Kowledge-based dynamic network safety calculations. Wissensbasierte dynamische Netzsicherheitsberechnungen

Energy Technology Data Exchange (ETDEWEB)

Kulicke, B [Inst. fuer Hochspannungstechnik und Starkstromanlagen, Berlin (Germany); Schlegel, S [Inst. fuer Hochspannungstechnik und Starkstromanlagen, Berlin (Germany)

1993-06-28

An important part of network operation management is the estimation and maintenance of the security of supply. So far the control personnel has only been supported by static network analyses and safety calculations. The authors describe an expert system, which is coupled to a real time simulation program on a transputer basis, for dynamic network safety calculations. They also introduce the system concept and the most important functions of the expert system. (orig.)

NPP Krsko core calculations to improve operational safety

International Nuclear Information System (INIS)

Ivekovic, I.; Grgic, D.; Nemec, T.

2007-01-01

Calculation tools and methodology used to perform independent calculations of cumulative influence of different changes related to fuel and core operation of NPP Krsko were described. Some examples of steady state and transient results are used to illustrate potential improvements to understanding and reviewing plant safety. (author)

Operating experience: safety perspective

International Nuclear Information System (INIS)

Piplani, Vivek; Krishnamurthy, P.R.; Kumar, Neeraj; Upadhyay, Devendra

2015-01-01

Operating Experience (OE) provides valuable information for improving NPP safety. This may include events, precursors, deviations, deficiencies, problems, new insights to safety, good practices, lessons and corrective actions. As per INSAG-10, an OE program caters as a fundamental means for enhancing the defence-in-depth at NPPs and hence should be viewed as ‘Continuous Safety Performance Improvement Tool’. The ‘Convention on Nuclear Safety’ also recognizes the OE as a tool of high importance for enhancing the NPP safety and its Article 19 mandates each contracting party to establish an effective OE program at operating NPPs. The lessons drawn from major accidents at Three Mile Island, Chernobyl and Fukushima Daiichi NPPs had prompted nuclear stalwarts to change their safety perspective towards NPPs and to frame sound policies on issues like safety culture, severe accident prevention and mitigation. An effective OE program, besides correcting current/potential problems, help in proactively improving the NPP design, operating and maintenance procedures, practices, training, etc., and thus plays vital role in ensuring safe and efficient operation of NPPs. Further it enhances knowledge with regard to equipment operating characteristics, system performance trends and provides data for quantitative and qualitative safety analysis. Besides all above, an OE program inculcates a learning culture in the organisation and thus helps in continuously enhancing the expertise, technical competency and knowledge base of its staff. Nuclear and Radiation Facilities in India are regulated by Atomic Energy Regulatory Board (AERB). Operating Plants Safety Division (OPSD) of AERB is involved in managing operating experience activities. This paper provides insights about the operating experience program of OPSD, AERB (including its on-line data base namely OPSD STAR) and its utilisation in improving the regulations and safety at Indian NPPs/projects. (author)

Activation calculation and environmental safety analysis for fusion experimental breeder (FEB)

Energy Technology Data Exchange (ETDEWEB)

Kaiming, Feng [Southwest Inst. of Physics, Leshan, SC (China)

1996-04-01

An activation calculation code FDKR and decay chain data library AFDCDLIB are used to calculate the radioactivity, decay heat, dose rate and biological hazard potential (BHP) form activation products, actinides and fission products in a Fusion Experiment Breeder (FEB). The code and library are introduced briefly, and calculation results and decay curves of related hazards after one year operation with 150 MW fusion power are given. The total radioactivity inventory, decay heat and BHP are 5.74 x 10{sup 20} Bq, 8.34 MW and 4.08 x 10{sup 8} km{sup 3} of air, respectively, at shutdown. Results obtained show that the first wall of FEB can meet the nuclear waste disposal criteria for the NRC 10 CFR61 Class C after a few weeks from shutdown. The inventory of important actinides for the fuel reprocessing, such as {sup 232}U and {sup 237}Np were also calculated. It was shown that their concentrations do not excess the limit value of environmental safety required. (9 refs., 4 figs., 9 tabs.).

Nuclear criticality safety experiments, calculations, and analyses - 1958 to 1982. Volume 2. Summaries. Complilation of papers from the Transactions of the American Nuclear Society

International Nuclear Information System (INIS)

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

1982-01-01

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

Nuclear criticality safety experiments, calculations, and analyses - 1958 to 1982. Volume 2. Summaries. Complilation of papers from the Transactions of the American Nuclear Society

Energy Technology Data Exchange (ETDEWEB)

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

1982-10-21

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

Analysis and Insights About FE-Calculations of the EC-Forever-Experiments

International Nuclear Information System (INIS)

Willschuetz, H.G.; Altstadt, E.; Weiss, F.P.; Sehgal, B.R.

2002-01-01

To get an improved understanding and knowledge of the melt pool convection and the vessel creep and possible failure processes and modes occurring during the late phase of a core melt down accident the FOREVER-experiments are currently underway at the Division of Nuclear Power Safety of the Royal Institute of Technology Stockholm. These experiments are simulating the behaviour of the lower head of the RPV under the thermal loads of a convecting melt pool with decay heating, and under the pressure loads that the vessel experiences in a depressurization scenario. Due to the multi axial creep deformation of the vessel with a non-uniform temperature field these experiments are on the one hand an excellent source of data to validate numerical creep models which are developed on the basis of uniaxial creep tests. On the other hand the results of pre-test calculations can be used to optimize the experimental procedure and by supporting decision making during the experiment. For that, a Finite Element model is developed based on a multi-purpose code. After post-test calculations for the FOREVER-C2 experiment, pre-test calculations for the forthcoming experiments are performed. Additionally metallographic post test investigations of the experiments are conducted to improve the numerical damage model and to adjust the correlation between the metallographic observations and the calculated damage. Taking into account both - experimental and numerical results - gives a good opportunity to improve the simulation and understanding of real accident scenarios. After analysing the calculations, it seems to be advantageous to introduce a vessel support which can unburden the vessel from a part of the mechanical load and, therefore, avoid the vessel failure or at least prolong the time to failure. This can be a possible accident mitigation strategy. Additionally, it is possible to install an absolutely passive automatic control device to initiate the flooding of the reactor pit to

Dry critical experiments and analyses performed in support of the Topaz-2 Safety Program

International Nuclear Information System (INIS)

Pelowitz, D.B.; Sapir, J.; Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Kompanietz, G.B.; Krutov, A.M.; Polyakov, D.N.; Loynstev, V.A.

1994-01-01

In December 1991, the Strategic Defense Initiative Organization decided to investigate the possibility of launching a Russian Topaz-2 space nuclear power system. Functional safety requirements developed for the Topaz mission mandated that the reactor remain subcritical when flooded and immersed in water. Initial experiments and analyses performed in Russia and the United States indicated that the reactor could potentially become supercritical in several water- or sand-immersion scenarios. Consequently, a series of critical experiments was performed on the Narciss M-II facility at the Kurchatov Institute to measure the reactivity effects of water and sand immersion, to quantify the effectiveness of reactor modifications proposed to preclude criticality, and to benchmark the calculational methods and nuclear data used in the Topaz-2 safety analyses. In this paper we describe the Narciss M-II experimental configurations along with the associated calculational models and methods. We also present and compare the measured and calculated results for the dry experimental configurations

Dry critical experiments and analyses performed in support of the TOPAZ-2 safety program

International Nuclear Information System (INIS)

Pelowitz, D.B.; Sapir, J.; Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Kompanietz, G.B.; Krutov, A.M.; Polyakov, D.N.; Lobynstev, V.A.

1995-01-01

In December 1991, the Strategic Defense Initiative Organization decided to investigate the possibility of launching a Russian Topaz-2 space nuclear power system. Functional safety requirements developed for the Topaz mission mandated that the reactor remain subcritical when flooded and immersed in water. Initial experiments and analyses performed in Russia and the United States indicated that the reactor could potentially become supercritical in several water- or sand-immersion scenarios. Consequently, a series of critical experiments was performed on the Narciss M-II facility at the Kurchatov Institute to measure the reactivity effects of water and sand immersion, to quantify the effectiveness of reactor modifications proposed to preclude criticality, and to benchmark the calculational methods and nuclear data used in the Topaz-2 safety analyses. In this paper we describe the Narciss M-II experimental configurations along with the associated calculational models and methods. We also present and compare the measured and calculated results for the dry experimental configurations. copyright 1995 American Institute of Physics

International report to validate criticality safety calculations for fissile material transport

International Nuclear Information System (INIS)

Whitesides, G.E.

1984-01-01

During the past three years a Working Group established by the Organization for Economic Co-operation and Development's Nuclear Energy Agency (OECD-NEA) in Paris, France, has been studying the validity and applicability of a variety of criticality safety computer programs and their associated nuclear data for the computation of the neutron multiplication factor, k/sub eff/, for various transport packages used in the fuel cycle. The principal objective of this work has been to provide an internationally acceptable basis for the licensing authorities in a country to honor licensing approvals granted by other participating countries. Eleven countries participated in the initial study which consisted of examining criticality safety calculations for packages designed for spent light water reactor fuel transport. This paper presents a summary of this study which has been completed and reported in an OECD-NEA Report No. CSNI-71. The basic goal of this study was to outline a satisfactory validation procedure for this particular application. First, a set of actual critical experiments were chosen which contained the various material and geometric properties present in typical LWR transport containers. Secondly, calculations were made by each of the methods in order to determine how accurately each method reproduced the experimental values. This successful effort in developing a benchmark procedure for validating criticality calculations for spent LWR transport packages along with the successful intercomparison of a number of methods should provide increased confidence by licensing authorities in the use of these methods for this area of application. 4 references, 2 figures

Calculation of the BREN house shielding experiments

International Nuclear Information System (INIS)

Woolson, William A.; Gritzner, Michael L.

1987-01-01

The BREN house transmission experiments provide an excellent set of measurements to validate the calculational procedures that will be used to derive house shielding estimates for the revised dosimetry of the survivors of the Hiroshima and Nagasaki A-bombs. The BREN experiments were performed in realistic full scale models of Japanese residences. Although the radiation spectra and relative intensities of neutrons and gamma rays incident on the houses from the HPRR and the 60 Co source are not appropriate for direct application to the A-bomb survivors, they cover the full energy range of importance. The codes and calculations required to compare with BREN experiments are the same as those needed for the A-bomb dosimetry. They consist of a two-dimensional discrete-ordinates calculation of the free field coupled to an adjoint Monte Carlo calculation in detailed house geometry. The agreement obtained between calculations and the experiments is excellent for neutrons and 60 Co gamma rays. Every house transmission calculation spanning simple to complex configurations and detector locations for the 60 Co and HPRR was within an acceptable margin of error. The gamma-ray TF calculations for the reactor source did not agree well with the experiments. Analysis of this discrepancy, however, strongly indicates that the problem probably does not reside in the calculational procedure but in the measurements themselves. In conclusion, it is believed that the excellent agreement of our calculations with the BREN experiments validates the calculational procedure which is planed to be applied o estimating the house shielding for survivors of the Hiroshima and Nagasaki A-bombs. Certainly, the calculations for Hiroshima and Nagasaki will involve modifications to the code used for the computations reported here, but to the extent that these modifications involve increased calculational complexity to treat more realistic materials and configurations, the benchmark established by these

Ensuring the validity of calculated subcritical limits

International Nuclear Information System (INIS)

Clark, H.K.

1977-01-01

The care taken at the Savannah River Laboratory and Plant to ensure the validity of calculated subcritical limits is described. Close attention is given to ANSI N16.1-1975, ''Validation of Calculational Methods for Nuclear Criticality Safety.'' The computer codes used for criticality safety computations, which are listed and are briefly described, have been placed in the SRL JOSHUA system to facilitate calculation and to reduce input errors. A driver module, KOKO, simplifies and standardizes input and links the codes together in various ways. For any criticality safety evaluation, correlations of the calculational methods are made with experiment to establish bias. Occasionally subcritical experiments are performed expressly to provide benchmarks. Calculated subcritical limits contain an adequate but not excessive margin to allow for uncertainty in the bias. The final step in any criticality safety evaluation is the writing of a report describing the calculations and justifying the margin

Fusion integral experiments and analysis and the determination of design safety factors - I: Methodology

International Nuclear Information System (INIS)

Youssef, M.Z.; Kumar, A.; Abdou, M.A.; Oyama, Y.; Maekawa, H.

1995-01-01

The role of the neutronics experimentation and analysis in fusion neutronics research and development programs is discussed. A new methodology was developed to arrive at estimates to design safety factors based on the experimental and analytical results from design-oriented integral experiments. In this methodology, and for a particular nuclear response, R, a normalized density function (NDF) is constructed from the prediction uncertainties, and their associated standard deviations, as found in the various integral experiments where that response, R, is measured. Important statistical parameters are derived from the NDF, such as the global mean prediction uncertainty, and the possible spread around it. The method of deriving safety factors from many possible NDFs based on various calculational and measuring methods (among other variants) is also described. Associated with each safety factor is a confidence level, designers may choose to have, that the calculated response, R, will not exceed (or will not fall below) the actual measured value. An illustrative example is given on how to construct the NDFs. The methodology is applied in two areas, namely the line-integrated tritium production rate and bulk shielding integral experiments. Conditions under which these factors could be derived and the validity of the method are discussed. 72 refs., 17 figs., 4 tabs

Radiological safety design considerations for fusion research experiments

International Nuclear Information System (INIS)

Crase, K.W.; Singh, M.S.

1979-01-01

A wide variety of fusion research experiments are in the planning or construction stages. Two such experiments, the Nova Laser Fusion Facility and the Mirror Fusion Test Facility (MFTF), are currently under construction at Lawrence Livermore Laboratory. Although the plasma chamber vault for MFTF and the Nova target room will have thick concrete walls and roofs, the radiation safety problems are made complex by the numerous requirements for shield wall penetrations. This paper addresses radiation safety considerations for the MFTF and Nova experiments, and the need for integrated safety considerations and safety technology development during the planning stages of fusion experiments

Safety review of experiments at Albuquerque Operations Office

International Nuclear Information System (INIS)

Elliott, K.

1984-01-01

The Department of Energy (DOE) Albuquerque Operations Office is responsible for the safety overview of nuclear reactor and critical assembly facilities at Sandia National Laboratories, Los Alamos National Laboratory, and the Rocky Flats Plant. The important safety concerns with these facilities involve the complex experiments that are performed, and that is the area emphasized. A determination is made by the Albuquerque Office (AL) with assistance from DOE/OMA whether or not a proposed experiment is an unreviewed safety question. Meetings are held with the contractor to resolve and clarify questions that are generated during the review of the proposed experiment. The AL safety evaluation report is completed and any recommendations are discussed. Prior to the experiment a preoperational appraisal is performed to assure that personnel, procedures, and equipment are in readiness for operations. During the experiment, any abnormal condition is reviewed in detail to determine any safety concerns

Safety Assurance for Irradiating Experiments in the Advanced Test Reactor

Energy Technology Data Exchange (ETDEWEB)

T. A. Tomberlin; S. B. Grover

2004-11-01

The Advanced Test Reactor (ATR), located at the Idaho National Engineering and Environmental Laboratory (INEEL), was specifically designed to provide a high neutron flux test environment for conducting a variety of experiments. This paper addresses the safety assurance process for two general types of experiments conducted in the ATR facility and how the safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore, this type of experiment is addressed in more detail in the ATR safety basis. This allows the individual safety analysis for this type of experiment to be more standardized. The second type of experiment is defined in more general terms in the ATR safety basis and is permitted under more general controls. Therefore, the individual safety analysis for the second type of experiment tends to be more unique and is tailored to each experiment.

Safety Assurance for Irradiating Experiments in the Advanced Test Reactor

International Nuclear Information System (INIS)

T. A. Tomberlin; S. B. Grover

2004-01-01

The Advanced Test Reactor (ATR), located at the Idaho National Engineering and Environmental Laboratory (INEEL), was specifically designed to provide a high neutron flux test environment for conducting a variety of experiments. This paper addresses the safety assurance process for two general types of experiments conducted in the ATR facility and how the safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore, this type of experiment is addressed in more detail in the ATR safety basis. This allows the individual safety analysis for this type of experiment to be more standardized. The second type of experiment is defined in more general terms in the ATR safety basis and is permitted under more general controls. Therefore, the individual safety analysis for the second type of experiment tends to be more unique and is tailored to each experiment

The role of quality management in safety case development - Nagra's experience

International Nuclear Information System (INIS)

Schneider, Juerg W.; Zuidema, Piet

2014-01-01

This paper discusses the role of quality management (QM) in safety case development based on Nagra's experience from a broad range of projects. These include Project Gewahr (L/ILW and HLW, Nagra, 1985), the Wellenberg Project (L/ILW, Nagra, 1994), Project Opalinus Clay (HLW, Nagra, 2002a, 2002b), and recent project work needed in the context of the Swiss site selection process (L/ILW and HLW, Nagra, 2008a, 2008b, 2008c, 2010). Broadly speaking, Nagra's Quality Management policy is focused on ensuring: i) the quality of the disposal system (siting, design and implementation); ii) the quality of the underlying scientific understanding, which are seen as key elements of a credible safety case, along with the quality of the safety calculations themselves and of compiling the safety case, including the drawing of conclusions (Nagra, 2002a). All aspects of QM discussed in this paper should be seen in this context. (authors)

Investigation of the possibility of a calculative reactor safety estimation in the licence procedure for nuclear reactors

International Nuclear Information System (INIS)

Adler, B.; Kampf, T.

1975-12-01

Up to now it is impossible to calculate completely the safety of nuclear reactors. Therefore the authors have collected and employed a number of at a high degree independent safety parameters for mathematical evaluation of the reactor safety. By means of computer programs such parameters from about 400 research reactors have been analysed and the fluctuation ranges of their greatest density were determined. The limits of these fluctuation ranges are quickly available and can be used as recommended values for the layout and for the safety estimation of research reactors. A comparison of the existing layout recommendations and the determined fluctuation ranges in most cases shows a good agreement. In some cases corrections and new layout recommendations have been proposed. The determined fluctuation ranges found their first practical application in the estimation of the Rossendorf Equipment for Critical Experiments (RAKE). (author)

Cluster monte carlo method for nuclear criticality safety calculation

International Nuclear Information System (INIS)

Pei Lucheng

1984-01-01

One of the most important applications of the Monte Carlo method is the calculation of the nuclear criticality safety. The fair source game problem was presented at almost the same time as the Monte Carlo method was applied to calculating the nuclear criticality safety. The source iteration cost may be reduced as much as possible or no need for any source iteration. This kind of problems all belongs to the fair source game prolems, among which, the optimal source game is without any source iteration. Although the single neutron Monte Carlo method solved the problem without the source iteration, there is still quite an apparent shortcoming in it, that is, it solves the problem without the source iteration only in the asymptotic sense. In this work, a new Monte Carlo method called the cluster Monte Carlo method is given to solve the problem further

US nuclear safety. Review and experience

International Nuclear Information System (INIS)

Hanauer, S.H.

1977-01-01

The paper deals with the evolution of reactor safety principles, design bases, regulatory requirements, and experience in the United States. Safety concerns have evolved over the years, from reactivity transients and shut-down systems, to blowdowns and containment, to severe design basis accidents and mitigating systems, to the performance of actual materials, systems and humans. The primary safety concerns of one epoch have been superseded in considerable measure by those of later times. Successive plateaus of technical understanding are achieved by solutions being found to earlier problems. Design studies, research, operating experience and regulatory imperatives all contribute to the increased understanding and thus to the safety improvements adopted and accepted. The improvement of safety with time, and the ability of existing reactors to operate safely in the face of new concerns, has confirmed the correctness and usefulness of the defence-in-depth approach and safety margins used in safety design in the United States of America. A regulatory programme such as the one in the United States justifies its great cost by its important contributions to safety. Yet only the designers, constructors and operators of nuclear power plants can actually achieve public safety. The regulatory programme audits, assesses and spot-checks the actual work. Since neither materials nor human beings are flawless, mistakes will be made; that is why defence-in-depth and safety margins are provided. The regulatory programme should enhance safety by decreasing the frequency of uncorrected mistakes. Maintenance of public safety also requires technical and managerial competence and attention in the organizations responsible for nuclear plants as well as regulatory organizations. (author)

Evaluation of operating experience with safety values

International Nuclear Information System (INIS)

Bung, W.; Hoemke, P.; Oberender, W.; Paul, H.; Rueter, W.

1985-01-01

This report describes statistical investigations of 2076 functional tests carried out on power operated safety valves in conventional power plants in 1972 until 1983 with special regard to Common Mode-Failures. The results clearly show that Common Mode-Failures play an important part of non-availability for the controlled safety valves, especially in the control system. The 'Deutsche Risikostudie' does not consider any Common Mode-Failures of the primary safety valves. However there is no significant increase of the risk resulted by the primary safety valves in the 'Referenzanlage' if the calculated Common Mode-Failures probabilities are considered. (orig.) [de

Development of Audit Calculation Methodology for RIA Safety Analysis

Energy Technology Data Exchange (ETDEWEB)

Lee, Joosuk; Kim, Gwanyoung; Woo, Swengwoong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-05-15

The interim criteria contain more stringent limits than previous ones. For example, pellet-to-cladding mechanical interaction(PCMI) was introduced as a new failure criteria. And both short-term (e.g. fuel-to coolant interaction, rod burst) and long-term(e.g., fuel rod ballooning, flow blockage) phenomena should be addressed for core coolability assurance. For dose calculations, transient-induced fission gas release has to be accounted additionally. Traditionally, the approved RIA analysis methodologies for licensing application are developed based on conservative approach. But newly introduced safety criteria tend to reduce the margins to the criteria. Thereby, licensees are trying to improve the margins by utilizing a less conservative approach. In this situation, to cope with this trend, a new audit calculation methodology needs to be developed. In this paper, the new methodology, which is currently under developing in KINS, was introduced. For the development of audit calculation methodology of RIA safety analysis based on the realistic evaluation approach, preliminary calculation by utilizing the best estimate code has been done on the initial core of APR1400. Followings are main conclusions. - With the assumption of single full-strength control rod ejection in HZP condition, rod failure due to PCMI is not predicted. - And coolability can be assured in view of entalphy and fuel melting. - But, rod failure due to DNBR is expected, and there is possibility of fuel failure at the rated power conditions also.

[Operating Room Nurses' Experiences of Securing for Patient Safety].

Science.gov (United States)

Park, Kwang Ok; Kim, Jong Kyung; Kim, Myoung Sook

2015-10-01

This study was done to evaluate the experience of securing patient safety in hospital operating rooms. Experiential data were collected from 15 operating room nurses through in-depth interviews. The main question was "Could you describe your experience with patient safety in the operating room?". Qualitative data from the field and transcribed notes were analyzed using Strauss and Corbin's grounded theory methodology. The core category of experience with patient safety in the operating room was 'trying to maintain principles of patient safety during high-risk surgical procedures'. The participants used two interactional strategies: 'attempt continuous improvement', 'immersion in operation with sharing issues of patient safety'. The results indicate that the important factors for ensuring the safety of patients in the operating room are manpower, education, and a system for patient safety. Successful and safe surgery requires communication, teamwork and recognition of the importance of patient safety by the surgical team.

First start-up of nuclear criticality safety experiment facility for uranyl nitrate solution

International Nuclear Information System (INIS)

Zhu Qingfu; Shi Yongqian; Shen Leisheng; Hu Dingsheng; Zhao Shouzhi; He Tao; Sun Zheng; Lin Shenghuo; Yao Shigui

2005-01-01

The uranyl nitrate solution experiment facility for the research on nuclear criticality safety is described. The nuclear fuel loading steps in the first start-up for water-reflected core are presented. During the experiments, the critical volume of uranyl nitrate solution was determined as 20479.62 mL with count rate inverse extrapolation method, reactivity interpolation method, and steady power method. By calculation, critical mass of 235 U was derived as 1579.184 g from experimental data. The worth of control rods was also calibrated in the first start-up of the facility. (authors)

US nuclear safety review and experience

International Nuclear Information System (INIS)

Gilinsky, V.

1977-01-01

The nuclear safety review of commercial nuclear power reactors has changed over the years from the relatively simple review of Dresden 1 in 1955 to the highly complex and sophisticated regulatory process which characterizes today's reviews. Four factors have influenced this evolution: (1) maturing of the technology and industry; (2) development of the regulatory process and associated staff; (3) feedback of operating experience; and (4) public awareness and participation. The NRC's safety review responsibilities start before an application is tendered and end when the plant is decommissioned. The safety review for reactor licensing is a comprehensive, two-phase process designed to assure that all the established conservative acceptance criteria are satisfied. Operational safety is assured through a strong inspection and enforcement program which includes shutting down operating facilities when necessary to protect the health and safety of the public. The safety of operating reactors is further insured through close regulation of license changes and selective backfitting of new regulatory requirements. An effective NRC standards development program has been implemented and coordinates closely with the national standards program. A confirmatory safety research program has been developed. Both of these efforts are invaluable to the nuclear safety review because they provide the staff with key tools needed to carry out its regulatory responsibilities. Both have been given increased emphasis since the formation of the NRC in 1975. The safety review process will continue to evolve, but changes will be slower and more deliberate. It will be influenced by standardization, early site reviews and development of advanced reactor concepts. New legislation may make possible changes which will simplify and shorten the regulatory process. Certainly the experience provided by the increasing number and types of operating plants will have a very strong impact on future trends in the

Ultrasonic thermometry system for measuring very high temperatures in reactor safety experiments

International Nuclear Information System (INIS)

Carlson, G.A.; Sullivan, W.H.; Plein, H.G.; Kerley, T.M.

1979-06-01

Ultrasonic thermometry has many potential applications in reactor safety experiments, where extremely high temperatures and lack of visual access may preclude the use of conventional diagnostics. This report details ultrasonic thermometry requirements for one such experiment, the molten fuel pool experiment. Sensors, transducers, and signal processing electronics are described in detail. Axial heat transfer in the sensors is modelled and found acceptably small. Measurement errors, calculations of their effect, and ways to minimize them are given. A rotating sensor concept is discussed which holds promise of alleviating sticking problems at high temperature. Applications of ultrasonic thermometry to three in-core experiments are described. In them, five 10-mm-length sensor elements were used to measure axial temperatures in a UO 2 or UO 2 -steel system fission-heated to about 2860 0 C

Search for a transport method for the calculation of the PWR control and safety clusters

International Nuclear Information System (INIS)

Bruna, G.B.; Van Frank, C.; Vergain, M.L.; Chauvin, J.P.; Palmiotti, G.; Nobile, M.

1990-01-01

The project studies of power reactors rely mainly on diffusion calculations, but transport ones are often needed for assessing fine effects, intimately linked to geometry and spectrum heterogeneities. Accurate transport computations are necessary, in particular, for shielded cross section generation, and when homogenization and dishomogenization processes are involved. The transport codes, generally, offer the user a variety of computational options, related to different approximation levels. In every case, it is obviously desirable to be able to choose the reliable degree of approximation to be accepted in any particular computational circumstance of the project. The search for such adapted procedures is to be made on the basis of critical experiments. In our studies, this task was made possible by the availability of suitable results of the CAMELEON critical experiment, carried on in the EOLE facility at CEA's Center of Cadarache. In this paper, we summarize some of the work in progress at FRAMATOME on the definition of an assembly based transport calculation scheme to be used for PWR control and safety cluster computations. Two main items, devoted to the search of the optimum computational procedures, are presented here: - a parametrical study on computational options, made in an infinite medium assembly geometry, - a series of comparisons between calculated and experimental values of pin power distribution

Program of nuclear criticality safety experiment at JAERI

International Nuclear Information System (INIS)

Kobayashi, Iwao; Tachimori, Shoichi; Takeshita, Isao; Suzaki, Takenori; Ohnishi, Nobuaki

1983-11-01

JAERI is promoting the nuclear criticality safety research program, in which a new facility for criticality safety experiments (Criticality Safety Experimental Facility : CSEF) is to be built for the experiments with solution fuel. One of the experimental researches is to measure, collect and evaluate the experimental data needed for evaluation of criticality safety of the nuclear fuel cycle facilities. Another research area is a study of the phenomena themselves which are incidental to postulated critical accidents. Investigation of the scale and characteristics of the influences caused by the accident is also included in this research. The result of the conceptual design of CSEF is summarized in this report. (author)

Slope Safety Calculation With A Non-Linear Mohr Criterion Using Finite Element Method

DEFF Research Database (Denmark)

Clausen, Johan; Damkilde, Lars

2005-01-01

Safety factors for soil slopes are calculated using a non-linear Mohr envelope. The often used linear Mohr-Coulomb envelope tends to overestimate the safety as the material parameters are usually determined at much higher stress levels, than those present at slope failure. Experimental data...

Calculation of partial derivatives of thermophysical properties of sodium for safety analysis

International Nuclear Information System (INIS)

Shan Jianqiang; Qiu Suizhang; Zhu Jizhou; Zhang Guiqin

1997-01-01

According to the characters of safety analysis of LMFBR, the partial derivatives formula of some special thermophysical properties of sodium, including single-and two-phase properties, are calculated based on the basic Maxwell equations, and on the formulae of basic thermophysical properties of sodium which were verified abroad. The present study can provide theoretical base for safety analysis of LMFBR

Use of safety experience feedback to design new nuclear units

International Nuclear Information System (INIS)

Lange, D.; Crochon, J.P.

1985-06-01

For the designer, and about safety, the experience feedback can take place in 3 fields: the operating experience feedback (incidents analysis), the ''study'' experience feedback (improvement of justification and evolution of safety considerations), and the fabrication experience feedback. Some examples are presented for each field [fr

LMFBR operational safety: the EBR-II experience

International Nuclear Information System (INIS)

Sackett, J.I.; Allen, N.L.; Dean, E.M.; Fryer, R.M.; Larson, H.A.; Lehto, W.K.

1978-01-01

The mission of the Experimental Breeder Reactor II (EBR-II) has evolved from that of a small LMFBR demonstration plant to a major irradiation-test facility. Because of that evolution, many operational-safety issues have been encountered. The paper describes the EBR-II operational-safety experience in four areas: protection-system design, safety-document preparation, tests of off-normal reactor conditions, and tests of elements with breached cladding

Exploring relationships between hospital patient safety culture and Consumer Reports safety scores.

Science.gov (United States)

Smith, Scott Alan; Yount, Naomi; Sorra, Joann

2017-02-16

A number of private and public companies calculate and publish proprietary hospital patient safety scores based on publicly available quality measures initially reported by the U.S. federal government. This study examines whether patient safety culture perceptions of U.S. hospital staff in a large national survey are related to publicly reported patient safety ratings of hospitals. The Agency for Healthcare Research and Quality Hospital Survey on Patient Safety Culture (Hospital SOPS) assesses provider and staff perceptions of hospital patient safety culture. Consumer Reports (CR), a U.S. based non-profit organization, calculates and shares with its subscribers a Hospital Safety Score calculated annually from patient experience survey data and outcomes data gathered from federal databases. Linking data collected during similar time periods, we analyzed relationships between staff perceptions of patient safety culture composites and the CR Hospital Safety Score and its five components using multiple multivariate linear regressions. We analyzed data from 164 hospitals, with patient safety culture survey responses from 140,316 providers and staff, with an average of 856 completed surveys per hospital and an average response rate per hospital of 56%. Higher overall Hospital SOPS composite average scores were significantly associated with higher overall CR Hospital Safety Scores (β = 0.24, p Consumer Reports Hospital Safety Score, which is a composite of patient experience and outcomes data from federal databases. As hospital managers allocate resources to improve patient safety culture within their organizations, their efforts may also indirectly improve consumer-focused, publicly reported hospital rating scores like the Consumer Reports Hospital Safety Score.

Safety experience on EDF's PWRs

International Nuclear Information System (INIS)

Tanguy, P.

1986-01-01

The french nuclear programme has been widely publicized. In 1985, the total nuclear electricity generated was around 216 GWh, i. e. 70% of the electricity produced by electricity de France (EDF). If we consider only pressurized water reactors, at the end of 1985, 37 units were in operation (32 900 MWe and 5 1300 MWe) and 18 were under construction. I intend to review our experience with the safety of PWR's, but I will first present briefly some aspects related to the safety organization in France and the standardization policy. (author) [pt

Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

International Nuclear Information System (INIS)

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

2009-01-01

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

Glovebox and Experiment Safety

Science.gov (United States)

Maas, Gerard

2005-12-01

Human spaceflight hardware and operations must comply with NSTS 1700.7. This paper discusses how a glovebox can help.A short layout is given on the process according NSTS/ISS 13830, explaining the responsibility of the payload organization, the approval authority of the PSRP and the defined review phases (0 till III).Amongst others, the following requirement has to be met:"200.1 Design to Tolerate Failures. Failure tolerance is the basic safety requirement that shall be used to control most payload hazards. The payload must tolerate a minimum number of credible failures and/or operator errors determined by the hazard level. This criterion applies when the loss of a function or the inadvertent occurrence of a function results in a hazardous event.200.1a Critical Hazards. Critical hazards shall be controlled such that no single failure or operator error can result in damage to STS/ISS equipment, a nondisabling personnel injury, or the use of unscheduled safing procedures that affect operations of the Orbiter/ISS or another payload.200.1b Catastrophic Hazards. Catastrophic hazards shall be controlled such that no combination of two failures or operator errors can result in the potential for a disabling or fatal personnel injury or loss of the Orbiter/ISS, ground facilities or STS/ISS equipment."For experiments in material science, biological science and life science that require real time operator manipulation, the above requirement may be hard or impossible to meet. Especially if the experiment contains substances that are considered hazardous when released into the habitable environment. In this case operation of the experiment in a glovebox can help to comply.A glovebox provides containment of the experiment and at the same time allows manipulation and visibility to the experiment.The containment inside the glovebox provides failure tolerance because the glovebox uses a negative pressure inside the working volume (WV). The level of failure tolerance is dependent of

Decay Power Calculation for Safety Analysis of Innovative Reactor Systems

International Nuclear Information System (INIS)

Shwageraus, E.; Fridman, E.

2008-01-01

In this work, we verified the decay heat calculation capabilities of BGCore computer code system developed recently at Ben-Gurion University. Decay power was calculated for a typical UO 2 fuel in Pressurized Water Reactor environment using BGCore code and using procedure prescribed by the ANS/ANSI-2005 standard. Very good agreement between the two methods was obtained. Once BGCore calculation capabilities were verified, we calculated decay power as a function of time after shutdown for various reactors with innovative fuels, for which no standard procedure is currently available. Notable differences were observed for decay power of the advanced reactors as compared with conventional UO 2 LWR. The observed differences suggest that the design of new reactors safety systems must be based on corresponding decay power curves for each individual case in order to assure the desired performance of such systems. (authors)

Large Scale Experiments on Spacecraft Fire Safety

Science.gov (United States)

Urban, David; Ruff, Gary A.; Minster, Olivier; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu;

In-pile experiments and test facilities proposed for fast reactor safety

International Nuclear Information System (INIS)

Grolmes, M.A.; Avery, R.; Goldman, A.J.; Fauske, H.K.; Marchaterre, J.F.; Rose, D.; Wright, A.E.

1976-01-01

The role of in-pile experiments in support of the resolution of fast breeder reactor safety and licensing issues has been re-examined, with emphasis on key safety issues. Experiment needs have been related to the specific characteristics of these safety issues and to realistic requirements for additional test facility capabilities which can be achieved and utilized within the next ten years. It is found that those safety issues related to the energetics of core disruptive accidents have the largest impact on new facility requirements. However, utilization of existing facilities with modifications can provide for a continuing increase in experiment capability and experiment results on a timely bases. Emphasis has been placed upon maximum utilization of existing facilities and minimum requirements for new facilities. This evaluation has concluded that a new Safety Test Facility, STF, along with major modifications to the EBR II facility, improvement in TREAT capabilities, the existing Sodium Loop Safety Facility and corresponding Support Facilities provide the essential elements of the Safety Research Experiment Facilities (SAREF) required for resolution of key issues

ABWR (K-6/7) construction experience (computer-based safety system)

International Nuclear Information System (INIS)

Yokomura, T.

1998-01-01

TEPCO applied a digital safety system to Kashiwazaki-Kariwa Nuclear Power Station Unit Nos. 6 and 7, the world's first ABWR plant. Although this was the first time to apply a digital safety logic system in Japan, we were able to complete construction of K-6/7 very successfully and without any delay. TEPCO took a approach of developing a substantial amount of experience in digital non- safety systems before undertaking the design of the safety protection system. This paper describes the history, techniques and experience behind achieving a highly reliable digital safety system. (author)

PNRA Process for Utilizing Experience Feedback for Enhancing Nuclear Safety

International Nuclear Information System (INIS)

Shah, Z.H.

2016-01-01

One of the elements essential for any organization to become a learning organization is to learn from its own and others experience. The importance of utilizing experience feedback for enhancing operational safety is highlighted in nuclear industry again and again and this has resulted in establishment of several national and international forums. In addition, IAEA action plan on nuclear safety issued after Fukushima accident further highlighted the importance of experience sharing among nuclear community to enhance global nuclear safety regime. PNRA utilizes operating experience feedback gathered through different sources in order to improve its regulatory processes. During the review of licensing submissions, special emphasis is given to utilize the lessons learnt from experience feedback relating to nuclear industry within and outside the country. This emphasis has gradually resulted in various safety improvements in the facilities and processes. Accordingly, PNRA has developed a systematic process of evaluation of international operating experience feedback with the aim to create safety conscious approach. This process includes collecting information from different international forums such as IAEA, regulatory bodies of other countries and useful feedback of past accidents followed by its screening, evaluation and suggesting recommendations both for PNRA and its licensees. As a result of this process, several improvements concerning regulatory inspection plans of PNRA as well as in regulatory decision making and operational practices of licensees have been highlighted. This paper will present PNRA approach for utilizing experience feedback in its regulatory processes for enhancing / improving nuclear safety. (author)

Decay Power Calculation for Safety Analysis of Innovative Reactor Systems

Energy Technology Data Exchange (ETDEWEB)

Shwageraus, E.; Fridman, E. [Department of Nuclear Engineering, Ben-Gurion University of the Negev Beer-Sheva 84105 (Israel)

2008-07-01

In this work, we verified the decay heat calculation capabilities of BGCore computer code system developed recently at Ben-Gurion University. Decay power was calculated for a typical UO{sub 2} fuel in Pressurized Water Reactor environment using BGCore code and using procedure prescribed by the ANS/ANSI-2005 standard. Very good agreement between the two methods was obtained. Once BGCore calculation capabilities were verified, we calculated decay power as a function of time after shutdown for various reactors with innovative fuels, for which no standard procedure is currently available. Notable differences were observed for decay power of the advanced reactors as compared with conventional UO{sub 2} LWR. The observed differences suggest that the design of new reactors safety systems must be based on corresponding decay power curves for each individual case in order to assure the desired performance of such systems. (authors)

The experiences of research reactor accident to safety improvement

International Nuclear Information System (INIS)

Wiranto, S.

1999-01-01

The safety of reactor operation is the main factor in order that the nuclear technology development program can be held according the expected target. Several experience with research reactor incidents must be learned and understood by the nuclear program personnel, especially for operators and supervisors of RSG-GA. Siwabessy. From the incident experience of research reactor in the world, which mentioned in the book 'Experience with research reactor incidents' by IAEA, 1995, was concluded that the main cause of research reactor accidents is understandless about the safety culture by the nuclear installation personnel. With learn, understand and compare between this experiences and the condition of RSG GA Siwabessy is expended the operators and supervisors more attention about the safety culture, so that RSG GA Siwabessy can be operated successfull, safely according the expected target

HTR-PM Safety requirement and Licensing experience

International Nuclear Information System (INIS)

Li Fu; Zhang Zuoyi; Dong Yujie; Wu Zongxin; Sun Yuliang

2014-01-01

HTR-PM is a 200MWe modular pebble bed high temperature reactor demonstration plant which is being built in Shidao Bay, Weihai, Shandong, China. The main design parameters of HTR-PM were fixed in 2006, the basic design was completed in 2008. The review of Preliminary Safety Analysis Report (PSAR) of HTR-PM was started in April 2008, completed in September 2009. In general, HTR- PM design complies with the current safety requirement for nuclear power plant in China, no special standards are developed for modular HTR. Anyway, Chinese Nuclear Safety Authority, together with the designers, developed some dedicated design criteria for key systems and components and published the guideline for the review of safety analysis report of HTR-PM, based on the experiences from licensing of HTR-10 and new development of nuclear safety. The probabilistic safety goal for HTR-PM was also defined by the safety authority. The review of HTR-PM PSAR lasted for one and a half years, with 3 dialogues meetings and 8 topics meetings, with more than 2000 worksheets and answer sheets. The heavily discussed topics during the PSAR review process included: the requirement for the sub-atmospheric ventilation system, the utilization of PSA in design process, the scope of beyond design basis accidents, the requirement for the qualification of TRISO coating particle fuel, and etc. Because of the characteristics of first of a kind for the demonstration plant, the safety authority emphasized the requirement for the experiment and validation, the PSAR was licensed with certain licensing conditions. The whole licensing process was under control, and was re-evaluated again after Fukushima accident to be shown that the design of HTR-PM complies with current safety requirement. This is a good example for how to license a new reactor. (author)

Validation of KENO V.a for criticality safety calculations involving WR-1 fast-neutron fuel arrangements

Energy Technology Data Exchange (ETDEWEB)

Gauld, I. C.

1991-07-15

The KENO V.a criticality safety code, used with the SCALE 27-energy-group ENDF/B-IV-based cross-section library, has been validated for low-enriched uranium carbide (UC) WR-1 fast-neutron (FN) fuel arrangements. Because of a lack of relevant experimental data for UC fuel in the published literature, the validation is based primarily on calculational comparisons with critical experiments for fuel types with a range of enrichments and densities that cover those of the FN UC fuel. The ability of KENO V.a to handle the unique annular pin arrangement of the WR-1 FN fuel bundle was established using a comparison with the MCNP3B code used with a continuous-energy ENDF/B-V-based cross-section library. This report is part of the AECL--10146 report series documenting the validation of the KENO V.a criticality safety code.

Shields calculations for teletherapy equipment. Regulatory approach of the National Center of Nuclear Safety

International Nuclear Information System (INIS)

Fuente P, A. de la; Dumenigo G, C.; Quevedo G, J.R.; Lopez F, Y.

2006-01-01

The evaluation of applications of construction licenses for the new services of radiotherapy has occupied a significant space in the activity developed by the National Center of Nuclear Safety (CNSN) in the last 2 years. Presently work the experiences of the authors in the evaluation of the required shield for the local where cobalt therapy equipment and lineal accelerators of medical use are used its are exposed, the practical problems detected are approached during the application of the methodologies recommended in both cases and its are discussed which have been the suppositions of items accepted by the Regulatory Authority for the realization of these shield calculations. The accumulated experience allows to assure that the realistic application of the item data and the rational use of the engineering logic makes possible to design local for radiotherapy equipment that fulfill the established dose restrictions in the in use legislation in Cuba, without it implies an excessive expense of construction materials. (Author)

Corrosion calculations report for the safety assessment SR-Site

International Nuclear Information System (INIS)

2010-12-01

This report is a compilation of the quantitative assessments of corrosion of the copper canisters in a KBS-3 repository. The calculations are part of the safety assessment SR-Site that is the long-term safety assessment to support the license application for building a final repository for spent nuclear fuel at Forsmark, Sweden. The safety assessment methodology gives the frame for the structured and documented approach to assess all conceivable corrosion processes. The quantitative assessments are done in different ways depending on the nature of the process and on the implications for the long-term safety. The starting point for the handling of the corrosion processes is the description of all known corrosion processes for copper with the current knowledge base and applied to the specific system and geology. Already at this stage some processes are excluded for further analysis, for example if the repository environment is not a sufficient prerequisite for the process to occur. The next step is to identify processes where the extent of corrosion could be bounded, e.g. by a mass balance approach. For processes where a mass balance is not limiting, the mass transport of corrodants (or corrosion products) is taken into account. A simple approach would be just to calculate the diffusive transport of corrodants through the bentonite, but generally the transport resistance for the interface between groundwater in a rock fracture intersecting the deposition hole and the bentonite buffer is more important. In SR-Site, the concept of equivalent flowrate, Q eq , is used. This assessment is done integrated with the evaluation of the geochemical and hydrogeological evolution of the repository. For most of the corrosion processes analysed, the corrosion depth is much smaller than the copper shell thickness, even for the assessment time of 10 6 years. Several processes give corrosion depths less than 100 μm, but no process give corrosion depths larger than a few millimetres

Corrosion calculations report for the safety assessment SR-Site

Energy Technology Data Exchange (ETDEWEB)

2010-12-15

This report is a compilation of the quantitative assessments of corrosion of the copper canisters in a KBS-3 repository. The calculations are part of the safety assessment SR-Site that is the long-term safety assessment to support the license application for building a final repository for spent nuclear fuel at Forsmark, Sweden. The safety assessment methodology gives the frame for the structured and documented approach to assess all conceivable corrosion processes. The quantitative assessments are done in different ways depending on the nature of the process and on the implications for the long-term safety. The starting point for the handling of the corrosion processes is the description of all known corrosion processes for copper with the current knowledge base and applied to the specific system and geology. Already at this stage some processes are excluded for further analysis, for example if the repository environment is not a sufficient prerequisite for the process to occur. The next step is to identify processes where the extent of corrosion could be bounded, e.g. by a mass balance approach. For processes where a mass balance is not limiting, the mass transport of corrodants (or corrosion products) is taken into account. A simple approach would be just to calculate the diffusive transport of corrodants through the bentonite, but generally the transport resistance for the interface between groundwater in a rock fracture intersecting the deposition hole and the bentonite buffer is more important. In SR-Site, the concept of equivalent flowrate, Q{sub eq}, is used. This assessment is done integrated with the evaluation of the geochemical and hydrogeological evolution of the repository. For most of the corrosion processes analysed, the corrosion depth is much smaller than the copper shell thickness, even for the assessment time of 106 years. Several processes give corrosion depths less than 100 mum, but no process give corrosion depths larger than a few

Method of calculating the safety factor profile on the HT-7 tokamak

International Nuclear Information System (INIS)

Zhang Xianmei; Lu Yuancheng; Wan Baonian

2001-01-01

A method of calculating the safety factor profile on the HT-7 tokamak has been described. It is derived from Maxwell's equations, among which the authors mainly use two of them: one is the magnetic field diffusion equation, and the other is Ampere's Law. This method can be also used to evaluate the safety factor on other devices with a circular cross sections. It is helpful to the study of the plasma MHD behavior on the HT-7 tokamak

Calculations of the startup experiments at the Poolside Facility

Energy Technology Data Exchange (ETDEWEB)

Williams, M.L.; Maerker, R.E.

1982-01-01

Discrete ordinate calculations are made and the results compared with measurements performed in the startup experiment at the Poolside Facility. Because of the physical size of the simulated surveillance capsule used in this experiment, the analytic procedure is more complicated than one adopted in earlier calculations of the PCA-PVF and PSF. The comparisons indicate the pressure vessel fluences in the long-term irradiation experiments still presently going on at the PSF, and which are geometrically identical to the startup experiment, can only be predicted to within about 20%.

Calculations of the startup experiments at the Poolside Facility

International Nuclear Information System (INIS)

Williams, M.L.; Maerker, R.E.

1982-01-01

Discrete ordinate calculations are made and the results compared with measurements performed in the startup experiment at the Poolside Facility. Because of the physical size of the simulated surveillance capsule used in this experiment, the analytic procedure is more complicated than one adopted in earlier calculations of the PCA-PVF and PSF. The comparisons indicate the pressure vessel fluences in the long-term irradiation experiments still presently going on at the PSF, and which are geometrically identical to the startup experiment, can only be predicted to within about 20%

Safety engineering experiments of explosives

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Noboru

1987-07-24

The outline of large scale experiments carried out every year since 1969 to obtain fundamental data and then establish the safety engineering standards concerning the manufacturing, storage and transportation, etc. of all explosives was described. Because it becomes recently difficult to ensure the safety distance in powder magazines and powder plants, the sandwich structure with sand is thought to be suitable as the neighboring barrier walls. The special vertical structure for embankments to provide against a emergency explosion is effective to absorb the blast. Explosion behaviors such as initiating sensitivity, detonation, sympathetic detonation, and shock occurence of the ANFO explosives in place of dynamite and the slurry explosives were studied. The safety engineering standards for the manufacturing and application of explosives were studied to establish because accidents by tabacco fire are not still distinguished. Much data concerning early stage fire fighting, a large quantity of flooding and shock occurence from a assumption of ignition during machining in the propellants manufacturing plant, could be obtained. Basic studies were made to prevent pollution in blasting sites. Collected data are utilized for the safety administration after sufficient discussion. (4 figs, 2 tabs, 3 photos, 17 refs)

Validation of VHTRC calculation benchmark of critical experiment using the MCB code

Directory of Open Access Journals (Sweden)

Stanisz Przemysław

2016-01-01

Full Text Available The calculation benchmark problem Very High Temperature Reactor Critical (VHTR a pin-in-block type core critical assembly has been investigated with the Monte Carlo Burnup (MCB code in order to validate the latest version of Nuclear Data Library based on ENDF format. Executed benchmark has been made on the basis of VHTR benchmark available from the International Handbook of Evaluated Reactor Physics Benchmark Experiments. This benchmark is useful for verifying the discrepancies in keff values between various libraries and experimental values. This allows to improve accuracy of the neutron transport calculations that may help in designing the high performance commercial VHTRs. Almost all safety parameters depend on the accuracy of neutron transport calculation results that, in turn depend on the accuracy of nuclear data libraries. Thus, evaluation of the libraries applicability to VHTR modelling is one of the important subjects. We compared the numerical experiment results with experimental measurements using two versions of available nuclear data (ENDF-B-VII.1 and JEFF-3.2 prepared for required temperatures. Calculations have been performed with the MCB code which allows to obtain very precise representation of complex VHTR geometry, including the double heterogeneity of a fuel element. In this paper, together with impact of nuclear data, we discuss also the impact of different lattice modelling inside the fuel pins. The discrepancies of keff have been successfully observed and show good agreement with each other and with the experimental data within the 1 σ range of the experimental uncertainty. Because some propagated discrepancies observed, we proposed appropriate corrections in experimental constants which can improve the reactivity coefficient dependency. Obtained results confirm the accuracy of the new Nuclear Data Libraries.

Periodic Safety Review of Nuclear Power Plants: Experience of Member States

International Nuclear Information System (INIS)

2010-04-01

Routine reviews of nuclear power plant operation (including modifications to hardware and procedures, operating experience, plant management and personnel competence) and special reviews following major events of safety significance are the primary means of safety verification. In addition, many Member States of the IAEA have initiated systematic safety reassessments, termed periodic safety reviews, of nuclear power plants, to assess the cumulative effects of plant ageing and plant modifications, operating experience, technical developments and siting aspects. The reviews include an assessment of plant design and operation against current safety standards and practices, and they have the objective of ensuring a high level of safety throughout the plant's operating lifetime. They are complementary to the routine and special safety reviews and do not replace them. Periodic safety reviews of nuclear power plants are considered an effective way to obtain an overall view of actual plant safety, and to determine reasonable and practical modifications that should be made in order to maintain a high level of safety. They can be used as a means of identifying time limiting features of the plant in order to determine nuclear power plant operation beyond the designed lifetime. The periodic safety review process can be used to support the decision making process for long term operation or licence renewal. Since 1994, the use of periodic safety reviews by Member States has substantially broadened and confirmed its benefits. Periodic safety review results have, for example, been used by some Member States to help provide a basis for continued operation beyond the current licence term, to communicate more effectively with stakeholders regarding nuclear power plant safety, and to help identify changes to plant operation that enhance safety. This IAEA-TECDOC is intended to assist Member States in the implementation of a periodic safety review. This publication complements the

Decay heat experiment and validation of calculation code systems for fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Wada, Masayuki

1999-10-01

Although accurate estimation of decay heat value is essential for safety analyses of fusion reactors against loss of coolant accidents and so on, no experimental work has been devoted to validating the estimation. Hence, a decay heat measurement experiment was performed as a task (T-339) of ITER/EDA. A new detector, the Whole Energy Absorption Spectrometer (WEAS), was developed for accurate and efficient measurements of decay heat. Decay heat produced in the thirty-two sample materials which were irradiated by 14-MeV neutrons at FNS/JAERI were measured with WEAS for a wide cooling time period from 1 min to 400 days. The data presently obtained were the first experimental decay heat data in the field of fusion. Validity of decay heat calculation codes of ACT4 and CINAC-V4, activation cross section libraries of FENDL/A-2.0 and JENDL Activation File, and decay data was investigated through analyses of the experiment. As a result, several points that should be modified were found in the codes and data. After solving the problems, it was demonstrated that decay heat valued calculated for most of samples were in good agreement with the experimental data. Especially for stainless steel 316 and copper, which were important materials for ITER, decay heat could be predicted with accuracy of {+-}10%. (author)

Decay heat experiment and validation of calculation code systems for fusion reactor

International Nuclear Information System (INIS)

Maekawa, Fujio; Ikeda, Yujiro; Wada, Masayuki

1999-10-01

Although accurate estimation of decay heat value is essential for safety analyses of fusion reactors against loss of coolant accidents and so on, no experimental work has been devoted to validating the estimation. Hence, a decay heat measurement experiment was performed as a task (T-339) of ITER/EDA. A new detector, the Whole Energy Absorption Spectrometer (WEAS), was developed for accurate and efficient measurements of decay heat. Decay heat produced in the thirty-two sample materials which were irradiated by 14-MeV neutrons at FNS/JAERI were measured with WEAS for a wide cooling time period from 1 min to 400 days. The data presently obtained were the first experimental decay heat data in the field of fusion. Validity of decay heat calculation codes of ACT4 and CINAC-V4, activation cross section libraries of FENDL/A-2.0 and JENDL Activation File, and decay data was investigated through analyses of the experiment. As a result, several points that should be modified were found in the codes and data. After solving the problems, it was demonstrated that decay heat valued calculated for most of samples were in good agreement with the experimental data. Especially for stainless steel 316 and copper, which were important materials for ITER, decay heat could be predicted with accuracy of ±10%. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Stuke, Maik; Peters, Elisabeth; Sommer, Fabian

2016-11-15

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

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

International Nuclear Information System (INIS)

Stuke, Maik; Peters, Elisabeth; Sommer, Fabian

2016-11-01

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

Development and assessment of modular models of calculation for the interpretation of rod-melting experiments

International Nuclear Information System (INIS)

Tuerk, W.

1980-01-01

By the example of recalculations of rod-melting experiment it is shown how a modular simulation model for complex systems can be formulated within the scope of RSYST1. The procedure of code development as well as the physical and numerical methods and approximations of the simulation model are described. To each important physical process a code module is assigned. The individual moduls describe heat production, rod heat-up, rod oxidation, rod environment, rod deformation by thermal expansion and can buckling, melting of the rod, rod failure, and flowing off of the melted mass. A comparison of the results for the overall model with the result of different experiments indicates that the phenomena during heat-up and melting of the rod are treated in agreement with the experiments. The results of the calculation model and its submodels are thus largely supported by experiments. Therefore further predictions with a high level of confidence can be made with the model within the scope of reactor safety research. (orig.) [de

An Assessment of SKB's Performance Assessment Calculations in the Interim Main Report for the Safety Assessment SR-Can

International Nuclear Information System (INIS)

Maul, Philip; Robinson, Peter

2005-03-01

SKB have published their Interim Main Report of the safety assessment SR-Can, which is intended to establish the framework for what will be submitted in 2006 in support of a licence application for construction of the spent fuel encapsulation plant. This follows on from the SR-Can Planning Document published in 2003. The purpose of the Interim Report is stated to be to demonstrate the methodology that will be used for safety assessment. The present report evaluates the information provided in the Interim SR-Can Report that is relevant to the Performance Assessment (PA) calculations that SKB intend to undertake, using independent calculations to facilitate this process. SKB consider that the primary safety function is to isolate completely the fuel within the canisters over the entire assessment period. Should a canister be damaged, the secondary safety function is to ensure that any release is retarded and dispersed sufficiently to ensure that concentrations levels in the accessible environment cannot cause unacceptable consequences. In this report PA calculations are considered to include both a high-level representation of the evolution of the system (relevant to the primary safety function), and any subsequent radionuclide transport (relevant to the secondary safety function). The main conclusions drawn are: 1. The effects of climate evolution on engineered barriers have not been analysed in detail in the Interim Report, and this limits the usefulness of the preliminary calculations that have been undertaken. 2. A key aspect of SKB's approach is the use of an integrated near-field evolution model. The information provided on this model demonstrates its capability efficiently to reproduce calculations from individual process models, but insufficient information is given at the present time to justify statements about interactions between processes. In particular it is assumed that relatively short term thermal and resaturation processes do not affect the

TRIGA criticality experiment for testing burn-up calculations

International Nuclear Information System (INIS)

Persic, Andreja; Ravnik, Matjaz; Zagar, Tomaz

1999-01-01

A criticality experiment with partly burned TRIGA fuel is described. 20 wt % enriched standard TRIGA fuel elements initially containing 12 wt % U are used. Their average burn-up is 1.4 MWd. Fuel element burn-up is calculated in 2-D four group diffusion approximation using TRIGLAV code. The burn-up of several fuel elements is also measured by reactivity method. The excess reactivity of several critical and subcritical core configurations is measured. Two core configurations contain the same fuel elements in the same arrangement as were used in the fresh TRIGA fuel criticality experiment performed in 1991. The results of the experiment may be applied for testing the computer codes used for fuel burn-up calculations. (author)

Operational safety experience feedback by means of unusual event reports

International Nuclear Information System (INIS)

1996-07-01

Operational experience of nuclear power plants can be used to great advantage to enhance safety performance provided adequate measures are in place to collect and analyse it and to ensure that the conclusions drawn are acted upon. Feedback of operating experience is thus an extremely important tool to ensure high standards of safety in operational nuclear power plants and to improve the capability to prevent serious accidents and to learn from minor deviations and equipment failures - which can serve as early warnings -to prevent even minor events from occurring. Mechanisms also need to be developed to ensure that operating experience is shared both nationally as well as internationally. The operating experience feedback process needs to be fully and effectively established within the nuclear power plant, the utility, the regulatory organization as well as in other institutions such as technical support organizations and designers. The main purpose of this publication is to reflect the international consensus as to the general principles and practices in the operational safety experience feedback process. The examples of national practices for the whole or for particular parts of the process are given in annexes. The publication complements the IAEA Safety Series No.93 ''Systems for Reporting Unusual Events in Nuclear Power Plants'' (1989) and may also give a general guidance for Member States in fulfilling their obligations stipulated in the Nuclear Safety Convention. Figs, tabs

Operational safety experience feedback by means of unusual event reports

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

Operational experience of nuclear power plants can be used to great advantage to enhance safety performance provided adequate measures are in place to collect and analyse it and to ensure that the conclusions drawn are acted upon. Feedback of operating experience is thus an extremely important tool to ensure high standards of safety in operational nuclear power plants and to improve the capability to prevent serious accidents and to learn from minor deviations and equipment failures - which can serve as early warnings -to prevent even minor events from occurring. Mechanisms also need to be developed to ensure that operating experience is shared both nationally as well as internationally. The operating experience feedback process needs to be fully and effectively established within the nuclear power plant, the utility, the regulatory organization as well as in other institutions such as technical support organizations and designers. The main purpose of this publication is to reflect the international consensus as to the general principles and practices in the operational safety experience feedback process. The examples of national practices for the whole or for particular parts of the process are given in annexes. The publication complements the IAEA Safety Series No.93 ``Systems for Reporting Unusual Events in Nuclear Power Plants`` (1989) and may also give a general guidance for Member States in fulfilling their obligations stipulated in the Nuclear Safety Convention. Figs, tabs.

Impact of nuclear data uncertainty on safety calculations for spent nuclear fuel geological disposal

Directory of Open Access Journals (Sweden)

Herrero J.J.

2017-01-01

Full Text Available In the design of a spent nuclear fuel disposal system, one necessary condition is to show that the configuration remains subcritical at time of emplacement but also during long periods covering up to 1,000,000 years. In the context of criticality safety applying burn-up credit, k-eff eigenvalue calculations are affected by nuclear data uncertainty mainly in the burnup calculations simulating reactor operation and in the criticality calculation for the disposal canister loaded with the spent fuel assemblies. The impact of nuclear data uncertainty should be included in the k-eff value estimation to enforce safety. Estimations of the uncertainty in the discharge compositions from the CASMO5 burn-up calculation phase are employed in the final MCNP6 criticality computations for the intact canister configuration; in between, SERPENT2 is employed to get the spent fuel composition along the decay periods. In this paper, nuclear data uncertainty was propagated by Monte Carlo sampling in the burn-up, decay and criticality calculation phases and representative values for fuel operated in a Swiss PWR plant will be presented as an estimation of its impact.

Advanced Test Reactor (ATR) Facility 10CFR830 Safety Basis Related to Facility Experiments

International Nuclear Information System (INIS)

Tomberlin, T.A.

2002-01-01

The Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Test Reactor (ATR), a DOE Category A reactor, was designed to provide an irradiation test environment for conducting a variety of experiments. The ATR Safety Analysis Report, determined by DOE to meet the requirements of 10 CFR 830, Subpart B, provides versatility in types of experiments that may be conducted. This paper addresses two general types of experiments in the ATR facility and how safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore this type of experiment is addressed with more detail in the safety basis. This allows individual safety analyses for these experiments to be more routine and repetitive. The second type of experiment is less defined and is permitted under more general controls. Therefore, individual safety analyses for the second type of experiment tend to be more unique from experiment to experiment. Experiments are also discussed relative to ''major modifications'' and DOE-STD-1027-92. Application of the USQ process to ATR experiments is also discussed

Safety margins and retrofit. The technical calculation perspective; Sicherheitsmargen durch Nachruestung aus Sicht der technischen Berechnung

Energy Technology Data Exchange (ETDEWEB)

Daichendt, Matthias [Kraftanlagen Heidelberg GmbH, Heidelberg (Germany). Systemtechnik - Technische Berechnungen

2016-01-15

Safety margins are an essential factor of the safety philosophy for nuclear power plants. They support to cover future requirements even today. The basic safety concept is one key topic as also aspects of process engineering, the dimensioning and mechanical analysis of systems and ageing management. Calculations with today's capabilities are an integral part of the determination of safety margins. They can be used to analyse and to assess retrofit measures.

Development of Large-Scale Spacecraft Fire Safety Experiments

DEFF Research Database (Denmark)

Ruff, Gary A.; Urban, David L.; Fernandez-Pello, A. Carlos

2013-01-01

exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low...... of the spacecraft fire safety risk. The activity of this project is supported by an international topical team of fire experts from other space agencies who conduct research that is integrated into the overall experiment design. The large-scale space flight experiment will be conducted in an Orbital Sciences...

Access safety systems - New concepts from the LHC experience

International Nuclear Information System (INIS)

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

2012-01-01

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

Main lessons for FBR safety study from the CABRI experiments

International Nuclear Information System (INIS)

Sato, Ikken

2006-01-01

CABRI project has been carried out FBR safety study with international cooperation of five nations since 1978. The project consists of four periods such as CABRI-1, CABRI-2, CABRI-FAST and CABRI-RAFT. The objects and the main information for hypothetical core decay accident and safety study of fuel are described. The behavior of core decay accident was studied in the first period (CABRI-1), the safety study of fuel was investigated after the second period (CABRI-2). Change of phenomena at the initial process of core decay accident, comparison between analysis and data of fuel diffusion behavior of neutron horoscope by CABRI-2 experiment, representative in-core experiment under slow TOP conditions, the damaged and undamaged pin under slow TOP conditions, the exterior of CABRI and TREAT and the upper part of CABRI and TREAT reactor are shown. CABRI experiments changed to LWR safety study and a part of TREAT is stated. (S.Y.)

Measuring safety climate in a nuclear power plant - an experience sharing

International Nuclear Information System (INIS)

Vincy, M.U.; Varshney, Aloke; Khot, Pankaj

2016-01-01

In this paper the author discusses the experience gained in safety climate measurement of an Indian nuclear power plant. Safety performance is increasingly part of an organization's sustainable development. Nuclear power stations are falling under the category 'high reliability' industries in the world as far as work safety is concerned. Both the research and the practical experience continually point to two underlying factors that drive safety outcomes: the quality of an organisation's leadership and the resulting culture. After years of development in safety technology and safety management system in the industry, management of nuclear industry world over has come to recognize that safety culture has to be addressed if high standards of health and safety are to be maintained. Therefore, nuclear industries in India have been carrying out measurement of safety climate for more than ten years. The objectives of the study are to examine people's values, attitude, perception, competencies, and patterns of behaviour that determine the commitment to, and effectiveness of health and safety management in the industry based on a questionnaires survey and their analysis

Safety analysis calculations for research and test reactors

Energy Technology Data Exchange (ETDEWEB)

Chen, S Y; MacDonald, R; MacFarlane, D [Argonne National Laboratory, Argonne, IL (United States)

1983-08-01

The goal of the RERTR (Reduced Enrichment in Research and Test Reactor) Program at ANL is to provide technical means for conversion of research and test reactors from HEU (High-Enrichment Uranium) to LEU (Low-Enrichment Uranium) fuels. In exploring the feasibility of conversion, safety considerations are a prime concern; therefore, safety analyses must be performed for reactors undergoing the conversion. This requires thorough knowledge of the important safety parameters for different types of reactors for both HEU and LEU fuel. Appropriate computer codes are needed to predict transient reactor behavior under postulated accident conditions. In this discussion, safety issues for the two general types of reactors i.e., the plate-type (MTR-type) reactor and the rod-type (TRIGA-type) reactor, resulting from the changes associated with LEU vs. HEU fuels, are explored. The plate-type fuels are typically uranium aluminide (UAl{sub x}) compounds dispersed in aluminum and clad with aluminum. Moderation is provided by the water coolant. Self shut-down reactivity coefficients with EU fuel are entirely a result of coolant heating, whereas with LEU fuel there is an additional shut down contribution provided by the direct heating of the fuel due to the Doppler coefficient. In contrast, the rod-type (TRIGA) fuels are mixtures of zirconium hydride, uranium, and erbium. This fuel mixture is formed into rods ( {approx} 1 cm diameter) and clad with stainless steel or Incoloy. In the TRIGA fuel the self-shutdown reactivity is more complex, depending on heating of the fuel rather than the coolant. The two most important mechanisms in providing this feedback are: spectral hardening due to neutron interaction with the ZrH moderator as it is heated and Doppler broadening of resonances in erbium and U-238. Since these phenomena result directly from heating of the fuel, and do not depend on heat transfer to the moderator/coolant, the coefficients are prompt acting. Results of transient

Preliminary Safety Analysis Report for the Tokamak Physics Experiment

International Nuclear Information System (INIS)

Motloch, C.G.; Bonney, R.F.; Levine, J.D.; Masson, L.S.; Commander, J.C.

1995-04-01

This Preliminary Safety Analysis Report (PSAR), includes an indication of the magnitude of facility hazards, complexity of facility operations, and the stage of the facility life-cycle. It presents the results of safety analyses, safety assurance programs, identified vulnerabilities, compensatory measures, and, in general, the rationale describing why the Tokamak Physics Experiment (TPX) can be safely operated. It discusses application of the graded approach to the TPX safety analysis, including the basis for using Department of Energy (DOE) Order 5480.23 and DOE-STD-3009-94 in the development of the PSAR

Temperature and void reactivity coefficient calculations for the high flux isotope reactor safety analysis report

International Nuclear Information System (INIS)

Engle, W.W. Jr.; Williams, L.R.

1994-07-01

This report provides documentation of a series of calculations performed in 1991 in order to provide input for the High Flux Isotope Reactor Safety Analysis Report. In particular, temperature and void reactivity coefficients were calculated for beginning-of-life, end-of-life, and xenon equilibrium (29 h) conditions. Much of the data used to prepare the computer models for these calculations was derived from the original HFIR nuclear design study

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-05-15

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

Safety requirements and safety experience of nuclear facilities in the Federal Republic of Germany

International Nuclear Information System (INIS)

Schnurer, H.L.

1977-01-01

Peaceful use of nuclear energy within the F.R.G. is rapidly growing. The Energy Programme of the Federal Government forecasts a capacity of up to 50.000 MW in 1985. Whereas most of this capacity will be of the LWR-Type, other activities are related to LMFBR - and HTGR - development, nuclear ships, and facilities of the nuclear fuel cycle. Safety of nuclear energy is the pacemaker for the realization of nuclear programmes and projects. Due to a very high population - and industrialisation density, safety has the priority before economical aspects. Safety requirements are therefore extremely stringent, which will be shown for the legal, the technical as well as for the organizational area. They apply for each nuclear facility, its site and the nuclear energy system as a whole. Regulatory procedures differ from many other countries, assigning executive power to state authorities, which are supervised by the Federal Government. Another particularity of the regulatory process is the large scope of involvement of independent experts within the licensing procedures. The developement of national safety requirements in different countries generates a necessity to collaborate and harmonize safety and radiation protection measures, at least for facilities in border areas, to adopt international standards and to assist nuclear developing countries. However, different nationally, regional or local situations might raise problems. Safety experience with nuclear facilities can be concluded from the positive construction and operation experience, including also a few accidents and incidents and the conclusions, which have been drawn for the respective factilities and others of similar design. Another tool for safety assessments will be risk analyses, which are under development by German experts. Final, a scope of future problems and developments shows, that safety of nuclear installations - which has reached a high performance - nevertheless imposes further tasks to be solved

Safety aspects and operating experience of LWR plants in Japan

International Nuclear Information System (INIS)

Aoki, S.; Yoshioka, T.; Toyota, M.; Hinoki, M.

1977-01-01

To develop nuclear power generation for the future, it is necessary to put further emphasis on safety assurance and to endeavour to devise measures to improve plant availability, based on the careful analysis of causes that reduce plant availability. The paper discusses the results of studies on the following items from such viewpoints: (1) Safety and operating experience of LWR nuclear power plants in Japan: operating experience with LWRs; improvements in LWR design during the past ten years; analysis of the factors affecting plant availability; (2) Assurance of safety and measures to increase availability: measures for safety and environmental protection; measures to reduce radiation exposure of employees; appropriateness of maintenance and inspection work; measures to increase plant availability; measures to improve reliability of equipment and components; (3) Future technical problems. (author)

Experience of safety and performance improvement for fuel handling equipment

International Nuclear Information System (INIS)

Gyoon Chang, Sang; Hee Lee, Dae

2014-01-01

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

Calculation of the state of safety (SOS) for lithium ion batteries

Science.gov (United States)

Cabrera-Castillo, Eliud; Niedermeier, Florian; Jossen, Andreas

2016-08-01

As lithium ion batteries are adopted in electric vehicles and stationary storage applications, the higher number of cells and greater energy densities increases the risks of possible catastrophic events. This paper shows a definition and method to calculate the state of safety of an energy storage system based on the concept that safety is inversely proportional to the concept of abuse. As the latter increases, the former decreases to zero. Previous descriptions in the literature are qualitative in nature but don't provide a numerical quantification of the safety of a storage system. In the case of battery testing standards, they only define pass or fail criteria. The proposed state uses the same range as other commonly used state quantities like the SOC, SOH, and SOF, taking values between 0, completely unsafe, and 1, completely safe. The developed function combines the effects of an arbitrary number of subfunctions, each of which describes a particular case of abuse, in one or more variables such as voltage, temperature, or mechanical deformation, which can be detected by sensors or estimated by other techniques. The state of safety definition can be made more general by adding new subfunctions, or by refining the existing ones.

Verification Results of Safety-grade Optical Modem for Core Protection Calculator (CPC) in Korea Standard Nuclear Power Plant (KSNP)

Energy Technology Data Exchange (ETDEWEB)

Kim, Jangyeol; Son, Kwangseop; Lee, Youngjun; Cheon, Sewoo; Cha, Kyoungho; Lee, Jangsoo; Kwon, Keechoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

We confirmed that the coverage criteria for a safety-grade optical modem of a Core Protection Calculator is satisfactory using a traceability analysis matrix between high-level requirements and lower-level system test case data set. This paper describes the test environment, test components and items, a traceability analysis, and system tests as a result of system verification and validation based on Software Requirement Specifications (SRS) for a safety-grade optical modem of a Core Protection Calculator (CPC) in a Korea Standard Nuclear Power Plant (KSNP), and Software Design Specifications (SDS) for a safety-grade optical modem of a CPC in a KSNP. All tests were performed according to the test plan and test procedures. Functional testing, performance testing, event testing, and scenario based testing for a safety-grade optical modem of a Core Protection Calculator in a Korea Standard Nuclear Power Plant as a thirty-party verifier were successfully performed.

Feedback of safety - related operational experience: Lessons learned

Energy Technology Data Exchange (ETDEWEB)

Elias, D [Commonwealth Edison Co. (United States)

1997-09-01

The presentation considers the following aspects of feedback of safety-related operational experience: lessons learned program, objectives, personnel characteristics; three types of documents for transmitting lessons learned issues.

Feedback of safety - related operational experience: Lessons learned

International Nuclear Information System (INIS)

Elias, D.

1997-01-01

The presentation considers the following aspects of feedback of safety-related operational experience: lessons learned program, objectives, personnel characteristics; three types of documents for transmitting lessons learned issues

KENO-IV code benchmark calculation, (6)

International Nuclear Information System (INIS)

Nomura, Yasushi; Naito, Yoshitaka; Yamakawa, Yasuhiro.

1980-11-01

A series of benchmark tests has been undertaken in JAERI in order to examine the capability of JAERI's criticality safety evaluation system consisting of the Monte Carlo calculation code KENO-IV and the newly developed multigroup constants library MGCL. The present report describes the results of a benchmark test using criticality experiments about Plutonium fuel in various shape. In all, 33 cases of experiments have been calculated for Pu(NO 3 ) 4 aqueous solution, Pu metal or PuO 2 -polystyrene compact in various shape (sphere, cylinder, rectangular parallelepiped). The effective multiplication factors calculated for the 33 cases distribute widely between 0.955 and 1.045 due to wide range of system variables. (author)

Critical experiments facility and criticality safety programs at JAERI

International Nuclear Information System (INIS)

Kobayashi, Iwao; Tachimori, Shoichi; Takeshita, Isao; Suzaki, Takenori; Miyoshi, Yoshinori; Nomura, Yasushi

1985-10-01

The nuclear criticality safety is becoming a key point in Japan in the safety considerations for nuclear installations outside reactors such as spent fuel reprocessing facilities, plutonium fuel fabrication facilities, large scale hot alboratories, and so on. Especially a large scale spent fuel reprocessing facility is being designed and would be constructed in near future, therefore extensive experimental studies are needed for compilation of our own technical standards and also for verification of safety in a potential criticality accident to obtain public acceptance. Japan Atomic Energy Research Institute is proceeding a construction program of a new criticality safety experimental facility where criticality data can be obtained for such solution fuels as mainly handled in a reprocessing facility and also chemical process experiments can be performed to investigate abnormal phenomena, e.g. plutonium behavior in solvent extraction process by using pulsed colums. In FY 1985 detail design of the facility will be completed and licensing review by the government would start in FY 1986. Experiments would start in FY 1990. Research subjects and main specifications of the facility are described. (author)

Experience of RIA safety analyses performance for NPP Temelin core arranged with TVSA-T fuel assemblies

International Nuclear Information System (INIS)

Kryukov, S.A.; Lizorkin, M.P.

2010-01-01

The contents of the presentation are as follows: 1. Definition of categories for initiating events; 2. Acceptance criteria for safety assessment; 3. Main aspects of safety assessment methodology; 4. Main stages of calculation analysis; 5. Interface with other parts of the core design; 6. Codes used for calculation; 6.1 Main performances of code package TIGR-1; 6.2 Main performances of code BIPR-7A; 7. TIGR-1 accounting of design margins in calculation of fuel rod powers; 8. Peculiar features of Instrumentation and Control System for Temelin NPP; 9. Calculations; 10. Checklist of margin data important for reload safety assessment. (P.A.)

Return on experience. Building tomorrow's safety rules

International Nuclear Information System (INIS)

Anon.

2013-01-01

Based on some experiments and witnesses, this set of articles outlines the importance of the return on experience in the evolution of process for improving the safety of nuclear installations. As an example, an article notably addresses the failures of Diesel engines which are used as spare generators in nuclear power stations: failures have been analysed and attributed to bearings, and more specifically to the degradation of their surface, and a third generation of bearings has been designed and produced. An article outlines that different industrials belonging to the nuclear sector as well as to other sectors share their returns on experience

RP-10: commissioning. Reproduction by physical experiences calculation

International Nuclear Information System (INIS)

Higa, Manabu; Madariaga, M.R.

1990-01-01

This work presents the neutronic calculation results, most of which were carried out after such experiences, to verify the calculation methodology developed at the Analysis and Calculation Department of the National Atomic Energy Commission (CNEA). The results obtained were satisfactory, proving that the calculation methodology used is adequate for the design of this type of reactors. The only important disagreement is to evaluate the reactivity excess and cut reactivity, but this responds to a criterion difference and/or that of definition for these parameters. The positions of criticality with errors lower than 100 pcm were predicted. The differential and integral reactivities for the calibration of bars, as well as the flux distribution, are reproduced in a reasonable degree in relation to differences inferior to 10%. (Author) [es

Safety climate mapping in a nuclear power plant - an experience sharing

International Nuclear Information System (INIS)

Vincy, M.U.; Varshney, Aloke; Khot, Pankaj

2016-01-01

In this paper the author discusses the experience gained in safety climate measurement of an Indian nuclear power plant. Safety performance is increasingly part of an organisation's sustainable development. Nuclear power stations are falling under the category 'high reliability' industries in the world as far as work safety is concerned. Both the research and the practical experience continually point to two underlying factors that drive safety outcomes: the quality of an organisation's leadership and the resulting culture. After years of development in safety technology and safety management system in the industry, management of nuclear industry world over has come to recognize that safety culture has to be addressed if high standards of health and safety are to be maintained. Therefore, nuclear industries in India have been carrying out measurement of safety climate for more than ten years. The objectives of the study are to examine people's values, attitude, perception, competencies, and patterns of behaviour that determine the commitment to, and effectiveness of health and safety management in the industry based on questionnaires survey and their analysis. A questionnaire, consists of 66 statements with 11 attributes, was designed to seek the views of managers, supervisors and front line workers on key aspects of the safety culture. Each of the discrete group was also classified according to their role in the organisation

An approach of sensitivity and uncertainty analyses methods installation in a safety calculation

International Nuclear Information System (INIS)

Pepin, G.; Sallaberry, C.

2003-01-01

Simulation of the migration in deep geological formations leads to solve convection-diffusion equations in porous media, associated with the computation of hydrogeologic flow. Different time-scales (simulation during 1 million years), scales of space, contrasts of properties in the calculation domain, are taken into account. This document deals more particularly with uncertainties on the input data of the model. These uncertainties are taken into account in total analysis with the use of uncertainty and sensitivity analysis. ANDRA (French national agency for the management of radioactive wastes) carries out studies on the treatment of input data uncertainties and their propagation in the models of safety, in order to be able to quantify the influence of input data uncertainties of the models on the various indicators of safety selected. The step taken by ANDRA consists initially of 2 studies undertaken in parallel: - the first consists of an international review of the choices retained by ANDRA foreign counterparts to carry out their uncertainty and sensitivity analysis, - the second relates to a review of the various methods being able to be used in sensitivity and uncertainty analysis in the context of ANDRA's safety calculations. Then, these studies are supplemented by a comparison of the principal methods on a test case which gathers all the specific constraints (physical, numerical and data-processing) of the problem studied by ANDRA

Experience gained in enhancing operational safety at ComEd's nuclear power plants

International Nuclear Information System (INIS)

Elias, D.

1997-01-01

The following aspects of experience gained in enhancing operational safety at Comed's nuclear power plants are discussed: nuclear safety policy; centralization/decentralization; typical nuclear operating organization; safety review boards; human performance enhancement; elements of effective nuclear oversight

Operating experience feedback from safety significant events at research reactors

Energy Technology Data Exchange (ETDEWEB)

Shokr, A.M. [Atomic Energy Authority, Abouzabal (Egypt). Egypt Second Research Reactor; Rao, D. [Bhabha Atomic Research Centre, Mumbai (India)

2015-05-15

Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

Operating experience feedback from safety significant events at research reactors

International Nuclear Information System (INIS)

Shokr, A.M.

2015-01-01

Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

Calculating Program for Decommissioning Work Productivity based on Decommissioning Activity Experience Data

Energy Technology Data Exchange (ETDEWEB)

Song, Chan-Ho; Park, Seung-Kook; Park, Hee-Seong; Moon, Jei-kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

KAERI is performing research to calculate a coefficient for decommissioning work unit productivity to calculate the estimated time decommissioning work and estimated cost based on decommissioning activity experience data for KRR-2. KAERI used to calculate the decommissioning cost and manage decommissioning activity experience data through systems such as the decommissioning information management system (DECOMMIS), Decommissioning Facility Characterization DB System (DEFACS), decommissioning work-unit productivity calculation system (DEWOCS). In particular, KAERI used to based data for calculating the decommissioning cost with the form of a code work breakdown structure (WBS) based on decommissioning activity experience data for KRR-2.. Defined WBS code used to each system for calculate decommissioning cost. In this paper, we developed a program that can calculate the decommissioning cost using the decommissioning experience of KRR-2, UCP, and other countries through the mapping of a similar target facility between NPP and KRR-2. This paper is organized as follows. Chapter 2 discusses the decommissioning work productivity calculation method, and the mapping method of the decommissioning target facility will be described in the calculating program for decommissioning work productivity. At KAERI, research on various decommissioning methodologies of domestic NPPs will be conducted in the near future. In particular, It is difficult to determine the cost of decommissioning because such as NPP facility have the number of variables, such as the material of the target facility decommissioning, size, radiographic conditions exist.

Calculating Program for Decommissioning Work Productivity based on Decommissioning Activity Experience Data

International Nuclear Information System (INIS)

Song, Chan-Ho; Park, Seung-Kook; Park, Hee-Seong; Moon, Jei-kwon

2014-01-01

KAERI is performing research to calculate a coefficient for decommissioning work unit productivity to calculate the estimated time decommissioning work and estimated cost based on decommissioning activity experience data for KRR-2. KAERI used to calculate the decommissioning cost and manage decommissioning activity experience data through systems such as the decommissioning information management system (DECOMMIS), Decommissioning Facility Characterization DB System (DEFACS), decommissioning work-unit productivity calculation system (DEWOCS). In particular, KAERI used to based data for calculating the decommissioning cost with the form of a code work breakdown structure (WBS) based on decommissioning activity experience data for KRR-2.. Defined WBS code used to each system for calculate decommissioning cost. In this paper, we developed a program that can calculate the decommissioning cost using the decommissioning experience of KRR-2, UCP, and other countries through the mapping of a similar target facility between NPP and KRR-2. This paper is organized as follows. Chapter 2 discusses the decommissioning work productivity calculation method, and the mapping method of the decommissioning target facility will be described in the calculating program for decommissioning work productivity. At KAERI, research on various decommissioning methodologies of domestic NPPs will be conducted in the near future. In particular, It is difficult to determine the cost of decommissioning because such as NPP facility have the number of variables, such as the material of the target facility decommissioning, size, radiographic conditions exist

"Nursing Students Assaulted": Considering Student Safety in Community-Focused Experiences.

Science.gov (United States)

Maneval, Rhonda E; Kurz, Jane

2016-01-01

Community nursing experiences for undergraduate students have progressed beyond community-based home visits to a wide array of community-focused experiences in neighborhood-based centers, clinics, shelters, and schools. Our Bachelor of Science in Nursing program chose to use sites situated within neighborhoods close to campus in order to promote student and faculty engagement in the local community. These neighborhood sites provide opportunities for students to deliver nursing services to underserved and vulnerable populations experiencing poverty and health disparities. Some of these neighborhoods are designated as high crime areas that may potentially increase the risk of harm to students and faculty. There is a need to acknowledge the risk to personal safety and to proactively create policies and guidelines to reduce potential harm to students engaged in community-focused experiences. When a group of baccalaureate nursing students was assaulted while walking to a neighborhood clinic, the faculty was challenged as how to respond given the lack of policies and guidelines. Through our experience, we share strategies to promote personal safety for students and recommend transparency by administrators regarding potential safety risks to students engaged in community-focused fieldwork activities. Copyright © 2016 Elsevier Inc. All rights reserved.

Design calculations for MAW storage experiment in the Asse salt mine

International Nuclear Information System (INIS)

Nipp, H.K.

1987-01-01

Several thermal pre-calculations examine what heat release is necessary in the storage experiment in order to produce a temperature level relevant to final storage at the edge of the borehole. It was found that the initial power must be 350-400 W/m. The thermo-mechanical design calculations are done on symmetrical equivalent models, in order to avoid a genuine spatial calculation. The results of the calculations show that the recovery of the radioactive waste is guaranteed over the whole experimental period, as the selected convergence space of 11 or 14 cm is sufficiently large. From the rock mechanics point of view, the MAW storage experiment is designed for the 800 m seam of the Asse mine, as no critical stresses are expected from calculations for the area of the borehole. (orig./RB) [de

Implications of passive safety based on historical industrial experience

International Nuclear Information System (INIS)

Forsberg, C.W.

1988-01-01

In the past decade, there have been multiple proposals for applying different technologies to achieve passively safe light water reactors (LWRs). A key question for all such concepts is, ''What are the gains in safety, costs, and reliability for passive safety systems.'' Using several types of historical data, estimates have been made of gains from passive safety and operating systems, which are independent of technology. Proposals for passive safety in reactors usually have three characteristics: (1) Passive systems with no moving mechanical parts, (2) systems with far fewer components and (3) more stringent design criteria for safety-related and process systems. Each characteristic reduces the potential for an accident and may increase plant reliability. This paper addresses gains from items (1) and (2). Passive systems often allow adoption of more rigorous design criteria which would be either impossible or economically unfeasible for active systems. This important characteristic of passive safety systems cannot be easily addressed using historical industrial experience

The importance for nuclear safety of efficient feedback of operational experience

International Nuclear Information System (INIS)

1987-09-01

Experience of practical operation is a valuable source of information for improving and optimizing the safety and reliability of nuclear power plants. Therefore it is essential to collect information on abnormal events occurring at plants during operation and on all deviations from normal performance by systems and personnel that could be precursors of accidents. For this purpose it is necessary to establish hierarchical systems to feedback operational safety experience at utility, national and international levels and to make these systems as effective as possible. The present report attempts to identify the safety objectives of these systems, to analyse the difficulties presently encountered and to suggest possible improvements

Evaluation of operating experience for early recognition of deteriorating safety performance

International Nuclear Information System (INIS)

Beckmerhagen, I.A.; Berg, H.P.

2004-01-01

One of the most difficult challenges facing nuclear power plants is to recognize the early signs of degrading safety performance before regulatory requirements are imposed or serious incidents or accidents occur. Today, the nuclear industry is striving for collecting more information on occurrences that could improve the operational safety performance. To achieve this, the reporting threshold has been lowered from incidents to anomalies with minor or no impact to safety. Industry experience (also outside nuclear industry) has shown that these are typical issues which should be considered when looking for such early warning signs. Therefore, it is important that nuclear power plant operators have the capability to trend, analyse and recognize early warning signs of deteriorating performance. It is necessary that plant operators are sensitive to these warning signs which may not be immediately evident. Reviewing operating experience is one of the main tasks for plant operators in their daily activities. Therefore, self assessment should be at the centre of any operational safety performance programme. One way of applying a self assessment program is through the following four basic elements: operational data, events, safety basis, and related experience. This approach will be described in the paper in more details. (authors)

W-1 Sodium Loop Safety Facility experiment centerline fuel thermocouple performance

International Nuclear Information System (INIS)

Meyers, S.C.; Henderson, J.M.

1980-05-01

The W-1 Sodium Loop Safety Facility (SLSF) experiment is the fifth in a series of experiments sponsored by the Department of Energy (DOE) as part of the National Fast Breeder Reactor (FBR) Safety Assurance Program. The experiments are being conducted under the direction of Argonne National Laboratory (ANL) and Hanford Engineering Development Laboratory (HEDL). The irradiation phase of the W-1 SLSF experiment was conducted between May 27 and July 20, 1979, and terminated with incipient fuel pin cladding failure during the final boiling transient. Experimental hardware and facility performed as designed, allowing completion of all planned tests and test objectives. This paper focuses on high temperature in-fuel thermocouples and discusses their development, fabrication, and performance in the W-1 experiment

Results from synthesis of calculation cases illustrating overall system performance in the safety assessment in H12 report

International Nuclear Information System (INIS)

Makino, Hitoshi; Sawada, Atsushi; Wakasugi, Keiichiro; Kato, Tomoko; Uchida, Masahiro; Miyahara, Kaname

2002-02-01

JNC (Japan Nuclear Cycle Development Institute) had proceeded R and D activities to provide a scientific and technical basis for geological disposal of HLW in Japan. The second progress report (H12) documented the progress of R and D and the Japanese version was submitted to the AEC (the Atomic Energy Commission) in November 1999. This report summarizes the calculation results for nuclide migration in 'Synthesis of Calculation Cases Illustrating Overall System Performance', which are performed to examine the safety of the geological disposal concept in Japan in the Safety Assessment in H12 Report. In addition, a set of calculation result for nuclide migration through each pathway in one-dimensional multiple pathway model (a set of 48 segments) are summarized for the Reference Case in H12 Report, and calculated dose conversion factors are also summarized against the combinations of potential Geosphere-Biosphere Interfaces (GBI) and potential exposure groups. Digital data of the calculation results are summarized in Appendix CD-ROM as Microsoft EXCEL files. (author)

Modelling and simulation in nuclear safety and the role of experiment

International Nuclear Information System (INIS)

Baek, W-P.

2015-01-01

'Full text:' Modeling and simulation (M&S) technology is a key element in assuring and enhancing the safety of nuclear installations. The M&S technology has been progressed continuously with the introduction of new designs, improved understanding on relevant physical processes, and the improvement of computing environment. This presentation covers the role, progresses and prospect of M&S technology relevant to nuclear safety. Special attention is given to the effective interaction between M&S and experiment. The expected role of experiment to motivate the advancement of M&S technology is emphasized with some typical examples. Finally, relevant R&D activities of Korea are introduced for thermal-hydraulics and severe accident safety. (author)

Radiation shielding calculation using MCNP

International Nuclear Information System (INIS)

Masukawa, Fumihiro

2001-01-01

To verify the Monte Carlo code MCNP4A as a tool to generate the reference data in the shielding designs and the safety evaluations, various shielding benchmark experiments were analyzed using this code. These experiments were categorized in three types of the shielding subjects; bulk shielding, streaming, and skyshine. For the variance reduction technique, which is indispensable to get meaningful results with the Monte Carlo shielding calculation, we mainly used the weight window, the energy dependent Russian roulette and spitting. As a whole, our analyses performed enough small statistical errors and showed good agreements with these experiments. (author)

Nurses' experiences and perspectives on medication safety practices: an explorative qualitative study.

Science.gov (United States)

Smeulers, Marian; Onderwater, Astrid T; van Zwieten, Myra C B; Vermeulen, Hester

2014-04-01

To explore nurses' experiences with and perspectives on preventing medication administration errors. Insight into nurses' experiences with and perspectives on preventing medication administration errors is important and can be utilised to tailor and implement safety practices. A qualitative interview study of 20 nurses in an academic medical centre was conducted between March and December of 2011. Three themes emerged from this study: (1) nurses' roles and responsibilities in medication safety: aside from safe preparation and administration, the clinical reasoning of nurses is essential for medication safety; (2) nurses' ability to work safely: knowledge of risks and nurses' work circumstances influence their ability to work safely; and (3) nurses' acceptance of safety practices: advantages, feasibility and appropriateness are important incentives for acceptance of a safety practice. Nurses' experiences coincide with the assumption that they are in a pre-eminent position to enable safe medication management; however, their ability to adequately perform this role depends on sufficient knowledge to assess the risks of medication administration and on the circumstances in which they work. Safe medication management requires a learning climate and professional practice environment that enables further development of professional nursing skills and knowledge. © 2014 John Wiley & Sons Ltd.

Using the Tritium Plasma Experiment to evaluate ITER PFC safety

International Nuclear Information System (INIS)

Longhurst, G.R.; Anderl, R.A.; Bartlit, J.R.; Causey, R.A.; Haines, J.R.

1993-01-01

The Tritium Plasma Experiment was assembled at Sandia National Laboratories, Livermore to investigate interactions between dense plasmas at low energies and plasma-facing component materials. This apparatus has the unique capability of replicating plasma conditions in a tokamak divertor with particle flux densities of 2 x 10 19 ions/cm 2 · s and a plasma temperature of about 15 eV using a plasma that includes tritium. With the closure of the Tritium Research Laboratory at Livermore, the experiment was moved to the Tritium Systems Test Assembly facility at Los Alamos National Laboratory. An experimental program has been initiated there using the Tritium Plasma Experiment to examine safety issues related to tritium in plasma-facing components, particularly the ITER divertor. Those issues include tritium retention and release characteristics, tritium permeation rates and transient times to coolant streams, surface modification and erosion by the plasma, the effects of thermal loads and cycling, and particulate production. A considerable lack of data exists in these areas for many of the materials, especially beryllium, being considered for use in ITER. Not only will basic material behavior with respect to safety issues in the divertor environment be examined, but innovative techniques for optimizing performance with respect to tritium safety by material modification and process control will be investigated. Supplementary experiments will be carried out at the Idaho National Engineering Laboratory and Sandia National Laboratory to expand and clarify results obtained on the Tritium Plasma Experiment

LMFBR safety experiment facility planning and analysis

International Nuclear Information System (INIS)

Stevenson, M.G.; Scott, J.H.

1976-01-01

In the past two years considerable effort has been placed on the planning and design of new facilities for the resolution of LMFBR safety issues. The paper reviews the key issues, the experiments needed to resolve them, and the design aspects of proposed new facilities. In addition, it presents a decision theory approach to selecting an optimal combination of modified and new facilities

Development of a Seismic Setpoint Calculation Methodology Using a Safety System Approach

International Nuclear Information System (INIS)

Lee, Chang Jae; Baik, Kwang Il; Lee, Sang Jeong

2013-01-01

The Automatic Seismic Trip System (ASTS) automatically actuates reactor trip when it detects seismic activities whose magnitudes are comparable to a Safe Shutdown Earthquake (SSE), which is the maximum hypothetical earthquake at the nuclear power plant site. To ensure that the reactor is tripped before the magnitude of earthquake exceeds the SSE, it is crucial to reasonably determine the seismic setpoint. The trip setpoint and allowable value for the ASTS for Advanced Power Reactor (APR) 1400 Nuclear Power Plants (NPPs) were determined by the methodology presented in this paper. The ASTS that trips the reactor when a large earthquake occurs is categorized as a non safety system because the system is not required by design basis event criteria. This means ASTS has neither specific analytical limit nor dedicated setpoint calculation methodology. Therefore, we developed the ASTS setpoint calculation methodology by conservatively considering that of PPS. By incorporating the developed methodology into the ASTS for APR1400, the more conservative trip setpoint and allowable value were determined. In addition, the ZPA from the Operating Basis Earthquake (OBE) FRS of the floor where the sensor module is located is 0.1g. Thus, the allowance of 0.17g between OBE of 0.1 g and ASTS trip setpoint of 0.27 g is sufficient to prevent the reactor trip before the magnitude of the earthquake exceeds the OBE. In result, the developed ASTS setpoint calculation methodology is evaluated as reasonable in both aspects of the safety and performance of the NPPs. This will be used to determine the ASTS trip setpoint and allowable for newly constructed plants

Use of operational experience in fire safety assessment of nuclear power plants

International Nuclear Information System (INIS)

2000-01-01

collection of data related to fire safety occurrences in NPPs, the so called operational experience and the use of such operational experience in NPPs. This report provides good practice information on data needs, data reporting requirements and some advice on database features. In addition, this publication provides information on the applications of fire related operational experience, highlighting their benefits. This publication has been developed to complement other IAEA publications related to fire safety analysis within the framework of the IAEA programme of fire safety

Experience gained in enhancing operational safety at ComEd`s nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Elias, D [Commonwealth Edison Co. (United States)

1997-09-01

The following aspects of experience gained in enhancing operational safety at Comed`s nuclear power plants are discussed: nuclear safety policy; centralization/decentralization; typical nuclear operating organization; safety review boards; human performance enhancement; elements of effective nuclear oversight.

PReSaFe: A model of barriers and facilitators to patients providing feedback on experiences of safety.

Science.gov (United States)

De Brún, Aoife; Heavey, Emily; Waring, Justin; Dawson, Pamela; Scott, Jason

2017-08-01

The importance of involving patients in reporting on safety is increasingly recognized. Whilst studies have identified barriers to clinician incident reporting, few have explored barriers and facilitators to patient reporting of safety experiences. This paper explores patient perspectives on providing feedback on safety experiences. Patients (n=28) were invited to take part in semi-structured interviews when given a survey about their experiences of safety following hospital discharge. Transcripts were thematically analysed using NVivo10. Patients were recruited from four hospitals in the UK. Three themes were identified as barriers and facilitators to patient involvement in providing feedback on their safety experiences. The first, cognitive-cultural, found that whilst safety was a priority for most, some felt the term was not relevant to them because safety was the "default" position, and/or because safety could not be disentangled from the overall experience of care. The structural-procedural theme indicated that reporting was facilitated when patients saw the process as straightforward, but that disinclination or perceived inability to provide feedback was a barrier. Finally, learning and change illustrated that perception of the impact of feedback could facilitate or inhibit reporting. When collecting patient feedback on experiences of safety, it is important to consider what may help or hinder this process, beyond the process alone. We present a staged model of prerequisite barriers and facilitators and hypothesize that each stage needs to be achieved for patients to provide feedback on safety experiences. Implications for collecting meaningful data on patients' safety experiences are considered. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Presurized water reactor safety approach and analysis. From conception to experience feedback

International Nuclear Information System (INIS)

Libmann, J.

1987-04-01

This report deals in ten chapters, with the following subjects: 1. Safety approach methods; 2. Study of accidents; 3. Safety analysis; 4. Study of internal aggressions or those involved by the site; 5. Consideration of complementary situations; 6. Three Mile Island accident; 7. Safety during operation and experience feedback; 8. An example of analysis: steam generator closure plug; 9. Probabilistic safety evaluation; 10. Chernobyl accident. 30 refs [fr

Comparison of SOLA-FLX calculations with experiments at systems, science and software

International Nuclear Information System (INIS)

Dienes, J.K.; Hirt, C.W.; Stein, L.R.

1977-03-01

Preliminary results of a comparison between hydroelastic calculations at the Los Alamos Scientific Laboratory and experiments at Systems, Science and Software are described. The axisymmetric geometry is an idealization of a pressurized water reactor at a scale of 1/25. Reasons for some of the discrepancies are described, and suggestions for improving both experiments and calculations are discussed

Sophisticated Calculation of the 1oo4-architecture for Safety-related Systems Conforming to IEC61508

International Nuclear Information System (INIS)

Hayek, A; Al Bokhaiti, M; Schwarz, M H; Boercsoek, J

2012-01-01

With the publication and enforcement of the standard IEC 61508 of safety related systems, recent system architectures have been presented and evaluated. Among a number of techniques and measures to the evaluation of safety integrity level (SIL) for safety-related systems, several measures such as reliability block diagrams and Markov models are used to analyze the probability of failure on demand (PFD) and mean time to failure (MTTF) which conform to IEC 61508. The current paper deals with the quantitative analysis of the novel 1oo4-architecture (one out of four) presented in recent work. Therefore sophisticated calculations for the required parameters are introduced. The provided 1oo4-architecture represents an advanced safety architecture based on on-chip redundancy, which is 3-failure safe. This means that at least one of the four channels have to work correctly in order to trigger the safety function.

Development of a harmonized approach to safety assessment of decommissioning: Lessons learned from international experience (DeSa project)

International Nuclear Information System (INIS)

Percival, K.; Nokhamzon, J.-G.; Ferch, R.; Batandjieva, B.

2006-01-01

The number of nuclear facilities being or planned to be shutdown as they reach the end of their design life, due to accidents or other political and social factors has been increasing worldwide. This has led to an increase in the awareness of regulators and operators of the importance of development and implementation of adequate safety requirements and criteria for decommissioning of these facilities. A general requirement at international and national levels, even for new facilities to be commissioned, is the development of a decommissioning plan, which includes evaluation of potential radiological consequences to public and workers during planned and accidental decommissioning activities. Experience has been gained in the safety assessment of decommissioning at various sites with different complexities and hazard potentials. This experience shows that various approaches have been used in conducting safety assessments and that there is a need for harmonisation of these approaches and for transferring the good practice and lessons learned to other countries, in particular developing countries with limited financial and human resources. The IAEA launched an international project on Evaluation and Demonstration of Safety during Decommissioning (DeSa) in 2004 to provide a forum for exchange of lessons learned between site operators, regulators, safety assessors and other specialists in safety assessment of decommissioning of nuclear power plants, research reactors, laboratories, nuclear fuel cycle facilities, etc. This paper presents the lessons learned through the project up to date, i.e.; (i) a common approach to safety assessment is being applied worldwide with the following steps - establishment of assessment framework; description of the facility; definition of decommissioning activities; hazard identification and analysis; calculation of consequences; and analysis of results; (ii) a deterministic approach to safety assessment is most commonly applied; (iii) a

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

Science.gov (United States)

Graydon, Patrick J.; Holloway, C. Michael

2015-01-01

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

A comparison of FEMAXI-III code calculations with irradiation experiments

International Nuclear Information System (INIS)

Ito, K.; Sogame, M.; Ichikawa, M.; Nakajima, T.

1981-01-01

The FEMAXI-III code calculations were compared with in-pile diameter measurements in the Halden Boiling Water Reactor, in order to check the ability to analyse the pellet-cladding mechanical interaction. The results showed generally good agreement between calculations and measurements. The Studsvik INTER-RAMP Experiments were also analysed to examine the predictability of fuel rod failures. Good agreement was obtained between calculated and measured fission gas x release. The threshold stress to cause failure was estimated by means of FEMAXI-III. (author)

Proceedings of 2nd PHWR operating safety experience meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-04-01

Papers presented during the eight sessions of the meeting were devoted to the impact of PHWR operating experience on design of civil structures (reactor building integrity); operating experiences related to pressure tubes, nuclear steam supply system, plant stability; reactor maintenance and control systems, reactor operational safety. Some events concerned with reactor shutdown due to power failures are described, as well as action undertaken to prevent major damage.

Proceedings of 2nd PHWR operating safety experience meeting

International Nuclear Information System (INIS)

1991-04-01

Papers presented during the eight sessions of the meeting were devoted to the impact of PHWR operating experience on design of civil structures (reactor building integrity); operating experiences related to pressure tubes, nuclear steam supply system, plant stability; reactor maintenance and control systems, reactor operational safety. Some events concerned with reactor shutdown due to power failures are described, as well as action undertaken to prevent major damage

Experience related to the safety of advanced LMFBR fuel elements

International Nuclear Information System (INIS)

Kerrisk, J.F.

1975-07-01

Experiments and experience relative to the safety of advanced fuel elements for the liquid metal fast breeder reactor are reviewed. The design and operating parameters and some of the unique features of advanced fuel elements are discussed breifly. Transient and steady state overpower operation and loss of sodium bond tests and experience are discussed in detail. Areas where information is lacking are also mentioned

The experience of WNTI with Safety and Security Worldwide

International Nuclear Information System (INIS)

Neau, Henry-Jacques

2016-01-01

This paper gives an industrial perspective on safety and security issues based on the experience of WNTI members. It describes how safety is invested primarily in the package; not how the package is transported. Transport safety is therefore an engineering challenge, and all necessary technical information is available to enable this to be met. Security in transport involves various measures to guard against intentional malicious acts. The paper describes the international instruments relevant to security in the transport of nuclear fuel cycle materials and how both safety and security regulations must be coordinated and simplified to avoid conflicts. It considers potential risks, which must not be underestimated. However, the assessment of risks must be realistic and quantified, and the requirements placed on the industry appropriate. It is important to dispel exaggerated perceptions of danger in the minds of the public, politicians and regulators. (author)

Burnable poisons in the light water reactor design, microburnup experiments and calculations. Part of a coordinated programme on burnup calculations and experiments for thermal reactors

International Nuclear Information System (INIS)

Penndorf, K.

1976-04-01

Investigations on Research Agreement N 1519/CF (1.8.1974 - 31.7.1975) entitled ''Burnable poisons in light water reactor design, microburnup experiments and calculations'' were carried out in the frame of the IAEA's coordinated research programme on ''Burn-up calculation and experiments for thermal reactors''. The theoretical and experimental work on application of solid burnable poison used for reduction of the amount of boric acid necessary to control of PWR or to lower the number of control rods needed in a BWR. Solid burnable poisons are needed in present PWR designs for the reduction of the boron acid concentration in order to prevent positive coefficients of reactivity. The special operational conditions of a ship reactor lead to the application of this kind of poison for compensation of almost all burnup reactivity. This strengthens the necessity of a very accurate and many dimensional calculations because an appropriate binding of reactivity has to be kept over the whole cycle time. Several burnup experiments had been run in the 15 MW material test reactor FRG-II. The following devices have been irradiated: poison pins within and without PWR fuel pin lattice segments and fuel pins containing pellets with a poison core. Measurements of reactivity, fluence, fission product concentration have been performed. Methods applied were γ-scanning and neutron pulse, radiography and transmission measurement techniques. Evaluation of the experiments was done by one and two dimensional Ssub(N) transport burnup calculations. In parallel a collision probability transport burnup code for current PWR design work is being developed, the main feature of which is economy in manpower and computer time

Leadership for safety: industrial experience.

Science.gov (United States)

Flin, R; Yule, S

2004-12-01

The importance of leadership for effective safety management has been the focus of research attention in industry for a number of years, especially in energy and manufacturing sectors. In contrast, very little research into leadership and safety has been carried out in medical settings. A selective review of the industrial safety literature for leadership research with possible application in health care was undertaken. Emerging findings show the importance of participative, transformational styles for safety performance at all levels of management. Transactional styles with attention to monitoring and reinforcement of workers' safety behaviours have been shown to be effective at the supervisory level. Middle managers need to be involved in safety and foster open communication, while ensuring compliance with safety systems. They should allow supervisors a degree of autonomy for safety initiatives. Senior managers have a prime influence on the organisation's safety culture. They need to continuously demonstrate a visible commitment to safety, best indicated by the time they devote to safety matters.

Calculational assessment of critical experiments with mixed-oxide fuel pin arrays moderated by organic solution

International Nuclear Information System (INIS)

Smolen, G.R.; Funabashi, H.

1987-01-01

Critical experiments have been conducted with organically moderated mixed-oxide (MOX) fuel pin assemblies at the Pacific Northwest Lab. Critical Mass Lab. These experiments are part of a joint exchange program between the US Dept. of Energy and the Power Reactor and Nuclear Fuel Development Corp. of Japan in the area of criticality data development. The purpose of these experiments is to benchmark computer codes and cross-section libraries and to assess the reactivity difference between systems moderated by water and those moderated by an organic solution. Past studies have indicated that some organic mixtures may be better moderators than water. This topic is of particular importance to the criticality safety of fuel processing plants where fissile material is dissolved in organic solutions during the solvent extraction process. In the past, it has been assumed that the codes and libraries benchmarked with water-moderated experiments were adequate when performing design and licensing studies of organically moderated systems. Calculations presented in this paper indicated that the Scale code system and the 27-energy-group cross-section library accurately compute k/sub eff/ for organically moderated MOX fuel pin assemblies. Furthermore, the reactivity of an organic solution with a 32 vol % TBP/68 vol% NPH mixture in a heterogeneous configuration is the same, for practical purposes, as water

Calculational assessment of critical experiments with mixed oxide fuel pin arrays moderated by organic solution

International Nuclear Information System (INIS)

Smolen, G.R.

1987-01-01

Critical experiments have been conducted with organic-moderated mixed oxide (MOX) fuel pin assemblies at the Pacific Northwest Laboratory (PNL) Critical Mass Laboratory (CML). These experiments are part of a joint exchange program between the United States Department of Energy (USDOE) and the Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan in the area of criticality data development. The purpose of these experiments is to benchmark computer codes and cross-section libraries and to assess the reactivity difference between systems moderated by water and those moderated by an organic solution. Past studies have indicated that some organic mixtures may be better moderators than water. This topic is of particular importance to the criticality safety of fuel processing plants where fissile material is dissolved in organic solutions during the solvent extraction process. In the past, it has been assumed that the codes and libraries benchmarked with water-moderated experiments were adequate when performing design and licensing studies of organic-moderated systems. Calculations presented in this paper indicated that the SCALE code system and the 27-energy-group cross-section accurately compute k-effectives for organic moderated MOX fuel-pin assemblies. Furthermore, the reactivity of an organic solution with a 32-vol-% TBP/68-vol-% NPH mixture in a heterogeneous configuration is the same, for practical purposes, as water. 5 refs

Annotated references on shielding experiment and calculation of high energy particles

International Nuclear Information System (INIS)

Hirayama, H.; Ban, S.; Nakamura, T.

1990-12-01

The literature on shielding experiment and calculation of high energy particles above 20 MeV has been surveyed. The survey covers thirteen journals, from 1965 up to 1989. For each paper, applicable information is listed on type and energy of the projectile, the accelerator used, composition and thickness of the target and shielding materials, shielding geometry, the experimental and calculational methods, and the quantities obtained. The references on shielding experiment and on shielding calculation are accessed through two indices which list the projectile-target and shielding material combination, shielding geometry and the projectile energy range. The literature on neutron, photon and hadron production from thick target bombarded by charged particles has been surveyed mainly from 1984 as a complement of the previous work. (author)

Safety aspects and operating experience of LWR plants in Japan

International Nuclear Information System (INIS)

Aoki, S.; Hinoki, M.

1977-01-01

From the outset of nuclear power development in Japan, major emphasis has been placed on the safety of the nuclear power plants. There are now twelve nuclear power plants in operation with a total output of 6600 MWe. Their operating records were generally satisfactory, but in the 1974 to 1975 period, they experienced somewhat declined availability due to the repair work under the specific circumstances. After investigation of causes of troubles and the countermeasures thereof were made to ensure safety, they are now keeping good performance. In Japan, nuclear power plants are strictly subject to sufficient and careful inspection in compliance with the safety regulation, and are placed under stringent radiation control of employees. Under the various circumstances, however, the period of annual inspection tends to be prolonged more than originally planned, and this consequently is considered to be one of the causes of reduced availability. In order to develop nuclear power generation for the future, it is necessary to put further emphasis on the assurance of safety and to endeavor to devise measures to improve availability of the plants, based on the careful analysis of causes which reduce plant availability. This paper discusses the results of studies made for the following items from such viewpoints: (1) Safety and Operating Experience of LWR Nuclear Power Plants in Japan; a) Operating experience with light water reactors b) Improvements in design of light water reactors during the past ten years c) Analysis of the factors which affect plant availability; 2) Assurance of Safety and Measures to Increase Availability a) Measures for safety and environmental protection b) Measures to reduce radiation exposure of employees c) Appropriateness of maintenance and inspection work d) Measures to increase plant availability e) Measures to improve reliability of equipments and components; and 3) Future Technical Problems

Slope Safety Factor Calculations With Non-Linear Yield Criterion Using Finite Elements

DEFF Research Database (Denmark)

Clausen, Johan; Damkilde, Lars

2006-01-01

The factor of safety for a slope is calculated with the finite element method using a non-linear yield criterion of the Hoek-Brown type. The parameters of the Hoek-Brown criterion are found from triaxial test data. Parameters of the linear Mohr-Coulomb criterion are calibrated to the same triaxial...... are carried out at much higher stress levels than present in a slope failure, this leads to the conclusion that the use of the non-linear criterion leads to a safer slope design...

Safety analysis calculations for a mixed and full FLIP core in a TRIGA Mark II

International Nuclear Information System (INIS)

Ringle, John C.; Hornyik, K.; Robinson, A.H.; Anderson, T.V.; Johnson, A.G.

1976-01-01

The Oregon State TRIGA Reactor will be reloading with FLIP fuel in August 1976. As we are the first Mark II TRIGA with a circular grid pattern and graphite reflector to utilize FLIP fuel, the safety analysis calculations performed at other facilities using FLIP were only of limited use to us. A multigroup, multiregion, one-dimensional diffusion theory code was used to calculate power densities in six different operational cores - mixed to full FLIP. Pulsing characteristics were obtained from a computer code based on point kinetics, with adiabatic heating of the fuel, linear temperature dependence of the specific heat, and prompt fuel temperature feedback coefficient. The results of all pertinent calculations will be presented. (author)

Safety analysis calculations for research and test reactors

International Nuclear Information System (INIS)

Chen, S.Y.; MacDonald, R.; MacFarlane, D.

1983-01-01

Safety issues for the two general types of reactors, i.e., the plate-type (MTR-type) reactor and the rod-type (TRIGA-type) reactor, resulting from the changes associated with LEU vs HEU fuels, are explored. The plate-type fuels are typically uranium aluminide (UAl/sub x/) compounds dispersed in aluminum and clad with aluminum. Moderation is provided by the water coolant. Self shut-down reactivity coefficients with HEU fuel are entirely a result of coolant heating, whereas with LEU fuel there is an additional shut down contribution provided by the direct heating of the fuel due to the Doppler coefficient. In contrast, the rod-type (TRIGA) fuels are mixtures of zirconium hydride, uranium, and erbium. This fuel mixture is formed into rods (approx. 1 cm diameter) and clad with stainless steel or Incoloy. In the TRIGA fuel the self-shutdown reactivity is more complex, depending on heating of the fuel rather than the coolant. Results of transient calculations performed with existing computer codes, most suited for each type of reactor, are presented

The CERN Detector Safety System for LHC Experiments

CERN Document Server

Lüders, S; Morpurgo, G; Schmeling, S M

2003-01-01

The Detector Safety System (DSS), developed at CERN in common for the four LHC experiments under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the equipment protection for these experiments. Therefore, the DSS requires a high degree of both availability and reliability. It is composed of a Front-end and a Back-end part. The Front-end is based on a redundant Siemens PLC, to which the safety-critical part of the DSS task is delegated. The PLC Front-end is capable of running autonomously and of automati-cally taking predefined protective actions whenever re-quired. It is supervised and configured by the CERN-cho-sen PVSS SCADA system via a Siemens OPC server. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabili-ties. Configuration of the code running in the PLCs is completely data driven via the contents of a ?Configura-tion Database?. Thus, the DSS can easily adapt to the different and constantly evolving require...

Extended probabilistic system assessment calculations within the SKI project-90

International Nuclear Information System (INIS)

Pereira, A.

1993-03-01

The probabilistic system assessment calculation reported in the SKI Project-90 final documents were restricted to the following nuclides: 14 C, 129 I, 135 Cs, 237 Np and 240 Pu. In this report we have extended those calculations to another five nuclides: 79 Se, 243 Am, 240 Pu, 93 Zr and 99 Tc. The execution of probabilistic assessment calculations integrated in the context of SKIs first safety analysis exercise of an hypothetic final repository for high-level nuclear waste in Sweden, was a learning experience of relevance for the conduction of probabilistic safety assessment in future exercises. Some major conclusions and viewpoints of future need related with probabilistic assessment were withdrawn from this work and are presented in our report

Use of integral experiments to improve neutron propagation and gamma heating calculations

International Nuclear Information System (INIS)

Oceraies, Y.; Caumette, P.; Devillers, C.; Bussac, J.

1979-01-01

1) The studies to define and improve the accuracies of neutron propagation and gamma heating calculations from integral experiments are encompassed in the field of the fast reactor physics program at CEA. 2) A systematic analysis of neutron propagation in Fe-Na clean media, with variable volumic composition between 0 and 100% in sodium, has been performed on the HARMONIE source reactor. Gamma heating traverses in the core, the blankets and several control rods, have been measured in the R Z core program at MASURCA. The experimental techniques, the accuracies and the results obtained are given. The approximations of the calculational methods used to analyse these experiments and to predict the corresponding design parameters are also described. 3) Particular emphasis is given to the methods planned to improve fundamental data used in neutron propagation calculations, using the discrepancies observed between measured and calculated results in clean integral experiments. One of these approaches, similar to the techniques used in core physics, relies upon sensitivity studies and eventually on adjustment techniques applied to neutron propagation. (author)

Calculated k-effectives for light water reactor typical, U + Pu nitrate solution critical experiments

International Nuclear Information System (INIS)

Primm, R.T. III; Mincey, J.F.

1982-01-01

The Department of Energy's Consolidated Fuel Reprocessing Program has as a goal the design of nuclear fuel reprocessing equipment. In order to validate computer codes used for criticality analyses in the design of such equipment, k-effectives have been calculated for several U + Pu nitrate solution critical experiments. As of January 1981, descriptions of 45 unpoisoned, U + Pu solution experiments were available in the open literature. Twelve of these experiments were performed with solutions which have physical characteristics typical of dissolved, light water reactor fuel. This paper contains a discussion of these twelve experiments, a review of the calculational procedure used to determine k-effectives, and the results of the calculations

Experience With Laser Safety In The USA--A Review

Science.gov (United States)

Sliney, David H.

1986-10-01

Following several research programs in the 1960's aimed at studying the adverse biological effects of lasers and other optical radiation sources, laser occupational exposure limits were set and general safety standards were developed. Today, the experience from laser accidents and the development of new lasers and new applications have altered the format of the exposure limits and the safety procedures. It is critically important to distinguish between different biological injury mechanisms. The biological effects of ultraviolet radiation upon the skin and eye are additive over a period of at least one workday, and require different safety procedures. The scattered UV irradiance from excimer lasers may be quite hazardous, depending upon wavelength and action spectra. Since laser technology is young, the exposure of an individual in natural sunlight must be studied to evaluate the potential for chronic effects. The safety measures necessary in the use of lasers depend upon a hazard evaluation. The appropriate control measures and alternate means of enclosure, baffling, and operational control measures are presented. Present laser safety standards are explained briefly. Eye protective techniques and eyewear are considered for a variety of sources. The optical properties of enclosure materials are also discussed.

Large-Scale Spacecraft Fire Safety Experiments in ISS Resupply Vehicles

Science.gov (United States)

Ruff, Gary A.; Urban, David

2013-01-01

Our understanding of the fire safety risk in manned spacecraft has been limited by the small scale of the testing we have been able to conduct in low-gravity. Fire growth and spread cannot be expected to scale linearly with sample size so we cannot make accurate predictions of the behavior of realistic scale fires in spacecraft based on the limited low-g testing to date. As a result, spacecraft fire safety protocols are necessarily very conservative and costly. Future crewed missions are expected to be longer in duration than previous exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low-gravity, the need for realistic scale testing at reduced gravity has been demonstrated. To address this concern, a spacecraft fire safety research project is underway to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing at nearly full scale in low-gravity. This project is supported by the NASA Advanced Exploration Systems Program Office in the Human Exploration and Operations Mission Directorate. The activity of this project is supported by an international topical team of fire experts from other space agencies to maximize the utility of the data and to ensure the widest possible scrutiny of the concept. The large-scale space flight experiment will be conducted on three missions; each in an Orbital Sciences Corporation Cygnus vehicle after it has deberthed from the ISS. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew allows the fire products to be released into the cabin. The tests will be fully automated with the data downlinked at the conclusion of the test before the Cygnus vehicle reenters the

International Criticality Safety Benchmark Evaluation Project (ICSBEP) - ICSBEP 2015 Handbook

International Nuclear Information System (INIS)

Bess, John D.

2015-01-01

The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in October of 1992 by the United States Department of Energy (DOE). The project quickly became an international effort as scientists from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) became an official activity of the Nuclear Energy Agency (NEA) in 1995. This handbook contains criticality safety benchmark specifications that have been derived from experiments performed at various critical facilities around the world. The benchmark specifications are intended for use by criticality safety engineers to validate calculation techniques used to establish minimum subcritical margins for operations with fissile material and to determine criticality alarm requirements and placement. Many of the specifications are also useful for nuclear data testing. Example calculations are presented; however, these calculations do not constitute a validation of the codes or cross-section data. The evaluated criticality safety benchmark data are given in nine volumes. These volumes span approximately 69000 pages and contain 567 evaluations with benchmark specifications for 4874 critical, near-critical or subcritical configurations, 31 criticality alarm placement/shielding configurations with multiple dose points for each, and 207 configurations that have been categorised as fundamental physics measurements that are relevant to criticality safety applications. New to the handbook are benchmark specifications for neutron activation foil and thermoluminescent dosimeter measurements performed at the SILENE critical assembly in Valduc, France as part of a joint venture in 2010 between the US DOE and the French Alternative Energies and Atomic Energy Commission (CEA). A photograph of this experiment is shown on the front cover. Experiments that are found unacceptable for use as criticality safety benchmark experiments are discussed in these

Review of studies on criticality safety evaluation and criticality experiment methods

International Nuclear Information System (INIS)

Naito, Yoshitaka; Yamamoto, Toshihiro; Misawa, Tsuyoshi; Yamane, Yuichi

2013-01-01

Since the early 1960s, many studies on criticality safety evaluation have been conducted in Japan. Computer code systems were developed initially by employing finite difference methods, and more recently by using Monte Carlo methods. Criticality experiments have also been carried out in many laboratories in Japan as well as overseas. By effectively using these study results, the Japanese Criticality Safety Handbook was published in 1988, almost the intermediate point of the last 50 years. An increased interest has been shown in criticality safety studies, and a Working Party on Nuclear Criticality Safety (WPNCS) was set up by the Nuclear Science Committee of Organisation Economic Co-operation and Development in 1997. WPNCS has several task forces in charge of each of the International Criticality Safety Benchmark Evaluation Program (ICSBEP), Subcritical Measurement, Experimental Needs, Burn-up Credit Studies and Minimum Critical Values. Criticality safety studies in Japan have been carried out in cooperation with WPNCS. This paper describes criticality safety study activities in Japan along with the contents of the Japanese Criticality Safety Handbook and the tasks of WPNCS. (author)

New safety experiments in decommissioned superheated steam reactor at Karlstein

International Nuclear Information System (INIS)

Koerting, K.

1986-01-01

This article gives a concise summary of the Status Report of the Superheated Steam Reactor Safety Program (PHDR) Project, held at KfK on Dec. 5, 1985. The results discussed dealt with fire experiments, shock tests simulating airplane crashes, temperature shocks in the reactor pressure vessel, studies of crack detection in pressure vessels and blasting experiments associated with nuclear plant decommissioning

Review of irradiation experiments for water reactor safety research

International Nuclear Information System (INIS)

Tobioka, Toshiaki

1977-02-01

A review is made of irradiation experiments for water reactor safety research under way in both commercial power plants and test reactors. Such experiments are grouped in two; first, LWR fuel performance under normal and abnormal operating conditions, and second, irradiation effects on fracture toughness in LWR vessels. In the former are fuel densification, swelling, and the influence of power ramp and cycling on fuel rod, and also fuel rod behavior under accident conditions in in-reactor experiment. In the latter are the effects of neutron exposure level on the ferritic steel of pressure vessels, etc.. (auth.)

A test-type hyper-thermal neutron generator for neutron capture therapy - estimation of neutron energy spectrum by simulation calculations and TOF experiments

International Nuclear Information System (INIS)

Sakurai, Yoshinori; Kobayashi, Tooru; Kobayashi, Katsuhei

1999-01-01

In order to clarify the irradiation characteristics of hyper-thermal neutrons and the feasibility of a hyper-thermal neutron irradiation field for neutron capture therapy, a 'test-type' hyper-thermal neutron generator was designed and made. Graphite of 6 cm thickness and 21 cm diameter was selected as the high temperature scatterer. The scatterer is heated up to 1200 deg. C maximum using molybdenum heaters. The radiation heat is shielded by reflectors of molybdenum and stainless steel. The temperature is measured using three R-type thermo-couples and controlled by a program controller. The total thickness of the generator is designed to be as thin as possible, 20 cm in maximum, in the standing point of the neutron beam intensity. The thermal stability, controllability and safety of the generator at high temperature employment were confirmed by the heating tests. As one of the experiments for the characteristics estimation, the neutron energy spectrum dependent on the scatterer temperature was measured by the TOF (time of flight) method using the LINAC neutron generator. The estimations by simulation calculations were also performed. From the experiment and calculation results, it was confirmed that the neutron temperature shifted higher as the scatterer temperature was higher. The prospect of the feasibility of the 'hyper-thermal neutron irradiation field for NCT' was opened from the estimation results of the generator characteristics by the simulation calculations and experiments

Calculated K-effectives using ENDF/B-V data for U + Pu solution critical experiments

International Nuclear Information System (INIS)

Primm, R.T. III; Mincey, J.F.

1981-01-01

Effective multiplication factors for 12 critical experiments have been calculated using multigroup cross sections derived from the ENDF/B-V library. All 12 experiments contained mixed plutonium and uranium nitrate solutions. The range of hydrogen-to-fissile plutonium atom ratios spanned by these experiments was 200 to 2200. A comparison with K-effectives calculated with ENDF/B-IV data is presented

Assessing medical students' perceptions of patient safety: the medical student safety attitudes and professionalism survey.

Science.gov (United States)

Liao, Joshua M; Etchegaray, Jason M; Williams, S Tyler; Berger, David H; Bell, Sigall K; Thomas, Eric J

2014-02-01

To develop and test the psychometric properties of a survey to measure students' perceptions about patient safety as observed on clinical rotations. In 2012, the authors surveyed 367 graduating fourth-year medical students at three U.S. MD-granting medical schools. They assessed the survey's reliability and construct and concurrent validity. They examined correlations between students' perceptions of organizational cultural factors, organizational patient safety measures, and students' intended safety behaviors. They also calculated percent positive scores for cultural factors. Two hundred twenty-eight students (62%) responded. Analyses identified five cultural factors (teamwork culture, safety culture, error disclosure culture, experiences with professionalism, and comfort expressing professional concerns) that had construct validity, concurrent validity, and good reliability (Cronbach alphas > 0.70). Across schools, percent positive scores for safety culture ranged from 28% (95% confidence interval [CI], 13%-43%) to 64% (30%-98%), while those for teamwork culture ranged from 47% (32%-62%) to 74% (66%-81%). They were low for error disclosure culture (range: 10% [0%-20%] to 27% [20%-35%]), experiences with professionalism (range: 7% [0%-15%] to 23% [16%-30%]), and comfort expressing professional concerns (range: 17% [5%-29%] to 38% [8%-69%]). Each cultural factor correlated positively with perceptions of overall patient safety as observed in clinical rotations (r = 0.37-0.69, P safety behavioral intent item. This study provided initial evidence for the survey's reliability and validity and illustrated its applicability for determining whether students' clinical experiences exemplify positive patient safety environments.

The Detector Safety System of the ATLAS experiment

International Nuclear Information System (INIS)

Beltramello, O; Burckhart, H J; Franz, S; Jaekel, M; Jeckel, M; Lueders, S; Morpurgo, G; Santos Pedrosa, F dos; Pommes, K; Sandaker, H

2009-01-01

The ATLAS detector at the Large Hadron Collider at CERN is one of the most advanced detectors for High Energy Physics experiments ever built. It consists of the order of ten functionally independent sub-detectors, which all have dedicated services like power, cooling, gas supply. A Detector Safety System has been built to detect possible operational problems and abnormal and potentially dangerous situations at an early stage and, if needed, to bring the relevant part of ATLAS automatically into a safe state. The procedures and the configuration specific to ATLAS are described in detail and first operational experience is given.

Patient safety: numerical skills and drug calculation abilities of nursing students and registered nurses.

Science.gov (United States)

McMullan, Miriam; Jones, Ray; Lea, Susan

2010-04-01

This paper is a report of a correlational study of the relations of age, status, experience and drug calculation ability to numerical ability of nursing students and Registered Nurses. Competent numerical and drug calculation skills are essential for nurses as mistakes can put patients' lives at risk. A cross-sectional study was carried out in 2006 in one United Kingdom university. Validated numerical and drug calculation tests were given to 229 second year nursing students and 44 Registered Nurses attending a non-medical prescribing programme. The numeracy test was failed by 55% of students and 45% of Registered Nurses, while 92% of students and 89% of nurses failed the drug calculation test. Independent of status or experience, older participants (> or = 35 years) were statistically significantly more able to perform numerical calculations. There was no statistically significant difference between nursing students and Registered Nurses in their overall drug calculation ability, but nurses were statistically significantly more able than students to perform basic numerical calculations and calculations for solids, oral liquids and injections. Both nursing students and Registered Nurses were statistically significantly more able to perform calculations for solids, liquid oral and injections than calculations for drug percentages, drip and infusion rates. To prevent deskilling, Registered Nurses should continue to practise and refresh all the different types of drug calculations as often as possible with regular (self)-testing of their ability. Time should be set aside in curricula for nursing students to learn how to perform basic numerical and drug calculations. This learning should be reinforced through regular practice and assessment.

Gas-Induced Water-hammer Loads Calculation for Safety Related Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Seungchan; Yoon, Dukjoo [Korea Hydro and Nuclear Power Co., LTd, Daejeon (Korea, Republic of); Lee, Dooyong [Seoul National Univ., Seoul (Korea, Republic of)

2013-05-15

Of particular interest, gas accumulation can result in system pressure transient in pump discharge piping following a pump start. Consequently, this evolves into a gas-water, a water-hammer event and the accompanying force imbalances on the piping segments can be sufficient to challenge the piping supports and restraint. This paper describes an method performing to the water-hammer loads to determine the maximum loading that would occur in the piping system following the safety injection signal and to evaluate its integrity. For a given gas void volumes in the discharge piping, the result of the calculation shows the maximum loads of 18,894.2psi, which is smaller than the allowable criteria. Also, the maximum peak axial force imbalances acting on the support is 1,720lbf as above.

Gas-Induced Water-hammer Loads Calculation for Safety Related Systems

International Nuclear Information System (INIS)

Lee, Seungchan; Yoon, Dukjoo; Lee, Dooyong

2013-01-01

Of particular interest, gas accumulation can result in system pressure transient in pump discharge piping following a pump start. Consequently, this evolves into a gas-water, a water-hammer event and the accompanying force imbalances on the piping segments can be sufficient to challenge the piping supports and restraint. This paper describes an method performing to the water-hammer loads to determine the maximum loading that would occur in the piping system following the safety injection signal and to evaluate its integrity. For a given gas void volumes in the discharge piping, the result of the calculation shows the maximum loads of 18,894.2psi, which is smaller than the allowable criteria. Also, the maximum peak axial force imbalances acting on the support is 1,720lbf as above

Passive safety injection experiments and analyses (PAHKO)

International Nuclear Information System (INIS)

Tuunanen, J.

1998-01-01

PAHKO project involved experiments on the PACTEL facility and computer simulations of selected experiments. The experiments focused on the performance of Passive Safety Injection Systems (PSIS) of Advanced Light Water Reactors (ALWRs) in Small Break Loss-Of-Coolant Accident (SBLOCA) conditions. The PSIS consisted of a Core Make-up Tank (CMT) and two pipelines (Pressure Balancing Line, PBL, and Injection Line, IL). The examined PSIS worked efficiently in SBLOCAs although the flow through the PSIS stopped temporarily if the break was very small and the hot water filled the CMT. The experiments demonstrated the importance of the flow distributor in the CMT to limit rapid condensation. The project included validation of three thermal-hydraulic computer codes (APROS, CATHARE and RELAP5). The analyses showed the codes are capable to simulate the overall behaviour of the transients. The detailed analyses of the results showed some models in the codes still need improvements. Especially, further development of models for thermal stratification, condensation and natural circulation flow with small driving forces would be necessary for accurate simulation of the PSIS phenomena. (orig.)

The safety experience of New Zealand adventure tourism operators.

Science.gov (United States)

Bentley, Tim A; Page, Stephen; Walker, Linda

2004-01-01

This survey examined parameters of the New Zealand adventure tourism industry client injury risk. The research also sought to establish priorities for intervention to reduce adventure tourism risk, and identify client injury control measures currently in place (or absent) in the New Zealand adventure tourism industry, with a view to establishing guidelines for the development of effective adventure tourism safety management systems. This 2003 survey builds upon an exploratory study of New Zealand adventure tourism safety conducted by us during 1999. A postal questionnaire was used to survey all identifiable New Zealand adventure tourism operators. The questionnaire asked respondents about their recorded client injury experience, perceptions of client injury risk factors, safety management practices, and barriers to safety. Some 27 adventure tourism activities were represented among the responding sample (n=96). The highest client injury risk was reported in the snow sports, bungee jumping and horse riding sectors, although serious underreporting of minor injuries was evident across the industry. Slips, trips and falls (STF) were the major client injury mechanisms, and a range of risk factors for client injuries were identified. Safety management measures were inconsistently applied across the industry. The industry should consider the implications of poor injury reporting standards and safety management practices generally. Specifically, the industry should consider risk management that focuses on minor (e.g., STF) as well as catastrophic events.

Investigating heavy water zero power reactors with a new core configuration based on experiment and calculation results

Energy Technology Data Exchange (ETDEWEB)

Nasrazadani, Zahra; Salimi, Raana; Askari, Afrooz; Khorsandi, Jamshid; Mirvakili, Mohammad; Mashayekh, Mohammad [Reactor Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Esfahan (Iran, Islamic Republic of)

2017-02-15

The heavy water zero power reactor (HWZPR), which is a critical assembly with a maximum power of 100 W, can be used in different lattice pitches. The last change of core configuration was from a lattice pitch of 18-20 cm. Based on regulations, prior to the first operation of the reactor, a new core was simulated with MCNP (Monte Carlo N-Particle)-4C and WIMS (Winfrith Improved Multigroup Scheme)-CITATON codes. To investigate the criticality of this core, the effective multiplication factor (Keff) versus heavy water level, and the critical water level were calculated. Then, for safety considerations, the reactivity worth of D2O, the reactivity worth of safety and control rods, and temperature reactivity coefficients for the fuel and the moderator, were calculated. The results show that the relevant criteria in the safety analysis report were satisfied in the new core. Therefore, with the permission of the reactor safety committee, the first criticality operation was conducted, and important physical parameters were measured experimentally. The results were compared with the corresponding values in the original core.

Pre- and post- test calculation for the parameter-SF1 experiment with ATHLET-CD

Energy Technology Data Exchange (ETDEWEB)

Erdmann, W.; Trambauer, K.; Stuckert, J. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koln (Germany)

2006-07-01

The main objective of the PARAMETER-SF1 experiment in the frame of the ISTC project 3194 is the experimental and analytical investigation of the Russian VVER-1000 fuel rod assemblies behavior under simulated conditions of a severe accident. The special feature is to study the effect of flooding a superheated test bundle from the top (top quenching) which has not yet been investigated at all. - Simulation of the PARAMETER test facility To calculate the special effects of the top quenching, some aspects are important: detailed simulation of the bundle top, top and bottom quench front, heat losses at top/bottom of bundle, electrical heater power. - Main initial and boundary conditions The proposed initial and boundary conditions for the double-blind pre-test calculation were quite different from the actual experimental data during the test e.g.: electric power, mass flow (water, steam, argon), temperature. - Conclusions: first experiment with top flooding proposed initial condition given in the specification could not be performed during the experiment, bundle parameters deviated from anticipated values, thus, the pre-calculations not comparable with the experiment, post-calculations with ATHLET-CD showed good agreement with experiment data, top flooding is well predicted, calculational results sensitive with respect to: boundary conditions, nodalization. (authors)

Nuclear critical safety analysis for UX-30 transport of freight package

International Nuclear Information System (INIS)

Quan Yanhui; Zhou Qi; Yin Shenggui

2014-01-01

The nuclear critical safety analysis and evaluation for UX-30 transport freight package in the natural condition and accident condition were carried out with MONK-9A code and MCNP code. Firstly, the critical benchmark experiment data of public in international were selected, and the deflection and subcritical limiting value with MONK-9A code and MCNP code in calculating same material form were validated and confirmed. Secondly, the neutron efficiency multiplication factors in the natural condition and accident condition were calculated and analyzed, and the safety in transport process was evaluated by taking conservative suppose of nuclear critical safety. The calculation results show that the max value of k eff for UX-30 transport freight package is less than the subcritical limiting value, and the UX-30 transport freight package is in the state of subcritical safety. Moreover, the critical safety index (CSI) for UX-30 package can define zero based on the definition of critical safety index. (authors)

Burnup calculations for cadmium. A case study for HFR experiments

Energy Technology Data Exchange (ETDEWEB)

Pijlgroms, B.J.; Sciolla, C.M

2000-09-11

This report describes the pre-design burnup calculations performed for a cadmium shielded high fluence irradiation experiment in the HFR. The very high absorption cross section in cadmium causes problems in the calculations for two different reasons. Firstly, because of the large reaction rates the assumption that the flux and the cross sections remain piecewise constant is no longer true. Therefore the correct solution can only be obtained when using extremely small time steps which leads to excessive computing times. Secondly, the self-shielding in the cadmium becomes complete (black absorber) causing the depletion to progress in a shell-wise manner. As a consequence the depletion evolves nearly linear instead of exponential with time. Because of this the depletion codes are used in a regime for which these have not been designed leading to a systematic error. The analysis shows however that a good estimate for the burnup time can be obtained by extrapolation from calculations with practically sized time steps and a correction is derived to compensate the systematic error. The calculations were done using the OCTOPUS burnup code system, including the 3-D Monte-Carlo spectrum code MCNP-4B and the depletion code FISPACT-4.2. Verifications were performed with the WIMS code system. The first part of the report describes the study of the cadmium burnup calculations for a shielded steel sample with the emphasis on analyzing the requirements for obtaining the correct solution. The second part describes the time-dependent power production calculations with the steel replaced by lithium containing ceramic material such as to be used in the 'High Fluence Irradiation of Ceramics for Fusion' (HICU) experiment. 12 refs.

Investigating the experiences of New Zealand MRI technologists: Exploring intra-orbital metallic foreign body safety practices

Energy Technology Data Exchange (ETDEWEB)

Jacobs, Philippa K [River Radiology, Victoria Clinic, 750 Victoria Street, Hamilton, Waikato (New Zealand); Henwood, Suzanne [Unitec - Medical Imaging, Unitec Ratanui Street Henderson, Auckland (New Zealand); River Radiology, Victoria Clinic, 750 Victoria Street, Hamilton, Waikato (New Zealand)

2013-12-15

Qualitative research is lacking regarding the experiences of magnetic resonance imaging (MRI) technologists and their involvement in workplace safety practices. This article provides a gateway to explore, describe and document experiences of MRI technologists in New Zealand (NZ) pertaining to intra-orbital metallic foreign body (IMFB) safety practices. This phenomenological study describes the experiences of seven MRI technologists all with a minimum of 5 years' NZ work experience in MRI. The MRI technologists were interviewed face-to-face regarding their professional IMFB workplace experiences in order to explore historical, current and potential issues. Findings demonstrated that aspects of organization and administration are fundamentally important to MRI technologists. Varying levels of education and knowledge, as well as experience and skills gained, have significantly impacted on MRI technologists’ level of confidence and control in IMFB practices. Participants’ descriptions of their experiences in practice regarding decision-making capabilities further highlight the complexity of these themes. A model was developed to demonstrate the interrelated nature of the themes and the complexity of the situation in totality. Findings of this study have provided insight into the experiences of MRI technologists pertaining to IMFB safety practices and highlighted inconsistencies. It is hoped that these findings will contribute to and improve the level of understanding of MRI technologists and the practices and protocols involved in IMFB safety screening. The scarcity of available literature regarding IMFB safety practices highlights that more research is required to investigate additional aspects that could improve MRI technologists’ experiences.

Investigating the experiences of New Zealand MRI technologists: Exploring intra-orbital metallic foreign body safety practices

International Nuclear Information System (INIS)

Jacobs, Philippa K; Henwood, Suzanne

2013-01-01

Qualitative research is lacking regarding the experiences of magnetic resonance imaging (MRI) technologists and their involvement in workplace safety practices. This article provides a gateway to explore, describe and document experiences of MRI technologists in New Zealand (NZ) pertaining to intra-orbital metallic foreign body (IMFB) safety practices. This phenomenological study describes the experiences of seven MRI technologists all with a minimum of 5 years' NZ work experience in MRI. The MRI technologists were interviewed face-to-face regarding their professional IMFB workplace experiences in order to explore historical, current and potential issues. Findings demonstrated that aspects of organization and administration are fundamentally important to MRI technologists. Varying levels of education and knowledge, as well as experience and skills gained, have significantly impacted on MRI technologists’ level of confidence and control in IMFB practices. Participants’ descriptions of their experiences in practice regarding decision-making capabilities further highlight the complexity of these themes. A model was developed to demonstrate the interrelated nature of the themes and the complexity of the situation in totality. Findings of this study have provided insight into the experiences of MRI technologists pertaining to IMFB safety practices and highlighted inconsistencies. It is hoped that these findings will contribute to and improve the level of understanding of MRI technologists and the practices and protocols involved in IMFB safety screening. The scarcity of available literature regarding IMFB safety practices highlights that more research is required to investigate additional aspects that could improve MRI technologists’ experiences

Experience with performance based training of nuclear criticality safety engineers

International Nuclear Information System (INIS)

Taylor, R.G.

1993-01-01

Historically, new entrants to the practice of nuclear criticality safety have learned their job primarily by on-the-job training (OJT) often by association with an experienced nuclear criticality safety engineer who probably also learned their job by OJT. Typically, the new entrant learned what he/she needed to know to solve a particular problem and accumulated experience as more problems were solved. It is likely that more formalism will be required in the future. Current US Department of Energy requirements for those positions which have to demonstrate qualification indicate that it should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis i's incompletely developed in some areas. Details of this analysis are provided in this report

Nurses' experiences and perspectives on medication safety practices: an explorative qualitative study

NARCIS (Netherlands)

Smeulers, Marian; Onderwater, Astrid T.; van Zwieten, Myra C. B.; Vermeulen, Hester

2014-01-01

To explore nurses' experiences with and perspectives on preventing medication administration errors. Insight into nurses' experiences with and perspectives on preventing medication administration errors is important and can be utilised to tailor and implement safety practices. A qualitative

Critical experiment tests of bowing and expansion reactivity calculations for LMRS

International Nuclear Information System (INIS)

Schaefer, R.W.

1988-01-01

Experiments done in several LMR-type critical assemblies simulated core axial expansion, core radial expansion and bowing, coolant expansion, and control driveline expansion. For the most part new experimental techniques were developed to do these experiments. Calculations of the experiments basically used design-level methods, except when it was necessary to investigate complexities peculiar to the experiments. It was found that these feedback reactivities generally are overpredicted, but the predictions are within 30% of the experimental values. 14 refs., 2 figs., 4 tabs

Review of experiments and calculation procedures for ship collision and grounding damage

DEFF Research Database (Denmark)

Liu, Bin; Pedersen, Preben Terndrup; Zhu, Ling

2018-01-01

Abstract The paper presents a review of experiments and calculation procedures for the resistances of ship structural components subjected to impact loadings. The purpose of the paper is to highlight the importance of large-scale collision and grounding experiments and to discuss the technical...... and material characteristics. In recent literature, analytical and numerical calculations provide relatively accurate prediction of the purely plastic responses of ship structures under impact loads, but universal approaches have not been found for fracture predictions. The existing formulae for failure...

The detector safety system for LHC experiments

CERN Document Server

Schmeling, Sascha; Lüders, S; Morpurgo, Giulio

2004-01-01

The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four Large Hadron Collider (LHC)**1 experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC**2 front-end, to which the safety- critical part of the DSS task is delegated. This is then supervised by a PVSS**3 SCADA**4 system via an OPC**5 server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "configuration database." Thus, the DSS can easily adapt to the different and constantly ev...

To improve nuclear plant safety by learning from accident's experience

International Nuclear Information System (INIS)

Matsumoto, Hidezo; Kida, Masanori; Kato, Hiroyuki; Hara, Shin-ichi

1994-01-01

The ultimate goal of this study is to produce an expert system that enables the experience (records and information) gained from accidents to be put to use towards improving nuclear plant safety. A number of examples have been investigated, both domestic and overseas, in which experience gained from accidents was utilized by utilities in managing and operating their nuclear power stations to improve safety. The result of investigation has been used to create a general 'basic flow' to make the best use of experience. The ultimate goal is achieved by carrying out this 'basic flow' with artificial intelligence (AI). To do this, it is necessary (1) to apply language analysis to process the source information (primary data base; domestic and overseas accident's reports) into the secondary data base, and (2) to establish an expert system for selecting (screening) significant events from the secondary data base. In the processing described in item (1), a multi-lingual thesaurus for nuclear-related terms become necessary because the source information (primary data bases) itself is multi-lingual. In the work described in item (2), the utilization of probabilistic safety assessment (PSA), for example, is a candidate method for judging the significance of events. Achieving the goal thus requires developing various new techniques. As the first step of the above long-term study project, this report proposes the 'basic flow' and presents the concept of how the nuclear-related AI can be used to carry out this 'basic flow'. (author)

Application of the Dragon reactor experiment to the safety evaluation of current HTR systems

International Nuclear Information System (INIS)

Ashworth, F.P.O.; Faircloth, R.L.

1976-01-01

An important component of the confidence required for the safety assessment of high-temperature reactors is the experimental proof of phenomena such as fission product release or core corrosion. The most convincing experiments are those carried out in a reactor. This paper outlines the scope of experiments relevant to safety which can be done in the Dragon Reactor Experiment and describes as an example the experimental campaign and the current outcome of the work on validating the predictions of caesium release and migration. (author)

The French nuclear safety authority's experience with radioactive transport inspection

International Nuclear Information System (INIS)

Jacob, E.; Aguilar, J.

2004-01-01

About 300,000 radioactive material packages are transported annually in France. Most consist of radioisotopes for medical, pharmaceutical or industrial use. On the other hand, the nuclear industry deals with the transport of fuel cycle materials (uranium, fuel assemblies, etc.) and waste from power plants, reprocessing plants and research centers. France is also a transit country for shipments such as spent fuel packages from Switzerland or Germany, which are bound for Sellafield in Great Britain. The French nuclear safety authority (DGSNR: Directorate General for Nuclear Safety and Radioprotection) has been responsible since 1997 for the safety of radioactive material transport. This paper presents DGNSR's experience with transport inspection: a feedback of key points based on 300 inspections achieved during the past five years is given

A calculational system to aid economical use of MTRs

International Nuclear Information System (INIS)

Reitsma, F.; Joubert, W.R.

1999-01-01

The availability of a fast and accurate core neutronic calculational system is a valuable asset in the operation and utilization of research reactors. Its primary value lies in optimum reload design, fuel management, safety and utilization studies. In this paper the OSCAR-3 calculational system of the Atomic Energy Corporation of South Africa (AEC) is discussed in detail. The different components and important features are explained with a short summary of some comparisons with experiments. (author)

UK experience of safety requirements for thermal reactor stations

International Nuclear Information System (INIS)

Matthews, R.R.; Dale, G.C.; Tweedy, J.N.

1977-01-01

The paper summarises the development of safety requirements since the first of the Generating Boards' Magnox reactors commenced operation in 1962 and includes A.G.R. safety together with the preparation of S.G.H.W.R. design safety criteria. It outlines the basic principles originally adopted and shows how safety assessment is a continuing process throughout the life of a reactor. Some description is given of the continuous effort over the years to obtain increased safety margins for existing and new reactors, taking into account the construction and operating experience, experimental information, and more sophisticated computer-aided design techniques which have become available. The main safeguards against risks arising from the Generating Boards' reactors are the achievement of high standards of design, construction and operation, in conjunction with comprehensive fault analyses to ensure that adequate protective equipment is provided. The most important analyses refer to faults which can lead to excessive fuel element temperatures arising from an increase in power or a reduction in cooling capacity. They include the possibility of unintended control rod withdrawal at power or at start-up, coolant flow failure, pressure circuit failure, loss of boiler feed water, and failure of electric power. The paper reviews the protective equipment, and the policy for reactor safety assessments which include application of maximum credible accident philosophy and later the limited use of reliability and probability methods. Some of the Generating Boards' reactors are now more than half way through their planned working lives and during this time safety protective equipment has occasionally been brought into operation, often for spurious reasons. The general performance, of safety equipment is reviewed particularly for incidents such as main turbo-alternator trip, circulator failure, fuel element failures and other similar events, and some problems which have given rise to

Effects of an educational patient safety campaign on patients' safety behaviours and adverse events.

Science.gov (United States)

Schwappach, David L B; Frank, Olga; Buschmann, Ute; Babst, Reto

2013-04-01

Rationale, aims and objectives  The study aims to investigate the effects of a patient safety advisory on patients' risk perceptions, perceived behavioural control, performance of safety behaviours and experience of adverse incidents. Method  Quasi-experimental intervention study with non-equivalent group comparison was used. Patients admitted to the surgical department of a Swiss large non-university hospital were included. Patients in the intervention group received a safety advisory at their first clinical encounter. Outcomes were assessed using a questionnaire at discharge. Odds ratios for control versus intervention group were calculated. Regression analysis was used to model the effects of the intervention and safety behaviours on the experience of safety incidents. Results  Two hundred eighteen patients in the control and 202 in the intervention group completed the survey (75 and 77% response rates, respectively). Patients in the intervention group were less likely to feel poorly informed about medical errors (OR = 0.55, P = 0.043). There were 73.1% in the intervention and 84.3% in the control group who underestimated the risk for infection (OR = 0.51, CI 0.31-0.84, P = 0.009). Perceived behavioural control was lower in the control group (meanCon  = 3.2, meanInt  = 3.5, P = 0.010). Performance of safety-related behaviours was unaffected by the intervention. Patients in the intervention group were less likely to experience any safety-related incident or unsafe situation (OR for intervention group = 0.57, CI 0.38-0.87, P = 0.009). There were no differences in concerns for errors during hospitalization. There were 96% of patients (intervention) who would recommend other patients to read the advisory. Conclusions  The results suggest that the safety advisory decreases experiences of adverse events and unsafe situations. It renders awareness and perceived behavioural control without increasing concerns for safety and

Exploration of Important Issues for the Safety of SFR 1 using Performance Assessment Calculations

International Nuclear Information System (INIS)

Maul, P.R.; Robinson, P.C.

2002-06-01

SKB has produced a revised safety case for the SFR 1 disposal facility for low and intermediate level radioactive wastes at Forsmark: project SAFE. This assessment includes a Performance Assessment (PA) for the long term post-closure safety of the facility. SKI has a responsibility to scrutinise SKB's safety case that is shared with SSI. Quintessa has undertaken a review of SKB's case for the long term safety of SFR 1 to assist SKI's evaluation of SAFE, and this is given in SKI-R--02-61, henceforth referred to as the Quintessa Review. The current report describes the independent PA calculations that provided an input to that review. Since 1999 SKI has been developing a PA capability for SFR 1 using the AMBER software. Two key features of the approach taken have been: To represent the whole system in a single model; and To allow the time-dependency of all key features, events and processes to be represented. These capabilities allow a better understanding of the key features of the system to be obtained for different future evolutions (scenarios). This report presents a summary of the work undertaken to provide SKI with a PA capability for SFR 1 and the calculations undertaken with it. Calculations have been undertaken for radionuclides transported in groundwater and gas, but not for direct intrusion by humans into the wastes. It should be emphasised that the purpose of the Performance Assessment calculations described in this report is not to provide an alternative assessment of potential radiological impacts to that produced by SKB. The aim is to use the models that have been developed to investigate the important features of the system and to help SKI scrutinise the case put to them by SKB. The PA calculations that have been undertaken are by no means comprehensive, and various issues could be investigated further if required. The key issues that have been identified can be summarised as follows: 1. The SFR 1 system has a number of different timescales that can

Safety research experiment facilities, Idaho National Engineering Laboratory, Idaho. Final environmental impact statement

International Nuclear Information System (INIS)

Liverman, J.L.

1977-09-01

This environmental statement was prepared for the Safety Research Experiment Facilities (SAREF) Project. The purpose of the proposed project is to modify some existing facilities and provide a new test facility at the Idaho National Engineering Laboratory (INEL) for conducting fast breeder reactor (FBR) safety experiments. The SAREF Project proposal has been developed after an extensive study which identified the FBR safety research needs requiring in-reactor experiments and which evaluated the capability of various existing and new facilities to meet these needs. The proposed facilities provide for the in-reactor testing of large bundles of prototypical FBR fuel elements under a wide variety of conditions, ranging from those abnormal operating conditions which might be expected to occur during the life of an FBR power plant to the extremely low probability, hypothetical accidents used in the evaluation of some design options and in the assessment of the long-term potential risk associated with wide-acale deployment of the FBR

System of Modelling and Calculation Analysis of Neutron- Physical Experiments at Fast Reactors

International Nuclear Information System (INIS)

Moiseyev, A.V.

2008-01-01

There is an actual task on storage, processing and analysis of the unique experimental data received on power fast reactors for their subsequent use in projects of fast reactors of new (4.) generation. For modeling and carrying out analysis of experiments the integrated computing system MODEXSYS has been developed. In this system the mechanism for consecutive calculation of a fast reactor states with the detailed description of its components is created. The system includes the database describing fast reactor states, results of neutron-physical characteristics measurements at fast reactor, calculation and benchmark models of experiments and calculation results. In system convenient search means and the special graphics shell are provided. It has Interfaces for processing of calculation results and their analysis. MODEXSYS system has been applied for analysis of three types of experiments at fast reactor: k eff , control rod worth and energy release distribution. The most important results of this analysis are described. Application of MODEXSYS system will raise accuracy and reliability of forecasting of fast reactors neutron-physical characteristics; for BN-600 reactor recommended level of accuracy is resulted. (authors)

System of Modelling and Calculation Analysis of Neutron- Physical Experiments at Fast Reactors

Energy Technology Data Exchange (ETDEWEB)

Moiseyev, A.V. [SSC RF - IPPE, 1 Bondarenko Square, Obninsk, Kaluga Region 249033 (Russian Federation)

2008-07-01

There is an actual task on storage, processing and analysis of the unique experimental data received on power fast reactors for their subsequent use in projects of fast reactors of new (4.) generation. For modeling and carrying out analysis of experiments the integrated computing system MODEXSYS has been developed. In this system the mechanism for consecutive calculation of a fast reactor states with the detailed description of its components is created. The system includes the database describing fast reactor states, results of neutron-physical characteristics measurements at fast reactor, calculation and benchmark models of experiments and calculation results. In system convenient search means and the special graphics shell are provided. It has Interfaces for processing of calculation results and their analysis. MODEXSYS system has been applied for analysis of three types of experiments at fast reactor: k{sub eff}, control rod worth and energy release distribution. The most important results of this analysis are described. Application of MODEXSYS system will raise accuracy and reliability of forecasting of fast reactors neutron-physical characteristics; for BN-600 reactor recommended level of accuracy is resulted. (authors)

Calculations for the prediction of accident situation

International Nuclear Information System (INIS)

Perneczky, L.; Szabados, L.; Toth, I.

1987-11-01

The report deals with the analysis of the loss of feedwater transient assuming that the pressurizer safety valve remains open throughout the process. The scenario is the Paks NPP counterpart of the loss of feedwater test performed on the PMK-NVH facility. The initial and boundary conditions of the calculation agree with those of the experiment allowing direct comparison with experimental results. (author) 18 refs.; 34 figs

FLUENT calculations of the hydrogen distribution in a containment during the OECD-NEA THAI HM-2 experiment

International Nuclear Information System (INIS)

Visser, D.C.; Komen, E.M.J.; Houkema, M.; Siccama, N.B.; Kyttaelae, Juha; Huhtanen, Risto; Takasuo, Eveliina

2009-01-01

Hydrogen may be released into the containment atmosphere of a nuclear power plant during a severe accident. Locally, high hydrogen concentrations may be reached that can possibly cause fast deflagration or even detonation and put the integrity of the containment at risk. Therefore, the distribution and mixing of hydrogen is an important safety issue for nuclear power plants. Computer codes can be applied to predict the hydrogen distribution in the containment within the course of a hypothetical severe accident and get an estimate of the local hydrogen concentration in the various zones of the containment. In this way the risk associated with the hydrogen safety issue can be determined, and safety related measurements and procedures could be assessed. In order to validate the existing computer codes in the context of hydrogen distribution in the containment of a nuclear power plant, experimental benchmark studies have been performed in the German Thermal-hydraulics, Hydrogen, Aerosols and Iodine (THAI) facility in the framework of the OECD-NEA THAI project. In order to demonstrate the capabilities of the commercial Computational Fluid Dynamics (CFD) code FLUENT the THAI HM-2 test was simulated independently by NRG and VTT. In the first phase of the HM-2 test a stratified hydrogen rich light gas layer was established in the upper part of the THAI containment. In the second phase steam was injected at a lower position inducing a rising plume that gradually dissolved the stratified hydrogen-rich layer from below. Thermo-dynamic phenomena like natural convection, mixing, condensation, heat transfer and distribution in different zones that are expected in severe accidents are involved. The calculated results by NRG and VTT (on hydrogen concentration, temperature, pressure and flow velocity) are compared to the experimental results. The most important differences between the CFD model of NRG and VTT are the computational mesh, condensation model and treatment of the solid

Engineering Judgment and Natural Circulation Calculations

OpenAIRE

Ferreri, J. C.

2011-01-01

The analysis performed to establish the validity of computer code results in the particular field of natural circulation flow stability calculations is presented in the light of usual engineering practice. The effects of discretization and closure correlations are discussed and some hints to avoid undesired mistakes in the evaluations performed are given. Additionally, the results are presented for an experiment relevant to the way in which a (small) number of skilled, nuclear safety analysts...

New safety performance indicators for safety assessment of radioactive waste disposal facilities. Cuban experience

International Nuclear Information System (INIS)

Peralta Vital, J.L.; Castillo, R.G.; Olivera, J.

2002-01-01

The paper shows the Cuban experience on implementing geological disposal of radioactive waste and the necessity for identifying new safety performance indicators for the safety assessment (SA) of radioactive waste disposal facilities. The selected indicator was the concentration of natural radioactive elements (U, Ra, Th, K) in the Cuban geologic environment. We have carried out a group of investigations, which have allowed characterising the concentration for the whole Country, creating a wide database where this indicator is associated with the lithology. The main lithologies in Cuba are: the sedimentary rocks (70 percent of national occurrence), which are present in the three regions (limestone and lutite), and finally the igneous and metamorphic rocks. The results show the concentrations ranges of the natural radionuclides associated fundamentally to the variation in the lithology and geographical area of the Country. In Cuba, the higher concentration (ppm) of Uranium and Radium are referenced to the Central region associated to Skarn, while for Thorium (ppm) and Potassium (%), in the East region the concentration peaks in Tuffs have been found. The concentrations ranges obtained are preliminary, they characterise the behaviour of this parameter for the Cuban geology, but they do not represent limits for safety assessment purposes yet. Also other factors should be taken into account as the assessment context, time scales and others assumptions before establishing the final concentration limits for the natural radionuclides as a radiological and nuclear safety performance indicator complementary to dose and risk for safety assessment for radiological and nuclear facilities. (author)

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

Science.gov (United States)

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

2015-01-01

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

Safety Research Experiment Facilities, Idaho National Engineering Laboratory, Idaho. Draft environmental statement

International Nuclear Information System (INIS)

1977-01-01

This environmental statement was prepared in accordance with the National Environmental Policy Act of 1969 (NEPA) in support of the Energy Research and Development Administration's (ERDA) proposal for legislative authorization and appropriations for the Safety Research Experiment Facilities (SAREF) Project. The purpose of the proposed project is to modify some existing facilities and provide a new test facility at the Idaho National Engineering Laboratory (INEL) for conducting fast breeder reactor (FBR) safety experiments. The SAREF Project proposal has been developed after an extensive study which identified the FBR safety research needs requiring in-reactor experiments and which evaluated the capability of various existing and new facilities to meet these needs. The proposed facilities provide for the in-reactor testing of large bundles of prototypical FBR fuel elements under a wide variety of conditions, ranging from those abnormal operating conditions which might be expected to occur during the life of an FBR power plant to the extremely low probability, hypothetical accidents used in the evalution of some design options and in the assessment of the long-term potential risk associated with wide-scale deployment of the FBR

Experience of Tecnatom in Developing a Strong Leadership for Safety and Performance

International Nuclear Information System (INIS)

González, F.; Villadóniga, J. I.

2016-01-01

This paper presents experience and insights of Tecnatom in the support of internal and external clients to develop a strong Leadership for Safety. Several cases are presented briefly: (a) The leadership and culture change activities for a utility, a radwaste company, and for Tecnatom itself. One important characteristic of the work performed is the detailed consideration of the underlying organizational culture that underpins the safety culture. Measurable improvements have been achieved and some of the key insights are shared in this paper. (b) The development and implementation of a leadership model with 17 competencies, including safety explicitly. One benefit of this model is that allows to perform a quantitative assessment of leadership effectiveness, something vital to be able to ensure that leadership development actions are truly supporting safety. The model uses an approach to development oriented to strengths and the use of companion competencies to further develop leadership. Moreover it aims to produce significant improvements on safety but also on performance, since both are not competing goals when the proper leadership model is selected. The training material prepared was shortlisted in the 2014 Nuclear Training Awards. (c) The design and implementation of a training development program on Safety Culture, and required competencies of Leadership, for Top Managers of the nuclear industry, as part of the project NUSHARE of the European Commission’s 7th research framework program. The program is sensible to the reduced time availability of Top Managers and uses a combination of learning approaches (webinars, micro-elearnings, web meetings) that provide higher flexibility for the learner, but complemented with other proven methods (group dialog, journaling, mentoring, etc.) to ensure that the program is effective. All these experiences reveal that to improve the organizational Safety Culture we need to enhance Leadership for Safety and Performance

Patients' experiences of safety during haemodialysis treatment--a qualitative study

NARCIS (Netherlands)

Lovink, Marleen H; Kars, Marijke C; de Man-van Ginkel, Janneke M; Schoonhoven, Lisette

2015-01-01

AIM: To explore the experiences of safety of adult patients during their haemodialysis treatment. BACKGROUND: Haemodialysis is a complex treatment with a risk for harm that causes anxiety among many patients. To date, no in-depth study of haemodialysis patients' emotional responses to conditions of

Patients' experiences of safety during haemodialysis treatment - a qualitative study

NARCIS (Netherlands)

Lovink, M.H.; Kars, M.C.; Man-van Ginkel, J.M. de; Schoonhoven, L.

2015-01-01

AIM: To explore the experiences of safety of adult patients during their haemodialysis treatment. BACKGROUND: Haemodialysis is a complex treatment with a risk for harm that causes anxiety among many patients. To date, no in-depth study of haemodialysis patients' emotional responses to conditions of

Nuclear criticality safety calculations for a K-25 site vacuum cleaner

International Nuclear Information System (INIS)

Shor, J.T.; Haire, M.J.

1997-02-01

A modified Nilfisk model GSJ dry vacuum cleaner is used throughout the K-25 Site to collect dry forms of highly enriched uranium (HEU). When vacuuming, solids are collected in a cyclone-type separator vacuum cleaner body. Calculations were done with the SCALE (KENO V.a) computer code to establish conditions at which a nuclear criticality event might occur if the vacuum cleaner was filled with fissile solution. Conditions evaluated included full (12-in. water) reflection and nominal (1-in. water) reflection, and full (100%) and 20% 235 U enrichment. Validation analyses of SCALE/KENO and the SCALE 27-group cross sections for nuclear criticality safety applications indicate that a calculated k eff + 2σ eff + 2σ ≥ 0.9605 is considered unsafe and may be critical. Critical conditions were calculated to be 70 g U/L for 100% 235 U and full 12-in. water reflection. This corresponds to a minimum critical mass of approximately 1,400 g 235 U for the approximate 20.0-L volume of the vacuum cleaner. The actual volume of the vacuum cleaner is smaller than the modeled volume because some internal materials of construction were assumed to be fissile solution. The model was an overestimate, for conservatism, of fissile solution occupancy. At nominal reflection conditions, the critical concentration in a vacuum cleaner full of UO 2 F 2 solution was calculated to be 100 g 235 U/L, or 2,000 g mass of 100% 235 U. At 20% 235 U for the 20.0-L volume of the vacuum cleaner. At 15% 235 U enrichment and full reflection, critical conditions were not reached at any possible concentration of uranium as a uranyl fluoride solution. At 17.5% 235 U enrichment, criticality was reached at approximately 1,300 g U/L which is beyond saturation at 25 C

JET-ISX-B beryllium limiter experiment safety analysis report and operational safety requirements

International Nuclear Information System (INIS)

Edmonds, P.H.

1985-09-01

An experiment to evaluate the suitability of beryllium as a limiter material has been completed on the ISX-B tokamak. The experiment consisted of two phases: (1) the initial operation and characterization in the ISX experiment, and a period of continued operation to the specified surface fluence (10 22 atoms/cm 2 ) of hydrogen ions; and (2) the disassembly, decontamination, or disposal of the ISX facility. During these two phases of the project, the possibility existed for beryllium and/or beryllium oxide powder to be produced inside the vacuum vessel. Beryllium dust is a highly toxic material, and extensive precautions are required to prevent the release of the beryllium into the experimental work area and to prevent the contamination of personnel working on the device. Details of the health hazards associated with beryllium and the appropriate precautions are presented. Also described in appendixes to this report are the various operational safety requirements for the project

Temperature calculation in fire safety engineering

CERN Document Server

Wickström, Ulf

2016-01-01

This book provides a consistent scientific background to engineering calculation methods applicable to analyses of materials reaction-to-fire, as well as fire resistance of structures. Several new and unique formulas and diagrams which facilitate calculations are presented. It focuses on problems involving high temperature conditions and, in particular, defines boundary conditions in a suitable way for calculations. A large portion of the book is devoted to boundary conditions and measurements of thermal exposure by radiation and convection. The concepts and theories of adiabatic surface temperature and measurements of temperature with plate thermometers are thoroughly explained. Also presented is a renewed method for modeling compartment fires, with the resulting simple and accurate prediction tools for both pre- and post-flashover fires. The final chapters deal with temperature calculations in steel, concrete and timber structures exposed to standard time-temperature fire curves. Useful temperature calculat...

Part I. Fuel-motion diagnostics in support of fast-reactor safety experiments. Part II. Fission product detection system in support of fast reactor safety experiments

International Nuclear Information System (INIS)

Devolpi, A.; Doerner, R.C.; Fink, C.L.; Regis, J.P.; Rhodes, E.A.; Stanford, G.S.; Braid, T.H.; Boyar, R.E.

1986-05-01

In all destructive fast-reactor safety experiments at TREAT, fuel motion and cladding failure have been monitored by the fast-neutron/gamma-ray hodoscope, providing experimental results that are directly applicable to design, modeling, and validation in fast-reactor safety. Hodoscope contributions to the safety program can be considered to fall into several groupings: pre-failure fuel motion, cladding failure, post-failure fuel motion, steel blockages, pretest and posttest radiography, axial-power-profile variations, and power-coupling monitoring. High-quality results in fuel motion have been achieved, and motion sequences have been reconstructed in qualitative and quantitative visual forms. A collimated detection system has been used to observe fission products in the upper regions of a test loop in the TREAT reactor. Particular regions of the loop are targeted through any of five channels in a rotatable assembly in a horizontal hole through the biological shield. A well-type neutron detector, optimized for delayed neutrons, and two GeLi gamma ray spectrometers have been used in several experiments. Data are presented showing a time history of the transport of Dn emitters, of gamma spectra identifying volatile fission products deposited as aerosols, and of fission gas isotopes released from the coolant

Calculation to experiment comparison of SPND signals in various nuclear reactor environments

Energy Technology Data Exchange (ETDEWEB)

Barbot, Loic; Radulovic, Vladimir; Fourmentel, Damien [CEA, DEN, DER, Instrumentation, Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-Lez-Durance, (France); Snoj, Luka [Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, (Slovenia); Tarchalski, Mikolaj [National Centre for Nuclear Research, ulica Andrzeja Soltana 7, 05-400 Otwock (Swierk), (Poland); Dewynter-Marty, Veronique [CEA, DEN, DANS, DRSN, SIREN, LESCI, Saclay, F-91191 Gif sur Yvette, (France); Malouch, Fadhel [CEA, DEN, DANS, DM2S, SERMA, Saclay, F-91191 Gif sur Yvette, (France)

2015-07-01

In the perspective of irradiation experiments in the future Jules Horowitz Reactor (JHR), the Instrumentation Sensors and Dosimetry Laboratory of CEA Cadarache (France) is developing a numerical tool for SPND design, simulation and operation. In the frame of the SPND numerical tool qualification, dedicated experiments have been performed both in the Slovenian TRIGA Mark II reactor (JSI) and very recently in the French CEA Saclay OSIRIS reactor, as well as a test of two detectors in the core of the Polish MARIA reactor (NCBJ). A full description of experimental set-ups and neutron-gamma calculations schemes are provided in the first part of the paper. Calculation to experiment comparison of the various SPNDs in the different reactors is thoroughly described and discussed in the second part. Presented comparisons show promising final results. (authors)

Comparison of spallation-model calculations with experiment on neutron production in uranium

International Nuclear Information System (INIS)

Kazaritskij, V.D.; Sibirtsev, A.A.; Stepanov, N.V.

1988-01-01

Calculated differential cross-sections for neutrons emitted from a thin uranium target due to 590 MeV protons are compared with experiment. The HETC, HAMLET, D2N2 and EVAP codes were applied. The HAMLET results are most consistent with experiment. 12 refs.; 3 figs

Neutronic calculation of safety parameters for the RP-0 and RP-10 nuclear reactors

OpenAIRE

Lázaro, Gerardo; Deen, James R.; Woodruff, William L.

2002-01-01

Theoretical safety calculations were done with proved codes utilized by the staff of the RERTR program in the HEU to LEU core conversions. The studies were designed to evaluate the reactivity coefficients and kinetics parameters of the reactor involved in the evolution of peak power transients by reactivity insertion accidents. It was done to show the trend of these reactivity coefficients as a function of the core size and fuel depletion for RP10 cores. It was useful to get a better underst...

Thermal calculations pertaining to experiments in the Yucca Mountain Exploratory Shaft

International Nuclear Information System (INIS)

Montan, D.N.

1986-03-01

A series of thermal calculations have been presented that appear to satisfy the needs for design of the Yucca Mountain Exploratory Shaft Tests. The accuracy of the modeling and calculational techniques employed probably exceeds the accuracy of the thermal properties used. The rather close agreement between simple analytical methods (the PLUS Family) and much more complex methods (TRUMP) suggest that the PLUS Family might be appropriate during final design to model, in a single calculation, the entire test array and sequence. Before doing further calculations it is recommended that all available thermal property information be critically evaluated to determine ''best'' values to be used for conductivity and saturation. Another possibility is to design one or more of the test sequences to approximately duplicate the early phase of Heater Test 1. In that experiment an unplanned power outage for about two days that occurred a week into the experiment gave extremely useful data from which to determine the conductivity and diffusivity. In any case we urge that adequate, properly calibrated instrumentation with data output available on a quasi-real time basis be installed. This would allow us to take advantage of significant power changes (planned or not) and also help ''steer'' the tests to desired temperatures. Finally, it should be kept in mind that the calculations presented here are strictly thermal. No hydrothermal effects due to liquid and vapor pressures have been considered

Proceedings of the nuclear criticality technology safety project

Energy Technology Data Exchange (ETDEWEB)

Sanchez, R.G. [comp.

1997-06-01

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

Proceedings of the nuclear criticality technology safety project

International Nuclear Information System (INIS)

Sanchez, R.G.

1997-06-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Stuke, Maik (ed.)

2016-04-15

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

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

International Nuclear Information System (INIS)

Stuke, Maik

2016-04-01

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

Experiment to evaluate software safety

International Nuclear Information System (INIS)

Soubies, B.; Henry, J.Y.

1994-01-01

The process of licensing nuclear power plants for operation consists of mandatory steps featuring detailed examination of the instrumentation and control system by the safety authorities, including softwares. The criticality of these softwares obliges the manufacturer to develop in accordance with the IEC 880 standard 'Computer software in nuclear power plant safety systems' issued by the International Electronic Commission. The evaluation approach, a two-stage assessment is described in detail. In this context, the IPSN (Institute of Protection and Nuclear Safety), the technical support body of the safety authority uses the MALPAS tool to analyse the quality of the programs. (R.P.). 4 refs

Experiences in assessing safety culture

International Nuclear Information System (INIS)

Spitalnik, J.

2002-01-01

Based on several Safety Culture self-assessment applications in nuclear organisations, the paper stresses relevant aspects to be considered when programming an assessment of this type. Reasons for assessing Safety Culture, basic principles to take into account, necessary resources, the importance of proper statistical analyses, the feed-back of results, and the setting up of action plans to enhance Safety Culture are discussed. (author)

Overview of Experiments for Physics of Fast Reactors from the International Handbooks of Evaluated Criticality Safety Benchmark Experiments and Evaluated Reactor Physics Benchmark Experiments

Energy Technology Data Exchange (ETDEWEB)

Bess, J. D.; Briggs, J. B.; Gulliford, J.; Ivanova, T.; Rozhikhin, E. V.; Semenov, M. Yu.; Tsibulya, A. M.; Koscheev, V. N.

2017-07-01

is the critical experiments with fast reactor fuel rods in water, interesting in terms of justification of nuclear safety during transportation and storage of fresh and spent fuel. These reports provide a detailed review of the experiment, designate the area of their application and include results of calculations on modern systems of constants in comparison with the estimated experimental data.

Standardized dose factors for dose calculations - 1982 SRP reactor safety analysis report tritium, iodine, and noble gases

International Nuclear Information System (INIS)

Pillinger, W.L.; Marter, W.L.

1982-01-01

Standardized dose constants are recommended for calculation of offsite doses in the 1982 SRP Reactor Safety Analysis Report (SAR). Dose constants are proposed for inhalation of tritium and radioiodines and for submersion in a semi-infinite cloud of radioiodines and noble gases. The proposed constants, based on ICRP2 methodology for internal dose and methodology recommended by the US Nuclear Regulatory Commission for external dose, are compatible with dose calculational methods used at the Savannah River Plant and Savannah River Laboratory for normal releases of radioactivity. 8 references

Safety factors for neutron fluences in NPP safety assessment

International Nuclear Information System (INIS)

Demekhin, V.L.; Bukanov, V.N.; Il'kovich, V.V.; Pugach, A.M.

2016-01-01

In accordance with global practice and a number of existing regulations, the use of conservative approach is required for the calculations related to nuclear safety assessment of NPP. It implies the need to consider the determination of neutron fluence errors that is rather complicated. It is proposed to carry out the consideration by the way of multiplying the neutron fluences obtained with transport calculations by safety factors. The safety factor values are calculated by the developed technique based on the theory of errors, features of the neutron transport calculation code and the results obtained with the code. It is shown that the safety factor value is equal 1.18 with the confidence level of not less than 0.95 for the majority of VVER-1000 reactor places where neutron fluences are determined by MCPV code, and its maximum value is 1.25

Current MitraClip experience, safety and feasibility in the Netherlands

NARCIS (Netherlands)

Rahhab, Z.; Kortlandt, F. A.; Velu, J. F.; Schurer, R. A. J.; Delgado, V.; Tonino, P.; Boven, A. J.; van den Branden, B. J. L.; Kraaijeveld, A. O.; Voskuil, M.; Hoorntje, J.; van Wely, M. [=Marleen; van Houwelingen, K.; Bleeker, G. B.; Rensing, B.; Kardys, I.; Baan, J.; van der Heyden, J. A. S.; van Mieghem, N. M.

2017-01-01

Purpose Data on MitraClip procedural safety and efficacy in the Netherlands are scarce. We aim to provide an overview of the Dutch MitraClip experience. Methods We pooled anonymised demographic and procedural data of 1151 consecutive MitraClip patients, from 13 Dutch hospitals. Data was collected by

Researches in nuclear safety

International Nuclear Information System (INIS)

Souchet, Y.

2009-01-01

This article comprises three parts: 1 - some general considerations aiming at explaining the main motivations of safety researches, and at briefly presenting the important role of some organisations in the international conciliation, and the most common approach used in safety researches (analytical experiments, calculation codes, global experiments); 2 - an overview of some of the main safety problems that are the object of worldwide research programs (natural disasters, industrial disasters, criticality, human and organisational factors, fuel behaviour in accidental situation, serious accidents: core meltdown, corium spreading, failure of the confinement building, radioactive releases). Considering the huge number of research topics, this part cannot be exhaustive and many topics are not approached; 3 - the presentation of two research programs addressing very different problems: the evaluation of accidental releases in the case of a serious accident (behaviour of iodine and B 4 C, air infiltration, fission products release) and the propagation of a fire in a facility (PRISME program). These two programs belong to an international framework involving several partners from countries involved in nuclear energy usage. (J.S.)

Alterations in the evaporation and discharge calculations for safety and relief valves in the Almod pressurizer

International Nuclear Information System (INIS)

Madeira, A.A.

1986-01-01

Models to estimate bubble rise velocity for evaporation, and critical mass flow for pressurizer relief and safety valves discharge calculation were implemented in ALMOD, a digital code developed to perform primary loop simulation of a PWR type during operational transients or accidents without loss of coolant. These models can be utilized alternatively, depending on the requirements for the analyzed transient condition. (Author) [pt

Calculation of neutron background for underground experiments

Energy Technology Data Exchange (ETDEWEB)

Tomasello, V. [Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Physikalisches Institut, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 14, Tuebingen D-72076 (Germany)], E-mail: v.tomasello@sheffield.ac.uk; Kudryavtsev, V.A.; Robinson, M. [Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2008-10-01

New generation dark matter experiments aim at exploring the 10{sup -9}-10{sup -10}pb cross-section region for the WIMP-nucleon scalar interactions. Neutrons produced in the detector components are one of the main factors that can limit detector sensitivity. Estimation of the background from this source then becomes a crucial task for designing future large-scale detectors. Energy spectra and production rates for neutrons coming from radioactive contamination are required for all materials in and around the detector. In order to estimate neutron yields and spectra, the cross-sections of ({alpha},n) reactions and probabilities of transitions to different excited states should be known. Cross-sections and transition probabilities have been calculated using EMPIRE2.19 for several isotopes, and for some isotopes, a comparison with the experimental data is shown. The results have been used to calculate the neutron spectra from materials using the code SOURCES4A. Neutron background event rates from some detector components in a hypothetical dark matter detector based on Ge crystals have been estimated. Some requirements for the radiopurity of the materials have been deduced from the results of these simulations.

Calculation of neutron background for underground experiments

International Nuclear Information System (INIS)

Tomasello, V.; Kudryavtsev, V.A.; Robinson, M.

2008-01-01

New generation dark matter experiments aim at exploring the 10 -9 -10 -10 pb cross-section region for the WIMP-nucleon scalar interactions. Neutrons produced in the detector components are one of the main factors that can limit detector sensitivity. Estimation of the background from this source then becomes a crucial task for designing future large-scale detectors. Energy spectra and production rates for neutrons coming from radioactive contamination are required for all materials in and around the detector. In order to estimate neutron yields and spectra, the cross-sections of (α,n) reactions and probabilities of transitions to different excited states should be known. Cross-sections and transition probabilities have been calculated using EMPIRE2.19 for several isotopes, and for some isotopes, a comparison with the experimental data is shown. The results have been used to calculate the neutron spectra from materials using the code SOURCES4A. Neutron background event rates from some detector components in a hypothetical dark matter detector based on Ge crystals have been estimated. Some requirements for the radiopurity of the materials have been deduced from the results of these simulations

The development of safety cases for healthcare services: Practical experiences, opportunities and challenges

International Nuclear Information System (INIS)

Sujan, Mark; Spurgeon, Peter; Cooke, Matthew; Weale, Andy; Debenham, Philip; Cross, Steve

2015-01-01

There has been growing interest in the concept of safety cases for medical devices and health information technology, but questions remain about how safety cases can be developed and used meaningfully in the safety management of healthcare services and processes. The paper presents two examples of the development and use of safety cases at a service level in healthcare. These first practical experiences at the service level suggest that safety cases might be a useful tool to support service improvement and communication of safety in healthcare. The paper argues that safety cases might be helpful in supporting healthcare organisations with the adoption of proactive and rigorous safety management practices. However, it is also important to consider the different level of maturity of safety management and regulatory oversight in healthcare. Adaptations to the purpose and use of safety cases might be required, complemented by the provision of education to both practitioners and regulators. - Highlights: • Empirical description of safety case development at service level in healthcare. • Safety cases can support adoption of proactive and rigorous safety management. • Adaptation to purpose and use of safety cases might be required in healthcare. • Education should be provided to practitioners and regulators

AST-500 safety analysis experience

Energy Technology Data Exchange (ETDEWEB)

Falikov, A A; Bakhmetiev, A M; Kuul, V S; Samoilov, O B [OKBM, Nizhny Novgorod (Russian Federation)

1997-09-01

Characteristic AST-type NHR safety features and requirements are described briefly. The main approaches and results of design and beyond-design accidents analyses for the AST-500 NHR, and the results of probabilistic safety assessments are considered. It is concluded that the AST-500 possesses a high safety level in virtue of the development and realization in the design of self-protection, passivity and defence-in-depth principles. (author). 9 refs, 2 figs.

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

Alize 3 - first critical experiment for the franco-german high flux reactor - calculations; Alize 3 - premiere experience critique pour le reacteur a haut flux franco-allemand. Calculs

Energy Technology Data Exchange (ETDEWEB)

Scharmer, K [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

The results of experiments in the light water cooled D{sub 2}O reflected critical assembly ALIZE III have been compared to calculations. A diffusion model was used with 3 fast and epithermal groups and two overlapping thermal groups, which leads to good agreement of calculated and measured power maps, even in the case of strong variations of the neutron spectrum in the core. The difference of calculated and measured k{sub eff} was smaller than 0.5 per cent {delta}k/k. Calculations of void and structure material coefficients of the reactivity of 'black' rods in the reflector, of spectrum variations (Cd-ratio, Pu-U-ratio) and to the delayed photoneutron fraction in the D{sub 2}O reflector were made. Measurements of the influence of beam tubes on reactivity and flux distribution in the reflector were interpreted with regard to an optimum beam tube arrangement for the Franco- German High Flux Reactor. (author) [French] Les resultats des experiences faites dans la maquette critique ALIZE III, refrigeree a l'eau legere et reflechie par l'eau lourde, ont ete compares aux calculs. On a utilise un modele de la theorie de diffusion a trois groupes rapides et epithermiques et deux groupes thermiques qui se recouvrent. Ce modele a permis de calculer la distribution de puissance dans le coeur en bon accord avec les mesures, meme dans le cas d'une forte variation du spectre des neutrons dans le coeur. L'erreur entre k{sub eff} calcule et mesure etait inferieure a 0,5 pour cent {delta}k/k. Le coefficient de vide et des materiaux de structure, la reactivite des barres 'noires', les variations du spectre (rapport Cd, rapport Pu/U) et la fraction des photo-neutrons retardes sont egalement calcules. Les mesures de reactivite et de perturbation de flux dans le reflecteur, dues aux canaux, ont ete interpretees du point de vue d'un arrangement optimum des canaux pour le Reacteur a Haut Flux Franco-Allemand. (auteur)

Applying the results of probablistic safety analysis of nuclear power plants: a survey of experience

International Nuclear Information System (INIS)

Andrews, W.B.; Herttrich, M.; Koeberlein, K.; Schwager.

1985-01-01

To date, discussions of the many different types of potential applications of PRA/PSA results and insights to safety-decision-making have been mainly theoretical. Various safety goals have been proposed as decision criteria. However, the discussion on the role of PRA/PSA and Safety Goals in safety-decision-making, especially in licensing, is controversial. A Working Group of the OECD Nuclear Energy Agency is completing a compilation and evaluation of real examples of past and present practical experience with the application of probabilistic methods in reactor safety decision-making, with the idea of developing a common understanding in this area. More than fifty different cases where PRA has influenced decision-making have been surveyed. These include, for example, regulatory changes, fixing of licensing requirements, plant specific modifications of design of operation, prioritization of safety issues and emergency planning. This feedback of experience - both positive and negative - with PRA/PSA applications is considered to provide guidance on how probabilistic approaches can be introduced into current safety practices, and on desirable future developments in probabilistic methods and specific PSA/PRA studies. Generic insights from the survey are given

Valence electronic structure of the indene molecule: Experiment vs. GW calculations

Energy Technology Data Exchange (ETDEWEB)

Umari, P.; Stenuit, G. [CNR-IOM DEMOCRITOS Theory Elettra Group, Basovizza, Trieste (Italy); Castellarin-Cudia, C.; Feyer, V.; Di Santo, G.; Goldoni, A. [Sincrotrone Trieste S.C.p.A., Basovizza, Trieste (Italy); Borghetti, P.; Sangaletti, L. [Dipartimento di Matematica e Fisica, Universita Cattolica del Sacro Cuore, Brescia (Italy)

2011-04-15

We investigate the valence electronic properties in the gas phase of the indene molecule, which is one of the simplest polycyclic aromatic hydrocarbons, with photoemission spectroscopy using synchrotron light and through first-principles calculations using a many-body perturbation theory GW approach. We found an excellent agreement between theory and experiment. This allows us to assign to the peaks appearing in the photoemission spectrum the calculated molecular orbitals. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Physics experiments with the operating reactor

Energy Technology Data Exchange (ETDEWEB)

Cullington, G R; King, D C

1973-09-27

Experimental techniques have been developed and used on Dragon to give consistent information on excess reactivity and shut down margin. The reactivity measurements have been correlated with the theoretical calculations and have led to improvements in the calculations. The methods used and the results obtained are accepted by the Safety Committee as sufficient evidence for compliance with the fuel loading safety rules. Although the reactor was not designed as an experimental facility, flux and dose measurements experiments have been successfully carried out. Mass flow and negative reactivity transient measurements have been carried out. These are valuable for demonstration of the flexibility of the reactor system and for giving confidence in theoretical calculations.

Analysis of kyoto university reactor physics critical experiments using NCNSRC calculation methodology

International Nuclear Information System (INIS)

Amin, E.; Hathout, A.M.; Shouman, S.

1997-01-01

The kyoto university reactor physics experiments on the university critical assembly is used to benchmark validate the NCNSRC calculations methodology. This methodology has two lines, diffusion and Monte Carlo. The diffusion line includes the codes WIMSD4 for cell calculations and the two dimensional diffusion code DIXY2 for core calculations. The transport line uses the MULTIKENO-Code vax Version. Analysis is performed for the criticality, and the temperature coefficients of reactivity (TCR) for the light water moderated and reflected cores, of the different cores utilized in the experiments. The results of both Eigen value and TCR approximately reproduced the experimental and theoretical Kyoto results. However, some conclusions are drawn about the adequacy of the standard wimsd4 library. This paper is an extension of the NCNSRC efforts to assess and validate computer tools and methods for both Et-R R-1 and Et-MMpr-2 research reactors. 7 figs., 1 tab

DASHBOARDS AND CONTROL CHARTS. EXPERIENCES IN IMPROVING SAFETY AT HANFORD WASHINGTON

International Nuclear Information System (INIS)

PREVETTE, S.S.

2006-01-01

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

INTEGRAL BENCHMARKS AVAILABLE THROUGH THE INTERNATIONAL REACTOR PHYSICS EXPERIMENT EVALUATION PROJECT AND THE INTERNATIONAL CRITICALITY SAFETY BENCHMARK EVALUATION PROJECT

Energy Technology Data Exchange (ETDEWEB)

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

2008-09-01

Interest in high-quality integral benchmark data is increasing as efforts to quantify and reduce calculational uncertainties accelerate to meet the demands of next generation reactor and advanced fuel cycle concepts. The International Reactor Physics Experiment Evaluation Project (IRPhEP) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) continue to expand their efforts and broaden their scope to identify, evaluate, and provide integral benchmark data for method and data validation. Benchmark model specifications provided by these two projects are used heavily by the international reactor physics, nuclear data, and criticality safety communities. Thus far, 14 countries have contributed to the IRPhEP, and 20 have contributed to the ICSBEP. The status of the IRPhEP and ICSBEP is discussed in this paper, and the future of the two projects is outlined and discussed. Selected benchmarks that have been added to the IRPhEP and ICSBEP handbooks since PHYSOR’06 are highlighted, and the future of the two projects is discussed.

INTEGRAL BENCHMARKS AVAILABLE THROUGH THE INTERNATIONAL REACTOR PHYSICS EXPERIMENT EVALUATION PROJECT AND THE INTERNATIONAL CRITICALITY SAFETY BENCHMARK EVALUATION PROJECT

International Nuclear Information System (INIS)

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

2008-01-01

Interest in high-quality integral benchmark data is increasing as efforts to quantify and reduce calculational uncertainties accelerate to meet the demands of next generation reactor and advanced fuel cycle concepts. The International Reactor Physics Experiment Evaluation Project (IRPhEP) and the International Criticality Safety Benchmark Evaluation Project (ICSBEP) continue to expand their efforts and broaden their scope to identify, evaluate, and provide integral benchmark data for method and data validation. Benchmark model specifications provided by these two projects are used heavily by the international reactor physics, nuclear data, and criticality safety communities. Thus far, 14 countries have contributed to the IRPhEP, and 20 have contributed to the ICSBEP. The status of the IRPhEP and ICSBEP is discussed in this paper, and the future of the two projects is outlined and discussed. Selected benchmarks that have been added to the IRPhEP and ICSBEP handbooks since PHYSOR-06 are highlighted, and the future of the two projects is discussed

Perturbative methods for sensitivity calculation in safety problems of nuclear reactors: state-of-the-art

International Nuclear Information System (INIS)

Lima, Fernando R.A.; Lira, Carlos A.B.O.; Gandini, Augusto

1995-01-01

During the last two decades perturbative methods became an efficient tool to perform sensitivity analysis in nuclear reactor safety problems. In this paper, a comparative study taking into account perturbation formalisms (Diferential and Matricial Mthods and generalized Perturbation Theory - GPT) is considered. Then a few number of applications are described to analyze the sensitivity of some functions relavant to thermal hydraulics designs or safety analysis of nuclear reactor cores and steam generators. The behaviours of the nuclear reactor cores and steam generators are simulated, respectively, by the COBRA-IV-I and GEVAP codes. Results of sensitivity calculations have shown a good agreement when compared to those obtained directly by using the mentioned codes. So, a significative computational time safe can be obtained with perturbative methods performing sensitivity analysis in nuclear power plants. (author). 25 refs., 5 tabs

Burnup credit calculations for criticality safety justification for RBMK-1000 spent fuel of transport and storage systems

Directory of Open Access Journals (Sweden)

V. V. Galchenko

2010-12-01

Full Text Available In present paper the burnup credit calculations for TK-8 transport container and SVJP-1 spent fuel storage fa-cility of pool type with RBMK-1000 spent fuel during 100-years of cooling time were performed for criticality safety analysis purpose using MCNP and SCALE codes. Only actinides were taken into account for these critical systems. Two approaches were analyzed with isotopes distribution calculations along fuel assembly height and without it. The results show that subcriticality margin is increased considerably using burnup credit and isotopes distribution along fuel assembly height made this value more reasonable.

CFD Analysis of the Safety Injection Tank and Fluidic Device

Energy Technology Data Exchange (ETDEWEB)

Cho, Jai Oan; Nietiadi, Yohanes Setiawan; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Addad, Yacine [KUSTAR, Abu Dhabi (United Arab Emirates)

2016-05-15

One of the most important components in the ECCS is the safety injection tank (SIT). Inside the SIT, a fluidic device is installed, which passively controls the mass flow of the safety injection and eliminates the need for low pressure safety injection pumps. As more passive safety mechanisms are being pursued, it has become more important to understand flow structure and the loss mechanism within the fluidic device. Current computational fluid dynamics (CFD) calculations have had limited success in predicting the fluid flow accurately. This study proposes to find a more exact result using CFD and more realistic modeling to predict the performance during accident scenarios more accurately. The safety injection tank with fluidic device was analyzed thoroughly using CFD. The preliminary calculation used 60,000 meshes for the initial test calculation. The results fit the experimental results surprisingly despite its coarse grid. Nonetheless, the mesh resolution was increased to capture the vortex in the fluidic device precisely. Once a detailed CFD computation is finished, a small-scale experiment will be conducted for the given conditions. Using the experimental results and the CFD model, physical models can be improved to fit the results more accurately.

French concepts of ''passive safety''

International Nuclear Information System (INIS)

Dennielou, Y.; Serret, M.

1990-01-01

N 4 model, the French 1400 MW PWR of the 90's, exhibits many advanced features. As far as safety is concerned, the fully computerized control room design takes advantage of the operating experience feedback and largely improves the man machine interface. New post-accident procedures have been developed (the so-called ''physical states oriented procedures''). A complete consistent set of ''Fundamental Safety Rules'' have been issued. This however doesn't imply any significant modification of standard PWR with regard to the passive aspects of safety systems or functions. Nevertheless, traditional PWR safety systems largely use passive aspects: natural circulation, reactivity coefficients, gravity driven control rods, injection accumulators, so on. Moreover, probability calculations allow for comparison between the respective contributions of passive and of active failures. In the near future, eventual options of future French PWRs to be commissioned after 2000 will be evaluated; simplification, passive and forgiving aspects of safety systems will be thoroughly considered. (author)

Access Safety Systems – New Concepts from the LHC Experience

CERN Document Server

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

2011-01-01

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

Benchmark experiment to verify radiation transport calculations for dosimetry in radiation therapy; Benchmark-Experiment zur Verifikation von Strahlungstransportrechnungen fuer die Dosimetrie in der Strahlentherapie

Energy Technology Data Exchange (ETDEWEB)

Renner, Franziska [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany)

2016-11-01

Monte Carlo simulations are regarded as the most accurate method of solving complex problems in the field of dosimetry and radiation transport. In (external) radiation therapy they are increasingly used for the calculation of dose distributions during treatment planning. In comparison to other algorithms for the calculation of dose distributions, Monte Carlo methods have the capability of improving the accuracy of dose calculations - especially under complex circumstances (e.g. consideration of inhomogeneities). However, there is a lack of knowledge of how accurate the results of Monte Carlo calculations are on an absolute basis. A practical verification of the calculations can be performed by direct comparison with the results of a benchmark experiment. This work presents such a benchmark experiment and compares its results (with detailed consideration of measurement uncertainty) with the results of Monte Carlo calculations using the well-established Monte Carlo code EGSnrc. The experiment was designed to have parallels to external beam radiation therapy with respect to the type and energy of the radiation, the materials used and the kind of dose measurement. Because the properties of the beam have to be well known in order to compare the results of the experiment and the simulation on an absolute basis, the benchmark experiment was performed using the research electron accelerator of the Physikalisch-Technische Bundesanstalt (PTB), whose beam was accurately characterized in advance. The benchmark experiment and the corresponding Monte Carlo simulations were carried out for two different types of ionization chambers and the results were compared. Considering the uncertainty, which is about 0.7 % for the experimental values and about 1.0 % for the Monte Carlo simulation, the results of the simulation and the experiment coincide.

Experience with nuclear safety standards development in non-governmental international organizations

International Nuclear Information System (INIS)

Becker, K.

1985-01-01

Besides the IAEA as a 'governmental' organization dealing with basic safety recommendations addressed primarily to the national regulatory bodies in developing countries, two closely related non-governmental international standards organizations have gained extensive experience in the field of nuclear standardization. Over more than 25 years since their formation, both (a) the International Organization for Standardization's (ISO) Technical Committee 85 'Nuclear Energy', in particular in its Sub-Committee 3 'Reactor Technology and Safety' and (b) the International Electrotechnical Commission's (IEC) Technical Committee 45 'Nuclear Instrumentation' have published numerous standards. A brief review is given of these, draft standards, and other documents planned to become international standards. Many of them deal with rather specialized topics typical for 'industrial' standards such as standardized procedures, instruments, methods, materials, test methods, terminology, and signs and symbols, but others are directly related to more basic safety issues. In some areas such as quality assurance, seismic aspects of siting and terminology, there has been in the past occasional overlap in the activities of the NUSS programme, IEC and ISO. Letters of Understanding have since 1981 contributed to clarifying the borderlines and to avoiding redundant efforts. Also, some experiences and problems are described arising, for example, from the harmonization of different national safety philosophies and traditions into universally accepted international standards, and the transfer of international standards into national standards systems. Finally, based on a recent comprehensive compilation of some 3300 nuclear standards and standards projects, an attempt is made to present a cost/benefit analysis and an outlook on future developments. (author)

Analysis of the Rossendorf SEG experiments using the JNC route for reactor calculation

International Nuclear Information System (INIS)

Dietze, Klaus

1999-11-01

The integral experiments performed at the Rossendorf fast-thermal coupled reactor RRR/SEG have been reanalyzed using the JNC route for reactor calculation JENDL3.2/SLAROM/CITATION/JOINT/PERKY. The Rossendorf experiments comprise sample reactivity measurements with pure fission products and structural material in five configurations with different neutron and adjoint spectra. The shapes of the adjoint spectra have been designed to get high sensitivities to neutron capture or the scattering effect. The calculated neutron and adjoint spectra are in good agreement with former results obtained with the European route JEF2.2/ECCO/ERANOS. The C/E-values of the central reactivity worths of samples under investigation are given. Deviations in the results of both routes are due to the different libraries, codes, and self-shielding treatments used in the calculations. Results exceeding the experimental error are discussed. (author)

Summary of transient high-voltage calculations for the FRX-C experiment

International Nuclear Information System (INIS)

Kewish, R.W. Jr.; Rej, D.J.

1982-06-01

Calculations of the electrical circuit equations are performed over a wide range of parameters corresponding to the FRX-C field-reversed THETA-pinch experiment at Los Alamos. Without any plasma or external damping, serious voltage doubling and quadrupling of the main capacitor bank charge voltage are observed. These oscillating high voltages are found to be adequately suppressed by the strategic placement of external snubber circuitry. On the other hand, no doubling of the THETA-pinch preionization bank charge voltage is found. Calculations of the equations for the z-pinch preionization circuit are also performed

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-09-01

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

Differentiated thyroid cancer treatment with therapeutic doses of 131I calculated by dosimetry: our experience

International Nuclear Information System (INIS)

Fadel, Ana M.; Chebel, G.M.; Valdivieso, C.M.; Degrossi, Osvaldo J.; Cabrejas, R.; Cabrejas, M.L.

2006-01-01

The optimum dose for the differentiated thyroid cancer treatment is a motive of controversy. There exist two ways of deciding the dose to administer: the empirical method (fixed doses) and dosimetric calculation method. The use of fixed doses has demonstrated safety and effectiveness. Nevertheless there are cases in which the use of several small doses not resolves the metastases illness of the patients. Using the Benua-Leeper method for dosimetric calculation we have evaluated the maximum dose treatment that could be administered to 20 patients who showed persistent disease after several treatments with 131 I. (author) [es

Criticality calculations in reactor accelerator coupling experiment (Race)

International Nuclear Information System (INIS)

Reda, M.A.; Spaulding, R.; Hunt, A.; Harmon, J.F.; Beller, D.E.

2005-01-01

A Reactor Accelerator Coupling Experiment (RACE) is to be performed at the Idaho State University Idaho Accelerator Center (IAC). The electron accelerator is used to generate neutrons by inducing Bremsstrahlung photon-neutron reactions in a Tungsten- Copper target. This accelerator/target system produces a source of ∼1012 n/s, which can initiate fission reactions in the subcritical system. This coupling experiment between a 40-MeV electron accelerator and a subcritical system will allow us to predict and measure coupling efficiency, reactivity, and multiplication. In this paper, the results of the criticality and multiplication calculations, which were carried out using the Monte Carlo radiation transport code MCNPX, for different coupling design options are presented. The fuel plate arrangements and the surrounding tank dimensions have been optimized. Criticality using graphite instead of water for reflector/moderator outside of the core region has been studied. The RACE configuration at the IAC will have a criticality (k-effective) of about 0,92 and a multiplication of about 10. (authors)

Experiences with leak rate calculations methods for LBB application

Energy Technology Data Exchange (ETDEWEB)

Grebner, H.; Kastner, W.; Hoefler, A.; Maussner, G. [and others

1997-04-01

In this paper, three leak rate computer programs for the application of leak before break analysis are described and compared. The programs are compared to each other and to results of an HDR Reactor experiment and two real crack cases. The programs analyzed are PIPELEAK, FLORA, and PICEP. Generally, the different leak rate models are in agreement. To obtain reasonable agreement between measured and calculated leak rates, it was necessary to also use data from detailed crack investigations.

Experiences with leak rate calculations methods for LBB application

International Nuclear Information System (INIS)

Grebner, H.; Kastner, W.; Hoefler, A.; Maussner, G.

1997-01-01

In this paper, three leak rate computer programs for the application of leak before break analysis are described and compared. The programs are compared to each other and to results of an HDR Reactor experiment and two real crack cases. The programs analyzed are PIPELEAK, FLORA, and PICEP. Generally, the different leak rate models are in agreement. To obtain reasonable agreement between measured and calculated leak rates, it was necessary to also use data from detailed crack investigations

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-09-01

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

Recent additions of criticality safety related integral benchmark data to the ICSBEP and IRPHEP handbooks

International Nuclear Information System (INIS)

Briggs, J. B.; Scott, L.; Rugama, Y.; Sartori, E.

2009-01-01

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

REcent Additions Of Criticality Safety Related Integral Benchmark Data To The Icsbep And Irphep Handbooks

International Nuclear Information System (INIS)

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

2009-01-01

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

Analysis of the impact of correlated benchmark experiments on the validation of codes for criticality safety analysis

International Nuclear Information System (INIS)

Bock, M.; Stuke, M.; Behler, M.

2013-01-01

The validation of a code for criticality safety analysis requires the recalculation of benchmark experiments. The selected benchmark experiments are chosen such that they have properties similar to the application case that has to be assessed. A common source of benchmark experiments is the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments' (ICSBEP Handbook) compiled by the 'International Criticality Safety Benchmark Evaluation Project' (ICSBEP). In order to take full advantage of the information provided by the individual benchmark descriptions for the application case, the recommended procedure is to perform an uncertainty analysis. The latter is based on the uncertainties of experimental results included in most of the benchmark descriptions. They can be performed by means of the Monte Carlo sampling technique. The consideration of uncertainties is also being introduced in the supplementary sheet of DIN 25478 'Application of computer codes in the assessment of criticality safety'. However, for a correct treatment of uncertainties taking into account the individual uncertainties of the benchmark experiments is insufficient. In addition, correlations between benchmark experiments have to be handled correctly. For example, these correlations can arise due to different cases of a benchmark experiment sharing the same components like fuel pins or fissile solutions. Thus, manufacturing tolerances of these components (e.g. diameter of the fuel pellets) have to be considered in a consistent manner in all cases of the benchmark experiment. At the 2012 meeting of the Expert Group on 'Uncertainty Analysis for Criticality Safety Assessment' (UACSA) of the OECD/NEA a benchmark proposal was outlined that aimed for the determination of the impact on benchmark correlations on the estimation of the computational bias of the neutron multiplication factor (k eff ). The analysis presented here is based on this proposal. (orig.)

Development and experimental qualification of the new safety-criticality CRISTAL package

International Nuclear Information System (INIS)

Mattera, Ch.

1998-11-01

This thesis is concerned with Criticality-Safety studies related to the French Nuclear Fuel Cycle. We first describe the steps in the nuclear fuel cycle and the specific characteristics of these studies compared with those performed in Reactor Physics. In order to respond to the future requirements of the French Nuclear Program, we have developed a new package CRISTAL based on a recent cross sections library (CEA 93) and the newest accurate codes (APOLLO 2, MORET 4, TRIPOLI 4). The CRISTAL system includes two calculations routes: a design route which will be used by French Industry (COGEMA/SGN) and a reference route. To transfer this package to the French industry, we have elaborated calculation schemes for fissile solutions, dissolver media, transport casks and storage pools. Afterwards, these schemes have been used for the CRISTAL experimental validation. We have also contributed to the CRISTAL experimental database by reevaluating a French storage pool experiment: the CRISTO II experiment. This revaluation has been submitted to the OECD working group in order that this experiment can be used by international criticality safety engineers to validate calculations methods. This work represents a large contribution to the recommendation of accurate calculation schemes and to the experimental validation of the CRISTAL package. These studies came up to the French Industry expectations. (author)

Development and experimental testing of the new safety-criticality Cristal package

International Nuclear Information System (INIS)

Mattera, Ch.

1998-01-01

This thesis is concerned with Criticality-Safety studies related to the French Nuclear Fuel Cycle. We first describe the steps in the nuclear fuel cycle and the specific characteristics of these studies compared with those performed in Reactor Physics. In order to respond to the future requirements of the French Nuclear Program, we have developed a new package CRISTAL based on a recent cross sections library (CEA93) and the newest accurate codes (APOLLO2, MORET4, TRIPOLI4). The cristal system includes two calculations routes: a design route which will be used by French Industry (COGEMA/SGN) and a reference route.) To transfer this package to the French industry, we have elaborated calculation schemes for fissile solutions, dissolver media, transport casks and storage pools. Afterwards, these schemes have been used for the CRISTAL experimental validation. We have also contributed to the CRISTAL experimental database by reevaluating a French storage pool experiment: the CRISTO II experiment. This revaluation has been submitted to the OCDE working group in order that this experiment can be used by international criticality safety engineers to validate calculations methods. This work represents a large contribution to the recommendation of accurate calculation schemes and to the experimental validation of the CRISTAL package. These studies came up to the French Industry expectations. (author)

Lessons from feedback of safety operating experience for reactor physics

International Nuclear Information System (INIS)

Suchomel, J.; Rapavy, S.

1999-01-01

Analyses of events in WWER operations as a part of safety experience feedback provide a valuable source of lessons for reactor physics. Examples of events from Bohunice operation will be shown such as events with inadequate approach to criticality, positive reactivity insertions, expulsion of a control rod from shut-down reactor, problems with reactor protection system and control rods. (Authors)

Importance of LWR best-estimate safety calculations for analysis of Fukushima-like accidents

International Nuclear Information System (INIS)

Sanchez Espinoza, V.; Ivanov, K.

2011-01-01

The safety assessment of nuclear power plants relies heavily on numerical simulations, which must include the most important physical models that are representative for the reactor type of interest. The current trends in nuclear power generation and regulation are to perform safety studies by 'best-estimate' codes that allow a realistic modeling of nuclear and thermal-hydraulic processes of the reactor core and the entire plant behavior including control and protection functions. Realistic methods are referred to as 'best-estimate' calculations, implying that they use a set of data, correlations, and methods designed to represent the phenomena, using the best available techniques. The application of best-estimate methodologies in the licensing process requires the quantification of the embedded uncertainties of the used codes. In this field many international initiatives are underway under the umbrella of the OECD such as the Light Water Reactor Uncertainty Analysis in Modeling benchmark, Oskarshamn 2 Boiling Water Reactor (BWR) Stability benchmark, Kalinin-3 VVER-1000 benchmark, etc. that underlies the importance of these issues. The Fukushima accident has shown the importance of the knowledge of the initial phase of the accident regarding the state of the core, in-vessel structures, and containment as well as the amount of fissile material inventories that potentially can be released if the safety barriers fail. For the development of mitigation and prevention measures modeling of the sequence of the events along with understanding of the key physical phenomena driving the accident progression is important. The paper presents the best-estimate coupled methodologies implemented, validated and applied at the Karlsruhe Institute Technology (KIT) for both types of LWRs - Pressurized Water Reactors (PWRs) and BWRs. Example are given with a BWR steady state and transient simulations along with corresponding uncertainty quantification. The on-going development of high

Safety Research Experiment Facility Project. Conceptual design report. Volume II. Building and facilities

International Nuclear Information System (INIS)

1975-12-01

The conceptual design of Safety Research Experiment Facility (SAREF) site system includes a review and evaluation of previous geotechnical reports for the area where SAREF will be constructed and the conceptual design of access and in-plant roads, parking, experiment-transport-vehicle maneuvering areas, security fencing, drainage, borrow area development and restoration, and landscaping

Validation Study for an Atmospheric Dispersion Model, Using Effective Source Heights Determined from Wind Tunnel Experiments in Nuclear Safety Analysis

Directory of Open Access Journals (Sweden)

Masamichi Oura

2018-03-01

Full Text Available For more than fifty years, atmospheric dispersion predictions based on the joint use of a Gaussian plume model and wind tunnel experiments have been applied in both Japan and the U.K. for the evaluation of public radiation exposure in nuclear safety analysis. The effective source height used in the Gaussian model is determined from ground-level concentration data obtained by a wind tunnel experiment using a scaled terrain and site model. In the present paper, the concentrations calculated by this method are compared with data observed over complex terrain in the field, under a number of meteorological conditions. Good agreement was confirmed in near-neutral and unstable stabilities. However, it was found to be necessary to reduce the effective source height by 50% in order to achieve a conservative estimation of the field observations in a stable atmosphere.

Drug research methodology. Volume 1, The alcohol-highway safety experience and its applicability to other drugs

Science.gov (United States)

1980-03-01

This report presents the findings of a workshop concerning the alcohol and highway safety experience, which includes research efforts to define the drinking-driving problem and societal responses to reduce the increased highway safety risk attributab...

Reactor Thermal Hydraulic Numerical Calculation And Modeling

International Nuclear Information System (INIS)

Duong Ngoc Hai; Dang The Ba

2008-01-01

In the paper the results of analysis of thermal hydraulic state models using the numerical codes such as COOLOD, EUREKA and RELAP5 for simulation of the reactor thermal hydraulic states are presented. The calculations, analyses of reactor thermal hydraulic state and safety were implemented using different codes. The received numerical results, which were compared each to other, to experiment measurement of Dalat (Vietnam) research reactor and published results, show their appropriateness and capacity for analyses of different appropriate cases. (author)

The Department of Energy nuclear criticality safety program

International Nuclear Information System (INIS)

Felty, J.R.

2004-01-01

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

EXPERIENCE NETWORKING UNIVERSITY OF EDUCATION TRAINING MASTERS SAFETY OF LIFE

Directory of Open Access Journals (Sweden)

Elvira Mikhailovna Rebko

2016-02-01

Full Text Available The article discloses experience networking of universities (Herzen State Pedagogical University and Sakhalin State University in the development and implementation of joint training programs for master’s education in the field of life safety «Social security in the urban environment». The novelty of the work is to create a schematic design of basic educational training program for master’s education in the mode of networking, and to identify effective instructional techniques and conditions of networking.Purpose – present the results of the joint development of a network of the basic educational program (BEP, to identify the stages of networking, to design a generalized scheme of development and implementation of a network of educational training program for master’s education in the field of life safety.Results generalized model of networking partner institutions to develop and implement the basic educational program master.Practical implications: the education process for Master of Education in the field of health and safety in Herzen State Pedagogical University and Sakhalin State University.

Quantification of design margins and safety factors based on the prediction uncertainty in tritium production rate from fusion integral experiments of the USDOE/JAERI collaborative program on fusion blanket neutronics

International Nuclear Information System (INIS)

Youssef, M.Z.; Konno, C.; Maekawa, F.; Ikeda, Y.; Kosako, K.; Nakagawa, M.; Mori, T.; Maekawa, H.

1995-01-01

Several fusion integral experiments were performed within a collaboration between the USA and Japan on fusion breeder neutronics aimed at verifying the prediction accuracy of key neutronics parameters in a fusion reactor blanket based on current neutron transport codes and basic nuclear databases. The focus has been on the tritium production rate (TRP) as an important design parameter to resolve the issue of tritium self-sufficiency in a fusion reactor. In this paper, the calculational and experimental uncertainties (errors) in local TPR in each experiment performed i were interpolated and propagated to estimate the prediction uncertainty u i in the line-integrated TPR and its standard deviation σ i . The measured data are based on Li-glass and NE213 detectors. From the quantities u i and σ i , normalized density functions (NDFs) were constructed, considering all the experiments and their associated analyses performed independently by the UCLA and JAERI. Several statistical parameters were derived, including the mean prediction uncertainties u and the possible spread ±σ u around them. Design margins and safety factors were derived from these NDFs. Distinction was made between the results obtained by UCLA and JAERI and between calculational results based on the discrete ordinates and Monte Carlo methods. The prediction uncertainties, their standard deviations and the design margins and safety factors were derived for the line-integrated TPR from Li-6 T 6 , and Li-7 T 7 . These parameters were used to estimate the corresponding uncertainties and safety factor for the line-integrated TPR from natural lithium T n . (orig.)

Performance improvement of the Annular Core Pulse Reactor for reactor safety experiments

International Nuclear Information System (INIS)

Reuscher, J.A.; Pickard, P.S.

1976-01-01

The Annular Core Pulse Reactor (ACPR) is a TRIGA type reactor which has been in operation at Sandia Laboratories since 1967. The reactor is utilized in a wide variety of experimental programs which include radiation effects, neutron radiography, activation analysis, and fast reactor safety. During the past several years, the ACPR has become an important experimental facility for the United States Fast Reactor Safety Research Program and questions of interest to the safety of the LMFBR are being addressed. In order to enhance the capabilities of the ACPR for reactor safety experiments, a project to improve the performance of the reactor was initiated. It is anticipated that the pulse fluence can be increased by a factor of 2.0 to 2.5 utilizing a two-region core concept with high heat capacity fuel elements around the central irradiation cavity. In addition, the steady-state power of the reactor will be increased by about a factor of two. The new features of the improvements are described

Parameters calculation of shielding experiment

International Nuclear Information System (INIS)

Gavazza, S.

1986-02-01

The radiation transport methodology comparing the calculated reactions and dose rates for neutrons and gama-rays, with experimental measurements obtained on iron shield, irradiated in the YAYOI reactor is evaluated. The ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system, for cross sections generation collapsed by the ANISN code were used. The transport calculations were made using the DOT 3.5 code, adjusting the boundary iron shield source spectrum to the reactions and dose rates, measured at the beginning of shield. The neutron and gamma ray distributions calculated on the iron shield presented reasonable agreement with experimental measurements. An experimental arrangement using the IEA-R1 reactor to determine a shielding benchmark is proposed. (Author) [pt

Safety in the Utilization and Modification of Research Reactors. Specific Safety Guide

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-15

This Safety Guide is a revision of Safety Series No. 35-G2 on safety in the utilization and modification of research reactors. It provides recommendations on meeting the requirements for the categorization, safety assessment and approval of research reactor experiments and modification projects. Specific safety considerations in different phases of utilization and modification projects are covered, including the pre-implementation, implementation and post-implementation phases. Guidance is also provided on the operational safety of experiments, including in the handling, dismantling, post-irradiation examination and disposal of experimental devices. Examples of the application of the safety categorization process for experiments and modification projects and of the content of the safety analysis report for an experiment are also provided. Contents: 1. Introduction; 2. Management system for the utilization and modification of a research reactor; 3. Categorization, safety assessment and approval of an experiment or modification; 4. Safety considerations for the design of an experiment or modification; 5. Pre-implementation phase of a modification or utilization project; 6. Implementation phase of a modification or utilization project; 7. Post-implementation phase of a utilization or modification project; 8. Operational safety of experiments at a research reactor; 9. Safety considerations in the handling, dismantling, post-irradiation examination and disposal of experimental devices; 10. Safety aspects of out-of-reactor-core installations; Annex I: Example of a checklist for the categorization of an experiment or modification at a research reactor; Annex II: Example of the content of the safety analysis report for an experiment at a research reactor; Annex III: Examples of reasons for a modification at a research reactor.

Safety in the Utilization and Modification of Research Reactors. Specific Safety Guide

International Nuclear Information System (INIS)

2012-01-01

This Safety Guide is a revision of Safety Series No. 35-G2 on safety in the utilization and modification of research reactors. It provides recommendations on meeting the requirements for the categorization, safety assessment and approval of research reactor experiments and modification projects. Specific safety considerations in different phases of utilization and modification projects are covered, including the pre-implementation, implementation and post-implementation phases. Guidance is also provided on the operational safety of experiments, including in the handling, dismantling, post-irradiation examination and disposal of experimental devices. Examples of the application of the safety categorization process for experiments and modification projects and of the content of the safety analysis report for an experiment are also provided. Contents: 1. Introduction; 2. Management system for the utilization and modification of a research reactor; 3. Categorization, safety assessment and approval of an experiment or modification; 4. Safety considerations for the design of an experiment or modification; 5. Pre-implementation phase of a modification or utilization project; 6. Implementation phase of a modification or utilization project; 7. Post-implementation phase of a utilization or modification project; 8. Operational safety of experiments at a research reactor; 9. Safety considerations in the handling, dismantling, post-irradiation examination and disposal of experimental devices; 10. Safety aspects of out-of-reactor-core installations; Annex I: Example of a checklist for the categorization of an experiment or modification at a research reactor; Annex II: Example of the content of the safety analysis report for an experiment at a research reactor; Annex III: Examples of reasons for a modification at a research reactor.

New engineering safety factors for Loviisa NPP core calculations

Energy Technology Data Exchange (ETDEWEB)

Kuopanportti, Jaakko; Saarinen, Simo; Lahtinen, Tuukka; Ekstroem, Karoliina [Fortum Power and Heat Ltd., Fortum (Finland)

2017-09-15

In Loviisa NPP, there are two limiting thermal margins called the enthalpy rise margin and the linear heat rate margin that are monitored during normal operation. Engineering safety factors are applied in determination of both of these factors. The factors take into account the effect of various manufacturing tolerances, impact of the irradiation and simulation uncertainties on the local heat rate and on the enthalpy of the coolant. The engineering factors were re-evaluated during 2015 and the factors were approved by the Finnish radiation and nuclear safety authority in 2016. The re-evaluation was performed by considering all of the identified phenomena that affect the local heat rate or the enthalpy of the coolant. This paper summarizes the work that was performed during the re-evaluation of the engineering safety factors and presents the results for each uncertainty component. The new engineering safety factors are 1.115 for the linear heat rate and 1.100 for the enthalpy rise margin when the old factors were 1.12 and 1.16, respectively. The new factors improve the fuel economy by about 1%.

[Experience feedback committee: a method for patient safety improvement].

Science.gov (United States)

François, P; Sellier, E; Imburchia, F; Mallaret, M-R

2013-04-01

An experience feedback committee (CREX, Comité de Retour d'EXpérience) is a method which contributes to the management of safety of care in a medical unit. Originally used for security systems of civil aviation, the method has been adapted to health care facilities and successfully implemented in radiotherapy units and in other specialties. We performed a brief review of the literature for studies reporting data on CREX established in hospitals. The review was performed using the main bibliographic databases and Google search results. The CREX is designed to analyse incidents reported by professionals. The method includes monthly meetings of a multi-professional committee that reviews the reported incidents, chooses a priority incident and designates a "pilot" responsible for investigating the incident. The investigation of the incident involves a systemic analysis method and a written synthesis presented at the next meeting of the committee. The committee agrees on actions for improvement that are suggested by the analysis and follows their implementation. Systems for the management of health care, including reporting systems, are organized into three levels: the medical unit, the hospital and the country as a triple loop learning process. The CREX is located in the base level, short loop of risk management and allows direct involvement of care professionals in patient safety. Safety of care has become a priority of health systems. In this context, the CREX can be a useful vehicle for the implementation of a safety culture in medical units. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Experience on environmental qualification of safety-related components for Darlington Nuclear Generating Station

International Nuclear Information System (INIS)

Yu, A.S.; Kukreti, B.M.

1987-01-01

The proliferation of Nuclear Power Plant safety concerns has lead to increasing attention over the Environmental Qualification (EQ) of Nuclear Power Plant Safety-Related Components to provide the assurance that the safety related equipment will meet their intended functions during normal operation and postulated accident conditions. The environmental qualification of these components is also a Licensing requirement for Darlington Nuclear Generating Station. This paper provides an overview of EQ and the experience of a pilot project, in the qualification of the Main Moderator System safety-related functions for the Darlington Nuclear Generating Station currently under construction. It addresses the various phases of qualification from the identification of the EQ Safety-Related Components List, definition of location specific service conditions (normal, adbnormal and accident), safety-related functions, Environmental Qualification Assessments and finally, an EQ system summary report for the Main Moderator System. The results of the pilot project are discussed and the methodology reviewed. The paper concludes that the EQ Program developed for Darlington Nuclear Generating Station, as applied to the qualification of the Main Moderator System, contained all the elements necessary in the qualification of safety-related equipment. The approach taken in the qualification of the Moderator safety-related equipment proves to provide a sound framework for the qualification of other safety-related components in the station

Development and validation of a criticality calculation scheme based on French deterministic transport codes

International Nuclear Information System (INIS)

Santamarina, A.

1991-01-01

A criticality-safety calculational scheme using the automated deterministic code system, APOLLO-BISTRO, has been developed. The cell/assembly code APOLLO is used mainly in LWR and HCR design calculations, and its validation spans a wide range of moderation ratios, including voided configurations. Its recent 99-group library and self-shielded cross-sections has been extensively qualified through critical experiments and PWR spent fuel analysis. The PIC self-shielding formalism enables a rigorous treatment of the fuel double heterogeneity in dissolver medium calculations. BISTRO is an optimized multidimensional SN code, part of the modular CCRR package used mainly in FBR calculations. The APOLLO-BISTRO scheme was applied to the 18 experimental benchmarks selected by the OECD/NEACRP Criticality Calculation Working Group. The Calculation-Experiment discrepancy was within ± 1% in ΔK/K and always looked consistent with the experimental uncertainty margin. In the critical experiments corresponding to a dissolver type benchmark, our tools computed a satisfactory Keff. In the VALDUC fuel storage experiments, with hafnium plates, the computed Keff ranged between 0.994 and 1.003 for the various watergaps spacing the fuel clusters from the absorber plates. The APOLLO-KENOEUR statistic calculational scheme, based on the same self-shielded multigroup library, supplied consistent results within 0.3% in ΔK/K. (Author)

Evaluation of BOR-60 operation safety

International Nuclear Information System (INIS)

Minakov, A.A.; Antipin, G.K.; Efimov, V.N.; Kuzin, G.G.; Eschenko, L.V.; Eschenko, S.N.

1987-12-01

In this communication, BOR-60 reactor operation anomalies capable to produce a dangerous overheating of the core (SDC) is examined. On bases of calculations and reactor operation experience an event tree for SDC is built. Evaluations of probable anomalies entering in the event tree and reactor parameters modifications in case of anomalies are presented. In conclusion BOR-60 agree with the sovietic nuclear safety [fr

The CERN Detector Safety System for the LHC Experiments

CERN Document Server

Lüders, S; Morpurgo, G; Schmeling, S

2003-01-01

The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four LHC experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC front-end, to which the safety-critical part of the DSS task is delegated. This is then supervised by a PVSS SCADA system via an OPC server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "Configuration Database". Thus, the DSS can easily adapt to the different and constantly evolving requirements of the LHC experimen...

Safety concerns for superconducting magnets of upcoming fusion experiments

International Nuclear Information System (INIS)

Turner, L.R.

1983-01-01

-Several fusion experiments being constructed (Tore Supra) or contemplated (DCT 8, Alcator DCT) feature superconducting coils. These coils introduce the following safety concerns: 1. Internally Cooled Conductor (ICC). ICC's are found to be highly stable against short heat pulses, even when the coolant is stagnant or moving at low steady-state velocity. However, a large heat pulse is certain to quench the conductor. Thus, determining the stability limits is vital. 2. Helium II Cooling. Helium II has both unique advantages as a coolant and unique safety problems. 3. Shorted Turns. In magnets with shorts from operational accidents, the current can switch back and forth between the short and the shorted turns, as those alternatively go normal and superconducting. 4. Hybrid Superconducting-Normal Conducting Coil System. The possibility of unequal currents in the different magnets and thus of unexpected forces on the superconducting magnets is much greater than for an all-superconducting system. Analysis of these problems are presented

Raman spectra of long chain hydrocarbons: anharmonic calculations, experiment and implications for imaging of biomembranes.

Science.gov (United States)

Šebek, Jiří; Pele, Liat; Potma, Eric O; Gerber, R Benny

2011-07-28

First-principles anharmonic vibrational calculations are carried out for the Raman spectrum of the C-H stretching bands in dodecane, and for the C-D bands in the deuterated molecule. The calculations use the Vibrational Self-Consistent Field (VSCF) algorithm. The results are compared with liquid-state experiments, after smoothing the isolated-molecule sharp-line computed spectra. Very good agreement between the computed and experimental results is found for the two systems. The combined theoretical and experimental results provide insights into the spectrum, elucidating the roles of symmetric and asymmetric CH(3) and CH(2) hydrogenic stretches. This is expected to be very useful for the interpretation of spectra of long-chain hydrocarbons. The results show that anharmonic effects on the spectrum are large. On the other hand, vibrational degeneracy effects seem to be rather modest at the resolution of the experiments. The degeneracy effects may have more pronounced manifestations in higher-resolution experiments. The results show that first-principles anharmonic vibrational calculations for hydrocarbons are feasible, in good agreement with experiment, opening the way for applications to many similar systems. The results may be useful for the analysis of CARS imaging of lipids, for which dodecane is a representative molecule. It is suggested that first-principles vibrational calculations may be useful also for CARS imaging of other systems. This journal is © the Owner Societies 2011

Gun and optics calculations for the Fermilab recirculation experiment

International Nuclear Information System (INIS)

Kroc, T.

1997-10-01

Fermilab is investigating electron cooling to recycle 8 Gev antiprotons recovered from the Tevatron. To do so, it is developing an experiment to recirculate 2 Mev electrons generated by a Pelletron at National Electrostatics Corporation. This paper reports on the optics calculations done in support of that work. We have used the computer codes EGN2 and MacTrace to represent the gun area and acceleration columns respectively. In addition to the results of our simulations, we discuss some of the problems encountered in interfacing the two codes

Precision calculation of processes used for luminosity measurement at the ZEUS experiment

International Nuclear Information System (INIS)

Haas, T.; Makarenko, V.

2010-09-01

The process pe ± → pe ± γ with the photon emitted along the electron beam axis is used for luminosity measurement at HERA. In this paper the process is calculated including one-loop QED radiative corrections. In the ZEUS experiment, both the electron and the photon can be detected. Therefore both photon and electron spectra with and without the γ-e coincidence are analyzed. We also calculate the process pe ± → pe ± l - l + which contributes to the background in the electron tagger. (orig.)

Reliability calculations

International Nuclear Information System (INIS)

Petersen, K.E.

1986-03-01

Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

Current MitraClip experience, safety and feasibility in the Netherlands

OpenAIRE

Rahhab, Z.; Kortlandt, F.A.; Velu, J.F.; Schurer, R.A.J.; Delgado, V.; Tonino, P.; Boven, A.J. van; Branden, B.J.L. Van den; Kraaijeveld, A.O.; Voskuil, M.; Hoorntje, J.; Wely, M.H. van; Houwelingen, K. van; Bleeker, G.B.; Rensing, B.

2017-01-01

PURPOSE: Data on MitraClip procedural safety and efficacy in the Netherlands are scarce. We aim to provide an overview of the Dutch MitraClip experience. METHODS: We pooled anonymised demographic and procedural data of 1151 consecutive MitraClip patients, from 13 Dutch hospitals. Data was collected by product specialists in collaboration with local operators. Effect on mitral regurgitation was intra-procedurally assessed by transoesophageal echocardiography. Technical success and device succe...

Comparative analysis of calculations and experiment for uranium-graphite lattices with natural and slightly-enriched uranium

International Nuclear Information System (INIS)

Khrennikov, N.N.; Shchukin, A.V.

1988-01-01

Three sets of experiments carried out at different times and in different laboratories on measuring the material parameter for uranium-graphite lattices using natural and slightly enriched uranium are analyzed. Comparison with the calculations by the TRIFOGR and MCU (the Monte Carlo method) codes reveals resonable agreement between the calculation and experiment (of the order of 0.4% in K eff ). 17 refs.; 3 tabs

Structure-dynamic model verification calculation of PWR 5 tests

International Nuclear Information System (INIS)

Engel, R.

1980-02-01

Within reactor safety research project RS 16 B of the German Federal Ministry of Research and Technology (BMFT), blowdown experiments are conducted at Battelle Institut e.V. Frankfurt/Main using a model reactor pressure vessel with a height of 11,2 m and internals corresponding to those in a PWR. In the present report the dynamic loading on the pressure vessel internals (upper perforated plate and barrel suspension) during the DWR 5 experiment are calculated by means of a vertical and horizontal dynamic model using the CESHOCK code. The equations of motion are resolved by direct integration. (orig./RW) [de

Evaluation of Accuracy of Calculational Prediction of Criticality Based on ICSBEP Handbook Experiments

International Nuclear Information System (INIS)

Golovko, Yury; Rozhikhin, Yevgeniy; Tsibulya, Anatoly; Koscheev, Vladimir

2008-01-01

Experiments with plutonium, low enriched uranium and uranium-233 from the ICSBEP Handbook are being considered in this paper. Among these experiments it was selected only those, which seem to be the most relevant to the evaluation of uncertainty of critical mass of mixtures of plutonium or low enriched uranium or uranium-233 with light water. All selected experiments were examined and covariance matrices of criticality uncertainties were developed along with some uncertainties were revised. Statistical analysis of these experiments was performed and some contradictions were discovered and eliminated. Evaluation of accuracy of prediction of criticality calculations was performed using the internally consistent set of experiments with plutonium, low enriched uranium and uranium-233 remained after the statistical analyses. The application objects for the evaluation of calculational prediction of criticality were water-reflected spherical systems of homogeneous aqueous mixtures of plutonium or low enriched uranium or uranium-233 of different concentrations which are simplified models of apparatus of external fuel cycle. It is shows that the procedure allows to considerably reduce uncertainty in k eff caused by the uncertainties in neutron cross-sections. Also it is shows that the results are practically independent of initial covariance matrices of nuclear data uncertainties. (authors)

Experience in the development and practical use of working control levels for radiation safety

International Nuclear Information System (INIS)

Epishin, A.V.

1981-01-01

The experience of development and practical use of working control levels (WCL) of radiation safety in the Gorky region, is discussed. WCL are introduced by ''Radiation Safety Guides'' (RSG-76) and have great practical importance. Regional control levels of radiation safety are determined for certain types of operations implying radioactive hazard and differentiated according to the types of sources applied and types of operation. Dose rates, radioactive contamination of operating surfaces, skin, air and waste water are subject to normalization. Limits of individual radiation doses specified according to operation categories are included. 10 tables of regional WCL indices are developed [ru

Validation of the criticality calculation for fuel elements using the Gamtec 2 - Keno 2 and 4

International Nuclear Information System (INIS)

Teixeira, M.C.C.; Andrade, M.C. de

1990-01-01

For criticality safety in the fabrication, storage and transportation of fuel assemblies, subcriticality analysis must be done. The calculations are performed at CDTN with the GAMTEC computer code, to homogenize the fuel assembly in order to create 16 group cross-section library, and with KENO code, for determining the multiplication factor. To validate the calculational method, suitable Benchmark experiments have been done. The results show that the calculational model overestimates kef when kef+ 2 σ was considered. (author) [pt

Electronically excited states of chloroethylenes: Experiment and DFT calculations in comparison

International Nuclear Information System (INIS)

Khvostenko, O.G.

2014-01-01

Highlights: • B3LYP/6-311 + G(d,p) calculations of chloroethylenes molecules were performed. • Calculations were correlated with experiment on the molecules ground and excited states. • The general pattern of electron structure of chloroethylenes was obtained. • Necessity of this data for chloroethylenes negative ions study was noted. - Abstract: B3LYP/6-311 + G(d,p) calculations of ground and electronically excited states of ethylene, chloroethylene, 1,1-dichloroethylene, 1,2-dichloroethylene-cis, 1,2-dichloroethylene-trans trichloroethylene and tetrachloroethylene molecules have been performed. Molecular orbitals images and orbital correlation diagram are given. The calculation results for chloroethylenes electronically excited states were compared with experimental data from the energy-loss spectra obtained and generally considered previously by C.F. Koerting, K.N. Walzl and A. Kupperman. Several new additional triplet and singlet transitions were pointed out in these spectra considering the calculation results. The finding of the additional transitions was supported by the UV absorption spectrum of trichloroethylene recorded in big cuvette (10 cm), where the first three triplet and two low-intensive forbidden singlet transitions were registered. The first triplet of this compound was recorded to be at the same energy as was found with the energy-loss spectroscopy

Electronically excited states of chloroethylenes: Experiment and DFT calculations in comparison

Energy Technology Data Exchange (ETDEWEB)

Khvostenko, O.G., E-mail: khv@mail.ru

2014-08-15

Highlights: • B3LYP/6-311 + G(d,p) calculations of chloroethylenes molecules were performed. • Calculations were correlated with experiment on the molecules ground and excited states. • The general pattern of electron structure of chloroethylenes was obtained. • Necessity of this data for chloroethylenes negative ions study was noted. - Abstract: B3LYP/6-311 + G(d,p) calculations of ground and electronically excited states of ethylene, chloroethylene, 1,1-dichloroethylene, 1,2-dichloroethylene-cis, 1,2-dichloroethylene-trans trichloroethylene and tetrachloroethylene molecules have been performed. Molecular orbitals images and orbital correlation diagram are given. The calculation results for chloroethylenes electronically excited states were compared with experimental data from the energy-loss spectra obtained and generally considered previously by C.F. Koerting, K.N. Walzl and A. Kupperman. Several new additional triplet and singlet transitions were pointed out in these spectra considering the calculation results. The finding of the additional transitions was supported by the UV absorption spectrum of trichloroethylene recorded in big cuvette (10 cm), where the first three triplet and two low-intensive forbidden singlet transitions were registered. The first triplet of this compound was recorded to be at the same energy as was found with the energy-loss spectroscopy.

Activity of safety review for the facilities using nuclear material (2). Safety review results and maintenance experiences for hot laboratories

International Nuclear Information System (INIS)

Amagai, Tomio; Fujishima, Tadatsune; Mizukoshi, Yasutaka; Sakamoto, Naoki; Ohmori, Tsuyoshi

2009-01-01

In the site of O-arai Research and Development Center of Japan Atomic Energy Agency (JAEA), five hot laboratories for post-irradiation examination and development of plutonium fuels are operated more than 30 years. A safety review method for preventive maintenance on these hot laboratories includes test facilities and devices are established in 2003. After that, the safety review of these facilities and devices are done and taken the necessary maintenance based on the results in each year. In 2008, 372 test facilities and devices in these hot laboratories were checked and reviewed by this method. As a results of the safety review, repair issues of 38 facilities of above 372 facilities were resolved. This report shows the review results and maintenance experiences based on the results. (author)

Analysis of a calculation method for the determination of the value of safety or control bars

International Nuclear Information System (INIS)

Aguilar H, F.; Torres A, C.; Filio L, C.

1982-09-01

Due to the control or safety bars in a nuclear reactor are constituted by strongly absorbent materials, the Diffusion Theory like tool for the calculation of bar values is not directly applicable, should it use the Transport Theory. However the speed and economy of the Diffusion codes for the reactors calculation, those make attractiveness and by this reason its are used in the determination of characteristic parameters and even in the determination of bar values, not without before to make some theoretical developments that allow to make applicable this theory. The application of the Diffusion Theory in strongly absorbent media is based on the use of some effective cross sections distinct from the real ones obtained when imposing the reason that among the flow and it gradient in the external surface of such media (control element in general, bar type or flagstone) be similar to the one obtained using Transport Theory in all the control region (multiplicative and absorbent media) with those real cross sections. The effective cross sections were obtained of the Leopard-NUMICE cell code which has incorporate the respective calculation theory of effective cross sections. Later these constants its were used in the bidimensional diffusion code Exterminator-II, simulating in it, the distribution of safety or control bars. From the cell code its were also obtained the respective constants of the homogeneous fuel cell. The results as soon as those obtained bar values of the diffusion code, its were compared with some experimental results obtained in the Rφ Swedish reactor of natural uranium and heavy water. In this work an analysis of the bar value of one of them, trying to determine the applicability of the method is made. (Author)

Bias in calculated keff from subcritical measurements by the 252Cf-source-driven noise analysis method

International Nuclear Information System (INIS)

Mihalczo, J.T.; Valentine, T.E.

1995-01-01

The development of MCNP-DSP, which allows direct calculation of the measured time and frequency analysis parameters from subcritical measurements using the 252 Cf-source-driven noise analysis method, permits the validation of calculational methods for criticality safety with in-plant subcritical measurements. In addition, a method of obtaining the bias in the calculations, which is essential to the criticality safety specialist, is illustrated using the results of measurements with 17.771-cm-diam, enriched (93.15), unreflected, and unmoderated uranium metal cylinders. For these uranium metal cylinders the bias obtained using MCNP-DSP and ENDF/B-V cross-section data increased with subcriticality. For a critical experiment [height (h) = 12.629 cm], it was -0.0061 ± 0.0003. For a 10.16-cm-high cylinder (k ∼ 0.93), it was 0.0060 ± 0.0016, and for a subcritical cylinder (h = 8.13 cm, k ∼ 0.85), the bias was -0.0137 ± 0.0037, more than a factor of 2 larger in magnitude. This method allows the nuclear criticality safety specialist to establish the bias in calculational methods for criticality safety from in-plant subcritical measurements by the 252 Cf-source-driven noise analysis method

Sample size calculation while controlling false discovery rate for differential expression analysis with RNA-sequencing experiments.

Science.gov (United States)

Bi, Ran; Liu, Peng

2016-03-31

RNA-Sequencing (RNA-seq) experiments have been popularly applied to transcriptome studies in recent years. Such experiments are still relatively costly. As a result, RNA-seq experiments often employ a small number of replicates. Power analysis and sample size calculation are challenging in the context of differential expression analysis with RNA-seq data. One challenge is that there are no closed-form formulae to calculate power for the popularly applied tests for differential expression analysis. In addition, false discovery rate (FDR), instead of family-wise type I error rate, is controlled for the multiple testing error in RNA-seq data analysis. So far, there are very few proposals on sample size calculation for RNA-seq experiments. In this paper, we propose a procedure for sample size calculation while controlling FDR for RNA-seq experimental design. Our procedure is based on the weighted linear model analysis facilitated by the voom method which has been shown to have competitive performance in terms of power and FDR control for RNA-seq differential expression analysis. We derive a method that approximates the average power across the differentially expressed genes, and then calculate the sample size to achieve a desired average power while controlling FDR. Simulation results demonstrate that the actual power of several popularly applied tests for differential expression is achieved and is close to the desired power for RNA-seq data with sample size calculated based on our method. Our proposed method provides an efficient algorithm to calculate sample size while controlling FDR for RNA-seq experimental design. We also provide an R package ssizeRNA that implements our proposed method and can be downloaded from the Comprehensive R Archive Network ( http://cran.r-project.org ).

Calculational study of benchmark critical experiments on high-enriched uranyl nitrate solution systems

International Nuclear Information System (INIS)

Oh, I.; Rothe, R.E.

1978-01-01

Criticality calculations on minimally reflected, concrete-reflected, and plastic-reflected single tanks and on arrays of cylinders reflected by concrete and plastic have been performed using the KENO-IV code with 16-group Hansen-Roach neutron cross sections. The fissile material was high-enriched (93.17% 235 U) uranyl nitrate [UO 2 (NO 3 ) 2 ] solution. Calculated results are compared with those from a benchmark critical experiments program to provide the best possible verification of the calculational technique. The calculated k/sub eff/'s underestimate the critical condition by an average of 1.28% for the minimally reflected single tanks, 1.09% for the concrete-reflected single tanks, 0.60% for the plastic-reflected single tanks, 0.75% for the concrete-reflected arrays of cylinders, and 0.51% for the plastic-reflected arrays of cylinders. More than half of the present comparisons were within 1% of the experimental values, and the worst calculational and experimental discrepancy was 2.3% in k/sub eff/ for the KENO calculations

The Belgian experience on the backfitting and safety upgrading of old operating nuclear power plants

International Nuclear Information System (INIS)

Brognon, T.

1993-01-01

The paper describes the methodology for backfitting and safety upgrading during the reevaluation of the Belgian NPP's: first generation (Doel-1, Doel-2, Tihange-1) and second generation plants (Doel-3, Doel-4, Tihange-2 and Tihange-3). A list of essential safety subjects and topics is given. The experience has proved the feasibility of a safety upgrading of operating NPP without injury to its availability, the benefit of a close cooperation between owner, engineering company and safety authorities throughout the project. A global approach to solving numerous specific deficiencies along with the optimization of the investments regarding the safety improvement of the NPP is suggested. Further increase of the know-how will be achieved through the present Belgian programme along with similar activities abroad. (R.I.)

Safety in Cryogenics – Safety device sizing

CERN Multimedia

CERN. Geneva

2016-01-01

The calculation is separated in three operations: o The estimation of the loads arriving on the component to protect, o The calculation of the mass flow to evacuate, o And the sizing of the safety device.

MELCOR 1.8.1 calculations of ISP31: The CORA-13 experiment

International Nuclear Information System (INIS)

Gross, R.J.; Thompson, S.L.; Martinez, G.M.

1993-06-01

The MELCOR code was used to simulate one of GRS's (a reactor research group in Germany) core degradation experiments conducted in the CORA out-of-pile test facility. This test, designated CORA-13, was selected as one of the International Standard Problems, Number ISP31, by the Organization for Economic Cooperation and Development. In this blind calculation, only initial and boundary conditions were provided. The experiment consisted of a small core bundle of twenty-five PWR fuel elements that was electrically heated to temperatures greater than 2,800 K. The experiment composed three phases: a 3,000 second gas preheat phase, an 1,870 second transient phase, and a 180 second water quench phase. MELCOR predictions are compared both to the experimental data and to eight other ISP31 submittals. Temperatures of various components, energy balance, zircaloy oxidation, and core blockage are examined. Up to the point where oxidation was significant, MELCOR temperatures agreed very well with the experiment -- usually to within 50 K. MELCOR predicted oxidation to occur about 100 seconds earlier and at a faster rate than experimental data. The large oxidation spike that occurred during quench was not predicted. However, the experiment produced 210 grams of hydrogen, while MELCOR predicted 184 grams, which was one of the closest integral predictions of the nine submittals. Core blockage was of the right magnitude; however, material collected on the lower grid spacer in the experiment at an axial location of 450 mm, while in MELCOR the material collected at the 50 to 150 mm location. In general, compared to the other submittals, the MELCOR calculation was superior

MELCOR 1.8.1 calculations of ISP31: The CORA-13 experiment

Energy Technology Data Exchange (ETDEWEB)

Gross, R.J.; Thompson, S.L.; Martinez, G.M.

1993-06-01

The MELCOR code was used to simulate one of GRS`s (a reactor research group in Germany) core degradation experiments conducted in the CORA out-of-pile test facility. This test, designated CORA-13, was selected as one of the International Standard Problems, Number ISP31, by the Organization for Economic Cooperation and Development. In this blind calculation, only initial and boundary conditions were provided. The experiment consisted of a small core bundle of twenty-five PWR fuel elements that was electrically heated to temperatures greater than 2,800 K. The experiment composed three phases: a 3,000 second gas preheat phase, an 1,870 second transient phase, and a 180 second water quench phase. MELCOR predictions are compared both to the experimental data and to eight other ISP31 submittals. Temperatures of various components, energy balance, zircaloy oxidation, and core blockage are examined. Up to the point where oxidation was significant, MELCOR temperatures agreed very well with the experiment -- usually to within 50 K. MELCOR predicted oxidation to occur about 100 seconds earlier and at a faster rate than experimental data. The large oxidation spike that occurred during quench was not predicted. However, the experiment produced 210 grams of hydrogen, while MELCOR predicted 184 grams, which was one of the closest integral predictions of the nine submittals. Core blockage was of the right magnitude; however, material collected on the lower grid spacer in the experiment at an axial location of 450 mm, while in MELCOR the material collected at the 50 to 150 mm location. In general, compared to the other submittals, the MELCOR calculation was superior.

Angra-1 probabilistic safety study-phase B

International Nuclear Information System (INIS)

Fernandes Filho, T.L.; Gibelli, S.M.O.

1988-05-01

This study represents the Phase B of the Angra-1 Probabilistic Safety Study and is the the final report prepared for the IAEA under Research Contract No. 3423/R2/RB. The three main items covered in this report are the establishment of interim safety goals, analysis of Angra-1 operational experience and development of emergency procedures to address severe accidents. For establishment of interim safety goals a methodology for calculating consequences and risks associated to the Angra-1 operation was developed based on the available data and codes. The proposed safety goals refer to the individual risk of early fatality for people living in the vicinity of the plant, colective risk of cancer fatalities for people living near the plant, the propobability of core melt occurrence and the probability of dominant accident sequences. (author) [pt

Analysis of SCARABEE BE+3 experiment with ASTEC-Na and comparison with other SFR safety analysis codes

International Nuclear Information System (INIS)

Bandini, Giacomino; Ederli, Stefano; Perez-Martin, Sara; Pfrang, Werner; Girault, Nathalie; Cloarec, Laure

2017-01-01

The ASTEC-Na code was further developed and assessed in the frame of JASMIN project of the 7th EU Framework Program to extend the original capability of ASTEC, dealing with severe accident analysis in LWR to Sodium-cooled Fast Reactors (SFR). The in-pile BE+3 experiment from the SCARABEE-N program has been simulated with ASTEC-Na for thermal-hydraulic models validation purpose. The adequacy of ASTEC-Na thermal-hydraulic models has been also investigated through the comparison with other safety analysis codes. The analysis of SCARABEE BE+3 test confirms the good performance of ASTEC-Na code in the calculation of single-phase conditions and boiling onset, while larger deviations are encountered in the analysis of the two-phase conditions, mainly regarding the propagation of the boiling front. Furthermore, reasonable agreement was found with other code results. (author)

Buckling calculations with the CEASEMT system for elliptical heads subjected to an internal pressure. Comparison with the Saclay experiments

International Nuclear Information System (INIS)

Bung, Hariddh; Alix, Michel; Hoffmann, Alain.

1980-06-01

In this paper, Buckling calculations with the CEASEMT System (INCA) are compared with experimental results obtained on elliptical heads subjected to an internal pressure. Tests were performed with 18 ellipsoidal heads welded on cylinders made of carbon steel A 36-401, stainless steel Z6CN18-09 and aluminium-magnesium alloys (AG3). Experimental data are higher than calculated data, this leads to a good safety factor [fr

EXPERIENCE NETWORKING UNIVERSITY OF EDUCATION TRAINING MASTERS SAFETY OF LIFE

OpenAIRE

Elvira Mikhailovna Rebko

2016-01-01

The article discloses experience networking of universities (Herzen State Pedagogical University and Sakhalin State University) in the development and implementation of joint training programs for master’s education in the field of life safety «Social security in the urban environment». The novelty of the work is to create a schematic design of basic educational training program for master’s education in the mode of networking, and to identify effective instructional techniques and conditions...

Compilation report of VHTRC temperature coefficient benchmark calculations

Energy Technology Data Exchange (ETDEWEB)

Yasuda, Hideshi; Yamane, Tsuyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1995-11-01

A calculational benchmark problem has been proposed by JAERI to an IAEA Coordinated Research Program, `Verification of Safety Related Neutronic Calculation for Low-enriched Gas-cooled Reactors` to investigate the accuracy of calculation results obtained by using codes of the participating countries. This benchmark is made on the basis of assembly heating experiments at a pin-in block type critical assembly, VHTRC. Requested calculation items are the cell parameters, effective multiplication factor, temperature coefficient of reactivity, reaction rates, fission rate distribution, etc. Seven institutions from five countries have joined the benchmark works. Calculation results are summarized in this report with some remarks by the authors. Each institute analyzed the problem by applying the calculation code system which was prepared for the HTGR development of individual country. The values of the most important parameter, k{sub eff}, by all institutes showed good agreement with each other and with the experimental ones within 1%. The temperature coefficient agreed within 13%. The values of several cell parameters calculated by several institutes did not agree with the other`s ones. It will be necessary to check the calculation conditions again for getting better agreement. (J.P.N.).

Probabilistic safety assessment in the chemical and nuclear industries

CERN Document Server

Fullwood, Ralph R

2000-01-01

Probabilistic Safety Analysis (PSA) determines the probability and consequences of accidents, hence, the risk. This subject concerns policy makers, regulators, designers, educators and engineers working to achieve maximum safety with operational efficiency. Risk is analyzed using methods for achieving reliability in the space program. The first major application was to the nuclear power industry, followed by applications to the chemical industry. It has also been applied to space, aviation, defense, ground, and water transportation. This book is unique in its treatment of chemical and nuclear risk. Problems are included at the end of many chapters, and answers are in the back of the book. Computer files are provided (via the internet), containing reliability data, a calculator that determines failure rate and uncertainty based on field experience, pipe break calculator, event tree calculator, FTAP and associated programs for fault tree analysis, and a units conversion code. It contains 540 references and many...

HTR-PROTEUS benchmark calculations. Pt. 1. Unit cell results LEUPRO-1 and LEUPRO-2

International Nuclear Information System (INIS)

Hogenbirk, A.; Stad, R.C.L. van der; Janssen, A.J.; Klippel, H.T.; Kuijper, J.C.

1995-09-01

In the framework of the IAEA Co-ordinated Research Programme (CRP) on 'Validation of Safety Related Physics Calculations for Low-Enriched (LEU) HTGRs' calculational benchmarks are performed on the basis of LEU-HTR pebble-bed critical experiments carried out in the PROTEUS facility at PSI, Switzerland. Of special interest is the treatment of the double heterogeneity of the fuel and the spherical fuel elements of these pebble bed core configurations. Also of interest is the proper calculation of the safety related physics parameters like the effect of water ingress and control rod worth. This document describes the ECN results of the LEUPRO-1 and LEUPRO-2 unitcell calculations performed with the codes WIMS-E, SCALE-4 and MCNP4A. Results of the LEUPRO-1 unit cell with 20% water ingress in the void is also reported for both the single and the double heterogeneous case. Emphasis is put on the intercomparison of the results obtained by the deterministic codes WIMS-E and SCALE-4, and the Monte Carlo code MCNP4A. The LEUPRO whole core calculations will be reported later. (orig.)

Activation calculations for dismantling - The feedback of a 7 years experience in activation calculations for graphite gas cooled reactors in France

International Nuclear Information System (INIS)

Eid, M.; Nimal, J.C.; Gerat, L.M.

1994-01-01

This is a revision of the past seven years experience in activation calculations for dismantling. It aims at evaluating the experience and at making better understanding to help in decision making during the following phases. Five gas cooled reactors are shutdown and are waiting for the EDF (Electricite De France) dismantling decision. The sixth (BUGEY1) will be shutdown by 1994 and will be waiting a dismantling decision as well. (authors). 3 figs., 3 tabs

Safety analysis SFR 1. Long-term safety

Energy Technology Data Exchange (ETDEWEB)

2008-12-15

An updated assessment of the long-term safety of SKB's final repository for radioactive operational waste, SFR 1, is presented in this report. The report is included in the safety analysis report for SFR 1. The most recent account of long-term safety was submitted to the regulatory authorities in 2001. The present report has been compiled on SKB's initiative to address the regulatory authorities' viewpoints regarding the preceding account of long-term safety. Besides the new mode of working with safety functions there is another important difference between the 2001 safety assessment and the current assessment: The time horizon in the current assessment has been extended to 100,000 years in order to include the effect of future climate changes. The purpose of this renewed assessment of the long-term safety of SFR 1 is to show with improved data that the repository is capable of protecting human health and the environment against ionizing radiation in a long-term perspective. This is done by showing that calculated risks lie below the risk criteria stipulated by the regulatory authorities. SFR 1 is built to receive, and after closure serve as a passive repository for, low. and intermediate-level radioactive waste. The disposal chambers are situated in rock beneath the sea floor, covered by about 60 metres of rock. The underground part of the facility is reached via two tunnels whose entrances are near the harbour. The repository has been designed so that it can be abandoned after closure without further measures needing to be taken to maintain its function. The waste in SFR 1 is short-lived low- and intermediate-level waste. After 100 years the activity is less than half, and after 1,000 years only about 2% of the original activity remains. The report on long-term safety comprises eleven chapters. Chapter 1 Introduction. The chapter describes the purpose, background, format and contents of SAR-08, applicable regulations and injunctions, and the regulatory

Safety analysis SFR 1. Long-term safety

International Nuclear Information System (INIS)

2008-12-01

An updated assessment of the long-term safety of SKB's final repository for radioactive operational waste, SFR 1, is presented in this report. The report is included in the safety analysis report for SFR 1. The most recent account of long-term safety was submitted to the regulatory authorities in 2001. The present report has been compiled on SKB's initiative to address the regulatory authorities' viewpoints regarding the preceding account of long-term safety. Besides the new mode of working with safety functions there is another important difference between the 2001 safety assessment and the current assessment: The time horizon in the current assessment has been extended to 100,000 years in order to include the effect of future climate changes. The purpose of this renewed assessment of the long-term safety of SFR 1 is to show with improved data that the repository is capable of protecting human health and the environment against ionizing radiation in a long-term perspective. This is done by showing that calculated risks lie below the risk criteria stipulated by the regulatory authorities. SFR 1 is built to receive, and after closure serve as a passive repository for, low. and intermediate-level radioactive waste. The disposal chambers are situated in rock beneath the sea floor, covered by about 60 metres of rock. The underground part of the facility is reached via two tunnels whose entrances are near the harbour. The repository has been designed so that it can be abandoned after closure without further measures needing to be taken to maintain its function. The waste in SFR 1 is short-lived low- and intermediate-level waste. After 100 years the activity is less than half, and after 1,000 years only about 2% of the original activity remains. The report on long-term safety comprises eleven chapters. Chapter 1 Introduction. The chapter describes the purpose, background, format and contents of SAR-08, applicable regulations and injunctions, and the regulatory

Safety analysis SFR 1. Long-term safety

Energy Technology Data Exchange (ETDEWEB)

2008-12-15

An updated assessment of the long-term safety of SKB's final repository for radioactive operational waste, SFR 1, is presented in this report. The report is included in the safety analysis report for SFR 1. The most recent account of long-term safety was submitted to the regulatory authorities in 2001. The present report has been compiled on SKB's initiative to address the regulatory authorities' viewpoints regarding the preceding account of long-term safety. Besides the new mode of working with safety functions there is another important difference between the 2001 safety assessment and the current assessment: The time horizon in the current assessment has been extended to 100,000 years in order to include the effect of future climate changes. The purpose of this renewed assessment of the long-term safety of SFR 1 is to show with improved data that the repository is capable of protecting human health and the environment against ionizing radiation in a long-term perspective. This is done by showing that calculated risks lie below the risk criteria stipulated by the regulatory authorities. SFR 1 is built to receive, and after closure serve as a passive repository for, low. and intermediate-level radioactive waste. The disposal chambers are situated in rock beneath the sea floor, covered by about 60 metres of rock. The underground part of the facility is reached via two tunnels whose entrances are near the harbour. The repository has been designed so that it can be abandoned after closure without further measures needing to be taken to maintain its function. The waste in SFR 1 is short-lived low- and intermediate-level waste. After 100 years the activity is less than half, and after 1,000 years only about 2% of the original activity remains. The report on long-term safety comprises eleven chapters. Chapter 1 Introduction. The chapter describes the purpose, background, format and contents of SAR-08, applicable regulations and injunctions, and the

Safety analysis report for the Hanford Critical Mass Laboratory: Supplement No. 2. Experiments with heterogeneous assemblies

International Nuclear Information System (INIS)

Gore, B.F.; Davenport, L.C.

1981-04-01

Factors affecting the safety of criticality experiments using heterogeneous assemblies are described and assessed. It is concluded that there is no substantial change in safety from experiments already being routinely performed at the Critical Mass Laboratory (CML), and that laboratory and personnel safety are adequately provided by the combination of engineered and administrative safety limits enforced at the CML. This conclusion is based on the analysis of operational controls, potential hazards, and the consequences of accidents. Contingencies considered that could affect nuclear criticality include manual changes in fuel loadings, water flooding, fire, explosion, loss of services, earthquake, windstorm, and flood. Other potential hazards considered include radiation exposure to personnel, and potential releases within the Assembly Room and outside to the environment. It is concluded that the Maximum Credible Nuclear Burst of 3 x 10 18 fissions (which served as the design basis for the CML) is valid for heterogeneous assemblies as well as homogeneous assemblies. This is based upon examination of the results of reactor destructive tests and the results of the SL-1 reactor destructive accident. The production of blast effects which might jeopardize the CML critical assembly room (of thick reinforced concrete) is not considered credible due to the extreme circumstances required to produce blast effects in reactor destructive tests. Consequently, it is concluded that, for experiments with heterogeneous assemblies, the consequences of the Maximum Credible Burst are unchanged from those previously estimated for experiments with homogeneous systems

Variability of patient safety culture in Belgian acute hospitals.

Science.gov (United States)

Vlayen, Annemie; Schrooten, Ward; Wami, Welcome; Aerts, Marc; Barrado, Leandro Garcia; Claes, Neree; Hellings, Johan

2015-06-01

The aim of this study was to measure differences in safety culture perceptions within Belgian acute hospitals and to examine variability based on language, work area, staff position, and work experience. The Hospital Survey on Patient Safety Culture was distributed to hospitals participating in the national quality and safety program (2007-2009). Hospitals were invited to participate in a comparative study. Data of 47,136 respondents from 89 acute hospitals were used for quantitative analysis. Percentages of positive response were calculated on 12 dimensions. Generalized estimating equations models were fitted to explore differences in safety culture. Handoffs and transitions, staffing, and management support for patient safety were considered as major problem areas. Dutch-speaking hospitals had higher odds of positive perceptions for most dimensions in comparison with French-speaking hospitals. Safety culture scores were more positive for respondents working in pediatrics, psychiatry, and rehabilitation compared with the emergency department, operating theater, and multiple hospital units. We found an important gap in safety culture perceptions between leaders and assistants within disciplines. Administration and middle management had lower perceptions toward patient safety. Respondents working less than 1 year in the current hospital had more positive safety culture perceptions in comparison with all other respondents. Large comparative databases provide the opportunity to identify distinct high and low scoring groups. In our study, language, work area, and profession were identified as important safety culture predictors. Years of experience in the hospital had only a small effect on safety culture perceptions.

Neutronic, thermal-hydraulics and safety calculations of a Miniplate Irradiation Device (MID) of dispersion type fuel elements

International Nuclear Information System (INIS)

Domingos, Douglas Borges

2010-01-01

Neutronic, thermal-hydraulics and accident analysis calculations were developed to estimate the safety of a Miniplate Irradiation Device (MID) to be placed in the IEA-R1 reactor core. The irradiation device is used to receive miniplates of U 3 O 8 -Al and U 3 Si 2 - Al dispersion fuels, LEU type (19.75 % 235 U) with uranium densities of, respectively, 3.2 gU/cm 3 and 4.8 gU/cm 3 . The fuel miniplates will be irradiated to nominal 235 U burnup levels of 50% and 80%, in order to qualify the above high-density dispersion fuels to be used in the Brazilian Multipurpose Reactor (RMB), now in the conception phase. For the neutronic calculation, the computer codes CITATION and 2DB were utilized. The computer code FLOW was used to calculate the coolant flow rate in the irradiation device, allowing the determination of the fuel miniplate temperatures with the computer model MTRCR-IEA-R1. A postulated Loss of Coolant Accident (LOCA) was analyzed with the computer codes LOSS and TEMPLOCA, allowing the calculation of the fuel miniplate temperatures after the reactor pool draining. The calculations showed that the irradiation should occur without adverse consequences in the IEA-R1 reactor. (author)

Playing it safe: Patron safety strategies and experience of violence in night-time entertainment districts.

Science.gov (United States)

Zhou, Jin; Droste, Nicolas; Curtis, Ashlee; Zinkiewicz, Lucy; Miller, Peter

2018-03-01

Incidences of violence are elevated in night-time entertainment districts. Research suggests that safety-related behavioural strategies adopted while drinking can reduce negative alcohol-related outcomes. The current study investigates the use of safety strategies and its association with experiences of violence among patrons from the general population. Patron interviews (N = 3949) were conducted in and around licenced venues in Newcastle (New South Wales) and Geelong (Victoria) during peak trading hours (Friday and Saturday, 21:00-01:00 h). Participants (mean age = 24.3, SD = 5.8; male 54.4%) were asked to report what measures, if any, they used to keep safe when drinking and whether they had been involved in a violent incident in the last 12 months. After controlling for patron demographics and location, the use of multiple (more than one) safety strategies was significantly associated with reduced odds of involvement in a violent incident (odds ratio = 0.64, 95% confidence interval 0.49-0.85, P = 0.002). Significant gender differences were observed in the number and type of safety strategies reported. Increasing the number of safety-related behaviours during drinking occasions is associated with a small but significant reduction in experiencing alcohol-related harms, such as violence. [Zhou J, Droste N, Curtis A, Zinkiewicz L, Miller P. Playing it safe: Patron safety strategies and experience of violence in night-time entertainment districts. © 2017 Australasian Professional Society on Alcohol and other Drugs.

Neutron flux calculations for criticality safety analysis using the narrow resonance approximations. Vol. 2

Energy Technology Data Exchange (ETDEWEB)

Hathout, A M [National Center for Nuclear Safety and Radiation Control, NC-NSRC, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

The narrow resonance approximation is applicable for all low-energy resonances and the heaviest nuclides. It is of great importance in neutron calculations, hence, fertile isotopes do not undergo fission at resonance energies. The effect of overestimating the self shielded group averaged cross-section data for a given resonance nuclide can be fairly serious. In the present work, a detailed study, and derivation of the problem of self-shielding are carried-out through the information of Hansen-roach library which is used for criticality safety analysis. The intermediate neutron flux spectrum is analyzed, using the narrow resonance approximation. The resonance self-shielded values of various cross-sections are determined. 4 figs., 3 tabs.

Experience and lessons learned in the assessment of safety justifications for experiments mounted in research reactors

International Nuclear Information System (INIS)

Cox, R.F.

1990-01-01

Some experiments in research reactors are arguably a risky undertaking due to their uncertain outcome. The justifications for such experiments require careful assessment to validate their undertaking. The public, the operators and the installation itself must be safeguarded. Assessment of the potential risk is an acquired skill but in doing so the route can be eased by learning from the lessons experience can teach. This paper, essentially for the usage of safety managers, sets out some of the issues relating to the assessment process gained from our experience over a few tens of years in the assessment of experiments. Many of the conclusions reached may appear all too obvious viewed in retrospect, but they were not necessarily clear at the time. Those organizations setting up assessment teams may find some of the conclusions of value such that their proposed management system can embrace methodologies for assessment that can avoid or lessen the impact of some of the pitfalls we have tried to identify. Failure to recognise some of these points may run the risk of delayed clearances, dilated timescales and cost overruns. It is in the hope of reducing all these penalties that we offer our experiences

Statistics and integral experiments in the verification of LOCA calculations models

International Nuclear Information System (INIS)

Margolis, S.G.

1978-01-01

The LOCA (loss of coolant accident) is a hypothesized, low-probability accident used as a licensing basis for nuclear power plants. Computer codes which have been under development for at least a decade have been the principal tools used to assess the consequences of the hypothesized LOCA. Models exist in two versions. In EM's (Evaluation Models) the basic engineering calculations are constrained by a detailed set of assumptions spelled out in the Code of Federal Regulations (10 CFR 50, Appendix K). In BE Models (Best Estimate Models) the calculations are based on fundamental physical laws and available empirical correlations. Evaluation models are intended to have a pessimistic bias; Best Estimate Models are intended to be unbiased. Because evaluation models play a key role in reactor licensing, they must be conservative. A long-sought objective has been to assess this conservatism by combining Best Estimate Models with statisticallly established error bounds, based on experiment. Within the last few years, an extensive international program of LOCA experiments has been established to provide the needed data. This program has already produced millions of measurements of temperature, density, and flow and millions of more measurements are yet to come

An example demonstrating the conservatism of pipe calculations using KTA safety standard 3201.2

International Nuclear Information System (INIS)

Zeitner, W.

1991-01-01

The conservatism of the code calculation is demonstrated by using an example of a highly stressed pipe subject to internal pressure and a dynamic bending moment. For this reason the allowable code loadings are compared with the load carrying capacity, which is derived by realistic analysis (plastic strains) and experiment. The latter analysis is based on measured stress-strain curves of materials and stresses at which crack initiation occurs. The experiment shows that the pipe is capable of withstanding considerably higher loads than the code permits. The realistic analysis explains this discrepancy. (orig.)

Developing and Strengthening of Safety Culture at Ukrainian NPPs: Experience of NNEGC “Energoatom”

International Nuclear Information System (INIS)

Sheyko, Y.; Kotin, P.

2016-01-01

, including: • Self evaluation of safety culture; • Questioning the staff; • Independent audits of safety culture. NAEC “Energoatom” seeks to take into account international experience, and to participate in conferences (such as this one), seminars and workshops held under the auspices of the IAEA, as well as to follow the guidelines and standards of the IAEA in the organization of activities to improve the safety culture. Other sources of international experience in this field are the EU-funded projects of “soft” assistance and guidance of other authorised international nuclear industry organizations such as WANO. In this regard, it should be mentioned WANO guidance document GL 2002-02 “Principles of effective personnel organization” that identifies five fundamental principles relating to human factors, and important for the development of a sustainable safety culture in the organization: • Even the best experts make mistakes; • A situation fraught with errors is predictable, manageable and preventable; • Human behavior is determined by organizational processes and values; • Highest efficiency operation is achieved through the promotion and support; • Violations can be avoided by understanding the causes of errors and implementing lessons learned. Within the framework of the international programs of EC “soft” aid in recent years, the projects that contribute to the development of a safety culture in the NAEC “Energoatom” have been either carried out or are ongoing. These projects include the solution of certain problems (for example, in the area of human factor—the task of “no punishment for error” approach establishment), as well as more common tasks of improving overall safety culture, such as: • Implementation of programs to inform senior staff and management, including the essential features needed to create a strong culture of safety; creating conditions for the improvement of the organizational and managerial impact on the

Calculations of Neutral Beam Ion Confinement for the National Spherical Torus Experiment

International Nuclear Information System (INIS)

Redi, M.H.; Darrow, D.S.; Egedal, J.; Kaye, S.M.; White, R.B.

2002-01-01

The spherical torus (ST) concept underlies several contemporary plasma physics experiments, in which relatively low magnetic fields, high plasma edge q, and low aspect ratio combine for potentially compact, high beta and high performance fusion reactors. An important issue for the ST is the calculation of energetic ion confinement, as large Larmor radius makes conventional guiding center codes of limited usefulness and efficient plasma heating by RF and neutral beam ion technology requires minimal fast ion losses. The National Spherical Torus Experiment (NSTX) is a medium-sized, low aspect ratio ST, with R=0.85 m, a=0.67 m, R/a=1.26, Ip*1.4 MA, Bt*0.6 T, 5 MW of neutral beam heating and 6 MW of RF heating. 80 keV neutral beam ions at tangency radii of 0.5, 0.6 and 0.7 m are routinely used to achieve plasma betas above 30%. Transport analyses for experiments on NSTX often exhibit a puzzling ion power balance. It will be necessary to have reliable beam ion calculations to distinguish among the source and loss channels, and to explore the possibilities for new physics phenomena, such as the recently proposed compressional Alfven eigenmode ion heating

Calculating Preference Weights for the Labor and Delivery Index: A Discrete Choice Experiment on Women’s Birth Experiences

NARCIS (Netherlands)

Gärtner, F.R.; Bekker-Grob, E.W. de; Stiggelbout, A.M.; Rijnders, M.E.; Freeman, L.M.; Middeldorp, J.M.; Bloemenkamp, K.W.; Miranda E. de; Akker-van Marle, M.E. van den

2015-01-01

Objective The aim of this study was to calculate preference weights for the Labor and Delivery Index (LADY-X) to make it suitable as a utility measure for perinatal care studies. Methods In an online discrete choice experiment, 18 pairs of hypothetical scenarios were presented to respondents, from

Large Scale Experiments on Spacecraft Fire Safety

DEFF Research Database (Denmark)

Urban, David L.; Ruff, Gary A.; Minster, Olivier

2012-01-01

-based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal-gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame......Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due...... to the complexity, cost and risk associ-ated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground...

Validation experiments of nuclear characteristics of the fast-thermal system HERBE

International Nuclear Information System (INIS)

Pesic, M.; Zavaljevski, N.; Marinkovic, P.; Stefanovis, D.; Nikolic, D.; Avdic, S.

1992-01-01

In 1988/90 a coupled fast-thermal system HERBE at RB reactor, based on similar facilities, is designed and realized. Fast core of HERBE is built of natural U fuel in RB reactor center surrounded by the neutron filter and neutron converter located in an independent Al tank. Fast zone is surrounded by thermal neutron core driver. Designed nuclear characteristics of HERBE core are validated in the experiments described in the paper. HERBE cell parameters were calculated with developed computer codes: VESNA and DENEB. HERBE system criticality calculation are performed with 4G 2D RZ computer codes GALER and TWENTY GRAND, 1D multi-group AVERY code and 3D XYZ few-group TRITON computer code. The experiments for determination of critical level, dρ/dH, and reactivity of safety rods are accomplished in order to validate calculation results. Specific safety experiment is performed in aim to determine reactivity of flooded fast zone in possible accident. A very good agreements with calculation results are obtained and the validation procedures are presented. It is expected that HERBE will offer qualitative new opportunities for work with fast neutrons at RB reactor including nuclear data determination. (author)

Nature-Based Strategies for Improving Urban Health and Safety.

Science.gov (United States)

Kondo, Michelle C; South, Eugenia C; Branas, Charles C

2015-10-01

Place-based programs are being noticed as key opportunities to prevent disease and promote public health and safety for populations at-large. As one key type of place-based intervention, nature-based and green space strategies can play an especially large role in improving health and safety for dwellers in urban environments such as US legacy cities that lack nature and greenery. In this paper, we describe the current understanding of place-based influences on public health and safety. We focus on nonchemical environmental factors, many of which are related to urban abandonment and blight. We then review findings from studies of nature-based interventions regarding impacts on health, perceptions of safety, and crime. Based on our findings, we suggest that further research in this area will require (1) refined measures of green space, nature, and health and safety for cities, (2) interdisciplinary science and cross-sector policy collaboration, (3) observational studies as well as randomized controlled experiments and natural experiments using appropriate spatial counterfactuals and mixed methods, and (4) return-on-investment calculations of potential economic, social, and health costs and benefits of urban greening initiatives.

Assessment of uncertainty in full core reactor physics calculations using statistical methods

International Nuclear Information System (INIS)

McEwan, C.

2012-01-01

The best estimate method of safety analysis involves choosing a realistic set of input parameters for a proposed safety case and evaluating the uncertainty in the results. Determining the uncertainty in code outputs remains a challenge and is the subject of a benchmarking exercise proposed by the Organization for Economic Cooperation and Development. The work proposed in this paper will contribute to this benchmark by assessing the uncertainty in a depletion calculation of the final nuclide concentrations for an experiment performed in the Fukushima-2 reactor. This will be done using lattice transport code DRAGON and a tool known as DINOSAUR. (author)

Assessment of uncertainty in full core reactor physics calculations using statistical methods

Energy Technology Data Exchange (ETDEWEB)

McEwan, C., E-mail: mcewac2@mcmaster.ca [McMaster Univ., Hamilton, Ontario (Canada)

2012-07-01

The best estimate method of safety analysis involves choosing a realistic set of input parameters for a proposed safety case and evaluating the uncertainty in the results. Determining the uncertainty in code outputs remains a challenge and is the subject of a benchmarking exercise proposed by the Organization for Economic Cooperation and Development. The work proposed in this paper will contribute to this benchmark by assessing the uncertainty in a depletion calculation of the final nuclide concentrations for an experiment performed in the Fukushima-2 reactor. This will be done using lattice transport code DRAGON and a tool known as DINOSAUR. (author)

Qualification of calculation aids for PSA

International Nuclear Information System (INIS)

Goetz, K.; Hennigs, W.; Kirstein, B.M.; Reinhardt, C.

1998-01-01

In Germany Probabilistic Safety Analysis (PSA) are part of the evaluation of a nuclear power plants safety. The German PSA guide stipulates that the used software must enable a PSA according to the state of the art. This software must be qualified to assure that its features, mathematic methods and its performance enable a PSA like this. In this research work specifications and requirements are developed, which allow the testing of software. A procedure was developed to qualify PSA software according to the PSA guide and the experiences of users of PSA. Setting up a procedure, a tool for a systematic and uniform examination was crated. Additionally the options, mathematic fundamentals and performance of PSA-programs were analyzed. According to this all programs that were analyzed are capable to sovle their original task, that is the calculation of the safety of high available system based on high available components. Against that the requirements of modern PSA, e.g. to handle less available functions, HRA and fire analyses, based on the use of modern software and the implementation of new developments in the field of PSA are not supported adequately by all programs. (orig.) [de

Integrated, digital experiment transient control and safety protection of an in-pile test

International Nuclear Information System (INIS)

Thomas, R.W.; Whitacre, R.F.; Klingler, W.B.

1982-01-01

The Sodium Loop Safety Facility experimental program has demonstrated that in-pile loop fuel failure transient tests can be digitally controlled and protected with reliability and precision. This was done in four nuclear experiments conducted in the Engineering Test Reactor operated by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory. Loop sodium flow and reactor power transients can be programmed to sponsor requirements and verified prior to the test. Each controller has redundancy, which reduces the effect of single failures occurring during test transients. Feedback and reject criteria are included in the reactor power control. Timed sequencing integrates the initiation of the controllers, programmed safety set-points, and other experiment actions (e.g., planned scram). Off-line and on-line testing is included. Loss-of-flow, loss-of-piping-integrity, boiling-window, transient-overpower, and local fault tests have been successfully run using this system

Application of the REMIX thermal mixing calculation program for the Loviisa reactor

International Nuclear Information System (INIS)

Kokkonen, I.; Tuomisto, H.

1987-08-01

The REMIX computer program has been validated to be used in the pressurized thermal shock study of the Loviisa reactor pressure vessel. The program has been verified against the data from the thermal and fluid mixing experiments. These experiments have been carried out in Imatran voima Oy to study thermal mixing of the high-pressure safety injection water in the Loviisa VVER-440 type pressurized water reactor. The verified REMIX-versions were applied to reactor calculations in the probabilistic pressurized thermal shock study of the Loviisa Plant

Safety analysis for research reactors

International Nuclear Information System (INIS)

2008-01-01

computational tools and presentation of the results of the analysis. It also discusses various factors that need to be considered to ensure that the safety analysis is of an acceptable quality. In specific terms, the calculations and methods in this report can be used for the safety analysis of newly designed research reactors, modifications and experiments with impact on safety, and upgrades of existing reactors, and can also be used for updating or reassessing previous safety analyses of operating research reactors. This publication will be particularly useful to organizations, safety analysts and reviewers in fulfilling regulatory requirements and recommendations related to the preparation of the safety analysis and its presentation in the safety analysis report. In addition, it will help regulators conduct safety reviews and assessments of the topics covered

WSRC approach to validation of criticality safety computer codes

International Nuclear Information System (INIS)

Finch, D.R.; Mincey, J.F.

1991-01-01

Recent hardware and operating system changes at Westinghouse Savannah River Site (WSRC) have necessitated review of the validation for JOSHUA criticality safety computer codes. As part of the planning for this effort, a policy for validation of JOSHUA and other criticality safety codes has been developed. This policy will be illustrated with the steps being taken at WSRC. The objective in validating a specific computational method is to reliably correlate its calculated neutron multiplication factor (K eff ) with known values over a well-defined set of neutronic conditions. Said another way, such correlations should be: (1) repeatable; (2) demonstrated with defined confidence; and (3) identify the range of neutronic conditions (area of applicability) for which the correlations are valid. The general approach to validation of computational methods at WSRC must encompass a large number of diverse types of fissile material processes in different operations. Special problems are presented in validating computational methods when very few experiments are available (such as for enriched uranium systems with principal second isotope 236 U). To cover all process conditions at WSRC, a broad validation approach has been used. Broad validation is based upon calculation of many experiments to span all possible ranges of reflection, nuclide concentrations, moderation ratios, etc. Narrow validation, in comparison, relies on calculations of a few experiments very near anticipated worst-case process conditions. The methods and problems of broad validation are discussed

[Towards a safety culture in the neonatal unit: Six years experience].

Science.gov (United States)

Esqué Ruiz, M T; Moretones Suñol, M G; Rodríguez Miguélez, J M; Parés Tercero, S; Cortés Albuixech, R; Varón Ramírez, E M; Figueras Aloy, J

2015-10-01

A safety culture is the collective effort of an institution to direct its resources toward the goal of safety. An analysis is performed on the six years of experience of the Committee on the Safety of Neonatal Patient. A mailbox was created for the declaration of adverse events, and measures for their correction were devised, such as case studies, continuous education, prevention of nosocomial infections, as well as information on the work done and its assessment. A total of 1287 reports of adverse events were received during the six years, of which 600 (50.8%) occurred in the neonatal ICU, with 15 (1.2%) contributing to death, and 1282 (99.6%) considered preventable. Simple corrective measures (notification, security alerts, etc.) were applied in 559 (43.4%), intermediate measures (protocols, monthly newsletter, etc.) in 692 (53.8%), and more complex measures (causal analysis, scripts, continuous education seminars, prospective studies, etc.) in 66 (5.1%). As regards nosocomial infections, the prevention strategies implemented (hand washing, insertion and maintenance of catheters) directly affected their improvement. Two surveys were conducted to determine the level of satisfaction with the Committee on the Safety of Neonatal Patient. A rating 7.5/10 was obtained in the local survey, while using the Spanish version of the Hospital Survey on Patient Safety Culture the rate was 7.26/10. A path to a culture of safety has been successfully started and carried out. Reporting the adverse events is the key to obtaining information on their nature, etiology and evolution, and to undertake possible prevention strategies. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

Accomplishment of 10-year research in NUCEF and future development. Criticality safety research

International Nuclear Information System (INIS)

Miyoshi, Yoshinori

2005-01-01

Since 1995, static and transient critical experiments on low enriched uranyl nitrate solution have been performed using two solution type criticality facilities, STACY and TRACY constructed in NUCEF. The obtained fundamental and systematic data on aqueous solution were used to validate the criticality safety calculation codes and to develop the transient analyses codes for criticality accident evaluation. This paper describes the outline of the criticality safety research conducted in NUCEF. (author)

Operational safety performance indicator system at the Dukovany Nuclear Power Plant - Experience with indicator aggregation

International Nuclear Information System (INIS)

Mandula, J.

2001-01-01

The operational safety performance indicators serve as an important tool of performance monitoring and management at the Dukovany NPP. A software-supported system has been developed, which has included: data collection, central data storage, graphic output production and periodical report generation. Analyses of performance indicator trends together with evaluation in respect of annually updated target values and acceptance criteria are used for operational safety reviews forming an integral part of continual self-assessment process. This contribution has been focused on experience obtained during development of the operational safety assessment model using indicator aggregation. It summarises problems that had to be paid specific attention in the development process. Thanks to their solution, the model has become a synoptic monitor and a useful tool for operational safety assessment. (author)

Influence of delayed neutron parameter calculation accuracy on results of modeled WWER scram experiments

International Nuclear Information System (INIS)

Artemov, V.G.; Gusev, V.I.; Zinatullin, R.E.; Karpov, A.S.

2007-01-01

Using modeled WWER cram rod drop experiments, performed at the Rostov NPP, as an example, the influence of delayed neutron parameters on the modeling results was investigated. The delayed neutron parameter values were taken from both domestic and foreign nuclear databases. Numerical modeling was carried out on the basis of SAPFIR 9 5andWWERrogram package. Parameters of delayed neutrons were acquired from ENDF/B-VI and BNAB-78 validated data files. It was demonstrated that using delay fraction data from different databases in reactivity meters led to significantly different reactivity results. Based on the results of numerically modeled experiments, delayed neutron parameters providing the best agreement between calculated and measured data were selected and recommended for use in reactor calculations (Authors)

Safety evaluation by living probabilistic safety assessment. Procedures and applications for planning of operational activities and analysis of operating experience

International Nuclear Information System (INIS)

Johanson, Gunnar; Holmberg, J.

1994-01-01

Living Probabilistic Safety Assessment (PSA) is a daily safety management system and it is based on a plant-specific PSA and supporting information systems. In the living use of PSA, plant status knowledge is used to represent actual plant safety status in monitoring or follow-up perspective. The PSA model must be able to express the risk at a given time and plant configuration. The process, to update the PSA model to represent the current or planned configuration and to use the model to evaluate and direct the changes in the configuration, is called living PSA programme. The main purposes to develop and increase the usefulness of living PSA are: Long term safety planning: To continue the risk assessment process started with the basic PSA by extending and improving the basic models and data to provide a general risk evaluation tool for analyzing the safety effects of changes in plant design and procedures. Risk planning of operational activities: To support the operational management by providing means for searching optimal operational maintenance and testing strategies from the safety point of view. The results provide support for risk decision making in the short term or in a planning mode. The operational limits and conditions given by technical specifications can be analyzed by evaluating the risk effects of alternative requirements in order to balance the requirements with respect to operational flexibility and plant economy. Risk analysis of operating experience: To provide a general risk evaluation tool for analyzing the safety effects of incidents and plant status changes. The analyses are used to: identify possible high risk situations, rank the occurred events from safety point of view, and get feedback from operational events for the identification of risk contributors. This report describes the methods, models and applications required to continue the process towards a living use of PSA. 19 tabs, 20 figs

10 CFR 70.62 - Safety program and integrated safety analysis.

Science.gov (United States)

2010-01-01

...; (iv) Potential accident sequences caused by process deviations or other events internal to the... have experience in nuclear criticality safety, radiation safety, fire safety, and chemical process... this safety program; namely, process safety information, integrated safety analysis, and management...

Engineering Judgment and Natural Circulation Calculations

International Nuclear Information System (INIS)

Ferreri, J.C.; Ferreri, J.C.

2011-01-01

The analysis performed to establish the validity of computer code results in the particular field of natural circulation flow stability calculations is presented in the light of usual engineering practice. The effects of discretization and closure correlations are discussed and some hints to avoid undesired mistakes in the evaluations performed are given. Additionally, the results are presented for an experiment relevant to the way in which a (small) number of skilled, nuclear safety analysts and researchers react when facing the solution of a natural circulation problem. These results may be also framed in the concept of Engineering Judgment and are potentially useful for Knowledge Management activities.

Regulatory Experience of the Embedded Digital Devices for Safety I and C Systems on Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. M.; Lee, H. K.; Park, H. S. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2016-10-15

Conventional I and C(Instrumentation and Control) systems are tend to becoming unavailable and being replaced by smart equipment. These smart equipment is usually called embedded digital devices (EDDs) or industrial digital devices of limited functionality. Usually, some of these devices are found embedded in plant equipment such as sensing instrumentation, motors, pumps, actuators and breakers. They typically have a micro-processor, RAM, communication interface, a power source, etc. The U.S. Nuclear Regulatory Commission (US NRC) is concerning that these EDDs might exist in procured equipment used in safety systems without the devices having been explicitly identified in procurement documentation. This paper addresses the regulatory experiences of KINS of the EDDs for safety I and C systems and the future works for them. In this paper, we showed regulatory experiences of EDDs which used for safety grade equipment. EDDs might exist in safety grade procured equipment without explicit identification. Undetected defects of EDDs might be the potential safety concerns. EDDs should meet certain specific requirements in order to be selected and used in safety I and C system. We have plan to develop technical positions for identification and qualifying them. The technical position will address, but may not be limited to, quality and reliability, CCFs via software errors, EMC, and CGID for EDDs.

Mathematical calculation skills required for drug administration in undergraduate nursing students to ensure patient safety: A descriptive study: Drug calculation skills in nursing students.

Science.gov (United States)

Bagnasco, Annamaria; Galaverna, Lucia; Aleo, Giuseppe; Grugnetti, Anna Maria; Rosa, Francesca; Sasso, Loredana

2016-01-01

In the literature we found many studies that confirmed our concerns about nursing students' poor maths skills that directly impact on their ability to correctly calculate drug dosages with very serious consequences for patient safety. The aim of our study was to explore where students had most difficulty and identify appropriate educational interventions to bridge their mathematical knowledge gaps. This was a quali-quantitative descriptive study that included a sample of 726 undergraduate nursing students. We identified exactly where students had most difficulty and identified appropriate educational interventions to bridge their mathematical knowledge gaps. We found that the undergraduate nursing students mainly had difficulty with basic maths principles. Specific learning interventions are needed to improve their basic maths skills and their dosage calculation skills. For this purpose, we identified safeMedicate and eDose (Authentic World Ltd.), only that they are only available in English. In the near future we hope to set up a partnership to work together on the Italian version of these tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Calculation of Flooding Level using CFX Code

International Nuclear Information System (INIS)

Oh, Seo Bin; Kim, Keon Yeop; Lee, Hyung Ho

2015-01-01

The plant design should consider internal flooding by postulated pipe ruptures, component failures, actuation of spray systems, and improper system alignment. The flooding causes failure of safety-related equipment and affects the integrity of the structure. The safety-related equipment should be installed above the flood level for protection against flooding effects. Conservative estimates of the flood level are important when a DBA occurs. The flooding level can be calculated simply applying Bernoulli's equation. However, in this study, a realistic calculation is performed with ANSYS CFX code. In calculation with CFX, air-core vortex phenomena, and turbulent flow can be simulated, which cannot be calculated analytically. The flooding level is evaluated by analytical calculation and CFX analysis for an assumed condition. The flood level is calculated as 0.71m and 1.1m analytically and with CFX simulation, respectively. Comparing the analytical calculation and simulation, they are similar, but the analytical calculation is not conservative. There are many factors reducing the drainage capacity such as air-core vortex, intake of air, and turbulent flow. Therefore, in case of flood level evaluation by analytical calculation, a sufficient safety margin should be considered

Parameters calculation of a shielding experiment and evaluation of calculation methodology

International Nuclear Information System (INIS)

Gavazza, S.; Otto, A.C.; Gomes, I.C.; Maiorino, J.R.

1986-01-01

In this text is carried out the evaluation of radiation transport methodology, comparying the calculated reactions and dose rates, for neutrons and gamma-rays, with the experimental measurements obtained on iron shield, irradiated in YAYOI reactor. Were employed the ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system for generation of cross sections, collapsed by the ANISN code. The transport calculation were made by using the DOT 3.5 code, adjusting the spectrum of the iron shield boundary source to the reactions and dose rates, measured at the beginning of shield. The distributions calculated for neutrons and gamma-rays, on iron shield, presented coherence with the experimental measurements. (Author) [pt

Probabilistic Safety Goals. Phase 1 Status and Experiences in Sweden and Finland

International Nuclear Information System (INIS)

Holmberg, Jan-Erik; Knochenhauer, Michael

2007-02-01

The outcome of a probabilistic safety assessment (PSA) for a nuclear power plant is a combination of qualitative and quantitative results. Quantitative results are typically presented as the Core Damage Frequency (CDF) and as the frequency of an unacceptable radioactive release. In order to judge the acceptability of PSA results, criteria for the interpretation of results and the assessment of their acceptability need to be defined. Ultimately, the goals are intended to define an acceptable level of risk from the operation of a nuclear facility. However, safety goals usually have a dual function, i.e., they define an acceptable safety level, but they also have a wider and more general use as decision criteria. The exact levels of the safety goals differ between organisations and between different countries. There are also differences in the definition of the safety goal, and in the formal status of the goals, i.e., whether they are mandatory or not. In this first phase of the project, the aim has been on providing a clear description of the issue of probabilistic safety goals for nuclear power plants, to define and describe important concepts related to the definition and application of safety goals, and to describe experiences in Finland and Sweden. Based on a series of interviews and on literature reviews as well as on a limited international over-view, the project has described the history and current status of safety goals in Sweden and Finland, and elaborated on a number of issues, including the following: The status of the safety goals in view of the fact that they have been exceeded for much of the time they have been in use, as well as the possible implications of these exceedances. Safety goals as informal or mandatory limits. Strategies for handling violations of safety goals, including various graded approaches, such as ALARP (As Low As Reasonably Practicable). Relation between safety goals defined on different levels, e.g., for core damage and for

Probabilistic safety goals. Phase 1 - Status and experiences in Sweden and Finland

International Nuclear Information System (INIS)

Holmberg, J.E.; Knochenhauer, M.

2007-03-01

The outcome of a probabilistic safety assessment (PSA) for a nuclear power plant is a combination of qualitative and quantitative results. Quantitative results are typically presented as the Core Damage Frequency (CDF) and as the frequency of an unacceptable radioactive release. In order to judge the acceptability of PSA results, criteria for the interpretation of results and the assessment of their acceptability need to be defined. Ultimately, the goals are intended to define an acceptable level of risk from the operation of a nuclear facility. However, safety goals usually have a dual function, i.e., they define an acceptable safety level, but they also have a wider and more general use as decision criteria. The exact levels of the safety goals differ between organisations and between different countries. There are also differences in the definition of the safety goal, and in the formal status of the goals, i.e., whether they are mandatory or not. In this first phase of the project, the aim has been on providing a clear description of the issue of probabilistic safety goals for nuclear power plants, to define and describe important concepts related to the definition and application of safety goals, and to describe experiences in Finland and Sweden. Based on a series of interviews and on literature reviews as well as on a limited international over-view, the project has described the history and current status of safety goals in Sweden and Finland, and elaborated on a number of issues, including the following: 1) The status of the safety goals in view of the fact that they have been exceeded for much of the time they have been in use, as well as the possible implications of these exceedances. 2) Safety goals as informal or mandatory limits. 3) Strategies for handling violations of safety goals, including various graded approaches, such as ALARP (As Low As Reasonably Practicable). 4) Relation between safety goals defined on different levels, e.g., for core damage

Probabilistic Safety Goals. Phase 1 Status and Experiences in Sweden and Finland

Energy Technology Data Exchange (ETDEWEB)

Holmberg, Jan-Erik (VTT, FI-02044 VTT (Finland)); Knochenhauer, Michael (Relcon Scandpower AB, SE-172 25 Sundbyberg (Sweden))

2007-02-15

The outcome of a probabilistic safety assessment (PSA) for a nuclear power plant is a combination of qualitative and quantitative results. Quantitative results are typically presented as the Core Damage Frequency (CDF) and as the frequency of an unacceptable radioactive release. In order to judge the acceptability of PSA results, criteria for the interpretation of results and the assessment of their acceptability need to be defined. Ultimately, the goals are intended to define an acceptable level of risk from the operation of a nuclear facility. However, safety goals usually have a dual function, i.e., they define an acceptable safety level, but they also have a wider and more general use as decision criteria. The exact levels of the safety goals differ between organisations and between different countries. There are also differences in the definition of the safety goal, and in the formal status of the goals, i.e., whether they are mandatory or not. In this first phase of the project, the aim has been on providing a clear description of the issue of probabilistic safety goals for nuclear power plants, to define and describe important concepts related to the definition and application of safety goals, and to describe experiences in Finland and Sweden. Based on a series of interviews and on literature reviews as well as on a limited international over-view, the project has described the history and current status of safety goals in Sweden and Finland, and elaborated on a number of issues, including the following: The status of the safety goals in view of the fact that they have been exceeded for much of the time they have been in use, as well as the possible implications of these exceedances. Safety goals as informal or mandatory limits. Strategies for handling violations of safety goals, including various graded approaches, such as ALARP (As Low As Reasonably Practicable). Relation between safety goals defined on different levels, e.g., for core damage and for

Probabilistic safety goals. Phase 1 - Status and experiences in Sweden and Finland

Energy Technology Data Exchange (ETDEWEB)

Holmberg, J.E. [VTT (Finland); Knochenhauer, M. [Relcon Scandpower AB (Sweden)

2007-03-15

The outcome of a probabilistic safety assessment (PSA) for a nuclear power plant is a combination of qualitative and quantitative results. Quantitative results are typically presented as the Core Damage Frequency (CDF) and as the frequency of an unacceptable radioactive release. In order to judge the acceptability of PSA results, criteria for the interpretation of results and the assessment of their acceptability need to be defined. Ultimately, the goals are intended to define an acceptable level of risk from the operation of a nuclear facility. However, safety goals usually have a dual function, i.e., they define an acceptable safety level, but they also have a wider and more general use as decision criteria. The exact levels of the safety goals differ between organisations and between different countries. There are also differences in the definition of the safety goal, and in the formal status of the goals, i.e., whether they are mandatory or not. In this first phase of the project, the aim has been on providing a clear description of the issue of probabilistic safety goals for nuclear power plants, to define and describe important concepts related to the definition and application of safety goals, and to describe experiences in Finland and Sweden. Based on a series of interviews and on literature reviews as well as on a limited international over-view, the project has described the history and current status of safety goals in Sweden and Finland, and elaborated on a number of issues, including the following: 1) The status of the safety goals in view of the fact that they have been exceeded for much of the time they have been in use, as well as the possible implications of these exceedances. 2) Safety goals as informal or mandatory limits. 3) Strategies for handling violations of safety goals, including various graded approaches, such as ALARP (As Low As Reasonably Practicable). 4) Relation between safety goals defined on different levels, e.g., for core damage

Analysis of ATLAS FLB-EC6 Experiment using SPACE Code

International Nuclear Information System (INIS)

Lee, Donghyuk; Kim, Yohan; Kim, Seyun

2013-01-01

The new code is named SPACE(Safety and Performance Analysis Code for Nuclear Power Plant). As a part of code validation effort, simulation of ATLAS FLB(Feedwater Line Break) experiment using SPACE code has been performed. The FLB-EC6 experiment is economizer break of a main feedwater line. The calculated results using the SPACE code are compared with those from the experiment. The ATLAS FLB-EC6 experiment, which is economizer feedwater line break, was simulated using the SPACE code. The calculated results were compared with those from the experiment. The comparisons of break flow rate and steam generator water level show good agreement with the experiment. The SPACE code is capable of predicting physical phenomena occurring during ATLAS FLB-EC6 experiment

Industry use of operating experience to achieve improved nuclear plant safety

International Nuclear Information System (INIS)

Zebroski, E.L.

1981-01-01

A principal lesson drawn from the accident at Three Mile Island was the need for a comprehensive and rigorous system for analysis and feedback of operating experience to reactor operators. Chief executives of US utilities directed in mid-1979 that an intensive and rigorous system of analysis and feedback of operating experience be established. This system is commonly referred to as the ''Significant Events Program''. Since April 1980, the Nuclear Safety Analysis Center (NSAC) has been joined by the Institute for Nuclear Power Operations (INPO) in the field investigation of significant operating events. NSAC has responsibility for analysis of the design and physical events aspects, while INPO has primary responsibility for the operators' aspects, including procedures and training. The process of screening, analysis and feedback of operating experience is now functioning as a seven-step process. A variety of data sources is used, including License Event Reports and outage and major maintenance reports. These are compiled and indexed in convenient form. However, such data bases are used only as incidental tools for the basic investigations and analytical efforts. Rapid dissemination of results is provided by a computer-aided conferencing system, which links 70 operating LWR reactors in the USA, and which has now been extended to four utilities outside the USA, representing several dozen more reactors. Major safety and economic incentives are evident for the rigorous use of such operating experience and for participation in a comprehensive system. Traditional habits of secrecy are recognized as obstacles to timely communication. A principal responsibility of top management of reactor-operating organizations is to overcome such habits where they are counter to the public interest, as well as to the health and survival interest of the utility itself

Validation of the EIR LWR calculation methods for criticality assessment of storage pools

International Nuclear Information System (INIS)

Grimm, P.; Paratte, J.M.

1986-11-01

The EIR code system for the calculation of light water reactors is presented and the methods used are briefly described. The application of the system to various types of critical experiments and benchmark problems proves its good accuracy, even for heterogeneous configurations containing strong neutron absorbers such as Boral. Since the multiplication factor k eff is normally somewhat overpredicted and the spread of the results is small, this code system is validated for the calculation of storage pools, taking into account a safety margins of 1.5% on k eff . (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-10-01

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

Full scale reactor safety experiments performed in the Marviken Power Station Sweden

International Nuclear Information System (INIS)

Thoren, H.G.; Ericson, L.

1977-01-01

Since 1972 experiments oriented towards increasing the understanding of reactor safety processes have been performed at the Marviken Power Station. This was originally built as a direct cycle BHWR but was never taken into nuclear operation. In addition to Sweden, the countries represented in these experiments are Denmark, the Federal Republic of Germany, Finland, Norway, the United States, the Netherlands, France and Japan. The first series of sixteen experiments included studies of the response of the PS-containment to simulated ruptures in the pipe systems that are connected to the pressure vessel. These tests were completed in 1973 and also included experimental studies of iodine transport, containment leakage, the behaviour of auxiliary components under accident conditions and pressure fluctuations in the wetwell water pool. One of the more essential findings of the tests was that the containment performance was in accordance with the pre-test calculations. A second series of eight blowdown tests was begun in February 1976. The main purpose of these tests is to provide additional information as to the characteristics of the pressure oscillations inside the containment and primarily in the wetwell water pool under different conditions. These oscillations were observed in the first series of blowdowns but only low frequencies could then be detected due to limitations in the measurement system. The measurement system was therefore substantially extended for this second series of experiments. A summary of the results from these two sets of blowdown tests are given in the paper. In 1976 preparations for a new test program were initiated. The objective of these tests is to improve the understanding of critical flow in the low quality and subcooled flow regions through short length, large diameter pipes. Extensive modifications of the test facility will be necessary in order to allow a discharge flow through openings which are up to 500 mm in diameter. Advanced plans

Safety culture : a significant influence on safety in transportation

Science.gov (United States)

2017-08-01

An organizations safety culture can influence safety outcomes. Research and experience show that when safety culture is strong, accidents are less frequent and less severe. As a result, building and maintaining strong safety cultures should be a t...

Specification of materials Data for Fire Safety Calculations based on ENV 1992-1-2

DEFF Research Database (Denmark)

Hertz, Kristian Dahl

1997-01-01

of constructions of any concrete exposed to any time of any fire exposure can be calculated.Chapter 4.4 provides information on what should be observed if more general calculation methods are used.Annex A provides some additional information on materials data. This chapter is not a part of the code......The part 1-2 of the Eurocode on Concrete deals with Structural Fire Design.In chapter 3, which is partly written by the author of this paper, some data are given for the development of a few material parameters at high temperatures. These data are intended to represent the worst possible concrete...... to experience form tests on structural specimens based on German siliceous concrete subjected to Standard fire exposure until the time of maximum gas temperature.Chapter 4.3, which is written by the author of this paper, provides a simplified calculation method by means of which the load bearing capacity...

Organization and Nuclear Safety: Safety culture

International Nuclear Information System (INIS)

Martin Marquinez, A.

1998-01-01

This book presents the experience in nuclear safety and its influence in the exploitation on nuclear power plants. The safety organization and quality management before and after Chernobylsk and three mile island accidents

Safety assessment of Novi Han radioactive waste repository - features, problems, results and perspectives

International Nuclear Information System (INIS)

Mateeva, M.

2000-01-01

This paper summarizes the work done and the achievements reached in the Novi Han radioactive waste repository safety assessment within the IAEA Model Project 'Increasing the safety of Novi Han radioactive waste repository BUL 4/005'. The overall safety assessment has a wide context, but the work reported here relates only to some details and results concerning the development and implementation of the appropriate methodology approach, model and computer code used for the calculations. Different steps and procedures are included for a better practical understanding of the obtained results during the safety assessment performance. The methodology approach is widely based on an international experience in safety analysis and implemented for evaluation computer code AMBER, which is one of the recommended from the safety assessments experts. (author)

Criticality calculations for safety analysis

International Nuclear Information System (INIS)

Vellozo, S.O.

1981-01-01

Criticality studies in uranium nitrate and plutonium nitrate aqueous solutions were done. For uranium compound three basic computer codes are used: GAMTEC-II, DTF-IV, KENO-IV. Water was used as refletor and the results obtained with the different computer codes were analyzed and compared with the 'Handbuck zur Kriticalitat'. The cross sections and the cylindrical geometry were generated by Gamtec-II computer code. In the second compound the thickness of the recipient with plutonium nitrate are used with rectangular geometry and concret reflector. The effective multiplication constant was calculated with the Gamtec-II and Keno-IV library. The results show many differences. (E.G) [pt

Improving the international system for operating experience feedback. INSAG-23. A report by the International Nuclear Safety Group

International Nuclear Information System (INIS)

2008-01-01

The operational safety performance of nuclear facilities has, in general, improved notably over time throughout the world. This has been achieved, in part, through operating experience feedback (OEF) and the introduction of new technology. While the continued strong safety performance by operators is encouraging, safety significant events continue to recur in nuclear installations. This indicates that operators are not learning and applying the lessons that experience can teach us. This report focuses on systems that are operated by intergovernmental organizations with close contacts to national regulatory authorities. These systems provide an alternative network to the worldwide system employed by the operators of nuclear facilities known as the World Association of Nuclear Operators (WANO). The WANO system is restricted to its members, who have concluded that keeping the information exchanged confidential improves its usefulness. INSAG recognizes the merits of this approach, particularly in light of the primary responsibility of licensed operators for the safety of their facilities. Nevertheless, INSAG encourages WANO to share key safety lessons with national regulatory authorities and intergovernmental organization

Alize 3 - first critical experiment for the franco-german high flux reactor - calculations

International Nuclear Information System (INIS)

Scharmer, K.

1969-01-01

The results of experiments in the light water cooled D 2 O reflected critical assembly ALIZE III have been compared to calculations. A diffusion model was used with 3 fast and epithermal groups and two overlapping thermal groups, which leads to good agreement of calculated and measured power maps, even in the case of strong variations of the neutron spectrum in the core. The difference of calculated and measured k eff was smaller than 0.5 per cent δk/k. Calculations of void and structure material coefficients of the reactivity of 'black' rods in the reflector, of spectrum variations (Cd-ratio, Pu-U-ratio) and to the delayed photoneutron fraction in the D 2 O reflector were made. Measurements of the influence of beam tubes on reactivity and flux distribution in the reflector were interpreted with regard to an optimum beam tube arrangement for the Franco- German High Flux Reactor. (author) [fr

The calculation and experiment verification of geometry factors of disk sources and detectors

International Nuclear Information System (INIS)

Shi Zhixia; Minowa, Y.

1993-01-01

In alpha counting the efficiency of counting system is most frequently determined from the counter response to a calibrated source. Whenever this procedure is used, however, question invariably arise as to the integrity of the standard source, or indeed the validity of the primary calibration. As a check, therefore, it is often helped to be able to calculate the disintegration rate from counting rate data. The conclusion are: 1. If the source is thin enough the error E is generally less than 5%. It is acceptable in routine measurement. When the standard source lacks for experiment we can use the geometry factor calculated instead of measured efficiency. 2. The geometry factor calculated can be used to correct the counter system, study the effect of each parameters and identify those parameters needing careful control. 3. The method of overlapping area of the source and the projection of the detector is very believable, simple and convenient for calculating geometry. (5 tabs.)

Nuclear Criticality Safety Assessment Using the SCALE Computer Code Package. A demonstration based on an independent review of a real application

International Nuclear Information System (INIS)

Mennerdahl, Dennis

1998-06-01

The purpose of this project was to instruct a young scientist from the Lithuanian Energy Institute (LEI) on how to carry out an independent review of a safety report. In particular, emphasis, was to be put on how to use the personal computer version of the calculation system SCALE 4.3 in this process. Nuclear criticality safety together with radiation shielding from gamma and neutron sources were areas of interest. This report concentrates on nuclear criticality safety aspects while a separate report covers radiation shielding. The application was a proposed storage cask for irradiated fuel assemblies from the Ignalina RBMK reactors in Lithuania. The safety report contained various documents involving many design and safety considerations. A few other documents describing the Ignalina reactors and their operation were available. The time for the project was limited to approximately one month, starting 'clean' with a SCALE 4.3 CD-ROM, a thick safety report and a fast personal computer. The results should be of general interest to Swedish authorities, in particular related to shielding where experience in using advanced computer codes like those available in SCALE is limited. It has been known for many years that criticality safety is very complicated, and that independent reviews are absolutely necessary to reduce the risk from quite common errors in the safety assessments. Several important results were obtained during the project. Concerning use of SCALE 4.3, it was confirmed that a young scientist, without extensive previous experience in the code system, can learn to use essentially all options. During the project, it was obvious that familiarity with personal computers, operating systems (including network system) and office software (word processing, spreadsheet and Internet browser software) saved a lot of time. Some of the Monte Carlo calculations took several hours. Experience is valuable in quickly picking out input or source document errors. Understanding

Comparison of MCNP calculations against measurements in moderator temperature experiments with CANFLEX-LEU in ZED-2

International Nuclear Information System (INIS)

Watts, D.G.; Adams, F.P.; Zeller, M.B.; Bromley, B.P.

2008-01-01

This paper summarizes sample calculations of MCNP5 compared against measurements of moderator temperature coefficient experiments in the ZED-2 critical facility with CANFLEX-LEU fuel. MCNP5 is tested for key parameters associated with various reactor physics phenomena of interest for CANDU/ACR-1000) reactors, including reactivity changes with coolant density, moderator density, and moderator temperature, and also normalized flux distributions. The experimental data for these comparisons were obtained from critical experiments in AECL's ZED-2 critical facility using CANFLEX-LEU fuel in a 24-cm square lattice pitch. These comparisons establish biases/uncertainties in the calculation of k-eff, coolant void reactivity, and moderator temperature coefficient of reactivity. Results show very little bias in the moderator temperature coefficient of reactivity, and very good agreement in the calculation of normalized flux distributions. (author)

Identifying patient-centred recommendations for improving patient safety in General Practices in England: a qualitative content analysis of free-text responses using the Patient Reported Experiences and Outcomes of Safety in Primary Care (PREOS-PC) questionnaire.

Science.gov (United States)

Ricci-Cabello, Ignacio; Saletti-Cuesta, Lorena; Slight, Sarah P; Valderas, Jose M

2017-10-01

There is a growing interest in identifying strategies to achieve safer primary health-care provision. However, most of the research conducted so far in this area relies on information supplied by health-care providers, and limited attention has been paid to patients' perspectives. To explore patients' experiences and perceptions of patient safety in English general practices with the aim of eliciting patient-centred recommendations for improving patient safety. The Patient Reported Experiences and Outcomes of Safety in Primary Care questionnaire was sent to a random sample of 6736 primary care users registered in 45 English practices. We conducted a qualitative content analysis of responses to seven open-ended items addressing patients' experiences of safety problems, lessons learnt as a result of such experiences and recommendations for safer health care. A total of 1244 (18.4%) participants returned completed questionnaires. Of those, 678 (54.5%) responded to at least one open-ended question. Two main themes emerged as follows: (i) experiences of safety problems and (ii) good practices and recommendations to improve patient safety in primary care. Most frequent experiences of safety problems were related to appointments, coordination between providers, tests, medication and diagnosis. Patients' responses to these problems included increased patient activation (eg speaking up about concerns with their health care) and avoidance of unnecessary health care. Recommendations for safer health care included improvements in patient-centred communication, continuity of care, timely appointments, technical quality of care, active monitoring, teamwork, health records and practice environment. This study identified a number of patient-centred recommendations for improving patient safety in English general practices. © 2017 The Authors Health Expectations Published by John Wiley & Sons Ltd.

Shielding repair of N.S. Mutsu and related safety features

International Nuclear Information System (INIS)

Kishimoto, K.; Miyakoshi, J.

1978-01-01

The abnormal radiation level observed on the upper deck of N.S. Mutsu was caused by neutrons streaming through an annular air gap between the reactor pressure vessel and the primary shield. In order to lower this level, a modification of shielding has been planned, for which a shielding mock-up experiment was carried. The foregoing modifications brought some change to the expected behavior of the reactor plant under ship accident situations, and studies were performed to verify plant safety, such as calculations to determine containment vessel integrity and decay heat removal after sinking, and calculations supported by experiment to ascertain the structural strength of the double bottom upon stranding of the ship

Loading, absorption, and Fokker-Planck calculations for upcoming ICRF experiments on ATF

International Nuclear Information System (INIS)

Shepard, T.D.; Carter, M.D.; Goulding, R.H.; Kwon, M.

1989-01-01

ICRF experiments on ATF at the 100-kW level are planned for the current 1989 operating period. These plans include the 2ω/sub cH/ regime at f/sub RF/ = 28.88 MHz, D(H) at 14.44 MHz, and 4 He( 3 He) and D( 3 He) at 9.63 MHz. ECH target plasmas have n/sub eO/ /approxreverse arrowlt/ 0.15 /times/ 10 20 m/sup /minus/3/ and B = 0.95 T. The density and temperature profiles obtained are broader than those from 1988, owing to recent field error corrections. The values used for target-plasma parameters in the calculations were taken from initial 1989 ATF data. Loading and absorption calculations have been performed using the 3D RF heating code ORION with a helically symmetric equilibrium, and Fokker-Planck calculations were performed using the steady-state code RFTRANS with two velocity dimensions and one spatial dimension. 6 refs., 3 figs

Calculation of combustible waste fraction (CWF) estimates used in organics safety issue screening

International Nuclear Information System (INIS)

Heasler, P.G.; Gao, F.; Toth, J.J.

1998-08-01

This report describes how in-tank measurements of moisture (H 2 O) and total organic carbon (TOC) are used to calculate combustible waste fractions (CWF) for 138 of the 149 Hanford single shell tanks. The combustible waste fraction of a tank is defined as that proportion of waste that is capable of burning when exposed to an ignition source. These CWF estimates are used to screen tanks for the organics complexant safety issue. Tanks with a suitably low fraction of combustible waste are classified as safe. The calculations in this report determine the combustible waste fractions in tanks under two different moisture conditions: under current moisture conditions, and after complete dry out. The first fraction is called the wet combustible waste fraction (wet CWF) and the second is called the dry combustible waste fraction (dry CWF). These two fractions are used to screen tanks into three categories: if the wet CWF is too high (above 5%), the tank is categorized as unsafe; if the wet CWF is low but the dry CWF is too high (again, above 5%), the tank is categorized as conditionally safe; finally, if both the wet and dry CWF are low, the tank is categorized as safe. Section 2 describes the data that was required for these calculations. Sections 3 and 4 describe the statistical model and resulting fit for dry combustible waste fractions. Sections 5 and 6 present the statistical model used to estimate wet CWF and the resulting fit. Section 7 describes two tests that were performed on the dry combustible waste fraction ANOVA model to validate it. Finally, Section 8 presents concluding remarks. Two Appendices present results on a tank-by-tank basis

SFR Safety Considerations

International Nuclear Information System (INIS)

Glatz, Jean-Paul

2012-01-01

Objectives of the Safety and Operation Project: • analysis and experiments that support approaches and assess performance of specific safety features, • development and verification of computational tools and validation of models employed in safety assessment and facility licensing, and • valorisation of reactor operation, from experience and testing in operating SFR plants

A pedestal temperature model with self-consistent calculation of safety factor and magnetic shear

International Nuclear Information System (INIS)

Onjun, T; Siriburanon, T; Onjun, O

2008-01-01

A pedestal model based on theory-motivated models for the pedestal width and the pedestal pressure gradient is developed for the temperature at the top of the H-mode pedestal. The pedestal width model based on magnetic shear and flow shear stabilization is used in this study, where the pedestal pressure gradient is assumed to be limited by first stability of infinite n ballooning mode instability. This pedestal model is implemented in the 1.5D BALDUR integrated predictive modeling code, where the safety factor and magnetic shear are solved self-consistently in both core and pedestal regions. With the self-consistently approach for calculating safety factor and magnetic shear, the effect of bootstrap current can be correctly included in the pedestal model. The pedestal model is used to provide the boundary conditions in the simulations and the Multi-mode core transport model is used to describe the core transport. This new integrated modeling procedure of the BALDUR code is used to predict the temperature and density profiles of 26 H-mode discharges. Simulations are carried out for 13 discharges in the Joint European Torus and 13 discharges in the DIII-D tokamak. The average root-mean-square deviation between experimental data and the predicted profiles of the temperature and the density, normalized by their central values, is found to be about 14%

Conducting organizational safety reviews - requirements, methods and experience

International Nuclear Information System (INIS)

Reiman, T.; Oedewald, P.; Wahlstroem, B.; Rollenhagen, C.; Kahlbom, U.

2008-03-01

Organizational safety reviews are part of the safety management process of power plants. They are typically performed after major reorganizations, significant incidents or according to specified review programs. Organizational reviews can also be a part of a benchmarking between organizations that aims to improve work practices. Thus, they are important instruments in proactive safety management and safety culture. Most methods that have been used for organizational reviews are based more on practical considerations than a sound scientific theory of how various organizational or technical issues influence safety. Review practices and methods also vary considerably. The objective of this research is to promote understanding on approaches used in organizational safety reviews as well as to initiate discussion on criteria and methods of organizational assessment. The research identified a set of issues that need to be taken into account when planning and conducting organizational safety reviews. Examples of the issues are definition of appropriate criteria for evaluation, the expertise needed in the assessment and the organizational motivation for conducting the assessment. The study indicates that organizational safety assessments involve plenty of issues and situations where choices have to be made regarding what is considered valid information and a balance has to be struck between focus on various organizational phenomena. It is very important that these choices are based on a sound theoretical framework and that these choices can later be evaluated together with the assessment findings. The research concludes that at its best, the organizational safety reviews can be utilised as a source of information concerning the changing vulnerabilities and the actual safety performance of the organization. In order to do this, certain basic organizational phenomena and assessment issues have to be acknowledged and considered. The research concludes with recommendations on

Conducting organizational safety reviews - requirements, methods and experience

Energy Technology Data Exchange (ETDEWEB)

Reiman, T.; Oedewald, P.; Wahlstroem, B. [Technical Research Centre of Finland, VTT (Finland); Rollenhagen, C. [Royal Institute of Technology, KTH, (Sweden); Kahlbom, U. [RiskPilot (Sweden)

2008-03-15

Organizational safety reviews are part of the safety management process of power plants. They are typically performed after major reorganizations, significant incidents or according to specified review programs. Organizational reviews can also be a part of a benchmarking between organizations that aims to improve work practices. Thus, they are important instruments in proactive safety management and safety culture. Most methods that have been used for organizational reviews are based more on practical considerations than a sound scientific theory of how various organizational or technical issues influence safety. Review practices and methods also vary considerably. The objective of this research is to promote understanding on approaches used in organizational safety reviews as well as to initiate discussion on criteria and methods of organizational assessment. The research identified a set of issues that need to be taken into account when planning and conducting organizational safety reviews. Examples of the issues are definition of appropriate criteria for evaluation, the expertise needed in the assessment and the organizational motivation for conducting the assessment. The study indicates that organizational safety assessments involve plenty of issues and situations where choices have to be made regarding what is considered valid information and a balance has to be struck between focus on various organizational phenomena. It is very important that these choices are based on a sound theoretical framework and that these choices can later be evaluated together with the assessment findings. The research concludes that at its best, the organizational safety reviews can be utilised as a source of information concerning the changing vulnerabilities and the actual safety performance of the organization. In order to do this, certain basic organizational phenomena and assessment issues have to be acknowledged and considered. The research concludes with recommendations on

Calculations of the SNL experiments Sup1 and Sup2 with CONTAIN 2

International Nuclear Information System (INIS)

Jacobs, G.; Noebel, R.; Wendlandt, T.

2000-01-01

Post-test calculations using the CONTAIN code were performed for the SNL melt dispersal/DCH tests SUP-1 und SUP-2, resulting in a workable input model for future applications to high-temperature melt dispersal experiments as well as for prototypes with tight annular reactor cavity geometries. (orig.) [de

Simplified application of probabilistic safety analysis in nuclear power plants by means of artificial neural networks

International Nuclear Information System (INIS)

Oehmgen, T.; Knorr, J.

2004-01-01

Probabilistic safety analyses (PSA) are conducted to assess the balanced nature of plant design in terms of technical safety and the administrative management of plant operation in nuclear power plants. In the evaluation shown in this article of the operating experience accumulated in two nuclear power plants, all failures are traced back consistently to the plant media and component levels, respectively, for the calculation of reliability coefficients. Moreover, the use of neural networks for probabilistic calculations is examined. The results are verified on the basis of test examples. Calculations with neural networks are very easy to carry out in a kind of 'black box'. There is a possibility, for instance, to use the system in plant maintenance. (orig.) [de

Modeling the hospital safety partnership preferences of patients and their families: a discrete choice conjoint experiment

Directory of Open Access Journals (Sweden)

Cunningham CE

2016-07-01

Full Text Available Charles E Cunningham,1 Tracy Hutchings,2 Jennifer Henderson,2 Heather Rimas,1 Yvonne Chen1 1Department of Psychiatry and Behavioural Neurosciences, Faculty of Health Sciences, Michael G DeGroote School of Medicine, McMaster University, 2Department of Quality and Performance, Hamilton Health Sciences, Hamilton, ON, Canada Background: Patients and their families play an important role in efforts to improve health service safety. Objective: The objective of this study is to understand the safety partnership preferences of patients and their families. Method: We used a discrete choice conjoint experiment to model the safety partnership preferences of 1,084 patients or those such as parents acting on their behalf. Participants made choices between hypothetical safety partnerships composed by experimentally varying 15 four-level partnership design attributes. Results: Participants preferred an approach to safety based on partnerships between patients and staff rather than a model delegating responsibility for safety to hospital staff. They valued the opportunity to participate in point of service safety partnerships, such as identity and medication double checks, that might afford an immediate risk reduction. Latent class analysis yielded two segments. Actively engaged participants (73.3% comprised outpatients with higher education, who anticipated more benefits to safety partnerships, were more confident in their ability to contribute, and were more intent on participating. They were more likely to prefer a personal engagement strategy, valued scientific evidence, preferred a more active approach to safety education, and advocated disclosure of errors. The passively engaged segment (26.7% anticipated fewer benefits, were less confident in their ability to contribute, and were less intent on participating. They were more likely to prefer an engagement strategy based on signage. They preferred that staff explain why they thought patients should help

Spent fuel storage criticality safety

Energy Technology Data Exchange (ETDEWEB)

Amin, E M; Elmessiry, A M [National center of nuclear safety and radiation control atomic energy authority, (Egypt)

1995-10-01

The safety aspects of the spent fuel storage pool of the Egyptian test and research reactor one (ET-R R-1) has to be assessed as part of a general overall safety evaluation to be included in a safety analysis report (SAR) for this reactor. The present work treats the criticality safety of the spent fuel storage pool. Conservative calculations based on using fresh fuel has been performed, as well as less conservative using burned fuel. The calculations include cross library generation for burned and fresh fuel for the ET-R R-1 fuel type. The WIMS-D 4 code has been used in library generation and burn up calculation the critically calculations are performed using the one dimensional transport code (ANISN) and the two dimensional diffusion code (DIXY2). The possibility of increasing the storage efficiency either by insertion of absorber sheets of soluble boron salts or by reduction of fuel rod separation has been studied. 8 figs., 2 tabs.

Spent fuel storage criticality safety

International Nuclear Information System (INIS)

Amin, E.M.; Elmessiry, A.M.

1995-01-01

The safety aspects of the spent fuel storage pool of the Egyptian test and research reactor one (ET-R R-1) has to be assessed as part of a general overall safety evaluation to be included in a safety analysis report (SAR) for this reactor. The present work treats the criticality safety of the spent fuel storage pool. Conservative calculations based on using fresh fuel has been performed, as well as less conservative using burned fuel. The calculations include cross library generation for burned and fresh fuel for the ET-R R-1 fuel type. The WIMS-D 4 code has been used in library generation and burn up calculation the critically calculations are performed using the one dimensional transport code (ANISN) and the two dimensional diffusion code (DIXY2). The possibility of increasing the storage efficiency either by insertion of absorber sheets of soluble boron salts or by reduction of fuel rod separation has been studied. 8 figs., 2 tabs

National Nuclear Safety Department Experience of Supervision over Safety Culture of BNPP-1

International Nuclear Information System (INIS)

Sepanloo, K.; Ardeshir, A.T.

2016-01-01

The analysis of the past major NPPs accidents, TMI, Chernobyl and Fukushima Daiichi shows that causes of these accidents can be explained by a complex combination of human, technological and organizational factors. One of the findings of accident investigations and risk assessments is the growing recognition of the impact of cultural context of work practices on safety. The assumed link between culture and safety, epitomized through the concept of safety culture, has been the subject of extensive research in recent years. The term “safety culture” was first introduced into the nuclear industry by the IAEA in INSAG-1 to underline the role and importance of the organizational factors. The objective of this paper is to conduct an assessment of some safety culture indicators of Bushehr Nuclear Power Plant (BNPP-1).

Development of reliability database for safety-related I and C component based on operating experience of KSNP

International Nuclear Information System (INIS)

Jang, S. C.; Han, S. H.; Min, K. R.

2001-01-01

Reliability database for safety-related I and C components has been developed, based on domestic operating experience of total 8.63 years from four units-Yonggwang Units 3 and 4, and Ulchin Units 3 and 4. This plant-specific data of safety-related I and C components has compared with operating experience for CE-supplied plants in U.S.A. As a results, we found that on the whole the domestic reliability data was similar to CE-supplied plants in USA, through lots of failures occurred early in the commercial operation were included in our analyses without percolation

MCNPTM criticality primer and training experiences

International Nuclear Information System (INIS)

Briesmeister, J.; Forster, R.A.; Busch, R.

1995-01-01

With the closure of many experimental facilities, the nuclear criticality safety analyst is increasingly required to rely on computer calculations to identify safe limits for the handling and storage of fissile materials. However, the analyst may have little experience with the specific codes available at his or her facility. Usually, the codes are quite complex, black boxes capable of analyzing numerous problems with a myriad of input options. Documentation for these codes is designed to cover all the possible configurations and types of analyses but does not give much detail on any particular type of analysis. For criticality calculations, the user of a code is primarily interested in the value of the effective multiplication factor for a system (k eff ). Most codes will provide this, and truckloads of other information that may be less pertinent to criticality calculations. Based on discussions with code users in the nuclear criticality safety community, it was decided that a simple document discussing the ins and outs of criticality calculations with specific codes would be quite useful. The Transport Methods Group, XTM, at Los Alamos National Laboratory (LANL) decided to develop a primer for criticality calculations with their Monte Carlo code, MCNP. This was a joint task between LANL with a knowledge and understanding of the nuances and capabilities of MCNP and the University of New Mexico with a knowledge and understanding of nuclear criticality safety calculations and educating first time users of neutronics calculations. The initial problem was that the MCNP manual just contained too much information. Almost everything one needs to know about MCNP can be found in the manual; the problem is that there is more information than a user requires to do a simple k eff calculation. The basic concept of the primer was to distill the manual to create a document whose only focus was criticality calculations using MCNP

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

International Nuclear Information System (INIS)

Perez, S.

2002-01-01

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

Nuclear criticality safety calculational analysis for small-diameter containers

International Nuclear Information System (INIS)

LeTellier, M.S.; Smallwood, D.J.; Henkel, J.A.

1995-11-01

This report documents calculations performed to establish a technical basis for the nuclear criticality safety of favorable geometry containers, sometimes referred to as 5-inch containers, in use at the Portsmouth Gaseous Diffusion Plant. A list of containers currently used in the plant is shown in Table 1.0-1. These containers are currently used throughout the plant with no mass limits. The use of containers with geometries or material types other than those addressed in this evaluation must be bounded by this analysis or have an additional analysis performed. The following five basic container geometries were modeled and bound all container geometries in Table 1.0-1: (1) 4.32-inch-diameter by 50-inch-high polyethylene bottle; (2) 5.0-inch-diameter by 24-inch-high polyethylene bottle; (3) 5.25-inch-diameter by 24-inch-high steel can (open-quotes F-canclose quotes); (4) 5.25-inch-diameter by 15-inch-high steel can (open-quotes Z-canclose quotes); and (5) 5.0-inch-diameter by 9-inch-high polybottle (open-quotes CO-4close quotes). Each container type is evaluated using five basic reflection and interaction models that include single containers and multiple containers in normal and in credible abnormal conditions. The uranium materials evaluated are UO 2 F 2 +H 2 O and UF 4 +oil materials at 100% and 10% enrichments and U 3 O 8 , and H 2 O at 100% enrichment. The design basis safe criticality limit for the Portsmouth facility is k eff + 2σ < 0.95. The KENO study results may be used as the basis for evaluating general use of these containers in the plant

Critical experiments analysis by ABBN-90 constant system

Energy Technology Data Exchange (ETDEWEB)

Tsiboulia, A.; Nikolaev, M.N.; Golubev, V. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)] [and others

1997-06-01

The ABBN-90 is a new version of the well-known Russian group-constant system ABBN. Included constants were calculated based on files of evaluated nuclear data from the BROND-2, ENDF/B-VI, and JENDL-3 libraries. The ABBN-90 is intended for the calculation of different types of nuclear reactors and radiation shielding. Calculations of criticality safety and reactivity accidents are also provided by using this constant set. Validation of the ABBN-90 set was made by using a computerized bank of evaluated critical experiments. This bank includes the results of experiments conducted in Russia and abroad of compact spherical assemblies with different reflectors, fast critical assemblies, and fuel/water-solution criticalities. This report presents the results of the calculational analysis of the whole collection of critical experiments. All calculations were produced with the ABBN-90 group-constant system. Revealed discrepancies between experimental and calculational results and their possible reasons are discussed. The codes and archives INDECS system is also described. This system includes three computerized banks: LEMEX, which consists of evaluated experiments and their calculational results; LSENS, which consists of sensitivity coefficients; and LUND, which consists of group-constant covariance matrices. The INDECS system permits us to estimate the accuracy of neutronics calculations. A discussion of the reliability of such estimations is finally presented. 16 figs.

Assessment of the available {sup 233}U cross-section evaluations in the calculation of critical benchmark experiments

Energy Technology Data Exchange (ETDEWEB)

Leal, L.C.; Wright, R.Q.

1996-10-01

In this report we investigate the adequacy of the available {sup 233}U cross-section data for calculation of experimental critical systems. The {sup 233}U evaluations provided in two evaluated nuclear data libraries, the U.S. Data Bank [ENDF/B (Evaluated Nuclear Data Files)] and the Japanese Data Bank [JENDL (Japanese Evaluated Nuclear Data Library)] are examined. Calculations were performed for six thermal and ten fast experimental critical systems using the S{sub n} transport XSDRNPM code. To verify the performance of the {sup 233}U cross-section data for nuclear criticality safety application in which the neutron energy spectrum is predominantly in the epithermal energy range, calculations of four numerical benchmark systems with energy spectra in the intermediate energy range were done. These calculations serve only as an indication of the difference in calculated results that may be expected when the two {sup 233}U cross-section evaluations are used for problems with neutron spectra in the intermediate energy range. Additionally, comparisons of experimental and calculated central fission rate ratios were also made. The study has suggested that an ad hoc {sup 233}U evaluation based on the JENDL library provides better overall results for both fast and thermal experimental critical systems.

Assessment of the Available (Sup 233)U Cross Sections Evaluations in the Calculation of Critical Benchmark Experiments

Energy Technology Data Exchange (ETDEWEB)

Leal, L.C.

1993-01-01

In this report we investigate the adequacy of the available {sup 233}U cross-section data for calculation of experimental critical systems. The {sup 233}U evaluations provided in two evaluated nuclear data libraries, the U. S. Data Bank [ENDF/B (Evaluated Nuclear Data Files)] and the Japanese Data Bank [JENDL (Japanese Evaluated Nuclear Data Library)] are examined. Calculations were performed for six thermal and ten fast experimental critical systems using the Sn transport XSDRNPM code. To verify the performance of the {sup 233}U cross-section data for nuclear criticality safety application in which the neutron energy spectrum is predominantly in the epithermal energy range, calculations of four numerical benchmark systems with energy spectra in the intermediate energy range were done. These calculations serve only as an indication of the difference in calculated results that may be expected when the two {sup 233}U cross-section evaluations are used for problems with neutron spectra in the intermediate energy range. Additionally, comparisons of experimental and calculated central fission rate ratios were also made. The study has suggested that an ad hoc {sup 233}U evaluation based on the JENDL library provides better overall results for both fast and thermal experimental critical systems.

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

Proceedings of the specialist meeting on nuclear fuel and control rods: operating experience, design evolution and safety aspects

International Nuclear Information System (INIS)

1997-01-01

Design and management of nuclear fuel has undergone a strong evolution process during past years. The increase of the operating cycle length and of the discharge burnup has led to the use of more advanced fuel designs, as well as to the adoption of fuel efficient operational strategies. The analysis of recent operational experience highlighted a number of issues related to nuclear fuel and control rod events raising concerns about the safety aspects of these new designs and operational strategies, which led to the organisation of this Specialists Meeting on fuel and control rod issues. The meeting was intended to provide a forum for the exchange of information on lessons learned and safety concern related to operating experience with fuel and control rods (degradation, reliability, experience with high burnup fuel, and others). After an opening session 6 papers), this meeting was subdivided into four sessions: Operating experience and safety concern (technical session I - 6 papers), Fuel performance and operational issues (technical session II - 7 papers), Control rod issues (technical session III - 9 papers), Improvement of fuel design (technical session IV.A - 4 papers), Improvement on fuel fabrication and core management (technical session IV.B - 6 papers)

Comparison of MCNP and WIMS-AECL/RFSP calculations against critical heavy water experiments in ZED-2 with CANFLEX-LVRF and CANFLEX-LEU fuels

International Nuclear Information System (INIS)

Bromley, B. P.; Watts, D. G.; Pencer, J.; Zeller, M.; Dweiri, Y.

2009-01-01

This paper summarizes calculations of MCNP5 and WIMS-AECL/RFSP compared against measurements in coolant void substitution experiments in the ZED-2 critical facility with CANFLEX R-LEU/RU (Low Enriched Uranium, Recovered Uranium) reference fuels and CANFLEX-LVRF (Low Void Reactivity Fuel) test fuel, and H 2 O/air coolants. Both codes are tested for the prediction of the change in reactivity with complete voiding of all fuel channels, and that for a checkerboard voiding pattern. Understanding these phenomena is important for the ACR-1000 R reactor. Comparisons are also made for the prediction of the axial and radial neutron flux distributions, as measured by copper foil activation. The experimental data for these comparisons were obtained from critical mixed lattice / substitution experiments in AECL's ZED-2 critical facility using CANFLEX-LEU/RU and CANFLEX-LVRF fuel in a 24-cm square lattice pitch at 25 degrees C. Substitution analyses were performed to isolate the properties (buckling, bare critical lattice dimensions) of the CANFLEX-LVRF fuel. This data was then used to further test the lattice physics codes. These comparisons establish biases/uncertainties and errors in the calculation of k eff , coolant void reactivity, checkerboard coolant void reactivity, and flux distributions. Results show small to modest biases in void reactivity and very good agreement for flux distributions. The importance of boundary conditions and the modeling of un-moderated fuel in the critical experiments are demonstrated. This comparison study provides data that supports code validation and gives good confidence in the reactor physics tools used in the design and safety analysis of the ACR-1000 reactor. (authors)

The usability of ventilators: a comparative evaluation of use safety and user experience.

Science.gov (United States)

Morita, Plinio P; Weinstein, Peter B; Flewwelling, Christopher J; Bañez, Carleene A; Chiu, Tabitha A; Iannuzzi, Mario; Patel, Aastha H; Shier, Ashleigh P; Cafazzo, Joseph A

2016-08-20

The design complexity of critical care ventilators (CCVs) can lead to use errors and patient harm. In this study, we present the results of a comparison of four CCVs from market leaders, using a rigorous methodology for the evaluation of use safety and user experience of medical devices. We carried out a comparative usability study of four CCVs: Hamilton G5, Puritan Bennett 980, Maquet SERVO-U, and Dräger Evita V500. Forty-eight critical care respiratory therapists participated in this fully counterbalanced, repeated measures study. Participants completed seven clinical scenarios composed of 16 tasks on each ventilator. Use safety was measured by percentage of tasks with use errors or close calls (UE/CCs). User experience was measured by system usability and workload metrics, using the Post-Study System Usability Questionnaire (PSSUQ) and the National Aeronautics and Space Administration Task Load Index (NASA-TLX). Nine of 18 post hoc contrasts between pairs of ventilators were significant after Bonferroni correction, with effect sizes between 0.4 and 1.09 (Cohen's d). There were significantly fewer UE/CCs with SERVO-U when compared to G5 (p = 0.044) and V500 (p = 0.020). Participants reported higher system usability for G5 when compared to PB980 (p = 0.035) and higher system usability for SERVO-U when compared to G5 (p ventilators from market leaders compare and highlights the importance of medical technology design. Within the boundaries of this study, we can infer that SERVO-U demonstrated the highest levels of use safety and user experience, followed by G5. Based on qualitative data, differences in outcomes could be explained by interaction design, quality of hardware components used in manufacturing, and influence of consumer product technology on users' expectations.

The impact and applicability of critical experiment evaluations

Energy Technology Data Exchange (ETDEWEB)

Brewer, R. [Los Alamos National Lab., NM (United States)

1997-06-01

This paper very briefly describes a project to evaluate previously performed critical experiments. The evaluation is intended for use by criticality safety engineers to verify calculations, and may also be used to identify data which need further investigation. The evaluation process is briefly outlined; the accepted benchmark critical experiments will be used as a standard for verification and validation. The end result of the project will be a comprehensive reference document.

HACCP and water safety plans in Icelandic water supply: preliminary evaluation of experience.

Science.gov (United States)

Gunnarsdóttir, María J; Gissurarson, Loftur R

2008-09-01

Icelandic waterworks first began implementing hazard analysis and critical control points (HACCP) as a preventive approach for water safety management in 1997. Since then implementation has been ongoing and currently about 68% of the Icelandic population enjoy drinking water from waterworks with a water safety plan based on HACCP. Preliminary evaluation of the success of HACCP implementation was undertaken in association with some of the waterworks that had implemented HACCP. The evaluation revealed that compliance with drinking water quality standards improved considerably following the implementation of HACCP. In response to their findings, waterworks implemented a large number of corrective actions to improve water safety. The study revealed some limitations for some, but not all, waterworks in relation to inadequate external and internal auditing and a lack of oversight by health authorities. Future studies should entail a more comprehensive study of the experience with the use of HACCP with the purpose of developing tools to promote continuing success.

Safety evaluation of the NSRR facility relevant to the modification for improved pulse operation and preirradiated fuel experiments

International Nuclear Information System (INIS)

Inabe, Teruo; Terakado, Yoshibumi; Tanzawa, Sadamitsu; Katagiri, Hiroshi; Kobayashi, Hideo

1988-11-01

The Nuclear Safety Research Reactor (NSRR) is a pulse reactor for the inpile experiments to study the fuel behavior under reactivity initiated accident conditions. The present operation modes of the NSRR consist of the steady state operation up to 300 kW and the natural pulse operation in which a sharp pulsed power is generated from substantially zero power level. In addition to these, two new modes of shaped pulse operation and combined pulse operation will be conducted in the near future as the improved pulse operations. A transient power up to 10 MW will be generated in the shaped pulse operation, and a combination of a transient power up to 10 MW and a sharp pulsed power will be generated in the combined pulse operation. Furthermore, preirradiated fuel rods will be employed in the future experiments whereas the present experiments are confined to the test specimens of unirradiated fuel rods. To provide for these programs, the fundamental design works relevant to the modification of the reactor facility including the reactor instrumentation and control systems and experimental provision were developed. The reactor safety evaluation is prerequisite for confirming the propriety of the fundamental design of the reactor facility from the safety point of view. The safety evaluation was therefore conducted postulating such events that would bring about abnormal conditions in the reactor facility. As a result of the safety evaluation, it has been confirmed as to the NSRR facility after modification that the anticipated transients, the postulated accidents, the major accident and the hypothetical accident do not result respectively in any serious safety problem and that the fundamental design principles and the reactor siting are adequate and acceptable. (author)

Status of Safety and Environmental Activities for Inertial Fusion Energy

International Nuclear Information System (INIS)

Latkowski, J.F.; Reyes, S.; Cadwallader, L.C.; Sharpe, J.P.; Marshall, T.D.; Merrill, B.J.; Moore, R.L.; Petti, D.A.; Falquina, R.; Rodriguez, A.; Sanz, J.; Cabellos, O.

2003-01-01

Over the past several years, significant progress has been made in the analysis of safety and environmental (S and E) issues for inertial fusion energy (IFE). Detailed safety assessments have been performed for the baseline power plant concepts, as well as for a conceptual target fabrication facility. Safety analysis results are helping to drive the agenda for experiments. A survey of the S and E characteristics - both radiological and chemical - of candidate target materials has been completed. Accident initiating events have been identified and incorporated into master logic diagrams, which will be essential to the detailed safety analyses that will be needed in the future. Studies of aerosol generation and transport will have important safety implications. A Monte Carlo-based uncertainty analysis procedure has been developed for use in neutron activation calculations. Finally, waste management issues are receiving increased attention and are deserving of further discussion

Reliability Calculations

DEFF Research Database (Denmark)

Petersen, Kurt Erling

1986-01-01

Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

Experience in safety review of design solutions of the state-of-the-art WWER-type NPPs

International Nuclear Information System (INIS)

Khamaza, A.A.

2015-01-01

The experience of the Federal Budget Institution of the Scientific and Technical Center for Nuclear and Radiation Safety in the field of expertise of the safety rationales for nuclear power plants with WWER-type reactors of new projects is disclosed. In determining the priority, in addition to the necessary time and financial resources, it also took into account the extent to which these activities significantly affect the completeness of the implementation of levels of defense in depth related to the management of beyond-design-basis accidents, including severe ones. And also, what impact does this or that measure have on reducing the likelihood of the onset of severe radiation effects. When examining the safety justification for new design solutions (including for nuclear power plants with a reactor type WWER), it is advisable to adhere to the following approach: during the examination it is necessary to study the experience in the country and the world related to the proposed new design solutions; It is preferable to take advantage of the differential approach to assessing various aspects related to nuclear and radiation safety. The result of the examination of the justification for new design solutions may be recommendations on the development of existing regulatory documents or development of the Regulatory Authority [ru

Enforcement of radiation safety standards and experience in the regulatory control of exposures

International Nuclear Information System (INIS)

Krishnamurthi, T.N.

1997-01-01

Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author)

Reactor safety

International Nuclear Information System (INIS)

Butz, H.P.; Heuser, F.W.; May, H.

1985-01-01

The paper comprises an introduction into nuclear physics bases, the safety concept generally speaking, safety devices of pwr type reactors, accident analysis, external influences, probabilistic safety assessment and risk studies. It further describes operational experience, licensing procedures under the Atomic Energy Law, research in reactor safety and the nuclear fuel cycle. (DG) [de

Regulatory Oversight of Safety Culture — Korea’s Experience

International Nuclear Information System (INIS)

Jung, S.J.; Choi, Y.S.; Kim, J.T.

2016-01-01

In Korea, a regulatory oversight program of safety culture was launched in 2012 to establish regulatory measures against several events caused by weak safety culture in the nuclear industry. This paper is intended to introduce the preliminary regulatory oversight framework, development and validation of safety culture components, pilot safety culture inspection results and lessons learned. The safety culture model should be based on a sound understanding of the national culture and industry characteristics where the model will be applied. The nuclear safety culture oversight model is being developed and built on the Korean regulatory system to independently assess the nuclear power operating organizations’ safety culture.

Calculating exclusion limits for weakly interacting massive particle direct detection experiments without background subtraction

International Nuclear Information System (INIS)

Green, Anne M.

2002-01-01

Competitive limits on the weakly interacting massive particle (WIMP) spin-independent scattering cross section are currently being produced by 76 Ge detectors originally designed to search for neutrinoless double beta decay, such as the Heidelberg-Moscow and IGEX experiments. In the absence of background subtraction, limits on the WIMP interaction cross section are set by calculating the upper confidence limit on the theoretical event rate, given the observed event rate. The standard analysis technique involves calculating the 90% upper confidence limit on the number of events in each bin, and excluding any set of parameters (WIMP mass and cross section) which produces a theoretical event rate for any bin which exceeds the 90% upper confidence limit on the event rate for that bin. We show that, if there is more than one energy bin, this produces exclusion limits that are actually at a lower degree of confidence than 90%, and are hence erroneously tight. We formulate criteria which produce true 90% confidence exclusion limits in these circumstances, including calculating the individual bin confidence limit for which the overall probability that no bins exceed this confidence limit is 90% and calculating the 90% minimum confidence limit on the number of bins which exceed their individual bin 90% confidence limits. We then compare the limits on the WIMP cross section produced by these criteria with those found using the standard technique, using data from the Heidelberg-Moscow and IGEX experiments

Safety concept of high-temperature reactors based on the experience with AVR and THTR

International Nuclear Information System (INIS)

Wachholz, Winfried; Kroeger, Wolfgang

1990-01-01

In the Federal Republic of Germany a reactor is considered safe if verification has been furnished that the requirements contained in paragraph 7 of the Federal German Atomic Energy Act are met for this reactor: demonstration of sufficient precautions against damage required according to the actual state of the art, and especially compliance with the dose rate limits for normal operation and accidental conditions. These requirements result in a deterministic multi-stage safety concept with specified requirements for the engineered safety systems. In recent years, proposals for enhanced safety of nuclear power reactors or a radical change in safety philosophy have been made. This is characterised by 'inherently safe', 'super safe' and similar slogans. A quantitative definition of these requirements has not yet been established, but it is clear as a common objective that the event of beyond design basis accidents evacuation, relocation, and large scale contamination of ground should not occur. As a consequence of the Chernobyl accident the safety of all the NPPs in Germany has been reviewed. This analysis was completed for the THTR reactor in 1988. The same has been done for AVR reactor. The final evaluation of the HTR specific safety features have been fully confirmed. The HTR concepts under development are based on this experience. The HTR-Modul unit is currently being designed

Criticality experiment for No.2 core of DF-VI fast neutron criticality facility

International Nuclear Information System (INIS)

Yang Lijun; Liu Zhenhua; Yan Fengwen; Luo Zhiwen; Chu Chun; Liang Shuhong

2007-01-01

At the completion of the DF-VI fast neutron criticality facility, its core changed, and it was restarted and a series of experiments and measurements were made. According to the data from 29 criticality experiments, the criticality element number and mass were calculated, the control rod reactivity worth were measured by period method and rod compensate method, reactivity worth of safety rod and safety block were measured using reactivity instrument; the reactivity worth of outer elements and radial distribution of elements were measured too. Based on all the measurements mentioned above, safety operation parameters for core 2 in DF-VI fast neutron criticality facility were conformed. (authors)

The use of SIPA 2 simulator for safety studies experience feedbacks and future developments

International Nuclear Information System (INIS)

Dumas, J.M.; Leteinturier, D.

1999-01-01

SIPA 2 experience feedbacks from the beginning of its use at IPSN in 1991 and trends for the next five years are presented. The simulator has been used for three applications: training of engineers working in safety analysis, preparation of national crisis drills, safety studies. In each application, experience feedbacks are analysed to show encountered advantages and difficulties. Trends for the next five years are: extension of the engineer training program (new training courses about normal operating conditions or about beyond design basis accidents), improvements in the validation of simulation configurations (in particular comparison with Cathare 2 new version results) increase of the simulation scope in connection with the SCAR project (taking into account the current power plant datapackage, the improvement of thermalhydraulic models, the extent of the system representation, new neutronic models and description of severe accident conditions). For each trend above, a detail of the planned actions is given. (author)

Steam--water mixing in nuclear reactor safety loss-of-coolant experiments

International Nuclear Information System (INIS)

Naff, S.A.; Schwarz, W.F.

1978-01-01

Computer models used to predict the response of reactors to hypothesized accidents necessarily incorporate approximating assumptions. To verify the models by comparing predicted and measured responses in test facilities, these assumptions must be confirmed to be realistic. Recent experiments in facilities capable of repeatedly duplicating the transient behavior of a pressurized water reactor undergoing a pipe rupture show that the assumption of complete water-steam mixing during the transient results in the predicted decompression being faster than that observed. Water reactor safety studies currently in progress include programs aimed at the verification of computer models or ''codes'' used to predict reactor system responses to various hypothesized accidents. The approach is to compare code predictions of transients with the actual test transients in experimental facilities. The purpose of this paper is to explain an important instance in which predictions and data are not in complete agreement and to indicate the significance to water reactor safety studies

HTC Experimental Program: Validation and Calculational Analysis

Energy Technology Data Exchange (ETDEWEB)

Fernex, F.; Ivanova, T.; Bernard, F.; Letang, E. [Inst Radioprotect and Surete Nucl, F-92262 Fontenay Aux Roses (France); Fouillaud, P. [CEA Valduc, Serv Rech Neutron and Critcite, 21 - Is-sur-Tille (France); Thro, J. F. [AREVA NC, F-78000 Versailles (France)

2009-05-15

In the 1980's a series of the Haut Taux de Combustion (HTC) critical experiments with fuel pins in a water-moderated lattice was conducted at the Apparatus B experimental facility in Valduc (Commissariat a I'Energie Atomique, France) with the support of the Institut de Radioprotection et de Surete Nucleaire and AREVA NC. Four series of experiments were designed to assess profit associated with actinide-only burnup credit in the criticality safety evaluation for fuel handling, pool storage, and spent-fuel cask conditions. The HTC rods, specifically fabricated for the experiments, simulated typical pressurized water reactor uranium oxide spent fuel that had an initial enrichment of 4. 5 wt% {sup 235}U and was burned to 37.5 GWd/tonne U. The configurations have been modeled with the CRISTAL criticality package and SCALE 5.1 code system. Sensitivity/uncertainty analysis has been employed to evaluate the HTC experiments and to study their applicability for validation of burnup credit calculations. This paper presents the experimental program, the principal results of the experiment evaluation, and modeling. The HTC data applicability to burnup credit validation is demonstrated with an example of spent-fuel storage models. (authors)

Merger of Nuclear Data with Criticality Safety Calculations

Energy Technology Data Exchange (ETDEWEB)

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

1999-09-20

In this paper we report on current activities related to the merger of differential/integral data (especially in the resolved-resonance region) with nuclear criticality safety computations. Techniques are outlined for closer coupling of many processes � measurement, data reduction, differential-data analysis, integral-data analysis, generating multigroup cross sections, data-testing, criticality computations � which in the past have been treated independently.

Merger of Nuclear Data with Criticality Safety Calculations

International Nuclear Information System (INIS)

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

1999-01-01

In this paper we report on current activities related to the merger of differential/integral data (especially in the resolved-resonance region) with nuclear criticality safety computations. Techniques are outlined for closer coupling of many processes measurement, data reduction, differential-data analysis, integral-data analysis, generating multigroup cross sections, data-testing, criticality computations which in the past have been treated independently

Critical experiments on low enriched uranyl nitrate solution with STACY

International Nuclear Information System (INIS)

Miyoshi, Yoshinori

1996-01-01

As the STACY started steady operations, systematic criticality data on low enriched uranyl nitrate solution system could be accumulated. Main experimental parameters for the cylindrical tank of 60 cm in diameter were uranium concentration and the reflector condition. Basic data on a simple geometry will be helpful for the validation of the standard criticality safety codes, and for evaluating the safety margin included in the criticality designs. Experiments on the reactivity effects of structural materials such as borated concrete and polyethylene are on schedule next year as the second series of experiments using 10 wt% enriched uranyl solution. Furthermore, neutron interacting experiments with two slab tanks will be performed to investigate the fundamental properties of neutron interaction effects between core tanks. These data will be useful for making more reasonable calculation models and for evaluating the safety margin in the criticality designs for the multiple unit system. (J.P.N.)

Shields calculations for teletherapy equipment. Regulatory approach of the National Center of Nuclear Safety; Calculos de blindajes para equipos de teleterapia, enfoque regulatorio del Centro Nacional de Seguridad Nuclear

Energy Technology Data Exchange (ETDEWEB)

Fuente P, A. de la; Dumenigo G, C.; Quevedo G, J.R.; Lopez F, Y. [Centro Nacional de Seguridad Nuclear, Calle 28 No. 504 e/5 y 7 Ave. Miramar, Playa, Ciudad de la Habana (Cuba)]. e-mail: andres@orasen.co.cu

2006-07-01

The evaluation of applications of construction licenses for the new services of radiotherapy has occupied a significant space in the activity developed by the National Center of Nuclear Safety (CNSN) in the last 2 years. Presently work the experiences of the authors in the evaluation of the required shield for the local where cobalt therapy equipment and lineal accelerators of medical use are used its are exposed, the practical problems detected are approached during the application of the methodologies recommended in both cases and its are discussed which have been the suppositions of items accepted by the Regulatory Authority for the realization of these shield calculations. The accumulated experience allows to assure that the realistic application of the item data and the rational use of the engineering logic makes possible to design local for radiotherapy equipment that fulfill the established dose restrictions in the in use legislation in Cuba, without it implies an excessive expense of construction materials. (Author)

Russian system of computerized analysis for licensing at atomic industry (SCALA) and its validation on ICSBEP handbook data and on some burnup calculations

International Nuclear Information System (INIS)

Ivanova, T.; Polyakov, A.; Saraeva, T.; Tsiboulia, A.

2001-01-01

Validation of criticality calculations using SCALA was performed using data presented in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. This paper contains the results of statistical analysis of discrepancies between calculated and benchmark-model k eff and conclusions about uncertainties of criticality prediction for different types of multiplying systems following from this analysis. (authors)

Criticality safety studies at VTT Energy

International Nuclear Information System (INIS)

Roine, T.; Anttila, M.

1995-01-01

At VTT Energy a compact reactor physics calculation system is applied in many kind of problems. Generation of group constants for static and dynamic core calculations, flux and dose rate calculations as well as criticality safety studies are performed basically with the same codes. In the presentation a short overview of the wide variety of criticality safety problems analyzed at VTT Energy is given. The calculation system with some illustrative examples is also described. (12 refs., 1 tab.)

High-voltage safety fuses for the transition-radiation tracking detector in the ATLAS experiment

NARCIS (Netherlands)

Voronov, SA; Voronov, YA; Onishchenko, EM; Simakov, AB; Sosnovtsev, VV; Suchkov, SI; Sugrobova, TA

2004-01-01

A safety fuse has been designed for the electrical protection of gas-filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kOmega resistance deposited by the photolithographic technique. The forced blow-out

Task Group on Safety Margins Action Plan (SMAP). Safety Margins Action Plan - Final Report

International Nuclear Information System (INIS)

Hrehor, Miroslav; Gavrilas, Mirela; Belac, Josef; Sairanen, Risto; Bruna, Giovanni; Reocreux, Michel; Touboul, Francoise; Krzykacz-Hausmann, B.; Park, Jong Seuk; Prosek, Andrej; Hortal, Javier; Sandervaag, Odbjoern; Zimmerman, Martin

2007-01-01

The international nuclear community has expressed concern that some changes in existing plants could challenge safety margins while fulfilling all the regulatory requirements. In 1998, NEA published a report by the Committee on Nuclear Regulatory Activities on Future Nuclear Regulatory Challenges. The report recognized 'Safety margins during more exacting operating modes' as a technical issue with potential regulatory impact. Examples of plant changes that can cause such exacting operating modes include power up-rates, life extension or increased fuel burnup. In addition, the community recognized that the cumulative effects of simultaneous changes in a plant could be larger than the accumulation of the individual effects of each change. In response to these concerns, CSNI constituted the safety margins action plan (SMAP) task group with the following objectives: 'To agree on a framework for integrated assessments of the changes to the overall safety of the plant as a result of simultaneous changes in plant operation / condition; To develop a CSNI document which can be used by member countries to assess the effect of plant change on the overall safety of the plant; To share information and experience.' The two approaches to safety analysis, deterministic and probabilistic, use different methods and have been developed mostly independently of each other. This makes it difficult to assure consistency between them. As the trend to use information on risk (where the term risk means results of the PSA/PRA analysis) to support regulatory decisions is growing in many countries, it is necessary to develop a method of evaluating safety margin sufficiency that is applicable to both approaches and, whenever possible, integrated in a consistent way. Chapter 2 elaborates on the traditional view of safety margins and the means by which they are currently treated in deterministic analyses. This chapter also discusses the technical basis for safety limits as they are used today

Calculating externalities from damages in occupational health and safety

Energy Technology Data Exchange (ETDEWEB)

Burtraw, D; Shefftz, J

1994-07-01

This paper surveys the theoretical basis for the possibility that coal miner occupational health and safety damages are not adequately internalized into the production cost of mining coal and thereby impose an external cost on society.

Calculating externalities from damages in occupational health and safety

International Nuclear Information System (INIS)

Burtraw, D.; Shefftz, J.

1994-01-01

This paper surveys the theoretical basis for the possibility that coal miner occupational health and safety damages are not adequately internalized into the production cost of mining coal and thereby impose an external cost on society

The role of safety analyses in site selection. Some personal observations based on the experience from the Swiss site selection process

Energy Technology Data Exchange (ETDEWEB)

Zuidema, Piet [Nagra, Wettingen (Switzerland)

2015-07-01

In Switzerland, the site selection process according to the ''Sectoral Plan for Deep Geological Repositories'' (BFE 2008) is underway since 2008. This process takes place in three stages. In stage 1 geological siting regions (six for the L/ILW repository and three for the HLW repository) have been identified, in stage 2 sites for the surface facilities have been identified for all siting regions in close co-operation with the sting regions and a narrowing down of the number of siting regions based on geological criteria will take place. In stage 3 the sites for a general license application are selected and the general license applications will be submitted which eventually will lead to the siting decision for both repository types. In the Swiss site selection process, safety has the highest priority. Many factors affect safety and thus a whole range of safety-related issues are considered in the identification and screening of siting possibilities. Besides dose calculations a range of quantitative and qualitative issues are considered. Dose calculations are performed in all three stages of the site selection process. In stage 1 generic safety calculations were made to develop criteria to be used for the identification of potential siting regions. In stage 2, dose calculations are made for comparing the different siting regions according to a procedure prescribed in detail by the regulator. Combined with qualitative evaluations this will lead to a narrowing down of the number of siting regions to at least two siting regions for each repository type. In stage 3 full safety cases will be prepared as part of the documentation for the general license applications. Besides the dose calculations, many other issues related to safety are analyzed in a quantitative and qualitative manner. These consider the 13 criteria defined in the Sectoral Plan and the corresponding indicators. The features analyzed cover the following broad themes: efficiency of

The role of safety analyses in site selection. Some personal observations based on the experience from the Swiss site selection process

International Nuclear Information System (INIS)

Zuidema, Piet

2015-01-01

In Switzerland, the site selection process according to the ''Sectoral Plan for Deep Geological Repositories'' (BFE 2008) is underway since 2008. This process takes place in three stages. In stage 1 geological siting regions (six for the L/ILW repository and three for the HLW repository) have been identified, in stage 2 sites for the surface facilities have been identified for all siting regions in close co-operation with the sting regions and a narrowing down of the number of siting regions based on geological criteria will take place. In stage 3 the sites for a general license application are selected and the general license applications will be submitted which eventually will lead to the siting decision for both repository types. In the Swiss site selection process, safety has the highest priority. Many factors affect safety and thus a whole range of safety-related issues are considered in the identification and screening of siting possibilities. Besides dose calculations a range of quantitative and qualitative issues are considered. Dose calculations are performed in all three stages of the site selection process. In stage 1 generic safety calculations were made to develop criteria to be used for the identification of potential siting regions. In stage 2, dose calculations are made for comparing the different siting regions according to a procedure prescribed in detail by the regulator. Combined with qualitative evaluations this will lead to a narrowing down of the number of siting regions to at least two siting regions for each repository type. In stage 3 full safety cases will be prepared as part of the documentation for the general license applications. Besides the dose calculations, many other issues related to safety are analyzed in a quantitative and qualitative manner. These consider the 13 criteria defined in the Sectoral Plan and the corresponding indicators. The features analyzed cover the following broad themes: efficiency of

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

Sodium Loop Safety Facility W-2 experiment fuel pin rupture detection system

International Nuclear Information System (INIS)

Hoffman, M.A.; Kirchner, T.L.; Meyers, S.C.

1980-05-01

The objective of the Sodium Loop Safety Facility (SLSF) W-2 experiment is to characterize the combined effects of a preconditioned full-length fuel column and slow transient overpower (TOP) conditions on breeder reactor (BR) fuel pin cladding failures. The W-2 experiment will meet this objective by providing data in two technological areas: (1) time and location of cladding failure, and (2) early post-failure test fuel behavior. The test involves a seven pin, prototypic full-length fast test reactor (FTR) fuel pin bundle which will be subjected to a simulated unprotected 5 cents/s reactivity transient overpower event. The outer six pins will provide the necessary prototypic thermal-hydraulic environment for the center pin

Using the Tritium Plasma Experiment to evaluate ITER PFC safety

International Nuclear Information System (INIS)

Longhurst, G.R.; Anderl, R.A.; Bartlit, J.R.; Causey, R.A.; Haines, J.R.

1993-01-01

The Tritium Plasma Experiment was assembled at Sandia National Labs., Livermore and is being moved to the Tritium Systems Test Assembly facility at Los Alamos National Lab. to investigate interactions between dense plasmas at low energies and plasma-facing component materials. This apparatus has the unique capability of replicating plasma conditions in a tokamak divertor with particle flux densities of 2 x 10 23 ions/m 2 .s and a plasma temperature of about 15 eV using a plasma that includes tritium. An experimental program has been initiated using the Tritium Plasma Experiment to examine safety issues related to tritium in plasma-facing components, particularly the ITER divertor. Those issues include tritium retention and release characteristics, tritium permeation rates and transient times to coolant streams, surface modification and erosion by the plasma, the effects of thermal loads and cycling, and particulate production. An industrial consortium led by McDonnell Douglas will design and fabricate the test fixtures

Enforcement of radiation safety standards and experience in the regulatory control of exposures

Energy Technology Data Exchange (ETDEWEB)

Krishnamurthi, T N [Health and Safety Div., Atomic Energy Regulatory Board, Mumbai (India)

1997-11-01

Regulatory provisions for radiation protection and their enforcement in India are discussed in this paper. The rules and regulations framed for radiation safety cover all the nuclear fuel cycle activities as well as the application of radiation sources in industrial, medical and research institutions. The enforcement aspects and experience in the control of exposures are presented. (author). 3 refs, 2 tabs.

Regulatory Experience on Safety Smart Transmitter's CCF of SKN 3 and 4

Energy Technology Data Exchange (ETDEWEB)

Kim, Y. M.; Jeong, C. H. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2014-10-15

Smart transmitters are digital I and C equipment which can replace analog transmitters. Non safety grade smart transmitters have been used for I and C systems of NPP(Nuclear Power Plant).. But, recently, smart transmitters have been used for safety grade I and C systems as well as non-safety grade I and C system for SKN 3 and 4. Smart transmitters execute measuring sensor values, generating output signals and adjusting range using software. Also, smart transmitters are basically capable of remote calibration through digital communication. The operating capability is more reliable and effective with remote calibration of smart transmitters, but there is potential vulnerability that causes the result no one wanted such as cyber attacks or software CCF. This paper addresses our regulatory experiences how to evaluate safety smart transmitter's CCF of SKN 3 and 4. Nuclear I and C equipment have increased the use on digital technology in safety system. According that, interest in a postulated software CCF is increasing. The software may be firmware or operating system of digital equipment. During SKN 3 and 4 operating license process, safety grade smart transmitter's adequacy was reviewed such as software V and V processes and equipment qualification. Also, it was analyzed that effect of the software CCFs of smart transmitters under DBA condition. Main concern was whether the postulated smart transmitter's software CCF may lead to an adverse safety consequence. We have future research plan to execute proof tests about our concerns and develop regulatory guide for smart transmitters.

Dalfampridine extended release tablets: 1 year of postmarketing safety experience in the US

Directory of Open Access Journals (Sweden)

Jara M

2013-03-01

Full Text Available Michele Jara,1 Graham Barker,2 Herbert R Henney 3rd1 1Acorda Therapeutics, Inc, Ardsley, NY, USA; 2Biogen Idec, Inc, Maidenhead, Berkshire, UK Background: Dalfampridine extended release tablets (dalfampridine-ER; prolonged-, modified, or sustained-release fampridine in some countries were approved in the US to improve walking in patients with multiple sclerosis, as demonstrated by improvement in walking speed. Postmarketing safety experience is available from exposure of approximately 46,000 patients in the US from product approval through March 2011. Objective: To provide a descriptive analysis of all spontaneously reported postmarketing adverse events (AEs for dalfampridine-ER since product launch. Methods: AE data were extracted from the safety database from product launch through March 31, 2011; AEs were classified using the Medical Dictionary for Regulatory Activities. Seizure cases were reviewed for patient demographics, time to event from treatment onset, and presence of additional risk factors. Results: The most frequently reported postmarketing AEs were similar to those reported during clinical development: dizziness, insomnia, balance disorder, headache, nausea, urinary tract infection, asthenia, and back pain (all included in US product labeling. New clinically significant findings are related to lack of efficacy and inappropriate dosing. Of the approximately 46,000 patients exposed, 85 seizures were reported (~5.4/1000 patient-years, of which 82 were reported or confirmed by a health care practitioner (~5.2/1000 patient-years. Beyond the intrinsic multiple sclerosis-related seizure risk, more than half of the 85 cases (62% had an additional potential risk factor for seizure including a previous history of convulsions, renal impairment, incorrect dosing, or use of concurrent medications with a labeled seizure risk. Duration of treatment prior to the seizure ranged from one dose to 365 days; 26/85 (31% patients suffered a seizure

Calculation of LWR kinetic parameter βeff. validation on the mistral experiments

International Nuclear Information System (INIS)

Santamarina, Alain; Erradi, Lahoussine