the flywheel. The tubes are in communication with a braking fluid reservoir. The flywheel and glass tubes are enclosed within a vacuum-tight housing.

Inherent security benefits of underground dry storage of nuclear materials

International Nuclear Information System (INIS)

Moore, R.D.; Zahn, T.

1997-07-01

This paper, augmented by color slides and handouts, will examine the inherent security benefits of underground dry storage of nuclear materials. Specific items to be presented include: the successful implementation of this type of storage configuration at Argonne National Laboratory - West; facility design concepts with security as a primary consideration; physical barriers achieved by container design; detection, assessment, and monitoring capabilities; and open-quotes self protectionclose quotes strategies. This is a report on the security features of such a facility. The technical operational aspects of the facility are beyond the scope of this paper

Achieving safety/risk goals for less ATR backup power upgrades

International Nuclear Information System (INIS)

Atkinson, S.A.

1995-01-01

The Advanced Test Reactor probabilistic risk assessment for internal fire and flood events defined a relatively high risk for a total loss of electric power possibly leading to core damage. Backup power sources were disabled due to fire and flooding in the diesel generator area with propagation of the flooding to a common switchgear room. The ATR risk assessment was employed to define options for relocation of backup power system components to achieve needed risk reduction while minimizing costs. The risk evaluations were performed using sensitivity studies and importance measures. The risk-based evaluations of relocation options for backup power systems saved over $3 million from what might have been otherwise considered open-quotes necessaryclose quotes for safety/risk improvement. The ATR experience shows that the advantages of a good risk assessment are to define risk significance, risk specifics, and risk solutions which enable risk goals to be achieved at the lowest cost

Aviation safety and ICAO

NARCIS (Netherlands)

Huang, Jiefang

2009-01-01

The thesis addresses the issue of aviation safety under the rule of law. Aviation safety is a global concern. While air transport is considered a safe mode of travel, it is susceptible to inherent risks of flight, the use of force, and terrorist acts. Consequently, within the framework of the

Environmental and safety issues of the fusion fuel cycle

International Nuclear Information System (INIS)

Crocker, J.G.

1980-01-01

This paper discusses the environmental and safety concerns inherent in the development of fusion energy, and the current Department of Energy programs seeking to: (1) develop safe and reliable techniques for tritium control; (2) reduce the quantity of activation products produced; and (3) provide designs to limit the potential for accidents that could result in release of radioactive materials. Because of the inherent safety features of fusion and the early start that has been made in safety problem recognition and solution, fusion should be among the lower risk technologies for generation of commercial power

Possibility of a pressurized water reactor concept with highly inherent heat removal following capability

International Nuclear Information System (INIS)

Araya, Fumimasa; Murao, Yoshio

1995-01-01

If the core power inherently follows change in heat removal rate from the primary coolant system within small thermal expansion of the coolant which can be absorbed in a practical size of pressurizer, reactor systems may have more safety and load following capability. In order to know possibility and necessary conditions of a concept on reactor core and primary coolant system of a pressurized water reactor (PWR) with such 'highly inherent heat removal following capability', transient analyses on an ordinary two-loop PWR have been performed for a transient due to 50% change in heat removal with the RETRAN-02 code. The possibility of a PWR concept with the highly inherent heat removal following capability has been demonstrated under the conditions of the absolute value of ratio of the coolant density reactivity coefficient to the Doppler reactivity coefficient more than 10x10 3 kg·cm 3 which is two to three times larger than that at beginning of cycle (BOC) in an ordinary PWR and realized by elimination of the chemical shim, the 12% lower average linear heat generation rate of 17.9 kW/m, and the 1.5 times larger pressurizer volume than those of the ordinary PWR. (author)

Metal-fuel modeling for inherently safe reactor designs

International Nuclear Information System (INIS)

Miles, K.J. Jr.

1987-01-01

Current development of breeder reactor systems has led to the renewed interest in metal fuels. These fuels have properties that enhance the inherent safety of the system, such as high thermal conductivity, compatibility with liquid sodium, and low fuel/cladding mechanical interaction. While metal-fuel irradiation behavior is well understood, there are some areas where more information is needed to fully understand the various safety-related phenomena, such as fuel/cladding chemical interaction, eutectic melting and penetration, and axial relocation of molten fuel prior to cladding breach. Because many of these phenomena can cause changes in the reactivity state of the system, their effects on whole-core normal, anticipated, and hypothetical accident scenarios need to be studied. The metal-fuel behavior model DEFORM-5 is being developed to provide the necessary phenomenological basis for these studies. The first stage in the DEFORM-5 development has been completed. Presently, DEFORM-5 calculates the cladding strain, life fraction, and eutectic penetration thinning for Types D9, HT9, or 316 steels. This first stage of DEFORM-5 has been used to analyze the TREAT M2, M3, and M4 transients with irradiated Experimental Breeder Reactor-II driver fuel. The paper shows the DEFORM-5 and experimental results for failure times for the test pins. The results provide confidence and validation of the DEFORM-5 modeling of the cladding behavior

Consensus achievement of leadership, organisational and individual factors that influence safety climate: Implications for nursing management.

Science.gov (United States)

Fischer, Shelly A; Jones, Jacqueline; Verran, Joyce A

2018-01-01

To validate a framework of factors that influence the relationship of transformational leadership and safety climate, and to enable testing of safety chain factors by generating hypotheses regarding their mediating and moderating effects. Understanding the patient safety chain and mechanisms by which leaders affect a strong climate of safety is essential to transformational leadership practice, education, and research. A systematic review of leadership and safety literature was used to develop an organising framework of factors proposed to influence the climate of safety. A panel of 25 international experts in leadership and safety engaged a three-round modified Delphi study with Likert-scored surveys. Eighty per cent of participating experts from six countries were retained to the final survey round. Consensus (>66% agreement) was achieved on 40 factors believed to influence safety climate in the acute care setting. Consensus regarding specific factors that play important roles in an organisation's climate of safety can be reached. Generally, the demonstration of leadership commitment to safety is key to cultivating a culture of patient safety. Transformational nurse leaders should consider and employ all three categories of factors in daily leadership activities and decision-making to drive a strong climate of patient safety. © 2017 John Wiley & Sons Ltd.

Conceptual design of inherently safe integral reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, J. I.; Chang, M. H.; Lee, D. J. and others

1999-03-01

The design concept of a 300 MWt inherently safe integral reactor(ISIR) for the propulsion of extra large and superhigh speed container ship was developed in this report. The scope and contents of this report are as follows : 1. The state of the art of the technology for ship-mounted reactor 2. Design requirements for ISIR 3. Fuel and core design 4. Conceptual design of fluid system 5. Conceptual design of reactor vessel assembly and primary components 6. Performance analyses and safety analyses. Installation of two ISIRs with total thermal power of 600MWt and efficiency of 21% is capable of generating shaft power of 126,000kW which is sufficient to power a container ship of 8,000TEU with 30knot cruise speed. Larger and speedier ship can be considered by installing 4 ISIRs. Even though the ISIR was developed for ship propulsion, it can be used also for a multi-purpose nuclear power plant for electricity generation, local heating, or seawater desalination by mounting on a movable floating barge. (author)

A Holistic Approach to Protection and Safety

International Nuclear Information System (INIS)

Yankovich, L.T.

2017-01-01

Natural Ecosystems Undergo Inherent Fluctuations and Changes that are Related to Physical, Geological, Biological and other Natural Processes Associated with the Cycles of Life and the Earth. In other words, the effects of human activities must be evaluated in the context of the 'baseline' processes that are inherent to and imposed on natural ecosystems. The IAEA has established ahierarchy of Safety Standards, consisting of a set of ''Safety Fundamentals'' at the highest level, followed by ''Requirements'', then recommendations or ''guidance''. Human activities involving the use of radiation and radioactive substances can cause radiation exposure to people and the environment. This exposure should be regulated and monitored in accordance with international safety standards and national legislation

Vowel Inherent Spectral Change

CERN Document Server

Assmann, Peter

2013-01-01

It has been traditional in phonetic research to characterize monophthongs using a set of static formant frequencies, i.e., formant frequencies taken from a single time-point in the vowel or averaged over the time-course of the vowel. However, over the last twenty years a growing body of research has demonstrated that, at least for a number of dialects of North American English, vowels which are traditionally described as monophthongs often have substantial spectral change. Vowel Inherent Spectral Change has been observed in speakers’ productions, and has also been found to have a substantial effect on listeners’ perception. In terms of acoustics, the traditional categorical distinction between monophthongs and diphthongs can be replaced by a gradient description of dynamic spectral patterns. This book includes chapters addressing various aspects of vowel inherent spectral change (VISC), including theoretical and experimental studies of the perceptually relevant aspects of VISC, the relationship between ar...

Engineered safeguards and passive safety features (safety analysis detailed report no. 6)

Energy Technology Data Exchange (ETDEWEB)

1988-01-15

The Safety-Analysis Summary lists the reactor's safety aspects for passive and active prevention of severe accidents and mitigation of accident consequences, i.e., intrinsic and passive protections of the plant; intrinsic and passive protections of the core; inherent decay-heat removal systems; rapid-shutdown systems; four physical containment barriers. This report goes into further details regarding some of this aspects.

Design features to achieve defence-in-depth in small and medium sized reactors

International Nuclear Information System (INIS)

Kuznetsov, Vladimir

2009-01-01

Broader incorporation of inherent and passive safety design features has become a 'trademark' of many advanced reactor concepts, including several evolutionary designs and nearly all innovative small and medium sized design concepts. Ensuring adequate defence-in-depth is important for reactors of smaller output because many of them are being designed to allow more proximity to the user, specifically, when non-electrical energy products are targeted. Based on the activities recently performed by the International Atomic Energy Agency, the paper provides a summary description of the design features used to achieve defence in depth in the eleven representative concepts of small and medium sized reactors. (author)

Inherent Anticipation in the Pharmaceutical and Biotechnology Industries.

Science.gov (United States)

Goldman, Michael; Evans, Georgia; Zappia, Andrew

2015-04-15

Pharmaceutical and biotech research often involves discovering new properties of, or new methods to use, existing compositions. The doctrine of inherent anticipation, however, prevents the issuance and/or validity of a patent for discoveries deemed to have been implicitly disclosed in the prior art. This can be a barrier to patent rights in these technologies. Inherent anticipation therefore creates uncertainty for patent protection in the pharmaceutical and biotech sciences. Despite this uncertainty, Federal Circuit jurisprudence provides guidance on the boundaries of the inherent anticipation doctrine. In view of the case law, certain strategies may be employed to protect inventions that may potentially be viewed as inherent in the prior art. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

Can the inherence heuristic explain vitalistic reasoning?

Science.gov (United States)

Bastian, Brock

2014-10-01

Inherence is an important component of psychological essentialism. By drawing on vitalism as a way in which to explain this link, however, the authors appear to conflate causal explanations based on fixed features with those based on general causal forces. The disjuncture between these two types of explanatory principles highlights potential new avenues for the inherence heuristic.

Development of physiotherapy inherent requirement statements - an Australian experience.

Science.gov (United States)

Bialocerkowski, Andrea; Johnson, Amanda; Allan, Trevor; Phillips, Kirrilee

2013-04-16

The United Nations Convention on the Rights of People with Disabilities promotes equal rights of people with a disability in all aspects of their life including their education. In Australia, Disability Discrimination legislation underpins this Convention. It mandates that higher education providers must demonstrate that no discrimination has occurred and all reasonable accommodations have been considered and implemented, to facilitate access and inclusion for a student with a disability. The first step to meeting legislative requirements is to provide students with information on the inherent requirements of a course. This paper describes the steps which were taken to develop inherent requirement statements for a 4-year entry-level physiotherapy program at one Australian university. Inherent requirement statements were developed using an existing framework, which was endorsed and mandated by the University. Items which described inherencies were extracted from Australian physiotherapy professional standards and statutory regulatory requirements, and units contained in the physiotherapy program. Data were integrated into the 8 prescribed domains: ethical behaviour, behavioural stability, legal, communication, cognition, sensory abilities, strength and mobility, and sustainable performance. Statements for each domain were developed using a 5-level framework (introductory statement, description of the inherent requirement, justification for inherency, characteristics of reasonable adjustments and exemplars) and reviewed by a University Review Panel. Refinement of statements continued until no further changes were required. Fifteen physiotherapy inherent requirement statements were developed. The eight domains identified in the existing framework, developed for Nursing, were relevant to the study of physiotherapy. The inherent requirement statements developed in this study provide a transparent, defensible position on the current requirements of physiotherapy study at

Safer Systems: A NextGen Aviation Safety Strategic Goal

Science.gov (United States)

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

2008-01-01

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

High temperature reactor safety and environment

International Nuclear Information System (INIS)

Brisbois, J.; Charles, J.

1975-01-01

High-temperature reactors are endowed with favorable safety and environmental factors resulting from inherent design, main-component safety margins, and conventional safety systems. The combination of such characteristics, along with high yields, prove in addition, that such reactors are plagued with few problems, can be installed near users, and broaden the recourse to specific power, therefore fitting well within a natural environment [fr

On safety enhancements for medical robots

International Nuclear Information System (INIS)

Ng, W.S.; Tan, C.K.

1996-01-01

Both software and hardware methods to enhance safety are discussed for active medical robots applied to, among others, neurosurgery, orthopaedic surgery and prostatectomy. This paper advocates that while it is practically difficult, if not impossible, for software reliability to be 100%, there are positive measures by which a medical robot system can be made adequately or inherently safe. Such measures avoid the problems of software reliability but turn to mathematical logic directly to build a safer system. Examples in a newly developed prototype, known as surgeon assistant robot for selected urological disorders (SARUD), are given to illustrate the concept. Although software measures to promote reliability of a system is less preferred compared to hardware measures, as it can never escape from operating on a hardware platform, it is suggested that a complementary/ hybrid approach can be a good solution for achieving a safe and flexible (by being reprogrammable) system. A totally independent safety monitor is being built. It can arrest a servo runaway and detect out-of-safe-boundary conditions, using encoder pulses as input. This dedicated system can resolve some major safety concerns of a medical robot such as SARUD

Safety Analysis for Key Design Features of KALIMER-600 Design Concept

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Bum; Kwon, Y. M.; Kim, E. K.; Suk, S. D.; Chang, W. P.; Jeong, H. Y.; Ha, K. S

2007-02-15

This report contains the safety analyses of the KALIMER-600 conceptual design which KAERI has been developing under the Long-term Nuclear R and D Program. The analyses have been performed reflecting the design developments during the second year of the 4th design phase in the program. The specific presentations are the key design features with the safety principles for achieving the safety objectives, the event categorization and safety criteria, and results on the safety analyses for the DBAs and ATWS events, the containment performance, and the channel blockages. The safety analyses for both the DBAs and ATWS events have been performed using SSC-K version 1.3., and the results have shown the fulfillment of the safety criteria for DBAs with conservative assumptions. The safety margins as well as the inherent safety also have been confirmed for the ATWS events. For the containment performance analysis, ORIGEN-2.1 and CONTAIN-LMR have been used. In results, the structural integrity has been acceptable and the evaluated exposure dose rate has been complied with 10 CFR 100 and PAG limits. The analysis results for flow blockages of 6-subchannels, 24-subchannels, and 54- subchannels with the MATRA-LMR-FB code, have assured the integrity of subassemblies.

Strengthening Safety Culture as an Overriding Priority, in Achieving Global Nuclear Security Approach

International Nuclear Information System (INIS)

Kolundzija, V.

2006-01-01

In the IAEA glossary safety culture is defined as the assembly of characteristics and attitudes in organizations and individuals, which establishes that, as an overriding priority, protection and safety issues receive the attention warranted by their significance. It has been observed that a safety culture, as a part of both security and safety, possesses a few obstacles that should be noticed: safety culture cannot be directly regulated; variation in national cultures means that what constitutes as a good approach to enhancing safety culture in one country may not be the best approach in another. Three stages have been identified in developing and strengthening safety culture: 1 A technical issue (rules and regulations)/ first stage 2 Good safety performance (primarily in terms of safety targets or goals)/ second stage 3 A continuing process of improvement to which everyone can contribute/ third stage There are several key issues in safety culture, such as: a commitment, use of procedures, a conservative decision making (STAR) a reporting culture. Organizations and individuals should have attention on these. Overall common goals are to achieve and maintain a high level of safety and security of radioactive sources as well as facilities. Measures that are concerned on safeguards restrict access to the radioactive sources, conditioning and/or recycling of sources, and systems for detection the passage of the radioactive sources at strategic points, have gained main support. The main partners in implementation these measures are: IAEA, USA, Russian Federation, G8- Global Partnership, and European Union The member states of the IAEA have at their disposal internationally agreed standards. Current differences in applying standards in the IAEA member states are mainly related to state preparedness to cope with demands. Developing and less developed countries with small and medium nuclear programmes have difficulties to accept rules and regulations, to establish

Inherent Safety Features and Passive Prevention Approaches for Pb/Bi-cooled Accelerator-Driven Systems

Energy Technology Data Exchange (ETDEWEB)

Carlsson, Johan

2003-03-01

This thesis is devoted to the investigation of passive safety and inherent features of subcritical nuclear transmutation systems - accelerator-driven systems. The general objective of this research has been to improve the safety performance and avoid elevated coolant temperatures in worst-case scenarios like unprotected loss-of-flow accidents, loss-of-heat-sink accidents, and a combination of both these accident initiators. The specific topics covered are emergency decay heat removal by reactor vessel auxiliary cooling systems, beam shut-off by a melt-rupture disc, safety aspects from locating heat-exchangers in the riser of a pool-type reactor system, and reduction of pressure resistance in the primary circuit by employing bypass routes. The initial part of the research was focused on reactor vessel auxiliary cooling systems. It was shown that an 80 MW{sub th} Pb/Bi-cooled accelerator-driven system of 8 m height and 6 m diameter vessel can be well cooled in the case of loss-of-flow accidents in which the accelerator proton beam is not switched off. After a loss-of-heat-sink accident the proton beam has to be interrupted within 40 minutes in order to avoid fast creep of the vessel. If a melt-rupture disc is included in the wall of the beam pipe, which breaks at 150 K above the normal core outlet temperature, the grace period until the beam has to be shut off is increased to 6 hours. For the same vessel geometry, but an operating power of 250 MW{sub th} the structural materials can still avoid fast creep in case the proton beam is shut off immediately. If beam shut-off is delayed, additional cooling methods are needed to increase the heat removal. Investigations were made on the filling of the gap between the guard and the reactor vessel with liquid metal coolant and using water spray cooling on the guard vessel surface. The second part of the thesis presents examinations regarding an accelerator-driven system also cooled with Pb/Bi but with heat-exchangers located

Inherent Safety Features and Passive Prevention Approaches for Pb/Bi-cooled Accelerator-Driven Systems

International Nuclear Information System (INIS)

Carlsson, Johan

2003-03-01

This thesis is devoted to the investigation of passive safety and inherent features of subcritical nuclear transmutation systems - accelerator-driven systems. The general objective of this research has been to improve the safety performance and avoid elevated coolant temperatures in worst-case scenarios like unprotected loss-of-flow accidents, loss-of-heat-sink accidents, and a combination of both these accident initiators. The specific topics covered are emergency decay heat removal by reactor vessel auxiliary cooling systems, beam shut-off by a melt-rupture disc, safety aspects from locating heat-exchangers in the riser of a pool-type reactor system, and reduction of pressure resistance in the primary circuit by employing bypass routes. The initial part of the research was focused on reactor vessel auxiliary cooling systems. It was shown that an 80 MW th Pb/Bi-cooled accelerator-driven system of 8 m height and 6 m diameter vessel can be well cooled in the case of loss-of-flow accidents in which the accelerator proton beam is not switched off. After a loss-of-heat-sink accident the proton beam has to be interrupted within 40 minutes in order to avoid fast creep of the vessel. If a melt-rupture disc is included in the wall of the beam pipe, which breaks at 150 K above the normal core outlet temperature, the grace period until the beam has to be shut off is increased to 6 hours. For the same vessel geometry, but an operating power of 250 MW th the structural materials can still avoid fast creep in case the proton beam is shut off immediately. If beam shut-off is delayed, additional cooling methods are needed to increase the heat removal. Investigations were made on the filling of the gap between the guard and the reactor vessel with liquid metal coolant and using water spray cooling on the guard vessel surface. The second part of the thesis presents examinations regarding an accelerator-driven system also cooled with Pb/Bi but with heat-exchangers located in the

Safety assessment of envisaged systems for automotive hydrogen supply and utilization

Energy Technology Data Exchange (ETDEWEB)

Landucci, Gabriele [Dipartimento di Ingegneria Chimica, Chimica Industriale e Scienza dei Materiali, Universita di Pisa, via Diotisalvi n.2, 56126 Pisa (Italy); Tugnoli, Alessandro; Cozzani, Valerio [Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Alma Mater Studiorum - Universita di Bologna, via Terracini n.28, 40131 Bologna (Italy)

2010-02-15

A novel consequence-based approach was applied to the inherent safety assessment of the envisaged hydrogen production, distribution and utilization systems, in the perspective of the widespread hydrogen utilization as a vehicle fuel. Alternative scenarios were assessed for the hydrogen system chain from large scale production to final utilization. Hydrogen transportation and delivery was included in the analysis. The inherent safety fingerprint of each system was quantified by a set of Key Performance Indicators (KPIs). Rules for KPIs aggregation were considered for the overall assessment of the system chains. The final utilization stage resulted by large the more important for the overall expected safety performance of the system. Thus, comparison was carried out with technologies proposed for the use of other low emission fuels, as LPG and natural gas. The hazards of compressed hydrogen-fueled vehicles resulted comparable, while reference innovative hydrogen technologies evidenced a potentially higher safety performance. Thus, switching to the inherently safer technologies currently under development may play an important role in the safety enhancement of hydrogen vehicles, resulting in a relevant improvement of the overall safety performance of the entire hydrogen system. (author)

Safety and Health Division achievements during 40 years

International Nuclear Information System (INIS)

Noriah Mod Ali

2012-01-01

During her speech, presenter outlined several issues regarding on establishment of Safety and Health Division since 40 years. This division contain of 3 sub unit; Physical Safety Group, Medical Physic Group and Non-ionizing Radiation group (NIR). The objectives of this division to implement R and D activities and services regarding safety and radiological health also non-radiological to ensure public safety, environment and asset suit with obligations established by authorities, IAEA standards and regulations.(author)

Engineering judgement and bridging the fire safety gap in existing nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Qamheiah, G.; Wu, Y., E-mail: gqamheiah@plcfire.com, E-mail: dwu@plcfire.com [PLC Fire Safety Solutions, Mississauga, ON (Canada)

2014-07-01

Canadian nuclear power plants were constructed in the 1960's through the 1980's. Fire safety considerations were largely based on guidance from general building and fire codes in effect at the time. Since then, nuclear specific fire safety standards have been developed and adopted by the Regulator, increasing the expected level of fire safety in the process. Application of the standards to existing plants was largely limited to operational requirements viewed as retroactive. However, as existing facilities undergo modifications or refurbishment for the purpose of life extension, the expectation is that the design requirements of these fire safety standards also be satisfied. This creates considerable challenges for existing nuclear power plants as fire safety requirements such as those intended to assure means for safe egress, prevention of fire spread and protection of redundancy rely upon fire protection features that are inherent in the physical infrastructural design. This paper focuses on the methodology for conducting fire safety gap analyses on existing plants, and the integral role that engineering judgement plays in the development of viable and cost effective solutions to achieve the objectives of the current fire safety standards. (author)

The inherent inefficiency of simultaneously feasible financial transmission rights auctions

International Nuclear Information System (INIS)

Deng, Shi-Jie; Oren, Shmuel; Meliopoulos, A.P.

2010-01-01

Empirical evidence from the New York ISO shows that the clearing prices for point-to-point congestion revenue rights, also known as financial transmission rights (FTRs), resulting from centralized auctions conducted by Independent System Operators differ significantly and systematically from the realized congestion revenues that determine the accrued payoffs of these rights. The question addressed by this paper is whether such deviations are due to price discovery errors which will eventually vanish or due to inherent inefficiencies in the auction structure. We show that even with perfect foresight of average congestion rents the clearing prices for the FTRs depend on the bid quantity and therefore may not be priced correctly in the financial transmission right (FTR) auction. In particular, we prove that quantity limits on the FTR bids may cause the auction clearing prices to differ from the bid prices. This phenomenon which is inherent in the theoretical properties of the optimization algorithm used to clear the auction, is further illustrated through numerical simulations with test systems. We conclude that price discovery alone would not remedy the discrepancy between the auction prices and the realized values of the FTRs. Secondary markets or frequent reconfiguration auctions are necessary in order to achieve such convergence. (author)

Safety features and licensing of CNNC-ACP100

Energy Technology Data Exchange (ETDEWEB)

Zhong, F., E-mail: Zhongfj2000@163.com [Nuclear Power Inst. of China, National Key Lab. of Science and Technology on Reactor System Design Technology (China)

2014-07-01

ACP100 is an innovatory modular pressurized water reactor, the engineering safety systems fully adopt passive safety design technology. Its inherent safety and passive features/systems are verified via testing facilities and are highlighted at certain levels of defence in depth. The licensing of ACP 100 is within current LWR framework and meets up-to-date codes and requirements in nuclear safety. (author)

Development of the Digital Reactor Safety System

International Nuclear Information System (INIS)

Lee, Dong Young; Lee, C. K.; Hwang, I. K.

2008-04-01

Objectives of Project - Development of Digital Safety Grade PLC and Licensing - Development of Safety System(RPS) and Licensing - Development of Safety System(ESF-CCS) and Licensing Content and Result of Project - POSAFE-Q PLC : Development of PLC platform for Shin-UCN unit 1 and 2 ·Development Scope : Processor module, Power module, 3 kinds of Communication module, Bus extension module(Master and Slave), 16 kinds of Input and Output module ·PLC application software development tool(pSET) - IDiPS RPS and IDiPS ESF-CCS : Development of PPS for Sin-UCN 1 and 2 ·Development Scope - 4-channels RPS with the KNICS inherent architecture - A part of 1-channels ESF-CCS with the KNICS inherent architecture - Licensing ·optical Report Submitted and Expected to finish the licensing process until Aug. 2008

Perspectives on understanding and verifying the safety terrain of modular high temperature gas-cooled reactors

Energy Technology Data Exchange (ETDEWEB)

Carlson, Donald E., E-mail: donald@carlsonperin.net [11221 Empire Lane, Rockville, MD 20852 (United States); Ball, Sydney J., E-mail: beckysyd@comcast.net [100 Greywood Place, Oak Ridge, TN 37830 (United States)

2016-09-15

The passive safety characteristics of modular high temperature gas-cooled reactors (HTGRs) are conceptually well known and are largely supported by insights from past and ongoing research. This paper offers perspectives on selected issues in areas where further analysis and testing achievable within existing research and demonstration programs could help address residual uncertainties and better support the analysis of safety performance and the regulatory assessment of defense in depth. Areas considered include the evaluation of normal and anomalous core operating conditions and the analysis of accidents involving loss of forced cooling, coolant depressurization, air ingress, moisture ingress, and reactivity events. In addition to discussing associated uncertainties and potential measures to address them, this paper also proposes supplemental “safety terrain” studies that would use realistic assessments of postulated extreme event sequences to establish a more comprehensive understanding of the inherent behaviors and ultimate safety capabilities of modular HTGRs.

Inherently safe SNR shutdown system with Curie point controlled sensor/switch unit

International Nuclear Information System (INIS)

Mueller, K.; Norajitra, P.; Reiser, H.

1987-02-01

Inherent shutdown due to increase in the sodium temperature at the core outlet is triggered by interruption of the current supply to the electromagnet coupling of absorber elements via curie point controlled sensor/switch units. These switches are arranged above suitable fuel element positions and spatially independent of the shutdown elements. Compared with other similar systems very short response times are achieved. A prototype switch unit has already undergone extensive testing. These tests have confirmed that switching takes place in a very narrow temperature range. (orig./HP) [de

Conceptual design of Inherently Safe Fast Reactor (ISFR)

International Nuclear Information System (INIS)

Asahi, Yoshiro

2003-01-01

ISFR is a boiling heavy water fast reactor of process inherent ultimate safety (PIUS) type. ISFR may breed fuel in the core. Owing to a positive void coefficient, the application of the PIUS concept to ISFR is not straightforward. Thus, the gap conductance is small so that the time constant τ α of the positive void feedback process is sufficiently large, while the initially-closed two-way check valves to be used as passive switches to the pumps are installed at the lower honeycombs. As a result, the passive shutdown mechanisms can come into effect sufficiently soon to suppress the positive feedback reactivity. Both large τ α and the passive switches also help stabilize the system so that ISFR can perform a constant power operation with a simple control logic for the main coolant pump speed. In a steam generator tube rupture, fuel temperature was found to smoothly decrease to the decay heat level with nucleate boiling. The feasibility of ISFR was proved only to some extent. (author)

Coal mine safety achievements in the USA and the contribution of NIOSH research

Energy Technology Data Exchange (ETDEWEB)

Esterhuizen, G.S.; Gurtunca, R.G. [NIOSH, Washington, DC (United States)

2006-12-15

Over the past century coal miner safety and health have seen tremendous improvements: the fatality and injury rates continue to decrease while productivity continues to increase. Many of the hazards that plagued miners in the past, such as coal bumps, methane and coal dust explosions, ground fall accidents and health issues have been significantly reduced. The contribution of NIOSH research includes products for prevention and survival of mine fires, methane control measures, design procedure for underground coal mines, methods for excavation surface controls, methods and procedures for blasting, laser usage in underground mines and prevention of electrocution from overhead power lines that have reduced accidents and injuries in underground coal mines. Health research has produced products such as the personal dust monitor, noise abating technologies and ergonomic solutions for equipment operators. Research priorities at NIOSH are set by considering surveillance statistics, stakeholder inputs and loss control principles. Future research in coal mining is directed towards respiratory diseases, noise-induced hearing loss, repetitive musculoskeletal injuries, traumatic injuries, falls of ground and mine disasters. The recent spate of accidents in coal mines resulted in the Miner Act of 2006, which includes a specific role for NIOSH in future mine safety research and development. The mine safety achievements in the USA reflect the commitment of industry, labour, government and research organizations to improving the safety of the mine worker.

Laser safety tools and training

CERN Document Server

Barat, Ken

2008-01-01

Lasers perform many unique functions in a plethora of applications, but there are many inherent risks with this continually burgeoning technology. Laser Safety: Tools and Training presents simple, effective ways for users in a variety of facilities to evaluate the hazards of any laser procedure and ensure they are following documented laser safety standards.Designed for use as either a stand-alone volume or a supplement to Laser Safety Management, this text includes fundamental laser and laser safety information and critical laser use information rarely found in a single source. The first lase

Continuous improvement of the MHTGR safety and competitive performance

International Nuclear Information System (INIS)

Eichenberg, T.W.; Etzel, K.T.; Mascaro, L.L.; Rucker, R.A.

1992-05-01

An increase in reactor module power from 350 to 450 MW(t) would markedly improve the economics of the Modular High Temperature Gas-Cooled Reactor (MHTGR). The higher power level was recommended as the result of an in-depth cost reduction study undertaken to compete with the declining price of fossil fuel. The safety assessment confirms that the high level of safety, which relies on inherent characteristics and passive features, is maintained at the elevated power level. Preliminary systems, nuclear, and safety performance results are discussed for the recommended 450 MW(t) design. Optimization of plant parameters and design modifications accommodated the operation of the steam generator and circulator at the higher power level. Events in which forced cooling is lost, designated as conduction cooldowns are described in detail. For the depressurized conduction cooldown, without full helium inventory, peak fuel temperatures are significantly lowered. A more negative temperature coefficient of reactivity was achieved while maintaining an adequate fuel cycle and reactivity control. Continual improvement of the MHTGR delivers competitive performance without relinquishing the high safety margins demanded of the next generation of power plants

25 Years of Community Activities towards Harmonization of Nuclear Safety Criteria and Requirements - Achievements and Prospects

International Nuclear Information System (INIS)

Lillington, J.N.; Turland, B.D.; Haste, T.J.; Seiler, J.M.; Carretero, A.; Perez, T.; Geutges, A.; Van Hienen, J.F.A.; Jehee, J.N.T.; Sehgal, B.R.; Mattila, L.; Holmstrom, H.; Karwat, H.; Maroti, L.; Toth, I.; Husarcek, J.

2001-10-01

The main objective was to advise the EC on future challenges and opportunities in terms of enhanced co-operation in the area of nuclear safety and harmonization of safety requirements and practices in an enlarged European Union. The activities were divided into 3 sub-tasks as follows: part A, to prepare an analysis, synthesis and assessment of the main achievements from Community activities related to the Resolutions on the technological problems of nuclear safety of 1975 and 1992, with due consideration for related research activities; part B, to prepare an overview of safety philosophies and practices in EU Member States, taking account of their specific national practices in terms of legal framework, type and age of operating nuclear reactors; part C, to provide elements of a strategy for future activities in the frame of the Council Resolutions, with particular attention to the context of enlargement of the EU. (author)

Model development for the dynamic analysis of the OSU inherently safe reactor. Part 1

International Nuclear Information System (INIS)

Aybar, H.S.

1992-01-01

Faculty and students in the Nuclear Engineering Program at the Ohio State University (OSU) have proposed a conceptual design for an inherently safe 340 MWe power reactor. The design is based on the state-of-the-art technology of LWRs and the High Temperature Gas- cooled Reactors (HTGRs). The OSU Inherently Safe Reactor (OSU-ISR) concept uses shorter than standard BWR fuel elements in the reactor core. All the fluid on the primary side is contained within a Prestressed Concrete Reactor Vessel (PCRV). This important feature significantly reduces the probability of a LOCA. A new feature of the OSU-ISR is an operator independent steam driven Emergency Core Cooling System (ECCS) housed within the PCRV. In accident conditions where the steam generators are incapacitated, steam from the core drives a jet injector, which takes water from the suppression pool and pumps it into the core cavity to maintain core coverability. The preliminary analysis of the concept was performed as a design project in the Nuclear Engineering Program at the OSU during the Spring of 1985, and published in ''Nuclear Technology.'' The use of a PCRV for ducting and containment and the replacement of forced recirculation with natural circulation on the primary side significantly improve the inherent safety of the plant. Currently, work is in progress for the refinement of the OSU-ISR concept, partially supported by a grant from the U.S. Department of Energy

Alternate approaches to nuclear safety

International Nuclear Information System (INIS)

Crane, A.T.

1985-01-01

For the US nuclear power industry to expand, a greatly increased portion of the public must come to share the industry's confidence in reactor safety. Major obstacles to establishing this confidence are frequent incidents with potential safety implications and a lack of incontrovertible proof that the risk of a major accident is very low. The most important step toward overcoming these obstacles would be for each utility to operate, maintain, and evaluate its reactors according to far higher standards. With improvements in reliability and safety margins, existing plants would be a stimulus for building new ones rather than an impediment. If changes to the operation of existing plants and improvements to the design of future ones were inadequate, the only hope for a revival of the nuclear industry would be an alternative reactor so obviously safe that risk would no longer be an issue. Three possible concepts are the modular high-temperature gas reactor, the process inherent ultimate safety reactor, and the liquid-metal fast reactor. All three have inherent safety features that should make a meltdown essentially impossible. They cannot know just how great the advantage of these alternate reactors would be, but the benefits of developing one or more of the concepts appear great

PHWR safety: design, siting and construction

International Nuclear Information System (INIS)

Sharma, V.K.

2002-01-01

In all activities associated with NPPs viz. siting, design, construction, commissioning and operation, safety is given overriding importance. The safety design principles of PHWRs are based on defence-in-depth approach, physical and functional separation between process and safety systems and also among various safety systems, redundancy to meet single failure criteria and postulation of a number of design basis events for which the plant must be designed. Apart from engineered safety systems, PHWRs have inherent characteristics which contribute to safety. In siting of a NPP, it is required to ensure that the given site does not pose undue radiological hazard to public and the environment both during normal operation as well as during and following an accident condition. For this purpose, all site related external events, both natural and man induced, are assessed for their effect on the plant and are considered as part of the design basis. Possible radiological impact of the NPP on environment and surrounding population is assessed and ensured to be within acceptable limits. During construction phase, it is essential that the NPP be built in accordance with design intent and with required quality of workmanship to ensure that the NPP will remain safe during all states of operation. This is achieved through careful execution and QA activities encompassing all aspects of component fabrication at manufacturer works, civil construction, site erection, assembly, and commissioning. Future trends in nuclear safety will continue to be based on existing principles which have proved to be sound. These will be further strengthened by features such as increasing use of passive means of performing safety functions and a more explicit treatment of severe accidents. (author)

The role of the regulator in promoting and evaluating safety culture. Operating experience feedback programme approach

International Nuclear Information System (INIS)

Perez, S.

2002-01-01

Promoting and Evaluating Safety Culture (S.C.) in Operating Organizations must be one of the main Nuclear Regulator goals to achieve. This can be possible only if each and every one of the regulatory activities inherently involves S.C. It can be seen throughout attitudes, values, uses and practices in both individuals and the whole regulatory organization. One among all the regulatory tools commonly used by regulators to promote and evaluate the commitment of the licensees with safety culture as a whole involves organizational factors and particular attention is directed to the operating organization. This entailed a wide range of activities, including all those related with management of safety performance. Operating Experience Feedback Programme as a tool to enhance safety operation is particularly useful for regulators in the evaluation of the role of S.C. in operating organization. Safety Culture is recognized as a subset of the wider Organizational Culture. Practices that improve organizational effectiveness can also contribute to enhance safety. An effective event investigation methodology is a specific practice, which contributes to a healthy Safety Culture. (author)

Inherent-opening-controlled pattern formation in carbon nanotube arrays

International Nuclear Information System (INIS)

Huang Xiao; Zhou, Jijie J; Sansom, Elijah; Gharib, Morteza; Haur, Sow Chorng

2007-01-01

We have introduced inherent openings into densely packed carbon nanotube arrays to study self-organized pattern formation when the arrays undergo a wetting-dewetting treatment from nanotube tips. These inherent openings, made of circular or elongated hollows in nanotube mats, serve as dewetting centres, from where liquid recedes from. As the dewetting centres initiate dry zones and the dry zones expand, surrounding nanotubes are pulled away from the dewetting centres by liquid surface tension. Among short nanotubes, the self-organized patterns are consistent with the shape of the inherent openings, i.e. slender openings lead to elongated trench-like structures, and circular holes result in relatively round nest-like arrangements. Nanotubes in a relatively high mat are more connected, like in an elastic body, than those in a short mat. Small cracks often initialize themselves in a relatively high mat, along two or more adjacent round openings; each of the cracks evolves into a trench as liquid dries up. Self-organized pattern control with inherent openings needs to initiate the dewetting process above the nanotube tips. If there is no liquid on top, inherent openings barely enlarge themselves after the wetting-dewetting treatment

Preliminary safety analysis of unscrammed events for KLFR

International Nuclear Information System (INIS)

Kim, S.J.; Ha, G.S.

2005-01-01

The report presents the design features of KLFR; Safety Analysis Code; steady-state calculation results and analysis results of unscrammed events. The calculations of the steady-state and unscrammed events have been performed for the conceptual design of KLFR using SSC-K code. UTOP event results in no fuel damage and no centre-line melting. The inherent safety features are demonstrated through the analysis of ULOHS event. Although the analysis of ULOF has much uncertainties in the pump design, the analysis results show the inherent safety characteristics. 6% flow of rated flow of natural circulation is formed in the case of ULOF. In the metallic fuel rod, the cladding temperature is somewhat high due to the low heat transfer coefficient of lead. ULOHS event should be considered in design of RVACS for long-term cooling

Measurement of inherent optical properties in the Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Suresh, T.; Desa, E.; Kurian, J.; Mascarenhas, A.A.M.Q.

Inherent optical properties, absorption and began attenuation were measured in situ using a reflective tube absorption meter at nint wavelength, 412, 440, 488, 510, 555, 630, 650, 676 and 715 nm, in the Arabian Sea during March. Since inherent...

Development of physiotherapy inherent requirement statements – an Australian experience

Science.gov (United States)

2013-01-01

Background The United Nations Convention on the Rights of People with Disabilities promotes equal rights of people with a disability in all aspects of their life including their education. In Australia, Disability Discrimination legislation underpins this Convention. It mandates that higher education providers must demonstrate that no discrimination has occurred and all reasonable accommodations have been considered and implemented, to facilitate access and inclusion for a student with a disability. The first step to meeting legislative requirements is to provide students with information on the inherent requirements of a course. This paper describes the steps which were taken to develop inherent requirement statements for a 4-year entry-level physiotherapy program at one Australian university. Case presentation Inherent requirement statements were developed using an existing framework, which was endorsed and mandated by the University. Items which described inherencies were extracted from Australian physiotherapy professional standards and statutory regulatory requirements, and units contained in the physiotherapy program. Data were integrated into the 8 prescribed domains: ethical behaviour, behavioural stability, legal, communication, cognition, sensory abilities, strength and mobility, and sustainable performance. Statements for each domain were developed using a 5-level framework (introductory statement, description of the inherent requirement, justification for inherency, characteristics of reasonable adjustments and exemplars) and reviewed by a University Review Panel. Refinement of statements continued until no further changes were required. Fifteen physiotherapy inherent requirement statements were developed. The eight domains identified in the existing framework, developed for Nursing, were relevant to the study of physiotherapy. Conclusions The inherent requirement statements developed in this study provide a transparent, defensible position on the

Finite-time and fixed-time leader-following consensus for multi-agent systems with discontinuous inherent dynamics

Science.gov (United States)

Ning, Boda; Jin, Jiong; Zheng, Jinchuan; Man, Zhihong

2018-06-01

This paper is concerned with finite-time and fixed-time consensus of multi-agent systems in a leader-following framework. Different from conventional leader-following tracking approaches where inherent dynamics satisfying the Lipschitz continuous condition is required, a more generalised case is investigated: discontinuous inherent dynamics. By nonsmooth techniques, a nonlinear protocol is first proposed to achieve the finite-time leader-following consensus. Then, based on fixed-time stability strategies, the fixed-time leader-following consensus problem is solved. An upper bound of settling time is obtained by using a new protocol, and such a bound is independent of initial states, thereby providing additional options for designers in practical scenarios where initial conditions are unavailable. Finally, numerical simulations are provided to demonstrate the effectiveness of the theoretical results.

The importance of safety in achieving the widespread use of hydrogen as a fuel

Energy Technology Data Exchange (ETDEWEB)

Edeskuty, F.J.

1997-09-01

The advantages of hydrogen fuel have been adequately demonstrated on numerous occasions. However, two major disadvantages have prevented any significant amount of corresponding development. These disadvantages have been in the economics of producing sufficient quantities of hydrogen and in the safety (both real and perceived) of its use. To date work has mostly been properly centered on solving the economic problems. However, a greater effort on the safety of new hydrogen systems now being proposed also deserves consideration. To achieve the greatest safety in the expansion of the use of hydrogen into its wide-spread use as a fuel, attention must be given to four considerations. These are, obtaining knowledge of all the physical principles involved in the new uses, having in place the regulations that allow the safe interfacing of the new systems, designing and constructing the new systems with safety in mind, and the training of the large number of people that will become the handlers of the hydrogen. Existing organizations that produce, transport, or use hydrogen on a large scale have an excellent safety record. This safety record comes as a consequence of dedicated attention to the above-mentioned principles. However, where these principles were not closely followed, accidents have resulted. Some examples can be cited. As the use of hydrogen becomes more widespread, there must be a mechanism for assuring the universal application of these principles. Larger and more numerous fleet operations with hydrogen fuel may be the best way to begin the indoctrination of the general public to the more general use of hydrogen fuel. Demonstrated safe operation with hydrogen is vital to its final acceptance as the fuel of choice.

The representation of inherent properties.

Science.gov (United States)

Prasada, Sandeep

2014-10-01

Research on the representation of generic knowledge suggests that inherent properties can have either a principled or a causal connection to a kind. The type of connection determines whether the outcome of the storytelling process will include intuitions of inevitability and a normative dimension and whether it will ground causal explanations.

Harmonization of legislation and regulations to achieve food safety: US and Canada perspective.

Science.gov (United States)

Keener, Larry; Nicholson-Keener, Sophia M; Koutchma, Tatiana

2014-08-01

Trade in food and food ingredients among the nations of the world is rapidly expanding and, with this expansion, new supply chain partners, from globally disparate geographic regions, are being enrolled. Food and food ingredients are progressively sourced more from lesser developed nations. Food safety incidents in the USA and Canada show a high unfavorable correlation between illness outbreaks and imported foods. In the USA, for example, foodborne disease outbreaks caused by imported food appeared to rise in 2009 and 2010, and nearly half of the outbreaks, associated with imported food, implicated foods imported from areas which previously had not been associated with outbreaks. Projecting supply chains into new geographical regions raises serious questions about the capacity of the new supply chain partners to provide the requisite regulatory framework and sufficiently robust public health measures for ensuring the safety of the foods and foodstuffs offered for international trade. The laws, regulation and legislation among the many nations participating in the global food trade are, at best, inconsistent. These inconsistencies frequently give rise to trade disputes and cause large quantities of food to be at risk of destruction on the often dubious pretext that they are not safe. Food safety is often viewed through a political or normative lens. Often as not, this lens has been wrought absent scientific precision. Harmonization of food safety legislation around sound scientific principles, as advocated by the US Food Safety Modernization Act (FSMA), would ultimately promote trade and likely provide for incremental improvement in public health. Among the priority roles of most national governments are the advancement of commerce and trade, preservation of public health and ensuring domestic tranquility. Achieving these priorities is fundamental to creating and preserving the wealth of nations. Countries such as the Netherlands, Canada, Germany, Japan and the USA

The development of a small inherently safe homogeneous reactor for the production of medical isotopes

Energy Technology Data Exchange (ETDEWEB)

Carlin, G.E.; Bonin, H.W., E-mail: george.carlin@rmc.ca [Royal Military College of Canada, Kingston, Ontario (Canada)

2013-07-01

The use of radioisotopes for various procedures in the health care industry has become one of the most important practices in medicine. New interest has been found in the use of liquid fueled nuclear reactors to produce these isotopes due to the ease of fuel processing and ability to efficiently use LEU as the fuel source. A version of this reactor is being developed at the Royal Military College of Canada to act as a successor to the SLOWPOKE-2 platform. The thermal hydraulic and transient characteristics of a 20 kWt version are being studied to verify inherent safety abilities. (author)

Nuclear Criticality Safety Assessment for Tank 38H Salt Dissolution

International Nuclear Information System (INIS)

Davis, P.L.

1996-01-01

This assessment report of sample results of the accumulating insoluble solids from Tank 38H demonstrates that an inherent subcritical condition for nuclear criticality safety exists during saltcake dissolution. This report also defines criteria for future sampling of Tank 38H for continued verification of the inherent subcritical condition as saltcake dissolution proceeds

The safety of light water reactors

International Nuclear Information System (INIS)

Pershagen, B.

1986-04-01

The book describes the principles and practices of reactor safety as applied to the design, regulation and operation of both pressurized water reactors and boiling water reactors. The central part of the book is devoted to methods and results of safety analysis. Some significant events are described, notably the Three Mile Island accident. The book concludes with a chapter on the PIUS principle of inherent reactor safety as applied to the SECURE type of reactor developed in Sweden. (G.B.)

The importance of safety in achieving the widespread use of hydrogen as a fuel

Energy Technology Data Exchange (ETDEWEB)

Edeskuty, F.J. [Los Alamos National Laboratory, Los Alamos, NM (United States)

1998-07-01

The advantages of hydrogen fuel have been adequately demonstrated on numerous occasions. However, two major disadvantages have prevented any significant amount of corresponding development. These disadvantages have been in the economics of producing sufficient quantities of hydrogen and in the safety (both real and perceived) of its use. To date, work has mostly been properly centered on solving the economic problems. However, a greater effort on the safety of new hydrogen systems now being proposed also deserves consideration. To achieve the greatest safety in the expansion of the use of hydrogen into its wide-spread use as a fuel, attention must be given to four considerations. These are, obtaining knowledge of all the physical principles involved in the new uses, using that knowledge to put in place the regulations that allow the safe interfacing of the new systems, designing and constructing the new systems with safety in mind, and the training of the large number of people that will become the handlers of the hydrogen. Existing organizations that produce, transport, or use hydrogen on a large scale have an excellent safety record. This safety record comes as a consequence of dedicated attention to the above-mentioned principle. However, where these principles were not closely followed, accidents have resulted. Some examples are cited. As the use of hydrogen becomes more wide-spread, there must be a mechanism for assuring the universal application of these principles. Larger and more numerous fleet operations with hydrogen fuel may be the best way to begin the indoctrination of the general public to the more general use of hydrogen fuel. Demonstrated safe operation with hydrogen is vital to its final acceptance as the fuel of choice. 18 refs.

A Mechanistic Reliability Assessment of RVACS and Metal Fuel Inherent Reactivity Feedbacks

Energy Technology Data Exchange (ETDEWEB)

Grabaskas, David; Brunett, Acacia J.; Passerini, Stefano; Grelle, Austin

2017-09-24

GE Hitachi Nuclear Energy (GEH) and Argonne National Laboratory (Argonne) participated in a two year collaboration to modernize and update the probabilistic risk assessment (PRA) for the PRISM sodium fast reactor. At a high level, the primary outcome of the project was the development of a next-generation PRA that is intended to enable risk-informed prioritization of safety- and reliability-focused research and development. A central Argonne task during this project was a reliability assessment of passive safety systems, which included the Reactor Vessel Auxiliary Cooling System (RVACS) and the inherent reactivity feedbacks of the metal fuel core. Both systems were examined utilizing a methodology derived from the Reliability Method for Passive Safety Functions (RMPS), with an emphasis on developing success criteria based on mechanistic system modeling while also maintaining consistency with the Fuel Damage Categories (FDCs) of the mechanistic source term assessment. This paper provides an overview of the reliability analyses of both systems, including highlights of the FMEAs, the construction of best-estimate models, uncertain parameter screening and propagation, and the quantification of system failure probability. In particular, special focus is given to the methodologies to perform the analysis of uncertainty propagation and the determination of the likelihood of violating FDC limits. Additionally, important lessons learned are also reviewed, such as optimal sampling methodologies for the discovery of low likelihood failure events and strategies for the combined treatment of aleatory and epistemic uncertainties.

Relationships among School Climate, School Safety, and Student Achievement and Well-Being: A Review of the Literature

Science.gov (United States)

Kutsyuruba, Benjamin; Klinger, Don A.; Hussain, Alicia

2015-01-01

School climate, safety and well-being of students are important antecedents of academic achievement. However, school members do not necessarily experience school climate in the same way; rather, their subjective perceptions of the environment and personal characteristics influence individual outcomes and behaviours. Therefore, a closer look at the…

Study on the KALIMER safety approach

International Nuclear Information System (INIS)

Kim, Eui Kwang; Han, Do Hee; Kim, Young Cheol.

1997-01-01

This study describes KALIMER's safety approach, how to establish the safety criteria and temperature limit, how to define safety evaluation events, and some safety research and development needs items. It is recommended that the KALIMER's approach to safety use seven levels of safety design and a defense-in-depth design approach with particular emphasis on inherent passive features. In order to establish as set DBEs for KALIMER safety evaluation, the procedure is explained how to define safety evaluation events. Final selection is to be determined later with the final establishment of design concepts. On the basis of preliminary studies and evaluation of the plant safety related areas, the KALIMER and PRISM have following three main difference that may require special research and development for KALIMER. (author). 7 refs., 6 tabs., 6 figs

Informing patients of risks inherent in treatment.

Science.gov (United States)

Griffith, Richard; Tengnah, Cassam

2009-11-01

Consent to treatment lies at the heart of autonomous decision making by patients who are entitled to make a free choice about whether to accept or refuse treatment. To help patients arrive at their decision district nurses must ensure that they give sufficient information about the nature and risks inherent in the treatment to allow an informed choice to be made. This article considers how much information regarding risks needs to be disclosed. It discusses how the law requires a different level of disclosure for patients who ask no questions about risks, those who make general enquiries about risks and those who ask specific questions about the risks inherent in treatment.

Does the inherence heuristic take us to psychological essentialism?

Science.gov (United States)

Marmodoro, Anna; Murphy, Robin A; Baker, A G

2014-10-01

We argue that the claim that essence-based causal explanations emerge, hydra-like, from an inherence heuristic is incomplete. No plausible mechanism for the transition from concrete properties, or cues, to essences is provided. Moreover, the fundamental shotgun and storytelling mechanisms of the inherence heuristic are not clearly enough specified to distinguish them, developmentally, from associative or causal networks.

Overheads, Safety Analysis and Engineering FY 1995 Site Support Program Plan WBS 6.3.5

Energy Technology Data Exchange (ETDEWEB)

DiVincenzo, E.P.

1994-09-27

The Safety Analysis & Engineering (SA&E) department provides core competency for safety analysis and risk documentation that supports achievement of the goals and mission as described in the Hanford Mission Plan, Volume I, Site Guidance (DOE-RL 1993). SA&E operations are integrated into the programs that plan and conduct safe waste management, environmental restoration, and operational activities. SA&E personnel are key members of task teams assigned to eliminate urgent risks and inherent threats that exist at the Hanford Site. Key to ensuring protection of public health and safety, and that of onsite workers, are the products and services provided by the department. SA&E will continue to provide a leadership role throughout the DOE complex with innovative, cost-effective approaches to ensuring safety during environmental cleanup operations. The SA&E mission is to provide support to direct program operations through safety analysis and risk documentation and to maintain an infrastructure responsive to the evolutionary climate at the Hanford Site. SA&E will maintain the appropriate skills mix necessary to fulfill the customers need to conduct all operations in a safe and cost-effective manner while ensuring the safety of the public and the onsite worker.

PRISM [Power Reactor Inherently Safe Module] design concept enhances waste management

International Nuclear Information System (INIS)

Thompson, M.L.; Berglund, R.C.

1989-01-01

PRISM, a modular advanced liquid metal reactor (ALMR), has been designed conceptually by GE under the US Department of Energy sponsorship. The concept design and analyses have been primarily focused on passive safety and improved construction and operating costs. Significantly, the unique design of multiple modules and features of PRISM enhance waste management over conventional reactor systems. This paper provides an overview of PRISM of these enhancements. Inherent to the ALMR's, the sodium coolant precludes crud buildup on reactor surfaces and in components and waste for disposal. Preliminary evaluations indicate this fundamental feature results in factors of 2-4 less waste volume and 2-3 orders of magnitude less curies per megawatt-electric for ultimate disposal. For example, the tap designed for sodium cleanup is expected to be exchanged only once every thirty years. Also, inherent to ALMR's, burning waste actinides and selected fission products to preclude their accumulation and burial is very attractive. The hard neutron spectrum of ALMR burns the actinides efficiently and is not poisoned by the actinides and fission products. The modular design of PRISM components (and the fuel cycle equipment) permit replacement without expensive and potentially hazardous volume reduction. For example, the functional components of the reference electromagnetic pump and IHK can be removed intact for waste disposal. Although development of the reference metal fuel is not completed, it is estimated that (low-level) waste from recycle of the fuel will result in significantly less volume than would be generated by aqueous recycle of oxide fuel. 6 refs., 10 figs

Quantification of the inherent uncertainty in the relaxation modulus and creep compliance of asphalt mixes

Science.gov (United States)

Kassem, Hussein A.; Chehab, Ghassan R.; Najjar, Shadi S.

2017-08-01

Advanced material characterization of asphalt concrete is essential for realistic and accurate performance prediction of flexible pavements. However, such characterization requires rigorous testing regimes that involve mechanical testing of a large number of laboratory samples at various conditions and set-ups. Advanced measurement instrumentation in addition to meticulous and accurate data analysis and analytical representation are also of high importance. Such steps as well as the heterogeneous nature of asphalt concrete (AC) constitute major factors of inherent variability. Thus, it is imperative to model and quantify the variability of the needed asphalt material's properties, mainly the linear viscoelastic response functions such as: relaxation modulus, E(t), and creep compliance, D(t). The objective of this paper is to characterize the inherent uncertainty of both E(t) and D(t) over the time domain of their master curves. This is achieved through a probabilistic framework using Monte Carlo simulations and First Order approximations, utilizing E^{*} data for six AC mixes with at least eight replicates per mix. The study shows that the inherent variability, presented by the coefficient of variation (COV), in E(t) and D(t) is low at small reduced times, and increases with the increase in reduced time. At small reduced times, the COV in E(t) and D(t) are similar in magnitude; however, differences become significant at large reduced times. Additionally, the probability distributions and COVs of E(t) and D(t) are mix dependent. Finally, a case study is considered in which the inherent uncertainty in D(t) is forward propagated to assess the effect of variability on the predicted number of cycles to fatigue failure of an asphalt mix.

Safety Analysis Of Actinide Recycled Fast Power Reactor

International Nuclear Information System (INIS)

Taufik, Mohammad

2001-01-01

Simulation for safety analysis of actinide recycled fast power reactor has been performed. The objective is to know reactor response about ULOF and ULOF and UTOP simultaneous accident. From parameter result such reactivity feedback, power, temperature, and cooled flow rate can conclusion that reactor have inherent safety system, which can back to new Equilibrium State

A real-life example of choosing an inherently safer process option

International Nuclear Information System (INIS)

Study, Karen

2007-01-01

While choosing an inherently safer alternative may seem straightforward, sometimes what seems to be the most obvious alternative may not provide the best risk reduction. The process designer must maintain a broad perspective to be able to recognize all potential hazards when evaluating design options. All aspects of operation such as start-up, shut-down, utility failure, as well as normal operation should be considered. Choosing the inherently safer option is best accomplished early in the option selection phase of a project; however, recycle back to the option selection phase may be needed if an option is not thoroughly evaluated early in the process. In this paper, a project to supply ammonia to a catalytic reactor will be reviewed. During the course of the project, an 'inherently safer' alternative was selected and later discarded due to issues uncovered during the detail design phase. The final option chosen will be compared to (1) the original design and (2) the initial 'inherently safer' alternative. The final option was inherently safer than both the original design and the initial 'inherently safer' alternative even though the design team initially believed that it would not be

Overview of fast reactor safety research and development in the USA

International Nuclear Information System (INIS)

Neuhold, R.J.; Avery, R.; Marchaterre, J.F.

1986-01-01

The liquid metal reactor (LMR) safety R and D program in the U.S. is presently focused on support of two modular innovative reactor concepts: PRISM - the General Electric Power Reactor Inherently Safe Module and SAFR - the Rockwell International Sodium Advanced Fast Reactor. These reactor plant concepts accommodate the use of either oxide fuel or the metal fuel which is under development in the Argonne National Laboratory (ANL) Integral Fast Reactor (IFR) program. Both concepts emphasize prevention of accidents through enhancement of inherent and passive safety characteristics. Enhancement of these characteristics is expected to be a major factor in establishing new and improved safety criteria and licensing arrangements with regulatory authorities for advanced reactors. Limited work is also continuing on the Large Scale Prototype Breeder (LSPB), a large pool plant design. Major elements of the current and restructured safety program are discussed. (author)

Inherent Risk or Risky Decision? Coach's Failure to Use Safety Device an Assumed Risk

Science.gov (United States)

Dodds, Mark A.; Bochicchio, Kristi Schoepfer

2013-01-01

The court examined whether a coach's failure to implement a safety device during pitching practice enhanced the risk to the athlete or resulted in a suboptimal playing condition, in the context of the assumption of risk doctrine.

Regulatory review of safety cases and safety assessments - associated challenges

International Nuclear Information System (INIS)

Bennett, D.G.; Ben Belfadhel, M.; Metcalf, P.E.

2006-01-01

Regulatory reviews of safety cases and safety assessments are essential for credible decision making on the licensing or authorization of radioactive waste disposal facilities. Regulatory review also plays an important role in developing the safety case and in establishing stakeholders' confidence in the safety of the facility. Reviews of safety cases for radioactive waste disposal facilities need to be conducted by suitably qualified and experienced staff, following systematic and well planned review processes. Regulatory reviews should be sufficiently comprehensive in their coverage of issues potentially affecting the safety of the disposal system, and should assess the safety case against clearly established criteria. The conclusions drawn from a regulatory review, and the rationale for them should be reproducible and documented in a transparent and traceable way. Many challenges are faced when conducting regulatory reviews of safety cases. Some of these relate to issues of project and programme management, and resources, while others derive from the inherent difficulties of assessing the potential long term future behaviour of engineered and environmental systems. The paper describes approaches to the conduct of regulatory reviews and discusses some of the challenges faced. (author)

On the Safety of Machine Learning: Cyber-Physical Systems, Decision Sciences, and Data Products.

Science.gov (United States)

Varshney, Kush R; Alemzadeh, Homa

2017-09-01

Machine learning algorithms increasingly influence our decisions and interact with us in all parts of our daily lives. Therefore, just as we consider the safety of power plants, highways, and a variety of other engineered socio-technical systems, we must also take into account the safety of systems involving machine learning. Heretofore, the definition of safety has not been formalized in a machine learning context. In this article, we do so by defining machine learning safety in terms of risk, epistemic uncertainty, and the harm incurred by unwanted outcomes. We then use this definition to examine safety in all sorts of applications in cyber-physical systems, decision sciences, and data products. We find that the foundational principle of modern statistical machine learning, empirical risk minimization, is not always a sufficient objective. We discuss how four different categories of strategies for achieving safety in engineering, including inherently safe design, safety reserves, safe fail, and procedural safeguards can be mapped to a machine learning context. We then discuss example techniques that can be adopted in each category, such as considering interpretability and causality of predictive models, objective functions beyond expected prediction accuracy, human involvement for labeling difficult or rare examples, and user experience design of software and open data.

The safety feature of hydraulic driving system of control rod for 200 MW nuclear heating reactor

International Nuclear Information System (INIS)

Chi Zongbo; Wu Yuanqiang

1997-01-01

The hydraulic driving system of control rod is used as control rod drive mechanism in 200 MW nuclear heating reactor. Design of this system is based on passive system, integrating drive and guide of control rod. The author analyzes the inherent safety and the design safety of this system, with mechanism of control rod not ejecting when the pressure of pressure vessel is lost, and calculating result of core not exposing when the amount of coolant is drained by broken pipe. The results indicate that this system has good safety feature, and assures reactor safety under any accident conditions, providing important technology support for 200 MW nuclear heating reactor with inherent safety feature

Safety and operating experience at EBR-II: lessons for the future

International Nuclear Information System (INIS)

Sackett, J.I.; Golden, G.H.

1981-01-01

EBR-II is a small LMFBR power plant that has performed safely and reliably for 16 years. Much has been learned from operating it to facilitate the design, licensing, and operation of large commercial LMFBR power plants in the US. EBR-II has been found relatively easy to keep in conformity with evolving safety requirements, largely because of inherent safety features of the plant. Such features reduce dependence on active safety systems to protect against accidents. EBR-II has experienced a number of plant-transient incidents, some planned, others inadvertent; none has resulted in any significant plant damage. The operating experience with EBR-II has led to the formulation of an Operational Reliability Test Program (ORTP), aimed at showing inherently safe performance of fuel and plant systems

System safety education focused on flight safety

Science.gov (United States)

Holt, E.

1971-01-01

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

Operating plant safety analysis needs

International Nuclear Information System (INIS)

Young, M.Y.; Love, D.S.

1992-01-01

The primary objective for nuclear power station owners is to operate and manage their plants safely. However, there is also a need to provide economical electric power, which requires that the unit be operated as efficiently as possible, consistent with the safety requirements. The objectives cited above can be achieved through the identification and use of available margins inherent in the plant design. As a result of conservative licensing and analytical approaches taken in the past, many of these margins may be found in the safety analysis limits within which plants currently operate. Improvements in the accuracy of the safety analysis, and a more realistic treatment of plant initial and boundary conditions, can make this margin available for a variety of uses which enhance plant performance, help to reduce O and M costs, and may help to extend licensed operation. Opportunities for improvement exist in several areas in the accident analysis normally performed for Chapter 15 of the FSAR. For example, recent modifications to the ECCS rule, 10CFR50.46 and Appendix K, allow use of margins previously unavailable in the analysis of the Loss of Coolant Accident (LOCA). To take advantage of this regulatory change, new methods are being developed to analyze both the large and small break loss of coolant accident (LOCA). As this margin is used, enhancements in the analysis of other transients will become necessary. The paper discusses accident analysis methods, future development needs, and analysis margin utilization in specific accident scenarios

The Joint Convention on the safety of spent fuel management and on the safety of radioactive waste management. An instrument to achieve a global safety

International Nuclear Information System (INIS)

Risoluti, P.

2006-01-01

The Joint Convention on the Safety of Spent Fuel Management and the Safety of Radioactive Waste Management (the Joint Convention) is the first legally binding international treaty in the area of radioactive material management. It was adopted by a Diplomatic Conference in September 1997 and opened for signature on 29 September 1997. The Convention entered into force on 18 June 1998, and to date (May 2006) has been ratified by 41 countries. The Joint Convention applies to spent fuel and radioactive waste resulting from civilian application. Its principal aim is to achieve and maintain a high degree of safety in their management worldwide. The Convention is an incentive instrument, not designed to ensure fulfilment of obligations through control and sanction, but by a volunteer peer review mechanism. The obligations of the Contracting Parties are mainly based on the international safety standards developed by the IAEA in past decades. The Convention is of interest of all countries generating radioactive waste. Therefore it is relevant not only for those using nuclear power, but for any country where application of nuclear energy in education, agriculture, medicine and industry is currently used. Obligations of Contracting Parties include attending a Review Meeting held every three years and prepare National Reports for review by the other Contracting Parties. In the National Reports basic information on inventory and facilities for management of radioactive materials has to be provided. Countries with small nuclear power and/or research programs or countries having radioactive materials only from nuclear application on medicine, agriculture or conventional industry, can benefit from the exchange of information and the technical knowledge gained by the reporting procedure set up by the Convention. The second Review Meeting is to be held at IAEA headquarters from 15 to 26 May 2006. This paper presents the objectives and the implementation status of the Convention, the

ELFR: The European Lead Fast Reactor. Design, Safety Approach and Safety Characteristics

International Nuclear Information System (INIS)

Alemberti, Alessandro

2012-01-01

• In the framework of the LEADER project, the safety approach for a Lead cooled fast reactor has been defined and, in particular, all the possible challenges to the main safety functions and their mechanisms have been specified, in order to better define the needed provisions. • On the basis of the above and taking into account the results of the safety analyses performed during previous project (ELSY), a reference configuration of the ELFR plant has been consolidated, by improving and updating the plant design features. In particular, the emerged safety concerns have been analyzed in the LEADER project and a new set of design options and safety provisions have been proposed. • The combination of favourable Lead coolant inherent characteristics and plant design features, specifically developed to face identified challenges, resulted in a very robust and forgiving design, even in very extreme conditions, as a Fukushima-like scenario

[OCCUPATIONAL HEALTH RISK ASSESSMENT AND MANAGEMENT IN WORKERS IN IMPROVEMENT OF NATIONAL POLICY IN OCCUPATIONAL HYGIENE AND SAFETY].

Science.gov (United States)

Shur, P Z; Zaĭtseva, N V; Alekseev, V B; Shliapnikov, D M

2015-01-01

In accordance with the international documents in the field of occupational safety and hygiene, the assessment and minimization of occupational risks is a key instrument for the health maintenance of workers. One of the main ways to achieve it is the minimization of occupational risks. Correspondingly, the instrument for the implementation of this method is the methodology of analysis of occupational risks. In Russian Federation there were the preconditions for the formation of the system for the assessment and management of occupational risks. As the target of the national (state) policy in the field of occupational safety in accordance with ILO Conventions it can be offered the prevention of accidents and injuries to health arising from work or related with it, minimizing the causes of hazards inherent in the working environment, as far as it is reasonably and practically feasible. Global trend ofusing the methodology of the assessment and management of occupational risks to life and health of citizens requires the improvement of national policies in the field of occupational hygiene and safety. Achieving an acceptable level of occupational risk in the formation of national policy in the field of occupational hygiene and safety can be considered as one of the main tasks.

Radiation protection and nuclear safety - achievements and the way ahead for ARPANSA

International Nuclear Information System (INIS)

Loy, J.

2001-01-01

Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), a fully independent legislative and regulatory agency, was announced in 1997, but formally came into existence in 1999. The first stage of its development as a regulator was guiding Commonwealth users of radiation sources and nuclear facilities through making licence applications. Assessing licences was complex, including because of the need to work with the public submission process for nuclear facilities. This presentation will briefly outline the legislative framework and the regulatory arrangements that were instrumental in the creation of ARPANSA and discusses at length the implementation phase and achievements to date. The Commonwealth jurisdiction differs from the States - ARPANSA's challenge is now to learn how to move to the surveillance and audit stage of licensing

Can a robot improve mine safety?

CSIR Research Space (South Africa)

Green, JJ

2010-09-01

Full Text Available Safety in mines is of paramount importance, especially in the labour intensive operations of South Africa, where upward of 300 000 people are employed on a daily basis in an environment that is inherently dangerous. On average approximately 50...

Fast breeder reactor safety : a perspective

International Nuclear Information System (INIS)

Kale, R.D.

1992-01-01

Taking into consideration India's limited reserves of natural and vast reserves of thorium, the fast reactor route holds a great promise for India's energy supply in future. The fast reactor fueled with 239 Pu/ 238 U (unused or depleted) produces (breeds) more fissionable fuel material 239 Pu than it consumes. Calculations show that a fast breeder reactor (FBR) increases energy potential of natural uranium by about 60 times. As the fast reactor can also convert 232 Th into 233 U which is a fissionable material, it can make India's thorium reserves a source of almost inexhaustible energy supply for a long time to come. Significant advantage of FBR plants cooled by sodium and their world-wide operating experience are reviewed. There are two main safety issues of FBR, one nuclear and the other non-nuclear. The nuclear issue concerns core disruptive accident and the non-nuclear one concerns the high chemical energy potential of sodium. These two issues are analysed and it is pointed that they are manageable by current design, construction and operational practices. Main findings of safety research during the last six to eight years in West European Countries and United States of America (US) are summarised. Three stage engineered safety provision incorporated into the design of the sodium cooled Fast Breeder Test Reactor (FBTR) commissioned at Kalpakkam are explained. The important design safety features of FBTR such as primary system containment, emergency core cooling, plant protection system, inherent safety features achieved through reactivity coefficients, and natural convection cooling are discussed. Theoretical analysis and experimental research in fast reactor safety carried out at the Indira Gandhi Centre for Atomic Research during the past some years are reviewed. (M.G.B.)

Summary of advanced LMR [Liquid Metal Reactor] evaluations: PRISM [Power Reactor Inherently Safe Module] and SAFR [Sodium Advanced Fast Reactor

International Nuclear Information System (INIS)

Van Tuyle, G.J.; Slovik, G.C.; Chan, B.C.; Kennett, R.J.; Cheng, H.S.; Kroeger, P.G.

1989-10-01

In support of the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) has performed independent analyses of two advanced Liquid Metal Reactor (LMR) concepts. The designs, sponsored by the US Department of Energy (DOE), the Power Reactor Inherently Safe Module (PRISM) [Berglund, 1987] and the Sodium Advanced Fast Reactor (SAFR) [Baumeister, 1987], were developed primarily by General Electric (GE) and Rockwell International (RI), respectively. Technical support was provided to DOE, RI, and GE, by the Argonne National Laboratory (ANL), particularly with respect to the characteristics of the metal fuels. There are several examples in both PRISM and SAFR where inherent or passive systems provide for a safe response to off-normal conditions. This is in contrast to the engineered safety systems utilized on current US Light Water Reactor (LWR) designs. One important design inherency in the LMRs is the ''inherent shutdown'', which refers to the tendency of the reactor to transition to a much lower power level whenever temperatures rise significantly. This type of behavior was demonstrated in a series of unscrammed tests at EBR-II [NED, 1986]. The second key design feature is the passive air cooling of the vessel to remove decay heat. These systems, designated RVACS in PRISM and RACS in SAFR, always operate and are believed to be able to prevent core damage in the event that no other means of heat removal is available. 27 refs., 78 figs., 3 tabs

Safety Design Approach for the Development of Safety Requirements for Design of Commercial HTGR

International Nuclear Information System (INIS)

Ohashi, Hirofumi; Sato, Hiroyuki; Nakagawa, Shigeaki; Tachibana, Yukio; Nishihara, Tetsuo; Yan, Xing; Sakaba, Nariaki; Kunitomi, Kazuhiko

2014-01-01

The research committee on “Safety requirements for HTGR design” was established in 2013 under the Atomic Energy Society of Japan to develop the draft safety requirements for the design of commercial High Temperature Gas-cooled Reactors (HTGRs), which incorporate the HTGR safety features demonstrated using the High Temperature Engineering Test Reactor (HTTR), lessons learned from the accident of Fukushima Daiichi Nuclear Power Station and requirements for the integration of the hydrogen production plants. The safety design approach for the commercial HTGRs which is a basement of the safety requirements is determined prior to the development of the safety requirements. The safety design approaches for the commercial HTGRs are to confine the radioactive materials within the coated fuel particles not only during normal operation but also during accident conditions, and the integrity of the coated fuel particles and other requiring physical barriers are protected by the inherent and passive safety features. This paper describes the main topics of the research committee, the safety design approaches and the safety functions of the commercial HTGRs determined in the research committee. (author)

Development and implementation of setpoint tolerances for special safety systems

International Nuclear Information System (INIS)

Oliva, A.F.; Balog, G.; Parkinson, D.G.; Archinoff, G.H.

1991-01-01

The establishment of tolerances and impairment limits for special safety system setpoints is part of the process whereby the plant operator demonstrates to the regulatory authority that the plant operates safely and within the defined plant licensing envelope. The licensing envelope represents the set of limits and plant operating state and for which acceptably safe plant operation has been demonstrated by the safety analysis. By definition, operation beyond this envelope contributes to overall safety system unavailability. Definition of the licensing envelope is provided in a wide range of documents including the plant operating licence, the safety report, and the plant operating policies and principles documents. As part of the safety analysis, limits are derived for each special safety system initiating parameter such that the relevant safety design objectives are achieved for all design basis events. If initiation on a given parameter occurs at a level beyond its limit, there is a potential reduction in safety system effectiveness relative to the performance credited in the plant safety analysis. These safety system parameter limits, when corrected for random and systematic instrument errors and other errors inherent in the process of periodic testing or calibration, are then used to derive parameter impairment levels and setpoint tolerances. This paper describes the methodology that has evolved at Ontario Hydro for developing and implementing tolerances for special safety system parameters (i.e., the shutdown systems, emergency coolant injection system and containment system). Tolerances for special safety system initiation setpoints are addressed specifically, although many of the considerations discussed here will apply to performance limits for other safety system components. The first part of the paper deals with the approach that has been adopted for defining and establishing setpoint limits and tolerances. The remainder of the paper addresses operational

The inherent politics of quality in public park management

DEFF Research Database (Denmark)

Lindholst, Andrej Christian; Konijnendijk, Cecil Cornelis; Fors, Hanna

2012-01-01

In this paper, we highlight and illustrate the inherent politics embedded in “quality” as a concept for managing public parks. Reflecting more generic quality concepts, contemporary quality models in park management include concepts for both operational, strategic and stakeholder management as well...... managing the park organisation itself. However, quality concepts and their application through various management models include as well as exclude the access, values and worldviews of particular interests. In this way, any particular quality concept and model embeds its own politics by inherent...... allocations of ‘who gets what, when and how’. We illustrate the inherent politics by providing a case study of a widely adopted quality model for operational management that has been adopted and implemented in Denmark as part of new public management reforms. In perspective, other quality concepts and models...

New perspectives on reactor safety

International Nuclear Information System (INIS)

Avery, R.

1986-01-01

Over the past few years a number of changes and new perspectives have come about in our approach to reactor safety. These changes have occurred over a period of time extending from as long ago as 1975, when WASH-1400 came out representing the first major application of probabilistic risk analysis (PRA) to US reactor plants. The period of change has extended from that time to the present, and includes new areas of focus such as safety goals, source term studies, and severe accident policy statement and approaches, including the IDCOR Program. It has also included a greatly increased interest in inherent safety. These areas are discussed in this paper

Management of safety, safety culture and self assessment

International Nuclear Information System (INIS)

Carnino, A.

2000-01-01

Safety management is the term used for the measures required to ensure that an acceptable level of safety is maintained throughout the life of an installation, including decommissioning. The safety culture concept and its implementation are described in part one of the paper. The principles of safety are now quite well known and are implemented worldwide. It leads to a situation where harmonization is being achieved as indicated by the entry into force of the Convention on Nuclear Safety. To go beyond the present nuclear safety levels, management of safety and safety culture will be the means for achieving progress. Recent events which took place in major nuclear power countries have shown the importance of the management and the consequences on safety. At the same time, electricity deregulation is coming and will impact on safety through reductions in staffing and in operation and maintenance cost at nuclear installations. Management of safety as well as its control and monitoring by the safety authorities become a key to the future of nuclear energy.(author)

Solid Biomass Climate Change Interventions Examined in a Context of Inherent Safety, Media Shifting and Emerging Risks

DEFF Research Database (Denmark)

Hedlund, Frank Huess; Astad, John

2014-01-01

benefits over safety concerns seems to run deep and not confined to the realm of only solid biomass. Danish environmental ambitions are very high and the costs to society of introducing solid biomass fuels are breathtaking. In this setting, the general failure to address safety risk s appears particularly...

EHS Open House: Learning Lab and Life Safety | Poster

Science.gov (United States)

Attendees of the Environment, Health, and Safety Program’s (EHS’) Open House had a chance to learn self-defense techniques, as well as visit with vendors demonstrating the latest trends in laboratory safety. “Working with sharps in labs is inherently dangerous, so EHS proactively focused on featuring equipment that would promote safer techniques,” said Siobhan Tierney, program

Inherent Reward and Risk (Part I): Towards a Universal Paradigm for Investment Analysis

OpenAIRE

Liang Zou

2000-01-01

In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own “inherent reward”and “inherent risk” that can be judged with common sense. Ijustify axiomatically the existence and uniqueness (ratio scale)of inherent reward (U) and inherent risk (D) that could beregarded as universal measures of reward and risk for any giveninvestment strategy. Incorporating the notion of “inherentefficien...

The R and D issues necessary to achieve the safety design of commercialized liquid-metal cooled fast reactors

International Nuclear Information System (INIS)

Shoji, Kotake; Koji, Dozaki; Shigenobu, Kubo; Yoshio, Shimakawa; Hajime, Niwa; Masakazu, Ichimiya

2002-01-01

Within the framework of the feasibility study on commercialized fast reactor cycle systems (hereafter described as F/S), the safety design principle is investigated and several kinds of design studies are now in progress. Among the designs for liquid-metal cooled fast reactor (LMR), the advanced loop type sodium cooled fast reactor (FR) is one of the promising candidate as future commercialized LMR. In this paper, the safety related research and development (R and D) issues necessary to achieve the safety design are described along the defence-in-depth principle, taking account of not only the system characteristics of the advanced loop concepts but also design studies and R and D experiences so far. Safety issues related to the hypothetical core disruptive accidents (CDA) are emphasized both from the prevention and mitigation. A re-criticality free core concept with a special fuel assembly is pursued by performing both analytical and experimental efforts, in order to realize the rational design and to establish easy-to-understand safety logic. Sodium related issues are also given to ensure plant availability and to enhance the acceptability to the public. (authors)

Perceptions and culture of safety among helicopter emergency medical service personnel in the UK.

Science.gov (United States)

Chesters, Adam; Grieve, Philip H; Hodgetts, Timothy J

2016-11-01

The use of helicopter emergency medical services (HEMS) has increased significantly in the UK since 1987. To date there has been no research that addresses HEMS pilots and medical crews' own ideas on the risks that they view as inherent in their line of work and how to mitigate these risks. The aim of this survey is to describe and compare the attitudes and perceptions towards risk in HEMS operations of these staff. A questionnaire was administered electronically to a representative selection of HEMS doctors, paramedics and pilots in the UK. A number of questions were grouped into common themes, and presented as Likert scales and ranking where appropriate. Descriptive and comparative results were presented and statistically analysed. The target sample of 100 consecutive respondents was achieved. All questionnaires were entirely completed. Respondents attributed the most risk to night HEMS operations without the use of night vision goggles, commercial pressure and mechanical aircraft failure. There was no statistical difference in overall perception of safety and years of experience (p=0.58) or between professions (p=0.08). Those who had experienced a crash were more likely to believe that HEMS operations are not inherently safe (p=0.05). We have surveyed a cross-section of the HEMS operational community in the UK in order to describe their perceptions of safety and risk within their professional life. Two-thirds of respondents believed that HEMS operations were inherently safe. Those who did not seemed to be influenced by personal experience of a crash or serious incident. We support increased operational training for clinical crewmembers, an increased emphasis on incident reporting and a culture of safety, and careful attention to minimum training and equipment requirements for all HEMS missions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Safety and anti-hyperglycemic efficacy of various tea types in mice

Science.gov (United States)

Han, Manman; Zhao, Guangshan; Wang, Yijun; Wang, Dongxu; Sun, Feng; Ning, Jingming; Wan, Xiachun; Zhang, Jinsong

2016-01-01

Tea, a beverage consumed worldwide, has proven anti-hyperglycemic effects in animal models. Better efficacies of tea beverages are frequently associated with high-dose levels, whose safety attracts considerable attention. Based on the inherent nature of tea catechin oxidation, fresh tea leaves are manufactured into diverse tea types by modulating the oxidation degree of catechins. The present study aimed to assess various tea types for their safety properties and anti-hyperglycemic effects. Mice were allowed free access to tea infusion (1:30, w/v) for one week, and the rare smoked tea caused salient adverse reactions, including hepatic and gastrointestinal toxicities; meanwhile, the widely-consumed green and black teas, unlike the rare yellow tea, suppressed growth in fast-growing healthy mice. When mice were fed a high-fat diet and allowed free access to tea infusion (1:30, w/v) for 25 days, only yellow tea significantly reduced blood glucose. Therefore, various teas showed different safety profiles as well as anti-hyperglycemic efficacy strengths. To achieve an effective and safe anti-hyperglycemic outcome, yellow tea, which effectively suppressed high-fat diet-induced early elevation of hepatic thioredoxin-interacting protein, is an optimal choice. PMID:27531374

Achieving reasonable conservatism in nuclear safety analyses

International Nuclear Information System (INIS)

Jamali, Kamiar

2015-01-01

In the absence of methods that explicitly account for uncertainties, seeking reasonable conservatism in nuclear safety analyses can quickly lead to extreme conservatism. The rate of divergence to extreme conservatism is often beyond the expert analysts’ intuitive feeling, but can be demonstrated mathematically. Too much conservatism in addressing the safety of nuclear facilities is not beneficial to society. Using certain properties of lognormal distributions for representation of input parameter uncertainties, example calculations for the risk and consequence of a fictitious facility accident scenario are presented. Results show that there are large differences between the calculated 95th percentiles and the extreme bounding values derived from using all input variables at their upper-bound estimates. Showing the relationship of the mean values to the key parameters of the output distributions, the paper concludes that the mean is the ideal candidate for representation of the value of an uncertain parameter. The mean value is proposed as the metric that is consistent with the concept of reasonable conservatism in nuclear safety analysis, because its value increases towards higher percentiles of the underlying positively skewed distribution with increasing levels of uncertainty. Insensitivity of the results to the actual underlying distributions is briefly demonstrated. - Highlights: • Multiple conservative assumptions can quickly diverge into extreme conservatism. • Mathematics and attractive properties provide basis for wide use of lognormal distribution. • Mean values are ideal candidates for representation of parameter uncertainties. • Mean values are proposed as reasonably conservative estimates of parameter uncertainties

Twenty years of improvements in LWR safety

International Nuclear Information System (INIS)

Franks, S. III; Mulkey, J.P.; Moonka, A.

1996-01-01

Substantial improvements have been made in the safety of light-water reactors in the US during the past two decades, making currently operating reactors safer than ever before. Safety improvements have resulted both from regulatory and operational changes and from new knowledge and technology. The US Nuclear Regulatory Commission, the US Department of Energy, and the American nuclear power industry have worked together and with the international community to enhance the safety of existing plants and to incorporate lessons learned from prior operation into designs for a new generation of advanced, inherently safer reactors

Safety Aspects of Long Term Spent Fuel Dry Storage

International Nuclear Information System (INIS)

Botsch, Wolfgang; Smalian, S.; Hinterding, P.; Drotleff, H.; Voelzke, H.; Wolff, D.; Kasparek, E.

2014-01-01

As a consequence of the lack of a final repository for spent nuclear fuel (SF) and high level waste (HLW), long term interim storage of SF and HLW will be necessary. As with the storage of all radioactive materials, the long term storage of SF and HLW must conform to safety requirements. Safety aspects such as safe enclosure of radioactive materials, safe removal of decay heat, sub-criticality and avoidance of unnecessary radiation exposure must be achieved throughout the complete storage period. The implementation of these safety requirements can be achieved by dry storage of SF and HLW in casks as well as in other systems such as dry vault storage systems or spent fuel pools, where the latter is neither a dry nor a passive system. After the events of Fukushima, the advantages of passively and inherently safe dry storage systems have become more obvious. In Germany, dry storage of SF in casks fulfils both transport and storage requirements. Mostly, storage facilities are designed as concrete buildings above the ground; one storage facility has also been built as a rock tunnel. In all these facilities the safe enclosure of radioactive materials in dry storage casks is achieved by a double-lid sealing system with surveillance of the sealing system. The safe removal of decay heat is ensured by the design of the storage containers and the storage facility, which also secures to reduce the radiation exposure to acceptable levels. TUV and BAM, who work as independent experts for the competent authorities, inform about spent fuel management and issues concerning dry storage of spent nuclear fuel, based on their long experience in these fields. All relevant safety issues such as safe enclosure, shielding, removal of decay heat and sub-criticality are checked and validated with state-of-the-art methods and computer codes before the license approval. In our presentation we discuss which of these aspects need to be examined closer for a long term interim storage. It is shown

Analysis of solutions for passively activated safety shutdown devices for SFR

International Nuclear Information System (INIS)

Burgazzi, Luciano

2013-01-01

Highlights: • Innovative systems for emergency shut down of fast reactors are proposed. • The concepts of inherent and passive safety are put forward. • The relative analysis in terms of safety and reliability is presented. • A comparative assessment among the concepts is performed. • Path forward is tracked. -- Abstract: In order to enhance the inherent safety of fast reactors, innovative reactivity control systems have been proposed for intrinsic ultimate shut-down instead of conventional scram rods, to cope with the potential consequences of severe unprotected transient accidents, such as an energetic core disruptive accident, as in case of sodium fast reactors. The passive shut-down systems are designed to shut-down system only by inherent passive reactivity feedback mechanism, under unprotected accident conditions, implying failure of reactor protection system. They are conceived to be self-actuated without any signal elaboration, since the actuation of the system is triggered by the effects induced by the transient like material dilatation, in case of overheating of the coolant for instance, according to fast reactor design to meet the safety requirements. This article looks at different special shutdown systems specifically engineered for prevention of severe accidents, to be implemented on fast reactors, with main focus on the investigation of the performance of the self-actuated shutdown systems in sodium fast reactors

Overheads, Safety Analysis and Engineering FY 1995 Site Support Program Plan WBS 6.3.5

International Nuclear Information System (INIS)

DiVincenzo, E.P.

1994-01-01

The Safety Analysis ampersand Engineering (SA ampersand E) department provides core competency for safety analysis and risk documentation that supports achievement of the goals and mission as described in the Hanford Mission Plan, Volume I, Site Guidance (DOE-RL 1993). SA ampersand E operations are integrated into the programs that plan and conduct safe waste management, environmental restoration, and operational activities. SA ampersand E personnel are key members of task teams assigned to eliminate urgent risks and inherent threats that exist at the Hanford Site. Key to ensuring protection of public health and safety, and that of onsite workers, are the products and services provided by the department. SA ampersand E will continue to provide a leadership role throughout the DOE complex with innovative, cost-effective approaches to ensuring safety during environmental cleanup operations. The SA ampersand E mission is to provide support to direct program operations through safety analysis and risk documentation and to maintain an infrastructure responsive to the evolutionary climate at the Hanford Site. SA ampersand E will maintain the appropriate skills mix necessary to fulfill the customers need to conduct all operations in a safe and cost-effective manner while ensuring the safety of the public and the onsite worker

Risk management and safety

International Nuclear Information System (INIS)

Niehaus, F.; Novegno, A.

1985-01-01

Risk assessment, including probabilistic analyses, has made great progress over the past decade. In spite of the inherent uncertainties it has now become possible to utilize methods and results for decision making at various levels. This paper will, therefore, review risk management in industrial installations, risk management for energy safety policy and prospects of risk management in highly industrialized areas. (orig.) [de

Auxetic foam for snowsport safety devices

OpenAIRE

Allen, Tom; Duncan, Olly; Foster, Leon; Senior, Terry; Zampieri, Davide; Edeh, Victor; Alderson, Andrew

2017-01-01

Skiing and snowboarding are popular snow-sports with inherent risk of injury. There is potential to reduce the prevalence of injuries by improving and implementing snow-sport safety devices with the application of advanced materials. This paper investigates the application of auxetic foam to snow-sport safety devices. Composite pads - consisting of foam covered with a semi-rigid shell - were investigated as a simple model of body armour and a large 70 x 355 x 355 mm auxetic foam sample was fa...

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

Clinical efficacy and safety of achieving very low LDL-cholesterol concentrations with the PCSK9 inhibitor evolocumab: a prespecified secondary analysis of the FOURIER trial.

Science.gov (United States)

Giugliano, Robert P; Pedersen, Terje R; Park, Jeong-Gun; De Ferrari, Gaetano M; Gaciong, Zbigniew A; Ceska, Richard; Toth, Kalman; Gouni-Berthold, Ioanna; Lopez-Miranda, Jose; Schiele, François; Mach, François; Ott, Brian R; Kanevsky, Estella; Pineda, Armando Lira; Somaratne, Ransi; Wasserman, Scott M; Keech, Anthony C; Sever, Peter S; Sabatine, Marc S

2017-10-28

LDL cholesterol is a well established risk factor for atherosclerotic cardiovascular disease. How much one should or safely can lower this risk factor remains debated. We aimed to explore the relationship between progressively lower LDL-cholesterol concentrations achieved at 4 weeks and clinical efficacy and safety in the FOURIER trial of evolocumab, a monoclonal antibody to proprotein convertase subtilisin-kexin type 9 (PCSK9). In this prespecified secondary analysis of 25 982 patients from the randomised FOURIER trial, the relationship between achieved LDL-cholesterol concentration at 4 weeks and subsequent cardiovascular outcomes (primary endpoint was the composite of cardiovascular death, myocardial infarction, stroke, coronary revascularisation, or unstable angina; key secondary endpoint was the composite of cardiovascular death, myocardial infarction, or stroke) and ten prespecified safety events of interest was examined over a median of 2·2 years of follow-up. We used multivariable modelling to adjust for baseline factors associated with achieved LDL cholesterol. This trial is registered with ClinicalTrials.gov, number NCT01764633. Between Feb 8, 2013, and June 5, 2015, 27 564 patients were randomly assigned a treatment in the FOURIER study. 1025 (4%) patients did not have an LDL cholesterol measured at 4 weeks and 557 (2%) had already had a primary endpoint event or one of the ten prespecified safety events before the week-4 visit. From the remaining 25 982 patients (94% of those randomly assigned) 13 013 were assigned evolocumab and 12 969 were assigned placebo. 2669 (10%) of 25 982 patients achieved LDL-cholesterol concentrations of less than 0·5 mmol/L, 8003 (31%) patients achieved concentrations between 0·5 and less than 1·3 mmol/L, 3444 (13%) patients achieved concentrations between 1·3 and less than 1·8 mmol/L, 7471 (29%) patients achieved concentrations between 1·8 to less than 2·6 mmol/L, and 4395 (17%) patients achieved

78 FR 17140 - Upholstered Furniture Fire Safety Technology; Meeting and Request for Comments

Science.gov (United States)

2013-03-20

... retardant (FR) chemicals, specialty fibers/fabrics without FR chemicals, inherently fire resistant materials... Furniture Fire Safety Technology; Meeting and Request for Comments AGENCY: Consumer Product Safety... Commission (CPSC, Commission, or we) is announcing its intent to hold a meeting on upholstered furniture fire...

Safety related terms for advanced nuclear plants

International Nuclear Information System (INIS)

1995-12-01

The terms considered in this document are in widespread current use without a universal consensus as to their meaning. Other safety related terms are already defined in national or international codes and standards as well as in IAEA's Nuclear Safety Standards Series. Most of the terms in those codes and standards have been defined and used for regulatory purposes, generally for application to present reactor designs. There is no intention to duplicate the description of such regulatory terms here, but only to clarify the terms used for advanced nuclear plants. The following terms are described in this paper: Inherent safety characteristics, passive component, active component, passive systems, active system, fail-safe, grace period, foolproof, fault-/error-tolerant, simplified safety system, transparent safety

Safety related terms for advanced nuclear plants

International Nuclear Information System (INIS)

1991-09-01

The terms considered in this document are in widespread current use without a universal consensus as to their meaning. Other safety related terms are already defined in national or international codes and standards as well as in IAEA's Nuclear Safety Standards Series. Most of the terms in those codes and standards have been defined and used for regulatory purposes, generally for application to present reactor designs. There is no intention to duplicate the description of such regulatory terms here, but only to clarify the terms used for advanced nuclear plants. The following terms are described in this paper: Inherent safety characteristics, passive component, active component, passive systems, active system, fail-safe, grace period, foolproof, fault-/error-tolerant, simplified safety system, transparent safety

Specific features of goal setting in road traffic safety

Science.gov (United States)

Kolesov, V. I.; Danilov, O. F.; Petrov, A. I.

2017-10-01

Road traffic safety (RTS) management is inherently a branch of cybernetics and therefore requires clear formalization of the task. The paper aims at identification of the specific features of goal setting in RTS management under the system approach. The paper presents the results of cybernetic modeling of the cause-to-effect mechanism of a road traffic accident (RTA); in here, the mechanism itself is viewed as a complex system. A designed management goal function is focused on minimizing the difficulty in achieving the target goal. Optimization of the target goal has been performed using the Lagrange principle. The created working algorithms have passed the soft testing. The key role of the obtained solution in the tactical and strategic RTS management is considered. The dynamics of the management effectiveness indicator has been analyzed based on the ten-year statistics for Russia.

Priming patient safety: A middle-range theory of safety goal priming via safety culture communication.

Science.gov (United States)

Groves, Patricia S; Bunch, Jacinda L

2018-05-18

The aim of this paper is discussion of a new middle-range theory of patient safety goal priming via safety culture communication. Bedside nurses are key to safe care, but there is little theory about how organizations can influence nursing behavior through safety culture to improve patient safety outcomes. We theorize patient safety goal priming via safety culture communication may support organizations in this endeavor. According to this theory, hospital safety culture communication activates a previously held patient safety goal and increases the perceived value of actions nurses can take to achieve that goal. Nurses subsequently prioritize and are motivated to perform tasks and risk assessment related to achieving patient safety. These efforts continue until nurses mitigate or ameliorate identified risks and hazards during the patient care encounter. Critically, this process requires nurses to have a previously held safety goal associated with a repertoire of appropriate actions. This theory suggests undergraduate educators should foster an outcomes focus emphasizing the connections between nursing interventions and safety outcomes, hospitals should strategically structure patient safety primes into communicative activities, and organizations should support professional development including new skills and the latest evidence supporting nursing practice for patient safety. © 2018 John Wiley & Sons Ltd.

Preliminary safety analysis for key design features of KALIMER

Energy Technology Data Exchange (ETDEWEB)

Hahn, D. H.; Kwon, Y. M.; Chang, W. P.; Suk, S. D.; Lee, S. O.; Lee, Y. B.; Jeong, K. S

2000-07-01

KAERI is currently developing the conceptual design of a liquid metal reactor, KALIMER(Korea Advanced Liquid Metal Reactor) under the long-term nuclear R and D program. In this report, descriptions of the KALIMER safety design features and safety analyses results for selected ATWS accidents are presented. First, the basic approach to achieve the safety goal is introduced in chapter 1, and the safety evaluation procedure for the KALIMER design is described in chapter 2. It includes event selection, event categorization, description of design basis events, and beyond design basis events. In chapter 3, results of inherent safety evaluations for the KALIMER conceptual design are presented. The KALIMER core and plant system are designed to assure design performance during a selected set of events without either reactor control or protection system intervention. Safety analyses for the postulated anticipated transient without scram(ATWS) have been performed to investigate the KALIMER system response to the events. They are categorized as bounding events(BEs) because of their low probability of occurrence. In chapter 4, the design of the KALIMER containment dome and the results of its performance analysis are presented. The designs of the existing LMR containment and the KALIMER containment dome have been compared in this chapter. Procedure of the containment performance analysis and the analysis results are described along with the accident scenario and source terms. Finally, a simple methodology is introduced to investigate the core kinetics and hydraulic behavior during HCDA in chapter 5. Mathematical formulations have been developed in the framework of the modified bethe-tait method, and scoping analyses have been performed for the KALIMER core behavior during super-prompt critical excursions.

Functional safety of health information technology.

LENUS (Irish Health Repository)

Chadwick, Liam

2012-03-01

In an effort to improve patient safety and reduce adverse events, there has been a rapid growth in the utilisation of health information technology (HIT). However, little work has examined the safety of the HIT systems themselves, the methods used in their development or the potential errors they may introduce into existing systems. This article introduces the conventional safety-related systems development standard IEC 61508 to the medical domain. It is proposed that the techniques used in conventional safety-related systems development should be utilised by regulation bodies, healthcare organisations and HIT developers to provide an assurance of safety for HIT systems. In adopting the IEC 61508 methodology for HIT development and integration, inherent problems in the new systems can be identified and corrected during their development. Also, IEC 61508 should be used to develop a healthcare-specific standard to allow stakeholders to provide an assurance of a system\\'s safety.

Students' Perception of Live Lectures' Inherent Disadvantages

Science.gov (United States)

Petrovic, Juraj; Pale, Predrag

2015-01-01

This paper aims to provide insight into various properties of live lectures from the perspective of sophomore engineering students. In an anonymous online survey conducted at the Faculty of Electrical Engineering and Computing, University of Zagreb, we investigated students' opinions regarding lecture attendance, inherent disadvantages of live…

Dynamic operator actions analysis for inherently safe fast reactors and light water reactors

International Nuclear Information System (INIS)

Ho, V.; Apostolakis, G.

1988-01-01

A comparative dynamic human actions analysis of inherently safe fast reactors (ISFRs) and light water reactors (LWRs) in terms of systems response and estimated human error rates is presented. Brief overviews of the ISFR and LWR systems are given to illustrate the design differences. Key operator actions required by the ISFR reactor shutdown and decay heat removal systems are identified and are compared with those of the LWR. It is observed that, because of the passive nature of the ISFR safety-related systems, a large time window is available for operator actions during transient events. Furthermore, these actions are fewer in number, are less complex, and have lower error rates and less severe consequences than those of the LWRs. We expect the ISFR operator errors' contribution to risk is smaller (at least in the context of the existing human reliability models) than that of the LWRs. (author)

Management of safety and safety culture at the NPPs of Ukraine

International Nuclear Information System (INIS)

Koltakov, Vladimir

2002-01-01

The report contains general aspects of safety and safety culture. The brief description of operational characteristics and basic indexes of atomic power plants at the Ukraine are represented. The information referring to structure of NPPs of Operation organization license-holder, safety responsibility of both Regulatory and Utility Bodies also is given. The main part of the report include seven sections: 1. Practical application of safety management models; 2. erspective on the relationship between safety management and safety culture; 3. The role of leadership in achieving high standards of safety; 4. Current and future challengers that impact on safety culture and safety management (e.g. the impact of competition, changing, economic and political circumstances, workforce demographics, etc.); 5. Key lessons learned from major events; 6. Practical applications of safety culture concepts (e.g. learning organizations, training staff communications, etc.); 7. dvance in human performance. Some of the main pending safety and safety culture problems that are necessary to achieve in the near future are mentioned

Safety design requirements for safety systems and components of JSFR

International Nuclear Information System (INIS)

Kubo, Shigenobu; Shimakawa, Yoshio; Yamano, Hidemasa; Kotake, Shoji

2011-01-01

Safety design requirements for JSFR were summarized taking the development targets of the FaCT project and design feature of JSFR into account. The related safety principle and requirements for Monju, CRBRP, PRISM, SPX, LWRs, IAEA standards, goals of GIF, basic principle of INPRO etc. were also taken into account so that the safety design requirements can be a next-generation global standard. The development targets for safety and reliability are set based on those of FaCT, namely, ensuring safety and reliability equal to future LWR and related fuel cycle facilities. In order to achieve these targets, the defence-in-depth concept is used as the basic safety design principle. General features of the safety design requirements are 1) Achievement of higher reliability, 2) Achievement of higher inspectability and maintainability, 3) Introduction of passive safety features, 4) Reduction of operator action needs, 5) Design consideration against Beyond Design Basis Events, 6) In-Vessel Retention of degraded core materials, 7) Prevention and mitigation against sodium chemical reactions, and 8) Design against external events. The current specific requirements for each system and component are summarized taking the basic design concept of JSFR into account, which is an advanced loop-type large-output power plant with a mixed-oxide-fuelled core. (author)

Psychological aspects of food safety risk perception

DEFF Research Database (Denmark)

Scholderer, Joachim

signals, motivating approach. Novelty, and the detection of certain olfactory and visual cues associated with spoilage or contamination, act as orientation or threat signals and motivate closer inspection or avoidance. Anticipatory affects are an inherent part of these behaviour regulation systems...... problematic food safety behaviours are likely to occur. The presentation will begin with an overview of the relevant psychological mechanisms that regulate approach and avoidance behaviour with respect to potentially hazardous foods. Learned representations of familiarity and reward value act as safety...

Nuclear safety culture and nuclear safety supervision

International Nuclear Information System (INIS)

Chai Jianshe

2013-01-01

In this paper, the author reviews systematically and summarizes up the development process and stage characteristics of nuclear safety culture, analysis the connotation and characteristics of nuclear safety culture, sums up the achievements of our country's nuclear safety supervision, dissects the challenges and problems of nuclear safety supervision. This thesis focused on the relationship between nuclear safety culture and nuclear safety supervision, they are essential differences, but there is a close relationship. Nuclear safety supervision needs to introduce some concepts of nuclear safety culture, lays emphasis on humanistic care and improves its level and efficiency. Nuclear safety supervision authorities must strengthen nuclear safety culture training, conduct the development of nuclear safety culture, make sure that nuclear safety culture can play significant roles. (author)

A dynamic fail-safe approach to the design of computer-based safety systems

International Nuclear Information System (INIS)

Smith, I.C.; Miller, M.

1994-01-01

For over 30 years AEA Technology has carried out research and development in the field of nuclear instrumentation and protection systems. Throughout the course of this extensive period of research and development the dominant theme has been the achievement of fully fail-safe designs. These are defined as designs in which the failure of any single component will result in the unit output reverting to a demand for trip action status. At an early stage it was recognized that the use of dynamic rather than static logic could ease the difficulties inherent in achieving a fail-safe design. The first dynamic logic systems coupled logic elements magnetically. The paper outlines the evolution from these early concepts of a dynamic fail-safe approach to the design of computer-based safety systems. Details are given of collaboration between AEA Technology and Duke Power Co. to mount an ISAT TM demonstration at Duke's Oconee Nuclear Power Station

Structural safety assessment of a tokamak-type fusion facility for a through crack to cause cooling water leakage and plasma disruption

International Nuclear Information System (INIS)

Nakahira, Masataka

2004-01-01

A tokamak-type fusion machine has inherent safety associated with plasma shutdown. A small water leak can cause a plasma disruption although there is another possibility to terminate plasma without disruption. This plasma disruption will induce electromagnetic (EM) forces acting in the vacuum vessel (VV). From a radiological safety viewpoint, the VV is designed to form a physical barrier that encloses tritium and activated dust. If the VV can sustain an unstable fracture by EM forces from a through crack to cause the small leak, the structural safety will be assured and the inherent safety will be demonstrated. Therefore, a systematic approach to assure the structural safety is developed. A new analytical model to evaluate the through crack and leak rate of cooling water is proposed, with verification by experimental leak measurements. Based on the analysis, the critical crack length to terminate plasma is evaluated as about 2mm. On the other hand, the critical crack length for unstable fracture is obtained as about 400 mm. It is concluded that EM forces induced by the small leak to terminate plasma will not cause unstable fracture of the VV; thus the inherent safety is demonstrated. (author)

Tracking the Market Performance of Companies That Integrate a Culture of Health and Safety: An Assessment of Corporate Health Achievement Award Applicants.

Science.gov (United States)

Fabius, Raymond; Loeppke, Ronald R; Hohn, Todd; Fabius, Dan; Eisenberg, Barry; Konicki, Doris L; Larson, Paul

2016-01-01

The aim of this study was to assess the hypothesis that stock market performance of companies achieving high scores on either health or safety in the Corporate Health Achievement Award (CHAA) process will be superior to average index performance. The stock market performance of portfolios of CHAA winners was examined under six different scenarios using simulation and past market performance in tests of association framed to inform the investor community. CHAA portfolios out-performed the S&P average on all tests. This study adds to the growing evidence that a healthy and safe workforce correlates with a company's performance and its ability to provide positive returns to shareholders. It advances the idea that a proven set of health and safety metrics based on the CHAA evaluation process merits inclusion with existing measures for market valuation.

Observation and analysis of water inherent optical properties

Science.gov (United States)

Sun, Deyong; Li, Yunmei; Le, Chengfeng; Huang, Changchun

2008-03-01

Inherent optical property is an important part of water optical properties, and is the foundation of water color analytical model establishment. Through quantity filter technology (QFT) and backscattering meter BB9 (WETlabs Inc), absorption coefficients of CDOM, total suspended minerals and backscattering coefficients of total suspended minerals had been observed in Meiliang Bay of Taihu lake at summer and winter respectively. After analyzing the spectral characteristics of absorption and backscattering coefficients, the differences between two seasons had been illustrated adequately, and the reasons for the phenomena, which are related to the changes of water quality coefficient, had also been explained. So water environment states can be reflected by inherent optical properties. In addition, the relationship models between backscattering coefficients and suspended particle concentrations had been established, which can support coefficients for analytical models.

Safety analysis for 'Fugen'

International Nuclear Information System (INIS)

1997-10-01

The improvement of safety in nuclear power stations is an important proposition. Therefore also as to the safety evaluation, it is important to comprehensively and systematically execute it by referring to the operational experience and the new knowledge which is important for the safety throughout the period of use as well as before the construction and the start of operation of nuclear power stations. In this report, the results when the safety analysis for ''Fugen'' was carried out by referring to the newest technical knowledge are described. As the result, it was able to be confirmed that the safety of ''Fugen'' has been secured by the inherent safety and the facilities which were designed for securing the safety. The basic way of thinking on the safety analysis including the guidelines to be conformed to is mentioned. As to the abnormal transient change in operation and accidents, their definition, the events to be evaluated and the standards for judgement are reported. The matters which were taken in consideration at the time of the analysis are shown. The computation programs used for the analysis were REACT, HEATUP, LAYMON, FATRAC, SENHOR, LOTRAC, FLOOD and CONPOL. The analyses of the abnormal transient change in operation and accidents are reported on the causes, countermeasures, protective functions and results. (K.I.)

Conceptual safety design analysis of Korea advanced liquid metal reactor

International Nuclear Information System (INIS)

Suk, S. D.; Park, C. K.

1999-01-01

The national long-term R and D program, updated in 1977, requires Korea Atomic Energy Research Institute (KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor (KALIMER), along with supporting R and D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 Mwe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self-consistent design meeting a set of major safety design requirements for accident prevention. Some of the current emphasis includes those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve extensive supporting R and D programs. This paper summarizes some of the results of conceptual engineering and design analyses performed for the safety of KALIMER in the area of inherent safety, passive decay heat removal, sodium water reaction, and seismic isolation. (author)

Inherent reward & risk (Part I): Towards a universal paradigm for investment analysis

NARCIS (Netherlands)

Zou, L.

2000-01-01

In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own "inherent reward"and "inherent risk" that can be judged with common sense. Ijustify axiomatically the existence and uniqueness

Thermally responsive polymer electrolytes for inherently safe electrochemical energy storage

Science.gov (United States)

Kelly, Jesse C.

Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in electrochemical energy storage devices, while preserving the performance, lifetimes, and versatility that large-format systems require. Initial work focused on the development of a model system that demonstrated the concept of RPEs in an electrochemical device. Aqueous electrolyte solutions of polymers exhibiting properties that change in response to temperature were developed for applications in EDLCs and supercapacitors. These "smart materials" provide a means to control electrochemical systems where polymer phase separation at high temperatures affects electrolyte properties and inhibits device performance. Aqueous RPEs were synthesized using N-isopropylacrylamide, which governs the thermal properties, and fractions of acrylic acid or vinyl sulfonic acids, which provide ions to the solution. The molecular properties of these aqueous RPEs, specifically the ionic composition, were shown to influence the temperature-dependent electrolyte properties and the extent to which these electrolytes control the energy storage characteristics of a supercapacitor device. Materials with high ionic content provided the highest room temperature conductivity and electrochemical activity; however, RPEs with low ionic content provided the highest "on

Safety characteristics analysis of nuclear power plants with PHWR PT; Analiza sigurnosnh karakteristika nuklearnih elektrana sa reaktorima PHWR-PT tipa

Energy Technology Data Exchange (ETDEWEB)

Stosic, Z [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

1983-07-01

The paper deals with analysis of basic safety characteristics of heavy water Candu reactor. Inherent safety characteristics, r/a material inventory, systematization of normal abnormal and transient conditions, safety systems and availability analysis are considered. (author)

Specific safety measures for emergency lanes and shoulders of motorways : a proposal for motorways' authorities in the framework of the European research project Safety Standards for Road Design and Redesign SAFESTAR, Workpackage 1.1.

NARCIS (Netherlands)

Braimaister, L.

1999-01-01

This workpackage is one of seven workpackages of the European SAFESTAR project, launched by DG VII. Directing on safety standards and recommendations for the Trans-European Roadway Network (TERN), the workpackage considered safety measures on emergency lanes (stopping strips), which are inherent

Long range stress correlations in the inherent structures of liquids at rest

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Sadrul; Abraham, Sneha; Hudson, Toby; Harrowell, Peter [School of Chemistry, University of Sydney, Sydney, NSW 2006 (Australia)

2016-03-28

Simulation studies of the atomic shear stress in the local potential energy minima (inherent structures) are reported for binary liquid mixtures in 2D and 3D. These inherent structure stresses are fundamental to slow stress relaxation and high viscosity in supercooled liquids. We find that the atomic shear stress in the inherent structures (IS’s) of both liquids at rest exhibits slowly decaying anisotropic correlations. We show that the stress correlations contribute significantly to the variance of the total shear stress of the IS configurations and consider the origins of the anisotropy and spatial extent of the stress correlations.

Safety analysis for key design features of KALIMER-600 design concept

International Nuclear Information System (INIS)

Lee, Yong-Bum; Kwon, Y. M.; Kim, E. K.; Suk, S. D.; Chang, W. P.; Joeng, H. Y.; Ha, K. S.; Heo, S.

2005-03-01

KAERI is developing the conceptual design of a Liquid Metal Reactor, KALIMER-600 (Korea Advanced LIquid MEtal Reactor) under the Long-term Nuclear R and D Program. KALIMER-600 addresses key issues regarding future nuclear power plants such as plant safety, economics, proliferation, and waste. In this report, key safety design features are described and safety analyses results for typical ATWS accidents, containment design basis accidents, and flow blockages in the KALIMER design are presented. First, the basic approach to achieve the safety goal and main design features of KALIMER-600 are introduced in Chapter 1, and the event categorization and acceptance criteria for the KALIMER-600 safety analysis are described in Chapter 2, In Chapter 3, results of inherent safety evaluations for the KALIMER-600 conceptual design are presented. The KALIMER-600 core and plant system are designed to assure benign performance during a selected set of events without either reactor control or protection system intervention. Safety analyses for the postulated anticipated transient without scram (ATWS) have been performed using the SSC-K code to investigate the KALIMER-600 system response to the events. The objectives of Chapter 4, are to assess the response of KALIMER-600 containment to the design basis accidents and to evaluate whether the consequences are acceptable or not in the aspect of structural integrity and the exposure dose rate. In Chapter 5, the analysis of flow blockage for KALIMER-600 with the MATRA-LMR-FB code, which has been developed for the internal flow blockage in a LMR subassembly, are described. The cases with a blockage of 6-subchannel, 24-subchannel, and 54-subchannel are analyzed

Are classical process safety concepts relevant to nanotechnology applications?

International Nuclear Information System (INIS)

Amyotte, Paul R

2011-01-01

The answer to the question posed by the title of this paper is yes - with adaptation to the specific hazards and challenges found in the field of nanotechnology. The validity of this affirmative response is demonstrated by relating key process safety concepts to various aspects of the nanotechnology industry in which these concepts are either already practised or could be further applied. This is accomplished by drawing on the current author's experience in process safety practice and education as well as a review of the relevant literature on the safety of nanomaterials and their production. The process safety concepts selected for analysis include: (i) risk management, (ii) inherently safer design, (iii) human error and human factors, (iv) safety management systems, and (v) safety culture.

Analysis of multiple failure accident scenarios for development of probabilistic safety assessment model for KALIMER-600

International Nuclear Information System (INIS)

Kim, T.W.; Suk, S.D.; Chang, W.P.; Kwon, Y.M.; Jeong, H.Y.; Lee, Y.B.; Ha, K.S.; Kim, S.J.

2009-01-01

A sodium-cooled fast reactor (SFR), KALIMER-600, is under development at KAERI. Its fuel is the metal fuel of U-TRU-Zr and it uses sodium as coolant. Its advantages are found in the aspects of an excellent uranium resource utilization, inherent safety features, and nonproliferation. The probabilistic safety assessment (PSA) will be one of the initiating subjects for designing it from the aspects of a risk informed design (RID) as well as a technology-neutral licensing (TNL). The core damage is defined as coolant voiding, fuel melting, or cladding damage. Accident scenarios which lead to the core damage should be identified for the development of a Level-1 PSA model. The SSC-K computer code is used to identify the conditions which lead to core damage. KALIMER-600 has passive safety features such as passive shutdown functions, passive pump coast-down features, and passive decay heat removal systems. It has inherent reactivity feedback effects such as Doppler, sodium void, core axial expansion, control rod axial expansion, core radial expansion, etc. The accidents which are analyzed are the multiple failure accidents such as an unprotected transient overpower, a loss of flow, and a loss of heat sink events with degraded safety systems or functions. The safety functions to be considered here are a reactor trip, inherent reactivity feedback features, the pump coast-down, and the passive decay heat removal. (author)

Gas-cooled fast reactor safety

International Nuclear Information System (INIS)

Rickard, C.L.; Simon, R.H.; Buttemer, D.R.

1977-01-01

Initial conceptual design work on the GCFR began in the USA in the early 1960s and since the later 1960s has proceeded with considerable international cooperation. A 300 MWe GCFR demonstration plant employing three main cooling loops is currently being developed at General Atomic. A major preapplication licensing review of this demonstration plant was initiated in 1971 leading in 1974 to publication of a Safety Evaluation Report by the USAEC Directorate of Licensing. The preapplication review is continuing by addressing areas of concern identified in this report such that a major part of the work necessary to support the actual licensing of a GCFR demonstration plant has been established. The safety performance of the GCFR demonstration plant is based upon its inherent safety characteristics among which are the single phase and chemically inert coolant which is not activated and has a low reactivity worth, the negative core power and temperature reactivity coefficients and the small and negative steam reactivity worth. Recent studies of larger core designs indicate that as the reactor size increases central fuel, clad and coolant reactivity worths decrease and the Doppler coefficient becomes more negative. These inherent safety characteristics are complemented by safety design features such as enclosing the entire primary coolant system within a prestressed concrete pressure vessel (PCRV), providing two independent and diverse shutdown systems and residual heat removal (RHR) systems, limiting the worth of control rods to less than $1, employing pressure-equalized fuel rods, a core supported rigidly at its upper end and otherwise unrestrained and coolant downflow within the core to enhance debris removal should local melting occur. The structurally redundant PCRV design allows the potential depressurization leak area to be controlled and, since the PCRV is located within a containment building, coolant is present even after a depressurization accident and each RHR

Quantifying uncertainties in the estimation of safety parameters by using bootstrapped artificial neural networks

Energy Technology Data Exchange (ETDEWEB)

Secchi, Piercesare [MOX, Department of Mathematics, Polytechnic of Milan (Italy); Zio, Enrico [Department of Energy, Polytechnic of Milan, Via Ponzio 34/3, 20133 Milano (Italy)], E-mail: enrico.zio@polimi.it; Di Maio, Francesco [Department of Energy, Polytechnic of Milan, Via Ponzio 34/3, 20133 Milano (Italy)

2008-12-15

For licensing purposes, safety cases of Nuclear Power Plants (NPPs) must be presented at the Regulatory Authority with the necessary confidence on the models used to describe the plant safety behavior. In principle, this requires the repetition of a large number of model runs to account for the uncertainties inherent in the model description of the true plant behavior. The present paper propounds the use of bootstrapped Artificial Neural Networks (ANNs) for performing the numerous model output calculations needed for estimating safety margins with appropriate confidence intervals. Account is given both to the uncertainties inherent in the plant model and to those introduced by the ANN regression models used for performing the repeated safety parameter evaluations. The proposed framework of analysis is first illustrated with reference to a simple analytical model and then to the estimation of the safety margin on the maximum fuel cladding temperature reached during a complete group distribution header blockage scenario in a RBMK-1500 nuclear reactor. The results are compared with those obtained by a traditional parametric approach.

Memory accessibility shapes explanation: Testing key claims of the inherence heuristic account.

Science.gov (United States)

Hussak, Larisa J; Cimpian, Andrei

2018-01-01

People understand the world by constructing explanations for what they observe. It is thus important to identify the cognitive processes underlying these judgments. According to a recent proposal, everyday explanations are often constructed heuristically: Because people need to generate explanations on a moment-by-moment basis, they cannot perform an exhaustive search through the space of possible reasons, but may instead use the information that is most easily accessible in memory (Cimpian & Salomon 2014a, b). In the present research, we tested two key claims of this proposal that have so far not been investigated. First, we tested whether-as previously hypothesized-the information about an entity that is most accessible in memory tends to consist of inherent or intrinsic facts about that entity, rather than extrinsic (contextual, historical, etc.) facts about it (Studies 1 and 2). Second, we tested the implications of this difference in the memory accessibility of inherent versus extrinsic facts for the process of generating explanations: Does the fact that inherent facts are more accessible than relevant extrinsic facts give rise to an inherence bias in the content of the explanations generated (Studies 3 and 4)? The findings supported the proposal that everyday explanations are generated in part via a heuristic process that relies on easily accessible-and often inherent-information from memory.

Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

Directory of Open Access Journals (Sweden)

Yan Deng

Full Text Available Sustainable agriculture requires improved phosphorus (P management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L. roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1, and the threshold indicating a significant environmental risk was about 15 mg kg(-1, which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1, indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

Is the inherent potential of maize roots efficient for soil phosphorus acquisition?

Science.gov (United States)

Deng, Yan; Chen, Keru; Teng, Wan; Zhan, Ai; Tong, Yiping; Feng, Gu; Cui, Zhenling; Zhang, Fusuo; Chen, Xinping

2014-01-01

Sustainable agriculture requires improved phosphorus (P) management to reduce the overreliance on P fertilization. Despite intensive research of root adaptive mechanisms for improving P acquisition, the inherent potential of roots for efficient P acquisition remains unfulfilled, especially in intensive agriculture, while current P management generally focuses on agronomic and environmental concerns. Here, we investigated how levels of soil P affect the inherent potential of maize (Zea mays L.) roots to obtain P from soil. Responses of root morphology, arbuscular mycorrhizal colonization, and phosphate transporters were characterized and related to agronomic traits in pot and field experiments with soil P supply from deficiency to excess. Critical soil Olsen-P level for maize growth approximated 3.2 mg kg(-1), and the threshold indicating a significant environmental risk was about 15 mg kg(-1), which represented the lower and upper levels of soil P recommended in current P management. However, most root adaptations involved with P acquisition were triggered when soil Olsen-P was below 10 mg kg(-1), indicating a threshold for maximum root inherent potential. Therefore, to maintain efficient inherent potential of roots for P acquisition, we suggest that the target upper level of soil P in intensive agriculture should be reduced from the environmental risk threshold to the point maximizing the inherent potential of roots.

Is human fracture hematoma inherently angiogenic?

LENUS (Irish Health Repository)

Street, J

2012-02-03

This study attempts to explain the cellular events characterizing the changes seen in the medullary callus adjacent to the interfragmentary hematoma during the early stages of fracture healing. It also shows that human fracture hematoma contains the angiogenic cytokine vascular endothelial growth factor and has the inherent capability to induce angiogenesis and thus promote revascularization during bone repair. Patients undergoing emergency surgery for isolated bony injury were studied. Raised circulating levels of vascular endothelial growth factor were seen in all injured patients, whereas the fracture hematoma contained significantly higher levels of vascular endothelial growth factor than did plasma from these injured patients. However, incubation of endothelial cells in fracture hematoma supernatant significantly inhibited the in vitro angiogenic parameters of endothelial cell proliferation and microtubule formation. These phenomena are dependent on a local biochemical milieu that does not support cytokinesis. The hematoma potassium concentration is cytotoxic to endothelial cells and osteoblasts. Subcutaneous transplantation of the fracture hematoma into a murine wound model resulted in new blood vessel formation after hematoma resorption. This angiogenic effect is mediated by the significant concentrations of vascular endothelial growth factor found in the hematoma. This study identifies an angiogenic cytokine involved in human fracture healing and shows that fracture hematoma is inherently angiogenic. The differences between the in vitro and in vivo findings may explain the phenomenon of interfragmentary hematoma organization and resorption that precedes fracture revascularization.

Increasing the Fuel Economy and Safety of New Light-DutyVehicles

Energy Technology Data Exchange (ETDEWEB)

Wenzel, Tom; Ross, Marc

2006-09-18

One impediment to increasing the fuel economy standards forlight-duty vehicles is the long-standing argument that reducing vehiclemass to improve fuel economy will inherently make vehicles less safe.This technical paper summarizes and examines the research that is citedin support of this argument, and presents more recent research thatchallenges it. We conclude that the research claiming that lightervehicles are inherently less safe than heavier vehicles is flawed, andthat other aspects of vehicle design are more important to the on-roadsafety record of vehicles. This paper was prepared for a workshop onexperts in vehicle safety and fuel economy, organized by the William andFlora Hewlett Foundation, to discuss technologies and designs that can betaken to simultaneously improve vehicle safety and fuel economy; theworkshop was held in Washington DC on October 3, 2006.

Recent achievement within the French-German safety approach for future PWRs

International Nuclear Information System (INIS)

Gros, G.; Rollinger, F.; Frisch, W.; Simon, M.

1999-12-01

The development of the common French-German safety approach was accomplished on three working levels: the technical safety organisations GRS and IPSN provided the technical basis, the advisory groups GPR and RSK developed common recommendations, and the authorities BMU and DSIN adopted and issued the recommendations. The general safety approach issued in May 1993 contains safety objectives, general principles and some technical principles for future PWRs. Based on this general approach, more detailed recommendations have been developed in 1994 on key issues. The following period from 1995 on was characterised by a further refinement of the recommendations and the treatment of some new subjects such as digital I and C, man-machine-interface and core design. (authors)

On the maximum entropy distributions of inherently positive nuclear data

Energy Technology Data Exchange (ETDEWEB)

Taavitsainen, A., E-mail: aapo.taavitsainen@gmail.com; Vanhanen, R.

2017-05-11

The multivariate log-normal distribution is used by many authors and statistical uncertainty propagation programs for inherently positive quantities. Sometimes it is claimed that the log-normal distribution results from the maximum entropy principle, if only means, covariances and inherent positiveness of quantities are known or assumed to be known. In this article we show that this is not true. Assuming a constant prior distribution, the maximum entropy distribution is in fact a truncated multivariate normal distribution – whenever it exists. However, its practical application to multidimensional cases is hindered by lack of a method to compute its location and scale parameters from means and covariances. Therefore, regardless of its theoretical disadvantage, use of other distributions seems to be a practical necessity. - Highlights: • Statistical uncertainty propagation requires a sampling distribution. • The objective distribution of inherently positive quantities is determined. • The objectivity is based on the maximum entropy principle. • The maximum entropy distribution is the truncated normal distribution. • Applicability of log-normal or normal distribution approximation is limited.

A general index of inherent risk

OpenAIRE

Schnytzer, Adi; Westreich, Sara

2009-01-01

We extend the pioneering work of Aumann and Serrano by presenting an index of inherent riskiness of a gamble having the desirable properties of their index, while being applicable to gambles with either positive or negative expectations. As such, our index provides a measure of riskiness which is of use for both risk lovers and risk aversive gamblers, and is defined for all discrete and a large class of continuous gambles. We analyze abstract properties of our index, and present in addition t...

Summary of FY 1997 work related to JAPC-U.S. DOE contract study on improvement of core safety - study on GEM (III)

International Nuclear Information System (INIS)

Burke, T.M.

1998-01-01

FFTF was originally designed/constructed/operated to develop LMFBR fuels and materials. Inherent safety became a major focus of the US nuclear industry in the mid 1980's. The inherent safety characteristics of LMFBRs were recognized but additional enhancement was desired. The presentation contents are: Fast Flux Test Facility history and status; Overview of contract activities; Summary of loss of flow without scram with GEMs testing; and Summary of pump start with GEMs testing

Total safety management: An approach to improving safety culture

International Nuclear Information System (INIS)

Blush, S.M.

1993-01-01

A little over 4 yr ago, Admiral James D. Watkins became Secretary of Energy. President Bush, who had appointed him, informed Watkins that his principal task would be to clean up the nuclear weapons complex and put the US Department of Energy (DOE) back in the business of producing tritium for the nation's nuclear deterrent. Watkins recognized that in order to achieve these objectives, he would have to substantially improve the DOE's safety culture. Safety culture is a relatively new term. The International Atomic Energy Agency (IAEA) used it in a 1986 report on the root causes of the Chernobyl nuclear accident. In 1990, the IAEA's International Nuclear Safety Advisory Group issued a document focusing directly on safety culture. It provides guidelines to the international nuclear community for measuring the effectiveness of safety culture in nuclear organizations. Safety culture has two principal aspects: an organizational framework conducive to safety and the necessary organizational and individual attitudes that promote safety. These obviously go hand in hand. An organization must create the right framework to foster the right attitudes, but individuals must have the right attitudes to create the organizational framework that will support a good safety culture. The difficulty in developing such a synergistic relationship suggests that achieving and sustaining a strong safety culture is not easy, particularly in an organization whose safety culture is in serious disrepair

Tactical supply chain planning models with inherent flexibility

DEFF Research Database (Denmark)

Esmaeilikia, Masoud; Fahimnia, Behnam; Sarkis, Joeseph

2016-01-01

Supply chains (SCs) can be managed at many levels. The use of tactical SC planning models with multiple flexibility options can help manage the usual operations efficiently and effectively, whilst improve the SC resiliency in response to inherent environmental uncertainties. This paper defines ta...

How is success achieved by individuals innovating for patient safety and quality in the NHS?

Science.gov (United States)

Sheard, Laura; Jackson, Cath; Lawton, Rebecca

2017-09-11

Innovation in healthcare is said to be notoriously difficult to achieve and sustain yet simultaneously the health service is under intense pressure to innovate given the ever increasing demands placed upon it. Whilst many studies have looked at diffusion of innovation from an organisational perspective, few have sought to understand how individuals working in healthcare innovate successfully. We took a positive deviance approach to understand how innovations are achieved by individuals working in the NHS. We conducted in depth interviews in 2015 with 15 individuals who had received a national award for being a successful UK innovator in healthcare. We invited only those people who were currently (or had recently) worked in the NHS and whose innovation focused on improving patient safety or quality. Thematic analysis was used. Four themes emerged from the data: personal determination, the ability to broker relationships and make connections, the ways in which innovators were able to navigate organisational culture to their advantage and their ability to use evidence to influence others. Determination, focus and persistence were important personal characteristics of innovators as were skills in being able to challenge the status quo. Innovators were able to connect sometimes disparate teams and people, being the broker between them in negotiating collaborative working. The culture of the organisation these participants resided in was important with some being able to use this (and the current patient safety agenda) to their advantage. Gathering robust data to demonstrate their innovation had a positive impact and was seen as essential to its progression. This paper reveals a number of factors which are important to the success of innovators in healthcare. We have uncovered that innovators have particular personal traits which encourage a propensity towards change and action. Yet, for fruitful innovation to take place, it is important for relational networks and

Gas-cooled reactor safety and accident analysis

International Nuclear Information System (INIS)

1985-12-01

The Specialists' Meeting on Gas-Cooled Reactor Safety and Accident Analysis was convened by the International Atomic Energy Agency in Oak Ridge on the invitation of the Department of Energy in Washington, USA. The meeting was hosted by the Oak Ridge National Laboratory. The purpose of the meeting was to provide an opportunity to compare and discuss results of safety and accident analysis of gas-cooled reactors under development, construction or in operation, to review their lay-out, design, and their operational performance, and to identify areas in which additional research and development are needed. The meeting emphasized the high safety margins of gas-cooled reactors and gave particular attention to the inherent safety features of small reactor units. The meeting was subdivided into four technical sessions: Safety and Related Experience with Operating Gas-Cooled Reactors (4 papers); Risk and Safety Analysis (11 papers); Accident Analysis (9 papers); Miscellaneous Related Topics (5 papers). A separate abstract was prepared for each of these papers

Inherent Limitations in Mid-Wave and Long-Wave-IR Upconversion Detector

DEFF Research Database (Denmark)

Barh, Ajanta; Tseng, Yu-Pei; Pedersen, Christian

2017-01-01

Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper.......Inherent limitations in terms of optical losses, selection of nonlinear crystal(s), detection efficiency and pumping conditions in mid-wave (3-5 µm) and long-wave (8-12 µm) infrared frequency upconversion modules are investigated in this paper....

New trends in safety approach for commercial LMFBRS after SPX1

International Nuclear Information System (INIS)

Bergeonneau, P.; Moreau, J.; Cowking, C.B.; Friedel, G.; Pezzxilli, M.

1988-01-01

The experience gained from SPX1 project safety studies shows the trends for the definition of the new safety approach for the next generation of commercial LMFBR's. New trends in safety criteria, as seen in Europe, are presented in the first part of this paper. It is shown that they greatly emphasize the prevention actions even for minor events which can, in certain cases, lead to severe accidents. In the second part, an attempt is made to compare these new trends in Europe with the ones developed in the USA that put forward the inherent safety approach

Radiation safety audit

International Nuclear Information System (INIS)

Kadadunna, K.P.I.K.; Mod Ali, Noriah

2008-01-01

Audit has been seen as one of the effective methods to ensure harmonization in radiation protection. A radiation safety audit is a formal safety performance examination of existing or future work activities by an independent team. Regular audit will assist the management in its mission to maintain the facilities environment that is inherently safe for its employees. The audits review the adequacy of facilities for the type of use, training, and competency of workers, supervision by authorized users, availability of survey instruments, security of radioactive materials, minimization of personnel exposure to radiation, safety equipment, and the required record keeping. All approved areas of use are included in these periodic audits. Any deficiency found in the audit shall be corrected as soon as possible after they are reported. Radiation safety audit is a proactive approach to improve radiation safety practices and identify and prevent any potential radiation accident. It is an excellent tool to identify potential problem to radiation users and to assure that safety measures to eliminate or reduce the problems are fully considered. Radiation safety audit will help to develop safety culture of the facility. It is intended to be the cornerstone of a safety program designed to aid the facility, staff and management in maintaining a safe environment in which activities are carried out. The initiative of this work is to evaluate the need of having a proper audit as one of the mechanism to manage the safety using ionizing radiation. This study is focused on the need of having a proper radiation safety audit to identify deviations and deficiencies of radiation protection programmes. It will be based on studies conducted on several institutes/radiation facilities in Malaysia in 2006. Steps will then be formulated towards strengthening radiation safety through proper audit. This will result in a better working situation and confidence in the radiation protection community

Instrumentation and control program to support modernization of safety and control in NPPs

International Nuclear Information System (INIS)

Wilkinson, D.; James, R.; Naser, J.; Torok, R.

1997-01-01

The original analog IandC equipment of most operating nuclear power plants requires increasing maintenance efforts to sustain system performance. Decreasing availability of replacement parts and support organizations for analog technology accentuate obsolescence problems and resultant OandM cost increases. Modern technology, especially digital systems, offers improved functionality, performance and reliability; solutions to obsolescence of equipment; reduction in OandM costs; and the potential to enhance safety. Digital systems with their inherent advantages will be implemented only if reliable and cost-effective implementation is achieved and if the upgraded system supports reduced power production costs. EPRI and its member utilities are working together under the Integrated IandC Upgrade Initiative to address IandC issues. The present paper describes and gives the status of EPRI's Integrated IandC Upgrade Initiative. (author)

The safety characteristics of the HTR 500 reactor plant

International Nuclear Information System (INIS)

Wachholz, W.

1987-01-01

The HTR is a reactor having a passive safety. It is equipped with the usual active engineered safety systems in simplified form. Due to its inherent safety characteristics and the burst-safe prestressed concrete reactor vessel activity containment is ensured even without the effect of active safety systems. Even in the event of extremely hypothetical accidents the effect on the environment is low enough so that evacuation or relocation of the population is not required. Therefore large-scale damage of agricultural land and industrially used areas is safely ruled out. Thus the site selection for this type of reactor is not restricted i.e. an HTR can be constructed near industrial and urban center. (author)

Safety Analysis for Medium/Small Size Integral Reactor: Evaluation of Safety Characteristics for Small and Medium Integral Reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Hho jung; Seul, K W; Ahn, S K; Bang, Y S; Park, D G; Kim, B K; Kim, W S; Lee, J H; Kim, W K; Shim, T M; Choi, H S; Ahn, H J; Jung, D W; Kim, G I; Park, Y M; Lee, Y J [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)

1997-07-01

The Small and medium integral reactor is developed to be utilized for non-electric areas such as district heating and steam production for desalination and other industrial purposes, and then these applications may typically imply a closeness between the reactor and the user. It requires the reactor to be designed with the adoption of special functional and inherent safety features to ensure and promote a high level of safety and reliability, in comparison with the existing nuclear power plants. The objective of the present study is to establish the bases for the development of regulatory requirements and technical guides to address the special safety characteristics of the small and medium integral reactor. In addition, the study aims to identify and to propose resolutions to the possible safety concerns in the design of the small and medium integral reactor. 34 refs., 20 tabs. (author)

Is it about "pink" or about "girls"? The inherence heuristic across social and nonsocial domains.

Science.gov (United States)

Kinzler, Katherine D; Sullivan, Kathleen R

2014-10-01

The inherence heuristic provides an intriguing and novel explanation for early thought in a variety of domains. Exploring similarities and differences in inherent reasoning across social and nonsocial domains can help us understand the role that inherent thinking plays in the development of human reasoning and the process by which more elaborate essentialist reasoning develops.

Inherently safe in situ uranium recovery

International Nuclear Information System (INIS)

Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

2009-01-01

Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

Influence of Inherent Moisture Content on the Deformation ...

African Journals Online (AJOL)

Influence of Inherent Moisture Content on the Deformation. Properties of Coconut Tissues During Mechanical Oil. Expression. *J. J. Mpagalile1 and B. Clarke2. 1Department of ... The study confirmed that moisture content has an important role in the deformation of coconut ..... A micro penetration technique for mechanical.

The necessity of periodic fire safety review

International Nuclear Information System (INIS)

Mowrer, D.S.

1998-01-01

Effective fire safety requires the coordinated integration of many diverse elements. Clear fire safety objectives are defined by plant management and/or regulatory authorities. Extensive and time-consuming systematic analyses are performed. Fire safety features (both active and passive) are installed and maintained, and administrative programs are established and implemented to achieve the defined objectives. Personnel are rigorously trained. Given the time, effort and monetary resources expended to achieve a specific level of fire safety, conducting periodic assessments to verify that the specified level of fire safety has been achieved and is maintained is a matter of common sense. Periodic fire safety reviews and assessment play an essential role in assuring continual nuclear safety in the world's power plants

Evaluation of design variants for improved inherent regulation of advanced small modular reactors - 15325

International Nuclear Information System (INIS)

Vilim, R.B.; Passerini, S.

2015-01-01

This paper examines design variants that can improve inherent regulation in Advanced Small Modular Reactors (ASMR). It looks at the nature of unprotected upsets and then develops appropriate design measures to ensure that no upset can override a capability for safe self-regulation. This work adopts a reference sodium fast reactor (SFR) design to serve as a baseline for operational and safety performance and for comparison with variants on this design. The effect of design measures on plant stability is then examined. It is found that compared to full-power operation, the stability margin is reduced under islanded-operation. Islanded-operation is more likely for an ASMR deployed in a small regional electric grid with high penetration of renewable energy sources. The stability of core power production is a function of the inlet temperature coefficient, coolant transport times, and temperature-front attenuation in heat exchangers. The interaction of these phenomena with the control system is described

Preliminary safety evaluation for CSR1000 with passive safety system

International Nuclear Information System (INIS)

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

2014-01-01

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

Technical safety Organisations (TSO) contribute to European Nuclear Safety

International Nuclear Information System (INIS)

Repussard, J.

2010-01-01

Nuclear safety and radiation protection rely on science to achieve high level prevention objectives, through the analysis of safety files proposed by the licensees. The necessary expertise needs to be exercised so as to ensure adequate independence from nuclear operators, appropriate implementation of state of the art knowledge, and a broad spectrum of analysis, adequately ranking the positive and negative points of the safety files. The absence of a Europe-wide nuclear safety regime is extremely costly for an industry which has to cope with a highly competitive and open international environment, but has to comply with fragmented national regulatory systems. Harmonization is therefore critical, but such a goal is difficult to achieve. Only a gradual policy, made up of planned steps in each of the three key dimensions of the problem (energy policy at EU level, regulatory harmonization, consolidation of Europe-wide technical expertise capability) can be successful to achieve the required integration on the basis of the highest safety levels. TSO's contribute to this consolidation, with the support of the EC, in the fields of research (EURATOM-Programmes), of experience feedback analysis (European Clearinghouse), of training and knowledge management (European Training and Tutoring Institute, EUROSAFE). The TSO's network, ETSON, is becoming a formal organisation, able to enter into formal dialogue with EU institutions. However, nuclear safety nevertheless remains a world wide issue, requiring intensive international cooperation, including on TSO issues. (author)

Inherent reactor power controller for a metal-fueled ALMR

International Nuclear Information System (INIS)

Wood, R.T.; Wilson, T.L. Jr.

1990-01-01

Inherent power control for metal-fueled ALMR designs involves using reactivity thermal feedback effects to control reactor power. This paper describes how, using classical control design techniques, a control system for normal load following maneuvers was deigned for a pool-type ALMR. This design provides active control of power removal in the balance of plant, direct control of selected primary and intermediate loop temperatures, and passive control of reactor power. The inherent stability of the strong, fast reactivity feedback effects bring heat production in the core into balance with the heat removal system temperatures, which are controlled to meet power demand. A simulation of the control system successfully responded to a 10% step change in power demand by changing power at an acceptable rate without causing large temperature fluctuations or exceeding thermal limits

Experimental evidence for inherent Lévy search behaviour in foraging animals.

Science.gov (United States)

Kölzsch, Andrea; Alzate, Adriana; Bartumeus, Frederic; de Jager, Monique; Weerman, Ellen J; Hengeveld, Geerten M; Naguib, Marc; Nolet, Bart A; van de Koppel, Johan

2015-05-22

Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Simple frequency-dependent tools for analysis of inherent control limitations

Directory of Open Access Journals (Sweden)

Sigurd Skogestad

1991-10-01

Full Text Available By a plant's inherent control limitations we mean the characteristics of the plant which will cause poor control performance irrespective of what controller is used. Another frequently used term is 'dynamic resilience' which is the best closed-loop performance achievable using any controller. Since a plant's dynamic resilience cannot be altered by change of the control algorithm, but only by design modifications, it follows that the term controllability provides a link between process design and process control. In this paper we focus on two aspects of controllability. The plants' sensitivity to disturbances and the limitations imposed by interactions when using decentralized control. We use simple tools such as the RGA, the PRGA (Performance RGA and the closely related Closed Loop Disturbance Gain (CLDG. For example, if kth column of the CLDG is large, then this indicates that disturbance k will be difficult to reject. This may pinpoint the need for modifying the process. The PRGA provides a measure of interaction which also includes one-way coupling. In the paper we apply these measures to distillation column control and fluid catalytic cracker (FCC control.

Iser: an international inherently safe reactor concept

International Nuclear Information System (INIS)

Wakabayashi, Hiroaki

1988-01-01

Iser is a modular standardised 200-300 MWe power reactor based on the PIUS principle. It differs from PIUS in being simpler, and making full use of existing steel-vessel-based LWR technology. Iser is an inherently safe reactor concept under development in Japan. It is a generic concept, not a patented commodity, and it is expected that an international association to develop the concept will be formed. (U.K.)

COLD-SAT feasibility study safety analysis

Science.gov (United States)

Mchenry, Steven T.; Yost, James M.

1991-01-01

The Cryogenic On-orbit Liquid Depot-Storage, Acquisition, and Transfer (COLD-SAT) satellite presents some unique safety issues. The feasibility study conducted at NASA-Lewis desired a systems safety program that would be involved from the initial design in order to eliminate and/or control the inherent hazards. Because of this, a hazards analysis method was needed that: (1) identified issues that needed to be addressed for a feasibility assessment; and (2) identified all potential hazards that would need to be controlled and/or eliminated during the detailed design phases. The developed analysis method is presented as well as the results generated for the COLD-SAT system.

NASA's aviation safety research and technology program

Science.gov (United States)

Fichtl, G. H.

1977-01-01

Aviation safety is challenged by the practical necessity of compromising inherent factors of design, environment, and operation. If accidents are to be avoided these factors must be controlled to a degree not often required by other transport modes. The operational problems which challenge safety seem to occur most often in the interfaces within and between the design, the environment, and operations where mismatches occur due to ignorance or lack of sufficient understanding of these interactions. Under this report the following topics are summarized: (1) The nature of operating problems, (2) NASA aviation safety research, (3) clear air turbulence characterization and prediction, (4) CAT detection, (5) Measurement of Atmospheric Turbulence (MAT) Program, (6) Lightning, (7) Thunderstorm gust fronts, (8) Aircraft ground operating problems, (9) Aircraft fire technology, (10) Crashworthiness research, (11) Aircraft wake vortex hazard research, and (12) Aviation safety reporting system.

Safety philosophy of the GTHTR300

International Nuclear Information System (INIS)

Kunitomi, Kazuhiko; Katanishi, Shoji

2003-01-01

In parallel to successful operation of the Japan's first High Temperature Gas-cooed Reactor, HTTR (High Temperature Engineering Test Reactor), JAERI (Japan Atomic Energy Research Institute) started design and development of a high temperature gas cooled reactor with a gas turbine electric generation system, GTHTR300 (Gas Turbine High Temperature Reactor 300), in April 2001. The GTHTR300 is expected to be deployed in 2010s as a safe and economically competitive electric generation system in Japan. Unique safety philosophy is proposed for this system. Severe accidents are defined as any conditions beyond design base accidents, causing core damages with fission product releases to the environment, although all severe accident sequences are very low in probability. The new safety philosophy is to avoid most accidents, and to achieve a probability of severe accidents of 10 -8 /ry that is at least two orders lower than current reactors. Even in the worst event such as double guillotine break of a primary concentric duct, fuel temperature exceeding its failure limit and excessive fuel oxidation by air ingress can be avoided because of inherent safety features and the passive decay heat removal system. Furthermore, double confinement buildings are enough to keep reactor safety in such accidents. Elimination of a leak-tight steel containment vessel is a big economical advantage for this system. Another unique feature is that nearly full-scale worst accident simulation tests can be carried out to obtain licensing before commercial operations because safety assessment by analysis is not usually enough to convince the public and the regulators of trusting this safety concept. In current reactors no accident simulation tests are carried out before commercial operations although inspection and performance tests in normal condition are conducted. This paper describes the safety philosophy together with the outline of the design features of the GTHTR300, and the results of

Department of Energy's High Flux Beam Reactor (HFBR), September 15--19, 1980: An independent on-site safety review

International Nuclear Information System (INIS)

1981-02-01

The intent of this on-site safety review was to make a broad management assessment of HFBR operations, rather than conduct a detailed in-depth audit. The result of the review should only be considered as having identified trends or indications. The Team's observations and recommendations for the most part are based upon licensed reactor facility practices used to meet industry standards. These standards form the basis for many of the comments in this report. The Team believes that a uniform minimum standard of performance should be achieved in the operation of DOE reactors. In order to assure that this is accomplished, clear standards are necessary. Consistent with the past AEC and ERDA policy, the team has used the standards of the commercial nuclear power industry. It is recognized that this approach is conservative in that the HFBR reactor has a significantly greater degree of inherent safety (low pressure, temperature, power, etc.) than a licensed reactor

Safety of magnetic fusion facilities: Requirements

International Nuclear Information System (INIS)

1996-05-01

This Standard identifies safety requirements for magnetic fusion facilities. Safety functions are used to define outcomes that must be achieved to ensure that exposures to radiation, hazardous materials, or other hazards are maintained within acceptable limits. Requirements applicable to magnetic fusion facilities have been derived from Federal law, policy, and other documents. In addition to specific safety requirements, broad direction is given in the form of safety principles that are to be implemented and within which safety can be achieved

LEADIR-PS: providing unprecedented SMR safety and economics

Energy Technology Data Exchange (ETDEWEB)

Hart, R.S., E-mail: N2i2@xplornet.ca [Northern Nuclear Industries Incorporated, Cambridge, ON (Canada)

2015-07-01

Northern Nuclear Industries Incorporated (N{sup 2} I{sup 2}) is developing Small Modular Reactors (SMRs) called LEADIR-PS, an acronym for LEAD-cooled Integral Reactor-Passively Safe. LEADIR-PS integrates proven technologies including TRISO fuel, Pebble Bed core and graphite moderator, with molten lead coolant in an integral pool type reactor configuration to achieve unprecedented safety and economics. Plants under development are LEADIR-PS30, producing 30 MWth, LEADIR-PS100 producing 100 MWth and LEADIR-PS300 producing 300 MWth that are focused on serving the energy demands of areas with a small electrical grid and/or process heat applications. A plant consisting of six LEADIR-PS300 reactor modules serving a common turbine-generator, called the LEADIR-PS Six-Pack, is focused on serving areas with higher energy demands and a robust electricity grid. The Gen{sup +} I LEADIR-PS plants are inherently/passively safe. There is no potential for a Loss Of Coolant Accident, a reactivity transient without shutdown, a loss of heat sink, or hydrogen generation. No active systems or operator actions are required to assure safety. The unprecedented safety of LEADIR-PS reactors avoids large exclusion radius and demanding evacuation plan requirements. LEADIR-PS, with steam conditions of 370 {sup o}C and 12 MPa can serve over 85% of the world's non-transportation process heat demands. In Canada, the electricity and process heat demands, ranging from those of remote communities and the oil sands to densely populated areas can be served by LEADIR-PS. (author)

Quantification of Inherent Respirable Dust Generation Potential (IRDGP) of South African Coals

CSIR Research Space (South Africa)

Phillips, H

2003-08-01

Full Text Available Advisory Committee Project Summary Project Title: Inherent Respirable Dust Generation Potential (IRDGP) of South African Coals-SIM020604 Author(s): H.R.Phillips and B. K. Belle Agency: University of Witwatersrand Report Date: July2003... Related Projects: Health 607, Sim 02-06-03 Category: Occupational Health Applied Research Occupational Hygiene Summary Project SIM020604 was formulated to determine the Inherent Respirable Dust Generation Potential (IRDGP) of various South...

Conference: Nuclear Safety at the Ignalina NPP - Achievements and Challenges

International Nuclear Information System (INIS)

1999-01-01

Brief description of conference which took place in Vilnius on 8-9 April 1999 is presented. The aim of the international conference is to review the work carried out, to evaluate its influence on the nuclear safety, to get acquainted with the safety system of the Ignalina NPP. On December 31, the Ignalina NPP celebrated its 15 year anniversary. During that period the Ignalina NPP has produced more than 182 billion kWh of electricity. Nuclear power is not only immense economic benefit but also a syndrome of fear of an atomic bomb and the Chernobyl accident that has formed over the years. Numerous comprehensive international studies have been performed at the Ignalina NPP. After the Chernobyl accident many steps have been taken to improve the safety of the Ignalina NPP. The introduced changes guaranteed that the void coefficient remained negative in all possible circumstances. The Ignalina NPP is intensively preparing for licensing of unit 1

Safety design and evaluation policy for future FBRs in Japan

International Nuclear Information System (INIS)

Aizawa, Kiyoto

1991-01-01

The safety policy for fast breeder reactors (FBRs) has gradually matured in accordance with the development of FBRs. The safety assessment of the Japanese prototype FBR, Monju during the licensing process accelerated the maturity and the integration of knowledge and databases. Results are expected to be reflected in the establishment of the safety design and evaluation policy for FBRs. Although the methodologies and safety policies developed for LWRs are applicable in principle to future FBRs, it is neither rational nor realistic to treat safety only with these policies. It is recommended that one should develop the methodologies and safety policies starting from understanding of the inherent safety characteristics of FBR's through safety research, plant operating experience and design work. In the last few years, some technical committees were organized in Japan and have discussed key safety issues which are specific to FBRs in order to provide preparatory reports and to establish safety standards and guidelines for future commercial FBRs. (author)

Inherent hazards, poor reporting and limited learning in the solid biomass energy sector: A case study of a wheel loader igniting wood dust, leading to fatal explosion at wood pellet manufacturer

DEFF Research Database (Denmark)

Hedlund, Frank Huess; Astad, John; Nichols, Jeffrey

2014-01-01

are insufficiently developed and give ample room for potentially erroneous subjective individual judgment. It is a contributing factor that combustible dust, although with great hazard potential, is not classified as a dangerous substance. Accidents therefore fall outside the scope of systems designed to disseminate...... biomass, the accident investigation and any learning that subsequently took place. The paper argues that learning opportunities were missed repeatedly. Significant root causes were not identified; principles of inherent safety in design were ignored; the hazardous area classification was based on flawed...... lessons learned and prevent future accidents. More attention to safety is needed for the renewable energy and environmentally friendly biomass pellet industry also to become sustainable from a worker safety perspective....

Approaches to passive safety in advanced thermal reactors

International Nuclear Information System (INIS)

Moses, D.L.

1986-01-01

Since 1980, there has been a proliferation of thermal reactor designs which incorporate passive safety features. The evolution of this trend is briefly traced, and the nature of various passive safety features is discussed with regard to how they have been incorporated into evolving design concepts. The key aspects of the passive safety features include reduced core power density, enhanced passive heat sinks, inherent assured shutdown mechanisms, elimination/minimization of potential leak paths from the primary coolant systems, enhanced robustness of fuel elements and improved coolant chemistry and component materials. An increased reliance on purely passive safety features typically translates into larger reactor structures at reduced power ratings. Proponents of the most innovative concepts seek to offset the increased costs by simplifying licensing requirements and reducing construction time

Design and safety aspects of nuclear district heating reactors

International Nuclear Information System (INIS)

Brogli, R.; Mathews, D.; Pelloni, S.

1989-01-01

Extensive studies on the rationale, the potential and the technology of nuclear district heating have been performed in Switzerland. Beside economics the safety aspects were of primary importance. Due to the high costs to transport heat the heating reactor tend to be small and therefore, minimally staffed and located close to population centers. Stringed safety rules are therefore applying. Gas cooled reactors are well suited as district heating reactors since they have due to their characteristics several inherent features, significant safety margins and a remarkable radioactivity retention potential. Some ways to mitigate the effects of water ingress and graphite corrosion are under investigation. (author). 5 refs, 3 figs

New Paradigm in Nuclear Safety from Quality Assurance to Safety Management System

International Nuclear Information System (INIS)

Lim, Nam-Jin; Park, Chan-Gook; Nam, Ji-Hee; Kim, Kwan-Hyun; Kwon, Hyuk-il; Lee, Young-Gun Lee

2006-01-01

The initial concept of Quality Control (QC) controlling the quality of products is now evolving toward the Management System (MS) achieving safety, through Quality Assurance (QA) ensuring the quality of products and Quality Management (QM) managing the quality by a systematic approach. Nuclear safety can be achieved through an integrated MS that ensures the health, environmental, security, quality and economic requirements being considered together with nuclear safety requirements. MS approach is developed through realizing that most of nuclear accidents had occurred not by the malfunction of hardware or equipment, but by the human error. The MS is a set of inter-related or interacting elements (system) that establishes policies and objectives and which enables those objectives to be achieved in an efficient and effective way

The deep geologic repository technology programme: toward a geoscience basis for understanding repository safety

International Nuclear Information System (INIS)

Jensen, M.R.

2007-01-01

Within the Deep Geologic Repository Technology Programme (DGRTP) several Geoscience activities are focused on advancing the understanding of groundwater flow system evolution and geochemical stability in a Canadian Shield setting as affected by long-term climate change. A key aspect is developing confidence in predictions of groundwater flow patterns and residence times as they relate to the safety of a deep geologic repository for used nuclear fuel waste. This is being achieved through a coordinated multi-disciplinary approach intent on: i) demonstrating coincidence between independent geo-scientific data; ii) improving the traceability of geo-scientific data and its interpretation within a conceptual descriptive model(s); iii) improving upon methods to assess and demonstrate robustness in flow domain prediction(s) given inherent flow domain uncertainties (i.e. spatial chemical/physical property distributions, boundary conditions) in time and space; and iv) improving awareness amongst geo-scientists as to the utility of various geo-scientific data in supporting a safety case for a deep geologic repository. This multi-disciplinary DGRTP approach is yielding an improved understanding of groundwater flow system evolution and stability in Canadian Shield settings that is further contributing to the geo-scientific basis for understanding and communicating aspects of DGR safety. (author)

[THE CYTOMETRIC TECHNIQUE OF BINDING OF EOSIN-5-MALEIMIDE IN DIAGNOSTIC OF INHERENT SPHEROCYTOSIS].

Science.gov (United States)

Kuzminova, J A; Plyasunova, S A; Jogov, V V; Smetanina, N S

2016-03-01

The laboratory diagnostic of inherent spherocytosis is based on detection of spherocytes in peripheral blood, decreasing of index of sphericity, decreasing of osmotic resistance of erythrocytes. The new test of diagnostic of hereditary spherocytosis build on molecular defect was developed on the basis of binding extracellular fragments of protein of band 3 with eosin-5-maleimide (EMA-test). The study was carried out to implement comparative analysis of sensitivity and specificity of techniques applied to diagnose inherent spherocytosis. The sampling of 94 patients with various forms of anemias was analyzed All patients were applied complex clinical laboratory examination including analysis of osmotic resistance of erythrocytes, erythrocytometry and EMA-test as specific techniques of diagnostic of inherent spherocytosis. In 51 out of 94 patients (54%) decreasing of values of EMA-test was detected and in 47 patients diagnosis of inherent spherocytosis was confirmed. The standard values of EMA-test were established in 43 patients (46%) and 12 patients out of them with established diagnosis of inherent spherocytosis. Therefore, sensitivity of EMA-test made up to 79% and specificity - 80%. The most sensitive techniques of diagnostic remain osmotic resistance of erythrocytes (91%) and index of sphericity (up to 96%). But the highest specificity in this respect has EMA-test (80%). Nowadays, none of implemented techniques of diagnostic of inherent spherocytosis can be applied as a universal one. The implementation of complex examination is needed for proper diagnostic of disease.

Preliminary safety analysis for key design features of KALIMER with breakeven core

Energy Technology Data Exchange (ETDEWEB)

Hahn, Do Hee; Kwon, Y. M.; Chang, W. P.; Suk, S. D.; Lee, Y. B.; Jeong, K. S

2001-06-01

KAERI is currently developing the conceptual design of a Liquid Metal Reactor, KALIMER (Korea Advanced Liquid MEtal Reactor) under the Long-term Nuclear R and D Program. KALIMER addresses key issues regarding future nuclear power plants such as plant safety, economics, proliferation, and waste. In this report, descriptions of safety design features and safety analyses results for selected ATWS accidents for the breakeven core KALIMER are presented. First, the basic approach to achieve the safety goal is introduced in Chapter 1, and the safety evaluation procedure for the KALIMER design is described in Chapter 2. It includes event selection, event categorization, description of design basis events, and beyond design basis events.In Chapter 3, results of inherent safety evaluations for the KALIMER conceptual design are presented. The KALIMER core and plant system are designed to assure benign performance during a selected set of events without either reactor control or protection system intervention. Safety analyses for the postulated anticipated transient without scram (ATWS) have been performed to investigate the KALIMER system response to the events. In Chapter 4, the design of the KALIMER containment dome and the results of its performance analyses are presented. The design of the existing containment and the KALIMER containment dome are compared in this chapter. Procedure of the containment performance analysis and the analysis results are described along with the accident scenario and source terms. Finally, a simple methodology is introduced to investigate the core energetics behavior during HCDA in Chapter 5. Sensitivity analyses have been performed for the KALIMER core behavior during super-prompt critical excursions, using mathematical formulations developed in the framework of the Modified Bethe-Tait method. Work energy potential was then calculated based on the isentropic fuel expansion model.

Failure and factors of safety in piping system design

International Nuclear Information System (INIS)

Antaki, G.A.

1993-01-01

An important body of test and performance data on the behavior of piping systems has led to an ongoing reassessment of the code stress allowables and their safety margin. The codes stress allowables, and their factors of safety, are developed from limits on the incipient yield (for ductile materials), or incipient rupture (for brittle materials), of a test specimen loaded in simple tension. In this paper, we examine the failure theories introduced in the B31 and ASME III codes for piping and their inherent approximations compared to textbook failure theories. We summarize the evolution of factors of safety in ASME and B31 and point out that, for piping systems, it is appropriate to reconsider the concept and definition of factors of safety

Safety philosophies in the history of the West German nuclear industry

International Nuclear Information System (INIS)

Radkau, J.

1989-01-01

The article discusses the term 'philosophy' within the framework of the safety debate, examines the philosophy of 'inherent safety' and that of 'power plant siting away from agglomerations', as well as other concepts and approaches in safety engineering, as e.g. the maximum credible accident, the MCA and probabilistic approach, the practice-oriented safety philosophy, and human factors. Participation of the public as a legal requirement is discussed as a means of balancing the interests of various groups of the society, taking into account the possibility of abandoning a technology altogether as an ultimate consequence of the principle of participation of the public. (HSCH) [de

Managing change in the nuclear industry: The effects on safety. INSAG-18. A report by the International Nuclear Safety Advisory Group

International Nuclear Information System (INIS)

2003-01-01

The nuclear industry is going through a period of unprecedented change. The changes arise from the political and business environment in which the industry must operate, and from within the industry itself as it strives to become more competitive. These pressures have already led to significant changes in how nuclear enterprises are organized. The changes can be expected to continue. It is absolutely essential that throughout the period of time that organizational changes are taking place, and after the changes have occurred, very high standards of safety are maintained by all the elements that make up the industry. Changes can be made effectively and safely, and gains in efficiency and competitiveness, as well as safety, can be realized if changes are introduced carefully and managed well. Experience has shown that this is not a simple matter to achieve. Nuclear installations are complex, and it is inherently demanding to foresee all the implications that a change may have on safety. However, experience has shown very clearly that many changes have a strong potential to affect both the safety that has been built into a design and in the safety culture of an organization. Hence failure to manage change well can significantly affect the likelihood of an accident, the degree to which the assets of the company are put at risk and the company's reputation. This INSAG report is directed at members of boards of directors and senior executives who are responsible for the overall safety of an installation, who make decisions for change and who implement these decisions. It is also written for senior regulators who, on behalf of the public, ensure that boards of directors and executives meet their responsibilities for safety. This report discusses how and why change can challenge the maintenance of a high level of safety, and what can be done to control that challenge and hence reap all the benefits of change. It draws an analogy between the well established principles for

Operational-safety advantages of LMFBR's: the EBR-II experience and testing program

International Nuclear Information System (INIS)

Sackett, J.I.; Lindsay, R.W.; Golden, G.H.

1982-01-01

LMFBR's contain many inherent characteristics that simplify control and improve operating safety and reliability. The EBR-II design is such that good advantage was taken of these characteristics, resulting in a vary favorable operating history and allowing for a program of off-normal testing to further demonstrate the safe response of LMFBR's to upsets. The experience already gained, and that expected from the future testing program, will contribute to further development of design and safety criteria for LMFBR's. Inherently safe characteristics are emphasized and include natural convective flow for decay heat removal, minimal need for emergency power and a large negative reactivity feedback coefficient. These characteristics at EBR-II allow for ready application of computer diagnosis and control to demonstrate their effectiveness in response to simulated plant accidents. This latter testing objective is an important part in improvements in the man-machine interface

Beyond safety accountability

CERN Document Server

Geller, E Scott

2001-01-01

Written in an easy-to-read conversational tone, Beyond Safety Accountability explains how to develop an organizational culture that encourages people to be accountable for their work practices and to embrace a higher sense of personal responsibility. The author begins by thoroughly explaining the difference between safety accountability and safety responsibility. He then examines the need of organizations to improve safety performance, discusses why such performance improvement can be achieved through a continuous safety process, as distinguished from a safety program, and provides the practic

Behavioral based safety approaches

International Nuclear Information System (INIS)

Maria Michael Raj, I.

2009-01-01

Approach towards the establishment of positive safety culture at Heavy Water Plant, Tuticorin includes the adoption of several important methodologies focused on human behavior and culminates with achievement of Total Safety Culture where Quality and Productivity are integrated with Safety

Development of safety analysis technology for integral reactor; evaluation on safety concerns of integral reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Hee Chul; Kim, Woong Sik; Lee, J. H. [Korea Institute of Nuclear Safety, Taejeon (Korea)

2002-03-01

The Nuclear Desalination Plant (NDP) is being developed to produce electricity and fresh water, and is expected to locate near population zone. In the aspect of safety, it is required to protect the public and environment from the possible releases of fission products and to prevent the fresh water from the contamination of radioactivity. Thus, in this study, the safety characteristics of the integral reactor adopting passive and inherent safety features significantly different from existing nuclear power plants were investigated. Also, safety requirements applicable to the NDP were analyzed based on the regulatory requirements for current light water reactor and advanced reactor designs, and user requirements for small-medium size reactors. Based on these analyses, some safety concerns to be considered in the design stage have been identified and discussed. They include the use of proven technology for new safety features, systematic event classification and selection, strengthening containment function, and the safety impacts on desalination-related systems. The study presents the general safety requirements applicable to licensing of an integral reactor and suggests additional regulatory requirements, which need to be developed, based on the direction to resolution of the safety concerns. The efforts to identify and technically resolve the safety concerns in the design stage will provide the early confidence of SMART safety and the technical basis to evaluate the safety to designers and reviewers in the future. Suggestion on the development of additional regulatory requirements will contribute for the regulator to taking actions for licensing of an integral reactor. 66 refs., 5 figs., 24 tabs. (Author)

Safety culture activities in HANARO

International Nuclear Information System (INIS)

Lim, I. C.; Park, C.; Hwang, S. R.; Choi, H. Y.; Jeon, B. J.

2002-01-01

The yearly operation time and the number of users in HANARO are increasing since its initial criticality has been achieved in 1995. This achievement is partly in debt to the spread of safety culture to operators and reactor users. In this paper, the activities done by the reactor operation organization on safety culture are described, and their further efforts identified to be necessary for the improvement and dissemination of safety culture and are presented

Development of safety analysis technology for integral reactor

Energy Technology Data Exchange (ETDEWEB)

Sim, Suk K.; Song, J. H.; Chung, Y. J. and others

1999-03-01

Inherent safety features and safety system characteristics of the SMART integral reactor are investigated in this study. Performance and safety of the SMART conceptual design have been evaluated and confirmed through the performance and safety analyses using safety analysis system codes as well as a preliminary performance and safety analysis methodology. SMART design base events and their acceptance criteria are identified to develop a preliminary PIRT for the SMART integral reactor. Using the preliminary PIRT, a set of experimental program for the thermal hydraulic separate effect tests and the integral effect tests was developed for the thermal hydraulic model development and the system code validation. Safety characteristics as well as the safety issues of the integral reactor has been identified during the study, which will be used to resolve the safety issues and guide the regulatory criteria for the integral reactor. The results of the performance and safety analyses performed during the study were used to feedback for the SMART conceptual design. The performance and safety analysis code systems as well as the preliminary safety analysis methodology developed in this study will be validated as the SMART design evolves. The performance and safety analysis technology developed during the study will be utilized for the SMART basic design development. (author)

Radial core expansion reactivity feedback in advanced LMRs: uncertainties and their effects on inherent safety

International Nuclear Information System (INIS)

Wigeland, R.A.; Moran, T.J.

1988-01-01

An analytical model for calculating radial core expansion, based on the thermal and elastic bowing of a single subassembly at the core periphery, is used to quantify the effect of uncertainties on this reactivity feedback mechanism. This model has been verified and validated with experimental and numerical results. The impact of these uncertainties on the safety margins in unprotected transients is investigated with SASSYS/SAS4A, which includes this model for calculating the reactivity feedback from radial core expansion. The magnitudes of these uncertainties are not sufficient to preclude the use of radial core expansion reactivity feedback in transient analysis

National and international safety, safeguardability and security

International Nuclear Information System (INIS)

Wakabayashi, Hiroaki

1987-01-01

All nuclear power and fuel cycle facility development must comply with the predecided national regulation and security codes which each country's Atomic Energy Commission stipulates. Those codes will basically evolve as technologies and the social system will develop, change and shift. It is also to be noted that the IAEA's international guidelines have been adopted particularly by developing countries as a good reference for their proper establishment of their safety codes. The report first discusses the plant safety regulation of the inherently safe reactors in comparison to the existing code (or licensing guide) of the Japanese government. Then the new trend seen now in a regulatory body (the US NRC) is reviewed and a proposal of the smooth transition into the new philosophy is presented. In the second part of the paper, the fuel safeguarding and facility security (or physical protection) are discussed, because in the case of inherently safe reactors like ISER-PIUS, it seems that safety has much more to do with the safeguard and the security. In the third part, the international relevances to the security of the ISER-PIUS are discussed, because any ISER-PIUS will be meaningless unless they are used extensively and freely in any part of the world precluding the security concerns. In collaborative use of the state and international codes, regulatory guides and practices, it is evident that ISER-PIUS system can clear the requirements on all the aspects by ample margin. (Nogami, K.)

Safety Culture in Pre-operational Phases of Nuclear Power Plant Projects

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-09-15

An abundance of information exists on safety culture related to the operational phases of nuclear power plants; however, pre-operational phases present unique challenges. This publication focuses on safety culture during pre-operational phases that span the interval from before a decision to launch a nuclear power programme to first fuel load. It provides safety culture insights and focuses on eight generic issues: safety culture understanding; multicultural aspects; leadership; competencies and resource competition; management systems; learning and feedback; cultural assessments; and communication. Each issue is discussed in terms of: specific challenges; desired state; approaches and methods; and examples and resources. This publication will be of interest to newcomers and experienced individuals faced with the opportunities and challenges inherent in safety culture programmes aimed at pre-operational activities.

Safety Culture in Pre-operational Phases of Nuclear Power Plant Projects

International Nuclear Information System (INIS)

2012-01-01

An abundance of information exists on safety culture related to the operational phases of nuclear power plants; however, pre-operational phases present unique challenges. This publication focuses on safety culture during pre-operational phases that span the interval from before a decision to launch a nuclear power programme to first fuel load. It provides safety culture insights and focuses on eight generic issues: safety culture understanding; multicultural aspects; leadership; competencies and resource competition; management systems; learning and feedback; cultural assessments; and communication. Each issue is discussed in terms of: specific challenges; desired state; approaches and methods; and examples and resources. This publication will be of interest to newcomers and experienced individuals faced with the opportunities and challenges inherent in safety culture programmes aimed at pre-operational activities.

On the rationale of resilience in the domain of safety: A literature review

International Nuclear Information System (INIS)

Bergström, Johan; Winsen, Roel van; Henriqson, Eder

2015-01-01

Resilience is becoming a prevalent agenda in safety research and organisational practice. In this study we examine how the peer-reviewed safety science literature (a) formulates the rationale behind the study of resilience; (b) constructs resilience as a scientific object; and (c) constructs and locates the resilient subject. The results suggest that resilience engineering scholars typically motivate the need for their studies by referring to the inherent complexities of modern socio-technical systems; complexities that make these systems inherently risky. The object of resilience then becomes the capacity to adapt to such emerging risks in order to guarantee the success of the inherently risky system. In the material reviewed, the subject of resilience is typically the individual, either at the sharp end or at higher managerial levels. The individual is called-upon to adapt in the face of risk to secure the continuous performance of the system. Based on the results from how resilience has been introduced in safety sciences we raise three ethical questions for the field to address: (1) should resilience be seen as people thriving despite of, or because of, risk?; (2) should resilience theory form a basis for moral judgement?; and finally (3) how much should resilience be approached as a trait of the individual? - Highlights: • The article reviews the object of resilience in the safety science literature. • The literature offers a clear link between the notions of complexity and danger. • Danger is managed through adaptive capacity (resilience), typically at the sharp end. • The ethical implications of accepting danger at the sharp end need to be debated

Sparse modeling applied to patient identification for safety in medical physics applications

Science.gov (United States)

Lewkowitz, Stephanie

Every scheduled treatment at a radiation therapy clinic involves a series of safety protocol to ensure the utmost patient care. Despite safety protocol, on a rare occasion an entirely preventable medical event, an accident, may occur. Delivering a treatment plan to the wrong patient is preventable, yet still is a clinically documented error. This research describes a computational method to identify patients with a novel machine learning technique to combat misadministration. The patient identification program stores face and fingerprint data for each patient. New, unlabeled data from those patients are categorized according to the library. The categorization of data by this face-fingerprint detector is accomplished with new machine learning algorithms based on Sparse Modeling that have already begun transforming the foundation of Computer Vision. Previous patient recognition software required special subroutines for faces and different tailored subroutines for fingerprints. In this research, the same exact model is used for both fingerprints and faces, without any additional subroutines and even without adjusting the two hyperparameters. Sparse modeling is a powerful tool, already shown utility in the areas of super-resolution, denoising, inpainting, demosaicing, and sub-nyquist sampling, i.e. compressed sensing. Sparse Modeling is possible because natural images are inherently sparse in some bases, due to their inherent structure. This research chooses datasets of face and fingerprint images to test the patient identification model. The model stores the images of each dataset as a basis (library). One image at a time is removed from the library, and is classified by a sparse code in terms of the remaining library. The Locally Competitive Algorithm, a truly neural inspired Artificial Neural Network, solves the computationally difficult task of finding the sparse code for the test image. The components of the sparse representation vector are summed by ℓ1 pooling

Nuclear safety in Slovak Republic. Regulatory aspects of NPP nuclear safety

International Nuclear Information System (INIS)

Lipar, M.

1999-01-01

Regulatory Authority (UJD) is appointed by the Slovak Republic National Council as an Executive Authority for nuclear safety supervision. Nuclear safety legislation, organisation and resources of UJD, its role and responsibilities are described together with its inspection and licensing functions and International cooperation concerning improvements of safety effectiveness. Achievements of UJD are listed in detail

Inherent veilige 80 km/uur-wegen : ontwikkeling van een strategie voor een duurzaam-veilige (her)inrichting van doorgaande 80 km/uur-wegen. Deel I: keuze van de relevante wegen en het opstellen van criteria en eisen.

NARCIS (Netherlands)

Minnen, J. van

1993-01-01

The former Dienst Verkeerskunde of Rijkswaterstaat commissioned SWOV Institute for Road Safety Research to develop a strategy for an "inherent safe" reconstruction of 80 km/h through roads in the Netherlands. The first part of this study is the conceptualization phase. It classifies 80 km/h through

Safety related experience in FFTF startup and operation

International Nuclear Information System (INIS)

Peterson, R.E.; Halverson, T.G.; Daughtry, J.W.

1982-06-01

The Fast Flux Test Facility (FFTF) is a 400 MW(t) sodium cooled fast reactor operating at the Hanford Engineering Development Laboratory, Richland, Washington, to conduct fuels and materials testing in support of the US LMFBR program. Startup and initial power ascension testing of the facility involved a comprehensive series of readiness reviews and acceptance tests, many of which relate to the inherent safety of the plant. Included are physics measurements, natural circulation, integrated containment leakage, shielding effectiveness, fuel failure detection, and plant protection system tests. Described are the measurements taken to confirm the design safety margins upon which the operating authorization of the plant was based. These measurements demonstrate that large margins of safety are available in the FFTF design

SAFR: a marriage of safety and innovation in LMR design

International Nuclear Information System (INIS)

Lancet, R.T.; Mills, J.C.

1985-01-01

The Sodium Advanced Fast Reactor (SAFR) is a natural evolution of earlier designs, given the current economic and licensing environment. Stringent safety and economic goals have been established for the SAFR plant. This paper describes how these goals are being satisfied, with the primary emphasis being placed on safety. The top level safety goals are: (a) to provide inherently safe responses to all credible events (b) to minimize the potential for severe accidents, and (c) to eliminate the need for evacuation, (d) limited financial risk, (e) assured investment protection, (f) minimum development risk, (g) high capacity factor, (h) long plant life, and (i) low personnel radiation exposure

Liver-inherent immune system: its role in blood-stage malaria.

Science.gov (United States)

Wunderlich, Frank; Al-Quraishy, Saleh; Dkhil, Mohamed A

2014-01-01

The liver is well known as that organ which is obligately required for the intrahepatocyte development of the pre-erythrocytic stages of the malaria-causative agent Plasmodium. However, largely neglected is the fact that the liver is also a central player of the host defense against the morbidity- and mortality-causing blood stages of the malaria parasites. Indeed, the liver is equipped with a unique immune system that acts locally, however, with systemic impact. Its main "antipodal" functions are to recognize and to generate effective immunoreactivity against pathogens on the one hand, and to generate tolerance to avoid immunoreactivity with "self" and harmless substances as dietary compounds on the other hand. This review provides an introductory survey of the liver-inherent immune system: its pathogen recognition receptors including Toll-like receptors (TLRs) and its major cell constituents with their different facilities to fight and eliminate pathogens. Then, evidence is presented that the liver is also an essential organ to overcome blood-stage malaria. Finally, we discuss effector responses of the liver-inherent immune system directed against blood-stage malaria: activation of TLRs, acute phase response, phagocytic activity, cytokine-mediated pro- and anti-inflammatory responses, generation of "protective" autoimmunity by extrathymic T cells and B-1 cells, and T cell-mediated repair of liver injuries mainly produced by malaria-induced overreactions of the liver-inherent immune system.

Passive and engineered safety features of the prototype fast reactor (PFR), Dounreay

International Nuclear Information System (INIS)

Gregory, C.V.

1991-01-01

Prototype fast reactor (PFR) combines passive and engineered safety features. Natural convection, a strong negative power coefficient, the decay heat removal system, and a fuel design able to operate beyond failure are all inherent and passive safety features of the PFR. The reliable shutdown system and the protection provided against SGU leaks are example of engineered protection. Experience at PFR demonstrates the worth and potential of a range of passive and engineered safeguards

Behavior based safety

International Nuclear Information System (INIS)

Sudhikumaran, T.V.; Mehta, S.C.; Goyal, D.K.

2009-01-01

Behaviour Based Safety (popularly known as BBS) is a new methodology for achieving injury free work place and total Safety Culture. BBS is successfully being implemented and is being practiced as a work methodology for achieving a loss and injury free work environment and work practice. Through BBS, it was brought out that the root causes of all Industrial accidents some how originate from the 'at risk' behaviour of some individual or group of individuals at some level. The policy of NPCIL is to excel in the field of Industrial and Fire Safety in comparison to international standards. This article indents to bring out the various parameters helping in installing BBS programme at any plant. (author)

Safety evaluations required in the safety regulations for Monju and the validity confirmation of safety evaluation methods

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

The purposes of this study are to perform the safety evaluations of the fast breeder reactor 'Monju' and to confirm the validity of the safety evaluation methods. In JFY 2012, the following results were obtained. As for the development of safety evaluation methods needed in the safety examination achieved for the reactor establishment permission, development of the analysis codes, such as a core damage analysis code, were carried out according to the plan. As for the development of the safety evaluation method needed for the risk informed safety regulation, the quantification technique of the event tree using the Continuous Markov chain Monte Carlo method (CMMC method) were studied. (author)

Accommodation of unprotected accidents by inherent safety design features in metallic and oxide-fueled LMFBRs

International Nuclear Information System (INIS)

Su, S.F.; Cahalan, J.E.; Sevy, R.H.

1985-01-01

This paper presents the results of a systematic study of the effectiveness of intrinsic design features to mitigate the consequences of unprotected accidents in metallic and oxide-fueled LMFBRs. The accidents analyzed belong to the class generally considered to lead to core disruption; unprotected loss-of-flow (LOF) and transient over-power (TOP). The results of the study demonstrate the potential for design features to meliorate accident consequences, and in some cases to render them benign. Emphasis is placed on the relative performance of metallic and oxide-fueled core designs, and safety margins are quantified in sensitivity studies. All analyses were carried out using the SASSYS LMFBR systems analysis code (1)

Managing change in the nuclear industry: The effects on safety. INSAG-18. A report by the International Nuclear Safety Advisory Group (Russian Edition)

International Nuclear Information System (INIS)

2015-01-01

The nuclear industry is going through a period of unprecedented change. The changes arise from the political and business environment in which the industry must operate, and from within the industry itself as it strives to become more competitive. These pressures have already led to significant changes in how nuclear enterprises are organized. The changes can be expected to continue. It is absolutely essential that throughout the period of time that organizational changes are taking place, and after the changes have occurred, very high standards of safety are maintained by all the elements that make up the industry. Changes can be made effectively and safely, and gains in efficiency and competitiveness, as well as safety, can be realized if changes are introduced carefully and managed well. Experience has shown that this is not a simple matter to achieve. Nuclear installations are complex, and it is inherently demanding to foresee all the implications that a change may have on safety. However, experience has shown very clearly that many changes have a strong potential to affect both the safety that has been built into a design and in the safety culture of an organization. Hence failure to manage change well can significantly affect the likelihood of an accident, the degree to which the assets of the company are put at risk and the company's reputation. This INSAG report is directed at members of boards of directors and senior executives who are responsible for the overall safety of an installation, who make decisions for change and who implement these decisions. It is also written for senior regulators who, on behalf of the public, ensure that boards of directors and executives meet their responsibilities for safety. This report discusses how and why change can challenge the maintenance of a high level of safety, and what can be done to control that challenge and hence reap all the benefits of change. It draws an analogy between the well established principles

Perspective channel-type reactor with enhanced safety

International Nuclear Information System (INIS)

Adamov, E.O.; Grozdov, I.I.; Kuznetsov, S.P.; Petrov, A.A.; Rozhdestvensky, M.I.; Cherkashov, Yu.M.

1994-01-01

Following the search for new design solutions to develop within the framework of channel trends the reactor with enhanced safety the Research and Development Institute of Power Engineering has developed the design of the multiloop boiling water reactor (MKER). The MKER enhanced safety is attained when involving the inherent safety features, passive safety systems as well as the accident consequences confinement devices. The design realizes several advantages which are typical of the channel-type reactors, namely: The design desintegration simplifying the manufacture, control, equipment delivery and decreasing, versus the pressure vessel reactors, the accident effect if it proceeds in an explosive manner; small operating reactivity margin and fuel burnup increased due to continuous refuelling; fuel cycle flexibility allowing comparatively easily to adopt the reactor to the conjuncture of the country fuel balance; multiloop circuit of the main coolant which reduces the degree and effect of the accidents connected with the equipment and pipings rupture; monitoring of the channels and fuel assemblies leak-tightness. (orig.)

Molten salt reactors - safety options galore

International Nuclear Information System (INIS)

Gat, U.; Dodds, H.L.

1997-01-01

Safety features and attributes of molten salt reactors (MSR) are described. The unique features of fluid fuel reactors of on-line continuous processing and the ability for so-called external cooling result in simple and safe designs with low excess reactivity, low fission product inventory, and small source term. These, in turn, make a criticality accident unlikely and reduce the severity of a loss of coolant to where they are no longer severe accidents. A melt down is not an accident for a reactor that uses molten fuel. The molten salts are stable, non-reactive and efficient heat transfer media that operate at high temperatures at low pressures and are highly compatible with selected structural materials. All these features reduce the accident plethora. Freeze valves can be used for added safety. An ultimate safe reactor (U.S.R) is described with safety features that are passive, inherent and non-tamperable (PINT)

Safety performance comparation of MOX, nitride and metallic fuel based 25-100 MWe Pb-Bi cooled long life fast reactors without on-site refuelling

International Nuclear Information System (INIS)

Su'ud, Zaki

2008-01-01

In this paper the safety performance of 25-100 MWe Pb-Bi cooled long life fast reactors based on three types of fuels: MOX, nitride and metal is compared and discussed. In the fourth generation NPP paradigm, especially for Pb-Bi cooled fast reactors, inherent safety capability is necessary against some standard accidents such as unprotected loss of flow (ULOF), unprotected rod run-out transient over power (UTOP), unprotected loss of heat sink (ULOHS). Selection of fuel type will have important impact on the overall system safety performance. The results of safety analysis of long life Pb-Bi cooled fast reactors without on-site fuelling using nitride, MOX and metal fuel have been performed. The reactors show the inherent safety pattern with enough safety margins during ULOF and UTOP accidents. For MOX fuelled reactors, ULOF accident is more severe than UTOP accident while for nitride fuelled cores UTOP accident may push power much higher than that comparable MOX fuelled cores. (author)

Development of Safety Analysis Technology for Integral Reactor

Energy Technology Data Exchange (ETDEWEB)

Sim, S. K. [Korea Atomic Energy Research Institute, Taejeon (Korea); Seul, K. W.; Kim, W. S.; Kim, W. K.; Yun, Y. G.; Ahn, H. J.; Lee, J. S.; Sin, A. D. [Korea Institute of Nuclear Safety, Taejeon (Korea)

2000-03-01

The Nuclear Desalination Plant(NDP) is being developed to produce electricity and fresh water, and is expected to locate near population zone. In the aspect of safety, it is required to protect the public and environment from the possible releases of fission products and to prevent the fresh water from the contamination of radioactivity. Thus, in a present study, the safety characteristics of the integral reactor adopting passive and inherent safety features significantly different from existing nuclear power plants were investigated based on the design of foreign and domestic integral reactors. Also, safety requirements applicable to the NDP were analyzed based on the regulatory requirements for current and advanced reactor designs, and use requirements for small-medium size reactors. Based on these analyses, some safety concerns to be considered in the design stage have been identified. They includes the use of proven technology for new safety systems, the systematic classification and selection of design basis accidents, and the safety assurance of desalination-related systems. These efforts to identify and resolve the safety concerns in the design stage will provide the early confidence of SMART safety to designers, and the technical basis to evaluate the safety to reviewers in the future. 8 refs., 20 figs., 4 tabs. (Author)

The distribution of inherent phosphorus in fifteen water treatment ...

African Journals Online (AJOL)

The aim of this investigation was to characterise the chemical properties relevant to P-sorption/desorption processes of 15 South African WTR and to determine the inherent distribution of P within the WTR using a chemical fractionation procedure. The pH, exchangeable Ca and organic carbon content ranged from 4.77 to ...

Rational quantitative safety goals: a summary

International Nuclear Information System (INIS)

Unwin, S.D.; Hayns, M.R.

1984-08-01

We introduce the notion of a Rational Quantitative Safety Goal. Such a goal reflects the imprecision and vagueness inherent in any reasonable notion of adequate safety and permits such vagueness to be incorporated into the formal regulatory decision-making process. A quantitative goal of the form, the parameter x, characterizing the safety level of the nuclear plant, shall not exceed the value x 0 , for example, is of a non-rational nature in that it invokes a strict binary logic in which the parameter space underlying x is cut sharply into two portions: that containing those values of x that comply with the goal and that containing those that do not. Here, we utilize an alternative form of logic which, in accordance with any intuitively reasonable notion of safety, permits a smooth transition of a safety determining parameter between the adequately safe and inadequately safe domains. Fuzzy set theory provides a suitable mathematical basis for the formulation of rational quantitative safety goals. The decision-making process proposed here is compatible with current risk assessment techniques and produces results in a transparent and useful format. Our methodology is illustrated with reference to the NUS Corporation risk assessment of the Limerick Generating Station

National nuclear safety report 2005. Convention on nuclear safety

International Nuclear Information System (INIS)

2006-01-01

This National Nuclear Safety Report was presented at the 3rd. Review meeting. In general the information contained in the report are: Highlights / Themes; Follow-up from 2nd. Review meeting; Challenges, achievements and good practices; Planned measures to improve safety; Updates to National report to 3rd. Review meeting; Questions from peer review of National Report; and Conclusions

A new small HTGR power plant concept with inherently safe features--An engineering and economic challenge

International Nuclear Information System (INIS)

McDonald, C.F.; Sonn, D.L.

1983-01-01

This paper outlines a small nuclear plant concept which is not meant to replace the large nuclear power plants that will continue to be needed by the industrialized nations, but rather recognizes the needs of the smaller energy user, both for special applications in the US and for the developing nations. The small High-Temperature Gas-Cooled Reactor (HTGR), whose introduction will be very dependent on market forces, represents only one approach to meet these needs. The design of a small power plant that could be inherently safer and that might have costs less than those indicated by the traditional reverse-economy-of-scale effect is discussed. Topics considered include power plant economics, the small steam cycle HTGR thermodynamic cycle, the reactor nuclear heat source layout, the reactor heat removal system (main loop cooling, a vessel cooling system with reactor pressurized, vessel cooling system with reactor depressurized), safety considerations, investment risk protection, the technology base, and applications for the small HTGR plant concept

Basis, evidences and consequences of the inherent stellar encocooning

CERN Document Server

Celis, L

2002-01-01

Based on 7093 observations with photoelectrical photometrical measurements of 191 Mira stars, the following equations (from the papers [1] to [18]) give the basis to establish the Inherent Stellar Encocooning with the spectro-photometric characteristics of the red giant variable stars, especially the Miras, which have large amplitudes (approx 50% of giant variables). The specific basis that justifies a progressive covering with ionized molecules, cold gases, dust and grains are: The relation of the visual amplitudes A sub v =A sub r +E sub A whose real luminosity separate the intrinsic pulsation and amplitude excess effects due to the presence of molecules [145] and an opaque envelope of cool gases; The relation of the visual absolute magnitudes M sub v =M sub v sub r (P)+M sub a (delta sub T sub i sub O V) which is affected by an inherent absorption and/or occultation, and; The relation that defines the probable absolute luminosity and depends on the period and the (Sa) spectral type at maximum M sub v =-2.2...

Implementation of the safety culture for HANARO Safety Management

International Nuclear Information System (INIS)

Wu, Jongsup; Han, Geeyang; Kim, Iksoo

2008-01-01

Safety is the fundamental principal upon which the management system is based. The IAEA INSAG(International Nuclear Safety Group) states the general aims of the safety management system. One of which is to foster and support a strong safety culture through the development and reinforcement of good safety attitudes and behavior in individuals and teams so as to allow them to carry out their tasks safety. The safety culture activities have been implemented and the importance of safety management in nuclear activities for a reactor application and utilization has also been emphasized more than 10 years in HANARO which is a 30 MW multi-purpose research reactor and achieved its first criticality in February 1995. The safety culture activities and implementations have been conducted continuously to enhance its safe operation like the seminars and lectures related to safety matters, participation in international workshops, the development of safety culture indicators, the survey on the attitude of safety culture, the development of operational safety performance indicators (SPIs), the preparation of a safety text book and the development of an e-Learning program for safety education. (author)

Safety from physical viewpoint: ''two-risk model in multiple risk problem''

International Nuclear Information System (INIS)

Kuz'Min, I.I.; Akimov, V.A.

1998-01-01

Full text of publication follows: the problem of safety provision for people and environment within the framework of a certain socio-economic system (SES) as a problem of managing a great number of interacting risks characterizing numerous hazards (natural, manmade, social, economic once, etc.) inherent in the certain SES has been discussed. From the physical point of view, it can be considered a problem of interaction of many bodies which has no accurate mathematical solution even if the laws of interaction of this bodies are known. In physics, to solve this problem, an approach based on the reduction of the above-mentioned problem of the problem of two-body interaction which can be solved accurately in mathematics has been used. The report presents a similar approach to the problem of risk management in the SES. This approach includes the subdivision of numerous hazards inherent within the framework of the SES into two classes of hazards, so that each of the classes could be considered an integrated whole one, each of them being characterized by the appropriate risk. Consequently, problem of 'multiple-risk' management (i.e. the problem of many bodies, as represented in physics) can be reduced to the 'two-risk' management problem (that is, to the problem two-bodies). Within the framework of the two-risk model the optimization of costs to reduce the two kinds of risk, that is, the risk inherent in the SES as a whole, as well as the risk potentially provoked by lots of activities to be introduced in the SES economy has been described. The model has made it possible to formulate and prove the theorem of equilibrium in risk management. Using the theorem, a relatively simple and practically applicable procedure of optimizing the threshold costs to reduce diverse kinds of risk has been elaborated. The procedure provides to assess the minimum value of the cost that can be achieved regarding the socio-economic factors typical of the SES under discussion. The aimed

A chief safety officer as the driver and guardian of a great safety rating.

Science.gov (United States)

Steck, Oliver; Zenker, Daniel; Beatty, Tom

2013-02-01

If the Pharmaceutical Industry were to align to broad metrics that objectively state each product's "Safety Rating" two things would happen. First, Life Sciences companies would refocus dramatically on safety (followed by outcomes). Second, companies that have the highest aggregate "Safety Rating" would enjoy a significant competitive advantage. To achieve and maintain a high safety rating, the role of Safety officer needs to be elevated to the C-Suite.

Achievements and future directions in the reactors physics and nuclear safety research

International Nuclear Information System (INIS)

Dumitrache, Ion

2001-01-01

A historical overlook is presented with respect to inception and development of reactor physics research and on the job training in Romania. First these activities were carried out at the Institute for Atomic Physics and Institute for Power Reactors (IRNE) in Bucharest and afterward at the Institute for Nuclear Technologies, later on transformed in the Institute of Nuclear Research at Pitesti. CYBER Computer installed at Pitesti allowed formation in as early as 1971 reactor specialists who worked out computer programs for neutron physics calculations. These specialists were able to assimilate the characteristic of CANDU 6 type reactor as well as the AECL methodology of simulating processes of CANDU reactor physics. At present four programs are under way. These are: 1. The nuclear reactor physics; 2. The nuclear facility safety; 3. Safety analyses for the transport and radioactive waste disposal; 4. Analyses for radiation shielding and biological protection. There are presented results of the work associated to the CANDU type reactor: 1. Adapting and improving the code system for neutron and thermohydraulic calculation for CANDU type reactor, as supplied by AECL; 2. The IRNE manual for CANDU reactor neutron designing; 3. Final sizing of shim rods of Cernavoda NPP Unit 2; 4. Tests and measurements of reactor physics at the Cernavoda NPP Unit 1 commissioning; 5. Simulation and independent analysis of thermosiphoning carried out at Cernavoda NPP Unit 1 commissioning; 6. Static and dynamical response of the detectors in the CANDU reactor core and their time evolution following the burnup in the neutron flux and their ageing effects; 7. PSA studies at Unit 1; 8. Safety analyses for the radioactive waste disposal at Saligny repository. Also, reported are the results of the work associated to the TRIGA reactor, as follows: 1. Flux measurements and neutron computations necessary in the reactor commissioning; 2. Cleaning up controversial issues relating to neutron flux

Impact of Passive Safety on FHR Instrumentation Systems Design and Classification

International Nuclear Information System (INIS)

Holcomb, David Eugene

2015-01-01

Fluoride salt-cooled high-temperature reactors (FHRs) will rely more extensively on passive safety than earlier reactor classes. 10CFR50 Appendix A, General Design Criteria for Nuclear Power Plants, establishes minimum design requirements to provide reasonable assurance of adequate safety. 10CFR50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors, provides guidance on how the safety significance of systems, structures, and components (SSCs) should be reflected in their regulatory treatment. The Nuclear Energy Institute (NEI) has provided 10 CFR 50.69 SSC Categorization Guideline (NEI-00-04) that factors in probabilistic risk assessment (PRA) model insights, as well as deterministic insights, through an integrated decision-making panel. Employing the PRA to inform deterministic requirements enables an appropriately balanced, technically sound categorization to be established. No FHR currently has an adequate PRA or set of design basis accidents to enable establishing the safety classification of its SSCs. While all SSCs used to comply with the general design criteria (GDCs) will be safety related, the intent is to limit the instrumentation risk significance through effective design and reliance on inherent passive safety characteristics. For example, FHRs have no safety-significant temperature threshold phenomena, thus enabling the primary and reserve reactivity control systems required by GDC 26 to be passively, thermally triggered at temperatures well below those for which core or primary coolant boundary damage would occur. Moreover, the passive thermal triggering of the primary and reserve shutdown systems may relegate the control rod drive motors to the control system, substantially decreasing the amount of safety-significant wiring needed. Similarly, FHR decay heat removal systems are intended to be running continuously to minimize the amount of safety-significant instrumentation needed to initiate

Demonstration of passive safety features in EBR-II

International Nuclear Information System (INIS)

Planchon, H.P. Jr.; Golden, G.H.; Sackett, J.I.

1987-01-01

Two tests of great importance to the design of future commercial nuclear power plants were carried out in the Experimental Breeder Reactor-II on April 3, 1986. These tests, (viewed by about 60 visitors, including 13 foreign LMR specialists) were a loss of flow without scram and a loss of heat sink without scram, both from 100% initial power. In these tests, inherent feedback shut the reactor down without damage to the fuel or other reactor components. This resulted primarily from advantageous characteristics of the metal driver fuel used in EBR-II. Work is currently underway at EBR-II to develop a control strategy that promotes inherent safety characteristics, including survivability of transient overpower accidents. In parallel, work is underway at EBR-II on the development of state-of-the-art plant diagnostic techniques

Defining safety culture and the nexus between safety goals and safety culture. 4. Enhancing Safety Culture Through the Establishment of Safety Goals

International Nuclear Information System (INIS)

Tateiwa, Kenji; Miyata, Koichi; Yahagi, Kimitoshi

2001-01-01

Safety culture is the perception of each individual and organization of a nuclear power plant that safety is the first priority, and at Tokyo Electric Power Company (TEPCO), we have been practicing it in everyday activities. On the other hand, with the demand for competitiveness of nuclear power becoming even more intense these days, we need to pursue efficient management while maintaining the safety level at the same time. Below, we discuss how to achieve compatibility between safety culture and efficient management as well as enhance safety culture. Discussion at Tepco: safety culture-nurturing activities such as the following are being implemented: 1. informing the employees of the 'Declaration of Safety Promotion' by handing out brochures and posting it on the intranet home page; 2. publishing safety culture reports covering stories on safety culture of other industry sectors, recent movements on safety culture, etc.; 3. conducting periodic questionnaires to employees to grasp how deeply safety culture is being established; 4. carrying out educational programs to learn from past cases inside and outside the nuclear industry; 5. committing to common ownership of information with the public. The current status of safety culture in Japan sometimes seems to be biased to the quest of ultimate safety; rephrasing it, there have been few discussions regarding the sufficiency of the quantitative safety level in conjunction with the safety culture. Safety culture is one of the most crucial foundations guaranteeing the plant's safety, and for example, the plant safety level evaluated by probabilistic safety assessment (PSA) could be said to be valid only on the ground that a sound and sufficient safety culture exists. Although there is no doubt that the safety culture is a fundamental and important attitude of an individual and organization that keeps safety the first priority, the safety culture in itself should not be considered an obstruction to efforts to implement

Implementation of the safety culture for HANARO safety management

Energy Technology Data Exchange (ETDEWEB)

Wu, Jongsup; Han, Geeyang; Kim, Iksoo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-11-15

Safety is the fundamental principal upon which a management system is based. The IAEA INSAG (International Nuclear Safety Group) states the general aims of a safety management system. One of which is to foster and support a strong safety culture through the development and reinforcement of good safety attitudes and behavior in individuals and teams, so as to allow them to carry out their tasks safely. The safety culture activities have been implemented and the importance of a safety management in nuclear activities for a reactor application and utilization has also been emphasized for more than 10 years in HANARO which is a 30MW multi-purpose research reactor that achieved its first criticality in February 1995. The safety culture activities and implementations have been conducted continuously to enhance its safe operation such as the seminars and lectures related to safety matters, participation in international workshops and the development of safety culture indicators, a survey on the attitude of HANARO staff toward the safety culture, the development of operational safety performance indicators (SPIs), the preparation of a safety text book and the development of a e-learning program for a safety education purpose.

Implementation of the safety culture for HANARO safety management

International Nuclear Information System (INIS)

Wu, Jongsup; Han, Geeyang; Kim, Iksoo

2008-01-01

Safety is the fundamental principal upon which a management system is based. The IAEA INSAG (International Nuclear Safety Group) states the general aims of a safety management system. One of which is to foster and support a strong safety culture through the development and reinforcement of good safety attitudes and behavior in individuals and teams, so as to allow them to carry out their tasks safely. The safety culture activities have been implemented and the importance of a safety management in nuclear activities for a reactor application and utilization has also been emphasized for more than 10 years in HANARO which is a 30MW multi-purpose research reactor that achieved its first criticality in February 1995. The safety culture activities and implementations have been conducted continuously to enhance its safe operation such as the seminars and lectures related to safety matters, participation in international workshops and the development of safety culture indicators, a survey on the attitude of HANARO staff toward the safety culture, the development of operational safety performance indicators (SPIs), the preparation of a safety text book and the development of a e-learning program for a safety education purpose

Compact All Solid State Oceanic Inherent Optical Property Sensor, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Light propagation in the sea and the consequent remote sensing signals seen by aircraft and spacecraft is fundamentally governed by the inherent optical properties...

Safety studies on Korean fusion DEMO plant using integrated safety assessment methodology

International Nuclear Information System (INIS)

Oh, Kyemin; Kang, Myoung-suk; Heo, Gyunyoung; Kim, Hyoung-chan

2014-01-01

Highlights: •The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant. •The concepts of integrated safety assessment methodology (ISAM) that can be applied in addressing regulatory requirements and recognizing safety issues for K-DEMO were emphasized. •Phenomena identification and ranking table (PIRT) was proposed. It can recognize vulnerabilities of systems and identify the gaps in technical areas requiring additional researches. •This work is expected to contribute on the conceptual design of safety features for K-DEMO to design engineers and the guidance for regulatory requirements to licensers. -- Abstract: The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant (K-DEMO) as a part of R and D program through the National Fusion Research Institute of Korea. Even though nuclear regulation and licensing framework is well setup due to the operating and design experience of Pressurized Water Reactors (PWRs) since 1970s, the regulatory authority of South Korea has concerns on the challenge of facing new nuclear facilities including K-DEMO due to the differences in systems, materials, and inherent safety feature from conventional PWRs. Even though the follow-up of the ITER license process facilitates to deal with significant safety issues of fusion facilities, a licensee as well as a licenser should identify the gaps between ITER and DEMO in terms of safety issues. First we reviewed the methods of conducting safety analysis for unprecedented nuclear facilities such as Generation IV reactors, particularly very high temperature reactor (VHTR), which is called as integrated safety assessment methodology (ISAM). Second, the analysis for the conceptual design of K-DEMO on the basis of ISAM was conducted. The ISAM consists of five analytical tools to develop the safety requirements from licensee

Safety studies on Korean fusion DEMO plant using integrated safety assessment methodology

Energy Technology Data Exchange (ETDEWEB)

Oh, Kyemin; Kang, Myoung-suk [Kyung Hee University, Youngin-si, Gyeonggi-do 446-701 (Korea, Republic of); Heo, Gyunyoung, E-mail: gheo@khu.ac.kr [Kyung Hee University, Youngin-si, Gyeonggi-do 446-701 (Korea, Republic of); Kim, Hyoung-chan [National Fusion Research Institute, Daejeon-si 305-333 (Korea, Republic of)

2014-10-15

Highlights: •The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant. •The concepts of integrated safety assessment methodology (ISAM) that can be applied in addressing regulatory requirements and recognizing safety issues for K-DEMO were emphasized. •Phenomena identification and ranking table (PIRT) was proposed. It can recognize vulnerabilities of systems and identify the gaps in technical areas requiring additional researches. •This work is expected to contribute on the conceptual design of safety features for K-DEMO to design engineers and the guidance for regulatory requirements to licensers. -- Abstract: The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant (K-DEMO) as a part of R and D program through the National Fusion Research Institute of Korea. Even though nuclear regulation and licensing framework is well setup due to the operating and design experience of Pressurized Water Reactors (PWRs) since 1970s, the regulatory authority of South Korea has concerns on the challenge of facing new nuclear facilities including K-DEMO due to the differences in systems, materials, and inherent safety feature from conventional PWRs. Even though the follow-up of the ITER license process facilitates to deal with significant safety issues of fusion facilities, a licensee as well as a licenser should identify the gaps between ITER and DEMO in terms of safety issues. First we reviewed the methods of conducting safety analysis for unprecedented nuclear facilities such as Generation IV reactors, particularly very high temperature reactor (VHTR), which is called as integrated safety assessment methodology (ISAM). Second, the analysis for the conceptual design of K-DEMO on the basis of ISAM was conducted. The ISAM consists of five analytical tools to develop the safety requirements from licensee

Framework of nuclear safety and safety assessment

International Nuclear Information System (INIS)

Furuta, Kazuo

2007-01-01

Since enormous energy is released by nuclear chain reaction mainly as a form of radiation, a great potential risk accompanies utilization of nuclear energy. Safety has been continuously a critical issue therefore from the very beginning of its development. Though the framework of nuclear safety that has been established at an early developmental stage of nuclear engineering is still valid, more comprehensive approaches are required having experienced several events such as Three Mile Island, Chernobyl, and JCO. This article gives a brief view of the most basic principles how nuclear safety is achieved, which were introduced and sophisticated in nuclear engineering but applicable also to other engineering domains in general. (author)

Implementation of the safety culture for HANARO safety management

Energy Technology Data Exchange (ETDEWEB)

Wu, Jong Sup; Han, Gee Yang; Kim, Ik Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-11-15

Safety is the fundamental principal upon which a management system is based. The IAEA INSAG(International Nuclear Safety Group) states the general aims of a safety management system. One of which is to foster and support a strong safety culture through the development and reinforcement of good safety attitudes and behavior in individuals and teams, so as to allow them to carry out their tasks safety. The safety culture activities have been implemented and the importance of a safety management in nuclear activities for a reactor application and utilization has also been emphasized for more than 10 years in HANARO which is a 30 MW multi purpose research reactor that achieved its first criticality in February 1995. The safety culture activities and implementation have been conducted continuously to enhance its safe operation such as the seminars and lectures related to safety matters, participation in international workshops and the development of safety culture indicators, a survey on the attitude of HANARO staff toward the safety culture indicators, a survey on the attitude of HANARO staff toward the safety culture, the development of operational safety performance indicators (SPIs), the preparation of a safety text book and the development of an e Learning program for a safety education purpose.

Implementation of the safety culture for HANARO safety management

International Nuclear Information System (INIS)

Wu, Jong Sup; Han, Gee Yang; Kim, Ik Soo

2008-01-01

Safety is the fundamental principal upon which a management system is based. The IAEA INSAG(International Nuclear Safety Group) states the general aims of a safety management system. One of which is to foster and support a strong safety culture through the development and reinforcement of good safety attitudes and behavior in individuals and teams, so as to allow them to carry out their tasks safety. The safety culture activities have been implemented and the importance of a safety management in nuclear activities for a reactor application and utilization has also been emphasized for more than 10 years in HANARO which is a 30 MW multi purpose research reactor that achieved its first criticality in February 1995. The safety culture activities and implementation have been conducted continuously to enhance its safe operation such as the seminars and lectures related to safety matters, participation in international workshops and the development of safety culture indicators, a survey on the attitude of HANARO staff toward the safety culture indicators, a survey on the attitude of HANARO staff toward the safety culture, the development of operational safety performance indicators (SPIs), the preparation of a safety text book and the development of an e Learning program for a safety education purpose

Mathematical Safety Assessment Approaches for Thermal Power Plants

Directory of Open Access Journals (Sweden)

Zong-Xiao Yang

2014-01-01

Full Text Available How to use system analysis methods to identify the hazards in the industrialized process, working environment, and production management for complex industrial processes, such as thermal power plants, is one of the challenges in the systems engineering. A mathematical system safety assessment model is proposed for thermal power plants in this paper by integrating fuzzy analytical hierarchy process, set pair analysis, and system functionality analysis. In the basis of those, the key factors influencing the thermal power plant safety are analyzed. The influence factors are determined based on fuzzy analytical hierarchy process. The connection degree among the factors is obtained by set pair analysis. The system safety preponderant function is constructed through system functionality analysis for inherence properties and nonlinear influence. The decision analysis system is developed by using active server page technology, web resource integration, and cross-platform capabilities for applications to the industrialized process. The availability of proposed safety assessment approach is verified by using an actual thermal power plant, which has improved the enforceability and predictability in enterprise safety assessment.

Confined Site Construction: A qualitative investigation of critical issues affecting management of Health and Safety

OpenAIRE

Spillane, John P.; Oyedele, Lukumon O.; Von Meding, Jason; Konanahalli, Ashwini; Jaiyeoba, Babatunde E.; Tijani, Iyabo K.

2011-01-01

The construction industry is inherently risky, with a significant number of accidents and disasters occurring, particularly on confined construction sites. This research investigates and identifies the various issues affecting successful management of health and safety in confined construction sites. The rationale is that identifying the issues would assist the management of health and safety particularly in inner city centres which are mostly confined sites. Using empiricism epistemology, th...

Safety

International Nuclear Information System (INIS)

Jones, P.M.S.

1987-01-01

Aspects of fission reactors are considered - control, heat removal and containment. Brief descriptions of the reactor accidents at the SL-1 reactor (1961), Windscale (1957), Browns Ferry (1975), Three Mile Island (1979) and Chernobyl (1986) are given. The idea of inherently safe reactor designs is discussed. Safety assessment is considered under the headings of preliminary hazard analysis, failure mode analysis, event trees, fault trees, common mode failure and probabalistic risk assessments. These latter can result in a series of risk distributions linked to specific groups of fault sequences and specific consequences. A frequency-consequence diagram is shown. Fatal accident incidence rates in different countries including the United Kingdom for various industries are quoted. The incidence of fatal cancers from occupational exposure to chemicals is tabulated. Human factors and the acceptability of risk are considered. (U.K.)

The Development and Evaluation of Inherent RPCS for the APR1400

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae D.; Ryu, Seok H.; Jung, Dong C.; Kim, Joon S.; Baek, Byung C.; Sung, Song K.; You, Guk J. [KNF, Daejeon (Korea, Republic of); Kim, Han G. [KHNP, Daejeon (Korea, Republic of); Chi, Sung G. [KOPEC, Daejeon (Korea, Republic of)

2008-10-15

The APR1400 RPCS (Reactor Power Cutback System) is designed to rapidly reduce the core power to eliminate the need for a reactor trip following a large load rejection or a loss of two main feedwater pumps at high power. GDC (General Design Criteria) 25 says 'Protection system requirements for reactivity control malfunctions. The protection system shall be designed to assure that SAFDL (Specified Acceptable Fuel Design Limits) are not exceeded for any single malfunction of the reactivity control systems, such as accidental withdrawal (not ejection or dropout) of control rods.' In order to comply GDC 25, CPCS (Core Protection Calculator System) will apply a big power penalty({approx} 1.3) to determine the minimum DNBR (Departure from Nucleate Boiling Ratio), the maximum LPD(Local Power Density) and reactor may immediately trip by CPCS low DNBR and high LPD during high power operation for 12-finger CEA drop. The purpose of this study is to develop the inherent RPCS to avoid unwanted reactor trips due to a 12-finger CEA drop. In order to accomplish this purpose, the CPCS should be modified to send RPCS actuation signal and not to apply power penalty due to 12-finger CEA drop for a shot period. During this period which is determined by assessment of safety, the SAFDL will not be violated without any CPCS trip function. The system and CPCS performance is evaluated to verify that CPCS trip does not occurred during 12-finger CEA drop event.

The integral fast reactor (IFR) concept: Physics of operation and safety

International Nuclear Information System (INIS)

Wade, D.C.; Chang, Y.I.

1987-01-01

The IFR concept employs a pool layout, a U/Pu/Zr metal alloy fuel and a closed fuel cycle based on pyrometallurgical reprocessing and injection casting refabrication. The reactor physics issues of designing for inherent safety and for a closed fissile self-sufficient integral fuel cycle with uranium startup and potential actinide transmutation are discussed

The integral fast reactor (IFR) concept: physics of operation and safety

International Nuclear Information System (INIS)

Wade, D.C.; Chang, Y.I.

1987-01-01

The IFR concept employs a pool layout, a U/Pu/Zr metal alloy fuel and a closed fuel cycle based on pyrometallurgical reprocessing and injection casting refabrication. The reactor physics issues of designing for inherent safety and for a closed fissile self-sufficient integral fuel cycle with uranium startup and potential actinide transmutation are discussed

Integral Fast Reactor concept

Energy Technology Data Exchange (ETDEWEB)

Till, C.E.; Chang, Y.I.

1986-01-01

The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path.

Integral Fast Reactor concept

International Nuclear Information System (INIS)

Till, C.E.; Chang, Y.I.

1986-01-01

The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path

The Integral Fast Reactor concept

International Nuclear Information System (INIS)

Till, C.E.; Chang, Y.I.

1986-01-01

The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes the key features and potential advantages of the IFR concept, its technology development status, fuel cycle economics potential, and its future development path

Safety and Mission Assurance: A NASA Perspective

Science.gov (United States)

Higginbotham, Scott A.

2016-01-01

Manned spaceflight is an incredibly complex and inherently risky human endeavor. As the result of the lessons learned through years of triumph and tragedy, the National Aeronautics and Space Administration (NASA) has embraced a comprehensive and integrated approach to the challenge of ensuring safety and mission success. This presentation will provide an overview of some of the techniques employed in this effort, with a focus on the processing operations performed at the Kennedy Space Center (KSC).

Chimera Type Behavior in Nonlocal Coupling System with Two Different Inherent Frequencies

Science.gov (United States)

Lin, Larry; Li, Ping-Cheng; Tseng, Hseng-Che

2014-03-01

From the research of Kuramoto and Strogatz, arrays of identical oscillators can display a remarkable pattern, named chimera state, in which phase-locked oscillators coexist with drifting ones in nonlocal coupling oscillator system. We consider further in this study, two groups of oscillators with different inherent frequencies and arrange them in a ring. When the difference of the inherent frequencies is within some specific parameter range, oscillators of nonlocal coupling system show two distinct chimera states. When the parameter value exceeds some threshold value, two chimera states disappear. They show different features. The statistical dynamic behavior of the system can be described by Kuramoto theory.

Probabilistic safety criteria for improvement of Nuclear Power Plant design and operation

Energy Technology Data Exchange (ETDEWEB)

Cho, Nam Jin; Chung, Woo Sick; Park, Moon Kyu [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1991-12-15

The procedure of this study is to : research on the status of IAEA(International Atomic Energy Agency) member states about the policy of safety goals, study figures of merit and demerit that inherently exist in the existing methodology for reliability allocation, develop an efficient methodology for allocating reliability from top-level safety goals to intermediate and low-level PSC, write a computer code on the basis of the methodology proposed in the study, and apply the methodology to Surry Unit 1 that is the type of PWR.

Inherently safe in situ uranium recovery

Science.gov (United States)

Krumhansl, James L; Brady, Patrick V

2014-04-29

An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

Geometries inherent to N=1 supergravities

International Nuclear Information System (INIS)

Galperin, A.S.; Ogievetsky, V.I.; Sokatchev, E.S.

1981-01-01

The first part of the talk is devoted to a consideration of linearized N=1 supergravities. The second main part deals with complex geometries inherent to different N=1 supergravities. A special attention is paid to a new version with local symmetry. It is connected to the special nonminimal case (n=0) having a remarkable property of supervolume preservation in Csup(4.4) superspace. Therefore the superdeterminant of change of variables from left to right-handed Rsup(4.4) parametrization is a dimensionless scalar. This geometric invariant has to be constrained to obtain an action. Solving such a constraint on vector and spinor prepotentials in Wess-Zumino gauge one obtains the new supergravity with 12+12 fields and local symmetry. A possible relaxation of this constraint is briefly considered (16+16 fields version) [ru

A study for structural safety of ISER reactor building under impact load

International Nuclear Information System (INIS)

Takeuchi, Yoichiro; Hasegawa, Toshiyasu; Mutoh, Atsushi; Wakabayashi, Hiroaki.

1991-01-01

ISER (Inherently Safe and Economical Reactor) proposed in Japan by an academic circle and industries is expected to be used world-wide particularly in developing countries where an energy crunch is feared in the 21-st century. A certain level of hardened structures for plant safety seems to be effective and may be required by the regulatory body, since the ISER is claimed to be inherently safe even against a kind of external load. This paper concerns impact resistant design of ISER. A brief state-of-the-art review on related works, impact resistant design flow and results of some preliminary analysis of a proposed ISER model is also presented. (author)

A study on the methodology of probabilistic safety assessment for KALIMER

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kwan Seong; Kwon, Young Min; Lee, Yong Bum; Jeong, Hae Yong; Yang, Joon Eon; Ha, Kyu Suk; Hahn, Do Hee [Korea Atomic Energy Research Institute, Taejeon (Korea)

2002-03-01

Existing Probabilistic Safety Assessment(PSA) is a method for Light Water Reactor or Pressurized Heavy Water Reactor. Because KALIMER is different from these reactor, the new methodology of PSA need to be developed. In this paper, the PSA of Power Reactor Inherently Safety Module(PRISM) is analyzed, and Initiating Event such as Experiential Assessment, Logical Assessment and Failure Mode Effect Analysis(FMEA) is reviewed. Also, Pipe Damage Frequency Method is suggested for KALIMER. And the Reliability Physical method of Passive System, which is a chief safety system of KALIMER, is reviewed and its applicability is investigated. Finally, for the Preliminary PSA of KALIMER, Intermediate Heat Transfer System is analyzed. 23 refs., 10 figs., 13 tabs. (Author)

Multi-dimensional Code Development for Safety Analysis of LMR

International Nuclear Information System (INIS)

Ha, K. S.; Jeong, H. Y.; Kwon, Y. M.; Lee, Y. B.

2006-08-01

A liquid metal reactor loaded a metallic fuel has the inherent safety mechanism due to the several negative reactivity feedback. Although this feature demonstrated through experiments in the EBR-II, any of the computer programs until now did not exactly analyze it because of the complexity of the reactivity feedback mechanism. A multi-dimensional detail program was developed through the International Nuclear Energy Research Initiative(INERI) from 2003 to 2005. This report includes the numerical coupling the multi-dimensional program and SSC-K code which is used to the safety analysis of liquid metal reactors in KAERI. The coupled code has been proved by comparing the analysis results using the code with the results using SAS-SASSYS code of ANL for the UTOP, ULOF, and ULOHS applied to the safety analysis for KALIMER-150

Safety philosophy of gas turbine high temperature reactor (GTHTR300)

International Nuclear Information System (INIS)

Shoji Katanishi; Kazuhiko Kunitomi; Shusaku Shiozawa

2002-01-01

Japan Atomic Energy Research Institute (JAERI) has undertaken the study of an original design concept of gas turbine high temperature reactor, the GTHTR300. The general concept of this study is development of a greatly simplified design that leads to substantially reduced technical and cost requirements. Newly proposed design features enable the GTHTR300 to be an efficient and economically competitive reactor in 2010's. Also, the GTHTR300 fully takes advantage of its inherent safety characteristics. The safety philosophy of the GTHTR300 is developed based on the HTTR (High Temperature Engineering Test Reactor) of JAERI which is the first HTGR in Japan. Major features of the newly proposed safety philosophy for the GTHTR300 are described in this article. (authors)

Performance standards of road safety management

Directory of Open Access Journals (Sweden)

Čabarkapa Milenko R.

2016-01-01

Full Text Available Road safety management controlling means the process of finding out the information whether the road safety is improving in a measure to achieve the objectives. The process of control consists of three basic elements: definition of performances and standards, measurement of current performances and comparison with the set standards, and improvement of current performances, if they deviate from the set standards. The performance standards of road safety management system are focused on a performances measurement, in terms of their design and characteristics, in order to support the performances improvement of road safety system and thus, ultimately, improve the road safety. Defining the performance standards of road safety management system, except that determines the design of the system for performances measurement, directly sets requirements whose fulfillment will produce a road safety improvement. The road safety management system, based on the performance standards of road safety, with a focus on results, will produce the continuous improvement of road safety, achieving the long-term 'vision zero', the philosophy of road safety, that human life and health take priority over mobility and other traffic objectives of the road traffic.

Safety features of the MAPLE-X10 reactor design

International Nuclear Information System (INIS)

Lee, A.G.; Bishop, W.E.; Heeds, W.

1990-09-01

The MAPLE-X10 reactor is a D 2 0-reflected, H 2 0-cooled and -moderated pool-type reactor under construction at the Chalk River Nuclear Laboratories. This 10-MW reactor will produce key medical and industrial radio-isotopes such as 99 Mo, 125 I, and 192 Ir. As the prototype for the MAPLE research reactor concept, the reactor incorporates diverse safety features both inherent in the design and in the added engineered systems. The safety requirements are analogous to those of the Canadian CANDU power reactor since standards for the licensing of new research reactors have not been developed yet by the licensing authority in Canada

Safety features of the MAPLE-X10 reactor design

International Nuclear Information System (INIS)

Lee, A.G.; Bishop, W.E.; Heeds, W.

1990-01-01

This paper reports on the MAPLE-X10 reactor D 2 O-reflected, H 2 O-cooled and -moderated pool- type reactor, under construction at the Chalk River Nuclear Laboratories. This 10-MW will produce key medical and industrial radioisotopes such as 99 Mo, 125 I, and 192 Ir. The prototype for the MAPLE research reactor concept, the reactor incorporates diverse safety features both inherent in the design and in the added engineered systems. The safety requirements are analogous to those of the Canadian CANDU power reactor as standards for the licensing of new research reactors have not been developed by the licensing authority in Canada

Promoting and assessment of safety culture within regulatory body

International Nuclear Information System (INIS)

Awasthi, Sumit; Bhattacharya, D.; Koley, J.; Krishnamurthy, P.R.

2015-01-01

Regulators have an important role to play in assisting organizations under their jurisdiction to develop positive safety cultures. It is therefore essential for the regulator to have a robust safety culture as an inherent strategy and communication of this strategy to the organizations it supervises. Atomic Energy Regulatory Board (AERB) emphasizes every utility to institute a good safety culture during various stages of a NPP. The regulatory requirement for establishing organisational safety culture within utility at different stages are delineated in the various AERB safety codes which are presented in the paper. Although the review and assessment of the safety culture is a part of AERB’s continual safety supervision through existing review mechanism, AERB do not use any specific indicators for safety culture assessment. However, establishing and nurturing a good safety culture within AERB helps in encouraging the utility to institute the same. At the induction level AERB provides training to its staffs for regulatory orientation which include a specific course on safety culture. Subsequently, the junior staffs are mentored by seniors while involving them in various regulatory processes and putting them as observers during regulatory decision making process. Further, AERB established a formal procedure for assessing and improving safety culture within its staff as a management system process. The paper describes as a case study the above safety culture assessment process established within AERB

Inherent safety that the reactivity effect of core bending in fast reactors brings about

International Nuclear Information System (INIS)

Nakagawa, Masatoshi; Yagawa, Genki.

1994-01-01

FBRs have the merit on safety by low operation pressure and the large heat capacity of coolant, in addition, due to the core temperature rise at the time of accidents and the thermal expansion of core structures, the negative feedback of reactivity can be expected. Recently, attention has been paid to the negative feedback of reactivity due to core bending. It can be expected also in the core of limited free bow type. Bending is caused by the difference of thermal expansion on six surfaces of hexagonal wrapper tubes. The bending changes core reactivity and exerts effects to fuel exchange force and operation, insertion of control rods and the structural soundness of fuel assemblies. for the purpose of limiting the effect that core bending exerts to core characteristics to allowable range, core constraint mechanism is installed. The behavior of core bending at the time of anticipated transient without scram is explained. The example of the analysis of PRISM reactor is shown. The experiment that confirmed the negative feedback of reactivity due to core bending under the condition of ULOF was that at the fast flux test facility. (K.I.)

Inherent Error in Asynchronous Digital Flight Controls.

Science.gov (United States)

1980-02-01

operation will be eliminated. If T* is close to T, the inherent error (eA) is a small value. Then the deficiency of the basic model, which is de... tK2 at m ~VCONTR0RKIPPIL I~+ R tKT 2 TKT 5 ~I G E 1 i V OTN TRIL 2-REDN HNE IjT e UT 3 ~49__I 4.) 4 -4 - 4.-4 U 4.) k-4E-- Iz E-4 P E-44)-4. 4.)l 1s...indicate the channel failure. To reduce this deficiency , the new model computes a tolerance value equal to the maximum steady-state sample covariance of the

Novel OSNR Monitoring Technique in Dense WDM Systems using Inherently Generated CW Monitoring Channels

DEFF Research Database (Denmark)

Petersen, Martin Nordal

2007-01-01

We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing.......We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing....

A literature review of safety culture.

Energy Technology Data Exchange (ETDEWEB)

Cole, Kerstan Suzanne; Stevens-Adams, Susan Marie; Wenner, Caren A.

2013-03-01

Workplace safety has been historically neglected by organizations in order to enhance profitability. Over the past 30 years, safety concerns and attention to safety have increased due to a series of disastrous events occurring across many different industries (e.g., Chernobyl, Upper Big-Branch Mine, Davis-Besse etc.). Many organizations have focused on promoting a healthy safety culture as a way to understand past incidents, and to prevent future disasters. There is an extensive academic literature devoted to safety culture, and the Department of Energy has also published a significant number of documents related to safety culture. The purpose of the current endeavor was to conduct a review of the safety culture literature in order to understand definitions, methodologies, models, and successful interventions for improving safety culture. After reviewing the literature, we observed four emerging themes. First, it was apparent that although safety culture is a valuable construct, it has some inherent weaknesses. For example, there is no common definition of safety culture and no standard way for assessing the construct. Second, it is apparent that researchers know how to measure particular components of safety culture, with specific focus on individual and organizational factors. Such existing methodologies can be leveraged for future assessments. Third, based on the published literature, the relationship between safety culture and performance is tenuous at best. There are few empirical studies that examine the relationship between safety culture and safety performance metrics. Further, most of these studies do not include a description of the implementation of interventions to improve safety culture, or do not measure the effect of these interventions on safety culture or performance. Fourth, safety culture is best viewed as a dynamic, multi-faceted overall system composed of individual, engineered and organizational models. By addressing all three components of

Study on the experimental VHTR safety with analysis for a hypothetical rapid depressurization accident

International Nuclear Information System (INIS)

Mitake, S.; Suzuki, K.; Ohno, T.; Okada, T.

1982-01-01

A hypothetical rapid depressurization accident of the experimental VHTR has been analyzed, including all phenomena in the accident, from its initiating depressurization of the coolant to consequential radiological hazard. Based on reliability analysis of the engineered safety features, all possible sequences, in which the safety systems are in success or in failure, have been investigated with event tree analysis. The result shows the inherent safety characteristics of the reactor and the effectiveness of the engineered safety features. And through the analysis, it has been indicated that further investigations on some phenomena in the accident, e.g., air ingress by natural circulation flow and fission product transport in the plant, will bring forth more reasonable and sufficient safety of the reactor

Knowledge Management for Safety Regulators: Cooperation to Achieve a Much Needed Product

International Nuclear Information System (INIS)

Mallick, S.

2016-01-01

Full text: Knowledge management (KM) has been identified by a number of IAEA documents as one of the key factors that can contribute to the safe and efficient operation of nuclear facilities in Member States. The IAEA Strategic Approaches to Education and Training in Nuclear and Radiation, Transport and Waste Safety identify and underline KM as an important line of action for effective national and organizational strategies in education and training. The capacity building “umbrella concept”, developed within the Action Plan in Nuclear Safety, also recognizes KM as one of the main four pillars (Education and Training, Human Resource Development, Knowledge Management and Knowledge Networks) of capacity building. Within existing IAEA publications, there is currently no specific practical guidance on how to develop and implement KM programmes for regulators. As such, in 2014, the IAEA Steering Committee on Regulatory Capacity Building and Knowledge Management requested the IAEA to develop a publication providing such practical guidance. The objective of the publication is to provide practical guidance to Member States on how to plan, establish and maintain an effective safety KM programme for regulators of facilities and activities. The report will identify benefits and uses of KM by regulators and will describe how a regulator could use KM in support of its functions. This presentation will provide an overview of the Knowledge Management for Safety Regulators document while highlighting the cross-departmental cooperation (i.e., NS and NE) used in its development. Furthermore, this presentation will provide insight into the challenges currently being faced by safety regulators vis-à-vis KM programmes and present potential paths forward with respect to the definition of efficient and effective KM indicators. (author

Veterinary education on fostering food safety and governance achieving a healthy nation in Bangladesh

Directory of Open Access Journals (Sweden)

M. Mufizur Rahman

2013-08-01

Full Text Available Since veterinary medicine plays an important role in assuring a nation's food safety, therefore the present status of our food safety, where large numbers of consumers in Bangladesh have become victims of consuming adulterated foods, needs to be enhanced and governed by the guideline of veterinary and public health educators. This article highlights the need of an integrated collaborative approach between academicians and government officials for the creation and dissemination of food-safety teaching driving force to mitigate food borne diseases, ensure food safety, control mischievous and fraudulent adulteration – all destined to a harmonious national health strategic action plan. Veterinary education is very effective for cor- rect implementation of the stable to table concept and best serves the public when it is updated on current market needs of food products and measures protecting animal health. Universities in Europe and USA have adjusted their veterinary medicine curricula during the past few years. Experts predicted determinant changes by 2020 that would influence the work of the veterinarians. All of them are in favor of placing food quality and food safety and public health as the highest priorities in future veterinary education. In Bangladesh, Universities and Veterinary Colleges are producing qualified Veterinary Food Hygienists to deal with matters of health and demands for consumers’ food protection. The veterinary education blends veterinarians with strong capacity to advocate the assurance of food quality and safety from farm to fork. Government in collaboration with veterinary food hygienist should advocate academic and field covered sciencebased food safety system. It is hoped that in the near future Bangladesh will come forward with veterinary public health responsibilities incorporated in national food safety program. The concerned authorities in collaboration with international public health authority like WHO should

Comparative analysis of operation and safety of subcritical nuclear systems and innovative critical reactors; Analyse comparative du fonctionnement et de la surete de systemes sous-critiques et de reacteurs critiques innovants

Energy Technology Data Exchange (ETDEWEB)

Bokov, P.M

2005-05-01

The main goal of this thesis work is to investigate the role of core subcriticality for safety enhancement of advanced nuclear systems, in particular, molten salt reactors, devoted to both energy production and waste incineration/transmutation. The inherent safety is considered as ultimate goal of this safety improvement. An attempt to apply a systematic approach for the analysis of the subcriticality contribution to inherent properties of hybrid system was performed. The results of this research prove that in many cases the subcriticality may improve radically the safety characteristics of nuclear reactors, and in some configurations it helps to reach the 'absolute' intrinsic safety. In any case, a proper choice of subcriticality level makes all analyzed transients considerably slower and monotonic. It was shown that the weakest point of the independent-source systems with respect to the intrinsic safety is thermohydraulic unprotected transients, while in the case of the coupled-source systems the excess reactivity/current insertion events remain a matter of concern. To overcome these inherent drawbacks a new principle of realization of a coupled sub-critical system (DENNY concept) is proposed. In addition, the ways to remedy some particular safety-related problems with the help of the core sub-criticality are demonstrated. A preliminary safety analysis of the fast-spectrum molten salt reactor (REBUS concept) is also carried out in this thesis work. Finally, the potential of the alternative (to spallation) neutron sources for application in hybrid systems is examined. (author)

Reactor Safety Analysis

International Nuclear Information System (INIS)

Arien, B.

2000-01-01

The objective of SCK-CEN's programme on reactor safety is to develop expertise in probabilistic and deterministic reactor safety analysis. The research programme consists of two main activities, in particular the development of software for reliability analysis of large systems and participation in the international PHEBUS-FP programme for severe accidents. Main achievements in 1999 are reported

Risk, fear and public safety

International Nuclear Information System (INIS)

Siddall, E.

1981-04-01

Part 1 of the paper advocates a rational approach to public safety based on unbiassed quantitative assessment of overall risks and benefits of any technological activity. It shows that improved safety should be attainable at less cost than is the case at present. Part 2 offers an explanation of why so little has been achieved in this direction and outlines the major errors in present practices. Part 3 suggests what might realistically be done towards the achievement of some of the possible benefits. Factors which are important in the study of safety and evidence supporting the arguments are discussed in six appendices. It is urged that the scientific and technological community should improve its understanding of safety as a specialization and should endeavour to lead rather than follow in our present political system

Disease resistance is related to inherent swimming performance in Atlantic salmon.

Science.gov (United States)

Castro, Vicente; Grisdale-Helland, Barbara; Jørgensen, Sven M; Helgerud, Jan; Claireaux, Guy; Farrell, Anthony P; Krasnov, Aleksei; Helland, Ståle J; Takle, Harald

2013-01-21

Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon.Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously). Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis) and gene expression analyses of the host response in selected organs. An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

Disease resistance is related to inherent swimming performance in Atlantic salmon

Directory of Open Access Journals (Sweden)

Castro Vicente

2013-01-01

Full Text Available Abstract Background Like humans, fish can be classified according to their athletic performance. Sustained exercise training of fish can improve growth and physical capacity, and recent results have documented improved disease resistance in exercised Atlantic salmon. In this study we investigated the effects of inherent swimming performance and exercise training on disease resistance in Atlantic salmon. Atlantic salmon were first classified as either poor or good according to their swimming performance in a screening test and then exercise trained for 10 weeks using one of two constant-velocity or two interval-velocity training regimes for comparison against control trained fish (low speed continuously. Disease resistance was assessed by a viral disease challenge test (infectious pancreatic necrosis and gene expression analyses of the host response in selected organs. Results An inherently good swimming performance was associated with improved disease resistance, as good swimmers showed significantly better survival compared to poor swimmers in the viral challenge test. Differences in mortalities between poor and good swimmers were correlated with cardiac mRNA expression of virus responsive genes reflecting the infection status. Although not significant, fish trained at constant-velocity showed a trend towards higher survival than fish trained at either short or long intervals. Finally, only constant training at high intensity had a significant positive effect on fish growth compared to control trained fish. Conclusions This is the first evidence suggesting that inherent swimming performance is associated with disease resistance in fish.

Critical review of safety performance metrics

NARCIS (Netherlands)

Karanikas, Nektarios

2016-01-01

Various tools for safety performance measurement have been introduced in order to fulfil the need for safety monitoring in organisations, which is tightly related to their overall performance and achievement of their business goals. Such tools include accident rates, benchmarking, safety culture and

Inherent wettability of different rock surfaces at nanoscale: a theoretical study

Science.gov (United States)

Chang, Xiao; Xue, Qingzhong; Li, Xiaofang; Zhang, Jianqiang; Zhu, Lei; He, Daliang; Zheng, Haixia; Lu, Shuangfang; Liu, Zilong

2018-03-01

Investigating the inherent wettability of rock surfaces at nanoscale is of great importance in ore floatation and oil recovery field. Using molecular dynamics simulations, we systematically study the wetting behavior of water on different rock surfaces (silica, calcite, gypsum, halite and graphite) at nanoscale. It is demonstrated that the inherent rock wettability follows the order of gypsum > calcite > halite > silica > graphite. Remarkably, we also manifest that the polarity of oil molecules can affect the water contact angles on silica surface. For example, the water contact angles on silica surface in hexane, dodecane, thiophene and toluene are 58 ± 2°, 63 ± 3°, 90 ± 1°, 118 ± 1°, respectively. Furthermore, we investigate the wetting behavior of water on heterogeneous rock surfaces and find that water molecules can move from hydrophobic surface to hydrophilic surface.

Interdependency control : compensation strategies for the inherent vulnerability of critical infrastructure networks

International Nuclear Information System (INIS)

Mao, D.; Sotoodeh, M.; Monu, K.; Marti, J.R.; Srivastava, K.D.

2009-01-01

Today's increasingly interacting national critical infrastructures (NCIs) can tolerate most stochastic local disturbances. However, they are extremely fragile under global disturbances, as the latter may either push the whole system into a critical state or reveal many unexpected hidden interdependencies, inducing or triggering cascading failures among all possible layers. This robust yet fragile duality is an inherent vulnerability of modern infrastructures. It is therefore expected that weather-related disasters will be more frequent under a changing climate. This paper proposed an interdependency control strategy (ICS) that would maintain the survival of the most critical services, and compensate for this inherent vulnerability during emergency states. The paper also proposed a generalized adjacency matrix (GAM) to represent the physical interdependencies intra/inter of various infrastructure networks. The vulnerable section in the network can be identified, based on computed results of GAM, number of islands in the network, and influence domain(s) of each component. These features render ICS more effective and convincing. Last, the paper proposed a survivability index for isolated sub-networks and described relevant measures for improving this index during the four phases of emergency management. It was concluded that the proposed strategy is an effective means to reduce the inherent vulnerability and increase the resiliency of these critical infrastructures networks. 20 refs., 5 figs

Modular High Temperature Gas-Cooled Reactor Safety Basis and Approach

Energy Technology Data Exchange (ETDEWEB)

David Petti; Jim Kinsey; Dave Alberstein

2014-01-01

Various international efforts are underway to assess the safety of advanced nuclear reactor designs. For example, the International Atomic Energy Agency has recently held its first Consultancy Meeting on a new cooperative research program on high temperature gas-cooled reactor (HTGR) safety. Furthermore, the Generation IV International Forum Reactor Safety Working Group has recently developed a methodology, called the Integrated Safety Assessment Methodology, for use in Generation IV advanced reactor technology development, design, and design review. A risk and safety assessment white paper is under development with respect to the Very High Temperature Reactor to pilot the Integrated Safety Assessment Methodology and to demonstrate its validity and feasibility. To support such efforts, this information paper on the modular HTGR safety basis and approach has been prepared. The paper provides a summary level introduction to HTGR history, public safety objectives, inherent and passive safety features, radionuclide release barriers, functional safety approach, and risk-informed safety approach. The information in this paper is intended to further the understanding of the modular HTGR safety approach. The paper gives those involved in the assessment of advanced reactor designs an opportunity to assess an advanced design that has already received extensive review by regulatory authorities and to judge the utility of recently proposed new methods for advanced reactor safety assessment such as the Integrated Safety Assessment Methodology.

Management of safety culture

International Nuclear Information System (INIS)

Kavsek, D.

2004-01-01

The strengthening of safety culture in an organization has become an increasingly important issue for nuclear industry. A high level of safety performance is essential for business success in intensely competitive global environment. This presentation offers a discussion of some principles and activities used in enhancing safety performance and appropriate safety behaviour at the Krsko NPP. Over the years a number of events have occurred in nuclear industry that have involved problems in human performance. A review of these and other significant events has identified recurring weaknesses in plant safety culture and policy. Focusing attention on the strengthening of relevant processes can help plants avoid similar undesirable events. The policy of the Krsko NPP is that all employees concerned shall constantly be alert to opportunities to reduce risks to the lowest practicable level and to achieve excellence in plant safety. The most important objective is to protect individuals, society and the environment by establishing and maintaining an effective defense against radiological hazard in the nuclear power plant. It is achieved through the use of reliable structures, components, systems, and procedures, as well as plant personnel committed to a strong safety culture. The elements of safety culture include both organizational and individual aspects. Elements commonly included at the organizational level are senior management commitment to safety, organizational effectiveness, effective communication, organizational learning, and a culture that encourages identification and resolution of safety issues. Elements identified at the individual level include personal accountability, a questioning attitude, communication, procedural adherence, etc.(author)

The role of risk assessment and safety analysis in integrated safety assessments

International Nuclear Information System (INIS)

Niall, R.; Hunt, M.; Wierman, T.E.

1990-01-01

To ensure that the design and operation of both nuclear and non- nuclear hazardous facilities is acceptable, and meets all societal safety expectations, a rigorous deterministic and probabilistic assessment is necessary. An approach is introduced, founded on the concept of an ''Integrated Safety Assessment.'' It merges the commonly performed safety and risk analyses and uses them in concert to provide decision makers with the necessary depth of understanding to achieve ''adequacy.'' 3 refs., 1 fig

Planificación e implementación de la Seguridad Sostenible en Holanda = Planning and implementation of Sustainable Safety in The Netherlands.

NARCIS (Netherlands)

Wegman, F.C.M. Aarts, L.T. & Bax, C.A.

2008-01-01

From the early 1990s Holland has been developing a concept of sustainable road safety to tackle the risks Inherent to mobility. Subsequent to introducing the sustainable safety concept in 1992, a series of steps were taken to apply measures in line with the Dutch concept. The most important step was

PX–An Innovative Safety Concept for an Unmanned Reactor

Directory of Open Access Journals (Sweden)

Sung-Jae Yi

2016-02-01

Full Text Available An innovative safety concept for a light water reactor has been developed at the Korea Atomic Energy Research Institute. It is a unique concept that adopts both a fast heat transfer mechanism for a small containment and a changing mechanism of the cooling geometry to take advantage of the potential, thermal, and dynamic energies of the cold water in the containment. It can bring about rapid cooling of the containment and long-term cooling of the decay heat. By virtue of this innovative concept, nuclear fuel damage events can be prevented. The ultimate heat transfer mechanism contributes to minimization of the heat exchanger size and containment volume. A small containment can ensure the underground construction, which can use river or seawater as an ultimate heat sink. The changing mechanism of the cooling geometry simplifies several safety systems and unifies diverse functions. Simplicity of the present safety system does not require any operator actions during events or accidents. Therefore, the unique safety concept of PX can realize both economic competitiveness and inherent safety.

Safety of High Speed Ground Transportation Systems : Analytical Methodology for Safety Validation of Computer Controlled Subsystems : Volume 2. Development of a Safety Validation Methodology

Science.gov (United States)

1995-01-01

This report describes the development of a methodology designed to assure that a sufficiently high level of safety is achieved and maintained in computer-based systems which perform safety cortical functions in high-speed rail or magnetic levitation ...

THE FLUORBOARD A STATISTICALLY BASED DASHBOARD METHOD FOR IMPROVING SAFETY

International Nuclear Information System (INIS)

PREVETTE, S.S.

2005-01-01

The FluorBoard is a statistically based dashboard method for improving safety. Fluor Hanford has achieved significant safety improvements--including more than a 80% reduction in OSHA cases per 200,000 hours, during its work at the US Department of Energy's Hanford Site in Washington state. The massive project on the former nuclear materials production site is considered one of the largest environmental cleanup projects in the world. Fluor Hanford's safety improvements were achieved by a committed partnering of workers, managers, and statistical methodology. Safety achievements at the site have been due to a systematic approach to safety. This includes excellent cooperation between the field workers, the safety professionals, and management through OSHA Voluntary Protection Program principles. Fluor corporate values are centered around safety, and safety excellence is important for every manager in every project. In addition, Fluor Hanford has utilized a rigorous approach to using its safety statistics, based upon Dr. Shewhart's control charts, and Dr. Deming's management and quality methods

Safety first!

CERN Multimedia

2016-01-01

Among the many duties I assumed at the beginning of the year was the ultimate responsibility for Safety at CERN: the responsibility for the physical safety of the personnel, the responsibility for the safe operation of the facilities, and the responsibility to ensure that CERN acts in accordance with the highest standards of radiation and environmental protection.   The Safety Policy document drawn up in September 2014 is an excellent basis for the implementation of Safety in all areas of CERN’s work. I am happy to commit during my mandate to help meet its objectives, not least by ensuring the Organization makes available the necessary means to achieve its Safety objectives. One of the main objectives of the HSE (Occupational Health and Safety and Environmental Protection) unit in the coming months is to enhance the measures to minimise CERN’s impact on the environment. I believe CERN should become a role model for an environmentally-aware scientific research laboratory. Risk ...

How Feelings of Safety at School Affect Educational Outcomes

OpenAIRE

Johanna Lacoe

2013-01-01

Persistent racial and ethnic gaps in educational achievement have focused policy attention on school climate and safety as important elements of educational performance. In a special issue of Educational Researcher focused on safety and order in schools, Cornell and Mayer (2010) argue that school safety and school order are fundamental to studies of the achievement gap, teacher attrition, and student engagement. This paper represents the first large-scale analysis of how feelings of safety at...

Effect of x-ray treatments on pathogenic bacteria, inherent microbiota, color, and texture on parsley leaves.

Science.gov (United States)

Mahmoud, Barakat S M

2012-10-01

This work is a part of systematic studies of the effect of X-ray treatments on fresh produce. The main objective of this investigation was to study the effects of X-ray treatments in reducing the concentration of artificially inoculated Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica, and Shigella flexneri, and inherent microbiota on parsley leaves. The secondary objective was to study the effects of X-ray treatments on color and texture parameters on treated parsley leaves. The Dip-inoculated method was used to inoculate parsley leaves with a mixture of two or three strains of each tested organism at 10(8) to 10(9) colony-forming unit (CFU)/mL; the inoculated parsley leaves were then air-dried and followed by treatment with different doses of X-ray (0, 0.1, 0.5, 1.0, and 1.5 kGy) at 22°C and 55-60% relative humidity. Surviving bacterial populations on parsley leaves were evaluated using a nonselective medium (tryptic soy agar) with a selective medium overlay for each bacterium: E. coli O157:H7 (CT-SMAC agar), L. monocytogenes (MOA), and S. enterica and S. flexneri (XLD). Approximately 5.8, 3.1, 5.7, and 5.2 log CFU reductions of E. coli O157:H7, L. monocytogenes, S. enterica, and Shigella flexneri were achieved by treatment with 1.0 kGy X-ray, respectively. Furthermore, the populations of E. coli O157:H7, L. monocytogenes, S. enterica, and Shigella flexneri were reduced to less than the detectable limit (1.0 log CFU/g) by treatment with 1.5 kGy X-ray. Treatment with 1.5 kGy X-ray significantly reduced the initial inherent microbiota on parsley leaves, and inherent levels were significantly (p 0.05) in color or texture of control and treated samples with 0.1-1.5 X-ray were observed. The results of investigation indicated that X-ray is an effective technology to eliminate E. coli O157:H7, L. monocytogenes, S. enterica, and Shigella flexneri, and to extend the shelf life of parsley leaves.

Plants status monitor: Modelling techniques and inherent benefits

International Nuclear Information System (INIS)

Breeding, R.J.; Lainoff, S.M.; Rees, D.C.; Prather, W.A.; Fickiessen, K.O.E.

1987-01-01

The Plant Status Monitor (PSM) is designed to provide plant personnel with information on the operational status of the plant and compliance with the plant technical specifications. The PSM software evaluates system models using a 'distributed processing' technique in which detailed models of individual systems are processed rather than by evaluating a single, plant-level model. In addition, development of the system models for PSM provides inherent benefits to the plant by forcing detailed reviews of the technical specifications, system design and operating procedures, and plant documentation. (orig.)

40 CFR 88.312-93 - Inherently Low-Emission Vehicle labeling.

Science.gov (United States)

2010-07-01

... stroke width not less than 0.5 inches (1.3 centimeters). In addition, the words “INHERENTLY LOW-EMISSION..., the words “CLEAN AIR VEHICLE” must be present in lettering no smaller than 0.8 inches (2.0 centimeters... loan to someone who has not demonstrated eligibility for expanded TCMs available to ILEVs according to...

Department of Energy's Advanced Test Reactor (ATR), July 14--18, 1980: An independent on-site safety review

International Nuclear Information System (INIS)

1981-02-01

The intent of this review was not to conduct a detailed in-depth audit, but rather to make a broad management assessment of ATR operations. The results of the review should only be considered as having identified trends or indications. The Team's observations and recommendations for the most part are based upon standards used for licensed reactor facility practices. These standards form the basis for many of the comments in this report. The Team believes that a uniform minimum standard of performance should be achieved in the operation of DOE reactors. In order to assure that this is accomplished, clear standards are necessary. Consistent with the past AEC and ERDA policy, the Team has used the standards of the commercial nuclear power industry. It is recognized that this approach is conservative, in that the ATR reactor has a significantly greater degree of inherent safety (lower pressure, temperature, power, etc.) than a licensed reactor. Although the Review Team found no indications or evidence that the plant is being operated in an unsafe manner, various areas were identified where improvements are either needed or should be considered to increase the safety of reactor operations

Evaluation of common mode failure of safety functions for limiting fault events

International Nuclear Information System (INIS)

Rezendes, J.P.; Hyde, A.W.

2004-01-01

The draft U.S. Nuclear Regulatory Commission (NRC) policy on digital protection system software requires all Advanced Light Water Reactors (ALWRs) to be evaluated assuming a hypothetical common mode failure (CMF) which incapacitates the normal automatic initiation of safety functions. The System 80 + ALWR has been evaluated for such hypothetical conditions. The results show that the diverse automatic and manual protective systems in System 80 + provide ample safety performance margins relative to core coolability, offsite radiological releases. Reactor Coolant System (RCS) pressurization and containment integrity. This deterministic evaluation served to quantify the significant inherent safety margins in the System 80 + Standard Plant design even in the event of this extremely low probability scenario of a common mode failure. (author)

Inherent and antigen-induced airway hyperreactivity in NC mice

Directory of Open Access Journals (Sweden)

Tetsuto Kobayashi

1999-01-01

Full Text Available In order to clarify the airway physiology of NC mice, the following experiments were carried out. To investigate inherent airway reactivity, we compared tracheal reactivity to various chemical mediators in NC, BALB/c, C57BL/6 and A/J mice in vitro. NC mice showed significantly greater reactivity to acetylcholine than BALB/c and C57BL/6 mice and a reactivity comparable to that of A/J mice, which are known as high responders. Then, airway reactivity to acetylcholine was investigated in those strains in vivo. NC mice again showed comparable airway reactivity to that seen in A/J mice and a significantly greater reactivity than that seen in BALB/c and C57BL/6 mice. To investigate the effects of airway inflammation on airway reactivity to acetylcholine in vivo, NC and BALB/c mice were sensitized to and challenged with antigen. Sensitization to and challenge with antigen induced accumulation of inflammatory cells, especially eosinophils, in lung and increased airway reactivity in NC and BALB/c mice. These results indicate that NC mice exhibit inherent and antigen-induced airway hyperreactivity. Therefore, NC mice are a suitable strain to use in investigating the mechanisms underlying airway hyperreactivity and such studies will provide beneficial information for understanding the pathophysiology of asthma.

Sensors and actuators inherent in biological species

Science.gov (United States)

Taya, Minoru; Stahlberg, Rainer; Li, Fanghong; Zhao, Ying Joyce

2007-04-01

This paper addresses examples of sensing and active mechanisms inherent in some biological species where both plants and animals cases are discussed: mechanosensors and actuators in Venus Fly Trap and cucumber tendrils, chemosensors in insects, two cases of interactions between different kingdoms, (i) cotton plant smart defense system and (ii) bird-of-paradise flower and hamming bird interaction. All these cases lead us to recognize how energy-efficient and flexible the biological sensors and actuators are. This review reveals the importance of integration of sensing and actuation functions into an autonomous system if we make biomimetic design of a set of new autonomous systems which can sense and actuate under a number of different stimuli and threats.

Safety, security and safeguard

International Nuclear Information System (INIS)

Zakariya, Nasiru Imam; Kahn, M.T.E.

2015-01-01

Highlights: • The 3S interface in the design of PPS is hereby proposed. • The 3S synergy enhances the reduction in vulnerability and terrorism. • Highlighted were concept of detection, delay and response. - Abstract: A physical protection system (PPS) integrates people, procedures, and equipment for the protection of assets or facilities against theft, sabotage and terrorist attacks. Therefore, this paper proposes the use of a systematic and measurable approach to the design of PPS and its emphases on the concept of detection, delay and response. The proposed performance based PPS has the capability of defeating adversaries thereby achieving its targets. Therefore, timely detection of intrusion – based on the use of sensors, signal lines and alarm systems – is a major principle in the proposed system. Also the need for deterrence such as barriers in form of guards, access control, close circuit television (CCTV), strong policy and procedures, then the security culture amongst the facility workers was appropriately discussed. Since nuclear power is considered the only source that can provide large scale electricity with comparatively minimal impact on the environment, the paper also considered base guidelines for the application of PPS in any nuclear and radioactive facilities, followed with the necessity to incorporate inherent safety, security and safeguard (3S) synergy innovation in the physical protection system design and other characteristics that will enhance to reduce the vulnerability of nuclear facilities and materials to theft sabotage and terrorist attacks

Safety standards and safety record of nuclear power plants

International Nuclear Information System (INIS)

Davis, A.B.

1984-01-01

This paper focuses on the use of standards and the measurement and enforcement of these standards to achieve safe operation of nuclear power plants. Since a discussion of the safety standards that the Nuclear Regulatory Commission (NRC) uses to regulate the nuclear power industry can be a rather tedious subject, this discussion will provide you with not only a description of what safety standards are, but some examples of their application, and various indicators that provide an overall perspective on safety. These remarks are confined to the safety standards adopted by the NRC. There are other agencies such as the Environmental Protection Agency, the Occupational Safety and Health Administration, and the state regulatory agencies which impact on a nuclear power plant. The NRC has regulatory authority for the commercial use of the nuclear materials and facilities which are defined in the Atomic Energy Act of 1954 to assure that the public health and safety and national security are protected

A safety design approach for sodium cooled fast reactor core toward commercialization in Japan

International Nuclear Information System (INIS)

Kubo, Shigenobu

2012-01-01

JAEA’s safety approach for SFR core design is based on defence‐in‐depth concept, which includes DBAs and DECs (prevention and mitigation): • The reactor core is designed to have inherent reactivity feedback characteristics with negative power coefficient. • Operation temperature range is set sufficiently below the coolant boiling temperature so as to avoid coolant boiling against anticipated operational occurrences and DBAs. • If the plant state deviates from operational states, the safe reactor shutdown is achieved by automatic insertion of control rods. 2 active reactor shutdown systems are provided. • Failure of active reactor shutdown is assumed in a design extension condition . Passive shutdown capability is provided by SASS under such condition. • As a design extension condition, core disruptive accident is assumed. In order to prevent severe mechanical energy release which might cause containment function failure, core sodium void worth is limited below 6 dollars and molten fuel discharge capability is utilized by FAIDUS. (author)

Spreading the word of the concept 'inherent safety' in a general industrial setting in the Dutch province of Zeeland

NARCIS (Netherlands)

Jongen, M.J.M.; Dijkman, A.; Zwanikken, S.; Zwetsloot, G.I.J.M.; Gort, J.

2007-01-01

Recent accidents in The Netherlands in different kinds of industries, like fire works storage, catering and energy industry, triggered the Dutch government to start a national program to enhance the enforcement of industrial safety at the regional and municipal level. Stimulated by this program the

IAEA safety glossary. Terminology used in nuclear safety and radiation protection. 2007 ed

International Nuclear Information System (INIS)

2007-01-01

In developing and establishing standards of safety for protecting people and the environment from harmful effects of ionizing radiation and for the safety of facilities and activities that give rise to radiation risks, clear communication on scientific and technical concepts is essential. The principles, requirements and recommendations that are established and explained in the IAEA's safety standards and elaborated upon in other publications must be clearly expressed. To this end, this Safety Glossary defines and explains technical terms used in IAEA safety standards and other safety related publications, and provides information on their usage. The primary purpose of the Safety Glossary is to harmonize terminology and usage in the IAEA safety standards for protecting people and the environment from harmful effects of ionizing radiation, and in their application. Once definitions of terms have been established, they are, in general, intended to be observed in safety standards and other safety related publications and in the work of the IAEA Department of Nuclear Safety and Security generally. The achievement of consistently high quality in its publications contributes to the authority and credibility of the IAEA, and thus to its influence and effectiveness. High quality in publications and documents is achieved not only by review to ensure that the relevant requirements are met, but also by managing their preparation so as to achieve high quality in their drafting. The Safety Glossary provides guidance primarily for the drafters and reviewers of safety standards, including IAEA technical officers and consultants and bodies for the endorsement of safety standards. The Safety Glossary is also a source of information for users of IAEA safety standards and other safety and security related IAEA publications and for other IAEA staff - notably writers, editors, translators, revisers and interpreters. Users of the Safety Glossary, in particular drafters of national

IAEA safety glossary. Terminology used in nuclear safety and radiation protection. 2007 ed

International Nuclear Information System (INIS)

2007-06-01

In developing and establishing standards of safety for protecting people and the environment from harmful effects of ionizing radiation and for the safety of facilities and activities that give rise to radiation risks, clear communication on scientific and technical concepts is essential. The principles, requirements and recommendations that are established and explained in the IAEA's safety standards and elaborated upon in other publications must be clearly expressed. To this end, this Safety Glossary defines and explains technical terms used in IAEA safety standards and other safety related publications, and provides information on their usage. The primary purpose of the Safety Glossary is to harmonize terminology and usage in the IAEA safety standards for protecting people and the environment from harmful effects of ionizing radiation, and in their application. Once definitions of terms have been established, they are, in general, intended to be observed in safety standards and other safety related publications and in the work of the IAEA Department of Nuclear Safety and Security generally. The achievement of consistently high quality in its publications contributes to the authority and credibility of the IAEA, and thus to its influence and effectiveness. High quality in publications and documents is achieved not only by review to ensure that the relevant requirements are met, but also by managing their preparation so as to achieve high quality in their drafting. The Safety Glossary provides guidance primarily for the drafters and reviewers of safety standards, including IAEA technical officers and consultants and bodies for the endorsement of safety standards. The Safety Glossary is also a source of information for users of IAEA safety standards and other safety and security related IAEA publications and for other IAEA staff - notably writers, editors, translators, revisers and interpreters. Users of the Safety Glossary, in particular drafters of national

IAEA safety glossary. Terminology used in nuclear safety and radiation protection. 2007 ed

International Nuclear Information System (INIS)

2007-01-01

In developing and establishing standards of safety for protecting people and the environment from harmful effects of ionizing radiation and for the safety of facilities and activities that give rise to radiation risks, clear communication on scientific and technical concepts is essential. The principles, requirements and recommendations that are established and explained in the IAA's safety standards and elaborated upon in other publications must be clearly expressed. To this end, this Safety Glossary defines and explains technical terms used in IAEA safety standards and other safety related publications, and provides information on their usage. The primary purpose of the Safety Glossary is to harmonize terminology and usage in the IAEA safety standards for protecting people and the environment from harmful effects of ionizing radiation, and in their application. Once definitions of terms have been established, they are, in general, intended to be observed in safety standards and other safety related publications and in the work of the IAEA Department of Nuclear Safety and Security generally. The achievement of consistently high quality in its publications contributes to the authority and credibility of the IAEA, and thus to its influence and effectiveness. High quality in publications and documents is achieved not only by review to ensure that the relevant requirements are met, but also by managing their preparation so as to achieve high quality in their drafting. The Safety Glossary provides guidance primarily for the drafters and reviewers of safety standards, including IAEA technical officers and consultants and bodies for the endorsement of safety standards. The Safety Glossary is also a source of information for users of IAEA safety standards and other safety and security related IAEA publications and for other IAEA staff - notably writers, editors, translators, revisers and interpreters. Users of the Safety Glossary, in particular drafters of national

"Racialised Facilitative Capital" and the Paving of Differential Paths to Achievement of Afro-Trinidadian Boys

Science.gov (United States)

Rampersad, Ravi

2014-01-01

Bourdieu describes capital as the political building blocks of social order that give meaning to social accumulation and consumption. Through a combination of Bourdieu's sociology and critical race theory, this sojourn into Afro-Trinidadian boys' achievement seeks to elucidate an approach to understanding capital as inherently raced. This is…

"A Fiber Optic Ethernet With Inherent Migration Capability To FDDI"

Science.gov (United States)

Ferris, Kenneth D.; Chan, Tammy S.

1988-12-01

A Local Area Network (LAN) designed to a standard commercial interface, the Institute of Electrical and Electronics Engineers (IEEE) 802.3 or Ethernet, has been developed using fiber optics as the physical medium. The LAN, WhisperNet, operates in an active ring and thus has an inherent low cost migration path to a Fiber Distributed Data Interface (FDDI) implementation.

Developing an integrated dam safety program

International Nuclear Information System (INIS)

Nielsen, N. M.; Lampa, J.

1996-01-01

An effort has been made to demonstrate that dam safety is an integral part of asset management which, when properly done, ensures that all objectives relating to safety and compliance, profitability, stakeholders' expectations and customer satisfaction, are achieved. The means to achieving this integration of the dam safety program and the level of effort required for each core function have been identified using the risk management approach to pinpoint vulnerabilities, and subsequently to focus priorities. The process is considered appropriate for any combination of numbers, sizes and uses of dams, and is designed to prevent exposure to unacceptable risks. 5 refs., 1 tab

A Public-Private Consortium Advances Cardiac Safety Evaluation: Achievements of the HESI Cardiac Safety Technical Committee

Science.gov (United States)

The evaluation of cardiovascular side-effects is a critical element in the development of all new drugs and chemicals. Cardiac safety issues have been and continue to be a major cause of attrition and withdrawal due to Adverse Drug Reactions (ADRs) in pharmaceutical drug developm...

Advancements in the design of safety-related systems and components of the MARS nuclear plant

International Nuclear Information System (INIS)

Caira, M.; Caruso, G.; Naviglio, A.; Sorabella, L.; Farello, C.E.

1992-01-01

In the paper, the advancements in the design of safety-related systems and components of the MARS nuclear plant, equipped with a 600 MW th PWR, are described. These advancements are due to the special safety features of this plant, which relies completely on inherent and passive safety. In particular, the new steps of the design of the innovative, completely passive, and with an unlimited autonomy Emergency core Cooling System are described, together with the characteristics of the last version of the steam generator, developed in a new design involving disconnecting components, for a fast erection and an easy maintenance. (author)

Investigation on regulatory requirements for radiation safety management

International Nuclear Information System (INIS)

Han, Eun Ok; Choi, Yoon Seok; Cho, Dae Hyung

2013-01-01

NRC recognizes that efficient management of radiation safety plan is an important factor to achieve radiation safety service. In case of Korea, the contents to perform the actual radiation safety management are legally contained in radiation safety management reports based on the Nuclear Safety Act. It is to prioritize the importance of safety regulations in each sector in accordance with the current situation of radiation and radioactive isotopes-used industry and to provide a basis for deriving safety requirements and safety regulations system maintenance by the priority of radiation safety management regulations. It would be helpful to achieve regulations to conform to reality based on international standards if consistent safety requirements is developed for domestic users, national standards and international standards on the basis of the results of questions answered by radiation safety managers, who lead on-site radiation safety management, about the priority of important factors in radioactive sources use, sales, production, moving user companies, to check whether derived configuration requirements for radiation safety management are suitable for domestic status

Risk-based approach to long-term safety assessment for near surface disposal of radioactive waste in Korea

International Nuclear Information System (INIS)

Jeong, C.W.; Kim, K.I.; Lee, J.I.

2000-01-01

This paper presents the Korean regulatory approach to safety assessment consistent with probabilistic, risk-based long-term safety requirements for near surface disposal facilities. The approach is based on: (1) From the standpoint of risk limitation, normal processes and probabilistic disruptive events should be integrated in a similar manner in terms of potential exposures; and (2) The uncertainties inherent in the safety assessment should be reduced using appropriate exposure scenarios. In addition, this paper emphasizes the necessity of international guidance for quantifying potential exposures and the corresponding risks from radioactive waste disposal. (author)

Nuclear safety guide: TID--7016, Revision 2

International Nuclear Information System (INIS)

Thomas, J.T.

1978-01-01

The Nuclear Safety Guide was first issued in 1956 as classified AEC report LA-2063 and was reprinted the next year, unclassified, as TID-7016. Revision 1, published in 1961, extended the scope and refined the guiding information. Revision 2 of the Guide differs significantly from its predecessor in that the latter was intentionally conservative in its recommendations. Firmly based on experimental evidence of criticality, the original Guide and the first revision were considered to be of most value to organizations whose activities with fissionable materials were not extensive and, secondarily, that it would serve as a point of departure for members of established nuclear safety teams experienced in the field. The advance of calculational capability has permitted validated calculations to extend and substitute for experimental data. The broadened data base has enabled better interpolation, extension, and understanding of available information, especially in areas previously addressed by undefined but adequate factors of safety. The content has been thereby enriched in qualitative guidance. The information inherently contains, and the user can recapture, the quantitative guidance characteristic of the former Guides by employing appropriate safety factors

The role of health and safety experts in the management of hazardous and toxic wastes in Indonesia

Science.gov (United States)

Supriyadi; Hadiyanto

2018-02-01

Occupational Safety and Health Experts in Indonesia have an important role in integrating environmental health and safety factors, including in this regard as human resources assigned to undertake hazardous waste management. Comprehensive knowledge and competence skills need to be carried out responsibly, as an inherent professional occupational safety and health profession. Management leaders should continue to provide training in external agencies responsible for science in the management of toxic waste to enable occupational safety and health experts to improve their performance in the hierarchy of control over the presence of hazardous materials. This paper provides an overview of what strategies and competencies the Occupational Safety and Health expert needs to have in embracing hazardous waste management practices.

Deliberate practice theory: perceived relevance, effort, and inherent enjoyment of music practice: study II.

Science.gov (United States)

Hyllegard, Randy; Bories, Tamara L

2009-10-01

This study, based on the theory of deliberate practice, examined the practice relevance, effort, and inherent enjoyment aspects of the theory. 25 college undergraduates practiced playing a melody on an electronic keyboard for three 20-min. practice sessions. Following each session, the perceived relevance of the practice for improving performance of the melody, the effort needed to learn the melody, and the inherent enjoyment of the practice were each rated on 10-point scales. Findings were consistent with theory and similar to previous studies also involving music practice and other tasks.

Safety research in nuclear fuel cycle at PNC

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

This report collects the results of safety research in nuclear fuel cycle at Power Reactor and Nuclear Fuel Development Corporation, in order to answer to the Questionnaire of OECD/NEA. The Questionnaire request to include information concerning to research topic, description, main results (if available), reference documents, research institutes involved, sponsoring organization and other pertinent information about followings: a) Recently completed research projects. b) Ongoing (current) research projects. Achievements on following items are omitted by the request of OECD/NEA, uranium mining and milling, uranium refining and conversion to UF{sub 6}, uranium enrichment, fuel manufacturers, spent fuel storage, radioactive waste management, transport of radioactive materials, decommissioning. We select topics from the fields of a) nuclear installation, b) seismic, and c) PSA, in projects from frame of annual safety research plan for nuclear installations established by Nuclear Safety Commission. We apply for the above a) and b) projects as follows: a) Achievements in Safety Research, fiscal 1991-1995, b) fiscal 1996 Safety Research Achievements: Progress. (author)

Safety research in nuclear fuel cycle at PNC

International Nuclear Information System (INIS)

1998-09-01

This report collects the results of safety research in nuclear fuel cycle at Power Reactor and Nuclear Fuel Development Corporation, in order to answer to the Questionnaire of OECD/NEA. The Questionnaire request to include information concerning to research topic, description, main results (if available), reference documents, research institutes involved, sponsoring organization and other pertinent information about followings: a) Recently completed research projects. b) Ongoing (current) research projects. Achievements on following items are omitted by the request of OECD/NEA, uranium mining and milling, uranium refining and conversion to UF 6 , uranium enrichment, fuel manufacturers, spent fuel storage, radioactive waste management, transport of radioactive materials, decommissioning. We select topics from the fields of a) nuclear installation, b) seismic, and c) PSA, in projects from frame of annual safety research plan for nuclear installations established by Nuclear Safety Commission. We apply for the above a) and b) projects as follows: a) Achievements in Safety Research, fiscal 1991-1995, b) fiscal 1996 Safety Research Achievements: Progress. (author)

Manson Chicks and Microskirted Cuties : Pornification in Thomas Pynchon's Inherent Vice

NARCIS (Netherlands)

Cook, S.J.|info:eu-repo/dai/nl/411939432

2015-01-01

Many sexual encounters in Thomas Pynchon’s fiction have occurred beyond the mainstream, generating theatres of perversity which dramatise the death wish and enact power relations from wider arenas. However, in Inherent Vice they change in nature. With the exception of scenes which use Charles Manson

Strengthening the Global Nuclear Safety Regime. INSAG-21. A report by the International Nuclear Safety Group

International Nuclear Information System (INIS)

2014-01-01

The Global Nuclear Safety Regime is the framework for achieving the worldwide implementation of a high level of safety at nuclear installations. Its core is the activities undertaken by each country to ensure the safety and security of the nuclear installations within its jurisdiction. But national efforts are and should be augmented by the activities of a variety of international enterprises that facilitate nuclear safety - intergovernmental organizations, multinational networks among operators, multinational networks among regulators, the international nuclear industry, multinational networks among scientists, international standards setting organizations and other stakeholders such as the public, news media and non-governmental organizations (NGOs) that are engaged in nuclear safety. All of these efforts should be harnessed to enhance the achievement of safety. The existing Global Nuclear Safety Regime is functioning at an effective level today. But its impact on improving safety could be enhanced by pursuing some measured change. This report recommends action in the following areas: - Enhanced use of the review meetings of the Convention on Nuclear Safety as a vehicle for open and critical peer review and a source for learning about the best safety practices of others; - Enhanced utilization of IAEA Safety Standards for the harmonization of national safety regulations, to the extent feasible; - Enhanced exchange of operating experience for improving operating and regulatory practices; and - Multinational cooperation in the safety review of new nuclear power plant designs. These actions, which are described more fully in this report, should serve to enhance the effectiveness of the Global Nuclear Safety Regime

A simplified analysis of uncertainty propagation in inherently controlled ATWS events

International Nuclear Information System (INIS)

Wade, D.C.

1987-01-01

The quasi static approach can be used to provide useful insight concerning the propagation of uncertainties in the inherent response to ATWS events. At issue is how uncertainties in the reactivity coefficients and in the thermal-hydraulics and materials properties propagate to yield uncertainties in the asymptotic temperatures attained upon inherent shutdown. The basic notion to be quantified is that many of the same physical phenomena contribute to both the reactivity increase of power reduction and the reactivity decrease of core temperature rise. Since these reactivities cancel by definition, a good deal of uncertainty cancellation must also occur of necessity. For example, if the Doppler coefficient is overpredicted, too large a positive reactivity insertion is predicted upon power reduction and collapse of the ΔT across the fuel pin. However, too large a negative reactivity is also predicted upon the compensating increase in the isothermal core average temperature - which includes the fuel Doppler effect

Magnetic latch trigger for inherent shutdown assembly

International Nuclear Information System (INIS)

Sowa, E.S.

1976-01-01

An inherent shutdown assembly for a nuclear reactor is provided. A neutron absorber is held ready to be inserted into the reactor core by a magnetic latch. The latch includes a magnet whose lines of force are linked by a yoke of material whose Curie point is at the critical temperature of the reactor at which the neutron absorber is to be inserted into the reactor core. The yoke is in contact with the core coolant or fissionable material so that when the coolant or the fissionable material increase in temperature above the Curie point the yoke loses its magnetic susceptibility and the magnetic link is broken, thereby causing the absorber to be released into the reactor core. 6 claims, 3 figures

Evaluation of Patient Safety Culture and Organizational Culture as a Step in Patient Safety Improvement in a Hospital in Jakarta, Indonesia

Directory of Open Access Journals (Sweden)

Afrisya Iriviranty

2016-07-01

Full Text Available Introduction: Establishment of patient safety culture is the first step in the improvement of patient safety. As such, assessment of patient safety culture in hospitals is of paramount importance. Patient safety culture is an inherent component of organizational culture, so that the study of organizational culture is required in developing patient safety. This study aimed to evaluate patient safety culture among the clinical staff of a hospital in Jakarta, Indonesia and identify organizational culture profile. Materials and Methods: This cross-sectional, descriptive, qualitative study was conducted in a hospital in Jakarta, Indonesia in 2014. Sample population consisted of nurses, midwives, physicians, pediatricians, obstetrics and gynecology specialists, laboratory personnel, and pharmacy staff (n=152. Data were collected using the Hospital Survey on Patient Safety Culture developed by the Agency for Healthcare Research and Quality (AHRQ and Organizational Culture Assessment Instrument (OCAI. Results: Teamwork within units” was the strongest dimension of patient safety culture (91.7%, while “staffing” and “non-punitive response to error” were the weakest dimensions (22.7%. Moreover, clan culture was the most dominant type of organizational culture in the studied hospital. This culture serves as a guide for the changes in the healthcare organization, especially in the development of patient safety culture. Conclusion: According to the results of this study, healthcare providers were positively inclined toward the patient safety culture within the organization. As such, the action plan was designed through consensus decision-making and deemed effective in articulating patient safety in the vision and mission of the organization.

Preliminary safety design analysis of KALIMER

Energy Technology Data Exchange (ETDEWEB)

Suk, Soo Dong; Kwon, Y. M.; Kim, K. D. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-03-01

The national long-term R and D program updated in 1997 requires Korea Atomic Energy Research Institute(KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor (KALIMER), along with supporting R and D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 MWe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self consistent design meeting a set of the major safety design requirements for accident prevention. Some of current emphasis include those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve supporting R and D programs of substance. This document first introduces a set of safety design requirements and accident evaluation criteria established for the conceptual design of KALIMER and then summarizes some of the preliminary results of engineering and design analyses performed for the safety of KALIMER. 19 refs., 19 figs., 6 tabs. (Author)

Nuclear safety in France

International Nuclear Information System (INIS)

Tanguy, P.

1979-01-01

A brief description of the main safety aspects of the French nuclear energy programme and of the general safety organization is followed by a discussion on the current thinking in CEA on some important safety issues. As far as methodology is concerned, the use of probabilistic analysis in the licensing procedure is being extensively developed. Reactor safety research is aimed at a better knowledge of the safety margins involved in the present designs of both PWRs and LMFBRs. A greater emphasis should be put during the next years in the safety of the nuclear fuel cycle installations, including waste disposals. Finally, it is suggested that further international cooperation in the field of nuclear safety should be developed in order to insure for all countries the very high safety level which has been achieved up till now. (author)

Safety related terms for advanced nuclear plants; Terminos relacionados con la seguridad para centrales nucleares avanzadas

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

The terms considered in this document are in widespread current use without a universal consensus as to their meaning. Other safety related terms are already defined in national or international codes and standards as well as in IAEA's Nuclear Safety Standards Series. Most of the terms in those codes and standards have been defined and used for regulatory purposes, generally for application to present reactor designs. There is no intention to duplicate the description of such regulatory terms here, but only to clarify the terms used for advanced nuclear plants. The following terms are described in this paper: Inherent safety characteristics, passive component, active component, passive systems, active system, fail-safe, grace period, foolproof, fault-/error-tolerant, simplified safety system, transparent safety.

Safety logic systems of PFBR

International Nuclear Information System (INIS)

Sambasivan, S. Ilango

2004-01-01

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

Safety demonstration test (SR-1/S1C-1) plan of HTTR (Contract research)

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Shigeaki; Sakaba, Nariaki; Takada, Eiji; Tachibana, Yukio; Saito, Kenji; Furusawa, Takayuki; Sawa, Kazuhiro [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

2003-03-01

Safety demonstration tests in the HTTR (High Temperature Engineering Test Reactor) will be carried out in order to verify inherent safety features of the HTGR (High Temperature Gas-cooled Reactor). The first phase of the safety demonstration tests includes the reactivity insertion test by the control rod withdrawal and the coolant flow reduction test by the circulator trip. In the second phase, accident simulation tests will be conducted. By comparison of their experimental and analytical results, the prediction capability of the safety evaluation codes such as the core and the plant dynamics codes will be improved and verified, which will contribute to establish the safety design and the safety evaluation technologies of the HTGRs. The results obtained through its safety demonstration tests will be also utilised for the establishment of the safety design guideline, the safety evaluation guideline, etc. This paper describes the test program of the overall safety demonstration tests and the test method, the test conditions and the results of the pre-test analysis of the reactivity insertion test and the partial gas circulator trip test planned in March 2003. (author)

Drug policy in sport: hidden assumptions and inherent contradictions.

Science.gov (United States)

Smith, Aaron C T; Stewart, Bob

2008-03-01

This paper considers the assumptions underpinning the current drugs-in-sport policy arrangements. We examine the assumptions and contradictions inherent in the policy approach, paying particular attention to the evidence that supports different policy arrangements. We find that the current anti-doping policy of the World Anti-Doping Agency (WADA) contains inconsistencies and ambiguities. WADA's policy position is predicated upon four fundamental principles; first, the need for sport to set a good example; secondly, the necessity of ensuring a level playing field; thirdly, the responsibility to protect the health of athletes; and fourthly, the importance of preserving the integrity of sport. A review of the evidence, however, suggests that sport is a problematic institution when it comes to setting a good example for the rest of society. Neither is it clear that sport has an inherent or essential integrity that can only be sustained through regulation. Furthermore, it is doubtful that WADA's anti-doping policy is effective in maintaining a level playing field, or is the best means of protecting the health of athletes. The WADA anti-doping policy is based too heavily on principals of minimising drug use, and gives insufficient weight to the minimisation of drug-related harms. As a result drug-related harms are being poorly managed in sport. We argue that anti-doping policy in sport would benefit from placing greater emphasis on a harm minimisation model.

A case for inherent geometric and geodetic accuracy in remotely sensed VNIR and SWIR imaging products

Science.gov (United States)

Driver, J. M.

1982-01-01

Significant aberrations can occur in acquired images which, unless compensated on board the spacecraft, can seriously impair throughput and timeliness for typical Earth observation missions. Conceptual compensations options are advanced to enable acquisition of images with inherent geometric and geodetic accuracy. Research needs are identified which, when implemented, can provide inherently accurate images. Agressive pursuit of these research needs is recommended.

The Inherent Politics of Managing the Quality of Urban Green Spaces

DEFF Research Database (Denmark)

Lindholst, Christian; Sullivan, Sidney George; Konijnendijk van den Bosch, Cecil C.

2015-01-01

of such ‘inherent politics’ through a case study of a widespread approach to operationalizing quality in urban green space management. We conclude that adoption of any quality model has both limiting and enabling implications for public participation and decision-making and that a critical stance is needed within...

Evaluation of proposed German safety criteria for high-temperature gas-cooled reactors

International Nuclear Information System (INIS)

Barsell, A.W.

1980-05-01

This work reviews proposed safety criteria prepared by the German Bundesministerium des Innern (BMI) for future licensing of gas-cooled high-temperature reactor (HTR) concepts in the Federal Republic of Germany. Comparison is made with US General Design Criteria (GDCs) in 10CFR50 Appendix A and with German light water reactor (LWR) criteria. Implications for the HTR design relative to the US design and safety approach are indicated. Both inherent characteristics and design features of the steam cycle, gas turbine, and process heat concepts are taken into account as well as generic design options such as a pebble bed or prismatic core

Nuclear safety guide TID-7016 Revision 2

International Nuclear Information System (INIS)

Thomas, J.T.

1980-01-01

The present revision of TID-7016 Nuclear Safety Guide is discussed. This Guide differs significantly from its predecessor in that the latter was intentionally conservative in its recommendations. Firmly based on experimental evidence of criticality, the original Guide and the first revision were considered to be of most value to organizations whose activities with fissionable materials were not extensive and, secondarily, that it would serve as a point of departure for members of established nuclear safety teams, experienced in the field. The reader will find a significant change in the character of information presented in this version. Nuclear Criticality Safety has matured in the past twelve years. The advance of calculational capability has permitted validated calculations to extend and substitute for experimental data. The broadened data base has enabled better interpolation, extension, and understanding of available, information, especially in areas previously addressed by undefined but adequate factors of safety. The content has been thereby enriched in qualitative guidance. The information inherently contains, and the user can recapture, the quantitative guidance characteristic of the former Guides by employing appropriate safety factors. In fact, it becomes incumbent on the Criticality Safety Specialist to necessarily impose safety factors consistent with the possible normal and abnormal credible contingencies of an operation as revealed by his evaluation. In its present form the Guide easily becomes a suitable module in any compendium or handbook tailored for internal use by organizations. It is hoped the Guide will continue to serve immediate needs and will encourage continuing and more comprehensive efforts toward organizing nuclear criticality safety information

Conceptual Grounds of Navigation Safety

Directory of Open Access Journals (Sweden)

Vladimir Torskiy

2016-04-01

Full Text Available The most important global problem being solved by the whole world community nowadays is to provide sustainable mankind development. Recent research in the field of sustainable development states that civilization safety is impossible without transfer sustainable development. At the same time, sustainable development (i.e. preservation of human culture and biosphere is impossible as a system that serves to meet economical, cultural, scientific, recreational and other human needs without safety. Safety plays an important role in sustainable development goals achievement. An essential condition of effective navigation functioning is to provide its safety. The “prescriptive” approach to the navigation safety, which is currently used in the world maritime field, is based on long-term experience and ship accidents investigation results. Thus this approach acted as an the great fact in reduction of number of accidents at sea. Having adopted the International Safety Management Code all the activities connected with navigation safety problems solution were transferred to the higher qualitative level. Search and development of new approaches and methods of ship accidents prevention during their operation have obtained greater importance. However, the maritime safety concept (i.e. the different points on ways, means and methods that should be used to achieve this goal hasn't been formed and described yet. The article contains a brief review of the main provisions of Navigation Safety Conceptions, which contribute to the number of accidents and incidents at sea reduction.