The role of passive and inherent safety properties in Siemens/KWU nuclear power plants

International Nuclear Information System (INIS)

Gremm, O.

1990-01-01

In Siemens/KWU Nuclear Power Plants the applied safety concept consist of a well balanced combination of active, passive use well is inherent safety measures. In principle it is not possible to realise a safety concept exclusively with inherent and/or passive safety properties. The respective measures and arguments will be explained in detail in the presentation. In addition the Siemens/KWU safety concept with examples of the role of inherent and passive safety measures will be illustrated. (author). 9 refs, 9 figs

Passive and inherent safety technologies for light-water nuclear reactors

International Nuclear Information System (INIS)

Forsberg, C.W.

1990-07-01

Passive/inherent safety implies a technical revolution in our approach to nuclear power safety. This direction is discussed herein for light-water reactors (LWRs) -- the predominant type of power reactor used in the world today. At Oak Ridge National Laboratory (ORNL) the approach to the development of passive/inherent safety for LWRs consists of four steps: identify and quantify safety requirements and goals; identify and quantify the technical functional requirements needed for safety; identify, invent, develop, and quantify technical options that meet both of the above requirements; and integrate safety systems into designs of economic and reliable nuclear power plants. Significant progress has been achieved in the first three steps of this program. The last step involves primarily the reactor vendors. These activities, as well as related activities worldwide, are described here. 27 refs., 7 tabs

Safety assessment in plant layout design using indexing approach: implementing inherent safety perspective. Part 1 - guideword applicability and method description.

Science.gov (United States)

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

2008-12-15

Layout planning plays a key role in the inherent safety performance of process plants since this design feature controls the possibility of accidental chain-events and the magnitude of possible consequences. A lack of suitable methods to promote the effective implementation of inherent safety in layout design calls for the development of new techniques and methods. In the present paper, a safety assessment approach suitable for layout design in the critical early phase is proposed. The concept of inherent safety is implemented within this safety assessment; the approach is based on an integrated assessment of inherent safety guideword applicability within the constraints typically present in layout design. Application of these guidewords is evaluated along with unit hazards and control devices to quantitatively map the safety performance of different layout options. Moreover, the economic aspects related to safety and inherent safety are evaluated by the method. Specific sub-indices are developed within the integrated safety assessment system to analyze and quantify the hazard related to domino effects. The proposed approach is quick in application, auditable and shares a common framework applicable in other phases of the design lifecycle (e.g. process design). The present work is divided in two parts: Part 1 (current paper) presents the application of inherent safety guidelines in layout design and the index method for safety assessment; Part 2 (accompanying paper) describes the domino hazard sub-index and demonstrates the proposed approach with a case study, thus evidencing the introduction of inherent safety features in layout design.

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)

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)

Developing a model for hospital inherent safety assessment: Conceptualization and validation.

Science.gov (United States)

Yari, Saeed; Akbari, Hesam; Gholami Fesharaki, Mohammad; Khosravizadeh, Omid; Ghasemi, Mohammad; Barsam, Yalda; Akbari, Hamed

2018-01-01

Paying attention to the safety of hospitals, as the most crucial institute for providing medical and health services wherein a bundle of facilities, equipment, and human resource exist, is of significant importance. The present research aims at developing a model for assessing hospitals' safety based on principles of inherent safety design. Face validity (30 experts), content validity (20 experts), construct validity (268 examples), convergent validity, and divergent validity have been employed to validate the prepared questionnaire; and the items analysis, the Cronbach's alpha test, ICC test (to measure reliability of the test), composite reliability coefficient have been used to measure primary reliability. The relationship between variables and factors has been confirmed at 0.05 significance level by conducting confirmatory factor analysis (CFA) and structural equations modeling (SEM) technique with the use of Smart-PLS. R-square and load factors values, which were higher than 0.67 and 0.300 respectively, indicated the strong fit. Moderation (0.970), simplification (0.959), substitution (0.943), and minimization (0.5008) have had the most weights in determining the inherent safety of hospital respectively. Moderation, simplification, and substitution, among the other dimensions, have more weight on the inherent safety, while minimization has the less weight, which could be due do its definition as to minimize the risk.

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

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)

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

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

The minimum attention plant inherent safety through LWR simplification

International Nuclear Information System (INIS)

Turk, R.S.; Matzie, R.A.

1987-01-01

The Minimum Attention Plant (MAP) is a unique small LWR that achieves greater inherent safety, improved operability, and reduced costs through design simplification. The MAP is a self-pressurized, indirect-cycle light water reactor with full natural circulation primary coolant flow and multiple once-through steam generators located within the reactor vessel. A fundamental tenent of the MAP design is its complete reliance on existing LWR technology. This reliance on conventional technology provides an extensive experience base which gives confidence in judging the safety and performance aspects of the design

Inherent safety features in balance-of-plant layout

International Nuclear Information System (INIS)

Wattelet, P.L.; Green, K.J.

1992-01-01

Future nuclear units must be more economical to construct and operate, and, at the same time, clearly incorporate advances in safety over the current generation of light water reactors. To achieve these goals, the root causes of safety issues must be addressed. In this way, global, cost-effective solutions can be implemented. With simple, direct design approaches, the licensing risk is minimized and configuration control is enhanced. With proper planning in the early stages of plant design, postulated accidents and events can often be mitigated by passive features inherent in the basic structure and layout, eliminating expensive added protective structures and components often found in current designs. Korea Electric Power Corporation's Yonggwang (YGN) Units 3 and 4, shown in an artist's rendering in Figure 1, are now under construction in Korea. Engineering is more than 85% complete, and Unit 3 construction is more than 50% complete. Significant steps toward design simplification and safety enhancement have been made by addressing safety concerns very early in the design effort. The tools used to achieve this were improved symmetry and separation, isolation of potential hazards, and an improved design process

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)

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.

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

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)

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

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.)

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.).

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

Approaches to achieving inherently safe fusion power plants

International Nuclear Information System (INIS)

Piet, S.J.

1986-01-01

Achieving inherently safe fusion facilities and conceptual designs is a challenge to the fusion community. Success should provide fusion with important competitive advantages versus other energy technologies. Inherent safety should mean a facility designed with passive safety features such that the public is protected from any acute fatalities under all credible accidental circumstances. A key aspect to inherent safety is demonstrability - the ability to prove that a deign is as safe as claimed. Three complementary approaches to achieving inherent safety are examined: toxin inventory reduction, energy source reduction and design fault tolerance. Four levels of assurance are defined, associated with uncertainty in the words ''credible' and ''demonstrable.'' Sound reasons exist for believing that inherent safety puts a modest upper bound on all accident consequences; it should be considered a part of the collection of safety and environmental issues, which also include lower consequence accidents, waste management, and effluent control

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

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.

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)

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)

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

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.

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

Coupled neutronics/thermal-hydraulics and safety characteristics of liquid-fueled molten salt reactors

International Nuclear Information System (INIS)

Qiu, Suizheng; Zhang, Dalin; Liu, Minghao; Liu, Limin; Xu, Rongshuan; Gong, Cheng; Su, Guanghui

2016-01-01

Molten salt reactor (MSR) as one candidate of the Generation IV advanced nuclear power systems is attracted more attention in China due to its top ranked fuel cycle and thorium utilization. The MSRs are characterized by using liquid-fuel, which offers complicated coupling problem of neutronics and thermal hydraulics. In this paper, the fundamental model and numerical method are established to calculate and analyze the safety characteristics for liquid-fuel MSRs. The theories and methodologies are applied to the MOSART concept. The liquid-fuel flow effects on neutronics, reactivity coefficients and three operation parameters' influences at steady state are obtained, which provide the basic information for safety analysis. The unprotected loss of flow transient is calculated, the results of which shows the inherent safety characteristics of MOSART due to its strong negative reactivity feedbacks.

Coupled neutronics/thermal-hydraulics and safety characteristics of liquid-fueled molten salt reactors

Energy Technology Data Exchange (ETDEWEB)

Qiu, Suizheng; Zhang, Dalin; Liu, Minghao; Liu, Limin; Xu, Rongshuan; Gong, Cheng; Su, Guanghui [Xi' an Jiaotong Univ. (China). State Key Laboratory of Multiphase Flow in Power Engineering

2016-05-15

Molten salt reactor (MSR) as one candidate of the Generation IV advanced nuclear power systems is attracted more attention in China due to its top ranked fuel cycle and thorium utilization. The MSRs are characterized by using liquid-fuel, which offers complicated coupling problem of neutronics and thermal hydraulics. In this paper, the fundamental model and numerical method are established to calculate and analyze the safety characteristics for liquid-fuel MSRs. The theories and methodologies are applied to the MOSART concept. The liquid-fuel flow effects on neutronics, reactivity coefficients and three operation parameters' influences at steady state are obtained, which provide the basic information for safety analysis. The unprotected loss of flow transient is calculated, the results of which shows the inherent safety characteristics of MOSART due to its strong negative reactivity feedbacks.

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

Overall System Description and Safety Characteristics of Prototype Gen IV Sodium Cooled Fast Reactor in Korea

Directory of Open Access Journals (Sweden)

Jaewoon Yoo

2016-10-01

Full Text Available The Prototype Gen IV sodium cooled fast reactor (PGSFR has been developed for the last 4 years, fulfilling the technology demonstration of the burning capability of transuranic elements included in light water reactor spent nuclear fuel. The PGSFR design has been focused on the robustness of safety systems by enhancing inherent safety characteristics of metal fuel and strengthening passive safety features using natural circulation and thermal expansion. The preliminary safety information document as a major outcome of the first design phase of PGSFR development was issued at the end of 2015. The project entered the second design phase at the beginning of 2016. This paper summarizes the overall structures, systems, and components of nuclear steam supply system and safety characteristics of the PGSFR. The research and development activities to demonstrate the safety performance are also briefly introduced in the paper.

Overall system description and safety characteristics of Prototype Gen IV Sodium Cooled Fast Reactor in Korea

International Nuclear Information System (INIS)

Yoo, Jae Woon; Chang, Jin Wook; Lim, Jae Yong; Cheon, Jin Sik; Lee, Tae Ho; Kim, Sung Kyun; Lee, Kwi Lim; Joo, Hyung Kook

2016-01-01

The Prototype Gen IV sodium cooled fast reactor (PGSFR) has been developed for the last 4 years, fulfilling the technology demonstration of the burning capability of transuranic elements included in light water reactor spent nuclear fuel. The PGSFR design has been focused on the robustness of safety systems by enhancing inherent safety characteristics of metal fuel and strengthening passive safety features using natural circulation and thermal expansion. The preliminary safety information document as a major outcome of the first design phase of PGSFR development was issued at the end of 2015. The project entered the second design phase at the beginning of 2016. This paper summarizes the overall structures, systems, and components of nuclear steam supply system and safety characteristics of the PGSFR. The research and development activities to demonstrate the safety performance are also briefly introduced in the paper

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)

Safety characteristics of the integral fast reactor concept

International Nuclear Information System (INIS)

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

1985-01-01

The Integral Fast Reactor (IFR) concept is an innovative approach to liquid metal reactor design which is being studied by Argonne National Laboratory. Two of the key features of the IFR design are a metal fuel core design, based on the fuel technology developed at EBR-II, and an integral fuel cycle with a colocated fuel cycle facility based on the compact and simplified process steps made possible by the use of metal fuel. The paper presents the safety characteristics of the IFR concept which derive from the use of metal fuel. Liquid metal reactors, because of the low pressure coolant operating far below its boiling point, the natural circulation capability, and high system heat capacities, possess a high degree of inherent safety. The use of metallic fuel allows the reactor designer to further enhance the system capability for passive accommodation of postulated accidents

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.)

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

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)

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

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

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

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

Passive safety design characteristics of the KALIMER-600 burner reactor

International Nuclear Information System (INIS)

Kwon, Young-Min; Jeong, Hae-Yong; Cho, Chung-Ho; Ha, Ki-Seok; Kim, Sang-Ji

2009-01-01

The Korea Atomic Energy Research Institute (KAERI) has recently studied several burner core designs for a transuranics (TRU) transmutation based on the breakeven core geometry of KALIMER-600. The KALIMER-600 is a net electrical rating of 600MWe, sodium-cooled, metallic-fueled, pool-type reactor. For the burner core concept selected for the present analysis, the smearing fractions of the fuel rods in three fuel zones are changed while maintaining the cladding outer diameter and cladding thickness. The resulting fuel slug smearing fractions of the inner, middle, and outer core zones are 36%, 40%, and 48%, respectively. The TRU conversion ratio is 0.57 and the TRU enrichment of the driver fuel is set to 30.0 w/o because of the current practical limitation of the U-TRU-10%Zr metal fuel database. The purpose of this paper is to evaluate the safety performance characteristics provided by the passive safety design features in the KALIMER-600 burner reactor by using a system-wide safety analysis code. The present scoping analysis focuses on an assessment of the enhanced safety design features that provide passive and self-regulating responses to transient conditions and an evaluation of the safety margin during unprotected overpower, unprotected loss of flow, and unprotected loss of heat sink events. The analysis results show that the KALIMER-600 burner reactor provides larger safety margins with respect to the sodium boiling, fuel rod integrity, and structural integrity. The overall inherent safety can be enhanced by accounting for the reactivity feedback mechanisms in the design process. (author)

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.

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)

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

Gait characteristics in women's safety shoes.

Science.gov (United States)

Goto, Kanako; Abe, Kaoru

2017-11-01

Although workers in Japan are required to wear safety footwear, there is concern about occupational accidents that occur when wearing safety shoes. This study aimed to analyze the effect of wearing hardsoled safety shoes on both spatiotemporal gait characteristics and the muscle activity in the lower extremities. Seventeen young women participated in this study. A 5-m gait trial and a surface electromyography trial were conducted while the women walked in either safety shoes or sports shoes. Paired t-tests were performed to analyze the differences in gait characteristics when walking in the two different pairs of shoes. Walking in safety shoes was associated with a significant increase in vastus lateralis, biceps femoris and tibialis anterior activity. This increased muscle activity in the lower extremities is likely compensating for the lower flexibility of the safety shoes. Copyright © 2017 Elsevier Ltd. All rights reserved.

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)

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)

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

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.

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.)

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

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

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)

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.

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

Characteristics of safety critical organizations . work psychological perspective

International Nuclear Information System (INIS)

Oedewald, P.; Reiman, T.

2006-02-01

This book deals with organizations that operate in high hazard industries, such as the nuclear power, aviation, oil and chemical industry organisations. The society puts a great strain on these organisations to rigorously manage the risks inherent in the technology they use and the products they produce. In this book, an organisational psychology view is taken to analyse what are the typical challenges of daily work in these environments. The analysis is based on a literature review about human and organisational factors in safety critical industries, and on the interviews of Finnish safety experts and safety managers from four different companies. In addition to this, personnel interviews conducted in the Finnish nuclear power plants are utilised. The authors come up with eight themes that seem to be common organizational challenges cross the industries. These include e.g. how does the personnel understand the risks and what is the right level for rules and procedures to guide the work activities. The primary aim of this book is to contribute to the Finnish nuclear safety research and safety management discussion. However, the book is equally suitable for risk management, organizational development and human resources management specialists in different industries. The purpose is to encourage readers to consider how the human and organizational factors are seen in the field they work in. (orig.)

Special characteristics of safety organizations. Work psychological perspective

Energy Technology Data Exchange (ETDEWEB)

Oedewald, P.; Reiman, T.

2007-03-15

This book deals with organizations that operate in high hazard industries, such as the nuclear power, aviation, oil and chemical industry organizations. The society puts a great strain on these organizations to rigorously manage the risks inherent in the technology they use and the products they produce. In this book, an organizational psychology view is taken to analyse what are the typical challenges of daily work in these environments. The analysis is based on a literature review about human and organizational factors in safety critical industries, and on the interviews of Finnish safety experts and safety managers from four different companies. In addition to this, personnel interviews conducted in the Finnish nuclear power plants are utilised. The authors come up with eight themes that seem to be common organizational challenges cross the industries. These include e.g. how does the personnel understand the risks and what is the right level for rules and procedures to guide the work activities. The primary aim of this book is to contribute to the nuclear safety research and safety management discussion. However, the book is equally suitable for risk management, organizational development and human resources management specialists in different industries. The purpose is to encourage readers to consider how the human and organizational factors are seen in the field they work in. (orig.)

Special characteristics of safety organizations. Work psychological perspective

International Nuclear Information System (INIS)

Oedewald, P.; Reiman, T.

2007-03-01

This book deals with organizations that operate in high hazard industries, such as the nuclear power, aviation, oil and chemical industry organizations. The society puts a great strain on these organizations to rigorously manage the risks inherent in the technology they use and the products they produce. In this book, an organizational psychology view is taken to analyse what are the typical challenges of daily work in these environments. The analysis is based on a literature review about human and organizational factors in safety critical industries, and on the interviews of Finnish safety experts and safety managers from four different companies. In addition to this, personnel interviews conducted in the Finnish nuclear power plants are utilised. The authors come up with eight themes that seem to be common organizational challenges cross the industries. These include e.g. how does the personnel understand the risks and what is the right level for rules and procedures to guide the work activities. The primary aim of this book is to contribute to the nuclear safety research and safety management discussion. However, the book is equally suitable for risk management, organizational development and human resources management specialists in different industries. The purpose is to encourage readers to consider how the human and organizational factors are seen in the field they work in. (orig.)

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...

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 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

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)

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

Expected characteristics of future reactors for human beings

International Nuclear Information System (INIS)

Taketani, Kiyoaki

1992-01-01

Based on four reactor safety components (namely: a) God-given safety, b) Equipment safety, c) Quick-response safety, d) Containing safety), categorical assessment is made of various nuclear reactor concepts ranging from present existing reactors to future reactors based on innovative reactor design. In pursuit of nuclear reactor safety, ultimate characteristics of the ideal nuclear reactor are expected to coincide with those of an inherently safe reactor. A definition of 'inherently safe' has already been proposed by a committee in Japan. As a realistic and existable reactor, which is as close to the ideal reactor, a future reactor which is almost the same as a global reactor, is proposed. This global reactor must be constructable anywhere on earth and must permit easy operation and maintenance by anyone. It is also discussed to identify what behavior is expected of the global reactor under various conditions. At the same time, this future reactor which includes the global reactor, should solve a) the nuclear fuel resource issue, b) efficient utilization of fission energy and c) environmental issues as the greenhouse effect. (author). 7 refs., 2 figs

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...

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

Special characteristics of safety critical organizations. Work psychological perspective

Energy Technology Data Exchange (ETDEWEB)

Oedewald, P.; Reiman, T.

2007-03-15

This book deals with organizations that operate in high hazard industries, such as the nuclear power, aviation, oil and chemical industry organizations. The society puts a great strain on these organizations to rigorously manage the risks inherent in the technology they use and the products they produce. In this book, an organizational psychology view is taken to analyse what are the typical challenges of daily work in these environments. The analysis is based on a literature review about human and organizational factors in safety critical industries, and on the interviews of Finnish safety experts and safety managers from four different companies. In addition to this, personnel interviews conducted in the Finnish nuclear power plants are utilised. The authors come up with eight themes that seem to be common organizational challenges cross the industries. These include e.g. how does the personnel understand the risks and what is the right level for rules and procedures to guide the work activities. The primary aim of this book is to contribute to the nuclear safety research and safety management discussion. However, the book is equally suitable for risk management, organizational development and human resources management specialists in different industries. The purpose is to encourage readers to consider how the human and organizational factors are seen in the field they work in. (orig.)

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

Safety Characteristics in System Application of Software for Human Rated Exploration Missions for the 8th IAASS Conference

Science.gov (United States)

Mango, Edward J.

2016-01-01

system will launch only one mission per year even less during its developmental phases. Finally, the third is the partnered approach through the use of many different prime contractors, including commercial and international partners, to design and build the exploration systems. These three factors make the challenges to meet the mission preparations and the safety expectations extremely difficult to implement. As NASA leads a team of partners in the exploration beyond earth's influence, it is a safety imperative that the application software used to test, checkout, prepare and launch the exploration systems put safety of the hardware and mission first. Software safety characteristics are built into the design and development process to enable the human rated systems to begin their missions safely and successfully. Exploration missions beyond Earth are inherently risky, however, with solid safety approaches in both hardware and software, the boldness of these missions can be realized for all on the home planet.

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.

Analysis of Critical Characteristics for Safety Graded Personnel Computers in the KNICS Architecture

International Nuclear Information System (INIS)

Lee, Hyun Chul; Lee, Dong Young

2009-01-01

Critical characteristics analysis of a safety related item is to identify characteristics to be verified to replace an original item with the dedicated item. It is sure that the dedicated item meeting critical characteristics would perform its intended safety function instead of the specified item. KNICS project developed two safety systems: IDiPS RPS (Reactor Protection System) and IDiPS ESF-CCS (Engineered Safety Features-Component Control System). Two safety systems of IDiPS are equipped with personnel computers, so-called COMs (Cabinet Operator Modules), in their cabinets. The personnel computers, COMs, are responsible for safety system monitoring, testing, and maintaining. Even though two safety systems are safety critical system, the personnel computers of two systems, i.e. COMs, are not graded as safety-graded items. Regulation requirements are expected to be strengthened, and the functions of the personnel computer may be enhanced to include safety-related functions and safety functions, it would be necessary that the grade of the personnel computers is adjusted to a higher level, the safety grade. To try to upgrade a non safety system, i.e. COMs, to a safety system, its safety functions and requirements, i.e. critical characteristics, must be identified and verified. This paper describes the process of the identification of critical characteristics and the results of analysis

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

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

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

Study on team characteristics influencing on nuclear safety culture in Korea based on Bayesian networks

International Nuclear Information System (INIS)

Young-gab, K.; Chan-ho, S.; Jeong-jin, P.

2014-01-01

The safety culture of Korean nuclear power plants has been settled down as an organizational culture since the Chernobyl accident in 1986. Reason (1997) proposed that safety culture is a sub-culture of corporate culture and sub-culture is a term that can be used interchangeably to a sub-group of people (i.e., department, workgroup). Therefore, the safety culture of organization comprised of various teams can be told as a culture to reflect team characteristics and interact with each other. Team characteristics have something to do with a successful task performance and task efficiency. However, the team characteristics in nuclear power plant have to consider safety preferentially rather than performance. Team characteristics for a safety are necessary to ensure and enhance the safety of safety-critical system. This paper proposed team characteristics for a safety which influence on the strong and vulnerable area of safety culture. These characteristics were analyzed on the basis of the safety culture evaluation which was performed to measure the level of plant workers' safety culture in 2013. The model of team characteristics was constructed considering Bayesian inference and the result was proposed according to workers' awareness. Safety team characteristics have a direct or indirect effect on the safety of nuclear power plants. Therefore, if they are improved and trained continuously, the safety of nuclear power plants might be enhanced. (author)

Study on team characteristics influencing on nuclear safety culture in Korea based on Bayesian networks

Energy Technology Data Exchange (ETDEWEB)

Young-gab, K.; Chan-ho, S.; Jeong-jin, P., E-mail: iamkyg@khnp.co.kr, E-mail: chsung@khnp.co.kr, E-mail: jjpark82@khnp.co.kr [Korea Hydro & Nuclear Power Co., Central Research Inst., Yuseong-gu, Daejeon (Korea, Republic of)

2014-07-01

The safety culture of Korean nuclear power plants has been settled down as an organizational culture since the Chernobyl accident in 1986. Reason (1997) proposed that safety culture is a sub-culture of corporate culture and sub-culture is a term that can be used interchangeably to a sub-group of people (i.e., department, workgroup). Therefore, the safety culture of organization comprised of various teams can be told as a culture to reflect team characteristics and interact with each other. Team characteristics have something to do with a successful task performance and task efficiency. However, the team characteristics in nuclear power plant have to consider safety preferentially rather than performance. Team characteristics for a safety are necessary to ensure and enhance the safety of safety-critical system. This paper proposed team characteristics for a safety which influence on the strong and vulnerable area of safety culture. These characteristics were analyzed on the basis of the safety culture evaluation which was performed to measure the level of plant workers' safety culture in 2013. The model of team characteristics was constructed considering Bayesian inference and the result was proposed according to workers' awareness. Safety team characteristics have a direct or indirect effect on the safety of nuclear power plants. Therefore, if they are improved and trained continuously, the safety of nuclear power plants might be enhanced. (author)

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

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

Control of Industrial Safety Based on Dynamic Characteristics of a Safety Budget-Industrial Accident Rate Model in Republic of Korea.

Science.gov (United States)

Choi, Gi Heung; Loh, Byoung Gook

2017-06-01

Despite the recent efforts to prevent industrial accidents in the Republic of Korea, the industrial accident rate has not improved much. Industrial safety policies and safety management are also known to be inefficient. This study focused on dynamic characteristics of industrial safety systems and their effects on safety performance in the Republic of Korea. Such dynamic characteristics are particularly important for restructuring of the industrial safety system. The effects of damping and elastic characteristics of the industrial safety system model on safety performance were examined and feedback control performance was explained in view of cost and benefit. The implications on safety policies of restructuring the industrial safety system were also explored. A strong correlation between the safety budget and the industrial accident rate enabled modeling of an industrial safety system with these variables as the input and the output, respectively. A more effective and efficient industrial safety system could be realized by having weaker elastic characteristics and stronger damping characteristics in it. A substantial decrease in total social cost is expected as the industrial safety system is restructured accordingly. A simple feedback control with proportional-integral action is effective in prevention of industrial accidents. Securing a lower level of elastic industrial accident-driving energy appears to have dominant effects on the control performance compared with the damping effort to dissipate such energy. More attention needs to be directed towards physical and social feedbacks that have prolonged cumulative effects. Suggestions for further improvement of the safety system including physical and social feedbacks are also made.

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

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 Characteristics in System Application Software for Human Rated Exploration

Science.gov (United States)

Mango, E. J.

2016-01-01

NASA and its industry and international partners are embarking on a bold and inspiring development effort to design and build an exploration class space system. The space system is made up of the Orion system, the Space Launch System (SLS) and the Ground Systems Development and Operations (GSDO) system. All are highly coupled together and dependent on each other for the combined safety of the space system. A key area of system safety focus needs to be in the ground and flight application software system (GFAS). In the development, certification and operations of GFAS, there are a series of safety characteristics that define the approach to ensure mission success. This paper will explore and examine the safety characteristics of the GFAS development.

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.

The assessment of technological and safety aspects of small power reactor SMART

International Nuclear Information System (INIS)

Antariksawan, A.R.; Ekariansyah, Andi S.; Sony, D.T.; Suharno; Hastowo, Hudi

2002-01-01

This paper describes and discusses the technology and safety of small nuclear power plant SMART. The reactor SMART produces 300 MWth of power is cooled and moderated with light water and integral PWR type developed by KAERI. At present, the development activities had reached the end of basic design stage. The concept design of reactor SMART is based on safety enhancement, economic competitiveness and high performance. The fuel is uranium oxide with approximately 5% w/o enrichment. The safety characteristics of the core are shown with low power density around 62.6 W/cc, high negative reactivity coefficient, and high shutdown and thermal margin. Besides the inherent safety characteristics, SMART is equipped with engineered safety features and severe accident management system which are in compliance with the IAEA recommendations. The application of SMART for dual-purpose produces 90 Mwe and 40,000 to fresh water a day. Based on the technology and core characteristics of the reactor SMART, it is very interesting to be deeply assessed

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)

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

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

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.

Street Intersection Characteristics and Their Impacts on Perceived Bicycling Safety

Science.gov (United States)

2018-01-01

Safety concern is one of the core issues that deter people from bicycling in the US. Earlier studies have explored the associations between intersection design characteristics and bicyclist safety perceptions. Research shows that there are significan...

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

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

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

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)

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.

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

Inherent Tumor Characteristics That Limit Effective and Safe Resection of Giant Nonfunctioning Pituitary Adenomas.

Science.gov (United States)

Nishioka, Hiroshi; Hara, Takayuki; Nagata, Yuichi; Fukuhara, Noriaki; Yamaguchi-Okada, Mitsuo; Yamada, Shozo

2017-10-01

Surgical treatment of giant pituitary adenomas is sometimes challenging. We present our surgical series of giant nonfunctioning adenomas to shed light on the limitations of effective and safe tumor resection. The preoperative tumor characteristics, surgical approaches, outcome, and histology of giant nonfunctioning adenoma (>40 mm) in 128 consecutive surgical patients are reviewed. The follow-up period ranged from 19 to 113 months (mean 62.2 months). A transsphenoidal approach was used in the treatment of 109 patients and a combined transsphenoidal transcranial approach in 19 patients. A total of 93 patients (72.7%) underwent total resection or subtotal resection apart from the cavernous sinus (CS). The degree of tumor resection, excluding the marked CS invasion, was lower in tumors that were larger (P = 0.0107), showed massive intracranial extension (P = 0.0352), and had an irregular configuration (P = 0.0016). Permanent surgical complications developed in 28 patients (22.0%). Long-term tumor control was achieved in all patients by single surgery, including 43 patients with adjuvant radiotherapy. Most tumors were histologically benign, with a low MIB-1 index (inherent factors that independently limit effective resection. These high-risk tumors require an individualized therapeutic strategy. Copyright © 2017 Elsevier Inc. All rights reserved.

Is embedding entailed in consumer valuation of food safety characteristics?

DEFF Research Database (Denmark)

Mørkbak, Morten Raun; Christensen, Tove; Gyrd-Hansen, Dorte

2011-01-01

Consumers' preferences for food safety characteristics are investigated with a particular focus on the existence of an embedding effect. Embedding exists if consumer valuation of food safety is insensitive to scope. We conduct between-attribute external tests for embedding in two choice experiments...

Frequency and Variance of Communication Characteristics in Aviation Safety Events

NARCIS (Netherlands)

Karanikas, Nektarios; Kaspers, Steffen

2017-01-01

In the aviation sector, communication problems have contributed into 70% to 80% of safety occurrences. However, to date we haven’t depicted which communication aspects have affected aviation safety most frequently. Based on literature, we developed a tool which includes communication characteristics

Applicaiton and characteristics of food irradiation on food safety

International Nuclear Information System (INIS)

Ha Yiming

2010-01-01

Irradiation is one of non-thermal processing technology. Physical, chemical and biology effects were induced by the interaction of ionization irradiation and materials and acting on materials or food, then, food molecular was modified by rays and the harmful substances in it degraded. Irradiation is an effective method to improve food safety and extend the shelf life of food. In the article, the status of food safety at home and abroad in recently years was summarized, and the characteristic and application areas of irradiation technology in food safety were synthetically analyzed. (author)

quality and safety characteristics of cassava crisps sold in urban

African Journals Online (AJOL)

ACSS

QUALITY AND SAFETY CHARACTERISTICS OF CASSAVA CRISPS SOLD IN. URBAN KENYA. G.O. ABONG', S.I. SHIBAIRO, ... This study sought to characterise the quality and safety in terms of cyanide levels of cassava crisps ... Crantz) to food security and incomes for rural communities in sub-Saharan Africa, cannot be.

Critical Characteristics of Radiation Detection System Components to be Dedicated for use in Safety Class and Safety Significant System

International Nuclear Information System (INIS)

DAVIS, S.J.

2000-01-01

This document identifies critical characteristics of components to be dedicated for use in Safety Significant (SS) Systems, Structures, or Components (SSCs). This document identifies the requirements for the components of the common, radiation area, monitor alarm in the WESF pool cell. These are procured as Commercial Grade Items (CGI), with the qualification testing and formal dedication to be performed at the Waste Encapsulation Storage Facility (WESF) for use in safety significant systems. System modifications are to be performed in accordance with the approved design. Components for this change are commercially available and interchangeable with the existing alarm configuration This document focuses on the operational requirements for alarm, declaration of the safety classification, identification of critical characteristics, and interpretation of requirements for procurement. Critical characteristics are identified herein and must be verified, followed by formal dedication, prior to the components being used in safety related applications

Comparative analysis of safety related site characteristics

International Nuclear Information System (INIS)

Andersson, Johan

2010-12-01

This document presents a comparative analysis of site characteristics related to long-term safety for the two candidate sites for a final repository for spent nuclear fuel in Forsmark (municipality of Oesthammar) and in Laxemar (municipality of Oskarshamn) from the point of view of site selection. The analyses are based on the updated site descriptions of Forsmark /SKB 2008a/ and Laxemar /SKB 2009a/, together with associated updated repository layouts and designs /SKB 2008b and SKB 2009b/. The basis for the comparison is thus two equally and thoroughly assessed sites. However, the analyses presented here are focussed on differences between the sites rather than evaluating them in absolute terms. The document serves as a basis for the site selection, from the perspective of long-term safety, in SKB's application for a final repository. A full evaluation of safety is made for a repository at the selected site in the safety assessment SR-Site /SKB 2011/, referred to as SR-Site main report in the following

Comparative analysis of safety related site characteristics

Energy Technology Data Exchange (ETDEWEB)

Andersson, Johan (ed.)

2010-12-15

This document presents a comparative analysis of site characteristics related to long-term safety for the two candidate sites for a final repository for spent nuclear fuel in Forsmark (municipality of Oesthammar) and in Laxemar (municipality of Oskarshamn) from the point of view of site selection. The analyses are based on the updated site descriptions of Forsmark /SKB 2008a/ and Laxemar /SKB 2009a/, together with associated updated repository layouts and designs /SKB 2008b and SKB 2009b/. The basis for the comparison is thus two equally and thoroughly assessed sites. However, the analyses presented here are focussed on differences between the sites rather than evaluating them in absolute terms. The document serves as a basis for the site selection, from the perspective of long-term safety, in SKB's application for a final repository. A full evaluation of safety is made for a repository at the selected site in the safety assessment SR-Site /SKB 2011/, referred to as SR-Site main report in the following

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)

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

Characteristics of safety critical organizations . work psychological perspective; Turvallisuuskriittisten organisaatioiden toiminnan erityispiirteet

Energy Technology Data Exchange (ETDEWEB)

Oedewald, P.; Reiman, T. [VTT, Espoo (Finland)

2006-02-15

This book deals with organizations that operate in high hazard industries, such as the nuclear power, aviation, oil and chemical industry organisations. The society puts a great strain on these organisations to rigorously manage the risks inherent in the technology they use and the products they produce. In this book, an organisational psychology view is taken to analyse what are the typical challenges of daily work in these environments. The analysis is based on a literature review about human and organisational factors in safety critical industries, and on the interviews of Finnish safety experts and safety managers from four different companies. In addition to this, personnel interviews conducted in the Finnish nuclear power plants are utilised. The authors come up with eight themes that seem to be common organizational challenges cross the industries. These include e.g. how does the personnel understand the risks and what is the right level for rules and procedures to guide the work activities. The primary aim of this book is to contribute to the Finnish nuclear safety research and safety management discussion. However, the book is equally suitable for risk management, organizational development and human resources management specialists in different industries. The purpose is to encourage readers to consider how the human and organizational factors are seen in the field they work in. (orig.)

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.

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 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)

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)

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

International Nuclear Information System (INIS)

THOMAS, R.J.

2000-01-01

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

Impact of organisational characteristics on health and safety ...

African Journals Online (AJOL)

The construction industry makes a contribution to occupational accidents and ill health records in Nigeria. This study was designed to evaluate the impact of organisational characteristics on health and safety (H&S) management practices of Nigerian small and medium-sized construction enterprises (SMEs). The study ...

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.

Working Towards Unified Safety Design Criteria for Modular High Temperature Gas-cooled Reactor Designs

International Nuclear Information System (INIS)

Reitsma, Frederik; Silady, Fred; Kunitomi, Kazuhiko

2014-01-01

The Nuclear Power Development Section of the IAEA recently received approval for a Coordinated Research Project (CRP) to investigate and make proposals on modular High Temperature Gas-cooled Reactor (HTGR) Safety design criteria. It is expected that these criteria would consider past experience and existing safety standards in the light of modular HTGR material and design characteristics to propose safety design criteria. It will consider the deterministic and risk-informed safety design standards that apply to the wide spectrum of Off- normal events under development worldwide for existing and planned HTGRs. The CRP would also take into account lessons from the Fukushima Daiichi accident, clarifying the safety approach and safety evaluation criteria for design and beyond design basis events, including those events that can affect multiple reactor modules and/or are dependent on the application proximate to the plant site. (e. g., industrial process steam/heat). The logical flow of criteria is from the fundamental inherent safety characteristics of modular HTGRs and associated expected performance characteristics, to the safety functions required to ensure those characteristics during the wide spectrum of Off-normal events, and finally to specific criteria related to those functions. This is detailed in the paper with specific examples included of how it may be applied. The results of the CRP will be made available to the member states and HTGR community. (author)

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

Job characteristics and safety climate: the role of effort-reward and demand-control-support models.

Science.gov (United States)

Phipps, Denham L; Malley, Christine; Ashcroft, Darren M

2012-07-01

While safety climate is widely recognized as a key influence on organizational safety, there remain questions about the nature of its antecedents. One potential influence on safety climate is job characteristics (that is, psychosocial features of the work environment). This study investigated the relationship between two job characteristics models--demand-control-support (Karasek & Theorell, 1990) and effort-reward imbalance (Siegrist, 1996)--and safety climate. A survey was conducted with a random sample of 860 British retail pharmacists, using the job contents questionnaire (JCQ), effort-reward imbalance indicator (ERI) and a measure of safety climate in pharmacies. Multivariate data analyses found that: (a) both models contributed to the prediction of safety climate ratings, with the demand-control-support model making the largest contribution; (b) there were some interactions between demand, control and support from the JCQ in the prediction of safety climate scores. The latter finding suggests the presence of "active learning" with respect to safety improvement in high demand, high control settings. The findings provide further insight into the ways in which job characteristics relate to safety, both individually and at an aggregated level.

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)

Safety characteristics of the US advanced liquid metal reactor core

International Nuclear Information System (INIS)

Magee, P.M.; Dubberley, A.E.; Gyorey, G.L.; Lipps, A.J.; Wu, T.

1991-01-01

The U.S. Advanced Liquid Metal Reactor (ALMR) design employs innovative, passive features to provide an unprecedented level of public safety and the ability to demonstrate this safety to the public. The key features employed in the core design to produce the desired passive safety characteristics are: a small core with a tight restraint system, the use of metallic U-Pu-Zr fuel, control rod withdrawal limiters, and gas expansion modules. In addition, the reactor vessel and closure are designed to have the capability to withstand, with large margins, the maximum possible core disruptive accident without breach and radiological release. (author)

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)

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

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...

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

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)

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...

Development of the evaluation methods in reactor safety analyses and core characteristics

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

In order to support the safety reviews by NRA on reactor safety design including the phenomena with multiple failures, the computer codes are developed and the safety evaluations with analyses are performed in the areas of thermal hydraulics and core characteristics evaluation. In the code preparation of safety analyses, the TRACE and RELAP5 code were prepared to conduct the safety analyses of LOCA and beyond design basis accidents with multiple failures. In the core physics code preparation, the functions of sensitivity and uncertainty analysis were incorporated in the lattice physics code CASMO-4. The verification of improved CASMO-4 /SIMULATE-3 was continued by using core physics data. (author)

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 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

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

Inherent overload protection for the series resonant converter

Science.gov (United States)

King, R. J.; Stuart, T. A.

1983-01-01

The overload characteristics of the full bridge series resonant power converter are considered. This includes analyses of the two most common control methods presently in use. The first of these uses a current zero crossing detector to synchronize the control signals and is referred to as the alpha controller. The second is driven by a voltage controlled oscillator and is referred to as the gamma controller. It is shown that the gamma controller has certain reliability advantages in that it can be designed with inherent short circuit protection. Experimental results are included for an 86 kHz converter using power metal-oxide-semiconductor field-effect transistors (MOSFETs).

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)

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.

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)

INFLUENCE OF PLANNING, ORGANIZATIONAL CHARACTERISTICS AND REGULATION ON ROAD TRAFFIC SAFETY OF PEDESTRIANS

Directory of Open Access Journals (Sweden)

G. M. Kuharenok

2011-01-01

Full Text Available The paper presents results of research on planning, organizational characteristics and regulation modes at  the regulated pedestrian crossings, located out of crossroads in the street and road network of Minsk. Some regularities pertaining to the influence of the investigated characteristics on road traffic safety of pedestrians are revealed in the paper. Practical offers on increase of road traffic safety of pedestrians in the Republic of Belarus have been developed on the basis of the executed investigations and cited in the paper. 

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

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

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.)

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

Safety characteristics of potential waste transmutation systems

International Nuclear Information System (INIS)

Van Tuyle, G.J.

1993-01-01

For nuclear waste transmutation to alter significantly the need for geologic disposal of spent fuel from US Light-water reactors (LWRs), about 1.4% of the spent fuel (by mass) must be separated and transmuted. This includes the plutonium, the minor actinides, and four fission products: iodine. technetium, cesium and strontium. Regarding the actinides, fissioning of the plutonium, neptunium, americium, and curium generates a great deal of heat, so much so that most of the plutonium should be used to produce power. However, these actinides have some undesirable neutronic characteristics, and their utilization in reactors or subcritical (proton-accelerator) targets requires either a fast neutronic spectrum or a very high thermal-neutron flux. Transmutation of the fission products is generally by neutron capture, although this is difficult in the case of cesium and strontium. In this paper, various proposed means of transmuting the actinides and fission products are discussed, with the main focus being on the safety characteristics of each approach

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.

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.

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

Transformational leadership and safety performance among nurses: the mediating role of knowledge-related job characteristics.

Science.gov (United States)

Lievens, Ilse; Vlerick, Peter

2014-03-01

To report the impact of transformational leadership on two dimensions of nurses' safety performance (i.e. safety compliance and safety participation) and to study the mediating role of knowledge-related job characteristics in this relationship. Safety performance refers to the behaviours that employees exhibit to adhere to safety guidelines and to promote health and safety at their workplace. Nurses' safety performance is a major challenge for healthcare settings, urging the need to identify the key determinants and psychological mechanisms that influence it. A cross-sectional survey study. The study was carried out in September 2010 in a large Belgian hospital. We used self-administered questionnaires; 152 nurses participated. The hypotheses were tested using hierarchical regression analyses. In line with our first hypothesis, the results show that transformational leadership exerted a significant positive impact on both dimensions of nurses' safety performance. This positive relation was mediated by knowledge-related job characteristics, supporting our second hypothesis. Head nurses' transformational leadership can enhance nurses' compliance with and participation in safety. Furthermore, transformational head nurses are able to influence the perception that their nurses have about the kind and amount of knowledge in their job, which can also lead to increases in both dimensions of nurses' safety performance. This study therefore demonstrates the key impact that transformational head nurses have, both directly and indirectly, on the safety performance of their nurses. © 2013 John Wiley & Sons Ltd.

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)

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)

Breeder design for enhanced performance and safety characteristics

International Nuclear Information System (INIS)

Fischer, G.J.; Atefi, B.; Yang, J.W.; Galperin, A.; Segev, M.

1980-01-01

A fast breeder reactor design has been created which offers a considerably extended fuel cycle and excellent performance characteristics. An example of a core designed to operate on a ten-year fuel cycle is described in some detail. Use of metal fuel along with a moderator such as beryllium oxide dispersed throughout the core provides both design flexibility and safety advantages such as a strong Doppler feedback and limited sodium void reactivity gain. Local power variations are small for the entire cycle; control requirements are also modest, and fuel cycle costs are low

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

User requirements in the area of safety of innovative nuclear reactors and fuel cycle installations

International Nuclear Information System (INIS)

Kuczera, B.; Juhn, P.E.; Fukuda, K.; )

2002-01-01

Full text: Against the background of already existing IAEA and INSAC publications in the area of safety, in the framework of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) a set of user requirements for the safety of future nuclear installations has been established. Five top-level requirements are expected to apply to any type of innovative design. They should foster an increased level of safety that is transparent to and fully accepted by the general public. The approach to future reactor safety includes two complementary strategies: increased emphasis on inherent safety characteristics and enhancement of defense in depth. As compared to existing plants, the effectiveness of preventing measures should be highly enhanced, resulting in fewer mitigation measures. The targets and possible approaches of each of the five levels of defense developed for innovative reactor designs are outlined in the paper

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)

Principal characteristics of good safety culture

Energy Technology Data Exchange (ETDEWEB)

Zhong, W [International Atomic Energy Agency, Vienna (Austria)

1997-09-01

The presentation briefly discusses the following aspects of safety culture: what is safety culture; universal features of safety culture; the main elements of safety culture; requirements at policy level; safety culture at government level, regulatory body, operators; requirements on managers.

Principal characteristics of good safety culture

International Nuclear Information System (INIS)

Zhong, W.

1997-01-01

The presentation briefly discusses the following aspects of safety culture: what is safety culture; universal features of safety culture; the main elements of safety culture; requirements at policy level; safety culture at government level, regulatory body, operators; requirements on managers

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.

Construction safety monitoring based on the project's characteristic with fuzzy logic approach

Science.gov (United States)

Winanda, Lila Ayu Ratna; Adi, Trijoko Wahyu; Anwar, Nadjadji; Wahyuni, Febriana Santi

2017-11-01

Construction workers accident is the highest number compared with other industries and falls are the main cause of fatal and serious injuries in high rise projects. Generally, construction workers accidents are caused by unsafe act and unsafe condition that can occur separately or together, thus a safety monitoring system based on influencing factors is needed to achieve zero accident in construction industry. The dynamic characteristic in construction causes high mobility for workers while doing the task, so it requires a continuously monitoring system to detect unsafe condition and to protect workers from potential hazards. In accordance with the unique nature of project, fuzzy logic approach is one of the appropriate methods for workers safety monitoring on site. In this study, the focus of discussion is based on the characteristic of construction projects in analyzing "potential hazard" and the "protection planning" to be used in accident prevention. The data have been collected from literature review, expert opinion and institution of safety and health. This data used to determine hazard identification. Then, an application model is created using Delphi programming. The process in fuzzy is divided into fuzzification, inference and defuzzification, according to the data collection. Then, the input and final output data are given back to the expert for assessment as a validation of application model. The result of the study showed that the potential hazard of construction workers accident could be analysed based on characteristic of project and protection system on site and fuzzy logic approach can be used for construction workers accident analysis. Based on case study and the feedback assessment from expert, it showed that the application model can be used as one of the safety monitoring tools.

Evaluation of neutronic characteristics of in-pile test reactor for fast reactor safety research

Energy Technology Data Exchange (ETDEWEB)

Uto, N.; Ohno, S.; Kawata, N. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

1996-09-01

An extensive research program has been carried out at the Power Reactor and Nuclear Fuel Development Corporation for the safety of future liquid-metal fast breeder reactors to be commercialized. A major part of this program is investigation and planning of advanced safety experiments conducted with a new in-pile safety test facility, which is larger and more advanced than any of the currently existing test reactors. Such a transient safety test reactor generally has unique neutronic characteristics that require various studies from the reactor physics point of view. In this paper, the outcome of the neutronics study is highlighted with presenting a reference core design concept and its performance in regard to the safety test objectives. (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

Searching for Models Exhibiting High Circularly Polarized Luminescence: the Electroactive Inherently Chiral Oligothiophenes.

Science.gov (United States)

Benincori, Tiziana; Appoloni, Giulio; Mussini, Patrizia Romana; Arnaboldi, Serena; Cirilli, Roberto; Quartapelle Procopio, Elsa; Panigati, Monica; Abbate, Sergio; Mazzeo, Giuseppe; Longhi, Giovanna

2018-05-02

Two new inherently chiral oligothiophenes characterized by the atropisomeric 3,3'-bithianaphtene scaffold functionalized with fused ring bithiophene derivatives, namely 4H-cyclopenta [2,1-b3:4b']dithiophene (CPDT) and dithieno[3,3-b:2',3'-d]pyrrole (DTP), were synthesized. The racemates were fully characterized and resolved into antipodes by enantioselective HPLC. The enantiomers were analyzed through different chiroptical techniques: electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) were employed to attribute the absolute configuration (AC). Comparison of experimental and calculated VCD spectra confirmed the DFT calculated conformational characteristics. The compound functionalized with two CPDT units was oxidized with FeCl3 and ECD and CPL of the resulting material were measured. Circularly Polarized Luminescence (CPL) was measured in order to verify if inherently chiral oligothiophenes could be promising systems for chiral photonics applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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)

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

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

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

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

Fracture mechanics characteristics and associated safety margins for integrity assessment; Bruchmechanische Kennwerte und zugeordnete Sicherheitsfaktoren bei Integritaetsanalysen

Energy Technology Data Exchange (ETDEWEB)

Roos, E.; Schuler, X.; Stumpfrock, L.; Silcher, H. [Stuttgart Univ. (DE). Materialpruefungsanstalt (MPA)

2008-07-01

Within the integrity assessment of components and structural members of plants safety margins have to be applied, whose magnitude depend on several factors. Important factors influencing the magnitude of the safety margins are as for instance: Material behaviour (ductile / brittle behaviour), the event to be considered (local deformation / fracture), possible consequences of failure (human health, environmental damage, economic consequences) and many others. One important factor also is the fact, how precisely and reliably the appropriate material characteristics can be determined and how precisely and reliably the components behaviour can be predicted and assessed by means of this material characteristic. In contemporary safety assessment procedures by means of fracture mechanics evaluation tools (e.g. [1]) a concept of partial safety margins is proposed for application. The basic idea with this procedure is that only those sources of uncertainty have to be considered, which are relevant or may be relevant for the structure to be considered. For this purpose each source of possible uncertainty has to be quantified individually, finally only those singular safety margins are superimposed to a total safety margin which are relevant. The more the uncertainties have to be taken into account, the total safety margin to be applied, consequently will be larger. If some sources of uncertainty can be eliminated totally or can be minimized (for instance by a more reliable calculational procedure of the component loading or by more precise material characteristics), the total safety margin can be reduced. In this contribution the different procedures for the definition of safety margins within the integrity assessment by means of fracture mechanics procedures will be discussed. (orig.)

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.

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

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

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

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...

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 structural integrity in liquid metal fast breeder reactor safety

International Nuclear Information System (INIS)

Holmes, J.A.G.

1982-01-01

Extensive studies have demonstrated the favourable safety characteristics of liquid metal fast breeder reactors, which are attributable to both their inherent features and the engineered safeguards which are included. This requires demonstration that there is no risk of sudden catastrophic failure of the core support system allowing the core to drop off the control rods to give a prompt critical reactivity excursion. An important part of our work in support of the safety case for the U.K. Commercial Demonstration Fast Reactor is to demonstrate that such a failure is virtually incredible. This covers design features, study of the fracture behaviour of stainless steel structures, and inspection and monitoring during fabrication and service. The paper gives a broad description of the relevant design features and supporting work programme

Evaluation of Electrical Characteristics of Protective Equipment - a Prerequisite for Ensuring Safety and Health of Workers at Work

Science.gov (United States)

Buică, G.; Beiu, C.; Antonov, A.; Dobra, R.; Păsculescu, D.

2017-06-01

The protecting electrical equipment in use are subject to various factors generated by the use, maintenance, storage and working environment, which may change the characteristics of protection against electric shock. The study presents the results of research on the behaviour over time of protective characteristics of insulating covers of material of work equipment in use, in order to determine the type and periodicity of safety tests. There were tested and evaluated safety equipment with plastic and insulating rubber covers used in operations of verifying functionality, safety and maintenance of machinery used in manufacturing industries and specific services from electric, energy and food sector.

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.

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)

Natural Circulation Characteristics of an Integral Pressurized Water Reactor

International Nuclear Information System (INIS)

Junli Gou; Suizheng Qiu; Guanghui Su; Dounan Jia

2006-01-01

Natural circulation potential is of great importance to the inherent safety of a nuclear reactor. This paper presents a theoretical investigation on the natural circulation characteristics of an integrated pressurized water reactor. Through numerically solved the one-dimensional model, the steady-state single phase conservative equations for the primary circuit and the steady-state two-phase drift-flux conservative equations for the secondary side of the once-through steam generator, the natural circulation characteristics are studied. Based on the preliminary calculation analysis, it is found that natural circulation mass flow rate is proportional to the exponential function of the power, and the value of the exponent is related to working conditions of the steam generator secondary side. The higher height difference between the core center and the steam generator center is favorable to the heat removal capacity of the natural circulation. (authors)

School Safety, Severe Disciplinary Actions, and School Characteristics: A Secondary Analysis of the School Survey on Crime and Safety

Science.gov (United States)

Han, Seunghee; Akiba, Motoko

2011-01-01

On the basis of a secondary analysis of survey data collected from 1,872 secondary school principals in the 2005-2006 School Survey on Crime and Safety, we examined the frequency of and reasons for severe disciplinary actions and the relationship between school characteristics and severe disciplinary actions. We found that severe disciplinary…

Integrated Safety and Security Risk Assessment Methods: A Survey of Key Characteristics and Applications

OpenAIRE

Chockalingam, Sabarathinam; Hadziosmanovic, Dina; Pieters, Wolter; Teixeira, Andre; van Gelder, Pieter

2017-01-01

Over the last years, we have seen several security incidents that compromised system safety, of which some caused physical harm to people. Meanwhile, various risk assessment methods have been developed that integrate safety and security, and these could help to address the corresponding threats by implementing suitable risk treatment plans. However, an overarching overview of these methods, systematizing the characteristics of such methods, is missing. In this paper, we conduct a systematic l...

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.)

Safety of 5 MW district heating reactor (DHR) and hydraulic dynamic pressure drive control rods

International Nuclear Information System (INIS)

Wu Yuanqiang; Wang Dazhong

1991-11-01

The principles and movement characteristic of the hydraulic dynamic pressure drive for control rods in 5 MW district heating reactor are described with stress on analysis of its effects on reactor safety features. The drive is different from electric-magnetic drive for PWR or hydraulic drive for BWR. The drive cylinder is driven by dynamic pressure. In the new drive system, the reactor coolant (water) used as actuating medium is pressed by pump, then injected into a step cylinder which is set in the reactor core. The cylinder will move step by step by controlling flow, then the cylinder drives the neutron absorber and controls nuclear reaction. The drive is characterized by simplicity in structure, high reliability, inherent safety, reduction in reactor height, economy, etc

CANDU safety under severe accidents

International Nuclear Information System (INIS)

Snell, V.G.; Howieson, J.Q.; Frescura, G.M.; King, F.; Rogers, J.T.; Tamm, H.

1988-01-01

The characteristics of the CANDU reactor relevant to severe accidents are set first by the inherent properties of the design, and second by the Canadian safety/licensing approach. Probabilistic safety assessment studies have been performed on operating CANDU plants, and on the 4 x 880 MW(e) Darlington station now under construction; furthermore a scoping risk assessment has been done for a CANDU 600 plant. They indicate that the summed severe core damage frequency is of the order of 5 x 10 -6 /year. CANDU nuclear plant designers and owner/operators share information and operational experience nationally and internationally through the CANDU Owners' Group (COG). The research program generally emphasizes the unique aspects of the CANDU concept, such as heat removal through the moderator, but it has also contributed significantly to areas generic to most power reactors such as hydrogen combustion, containment failure modes, fission product chemistry, and high temperature fuel behaviour. Abnormal plant operating procedures are aimed at first using event-specific emergency operating procedures, in cases where the event can be diagnosed. If this is not possible, generic procedures are followed to control Critical Safety Parameters and manage the accident. Similarly, the on-site contingency plans include a generic plan covering overall plant response strategy, and a specific plan covering each category of contingency

Development of a safety analysis code for molten salt reactors

International Nuclear Information System (INIS)

Zhang Dalin; Qiu Suizheng; Su Guanghui

2009-01-01

The molten salt reactor (MSR) well suited to fulfill the criteria defined by the Generation IV International Forum (GIF) is presently revisited all around the world because of different attractive features of current renewed relevance. The MSRs are characterized by using the fluid-fuel, so that their technologies are fundamentally different from those used in the conventional solid-fuel reactors. In this work, in particular, the attention is focused on the safety characteristic analysis of the MSRs, in which a point kinetic model considering the flow effects of the fuel salt is established for the MSRs and calculated by developing a microcomputer code coupling with a simplified heat transfer model in the core. The founded models and developed code are applied to analyze the safety characteristics of the molten salt actinide recycler and transmuter system (MOSART) by simulating three types of basic transient conditions including the unprotected loss of flow, unprotected overcooling accident and unprotected transient overpower. Some reasonable results are obtained for the MOSART, which show that the MOSART conceptual design is an inherently stable reactor design. The present study provides some valuable information for the research and design of the new generation MSRs.

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.

The impact of road improvements on road safety and related characteristics

OpenAIRE

Francis John Gichaga

2017-01-01

This paper presents the historical and cultural background relating to road improvement and road safety characteristics in Kenya, a developing country in East Africa. Some who come from low-developed areas of developing countries often take time to comprehend the modern transportation infrastructure, especially roads, and have difficulty assimilating and customizing the same to their culturally tailored modes. This paper discusses two case studies: one on the socio-economic impact followin...

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

Work stress and patient safety: observer-rated work stressors as predictors of characteristics of safety-related events reported by young nurses.

Science.gov (United States)

Elfering, A; Semmer, N K; Grebner, S

This study investigates the link between workplace stress and the 'non-singularity' of patient safety-related incidents in the hospital setting. Over a period of 2 working weeks 23 young nurses from 19 hospitals in Switzerland documented 314 daily stressful events using a self-observation method (pocket diaries); 62 events were related to patient safety. Familiarity of safety-related events and probability of recurrence, as indicators of non-singularity, were the dependent variables in multilevel regression analyses. Predictor variables were both situational (self-reported situational control, safety compliance) and chronic variables (job stressors such as time pressure, or concentration demands and job control). Chronic work characteristics were rated by trained observers. The most frequent safety-related stressful events included incomplete or incorrect documentation (40.3%), medication errors (near misses 21%), delays in delivery of patient care (9.7%), and violent patients (9.7%). Familiarity of events and probability of recurrence were significantly predicted by chronic job stressors and low job control in multilevel regression analyses. Job stressors and low job control were shown to be risk factors for patient safety. The results suggest that job redesign to enhance job control and decrease job stressors may be an important intervention to increase patient safety.

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.

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

Payload Safety: Risk and Characteristic-Based Control of Engineered Nanomaterials

Science.gov (United States)

Abou, Seraphin Chally; Saad, Maarouf

2013-09-01

In the last decade progress has been made to assist organizations that are developing payloads intended for flight on the International Space Station (ISS) and/or Space Shuttle. Collaboration programs for comprehensive risk assessment have been initiated between the U.S. and the European Union to generate requirements and data needed to comply with payloads safety and to perform risk assessment and controls guidance. Yet, substantial research gaps remain, as do challenges in the translation of these research findings to control for exposure to nanoscale material payloads, and the health effects. Since nanomaterial structures are different from traditional molecules, some standard material properties can change at size of 50nm or less. Changes in material properties at this scale challenge our understanding of hazards posed by nanomaterial payloads in the ISS realistic exposure conditions, and our ability to anticipate, evaluate, and control potential health issues, and safety. The research question addressed in this framework is: what kind of descriptors can be developed for nanomaterial payloads risks assessment? Methods proposed incorporate elements of characteristic- based risk an alysis: (1) to enable characterization of anthropogenic nanomaterials which can result in incidental from natural nanoparticles; and (2) to better understand safety attributes in terms of human health impacts from exposure to varying types of engineered nanomaterials.

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

An experimental study of the flow characteristics of fluidic device in a passive safety injection tank

International Nuclear Information System (INIS)

Cho, Seok; Song, Chul Hwa; Won, Suon Yeon; Min, Kyong Ho; Chung, Moon Ki

1998-01-01

It is considered to adopt passive safety injection tank (SIT) as a enhanced safety feature in KNGR. Passive SIT employs a vortex chamber as a fluidic device, which control injection flow rate passively by the variation of flow resistance produced by vortex intensity within the vortex chamber. To investigate the flow characteristics of the vortex chamber many tests have been carried out by using small-scale test facility. In this report the effects of geometric parameters of vortex chamber on discharge flow characteristics and the velocity measurement result of flow field, measured by PIV, are presented and discussed. (author). 25 refs., 11 tabs., 31 figs

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)

Analysis Relationship Among Descriptor, References and Citation to Contruct the Inherent Structure of Document Collection

International Nuclear Information System (INIS)

Hasibuan, Zainal A.; Mustangimah

2001-01-01

There are many characteristics can be used to identify a document which cover characteristics of the documents, cited documents, and citing documents This research explored the inherent structure of a document collection as one of main components of information retrieval system. The characteristics examined are: descriptors, references (cited documents), and citations (citing documents). Three independent variables were studied: co-descriptor, bibliographic coupling, and co-citation. A test collection was constructed by searching on a single descriptor i nformation retrieval i n the CD-ROM version of Education Resource Information Clearinghouse (ERIC), covering the period 1981 through 1985. Descriptors were extracted from ERIC; cited and citing documents associated with the test collection were derived from Social Sciences Citation Index (SSCI), covering the period 1981 through 1990. Three hypothesis were tested in this study, that are: (1) the higher the frequency of co-descriptors between documents, the higher the frequencies of their bibliographic coupling and co-citation; (2) the higher the frequency of bibliographic coupling between documents, the higher the frequencies of their co-citation and co-descriptors; and (3) the higher the frequency of co-citation between documents, the higher the frequencies of their co-descriptors and bibliographic coupling. The results showed that all of three hypothesis are supported statistically and there is a significant linear relationship among the observed variables. It is mean that there is a significant relationship among descriptors, references, and citation, so that it can be used to construct the inherent structure of document collection in order to improve information retrieval system performance

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

Development of Basic Key Technologies for Gen IV SFR Safety Evaluation

International Nuclear Information System (INIS)

Jeong, Hae Yong; Kwon, Young Min; Kim, Tae Woon; Park, Soo Yong; Suk, Soo Dong; Lee, Kwi Lim; Lee, Yong Bum; Chang, Won Pyo; Ha, Kwi Seok; Hahn, Sang Hoon

2010-07-01

Safety issues and design requirements on control rod worth were identified through the evaluation of safety design characteristics and the preliminary safety evaluation. This results will be taken into account for the conceptual design studies of the demonstration reactor in the next stage. The Level-1 Pasa has been performed and a quantitative Cdf value was produced for the selected design from the several candidates. The inherent safety characteristics of the selected design were evaluated through the DBE and ATWS analyses. A surrogate material for Tru has been selected which is applicable to the study of liquidus/solidus temperature test for the metallic fuel containing Tru. A methodology for the regression analysis with surrogate material has been developed and valuable data on metal fuel liquidus/solidus temperature have been measured. A simple mechanistic model describing a bending of subassemblies has been formulated based on the foreign test data and existing models. Its applicability has been evaluated for the Phenix design. New criteria of the core damage for the SFR PSA were identified. The list of initiating events, system response event tree, and core response event tree, which constitute a PSA methodology for an SFR, have been introduced. By developing the SFR PIRT, phenomenological model features, which have to be satisfied in a safety code, were defined and the PIRT results were applied to the design of the PDRC test facility. Bases for a safety evaluation methodology for the SFR DBEs have been also prepared. A draft version of the topical report on the code for local fault analysis has been completed. Since 2007, the MARS-LMR code has been developed and assessments for model validation with the test data from EBR-II and Phenix reactor have been continued. The code has been applied to the evaluation of passive safety of a conceptual design of Gen IV SFR

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

Thermo-hydraulic characteristics of ship propulsion reactor in the conditions of ship motions and safety assessment

International Nuclear Information System (INIS)

Kobayashi, Michiyuki; Murata, Hiroyuki; Sawada, Kenichi; Inasaka, Fujio; Aya, Izuo; Shiozaki, Koki

1999-01-01

By inputting the experimental data, information and others on thermo-hydraulic characteristics of integrated ship propulsion reactor accumulated hitherto by the Ship Research Institute and some recent cooperation results into the nuclear ship engineering simulation system, it was conducted not only to contribute an improvement study on next ship reactor by executing general analysis and evaluation on motion characteristics under ship body motion conditions, safety at accidents, and others of the integrated ship reactor but also to investigate and prepare some measures to apply fundamental experiment results based on obtained here information to safety countermeasure of the nuclear ships. In 1997 fiscal year, on safety of the integrated ship propulsion reactor loading nuclear ship, by adding experimental data on unstable flow analysis and information on all around of the analysis to general data base fundamental program, development to intellectual data base program was intended; on effect of pulsation flow on thermo-hydraulic characteristics of ship propulsion reactor; after pulsation flow visualization experiment, experimental equipment was reconstructed into heat transfer type to conduct numerical analysis of pulsation flow by confirming validity of numerical analysis code under comparison with the visualization experiment results; and on thermo-hydraulic behavior in storage container at accident of active safety type ship propulsion reactor; a flashing vibration test using new apparatus finished on its higher pressurization at last fiscal year to examine effects of each parameter such as radius and length of exhausting nozzle and pool water temperature. (G.K.)

Neutronics safety analysis in severe transients of the dual-cooled waste transmutation blanket for the FDS-I

International Nuclear Information System (INIS)

Zheng, S.; Wu, Y.

2006-01-01

The conceptual design of the fusion-driven subcritical system FDS-I with the multifunctional subcritical dual-cooled waste transmutation (DWT) blanket proposed as a middle step toward the final application of fusion energy was presented previously. Safety is a key concern for the innovative conceptual system. The potential safety characteristic is expected as one of the advantages of FDS-I for the transmutation and incineration of nuclear waste compared with the critical reactor. With the intent of evaluating the inherent and passive safety features of FDS-I, the reactivity coefficients (e.g. the coolant density/void effect and the Doppler feedback), which are similar to those in critical reactors, and the kinetics quantities (e.g. neutron generation time and β eff ), which are influenced by the external neutron source of the source-driven system, are calculated and analyzed. In addition, the specific transient scenarios for FDS-I, which show the effects of the source power perturbation on the safety parameters, is presented

Nuclear safety and quality systems

International Nuclear Information System (INIS)

Kunaj, H.; Tireli, E.

2002-01-01

According to ISO 8402:1994 [1] Quality is totality of characteristics of an entity that bear on its ability to satisfy stated and implied needs. According to ISO 9000:2000 [3] Quality is degree to which a set of inherent characteristics fulfils the requirements.(author)

Thermo-hydraulic characteristics of ship propulsion reactor in the conditions of ship motions and safety assessment

International Nuclear Information System (INIS)

Kobayashi, Michiyuki; Aya, Izuo; Inasaka, Fujio; Murata, Hiroyuki; Odano, Naoteru; Shiozaki, Koki

1998-01-01

A research project from 1995-1999 had a plan to make experimental studies on (1) safety of nuclear ship loaded with an integral ship propulsion reactor (2) effects of pulsating flow on the thermo-hydraulic characteristics of ship propulsion reactor and (3) thermo-hydraulic behaviors of the reactor container at the time of accident in a passively safe ship propulsion reactor. Development of a data base for ship propulsion reactor was attempted using previous experimental data on the thermo-hydraulic characteristics of the reactor in the institute in addition to the present results aiming to make general analytical evaluation for the safety of the engineering-simulation system for nuclear ship. A general data base was obtained by integrating the data list and the analytical program for static characteristics. A test equipment which allows to visualize the pulsating flow was produced and visualization experiments have started. (M.N.)

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. The present revision 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 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 formerGuides 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

Nuclear safety guide. TID-7016, Revision 2

Energy Technology Data Exchange (ETDEWEB)

Thomas, J T [ed.

1978-05-01

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. The present revision 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 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 formerGuides 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.

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...

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)

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...

CANDU safety under severe accidents

International Nuclear Information System (INIS)

Snell, V.G.; Howieson, J.Q.; Alikhan, S.; Frescura, G.M.; King, F.; Rogers, J.T.; Tamm, H.

1996-01-01

The characteristics of the CANDU reactor relevant to severe accidents are set first by the inherent properties of the design, and second by the Canadian safety/licensing approach. The pressure-tube concept allows the separate, low-pressure, heavy-water moderator to act as a backup heat sink even if there is no water in the fuel channels. Should this also fail, the calandria shell itself can contain the debris, with heat being transferred to the water-filled shield tank around the core. Should the severe core damage sequence progress further, the shield tank and the concrete reactor vault significantly delay the challenge to containment. Furthermore, should core melt lead to containment overpressure, the containment behaviour is such that leaks through the concrete containment wall reduce the possibility of catastrophic structural failure. The Canadian licensing philosophy requires that each accident, together with failure of each safety system in turn, be assessed (and specified dose limits met) as part of the design and licensing basis. In response, designers have provided CANDUs with two independent dedicated shutdown systems, and the likelihood of Anticipated Transients Without Scram is negligible. Probabilistic safety assessment studies have been performed on operating CANDU plants, and on the 4 x 880 MW(e) Darlington station now under construction; furthermore a scoping risk assessment has been done for a CANDU 600 plant. They indicate that the summed severe core damage frequency is of the order of 5 x 10 -6 /year. 95 refs, 3 tabs

CANDU safety under severe accidents

Energy Technology Data Exchange (ETDEWEB)

Snell, V G; Howieson, J Q [Atomic Energy of Canada Ltd. (Canada); Alikhan, S [New Brunswick Electric Power Commission (Canada); Frescura, G M; King, F [Ontario Hydro (Canada); Rogers, J T [Carleton Univ., Ottawa, ON (Canada); Tamm, H [Atomic Energy of Canada Ltd. (Canada). Whiteshell Research Lab.

1996-12-01

The characteristics of the CANDU reactor relevant to severe accidents are set first by the inherent properties of the design, and second by the Canadian safety/licensing approach. The pressure-tube concept allows the separate, low-pressure, heavy-water moderator to act as a backup heat sink even if there is no water in the fuel channels. Should this also fail, the calandria shell itself can contain the debris, with heat being transferred to the water-filled shield tank around the core. Should the severe core damage sequence progress further, the shield tank and the concrete reactor vault significantly delay the challenge to containment. Furthermore, should core melt lead to containment overpressure, the containment behaviour is such that leaks through the concrete containment wall reduce the possibility of catastrophic structural failure. The Canadian licensing philosophy requires that each accident, together with failure of each safety system in turn, be assessed (and specified dose limits met) as part of the design and licensing basis. In response, designers have provided CANDUs with two independent dedicated shutdown systems, and the likelihood of Anticipated Transients Without Scram is negligible. Probabilistic safety assessment studies have been performed on operating CANDU plants, and on the 4 x 880 MW(e) Darlington station now under construction; furthermore a scoping risk assessment has been done for a CANDU 600 plant. They indicate that the summed severe core damage frequency is of the order of 5 x 10{sup -6}/year. 95 refs, 3 tabs.

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.

Lithium-Ion Electrolytes Containing Flame Retardant Additives for Increased Safety Characteristics

Science.gov (United States)

Smart, Marshall C. (Inventor); Smith, Kiah A. (Inventor); Bugga, Ratnakumar V. (Inventor); Prakash, Surya G. (Inventor); Krause, Frederick Charles (Inventor)

2014-01-01

The invention discloses various embodiments of Li-ion electrolytes containing flame retardant additives that have delivered good performance over a wide temperature range, good cycle life characteristics, and improved safety characteristics, namely, reduced flammability. In one embodiment of the invention there is provided an electrolyte for use in a lithium-ion electrochemical cell, the electrolyte comprising a mixture of an ethylene carbonate (EC), an ethyl methyl carbonate (EMC), a fluorinated co-solvent, a flame retardant additive, and a lithium salt. In another embodiment of the invention there is provided an electrolyte for use in a lithium-ion electrochemical cell, the electrolyte comprising a mixture of an ethylene carbonate (EC), an ethyl methyl carbonate (EMC), a flame retardant additive, a solid electrolyte interface (SEI) film forming agent, and a lithium salt.

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

Workers’ Age and the Impact of Psychological Factors on the Perception of Safety at Construction Sites

Directory of Open Access Journals (Sweden)

Muhammad Dawood Idrees

2017-05-01

Full Text Available The safety of construction workers is always a major concern at construction sites as the construction industry is inherently dangerous with many factors influencing worker safety. Several studies concluded that psychological factors such as workload, organizational relationships, mental stress, job security, and job satisfaction have significant effects on workers’ safety. However, research on psychological factors that are characteristic of different age groups have been limited. The aim of this study was to examine the impact of psychological factors on the perception of worker safety for two different age groups. After an extensive literature review, different psychological factors were identified, and a hypothetical research model was developed based on psychological factors that could affect workers’ perception of safety. A survey instrument was developed, and data were collected from seven different construction sites in Pakistan. Structural equation modeling (SEM was employed to test the hypothetical model for both age groups. The results revealed that workload and job satisfaction are significantly dominant factors on workers’ perception of safety in older workers, whereas organizational relationships, mental stress, and job security are dominant factors for younger workers at construction sites.

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...

Safety climate in the federal fire management community: Influences of organizational, environmental, group, and individual characteristics (Abstract)

Science.gov (United States)

Brooke Baldauf McBride; Anne E. Black

2012-01-01

This study examined the effects of organizational, environmental, group and individual characteristics on five components of safety climate in the US federal fire management community (HRO Practices, Leadership, Group Culture, Learning Orientation and Mission Clarity). Multiple analyses of variance revealed that all types of characteristics had a significant effect on...

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

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

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

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.

CONSUMER PREFERENCES FOR FOOD SAFETY ATTRIBUTES IN FRESH APPLES: MARKET SEGMENTS, CONSUMER CHARACTERISTICS, AND MARKETING OPPORTUNITIES

OpenAIRE

Baker, Gregory A.

1999-01-01

Past research has yielded conflicting results on consumer valuation of food safety characteristics. In this study, conjoint analysis is used to evaluate consumer responses to hypothetical apple products in a nationwide survey. Product characteristics include price, quality, pesticide use levels and the corresponding cancer risk, and type of government inspection. Consumers expressed a broad preference for reduced pesticide usage. Four market segments were identified corresponding to consumers...

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...

EC6 safety design improvements

Energy Technology Data Exchange (ETDEWEB)

Yu, S.; Lee, A.G.; Soulard, M. [Candu Energy Inc., Mississauga, ON (Canada)

2014-07-01

The Enhanced CANDU 6 (EC6) builds on the proven high performance design such as the Qinshan CANDU 6 reactor, and has made improvements to safety, operational performance, and has incorporated extensive operational feedback. Completion of all three phases of the pre-licensing design review by the Canadian Regulator - the Canadian Nuclear Safety Commission has provided a higher level of assurance that the EC6 reference design has taken modern regulatory requirements and expectations into account and further confirmed that there are no fundamental barriers to licensing the EC6 design in Canada. The EC6 design is based on the defence-in-depth principles in INSAG-10 and provides further safety features that address the lessons learned from Fukushima. With these safety features, the EC6 design has strengthened accident prevention as the first priority in the defence-in-depth strategy, as outlined in INSAG-10. As well, the EC6 design has incorporated further mitigation measures to provide additional protection of the public and the environment if the preventive measures fail. The EC6 design has an appropriate combination of inherent, passive safety characteristics, engineered features and administrative safety measures to effectively prevent and mitigate severe accident progressions. A strong contributor to the robustness and redundancy of CANDU design is the two-group separation philosophy. This ensures a high degree of independence between safety systems as well as physical separation and functional independence in how fundamental safety functions are provided. This paper will describe the following safety features based on the application of defence-in-depth and design approach to prevent beyond design basis events progressing to severe accidents and to mitigate the consequences if it occurs: Improved steam generator heat sink via a more reliable emergency heat removal system; Increased time before manual field actions are required via enhanced capacity of

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

Thermal-hydraulic transient characteristics of ship-propulsion reactor investigated through safety analysis

International Nuclear Information System (INIS)

Fujiki, Kazuo; Asaka, Hideaki; Ishida, Toshihisa

1986-01-01

Thermal-hydraulic behaviors in the reactor of Nuclear Ship ''Mutsu'' were investigated through safety evaluation of operational transients by using RETRAN and COBRA-IV codes. The results were compared to the transient behaviors of typical commercial PWR and the characteristics of transient thermal-hydraulic behaviors in ship-loaded reactor were figured out. ''Mutsu'' reactor has larger thermal margin than commercial PWR because it is designed to be used as ship-propulsion power source in the load-following operation mode. This margin makes transient behavior in general milder than in commercial PWR but high opening pressure set point of main-steam safety valves leads poor heat-sink condition after reactor trip. The effects of other small-sized components are also investigated. The findings in the paper will be helpful in the design of future advanced reactor for nuclear ship. (author)

The characteristics of patient safety culture in Japan, Taiwan and the United States.

Science.gov (United States)

Fujita, Shigeru; Seto, Kanako; Ito, Shinya; Wu, Yinghui; Huang, Chiu-Chin; Hasegawa, Tomonori

2013-01-14

Quality and safety issues are receiving growing attention. Patient safety culture (PSC) plays an important role in patient safety. The characteristics of PSC in various countries, each with a different set of values, have not been determined sufficiently. The aim of this study is to investigate the characteristics of PSC in Japan, Taiwan and the U.S. A cross-sectional survey was conducted in Japan and Taiwan using the Hospital Survey on PSC (HSOPS) questionnaire developed by the U.S. Agency for Healthcare Research and Quality (AHRQ). Data from Japan and Taiwan were also compared with the U.S. "2010 HSOPS Comparative Database" provided by AHRQ. Valid response rates in Japan, Taiwan and the U.S. were 66.5% (6,963/10,466), 85.7% (10,019/11,692) and 35.2% (291,341/827,424), respectively. The proportion of respondents with some experience of event reporting during the past 12 months was highest in Japan. In general, U.S. healthcare workers were likely to evaluate their PSC higher than that in Japan or Taiwan. The attitude of continuous improvement in Japan and event reporting of near misses in Taiwan were rated as low. In the U.S., staffing was rated as high. The results suggest that PSC varies among different countries, and the cultural setting of each country should be given special consideration in the development of effective intervention plans to improve PSC. Additional investigations with improved methodology and a common protocol are required to accurately compare PSCs among countries.

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...

The secure heating reactor

International Nuclear Information System (INIS)

Pind, C.

1987-01-01

The SECURE heating reactor was designed by ASEA-ATOM as a realistic alternative for district heating in urban areas and for supplying heat to process industries. SECURE has unique safety characteristics, that are based on fundamental laws of physics. The safety does not depend on active components or operator intervention for shutdown and cooling of the reactor. The inherent safety characteristics of the plant cannot be affected by operator errors. Due to its very low environment impact, it can be sited close to heat consumers. The SECURE heating reactor has been shown to be competitive in comparison with other alternatives for heating Helsinki and Seoul. The SECURE heating reactor forms a basis for the power-producing SECURE-P reactor known as PIUS (Process Inherent Ultimate Safety), which is based on the same inherent safety principles. The thermohydraulic function and transient response have been demonstrated in a large electrically heated loop at the ASEA-ATOM laboratories

Inherent variation in multiple shoe-sole test impressions.

Science.gov (United States)

Shor, Yaron; Wiesner, Sarena; Tsach, Tsadok; Gurel, Ron; Yekutieli, Yoram

2018-04-01

Shoeprints left at crime scenes are seldom perfect. Many prints are distorted or contaminated by various materials. Noisy background often contributes to vagueness on the shoeprints as well. Test impressions made from the suspect's shoes in the laboratory are considered a genuine replication of the shoe-sole. This naïve attitude is far from being correct. Consecutive test impressions made in the laboratory under strict similar conditions revealed differences among the exemplars of the same sole. Some of them are minor, but some are major, and can mislead the less experienced practitioners during the comparison process. This article focuses on the inherent within source variability between controlled shoeprints made from the same shoe, as it appears on the RACs. To describe and analyze this variability, repeated test impressions were prepared, and datasets were created. Several RACs were marked on each test impression, using an expert assisting software tool (developed in the authors' lab). The variance in repeated test impressions is demonstrated and possible sources are discussed. This variance should be considered when trying to establish the degree of matching between individual characteristics. Copyright © 2017. Published by Elsevier B.V.

Characteristics of the safety climate in teams with world-class safety ...

African Journals Online (AJOL)

interact to deliver a project successfully in terms of cost .... small-scale accidents occurring at high frequency and from diverse ... the team dynamics of role players in a construction project and .... modified safety pyramid to measure the impact of the safety climate ...... Methodological Centre for Vocational Education and.

Special characteristics of the safety analysis of HWRs

International Nuclear Information System (INIS)

Kugler, G.

1980-01-01

Two lectures are presented in this report. The CANDU-PHW reactor is used as a model for discussion. The first lecture describes the distinctive features of the CANDU reactor, and how they impact on reactor safety. In the second lecture the Canadian safety philosophy, the safety design objective, and other selected topics on reactor safety analysis are discussed. The material in this report was selected with a view to assisting those not familiar with the CANDU heavy water reactor design in evaluating the distinctive safety aspects of these reactors. (orig./RW)

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…

Human factors in safety assessment. Safety culture assessment

International Nuclear Information System (INIS)

Zhang Li; Deng Zhiliang; Wang Yiqun; Huang Weigang

1996-01-01

This paper analyses the present conditions and problems in enterprises safety assessment, and introduces the characteristics and effects of safety culture. The authors think that safety culture must be used as a 'soul' to form the pattern of modern safety management. Furthermore, they propose that the human safety and synthetic safety management assessment in a system should be changed into safety culture assessment. Finally, the assessment indicators are discussed

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)

Nuclear power plants near consumers from a safety-engineering point of view

International Nuclear Information System (INIS)

Kroeger, W.

1986-11-01

Special safety requirements must be met by a nuclear power station near the consumer. These requirements may not be formulated in a purely probabilistic way because of the methodological deficiencies identified. The existing protection concept is rather extended so as to include the requirement of engineered safeguards in order to limit the damage in case of a worst reactor accident. The suggested individual dose limit together with the calculation rules should ensure that the consequences of a worst accident are essentially limited to the plant and that no emergency protection measures and countermeasures need to be considered either in the short term or in the longer term to prevent health damage. The resulting features of a reactor near the consumer aim at better inherent safety characteristics, which is shown to be possible by reasonable technical means and which seems to have already been realized to a large extent in plants of small and perhaps also medium power already conceived. The way of thinking behind this suggestion is applicable to other sectors of industrial technology. Furthermore, it might serve as a basis in the discussion about general advanced safety criteria, which has been stimulated due to 'Chernobyl'. (orig./HP) [de

Measuring safety culture in Dutch primary care: psychometric characteristics of the SCOPE-PC questionnaire.

Science.gov (United States)

Verbakel, Natasha J; Zwart, Dorien L M; Langelaan, Maaike; Verheij, Theo J M; Wagner, Cordula

2013-09-17

Patient safety has been a priority in primary healthcare in the last years. The prevailing culture is seen as an important condition for patient safety in practice and several tools to measure patient safety culture have therefore been developed. Although Dutch primary care consists of different professions, such as general practice, dental care, dietetics, physiotherapy and midwifery, a safety culture questionnaire was only available for general practices. The purpose of this study was to modify and validate this existing questionnaire to a generic questionnaire for all professions in Dutch primary care. A validated Dutch questionnaire for general practices was modified to make it usable for all Dutch primary care professions. Subsequently, this questionnaire was administered to a random sample of 2400 practices from eleven primary care professions. The instrument's factor structure, reliability and validity were examined using confirmatory and explorative factor analyses. 921 questionnaires were returned. Of these, 615 were eligible for factor analysis. The resulting SCOPE-PC questionnaire consisted of seven dimensions: 'open communication and learning from errors', 'handover and teamwork', 'adequate procedures and working conditions', 'patient safety management', 'support and fellowship', 'intention to report events' and 'organisational learning' with a total of 41 items. All dimensions had good reliability with Cronbach's alphas ranging from 0.70-0.90, and the questionnaire had a good construct validity. The SCOPE-PC questionnaire has sound psychometric characteristics for use by the different professions in Dutch primary care to gain insight in their safety culture.

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...

Advancing medication infusion safety through the clinical integration of technology.

Science.gov (United States)

Gerhart, Donald; O'Shea, Kristen; Muller, Sharon

2013-01-01

Adverse drug events resulting from errors in prescribing or administering medications are preventable. Within a hospital system, numerous technologies are employed to address the common sources of medication error, including the use of electronic medical records, physician order entry, smart infusion pumps, and barcode medication administration systems. Infusion safety is inherently risky because of the high-risk medications administered and the lack of integration among the stand-alone systems in most institutions. Intravenous clinical integration (IVCI) is a technology that connects electronic medical records, physician order entry, smart infusion pumps, and barcode medication administration systems. It combines the safety features of an automatically programmed infusion pump (drug, concentration, infusion rate, and patient weight, all auto-programmed into the device) with software that provides visibility to real-time clinical infusion data. Our article describes the characteristics of IVCI at WellSpan Health and its impact on patient safety. The integrated infusion system has the capability of reducing medication errors, improving patient care, reducing in-facility costs, and supporting asset management. It can enhance continuous quality improvement efforts and efficiency of clinical work flow. After implementing IVCI, the institution realized a safer patient environment and a more streamlined work flow for pharmacy and nursing.

Driver characteristics associated with child safety seat usage in Malaysia: a cross-sectional study.

Science.gov (United States)

Kulanthayan, S; Razak, Ahmad; Schenk, Ellen

2010-03-01

The rapidly motorizing environment in Malaysia has made child occupant safety a current public health concern. The usage of child safety seats (CSS) is a widely regarded intervention to enhance child occupant safety, yet no study has been conducted on CSS in Malaysia. This study aims to determine the CSS usage rates in Malaysia and to assess driver characteristics that are associated with CSS usage. Nine variables - urban versus rural study location, age, gender, marital status, educational status, monthly family income, number of children present in the vehicle, distance traveled to the study location, and attitude - were examined through a cross-sectional study of interviewing drivers of 230 vehicles transporting at least one child safety in Malaysia. The results indicate that interventional efforts should focus on educational programs geared toward drivers that are less educated or extended family members who inconsistently transport young children. Furthermore, any educational efforts could be strongly enhanced by legislation mandating the use of CSS. Every effort should be made to thoroughly assess the effectiveness of any educational or legislative activities that are implemented. Copyright 2009 Elsevier Ltd. All rights reserved.

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)

TWRS safety SSCs: Requirements and characteristics

International Nuclear Information System (INIS)

Smith-Fewell, M.A.

1997-01-01

Safety Systems, Structures, and Components (SSCs) have been identified from hazard and accident analyses. These analyses were performed to support the Tank Waste Remediation System (TWRS) Final Safety Analysis Report (FSAR) and Basis for Interim Operation (BID). The text identifies and evaluates the SSCs and their supporting SSCs to show that they either prevent the occurrence of the accident or mitigate the consequences of the accident to below the acceptance guidelines. The requirements for the SSCs to fulfill these tasks are described

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

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

Safety Management Characteristics Reflected in Interviews at Swedish Nuclear Power Plants: A System Perspective Approach

Energy Technology Data Exchange (ETDEWEB)

Salo, Ilkka (Risk Analysis, Social and Decision Research Unit, Dept. of Psychology, Stockholm Univ., Stockholm (Sweden))

2005-12-15

The present study investigated safety management characteristics reflected in interviews with participants from two Swedish nuclear power plants. A document analysis regarding the plants' organization, safety policies, and safety culture work was carried out as well. The participants (n=9) were all nuclear power professionals, and the majority managers at different levels with at least 10 years of nuclear power experience. The interview comprised themes relevant for organizational safety and safety management, such as: organizational structures and organizational change, threats to safety, information feedback and knowledge transfer, safety analysis, safety policy, and accident and incident analysis and reporting. The results were in part modeled to important themes derived from a general system theoretical framework suggested by Svenson and developed by Svenson and Salo in relation to studies of 'non-nuclear' safety organizations. A primer to important features of the system theoretical framework is presented in the introductory chapter. The results from the interviews generated interesting descriptions about nuclear safety management in relation to the above themes. Regarding organizational restructuring, mainly centralizations of resources, several examples of reasons for the restructuring and related benefits for this centralization of resources were identified. A number of important reminders that ought to be considered in relation to reorganization were also identified. Regarding threats to the own organization a number of such was interpreted from the interviews. Among them are risks related to generation and competence change-over and risks related to outsourcing of activities. A thorough picture of information management and practical implications related to this was revealed in the interviews. Related to information feedback is the issue of organizational safety indicators and safety indicators in general. The interview answers indicated

Safety Management Characteristics Reflected in Interviews at Swedish Nuclear Power Plants: A System Perspective Approach

International Nuclear Information System (INIS)

Salo, Ilkka

2005-12-01

The present study investigated safety management characteristics reflected in interviews with participants from two Swedish nuclear power plants. A document analysis regarding the plants' organization, safety policies, and safety culture work was carried out as well. The participants (n=9) were all nuclear power professionals, and the majority managers at different levels with at least 10 years of nuclear power experience. The interview comprised themes relevant for organizational safety and safety management, such as: organizational structures and organizational change, threats to safety, information feedback and knowledge transfer, safety analysis, safety policy, and accident and incident analysis and reporting. The results were in part modeled to important themes derived from a general system theoretical framework suggested by Svenson and developed by Svenson and Salo in relation to studies of 'non-nuclear' safety organizations. A primer to important features of the system theoretical framework is presented in the introductory chapter. The results from the interviews generated interesting descriptions about nuclear safety management in relation to the above themes. Regarding organizational restructuring, mainly centralizations of resources, several examples of reasons for the restructuring and related benefits for this centralization of resources were identified. A number of important reminders that ought to be considered in relation to reorganization were also identified. Regarding threats to the own organization a number of such was interpreted from the interviews. Among them are risks related to generation and competence change-over and risks related to outsourcing of activities. A thorough picture of information management and practical implications related to this was revealed in the interviews. Related to information feedback is the issue of organizational safety indicators and safety indicators in general. The interview answers indicated that the area

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

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 aspects of pulsed YAYOI and Japan Linac Booster

International Nuclear Information System (INIS)

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

1976-01-01

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

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)

Safety analysis code SCTRAN development for SCWR and its application to CGNPC SCWR

International Nuclear Information System (INIS)

Wu, Pan; Gou, Junli; Shan, Jianqiang; Jiang, Yang; Yang, Jue; Zhang, Bo

2013-01-01

Highlights: ► A new safety analysis code named SCTRAN is developed for SCWRs. ► Capability of SCTRAN is verified by comparing with code APROS and RELAP5-3D. ► A new passive safety system is proposed for CGNPC SCWR and analyzed with SCTRAN. ► CGNPC SCWR is able to cope with two critical accidents for SCWRs, LOFA and LOCA. - Abstract: Design analysis is one of the main difficulties during the research and design of SCWRs. Currently, the development of safety analysis code for SCWR is still in its infancy all around the world, and very few computer codes could carry out the trans-critical calculations where significant changes in water properties would take place. In this paper, a safety analysis code SCTRAN for SCWRs has been developed based on code RETRAN-02, the best estimate code used for safety analysis of light water reactors. The ability of SCTRAN code to simulate transients where both supercritical and subcritical regimes are encountered has been verified by comparing with APROS and RELAP5-3D codes. Furthermore, the LOFA and LOCA transients for the CGNPC SCWR design were analyzed with SCTRAN code. The characteristics and performance of the passive safety systems applied to CGNPC SCWR were evaluated. The results show that: (1) The SCTRAN computer code developed in this study is capable to perform design analysis for SCWRs; (2) During LOFA and LOCA accidents in a CGNPC SCWR, the passive safety systems would significantly mitigate the consequences of these transients and enhance the inherent safety

Passive safety testing at the Fast Flux Test Facility

International Nuclear Information System (INIS)

Lucoff, D.M.

1989-01-01

During 1986, the Fast Flux Test Facility (FFTF) conducted several tests designed to improve the understanding of the passive safety characteristics of an oxide-fueled liquid-metal reactor (LMR). Static and dynamic tests were performed over a broad range of power, flow, and temperature conditions that extended beyond those for normal operation. Key results of these tests are presented. Stable operation at low power with natural circulation cooling was demonstrated. A passive safety enhancement feature, the gas expansion module (GEM) was developed specifically to offset the large amount of cooldown reactivity that needs to be controlled in an oxide-fueled LMR undergoing an unprotected loss-of-flow accident. Nine GEMs were built and successfully tested in FFTF. With the reactor at 50% power (200 MW (thermal)), the main coolant pumps were turned off and the normal control rod scram response was inhibited. The GEMs and inherent core reactivity feedback mechanisms took the core subcritical with a modest peak coolant temperature transient that reached 85 degrees C above the pretransient value and always maintained a >400 degrees C margin to the sodium boiling point (910 degrees C)

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

Qualitative analysis in reliability and safety studies

International Nuclear Information System (INIS)

Worrell, R.B.; Burdick, G.R.

1976-01-01

The qualitative evaluation of system logic models is described as it pertains to assessing the reliability and safety characteristics of nuclear systems. Qualitative analysis of system logic models, i.e., models couched in an event (Boolean) algebra, is defined, and the advantages inherent in qualitative analysis are explained. Certain qualitative procedures that were developed as a part of fault-tree analysis are presented for illustration. Five fault-tree analysis computer-programs that contain a qualitative procedure for determining minimal cut sets are surveyed. For each program the minimal cut-set algorithm and limitations on its use are described. The recently developed common-cause analysis for studying the effect of common-causes of failure on system behavior is explained. This qualitative procedure does not require altering the fault tree, but does use minimal cut sets from the fault tree as part of its input. The method is applied using two different computer programs. 25 refs

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.

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.

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.

Assessing progress in the development of safety culture

International Nuclear Information System (INIS)

Rotaru, Ioan; Ghita, Sorin

1999-01-01

The concept of safety culture was introduced by the International Nuclear Safety Advisory Group (INSAG) in the Summary Report on the Post-Accident Meeting on the Chernobyl Accident in 1986. The concept was further expanded in the 1988 INSAG-3 report, Basic Safety Principles for Nuclear Power Plants, and again in 1991 in the INSAG-4 report. Recognizing the increasing role that safety culture is expected to play in nuclear installations worldwide, the Convention on Nuclear Safety states the Contracting Parties' desire 'to promote an effective nuclear safety culture'. The concept of safety culture is defined in INSAG-4 as follows: Safety culture is that assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance. Safety culture is also an amalgamation of values, standards, morals and norms of acceptable behaviour. These are aimed at maintaining a self disciplined approach to the enhancement of safety beyond legislative and regulatory requirements. Therefore, the safety culture has to be inherent in the thoughts and actions of all the individuals at every level in an organization. The leadership provided by top management is crucial. Safety culture applies to conventional and personal safety as well as nuclear safety. All safety consideration are affected by common points of beliefs, attitudes, behaviour, and cultural differences, closely linked to a shared system of values and standards. The paper poses questions and tries to find answers relative to issues like: - how to assess progress; - specific organizational indicators of a progressive safety culture; - detection of incipient weaknesses in safety culture (organizational issues, employee issues, technology issues); - revitalizing a weakened safety culture; - overall assesment of safety culture; - general evaluation model. In conclusion, there is no consistent and

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...

Inherent Difference in Saliency for Generators with Different PM Materials

Directory of Open Access Journals (Sweden)

Sandra Eriksson

2014-01-01

Full Text Available The inherent differences between salient and nonsalient electrical machines are evaluated for two permanent magnet generators with different configurations. The neodymium based (NdFeB permanent magnets (PMs in a generator are substituted with ferrite magnets and the characteristics of the NdFeB generator and the ferrite generator are compared through FEM simulations. The NdFeB generator is a nonsalient generator, whereas the ferrite machine is a salient-pole generator, with small saliency. The two generators have almost identical properties at rated load operation. However, at overload the behaviour differs between the two generators. The salient-pole, ferrite generator has lower maximum torque than the NdFeB generator and a larger voltage drop at high current. It is concluded that, for applications where overload capability is important, saliency must be considered and the generator design adapted according to the behaviour at overload operation. Furthermore, if the maximum torque is the design criteria, additional PM mass will be required for the salient-pole machine.

Managing inherent complexity for sustainable walleye fisheries in Lake Erie

Science.gov (United States)

Roseman, Edward F.; Drouin, Richard; Gaden, Marc; Knight, Roger; Tyson, Jeff; Zhao, Yingming; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

2012-01-01

In Lake Erie, Walleye (Sander vitreus vitreus) is king. The naturally occurring species is the foundation of commercial fishing operations on the Canadian side of the lake and is a much-prized sport fish on the American side. Management of Lake Erie walleye fisheries is complex and takes place in an inter-jurisdictional setting composed of resource agencies from the states of Michigan (MDNR), Ohio (ODNR), Pennsylvania (PFBC), and New York (NYDEC) and the province of Ontario (OMNR). The complexity of walleye management is exacerbated by interactions among environmental and ecological changes in Lake Erie, complex life-history characteristics of the species, public demand for walleye, and cultural/governance differences among managing groups and their respective constituents. Success of future management strategies will largely hinge upon our ability to understand these inherent complexities and to employ tactics that successfully accommodate stock productivity and human demand in a highly dynamic environment. In this report, we review the history of Lake Erie walleye management, outline the multi-jurisdictional process for international management of walleye, and discuss strategies to address challenges facing managers.

The next generation of power reactors - safety characteristics

International Nuclear Information System (INIS)

Modro, S.M.

1995-01-01

The next generation of commercial nuclear power reactors is characterized by a new approach to achieving reliability of their safety systems. In contrast to current generation reactors, these designs apply passive safety features that rely on gravity-driven transfer processes or stored energy, such as gas-pressurized accumulators or electric batteries. This paper discusses the passive safety system of the AP600 and Simplified Boiling Water Reactor (SBWR) designs

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...

Introduction to safety theory

International Nuclear Information System (INIS)

Meyna, A.

1982-01-01

After a general introduction to safety theory, safety characteristics are defined and quantified. This is followed by a calculation of the safety characteristics of simple, safety-relevant systems in general and in consideration of common-mode errors. The qualitative and quantitative role of human errors is discussed for various models, and a simple man-machine model is developed for investigation of common-mode errors and human error. The main part of the paper deals with safety analysis in complex systems. After a general review, the common inductive and deductive methods of analysis are presented and commented on and their fields of application discussed. Analytical and simulation codes are presented as methods of evaluation for big, complex event trees - i.e. ''hazard trees in the sense of safety engineering (as a subset of safety relevance). After a basic classification and mathematical formulation of Markovian processes, the author shows that these may be used successfully for calculation of safety characteristics if transition rates are constant and if the number of system states is limited. (orig./RW) [de

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

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.

Advanced power reactors with improved safety characteristics

International Nuclear Information System (INIS)

Birkhofer, A.

1994-01-01

The primary objective of nuclear safety is the protection of individuals, society and environment against radiological hazards from accidental releases of radioactive materials contained in nuclear reactors. Hereto, these materials are enclosed by several successive barriers and the barriers protected against mishaps and accidents by a multi-level system of safety precautions. The evolution of reactor technology continuously improves this concept and its implementation. At a world-wide scale, several advanced reactor concepts are currently being considered, some of them already at a design stage. Essential safety objectives include both further strengthening the prevention of accidents and improving the containment of fission products should an accident occur. The proposed solutions differ considerably with regard to technical principles, plant size and time scales considered for industrial application. Two typical approaches can be distinguished: The first approach basically aims at an evolution of power reactors currently in use, taking into account the findings from safety research and from operation of current plants. This approach makes maximum use of proven technology and operating experience but may nevertheless include new safety features. The corresponding designs are often termed 'large evolutionary'. The second approach consists in more fundamental changes compared to present designs, often with strong emphasis on specific passive features protecting the fuel and fuel cladding barriers. Owing to the nature and capability of those passive features such 'innovative designs' are mostly smaller in power output. The paper describes the basic objectives of such developments and illustrates important technical concepts focusing on next generation plants, i.e. designs to be available for industrial application until the end of this decade. 1 tab. (author)

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

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

Video Game Structural Characteristics: A New Psychological Taxonomy

Science.gov (United States)

King, Daniel; Delfabbro, Paul; Griffiths, Mark

2010-01-01

Excessive video game playing behaviour may be influenced by a variety of factors including the structural characteristics of video games. Structural characteristics refer to those features inherent within the video game itself that may facilitate initiation, development and maintenance of video game playing over time. Numerous structural…

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.

ITER safety and operational scenario

International Nuclear Information System (INIS)

Shimomura, Y.; Saji, G.

1998-01-01

The safety and environmental characteristics of ITER and its operational scenario are described. Fusion has built-in safety characteristics without depending on layers of safety protection systems. Safety considerations are integrated in the design by making use of the intrinsic safety characteristics of fusion adequate to the moderate hazard inventories. In addition to this, a systematic nuclear safety approach has been applied to the design of ITER. The safety assessment of the design shows how ITER will safely accommodate uncertainties, flexibility of plasma operations, and experimental components, which is fundamental in ITER, the first experimental fusion reactor. The operation of ITER will progress step by step from hydrogen plasma operation with low plasma current, low magnetic field, short pulse and low duty factor without fusion power to deuterium-tritium plasma operation with full plasma current, full magnetic field, long pulse and high duty factor with full fusion power. In each step, characteristics of plasma and optimization of plasma operation will be studied which will significantly reduce uncertainties and frequency/severity of plasma transient events in the next step. This approach enhances reliability of ITER operation. (orig.)

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...

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

[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.

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

Use of ultrasounds in the food industry-Methods and effects on quality, safety, and organoleptic characteristics of foods: A review.

Science.gov (United States)

Arvanitoyannis, Ioannis S; Kotsanopoulos, Konstantinos V; Savva, Amalia G

2017-01-02

The use of ultrasounds has recently gained significant interest in the food industry mainly due to the new trends of consumers toward functional foods. Offering several advantages, this form of energy can be applied for the improvement of qualitative characteristics of high-quality foods as well as for assuring safety of a vast variety of foodstuffs, and at the same time minimizing any negative effects of the sensory characteristics of foods. Furthermore, the non-destructive nature of this technology offers several opportunities for the compositional analysis of foods. However, further research is required for the improvement of related techniques and the reduction of application costs in order to render this technology efficient for industrial use. This review paper covers the main applications of ultrasounds as well as several advantages of the use of the technology in combination with conventional techniques. The effects of ultrasounds on the characteristics, microbial safety, and quality of several foods are also detailed.

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.

Unprotected Accident Analyses of the 1200MWe GEN-IV Sodium-Cooled Fast Reactor Using the SSC-K Code

International Nuclear Information System (INIS)

Kwon, Young Min; Lee, Kwi Lim; Ha, Kwi Seok; Jeong, Hae Yong; Chang, Won Pyo; Seok, Su Dong; Lee, Yong Bum

2010-02-01

A conceptual design of an advanced breakeven sodium-cooled fast reactor (G4SFR) has recently been developed by KAERI under the national nuclear R and D plan. The G4SFR is a 1,200MWe metal-fueled pool-type sodium-cooled fast reactor adopting advanced safety design features. The G4SFR development plan focuses on particular technology development efforts to effectively meet the goals of the Generation-IV (GEN-IV) nuclear system such as efficient utilization of resources, economic competitiveness, a high standard of safety, and enhanced proliferation resistance. To enhance the safety of G4SFR, advanced design features of metal-fueled core, simple and large sodium-inventory primary heat transport system, and passive safety decay heat removal system are included in the reactor design. To evaluate potential safety characteristics of such advanced design features, the plant responses and safety margins were investigated using the system transient code SSC-K for three unprotected accidents of UTOP, ULOF, and ULOHS. It was shown that the G4SFR design has inherent and passive safety characteristics and is accommodating the selected ATWS events. The inherent safety mechanism of the reactor design makes the core shutdown with sufficient margin and passive removal of decay heat with matching the core power to heat sink by passive self-regulation. The self-regulation of power without scram is mainly due to the inherent negative reactivity feedback in conjunction with the large thermal inertia of the primary heat transport system and the passive decay heat removal. Such favorable inherent and passive safety behaviors of G4SFR are expected to virtually exclude the probability of severe accidents with potential for core damage

Micro-Encapsulated Phase Change Materials: A Review of Encapsulation, Safety and Thermal Characteristics

Directory of Open Access Journals (Sweden)

Ahmed Hassan

2016-10-01

Full Text Available Phase change materials (PCMs have been identified as potential candidates for building energy optimization by increasing the thermal mass of buildings. The increased thermal mass results in a drop in the cooling/heating loads, thus decreasing the energy demand in buildings. However, direct incorporation of PCMs into building elements undermines their structural performance, thereby posing a challenge for building integrity. In order to retain/improve building structural performance, as well as improving energy performance, micro-encapsulated PCMs are integrated into building materials. The integration of microencapsulation PCMs into building materials solves the PCM leakage problem and assures a good bond with building materials to achieve better structural performance. The aim of this article is to identify the optimum micro-encapsulation methods and materials for improving the energy, structural and safety performance of buildings. The article reviews the characteristics of micro-encapsulated PCMs relevant to building integration, focusing on safety rating, structural implications, and energy performance. The article uncovers the optimum combinations of the shell (encapsulant and core (PCM materials along with encapsulation methods by evaluating their merits and demerits.

The integral fast reactor

International Nuclear Information System (INIS)

Till, C.E.

1987-01-01

On April 3rd, 1986, two demonstrations of the inherent capability of sodium-cooled fast reactors to survive unprotected loss of cooling accidents were carried out on the experimental sodium-cooled power reactor, EBR-II, on the Idaho site of Argonne National Laboratory. Transients potentially of the most serious kind, one an unprotected loss of flow, the other an unprotected loss of heat sink, both initiated from full power. In both cases the reactor quietly shut itself down, without damage of any kind. These tests were a part of the on-going development program at Argonne to develop an advanced reactor with significant new inherent safety characteristics. Called the integral fast reactor, or IFR, the basic thrust is to develop everything that is needed for a complete nuclear power system - reactor, closed fuel cycle, and waste processing - as a single optimized entity, and, for simplicity in concept, as an integral part of a single plant. The particular selection of reactor materials emphasizes inherent safety characteristics also makes possible a simplified close fuel cycle and waste process improvements. The paper describes the IFR concept, the inherent safety, tests, and status of IFR development today

Safety climate in the US federal wildland fire management community: influences of organizational, environmental, group, and individual characteristics

Science.gov (United States)

Anne E. Black; Brooke Baldauf McBride

2013-01-01

This study examined the effects of organisational, environmental, group and individual characteristics on five components of safety climate (High Reliability Organising Practices, Leadership, Group Culture, Learning Orientation and Mission Clarity) in the US federal wildland fire management community. Of particular interest were differences between perceptions based on...

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

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

Characteristics of unit-level patient safety culture in hospitals in Japan: a cross-sectional study.

Science.gov (United States)

Fujita, Shigeru; Seto, Kanako; Kitazawa, Takefumi; Matsumoto, Kunichika; Hasegawa, Tomonori

2014-10-22

Patient safety culture (PSC) has an important role in determining safety and quality in healthcare. Currently, little is known about the status of unit-level PSC in hospitals in Japan. To develop appropriate strategies, characteristics of unit-level PSC should be investigated. Work units may be classified according to the characteristics of PSC, and common problems and appropriate strategies may be identified for each work unit category. This study aimed to clarify the characteristics of unit-level PSC in hospitals in Japan. In 2012, a cross-sectional study was conducted at 18 hospitals in Japan. The Hospital Survey on Patient Safety Culture questionnaire, developed by the United States Agency for Healthcare Research and Quality, was distributed to all healthcare workers (n =12,076). Percent positive scores for 12 PSC sub-dimensions were calculated for each unit, and cluster analysis was used to categorise the units according to the percent positive scores. A generalised linear mixed model (GLMM) was used to analyse the results of the cluster analysis, and odds ratios (ORs) for categorisation as high-PSC units were calculated for each unit type. A total of 9,124 respondents (75.6%) completed the questionnaire, and valid data from 8,700 respondents (72.0%) were analysed. There were 440 units in the 18 hospitals. According to the percent positive scores for the 12 sub-dimensions, the 440 units were classified into 2 clusters: high-PSC units (n =184) and low-PSC units (n =256). Percent positive scores for all PSC sub-dimensions for high-PSC units were significantly higher than those for low-PSC units. The GLMM revealed that the combined unit type of 'Obstetrics and gynaecology ward, perinatal ward or neonatal intensive care unit' was significantly more likely to be categorised as high-PSC units (OR =9.7), and 'Long-term care ward' (OR =0.2), 'Rehabilitation unit' (OR =0.2) and 'Administration unit' (OR =0.3) were significantly less likely to be categorised as high

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

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 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

PRISM: An innovative liquid metal fast breeder reactor

International Nuclear Information System (INIS)

Kruger, G.B.; Boardman, C.E.; Olich, E.E.; Switick, D.M.

1986-01-01

This paper describes an innovative sodium-cooled reactor concept employing small certified reactor modules coupled with a standardized steam generator system. The total plant employs nine PRISM reactors (power reactor inherently safe module) in three 415 MWe power blocks. The PRISM design concept utilizes inherent safety characteristics and modularity to improve licensability, reduce owner's risk, and reduce costs. The relatively small size of each reactor module facilitates the use of passive, inherent self-shutdown and shutdown heat removal features, which permit design simplification and reduction of safety-related systems. It is proposed that a single PRISM module be used in a full-scale integrated reactor safety test. Results from the test would be used to obtain NRC certification of the standard design

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)

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)

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

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)

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

Nuclear Safety Culture

International Nuclear Information System (INIS)

2017-01-01

Ethics is caring about people and Safety is caring that no physical harm comes to people.Therefore Safety is a type of Ethical Behavior. Culture: is The Way We Do Things Here.Safety Culture is mixture of organization traditions, values, attitudes and behaviors modeled by Its leaders and internalized by its members that serve to make nuclear safety the overriding priority. Safety Culture is that assembly of characteristics and attitudes in Organisations and individuals which established that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance

Safety characteristics of hydrogen at super ambient conditions: lubricant contamination influencing the auto ignition temperature

International Nuclear Information System (INIS)

Liebner, C.; Schroder, V.; Holtappels, K.

2006-01-01

Inventing hydrogen as a commonly used future energy carrier the long term social acceptance as well as the clean energy image strongly depends upon the safety of its applications. The safety characteristics of hydrogen build a special challenge e.g. in the field of combustion engine development. Small impurities from lubricants used in motors and pumps, may serve as radical source, strongly influencing the auto ignition temperature of hydrogen. Auto Ignition Temperature (AIT) of Hydrogen-Air mixtures were measured in closed autoclaves made from stainless steel, similar to the closed bomb method described in the European standard EN 1839. Initial pressures of 10 bar(a) and 30 bar(a) of a premixed stoichiometric hydrogen-air mixture were investigated. Auto ignition can be obtained about 100 K below the standard AIT (560 deg C, atmospheric pressure) and 300 K below the standard AIT when contaminated through motor oil. (authors)

Fall Protection Characteristics of Safety Belts and Human Impact Tolerance.

Science.gov (United States)

Hino, Yasumichi; Ohdo, Katsutoshi; Takahashi, Hiroki

2014-08-23

Many fatal accidents due to falls from heights have occurred at construction sites not only in Japan but also in other countries. This study aims to determine the fall prevention performance of two types of safety belts: a body belt 1) , which has been used for more than 40 yr in the Japanese construction industry as a general type of safety equipment for fall accident prevention, and a full harness 2, 3) , which has been used in many other countries. To determine human tolerance for impact trauma, this study discusses features of safety belts with reference 4-9) to relevant studies in the medical science, automobile crash safety, and aircrew safety. For this purpose, simple drop tests were carried out in a virtual workplace to measure impact load, head acceleration, and posture in the experiments, the Hybrid-III pedestrian model 10) was used as a human dummy. Hybrid-III is typically employed in official automobile crash tests (New Car Assessment Program: NCAP) and is currently recognized as a model that faithfully reproduces dynamic responses. Experimental results shows that safety performance strongly depends on both the variety of safety belts used and the shock absorbers attached onto lanyards. These findings indicate that fall prevention equipment, such as safety belts, lanyards, and shock absorbers, must be improved to reduce impact injuries to the human head and body during falls.

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 ...

Technical features of ABWR safety systems

International Nuclear Information System (INIS)

Sugisaki, Toshihiko; Tominaga, Kenji; Horiuchi, Tetsuo

1986-01-01

The engineering safety facilities of ABWRs have been disigned so as to have many excellent characteristics such as safety, reliability and economy, reflecting the merit of adopting new technology such as internal pumps and new control rod driving mechanism, and coupled with the safety peculiar to BWRs. In this paper, about ECCS, containment vessels and others which compose the engineering safety facilities of ABWRs, the characteristics related to the safety owing to the adoption of internal pumps and others, and the evaluation of the performance at the time of various accidents are discussed. As the results of safety evaluation, it was clarified that due to the safety peculiar to ABWRs and the characteristics of the safety facilities, the large increases of safety, reliability and economy have been planned in the ABWRs, and for example, core flooding can be maintained even at the time of a hypothetical loss of coolant accident. BWRs have the simple system constitution, good self controllability, large natural circulation ability, simple operation control method and excellent ability of confining heat and radioactivity. BWRs have three safety functions to stop reactors, to remove heat from reactors, and to confine radioactive substances. These functions of ABWRs were evaluated, and very high safety was confirmed. (Kako, I.)

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

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

Nurse characteristics, leadership, safety climate, emotional labour and intention to stay for nurses: a structural equation modelling approach.

Science.gov (United States)

Liang, Hui-Yu; Tang, Fu-In; Wang, Tze-Fang; Lin, Kai-Ching; Yu, Shu

2016-12-01

The aim of this study was to propose a theoretical model and apply it to examine the structural relationships among nurse characteristics, leadership characteristics, safety climate, emotional labour and intention to stay for hospital nurses. Global nursing shortages negatively affect the quality of care. The shortages can be reduced by retaining nurses. Few studies have independently examined the relationships among leadership, safety climate, emotional labour and nurses' intention to stay; more comprehensive theoretical foundations for examining nurses' intention to stay and its related factors are lacking. Cross-sectional. A purposive sample of 414 full-time nurses was recruited from two regional hospitals in Taiwan. A structured questionnaire was used to collect data from November 2013-June 2014. Structural equation modelling was employed to test the theoretical models of the relationships among the constructs. Our data supported the theoretical model. Intention to stay was positively correlated with age and the safety climate, whereas working hours per week and emotional labour were negatively correlated. The nursing position and transformational leadership indirectly affected intention to stay; this effect was mediated separately by emotional labour and the safety climate. Our data supported the model fit. Our findings provide practical implications for healthcare organizations and administrators to increase nurses' intent to stay. Strategies including a safer climate, appropriate working hours and lower emotional labour can directly increase nurses' intent to stay. Transformational leadership did not directly influence nurses' intention to stay; however, it reduced emotional labour, thereby increasing intention to stay. © 2016 John Wiley & Sons Ltd.

Review of the safety concept for fusion reactor concepts and transferability of the nuclear fission regulation to potential fusion power plants

Energy Technology Data Exchange (ETDEWEB)

Raeder, Juergen; Weller, Arthur; Wolf, Robert [Max-Planck-Institut fuer Plasmaphysik (IPP), Garching (Germany); Jin, Xue Zhou; Boccaccini, Lorenzo V.; Stieglitz, Robert; Carloni, Dario [Karlsruher Institute fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany); Pistner, Christoph [Oeko-Institut e.V., Darmstadt (Germany); Herb, Joachim [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Koeln (Germany)

2016-01-15

This paper summarizes the current state of the art in science and technology of the safety concept for future fusion power plants (FPPs) and examines the transferability of the current nuclear fission regulation to the concepts of future fusion power plants. At the moment there exist only conceptual designs of future fusion power plants. The most detailed concepts with regards to safety aspects were found in the European Power Plant Conceptual Study (PPCS). The plant concepts discussed in the PPCS are based on magnetic confinement of the plasma. The safety concept of fusion power plants, which has been developed during the last decades, is based on the safety concepts of installations with radioactive inventories, especially nuclear fission power plants. It applies the concept of defence in depth. However, there are specific differences between the implementations of the safety concepts due to the physical and technological characteristics of fusion and fission. It is analysed whether for fusion a safety concept is required comparable to the one of fission. For this the consequences of a purely hypothetical release of large amounts of the radioactive inventory of a fusion power plant and a fission power plant are compared. In such an event the evacuation criterion outside the plant is exceeded by several orders of magnitude for a fission power plant. For a fusion power plant the expected radiological consequences are of the order of the evacuation criterion. Therefore, a safety concept is also necessary for fusion to guarantee the confinement of the radioactive inventory. The comparison between the safety concepts for fusion and fission shows that the fundamental safety function ''confinement of the radioactive materials'' can be transferred directly in a methodical way. For a fusion power plant this fundamental safety function is based on both, physical barriers as well as on active retention functions. After the termination of the fusion

The PRISM concept for a safe, economic and testable liquid metal fast reactor plant

International Nuclear Information System (INIS)

Berglund, R.C.; Salerno, L.N.; Tippets, F.E.

1987-01-01

The PRISM project is underway at General Electric as part of an advanced reactor conceptual design program sponsored by the US Department of Energy. The PRISM concept emphasizes inherent safety, modular construction, and factory fabrication. These features are intended to improve the basis for public acceptance, reduce cost,improve licensability, and reduce the risk of schedule delays and cost increases during construction. A PRISM power plant comprises a number of reactor modules. The relatively small size of the reactor module facilitates the use of passive, inherent self-shutdown and shutdown heat removal features for safe accommodation of accidents. These inherent safety features permit simplification and reduction of conventional safety-related systems in the plant. Testing of a full-size prototype reactor module is planned in the late 1990's to demonstrate these inherent safety characteristics. It is intended that the results of the test be used to obtain certification of the design by the US Nuclear Regulatory Commission preparatory to use of reactor modules built to this standard design in licensed commercial plants

Inherent Electrochemistry and Charge Transfer Properties of Few-Layer Two Dimensional Ti3C2Tx MXene

KAUST Repository

Nayak, Pranati

2018-05-25

We report the effect of Ti3C2Tx MXene flake thickness on its inherent electrochemistry and heterogeneous charge transfer characteristics. It is shown that the Ti3C2Tx undergoes irreversible oxidation in the positive potential window, which strongly depends on the flake thickness and pH of the electrolyte. Few-layer Ti3C2Tx exhibits faster electron transfer kinetics (k0=0.09533 cm/s) with Fe(CN)64−/3− redox mediator compared to multi-layer Ti3C2Tx (k0= 0.00503 cm/s). In addition, few-layer free standing Ti3C2Tx film electrode remains intact after enduring irreversible oxidation.

Inherent Electrochemistry and Charge Transfer Properties of Few-Layer Two Dimensional Ti3C2Tx MXene

KAUST Repository

Nayak, Pranati; Jiang, Qiu; Mohanraman, Rajeshkumar; Anjum, Dalaver H.; Hedhili, Mohamed N.; Alshareef, Husam N.

2018-01-01

We report the effect of Ti3C2Tx MXene flake thickness on its inherent electrochemistry and heterogeneous charge transfer characteristics. It is shown that the Ti3C2Tx undergoes irreversible oxidation in the positive potential window, which strongly depends on the flake thickness and pH of the electrolyte. Few-layer Ti3C2Tx exhibits faster electron transfer kinetics (k0=0.09533 cm/s) with Fe(CN)64−/3− redox mediator compared to multi-layer Ti3C2Tx (k0= 0.00503 cm/s). In addition, few-layer free standing Ti3C2Tx film electrode remains intact after enduring irreversible oxidation.

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...

Characteristics of self-rating and rating by others of safety behavior

International Nuclear Information System (INIS)

Fukui, Hirokazu; Yoshida, Michio; Sugiman, Toshio; Watanabe, Toshie

2002-01-01

It is known that in questionnaire surveys in general, behavior that are recognized as socially desirable are more highly rated by the actors themselves than by others. Safety behavior can be viewed as behavior closely related to social desirability. Therefore, in the present study, multiple regression analysis was conducted to examine how the self-rating and rating by others of 'safety confirmation/report', which serves as one of the rating scales of safety climate and criterion for safety behavior rating, are related to other factors of safety climate. The analysis results reveal that the self-rating of 'safety confirmation/report' tends to give better scores than rating by others and is more strongly related to individual factors than organizational environmental factors. Meanwhile, the rating by others of safety confirmation/report' is strongly related to organizational environmental factors and demonstrates little or no link with individual factors. It can be said, therefore, that the rating by others of 'safety confirmation/report' reflects more accurately the influence of the organizational environment concerned than self-rating, and hence is more appropriate as a rating scale for safety climate. (author)

Characteristics of self-rating and rating by others of safety behavior

Energy Technology Data Exchange (ETDEWEB)

Fukui, Hirokazu [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan); Yoshida, Michio; Sugiman, Toshio; Watanabe, Toshie [Japan Institute for Group Dynamics, Fukuoka (Japan)

2002-09-01

It is known that in questionnaire surveys in general, behavior that are recognized as socially desirable are more highly rated by the actors themselves than by others. Safety behavior can be viewed as behavior closely related to social desirability. Therefore, in the present study, multiple regression analysis was conducted to examine how the self-rating and rating by others of 'safety confirmation/report', which serves as one of the rating scales of safety climate and criterion for safety behavior rating, are related to other factors of safety climate. The analysis results reveal that the self-rating of 'safety confirmation/report' tends to give better scores than rating by others and is more strongly related to individual factors than organizational environmental factors. Meanwhile, the rating by others of safety confirmation/report' is strongly related to organizational environmental factors and demonstrates little or no link with individual factors. It can be said, therefore, that the rating by others of 'safety confirmation/report' reflects more accurately the influence of the organizational environment concerned than self-rating, and hence is more appropriate as a rating scale for safety climate. (author)

Characteristics of the safety climate in teams with world-class safety ...

African Journals Online (AJOL)

Accidents and incidents in the construction environment are not reduced or eliminated effectively, despite numerous efforts made to improve health and safety in the industry. An extensive field of research has been conducted on how teams in the construction environment interact to deliver a project successfully in terms of ...

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

Recent research on inherent molecular structure, physiochemical properties, and bio-functions of food and feed-type Avena sativa oats and processing-induced changes revealed with molecular microspectroscopic techniques

Energy Technology Data Exchange (ETDEWEB)

Prates, Luciana Louzada [Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Yu, Peiqiang [Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

2017-05-16

Avena sativa oat is a cereal widely used as human food and livestock feed. However, the low metabolized energy and the rapid rumen degradations of protein and starch have limited the use of A. sativa oat grains. To overcome this disadvantage, new A. sativa oat varieties have been developed. Additionally, heat-related processing has been performed to decrease the degradation rate and improve the absorption of amino acids in the small intestine. The nutritive value is reflected by both chemical composition and inherent molecular structure conformation. However, the traditional wet chemical analysis is not able to detect the inherent molecular structures within an intact tissue. The advanced synchrotron-radiation and globar-based molecular microspectroscopy have been developed recently and applied to study internal molecular structures and the processing induced structure changes in A. sativa oats and reveal how molecular structure changes in relation to nutrient availability. This review aimed to obtain the recent information regarding physiochemical properties, molecular structures, metabolic characteristics of protein, and the heat-induced changes in new A. sativa oat varieties. The use of the advanced vibrational molecular spectroscopy was emphasized, synchrotron- and globar-based (micro)spectroscopy, to reveal the inherent structure of A. sativa oats at cellular and molecular levels and to reveal the heat processing effect on the degradation characteristics and the protein molecular structure in A. sativa oats. The relationship between nutrient availability and protein molecular inherent structure was also presented. Information described in this review gives better insight in the physiochemical properties, molecular structure, and the heat-induced changes in A. sativa oat detected with advanced molecular spectroscopic techniques in combinination with conventional nutrition study techniques.

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.

Safety Principles

Directory of Open Access Journals (Sweden)

V. A. Grinenko

2011-06-01

Full Text Available The offered material in the article is picked up so that the reader could have a complete representation about concept “safety”, intrinsic characteristics and formalization possibilities. Principles and possible strategy of safety are considered. A material of the article is destined for the experts who are taking up the problems of safety.

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

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).

Recent developments in IFE safety and tritium research and considerations for future nuclear fusion facilities

International Nuclear Information System (INIS)

Reyes, Susana; Anklam, Tom; Meier, Wayne; Campbell, Patrick; Babineau, Dave; Becnel, James; Taylor, Craig; Coons, Jim

2016-01-01

Highlights: • The safety characteristics and at risk inventories in an IFE facility are discussed. • The primary nuclear hazard is the potential exposure of workers and/or the public to tritium and/or neutronically activated products. • Recent technology developments in tritium processing are key for minimization of inventories. • Initial safety studies indicate that hazards associated to the use of liquid lithium can be appropriately managed. • Simulation of worst-case scenarios indicate that the accident consequences are limited and below the limit for public evacuation. - Abstract: Over the past five years, the fusion energy group at Lawrence Livermore National Laboratory (LLNL) has made significant progress in the area of safety and tritium research for Inertial Fusion Energy (IFE). Focus has been driven towards the minimization of inventories, accident safety, development of safety guidelines and licensing considerations. Recent technology developments in tritium processing and target fill have had a major impact on reduction of tritium inventories in the facility. A safety advantage of inertial fusion energy using indirect-drive targets is that the structural materials surrounding the fusion reactions can be protected from target emissions by a low-pressure chamber fill gas, therefore eliminating plasma-material erosion as a source of activated dust production. An important inherent safety advantage of IFE when compared to other magnetic fusion energy (MFE) concepts that have been proposed to-date (including ITER), is that loss of plasma control events with the potential to damage the first wall, such as disruptions, are non-conceivable, therefore eliminating a number of potential accident initiators and radioactive in-vessel source term generation. In this paper, we present an overview of the safety assessments performed to-date, comparing results to the US DOE Fusion Safety Standards guidelines and the recent lessons-learnt from ITER safety and

Recent developments in IFE safety and tritium research and considerations for future nuclear fusion facilities

Energy Technology Data Exchange (ETDEWEB)

Reyes, Susana, E-mail: reyes20@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA (United States); Anklam, Tom; Meier, Wayne; Campbell, Patrick [Lawrence Livermore National Laboratory, Livermore, CA (United States); Babineau, Dave; Becnel, James [Savannah River National Laboratory, Aiken, SC (United States); Taylor, Craig; Coons, Jim [Los Alamos National Laboratory, Los Alamos, NM (United States)

2016-11-01

Highlights: • The safety characteristics and at risk inventories in an IFE facility are discussed. • The primary nuclear hazard is the potential exposure of workers and/or the public to tritium and/or neutronically activated products. • Recent technology developments in tritium processing are key for minimization of inventories. • Initial safety studies indicate that hazards associated to the use of liquid lithium can be appropriately managed. • Simulation of worst-case scenarios indicate that the accident consequences are limited and below the limit for public evacuation. - Abstract: Over the past five years, the fusion energy group at Lawrence Livermore National Laboratory (LLNL) has made significant progress in the area of safety and tritium research for Inertial Fusion Energy (IFE). Focus has been driven towards the minimization of inventories, accident safety, development of safety guidelines and licensing considerations. Recent technology developments in tritium processing and target fill have had a major impact on reduction of tritium inventories in the facility. A safety advantage of inertial fusion energy using indirect-drive targets is that the structural materials surrounding the fusion reactions can be protected from target emissions by a low-pressure chamber fill gas, therefore eliminating plasma-material erosion as a source of activated dust production. An important inherent safety advantage of IFE when compared to other magnetic fusion energy (MFE) concepts that have been proposed to-date (including ITER), is that loss of plasma control events with the potential to damage the first wall, such as disruptions, are non-conceivable, therefore eliminating a number of potential accident initiators and radioactive in-vessel source term generation. In this paper, we present an overview of the safety assessments performed to-date, comparing results to the US DOE Fusion Safety Standards guidelines and the recent lessons-learnt from ITER safety and

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.

ITER-FEAT safety

International Nuclear Information System (INIS)

Gordon, C.W.; Bartels, H.-W.; Honda, T.; Raeder, J.; Topilski, L.; Iseli, M.; Moshonas, K.; Taylor, N.; Gulden, W.; Kolbasov, B.; Inabe, T.; Tada, E.

2001-01-01

Safety has been an integral part of the design process for ITER since the Conceptual Design Activities of the project. The safety approach adopted in the ITER-FEAT design and the complementary assessments underway, to be documented in the Generic Site Safety Report (GSSR), are expected to help demonstrate the attractiveness of fusion and thereby set a good precedent for future fusion power reactors. The assessments address ITER's radiological hazards taking into account fusion's favourable safety characteristics. The expectation that ITER will need regulatory approval has influenced the entire safety design and assessment approach. This paper summarises the ITER-FEAT safety approach and assessments underway. (author)

Medium-size high-temperature gas-cooled reactor

International Nuclear Information System (INIS)

Peinado, C.O.; Koutz, S.L.

1980-08-01

This report summarizes high-temperature gas-cooled reactor (HTGR) experience for the 40-MW(e) Peach Bottom Nuclear Generating Station of Philadelphia Electric Company and the 330-MW(e) Fort St. Vrain Nuclear Generating Station of the Public Service Company of Colorado. Both reactors are graphite moderated and helium cooled, operating at approx. 760 0 C (1400 0 F) and using the uranium/thorium fuel cycle. The plants have demonstrated the inherent safety characteristics, the low activation of components, and the high efficiency associated with the HTGR concept. This experience has been translated into the conceptual design of a medium-sized 1170-MW(t) HTGR for generation of 450 MW of electric power. The concept incorporates inherent HTGR safety characteristics [a multiply redundant prestressed concrete reactor vessel (PCRV), a graphite core, and an inert single-phase coolant] and engineered safety features

Safe Speeds and Credible Speed Limits (SaCredSpeed): New Vision for Decision Making on Speed Management.

NARCIS (Netherlands)

Aarts, L. Nes, N. van Wegman, F.C.M. Schagen, I.N.L.G. van & Louwerse, R.

2009-01-01

Speed is an inherent characteristic of mobility and a hazard to safety. Several approaches exist of how to manage speed. In the Netherlands, the emphasis has mainly been on harm minimisation during the last decades, due to the implementation of the Sustainable Safety vision. Speed management remains

Specialists' meeting on passive and active safety features of LMFRs

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-07-01

The objective of the meeting was to discuss and exchange information on passive and active safety concepts and to find some reasonable coupling of these concept, aiming at firmer establishment of plant safety and at the same time of plant cost reduction. The following main topical areas were discussed by delegates: (1) Overview - review of national status on the safety design approaches of LMFRs (2) Safety characteristics of decay heat removal system (DHRS) (3) Safety characteristics of reactor protection system (RPS) and reactor shutdown system (RSS) (4) Core safety characteristics.

Specialists' meeting on passive and active safety features of LMFRs

International Nuclear Information System (INIS)

1991-01-01

The objective of the meeting was to discuss and exchange information on passive and active safety concepts and to find some reasonable coupling of these concept, aiming at firmer establishment of plant safety and at the same time of plant cost reduction. The following main topical areas were discussed by delegates: (1) Overview - review of national status on the safety design approaches of LMFRs (2) Safety characteristics of decay heat removal system (DHRS) (3) Safety characteristics of reactor protection system (RPS) and reactor shutdown system (RSS) (4) Core safety characteristics

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.

Human characteristics affecting nuclear safety

International Nuclear Information System (INIS)

Skof, M.

1990-01-01

It is important to collect data about human behavior in work situation and data about work performance. On the basis of these data we can analyse human errors. Human reliability analysis gives us the input data to improve human behavior at a work place. We have tried to define those human characteristics that have impact on safe work and operation. Estimation of a work place was used for determination of important human characteristics. Performance estimations were used to define the availability of workers at a work place. To our experience it is very important to pay attention to R.A. and R.C. also in the area of human factor. Data for quality assurance in the area of human factor should be collected from selection procedure (the level of cognitive and conative abilities, the level of physical characteristics, the level of education and other personal data). Data for quality control should be collected from the periodical examinations of annual checking and evaluation of human working capacity as well as from training. For quality control of every day human performance data of staff estimation of their daily working performance and well-being should also be collected. With all these data more effective analyses of all events in nuclear power plants could be provided. Quality assurance and quality control in the area of human factor could help us to keep the optimum performance level of the plant staff and to avoid human errors. (author). 3 refs, 3 figs

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

Job Demands-Control-Support model and employee safety performance.

Science.gov (United States)

Turner, Nick; Stride, Chris B; Carter, Angela J; McCaughey, Deirdre; Carroll, Anthony E

2012-03-01

The aim of this study was to explore whether work characteristics (job demands, job control, social support) comprising Karasek and Theorell's (1990) Job Demands-Control-Support framework predict employee safety performance (safety compliance and safety participation; Neal and Griffin, 2006). We used cross-sectional data of self-reported work characteristics and employee safety performance from 280 healthcare staff (doctors, nurses, and administrative staff) from Emergency Departments of seven hospitals in the United Kingdom. We analyzed these data using a structural equation model that simultaneously regressed safety compliance and safety participation on the main effects of each of the aforementioned work characteristics, their two-way interactions, and the three-way interaction among them, while controlling for demographic, occupational, and organizational characteristics. Social support was positively related to safety compliance, and both job control and the two-way interaction between job control and social support were positively related to safety participation. How work design is related to employee safety performance remains an important area for research and provides insight into how organizations can improve workplace safety. The current findings emphasize the importance of the co-worker in promoting both safety compliance and safety participation. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Important viewpoints proposed for a safety approach of HTGR reactors in Europe

International Nuclear Information System (INIS)

Brinkmann, G.; Pirson, J.; Ehster, S.; Dominguez, M.T.; Mansani, L.; Coe, I.; Moormann, R.; Van der Mheen, W.

2006-01-01

The inherent safety features of modular High Temperature Reactors (HTRs) make events leading to severe core damage highly unlikely and constitute the main differentiating aspects compared to LWRs. Furthermore, while a known and stable regulatory environment has long been established for Light Water Reactors (LWRs), different ways of thinking may help to develop a more appropriate licensing process for HTR-based power plants. The HTR-L project funded by the European Commission in the 5th Framework Programme was dedicated to the definition of a common and coherent European safety approach and the identification of the main licensing issues for the licensing framework of the modular HTRs. Several topics were developed during the course of this project. Due to the characteristics of the HTR design, it has been necessary to define specific defence-in-depth requirements which have then been evaluated for implementation in the safety approach. Safety-related functions appropriate for the HTR design have also had to be identified and listed. On one hand, the different possible solicitations of the fuel particles constituted the starting point for the identification of the accidental conditions (by means of the Master Logic Diagrams methodology); these accidental conditions were classified and the most appropriate methods to consider ultra low probability severe accidents were examined. On the other hand, the elements constituting the source term and, in particular, the requirements for the confinement of radioactive products and the conditions required to prevent the need for a 'conventional' containment structure have been discussed. In the definition of the safety approach, attention has been paid to the need to maintain the potentially interesting economic perspectives of HTR reactors. Key issues to be addressed in the licensing process of the HTRs have also been identified. An innovative systems, structures and components classification method has been developed and

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 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....

78 FR 27419 - Final Safety Culture Policy Statement

Science.gov (United States)

2013-05-10

... organizational characteristics are present in a culture that promotes safety and environmental responsibility. A characteristic, in this case, is a pattern of thinking, feeling, and behaving that emphasizes safety...

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

Progress on the European Safety and Environmental Assessment of Fusion Power (SEAFP)

International Nuclear Information System (INIS)

Cook, I.

1994-01-01

The Safety and Environmental Assessment of Fusion Power (SEAFP) project was set up by the European Community Fusion Programme in response to recommendations made by a high level Fusion Programme Evaluation Board. The Evaluation Board stated that fusion potentially possesses ''inherent environmental and safety advantages over all current alternatives for base load electricity generation'', but that a ''convincing demonstration'' of these potential advantages is necessary. SEAFP is undertaken by three main participants: the NET Team, The Euratom/UKAEA Association, and European industry. Other EC fusion laboratories also participate. The work embraces the outline design of fusion power stations, the safety and environmental assessment of those designs, and interactions between design and assessment to improve the design. The project began in April 1992 and will report in December 1994. In the first year of the project, five candidate blanket concepts were developed in parallel. Other aspects of design were developed as far as possible independently of the blanket designs. Assessments were made of the technical merits of the candidate designs, and scoping calculations were used to provide preliminary assessments of their accident and waste management characteristics. Accident identification studies were used to select the bounding sequences to be analysed later in detail. Targets for safety and environmental performance were developed. This phase of the study culminated, in August 1993, in the selection of two plant models, one based on a water/martensitic steel/lithium-lead blanket, the other based on a helium/vanadium alloy/lithium oxide blanket, to be developed and assessed in more detail. Other design variants will be assessed through sensitivity studies. ((orig.))

The effect of facility characteristics on patient safety, patient experience, and service availability for procedures in non-hospital-affiliated outpatient settings: A systematic review.

Science.gov (United States)

Berglas, Nancy F; Battistelli, Molly F; Nicholson, Wanda K; Sobota, Mindy; Urman, Richard D; Roberts, Sarah C M

2018-01-01

Over recent decades, numerous medical procedures have migrated out of hospitals and into freestanding ambulatory surgery centers (ASCs) and physician offices, with possible implications for patient outcomes. In response, states have passed regulations for office-based surgeries, private organizations have established standards for facility accreditation, and professional associations have developed clinical guidelines. While abortions have been performed in office setting for decades, states have also enacted laws requiring that facilities that perform abortions meet specific requirements. The extent to which facility requirements have an impact on patient outcomes-for any procedure-is unclear. We conducted a systematic review to examine the effect of outpatient facility type (ASC vs. office) and specific facility characteristics (e.g., facility accreditation, emergency response protocols, clinician qualifications, physical plant characteristics, other policies) on patient safety, patient experience and service availability in non-hospital-affiliated outpatient settings. To identify relevant research, we searched databases of the published academic literature (PubMed, EMBASE, Web of Science) and websites of governmental and non-governmental organizations. Two investigators reviewed 3049 abstracts and full-text articles against inclusion/exclusion criteria and assessed the quality of 22 identified articles. Most studies were hampered by methodological challenges, with 12 of 22 not meeting minimum quality criteria. Of 10 studies included in the review, most (6) examined the effect of facility type on patient safety. Existing research appears to indicate no difference in patient safety for outpatient procedures performed in ASCs vs. physician offices. Research about specific facility characteristics is insufficient to draw conclusions. More and higher quality research is needed to determine if there is a public health problem to be addressed through facility

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.

Work Practice, Safety and Heedfulness. Studies of Organizational Reliability in Hospitals and Nuclear Power Plants

International Nuclear Information System (INIS)

Gauthereau, Vincent

2003-01-01

The study of safety in complex systems has focused on different issues over the past decades. This focus was often linked to the conclusions of previous accidents'/incidents' analyses. When accidents were attributed to technical causes, safety research focused on technical developments. When they were later attributed to 'human errors', safety research focused on this 'component'. And when, since the mid-eighties accidents have been attributed to 'organizational factors', safety research has focused on these very same 'organizational factors'. The present thesis argues for a 'practice view' over safety to be taken. This view is mainly drawn from the field of research on High Reliability Organizations (HRO). HRO theorists' point of view on safety is that we can operate complex systems safely despite the fact that we have made them so complex that they are prone to 'normal accidents'. Humans involved in the operation of our systems actually create safety. Safety is formed through the adaptation of work practice to local conditions, and this adaptation is part of safe operation. Safety is not only a substantial quality of our socio-technical systems: the discursive dimension of safety actually seems to be a central component of safety creation. However, the adaptive ability of HRO can sometimes become their downfall. Adaptation, which is the backbone of safety, can sometimes be a drawback as well. Consequently, the practice view of safety, proposed in the present work, argues that we need to further comprehend how work practice evolves over time, and more specifically what are the inherent characteristics of work practice that create this evolution. Empirical studies from health-care and nuclear power generation highlight different details about organizational reliability. For instance, one study of planning at a nuclear power plant draws our attention to the different roles of planning in the organization. Another study, within heath-care, underlines the evolution of

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.

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

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

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

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.

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 performance indicators used by the Russian Safety Regulatory Authority in its practical activities on nuclear power plant safety regulation

International Nuclear Information System (INIS)

Khazanov, A.L.

2005-01-01

The Sixth Department of the Nuclear, Industrial and Environmental Regulatory Authority of Russia, Scientific and Engineering Centre for Nuclear and Radiation Safety process, analyse and use the information on nuclear power plants (NPPs) operational experience or NPPs safety improvement. Safety performance indicators (SPIs), derived from processing of information on operational violations and analysis of annual NPP Safety Reports, are used as tools to determination of trends towards changing of characteristics of operational safety, to assess the effectiveness of corrective measures, to monitor and evaluate the current operational safety level of NPPs, to regulate NPP safety. This report includes a list of the basic SPIs, those used by the Russian safety regulatory authority in regulatory activity. Some of them are absent in list of IAEA-TECDOC-1141 ('Operational safety performance indicators for nuclear power plants'). (author)

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.)