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Sample records for alarm dosemeters

  1. A smart electronic personal dosemeter

    A compact, smart electronic personal dosemeter for X and gamma radiation in the range of 60 keV to 1.3 MeV has been developed using a silicon diode semiconductor detector. The dosemeter is based on Atmel's 89C2051 micro-controller. It gives a 70dB audio alarm, when the accumulated radiation dose exceeds a preset value. A serial 4K byte serial EEPROM in the dosemeter holds the identification details of the person. Using a built-in real time clock, the accumulated dose is also stored along with date and time every half an hour in the EEPROM to provide information of high dose levels if and when they occur. A serial communication interface RS232C, at 1200 baud, is provided for entering user ID and the alarm value into the EEPROM and also for downloading stored dose data to a PC. The accumulated dose is displayed on a 6-digit LCD display and the unit covers a range of 1μSv to 999999μSv. The details of the hardware and software implementation are discussed. (author)

  2. Operational experience of electronic active personal dosemeter and comparison with CaSo4:Dy TL dosemeter in Indian PHWR.

    Singh, Vishwanath P; Managanvi, S S; Bihari, R R; Bhat, H R

    2013-01-01

    Direct reading dosemeter has been used for day-to-day radiation exposure control and management for last four decades in Indian nuclear power plants (NPPs). Recently new real time, alarm and pre-alarm on equivalent dose/dose rate, storage of dose/dose rate and maximum dose rate, user-friendly electronic active personal dosemeter (APD) has been implemented into practice for the first time at Kaiga Atomic Power Station-3&4,  of Indian NPPs. The dosemeter showed tolerance level (L) 0.1085±0.0450 compared with 0.1869±0.0729 (average±SD) for CaSO4:Dy, TL dosemeter, having narrow range trumpet curve, nil electromagnetic interference. Records of >29 000 for APD and TL dosemeter were analysed for comparasion of the measurement of the individual dose. APD followed general acceptance rule of ±25 % for dose >1 mSv. Monthly Station collective dose by TL dosemeters and APD for normal reactor operation as well as outage are found in good agreement. Operational experiences and statistical analysis support that an APD dosemeter is reasonably equivalent to CaSO4:Dy TL dosemeter. The accuracy, reproducibility and repeatability of the measurement of radiation for (137)Cs are comparable with CaSO4:Dy, TL dosemeter. Operational experience of APD during the normal operation as well as outage showed as one of the best ALARA tool for occupational dose monitoring, control, management and future outage planning. PMID:23528326

  3. Passive neutron dosemeter design

    A passive neutron dosemeter was designed to be used in mixed radiation fields. The design was carried out using Monte Carlo method. The dosemeter model was a 25.4 cm-diameter polyethylene sphere with a thermoluminescent dosemeter, TLD600, located at the sphere center. This model was irradiated with 50 monoenergetic neutron sources with energies from 10-8 to 20 MeV. A 506.71 cm2-area disk was used to model the source term whose center was located at 100 cm from polyethylene sphere's center. The dosemeter response was compared with the responses of SNOOPY, Harwell 95/0075 and PNR-4. With these responses it was calculated the dosemeter responses for 252Cf, 252Cf/D2O and 239PuBe neutron sources. The passive dosemeter relative response has the same shape of SNOOPY, Harwell 95/0075 and PNR-4 dosemeters. Due to the type of thermal neutron detector used in the passive dosemeter the absolute response per unit fluence, is lower than the absolute response of SNOOPY, Harwell 95/0075 and PNR-4 dosemeters. However the passive dosemeter response in function of the average neutron energy of the 252Cf, 252Cf/D2O and 239PuBe neutron energy was more linear

  4. Two miniature electronic dosemeters Yperwatch - Gamcard

    Yperwatch and Gamcard were miniature electronic gamma personal dose and dose rate monitors. The Yperwatch is mounted in a wristwatch and the Gamcard in a case of the size of a standard credit card. The technology provides users with all the performance of a standard professional electronic dosemeter (integrated dose, dose rate, audible alarms, time in use). Yperwatch and Gamcard are based on well-proven electronic dosimetry technology, but with a greater ease of use. (author)

  5. New generation of ''legal'' dosemeters

    In the early 1980s research at the National Radiological Protection Board in the UK proved the feasibility of using solid state electronics in an entirely new dosimetry technology - capable of reaching right down into the low energy photon ranges, and able to detect beta radiation. In 1988 the NRPB undertook a joint venture with Siemens Plessey Controls to develop a marketable personal dosemeter meeting full Health and Safety Executive approval as a ''legal'' instrument. The Electronic Personal Dosemeter (EPD) was thus conceived, and will reach the pre-production stage early this year. The EPD makes use of state-of-the-art silicon integrated circuit technology, with a custom amplifier and microprocessor system. The liquid crystal display continuously shows the accumulated short-term penetrating dose in terms of the Hp (10) unit, and can also show superficial dose and dose rates. Because the EPD must be continuously powered, the custom lithium battery was commissioned to ensure a minimum service interval of 12 months. The EPD is the size and weight of a small pocket pager. Although dose data can be read directly from the EPD, a comprehensive data management system is needed to effect real-life use in industry. The EPD thus communicates by infra-red link to a reader unit which interfaces an IBM-compatible PC, allowing authorized personnel to read the dose memories and perform dose alarm threshold settings. (author)

  6. Acid dip for dosemeter

    Background signal in a PTFE based dosemeter caused by impurities in the PTFE and in the active component such as lithium fluoride is substantially reduced by treating the dosemeter with acid. The optimum treatment involves use of hydrofluoric acid at room temperature for approximately one minute, followed by thorough washing with methanol, and finally drying. This treatment is best applied after the original manufacture of the dosemeters. It may also be applied to existing dosemeters after they have been in use for some time. The treatment produces a permanent effect in reducing both the light induced signal and the non-light induced signal. The process may be applied to all types of dosemeter manufactured from PTFE or other plastics or resins which are able to resist brief exposure to acid. The treatment works particularly well with dosemeters based on PTFE and lithium fluoride. It is also applicable to dosemeters based on calcium sulphate, lithium borate and magnesium borate. Acids which may be used include hydrofluoric, hydrochloric, nitric, phosphoric and sulphuric. (author)

  7. Wallac automatic alarm dosimeter type RAD21

    The Automatic Alarm Dosimeter type RAD 21 is a batterypowered personal dosemeter and exposure rate alarm monitor, designed to be worn on the body, covering an exposure range from 0.1 to 999.9 mR and has an audible alarm which can be pre-set over the range 1 mR h-1 to 250 mR h-1. The instrument is designed to measure x- and γ radiation over the energy range 50 keV to 3 MeV. The facilities and controls, the radiation, electrical, environmental and mechanical characteristics, and the manual, have been evaluated. (U.K.)

  8. Personal neutron diode dosemeter

    The control and management of neutron doses, received by workers in nuclear power or research facilities, requires a knowledge of cumulated dose equivalent or dose equivalent rate in real time. Individual dosemeters so far developed for this purpose are scarce and not very satisfactory. Passive dosemeters such as TLD systems based on the albedo effect, nuclear emulsions or solid track detectors, do not give sufficiently accurate measurements. Furthermore, the increase in the quality factor and the more restrictive new ICRP recommendations diminish the maximum admissible threshold making currently used systems obsolete. Other than bubble dosemeter systems, based on thermodynamic effects of a superheated gel, no simple electronic device is available at the present time. The development of diode based dosimetric gamma badges, having a size similar to that of credit cards, has stimulated us to design and develop a personal neutron dosemeter based on a double diode system. The results obtained are very encouraging and practical models should become available in the near future. (author)

  9. Calibration of farmer dosemeters

    The Farmer Dosemeters of Atomic Energy Medical Centre (AEMC) Jamshoro were calibrated in the Secondary Standard Dosimetry Laboratory (SSDL) at PINSTECH, using the NPL Secondary Standard Therapy level X-ray exposure meter. The results are presented in this report. (authors)

  10. Principle and use of dosemeters

    The institute of nuclear physics of Orsay is accepted by the Ministry of Labour to insure the surveillance of workers individual external exposure against the danger of ionizing radiations and to execute monitoring of radiation protection. The dosemeters studied in this report are the photographic film dosemeters ( for x rays, gamma rays and beta - rays), the trace detectors (fast neutrons) and the radio thermo luminescent dosemeters. For each type, the principle and how to use it are given. (N.C.)

  11. The outlook for the application of electronic dosemeters as legal dosimetry

    This study analyses new trends of a set of 12 electronic personal dosemeters in order to gain an overview of their main advantages and limitations. Physical characteristics and radiological, mechanical and environmental performance were tested according to IEC-61526 Standard requirements. The study highlights the different behaviour of the selected dosemeters. In particular, it is demonstrated that three of the tested devices fulfilled most of the established requirements, whereas another three of them presented important faults. The parameters that need more development are, in general, the response at low energy photon and beta radiation, and the dose rate alarm features. In some cases, mechanical problems as well as interference in the response due to external electromagnetic fields were also found. However, the results of the study foresee a promising future for the application of the newest personal electronic dosemeters as legal personal dosemeters and show the need for internationally agreed technical requirements within the European countries. (author)

  12. European intercomparison of diagnostic dosemeters: calibration of the reference dosemeters

    The paper describes both the organisational and technical steps taken in the calibration of the reference dosemeters used in the intercomparison of diagnostic dosemeters carried out in Europe in 1990. A brief account is given on the activities by the coordinating centres in the 19 countries and by the calibrating institution to establish the operational framework necessary for carrying out the calibration. The second part describes the calibration of the dosemeters against PTB's primary standards in terms of the equipment used and of the individual steps of measurement taken. An assessment of the uncertainties associated with the calibration is presented

  13. Performance tests on the NRPB thermoluminescent dosemeter

    Shaw, K B

    1977-01-01

    Performance tests on the thermoluminescent dosemeter, designed at NRPB for use in the automated personal dosimetry system, are described. An ultra-thin lithium borate dosemeter has been developed for skin absorbed dose measurement. The X-ray, gamma-ray and beta-ray energy response of the dosemeter has been investigated and the angular response for the dosemeter has been examined. The annealing, read-out and stabilisation procedures for the dosemeter are described.

  14. Alarming atmospheres

    Højlund, Marie; Kinch, Sofie

    2014-01-01

    . As a response to this situation, our design artefact, the interactive furniture Kidkit, invites children to become accustomed to the alarming sounds sampled from the ward while they are waiting in the waiting room. Our design acknowledges how atmospheres emerge as temporal negotiations between the...

  15. Response of electret dosemeter to slow neutrons

    The response of the electret dosemeter to exposition of slow neutrons is studied. Different external coatings are used on the dosemeter (polyethylene, alminium, polyethylene + boron, aluminium + boron) and exposure curves (with and without water) are compared. (M.A.C.)

  16. Alarm filtering and presentation

    This paper discusses alarm filtering and presentation in the control room of nuclear and other process control plants. Alarm generation and presentation is widely recognized as a general process control problem. Alarm systems often fail to provide meaningful alarms to operators. Alarm generation and presentation is an area in which computer aiding is feasible and provides clear benefits. Therefore, researchers have developed several computerized alarm filtering and presentation approaches. This paper discusses problems associated with alarm generation and presentation. Approaches to improving the alarm situation and installation issues of alarm system improvements are discussed. The impact of artificial intelligence (AI) technology on alarm system improvements is assessed. (orig.)

  17. Acceptance testing of photographic film dosemeters

    The reports describes a system for acceptance testing of photographic film dosemeters in customary use in personal dosimetry. The system comprises a test of some of the fundamental dosimetric properties of the film. The acceptance test will be performed in connection with the semi-annual purchases of dosemeter film to the National Institute of Radiation Hygiene. The test program comprises both constancy tests and absolute requirements. The latter refer mainly to ISO 1757 - Personal photographic dosemeters. 2 refs

  18. History of development of electronic personal dosemeters

    The nuclear and accelerator facilities are now increasingly used, especially high-energy accelerators for various purposes such as nuclear physics, medical science, and engineering research. It is very important to monitor the personal dose equivalent of workers in such facilities by using a real-time personal dosemeter. As real-time personal dosemeter, the silicon semiconductor detectors are world-widely used in nuclear and accelerator facilities. We have developed the real-time personal dosemeters using GM-tube and silicon semiconductor detector from about 40 years before. This report describes the history of development of electronic personal dosemeters using at atomic power plants in Japan. (author)

  19. Colour dosemeters for high level radiation dosimetry

    Schönbacher, H.; Coninckx, F.; Miller, A.; Kruska, G.; Wulf, I.

    Development work was undertaken in order to produce a visual dosemeter system for measurement of radiation levels around the present and future high energy particle accelerators. This dosemeter should exhibit radiation induced colours in the visible part of the spectrum leading to a visual dose i...

  20. Electronic personal dosemeters - current position and trends

    The electronic personnel dosemeter has an arrangement of silicon photodiodes using two detectors of different sizes, connected in a simple circuit with single pre-amplifier and amplifier. An excellent relationship in energy and angle is obtained. The advantage of this dosemeter is the immediate availability of the dose information. (DG)

  1. Optimal Alarm Systems

    National Aeronautics and Space Administration — An optimal alarm system is simply an optimal level-crossing predictor that can be designed to elicit the fewest false alarms for a fixed detection probability. It...

  2. Problems at the Development of personal Beta-particle dosemeters-Beta Particle dosemeters-

    Workplaces at which beta radiation might significantly contribute to the doses to the extremities are increasingly found in radiation therapy, radiation source production and nuclear plants. for the measurement of the individual beta-particle dose, personal dosemeters for fingers, arms and legs are needed. Intercomparison measurements organised from 1996 by the PTB have shown that some dosemeter types based on TLD are suitable for this purpose and can be used as legal dosemeters for both photon and beta radiation. Also, some electronic personal photon dosemeters are investigated in beta radiation fields. it turned out that a few types are also sensitive to beta radiation and measure the personal dose equivalent rate to the skin with a low energy dependence. Only their wearing position is by far not optimal foe extremity dosimetry because they are worn on the chest. Advantages and disadvantages are discussed. The characterisation of workplaces is carried out by measuring dose profiles using area dosemeters. Investigations performed with several commercial types of these dosemeters furnish information about the selection of the suitable measuring device and its correct practical use. the development of improved dosemeters has to towards smaller detectors and higher sensitivity. Personal dosemeters have to be robust and acceptable to the user, which generally is not achieved for beta extremity dosemeters. It is an additional problem that even such dosemeters cannot always be worn in the appropriate place. (Author)

  3. Dosemeters for centralized personnel monitoring in the GDR

    Dosemeters used in the German Democratic Republic for centralized personnel monitoring are described in case of normal operation and accidents at NPP. Such dosemeters are as follows: photographic film dosemeters for the measurement of X and gamma radiation, and also for a rough evaluation of beta radiation; thermoluminescent dosemeters for measuring emergency doses of X and gamma radiation; thermoluminescent dosemeters for measuring arm irradiation by beta, gamma and X radiation; activation dosemeters for neutron emergency dosimetry, and also some special dosemeters. Their design, measuring ranges and measurement error are briefly discussed

  4. The development of an electronic dosemeter

    The National Radiological Protection Board (NRPB) and Siemens Plessey Controls Ltd are in the process of developing an electronic dosemeter suitable for use by an approved dosimetry service for classified workers. Pre-production dosemeters and readers have now been produced and trials in conjunction with the Health and Safety Executive will commence shortly with the aim of setting up an approved dosimetry service at NRPB based on the use of the dosemeter. The way it is proposed to organise the service will be discussed. (Author)

  5. Passive neutron dosemeter with activation detector

    Valero L, C.; Banuelos F, A.; Guzman G, K. A.; Borja H, C. G.; Hernandez D, V. M.; Vega C, H. R., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-10-15

    A passive neutron dosemeter with {sup 197}Au activation detector has been developed. The area dosemeter was made as a 20.5 {phi} x 20.5 cm{sup 2} polyethylene moderator, with a polyethylene pug where a {sup 197}Au foil can be located either parallel or perpendicular to moderator axis. Using Monte Carlo methods, with the MCNP5 code. With the fluence response and the fluence-to-equivalent dose conversion coefficients from ICRP-74, responses to H*(10) were also calculated, these were compared against responses of commercially available neutron area monitors and dosemeters. (Author)

  6. Study about the feasibility of using an electret dosemeter as a personal dosemeter

    A feasibility study of the electret dosemeters as a personnel dosemeter was carried out. Preliminary tests were applied, in order to assess the dosemeter response to radiation, linearity, stability, reproductibility, direcional dependence and energy dependence in energy range from 33 to 1250 KeV. In general the results are in agreement with the recommendations of the Commision of the European Communities (CEC) for the use of this device as a personnel dosemeter with the exception of the energy dependence and the stability at medium term. (Author)

  7. The need for comparison of diagnostic dosemeters

    One precondition for successfully implementing quality control in diagnostic radiology is that the measuring instruments used are of adequate quality. Among the measuring instruments used for quality control, dosemeters play a predominant role. Therefore it is essential to know the performance characteristics of a suitable dosemeter and to have information on the uncertainties and measurement errors found during acceptance testing. An outline will be given of the requirements on the accuracy of dosemeters. Such requirements have to address the task of the dosemeter and also take into account their technical feasibility. In order to gather information on the performance characteristics of field instruments, a programme for a European intercomparison has been developed which was carried out in 1988. The programme, together with its underlying ideas and its objectives, is presented in this paper. (author)

  8. Safety alarms at CERN

    Ninin, P; Henny, L

    1998-01-01

    In order to operate the CERN accelerators complex safely, the acquisition, transport and management of safety alarms is of crucial importance. The French regulatory authority [Direction de Sûreté des Installations Nucléaires de Base (INB)] defines them as Level 3 alarms; they represent as such a danger for the life and require an immediate intervention of the Fire Brigade. Safety alarms are generated by fire and flammable gas detection systems, electrical emergency stops, and other safety related systems. Level 3 alarms are transmitted for reliability reasons to their operation centre: the CERN Safety Control Room (SCR) using two different media: the hard-wired network and a computer based system. The hard-wired networks are connected to local panels summarizing in 34 security areas the overall CERN geography. The computer based system offers data management facilities such as alarm acquisition, distribution, archiving and information correlation. The Level 3 alarms system is in constant evolution in order...

  9. Glass as a gamma ray dosemeter

    The advantages of glass as a γ-rays dosemeter are studied. Experiments have shown that ordinary microscope object glass can be used as a dosemeter, which dose range for linear response extends from about 104-106 rads. Heat treatment of the irradiated samples accelerates the initial fading of coloration and stabilizes the residual optical density. On the other side cooling of them retards the initial fading. (author)

  10. New dose quantities for personnel dosemeters

    In 1985, the Workshop External Dosimetry (AKD) of the German-Swiss 'Fachverband fuer Strahlenschutz' and the Physikalisch-Technische Bundesanstalt (PTB) organized an intercomparison experiment in order to find out whether commonly used personal dosemeters are able to indicate the new ICRU dose quantities (ICRU 39) Hs (0,07) and Hp(10) recommended for personal dosimetry. A total number of 30 representative dosimetry systems participated at the interlaboratory test. These systems make use mainly of L and RPL dosemeters, but also film dosemeters and direct reading dosemeters have been chosen. The irradiations have been performed over the energy range 25-662 keV using irradiations free in air as well as on the ICRU sphere phantom. Under an angle of 00, 450 and on the rotating phantom. The effect of phantom type has been investigated using the ICRU sphere and the Alderson human phantom. With respect to the ICRU quantities, three categories of personal dosemeters have been found dosemeter systems which simultaneously indicate the exposure X as well as H'(0,07) and H'(10) without any change of the evaluation technique or energy compensation filter, dosemeter systems which must be improved either in the evaluation procedure or by using additional detector readings, and dosemeter systems which must be changed in the energy compensation filters. In different papers the participants discuss their own results. Additional contributions of the seminar are presented, which discuss general subjects of introducing new dose quantities and other concepts of calibration quantities for external dosimetry. (orig./HP)

  11. Personnel monitoring of radiations with thermoluminescent dosemeters

    The basics of personnel dosimetry technics, used by the Radiologic Protetion and Assessorie Service (SAPRA) are presented, consisting on use of thermoluminescent and CaSO4:Dy monitors in aggregated pellets by Teflon. The characteristics of this dosemeters, relating to the sensitivity, energetic dependence, spike temperature, characteristic emission curve, decay and light effect are shown. The thermoluminescent dosemeter measure system and the personnel monitoring system are also described. (C.G.C.)

  12. Self-indicating radiation alert dosemeter (SIRAD)

    In an event of a nuclear or dirty bomb explosion and a radiological accident, there is a need for self-indicating instant radiation dosemeter for monitoring radiation exposure. The self-indicating instant radiation alert dosemeter (SIRAD) is a credit card size radiation dosemeter for monitoring ionising radiation from a few hundredths of a Gray to a few Gray. It is always active and is ready to use. It needs no battery. The dosemeter develops colour instantly upon exposure, and the colour intensifies with dose. It has a colour chart so that the dose on the active element may be read by matching its colour with the chart that is printed next to it on the card. However, in this work, the dose is measured by the optical density of the element. The dosemeter cannot be reset. The response changes by 3 y at room temperature. It contains no hazardous materials. The dosemeter would meet the requirements of instantly monitoring high dose in an event of a nuclear or dirty bomb explosion or a radiation accident. (authors)

  13. Photodiode based dosemeter for patient dose monitoring

    This work describes the performance of a dosemeter, based on a photodiode device, compared to an ionization chamber for on-line dose monitoring applied to the patient during radiotherapy procedures. The dosemeter is constituted by two photodiodes, connected without polarisation to a digital current integrator. The dosemeter was tested in a water phantom and 60Co gamma ray. The depth dose distribution and the variation response with depth of the dosemeter were obtained. The results were compared to those obtained with a secondary standard, take as reference dosemeter. The response of this dosemeter had a deviation of 0,7 % from the ion chamber performance in water phantom measurement. The response variation with depth was less than 1 %. This is better than 8 % of diodes, determined by other authors. The developed device can substitute ion chambers in some routine absorbed dose to water measurements, with advantage of low cost and robust form. It has better performance than diodes, for given dose for patient. (author)

  14. Thermoluminescent lithium fluorides dosemeters in personnel monitoring in the GDR

    Described are thermoluminescent (TL) dosemeters of lithium fluoride used in centralized personnel monitoring in the GDR. Results of large-scale experiment are presented to compare the accuracy of readings of lithium fluoride or teflon dosemeter and that of film dosemeters. 332 persons were controlled for the experiment. A phantom was irradiated simultaneously by X and gamma radiation. The experience in application of thermoluminescent dosemeters to personnel monitoring of radiation load of a whole body and body parts using rings is described. Two Types of TL ring dosemeters for measuring X, gamma and deta radiations are presented. Advantage and shortcomings of TL dosemeters are noted

  15. The relative merits of discriminating and non-discriminating dosemeters

    Marshal, T. O.; Christensen, Palle; Julius, H. W.; Smith, J. W.

    1986-01-01

    The need for discriminating and non-discriminating personal dosemeters in the field of radiological protection is examined. The ability of various types of dosemeter to meet these needs is also discussed. It is concluded that there is a need for discriminating dosemeters but in the majority of...... cases a simple two element non-discriminating dosemeter will suffice. In cases where the use of discriminating dosemeters is justified, thermoluminescence dosemeters can be designed to provided information on radiation type and energy, but if further information is required the photographic film...

  16. Design of Alarm Clock

    Budík, Marek

    2015-01-01

    The goal of this thesis is to create alarm clock, which respect the functional, technical and aesthetic requirements of this device and attain an attractive design of this product. The final draft should be innovative, original and user attractive alarm clock.

  17. Digital Dosemeters - 'ALARA OD' - Personal and Environmental Monitoring Assembly

    Full text: The importance of prompt dose reporting rises when dose is received within short-time interval or when the radiation source suffers technical failures. New dosimetry concept, where radiation exposure is recognized as a private /or/ group hazard of each person involved in occupational ionizing sources handling, taking into account actual radiation quality of the source, based among other principles, on the principle of establishing the well defined controlled area is introduced. New digital dosemeter device, produced by ALARA Instruments Ltd., measures small occupational doses, including the background. Device is based on ionizing GM tube, a set of modern EEPROM memory chips and Li compound battery set. It operates in two modes and the measurements are continuously performed no matter which mode is on. First mode integrates the dose (including background). If user or dosemeter device enter the higher radiation field area second mode will separately start to measure the dose which is at least two times higher than the surrounding background. The level above which the higher field is considered has to be preprogrammed during the calibration of device. Level depends on the workplace type /or/ environmental conditions where the device will be used. Device is suitable as well for the low level measurements and for the high radiation outputs. When used in the stronger fields, several devices can form a field monitoring system. Device is suitable for the various non-occupational purposes. With some telecommunication electronics and technical improvement, this device is usable as a point (Ort) environmental measuring station. Probe is sensitive to the background radiation and it is fast enough to record any change in normal environmental radiation field, send the data to the central station and raise alarm if necessary. We have built a prototype for environmental monitoring connectable to any kind of telecommunication net. (author)

  18. Active neutron/photon personal dosemeters

    Though active personal dosemeters for photon fields reflect already a high level of development, there is still a need to advance the design of dosemeters for use in mixed neutron/photon fields and especially for monitoring the staff of nuclear power plants and the personnel accompanying transports of spent fuel flasks. The measurement of the neutron component is usually associated with problems. After a short description of the complex mixed fields in the nuclear fuel cycle, the commercially available active dosemeters and those under development will be listed and problems arising from their use in these fields will be discussed. Two new developments, the Siemens EPD-N2 and the PTB DOS-2002, which both are capable of indicating neutron and photon doses, will be described and discussed in detail. New response functions with respect to personal dose equivalent Hp(10) will be presented for neutrons. They have been determined by measurements in the quasi-monoenergetic reference fields at PTB in the energy range from 24 keV to 14.8 MeV and in fields with broad spectral distributions using the radionuclide sources 252Cf(bare), 252Cf(D2O,mod) - with and without cadmium shielding - 241Am-Be as well as a thermal neutron beam. The spectral distributions of all fields and the readings of the dosemeters in these fields were taken as inputs for an unfolding procedure to determine the dosemeter response in the overall energy region from thermal to 15 MeV. The procedure was tested by folding the dosemeter response with the broad neutron spectra and comparing with the readings of the dosemeters. Another problem in practical workplace fields is linked with high energy photons. Photons with energies from 6 MeV to 7 MeV from the 16O(n,pγ) reaction contribute to dose, particularly at reactors, and have to be taken into account when dosemeters are processed. Measurements with high energy photons were therefore performed with both devices and will be discussed. Finally, practical

  19. Intelligent Alarm Management System (IAMS)

    A large number of alarms in a nuclear power plant (NPP) are related to one causative event/alarm. When such an event happens, it triggers a cascade of alarms (called alarm avalanche) that comes in quick succession. These alarms may or may not come in a particular time-sequence each time the cause event is triggered. Alarm avalanches in an emergency situation can affect the performance of even the most seasoned operators. If a cause-consequence relationship can be established among a set of alarms, then such avalanches can be avoided by annunciating only the rootcause alarm. Intelligent Alarm Management System (IAMS) is a knowledge-based alarm processing system to reduce the number of presented alarms. The processing is based on the functional cause-consequence knowledge-base of the plant, wherein an alarm on a function denotes degradation/unavailability of the function.The knowledge is modeled using a graphical construct called Function Graph. (author)

  20. Angular and energetic dependence of photographic dosemeters for beta radiation

    Photographic dosemeters (Agfa-Gevaert) used in personal monitoring at IPEN/CNEN-SP (Brazil) are studied. The angular (between O and 1800) and energetic dependence in beta radiation exposures are discussed. The dosemeters are analysed with and without dosemeter - holder and retroscatter material. (M.A.C.)

  1. Colour dosemeters for high level radiation dosimetry

    Schönbacher, H.; Coninckx, F.; Miller, A.;

    1990-01-01

    interpretation or a dose measurement with a simple instrument such as a portable reflecting densitometer in the range of 10(3) to 10(6) Gy. Two projects were investigated: (1) a thin plastic film with a self adhesive tape containing a radiochromic dye which induces a colour change when exposed to ionising...... radiation; and (2) a paint containing a base substance with a pigment. The paint dosemeter remained unaffected by irradiation up to 3 x 10(4) Gy while the film dosemeter showed a measurable colour change from 10(4) Gy to 5 x 10(5) Gy. Above 10(6) Gy the film dosemeter is destroyed by radiation. Samples of...

  2. Smart smoke alarm

    Warmack, Robert J. Bruce; Wolf, Dennis A; Frank, Steven Shane

    2015-04-28

    Methods and apparatus for smoke detection are disclosed. In one embodiment, a smoke detector uses linear discriminant analysis (LDA) to determine whether observed conditions indicate that an alarm is warranted.

  3. Speech Alarms Pilot Study

    Sandor, Aniko; Moses, Haifa

    2016-01-01

    Speech alarms have been used extensively in aviation and included in International Building Codes (IBC) and National Fire Protection Association's (NFPA) Life Safety Code. However, they have not been implemented on space vehicles. Previous studies conducted at NASA JSC showed that speech alarms lead to faster identification and higher accuracy. This research evaluated updated speech and tone alerts in a laboratory environment and in the Human Exploration Research Analog (HERA) in a realistic setup.

  4. Neutron dosimetry with TL albedo dosemeters at high energy accelerators

    The GSF-Personal Monitoring Service uses the TLD albedo dosemeter as standard neutron personal dosemeter. Due to its low sensitivity for fast neutrons however, it is generally not recommended for workplaces at high-energy accelerators. Test measurements with the albedo dosemeter were performed at the accelerator laboratories of GSI in Darmstadt and DESY in Hamburg to reconsider this hypothesis. It revealed that the albedo dosemeter can also be used as personal dosemeter at these workplaces, because at all measurement locations a significant part of neutrons with lower energies could be found, which were produced by scattering at walls or the ground. (authors)

  5. Calibrations of pocket dosemeters using a comparison method

    This monograph is dedicated mainly to the calibration of pocket dosemeters. Various types of radiation sources used in hospitals and different radiation detectors with emphasis on ionization chambers are briefly presented. Calibration methods based on the use of a reference dosemeter were developed to calibrate all pocket dosemeters existing at the Radiation Physics and Metrology Laboratory. Some of these dosemeters were used in personnel dosimetry at hospitals. Moreover, a study was realized about factors that affect the measurements with pocket dosemeters in the long term, such as discharges due to cosmic radiation. A DBASE IV program was developed to store the information included in the hospital's registry

  6. Intercomparison of secondary standard dosemeters in Latin America

    The National Laboratory for Ionizing Radiation Metrology/IRD has promoted an intercomparison among secondary and tertiary dosemeters which have been used as national standards in Latin America. Thirteen therapy level and five protection level dosemeters were brought by representatives, of eight countries and were compared against two reference dosemeters brought by an IAEA staff member. As far as the stablished limits for discrepancies are concerned it was possible to detect that therapy level secondary standard dosemeters failed in 4 conditions when 46 were used; therapy tertiary dosemeters failed in 5 of the 15 test conditions and the protection level secondary dosemeters showed 4 discrepancies during the 21 test conditions. The exercise emphasized the importance of intercomparisons as part of a quality control programme to garantee the metrological quality and the coherency of standard dosemeters with international metrological system. (author)

  7. Video methods for evaluating physiologic monitor alarms and alarm responses.

    Bonafide, Christopher P; Zander, Miriam; Graham, Christian Sarkis; Weirich Paine, Christine M; Rock, Whitney; Rich, Andrew; Roberts, Kathryn E; Fortino, Margaret; Nadkarni, Vinay M; Lin, Richard; Keren, Ron

    2014-01-01

    False physiologic monitor alarms are extremely common in the hospital environment. High false alarm rates have the potential to lead to alarm fatigue, leading nurses to delay their responses to alarms, ignore alarms, or disable them entirely. Recent evidence from the U.S. Food and Drug Administration (FDA) and The Joint Commission has demonstrated a link between alarm fatigue and patient deaths. Yet, very little scientific effort has focused on the rigorous quantitative measurement of alarms and responses in the hospital setting. We developed a system using multiple temporarily mounted, minimally obtrusive video cameras in hospitalized patients' rooms to characterize physiologic monitor alarms and nurse responses as a proxy for alarm fatigue. This allowed us to efficiently categorize each alarm's cause, technical validity, actionable characteristics, and determine the nurse's response time. We describe and illustrate the methods we used to acquire the video, synchronize and process the video, manage the large digital files, integrate the video with data from the physiologic monitor alarm network, archive the video to secure servers, and perform expert review and annotation using alarm "bookmarks." We discuss the technical and logistical challenges we encountered, including the root causes of hardware failures as well as issues with consent, confidentiality, protection of the video from litigation, and Hawthorne-like effects. The description of this video method may be useful to multidisciplinary teams interested in evaluating physiologic monitor alarms and alarm responses to better characterize alarm fatigue and other patient safety issues in clinical settings. PMID:24847936

  8. Requirements of dosemeters for radiation protection

    This paper is intended to be as a guide for users in choosing the most suitable radiation detecting instrument for a specific use. The dosimetric characteristics and characteristics related to conditions of use for a dosemeter shall be considered before a choice can be made. All given information are strictly based on recommendations of ISO 4071-1978(E). (author)

  9. Unbiased metal oxide semiconductor ionising radiation dosemeter

    To assess the application of MOS devices as low dose rate dosemeters, the sensitivity is the major factor although little studies have been performed on that subject. It is studied here, as well as thermal stability and linearity of the response curve. Other advantages are specified such as large measurable dose range, low cost, small size, possibility of integration. (D.L.)

  10. The LEP alarm system

    Unlike alarm systems for previous accelerators, the LEP alarm system caters not only for the operation of the accelerator but also for technical services and provides the direct channel for personnel safety. It was commissioned during 1989 and has seen a continued development up to the present day. The system, comprising over 50 computers including 5 different platforms and 4 different operating systems, is described. The hierarchical structure of the software is outlined from the interface to the equipment groups, through the front end computers to the central server, and finally to the operator consoles. Reasons are given for choosing a conventional, as opposed to a 'knowledge based' approach. Finally, references are made to a prototype real time expert system for surveying the power converters of LEP, which was conducted during 1990 as part of the alarm development program. (author)

  11. Gynecological cancer alarm symptoms:

    Balasubramaniam, Kirubakaran; Ravn, Pernille; dePont Christensen, René;

    2016-01-01

    INTRODUCTION: To determine the proportion of patients who were referred to specialist care after reporting gynecological cancer alarm symptoms to their general practitioner. To investigate whether contact with specialist care was associated with lifestyle factors or socioeconomic status. MATERIAL...... care and odds ratios (ORs) for associations between specialist care contact, lifestyle factors and socioeconomic status. RESULTS: The study included 25 866 non-pregnant women; 2957 reported the onset of at least one gynecological cancer alarm symptom, and 683 of these (23.1%) reported symptoms to their.......17-2.95). CONCLUSIONS: Educational level influence contact with specialist care among patients with gynecological cancer alarm symptoms. Future studies should investigate inequalities in access to the secondary healthcare system. This article is protected by copyright. All rights reserved....

  12. Automatic exploitation system for photographic dosemeters

    The Laboratory of Dosimetry Exploitation (LED) has realized an equipment allowing to exploit automatically photographic film dosemeters. This system uses an identification of the films by code-bars and gives the doses measurement with a completely automatic reader. The principle consists in putting in ribbon the emulsions to be exploited and to develop them in a circulation machine. The measurement of the blackening film is realized on a reading plate having fourteen points of reading, in which are circulating the emulsions in ribbon. The exploitation is made with the usual dose calculation method, with special computers codes. A comparison on 2000 dosemeters has shown that the results are the same in manual and automatical methods. This system has been operating since July 1995 by the LED. (N.C.)

  13. Implementing new recommendations for calibrating personal dosemeters

    This paper analyses the differences between the calibration procedures for personal dosemeters recommended by ICRU 47 and ISO 4037-3. The tissue equivalence of the PMMA and the ISO water slab phantoms are analysed by means of the Penelope Monte Carlo code for monoenergetic and filtered X ray photon beams and compared with the results of two other independent codes. The influence of the calibration method is also verified experimentally, both on a thermoluminescence and an electronic personal dosemeter. Good consistency between both calibration procedures is shown provided that a correction factor for backscatter differences between the PMMA and the ICRU phantom is introduced. The Monte Carlo simulation is used to determine this correction to a greater accuracy. (author)

  14. Principle and use of dosemeters; Principe et utilisation des dosimetres

    Genet, S.; Ribaud, I.

    1997-12-31

    The institute of nuclear physics of Orsay is accepted by the Ministry of Labour to insure the surveillance of workers individual external exposure against the danger of ionizing radiations and to execute monitoring of radiation protection. The dosemeters studied in this report are the photographic film dosemeters ( for x rays, gamma rays and beta {sup -} rays), the trace detectors (fast neutrons) and the radio thermo luminescent dosemeters. For each type, the principle and how to use it are given. (N.C.).

  15. Passive neutron dosemeter-spectrometer for high-energy accelerators

    A passive neutron dosemeter-spectrometer (PNDS) with fission fragments converters is described. The results obtained show that it is a convenient and reliable instrument for neutron dose equivalent measurement in the calibration performing and response investigations of personnel dosemeters in mixed radiation fields behind accelerator shielding. Because of the possibility of neutron spectrum estimation in a wide energy range PNDS using is promissing in the neutron radiation fields research and also as an accidental neutron dosemeter. 23 refs.; 10 figs.; 4 tabs

  16. Factors affecting polyamide prototypes design of Albedo dosemeters

    This work studies the most important factors which affect the response of albedo neutron dosemeters containing LiF TLDs with the aim to improve their sensitivity. It includes tests of thickness and shape of the polyamide moderator body prototypes, albedo window diameter and TLD position inside the moderator. Analyzing the results, an albedo neutron dosemeter prototype, B4C covered, was developed. The prototype has a response three times higher than the albedo dosemeter now in use in Brazil. (author)

  17. PTB experience with design qualification testing of radiation dosemeters

    Radiation dosemeters with ionization chamber, a scintillator or a counting tube, are accepted for official calibration if the specimen has been approved by the PTB. The significance of the nowadays applied procedure, combining design qualification testing with subsequent calibration, is explained by comparing the measured data of the response of a given type A dosemeter, as a function of energy, dating back from periods prior to the introduction of the legal calibration duty, up to the dosemeter's official approval in 1982. (DG)

  18. Personal radiation monitoring with thermoluminescent dosemeters

    The technique of personal dosimetry used by SAPRA (Servico de Assessoria e Protecao Radiologica S/C Ltda., Brazil) is presented. Thermoluminescent monitors and CaSO4: Dy are used in pastilles united by teflon. Characteristics of the dosemeters are briefly reported. The system of thermoluminescent measurement, designed and constructed by SAPRA, and the system of personal monitoring are described. (M.A.C.)

  19. An extremity (wrist) dosemeter based on the Landauer InLight whole body dosemeter

    A number of Landauer's clients use wrist badges to monitor extremity doses surrounding the hand. In the past, in France, we have supplied clients with standard issue InLight (registered) whole body dosemeters, enclosed within a soft plastic pouch. A strap was used to secure the dosemeter around the wrist. The standard algorithm for whole body dosimetry was used to determine the dose-equivalent (Hp(0.07)). Clients requested a smaller and more comfortable design. Therefore, a new design was proposed in which only the InLight case and slide are contained within a smaller plastic pouch. This design is substantially smaller than the previous wrist badge and gives the client greater comfort while allowing the badges themselves to be read out using the same readers and procedures as our standard whole body dosemeters. A neutron dosemeter can also be included in this badge. This paper gives an overview of the new design and reports on type testing of the proposed wrist badge on an ICRU pillar (wrist) phantom, in terms of the energy and angular response. It was found that, while the standard algorithm for the InLight dosemeters performed well for photons and was correctly identifying the quality of the radiation exposure (low or high energy photons, low or high energy beta particles), there was a significant under response for beta particle exposures. Minor modifications to the algorithm were adopted. Finally, the recalculated results using the modified algorithm are compared to the requirements of the international standard for extremity dosemeters (ISO 12794:2000). (author)

  20. Dynamic alarm response procedures

    The Dynamic Alarm Response Procedure (DARP) system provides a robust, Web-based alternative to existing hard-copy alarm response procedures. This paperless system improves performance by eliminating time wasted looking up paper procedures by number, looking up plant process values and equipment and component status at graphical display or panels, and maintenance of the procedures. Because it is a Web-based system, it is platform independent. DARP's can be served from any Web server that supports CGI scripting, such as ApacheR, IISR, TclHTTPD, and others. DARP pages can be viewed in any Web browser that supports Javascript and Scalable Vector Graphics (SVG), such as NetscapeR, Microsoft Internet ExplorerR, Mozilla FirefoxR, OperaR, and others. (authors)

  1. Toxicity alarm: Case history

    In late fall 1991, the Novacor petrochemical plant near Joffre, Alberta experienced a toxicity alarm, the first since its startup 14 years ago. Fish exposed to a normal toxicity test were stressed within 2 h and showed 100% mortality after 24 h. A history of the events leading up to, during, and after the toxicity alarm is presented. The major effluent sources were three cooling water systems. Although these sources are well characterized, the event causes were not immediately clear. Initial toxic screening indicated that one was very toxic, another moderately toxic, and the third not toxic at all. All three systems utilized the same chemical treatment program to avoid fouling: stabilized phosphates with minor variants. The most toxic of the cooling systems operated at 10-12 cycles, had three chemicals for biocide control, and had three makeup streams. Toxic and nontoxic system characteristics were compared. An in-depth modified toxicity identification and evaluation program was then performed to identify and evaluate the cause of the toxicity alarm for future prevention. The most probable causes of toxicity were identified by elimination. The combination of high numbers of cycles, hydrocarbons in the makeup water, and bromine added as an antifoulant resulted in formation of aromatic bromamines which are capable of causing the toxic condition experienced. 2 tabs

  2. EURADOS intercomparison 2012 for neutron dosemeters

    EURADOS, within the work performed by Working Group 2 - Harmonization of Individual Monitoring in Europe, has started a self-sustained programme of regular intercomparisons and has successfully executed three intercomparisons for whole body photon dosemeters (IC2008, IC2010, IC2012) and one intercomparison for extremity dosemeters for photon and beta fields (IC2009). In 2012, the EURADOS intercomparison IC2012n was launched for personal neutron dosemeters routinely used to measure personal dose equivalent, Hp(10), in individual monitoring. No systems under development were allowed to participate. IC2012n was carried out by a EURADOS nominated Organization Group (OG) consisting of: Marie- Anne Chevallier (IRSN, F), Rodolfo Cruz-Suarez (IAEA, UN-Vienna), Marlies Luszik-Bhadra (PTB, D), Sabine Mayer (PSI, CH), David J. Thomas (NPL, UK), Rick Tanner (PHE, UK), Filip Vanhavere (SCK-CEN, B) led by a Coordinator, Elena Fantuzzi (ENEA, I). 31 participants registered for the comparison, with 34 dosimetry systems. In total 816 dosemeters were irradiated in selected neutron fields on an ISO slab phantom. The irradiations were performed at 2 European accredited laboratories which are both National Primary Metrology Laboratories for ionizing radiation: NPL (National Physical Laboratory, UK) and PTB (Physikalisch-Technische Bundesanstalt, D). All irradiations were carried out according to the irradiation plan developed by the OG. The overall results show that most, although not all, dosimetric systems perform acceptably well (within a factor of 2) for irradiations with a bare radionuclide source (252Cf at 0 ), whilst more than half of the systems underestimate the reference value for irradiations from non-normal angles of incidence irradiations (252Cf at 45 ) or for simulated workplace fields (252Cf(D2O) or 252Cf source behind a shadow cone). The performance for 250 keV mono-energetic neutron irradiations varies mainly reflecting the detection principle on which the dosimetric

  3. EURADOS intercomparison 2012 for neutron dosemeters

    Fantuzzi, E. [ENEA-Radiation Protection Institute, Bologna (Italy); Chevallier, M.A. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Cruz-Suarez, R. [International Atomic Energy Agency, Vienna (Austria); Luszik-Bhadra, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Mayer, S. [Paul Scherrer Institute (PSI), Villigen (Switzerland); Thomas, D.J. [National Physical Laboratory (NPL), Teddington (United Kingdom); Tanner, R. [Public Health England, Oxon (United Kingdom); Vanhavere, F. [SCK-CEN, Belgian Nuclear Research Centre, Mol (Belgium)

    2014-11-15

    EURADOS, within the work performed by Working Group 2 - Harmonization of Individual Monitoring in Europe, has started a self-sustained programme of regular intercomparisons and has successfully executed three intercomparisons for whole body photon dosemeters (IC2008, IC2010, IC2012) and one intercomparison for extremity dosemeters for photon and beta fields (IC2009). In 2012, the EURADOS intercomparison IC2012n was launched for personal neutron dosemeters routinely used to measure personal dose equivalent, Hp(10), in individual monitoring. No systems under development were allowed to participate. IC2012n was carried out by a EURADOS nominated Organization Group (OG) consisting of: Marie- Anne Chevallier (IRSN, F), Rodolfo Cruz-Suarez (IAEA, UN-Vienna), Marlies Luszik-Bhadra (PTB, D), Sabine Mayer (PSI, CH), David J. Thomas (NPL, UK), Rick Tanner (PHE, UK), Filip Vanhavere (SCK-CEN, B) led by a Coordinator, Elena Fantuzzi (ENEA, I). 31 participants registered for the comparison, with 34 dosimetry systems. In total 816 dosemeters were irradiated in selected neutron fields on an ISO slab phantom. The irradiations were performed at 2 European accredited laboratories which are both National Primary Metrology Laboratories for ionizing radiation: NPL (National Physical Laboratory, UK) and PTB (Physikalisch-Technische Bundesanstalt, D). All irradiations were carried out according to the irradiation plan developed by the OG. The overall results show that most, although not all, dosimetric systems perform acceptably well (within a factor of 2) for irradiations with a bare radionuclide source ({sup 252}Cf at 0 ), whilst more than half of the systems underestimate the reference value for irradiations from non-normal angles of incidence irradiations ({sup 252}Cf at 45 ) or for simulated workplace fields ({sup 252}Cf(D{sub 2}O) or {sup 252}Cf source behind a shadow cone). The performance for 250 keV mono-energetic neutron irradiations varies mainly reflecting the detection

  4. Clinical Alarms in Intensive Care Units: Perceived Obstacles of Alarm Management and Alarm Fatigue in Nurses

    Cho, Ok Min; Kim, Hwasoon; Lee, Young Whee; Cho, Insook

    2016-01-01

    Objectives The purpose of this descriptive study was to investigate the current situation of clinical alarms in intensive care unit (ICU), nurses' recognition of and fatigue in relation to clinical alarms, and obstacles in alarm management. Methods Subjects were ICU nurses and devices from 48 critically ill patient cases. Data were collected through direct observation of alarm occurrence and questionnaires that were completed by the ICU nurses. The observation time unit was one hour block. On...

  5. Comparison of main thermoluminescent properties of some TL dosemeters

    Prokic, M.; Bøtter-Jensen, L.

    Different types of TL dosemeters that are attractive for dosimetry practice were investigated and compared. The aim of this study was to evaluate the TL characteristics of different TL dosemeters using two basically different types of commercially available TL readers. The findings demonstrate that...

  6. The performance of the NRPB radon personal dosemeter

    The NRPB has developed a radon personal dosemeter for use in mines. The dosemeter is being introduced into operational service subject to approval by the appropriate authorities. The principle of operation of the dosemeter is established both experimentally and theoretically. The dosemeter acts as a radon diffusion chamber, excluding radon progeny and detritus, limiting access of moisture but allowing relatively free access of radon gas. The alpha particles from the decay of radon and its progeny are recorded in a piece of polyallyl diglycol carbonate (PADC). The net density of the electrochemically etched pits is proportional to the time integral of the radon gas concentration external to the dosemeter. Prior to its introduction, trials of the dosemeter have been carried out in various mines in the United Kingdom. These trials were in addition to laboratory investigations of the performance of the dosemeter under simulated miners' conditions. The performance of the dosemeter is reported in terms of its ability to measure the time integral of the radon gas concentration unaffected by the environmental condition. (author)

  7. Performance of the Harshaw DXT-RAD (TLD-100) dosemeter

    Moor, D.M. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)], E-mail: dmoor@dstl.gov.uk; Horspool, B.; Stokes, R.P. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)

    2008-02-15

    The Defence Science and Technology Laboratory (Dstl) has type-tested the Harshaw DXT-RAD dosemeter against the International Standard ISO 12794:2000(E) 'Individual thermoluminescence dosemeters for extremities and eyes' [International Organization for Standardization, 2000. International Standard ISO 12794:2000(E). Nuclear energy-radiation protection-individual thermoluminescence dosemeters for extremities and eyes]. The tests carried out included batch homogeneity, reproducibility, linearity, detection threshold, environmental stability (temperature, humidity and light), self irradiation, isotropy, energy response, dose-rate response and neutron response. The DXT-RAD dosemeter satisfied all the requirements of ISO 12794:2000(E), with the exception of its response at low photon energies and intermediate beta energies. However, it should be noted that other forms of the DXT-RAD dosemeter with a thinner entrance window are available to give an improved response to low-energy radiations.

  8. A new, passive dosemeter for gamma, beta and neutron radiations

    The Defence Science and Technology Laboratory (Dstl) provides personal radiation dosimetry to the UK Ministry of Defence. Dstl has recently developed a dosemeter that is based on a combination of thermoluminescent and etched-track detectors. The Dstl Combined Dosemeter is capable of assessing doses due to photons, beta particles and neutrons. This paper presents the laboratory type testing results for the Combined Dosemeter, and also describes the procedure for calibrating the dosemeter for use in workplace neutron fields. The Combined Dosemeter meets the type test requirements that are relevant to its intended applications, and gives neutron doses that are within 50% of the true dose in the workplaces in which it is used, even when the wearer has the potential to be exposed to a variety of neutron spectra (e.g. on board nuclear-powered submarines).

  9. A new, passive dosemeter for gamma, beta and neutron radiations.

    Jones, L A; Stokes, R P

    2011-03-01

    The Defence Science and Technology Laboratory (Dstl) provides personal radiation dosimetry to the UK Ministry of Defence. Dstl has recently developed a dosemeter that is based on a combination of thermoluminescent and etched-track detectors. The Dstl Combined Dosemeter is capable of assessing doses due to photons, beta particles and neutrons. This paper presents the laboratory type testing results for the Combined Dosemeter, and also describes the procedure for calibrating the dosemeter for use in workplace neutron fields. The Combined Dosemeter meets the type test requirements that are relevant to its intended applications, and gives neutron doses that are within 50% of the true dose in the workplaces in which it is used, even when the wearer has the potential to be exposed to a variety of neutron spectra (e.g. on board nuclear-powered submarines). PMID:21346288

  10. The Coast Alarm System Editor

    The OECD Halden Reactor Project has for several years worked in the field of alarm handling. COAST was developed based on long experience with several different methods for identification of plant status and detection of plant anomalies. COAST has been delivered to a number of different organisations which generate their own applications. With COAST one can implement many alarm generation or structuring methods. So far, the alarm system is defined using a COAST language, COLA. Now, a first version of an editor to implement alarm systems is available, to support alarm system designers to write and structure their COLA code. It is developed based on general guidelines for user interface design and a thorough discussion of different editor types. The most important functionality needed when designing alarm systems for complex processes was emphasized when choosing the type of editor. A structure-oriented editor is currently implemented, and the report gives a description for how to include graphic features towards a more complete editor in the future. Support and encouragement for reuse of code is obtained by defining classes in a class library browser. Separate applications with their specific object definitions are constructed in an application browser. In this way the alarm classes from the class libraries can easily be used in several applications. The application browser offers the possibility to organize the alarm objects in a structured hierarchy. In big complex alarm systems such a structuring feature is of vital importance to keep the overview of the alarm system and to perform maintenance. (author)

  11. Calibration and characterization of the extremities dosemeters

    The increase of the use of diagnostic techniques and therapy in the medical sector by using radiation sources, as in the nuclear medicine and interventionist radiology, is providing a great progress for the health improvement. However, these used techniques can generate an exposure workers increase. These expositions occur mainly on specific parts of the body such as the hands; these can stay in direct contact or very near to the radiation source due to the used technique during medical procedures. In both cases it is necessary a dosimetry of the specific parts of the body according to the national regulation on radiological protection; the Comissao Nacional de Energia Nuclear - CNEN responsible for the nuclear medicine through the CNEN-NN-3.01 standard and Agencia Nacional de Vigilancia Sanitaria - ANVISA responsible for the X ray diagnostic equipment through Portaria 453/98 standard of the Health department. In both cases the extremities dosimetry is necessary for these professionals checking the of application principles of radiological protection through the comparison of the found values of dose with the limits allowed for the current law. For this dosimetric verification it is necessary the characterization with the type tests and calibration of the extremities dosemeters, assuring the trustworthiness of the joined results. This work had as objective the calibration and characterization of the extremities dosemeters made at CDTN in the 'Personal Dose Equivalent for Extremities - Hp(0,07)', using a finger simulator in gamma radiation fields (60Co and 137Cs) and X rays; having the process of the system calibration accomplished based on international ISO/DIS 12794-1 standard, which establishes the performance criteria and tests for determining the performance of the thermoluminescence dosemeters to be used for measuring the radiation doses to the extremities due to photons. (author)

  12. Comparing different error-conditions in film dosemeter evaluation

    In the evaluation of a film used as a personal dosemeter it may be necessary to mark the dosemeters when possible error-conditions are recognised, such as errors that have an influence on the ability to make a correct evaluation of the dose value. In this project a comparison has been carried out to examine how two individual monitoring services, IMS [National Inst. of Radiation Hygiene (Denmark) (NIRH) and National Research Centre for Environment and Health (Germany) (GSF)], from two different EU countries mark their dosemeters. The IMS are different in size, type of customers and issuing period, but both use films as their primary dosemeters. The error-conditions examined are dosemeters exposed to moisture or light, contaminated dosemeters, films exposed outside the badge, missing filters in the badge, films inserted incorrectly in the badge and dosemeters not returned or returned too late to the IMS. The data are collected for the year 2003 where NIRH evaluated ∼50,000 and GSF ∼1.4 million film dosemeters. The percentage of film dosemeters is calculated for each error-condition as well as the distribution among eight different employee categories, i.e. medicine, nuclear medicine, nuclear industry, industry, radiography, laboratories, veterinary and others. It turned out, that incorrect insertion of the film in the badge was the most common error-condition observed at both IMS and that veterinarians, as the employee category, generally have the highest number of errors. NIRH has a significantly higher relative number of dosemeters in most error-conditions than GSF, which perhaps reflects that a comparison is difficult due to different systemic and methodical differences between the IMS and countries, e.g. regulations and monitoring programs etc. Also the non-existence of a common categorisation method for employee categories contributes to make a comparison like this difficult. (authors)

  13. PC based film badge dosemeter reader

    A dedicated stand alone film badge dosemeter reader based on a PC is designed for existing personnel monitoring films, kept in a multifilter cassette. The system is designed using a conventional, in use, single beam densitometer, with a little change in its hardware as an input device and all the features of the system are incorporated through PC software. The output of densitometer is fed to PC through an interface which controls the entire operation of the system. Details of the design and its performance are described. (author). 6 refs

  14. Area monitoring using neutron albedo thermoluminescence dosemeters

    Thermoluminescence dosemeters (TLD) were used for area monitoring around neutron sources applying the moderating sphere technique and the albedo technique in which LiF, 6LiF, 7LiF as well TLD-200 were used as TLD. Experimental results indicated that the thermoluminescence (TL) output for moderating sphere system is five times the TL output of the albedo system. In order to increase the TL output for the albedo system a paraffin slab was placed close to the albedo system. (author)

  15. Barium dithionate as an EPR dosemeter.

    Baran, M P; Bugay, O A; Kolesnik, S P; Maksimenko, V M; Teslenko, V V; Petrenko, T L; Desrosiers, M F

    2006-01-01

    Electron paramagnetic resonance (EPR) dosimetry is growing in popularity and this success has encouraged the search for other dosimetric materials. Previous studies of gamma-irradiated barium dithionate (BaS(2)O(6) x 2H(2)O) have shown promise for its use as a radiation dosemeter. This work studies in greater detail several essential attributes of the system. Special attention has been directed to the study of EPR response dependences on microwave power, irradiation temperature, minimum detectable dose and post-irradiation stability. PMID:16565205

  16. Thermal neutron dosimetry using MOSFET dosemeters

    Fragopoulou, M., E-mail: fragom@auth.g [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece); Siskos, S.; Manolopoulou, M.; Zamani, M. [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece); Sarrabayrouse, G. [LAAS du CNRS, University of Toulouse, 7 Av. Du Colonel Roche, 31077 Toulouse (France)

    2009-10-15

    Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their surface were used as neutron dosemeter. The effect of thermal neutron irradiation on the threshold voltage of the transistor was studied in order to determine the sensitivity of these detectors. Irradiations were performed at the thermal column of the reactor in IPTA, Demokritos, Athens and at the subcritical reactor of Nuclear Physics Laboratory, Thessaloniki. The sensitivity of the MOSFETs as a function of thermal neutron dose was found to be practically linear up to 100 mSv. The lower detectable dose appears to be depended on the dose rate.

  17. Improvement of personal dosimetry - Digital pocket dosemeter

    Physical dosimetric surveillance of professional groups working with various radiation sources is a regular procedure in Croatia, established almost 40 years ago. Data available point out that the majority of professionals under surveillance are those employed in medical facilities, most of them working with X-ray sources. Depending on the nature of professional activities, personnel occupationally exposed to radiation sources are obliged to wear either film badge, TLD or film+TLD badge. Unfortunately, due to the line of data processing, all standard dosemeters have the same disadvantage i.e. up to 40 days delay in dose reporting, regarding the time of actual exposure. The significance of such a delay raises in cases when radiation dose was received within the short time or when technical failure on the operating unit(s) is suspected. Bearing this in mind, the additional dosimetric monitoring becomes an imperative. Therefore, we decided to introduce a palette of digital pocket dosemeters, meant to be used in different workplaces in the radiation zone, each of them being adjusted to the specificities of a particular workplace

  18. A climate of alarm

    The conventional view among scientists is that man-made global warming is real and potentially devastating. Climate physicist Richard Lindzen tells Edwin Cartlidge why he disagrees. Lindzen believes that even if man were indeed responsible for the vast majority of the warming observed in the last 100 years, he thinks there is still no cause for alarm. He claims the climate models used by the IPCC are far too sensitive to changes in the concentration of atmospheric carbon dioxide, and estimates that the Earth will in fact warm up by perhaps just a few tenths of a degree over the next century. Needless to say, this is a conclusion that other climate researchers strongly disagree with. Certainly in public, Richard Lindzen is in the minority when it comes to his belief that man is not seriously heating up the Earth. (U.K.)

  19. A prototype personal neutron dosemeter with one silicon diode

    The performance of a personal neutron dosemeter with a single silicon diode using a linear combination of its pulse height information was studied. Its dosimetric behaviour in fields with neutrons of different energy and directional distribution is shown for neutron energies ranging from thermal to 100 MeV and for directions of incidence ranging from frontal to lateral. The dosemeter is photon-insensitive and its dose detection threshold is at about 20 μSv. The dosimetric characteristics are compared with those of commercial dosemeters based on silicon detectors. (author)

  20. Dosimetric characteristics of a TLD dosemeter with extremities

    It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm3 covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)

  1. Line supervision of alarm communications

    The objective of this paper is to explain the role and application of alarm communication link supervision in security systems such as for nuclear facilities. The vulnerabilities of the various types of alarm communication links will be presented. Throughout the paper, an effort has been made to describe only those technologies commercially available and to avoid speculative theoretical solutions

  2. Fundamental Principles of Alarm Design

    Us, Tolga; Jensen, Niels; Lind, Morten;

    2011-01-01

    Traditionally alarms are designed on the basis of empirical guidelines rather than on a sound scientific framework rooted in a theoretical foundation for process and control system design. This paper proposes scientific principles and a methodology for design of alarms based on a functional...... modeling technique (MFM) which represents a process in terms of its goals, functions and operating requirements. The reasoning capabilities of MFM enable identification of operational situations which threaten to generate an alarm and derivation of potential response scenarios. The design methodology can...... be applied to any engineering system which can be modeled by MFM. The methodology provides a set of alarms which can facilitate event interpretation and operator support for abnormal situation management. The proposed design methodology provides the information content of the alarms, but does not...

  3. Response of Alanine Dosemeter to Heavy Ions

    LiWenjian; SuXu; YangYingjie; YuanJianlei; DangBingrong; WangXiao; MaQiufeng; ZhouLibin; HaoJifang; MaoShuhong

    2003-01-01

    The amino acid L-α-alanine has been investigated for use as a radiation detector in low and high LET radiation fields[1]. The radiatioa detector is cheap and easy to handle. The radiation inducing free radicals are stable at normal laboratory conditions for doses below 104 Gy over a long period of time, which makes the detector useful for intercomparison and documentation purposes. The dosimetric features of alanine-based electron spin resonance (ESR) detectors in high energy electron beams used in radiotherapy were considered[2]. The 5 mm long alanine detectors were found to be the most suitable for carrying out in vivo dosimetry on patients undergoing electron beam radiotherapy. However, data concerning dosimetry of the alanine dosemeter to heavy charged particles are lacking, especially in China.

  4. Active electronic personal dosemeter in interventional radiology

    A recently developed active electronic personal dosemeter (AEPD) was utilised in order to measure the levels and the structure of occupational exposure to scattered X-ray radiation of medical staff who performed percutaneous revascularisation therapy that involves interventional radiology (IR) on the pelvis and upper leg arteries. The AEPDs, placed on the operators' and assistants' chests, that is, above the protective apron, continuously measured and recorded the received doses and, as a novelty, dose rates as a function of time, thus yielding a unique record of occupational doses and dose rates pattern at the working place. This paper presents and discusses one typical daily pattern in which seven percutaneous interventions were performed. (authors)

  5. Measurement analysis using the Fricke dosemeter

    The Fricke dosemeter has been used for absolute determination of the radiation dose between 40 and 350 Gy for X-rays, Gamma rays and fast electrons energies. The great inconvenient of that dosimetric system is the impossibility of using for measurements of exposure or low dose rates. A Fricke dosimetry system was implanted at the Nuclear Sciences Regional Center (CRCN), in Recife, Pernambuco state, Brazil, for the determination of radiation doses for spectrometry and mass dosimetry with plasma source. The statistical analysis of the obtained results have shown that using the spectrometric method that system cna be used for maintenance of factors of CRCN standard calibrations and the dose assessment thru mail system of radiotherapy centers of the country

  6. European intercomparison of diagnostic dosemeters: performance of the programme

    This paper reports on participants, organisation and measuring conditions of the European-wide intercomparison programme of dosemeters used in diagnostic radiology, in a programme carried out in 1990 on protectorate of the CEC. (author)

  7. European intercomparison of diagnostic dosemeters: performance of the programme

    This paper reports on participants, organisation and measuring conditions of the European-Wide intercomparison programme of dosemeters used in diagnostic radiology in a programme carried out in 1990 on protectorate of the CEC

  8. Household and workplace chemicals as retrospective luminescence dosemeters

    Thomsen, Kristina Jørkov; Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    , there are Other potential unheated crystalline materials found in the domestic and industrial environment which may also act as retrospective dosemeters, and may be considerably more sensitive. We have Surveyed the thermoluminescent and optically stimulated luminescent (OSL) characteristics of several...

  9. Alarm fatigue: a patient safety concern.

    Sendelbach, Sue; Funk, Marjorie

    2013-01-01

    Research has demonstrated that 72% to 99% of clinical alarms are false. The high number of false alarms has led to alarm fatigue. Alarm fatigue is sensory overload when clinicians are exposed to an excessive number of alarms, which can result in desensitization to alarms and missed alarms. Patient deaths have been attributed to alarm fatigue. Patient safety and regulatory agencies have focused on the issue of alarm fatigue, and it is a 2014 Joint Commission National Patient Safety Goal. Quality improvement projects have demonstrated that strategies such as daily electrocardiogram electrode changes, proper skin preparation, education, and customization of alarm parameters have been able to decrease the number of false alarms. These and other strategies need to be tested in rigorous clinical trials to determine whether they reduce alarm burden without compromising patient safety. PMID:24153215

  10. A CR-39 track dosemeter for routine individual neutron monitoring

    A personal neutron dosemeter for routine individual monitoring is proposed. It is based on a CR-39 track detector covered on three separate areas by converters with different boron contents and inserted into a commercial TLD albedo dosemeter capsule. The dose readings from three areas of the electrochemically etched CR-39 detector are combined to yield a dose equivalent response which is almost independent of the incident neutron energy in the range from thermal neutrons up to 20 MeV. In addition, the dose contributions of thermal, intermediate and fast neutrons can be determined separately. Unlike the TLD albedo dosemeter, which in general requires prior in-field calibration and whose use is then restricted to that field, this dosemeter can be used in neutron fields without any knowledge of the spectral distribution with the same calibration factor. The angular dependence of the dosemeter's response has been measured and compared with that of the directional dose equivalent H'(10). The lower limit of detection is 0.15 mSv. It is possible to obtain an independent, second dose reading from the same Cr-39 detector for neutron energies above 100 keV. The dosemeter has also been successfully tested for use in accident dosimetry applying chemical etching and an optical density reading of the CR-39 detector. (author)

  11. Alarm system advances and innovations

    Alarm: 'a signal (as a loud noise or flashing light) that warns or alerts; also: a device that signals... '. This statement, this definition as simple as it is sums up every alarm system for every control system that has ever existed, but what it's missing from it is the complexity and uniqueness required by a Nuclear Power Plant. With advances in computerized control and engineering technologies within these plants, the need for more comprehensive alarm control and monitoring systems is as critical as the operation itself. (authors)

  12. Fundamental principles of alarm design

    Traditionally alarms are designed on the basis of empirical guidelines rather than on a sound scientific framework rooted in a theoretical foundation for process and control system design. This paper proposes scientific principles and a methodology for design of alarms based on a functional modeling technique (MFM) which represents a process in terms of its goals, functions and operating requirements. The reasoning capabilities of MFM enable identification of operational situations which threaten to generate an alarm and derivation of potential response scenarios. The design methodology can be applied to any engineering system which can be modeled by MFM. The methodology provides a set of alarms which can facilitate event interpretation and operator support for abnormal situation management. The proposed design methodology provides the information content of the alarms, but does not deal with alarm presentation or display design issues. A hydraulically powered grinding process is employed as an industrially relevant system to show the applicability of the proposed design methodology with promising results. (author)

  13. Use of pagers with an alarm escalation system to reduce cardiac monitor alarm signals.

    Cvach, Maria M; Frank, Robert J; Doyle, Pete; Stevens, Zeina Khouri

    2014-01-01

    Alarm fatigue desensitizes nurses to alarm signals and presents potential for patient harm. This project describes an innovative method of communicating cardiac monitor alarms to pagers using an alarm escalation algorithm. This innovation was tested on 2 surgical progressive care units over a 6-month period. There was a significant decrease in mean frequency and duration of high-priority monitor alarms and improvement in nurses' perception of alarm response time, using this method of alarm communication. PMID:23963169

  14. Central alarm system replacement in NPP Krsko

    Current NPP Krsko central alarm system consists of three main segments. Main Control Board alarm system (BETA 1000), Ventilation Control Board alarm system (BETA 1000) and Electrical Control Board alarm system (BETA 1100). All sections are equipped with specific BetaTone audible alarms and silence, acknowledge as well as test push buttons. The main reason for central alarm system replacement is system obsolescence and problems with maintenance, due to lack of spare parts. Other issue is lack of system redundancy, which could lead to loss of several Alarm Light Boxes in the event of particular power supply failure. Current central alarm system does not provide means of alarm optimization, grouping or prioritization. There are three main options for central alarm system replacement: Conventional annunciator system, hybrid annunciator system and advanced alarm system. Advanced alarm system implementation requires Main Control Board upgrade, integration of process instrumentation and plant process computer as well as long time for replacement. NPP Krsko has decided to implement hybrid alarm system with patchwork approach. The new central alarm system will be stand alone, digital, with advanced filtering and alarm grouping options. Sequence of event recorder will be linked with plant process computer and time synchronized with redundant GPS signal. Advanced functions such as link to plant procedures will be implemented with plant process computer upgrade in outage 2006. Central alarm system replacement is due in outage 2004.(author)

  15. Characterization of the personal thermoluminescent dosemeter of LiF: Mg, Ti + Ptfe

    The objective of this work is to characterize the thermoluminescent dosemeters taken place in the laboratory in form of pellets of LiF: Mg, Ti + Ptfe like personal dosemeters, subjecting them to the operation tests proposed by the international standards and comparing them with the TLD-100, the Tl dosemeter more used at the moment for personal dosimetry

  16. Testing of a TLD and a direct ion storage (DIS) dosemeter for use as a personal dosemeter

    The dosimetric performance characteristics of a TLD system (Harshaw Model 6600 with TLD-100 LiF-pellets) installed at the Personal Dosimetry Laboratory of the Finnish Centre for Radiation and Nuclear Safety have been tested. Tests performed are based on the IEC Standard 1066. Along with the TLD system some novel direct ion storage (DIS) dosemeters (Rados Technology Oy) were also included in some of the tests and the results for DIS dosemeters were also compared with the performance criteria of IEC 1066. Direct comparison of the results between TLDs and DIS dosemeters is not made, as only a few of early stage design DIS dosemeters were available. The tests were made of photon radiation using the personal dose equivalent at 10 mm depth, i.e. Hp(10), as a testing quantity. Based on the recommendations of ICRU and ICRP and the results obtained the applicability of both types of dosemeters for use in an official personal dose monitoring system is assessed. (Author)

  17. Conversion from dosemeter readings to effective dose in individual dosimetric monitoring: effect of anisotropy of photon fields and dosemeter design

    Monte Carlo simulation (MCNP-4B code, ADAM phantom) was employed in order to estimate organ doses and doses to personal dosemeters of particular commercial design (one type of Harshaw dosemeter and two designs of RADOS dosemeters) in situations of irradiation of a person in photon radiation fields. For each photon energy and beam direction the partial conversion coefficients were calculated providing thus raw data for modeling of effective conversion coefficient in any photon radiation field. In practical situations, when specific orientation of a body in radiation field is not known or a person is changing his position and orientation, the most robust parameter representing geometry of exposure is anisotropy of radiation field. In order to assess effective conversion coefficients for variety of workplace conditions, both anisotropic field configuration and orientation of a person in radiation field were stochastically simulated and 95% percentile of stochastic distribution was taken as a value of effective conversion coefficient for given conditions of exposure. The value of effective conversion coefficient depends on anisotropy of radiation field and can be quantitatively derived for appropriate classes of anisotropy. For quasi-isotropic and moderately anisotropic fields effective conversion coefficient does not exceed unity (e.g. Hp(10) maintains conservatism) for all considered dosemeter types, while in strongly anisotropic fields Hp(10) is not conservative anymore and can underestimate effective dose. The described approach is illustrated by examples of appropriate effective conversion coefficients for several commonly used dosemeter types. (author)

  18. Official dosimetry with personal electronic dosemeters - The framework in Germany

    In Germany, personal electronic dosemeters (AEPDs) are presently applied mainly for operational radiation protection monitoring particularly in nuclear power engineering companies, large hospitals and research centres. This is done in addition to the official dosimetry of record. Therefore, frequently, double monitoring occurs - officially and operationally. A crucial advantage of AEPDs compared with passive dosemeters is the ability to adapt the monitoring period to the working time in controlled areas and to allow an immediate readout of the dose after leaving the controlled area, e.g. a job-related monitoring is possible by correlating the readout dose with the job performed. Germany started a general research project, consisting of two parts, for an optimised implementation of personal electronic dosemeters into official dosimetry. The use of AEPDs as official dosemeters depends on an approval by Federal and Federal State ('Laender') authorities as an official dosimetry system, which has to comply with special requirements ensuring that the legal requirements are fulfilled. The formulation of these special requirements is in the focus of part one of the research project, supervised by the Federal Office for Radiation Protection (BfS) and performed by the Gesellschaft fuer Anlagen-und Reaktorsicherheit (GRS) mbH. As a result of part one, a framework was developed which is the basis for a future technical implementation project. Part one is described in the paper, while part two is still to be initiated and will deal with the implementation and testing phase of the introduction of personal electronic dosemeters as official dosemeters. (authors)

  19. An international intercomparison of passive dosemeters, electronic dosemeters and dose rate meters used for environmental radiation measurements

    Bøtter-Jensen, L.; Thompson, I.M.G.

    1995-01-01

    To assist towards the harmonisation within the EC countries, the Eastern European countries and the USA, of the measurement of environmental dose rates from photon radiation an EC sponsored intercomparison of environmental dose rate meters, electronic dosemeters and TL dosemeters was performed...... during 1994. The intercomparison was organised by the Physikalisch Technische Bundesanstalt (PTB), Braunschweig, Germany, and by the Riso National Laboratory, Roskilde, Denmark. This paper describes the intercomparison experiments performed at the newly established Riso Natural Environmental Radiation...... Measurement Stations during the period 12 to 18 June 1994. The chief aims of the experiments were to allow the participants to check their home calibrations of their detectors and to intercompare the dosemeter responses of the individual environmental radiation measurement systems used in the USA, Eastern...

  20. The influence of the energy distribution of workplace fields on neutron personal dosemeter reading

    Variations in the energy dependence of response of neutron personal dosemeters cause systematic errors in the readings obtained in workplace fields. The magnitude of these errors has been determined theoretically by folding measured and calculated workplace energy distributions with dosemeter response functions, to determine the response of a given personal dosemeter in that field. These results have been analysed with consideration of the dosemeter response to various calibration spectra, and with reference to different workplaces. The dosemeters in the study are discussed in terms of the workplaces for which they can be suitably calibrated. Deficiencies in the published neutron energy distributions are identified

  1. Functional alarming and information retrieval

    This paper deals with two facets of the design and efficient utilisation by operating personnel of computer-based interfaces for monitoring and the supervisory control of complex industrial systems - e.g., power stations, chemical plants, etc. These are alarming and information retrieval both of which are extremely sensitive to computerisation. For example, the advent of computers for display requires that some means of assuring easy and rapid access to large amounts of relevant stored information be found. In this paper, alarming and information retrieval are linked together through a multilevel functional description of the target plant. This representation serves as a framework for structuring the access to information as well as defining associated ''alarms'' at the various descriptive levels. Particular attention is paid to the level where mass and energy flows and balances are relevant. It is shown that the number of alarms here is reduced considerably while information about content and interrelationships is enhanced - which at the same time eases the retrieval problem. (author)

  2. Comparison on characteristics of radio-photoluminescent glass dosemeters and thermoluminescent dosemeters

    The radio-photoluminescent glass dosemeter (RPLGD) system is applicable for measurement of radiation dose of X-rays and gamma rays by using radio-photoluminescent glass (silver-activated phosphate glass). When the radio-photoluminescent glass is exposed to ionizing radiation, stable luminescent centres are created. During pulsed ultraviolet laser excitation (337.1 nm) in the reader, the centres emit a radiation induced orange fluorescent light (600-700 nm). This phenomenon is called radio-photoluminescence. This study compared the RPLGD system with lithium fluoride (LiF) thermoluminescence dosimetry system and the results of the study revealed that the RPLGD had not only good basic characteristics for reproducibility of readout value, dose linearity, energy dependence and fading, but also infinite repeatable measurements and could be one of the most important radiation dose measurement instruments. (authors)

  3. EURADOS intercomparisons on whole body and extremity dosemeters (2008–2009) – Results and comparison of different dosemeter designs

    The EURADOS (European Radiation Dosimetry Group) working group (WG2) on Harmonisation of Individual Monitoring in Europe has shown that intercomparisons are fundamental for harmonisation of individual monitoring. As a result of these considerations, EURADOS started to prepare a series of continuous intercomparisons for individual monitoring services (IMS) in Europe. EURADOS has now successfully executed two intercomparison exercises, one for whole body dosemeters (2008) and one for extremity dosemeters (2009). Both exercises were performed without external funding, all costs being covered by the participants’ fees. More than 120 (!) different – mainly passive – dosimetry systems were tested from all over Europe until now and the results were analysed and compared. Although scientific studies were not the primary objective of these exercises specific additional information about the tested systems supplied by the participants for statistical analysis allows a detailed analysis of these results with respect to different parameters like dosemeter type, detector material, filter thickness or others design parameters. The influence of such parameters on the response values of the dosemeters is analysed and discussed in this paper. Both energy response as well as directional response for beta and photon radiation are considered. The influence of different design parameters e.g. detector material, is analysed by comparing the frequency distribution of the response values for different dosemeter groups. Pronounced differences for different detector materials (LiF:Mg,Ti, LiF:Mg,Cu,P and Li2B4O7/CaSO4) were found. The paper gives a comprehensive overview on the performance of various European dosimetry services and the influence of the dosemeter design on the resulting response values.

  4. Electronic personal neutron dosemeters for high energies: Measurements, new developments and further needs

    The results of measurements with neutron energies up to 60 MeV are shown for the personal neutron dosemeters Thermo Electron EPD-N2, ALOKA PDM-313 and the PTB prototype dosemeter DOS-2002. All dosemeters show dose equivalent responses that are about a factor of 10, too high at 60 MeV. A new prototype dosemeter - called DOS-2005 - consisting of a detector with a thin effective layer of 6 μm has been set up at PTB. The dose equivalent response of this dosemeter and that of the newly developed dosemeter SAPHYDOSE-N was measured up to 19 MeV. Both dosemeters indicate a more flat response at high neutron energies. Further needs - optimisations, measurements and calculations - for use at high-energy accelerators and in space are discussed. (authors)

  5. Design strategies of alarm system for SMART

    The high level goal of the SMART-AS (Alarm System for System-integrated Modular Advanced ReacTor) is for operators to enthusiastically accept a new technology that will improve their response to alarms during plant transient conditions. Three alarm system design characteristics were included: (1) alarm processing (degree of alarm reduction); (2) alarm availability (prioritization and suppression); and (3) alarm display (a dedicated tile format, a mixed tile and message list format, and a format in which alarm information is integrated into the process displays). The SMART-AS prioritizes alarms based on the state of the plant; reduces the amount of information presented to the operator by grouping and display the arms in accordance with the present state of the plant; and allows nuisance alarms to be suppressed. This paper provides an introduction into applying the data mining techniques for the alarm processing of SMART-AS. In this paper, we describe our data mining algorithms, and illustrate how to apply these algorithms to generate an alarm suppression model from the alarm data. (authors)

  6. Some characteristics of the AEOI Neutriran Albedo Neutron Personnel Dosemeter

    The Neutriran Albedo Personnel Neutron Dosemeter (NAPND) is based on the combination of a sensitive polymer such as polycarbonate (PC) in contact with 6LiF or 10B pellets in a cadmium cover. By adding a 10B pellet in front, the design of the dosemeter can be such that when worn on the body, direct thermal neutron induced alpha tracks (TNIAT), albedo neutron induced alpha tracks (ANIAT) and fast neutron induced recoil tracks (FNIRT) can be simultaneously detected in a single electrochemically etched PC foil. To establish a national personnel neutron dosimetry service in Iran, different parameters such as the effect of 10B(n,α)7Li convertor thickness, Cd thickness and its diameter, dosemeter distance from the phantom, dosemeter angle with phantom and directional response were studied using different phantoms. Under optimised conditions, a sensitivity of 1500 tracks.cm-2.mSv-1 for 252Cf neutrons with a lowest value of 0.05 mSv was measured. The results of these studies are reported and discussed. (author)

  7. About the measurements systems with pen and thermoluminescent dosemeters

    In this work it is presented dosimetric data obtained with pen and thermoluminescent dosemeters, which are used by the Occupational Exposure Personnel (OEP) of the Mexican Petroleum Institute (IMP)(1). It was marked several great characteristics as for example, the differences among units which use one and another dosemeter type. Likewise, it is given to know diverse problems that were had in the IMP at relating the data obtained with these dosemeters (which utilizes OEP) and the ICRP 60 recommendations 1990. One of the most important difficulties is to satisfy the recommended limits by ICRP, particularly those that are referring to the units and their complex calculations. With respect to the unities, the ICRP makes reference at the concepts 'dose equivalent' and 'effective dose' with the sievert unit, that the General Regulations for Radiological Safety associates with 'dose equivalent' and 'effective dose equivalent'. It was illustrated the type of dosimetric statistics which are obtained with the TLD lectures and a OEP pen dosemeter during 1997. (Author)

  8. Radiological environmental monitoring with LiF-700-H dosemeters

    Scarnichia, E.; Levanon, I.; Andres, P.; Miani, C.; Ramirez, S., E-mail: andresp@cab.cnea.gov.ar [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, Grupo Proteccion Radiologica, Exequiel Bustillo 5AV 9500, R8402AGP San Carlos de Bariloche, Rio Negro (Argentina)

    2011-10-15

    Since 2008 a radiological environmental monitoring with LiF-700-H has been carried out as a result of increasing the Ra-6 research reactor core power. The information obtained is used to evaluate and to quantify analytically the air kerma rate, the fading and the associated uncertainty by developing software tools (deconvolution and uncertainty algorithms). LiF-700-H dosemeters were chosen because of their high sensitivity to low air kerma rates. They show a very good stability and a negligible fading for two-month working periods. The air kerma rate detection limit (based on the 3{sigma} criterion) during these working periods is about 0.4 n Gy/h. Air kerma rates of about 70 n Gy/h are measured with this detection limit. Following the Nist guidelines, an algorithm was developed in order to find the associated uncertainty. It considers several aspects, such as the source activity decay, distance source-dosemeter during the calibration procedure, irradiation time, calibration factor, dosemeter readout, dosemeter sensitivity, TLD reader stability and fading. The associated uncertainty is found to be about 25% for a 95% confidence interval (k = 2.025), which can be considered acceptable when taking into account the very low air kerma rates estimated. The LiF-700-H response to different energies and its relationship with climate changes over the calendar year are planned as future tasks. (Author)

  9. Graphite mixed magnesium borate TL dosemeters for beta ray dosimetry

    Prokic, M; Christensen, Poul

    1984-01-01

    Sintered MgB4O7:Dy dosemeters with graphite contents from 1 to 10% were investigated for application for personnel dosimetry. Data are given on dose response, dose threshold, reproducibility, beta energy response and fading. Furthermore, results from practical field experiments are presented...

  10. Fire auto alarm system intelligent trend

    The author gives the course and trend of the fire alarm system going to more computerized and more intelligent. It is described that only the system applied artificial intelligent and confusion control is the true intelligent fire alarm system. The author gives the detailed analysis on the signal treatment of artificial intelligent applied to analogue fire alarm system as well as the alarm system controlled by confusion technology and artificial nervous net

  11. 10 CFR 74.57 - Alarm resolution.

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Alarm resolution. 74.57 Section 74.57 Energy NUCLEAR... Quantities of Strategic Special Nuclear Material § 74.57 Alarm resolution. (a) Licensees subject to § 74.51 shall provide the MC&A alarm resolution capabilities described in paragraphs (b) through (f) of...

  12. 21 CFR 876.2040 - Enuresis alarm.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Enuresis alarm. 876.2040 Section 876.2040 Food and... GASTROENTEROLOGY-UROLOGY DEVICES Monitoring Devices § 876.2040 Enuresis alarm. (a) Identification. An enuresis... type of device includes conditioned response enuresis alarms. (b) Classification. Class II...

  13. SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

    The ''Subsurface Fire Hazard Analysis'' (CRWMS M andO 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M andO 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree

  14. Establishing local workplace field correction factors for neutron personal dosemeters

    The present personal neutron dosemeters still need local correction factors to be able to provide accuracy comparable with photon dosemeters. Characterisation of the local neutron field is an indispensable part of neutron dosimetry to obtain such correction factors. It is often overlooked that besides characterisation in the neutron energy also the directional distribution of neutrons plays a crucial part in this characterisation. The authors have done such characterisation in the energy and angle for four workplace fields in Paks NPP. For this a relatively simple approximation method was used using the Nprobe for the energy distribution and measurements on the six sides of the slab phantom with personal dosemeters for the directional distribution. This allowed one to estimate a reference neutron Hp(10) rate and to compare it with the response of several neutron personal dosemeters. In October 2011, a measurement campaign was set-up in Paks NPP, which is a VVER reactor type. The measurements were performed to estimate reference values for personal dose equivalent rates dHp(10)/dt and to evaluate the behaviour of several personal dosemeters at different locations inside the plant. Two locations in the pump room and two locations in the reactor hall were chosen. Instead of just assuming that the fluence is unidirectional or that the fluence is isotropic, an attempt was made to estimate the directional distribution of the neutron field using a relatively simple measurement procedure. A number of active and passive personal dosemeters were placed on the six faces of a slab phantom and the results were analysed to obtain partial fluences in several directions of incidence. This method has important limitations, but is relatively simple to perform. The results show that it is very important to include the directional distribution in the Hp(10) evaluation. When comparing Hp(10)/dt and H*(10)/dt, H*(10) can be considered a conservative value for Hp(10). In the pump room H

  15. CERN alarms data management: state and improvements

    The CERN Alarms System - LASER is a centralized service ensuring the capturing, storing and notification of anomalies for the whole accelerator chain, including the technical infrastructure at CERN. The underlying database holds the pre-defined configuration data for the alarm definitions, for the Operators alarms consoles as well as the time-stamped, run-time alarm events, propagated through the Alarms Systems. The article will discuss the current state of the Alarms database and recent improvements that have been introduced. It will look into the data management challenges related to the alarms configuration data that is taken from numerous sources. Specially developed Extract-Transform-Load (ETL) processes must be applied to this data in order to transform it into an appropriate format and load it into the Alarms database. The recorded alarms events together with some additional data, necessary for providing events statistics to users, are transferred to the long-term alarms archive. The article will cover as well the data management challenges related to the recently developed suite of data management interfaces in respect of keeping data consistency between the alarms configuration data coming from external data sources and the data modifications introduced by the end-users. (authors)

  16. Alarm system for ABWR main control panels

    TOSHIBA has developed integrated digital control and instrumentation system for ABWR, which is the third-generation man machine interface system for main control room that we call A-PODIA (Advanced PODIA). A-Podia has been introduced the first actual ABWR plant in Japan. in A-PODIA, TOSHIBA has realized improvement of alarm system that all operator crews in the control room can recognize plant anomalies easily. The alarm system can recognize essential alarms for plant safety easily and understand annunciators with each integrated annunciators and their prioritized color easily by classifying alarms into plant-level essential annunciators, system-level integrated annunciators and equipment level individual annunciators with hierarchical structure. This paper describes conventional alarm system and the design philosophy, alarm system design and operation of ''Alarm System for ABWR Main Control Panels''. (author). 5 refs, 8 figs, 1 tab

  17. Alarm-Processing in Nuclear Power Plants

    Information overload due to the activation of a great number of alarms in a short time is a common problem for the operator in the control room of a industrial plant, mainly in complex process like the nuclear power plants.The problem is the conventional conception of the alarm system, that defines each alarm like a separated and independent entity of the global situation of the plant.A direct consequence is the generation of multiple alarms during a significative disturbance in the process, being most of them redundant and irrelevant to the actual process state wich involves an extra load to the operator, who wastes time in acting selecting the important alarms of the group that appears or lead to a an erroneous action.The present work first describes the techniques developed in the last years to attack the avalanche of alarms problem.Later we present our approach to alarm-processing: an expert system as alarm-filter.Our objective is collect in the system the state of the art in the development of advanced alarm systems, offering an improvement of the information flow to the operators through the suppression of nonsignificant alarms and a structured visualization of the process state.Such support is important during a disturbance for the identification of plant state, diagnosis, consequence prediction and corrective actions.The system is arranged in three stages: alarm-generation, alarm-filter and alarm-presentation.The alarm-generation uses conventional techniques or receives them from an external system.The alarm-filter uses suppression techniques based on: irrelevance analysis with the operation mode and the state of components, causal reasoning and static importance analysis.The alarm presentation is made through a structured way using a priority scheme with three level.The knowledge representation of each alarm is based on frames and a graph of alarms for global knowledge, where the connections between nodes represent causal and irrelevance relations

  18. HOME INSECURITY: NO ALARMS, FALSE ALARMS, AND SIGINT

    Lamb, Logan M [ORNL

    2014-01-01

    The market share of home security systems has substantially increased as vendors incorporate more desirable features: intrusion detection, automation, wireless, and LCD touch panel controls. Wireless connectivity allows vendors to manufacture cheaper, more featureful products that require little to no home modification to install. Consumer win, since adding devices is easier. The result: an ostensibly more secure, convenient, and connected home for a larger number of citizens. Sadly, this hypothesis is flawed; the idea of covering a home with more security sensors does not translate into a more secure home. Additionally, the number of homes using these vulnerable systems is large, and the growth rate is increasing producing a even larger problem. In this talk, I will demonstrate a generalized approach for compromising three systems: ADT, the largest home security dealer in North America; Honeywell, one of the largest manufacturers of security devices; and Vivint, a top 5 security dealer. We will suppress alarms, create false alarms, and collect artifacts that facilitate tracking the movements of individuals in their homes.

  19. On the use of albedo dosemeters at the Dukovany nuclear power plant

    The response of the albedo dosemeter which is used as a personnel neutron dosemeter at the Dukovany nuclear power plant was studied. The design of the dosemeter was modified against the original version, whereby its dimensions were reduced and the dosemeter was augmented with a Cd shield to protect it against incident thermal neutrons. The study showed that the neutron spectrum inside the nuclear power plant varies over a wide range, and a correct interpretation of the albedo dosemeter data requires the use of a factor whose values can differ by as much as an order of magnitude. The results of the study allowed a procedure to be recommended for determining the Hp(10) value of the plant personnel using this device as an individual neutron dosemeter. (author)

  20. Evaluation of BICRON NE MCP DXT-RAD passive extremity dosemeter

    Yuen, P S; Frketich, G; Rotunda, J

    1999-01-01

    Passive extremity dosemeters currently used in dosimetry communities worldwide have shortcomings. In general, an extremity dosemeter has too thick a detector element, and the dosemeter response is highly energy dependent for beta rays with energies ranging from 200 keV to 2 MeV. It often does not have dosemeter identification, causing problems in the chain of custody. It is often read manually, rendering reading/packing operations very labour intensive. As a result of collaboration between AECL and BICRON NE, a new extremity dosemeter, incorporating a highly sensitive LiF:Mg,Cu,P TLD and tentatively code named MCP DXT-RAD, was developed. It has been evaluated for radiological performance against an ISO draft standard for extremity dosemeters in twelve categories: homogeneity, detection threshold, beta ray energy response, beta angular response, photon energy response, photon angular response, reproducibility, stability under various climatic conditions, linearity, residue, self irradiation, and effect of ligh...

  1. Video systems for alarm assessment

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing closed-circuit television systems for video alarm assessment. There is a section on each of the major components in a video system: camera, lens, lighting, transmission, synchronization, switcher, monitor, and recorder. Each section includes information on component selection, procurement, installation, test, and maintenance. Considerations for system integration of the components are contained in each section. System emphasis is focused on perimeter intrusion detection and assessment systems. A glossary of video terms is included. 13 figs., 9 tabs

  2. The use of extremity dosemeters in a hospital environment

    A general overview is given on the use of extremity dosemeters, their calibration, the units and phantoms to be used. One of the major applications of extremity dosemeters is to monitor the personnel in a hospital environment. In nuclear medicine, brachytherapy and interventional radiology (IR) skin doses to hands and legs can be substantial. Here, we report on two studies that are presently being undertaken in Belgium. The first one tries to map the dose distribution on the hands, in function of the manipulation in nuclear medicine. Some preliminary results are also given from a nationwide survey study for patient and personnel doses during IR and cardiology. The radiologists' hands, legs and forehead are monitored during a whole range of procedures in different hospitals. (authors)

  3. Photon personal dosemeter calibration based on ISO 4037-3

    The aim of this paper is to present the results of the influence of this new standard compared with the previously approved calibration protocol. The former calibration protocol used a 30 cm x 30 cm x 15 cm PMMA phantom and included back-scatter correction factors estimated from Monte Carlo calculations. Previous studies (Ginjaume et al., 2001) had shown, for a specific type of dosemeter, that the differences between both calibrations were very small, within 2%. This work planned, within the framework of the 2001 national intercomparison, to enlarge the preliminary conclusions by studying the influence of the calibration procedure on a larger set of dosemeters, which would be representative of the different Spanish Dosimetry Services. We were also interested in confirming that the new calibration procedure would not influence the general performance of the services and the corresponding registered doses

  4. Household and workplace chemicals as retrospective luminescence dosemeters

    In the development of techniques for the retrospective assessment of the dose absorbed by communities living and working adjacent to the site of a nuclear accident, attention has concentrated on the use of natural minerals such as quartz and feldspar as dosemeters. These minerals are widely found in household earthenware and almost all types of bricks and concrete. Their main disadvantages are variable and often low sensitivity, and the possibility of a comparatively large natural dose prior to the accident, depending on the age of the building and the type of building material. However, there are other potential unheated crystalline materials found in the domestic and industrial environment which may also act as retrospective dosemeters, and may be considerably more sensitive. We have surveyed the thermoluminescent and optically stimulated luminescent (OSL) characteristics of several such chemicals and this paper reports on the OSL sensitivity, the size of the residual dose immediately after manufacture, stability and derived minimum detection limits. (author)

  5. Performance and approval procedures for active personal dosemeters

    Active personal dosemeters (APDs) are well accepted as useful and reliable instruments for individual dosimetry measurements. The increasing concern about studying the behaviour of APDs in pulsed fields is illustrated through revision of the results of the most representative studies on the performance of APDs in the last 5 y. The deficiencies of APDs in pulsed fields are discussed together with proposals to overcome them. Although there are no legal constraints or technical limitations for recognising APDs for legal dosimetry in facilities with continuous radiation fields, APDs continue to be mainly used as operational dosemeters. The approval procedures applicable to APDs, especially the approach undertaken by Germany, are presented. Finally, some trends in the developments and use of APDs are summarised. (authors)

  6. Test and optimization of two routine dosemeters for the dose quantity Hp(3)

    The individual monitoring service Seibersdorf uses two different passive dosemeter types based on thermo luminescence (TL) detectors for monitoring occupationally exposed persons in Austria. Whole body personal dosemeters for the personal dose equivalent quantities Hp(10) and Hp(0.07) worn on the trunk and dosemeters for the extremities for Hp(0.07) worn on a finger or wrist. Both routine dosemeters were calibrated and tested in terms of the personal dose equivalent Hp(3) assuming that the whole body dosemeter is worn on the chest (without or above a lead apron) and the modified ring/wrist dosemeter using a special strap worn on the forehead near the eyes (head band dosemeter). The test results show that it is possible to measure the dose quantity Hp(3) with these dosemeters that were originally not designed for this dose quantity. Only changes in the dose calculation algorithm and in the choice of the reference radiation quality were necessary to fulfil the requirements given in international standards for passive dosemeters in a wide energy (20 keV–1.3 MeV) and angular range (0°–60°). - Highlights: • Whole body dosemeter for Hp(10) and Hp(0.07) can also be used for Hp(3). • The dose algorithm for whole body dosemeter can be changed for Hp(3). • Extremity dosemeter for Hp(0.07) can also be used for Hp(3) on the forehead. • The reference energy has to be changed for Hp(3)

  7. Development of an universal personal dosemeter using semiconductor sensors for mixed radiation fields

    The objective of the project is to develop a pocket sized personal dosemeter using semiconductor materials. This dosemeter will be able to give a reading as close as possible to the dose equivalence in radiation fields existing around reactors, accelerators, X and gamma sources. Furthermore, the pocket dosemeter will give a flat energy response according to the most recent ICRP recommendations. (R.P.) 2 figs

  8. Thermoluminescence sensitivity variations in LiF PTFE dosemeters incurred by improper handling procedures

    Mason, E W; MacKinlay, Alistair F; Saunders, D

    1975-01-01

    A systematic study of some anomalous darkening effects and thermoluminescence sensitivity variations observed in LiF:PTFE thermoluminescent dosemeters is described. Various likely causes of such effects have been investigated. The manufacturer's recommended cleaning procedures have been found to be inadequate and, in some cases, have been found to actually promote discolouration of the dosemeters. Recommendations are given for the successful use of LiF:PTFE thermoluminescent dosemeters in personal dosimetry.

  9. Tracking alarm causes by logic diagram

    An operator should provide the correct and fast actions on a cause of alarms and failure for reducing the effect of failure. There are a lot of study. But most of those studies may use a physical knowledges or causal relationships. Most of those studies impose on high level information like the physical knowledges or causal relationships of failure rather than the logical states or process signals as the detail causes of failure. It is very difficult that the physical knowledges or causal relationships are to be implemented and verified. This paper proposes a methodology for tracking alarm by logic of alarms. This methodology uses the proper logical knowledges on the proven logic and alarm diagram or electrical alarm relay logic than the uncertain physical knowledges or causal relationships. This system is to display the highlighted alarm procedure related to the causes. The system can be used for operator to identify the detail causes of alarm without checking all candidates for causes in alarm response procedure and the logical states of alarm with alarm logic disgrams provided on CRT dynamically

  10. Aluminium nitrate ceramics: A potential UV dosemeter material

    Trinkler, L.; Bøtter-Jensen, L.; Berzina, B.

    The ceramic material AIN-Y2O3 is proposed as a potential ultraviolet radiation (UVR) dosemeter using optically stimulated luminescence (OSL) and thermally stimulated luminescence (TL). Experimental studies have shown that AIN ceramics exhibit attractive characteristics suitable for practical UV...... Al2O3:C; and (4) a large dynamic range TL signal (5 orders of magnitude). Although there is relatively high fading, it is demonstrated that AIN is a feasible material for UVR dosimetry using short integration times....

  11. Achievable precision and accuracy of dose determinations from routine dosemeters

    The concepts of accuracy and precision as associated with dose determinations from routine dosemeters are analyzed. The factors which are most important when considering the accuracy of such measurements are then discussed. These include environmental conditions such as humidity, temperature, dose rate and time since irradiation. Some examples are presented. It is concluded that precision under identical irradiation conditions for reproducibility can be ± 2% at the 95% confidence level. The corresponding accuracy should not be more than ± 5%. (U.K.)

  12. Dose equivalent conversion coefficients, instrument and dosemeter responses for a set of neutron radiation fields

    The results are presented of calculations of spectrum (energy and angle) weighted conversion coefficients from fluence to the quantities effective dose equivalent, ambient dose equivalent (H*(10)), directional dose equivalent at 10 mm (H'(10)) and MADE; and of the responses per unit fluence of a spherical rem meter, a nuclear emulsion dosemeter, an albedo dosemeter and a PADC (CR39) dosemeter, for a set of neutron spectra. Calculations have been performed for both unidirectional fields and for rotational symmetry. The values of conversion coefficients and instrument and dosemeter responses are compared. (author)

  13. Development of active environmental and personal neutron dosemeters

    For neutron dosimetry in the radiation environment surrounding nuclear facilities, two types of environmental neutron dosemeters, the high-sensitivity rem counter and the high-sensitivity multi-moderator, the so-called Bonner ball, have been developed and the former is commercially available from Fuji Electric Co. By using these detectors, the cosmic ray neutrons at sea level have been sequentially measured for about 3 y to investigate the time variation of neutron spectrum and ambient dose equivalent influenced by cosmic and terrestrial effects. Our Bonner ball has also been selected as the neutron detector in the International Space Station and has already been used to measure neutrons in the US experimental module. The real time wide-range personal neutron dosemeter which uses two silicon semiconductor detectors has been developed for personal dosimetry and is commercially available from Fuji Electric Co. This dosemeter has good characteristics, fitted to the fluence-to-dose conversion factor in the energy range from thermal energies to several tens of mega-electron-volts and is now widely used in various nuclear facilities. (authors)

  14. Improved characterization of the NRPB PADC neutron personal dosemeter

    Full text: The NRPB PADC neutron personal dosimetry service has been operating routinely since 1986. During its years of operation, many changes have been introduced, notably to the etch process, detector material, read system and the holder. The fast-neutron energy dependence of response of the dosemeter, 100 keV to 15 MeV, has been characterized using a set of monoenergetic neutron fields. Below 100 keV, the response determination has been restricted to a thermal calibration supported by MCNP calculations. New data from the SIGMA field at Cadarache, France and GKSS in Germany, allied to improved MCNP calculations have been used to enhance the understanding of the response to thermal and intermediate-energy neutrons. Additionally, a new set of monoenergetic irradiations up to 19 MeV performed at the Physikalisch-Technische Bundesanstalt has augmented the existing data for the fast-neutron response. These show great consistency with data previously obtained at the National Physical Laboratory in the UK. The response between the measured and calculated energies has been evaluated using measurements in fields with broad energy distributions. The new response characteristics of the field have been folded with workplace fields representative of those in which the dosemeter is worn, so that the optimum calibration for the dosemeter can be obtained. (author)

  15. Official dosimetry with individual electronic dosemeters - the concept in Germany

    Full text: Presently, in Germany passive dosemeters (film batches, RPL, TLD) are used for the official individual monitoring of occupational exposed personal. The application of electronic individual dosemeters (EPD) is carried out mainly for the operative radiation protection control particularly in nuclear power engineering companies, big hospitals und research centres. This means in such institutions double monitoring exists - legally and operatively. A crucial advantage of EPD compared to passive dosemeter is the possibility to adapt the monitoring period to the working time in the control area, e.g. a job related monitoring is available. Germany started a project for an optimized implementation of EPD into the official dosimetry. Objective of the project whose results will be described in the paper is the harmonization of radiation protection of companies workers and outside workers concerning the record of individual and job related exposures. The approval of the EPD by the Federal and Laender authorities as an official dosimetric system demands the implementation of special requirements concerning the data acquisition, data transfer and data evaluation. These issues are focuses of the Federal research project, supervised by the Federal Office for Radiation Protection (BfS) and performed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS), Cologne to develop a concept in the first stage. (author)

  16. New operational quantities and the angular response of personal dosemeters

    New quantities, especially the ambient dose equivalent H* and the personal dose equivalent Hp at a specified point within the body have been defined by international rules. Practically, the measurement instrument cannot be placed at this point, but at the nearest point at the surface of the body. Such a difference in position results in errors varying with the incident radiation. The definition of these new quantities raises (1) the problem of the appropriateness of the present instruments and (2) the comparison with the legal film dosemeter, which is practically isotropic. The use of new instruments, especially in nuclear power plants (NPPs), results in measurement discrepancies between photographic and operational dosemeters and thus required further work on the angular response of operational dosemeters. The angular variations of the operational quantity Hp were considered in order to supplement the tables of an IEC draft for angle values ranging between 75 deg and 180 deg by means of simple calculations not contradictory with more thorough studies. (authors). 13 refs., 15 figs., 1 tab., 1 appendix

  17. Micro-dosemeter instrument (MIDN) for assessing risk in space

    Radiation in space generally produces higher dose rates than that on the Earth's surface, and contributions from primary galactic and solar events increase with altitude within the magnetosphere. Presently, no personnel monitor is available to astronauts for real-time monitoring of dose, radiation quality and regulatory risk. This group is developing a prototypic instrument for use in an unknown, time-varying radiation field. This micro-dosemeter-dosemeter nucleon instrument is for use in a space-suit, spacecraft, remote rover and other applications. It provides absorbed dose, dose rate and dose equivalent in real time so that action can be taken to reduce exposure. Such a system has applications in health physics, anti-terrorism and radiation-hardening of electronics as well. The space system is described and results of ground-based studies are presented and compared with predictions of transport codes. An early prototype in 2007 was successfully launched, the only solid-state micro-dosemeter to have flown in space. Published by Oxford Univ. Press on behalf of the US Government 2011. (authors)

  18. On the calibration of radiotherapy dosemeters in Australia

    Full text: Dosemeters for external beam radiotherapy are calibrated in Australia by ARPANSA, against the national primary standards of exposure and absorbed dose. The primary standards are free air chambers for exposure at low and medium energy X-rays, a graphite cavity chamber for exposure at 60Co, and a graphite calorimeter for absorbed dose at 60Co and high energy (MV) X -rays. Radiotherapy dosemeters are calibrated against these standards using a well documented formalism to provide calibration factors suitable for use with dosimetry protocols. A dosemeter usually comprises an ionization chamber connected to an independent electrometer. These are calibrated separately if possible. A combined calibration factor is reported together with the electrometer calibration factor (sensitivity). The dosimetry protocol used in radiotherapy centres in Australia and New Zealand is currently the simplified version of the IAEA TRS277 protocol, published by the New Zealand NRL and recommended by the ACPSEM. This protocol requires the use of an exposure or air kerma calibration factor at 60Co (Nx or Nk) to evaluate the absorbed dose to air calibration factor ND. The chamber is then placed in a water phantom with its centre displaced from the reference point by peff. ARPANSA can also supply calibration factors in absorbed dose to water (ND,w), as required as input to the new IAEA CoP. If an absorbed dose to water calibration factor is used by the radiotherapy centre, the chamber should be placed with its centre at the reference point in the water phantom. ARPANSA has for some years coordinated the participation of Australian radiotherapy centres in the IAEA TLD Quality Audit service. Note that this service does not represent a calibration and should not be referred to as such. The only calibration is that provided by ARPANSA for a reference dosemeter at each radiotherapy centre. As soon as the ANSTO SSDL is operational, calibrations of reference dosemeters will also be available

  19. Alarm management for storage and transportation terminals; Gerenciamento de alarmes para terminais de transferencia e estocagem

    Loureiro, Patricia [PETROBRAS, Rio de Janeiro, RJ (Brazil); Feldman, Rafael Noac [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    Recently, in many industrial segments, it has been taken into account the issues related to the high amount of alarms that are announced in the control rooms, even if the industrial process is under normal conditions. Recent studies and surveys have shown that the three major problems related to it are: alarms that remain active during normal operation; alarms that remain chattering during an operational period; the phenomenon called Alarm flood, that occurs when an extensive amount of alarms is announced and the operator does not have enough time to take effective actions. In order to reduce or to eliminate the two above mentioned causes, alarm analysis and housekeeping, called Alarm Rationalization, have been efficient in major cases, because such facts occur mainly due to inadequate limits definition and/or equipment and instruments out of service or in maintenance. Such alarms are called in the literature as bad-actors or villains, and their occurrences may reach up to 50% of the daily total amount of alarms. This paper aims to present the main results of a project named Alarm Management for Transfer and Storage Terminals. The project development is based on two different terminal surveys, in order not only to identify the most frequent causes of undesirable alarms, but also to generate design standards. The main phases of the project are: alarm rationalization based on bad-actors detection; generate a set of design and operation standards; generate an Alarm Philosophy document for the Terminals. (author)

  20. Alarm system management: evidence-based guidance encouraging direct measurement of informativeness to improve alarm response.

    Rayo, Michael F; Moffatt-Bruce, Susan D

    2015-04-01

    Although there are powerful incentives for creating alarm management programmes to reduce 'alarm fatigue', they do not provide guidance on how to reduce the likelihood that clinicians will disregard critical alarms. The literature cites numerous phenomena that contribute to alarm fatigue, although many of these, including total rate of alarms, are not supported in the literature as factors that directly impact alarm response. The contributor that is most frequently associated with alarm response is informativeness, which is defined as the proportion of total alarms that successfully conveys a specific event, and the extent to which it is a hazard. Informativeness is low across all healthcare applications, consistently ranging from 1% to 20%. Because of its likelihood and strong evidential support, informativeness should be evaluated before other contributors are considered. Methods for measuring informativeness and alarm response are discussed. Design directions for potential interventions, as well as design alternatives to traditional alarms, are also discussed. With the increased attention and investment in alarm system management that alarm interventions are currently receiving, initiatives that focus on informativeness and the other evidence-based measures identified will allow us to more effectively, efficiently and reliably redirect clinician attention, ultimately improving alarm response. PMID:25734193

  1. TMACS test procedure TP001: Alarm management. Revision 6

    The TMACS Software Project Test Procedures translate the project's acceptance criteria into test steps. Software releases are certified when the affected Test Procedures are successfully performed and the customers authorize installation of these changes. This Test Procedure addresses the Alarm Management requirements of the TMACS. The features to be tested are: real-time alarming on high and low level and discrete alarms, equipment alarms, dead-band filtering, alarm display color coding, alarm acknowledgement, and alarm logging

  2. False alarm reduction in critical care.

    Clifford, Gari D; Silva, Ikaro; Moody, Benjamin; Li, Qiao; Kella, Danesh; Chahin, Abdullah; Kooistra, Tristan; Perry, Diane; Mark, Roger G

    2016-08-01

    High false alarm rates in the ICU decrease quality of care by slowing staff response times while increasing patient delirium through noise pollution. The 2015 PhysioNet/Computing in Cardiology Challenge provides a set of 1250 multi-parameter ICU data segments associated with critical arrhythmia alarms, and challenges the general research community to address the issue of false alarm suppression using all available signals. Each data segment was 5 minutes long (for real time analysis), ending at the time of the alarm. For retrospective analysis, we provided a further 30 seconds of data after the alarm was triggered. A total of 750 data segments were made available for training and 500 were held back for testing. Each alarm was reviewed by expert annotators, at least two of whom agreed that the alarm was either true or false. Challenge participants were invited to submit a complete, working algorithm to distinguish true from false alarms, and received a score based on their program's performance on the hidden test set. This score was based on the percentage of alarms correct, but with a penalty that weights the suppression of true alarms five times more heavily than acceptance of false alarms. We provided three example entries based on well-known, open source signal processing algorithms, to serve as a basis for comparison and as a starting point for participants to develop their own code. A total of 38 teams submitted a total of 215 entries in this year's Challenge. This editorial reviews the background issues for this challenge, the design of the challenge itself, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. Additionally we make some recommendations for future changes in the field of patient monitoring as a result of the Challenge. PMID:27454172

  3. Results of an inquiry concerning experience gained in the use of thermoluminescent and phosphate glass dosemeters

    The report summarizes the results of an inquiry among users of thermoluminescent and phosphate glass dosemeters, carried out within the framework of the working group for 'external radiation dose measurement' of the Fachverband fuer Strahlenschutz eV. The data presented came in from 24 laboratories, showing their experience in the use of 38 different dosemeters. (orig.)

  4. Studying the sensitivity of personnel neutron dosemeter PDM-303 to high-energy neutron radiation

    The sensitivity of the PDM-303 personnel neutron dosemeter to high-energy radiation behind the U-70 accelerator shield and neutron calibration fields of IHEP is investigated. It is found that this dosemeter has high sensitivity to high-energy neutrons. The fact requires introduction of correcting calibration coefficients in the case of its application in conditions of the U-70 accelerator radiation

  5. 46 CFR 130.450 - Machinery alarms.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms....

  6. Intelligent alarm-processing system for NPP

    Information on developing the intelligent alarm-processing system for NPPs with BWR reactors, which makes it possible to reduce the information load for the operators through the information volume optimization, related to identification of failures in the NPP operation, is presented. Calculational principles and methodological constituents for processing alarm signals are considered. Description of the system and simulation check results are presented

  7. The CANDU alarm analysis tool (CAAT)

    AECL undertook the development of a software tool to assist alarm system designers and maintainers based on feedback from several utilities and design groups. The software application is called the CANDU Alarm Analysis Tool (CAAT) and is being developed to: Reduce by one half the effort required to initially implement and commission alarm system improvements; improve the operational relevance, consistency and accuracy of station alarm information; record the basis for alarm-related decisions; provide printed reports of the current alarm configuration; and, make day-to-day maintenance of the alarm database less tedious and more cost-effective. The CAAT assists users in accessing, sorting and recording relevant information, design rules, decisions, and provides reports in support of alarm system maintenance, analysis of design changes, or regulatory inquiry. The paper discusses the need for such a tool, outlines the application objectives and principles used to guide tool development, describes the how specific tool features support user design and maintenance tasks, and relates the lessons learned from early application experience. (author). 4 refs, 2 figs

  8. Textile Moisture Sensor for Enuresis Alarm System

    Kašurina, I; Vališevskis, A; Ziemele, I; Viļumsone, A

    2012-01-01

    The aim of this research is to develop an enuresis alarm system with textile moisture sensor (electrode), which is more suitable for textile garments. Authors propose to design sensor by embroidery using conductive yarn. Conductive yarns are a preferable material for enuresis alarm sensors, since they blend with the textile structure of underwear and bedding sheet, inducing less stress on the treated person.

  9. Knowledge Discovery from Communication Network Alarm Databases

    2000-01-01

    The technique of Knowledge Discovery in Databases(KDD) to learn valuable knowledge hidden in network alarm databases is introduced. To get such knowledge, we propose an efficient method based on sliding windows (named as Slidwin) to discover different episode rules from time sequential alarm data. The experimental results show that given different thresholds parameters, large amount of different rules could be discovered quickly.

  10. Development of Two-Dosemeter Algorithm for Better Estimation of Effective Dose Equivalent and Effective Dose

    An optimal algorithm, which suitably combines two dosemeter readings, one dosemeter on the chest and the other on the back, for better estimation of effective dose equivalent (HE) and effective dose (E), was developed by utilising hundreds of broad parallel photon beam irradiation geometries. The developed algorithm, weighting front (chest) and back dosemeter readings by 0.58 and 0.42, respectively, was found to be superior to other currently available algorithms, neither underestimating HE or E by more than 14%, nor overestimating by more than a few tens of a per cent for a broad range of frontal and dorsal incident beams. Like other algorithms, however, this algorithm tends to overestimate HE and E significantly for the lateral, overhead and underfoot beam directions. This study also suggests that this overestimation problem significantly decreases when one uses typical commercial dosemeters instead of isotropic-responding dosemeters. (author)

  11. Performance of several active personal dosemeters in interventional radiology and cardiology

    Active personal dosemeters (APDs) are very useful instruments for optimizing radiation protection of workers and for increasing worker’s awareness of unexpected exposures. The challenge of monitoring personal equivalent doses with APDs in interventional fluoroscopy is that they must be sensitive to low energy photon beams and be able to record high dose rates. The aim of this work is to verify both the performance and the reliability of four active personal dosemeters (APDs) and one direct ion storage (DIS) dosemeter in typical X-ray radiation fields used during interventional radiology and cardiology (IR/IC) procedures. The values of the personal dose equivalent at a depth of 10 mm measured by the APDs are compared with the response of a whole body thermoluminescence dosemeter (TLD) as a reference dosemeter. The response is found to be satisfactory in the tested situations.

  12. Electron scattering effects on absorbed dose measurements with LiF-dosemeters

    The investigation deals with absorbed dose measurements with solid wall-less dosemeters. Electron scattering complicates both measurement of absorbed dose and its theoretical interpretation. The introduction of the dosemeter in a medium causes perturbations of the radiation field. This perturbation and its effect on the distribution of the absorbed dose inside the dosemeter is studied. Plane-parallel LiF-teflon dosemeters (0.005 - 0.1 g.cm-2) are irradiated by a photon beam (137Cs) in different media. The investigation shows that corrections must be made for perturbations caused by electron scattering phenomena. Correction factors are given for use in accurate absorbed dose determinations with thermoluminescent dosemeters. (Auth.)

  13. A Method for evaluating personal dosemeters in workplace with neutron fields

    Passive detectors, as albedo or track-etch, still dominate the field of neutron personal dosimetry, mainly due to their low-cost, high-reliability and elevated throughput. However, the recent appearance in the market of electronic personal dosemeters for neutrons presents a new option for personal dosimetry. In addition to passive detectors, electronic personal dosemeters necessitate correction factors, concerning their energy and angular response dependencies. This paper reports on the results of a method to evaluate personal dosemeters for workplace where neutrons are present. The approach here uses few instruments and does not necessitate a large mathematical workload. Qualitative information on the neutron energy spectrum is acquired using a simple spectrometer (Nprobe), reference values for H*(10) are derived from measurements with ambient detectors (Studsvik, Berthold and Harwell) and angular information is measured using personal dosemeters (electronic and bubbles dosemeters) disposed in different orientations on a slab phantom. (authors)

  14. A method for evaluating personal dosemeters in workplace with neutron fields.

    de Freitas Nascimento, Luana; Cauwels, Vanessa; Vanhavere, Filip

    2012-04-01

    Passive detectors, as albedo or track-etch, still dominate the field of neutron personal dosimetry, mainly due to their low-cost, high-reliability and elevated throughput. However, the recent appearance in the market of electronic personal dosemeters for neutrons presents a new option for personal dosimetry. In addition to passive detectors, electronic personal dosemeters necessitate correction factors, concerning their energy and angular response dependencies. This paper reports on the results of a method to evaluate personal dosemeters for workplace where neutrons are present. The approach here uses few instruments and does not necessitate a large mathematical workload. Qualitative information on the neutron energy spectrum is acquired using a simple spectrometer (Nprobe), reference values for H*(10) are derived from measurements with ambient detectors (Studsvik, Berthold and Harwell) and angular information is measured using personal dosemeters (electronic and bubbles dosemeters) disposed in different orientations on a slab phantom. PMID:21565843

  15. Results of the IAEA/RCA personal dosemeter intercomparison

    The intercomparison of personal dosemeters for photon was carried out between 1990 and 1996 as part of the IAEA/RCA 'strengthening of radiation protection infrastructure' project. Japan Nuclear Cycle Development Institute participated in the intercomparison as one of the in-house personal dosimetry service organizations in Japan and also served the host irradiating laboratory. This report summarizes the dose evaluation results obtained from the JNC-TLD badges in the past four intercomparison programs. In the latest intercomparison the evaluated doses agreed to the reference doses with an accuracy of 10%. (author)

  16. Active personal dosemeters for individual monitoring and other new developments

    In this paper, we will present a first (but not complete) status description of active personal dosemeters (APDs) and their implementation in European countries. In modern radiation protection practices, APDs are becoming absolutely necessary operational tools for satisfying the ALARA principle. Despite their success, they are relatively new for individual monitoring of workers. Regulation, legal requirements and calibration procedures are different in European member states. A catalogue of commercially available and prototype devices is presented. Improvement on devices and in implementation of calibration method are expected in the forthcoming years. End-user feedback experience and requirements are reported. (authors)

  17. Method of making isodose curve using thermoluminescence dosemeter

    Line source of 60Co in the form of needles and tubes are extensively used in radiotherapy in moulds, implants, and intracavitary techniques for the treatment of malignant lesions. It is important to have isodose distributions in tissue for those source for purposes of treatment planning. The isodose distributions have been obtained experimentally by using tinny lithium-fluoride (Lsub(i)F) thermoluminescent dosemeters (TLD) and they are compared to the theoretical results. The distinct advantages of Lsub(i)F (TLD) in such measurements are briefly discussed. (author)

  18. Estimation of the patient monitor alarm rate for a quantitative analysis of new alarm settings.

    de Waele, Stijn; Nielsen, Larry; Frassica, Joseph

    2014-01-01

    In many critical care units, default patient monitor alarm settings are not fine-tuned to the vital signs of the patient population. As a consequence there are many alarms. A large fraction of the alarms are not clinically actionable, thus contributing to alarm fatigue. Recent attention to this phenomenon has resulted in attempts in many institutions to decrease the overall alarm load of clinicians by altering the trigger thresholds for monitored parameters. Typically, new alarm settings are defined based on clinical knowledge and patient population norms and tried empirically on new patients without quantitative knowledge about the potential impact of these new settings. We introduce alarm regeneration as a method to estimate the alarm rate of new alarm settings using recorded patient monitor data. This method enables evaluation of several alarm setting scenarios prior to using these settings in the clinical setting. An expression for the alarm rate variance is derived for the calculation of statistical confidence intervals on the results. PMID:25571296

  19. Reactor alarm system development and application issues

    The new hardware and software technologies, and the need in research reactors for assistance systems in operation and maintenance, have given an appropriate background to develop a computer based system named ''Reactor Alarm System'' (RAS). RAS is a software package, user oriented, with emphasis on production, experiments and maintenance goals. It is designed to run on distributed systems conformed with microcomputers under QNX operating system. RAS main features are: a) Alarm Panel Display; b) Alarm Page; c) Alarm Masking and Inhibition; d) Alarms Color and Attributes; e) Condition Classification; and f) Arrangement Presentation. RAS design allows it to be installed as a part of a computer based Supervision and Control System in new installations or retrofit existing reactor instrumentation systems. The analysis of human factors during development stage and successive user feedback from different applications, brought out several RAS improvements: a) Multiple-copy alarm summaries; b) Improved alarm handling; c) Extended dictionary; and d) Enhanced hardware availability. It has proved successful in providing new capabilities for operators, and also has shown the continuous increase of user-demands, reflecting the expectations placed today on computer-based systems. (author). 6 figs, 1 tabs

  20. Alarm points for fixed oxygen monitors

    Oxygen concentration monitors were installed in a vault where numerous pipes carried inert cryogens and gases to the Mirror Fusion Test Facility (MFTF-B) experimental vessel at Lawrence Livermore National Laboratory (LLNL). The problems associated with oxygen-monitoring systems and the reasons why such monitors were installed were reviewed. As a result of this review, the MFTF-B monitors were set to sound an evacuation alarm when the oxygen concentration fell below 18%. We chose the 18% alarm criterion to minimize false alarms and to allow time for personnel to escape in an oxygen-deficient environment

  1. Calibration, performance and type testing of personal dosemeters used in ionising-radiation applications in Greece.

    Boziari, A; Hourdakis, C J

    2007-01-01

    Active Personal Dosemeters (APDs) are widely used in real-time personal dosimetry. Their performance, operational characteristics and limitations, as well as their calibration should be routinely checked to assure satisfactory operation and safe use. This study summarises the results of such type tests and calibrations performed in almost 4750 dosemeters at Ionising Radiation Calibration Laboratory (HIRCL) of Greek Atomic Energy Commission (GAEC). About 13.8% of the pencil type and 4.3% of the electronic dosemeters were found to be out of limits of acceptable performance. For the pencil type dosemeters, the mean calibration factor (CF+/-SD) for high- and low-dose categories was found to be 1.014+/-0.102 (range 0.793-1.458) and 0.995+/-0.059 (range 0.794-1.311), respectively. Of these >85% of them had reproducibility better than 90%, while <1% showed remarkable non-linearity and approximately 10% of them failed to retain the dose reading within the limits after 24 h. For the electronic dosemeters, the mean CF was 1.034+/-0.046 (range 0.967-1.238). The majority of them showed good reproducibility and linearity results while, after irradiation, the dose readings were not shifted through time. The energy response varies with the dosemeter type, reaching in one dosemeter type down to 50%. Both electronic and pencil did not showed electronic equilibrium problems. PMID:17185312

  2. A study of the irradiation temperature coefficient for L-alanine and DL-alanine dosemeters

    Alanine dosimetry is now well established both as a reference and routine dosemeter for industrial irradiation processing. Accurate dosimetry under the relatively harsh conditions of industrial processing requires a characterisation of the parameters that influence the dosemeter response. The temperature of the dosemeter during irradiation is a difficult quantity to measure so that the accuracy of the temperature coefficient that governs the dosemeter response becomes a critical factor. Numerous publications have reported temperature coefficients for several types of alanine dosemeters. The observed differences in the measured values were commonly attributed to the differences in the polymer binder or the experimental design of the measurement. However, the data demonstrated a consistent difference in the temperature coefficients between L-alanine and DL-alanine. Since there were no commonalities in the dosemeter composition or the measurement methods applied, a clear conclusion is not possible. To resolve this issue, the two isomeric forms of alanine dosemeters were prepared and irradiated in an identical manner. The results indicated that the DL-alanine temperature coefficient is more than 50% higher than the L-alanine temperature coefficient. (authors)

  3. A Selection of Data Structure for SMART Alarm System Database

    A design goal of SMART Alarm System is providing intelligence alarm information to operator in main control room. To achive this, we should apply advanced alarm process logics and manage alarm data sets for advanced alarm logic. SMART Alarm System must analyze a lot of alarm by the cycle to determines alarms. For this, performance optimization of database is essential. Especially, high performance of search function is required. In this paper, we propose most a suitable search method to database by compare several search methods

  4. An expert system for alarm diagnosis and filtering

    This paper describes an alarm processing system being developed at the Oak Ridge National Laboratory for implementation in the High Flux Isotope Reactor. The purpose of the system is to perform two related functions, alarm diagnosis and filtering, to aid nuclear plant operators in responding to the large number of alarms typically activated during a major plant transient. The alarm diagnostician determines the root cause of a pattern or sequence of alarms and generates an explanation of the events leading to the alarm sequence. The alarm filter identifies and deemphasize those alarms which are either irrelevant to the current plant condition or contribute no significant new information

  5. 46 CFR 63.15-7 - Alarms.

    2010-10-01

    ... periodically unattended machinery space, the auxiliary boiler trip alarm required by 46 CFR 62.35-50, Table 62... reset. (c) For steam boilers, operation of the lower low water cutoff must automatically sound...

  6. Recommendations for the LHC safety alarm system

    Laeger, H

    1999-01-01

    A working group was set up to define the LHC safety alarm system, also known as Alarm-of-Level-3-System (AL3S). The mandate asked for recommendations to be elaborated on four items: the overall concept of the AL3S for machine and experiments, the transmission and display of safety alarms, the AL3S during civil engineering construction, and the transition from the present LEP to the final LHC safety alarm system. The members of the working group represented a wide range of interest and experience including the CERN Fire Brigade, safety officers from experiments and machines, and specialists for safety and control systems. The recommendations highlight the need for a clear definition of responsibilities and procedures, well-engineered homogeneous systems across CERN, and they point to several important issues outside the mandate of the working group. These recommendations were presented, discussed and accepted by several CERN and LHC committees.

  7. Addressing the alarm analysis barrier - a tool for improving alarm systems

    This paper describes a software application tool for the initial specification and maintenance of the thousands of alarms in nuclear and other process control plants. The software program is used by system designers and maintainers to analyze, characterize, record and maintain the alarm information and configuration decisions for an alarm system. The tool provides a comprehensive design and information handling environment for: the existing alarm functions in current CANDU plants; the new alarm processing and presentation concepts developed under CANDU Owners Group (COG) sponsorship that are available to be applied to existing CANDU plants on a retrofit basis; and, the alarm functions to be implemented in new CANDU plants. (author). 3 refs., 1 fig

  8. Principal alarms in multivariate statistical process control

    González, Isabel; Sánchez, Ismael

    2006-01-01

    This paper describes a methodology for the simulation of multivariate out of control situations using in-control data. The method is based on finding the independent factors of the variability of the process, and shifting these factors one by one. These shifts are then translated in terms of the observed variables. The shifts provoked by the most important factors are called principal alarms. The principal alarms are plotted, visualizing the main deviations of the process. Also, a resampling ...

  9. Dosimetric characteristics of a TLD dosemeter with extremities; Caracteristicas dosimetricas de un dosimetro TLD de extremidades

    Molina P, D.; Diaz B, E.; Lien V, R. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo.Postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)

    1999-07-01

    It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm{sup 3} covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)

  10. A digital interface for preset time or voltage measurements using an ionising radiation dosemeter

    A digital interface circuit has been built to terminate charge collection measurements made with an ionising radiation dosemeter. A compact portable measurement system has been assembled, comprising a digital voltmeter, a period timer and the digital interface module. Digital signals from both the voltmeter and the timer are compared with separate preset limits, and the dosemeter measurement is terminated when one of these limits is reached. The operation of the dosemeter is outlined, and the interface circuit is described in detail. Modifications to the voltmeter and timer are described, and comprehensive users' instructions are given

  11. A new type active personal dosemeter with a solid state detector

    We have developed a new type personal dosemeter by using a B-10 doped silicon p-n junction detector with a polyethylene radiator and a polyethylene moderator. The purpose of this study was to develop a real time neutron dosemeter with a nearly flat response in the energy range from thermal to 15 MeV and low angular dependence to the incident neutron direction. The neutron response of the dosemeter was obtained with the Monte Carlo calculation and the monoenergetic neutron experiment in a free air field and also under a condition attached on a phantom

  12. Sensor fusion for intelligent alarm analysis

    The purpose of an intelligent alarm analysis system is to provide complete and manageable information to a central alarm station operator by applying alarm processing and fusion techniques to sensor information. This paper discusses the sensor fusion approach taken to perform intelligent alarm analysis for the Advanced Exterior Sensor (AES). The AES is an intrusion detection and assessment system designed for wide-area coverage, quick deployment, low false/nuisance alarm operation, and immediate visual assessment. It combines three sensor technologies (visible, infrared, and millimeter wave radar) collocated on a compact and portable remote sensor module. The remote sensor module rotates at a rate of 1 revolution per second to detect and track motion and provide assessment in a continuous 360 degree field-of-regard. Sensor fusion techniques are used to correlate and integrate the track data from these three sensors into a single track for operator observation. Additional inputs to the fusion process include environmental data, knowledge of sensor performance under certain weather conditions, sensor priority, and recent operator feedback. A confidence value is assigned to the track as a result of the fusion process. This helps to reduce nuisance alarms and to increase operator confidence in the system while reducing the workload of the operator

  13. Thermoluminescent dosemeter in a X-ray diffractometer

    In this work it was presented the results obtained of the dosimetry which was realized in a X-ray diffractometer for powders, trademark Siemens D5000, using the thermoluminescent signal generated by the X-rays in the commercial dosemeter TLD-100 of Harshaw, US. In according to the results obtained, the radiation quantity received by an analysed material in the diffractometer, will be proportional to exposure time and it can vary from unities until tenths of grays. These results are very outstanding when are analysed crystalline materials in a diffractometer, for knowing the present crystalline phases, mainly if these are highly sensitive to the ionizing radiation, as it is the case of the thermoluminescent materials. (Author)

  14. Sensitivity of a LR-115 based radon dosemeter

    Bagnoli, F; Bucci, S

    1999-01-01

    The first results of a study on the sensitivity of a LR-115 based radon dosemeter as a function of the absorber thickness are presented. The theoretical sensitivity was analytically calculated considering a constant detector response to alpha particles within a given energy range and up to a critical angle of incidence. The results are presented in two extreme situations: i) both radon and its decay products uniformly distributed in the chamber volume; ii) radon decay products uniformly deposited on the chamber walls. The agreement with the experimental curve shape appears better in the former case, suggesting that either the parameter values of the model could be different from the chosen values, or the model was too simplified.

  15. Characterisation of an electronic radon gas personal dosemeter

    The monitoring of radon exposure at workplaces is of great importance. Up to now passive measurement systems have been used for the registration of radon gas. Recently an electronic radon gas personal dosemeter came onto the market as an active measurement system for the registration of radon exposure (DOSEman; Sarad GmbH, Dresden, Germany). In this personal monitor, the radon gas diffuses through a membrane into a measurement chamber. A silicon detector system records spectroscopically the alpha decays of the radon gas and of the short-lived progeny 218Po and 214Po gathered onto the detector by an electrical field. In this work the calibration was tested and a proficiency test of this equipment was made. The diffusion behaviour of the radon gas into the measurement chamber, susceptibility to thoron, influence of humidity, accuracy and the detection limit were checked. (author)

  16. 1983 ORNL intercomparison of personnel neutron and gamma dosemeters

    Swaja, R.E.; Sims, C.S.; Greene, R.T.

    1985-01-01

    The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the conditions of this study in which exposures were carefully controlled and participants had information concerning exposure conditions and incident spectra prior to dosemeter analysis, only slightly more than half of all neutron and gamma dose equivalent estimates met regulatory accuracy standards relative to reference values. These results indicate that continued improvement of mixed-field personnel dosimetry is required by many participating organizations. 15 references, 30 tables.

  17. 1983 ORNL intercomparison of personnel neutron and gamma dosemeters

    The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the conditions of this study in which exposures were carefully controlled and participants had information concerning exposure conditions and incident spectra prior to dosemeter analysis, only slightly more than half of all neutron and gamma dose equivalent estimates met regulatory accuracy standards relative to reference values. These results indicate that continued improvement of mixed-field personnel dosimetry is required by many participating organizations. 15 references, 30 tables

  18. Study of performance of a dosemeter based on thermoluminescent materials for external personnel monitoring

    The performance of a dosemeter based on thermoluminescent materials, 7 LiF and 6 LiF, was investigated. The verification if the dosemeter response complies with tests recommended by national and international regulatory organizations was performed. Tests of angular and energy dependence, reproducibility, detectability threshold, batch homogeneity and others were carried out and the obtained response is herein presented. Dosemeter response was evaluated in terms of Hp(10). The tests were carried out taking into account the IRD-RT No 001.01/95 and IEC 1066 reporters that gave the guidelines for this evaluation. The obtained response showed that the studied dosemeter complies with the tests and can be employed for individual monitoring. (author)

  19. The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace.

    Sisto, R; Lega, D; Militello, A

    2001-01-01

    In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the Subjects UVB exposure has been evaluated. An original experimental set-up is presented. in a preliminary version, which ill be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measrable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small closes. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability. PMID:11878432

  20. Development of electronic personal neutron dosemeters: A european co-operation

    The European Commission recently sponsored an international research and development project, in which three 'active' personal neutron dosemeters were developed. Comparative irradiation experiments showed good results with respect to sensitivity and energy dependence of the response. (author)

  1. The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace

    In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the subjects UVB exposure has been evaluated. An original experimental set-up is presented, in a preliminary version, which will be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measurable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small doses. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability. (author)

  2. The role of phantom parameters on the response of the AEOI Neutriran Albedo Neutron Personnel Dosemeter

    The response of the AEOI Neutriran Albedo Neutron Personnel Dosemeter (NANPD) which can also be used for other albedo dosemeter types was determined on 18 different phantom configurations. The effects of type, geometry, material, thickness, dosemeter-to-phantom angle in particular with the presence of legs were investigated using a Pu-Be neutron source. It was concluded that the slab phantoms (single or double) and circular and elliptical cylinder phantoms seemed to provide a better response, whereas the ICRU sphere geometry does not seem to be appropriate for the calibration of albedo dosemeters. It is interesting to note that the presence of legs maintains the constancy of the response in a situation when a radiation worker bends down during work. (author)

  3. TL response of LiF: Mg, Cu, P dosemeters in function of the photon energy

    In this work the obtained results of studying the response of dosemeters of LiF: Mg, Cu, P + Ptfe, developed in the ININ, commercial dosemeters GR200A (LiF: Mg, Cu, P) of chinese manufacture and TLD-100 (LiF: Mg, Ti) US are presented, when irradiating them with X rays 16, 24, 34.5, 42, 100 and 145 keV of effective energy, with gamma rays of 662 keV (137 Cs) and 1252 keV (60 Co). The results are presented in function of the sensitivity that the dosemeters showed normalized to gamma radiation of 60 Co. It was appreciated that the dosemeters more equivalent to the tissue, they were those of LiF: Mg, Cu, P + Ptfe, while the less equivalent ones were the TLD-100. (Author)

  4. Determination of relevant parameters for the use of electronic dosemeters in pulsed fields of ionising radiation

    Active electronic dosemeters using counting techniques are used for radioprotection purposes in pulsed radiation fields in X-ray diagnostics or therapy. The disadvantage of the limited maximum measurable dose rate becomes significant in these radiation fields and leads to some negative effects. In this study, a set of relevant parameters for a dosemeter is described, which can be used to decide whether it is applicable in a given radiation field or not. The determination of these relevant parameters-maximum measurable dose rate in the radiation pulse, dead time of the dosemeter, indication per counting event and measurement cycle time-is specified. The results of the first measurements on the determination of these parameters for an electronic personal dosemeter of the type Thermo Fisher Scientific EPD Mk2 are shown. (authors)

  5. Personal neutron dosemeter of the Czech Republic: Review of basic properties, results of recent tests

    Trousil, J.; Spurný, František; Plichta, J.

    2006-01-01

    Roč. 14, 7/8 (2006), s. 246-253. ISSN 1210-7085 Institutional research plan: CEZ:AV0Z10480505 Keywords : detectors * dosemeters * personal dosimetry Subject RIV: DN - Health Impact of the Environment Quality

  6. Conversion factors for the ICRU dose equivalent quantities for calibrating radiation dosemeters

    Report describing the application of conversion factors for monoenergetic photon radiation and for X and gamma reference radiation used for dosemeter calibration with the aid of spherical or rectangular phantoms (environmental and individual monitoring). (DG)

  7. 46 CFR 97.37-9 - Carbon dioxide alarm.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  8. 46 CFR 78.47-9 - Carbon dioxide alarm.

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  9. 46 CFR 196.37-9 - Carbon dioxide alarm.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  10. 46 CFR 108.627 - Carbon dioxide alarm.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  11. 46 CFR 169.732 - Carbon dioxide alarm.

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  12. Recent developments on the CRS PADC (poly-allyl diglycol carbonate) fast neutron personal dosemeter

    The Dosimetry Laboratory of the Radiation Protection and Safety Centre in Algiers has developed a fast neutron personal dosemeter using a PADC detector. This dosemeter has been type tested in terms of the ICRU calibration quantity, directional dose equivalent at 10 mm, H'(10). This paper gives the results of type test measurements. In addition, some properties of five different PADC materials were investigated in this study. (author)

  13. Dosimetry. Performance requirements and quality of state of the art dosemeters

    The quality of dose measurements mainly depends on the correct calibration status of the used measuring equipment. In addition - depending on the measuring task - the measuring uncertainty is influenced by other metrological characteristics like energy- and directional response, linearity etc. defining the used dosemeter. Performance requirements of different dosemeter types, defined in national and international standards are reviewed, compared and discussed in this paper. (orig.)

  14. The legal duty of dosemeter calibration, seen from the users' point of view

    The procedure of official radiation dosemeter calibration, at least that for personal dosemeters and portable ambient dose rate measuring systems, is an established procedure well accepted by the users. As to the calibration of installed ambient dose rate meters, there are many problems still to be solved. One proposal for instance is to just carry through the design qualification tests, and to dispense of calibration and re-calibration of individual systems. (orig./HP)

  15. SMS-baserat alarm med positionering : GPS based alarm with positioning

    Nors, Niclas; Rehnström, Tom

    2008-01-01

    The study investigates how to design a low-cost, versatile event messaging system using SMS. A typical use case is a fire alarm or intrusion detector when equipped with appropriate sensors. With a GPS receiver connected, the actual position is included in the message, allowing for use as theft alarm in e.g. a car or in mobile home.

  16. Quality assurance of personal beta particle dosemeters used for individual monitoring of occupationally exposed persons

    As a result of investigations and intercomparison measurements organised from 1996 to 1999 by PTB, several types of personal dosemeters, all based on TLD, were selected by the dosimetry services for the measurement of the personal dose equivalent Hp(0.07) in beta and/or photon radiation fields. These dosemeters have now the status of legal personal beta partial-body dosemeters. Workplaces at which beta radiation might significantly contribute to the doses to the extremities are to be found today with increasing frequency in radiation therapy, radiation source production and nuclear power plants. Quality assurance for beta personal dosemeters is stipulated by guidelines for the official dosimetry service and is carried out by way of the intercomparison measurements organised periodically by the PTB. The results are evaluated based on the recommendations of the German Commission on Radiological Protection (SSK). The procedure of these intercomparison measurements will be explained in detail. The experience gained from three series of comparisons with seven types of fingering dosemeters will be described and the results will be presented. The anonymity of the dosemeter types and of the participants in the intercomparison will be preserved. (authors)

  17. Feasibility study of extremity dosemeter based on polyallyl-diglycol-carbonate (CR-39) for neutron exposure

    In nuclear facilities, some activities such as reprocessing, recycling and production of bare fuel rods expose the workers to mixed neutron-photon fields. For several workplaces, particularly in glove boxes, some workers expose their hands to mixed fields. The mastery of the photon extremity dosimetry is relatively good, whereas the neutron dosimetry still raises difficulties. In this context, the Inst. for Radiological Protection and Nuclear Safety (IRSN) has proposed a study on a passive neutron extremity dosemeter based on chemically etched CR-39 (PADC: polyallyl-diglycol-carbonate), named PN-3, already used in routine practice for whole body dosimetry. This dosemeter is a chip of plastic sensitive to recoil protons. The chemical etching process amplifies the size of the impact. The reading system for tracks counting is composed of a microscope, a video camera and an image analyser. This system is combined with the dose evaluation algorithm. The performance of the dosemeter PN-3 has been largely studied and proved by several laboratories in terms of passive individual neutron dosemeter which is used in routine production by different companies. This study focuses on the sensitivity of the extremity dosemeter, as well as its performance in the function of the level of the neutron energy. The dosemeter was exposed to monoenergetic neutron fields in laboratory conditions and to mixed fields in glove boxes at workplaces. (authors)

  18. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band (∼ 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  19. Personal neutron dosimetry in nuclear power plants using etched track and albedo thermoluminescence dosemeters

    Measurement of the personal dose equivalent rates for neutrons is a difficult task because available dosemeters do not provide the required energy response and sensitivity. Furthermore, the available wide calibration spectra recommended by the International Standard Organisation does not reproduce adequately the spectra encountered in practical situations of the nuclear industry. There is a real necessity to characterise the radiation field, in which workers can be exposed, and to calibrate personal dosemeters in order to determine the dose equivalent in these installations. For this reason, we measure the neutron spectrum with our Bonner sphere system and we fold this spectrum with energy-dependent fluence-to-dose conversion coefficients to obtain the reference dose equivalent rate. This reference value is then compared with the personal dosemeter reading to determine a field-specific correction factor. In this paper, we present the values of this field-specific correction factor for etched track and albedo thermoluminescence dosemeters at three measurement locations inside the containment building of the Vandellos II nuclear power plant. We have found that assigning to each personal dosemeter the mean value of the field-specific correction factors of the three measurement locations, allows the evaluation of neutron personal dose equivalent rate with a relative uncertainty of∼25 and 15% for the PADC and albedo dosemeters, respectively. (authors)

  20. Design and characterization of a personal extremity dosemeter for dose evaluation in Hp (0,07)

    This work describes the development of a personal extremity dosemeter in a finger ring format. The detector element used in this is a LiF:Mg, Ti, chip, manufactured by Harshaw-Bicron (TLD 100). An injection mold was manufactured for the production of a prototype batch of 600 polypropylene rings. The detector element was sealed in the ring using a tool also developed in this research. The ring may be chemically sterilized and its shape does not restrict finger mobility and the use under surgical gloves. The ring has a low cost and, with the exceptional of the chip, is disposable. The dosimetric system in the Thermoluminescent Dosimetry Laboratory of IRD was used for the characterization of the dosimetric properties of the extremity dosemeter. The irradiations were made at the Laboratorio Nacional das Radiacoes Ionizantes/IRD and in the Metrology Department of IPEN.The performance tests for characterization of the extremity dosemeter were accomplished based on the ISO/FDIS 12794 standard, which establishes the performance criteria and tests for determining the performance of thermoluminescence dosemeters to be used for measurement of radiation doses to the extremities due to photons. The operational units used for this personal extremity dosemeter calibration were Hp(0,07). The results show that the system developed for the personal extremity dosemeter fulfill the established requirements in the ISO/FDIS 12792 standard. (author)

  1. Design and test of an albedo personal neutron dosemeter based on PADC detectors

    Albedo dosemeters, usually based on thermo-luminescence detectors, have been frequently employed in personal neutron dosimetry. Their main advantages are the high sensitivity and the reduced angular dependence, whilst the disadvantages are the sensitivity to photons and the significant energy dependence of the response, which drops dramatically above 0.1 MeV. The present paper proposes an albedo dosemeter based on a planar PADC coupled with a 10B converter. This dosemeter shows good potentials in terms of photon insensitivity, limited angular dependence and high neutron sensitivity. Its use coupled with a dosemeter sensitive in the MeV region, should result in promising dosimetric performances. The response of the PADC based albedo dosemeter was characterized through irradiations in reference neutron fields of 241Am-Be, 252Cf and 252Cf(D2O) and Monte Carlo simulations with the code MCNP-4C. The paper presents the results of the experimental and computational studies and outlines the relevant dosimetric performance of the new albedo dosemeter.

  2. Individual monitoring with official electronic dosemeters in Germany - concepts and reality

    Full text: Active (electronic) personal dosemeters (APD) are radiometers, which are equipped as active or passive dosimeters. They can directly indicate a dose rate and/or the dose integrated during a certain period (direct-indicating, active electronic personal dosemeters mentioned) or only over a separate reader (direct-selectable, passive electronic personal dosemeters mentioned). A concept is presented for the use of passive or active electronic personal dosemeters in Germany as official dosemeters, e.g. in hospitals. The concept features a net-based approach for secure data communication between readers for passive and active electronic personal dosemeters und the official personal dosimetry monitoring service(s), taking the German policies (StrISchV und RoeV in hospitals) into account. The net-based solution includes a processor controlled interface via TCP/IP connected to the dosimetry reader(s), und reader interfaces, an official interim data bank and all the necessary equipment such as PC, Raid-configuration, USV support, network connection and further details. Investigations have been started to achieve highest-level data manipulation security, data completeness und data correctness. (author)

  3. Pre-alarm closed circuit television verification to reduce false alarm impact

    Closed circuit television (CCTV) plays an important role in modern security systems for protection of nuclear material. The functions of video are for detection and to assist in classification or assessment of alarms from other sensors. A nuclear facility with an extensive security system can experience a very high alarm rate, including false, nuisance and alarms occurring as part of routine operations. Video systems which include the Pre-Alarm Image Recall feature continuously capture and store a number of images from each camera. The images leading up to, at the instant of, and immediately after an alarm, can be displayed as a very valuable aid in assessment. The technology and operation of this feature is described, together with actual operating experience and a summary of the benefits which have been obtained from its use. (author)

  4. System for alarms analysis and optimization in petrochemicals plants; Sistema para analise e otimizacao de alarmes em plantas petroquimicas

    Leitao, Gustavo; Pifer, Aderson; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Saito, Kaku; Aquino, Leonardo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The present work presents a group of algorithms, techniques and functionalities on alarms management which can be used efficiently on the treatment of 'disturbances' caused by the informal management of the alarm systems. Among the disturbances handled by these techniques, there is the recognition of intermittent alarms and false alarms, location of alarm floods and correlation between alarms, aiming the identification of communal root causes. The results will be presented through a case study on petrochemical alarm plants. At last, the results obtained by the utilization of such functionalities will be presented and discussed. (author)

  5. Behavioral alarm treatment for nocturnal enuresis

    Rodrigo F. Pereira

    2010-06-01

    Full Text Available PURPOSES: To investigate the efficacy of alarm treatment in a sample of Brazilian children and adolescents with nocturnal enuresis and relate treatment success to age and type of clinical support. MATERIALS AND METHODS: During 32 weeks, 84 children and adolescents received alarm treatment together with weekly psychological support sessions for individual families or groups of 5 to 10 families. RESULTS: 71% of the participants achieved success, defined as 14 consecutive dry nights. The result was similar for children and adolescents and for individual or group support. The time until success was shorter for participants missing fewer support sessions. CONCLUSIONS: Alarm treatment was effective for the present sample, regardless of age or type of support. Missing a higher number of support sessions, which may reflect low motivation for treatment, increased the risk of failure.

  6. An evaluation approach for alarm processing improvement

    In light of the need to improve MMIS of NPPs, the advanced I and C research team of KAERI has embarked on developing an Alarm and Diagnosis-Integrated Operator Support System, called ADIOS, to filter or suppress unnecessary or nuisance alarms and diagnose abnormality of the plant process. ADIOS has been built in an object-oriented AI environment of G-2 expert system software tool, as presented in a companion paper. ADIOS then is evaluated according to the plan in three steps; (1) preliminary tests to refine the knowledge base and inference structure of ADIOS in such a dynamic environment, and also to evaluate the appropriateness of alarm-processing algorithms; (2) to ensure correctness, consistency, and completeness in the knowledge base using COKEP (Checker Of Knowledge base using Extended Petri net); and (3) the cognitive performance evaluation using the Simulation Analyzer with a Cognitive Operator Model (SACOM) in the KAERI's Integrated Test Facility (ITF). (author). 5 figs, 1 tab

  7. Decision-making and response strategies in interaction with alarms: the impact of alarm reliability, availability of alarm validity information and workload.

    Manzey, Dietrich; Gérard, Nina; Wiczorek, Rebecca

    2014-01-01

    Responding to alarm systems which usually commit a number of false alarms and/or misses involves decision-making under uncertainty. Four laboratory experiments including a total of 256 participants were conducted to gain comprehensive insight into humans' dealing with this uncertainty. Specifically, it was investigated how responses to alarms/non-alarms are affected by the predictive validities of these events, and to what extent response strategies depend on whether or not the validity of alarms/non-alarms can be cross-checked against other data. Among others, the results suggest that, without cross-check possibility (experiment 1), low levels of predictive validity of alarms ( ≤ 0.5) led most participants to use one of two different strategies which both involved non-responding to a significant number of alarms (cry-wolf effect). Yet, providing access to alarm validity information reduced this effect dramatically (experiment 2). This latter result emerged independent of the effort needed for cross-checkings of alarms (experiment 3), but was affected by the workload imposed by concurrent tasks (experiment 4). Theoretical and practical consequences of these results for decision-making and response selection in interaction with alarm systems, as well as the design of effective alarm systems, are discussed. PMID:25224606

  8. Alarm handling systems and techniques developed to match operator tasks

    This paper covers alarm handling methods and techniques explored at the Halden Project, and describes current status on the research activities on alarm systems. Alarm systems are often designed by application of a bottom-up strategy, generating alarms at component level. If no structuring of the alarms is applied, this may result in alarm avalanches in major plant disturbances, causing cognitive overload of the operator. An alarm structuring module should be designed using a top-down approach, analysing operator's tasks, plant states, events and disturbances. One of the operator's main tasks during plant disturbances is status identification, including determination of plant status and detection of plant anomalies. The main support of this is provided through the alarm systems, the process formats, the trends and possible diagnosis systems. The alarm system should both physically and conceptually be integrated with all these systems. 9 refs, 5 figs

  9. Development of the newly advanced alarm system for APWR plant

    We have been developing AMCB (Advanced Main Control Board) for APWR consisting of a large overview display and on operator console. We have adopted the alarm prioritizing functions, which are already in use in the existing Japanese PWR plants, for easier identification of the high priority alarms. Moreover, we have developed an alarm system with a large overview display, which presents alarms on the plant process flow diagram. This enhances the location aids and pattern recognition in the alarm identification process. This time, we made further improvement and studies for better and various functions combining a large overview display with a CRT display. We determined the alarm system specification as follows, taking account of flexible alarm recognition processes. (1) The high priority alarms can be identified upon the LOD (large overview display). On the display, the alarms are described on the plant flow diagram, and the alarm status is shown on the fixed position of process or equipment symbols. (2) Other alarms are identified on large overview display and on CRTs using a hierarchical process. (3) The alarm messages are divided into 4 different groups according to the plant systems, thus enabling to undertake the countermeasure operations, using only the CRT. Moreover, we integrated a computerized ARPs (Alarm Response Procedures) into the alarm system. (author). 4 figs, 5 tabs

  10. An Undergraduate Experiment in Alarm System Design.

    Martini, R. A.; And Others

    1988-01-01

    Describes an experiment involving data acquisition by a computer, digital signal transmission from the computer to a digital logic circuit and signal interpretation by this circuit. The system is being used at the Illinois Institute of Technology. Discusses the fundamental concepts involved. Demonstrates the alarm experiment as it is used in…

  11. Nuclear power plant alarm systems: Problems and issues

    Despite the incorporation of advanced technology into nuclear power plant alarm systems, human factors problems remain. This paper identifies to be addressed in order to allow advanced technology to be used effectively in the design of nuclear power plant alarm systems. The operator's use and processing of alarm system information will be considered. Based upon a review of alarm system research, issues related to general system design, alarm processing, display and control are discussed. It is concluded that the design of effective alarm systems depends on an understanding of the information processing capabilities and limitations of the operator. 39 refs

  12. Intercomparison program of personal dosemeters in the Argentine Republic

    During 1997, under the auspices of the Nuclear Regulatory Authority (ARN), its was held the third exercise of intercomparison of laboratories of personal dosimetry. The dosemeters were irradiated in X-ray beams ISO quality W60, W110, W200 and gamma sources cesium 137 and cobalt 60. The irradiation were performed kerma free in air and in phantom in order to study the capacity to evaluate both conditions. An extent range of doses (low-high) have been given 0.3 mSv- 20mSv in order to determine the operative performance o each laboratory. Over 19 laboratories of Argentina, participated 13 (65%) and finished the intercomparison 12 (60%) of them. The systems of dosimetry detection were based on film and TLD. During this intercomparison as inquiry about several items related with the laboratories have been made. In this work are shown the individual laboratory results of the intercomparison related with the acceptance curve criteria ICRP 60 and 55. (author)

  13. Measurement of doses to aviator pilots using thermoluminescent dosemeters

    During the development of their work, the aviator pilots are exposed at high levels of natural radiation of bottom caused mainly by the cosmic radiation of galactic origin and lot. For such reason, the Metropolitan Autonomous University (UAM) and the Union Association of Aviator Pilots (ASPA), subscribed an agreement with the purpose of to measure the doses of ionizing radiation received by the aviator pilots of diverse air companies that man different types of airships and to determine if these doses surpass the one limit of 0.11 mSv/h settled down by the IAEA for the public in general; and if therefore, these workers should be considered as personnel occupationally exposed. In this work the obtained results when measuring the absorbed dose received by Mexican civil aviator pilots during the development of their work, using thermoluminescent dosemeters of LiF:Mg,Cu,P + Ptfe of national production are presented. The obtained results during the years of 2001 and 2002 show that the monthly doses received by the pilots surpass the one it limits established for the public in general, for what they should be considered as personnel occupationally exposed. (Author)

  14. An Active Personal Dosemeter/Spectrometer for Neutrons

    A prototype of a highly sensitive active personal neutron dosemeter has been developed. It consists of a stack of four silicon detectors sandwiched between layers acting as neutron converters, moderators and absorbers. Its response to quasi-monoenergetic neutrons with energies up to 45 MeV and photons with energies up to 7 MeV has been measured and/or calculated for different angles of incident radiation. The personal dose equivalent determined from the reading obtained in some fields with broad energy distributions deviates by less than 30% from the reference values, both for normal incidence and incidence at 60 deg. to the normal. The detection threshold is about 3 μSv for fast neutrons, 1 μSv for intermediate neutrons and 0.007 μSv for thermal neutrons, even in mixed fields with a photon dose higher by a factor of 20. In addition, the evaluation procedures described give spectral and directional information about the field. (author)

  15. Study of charge reader probes for electret dosemeters

    Electrets are insulating materials with a quasi-permanent polarization. It can be made from carnauba wax, Teflon and other materials for several applications as transducers, electrophotography, high efficiency air filters and as radiation dosimeters. Electret dosemeters may be used for α, β, γ, X, e- and neutrons radiations with a low construction cost and a simple associated instrumentation. The probe, for charge measurements of the electret dosimeters, is an important device in the experimental set up and its geometry varies according to the geometry of the dosimeter or the scope of the measurements. In this work the development of several probes is described (cylindrical, 1/3 cylindrical and three points probes with different sizes). From the measurements one can demonstrate that cylindrical probe may be used for cylindrical electret geometry, 1/3 cylindrical probe for measurements of directional dependence of the dose and point probe for scanning measurements of plane areas. For high resolution, small point probe may be used and for high sensitivity, the probe-electret distance must be minimized taking account of the Paschen discharge. (author)

  16. Calibration of extremity dosemeters for gamma radiation fields

    In this work the kerma conversion factor are free in air, dose equivalent H(d,0) are presented, they were obtained theoretical and experimentally in finger and arm for gamma radiation fields. Extremity dosemeters put on surface finger and arm phantom have been irradiated. The finger phantom is a solid cylinder of PMMA polymethylmethacrylate 19 mm diameter and 300 mm height. The arm phantom is a 73 mm external diameter cylinder with PMMA walls 2.5 mm thick fill with water and 300 mm height. The radiation sources were cobalt 60 and cesium 137 from the Regional Center of Reference (CRR) of the National Commission of Atomic Energy (CNEA) and the Nuclear Regulatory Authority (ARN). Also in ISO wide X ray spectra W60, W110 and W200 have been irradiated. The results obtained show a good correlation with those published, they have a difference less than 7%. The factors will be applied to the evaluation of the equivalent doses coming from workers whose main irradiated zone is in the hands. (author)

  17. Perspectives on use of personal alarms by older fallers

    Kylie Johnston

    2010-08-01

    Full Text Available Kylie Johnston1, Karen Grimmer-Somers1, Michele Sutherland21International Centre for Allied Health Evidence, University of South Australia, Adelaide; 2Falls Prevention Unit, Department of Health, Government of South Australia, Adelaide, AustraliaBackground: Personal alarms are proposed as a reliable mechanism for older people to obtain assistance after falling. However, little is known about how older people feel about owning and using personal alarms.Aim: This paper reports on experiences of independently living older people, who have recently fallen, regarding alarm use and their independence.Method: Volunteers older than 65 years who had sustained a fall in the previous six months were sought via community invitations. Semistructured telephone interviews were conducted to gain information about their fall and their perspectives on personal alarm use. Interviews were content-analyzed to identify key concepts and themes.Results: Thirty-one interviews were conducted. Twenty callers owned personal alarms. Four subgroups of older fallers were identified; the first group used personal alarms effectively and were advocates for their benefits, the second group owned an alarm but did not use it effectively, the third group did not own alarms mostly because of cost, although were receptive to an alarm should one be provided, and the fourth group did not have an alarm and would not use it even if it was provided.Discussion: Personal alarms produce positive experiences when used effectively by the right people. The cost of personal alarms prohibits some older fallers from being effective alarm users. However, other elderly fallers remain unwilling to consider alarm use even if one was provided. In view of their cost, personal alarms should be targeted to people who will benefit most. ­Alternative strategies should be considered when alarms are unlikely to be used appropriately.Keywords: personal alarm devices, falls, older people, patient perspective

  18. Clinical Alarms in intensive care: implications of alarm fatigue for the safety of patients1

    Adriana Carla Bridi; Thiago Quinellato Louro; Roberto Carlos Lyra da Silva

    2014-01-01

    OBJECTIVES: to identify the number of electro-medical pieces of equipment in a coronary care unit, characterize their types, and analyze implications for the safety of patients from the perspective of alarm fatigue. METHOD: this quantitative, observational, descriptive, non-participatory study was conducted in a coronary care unit of a cardiology hospital with 170 beds. RESULTS: a total of 426 alarms were recorded in 40 hours of observation: 227 were triggered by multi-parametric monitors and...

  19. Calibration of personal dosemeters for X and gamma radiation in front of different phantoms

    If the directional dose equivalent H'(10) is to become the quantity for calibrating personal dosemeters, some questions as yet still open need to be answered, i.e. the choice of a phantom for the practical calibration procedure together with a suitable set of correction factors. The dose equivalent on the surface of the ICRU sphere can be derived from the dose equivalent on the surface of a phantom different in shape and/or material by applying a phantom-specific and energy-dependent correction factor. However, this has proved unsatisfactory for the calibration of dosemeters which respond differently to the scattered radiation from the phantom. Phantom-specific correction factors are presented and compared with the reponse of selected types of dosemeters exposed on the surface of different phantoms. The different response of dosemeters to scattered radiation is also of interest to the question of the extent to which the reading of a personal dosemeter worn on the trunk will change if it is calibrated on the surface of a phantom in terms of the directional dose equivalent, H'(10), instead of being calibrated in free air in terms of exposure or kerma. (author)

  20. Energy and angular dependence of the personal dosemeter in use at ITN-DPRSN

    In this paper the characterization of the dosimetry system and of the personal dosemeter in terms of the stability of the reader calibration factors and of the linearity of the response for the 137Cs reference radiation is presented. The energy and angular dependence of the whole body dosemeter are also shown. The energy dependence was determined performing irradiations with the X-ray narrow series beams N30, N40, N60, N80, N100, N120 and with the gamma reference radiations of 137Cs and 60Co [ISO 4037-1, 1996. X and Gamma Reference Radiation for Calibrating Dosemeters and Doserate Meters and for Determining Their Response as a Function of Photon Energy-Part 1: Radiation Characteristics and Production Methods. International Organization for Standardization, Geneva] in terms of Hp(10) incident on the ISO water slab phantom. The angular dependence of the dosemeter was determined for the angles 0 deg., ±20 deg., ±40 deg. and ±60 deg. with normal using the above mentioned radiation fields. All irradiations were performed at the Laboratorio de Metrologia das Radiacoes lonizantes of ITN-DPRSN. The experiments presented in this paper show the thermoluminescence dosimetry (TLD) system is stable and presents a linear behaviour over and extended dose range. The measurements allowed the determination of the energy dependence at normal incidence and of the angular dependence of the dosemeter currently in use. Further studies are being carried out in order to implement correction factors for supralinearity and low energy measurements

  1. Study on the response of indigenously developed CaSO4:Dy phosphor based neutron dosemeter

    In the present paper we report indigenous development of a neutron sensitive thermoluminescent (TL) dosemeter based on CaSO4:Dy Teflon TL disc. For large scale neutron monitoring of about 15,000 workers, engaged in the nuclear fuel cycle operation, the new dosemeter can be easily incorporated in the present TLD badge system used in personnel monitoring in our country just by a small change in the designing of the badge cassette. The study includes indigenous development of neutron dosemeter, response of the neutron dosemeter in terms of operational quantity to different energies of neutrons under various irradiation conditions. It was found that the thermal neutron sensitivity of the CaSO4:Dy Teflon neutron disc is about one third of TLD-600. However the thermal neutron sensitivity with respect to CaSO4:Dy Teflon gamma disc is about 42 times for in air irradiation and about 84 times for on-phantom irradiation conditions. This newly developed neutron disc can be used as a routine TL dosemeter in the mixed fields of gamma and neutron for neutron energy upto 500 keV for radiation workers engaged in nuclear fuel cycle operation. (author)

  2. Panic, Suffocation False Alarms, Separation Anxiety and Endogenous Opioids

    Preter, Maurice; KLEIN, DONALD F.

    2007-01-01

    This review paper presents an amplification of the suffocation false alarm theory (SFA) of spontaneous panic (Klein, 1993). SFA postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. That panic is distinct from Cannon’s emergency fear response and Selye’s General Alarm Syndrome is shown by the prominence of intense air hunger during these attac...

  3. Reducing False Intracranial Pressure Alarms using Morphological Waveform Features

    Scalzo, Fabien; Liebeskind, David; Hu, Xiao

    2012-01-01

    False alarms produced by patient monitoring systems in intensive care units (ICU) are a major issue that causes alarm fatigue, waste of human resources, and increased patient risks. While alarms are typically triggered by manually adjusted thresholds, the trend and patterns observed prior to threshold crossing are generally not used by current systems. This study introduces and evaluates a smart alarm detection system for intracranial pressure signal (ICP) that is based on advanced pattern re...

  4. Male monkeys remember which group members have given alarm calls

    Wich, Serge A.; Vries, Han de

    2005-01-01

    Primates give alarm calls in response to the presence of predators. In some species, such as the Thomas langur (Presbytis thomasi), males only emit alarm calls if there is an audience. An unanswered question is whether the audience's behaviour influences how long the male will continue his alarm calling. We tested three hypotheses that might explain the alarm calling duration of male Thomas langurs: the fatigue, group size and group member behaviour hypotheses. Fatigue and group size did not ...

  5. Automated Information System (AIS) Alarm System

    The Automated Information Alarm System is a joint effort between Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratory to demonstrate and implement, on a small-to-medium sized local area network, an automated system that detects and automatically responds to attacks that use readily available tools and methodologies. The Alarm System will sense or detect, assess, and respond to suspicious activities that may be detrimental to information on the network or to continued operation of the network. The responses will allow stopping, isolating, or ejecting the suspicious activities. The number of sensors, the sensitivity of the sensors, the assessment criteria, and the desired responses may be set by the using organization to meet their local security policies

  6. Integrated taut wire sensor alarm monitoring system

    For many years mechanical taut wire intrusion detection systems have played a key role in protecting high risk facilities. The taut wire sensor has the advantage that it combines a physical barrier with an intrusion sensor, a useful feature where no fence is installed or planned. However, mechanical taut wire sensors have proven to have several major disadvantages, including: no sensitivity adjustment, no sensor self-test feature, no remote control capability, and inflexible mounting constraints. This paper deals with a new generation of solid state taut wire sensor which overcomes the deficiencies of the aging mechanical design. The new sensor uses a microprocessor to filter out sources of nuisance alarms, yet maintains exceptional sensitivity to intrusion and tamper attempts. Being solid sate, the new sensor can be mounted in any orientation, even upside down. Moreover, when combined with a new, advanced alarm monitoring system, the solid state taut wire fence will support remote sensitivity adjustment and remote sensor self-test control

  7. Analyse fonctionnelle d’une alarme incendie

    Jacob Dominique; Lagonotte Patrick

    2011-01-01

    L’enseignement de l’électricité dans les départements Hygiène Sécurité Environnement (HSE) des I.U.T. ne comprend qu’un faible nombre d’heures en première et en deuxième année. Il est cependant intéressant d’utiliser ce peu de temps à la présentation d’applications de l’électricité liées à la sécurité. Les alarmes incendie sont installées dans de très nombreux bâtiments recevant du public ou des travailleurs. Une alarme incendie est en général discrète et personne ne s’en préoccupe jusqu’au j...

  8. Automated Information System (AIS) Alarm System

    Hunteman, W.

    1997-05-01

    The Automated Information Alarm System is a joint effort between Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratory to demonstrate and implement, on a small-to-medium sized local area network, an automated system that detects and automatically responds to attacks that use readily available tools and methodologies. The Alarm System will sense or detect, assess, and respond to suspicious activities that may be detrimental to information on the network or to continued operation of the network. The responses will allow stopping, isolating, or ejecting the suspicious activities. The number of sensors, the sensitivity of the sensors, the assessment criteria, and the desired responses may be set by the using organization to meet their local security policies.

  9. Optimal alarm system applied in coffee rust

    Luciene Resende Gonçalves

    2014-02-01

    Full Text Available Alarm systems have very great utility in detecting and warning of catastrophes. This methodology was applied via TARSO model with Bayesian estimation, serving as a forecasting mechanism for coffee rust disease. The coffee culture is very susceptible to this disease causing several records of incidence in most cultivated crops. Researches involving this limiting factor for production are intense and frequent, indicating environmental factors as responsible for the epidemics spread, which does not occur if these factors are not favorable. The fitting type used by the a posteriori probability, allows the system to be updated each time point. The methodology was applied to the rust index series in the presence of the average temperature series. Thus, it is possible to verify the alarm resulted or in a high catastrophe detection in points at which the catastrophe has not occurred, or in the low detections if the point was already in the catastrophe state.

  10. 30 CFR 57.4360 - Underground alarm systems.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground alarm systems. 57.4360 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Procedures/alarms/drills § 57.4360 Underground alarm systems. (a) Fire...

  11. 46 CFR 130.460 - Placement of machinery alarms.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to...

  12. 21 CFR 870.1100 - Blood pressure alarm.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood...

  13. Alarm fatigue: a roadmap for mitigating the cacophony of beeps.

    Purbaugh, Thomas

    2014-01-01

    The phenomenon known as alarm fatigue is the direct result of excessive alarms in hospitals. This article highlights the effects of alarm fatigue and reviews current clinical recommendations and guidelines to raise nurse awareness and provide tools to combat the problem. PMID:24310707

  14. Research and implementation of intelligent alarm transceiver

    Haobo long; XiaolingTian

    2015-01-01

    To design and implement a inteligent alarm transceiver, the sensor, such as temperature, voltage, video check. is used in transceiver. Then it analyses real-time acquisition data of sensor, if the transceiver is not working normaly, and the results are sent to the host computer. And the latter send fault information to user by mobile phone. During this period, without artificial participation, to achieve the purpose of inteligent warning. it can improve the maintenance efficiency of transceiver.

  15. Parental alarm calls suppress nestling vocalization.

    Platzen, Dirk; Magrath, Robert D.

    2004-01-01

    Evolutionary models suggest that the cost of a signal can ensure its honesty. Empirical studies of nestling begging imply that predator attraction can impose such a cost. However, parents might reduce or abolish this cost by warning young of the presence of danger. We tested, in a controlled field playback experiment, whether alarm calls cause 5-, 8- and 11-day-old nestlings of the white-browed scrubwren, Sericornis frontalis, to suppress vocalization. In this species, nestlings vocalize when...

  16. APLIKASI SENSOR CAHAYA UNTUK ALARM ANTI PENCURI

    Asita Shoman Muzaki; Arief Hendra Saptadi; Wahyu Pamungkas

    2013-01-01

    Kasus pencurian di rumah kosong yang ditinggal pergi oleh pemiliknya belakangan ini marak terjadi. Berangkat dari pemikiran ini penulis mencoba merancang alarm yang dapat mendeteksi pergerakan seseorang saat rumah dalam kondisi kosong, ditinggalkan oleh pemiliknya. Alat ini mempunyai prinsip kerja yaitu mendeteksi bayangan seseorang yang melewati titik tertentu. Perancangan dan pembuatan perangkat ini menggunakan sensor cahaya berupa LASER dan LDR yang dirangkai dengan transistor sebagai sakl...

  17. The former tests realized to a personal neutron dosemeter based on solid nuclear tracks detector

    Due to the increase in the use of neutron radiation a personal neutron dosemeter based on solid nuclear tracks detector (DSTN) was designed and constructed. The personal dosemeter design consists of three arrangements. The first one consists of a plastic nuclear tracks detector (LR115 or CR39) in contact with a LiF pellet. The second one is the same that above but it placed among two cadmium pellets and, the third one is formed by the alone detector without converter neither neutron absorber. The three arrangements are placed inside a plastic porta detector hermetically closed to avoid the bottom produced by environmental radon whichever both detectors (LR115 and CR39) are sensitive. In this work the former tests realized to that dosemeter are presented. (Author)

  18. A three element etched track neutron dosemeter with good angular and energy response characteristics

    A weakness of all single element etched track neutron dosemeters is that the sensitivity falls off too rapidly with increasing angle of incidence. This can lead to significant errors in practical situations. A possible solution is to incorporate in a single dosemeter one or more planar etched track detectors set at an angle to the body surface so that the sensitivity to obliquely incident neutrons is enhanced. The response of a dosemeter in which three planar elements are set in a pyramid structure is investigated. Relationships are developed which allow the response to be estimated for any given direction of incidence and any given angle between face and base of the pyramid. The results indicate that the response is close to that required to measure Hp(10) for any given direction of neutron incidence if the angle between face and base is between 30o and 40o. (author)

  19. Development of new generation-type multi-functional electronic personal dosemeters

    We have developed advanced new-generation-type small, light, multi-functional electronic personal dosemeters (NRF3 series) using silicon semiconductor radiation detectors for dose management of workers at nuclear power plants and accelerator facilities. These dosemeters are 60 x 78 x 27 mm3 in size and approximately 103 to 115 g in weight, which are capable of measuring personal gamma-ray dose equivalent (NRF30), gamma-ray and neutron dose equivalents (NRF31) and gamma-ray and beta-ray dose equivalents (NRF34). These dosemeters are driven by a lithium battery, CR123A, continuously for about 2000 hours in normal use and can read out the time sequential dose equivalent data via infrared (IR) communication. In addition to IR communication method, NRF31 can read out the dose equivalent data via radio communication using an exclusive radio communication unit. (author)

  20. Development of personal neutron dosemeters at the PTB and first measurements in the space station MIR

    A passive neutron dosemeter with thermoluminescence and etched-track detectors was used in the space station MIR in 1995 and 1997 and during some shuttle flights to MIR. High neutron doses of about 200 μSv d-1 were measured with track detectors, while the contribution of protons to the track density was estimated to be small. An active personal dosemeter based on silicon diodes providing a direct readout, improved sensitivity and spectrometric properties is proposed for additional monitoring. Firstly, measurements with a prototype were performed in the stray radiation fields of the CERN-EU Reference Radiation Facility. When mounted on a phantom at different positions, both the passive and the active dosemeter provide the directional distribution of neutrons via an unfolding procedure. This can be helpful for a better understanding of the complex radiation field in space and for comparisons with calculations

  1. Eurados trial performance test for personal dosemeters for external beta radiation

    Christensen, P.; Bordy, J.M.; Ambrosi, P.; Bartlett, D.T.; Colgan, T.; Hyvonen, H.; Stadtmann, H.

    On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU was...... accomplished, This paper deals with the part of the performance test concerned with exposure to beta radiation. Fifteen dosimetric services participated with whole-body dosemeters intended to measure beta doses (H-p(0.07)) of which 13 used thermoluminescent (TL) detectors and two used photographic films. Eight...... services participated with extremity dosemeters which all used TL detectors. A description is given of the irradiation set-up, the characteristics of the irradiation fields, the calibration quantity applied and the performance criteria used for the evaluation of the results. The paper discusses in detail...

  2. From films to thermoluminescence dosemeters: The Greek Atomic Energy Commission experience

    The personnel dosimetry department of the Greek Atomic Energy Commission (GAEC) assures the individual monitoring of almost 8000 occupationally exposed workers. Thermoluminescence dosimetry system replaced the existing photographic dosimetry system for the individual monitoring with the joint support of IAEA and GAEC. The thermoluminescence dosimetry system consists of two automated readers, one automated irradiator and about 20,000 dosemeters purchased from the Rados Co. The properties of two thermoluminescent materials have been compared: LiF has been chosen for the whole-body dosemeter configuration and Li2B4O7 for the extremities. The technical evaluation of the system has been performed according to the European and IEC standards. The overall uncertainty has been calculated. The existing database system, and the accounting and dispatching procedures have been adapted to the new demands. The system became operational on March 2000, and the official distribution of thermoluminescence dosemeters has begun. (author)

  3. Calibration of personal dosemeters in terms of the ICRU operational quantities

    The International Commission on Radiological Units and Measurements (ICRU) has defined several new operational quantities for radiation protection purposes. The quantities to be used for personal monitoring are defined at depths in the human body. Because these quantities are impossible to measure directly, the ICRU has recommended that personal dosemeters should be calibrated under simplified conditions on an appropriate phantom, such as the ICRU sphere. The US personal dosimetry accreditation programs make use of a 30 x 30 x 15 cm polymethymethacrylate (PMMA) phantom, therefore it is necessary to relate the response of dosemeters calibrated on this phantom to the ICRU operational quantities. Calculations of the conversion factors to compute dosemeter response in terms of the operational quantities have been performed using the code MCNP. These calculations have also been compared to experimental measurements using thermoluminescent (TLD) detectors

  4. Operational comparison of TLD albedo dosemeters and solid state nuclear tracks detectors in fuel fabrication facilities

    The authors carried out an operational study that compared the use of TLD albedo dosemeters and solid state nuclear tracks detector in plutonium environments of Japan Nuclear Cycle Development Inst., Tokai Works. A selected group of workers engaged in the fabrication process of MOX (Plutonium-Uranium mixed oxide) fuel wore both TLD albedo dosemeters and solid state nuclear tracks detectors. The TL readings were generally proportional to the counted etch-pits, and thus the dose equivalent results obtained from TLD albedo dosemeter agreed with those from solid state nuclear tracks detector within a factor of 1.5. This result indicates that, in the workplaces of the MOX fuel plants, the neutron spectrum remained almost constant in terms of time and space, and the appropriate range of field-specific correction with spectrum variations was small in albedo dosimetry. (authors)

  5. Determination of Energy and Angular Response of an Albedo Neutron Personal Dosemeter

    The result of the determination of energy and angular response for the albedo neutron personal dosemeter used by CPHR, is described. The dosemeters consist of two pairs of LiF detectors (6LiF+7LiF) separated by a piece of boron-loaded plastic. For the study, the dosemeters were irradiated in three mixed neutron-gamma fields (thermal neutrons, moderated 241Am-Be and 241Am-Be) and at two incidence angles of radiation (0 deg. and 60 deg. ). The variation of the sensibility at different neutron spectra and incidence angles of radiation was determined. The methodology of dose evaluation, applying the obtained coefficients, was established. (author)

  6. Dosemeter readings and effective dose to the cardiologist with protective clothing in a simulated interventional procedure

    A personal dosemeter issued for individual monitoring is calibrated in terms of personal dose equivalent, usually HP(10). In general it yields a reasonable estimate of effective dose (E) when the exposed person does not wear protective clothing. In interventional cardiology, however, a lead equivalent apron is worn and often a thyroid collar. A correction factor will then be necessary to convert a dosemeter reading to E. To explore this factor an interventional cardiology procedure is simulated based on exposure conditions typical for a modern hospital in the BENELUX area. The dose to the cardiologist is investigated using Monte Carlo simulation of radiation transport. It is concluded that a personal dosemeter may best be worn outside the apron at a central position high on the chest for least dependence on the beam direction. It will overestimate E by roughly a factor of 20 (apron and thyroid collar of 0.25 mm Pb). (authors)

  7. From films to thermoluminescence dosemeters: the Greek Atomic Energy Commission experience.

    Carinou, E; Drikos, G; Hourdakis, C; Hyvönen, H; Kamenopoulou, V

    2001-01-01

    The personnel dosimetry department of the Greek Atomic Energy Commission (GAEC) assures the individual monitoring of almost 8000 occupationally exposed workers. Thermoluminescence dosimetry systems will replace the existing photographic dosimetry system for the individual monitoring with the joint support of IAEA and GAEC. The thermoluminescence dosimetry system consists of two automated readers, one automated irradiator and about 20,000 dosemeters purchased from the Rados Co. The properties of two thermoluminescent materials have been compared: LiF has been chosen for the whole-body dosemeter configuration and Li2B4O7 for the extremities. The technical evaluation of the system has been performed according to the European and IEC standards. The overall uncertainty has been calculated. The existing database system, and the accounting and dispatching procedures have been adapted to the new demands. The system became operational on March 2000, and the official distribution of thermoluminescence dosemeters has begun. PMID:11586730

  8. Development of personal neutron dosemeters at the PTB and first measurements in the space station MIR

    Luszik-Bhadra, M; Schuhmacher, H

    2001-01-01

    A passive neutron dosemeter with thermoluminescence and etched-track detectors was used in the space station MIR in 1995 and 1997 and during some shuttle flights to MIR. High neutron doses of about 200 mu Sv d/sup -1/ were measured with track detectors, while the contribution of protons to the track density was estimated to be small. An active personal dosemeter based on silicon diodes providing a direct readout, improved sensitivity and spectrometric properties is proposed for additional monitoring. Firstly, measurements with a prototype were performed in the stray radiation fields of the CERN-EU Reference Radiation Facility. When mounted on a phantom at different positions, both the passive and the active dosemeter provide the directional distribution of neutrons via an unfolding procedure. This can be helpful for a better understanding of the complex radiation field in space and for comparisons with calculations. (21 refs).

  9. Estimating effective dose for a cardiac catheterisation procedure with single or double personal dosemeters

    In most countries of the European Union legislation requires individual determination and registration of the dose to radiological workers exposed to ionising radiation to check whether dose limits are exceeded. To assess stochastic risk, ideally effective dose (E) should be known. In practice, personal dose equivalent [Hp(10)] is used as it can be measured with a personal dosemeter. The dosemeter reading may provide a reasonable assessment of Hp(10), but it may deviate strongly from E, in particular in radiology procedures for medical diagnosis or intervention when protective clothing like lead-equivalent apron and thyroid collar is worn. In the literature various correction factors and algorithms to convert readings of single or dual dosemeters to an estimate of E can be found. An illustrative example of a cardiac catheterisation procedure, in which dose calculations are made by Monte Carlo simulation of radiation transport, shows that such corrections may still yield considerable overestimation. (authors)

  10. Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters

    The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of 215 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was 29 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey (authors)

  11. Developing a method and deriving an uncertainty budget for the internal calibration of dosemeters for radiographic equipment

    Any institution wishing to perform an internal cross calibration of its diagnostic dosemeters should first quantify the uncertainty associated with this to demonstrate that it remains appropriate for the measurements being undertaken. An uncertainty budget for internal cross calibration that covers a range of locally used dosemeters has been derived using the methodology of the International Atomic Energy Agency. The specific internal cross calibration protocol requirements necessary for this uncertainty budget to be valid are discussed. The final quantified uncertainty is 5.31%; this is dominated by the 5% uncertainty associated with the calibration of the reference instrument. The next largest contributions are from differences in temperature and pressure and dosemeter energy dependence. It has been demonstrated that with careful adherence to a well designed internal cross calibration protocol, dosemeters can be calibrated in-house against a calibrated reference dosemeter with very little increase in the associated calibration uncertainty. (paper)

  12. Validation of a MOSFET dosemeter system for determining the absorbed and effective radiation doses in diagnostic radiology

    This study aimed to validate a MOSFET dosemeter system for determining absorbed and effective doses (EDs) in the dose and energy range used in diagnostic radiology. Energy dependence, dose linearity and repeatability of the dosemeter were examined. The absorbed doses (ADs) were compared at anterior-posterior projection and the EDs were determined at posterior-anterior, anterior-posterior and lateral projections of thoracic imaging using an anthropomorphic phantom. The radiation exposures were made using digital radiography systems. This study revealed that the MOSFET system with high sensitivity bias supply set-up is sufficiently accurate for AD and ED determination. The dosemeter is recommended to be calibrated for energies <60 and >80 kVp. The entrance skin dose level should be at least 5 mGy to minimise the deviation of the individual dosemeter dose. For ED determination, dosemeters should be implanted perpendicular to the surface of the phantom to prevent the angular dependence error. (authors)

  13. Validation of a MOSFET dosemeter system for determining the absorbed and effective radiation doses in diagnostic radiology.

    Manninen, A-L; Kotiaho, A; Nikkinen, J; Nieminen, M T

    2015-04-01

    This study aimed to validate a MOSFET dosemeter system for determining absorbed and effective doses (EDs) in the dose and energy range used in diagnostic radiology. Energy dependence, dose linearity and repeatability of the dosemeter were examined. The absorbed doses (ADs) were compared at anterior-posterior projection and the EDs were determined at posterior-anterior, anterior-posterior and lateral projections of thoracic imaging using an anthropomorphic phantom. The radiation exposures were made using digital radiography systems. This study revealed that the MOSFET system with high sensitivity bias supply set-up is sufficiently accurate for AD and ED determination. The dosemeter is recommended to be calibrated for energies 80 kVp. The entrance skin dose level should be at least 5 mGy to minimise the deviation of the individual dosemeter dose. For ED determination, dosemeters should be implanted perpendicular to the surface of the phantom to prevent the angular dependence error. PMID:25213263

  14. Science communication and the Swedish acrylamide "alarm".

    Lofstedt, Ragnar E

    2003-01-01

    On April 24, 2002 the Swedish National Food Administration along with a group of researchers at the University of Stockholm raised an alarm regarding potential health risks associated with eating fried and baked foods such as potatoes and bread. Scientists had found high levels of acrylamide (up to 500 times more acrylamide than that allowed in drinking water by the World Health Organisation), a substance widely believed to cause cancer, in cooked high starch foods. The outcomes of this "alarm" were immediate. In Sweden sales of chips fell by 30-50 percent over a 3-day period following the press conference, and share prices among several fried food manufacturers fell substantially, as stock analysts were fearful that consumption of fried foods would decrease significantly. Four days after the press conference, however, consumers began eating fried food as normal and a number of researchers and journalists in Sweden and elsewhere took the view that the alarm had been both exaggerated and ill placed. In this study, I evaluate the science communication process associated with the scare, based on a content analysis of a select group of Swedish broad sheets from just previous to the April 2002 press conference to the present time (December 2002). In addition, the study is based on interviews with the various Swedish regulators involved in the process itself (in particular at the Swedish National Food Administration) as well as with the scientists responsible for the study at Stockholm University and relevant journalists and politicians. PMID:14530144

  15. External exposure rates measured with TL dosemeters in several regions in Israel

    Environmental exposure is the main source of background radiation measured by personal dosemeters, and thus influences the minimum occupational dose which can be detected by these devices. Since background levels depend on altitude and local geology we performed a survey of the external exposure at ten different locations in Israel. Indoor exposures due to natural radiation, comprising cosmic, terrestrial and building material components, were determined with the standard personal thermoluminescence LiF dosemeters (Harshaw TLD - I 00). The locations'chosen in this survey are listed in Table I and depicted in Figure 1. They were chosen to represent different altitudes, especially of densely populated areas. The dwellings were selected to represent typical work-places in Israel. Dosemeters were maintained indoors to simulate the actual environment they would normally encounter.Ten TLD - 100 were placed in each dwelling for 60 days or 122 days during the hot summer season. Each dosemeter consisted of a card with three identical chips of 0.38 mm thickness housed in a Harshaw 8814 type card - holder with a transparent window. Fading correction amounted to 6% or 8%.The ten dosemeters in each dwelling were divided into two sub groups: five were placed face up (window side up) and the other five face down, in order to investigate the possible contribution of light to the measured dose. Portable monitors, Bicron micro rem LE, were used to take momentary readings at the same locations. Results of the longer duration measurements (without fading correction) are presented in Table 1. No significant differences could be observed between dosemeters from the two sub groups in each location, implying that ambient light does not have a significant influence on the readings. (authors)

  16. Performance of a coupled albedo/CR-39 personal dosemeter for fast neutron radiation

    Full text: The individual monitoring of neutron radiation still constitutes a difficult task, due to the wide energy range of the workplace fields and the large variation of the fluence-to-Hp(10) conversion coefficient in such energy interval, which is very difficult to reproduce by the response of a personal dosemeter. Consequently, the overall uncertainty in the dose evaluation procedure is mainly due to the energy dependence of the dosemeter response, which, for commonly employed dosimetric techniques such as the CR-39 and TLD-albedo, is higher than ±50 % in the [0.5 - 4] MeV energy range. This problem can be reduced by using a workplace specific calibration factor, only applicable in those cases where an a priori knowledge of the neutron spectrum is provided. In order to provide accurate dosimetric evaluations in unknown spectra condition, a study was performed by combining the reading of electrochemically etched CR-39 and TLD-albedo dosemeters simultaneously exposed. Irradiation tests on a ISO slab phantom were performed in reference neutron fields at IRSN-Cadarache. A relation was found between the response of the CR-39 or albedo dosemeter and the CR-39/albedo quotient, allowing to correct the reading of each dosemeter. The algorithm was tested in realistic neutron fields of Spanish nuclear power plants, where the energy distribution is known from BSS measurements. The satisfactory results allow proposing the CR-39/TLD-albedo double dosemeter to improve the accuracy of the dose evaluation procedure in the fast neutron individual monitoring. (author)

  17. Test of household salt read by optically stimulated luminescence (OSL) as a personal dosemeter

    This study has investigated the optically stimulated luminescence (OSL) of household salt and chemically pure NaCl after exposure in different radiation environments. The response relative to thermoluminescent dosimetry using LiF has been investigated to determine if OSL in NaCl can be considered as an alternative to measurements of thermoluminescence in LiF. A selection of staff members at the Diagnostic Centre and the Department of Radiation Physics at Malmoe University Hospital (UMAS) carried small light-tight tubes, 3 mm (diameter) x 27 mm filled with salt. The measurements were accompanied by LiF-TL dosemeters using the regular system for personal dosimetry at UMAS. Similar kits of salt dosemeters were also positioned on the inside walls of a nuclear medicine laboratory and a proton therapy room at the The Svedberg Laboratory in Uppsala. NaCl-OSL dosemeters were also placed in the primary radiation beam of a mammography unit. The OSL in the salt was measured using an OSL reader (Risoe TL/OSL DA 15) at a temperature of 100oC using continuous wave OSL (CW-OSL) with blue LEDs (λ=470 nm). The TL-measurements were made with a TLD reader (Rados Dosacus) using 4.5 mm (diameter) x 0.9 mm LiF: Mg, Ti (Harshaw). Preliminary results show that household salt can be used to measure absorbed doses down to 200 μGy. Measurements also indicate a somewhat higher response relative to LiF-TL dosemeters at low photon energies. The effect may be attributed to the higher atomic number of NaCl (Z=11, 17) compared with LiF (Z=3; 9). We conclude that NaCl-OSL dosemeters appear to be an interesting alternative to TL dosemeters at occupational exposure. (author)

  18. Eurados trial performance test for personal dosemeters for external beta radiation

    Christensen, P.; Bordy, J.M.; Ambrosi, P.;

    2001-01-01

    On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU was...... accomplished, This paper deals with the part of the performance test concerned with exposure to beta radiation. Fifteen dosimetric services participated with whole-body dosemeters intended to measure beta doses (H-p(0.07)) of which 13 used thermoluminescent (TL) detectors and two used photographic films. Eight...

  19. Type testing of personal dosemeters for photon energy and angular response

    Julius, H.W.; Marshall, T.O.; Christensen, Poul;

    1994-01-01

    Performance criteria for personal dosemeters have been recently proposed in the CEC document 'Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation' (EUR 5287, Revised). The current experiment was carried out to demonstrate that TLD-based dosimetry...... systems can comply with these requirements. The emphasis of the experiment was on the dosemeter response as a function of photon energy and angle of incidence of the radiation. The tests were based on the ICRU operational quantities H(p) (0.07) and H(p) (10). All measurements were compared with the true...

  20. Connected TSEE/OSEE readouts of BeO thin-film dosemeters

    The commonly used TSEE readout for β- or X-irradiated BeO thinfilm dosemeters was complemented by OSEE readouts using blue ( 500 nm) light beams which caused different OSEE decay characteristics. By TSEE a dose range between 10-5 Gy and 10 Gy and by OSEE, a dose range between 10-3 Gy and 104 Gy could be covered. This means that the dose-measuring capacity of BeO thin-film dosemeters linearly comprises 9 orders of magnitude between the low-dose threshold and high-dose saturation. A relation between TSEE and OSEE signals was established by thermal bleaching experiments. (author)

  1. Determination of the dose rapidity of a 90 Sr beta radiation source using thermoluminescent dosemeters

    The thermoluminescent dosemeters developed in Mexico, have been used efficiently in environmental and personal dosimetry. When the dose rate of some source is not known can be estimated with the use of thermoluminescent dosemeters taking in account the geometrical array used in the irradiations for reproducibility of the results in posterior irradiations. In this work it was estimated the dose rate of a 90 Sr-90 Y beta radiation source which is property of the Nuclear Sciences Institute, UNAM, therefore it was l ended to the Metropolitan Autonomous University- Iztapalapa Unit for the characterization of new Tl materials, taking account of the institutional collaboration agreements. (Author)

  2. Sensitivity loss of LiF: Mg,Cu,P thermoluminescence dosemeters caused by oven annealing

    LiF:Mg,Cu,P is a very sensitive thermoluminescence material that can be used for personal dosimetry in radiology. But if this material is heated too much during annealing or reading it quickly loses its sensitivity. This study shows that an annealing oven in wide use can cause thermal damage to the dosemeters owing to inhomogeneous temperature distribution in the annealing tray. At annealing temperatures >240 deg. C, differences of only 1 deg. C lead to significant losses of sensitivity. Therefore, it is necessary to measure the distribution of temperature in the annealing tray for correct placement of the dosemeters in the tray. (authors)

  3. Recommendations to alarm systems and lessons learned on alarm system implementation

    Alarm systems have been of major concern within complex industrial processes for many years. Within the nuclear community, the TMI accident in 1979 was the first really serious event that showed also the importance of the man-machine aspects of the systems in general, and the alarm system in particular. The OECD Halden Reactor Project has been working with alarm systems since 1974. This report is an attempt to gather some of the knowledge that has been accumulated during the years in Halden, both in research and also in bilateral projects. Bilateral projects within this field have provided a practical basis of knowledge.A major part of this report consists of a set of recommendations, which reflect HRP's current understanding of how an alarm system should work. There are also recommendations on design methods. But also other issues are included, as system development and implementation experience, and experimental knowledge on the performance of alarm systems. Some open issues are also discussed. (Author). 54 refs., 15 figs

  4. Clinical Alarms in intensive care: implications of alarm fatigue for the safety of patients

    Adriana Carla Bridi

    2014-12-01

    Full Text Available OBJECTIVES: to identify the number of electro-medical pieces of equipment in a coronary care unit, characterize their types, and analyze implications for the safety of patients from the perspective of alarm fatigue.METHOD: this quantitative, observational, descriptive, non-participatory study was conducted in a coronary care unit of a cardiology hospital with 170 beds.RESULTS: a total of 426 alarms were recorded in 40 hours of observation: 227 were triggered by multi-parametric monitors and 199 were triggered by other equipment (infusion pumps, dialysis pumps, mechanical ventilators, and intra-aortic balloons; that is an average of 10.6 alarms per hour.CONCLUSION: the results reinforce the importance of properly configuring physiological variables, the volume and parameters of alarms of multi-parametric monitors within the routine of intensive care units. The alarms of equipment intended to protect patients have increased noise within the unit, the level of distraction and interruptions in the workflow, leading to a false sense of security.

  5. Changes in Default Alarm Settings and Standard In-Service are Insufficient to Improve Alarm Fatigue in an Intensive Care Unit: A Pilot Project

    Sowan, Azizeh Khaled; Gomez, Tiffany Michelle; Tarriela, Albert Fajardo; Reed, Charles Calhoun; Paper, Bruce Michael

    2016-01-01

    Background Clinical alarm systems safety is a national concern, specifically in intensive care units (ICUs) where alarm rates are known to be the highest. Interventional projects that examined the effect of changing default alarm settings on overall alarm rate and on clinicians’ attitudes and practices toward clinical alarms and alarm fatigue are scarce. Objective To examine if (1) a change in default alarm settings of the cardiac monitors and (2) in-service nursing education on cardiac monit...

  6. A Study on Performance Requirements for Advanced Alarm System

    A design goals of advanced alarm system is providing advanced alarm information to operator in main control room. To achive this, we applied computer based system to Alarm System. Because, It should apply data management and advanced alarm processing(ie. Data Base Mangegment System and S/W module for alarm processing). These are not impossible in analog based alarm system. And, preexitance research examples are made on digital computer. We have digital systems for test of advanced alarm system table and have tested and studied using by test equipment in the view point of the system performance, stability and security. In this paper, we discribed about general software architecture of preexitance research examples. Also, CPU performance and requirements of system software that served to accommodate it, stability and security

  7. The implications of probability matching for clinician response to vital sign alarms: a theoretical study of alarm fatigue.

    Bailey, James M

    2015-01-01

    Alarm fatigue has been recognised as a significant health technology safety risk. 'Probability matching', in which clinicians respond to the alarm at a rate identical to the perceived reliability of the alarm, has been postulated as a model to explain alarm fatigue. In this article, we quantitatively explore the implications of probability matching for systolic blood pressure alarms. We find that probability matching could have a profound effect on clinician response to the alarm, with a response rate of only 8.6% when the alarm threshold is 90 mm Hg and the optimal threshold for a systolic blood pressure alarm would only be 77 mm Hg. We use the mathematical framework to assess a mitigation strategy when clinicians have a limit to the capacity to respond. We find that a tiered alarm in which clinicians receive information on the severity of vital sign perturbation significantly improves the opportunity to rescue patients. Practitioner Summary: Using a theoretical model, we predict that probability matching, a postulated model of clinician behaviour, can result in a profound decrease in clinician response to alarms for decreased blood pressure. A mitigating strategy is to create alarms that convey information on the degree of vital sign perturbation. PMID:25849772

  8. Nuclear energy - Radiation protection - Individual thermoluminescence dosemeters for extremities and eyes

    This International Standard provides performance criteria and tests for determining the performance of thermoluminescence dosemeters intended to be used for the measurement of radiation doses to the eyes and extremities (fingers, and limbs defined as hands, feet, forearms including the elbow, and leg including the patella), for photons from 15 keV to 3 MeV and beta radiation from 0,5 MeV to 3 MeV. It is conditional upon the use of an appropriate reader, procedures and ancillary equipment. It does not cover information access and data processing. This International Standard provides performance criteria and tests for dosemeters intended to measure dose equivalent at depths of 7 mg cm-2 in tissue for fingers and limbs and 300 mg cm-2 in tissue for the eyes, including provision for the use of dosemeters only intended to be used once. Appropriate phantoms and dose conversion coefficients are recommended but others are not precluded. In all cases, performance is assessed under laboratory conditions which may not adequately simulate conditions actually experienced in personal dosimetry. For example, it may be necessary to sterilize dosemeters for medical applications. Therefore, caution is necessary in applying the results of these performance tests in real situations

  9. Effect of some parameters in the response of the Perspex 3042, Lot L amber dosemeters

    The answer of the dosimetric systems is affected by several factors, for what should know as these factors they influence in each one of the different dosimetric systems and by this way to minimize its effect in the value of the absorbed dose and to obtain exact dose values. One of the dosimetric systems more used in the high dose dosimetry like routine dosemeter for the control of the irradiation process are the Perspex dosemeters, for their speed in the obtaining the information, their easy manipulation and the precision that they present. To this dosemeters group they belong the same as the Red and Clear the Amber, which are adequate for the measurement of the radiation dose in the range of high doses. The objective of the present work is to obtain the calibration curves of the dosemeters Amber Perspex 3042, Lot L under our work conditions, like they are the irradiation temperatures and of storage and to know the influence of the rate dose in the value of the absorbed dose for different measurement wavelengths, as well as, the relationship among the one post-irradiation time and the specific absorbance value induced in function of the absorbed dose. (Author)

  10. Performance of special extremity dosemeters of BeO in fields of X and gamma radiation

    A dosimetric system, with a thermoluminescent reproducer and BeO dosemeters incorporated in a discardly metallic support, for using in extremities is tested, in relation theirs mains characteritics: determination of the detectable minimum expousure, linearity of the response of 60Co radiation, thermal fading at 500C and energetic dependence for X-radiation and gamma. (C.G.C.)

  11. EURADOS trial performance test for personal dosemeters for external beta radiation

    On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU was accomplished. This paper deals with the part of the performance test concerned with exposure to beta radiation. Fifteen dosimetric services participated with whole-body dosemeters intended to measure beta doses (Hp(0.07)) of which 13 used thermoluminescent (TL) detectors and two used photographic films. Eight services participated with extremity dosemeters which all used TL detectors. A description is given of the irradiation set-up, the characteristics of the irradiation fields, the calibration quantity applied and the performance criteria used for the evaluation of the results. The paper discussed in detail the results obtained from the exercise. In particular, based on the replies to a questionnaire issued to each participant, the results are analysed in relation to important design characteristics of the dosemeters taking part in the test. (author)

  12. Future development of the demands on therapy dosemeters with ionization chambers

    Only little will change with the introduction of the European internal market with regard to the demands on ionization chamber dosemeters used in radiotherapy, provided that the harmonized standard is aligned with IEC publication 731. Type licences for domestic calibration will be replaced by European Communities licences. (orig.)

  13. The development of a personal dosemeter for use by aircraft crew

    This paper describes preliminary work to develop a cosmic-radiation dosemeter for use by military aircraft crew. The dosemeter is based on a combination of CR-39 etched-track detectors and TLD-700 thermoluminescent detectors. It is intended that the CR-39 be used to assess the neutron dose, while the TLD-700 is used to assess the photon and charged particle dose. The sensitivity of CR-39 to the neutron component of cosmic radiation was estimated by irradiating samples of the plastic at the CERN-CEC High Energy Reference Field Facility. This facility produced a radiation field with a neutron spectrum resembling that of the neutron component of cosmic radiation a typical airflight altitudes. The response of the CR-39 was linear over the range of doses studied (0.2-6.0 mSv) and there was no significant fading in the six-month period after irradiation. The TLD-700 component of the dosemeter was calibrated using 137Cs gamma rays. The response of the TLD-700 was linear over the range of doses studied (0-1.1 mSv) with no significant fade in the six-month period after irradiation. It was concluded that a combination of CR-39 and TLD-700 detectors would provide an effective cosmic-radiation dosemeter for use by military aircraft crew. (author)

  14. Development and calibration of a neutron personal dosemeter using nuclear tracking solid detectors

    A personal neutron dosimetry, using two fission track solid detectors, with commercial name CR-39 and Makrofol-DE was developed, calibrated and tested. This dosemeter responds to the neutrons in the thermal, epithermal and fast energy intervals. Also, data from the different development phases are presented

  15. Influence of dosemeter position for the assessment of eye lens dose during interventional cardiology.

    Principi, Sara; Ginjaume, Mercè; Duch, Maria Amor; Sánchez, Roberto M; Fernández, Jose M; Vano, Eliseo

    2015-04-01

    The equivalent dose limit for the eye lens for occupational exposure recommended by the ICRP has been reduced to 20 mSv y(-1) averaged over defined periods of 5 y, with no single year exceeding 50 mSv. The compliance with this new requirement could not be easy in some workplace such as interventional radiology and cardiology. The aim of this study is to evaluate different possible approaches in order to have a good estimate of the eye lens dose during interventional procedures. Measurements were performed with an X-ray system Philips Allura FD-10, using a PMMA phantom to simulate the patient scattered radiation and a Rando phantom to simulate the cardiologist. Thermoluminescence (TL) whole-body and TL eye lens dosemeters together with Philips DoseAware active dosemeters were located on different positions of the Rando phantom to estimate the eye lens dose in typical cardiology procedures. The results show that, for the studied conditions, any of the analysed dosemeter positions are suitable for eye lens dose assessment. However, the centre of the thyroid collar and the left ear position provide a better estimate. Furthermore, in practice, improper use of the ceiling-suspended screen can produce partial protection of some parts of the body, and thus large differences between the measured doses and the actual exposure of the eye could arise if the dosemeter is not situated close to the eye. PMID:25514919

  16. Determination of the parameters of traps in thermoluminescent dosemeters of ZrO2: Eu + Ptfe

    In this work the manufacture of dosemeters in pellets form of ZrO2: Eu + Ptfe is described; which after were exposed to UV radiation (260 nm) were generated the corresponding thermoluminescent curves and in the basis to the properties of symmetry of the curves it was determined the kinetic order using the Chen and the Balarin criteria. (Author)

  17. A measurement of the response to fast neutrons of several materials dosemeters

    The response to fast neutrons was measured for three types of materials testing dosemeters: fast neutron dosimetry silicon diodes; beryllia, alumina and calcium fluoride TLDs; graphite walled ionisation chambers. The calibrations were made using a 3MW positive ion accelerator. The arrangement of the target, beam monitor and devices is described, and the measured fast neutron sensitivities are presented. (UK)

  18. Compliance of electronic personal neutron dosemeters with the new international standard IEC 61526

    Full text: The international standard IEC 1323 requires for personal neutron dosemeters a flat personal dose equivalent response within ± 50 % for monoenergetic neutrons in the energy region from 100 keV to 15 MeV and the response for neutrons with energies between thermal and 100 keV had to be stated by the manufacturer. Most of the electronic neutron dosemeters on the market are not able to fulfill this recommendation. Since realistic neutron fields at workplaces have broad spectral distributions and a limited contribution from neutrons with energies between thermal and 100 keV, the new IEC 61526 recommendation allows to replace some of the monoenergetic fields by workplace fields or a broad source having a maximal energy pike, in dose equivalent, close to the energy of the monoenergetic point in place of which it is used, but also gives limits in the energy region from thermal to 100 keV. This work shows results of recent measurements of the personal dose equivalent response for the dosemeters Thermo Electron EPD-N2, Aloka PDM-313 and the prototype dosemeter PTB DOS-2002 and discusses their compliance with respect to the new IEC 61526 standard. (author)

  19. Development of an improved dosemeter for assessments of risk to the eye

    To develop an improved dosemeter to assess photon and beta exposures of the eye lens, and in response to issues surrounding the preferred values of Hlens to be used for guiding operational radiation protection, a programme of re-optimization of the current PHE thermoluminescence dosemeter has been performed. In particular, refinements of the filter located in front of the sensitive 7LiF:Mg,Cu,P element have been considered, so that the dose response characteristics of the device provide a better and more conservative estimate of risk. The investigation was performed using the Monte Carlo modelling software MCNP5, to produce a final design that featured a filter containing a 9.5 mm diameter polypropylene hemisphere truncated to a maximum thickness of 3.0 mm. The responses of this design in photon and electron fields are presented here, contrasted against those of the existing PHE eye dosemeter, with respect to the operational quantity Hp(3,E,θ) and both current and suggested values for the absorbed dose per fluence risk profile for the lens of the eye. - Highlights: • A programme of re-optimization of the current PHE eye dosemeter has been performed. • A design featuring a truncated hemispherical filter was found to be optimal. • The shape of the filter better resembles the rotational profile of the eye. • Response characteristics depend on the calibration conditions taken to provide the best risk estimate

  20. Influence of dosemeter position for the assessment of eye lens dose during interventional cardiology

    The equivalent dose limit for the eye lens for occupational exposure recommended by the ICRP has been reduced to 20 mSv y-1 averaged over defined periods of 5 y, with no single year exceeding 50 mSv. The compliance with this new requirement could not be easy in some workplace such as interventional radiology and cardiology. The aim of this study is to evaluate different possible approaches in order to have a good estimate of the eye lens dose during interventional procedures. Measurements were performed with an X-ray system Philips Allura FD-10, using a PMMA phantom to simulate the patient scattered radiation and a Rando phantom to simulate the cardiologist. Thermoluminescence (TL) whole-body and TL eye lens dosemeters together with Philips DoseAware active dosemeters were located on different positions of the Rando phantom to estimate the eye lens dose in typical cardiology procedures. The results show that, for the studied conditions, any of the analysed dosemeter positions are suitable for eye lens dose assessment. However, the centre of the thyroid collar and the left ear position provide a better estimate. Furthermore, in practice, improper use of the ceiling-suspended screen can produce partial protection of some parts of the body, and thus large differences between the measured doses and the actual exposure of the eye could arise if the dosemeter is not situated close to the eye. (authors)

  1. JOYO operation support system 'JOYCAT' based on intelligent alarm handling

    An operation support system for the experimental fast reactor 'JOYO' was developed based on an intelligent alarm-handling. A specific feature of this system, called JOYCAT (JOYO Consulting and Analyzing Tool), is in its sequential processing structure that a uniform treatment by using design knowledge base is firstly applied for all activated alarms, and an exceptional treatment by using heuristic knowledge base is then applied only for the former results. This enables us to achieve real-time and flexible alarm-handling. The first alarm-handling determines the candidates of causal alarms, important alarms with which the operator should firstly cope, through identifying the cause-consequence relations among alarms based on the design knowledge base in which importance and activating conditions are described for each of 640 alarms in a frame format. The second alarm-handling makes the final judgement with the candidates by using the heuristic knowledge base described as production rules. Then, operation manuals concerning the most important alarms are displayed to operators. JOYCAT has been in commission since September of 1990, after a wide scope of validation tests by using an on-site full-scope training simulator. (author)

  2. Alarm management in gas pipeline plant: a case study

    Araujo, Juliano; Lima, Marcelo; Leitao, Gustavo; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Branco, Nicolau; Coelho, Robson; Elias, Gustavo Passos; Nunes, Marcelo [Transportadora Brasileira Gasoduto Bolivia-Brasil (TBG), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In order to improve the requirements of industrial processes, many decision support systems have been introduced in recent years. In this context, the alarm management systems have great relevance. On the other hand, the informatics revolution allowed a great increase of information concerning the operation of the industrial processes. Currently, process operators handle an excessive number of about 1.500 alarms per day. Thus, this overdose of information implies in the discredit of alarms. Then, in order to improve the operation activities of industrial processes, it is mandatory to incorporate procedures to evaluate and rationalize alarms. Since the EMMUA191 Standard is the reference guide to alarm management, but it does not specify how to execute an alarm management procedure, in this paper, a systematic procedure to evaluate alarms configurations in industrial processes is proposed. This procedure is in line with EMMUA191 and is composed by the following steps: to use statistics analyses to identify problematic alarms, such as occurrence, intermittency, correlation, and flooding calculation; to indicate problematic alarm group; and to propose a set of actions to be implemented. To validate our proposal, we present a case study in a gas pipeline plant using the BR-AlarmExpert software. (author)

  3. APLIKASI SENSOR CAHAYA UNTUK ALARM ANTI PENCURI

    Asita Shoman Muzaki

    2013-07-01

    Full Text Available Kasus pencurian di rumah kosong yang ditinggal pergi oleh pemiliknya belakangan ini marak terjadi. Berangkat dari pemikiran ini penulis mencoba merancang alarm yang dapat mendeteksi pergerakan seseorang saat rumah dalam kondisi kosong, ditinggalkan oleh pemiliknya. Alat ini mempunyai prinsip kerja yaitu mendeteksi bayangan seseorang yang melewati titik tertentu. Perancangan dan pembuatan perangkat ini menggunakan sensor cahaya berupa LASER dan LDR yang dirangkai dengan transistor sebagai saklar otomatis serta LED dan telepon rumah untuk melakukan panggilan kepada nomor telepon pemilik rumah. Komponen yang dipakai dalam pembuatan perangkat ini antara lain IC LM7805, LASER pointer, resistor, transistor BC108, LED, relay dan telepon rumah. Perancangan dan pembuatan alat menggunakan software multisim 10.1 sebagai simulator rangkaian, dan software eagle 5.1.1 untuk mendesain jalur rangkaian pada papan PCB. Saat cahaya LASER tidak sampai ke LDR karena terhalang oleh sesuatu, maka rangkaian output yang berupa indikator LED dan panggilan dari telepon rumah akan aktif. Kata kunci: alarm, sensor cahaya, saklar otomatis, relay.

  4. Radiation burden to hands from handling 99Mo-sup(99m)Tc generators measured by UVVVR finger dosemeters

    The doses to the fingers of seven technicians carrying out elutions of the 99Mo-sup(99m)Tc generators were monitored using LiF RTL dosemeters placed on the volar sides of the thumb, the index and middle fingers, and aluminophosphate glass RTL dosemeters fixed to the dorsal or the volar side of the ring finger. The finger doses corresponded to 0.4 to 1.9% of the annual permissible dose to hands. The maximum value measured in one technician was 14.3 mGy at a whole-body dose of 1.8 mGy as measured by a film dosemeter. (Ha)

  5. Calibration of a special neutron dosemeter based on solid-state track detectors and fission radiators in various neutron fields

    The calibration of a personnel neutron dosemeter in different neutron fields is described. The badge-like dosemeter contains 5 detectors: polycarbonate foil (10 μm, Makrofol KG), 232Th, natural uranium, natural uranium with boron, and natural uranium with cadmium. Detector sensitivity and calibration factors have been calculated and measured in radiation fields of 252Cf fission neutrons, WWR-S reactor neutrons with and without Cd and Fe shielding, 3-MeV (d,t) generator neutrons, and 238PuBe neutrons. Measurement range and achievable accuracy are discussed from the point of view of applying the dosemeter in routine and emergency uses

  6. General methods for alarm reduction; Larmsanering med generella metoder

    Ahnlund, Jonas; Bergquist, Tord; Raaberg, Martin [Lund Univ. (Sweden). Dept. of Information Technology

    2003-10-01

    The information in the control rooms has increased due to the technological advances in process control. Large industries produce large data quantities, where some information is unnecessary or even incorrect. The operator needs support from an advanced and well-adjusted alarm system to be able to separate a real event from a minor disturbance. The alarms must be of assistance and not a nuisance. An enhanced alarm situation qualifies an increased efficiency with fewer production disturbances and an improved safety. Yet, it is still unusual that actions are taken to improve the situation. An alarm cleanup with general methods can shortly be described as taking advantage of the control systems built-in functions, the possibility to modify or create function blocks and fine-tune the settings in the alarm system. In this project, we make use of an intelligent software, Alarm Cleanup Toolbox, that simulate different signal processing methods and tries to find improved settings on all the signals in the process. This is a fast and cost-efficient way to improve the overall alarm situation, and lays a foundation for more advanced alarm systems. An alarm cleanup has been carried out at Flintraennan district heating plant in Malmoe, where various signal processing methods has been implemented in a parallel alarm system. This made it possible to compare the two systems under the same conditions. The result is very promising, and shows that a lot of improvements can be achieved with very little effort. An analysis of the alarm system at Vattenreningen (the water purification process) at Heleneholmsverket in Malmoe has been carried out. Alarm Cleanup Toolbox has, besides suggesting improved settings, also found logical errors in the alarm system. Here, no implementation was carried out and therefore the results are analytical, but they validate the efficiency of the general methods. The project has shown that an alarm cleanup with general methods is cost-efficient, and that the

  7. Classification of alarm processing techniques and human performance issues

    Human factors reviews indicate that conventional alarm systems based on the one sensor, one alarm approach, have many human engineering deficiencies, a paramount example being too many alarms during major disturbances. As an effort to resolve these deficiencies, various alarm processing systems have been developed using different techniques. To ensure their contribution to operational safety, the impacts of those systems on operating crew performance should be carefully evaluated. This paper briefly reviews some of the human factors research issues associated with alarm processing techniques and then discusses a framework with which to classify the techniques. The dimensions of this framework can be used to explore the effects of alarm processing systems on human performance

  8. Experimental evaluation of human-system interaction on alarm design

    This study evaluates the practicability of automatic reset alarm system in Fourth Nuclear Power Plant (FNPP) of Taiwan. The features of auto-reset alarm system include dynamic prioritization of all alarm signals and fast system reset. Two experiments were conducted to evaluate the effect of automatic/manual reset on operation time, situational awareness (SA), task load index (TLX), and subjective ratings. All participants, including Experts and Novices, took part in the experiment on the alarm system simulator with Load Rejection procedure. The experimental results imply that the auto-reset alarm system may be applied in an advanced control room under Load Rejection procedure, because all participants' operation time were reduced as well as Novice's SA were raised up. Nevertheless, to ensure operating safety in FNPP, the effects of the auto-reset alarm system in other procedures/special situations still need to be tested in the near future

  9. Operator Performance Comparison of two VDT-based Alarm Systems

    This study is carried out to investigate performance differences between two alarm presentation methods from the viewpoint of human factors and to provide items to be improved. One of the alarm display methods considered in this study displays alarm lists on VDT combined with hardwired alarm panels. The other method displays alarms on plant mimic diagrams of VDT. This alarm display method has other features for operator aid with which operator can get detailed information on the activated alarm in the mimic diagrams, and the capability for alarm processing such as alarm reduction and prioritization. To compare the two display methods, a human factor experiment was performed with a plant simulator in the ITF (Integrated Test Facility) that plant operators run for 4 event scenarios. During the experiment, physiological measurements, system and operator action log, and audio/video recordings were collected. Operators subjective opinion was collected as well after the experiment. Time, error rate and situation awareness were major human factor criteria used for the comparison during the analysis stage of the experiment. No statistical significance was found in the results of our statistical comparison analysis. Several findings were identified, however, through the analysis of subjective opinions. (authors)

  10. Contribution of computerization to alarm processing: A French safety view

    Following the TMI accident and according to the requirement of the French safety authority, very important studies were performed by the French utility, Electricite de France (EDF), and assessed by the Institute for Nuclear Safety and Protection (IPSN) on reactor operation in conventional control rooms, particularly on alarm processing. These studies dealt with the man-machine interface, as well as design and exploitation requirements, presentation and management of alarm signals, and associated operating documents. The conclusions of these studies have led to improvements in French conventional control rooms. The current state of these control rooms and links between alarm sets and operating documents will be shortly presented in the first part of the paper. More recently, the computerized means implemented in the PWR 1400 MWe control rooms (N4) profoundly modified reactor operation. In particular, major advances concern alarm processing in comparison with conventional control rooms. The N4 plants provide a more rigorous approach in processing and presentation of alarms than in the past. Indeed, EDF wanted to have less alarms switched on during plant upsets and to make them more characteristic of a specific situation of the process. For example, computerization makes it easier to validate or inhibit alarms according to the situation, to allow the operator to manage alarm presentation and to propose on-line alarm sheets to the operator etc. This approach in comparison with conventional control rooms, and the IPSN assessment will be presented in the second part of this paper. (author)

  11. AI-based alarm processing for a nuclear power plant

    A real-time expert system is implemented using artificial intelligence and object-oriented technology for alarm processing and presentation in a nuclear power plant. The knowledge base is constructed based on some schemes to process and display alarms to the plant operators. The activated alarms are dynamically prioritized by the reasoning rules, and then, presented on the process mimic overview and by some other means. To demonstrate the proposed system, the alarm processing and presentation is carried out in a simulated environment of the TMI-2 accident

  12. Performance of a PADC personal neutron dosemeter at simulated and real workplace fields of the nuclear industry

    In the framework of the EVIDOS (Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields) project, funded by the EC, measurements with PADC personal neutron dosemeters were carried out at several workplace fields of the nuclear industry and at simulated workplace fields. The measured personal neutron dose equivalents of the PADC personal neutron dosemeter are compared with values that were assessed within the EVIDOS project by other partners. The detection limits for different spectra types are given. In cases were the neutron dose was too low to be measured by the PADC personal neutron dosemeter, the response is estimated by convoluting the responses to monoenergetic neutrons with the dose energy distribution measured within EVIDOS. The advantages and limitations of the PADC personal neutron dosemeter are discussed. (authors)

  13. Energy dependence of ulrathin LiF-dosemeters for high energy electrons and high energy X-radiation

    The energy dependence of ultrathin LiF-dosemeters for high energy electrons (5-40 MeV) and high energy X-radiation (6 MV, 42 MV) is experimentally determined. The experimental values are compared to values calculted earlier by other authors. The influence of the thickness of the dosemeters have been considered by comparison of experimental values for 0.03 mm thick dosemeters and theoretical values for 0.13 mm and 0.38 mm thick ones. Also different commersially available dosemeters have been compared by experiments. It is difficult to draw any other conclutions about the energy dependence than that the variation of the relative responce is within +- 3 percent (2S). However the results seems to be sulficient for clinical applications

  14. Investigation of a new TL individual dosemeter for measuring personal dose equivalent Hp(d) on different phantoms

    The results obtained with four different types of phantom and pertinent conversion coefficients show that the conversion coefficients for the TE slab phantom are suitable for the calibration of TLD individual dosemeters on a PMMA slab phantom. (Author)

  15. Correlating data from different sensors to increase the positive predictive value of alarms: an empiric assessment

    Yuval Bitan; O’Connor, Michael F.

    2012-01-01

    Objectives: Alarm fatigue from high false alarm rate is a well described phenomenon in the intensive care unit (ICU). Progress to further reduce false alarms must employ a new strategy. Highly sensitive alarms invariably have a very high false alarm rate. Clinically useful alarms have a high Positive-Predictive Value. Our goal is to demonstrate one approach to suppressing false alarms using an algorithm that correlates information across sensors and replicates the ways that human evaluators d...

  16. Use of a robotic manipulator in the simulation of the automation of a calibration process of dosemeters

    The development of a system based in a manipulative robot which simulates the operative sequence in a calibration process of dosemeters is presented. In this process it is performed the monitoring of the dosemeter positions and the calibrator by mean of an arm of articulated robot which develops the movement sequences and the taking a decision based on the information coming from the external sensors. (Author)

  17. Systematic errors in the readings of track etch neutron dosemeters caused by the energy dependence of response

    Tanner, R J; Bartlett, D T; Horwood, N

    1999-01-01

    A study has been performed to assess the extent to which variations in the energy dependence of response of neutron personal dosemeters can cause systematic errors in readings obtained in workplace fields. This involved a detailed determination of the response functions of personal dosemeters used in the UK. These response functions were folded with workplace spectra to ascertain the under- or over-response in workplace fields.

  18. Influence of the PMMA and the ISO slab phantom for calibrating personal dosemeters

    Wide agreement has been achieved among the main Bodies and Organisations involved in standardisation of radiation protection, related to the operational quantities for personal dosimetry. Since their definition in 1985, several reports have been published to clarify and define the experimental set up to be used for the calibration of dosemeters in terms of the above-mentioned quantities. Among these lines, ICRU 47 has listed five different phantoms that are used for calibration and whose results were accurate, within accepted uncertainties. However, to achieve uniformity in calibration procedures, the 30 cm x 30 cm x 15 cm PMMA slab phantom was recommended. The secondary calibration Laboratory from the Institut de Techniques Energetiques at the Technical University of Catalonia (UPC) agreed with the Spanish Nacional Laboratory to adopt the recommended PMMA phantom but to improve the accuracy of the calibration procedure, by introducing a correction factor for backscatter differences in a PMMA and an ICRU slab phantom. Such corrections were of the order of 8% for the low-energy X-ray qualities. Recently, ISO in ISO 4037-3, has proposed the ISO water slab phantom which consists of a 30 cm x 30 cm x 15 cm water phantom with PMMA walls (front wall 2.5 mm thick). This new phantom could be substituted by the above mentioned PMMA phantom for radiation qualities with mean energy equal or above that of 137Cs. The aim of this work is to compare the influence of both phantoms when calibrating personal dosemeters with photons. A set of four TL personal dosemeters that are used in the UPC personal dosimetry Service and an electronic personal dosemeter (SIEMENS EPD-2) were calibrated in terms of Hp(10) and Hp(0.07) using the two proposed phantoms. Calibration factors for ISO X-ray narrow spectra, 137Cs and 60Co were experimentally obtained for each phantom and compared. In the TL measurements, differences were found to be within TL statistical uncertainty, provided that a

  19. Comparative measurements of external radiation exposure using mobile phones, dental ceramic, household salt and conventional personal dosemeters

    Because retrospective dosimetry utilises commonly occurring materials and objects, it is particularly useful in cases of large-scale radiation accidents or malevolent acts with radioactive materials where casualties are inflicted on the general public and first emergency responders. The aim of this study was to investigate whether retrospective dosemeters can provide dose estimates with comparable accuracy like conventional personal dosemeters. Using an external source of radiation 137Cs and an anthropomorphic phantom, we simulated serious irradiation of a human body in anterior-posterior and rotational geometries. Retrospective luminescence dosimetry objects, such as mobile phones, dental ceramic and household salt, and conventional personal dosemeters (thermoluminescent and electronic) were fixed to the anthropomorphic phantom. The doses obtained were compared with specific reference values. In most cases, relative deviations between the measured doses and the reference values did not exceed 20%. As the retrospective and conventional dosemeters show no significant differences in laboratory conditions, the retrospective luminescence dosimetry objects represent a very promising tool if handled properly. - Highlights: • A serious external exposure of human body was simulated. • Doses were measured using both retrospective and conventional dosemeters. • Utilised retrospective dosimetry materials were alumina resistors from mobile phones, household salt and dental ceramic. • Doses obtained were compared with reference values. • Both retrospective and conventional dosemeters gave similar results

  20. 24 CFR 3280.208 - Smoke alarm requirements.

    2010-04-01

    ... locations: (i) To protect both the living area and kitchen space. Manufacturers are encouraged to locate the alarm in the living area remote from the kitchen and cooking appliances. A smoke alarm located within 20... other equipment discharging conditioned air through a ceiling grille into the living space; and (ii)...

  1. Successful use of the nocturnal urine alarm for diurnal enuresis.

    Friman, P C; Vollmer, D.

    1995-01-01

    We report the effects of using a urine alarm, typically employed for nocturnal enuresis, to treat chronic diurnal enuresis in a 15-year-old female resident at Boys' Town. The results of an ABAB reversal design indicate that the alarm eliminated wetting in both treatment phases and that continence was maintained at 3- and 6-month follow-up.

  2. Successful Use of the Nocturnal Urine Alarm for Diurnal Enuresis.

    Friman, Patrick C.; Vollmer, Dennis

    1995-01-01

    A urine alarm, typically used to treat nocturnal enuresis, was effectively used to treat diurnal enuresis in a 15-year-old female with depression, attention deficit hyperactivity disorder, and conduct disorder. The study indicated that the alarm eliminated wetting in both treatment phases and that continence was maintained at three-month and…

  3. Los Alamos Scientific Laboratory long-range alarm system

    The Los Alamos Scientific Laboratory (LASL) Long-Range Alarm System is described. The last few years have brought significant changes in the Department of Energy regulations for protection of classified documents and special nuclear material. These changes in regulations have forced a complete redesign of the LASL security alarm system. LASL covers many square miles of varying terrain and consists of separate technical areas connected by public roads and communications. A design study over a period of 2 years produced functional specifications for a distributed intelligence, expandable alarm system that will handle 30,000 alarm points from hundreds of data concentrators spread over a 250-km2 area. Emphasis in the design was on nonstop operation, data security, data communication, and upward expandability to incorporate fire alarms and the computer-aided dispatching of security and fire vehicles. All aspects of the alarm system were to be fault tolerant from the central computer system down to but not including the individual data concentrators. Redundant communications lines travel over public domain from the alarmed area to the central alarm station

  4. 33 CFR 401.16 - Propeller direction alarms.

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Propeller direction alarms. 401.16 Section 401.16 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller direction alarms. Every vessel of 1600...

  5. Alarm systems a guide to design, management and procurement

    Engineering Equipment and Materials Users' Association. London

    2013-01-01

    Alarm systems form an essential part of the operator interfaces to large modern industrial facilities. They provide vital support to the operators by warning them of situations that need their attention and have an important role in preventing, controlling and mitigating the effects of abnormal situations. Since it was first published in 1999, EEMUA 191 has become the globally accepted and leading guide to good practice for all aspects of alarm systems. The guide, developed by users of alarm systems with input from the GB Health and Safety Executive, gives comprehensive guidance on designing, managing and procuring an effective alarm system. The new Third Edition has been comprehensively updated and includes guidance on implementing the alarm management philosophy in practice; applications in geographically distributed processes; and performance metrics and KPIs.

  6. Reliability enhancement of criticality alarm system in CORAL

    This paper describes the challenges encountered in the Criticality Alarm System (CAS) installed in CORAL plant and explains the requirement and ways to make the system rugged, reliable and eliminate any false criticality alarms. To improve the reliability of the system the following improvements are required to be carried out viz. the power supply connections to the CAS, changes in wiring in the existing CASs, provision for electronic testing of the CAS remotely from control panel, connection of the criticality alarms to annunicator panel, design of common plant CAS alarm circuit with redundant DC power supplies, provision of alarm for mains and DC power supply failures, provision for transferring the CAS dose rate signals to the Radiation Data Acquisition Systems (RDAS) for event log and remote display and surveillance of CAS. (author)

  7. Dose imaging with gel-dosemeter layers: Optical analysis and dedicated software

    In radiotherapy involving thermal and epithermal neutrons, the knowledge of dose distributions, with separation of the contribution of each secondary radiation component, is of utmost importance. Layers of Fricke-Xylenol-Orange-infused gel dosemeters give the possibility of achieving such requirements because, owing to the layer-geometry, enriching or depleting the gel matrix of suitable isotopes does not sensibly alter neutron transport. The dosimetry method has been critically re-examined with the aim of improving its suitability to boron neutron capture therapy (BNCT) requirements, as it applies to the protocol of measurement and analysis, the sensitivity of the method and the range of the linearity of the dosemeters. Software has been developed and studied to obtain automatically the images of the various dose components with the established separation procedure. (authors)

  8. Monitoring radiation dose to the hands in nuclear medicine: location of dosemeters

    The relatively high radiation dose which can be received by the hands of staff in nuclear medicine departments means that in many departments it is necessary to monitor such doses. A convenient method is to use a TLD sachet in a plastic strip around a finger. This study was done to determine whether a dosemeter worn at the base of the middle finger was adequate to monitor the dose to the surface of the whole hand. Dosemeters were worn at the finger tips, finger base and palm of both hands, on two people while preparing and dispensing radiopharmaceuticals, and two others while giving injections using syringe shields. The pattern of distribution of radiation dose to the hands was similar for all workers and for both types of work. A single, convenient site (base of middle finger) may therefore be used for monitoring radiation dose to the hand. (author)

  9. The possibilities of personal albedo neutron dosemeter application at the Slovak cyclotron laboratory

    In addition to the production of short-lived radioisotopes, the Slovak Cyclotron Laboratory is also engaged in the application of neutron capture therapy, radiotherapy with fast neutrons, and proton therapy. Experiments were carried out where the operating quantities and conversion factors between the neutron fluence and the spatial or personal dose equivalent were determined by Bonner spectrometry over the entire range of energies used, employing a set of moderators. To obtain the requisite dosimetric parameters of the (n,γ) radiation fields, the deconvolution process (statistical regularization) was modified into a rather simple procedure, tractable by using a conventional PC AT. Calibration measurements were employed to obtain the dependence of the sensitivity of albedo dosemeters on the neutron dose ratios in two positions of the dosemeter (on the front and rear sides)

  10. State of the art in thermoluminescent dosimetry using dosemeters with automated read-out

    In the beginning, the results obtained with automated read-out TLD have been quite disappointing, both for manufacturers and users. In response to this, industry then seeked advice and assistance from those experienced in the practical use of dosemeters, and the development of the second generation of automated TLD has been a common task of manufacturers and purchosers. As a preliminary achievement of development work along this line, a dosemeter has been presented by a Japanese manufacturer, meeting the requirements in quite a satisfactory way. The device is characterized by a frequency of disturbance of -5, a microprocessor for controlling the measuring and control functions, possibility of active input of device parameters and boundary conditions, extensive self-control of operating functions, complete data protection, and thin-film detector technique. Pursuing this line of development, and taking into account future recommentations, automated thermoluminescent dosimetry does seem to be a promising alternative to current measuring techniques in personnel monitoring. (orig./RW)

  11. Characterization of a two-component thermoluminescent albedo dosemeter according to ISO 21909

    A two-component thermoluminescent albedo neutron monitoring system was developed at Instituto de Radioprotecao e Dosimetria, Brazil. As there is no Brazilian regulation for neutron individual monitoring service, the system was tested according to the ISO 21909 standard. This standard provides performance and test requirements for determining the acceptability of personal neutron dosemeters to be used for the measurement of personal dose equivalent, Hp(10), in neutron fields with energies ranging from thermal to 20 MeV. Up to 40 dosemeters were used in order to accomplish satisfactorily the requirements of some tests. Despite operational difficulties, this albedo system passed all ISO 21909 performance requirements. The results and problems throughout this characterization are discussed in this paper.

  12. Dissolution behaviour of 238U, 234U and 230Th deposited on filters from personal dosemeters

    Kinetics of dissolution of 238U, 234U and 230Th dust deposited on filters from personal alpha dosemeters was studied by means of a 26-d in vitro dissolution test with a serum ultra-filtrate simulant. Dosemeters had been used by miners at the uranium mine 'Dolni Rozinka' at Rozna, Czech Republic. The sampling flow-rate as declared by the producer is 4 l h-1 and the sampling period is typically 1 month. Studied filters contained 125 ± 6 mBq 238U in equilibrium with 234U and 230Th; no 232Th series nuclides were found. Half-time of rapid dissolution of 1.4 d for 238U and 234U and slow dissolution half-times of 173 and 116 d were found for 238U and 234U, respectively. No detectable dissolution of 230Th was found. (authors)

  13. Determination of the response function for two personal neutron dosemeter designs based on PADC.

    Mayer, S; Assenmacher, F; Boschung, M

    2014-10-01

    Since 1998 neutron dosimetry based on PADC (poly allyl diglycol carbonate) is done with a so-called original Paul Scherrer Institute (PSI) design at PSI. The original design (i.e. holder) was later changed. Both designs are optimised for use in workplaces around high-energy accelerators, where the neutron energy spectra are dominated by fast neutrons ranging up to some 100 MeV. In addition to the change of the dosemeter design a new evaluation method based on a microscope scanning technique has been introduced and the etching conditions have been optimised. In the present work, the responses obtained with the original and the new dosemeter designs are compared for fields of radionuclide sources and monoenergetic reference fields using the new evaluation method. The response curves in terms of the personal dose equivalent for normally incident neutrons were built as functions of the incident neutron energy. PMID:24179145

  14. Exposure levels to radiation in a nuclear medicine laboratory: measurements with thermoluminescence dosemeters

    Since 1996 in the Nuclear medicine Department and another routine and research departments of the National Institute of Medical and Nutrition Sciences (INCMNSZ) are working at least with 12 radioactive sources opened and sealed. However, it was unknown if with the Tl personal dosemeters with lithium fluoride crystals (LiF), could be possible to receive information about the equivalent dose for each radionuclide or if there was some radionuclide that by being low energy emissor or beta energy emissor, it did not represent an ionization power sufficient to excite the crystals of the thermoluminescent dosemeters (DTL). In this work the obtained results with control dosemeters of diverse source opened or sealed are shown, which were put at 1 cm of the LiF crystals during a time exposure 18 hours. Therefore the objective of this work is to verify which sources excite or not to DTL crystals and taking the pertinent safety measures for each radionuclide. The conclusion is that the majority of dosemeters were excited by beta or gamma radiation of the radionuclides and that LiF crystals are able to receive equivalent doses until 1200 mSv, being this a guarantee for the staff, that in an any moment could be exposed to high dose in his working day. Also it was corroborated that the radionuclides more energizer are: iodine-131, iodine-125 and sodium-22 while the phosphorus-32 must be managed with careful, since the exposure to hands can result significant, just like the technetium-99m (99m Tc). (Author)

  15. Development of an universal personal dosemeter using semiconductor sensors for mixed radiation fields

    The objectives of the project are: the development of an electronic personal dosemeter using semiconductors for mixed field radiation monitoring; computer simulation of the optimal design of the filters and converters associated with silicon detectors; and optimization of the silicon detectors. The objective for the reporting period is to develop a portable pocket sized system able to measure both the γ-ray and neutron doses for personal dosimetry. (R.P.) 5 refs., 3 tabs

  16. Determination of the dose index in computerized tomography using thermoluminescent dosemeters

    In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

  17. Response of dosemeters in the radiation field generated by a TW-class laser system

    State-of-the-art laser systems are able to generate ionising radiation of significantly high energies by focusing ultra-short and intense pulses onto targets. Thus, measures ensuring the radiation protection of both working personnel and the general public are required. However, commercially available dosemeters are primarily designed for measurement in continuous fields. Therefore, it is important to explore their response to very short pulses. In this study, the responses of dosemeters in a radiation field generated by iodine high-power and Ti:Sapphire laser systems are examined in proton and electron acceleration experiments. Within these experiments, electron bunches of femtosecond pulse duration and 100-MeV energy and proton bunches with sub-nanosecond pulse duration and energy of several megaelectronvolts were generated in single-shot regimes. Responses of typical detectors (TLD, films and electronic personal dosemeter) were analysed and compared. Further, a first attempt was carried out to characterise the radiation field generated by TW-class laser systems. Passive and active dosemeters were used for characterisation of pulsed radiation fields generated by lasers within electron and proton acceleration experiments. Generally, passive, compared with active, systems have the disadvantage of a postponed read-out. However, behaviour of passive systems in the pulsed field seems to be more reliable. Still, results of this study suggest that it might be possible to use active systems under special conditions. Whereas EPDs are not able to reliably detect very short pulses at low repetition rates, their response is promising at higher repetition rates for off-beam locations. Finally, it appears that the definition of the source term of a laser-generated field is not as straightforward as was anticipated. Obtaining a more accurate source term definition for radioprotection purposes would require knowledge and combination of data of at least two sources: generated

  18. Contribution to the development study of a personal fast neutron dosemeter using nuclear emulsion

    This work deals with the response of a personal neutron dosemeter using nuclear emulsion. The main characteristics of the detector are studied with the help of a computer programme simulating the conditions of the formation of recoil protons tracks recorded by nuclear emulsions. The lecture limits of nuclear emulsions with light microscope and the validity of our computer code are checked by comparing our theoretical values with experimental results

  19. THE RESULTS OF THE EURADOS INTERCOMPARISON IC2014 FOR WHOLE-BODY DOSEMETERS IN PHOTON FIELDS.

    Stadtmann, H; Grimbergen, T W M; Figel, M; Romero, A M; McWhan, A F; Gärtner, C

    2016-09-01

    The European Dosimetry Group (EURADOS) first started performing international intercomparisons for whole-body dosemeters for individual monitoring services in 1998. Since 2008, these whole-body intercomparisons have been performed on a regular basis. In this latest intercomparison (IC2014), 96 monitoring services from 35 countries (mostly European) participated with 112 dosimetry systems. Unlike in the previous intercomparisons, the whole registration, communication and data exchange process was handled by a new on-line platform. All dosemeter irradiations were carried out in the Seibersdorf accredited dosimetry laboratory. The irradiation plan consisted of nine irradiation setups with five different photon radiation qualities (S-Cs, S-Co, RQR7, W-80 and W-150) and two different angles of radiation incidence (0° and 60°). The paper describes and analyses the individual results for the personal dose equivalent quantities Hp(10) and if requested, Hp(0.07), for all participating systems and compares these results with the ISO 14146 'trumpet curve' performance criteria. The results show that 100 systems (89 % of all systems) do fulfil the general ISO 14146 performance criteria. This paper gives an overview on the performance of the participating individual monitoring services and the influence of the dosemeter type on the observed response values. PMID:26763903

  20. A portable versatile x- and gamma-ray dosemeter with ditigal display for medical use.

    Sankaran, A; Gangadharan, P

    1980-05-01

    A multipurpose dosemeter based on analogue-to-digita (A-d) conversion has been developed using solid state devices, micropower integrated circuits and displays. The A-D converter combines the features of a MOSFET electrometer, a voltage-to-frequency converter, the automatic Townsend balance, LED(LCD) display for exposure, analogue output and has a voltage-measuring accuracy of +/- 0.1% FS +/- 1 digit. The dosemeter, which is designed to measure a wide range of x- and gamma-ray exposure rates (1 mR h-1 to 1000 R min-1) and exposures (1 mR to 1000 R) with a variety of air-equivalent ionisation chambers, is compact, rugged and battery or AC mains powered. It is designed to provide trouble-free performance, easy operation and maintenance and to be independent of climatic conditions. Combining the features of a survey meter, dosemeter and a radioisotope calibrator, it can be fabricated using the facilities locally available in hospitals or universities. PMID:7403264

  1. A portable versatile x-and γ-ray dosemeter with digital display for medical use

    A multipurpose dosemeter based on analogue-to-digital (A-D) conversion has been developed using solid state devices, micropower integrated circuits and displays. The A-D converter combines the features of a MOSFET electrometer, a voltage-to-frequency converter, the automatic Townsend balance, LED(LCD) display for exposure, analogue output and has a voltage-measuring accuracy of +-O.1% FS+-1 digit. The dosemeter which is designed to measure a wide range of X- and γ-ray exposure rates (1 mRh-1 to 1000 R min-1) and exposures (1 mR to 1000 R) with a variety of air-equivalent ionisation chambers, is compact, rugged and battery or AC mains powered. It is designed to provide trouble-free performance, easy operation and maintenance and to be independent of climatic conditions. Combining the features of a survey meter, dosemeter and a radioisotope calibrator, it can be fabricated using the facilities locally available in hospitals or universities. (author)

  2. Investigation of a BeO-based optically stimulated luminescence dosemeter

    The optical sensitivity of BeO-based luminophors has been well-known for many years. The optical stimulation of BeO with blue light is most effective. Then the dosemeters emit luminescent light in the ultraviolet-range around 325 nm. Matched on these facts a simple optically stimulated luminescence (OSL) treatment has been developed. Intense blue light-emitting diodes are used for cw-stimulation. A Hamamatsu solar blind photomultiplier detects the OSL-light. Good separation of both spectral ranges by optical filters is very important. The dosemeter has a linear dose response between ∼20 μGy and >10 Gy. It was suggested, that a modification of stimulation conditions would allow measurements down to 1 μGy. Fading, photon energy dependence and reproducibility of OSL-signal correspond well with requirements to clinical and personal dosemeters. In addition, basic questions of the OSL-process in BeO have been investigated. A relevant point of interest was the dependency of the OSL-signal on stimulation power. (authors)

  3. Performance testing of personal dosemeters from eleven dosimetry services in Sweden

    The Swedish regulation, SSI FS 98:5, requires that radiological workers of category A use dosemeters from an approved personal dosimetry service. The 11 services operating in Sweden at the moment use five different types of dosemeter. All have been tested for their ability to determine Hp(10) and some of them to determine Hp(0.07) according to the European Commission report Radiation Protection 73, EUR 14852, of 1994. The five unique systems have been tested regarding the angular and energy dependence of the response of the dosemeters. The test points for the determination of Hp(10) are all, except one, within the trumpet curve and for the unique systems it is shown that the uncertainty related to angular response at three different energies is within the required ±40% except for the lowest X ray quality 40 kV. The energy dependence dominates over the directional dependence and the choice of radiation quality for calibration is of great importance for the system performance. (author)

  4. A new personal dosemeter for the individual monitoring of exposure to radon gas

    Rn-Disk dosemeter, a new close-type radon device, is here proposed. Rn-Disk passive monitor consists in a diffusion chamber, made by conductive plastic material (polypropylene enriched with carbon), that holds CR-39 plastics solid-state track detectors (SSNTD). The Rn-Disk passive device (patent pending) has been designed and developed to assess radon exposure received by workers and members of the public. This passive device is an ON/OFF chamber, made of an upper and lower half which snap together during assembly. In particular, it has been designed to exclude radon progeny and dusts entry whilst it allows access of radon gas. The operation principle is based on the revolving cap capability to rotate between 0o and 180o toward its base. This paper includes: a general description of Rn-Disk passive device; preliminary results of several type-tests and qualification tests, conducted in order to define the performances of the Rn-Disk dosemeter, when a CR-39 detector is enclosed in. Emphasis has been given to the investigation of Rn-Disk dosemeter performances in term of sensitivity, level of precision and accuracy of radon measurements, reproducibility, influence of environmental parameters (as temperature, humidity, dusts, etc.), etc. in accordance with ISO standards requirements. (author)

  5. From alarm systems to smart houses.

    Vlaskamp, F J

    1992-01-01

    The percentage of senior citizens in the Netherlands will rise in coming years. The expected percentage for the year 2010 of persons over age 65 in the total population is 15%. More persons over age 65 than ever before will continue to live in their own environment. Emergency response systems (ERS) can support independent living. The most common type of organization distributing ERS is a small, partly subsidized local alarm organization run by a social welfare office for the elderly. Government subsidy has been reduced in recent years which has motivated small organizations to join together into larger regional organizations in order to get a more solid financial base. On the other hand new semi-commercial and commercial organizations have come into being. These developments are part of the growing importance of home care, leading to more medical applications of ERS. User satisfaction with ERS is high. Portable triggers can enhance the effectiveness of the system. However, many users do not wear the portable trigger when feeling well. Future technical developments will result in multifunctionality of ERS-devices. In the long term the hardware of today will be integrated in a multimedia home terminal replacing the telephone. The portable trigger will remain the only specific hardware at home for ERS. PMID:10126436

  6. Pattern discovery in critical alarms originating from neonates under intensive care.

    Joshi, Rohan; van Pul, Carola; Atallah, Louis; Feijs, Loe; Van Huffel, Sabine; Andriessen, Peter

    2016-04-01

    Patient monitoring generates a large number of alarms, the vast majority of which are false. Excessive non-actionable medical alarms lead to alarm fatigue, a well-recognized patient safety issue. While multiple approaches to reduce alarm fatigue have been explored, patterns in alarming and inter-alarm relationships, as they manifest in the clinical workspace, are largely a black-box and hamper research efforts towards reducing alarms. The aim of this study is to detect opportunities to safely reduce alarm pressure, by developing techniques to identify, capture and visualize patterns in alarms. Nearly 500 000 critical medical alarms were acquired from a neonatal intensive care unit over a 20 month period. Heuristic techniques were developed to extract the inter-alarm relationships. These included identifying the presence of alarm clusters, patterns of transition from one alarm category to another, temporal associations amongst alarms and determination of prevalent sequences in which alarms manifest. Desaturation, bradycardia and apnea constituted 86% of all alarms and demonstrated distinctive periodic increases in the number of alarms that were synchronized with nursing care and enteral feeding. By inhibiting further alarms of a category for a short duration of time (30 s/60 s), non-actionable physiological alarms could be reduced by 20%. The patterns of transition from one alarm category to another and the time duration between such transitions revealed the presence of close temporal associations and multiparametric derangement. Examination of the prevalent alarm sequences reveals that while many sequences comprised of multiple alarms, nearly 65% of the sequences were isolated instances of alarms and are potentially irreducible. Patterns in alarming, as they manifest in the clinical workspace were identified and visualized. This information can be exploited to investigate strategies for reducing alarms. PMID:27027383

  7. Development of portable memory type radiation alarm monitor

    A radiation alarm monitor has been developed and manufactured in order to protect radiation workers from over-exposure. A visual and audible alarm system has been attached to initiate evacuation when accident occurs such as an unexpected change of radiation level or an over-exposure. The radiation alarm monitor installed with microprocessor can record the information of radiation field change between 90 min. before the alarm and 30 min. after the alarm and also provide the data to an IBM compatible computer to analyze the accidents and to set a counter plan. It features a wide detection range of radiation field(10 mR/h-100 R/h), radiation field data storage, portability, high precision (±5%) due to self-calibration function, and adaption of a powerful alarm system. According to ANSI N42.17A, the most stringent test standards, performance tests were carried out under various conditions of temperature, humidity, vibration, and electromagnetic wave hindrance at Korea Research Institute of Standards and Science(KRISS). As a result, the Radiation Alarm Monitor passed all tests

  8. DTR, Taut Wire System: An alarm barrier with experience

    The Taut Wire Fence Alarm System concept was developed and introduced more that fifteen years ago in Israel. A sudden expansion of the nations's border lines, the difficulty to monitor intrusions along those elongated lines and the need for timely as well as accurate armed response to an intrusion attempt dictated the need for an alarming barrier. Traditionally, protection of perimeters was accomplished by the installation of a fence or other type obstacles (man made or natural) and surveillance by manned patrols, fixed observation posts, and/or electronic devices. Defense planners recognized therefore the need for an alarming barrier. A concentrated effort by scientists solved the problem by developing the first Taut Wire Fence Alarm System in a configuration of an alarm barrier. The system was specified to have an extremely low false alarm rate (FAR/NAR), high probability of detection, the capability to follow various terrains, operability in a wide range of environmental conditions, a capability to delay an intruder, ease of installation by unskilled labor, and low maintenance requirements. The authors try here to explain the various constraints and considerations given during the design stages of the Taut Wire Alarm System so as to bring the present magnitude of users to a better understanding of the system's operation

  9. Thermoluminescent response of dosemeters TLD-100 exposed to distinct baker protocols, irradiation and reading

    The interest that motivated the realization of this work is the opposing discrepancy among the values of the efficiency thermoluminescent of heavy charged particles (PCP) regarding gamma radiation (ηPCP, γ) reported in different works and gathered recently for Horowitz (Ho 01). The measures of relative thermoluminescent efficiency have importance in relation to the dosimetry associated to medical therapy with heavy charged particle. The measurement of ηPCP, γ depends of multiple experimental factors. To understand this dependence it was quantified the effect of using different procedures experimental in the estimate of the relative thermoluminescent efficiency of dosemeters TLD-100 (LiF: Ti; Mg) for protons of 3 MeV regarding gamma rays of 60Co (ηPCP, γ), varying the lot, the presentation, the one baked and the team reader. When was used the same global procedure values they were obtained for (ηPCP, γ) inside the interval [0.30, 0.58] for the peak 5 and [0.35, 0.76] for the total thermoluminescent signal (Tl). At the use different equipment, baked and lot are obtained maximum differences of 30%, 12% and 6% respectively in the values of (ηPCP, γ) for the peak 5, and 25%, 28% and 7% for the total Tl signal. The changes more significant of 36% and 44% for peak 5 and total signal respectively are obtained when changing the presentation of the dosemeter. As a complementary investigation it was studied the distribution of the Tl signal of each peak in the deconvolution of the curve of brightness with regard to the total signal in exposed dosemeters to high fluence of protons (1x1010 p/cm2) varying the experimental protocol. It was found that the distribution of the Tl signal has a difference of the order of 5% when changing the used reading team. It was observed that the contribution of the peak 5 regarding the total signal are preserved when changing baked and that it results to be 8% greater for the presentation in dosemeters of 1 x 1 x 1 mm3 that for

  10. Computational Human Performance Modeling For Alarm System Design

    Jacques Hugo

    2012-07-01

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators’ alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  11. Design of SMART alarm system using main memory database

    To achieve design goal of SMART alarm system, first of all we have to decide on how to handle and manage alarm information and how to use database. So this paper analyses concepts and deficiencies of main memory database applied in real time system. And this paper sets up structure and processing principles of main memory database using nonvolatile memory such as flash memory and develops recovery strategy and process board structures using these. Therefore this paper shows design of SMART alarm system is suited functions and requirements

  12. Tl response of LiF: Mg, Cu, P + PTFE (Mexico) and GR200A (China) dosemeters

    TLD-100 was the commercial dosemeter more known since some decades ago. This dosemeter was considered for many research groups as the reference material for developing new Tl materials for ionizing radiation dosimetry. Actually it seems that TLD-100 is going to be replaced by the Chinese material GR200A, as reference material due that this material in addition to be considered as a tissue equivalent material, is 30 to 35 times more sensitive that TLD- 100. Results of the study of the Tl response of LiF: Mg, Cu, P + Ptfe developed at ININ-Mexico, comparing them with those of GR200A are presented. These results showed that the sensitivity (s = Tl intensity/weight x dose) to gamma radiation of the LiF: Mg, Cu, P + Ptfe dosimeters was 4.34 meanwhile that of the commercial dosemeter was 3.41. Detection threshold of the dosemeters studied was 2.22 and 0.52 μGy respectively Repeatability after 10 cycles Irradiation-reading-annealing was ±1.39% and ±1.86% respectively. Both types of dosemeters presented a linear response as a function of gamma radiation in the range from 0.02 mGy and 100 Gy. (Author)

  13. H p(0.07) photon dosemeters for eye lens dosimetry: Calibration on a rod vs. a slab phantom

    In recent years, several papers dealing with eye lens dosimetry have been published as epidemiological studies are implying that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, only few dosemeters for the appropriate quantity Hp(3) are available. Partial-body dosemeters are usually designed to measure the quantity Hp(0.07) calibrated on a rod phantom representing a finger while a slab phantom much better represents the head. Therefore, in this work it was investigated whether dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom can also be worn on the head (close to the eyes) and still deliver correct results (Hp(0.07) on a head). For that purpose, different types of partial-body dosemeters from routine use were irradiated at different photon energies on both a rod and a slab phantom. It turned out that their response values are within ±5% independent of the phantom if the quantity value for the respective phantom is used. Thus, partial-body dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom may be worn on the head and used to monitor the eye lens dose due to photon radiation via the measurement of Hp(0.07) on the head. (authors)

  14. rf duress alarms: market survey and preliminary characterization

    This report represents the first phase of the duress alarm studies. Presented here are the results of an extensive market survey and some preliminary observations on the effectiveness of many system components

  15. A weighted dissimilarity index to isolate faults during alarm floods

    Charbonnier, S; Gayet, P

    2015-01-01

    A fault-isolation method based on pattern matching using the alarm lists raised by the SCADA system during an alarm flood is proposed. A training set composed of faults is used to create fault templates. Alarm vectors generated by unknown faults are classified by comparing them with the fault templates using an original weighted dissimilarity index that increases the influence of the few alarms relevant to diagnose the fault. Different decision strategies are proposed to support the operator in his decision making. The performances are evaluated on two sets of data: an artificial set and a set obtained from a highly realistic simulator of the CERN Large Hadron Collider process connected to the real CERN SCADA system.

  16. Changes in 900 MW PWR alarm processing policy

    Following a brief description of the current 900 MW PWR alarm processing system, this document presents the feasibility study carried out within the scope of the Instrumentation and Control Refurbishment project (R2C). (author). 4 figs, tabs

  17. Measurement of the Portsmouth Gaseous Diffusion Plant criticality accident alarm

    Measurements of the Portsmouth Gaseous Diffusion Plant's nuclear criticality accident radiation alarm signal response time, sound wave frequency, and sound volume levels were made to demonstrate compliance with ANSI/ANS-8.3-1986. A steady-state alarm signal is produced within one-half second of obtaining a two-out-of-three detector trip. The fundamental alarm sound wave frequency is 440 hertz. The sound volume levels are greater than 10 decibels above background and ranged from 100 to 125 A-weighted decibels. The requirements of the standard were met; however the recommended maximum sound volume level of 115 dBA was exceeded. Emergency procedures require immediate evacuation upon initiation of a facility's radiation alarm. Comparison with standards for allowable time of exposure at different noise levels indicate that the elevated noise level at this location does not represent an occupational injury hazard. 8 refs., 5 figs

  18. rf duress alarms: market survey and preliminary characterization

    Draper, B.L.

    1979-05-01

    This report represents the first phase of the duress alarm studies. Presented here are the results of an extensive market survey and some preliminary observations on the effectiveness of many system components.

  19. ARC Code TI: Optimal Alarm System Design and Implementation

    National Aeronautics and Space Administration — An optimal alarm system can robustly predict a level-crossing event that is specified over a fixed prediction horizon. The code contained in this packages provides...

  20. Chimpanzee Alarm Call Production Meets Key Criteria for Intentionality

    Schel, Anne Marijke; Simon W Townsend; Machanda, Zarin; Zuberbühler, Klaus; Slocombe, Katie E.

    2013-01-01

    Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i) sociall...

  1. Chimpanzee alarm call production meets key criteria for intentionality

    Schel, Anne M.; Simon W Townsend; Machanda, Zarin; Zuberbühler, Klaus; Slocombe, Katie E.

    2013-01-01

    Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i) sociall...

  2. Heterospecific alarm call recognition in a non-vocal reptile

    Vitousek, Maren N; Adelman, James S; Gregory, Nathan C; Clair, James J. H. St

    2007-01-01

    The ability to recognize and respond to the alarm calls of heterospecifics has previously been described only in species with vocal communication. Here we provide evidence that a non-vocal reptile, the Galápagos marine iguana (Amblyrhynchus cristatus), can eavesdrop on the alarm call of the Galápagos mockingbird (Nesomimus parvulus) and respond with anti-predator behaviour. Eavesdropping on complex heterospecific communications demonstrates a remarkable degree of auditory discrimination in a ...

  3. A study of reset mode in advanced alarm system simulator

    An automation function has been widely applied in main control room of nuclear power plants. That leads to a new issue of human-automation interaction, which considers human operational performance in automated systems. In this research is the automation alarm reset in the advanced alarm system (AAS) of Advanced Nuclear Power Plant in Taiwan. Since alarms are very crucial for the understanding of the status of the plant as well as the reset function of alarm system will be changed from fully manual to fully automatic, it is very important to test and evaluate the performance and the effect of reset modes in AAS. The purpose of this paper is to evaluate the impact of the auto-reset alarm system on the plant performance and on operators' preference and task load. To develop a dynamic simulator as an AAS was conducted to compare manual and automatic reset function of alarm system on task performance and subjective ratings of task workload, comprehension, and preference. The simulation includes PCTRAN model and alarm software processing. The final results revealed that, using the auto-reset mode, participants had lower task load index (TLX) on effort in the first test trial and was more satisfied in multiple tasks condition. In contrast, using manual reset mode, participants were more satisfied on alarm handling, monitoring, and decision making. In other words, either reset mode in the study has unique features to assist operator, but is insufficient. The reset function in AAS therefore should be very flexible. Additionally, the experimental results also pointed out that the user interfaces need to be improved. Those experiences will be helpful for human factors verification and validation in the near future. (authors)

  4. ALARM SYSTEM FOR A BOILER SYSTEM CONTROL ON ENERGY ENTERPRISE

    Lueder, Arndt; Ryshentseva, Daria

    2014-01-01

    As the problem of good qualified functioning of a boiler every year is taking place, there is an interest to create an advanced error alarm system, which, as its mission, has the timely notification of the controlled object functioning errors. Thus, in this paper the improved model of the alarm system object control is proposed, the question of an error-free object functioning problem solving is raised. The proposed model includes such approaches to solve this problem as artificial intelligen...

  5. Frog Swarms: Earthquake Precursors or False Alarms?

    Grant, Rachel A; Conlan, Hilary

    2013-01-01

    In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of "frog swarms" from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported "frog swarms" are actually normal behaviour, probably caused by juvenile animals migrating away from their breeding pond, after a fruitful reproductive season. As amphibian populations undergo large fluctuations in numbers from year to year, this phenomenon will not occur on a yearly basis but will depend on successful reproduction, which is related to numerous climatic and geophysical factors. Hence, most large swarms of amphibians, particularly those involving very small frogs and occurring in late spring or summer, are not unusual and should not be considered earthquake precursors. In addition, it is likely that reports of several mass migration of small toads prior to the Great Sichuan Earthquake in 2008 were not linked to the subsequent M = 7.9 event (some occurred at a great distance from the epicentre), and were probably co

  6. Influence of the stem effect on radioluminescence signals from optical fibre Al2O3:C dosemeters

    Marckmann, C.J.; Aznar, M.C.; Andersen, C.E.;

    2006-01-01

    This paper analyses the influence of the Cerenkov radiation and other noise sources, the so-called stem effect, on radioluminescence (RL) signals generated in optical fibre Al2O3:C dosemeters used in medical dosimetry. The optical fibre dosemeter consists of a sensitive Al2O3:C crystal coupled...

  7. Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study

    J. Koivisto; D. Schulze; J. Wolff; D. Rottke

    2014-01-01

    Objectives: The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Methods: Organ and effective

  8. False-alarm characterization in hyperspectral gas-detection applications

    DiPietro, Robert S.; Truslow, Eric; Manolakis, Dimitris G.; Golowich, Steven E.; Lockwood, Ronald B.

    2012-09-01

    Chemical cloud detection using long-wave infrared (LWIR) hyperspectral-imaging sensors has many civilian and military applications, including chemical warfare threat mitigation, environmental monitoring, and emergency response. Current capabilities are limited by variation in background clutter as opposed to the physics of photon detection, and this makes the statistical characterization of clutter and clutter-induced false alarms essential to the design of practical systems. In this exploratory work, we use hyperspectral data collected both on the ground and in the air to spectrally and spatially characterize false alarms. Focusing on two widely-used detectors, the matched filter (MF) and the adaptive cosine estimator (ACE), we compare empirical false-alarm rates to their theoretical counterparts - detector output under Gaussian, t and t-mixture distributed data - and show that these models often underestimate false-alarm rates. Next, we threshold real detection maps and show that true detections and false alarms often exhibit very different spatial behavior. To exploit this difference and understand how spatial processing affects performance, the spatial behavior of false alarms must be understood. We take a first step in this direction by showing that, although the behavior may `look' quite random, it is not well captured by the complete-spatial-randomness model. Finally, we describe how our findings impact the design of real detection systems.

  9. Perimeter security alarm system based on fiber Bragg grating

    Zhang, Cui; Wang, Lixin

    2010-11-01

    With the development of the society and economy and the improvement of living standards, people need more and more pressing security. Perimeter security alarm system is widely regarded as the first line of defense. A highly sensitive Fiber Bragg grating (FBG) vibration sensor based on the theory of the string vibration, combined with neural network adaptive dynamic programming algorithm for the perimeter security alarm system make the detection intelligently. Intelligent information processing unit identify the true cause of the vibration of the invasion or the natural environment by analyzing the frequency of vibration signals, energy, amplitude and duration. Compared with traditional perimeter security alarm systems, such as infrared perimeter security system and electric fence system, FBG perimeter security alarm system takes outdoor passive structures, free of electromagnetic interference, transmission distance through optical fiber can be as long as 20 km It is able to detect the location of event within short period of time (high-speed response, less than 3 second).This system can locate the fiber cable's breaking sites and alarm automatically if the cable were be cut. And the system can prevent effectively the false alarm from small animals, birds, strong wind, scattering things, snowfalls and vibration of sensor line itself. It can also be integrated into other security systems. This system can be widely used in variety fields such as military bases, nuclear sites, airports, warehouses, prisons, residence community etc. It will be a new force of perimeter security technology.

  10. An alarm processing system for a nuclear power plant using artificial intelligence techniques

    This paper reports on an alarm processing system (APS) developed that uses artificial intelligence techniques to help operators to make decisions. Alarms in nuclear power plants are classified into generalized and special alarms. Generalized alarms are further classified into global and local alarms. For each type of alarm, the specific processing rules are applied to filter and suppress unnecessary and potentially misleading alarms. The processing for the generalized alarms is based on model-based reasoning. The special alarms are processed by the cause-consequence check rules. The priorities of alarms are determined according to both the plant state and the consistencies among the alarms. This APS is built on a workstation using the Prolog language

  11. EXPERIMENTAL STUDY OF INDIVIDUAL THERMOLUMINESCENT DOSEMETERS PERFORMANCES FOR MEASURING THE DOSE EQUIVALENTS IN SKIN AND EYE LENS

    E. N. Sheleenkova

    2014-01-01

    Full Text Available The article gives a comparative analysis of existing and newly developed thermoluminescent detectors DTG-4, TTLD-580, TLD-1011(TM and DTVS-01 and dosemeters MKD-A and MKD-B for the purposes of individual dosimetric control of skin and eye lens exposure to radiation. The dependence of sensitivity of different thermoluminescent dosemeters, designed for dose equivalents measurements in skin and eye lens on the type (photons and ȕ-particles and energy of radiation was determined experimentally. There are conclusions about the limits of applicability of existing detectors and dosemeters under different radiation exposure conditions. The article evaluates the possibility of different dosimeter use for specific radiation exposure conditions.

  12. Performance of a personal neutron dosemeter based on direct ion storage at workplace fields in the nuclear industry

    In the framework of the EVIDOS project, funded by the EC, measurements were carried out using dosemeters, based on ionisation chambers with direct ion storage (DIS-N), at several workplace fields, namely, at a fuel processing plant, a boiling and a pressurised water reactor, and near transport and storage casks. The measurements and results obtained with the DIS-N in these workplaces, which are representative for the nuclear industry, are described in this study. Different dosemeter configurations of converter and shielding materials were considered. The results are compared with values for personal dose equivalent which were assessed within the EVIDOS project by other partners. The advantages and limitations of the DIS-N dosemeter are discussed. (authors)

  13. Characteristics and performance of the Sunna high dose dosemeter using green photoluminescence and UV absorption readout methods

    Miller, S.D.; Murphy, M.K.; Tinker, M.R.; Kovacs, A.; McLaughlin, W

    2002-07-01

    Growth in the use of ionising radiation for medical sterilisation and the potential for wide-scale international food irradiation have created the need for robust, mass-producible, inexpensive, and highly accurate radiation dosemeters. The Sunna dosemeter, lithium fluoride injection-moulded in a polyethylene matrix, can be read out using either green photoluminescence or ultraviolet (UV) absorption. The Sunna dosemeter can be mass-produced inexpensively with high precision. Both the photoluminescent and the UV absorption reader are simple and inexpensive. Both methods of analysis display negligible humidity effects, minimal dose rate dependence, acceptable post-irradiation effects, and permit measurements with a precision of nearly 1% 1s. The UV method shows negligible irradiation temperature effects from -30 deg. C to +60 deg. C. The photoluminescence method shows negligible irradiation temperature effects above room temperature for sterilisation dose levels and above. The dosimetry characteristics of these two readout methods are presented along with performance data in commercial sterilisation facilities. (author)

  14. Influence of the stem effect on radioluminescence signals from optical fibre Al2O3:C dosemeters

    This paper analyses the influence of the Cerenkov radiation and other noise sources, the so-called stem effect, on radioluminescence (RL) signals generated in optical fibre Al2O3:C dosemeters used in medical dosimetry. The optical fibre dosemeter consists of a sensitive Al2O3:C crystal coupled to an optical fibre cable that carries the RL and optically stimulated luminescence (OSL) signals generated in the Al2O3:C crystal. During irradiation of the dosemeter, the real-time dose rate can be determined from the RL signal and after irradiation the total dose absorbed is determined from the OSL signal stimulated using a focused green solid-state laser. In particular, the components of the stem effect generated in the fibres were analysed to determine their impact on the RL signal. (authors)

  15. Characteristics and performance of the Sunna high dose dosemeter using green photoluminescence and UV absorption readout methods

    Growth in the use of ionising radiation for medical sterilisation and the potential for wide-scale international food irradiation have created the need for robust, mass-producible, inexpensive, and highly accurate radiation dosemeters. The Sunna dosemeter, lithium fluoride injection-moulded in a polyethylene matrix, can be read out using either green photoluminescence or ultraviolet (UV) absorption. The Sunna dosemeter can be mass-produced inexpensively with high precision. Both the photoluminescent and the UV absorption reader are simple and inexpensive. Both methods of analysis display negligible humidity effects, minimal dose rate dependence, acceptable post-irradiation effects, and permit measurements with a precision of nearly 1% 1s. The UV method shows negligible irradiation temperature effects from -30 deg. C to +60 deg. C. The photoluminescence method shows negligible irradiation temperature effects above room temperature for sterilisation dose levels and above. The dosimetry characteristics of these two readout methods are presented along with performance data in commercial sterilisation facilities. (author)

  16. Integrating dosemeters for the determination of the radiation exposure of miners exposed to short-lived radon daughter products

    For the determination of the radiation exposure by short-lived radon daughters integrating measuring instruments are especially suited, because variations of activity concentrations can cause essential errors using short-term dosemeters. At present a measuring instrument based on thermluminescence detectors is used by the SAAS as a stationary area monitor. An electronic personal dosemeter with a semiconductor detector exists as a prototype. Structure and mechanism of both the measuring instruments are described and the feasibility of application in workplaces exposed to radon daughter products are discussed. Proceeding from experience gained in development and application of these instruments an outlook is given for the possibility to develop an applicable universal component system used for standardization of Ra and Ra daughter dosemeters within the CMEA

  17. SuperAlarm: System and Methods to Predict In-Hospital Patient Deterioration and Alleviate Alarm Fatigue

    Bai, Yong

    2016-01-01

    A diverse array of continuous, multi-parameter and alarm-equipped physiologic monitoring devices have been deployed in modern intensive care units (ICUs) and other critical care settings to detect changes in a patient's status. Alarm signals activated by the monitors are intended to alert caregivers to either abnormalities in a patient's normal state or device malfunctions in order to prevent adverse events, and hence improve quality of care and patient safety. The majority of patients who ev...

  18. Estimation of overall uncertainty for various whole body and extremity TLDs, film and CR39 dosemeters

    Full text: Global Dosimetry Solutions (GDS) is a commercial dosimetry processor for occupational personnel dosimetry. The laboratory offers both film and Harshaw luminescent (TL) dosimeters (TLD) for radiation types that include gamma rays, beta particles and x-rays. Additionally, neutrons are monitored utilizing either TLD's or CR39 track-etch dosemeters. To reduce the probability of introducing random and systematic error into the dosimetry program the laboratory is committed to a strong quality program that provides for: standardization and qualification of procedures including uniform systematic methods, and the proper training of personnel; regular calibration of equipment against recognized standards; provisions for analysis of duplicate samples, including irradiated and unirradiated control dosemeters where appropriate; provisions for control of procurement, storage, and use of all chemicals used in analytical procedures; independent review and checking of calculations, quality control data, and other quality assurance data; routine blind testing of dosemeters; direct inspection of laboratory work and records; provisions for taking corrective actions; retention of quality records for later retrieval. Sources of uncertainty were evaluated for both type A and type B uncertainties, including: GDS Radiological Calibration Facility; J.L. Shepherd Model 81 137Cs Irradiator; Keithly Model 616 electrometer and Xradin Model A3 and A5 ion chambers; NIST Irradiation Facility Sources of Uncertainty; NIST-traceable calibration; ion chamber/electrometer uncertainty; irradiator beam non-uniformity; irradiator shutter; Environmental Factors; Harshaw Reader Repeatability; Panasonic Reader and Badge Reproducibility; Film Densitometer Uncertainty; Film Emulsion/ Batch Variability; TLD Signal Fade; TLD Badge Repeatability; Angular Dependence; Radiation Type/Energy Dependence; CR39 Batch Variability; CR39 Focus Data; CR39 Irradiations; CR39 Foil Repeatability. (author)

  19. Determination of the response function for two personal neutron dosemeter designs based on PADC

    Since 1998 neutron dosimetry based on PADC (poly allyl diglycol carbonate) is done with a so-called original Paul Scherrer Institute (PSI) design at PSI. The original design (i.e. holder) was later changed. Both designs are optimised for use in workplaces around high-energy accelerators, where the neutron energy spectra are dominated by fast neutrons ranging up to some 100 MeV. In addition to the change of the dosemeter design a new evaluation method based on a microscope scanning technique has been introduced and the etching conditions have been optimised. In the present work, the responses obtained with the original and the new dosemeter designs are compared for fields of radionuclide sources and monoenergetic reference fields using the new evaluation method. The response curves in terms of the personal dose equivalent for normally incident neutrons were built as functions of the incident neutron energy. The time- and cost-intensive establishment of experimentally determined response curves for personal neutron dosemeters is necessary for its dosimetric characterisation and the re-measurement in certain time intervals is obligatory for quality assurance. Therefore, the response of the two PSI designs were measured in reference fields of radionuclide sources and of (quasi-) monoenergetic beams with energies from 24 keV up to 100 MeV. At some energies the differences to the old response curve have been observed. However, in routine dosimetry at workplace fields around high-energy accelerators, where a broad neutron spectrum is faced, these differences are expected to play a minor role and therefore no changes in the routine evaluation procedure of PSI were made. However, work is in progress on folding the new response curves with already measured neutron spectra of workplace fields as well as work is in progress on including the information obtained by the evaluation of the 'thermal' channel from the area under the LiF chip. (authors)

  20. Experience on evaluation of passive neutron dosemeters according to ISO 21909

    This paper presents experience, found problems and lessons learnt during the evaluations of various TLD and CR-39 passive neutron dosemeters according to ISO 21909. Recommendations for the standard, being currently in revision, are also discussed. The edition 2005 of ISO 21909 is a good first step for having an international standard for testing passive neutron dosimetry systems. However, this standard has many imperfections and this paper tried to bring up some of them. Experience and optimisation of the whole evaluation process according to this standard were also discussed. (author)

  1. Development of an universal personal dosemeter using semiconductor sensors for mixed radiation fields

    The objectives of the project are: the development of a semiconducting detector system to be used in a personal dosemeter, and the investigation of its dosimetric properties; acquisition of a comprehensive set of data for systematic studies of the response and its energy dependence. The objective for the reporting period is the completion of the investigation of the relevant parameters determining the response and its energy dependence of the Si-diodes covered with compensating filters of different materials. (R.P.) 7 figs

  2. Development of a new electronic personal neutron dosemeter using a CMOS active pixel sensor

    A CMOS active pixel sensor, originally designed for the tracking of minimum ionising charged particles in high-energy physics, has been recently used for the detection of fast neutrons. Data were taken at the IRSN Cadarache facility with a 241Am-Be ISO source and a polyethylene radiator. A high-intrinsic efficiency (1.2 x 10-3) has been obtained. It is in good agreement with both calculations and a MCNPX Monte Carlo simulation. This experiment paves the way for a fully electronic personal neutron dosemeter. (authors)

  3. Calibration process of survey meters and dosemeters at Standard Dosimetry Laboratory, Nuclear Energy Unit, Malaysia

    Techniques of calibration and its possible uses are reviewed and discussed. Three main techniques identified are substitution, simultaneous irradiation and inverse square law. The scope of application of each technique is discussed in detail. In addition, tests which are performed on the calibrated dosemeters including energy dependence, angular dependence as well as linearity are explained. For the above purposes, photon radiations from 30 keV to 1250 keV were used. The radiations are obtained by means of an X-ray machine, PHILIPS Model MCN 32, Cs 137 and C60. At the end of the report, several forms tht are required for giving the calibration services are attached. (author)

  4. Overview of active personal dosemeters for individual monitoring in the European Union

    Full text: In 2001 EURADOS, the working group on harmonization of individual monitoring in Europe and the dissemination of information on new techniques in this field carried out a survey aimed at analyzing the status of the national regulation, use and recent developments in active personal devices (APD) for external individual monitoring. The analysis of the status of APD in 15 EU member states highlighted the extensive use of APD for operational dosimetry, but only very rare recognition for legal dose recording. A catalogue with the main characteristics of the most common APD in Europe and some of the latest developments is presented in this communication. Information has been obtained from the European Radiation Protection and Nuclear Safety Authorities, technical exhibitions in recent scientific meetings and the internet. Information on the type of detector used, physical characteristics, radiological, environmental and mechanical performance, and, when available, dose recording procedure, type testing or the approval document are given in the paper. Developments in this field are currently very rapid and therefore the list of dosemeters cannot be complete, but it is an extensive selection of the main devices available at present. Most devices are calibrated in units of personal dose equivalent, Hp(10) or Hp(10) and Hp(0.07) when they are manufactured for the European market and fulfil the requirements of size and weight according to the IEC 61526 and IEC 61283 Standards. Generally speaking, the overall radiological response of the active personal dosemeters for gamma and beta radiation is comparable to standard passive systems and the environmental performance is satisfactory, especially in the case of the latest developments. Poor performance at low photon energy or in external electromagnetic fields described for earlier dosemeters has now been overcome by several APDs. However, there are still big differences in performance and type testing procedures

  5. Characterization of X-ray beams by attenuation method for personnel dosemeters calibration

    It has been used the attenuation method to characterize the X rays beams used for calibration of personal dosemeters at Calibration and Dosimetry Laboratory of Peruvian Institute of Nuclear Energy (IPEN). Voltages applied to the X ray tube and the additional filters have been made according to publication ANSI No.13. Half value layer, the homogeneity coefficient and mean energy were determined from attenuation data. Average relative differences of 3, 40 and 4 % respectively were found with respect to values published in ANSI No.13. Also spectral distributions and their resolutions were determined. Relative differences of 16 and 9% respectively were found in comparison with values calculated by the Montecarlo's Method. (author)

  6. Characterisation of N-acetyl-D-glucosamine (NAG) as a lyoluminescent dosemeter

    Lyoluminescent properties of N-acetyl-D-glucosamine (NAG) were investigated for their suitability as a dosemeter in a lyoluminescent system using sensitised solutions as solvents. Temperature and pH of the solvents were also varied. The detection limit for the system NAG-luminol at 200C using a solvent pH value of 10.6 was of the order of 3 mGy. The reproducibility was within ± 5% for doses of the order of 1 Gy. Measurements with isoluminol showed slightly higher amplification of the LL signal than that obtained with luminol. (author)

  7. Dose characterization in radiation mixed field using thermoluminescent dosemeters at the installation for studies on BNCT

    This work presents the methodology used for characterization of the absorbed dose due to the gamma radiation (in mixed field of neutrons and gamma), at the installation for studies on BNCT, using thermoluminescent dosemeters. Information is supplied concerning to the obtention of the Victoreen 2800M TL reader parameters, used for performing the TLDs readings, and are presented the construction results of the calibration curves for the TLDs 400 and TLDs 700. From these calibration curves it was determined the absorbed dose due to the gamma radiation in the position of sample irradiation at the installation for the BNCT studies

  8. Study of some characteristic dosimetric of the LIF:Mg, You (JR1152C) for their employment as environmental dosemeter

    As the interest grows in knowing the effects on the health of the drops dose of natural or artificial radiation, it is made but necessary a system dosimetric able to measure those dose levels accurately. P but of twenty years the dosemeters thermoluminescent (TL) they have constituted a simple and beautiful method for such mensurations. In the work the rehearsals of homogeneity, reproducibility, line lay, detection threshold, auto irradiation, residual, fading and angular dependence are described. The results demonstrate that the dosemeter satisfies the main requirements to be an employee in the environmental monitoring

  9. Alarm pheromone processing in the ant brain: an evolutionary perspective

    Makoto Mizunami

    2010-06-01

    Full Text Available Social insects exhibit sophisticated communication by means of pheromones, one example of which is the use of alarm pheromones to alert nestmates for colony defense. We review recent advances in the understanding of the processing of alarm pheromone information in the ant brain. We found that information about formic acid and n-undecane, alarm pheromone components, is processed in a set of specific glomeruli in the antennal lobe of the ant Camponotus obscuripes. Alarm pheromone information is then transmitted, via projection neurons, to the lateral horn and the calyces of the mushroom body of the protocerebrum. In the lateral horn, we found a specific area where terminal boutons of alarm pheromone-sensitive projection neurons are more densely distributed than in the rest of the lateral horn. Some neurons in the protocerebrum responded specifically to formic acid or n-undecane and they may participate in the control of behavioral responses to each pheromone component. Other neurons, especially those originating from the mushroom body lobe, responded also to non-pheromonal odors and may play roles in integration of pheromonal and non-pheromonal signals. We found that a class of neurons receive inputs in the lateral horn and the mushroom body lobe and terminate in a variety of premotor areas. These neurons may participate in the control of aggressive behavior, which is sensitized by alarm pheromones and is triggered by non-pheromonal sensory stimuli associated with a potential enemy. We propose that the alarm pheromone processing system has evolved by differentiation of a part of general odor processing system.

  10. Alarm reduction with correlation analysis; Larmsanering genom korrelationsanalys

    Bergquist, Tord; Ahnlund, Jonas; Johansson, Bjoern; Gaardman, Lennart; Raaberg, Martin [Lund Univ. (Sweden). Dept. of Information Technology

    2004-09-01

    This project's main interest is to improve the overall alarm situation in the control rooms. By doing so, the operators working environment is less overstrained, which simplifies the decision-making. According to a study of the British refinery industry, the operators make wrong decisions in four times out of ten due to badly tuned alarm systems, with heavy expenses as a result. Furthermore, a more efficiently alarm handling is estimated to decrease the production loss with between three and eight percent. This sounds, according to Swedish standards, maybe a bit extreme, but there is no doubt about the benefits of having a well-tuned alarm system. This project can be seen as an extension of 'General Methods for Alarm Reduction' (VARMEFORSK--835), where the process improvements were the result of suggestions tailored for every signal. Here, instead causal dependences in the process are examined. A method for this, specially designed to fit process signals, has been developed. It is called MLPC (Multiple Local Property Correlation) and could be seen as an unprejudiced way of increase the information value in the process. There are a number of ways to make use of the additional process understanding a correlation analysis provides. In the report some are mentioned, foremost aiming to improve the alarm situation for operators. Signals from two heating plants have been analyzed with MLPC. In simulations, with the use of the result from these analyses as a base, a large number of alarms have been successfully suppressed. The results have been studied by personal with process knowledge, and they are very positive to the use of MLPC and they express many benefits by the clarification of process relations. It was established in 'General Methods for Alarm Reduction' that low pass filter are superior to mean value filter and time delay when trying to suppress alarms. As a result, a module for signal processing has been developed. The main purpose is

  11. Reducing SCADA System Nuisance Alarms in the Water Industry in Northern Ireland.

    O'Donoghue, Nigel; Phillips, Debra H; Nicell, Ciaran

    2015-08-01

    The advancement of telemetry control for the water industry has increased the difficulty of managing large volumes of nuisance alarms (i.e., alarms that do not require a response). The aim of this study was to identify and reduce the number of nuisance alarms that occur for Northern Ireland (NI) Water by carrying out alarm duration analysis to determine the appropriate length of persistence (an advanced alarm management tool) that could be applied. All data were extracted from TelemWeb (NI Water's telemetry monitoring system) and analyzed in Excel. Over a 6-week period, an average of 40 000 alarms occurred per week. The alarm duration analysis, which has never been implemented before by NI Water, found that an average of 57% of NI Water alarms had a duration of <5 minutes. Applying 5-minute persistence, therefore, could prevent an average 26 816 nuisance alarms per week. Most of these alarms were from wastewater assets. PMID:26237691

  12. FAULT DIAGNOSIS WITH MULTI-STATE ALARMS IN A NUCLEAR POWER CONTROL SIMULATOR

    Austin Ragsdale; Roger Lew; Brian P. Dyre; Ronald L. Boring

    2012-10-01

    This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effect of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. We used sensitivity and criterion based on Signal Detection Theory to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

  13. Fault Diagnosis with Multi-State Alarms in a Nuclear Power Control Simulation

    Stuart A. Ragsdale; Roger Lew; Ronald L. Boring

    2014-09-01

    This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effects of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized the use of three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. Sensitivity and criterion based on the Signal Detection Theory were used to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

  14. Nuclear-power-plant perimeter-intrusion alarm systems

    Timely intercept of an intruder requires the examination of perimeter barriers and sensors in terms of reliable detection, immediate assessment and prompt response provisions. Perimeter security equipment and operations must at the same time meet the requirements of the Code of Federal Regulations, 10 CFR 73.55 with some attention to the performance and testing figures of Nuclear Regulatory Guide 5.44, Revision 2, May 1980. A baseline system is defined which recommends a general approach to implementing perimeter security elements: barriers, lighting, intrusion detection, alarm assessment. The baseline approach emphasizes cost/effectiveness achieved by detector layering and logic processing of alarm signals to produce reliable alarms and low nuisance alarm rates. A cost benefit of layering along with video assessment is reduction in operating expense. The concept of layering is also shown to minimize testing costs where detectability performance as suggested by Regulatory Guide 5.44 is to be performed. Synthesis of the perimeter intrusion alarm system and limited testing of CCTV and Video Motion Detectors (VMD), were performed at E-Systems, Greenville Division, Greenville, Texas during 1981

  15. Nuclear-power-plant perimeter-intrusion alarm systems

    Halsey, D.J.

    1982-04-01

    Timely intercept of an intruder requires the examination of perimeter barriers and sensors in terms of reliable detection, immediate assessment and prompt response provisions. Perimeter security equipment and operations must at the same time meet the requirements of the Code of Federal Regulations, 10 CFR 73.55 with some attention to the performance and testing figures of Nuclear Regulatory Guide 5.44, Revision 2, May 1980. A baseline system is defined which recommends a general approach to implementing perimeter security elements: barriers, lighting, intrusion detection, alarm assessment. The baseline approach emphasizes cost/effectiveness achieved by detector layering and logic processing of alarm signals to produce reliable alarms and low nuisance alarm rates. A cost benefit of layering along with video assessment is reduction in operating expense. The concept of layering is also shown to minimize testing costs where detectability performance as suggested by Regulatory Guide 5.44 is to be performed. Synthesis of the perimeter intrusion alarm system and limited testing of CCTV and Video Motion Detectors (VMD), were performed at E-Systems, Greenville Division, Greenville, Texas during 1981.

  16. Photon energy dependence of three fortuitous dosemeters from personal electronic devices, measured by optically stimulated luminescence

    New data are presented with regard to the relative OSL sensitivity of three different emergency dosemeters irradiated to various photon energies approximately between 48 and 1250 keV using blue excitation light. Investigated components extracted from commonly worn objects include those from USB flash drives (alumina substrate), mobile phones (Ba-rich silicate) and credit cards (chip card module). Several basic properties have been investigated such as the overall radiation sensitivity, the shape of the decay curve and fading of the OSL signal. An increase of the sensitivity for low energies relative to 60Co gamma rays can be observed for the three dosemeters, the increase being very pronounced for the Ba-rich component (factor of 10) and less pronounced for the chip card module (factor of 2). It is concluded that proper dose correction factors for photon energy have to be applied in order to accurately determine the absorbed dose to tissue. The OSL sensitivity to neutron irradiation was investigated as well, but this was found to be less than the gamma sensitivity. (authors)

  17. Neutron dosimetry inside the containment building of Spanish nuclear power plants with PADC based dosemeters

    The Spanish Nuclear Safety Council (Consejo de Seguridad Nuclear, CSN) recommends performing neutron individual dose assignments at workplaces based on ambient dose equivalent measurements using area monitors and by estimating the amount of time that workers spend in the different monitored environments. In addition, some Spanish nuclear power plants estimate the neutron dose equivalent using albedo thermoluminescence dosemeters (TLD). In the period 2004-2006, our group, together with other research centers, participated in a project, funded by the CSN, with the support of the Spanish Nuclear Power Plants Association (UNESA), to investigate in situ which could be the best practical procedure for individual neutron dose monitoring in nuclear power plants. As part of this survey, several units of the UAB PADC based neutron dosemeter were exposed, on a methacrylate phantom simulating a human body, at four different places inside the containment building of the Asco I nuclear power plant. The influence of different types of calibration neutron fields is analysed and the dose equivalent for each point is estimated.

  18. Development of advanced-type multi-functional electronic personal dosemeter

    An advanced-type small, light, multi-functional electronic personal dosemeter has been developed using silicon semiconductor radiation detectors for dose management of workers at nuclear power plants and accelerator facilities. This dosemeter is 62 x 82 x 27 mm3 in size and ∼130 g in weight, which is capable of measuring personal gamma ray and neutron dose equivalents, Hp(10), simultaneously. The neutron dose equivalent can be obtained using two types of silicon semiconductors: a slow-neutron sensor (1 MeV). The slow neutron sensor is a 10 x 10 mm2 p-type silicon on which a natural boron layer is deposited around an aluminium electrode. The fast neutron sensor is also a 10 x 10 mm2 p-type silicon crystal on which an amorphous silicon hydride is deposited. The neutron energy response corresponding to the fluence-to-dose-equivalent conversion coefficient given by ICRP Publication 74 has been evaluated using a monoenergetic neutron source from 250 keV to 15 MeV at the Fast Neutron Laboratory of Tohoku Univ.. As the result, the Hp(10) response to neutrons in the energy range of 250 keV and 4.4 MeV within ±50% difference has been obtained. (authors)

  19. Development of New Personal Dosemeter for Low Energy X Rays by Using an Imaging Plate

    A new personal dosemeter for low energy X rays is being developed using an imaging plate (IP) fabricated by Fuji Film Co. Ltd which has 103 times higher sensitivity than that of the conventional X ray film badge and makes possible the direct reading of PSL (photostimulated luminescence). To investigate the sensitivity with X ray energy, the plate, which was contacted by various filters was exposed on an acrylic phantom and in free air to X rays of effective energies 12, 18, 31, 50, 60, 69, 80, 101 and 120 keV. The filter set was composed of Al, Zn, Cu, Cd, and Pb, and their thicknesses were 0.1 mm to 1.0 mm. The exposure doses were 0.01 to 0.1 mSv. The sensitivity of the IP without filter in free air showed a large dependence on X ray energy. The data with filters were therefore combined and by taking the weighted sum of these data the flat energy response to the dose equivalent, which is necessary for the personal dosemeter, could be obtained. (author)

  20. ENEA extremity dosemeter based on LiF(Mg,Cu,P) to evaluate Hp(3,α)

    Recent epidemiological studies suggest a rather low-dose threshold (p(d), in paragraph(136), reads that '... a depth d=3 mm has been proposed for the rare case of monitoring the dose to the lens of the eye. In practice, however, Hp(3) has rarely been monitored and Hp(0.07) can be used for the same monitoring purpose... '. As recommended on the EU 'Technical recommendations for monitoring individuals occupationally exposed to external radiation', a test on the ENEA TL extremity dosemeter is herein reported. The results within the actual EU founded Optimization of Radiation protection for Medical staff (ORAMED) Project, whose WP2 is aimed at the quantity Hp(3) and eye lens dosimetry in practice, are taken into account. The paper summarises the main aspects of the study carried out at ENEA-Radiation Protection Inst. (Bologna (Italy)) to provide practical solutions (in the use and the design) to evaluate the response of the ENEA TL extremity dosemeter in terms of Hp(3). (authors)

  1. Studies on the homogeneity of photon fields for contemporary calibration of personal dosemeters on slab phantoms

    The most recent ICRU recommendations suggest to calibrate photon personal dosemeters on a slab phantom instead of a spherical phantom ads previously proposed. This kind of phantoms due to their geometric characteristics can in principle allow a contemporary calibration of several dosemeters at a time. In this framework, particular attention has to be devoted to the evaluation of the limits of the so-called 'homogeneity area' to be employed. According to the ISO Standard 4037 an homogeneity of the calibration field within 5% (±2.5%) is permissible. A rather detailed analysis on this subject has been therefore carried out using the Monte Carlo code MCNP to evaluate the backscattering profiles on PMMA and water filled PMMA phantoms both for normal and oblique incident radiation. At the same time, some air kerma free in air profiles for seven ISO Narrow and Wide Series beams measured at PTB (Braunschweig Germany) were used to model a more realistic irradiation situation. The calculated data were partially compared with experimental results from other European Laboratories

  2. Dosimetric monitoring by thermoluminescent dosemeters of employers working in ionizing radiation fields

    Radiation Protection Commission was established in the Ministry of Health and Environment as Regulatory Authority, organizes and supervises all activities related with radiation protection, as the license, inspection, dosemetric personal control, medical examination, radioactive waste management, etc. Actually in our country are exerting some activities, which intend to covert the principal tasks in the field of radiation protection. Such activities are dosemetric personnel control based on TLD, radioactive environmental monitoring, radioactive waste management, calibration of dosemetric equipment's, etc. This paper describes the realization of personnel monitoring by thermoluminescent dosemeters TLD - 100 chips and cards were furnished by IAEA some years ago. Various experiments to determine the dependence of the response of dosemeters versus dose and versus orientation, the fading and lower detectable dose. The personnel monitoring of workers that work in ionizing radiation field were in charge of Institute of Nuclear Physics (INP). Actually in Albania was established the personnel monitoring service for employers of INP, Oncological Centre, Nuclear Medicine Centre and some other nuclear units in Tirana city. On the near future year exists the possibility to extend personnel monitoring for all physicians and technicians of rontgendiagnostic units of Durres, Shkodra, Elbasan cities. (author). 4 refs, 2 tabs

  3. Photon energy dependence of three fortuitous dosemeters from personal electronic devices, measured by optically stimulated luminescence.

    Beerten, Koen; Vanhavere, Filip

    2010-08-01

    New data are presented with regard to the relative OSL sensitivity of three different emergency dosemeters irradiated to various photon energies approximately between 48 and 1250 keV using blue excitation light. Investigated components extracted from commonly worn objects include those from USB flash drives (alumina substrate), mobile phones (Ba-rich silicate) and credit cards (chip card module). Several basic properties have been investigated such as the overall radiation sensitivity, the shape of the decay curve and fading of the OSL signal. An increase of the sensitivity for low energies relative to (60)Co gamma rays can be observed for the three dosemeters, the increase being very pronounced for the Ba-rich component (factor of 10) and less pronounced for the chip card module (factor of 2). It is concluded that proper dose correction factors for photon energy have to be applied in order to accurately determine the absorbed dose to tissue. The OSL sensitivity to neutron irradiation was investigated as well, but this was found to be less than the gamma sensitivity. PMID:20304766

  4. Calibration of the IRD two-component TLD albedo neutron dosemeter in some moderated neutron fields

    Freitas, Bruno M.; Silva, Ademir X. da, E-mail: bfreitas@nuclear.ufrj.br, E-mail: ademir@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Martins, Marcelo M.; Pereira, Walsan W.; Mauricio, Claudia L.P., E-mail: marcelo@ird.gov.br, E-mail: walsan@ird.gov.br, E-mail: claudia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    In some stray neutron fields, like those found in practices involving the handling of radionuclide sources, the neutron calibration factor for albedo neutron dosemeter can vary widely compared to the factor for bare sources. This is the case for well logging, which is the area with the largest number of workers exposed to neutrons in Brazil. The companies employ routinely {sup 241}Am-Be neutron sources. The albedo response variation is mainly due to the presence of scattered and moderated neutrons. This paper studies the response variation of the two-component TLD albedo neutron dosemeter used in the neutron individual monitoring service of Instituto de Radioprotecao e Dosimetria, in different radionuclide neutron source beams. The neutron spectra were evaluated applying a Bonner sphere spectrometer with a {sup 6}LiI(Eu) detector in the Brazilian National Metrology Neutron Laboratory. Standard neutron sources of {sup 241}Am-Be and {sup 252}Cf were employed, besides {sup 238}Pu-Be. Measurements were also made with scattered and moderated neutron beams, including {sup 252}Cf(D{sub 2}O) reference spectrum, {sup 241}Am-Be moderated with paraffin and silicone and a thermal neutron flux facility. New neutron calibration factors, as a function of the incident to albedo neutron ratio, were proposed for use in the albedo algorithm for occupational fields where the primary neutron beam is one of those studied sources. (author)

  5. Calibration of the IRD two-component TLD albedo neutron dosemeter in some moderated neutron fields

    In some stray neutron fields, like those found in practices involving the handling of radionuclide sources, the neutron calibration factor for albedo neutron dosemeter can vary widely compared to the factor for bare sources. This is the case for well logging, which is the area with the largest number of workers exposed to neutrons in Brazil. The companies employ routinely 241Am-Be neutron sources. The albedo response variation is mainly due to the presence of scattered and moderated neutrons. This paper studies the response variation of the two-component TLD albedo neutron dosemeter used in the neutron individual monitoring service of Instituto de Radioprotecao e Dosimetria, in different radionuclide neutron source beams. The neutron spectra were evaluated applying a Bonner sphere spectrometer with a 6LiI(Eu) detector in the Brazilian National Metrology Neutron Laboratory. Standard neutron sources of 241Am-Be and 252Cf were employed, besides 238Pu-Be. Measurements were also made with scattered and moderated neutron beams, including 252Cf(D2O) reference spectrum, 241Am-Be moderated with paraffin and silicone and a thermal neutron flux facility. New neutron calibration factors, as a function of the incident to albedo neutron ratio, were proposed for use in the albedo algorithm for occupational fields where the primary neutron beam is one of those studied sources. (author)

  6. Portable transfer digital dosemeter for beam output measurements with X and gamma rays, electrons and neutrons.

    Sankaran, A; Gokarn, R S; Gangadharan, P

    1981-04-01

    This instrument was developed in response to a requirement for an accurate, stable and portable transfer dosemeter for calibration, at therapy dose levels, of equipment used for generating X and gamma rays, electrons and neutrons. The detector is a 0.5 cm3 ionization chamber capable of fitting various wall materials reproducibly at the end of the chamber stem. The measuring system uniquely combines the features of a MOSFET electrometer and an automatic Townsend balance. When used for X, gamma and neutron radiations, the instrument measures the tissue kerma in free air on two ranges: 0.001 - 1.999 Gy (0.1 - 199.9 rad) and 0.01 - 19.99 Gy (1 - 1999 rad) or their exposure equivalents, with autoranging feature when the first range is exceeded. The polarizing voltage (180 V) can be reversed for electron and neutron dosimetry. The dosemeter has a measuring accuracy of +/- 0.2% FS +/- 1 digit and operates on four 1.5 V torchlight cells or on AC mains (200-250 V, 50 - 60 Hz). It utilizes solid state devices, CMOS integrated circuits and displays, and is not affected by RF fields. The instrument is enclosed in a brief-case for portability and is easy to operate and maintain in a hospital. PMID:7225720

  7. Portable transfer digital dosemeter for beam output measurements with X and gamma rays, electrons and neutrons

    This instrument was developed in response to a requirement for an accurate, stable and portable transfer dosemeter for calibration, at therapy dose levels, of equipment used for generating X and γ rays, electrons and neutrons. The detector is a 0.5 cm3 ionization chamber capable of fitting various wall materials reproducibly at the end of the chamber stem. The measuring system uniquely combines the features of a MOSFET electrometer and an automatic Townsend balance. When used for X, γ and neutron radiations, the instrument measures the tissue kerma in free air on two ranges: 0.001-1.999 Gy(0.1-199.9 rad) and 0.01-19.99 Gy(1-1999 rad) or their exposure equivalents, with autoranging feature when the first range is exceeded. The polarizing voltage (180 V) can be reversed for electron and neutron dosimetry. The dosemeter has a measuring accuracy of +-0.2% FS +-1 digit and operates on four 1.5 V torchlight cells or on AC mains (200-250 V, 50-60 Hz). It utilizes solid state devices, CMOS integrated circuits and displays, and is not affected by RF fields. The instrument is enclosed in a briefcase for portability and is easy to operate and maintain in a hospital. (author)

  8. Implementation of alarm system for vibration monitoring of KOMAC facility

    For operating 100 MeV linac, Devices have to be operated in certain order. Thus malfunction of a device cause damage to linac and related devices. To protect linac, machine protect system (MPS) has been developed. The MPS protects the components by monitoring hardwired signals. When values of operating parameters go beyond or below limit, alarm will be generated and interlock system which stops related devices in certain sequence will run. Other factor, giving damage to linac is disaster. A strong vibration such as earthquake causes malfunction of devices and damage to linac. Against disaster, the monitoring system based on Experimental Physics and Industrial Control System (EPICS) was implemented. Configuration and Implementation of the monitoring system are presented and some preliminary results are reported. KOMAC implemented alarm system for a strong vibration and fire. Alarm is generated in unusual situation. Coping rapidly with situation, damages for Linac and related devices can be reduced

  9. Development of a criticality monitoring and alarm system

    In this work we are presenting the development of a Criticality Monitor and Alarm System (SIMAC). It monitors the burst of radiation produced during such an accident and triggers an alarm for evacuation in case the radiation exceeds a pre-established threshold. It consists of two subsystems, one for gamma rays and the other for neutrons. Each subsystem has three independent detectors modules. Each module is composed of an ion chamber plus its associated electronics, feeding a logic module that in turn would trigger the evacuation alarm. An additional feature is a PC interface for data acquisition. The radiation detectors are ion chambers working in current mode. The electronics associated to each detector can manage a wide signal range using a logarithmic converter. (author)

  10. Field response of tadpoles to conspecific and heterospecific alarm

    Adams, M.J.; Claeson, S.

    1998-01-01

    Many organisms use chemical cues from a variety of sources to mediate predator avoidance. Response to heterospecific alarm cues has been demonstrated for tadpoles within but not among taxa and alarm response behavior has seldom been examined under field conditions. This study examined the response of three sympatric amphibian larvae and predaceous larval Dytiscus sp. (diving beetle) to damage-release signals in natural ponds by using capture rates from treated funnel traps as an index of larval behavior. Hyla regilla (Pacific tree frog) tadpoles avoided traps treated with either crushed conspecifics or with Rana aurora (red-legged frog) tadpoles but the larger ranids and Arabystoma macrodactylum (long-toed salamander) did not respond to either treatment. H. regilla tadpoles were likely susceptible to any potential predators of ranid tadpoles in these ponds and this result is consistent with the hypothesis that a response to heterospecific alarm occurs in sympatric prey with shared predators.

  11. Statistical Study of False Alarms of Geomagnetic Storms

    Leer, Kristoffer; Vennerstrøm, Susanne; Veronig, A.;

    Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue....... A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs. The ability to identify potential false...... alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates...

  12. In-vivo dosimetry in radiotherapy: a comparison of the response of semiconductor and thermoluminescence (TLD700) dosemeters

    Vynckier, S. [Universite Catholique de Louvain, Brussels (Belgium). Cliniques Universitaires St. Luc; Greffe, J.L.; Loncol, T.; Vanneste, F.; Octave-Prignot, M.; Denis, J.M.; De Patoul, N.

    1995-12-01

    Semiconductor dosemeters and thermoluminescence dosemeters were calibrated in view of in-vivo dosimetry. Their response in a 8 MV photon beam and the respective correction factors for the treatment conditions were systematically studied. A total of 249 entrance and exit measurements with this dual detector combination were performed, mainly for treatments of the head and neck region. The resulting entrance and exit doses were compared with the expected doses at these positions, calculated on basis of the treatment and patient parameters. The results at the entrance showed a value of 1.010 (2.8% for the ratio of the measured to the calculated dose by diodes, 1.013) 4.9% for the ratio of the measured to the calculated dose by TLD and 1.003 (3.6% for the ratio of the measured dose by TLD to diodes. With respect the exit dose, the results were 0.998) 4.9%, 1.016 (7.7% and 1.019) 7.0% respectively after correction for the heterogeneity`s. Although the standard deviation for the TLD dosemeters is systematically larger than the standard deviation for the diodes, it is concluded that both dosemeters will yield similar results for-in-vivo dosimetry, if utilized under the same conditions.

  13. Valuation of a CD-96 reader dedicated to quick read-out and archivisation of foil dosemeter absorbance

    A check of the useful parameters of CD-96 reader is presented. The reader was constructed in the Department of Radioisotope Instruments and Methods of the INCT and dedicated to quick read-out of the foil dosemeter absorbances and for their archivisation. (author)

  14. PROLOG language application for alarm system realization in accelerator control

    Such PROLOG features as backtracking, matching and recursive data representation are powerful tools for ALARM system realization. Although the main idea is the possibility to describe some technical system in recursive form, backtracking and matching are ideal for processing recursive data structures. This paper represents a technique which would allow PROLOG language application for ALARM system realization using an example of the KEK LINAC magnet system. The technique is based on an object-oriented internal data representation in terms of objects, properties, relations and knowledge conception. In addition, each property value is characterized by a typical 'time life'. (author)

  15. Emotional responses to the experience of cancer 'alarm' symptoms

    Whitaker, KL; Cromme, S; Winstanley, K.; Renzi, C.; Wardle, J.

    2015-01-01

    Abstract Objective To qualitatively explore associations between emotional responses to experience of cancer ‘alarm’ symptoms and help‐seeking in a community sample of adults. Method Interviewees (n = 62) were recruited from a community sample (n = 2042) of adults aged ≥50 years, who had completed a health survey that included a list of cancer alarm symptoms. Participants who had reported an alarm symptom both at baseline and 3‐month follow‐up (n = 271), and who had consented to contact (n = ...

  16. MCNP simulation of the incident and Albedo neutron response of the IRD Albedo Neutron Dosemeter for 241Am-Be moderated sources

    The IRD TLD Albedo dosemeter measures both incident and albedo neutron component. The incident to Albedo ratio is used to take into account the energy dependence of its response. In this paper, the behavior of the IRD Albedo dosemeter response as a function of the incident to Albedo ratio for 241Am-Be sources was simulated to improve its algorithm. The simulation was performed in MCNPX transport code and presents a good agreement with experimental measurements. The results obtained in this work are very useful to improve the accuracy of the IRD Albedo dosemeter at real neutron workplace. (author)

  17. The investigation of correspondence of indications of the albedo dosemeter DVGN-01 to personnel irradiation doses in the fields of neutron radiation at the JINR nuclear power installations

    The calculated results of the research correspondence of the indication of the individual albedo dosemeter DVGN-01 to the individual equivalent dose for neutrons Hp(10) and to the effective dose for neutrons Eeff in the neutron fields at the JINR Nuclear Power Installations (JNPI) at different geometries of irradiations are presented. It has been shown that the correction coefficients are required for specific estimation of doses by the dosemeter. The coefficients were calculated using the energy sensitivity curve of the dosemeter and the known neutron spectra at the JNPI. By using the correction factors the uncertainties of both doses would not exceed the limits given to the personnel according to standards

  18. Study on routines and procedures of calibration of clinical dosemeter on gamma radiation beams at the IPEN-CNEN/SP, Brazil

    The calibration consists in the comparison of the equipment to be calibrated with other equipment already calibrated by another standard, which means the equipment that will accomplish shall be considered secondary or tertiary, depending on the calibration that will be accomplished. As the clinical dosemeters are used for quality control services in the hospitals, these dosemeters need a reliable measurement precision. Therefore, this work intends to demonstrate the importance of the clinical dosemeter and the calibration, requiring special care face to all clinical set

  19. Design of alarm systems in Swedish nuclear power plants

    Research within the area of improving alarm system design and performance has mainly focused on new alarm systems. However, smaller modernisations of legacy systems are more common in the Swedish nuclear industry than design of totally new systems. This imposes problems when the new system should function together with the old system. This project deals with the special concerns raised by modernisation projects. The objective of the project has been to increase the understanding of the relationship between the operator's performance and the design of the alarm system. Of major concern has been to consider the cognitive abilities of the operator, different operator roles and work situations, and varying need of information. The aim of the project has been to complement existing alarm design guidance and to develop user-centred alarm design concepts. Different case studies have been performed in several industry sectors (nuclear, oil refining, pulp and paper, aviation and medical care) to identify best practice. Several empirical studies have been performed within the nuclear area to investigate the operator's need of information, performance and workload in different operating modes. The aspect of teamwork has also been considered. The analyses show that the operator has different roles in different work situations which affect both the type of information needed and how the information is processed. In full power operation, the interaction between the operator and the alarm system is driven by internal factors and the operator tries to maintain high situation awareness by actively searching for information. The operator wants to optimise the process and need detailed information with possibilities to follow-up and get historical data. In disturbance management, the operator is more dependent on external information presented by the alarm system. The new compilation of alarm guidance is based on the operator's varying needs in different working situations and is

  20. Logic Alarm Cause Tracking System(LogACTs) for Wolsong 3 and 4

    KAERI I and C. HF Research team has developed an alarm root cause tracking system (ACTs), an alarm and diagnosis-integrated operator support system (ADIOS), and a dynamic alarm system (DAS). An alarm processing and presentation system, LogACTs(Logic Alarm Cause Tracking system) of their researches is developed and installed into the main control room(MCR) of the Wolsong nuclear power plant(NPP) unit 3. The system is integrated with tracking the logics of an alarm, finding the causes of an alarm, displaying the highlighted alarm procedure related to the causes, and suppressing and filtering nuisance alarms due to the physical or logical connections between components or systems in an abnormal state

  1. Development experience and strategy for the combined algorithm on the alarm processing and diagnosis

    In this paper, I presented the development experience on the alarm processing and fault diagnosis which has been achieved from early 1988 to late 1995. The scope covered is the prototype stage, the development stage of on-line operator-aid system, and an intelligent human-machine interface system. In the second part, I proposed a new method (APEXS) of multi-alarm processing to select the causal alarm(s) among occurred alarms by using the time information of each occurred alarm and alarm tree knowledge and the corresponding diagnosis method based on the selected causal alarm(s) by using the prescribed qualitative model. With more knowledge base about the plant and some modification suitable for real environment, APEXS will be able to adapt to a real steam power plant. (author). 18 refs, 3 figs, 1 tab

  2. Detection of false arrhythmia alarms with emphasis on ventricular tachycardia.

    Rodrigues, Rui; Couto, Paula

    2016-08-01

    Our approach to detecting false arrhythmia alarms in the intensive care unit breaks down into several tasks. It involves beat detection on different signals: electrocardiogram, photoplethysmogram and arterial blood pressure. The quality of each channel has to be estimated in order to evaluate the reliability of obtained beat detections. The information about the heart rate from the different channels must be integrated in order to find a final conclusion. Some alarm types require particular detectors as is the case of ventricular fibrillation. To identify false ventricular tachycardia alarms we needed to classify heart beats as normal/ventricular. For that purpose we introduce a new feature, QRS polarity type. This feature was important in order to reduce misclassification of ventricular beats: there was an improvement in the ventricular tachycardia alarm true positive rate from 69% to 81%. However, the true negative rate was reduced from 95% to 69% and our global challenge score (real-time event) dropped from 79.02 to 74.28. Our challenge algorithm achieved the third best score in the 2015 PhysioNet/CinC challenge event 1 (real time). PMID:27454934

  3. False alarms in fault-tolerant dominating sets in graphs

    Mateusz Nikodem

    2012-01-01

    Full Text Available We develop the problem of fault-tolerant dominating sets (liar's dominating sets in graphs. Namely, we consider a new kind of fault - a false alarm. Characterization of such fault-tolerant dominating sets in three different cases (dependent on the classification of the types of the faults are presented.

  4. Integrated alarm annunciation and entry control systems -- Survey results

    Clever, J.J.; Arakaki, L.H.; Monaco, F.M.; Juarros, L.E.; Quintana, G.R.

    1993-10-01

    This report provides the results and analyses of a detailed survey undertaken in Summer 1993 to address integrated intrusion detection alarm annunciation and entry control system issues. This survey was undertaken as a first attempt toward beginning to answer questions about integrated systems and commercial capabilities to meet or partially meet US Department of Energy (DOE) site needs.

  5. An object-oriented alarm-filtering system

    This paper discusses an alarm-filtering system (AFS) being developed by EG and G Idaho, Inc. for the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory. The ultimate goal of this project is to place AFS into ATR's reactor control room to act as an aid during major plant transients. In addition, methods of alarm analysis are investigated based on functional relationships rather than on a historical approach utilizing cause-consequence trees. Artificial intelligence techniques, including object-oriented programming, are also demonstrated as useful in analyzing alarms and alarm sequences. After a brief description of the problem AFS addresses, this paper discusses the design constraints and human factors that influenced the development of the system. The reader is then presented with operational and architectural descriptions of the system as well as what directions the future development of AFS may take. The fact that AFS is being considered as a partial solution to the problems discussed in the next section demonstrates the viability of its underlying technology and approach

  6. 29 CFR 1910.165 - Employee alarm systems.

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Fire Protection Other Fire Protection Systems § 1910.165 Employee... communication system also serves as the employee alarm system, all emergency messages shall have priority...

  7. Cost-Effective School Alarm Systems. Security Topics Series.

    Kaufer, Steve

    This document outlines considerations in the selection of a cost-effective school-alarm system. Steps in the planning process include: conducting a district needs assessment; gathering input from all staff levels; consulting technical expertise; and selecting a security system that can be integrated with other site needs. It further describes the…

  8. Chemical alarm in the termite Termitogeton planus (Rhinotermitidae)

    Dolejšová, Klára; Krasulová, Jana; Kutalová, K.; Hanus, Robert

    2014-01-01

    Roč. 40, 11/12 (2014), s. 1269-1276. ISSN 0098-0331 R&D Projects: GA ČR GAP506/10/1570 Institutional support: RVO:61388963 Keywords : termites * soldiers * frontal gland * alarm pheromone * Rhinotermitidae * Termitogeton Subject RIV: CC - Organic Chemistry Impact factor: 2.747, year: 2014

  9. Integrated alarm annunciation and entry control systems -- Survey results

    This report provides the results and analyses of a detailed survey undertaken in Summer 1993 to address integrated intrusion detection alarm annunciation and entry control system issues. This survey was undertaken as a first attempt toward beginning to answer questions about integrated systems and commercial capabilities to meet or partially meet US Department of Energy (DOE) site needs

  10. 46 CFR 120.550 - General alarm systems.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false General alarm systems. 120.550 Section 120.550 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION...

  11. False Alarm Probability Estimation for Compressive Sensing Radar

    Anitori, L.; Otten, M.P.G.; Hoogeboom, P.

    2011-01-01

    In this paper false alarm probability (FAP) estimation of a radar using Compressive Sensing (CS) in the frequency domain is investigated. Compressive Sensing is a recently proposed technique which allows reconstruction of sparse signal from sub-Nyquist rate measurements. The estimation of the FAP is

  12. SGLT-2 inhibition and glucagon: Cause for alarm?

    Kibbey, Richard G

    2015-07-01

    Recent studies raised the alarm that the inhibition of sodium-coupled glucose transporter type-2 in humans increases endogenous glucose production rates by an unclear mechanism. Surprisingly, a potential explanation may be linked directly to the alpha-cell. Is this a mechanistic spoiler or an added benefit? PMID:26059706

  13. 46 CFR 162.050-35 - Bilge alarm: Approval tests.

    2010-10-01

    ... concentration of iron oxide. Any change in the bilge alarm reading during the 5 minutes is recorded. (3) Repeat steps in paragraphs (c)(1) and (2) of this section using iron oxide concentrations of 50 ppm and 100 ppm... performed using test fluids described in § 162.050-20. (3) The oil content of each sample must be...

  14. Photon beam audits for radiation therapy clinics: A pilot mailed dosemeter study in Turkey

    A thermoluminescent dosemeter (TLD) mailed dose audit programme was performed at five radiotherapy clinics in Turkey. The intercomparison was organised by the Univ. of Wisconsin Radiation Calibration Laboratory (UWRCL), which was responsible for the technical aspects of the study including reference irradiations, distribution, collection and evaluation. The purpose of these audits was to perform an independent dosimetry check of the radiation beams using TLDs sent by mail. Acrylic holders, each with five TLD chips inside and instructions for their irradiation to specified absorbed dose to water of 2 Gy, were mailed to all participating clinics. TLD irradiations were performed with a 6 MV linear accelerator and 60Co photon beams. The deviations from the TL readings of UWRCL were calculated. Discrepancies inside the limits of ±5 % between the participant-stated dose, and the TLD-measured dose were considered acceptable. One out of 10 beams checked was outside this limit, with a difference of 5.8 %. (authors)

  15. Optimal dislocation of thermoluminescent dosemeters in NPP vicinity for detecting external gamma radiation

    The problem on optimal dislocation of thermoluminescent dosemeters(TLD) in the NPP vicinity for detecting external gamma radiation during normal operation and accidental disposal is solved. To solve this problem, the dose of external gamma radiation in the NPP vicinity during disposal of the noble gas mixture with regard to real weather conditions is calculated. The model of scattering in the Paskwill-Gifford atmosphere and a dose nucleus calculated by Lachti and others is used in calculations. Weather condition data necessary for calculation in different regions of NPP disposition in the European part of the USSR are systematized. To solve problems on the optimization of efficiency control and calculation, the calculational program, which permits to regard arbitrary distribution of population density in NPP surroundings, is

  16. Angular dependence of thermoluminescent dosemeters for gamma and beta radiation in nuclear medicine

    The gamma and beta radiation sources are widely used in Nuclear Medicine for diagnostic and therapeutic purposes. Workers of these services receive dose of whole body and end due to the activities of the therapeutic dose preparation and testing, administration radiopharmaceuticals and obtention of image. Hands receive higher doses than other parts of the body. Currently the individual monitoring for the gamma radiation is already well established; However, the determination of the dose due to beta radiation still faces some difficulties. In this work it was studied the angular dependence of thermoluminescent dosemeters detectors in beams of gamma and beta radiation. Detectors of CaSO4:Dy + Teflon produced at IPEN - the Brazilian Institute for Nuclear and Energy Researches - were used. The angular dependence was studied varying the angle between 0 and 180 deg. The results obtained proved to be suitable for use in individual monitoring of workers exposed to beta and gamma radiation

  17. Automation of radiation dosimetry using PTW dosemeter and LabVIEWTM

    Automation of UNIDOS 'Dosemeter' using personal computer (PC) is discussed in this paper. In order to save time and eliminate human operation errors during the radiation dosimetry, suitable software, using LabVIEWTM graphical programming language, was written to automate and facilitate the processes of measurements, analysis and data storage. The software calculates the calibration factor of the ionization chamber in terms of air kerma or absorbed dose to water according to IAEA dosimetry protocols. It also has the ability to print a calibration certificate. The obtained results using this software are found to be more reliable and flexible than those obtained by manual methods previously employed. Using LabVIEWTM as a development tool is extremely convenient to make things easier when software modifications and improvements are needed.

  18. Neutron spectrometry and dosimetry measurement at workplaces for calibration of individual PGP-DIN dosemeters

    Measurements to determine new coefficients for individual neutron dosimeters PGP-DIN complying with the ICRP 60 recommendations were performed at two workplaces at the CEA of Valduc: a storage room and a plutonium reprocessing plant. Two spectrometry campaigns were performed allowing a better assessment of doses received by operators working at these workplaces. Neutron energy fluence and ambient dose equivalent rate H*(10) distributions were measured as function of neutron energy by using the ROSPEC device and BONNER spheres spectrometer. The radiation field being mixed neutron and gamma, the gamma component was also evaluated: neutron and photon dose-rate meters were used to evaluate the ambient dose rate equivalent. Individual dosemeters were positioned on an ISO water slab phantom. In addition, calculations were performed using the MCNP simulation code for different configurations. (authors)

  19. X-ray beams characterization by the attenuation method for the personal dosemeters calibration

    The choice of the attenuation method to characterize the x-ray beams used in the calibration of personal dosemeters at the Calibration and Dosimetry Laboratory of the Peruvian Institute of Nuclear Energy (IPEN). Voltages applied to the X-ray tube and the addition of filters have been made according to the publication ANSI No. 13. Half value layer, homogeneity coefficient and mean energy were determined from attenuation data. Average relative differences of 3, 40 and 4% respectively were found with respect to values published in ANSI No. 13. Also spectral distributions and their resolutions were determined. relative differences of 6 and 19% respectively were found in comparison with values calculated by the Monte Carlo Method

  20. Absorbed dose measurements in mammography using Monte Carlo method and ZrO2+PTFE dosemeters

    Mammography test is a central tool for breast cancer diagnostic. In addition, programs are conducted periodically to detect the asymptomatic women in certain age groups; these programs have shown a reduction on breast cancer mortality. Early detection of breast cancer is achieved through a mammography, which contrasts the glandular and adipose tissue with a probable calcification. The parameters used for mammography are based on the thickness and density of the breast, their values depend on the voltage, current, focal spot and anode-filter combination. To achieve an image clear and a minimum dose must be chosen appropriate irradiation conditions. Risk associated with mammography should not be ignored. This study was performed in the General Hospital No. 1 IMSS in Zacatecas. Was used a glucose phantom and measured air Kerma at the entrance of the breast that was calculated using Monte Carlo methods and ZrO2+PTFE thermoluminescent dosemeters, this calculation was completed with calculating the absorbed dose. (author)

  1. Cosmic-radiation dosimetry using electronic personal dosemeter (EPD) at commercial aircraft altitude

    Electronic Personal Dosemeter (EPD) was examined for effectiveness in cosmic radiation dosimetry at aircraft altitude through the measurements in a Japan-US round trip. The EPD value (Hepd) of individual dose equivalent, penetrating, Hp(10), was considered to be almost equal the deep absorbed dose attributed to electrons at the aircraft altitude. By assuming the fractions and the effective quality factors for other components (muons, protons, and neutrons) based on model-calculation data, an empirical equation to estimate a conservative deep dose-equivalent at 5 cm-tissue depth, H(50), was given as H(50)=3.1 x Hepd. Estimated H(50) values in the international flights were 4.9 μSv h-1 from Tokyo to New York and 3.6 μSv h-1 from Los Angeles to Tokyo. These values agreed well with the predicted values presented by NCRP. (author)

  2. Measurement analysis using the Fricke dosemeter; Analise de medicoes com o dosimetro Fricke

    Pedrosa, G.A.C. [Instituto Nacional de Metrologia (INMETRO), Rio de Janeiro, RJ (Brazil)], e-mail: gcpedrosa@inmetro.gov.br; Dantas, C.C. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear], e-mail: ccd@ufpe.br; Campos, C.A. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: auster@elogica.com.br

    2003-07-01

    The Fricke dosemeter has been used for absolute determination of the radiation dose between 40 and 350 Gy for X-rays, Gamma rays and fast electrons energies. The great inconvenient of that dosimetric system is the impossibility of using for measurements of exposure or low dose rates. A Fricke dosimetry system was implanted at the Nuclear Sciences Regional Center (CRCN), in Recife, Pernambuco state, Brazil, for the determination of radiation doses for spectrometry and mass dosimetry with plasma source. The statistical analysis of the obtained results have shown that using the spectrometric method that system cna be used for maintenance of factors of CRCN standard calibrations and the dose assessment thru mail system of radiotherapy centers of the country.

  3. Application of whole-body personal TL dosemeters in mixed field beta-gamma radiation

    Application of whole-body personal TL dosemeters based on a high-sensitivity LiF:Mg,Cu,P (MCP-N) in mixed field beta-gamma radiation has been characterised. The measurements were carried out with 90Sr/90Y, 85Kr and 137Cs point sources to calculate the energy response and linearity of the TLD response in a dose range of 0.1-30 mSv. From the result, calibration curves were obtained, enabling the readout of individual dose equivalent Hp(10) from gamma radiation and Hp(0.07) from beta radiation in mixed field beta-gamma. Limitation of the methodology and its application are presented and discussed. (authors)

  4. Automation of radiation dosimetry using PTW dosemeter and LabVIEW™

    Weiss, C.; Al-Frouh, K.; Anjak, O.

    2011-10-01

    Automation of UNIDOS "Dosemeter" using personal computer (PC) is discussed in this paper. In order to save time and eliminate human operation errors during the radiation dosimetry, suitable software, using LabVIEW™ graphical programming language, was written to automate and facilitate the processes of measurements, analysis and data storage. The software calculates the calibration factor of the ionization chamber in terms of air kerma or absorbed dose to water according to IAEA dosimetry protocols. It also has the ability to print a calibration certificate. The obtained results using this software are found to be more reliable and flexible than those obtained by manual methods previously employed. Using LabVIEW™ as a development tool is extremely convenient to make things easier when software modifications and improvements are needed.

  5. Evaluation of the calibration procedure of active personal dosemeters for interventional radiology.

    Bordy, J-M; Daures, J; Clairand, I; Denozière, M; Donadille, L; d'Errico, F; Gouriou, J; Itié, C; Struelens, L

    2008-01-01

    An overview of the use of active personal dosemeters (APD) in interventional radiology is presented. It is based on the work done by the working package 7 of the CONRAD coordinated action supported by the EC within the frame of the 6th FP. This study was done in collaboration with the working package 4 of CONRAD to deal with the calculations required for studying the new calibration facility. The main requirements of the standard for the APD and the difficulties caused by the use of pulsed radiations are presented through the results of an intercomparison organised in a realistic calibration facility similar to the workplace situation in interventional radiology. The main characteristics of this facility are presented. PMID:18757898

  6. Two-dimensional differential calibration method for a neutron dosemeter using a thermal neutron beam.

    Matsumoto, Tetsuro; Harano, Hideki; Masuda, Akihiko; Nishiyama, Jun; Matsue, Hideaki; Uritani, Akira; Nunomiya, Tomoya

    2013-08-01

    A new thermal neutron calibration method to experimentally determine the energy response function of a neutron detector using a pulse parallel beam and the time-of-flight (TOF) technique is developed. The calibration method was experimentally demonstrated for a (3)He proportional counter and an electric personal dosemeter using a pulsed thermal neutron beam from the research reactor JRR-3M. The responses of the detectors were successfully obtained as a function of neutron energy. However, detailed information on the detector structure is required to obtain the spatial response distribution for the detector. The authors further propose an improved calibration method obtaining the spatial response distribution using a pulsed narrow beam, the TOF technique and a beam scanning technique. PMID:23509397

  7. Thermoluminescent dosemeters for determining the energy absorbed during X-ray radiography of the vertebral column

    The dose and absorbed energy during normal diagnostic X-ray of various sections of the vertebral column were determined with LiF-dosemeters in a phantom. The paper describes a method to be used to determine integral doses from the dose measurements. The energy absorbed for one X-ray picture of the vertebral column is between 5 and 30 mJ. Compared to other diagnostical X-rays the quantity of the energy absorbed during X-ray of the vertebral column is rather high and is only reached by X-rays in the pelvic region. The speculations on the rate of incidence of malignent neoplasms on the basis of diagnostical X-ray of the vertebral column reveal a value of 50 per 60 x 106 persons. This value is likely to overestimate the risk, seems, however, to be low in comparison to other risks of every day life (traffic accident, mountainering, etc). (orig./HP)

  8. Mine test of thermoluminescence energy discriminatory track etch personal dosemeters in uranium mines having nearly equal concentrations of radon and thoron daughters

    Energy discriminatory CEA track etch dosemeters and LiF thermoluminescence dosemeters were used to record the total dose in a uranium mine atmosphere containing both radon daughters and thoron daughters in approximately equal concentrations. In addition, the track etch dosemeters were used to record the individual concentrations of RaA, RaC' and ThC', thereby allowing calculation of the separate radon daughter and thoron daughter working levels. The pump performance of the dosemeters was characterized in terms of durability, stability and sensitivity to attitude, vibration and impact. Grab sampling results taken in the work area were not representative of all of the individual miner exposures because of the strong effect of job function on exposure. (author)

  9. Retrofitting alarm prioritization at Bruce A: strategy development and implementation experience

    A prioritization strategy for computer-displayed control room alarms has been developed for Bruce A to better assist operations staff in visually identifying key alarms and judging the relative importance of alarms. The strategy consists of assigning each alarm indicative of a problem to be addressed to one of five priority categories. Each alarm is assigned to an alarm category based on an off-line analysis of the consequence and response characteristics applicable to the alarm for three plant operating contexts. The colour of the alarm message is used to convey the priority category of each alarm in computer-based alarm displays. In addition, alarms indicative of non-problematic changes in the state of plant equipment and processes are given a separate colour assignment to visually differentiate them from alarms indicative of problems. This paper outlines the user-based approach employed in the prioritization strategy development, describes the key features of the prioritization strategy adopted, and discusses the initial experience in systematically determining the priority assignments for all 6000 computer-based alarms associated with each generating unit. (author)

  10. The β-ray energy and angular response of the EYE-D™ eye-lens dosemeter

    Following the recent ICRP recommendation to decrease the limit of occupational exposure to the eye lens from 150 mSv to 20 mSv/year, a dedicated individual eye-lens dosemeter, EYE-D™, was developed at the IFJ PAN. This dosemeter uses MCP-N (LiF:Mg,Cu,P) thermoluminescent detectors covered with a polyamide capsule and was so far optimized to achieve a flat photon energy and angular response for X-ray exposures typical in interventional radiology. To verify the applicability of this eye-lens dosemeter in external β-ray fields which arise, e.g. in nuclear medicine procedures, we measured and calculated its β-ray energy and angular response. Measurements, applying β-rays from Sr-90/Y-90 isotope, were performed at the Beta Secondary Standard type 2 (BSS 2) in CLOR. Calculations, using the PENELOPE Monte Carlo transport code which simulates coupled electron and photon transport in arbitrary materials, were performed for P-32, K-42 and Sr-90/Y-90 fields to simulate doses received by the eye lens within the human body. PENELOPE Monte Carlo transport code was also used to calculate doses received with EYE-D™ detectors. We found good agreement between the measured and calculated energy and angular responses which confirms the suitability of this dosemeter in assessing Hp(3) to estimate the eye lens. Obtained results and conclusions, however preliminary, conform with current ICRP recommendations when performing individual radiation protection dosimetry in external β-ray fields occurring in nuclear industry and nuclear medicine activities. -- Highlights: •The applicability of EYE-D™ eye-lens dosemeter in external β-ray fields have been investigated. •Measurements and calculations β-ray energy and angular response of EYE-D™ have been performed. •A comparison of calculations results with experimental data is presented. •Obtained results confirmed the suitability of this dosemeter in assessing Hp(3) to estimate the eye lens

  11. Referral to the accident and emergency department following the use of community alarms

    Youssef, G.; Underhill, T; Tovey, C

    2000-01-01

    Objectives—To assess the degree of appropriate referral to the accident and emergency (A&E) department following the use of a community alarm where a mobile warden works in conjunction with the community alarm control centre.

  12. Integrating monitor alarms with laboratory test results to enhance patient deterioration prediction.

    Bai, Yong; Do, Duc H; Harris, Patricia Rae Eileen; Schindler, Daniel; Boyle, Noel G; Drew, Barbara J; Hu, Xiao

    2015-02-01

    Patient monitors in modern hospitals have become ubiquitous but they generate an excessive number of false alarms causing alarm fatigue. Our previous work showed that combinations of frequently co-occurring monitor alarms, called SuperAlarm patterns, were capable of predicting in-hospital code blue events at a lower alarm frequency. In the present study, we extend the conceptual domain of a SuperAlarm to incorporate laboratory test results along with monitor alarms so as to build an integrated data set to mine SuperAlarm patterns. We propose two approaches to integrate monitor alarms with laboratory test results and use a maximal frequent itemsets mining algorithm to find SuperAlarm patterns. Under an acceptable false positive rate FPRmax, optimal parameters including the minimum support threshold and the length of time window for the algorithm to find the combinations of monitor alarms and laboratory test results are determined based on a 10-fold cross-validation set. SuperAlarm candidates are generated under these optimal parameters. The final SuperAlarm patterns are obtained by further removing the candidates with false positive rate>FPRmax. The performance of SuperAlarm patterns are assessed using an independent test data set. First, we calculate the sensitivity with respect to prediction window and the sensitivity with respect to lead time. Second, we calculate the false SuperAlarm ratio (ratio of the hourly number of SuperAlarm triggers for control patients to that of the monitor alarms, or that of regular monitor alarms plus laboratory test results if the SuperAlarm patterns contain laboratory test results) and the work-up to detection ratio, WDR (ratio of the number of patients triggering any SuperAlarm patterns to that of code blue patients triggering any SuperAlarm patterns). The experiment results demonstrate that when varying FPRmax between 0.02 and 0.15, the SuperAlarm patterns composed of monitor alarms along with the last two laboratory test results

  13. "Turn it off!": diabetes device alarm fatigue considerations for the present and the future.

    Shivers, Joseph P; Mackowiak, Linda; Anhalt, Henry; Zisser, Howard

    2013-05-01

    Safe and widespread use of diabetes technology is constrained by alarm fatigue: when someone receives so many alarms that he or she becomes less likely to respond appropriately. Alarm fatigue and related usability issues deserve consideration at every stage of alarm system design, especially as new technologies expand the potential number and complexity of alarms. The guiding principle should be patient wellbeing, while taking into consideration the regulatory and liability issues that sometimes contribute to building excessive alarms. With examples from diabetes devices, we illustrate two complementary frameworks for alarm design: a "patient safety first" perspective and a focus on human factors. We also describe opportunities and challenges that will come with new technologies such as remote monitoring, adaptive alarms, and ever-closer integration of glucose sensing with insulin delivery. PMID:23759412

  14. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR

    Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)

    1998-12-31

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  15. Study of a selection of 10 historical types of dosemeter: variation of the response to Hp(10) with photon energy and geometry of exposure.

    Thierry-Chef, I; Pernicka, F; Marshall, M; Cardis, E; Andreo, P

    2002-01-01

    An international collaborative study of cancer risk among workers in the nuclear industry is tinder way to estimate direetly the cancer risk following protracted low-dose exposure to ionising radiation. An essential aspect of this study is the characterisation and quantification of errors in available dose estimates. One major source of errors is dosemeter response in workplace exposure conditions. Little information is available on energy and geometry response for most of the 124 different dosemeters used historically in participating facilities. Experiments were therefore set up to assess this. using 10 dosemeter types representative of those used over time. Results show that the largest errors were associated with the response of early dosemeters to low-energy photon radiation. Good response was found with modern dosemeters. even at low energy. These results are being used to estimate errors in the response for each dosemeter type, used in the participating facilities, so that these can be taken into account in the estimates of cancer risk. PMID:12408486

  16. Practical consequences for the use of a personal dosemeter for fast neutrons at high-energy accelerators based on PADC detectors exposed up to one year

    Since 1998, Paul Scherrer Institut has employed the routine use of a personal neutron dosimetry system based on chemically etched PADC (poly allyl diglycol carbonate) detectors and automatic track counting. In 2004, a new concept for individual monitoring at high-energy accelerators was implemented. In this concept the photon dosemeter of a combined photon/neutron dosemeter is evaluated monthly. The neutron dosemeter is only evaluated if the personal photon dose exceeds 2 mSv, or if the exposition period of the neutron dosemeter exceeds one year. Significant consequences for the evaluation of the neutron dosemeter in the dosimetry service were evidenced in the new concept. The wearing period of the neutron dosemeter can range from 1 to 12 months, potentially longer. Therefore, the long-term behavior of background track density and variation of response to Am-Be within 17 months was studied. The effects of 'fading' and 'aging' that influence the response of PADC detectors are determined. The application of an algorithm for neutron dose calculation takes into account long-term behavior and is described. Furthermore, repeated field calibrations were performed at the CERN-EU high-energy reference field (CERF) facility.

  17. Chimpanzee alarm call production meets key criteria for intentionality.

    Schel, Anne Marijke; Townsend, Simon W; Machanda, Zarin; Zuberbühler, Klaus; Slocombe, Katie E

    2013-01-01

    Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i) socially directed and given to the arrival of friends, (ii) associated with visual monitoring of the audience and gaze alternations, and (iii) goal directed, as calling only stopped when recipients were safe from the predator. Our results demonstrate that certain vocalisations of our closest living relatives qualify as intentional signals, in a directly comparable way to many great ape gestures. We conclude that our results undermine a central argument of gestural theories of language evolution and instead support a multimodal origin of human language. PMID:24146908

  18. Chimpanzee alarm call production meets key criteria for intentionality.

    Anne Marijke Schel

    Full Text Available Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i socially directed and given to the arrival of friends, (ii associated with visual monitoring of the audience and gaze alternations, and (iii goal directed, as calling only stopped when recipients were safe from the predator. Our results demonstrate that certain vocalisations of our closest living relatives qualify as intentional signals, in a directly comparable way to many great ape gestures. We conclude that our results undermine a central argument of gestural theories of language evolution and instead support a multimodal origin of human language.

  19. Fault tolerant microcomputer based alarm annunciator for Dhruva reactor

    The Dhruva alarm annunciator displays the status of 624 alarm points on an array of display windows using the standard ringback sequence. Recognizing the need for a very high availability, the system is implemented as a fault tolerant configuration. The annunciator is partitioned into three identical units; each unit is implemented using two microcomputers wired in a hot standby mode. In the event of one computer malfunctioning, the standby computer takes over control in a bouncefree transfer. The use of microprocessors has helped built-in flexibility in the system. The system also provides built-in capability to resolve the sequence of occurrence of events and conveys this information to another system for display on a CRT. This report describes the system features, fault tolerant organisation used and the hardware and software developed for the annunciation function. (author). 8 figs

  20. Development of the effectiveness measure for an advanced alarm system using signal detection theory

    Since many alarms which are activated during major process deviations or accidents in nuclear power plants can result in negative effects for operators, various types of advanced alarm systems that can select important alarms for the identification of process deviation have been developed to reduce the operator's workload. However, the irrelevant selection of important alarms could distract the operator from correct identification of process deviation. Therefore, to evaluate the effectiveness of the advanced alarm system, a tradeoff between the alarm reduction rate (how many alarms are reduced?) and informativeness (how many important alarms that are conducive to identifying process deviation are provided?) of an advanced alarm system should be considered. In this paper, a new measure is proposed to evaluate the effectiveness of an advanced alarm system with regard to the identification of process deviation. Here, the effectiveness measure is the combination of informativeness measure and reduction rate, and the informativeness measure means the information processing capability performed by the advanced alarm system including wrong rejection and wrong acceptance, and it can be calculated using the signal detection theory (SDT). The effectiveness of the prototype alarm system was evaluated using the loss of coolant accident (LOCA) scenario, and the validity of the effectiveness measure was investigated from two types of the operator response, such as the identification accuracy and the operator's preference for the identification of LOCA

  1. Preventing Charlie's in a chocolate factory: a human factors perspective of alarm handling in confectionary manufacture

    Stanton, Neville A.

    1991-01-01

    The article analyses the results of a survey of a small population of Control Desk Engineers at a UK manufacturing plant. Specific objectives were to elicit the engineers' definition of the term `alarm', to examine their alarm handling activities, and to get information on problems with the alarm system

  2. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  3. Seismic alarm system for Ignalina nuclear power plant

    A seismic alarm system will be installed at the Ignalina Nuclear Power Plant (INPP) in Lithuania. There are two reactors, both RMBK 1500 MW units. Each reactor is a water cooled, graphite moderated, channel type reactor. INPP has the most advanced version of the RMBK reactor design series. The first and second units of INPP went into service at the end of 1983 and in August 1987 respectively. Their design lifetime is approx. 30 years. The various buildings and plant have been designed for two earthquake levels, that is the design earthquake and the maximum possible earthquake with peak ground accelerations ranging from 1.2% to 10% of the acceleration due to gravity. Certain parts of the buildings and some of the equipment of the first and second units do not comply with Western seismic standards. As seismic strengthening of the existing buildings and equipment is not feasible economically, a reactor protection system based on an earthquake early warning system was recommended. This system essentially consists of six seismic stations encircling INPP at a radial distance of approx. 30 km and a seventh station at INPP. Each station includes three seismic substations each 500 m apart. The ground motion at each station is measured continuously by three accelerometers and one seismometer. Data is transmitted via telemetry to the control centre at INPP. Early warning alarms are generated if a seismic threshold is exceeded. This paper discusses the characteristics of INPP, the seismic alarm system presently under construction and the experience with other early warning and seismic alarm systems. (author)

  4. Chimpanzee alarm call production meets key criteria for intentionality

    Anne Marijke Schel; Simon W Townsend; Zarin Machanda; Klaus Zuberbühler; Slocombe, Katie E.

    2013-01-01

    BBSRC-funded, but difficult to identify the specific grant. Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality...

  5. The double slit experiment and the time reversed fire alarm

    Halabi, Tarek

    2009-01-01

    When both slits of the double slit experiment are open, closing one paradoxically increases the detection rate at some points on the detection screen. Feynman famously warned that temptation to "understand" such a puzzling feature only draws us into blind alleys. Nevertheless, we gain insight into this feature by drawing an analogy between the double slit experiment and a time reversed fire alarm. Much as closing the slit increases probability of a future detection, ruling out fire drill scen...

  6. Design of Textile Moisture Sensor for Enuresis Alarm System

    Kašurina, I; Vališevskis, A; Briedis, U; Viļumsone, A

    2012-01-01

    To improve the comfort properties of nocturnal enuresis alarm system, a modular humidity sensor should be replaced with a textile sensor. During research, two-electrode textile moisture sensor has been developed to study its electrical properties. To define the optimal type of a sensor, several sensor samples have been made using different configurations of sensor electrodes, yarn type and distance between parallel seams. Samples of sensor have been tested in terms of sig...

  7. Radiation protection of medical staff: a coordinated action by EURADOS on extremely dosimetry and the use of active personnel dosemeters (CONRAD)

    subgroup of WG9 dealt specifically with the use of extremity dosemeters in medical radiation fields. Active personal dosimeters (APDs) are very efficient tools to monitor occupational doses in real time during exposure and provide selectable alarm levels to avoid high doses. Interventional radiology operators belong to a specific worker category, which would benefit from a real time, accurate assessment of their dose. Another subgroup dealt with the adequate dosimetry of scattered photons, using APDs. They must be able to respond to low-energy (10-100 keV) and pulsed radiation with relatively high instantaneous dose rates

  8. Comparison of neutron dose quantities and instrument and dosemeter readings at representative locations in an MOX fuel fabrication plant

    Bartlett, D T; Tanner, R J; Haley, R M; Cooper, A J

    2002-01-01

    The relationships between operational and protection quantities, and values of personal dosemeter and instrument readings have been determined for a recently designed MOX fuel fabrication plant. The relationships between the quantities, and the readings of personal dosemeters are sensitive to both the energy and direction distribution of neutron fluence. The energy distributions were calculated using the Monte Carlo code MCBEND. The direction distribution was addressed by calculating independently, spectral components for which the direction distribution could be reasonably assumed. At representative locations, and for assumed worker orientations, the radiation field is analysed as having, in general, three components--a direct, unidirectional component from the nearest identified discrete source, which is considered incident A-P, several unidirectional components from other such sources which are treated as a rotational component and a scattered isotropic component. The calculated spectra were folded with co...

  9. Nurses' Perceptions and Practices Toward Clinical Alarms in a Transplant Cardiac Intensive Care Unit: Exploring Key Issues Leading to Alarm Fatigue

    Sowan, Azizeh Khaled; Tarriela, Albert Fajardo; Gomez, Tiffany Michelle; Reed, Charles Calhoun; Rapp, Kami Marie

    2015-01-01

    Background Intensive care units (ICUs) are complex work environments where false alarms occur more frequently than on non-critical care units. The Joint Commission National Patient Safety Goal .06.01.01 targeted improving the safety of clinical alarm systems and required health care facilities to establish alarm systems safety as a hospital priority by July 2014. An important initial step toward this requirement is identifying ICU nurses’ perceptions and common clinical practices toward clini...

  10. Alarm handling for health monitoring: operator strategies used in an electrical control room of a rail network

    Dadashi, Nastaran; Wilson, John R; Golightly, David; Sharples, Sarah

    2016-01-01

    Alarm management is a key component of the successful operation of a prognostic or health-monitoring technology. Although alarms can alert the operator to critical information, false alarms and alarm flooding can cause major difficulties for successfully diagnosing and acting upon infrastructure faults. Human factors approaches seek to design more-effective alarm systems through a deep understanding of the contextual factors that influence alarm response, including strategies and heuristics u...

  11. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of high temperature peaks in TLD-100 dosemeters

    This work presents measures of relative thermoluminescent efficiency of those high temperature peaks of TLD-100 dosemeters exposed to protons of 1.5 MeV and to helium nuclei of 3 and 7.5 MeV. A rigorous reading and of deconvolution protocol was used for the calculation of the TL efficiencies. Additionally an Excel program that facilitated the deconvolution adjustment process of the glow curves was elaborated. (Author)

  12. New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation

    The quantities introduced by ICRU for the radiological monitoring are commented, specially those implied in individual protection against external photons. A procedure is proposed in order to standardize the individual dosemeters by using the kerma in air references of CIEMAT-JEN. The reference radiation beams are described in connection with ISO standards. Provisional values are selected for the appropriate conversion and correction factors. (Author) 23 refs

  13. The routine calibration in terms of the new ICRU quantities of personal dosemeters to be worn on the trunk

    A brief article describes the routine calibration of personal dosemeters in terms of the phantom quantities directional dose equivalent at 0.07 mm, H' (0.07) and at 10 mm, H' (10) for which internationally recommended conversion coefficients from air kerma or neutron fluence are available. These quantities are the calibration quantities for the measurement of individual dose equivalent, superficial, and individual dose equivalent, penetrating respectively. (U.K.)

  14. Performance of a personal neutron dosemeter based on direct ion storage at workplace fields in the nuclear industry

    Full text: Devices for personal dosimetry in neutron or mixed neutron-photon fields are still far less established than systems for photon radiation only. The DIS-N dosemeter based on ionization chambers with Direct Ion Storage developed by RADOS has the potential to contribute to the improvement of this situation. A double-chamber system allows for differential readings to separate the neutron from the photon dose. The sensitivity to neutrons can be altered by using different converter materials, i.e. polyethylene containing lithium or the tissue equivalent material A-150 containing boron. The dose response can further be modified by surrounding and thus shielding the detectors with additional material mainly to reduce the sensitivity to thermal neutrons. In the framework of the EVIDOS project, funded by the EC, measurements with DIS-N dosemeters were carried out at several workplace fields, namely at a fuel processing plant, a boiling and a pressurized water reactor and near transport and storage casks. The measurements and results obtained with the DIS-N in these workplaces, which are representative for the nuclear industry, are described. Different configurations of converter and shielding materials were considered. The results are compared with reference values for personal dose equivalent which were assessed within the EVIDOS project by other partners. The advantages and limitations of the DIS-N dosemeter are discussed. (author)

  15. Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington

    Greenfield, Bryce A. [Univ. of New Mexico, Albuquerque, NM (United States)

    2009-12-01

    A detailed instructional manual was created to guide criticality safety engineers through the process of designing a criticality alarm system (CAS) for Department of Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements were both addressed. A list of design tasks and technical subtasks are thoroughly analyzed to provide concise direction for how to complete the analysis. An example of the application of the design methodology, the Criticality Alarm System developed for the Radioisotope Production Laboratory (RPL) of Richland, Washington is also included. The analysis for RPL utilizes the Monte Carlo code MCNP5 for establishing detector coverage in the facility. Significant improvements to the existing CAS were made that increase the reliability, transparency, and coverage of the system.

  16. Reducing SCADA System Nuisance Alarms in the Water Industry in Northern Ireland

    O'Donoghue, Nigel; Phillips, Debra H.; Nicell, Ciaran

    2015-01-01

    The advancement of telemetry control for the water industry has increased the difficulty of 14 managing large volumes of nuisance alarms (i.e. alarms that do not require a response). The aim 15 of this study was to identify and reduce the number of nuisance alarms that occur for Northern 16 Ireland (NI) Water by carrying-out alarm duration analysis to determine the appropriate length of 17 persistence (an advanced alarm management tool) that could be applied. All data was extracted 18 from Te...

  17. Estimating the uncertainty in measurement of occupational exposure with personal dosemeters

    Full text: In the 1990 Recommendations of the ICRP it is stated that an uncertainty of a factor 1.5 in either direction 'will not be unusual' in a dose measured under workplace conditions. In many documents like the EU Technical recommendations, the IAEA Safety Guides and papers in scientific journals, this statement is understood to be a starting point for developing type-test criteria and criteria for approval of dosimetric systems. And, although meant to refer to effective dose it is usually understood to refer to personal dose equivalent as well. When using a personal dosemeter, the quantity to be measured, personal dose equivalent, is derived from a number of input quantities such as light output of one or more TLDs or densities of areas on a film, sensitivity of the detection material, properties of the evaluating equipment and dose due to background radiation. Each of these input quantities is the result of a measurement that is inexact and thus resulting in an inexact value for the dose. In cases where the transformation of the raw measurements into the quantity to be estimated, measurand, only involves linear transformations and the distributions of the errors in the input quantities are Gaussian or at least symmetrical and Gausslike, then the uncertainty in the measurand can more or less reliably be derived from the uncertainties in the input quantities using the familiar 'general law of error propagation'. In cases where the evaluation involves non-linear transformations and/or the probability distributions of the input quantities are not well approximated by Gaussian distributions then it is far from obvious that the familiar techniques will result in a realistic estimate of the uncertainty in the dose. This paper presents a method using Monte Carlo techniques that does not depend on the validity of the general law of error propagation. The method is based on the 'Guide to the Expression of Uncertainty in Measurement' and the 'Supplement 1: Numerical

  18. Development of a extremity thermoluminescence dosemeter for photon dose equivalent assessment

    An extremely thermoluminescence dosimeter, to be used when the extremity may become the limiting organ, based on CaSO4:Dy pellet was developed to be worn as wristlet by technicians who work with unsealed sources or handle radioactive materials. This system permits photon dose equivalent assessment as well as the effective energy determination. Such dosemeter has to be worn in addition to a whole-body dosemeter. The system consists of two pieces of polyethylene with dimensions of 40 mm x 20 mm x 10 mm that can be superimposed and three discs of CaSO4:Dy plus Teflon (PTFE), as sensitive material, between different filters. The detectors are produced by the Dosimetric Materials Laboratory of IPEN and have diameter of 6.0 mm and a thickness of 0.8 mm. One detector is placed between plastic filters of 3.0 mm thickness that guarantees electronic equilibrium for 60Co gamma rays. Another detector is located between 1.0 mm thick lead filters plus 3.0 mm plastic filters. A third detector is sandwiched between filters of lead 0.8 mm thick with a central hole of 2.0 mm diameter and plastic filters of 3.0 mm thickness. The detectors are sealed in a plastic film 20 mg.cm-2 thick. All TL detectors are in contact with filters. The filter area is a little larger than the TL detector. The validation of the proposed dosimetric system was performed for 60Co gamma doses between 0.1 and 200 mGy. In this range the relationship dose-response is linear. The energy response of the dosimetric system was evaluated for an energy range between 30 and 662 keV. The maximum, relative to 60Co, energy dependence TL response is observed at 31.2 keV (factor 10.2). To obtain the dose equivalent and the effective energy from the correlation between the three TL readings was developed an algorithm. Taking into account the results obtained in simulated laboratory comparisons, better than ±5%, we conclude that the proposed dosimetric system agrees with the requirements for its application as extremity

  19. A High-confidence Cyber-Physical Alarm System: Design and Implementation

    Ma, Longhua; Xia, Feng; Xu, Ming; Yao, Jun; Shao, Meng

    2010-01-01

    Most traditional alarm systems cannot address security threats in a satisfactory manner. To alleviate this problem, we developed a high-confidence cyber-physical alarm system (CPAS), a new kind of alarm systems. This system establishes the connection of the Internet (i.e. TCP/IP) through GPRS/CDMA/3G. It achieves mutual communication control among terminal equipments, human machine interfaces and users by using the existing mobile communication network. The CPAS will enable the transformation in alarm mode from traditional one-way alarm to two-way alarm. The system has been successfully applied in practice. The results show that the CPAS could avoid false alarms and satisfy residents' security needs.

  20. Human factors engineering guidance for the review of advanced alarm systems

    O`Hara, J.M.; Brown, W.S.; Higgins, J.C.; Stubler, W.F. [Brookhaven National Lab., Upton, NY (United States)

    1994-09-01

    This report provides guidance to support the review of the human factors aspects of advanced alarm system designs in nuclear power plants. The report is organized into three major sections. The first section describes the methodology and criteria that were used to develop the design review guidelines. Also included is a description of the scope, organization, and format of the guidelines. The second section provides a systematic review procedure in which important characteristics of the alarm system are identified, described, and evaluated. The third section provides the detailed review guidelines. The review guidelines are organized according to important characteristics of the alarm system including: alarm definition; alarm processing and reduction; alarm prioritization and availability; display; control; automated; dynamic, and modifiable characteristics; reliability, test, maintenance, and failure indication; alarm response procedures; and control-display integration and layout.

  1. Human factors engineering guidance for the review of advanced alarm systems

    This report provides guidance to support the review of the human factors aspects of advanced alarm system designs in nuclear power plants. The report is organized into three major sections. The first section describes the methodology and criteria that were used to develop the design review guidelines. Also included is a description of the scope, organization, and format of the guidelines. The second section provides a systematic review procedure in which important characteristics of the alarm system are identified, described, and evaluated. The third section provides the detailed review guidelines. The review guidelines are organized according to important characteristics of the alarm system including: alarm definition; alarm processing and reduction; alarm prioritization and availability; display; control; automated; dynamic, and modifiable characteristics; reliability, test, maintenance, and failure indication; alarm response procedures; and control-display integration and layout

  2. An experimental investigation of the effects of alarm processing and display on operator performance

    O`Hara, J.; Brown, W. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology; Hallbert, B.; Skraaning, G. [Halden Reactor Project (Norway); Wachtel, J.; Persensky, J. [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research

    1998-03-01

    This paper describes a research program sponsored by the US Nuclear Regulatory Commission to address the human factors engineering (HFE) aspects of nuclear power plant alarm systems. The overall objective of the program is to develop HFE review guidance for advanced alarm systems. As part of this program, guidance has been developed based on a broad base of technical and research literature. In the course of guidance development, aspects of alarm system design for which the technical basis was insufficient to support complete guidance development were identified. The primary purpose of the research reported in this paper was to evaluate the effects of three of these alarm system design characteristics on operator performance in order to contribute to the understanding of potential safety issues and to provide data to support the development of design review guidance in these areas. Three alarm system design characteristics studied were (1) alarm processing (degree of alarm reduction), (2) alarm availability (dynamic prioritization and suppression), and (3) alarm display (a dedicated tile format, a mixed tile and message list format, and a format in which alarm information is integrated into the process displays). A secondary purpose was to provide confirmatory evidence of selected alarm system guidance developed in an earlier phase of the project. The alarm characteristics were combined into eight separate experimental conditions. Six, two-person crews of professional nuclear power plant operators participated in the study. Following training, each crew completed 16 test trials which consisted of two trials in each of the eight experimental conditions (one with a low-complexity scenario and one with a high-complexity scenario). Measures of process performance, operator task performance, situation awareness, and workload were obtained. In addition, operator opinions and evaluations of the alarm processing and display conditions were collected. No deficient

  3. Semi-supervised detection of intracranial pressure alarms using waveform dynamics

    Patient monitoring systems in intensive care units (ICU) are usually set to trigger alarms when abnormal values are detected. Alarms are generated by threshold-crossing rules that lead to high false alarm rates. This is a recognized issue that causes alarm fatigue, waste of human resources, and increased patient risks. Recently developed smart alarm models require alarms to be validated by experts during the training phase. The manual annotation process involved is time-consuming and virtually impossible to achieve for the thousands of alarms recorded in the ICU every week. To tackle this problem, we investigate in this study if the use of semi-supervised learning methods, that can naturally integrate unlabeled data samples in the model, can be used to improve the accuracy of the alarm detection. As a proof of concept, the detection system is evaluated on intracranial pressure (ICP) signal alarms. Specific morphological and trending features are extracted from the ICP signal waveform to capture the dynamic of the signal prior to alarms. This study is based on a comprehensive dataset of 4791 manually labeled alarms recorded from 108 neurosurgical patients. A comparative analysis is provided between kernel spectral regression (SR-KDA) and support vector machine (SVM) both modified for the semi-supervised setting. Results obtained during the experimental evaluations indicate that the two models can significantly reduce false alarms using unlabeled samples; especially in the presence of a restrained number of labeled examples. At a true alarm recognition rate of 99%, the false alarm reduction rates improved from 9% (supervised) to 27% (semi-supervised) for SR-KDA, and from 3% (supervised) to 16% (semi-supervised) for SVM. (paper)

  4. Krohne Flow Indicator and High Flow Alarm - Local Indicator and High Flow Alarm of Helium Flow from the SCHe Purge Lines C and D to the Process Vent

    Flow Indicators/alarms FI/FSH-5*52 and -5*72 are located in the process vent lines connected to the 2 psig SCHe purge lines C and D. They monitor the flow from the 2 psig SCHe purge going to the process vent. The switch/alarm is non-safety class GS

  5. Krohne Flow Indicator and High Flow Alarm Local Indicator and High Flow Alarm of Helium Flow from the SCHe Purge Lines C and D to the Process Vent

    MISKA, C.R.

    2000-09-03

    Flow Indicators/alarms FI/FSH-5*52 and -5*72 are located in the process vent lines connected to the 2 psig SCHe purge lines C and D. They monitor the flow from the 2 psig SCHe purge going to the process vent. The switch/alarm is non-safety class GS.

  6. Evaluation of the directional dose equivalent H,(0.07) for ring dosemeters

    The personnel dosimetry laboratory (LDP) of the Metrology department received an user's of radiation beta application that incidentally had irradiated 14 couples of ring dosemeters for extremities of the type TLD-100 given by the LDP. This sample of 14 couples of rings tentatively it was irradiated in the months of July-August of the year 2004, and he requested in an expedite way the evaluation of the received dose equivalent. The LSCD builds two calibration curves in terms of the directional dose equivalent H'(0.07) using two sources patterns of 90 Sr-90 Y for beta radiation: one of 74 MBq and another of 1850 MBq with traceability to the PTB. The first curve in the interval of 0 to 5 mSv, the second in the range of 5 to 50 mSv, taking into account effects by positioned of the rings in the phantom. Both calibration curves were validated by adjustment lack, symmetry of residuals and normality of the same ones. It is evaluated and analyzing the H'(0.007) for these 14 couples of rings using the Tukey test of media of a single road. It was found that the H, its could be classified in 4 groups, and that the probability that its has irradiated in a random way it was smaller to the level at α = 0.05. (Author)

  7. Cosmic-radiation dosimetry using electronic personal dosemeter (EPD) at commercial aircraft altitude

    Yasuda, Hiroshi; Fujitaka, Kazunobu [National Inst. of Radiological Sciences, Chiba (Japan). International Space Radiation Lab.

    2000-02-01

    Electronic Personal Dosemeter (EPD) was examined for effectiveness in cosmic radiation dosimetry at aircraft altitude through the measurements in a Japan-US round trip. The EPD value (H{sub epd}) of individual dose equivalent, penetrating, H{sub p}(10), was considered to be almost equal the deep absorbed dose attributed to electrons at the aircraft altitude. By assuming the fractions and the effective quality factors for other components (muons, protons, and neutrons) based on model-calculation data, an empirical equation to estimate a conservative deep dose-equivalent at 5 cm-tissue depth, H(50), was given as H(50)=3.1 x H{sub epd}. Estimated H(50) values in the international flights were 4.9 {mu}Sv h{sup -1} from Tokyo to New York and 3.6 {mu}Sv h{sup -1} from Los Angeles to Tokyo. These values agreed well with the predicted values presented by NCRP. (author)

  8. The influence of time-temperature on the behaviour of TLD-100 as personal dosemeters

    Since 1965, the survey of individual exposure for the people working in the medical field is carried out within the Institute of Hygiene and Public Health, by a central service belonging to the Romanian Ministry of Health. During this period 6500 persons per month were monitored, using film-badges. The relative low sensitivity of film dosemeters lead to a decrease of confidence in this old system. Furthermore, the film badges do not have appropriate filters for measuring the personal equivalent doses Hp(10) and Hp(0.07), as are the new recommendations of ICRP and IAEA. These facts made clear there is a necessity of changing this type of monitoring system with another one, having a higher sensitivity and allowing the measurement of personal equivalent doses Hp(10) and Hp(0.07). The decision was to switch to a TL dosimetry system, namely the Harshaw 6600 System. The performances of this new system have to be checked by the TL Dosimetry Group, at the Institute of Hygiene and Public Health, before being officially accepted as the new individual dosimetry system. The paper presents the results of some of the test performed on the TLD-100 chips, concerning the influence of the heating rate and pre-heat temperature and duration (the time-temperature profiles) and the fading of the detectors. (author)

  9. The effect of radiation on bioluminescent bacteria: possible use of luminescent bacteria as a biological dosemeter

    The purpose of the study was to investigate the response of the bioluminescent Photobacterium phosphoreum to radiation, and the possible use of the bacteria as a biological radiation dosemeter, i.e. a water-equivalent biological system that will compare beams not merely on the basis of absorbed dose, but also have intrinsic RBE values for different radiation beams. Samples were irradiated by a 12 MeV electron beam at a dose rate of 3.0 Gy min-1, by 60Co gamma rays at 2.85 Gy min-1, and by 100 kVsub(p) x-rays at a dose rate of 2.13 Gy min-1. To study dose-rate dependence, the survival fraction was obtained for a 12 MeV electron beam at 0.50 and 12 Gy min-1 for 20.0 Gy. The survival fraction proved to be independent of dose rate in this range. The results presented in this work indicate that by using bioluminescent bacteria, RBE measurements can be markedly simplified and the results interpreted unequivocally. (U.K.)

  10. Use of active personal dosemeters in interventional radiology and cardiology: Tests in hospitals – ORAMED project

    Although active personal dosemeters (APDs) are not used quite often in hospital environments, the possibility to assess the dose and/or dose rate in real time is particularly interesting in interventional radiology and cardiology (IR/IC) since operators can receive relatively high doses while standing close to the primary radiation field. A study concerning the optimization of the use of APDs in IR/IC was performed in the framework of the ORAMED project, a Collaborative Project (2008–2011) supported by the European Commission within its 7th Framework Program. This paper reports on tests performed with APDs on phantoms using an X-ray facility in a hospital environment and APDs worn by interventionalists during routine practice in different European hospitals. The behaviour of the APDs is more satisfactory in hospitals than in laboratories with respect to the influence of the tube peak high voltage and pulse width, because the APDs are tested in scattered fields with dose equivalent rates generally lower than 1 Sv.h−1. .

  11. Active personal dosemeters in interventional radiology: Tests in laboratory conditions and in hospitals

    The work package 3 of the ORAMED project, Collaborative Project (2008-11) supported by the European Commission within its seventh Framework Programme, is focused on the optimisation of the use of active personal dosemeters (APDs) in interventional radiology and cardiology (IR/IC). Indeed, a lack of appropriate APD devices is identified for these specific fields. Few devices can detect low-energy X rays (20-100 keV), and none of them are specifically designed for working in pulsed radiation fields. The work presented in this paper consists in studying the behaviour of some selected APDs deemed suitable for application in IR/IC. For this purpose, measurements under laboratory conditions, both with continuous and pulsed X-ray beams, and tests in real conditions on site in different European hospitals were performed. This study highlights the limitations of APDs for this application and the need of improving the APD technology so as to fulfil all needs in the IR/IC field. (authors)

  12. Performance of CVD diamond as an optically and thermally stimulated luminescence dosemeter

    Diamond is a material with extreme physical properties. Its radiation hardness, chemical inertness and tissue equivalence qualify it as an ideal material for radiation dosimetry. In the present work, the optically stimulated luminescence (OSL) and thermoluminescence (TL) characteristics of a 10 μm thick CVD diamond (polycrystalline diamond films prepared by chemical vapor deposition) film were studied in order to test its performance as a beta radiation dosemeter. The TL response is composed of four main TL glow peaks; two of these are in the range of 150-200 deg. C and two additional peaks in the 250-400 deg. C temperature range. The integrated TL as a function of radiation dose is linear up to 100 Gy and increases with increasing dose exposure. The dose dependence of the integrated OSL exhibits a similar behavior. The observed OSL/TL behavior for the CVD diamond film clearly demonstrate its capability for applications in radiation dosimetry with special relevance in medical dosimetry owing to the diamond's intrinsic material properties. (authors)

  13. Investigations of the luminescence of phosphate glasses with respect to their application as solid dosemeters

    A comprehensive presentation of the luminescent properties of phosphate glass is worked out. The extensive investigations show an essential enlargement of the knowledge on the luminescence of phosphate glass existing hitherto. These results form the basis for a detailed discussion of the luminescence mechanism. By applying additional results of measurements concerning optical and paramagnetic absorption, enabling the access to the atomic effect, propositions were developed for models of absorption, excitation and luminous centers relevant for dosimetry for which Ag++ was found to be the constituent determining the centers. The interpretation of the luminescence phenomena within the frame of these models leads to considerable corrections on the existing concepts. At the same time the comparability of Ag-doped phosphate glasses and alkali halogenides is shown with respect to their luminescence behaviour, and with it an argument for the existence of crystal-like short-order regions in the amorphous glass is provided. This result serves as a basis for a discussion of the centers in the band model. Further investigations dealt with the quantities of influence for the practical application of the dosemeter. By interpretation of these results explanations are given for the effect of irradiation and evaluation temperatures, of LET, the dose, and UV light on the measuring signal. The phenomenon of 'pre-dose', for which especially surface effects have been detected as cause, is discussed under the aspect of a boundary layer theory. (orig./HP)

  14. Cosmic radiation protection dosimetry using an electronic personal dosemeter (Siemens EPD) on selected international flights

    The effectiveness of an Electronic Personal Dosemeter (Siemens EPD) for cosmic-radiation dosimetry at aviation altitudes was examined on eight international flights between March and September, 1998. The EPD values (Hepd) of the dose equivalent from penetrating radiation, Hp(10), were assumed to be almost the same as the electron absorbed doses during those flights. Based on the compositions of cosmic radiation in the atmosphere and the 1977 ICRP recommendation, an empirical equation to conservatively estimate the personal dose equivalent (Hp77) at a depth of 5 cm was derived as Hp77=3.1 x Hepd. The personal dose equivalent (Hp90) based on the 1990 ICRP recommendation was given by Hp90=4.6 x Hepd; the conservative feature of Hp90 was confirmed in a comparison with the calculated effective doses by means of the CARI-6 code. It is thus expected that the EPD will be effectively used for radiation protection dosimetry on selected international flights. (author)

  15. The implementation in routine of the ENEA new personal photon dosemeter

    The ENEA photon dosemeter, introduced in 1995, consisting of two differently filtrated LiF(Mg,Cu,P) detectors, has been modified recently. The ABS (acrylonitrile butadiene styrene) plastic support has been replaced by a new aluminium card supporting the same two detectors (LiF(Mg,Cu,P) GR200). The new card, fully developed at the ENEA-Radiation Protection Inst. (which is going to be patented), can now be processed through a Harshaw Model 6600 Automated TLD Reader, a hot gas reader. This paper reports the results of the individual calibration of ∼60,000 LiF(Mg,Cu,P) GR200 detectors inserted on the new aluminium cards. Before the implementation in routine of the new cards, the reader has been characterised. Steps and tests to be made to use the card in routine (i.e. reader stability, linearity, reproducibility, etc.) are reported. The whole dosimetric system now combines the very good performances of the Harshaw Model 6600 reader and that of LiF(Mg,Cu,P) thermoluminescent material. (authors)

  16. Thermoluminescent and optical processes in alkaline halogenides dosemeters contaminated with Europium

    Recent research results are presented about the properties of the optical processes of photo transferred thermoluminescence (TLFT), optical whitening (BO), thermoluminescence induced by light (TLL) and its effect in the thermoluminescent curve (Tl) produced by ionizing and non-ionizing radiation. The systematic analysis of all these processes, acquires a singular importance due that actually the alkaline halogenide crystals are object of intense investigations which analyse their potential applications as detectors and radiation dosemeters through stimulated optical luminescence techniques or thermoluminescence. The obtained data show that the Tl curve of material with this nature can be enormously affected by exposure of phosphorus to the environmental light or UV. This is in part due to liberation processes of charge bearers are shouted and makes a subsequent trapping in less temperature traps; at the same time that induce changes in the intensity of determined Tl bands. Additionally, also it is observed that mentioned phenomena are related as with wavelength of incident light as of the illumination time. Finally, the obtained information allows to conclude that although the illumination effect is extremely complex, it is associated and can be explained mainly with phenomena that implicate the electrons excitation trapped in form of F centers and trapping mechanisms or radioactive and non-radioactive recombination. (Author)

  17. TPLC-32 based alarm annunciation system for Dhruva

    The Control and Instrumentation (C and I) Systems of Dhruva Research Reactor have been designed in late seventies and are facing not only obsolescence but have limited diagnostic features. Since the expected life of C and I systems is typically twenty years, it was considered appropriate to upgrade some of the major systems including Alarm Annunciation System (AAS). The AAS of Dhruva is a Safety Class IB system that is used for processing alarm inputs and alerting the Main Control Room operator by driving LED based windows and audio annunciation in the Main Control Room. The AAS is also used for sequencing and logging of alarms on Operator Console. AAS is designed using qualified configurable platform Trombay Programmable Logic Controller-32 (TPLC-32) indigenously developed in BARC. The platform based design provides complete configurability, such that it can be used to build different systems for diverse applications. The AAS for Dhruva is first TPLC-32 based system to be deployed in any Indian Nuclear Reactor. The entire cycle involved conceptualization of system, making system requirement specifications, detailing the concept, design, fabrication, creation of test facilities, testing, validation of system performance, preparation of various documents for the regulatory safety clearances, installation and commissioning of the systems. This upgrade of AAS has helped enhancing safety, mitigates obsolescence and provided improved O and M features. Executing this upgrade in operating reactor posed additional constraints such as high level of safety, limited down time etc and this could be addressed through long term planning and implementation strategies based on innovative ideas and previous experience in installation and commissioning. Being an in-house product, long-term support for maintenance mitigating the obsolescence and technology up gradation is ensured. This paper provides technical information on AAS system design, its important features, the testing

  18. Alarm coding of a model-based display

    This paper discusses and illustrates alarm coding of a model based display. The model based display synthesizes the heat engine cycle within a light water reactor. A digital computer uses measured process variables to form an icon of the heat engine cycle. The Rankine Cycle, a heat engine cycle, serves to structure the data in terms of the temperature and entropy properties of water. The iconic display serves as a visual knowledge base of the plant process for the operator, thereby reducing the operator's mental workload in evaluating the process

  19. Detecting outliers in multivariate data while controlling false alarm rate

    André Achim

    2012-06-01

    Full Text Available Outlier identification often implies inspecting each z-transformed variable and adding a Mahalanobis D^2. Multiple outliers may mask each other by increasing variance estimates. Caroni and Prescott (1992 proposed a multivariate extension of Rosner’s (1983 technique to circumvent masking, taking sample size into account to keep the false alarm risk below, say, alpha = .05. Simulations studies here compare the single multivariate approach to "multiple-univariate plus multivariate" tests, each at a Bonferroni corrected alpha level, in terms of power at detecting outliers. Results suggest the former is better only up to about 12 variables. Macros in an Excel spreadsheet implement these techniques.

  20. Changes are detected - cameras and video systems are monitoring the plant site, only rarely giving false alarm

    The main purpose of automatic data acquisition and processing for monitoring goals is to relieve the security personnel from monotonous observation tasks. The novel video systems can be programmed to detect moving target alarm signals, or accept alarm-suppressing image changes. This allows an intelligent alarm evaluation for physical protection in industry, differentiating between real and false alarm signals. (orig.)

  1. Concatenation of 'alert' and 'identity' segments in dingoes' alarm calls.

    Déaux, Eloïse C; Allen, Andrew P; Clarke, Jennifer A; Charrier, Isabelle

    2016-01-01

    Multicomponent signals can be formed by the uninterrupted concatenation of multiple call types. One such signal is found in dingoes, Canis familiaris dingo. This stereotyped, multicomponent 'bark-howl' vocalisation is formed by the concatenation of a noisy bark segment and a tonal howl segment. Both segments are structurally similar to bark and howl vocalisations produced independently in other contexts (e.g. intra- and inter-pack communication). Bark-howls are mainly uttered in response to human presence and were hypothesized to serve as alarm calls. We investigated the function of bark-howls and the respective roles of the bark and howl segments. We found that dingoes could discriminate between familiar and unfamiliar howl segments, after having only heard familiar howl vocalisations (i.e. different calls). We propose that howl segments could function as 'identity signals' and allow receivers to modulate their responses according to the caller's characteristics. The bark segment increased receivers' attention levels, providing support for earlier observational claims that barks have an 'alerting' function. Lastly, dingoes were more likely to display vigilance behaviours upon hearing bark-howl vocalisations, lending support to the alarm function hypothesis. Canid vocalisations, such as the dingo bark-howl, may provide a model system to investigate the selective pressures shaping complex communication systems. PMID:27460289

  2. A NEW INVENTION OF ALARM REMINDER LOCKING (ARL SECURITY SYSTEM

    M.S.M. Effendi

    2016-02-01

    Full Text Available Alarm Reminder Locking (ARL Security System mainly focuses on a door security system, which can install in the door area to increase the security level for home, office room, hostel or other places. This system used Arduino Controller and Global System for Mobile Communication (GSM technology, which is the cheapest source to embed the security system to transmit the Short Message Service (SMS alert data. This device integrates three functions that are alarming, reminder and locked for a purpose of safety and connecting via mobile phone to remind the users through SMS. This device has a 3 modes of operation which is the system will be functional when the door is not improperly closed for the first reminder with the buzzer alert. The second mode is automated locked will be activated when users closed the door, but did not lock manually. Intrusion mode will activate while auto locked modes are interrupted without proper access. All this integrated system will provide high security access against intrusion occurrence. This security device will bring a new benefit to the user to consider about the userfriendly application, low power consumption and reasonable cost to install.

  3. Pocket dosimeter with alarm 'REM-Master-S'

    The pocket dosimeters with alarm presently used in nuclear power stations, laboratories, hospitals and so on are mainly of GM counter type, and have such problems as short service life and large characteristic fluctuation. Fuji Electric developed a new type of the dosimeters with alarm ''REM MASTER-S'', which adopted semiconductor detectors and has such features as the measuring range is wider than conventional type, the service life is long, and the size is small and convenient to carry. It is provided with data transmitting and reading functions by opto-electronic communication method so that the exposure dose of individuals can be efficiently controlled. For the development of this new type of dosimeters, Fuji Electric used its technology and experience accumulated in the manufacture of radiation monitors for years. The specifications are as follows. Type: NRS, sensor: silicon semiconductor detector, type S 104S, kind of radiation: X-ray and gamma-ray from 100 keV to 3 MeV, energy dependence: within +-20% from 100 keV to Co-60 (1.3 MeV), integrated calibration accuracy: within +-10% at 100 mR/h with Cs-137 source, linearity of dosage ratio: within +-15% from 10 mR/h to 10 R/h with Cs-137 source, display: 4-digit digital indicator from 0 to 9999 mR, and so on. The application range is shown. (Kako, I.)

  4. Utilization of thermoluminescent dosemeters for determination of exposure or absorbed dose in a radiation gamma or X radiation field with unknown spectral distribution

    Having in view the choice of the best pair of dosemeters to be used in the 'Tandem' method, the main response characteristics of LiF:Mg, Ti, Li2B4O7:Mn, CaSO4Dy, CaF2:Mn and CaF2:Dy thermoluminescent dosemeters and also some critical parameters in their calibration and evaluation processes were studied. Three different physical forms of TLD's were investigated: hot pressed chips, disc teflon dosemeters and glass mini TLD's. Their calibration factors were obtained for the energy of Cobalt-60 gamma rays. Their energy dependences normalized to 60Co radiation were determined using spectral width as parameter. 'Tandens' formed by all TLD's evaluated were compaired. (E.G.)

  5. Effect of the energy dependence of response of neutron personal dosemeters routinely used in the UK on the accuracy of dose estimation

    Tanner, R J; Thomas, D J

    2002-01-01

    A large set of neutron energy distributions have been classified by workplace to provide a guide to the neutron fields to which workers in particular industries are likely to be exposed. These have been combined (folded) with the results of a major programme of neutron personal dosemeter response function measurements, to provide results for the systematic errors that those dosemeters would give in workplaces. Data for neutron doses recorded for UK classified workers have been taken from the CIDI tables, and related to the results from the folding process. It has hence been possible to draw conclusions about the probable systematic errors that result from the use of the currently available neutron personal dosemeters, which have inherent problems associated with their energy dependence of response.

  6. “Turn It Off!”: Diabetes Device Alarm Fatigue Considerations for the Present and the Future

    Shivers, Joseph P.; Mackowiak, Linda; Anhalt, Henry; Zisser, Howard

    2013-01-01

    Safe and widespread use of diabetes technology is constrained by alarm fatigue: when someone receives so many alarms that he or she becomes less likely to respond appropriately. Alarm fatigue and related usability issues deserve consideration at every stage of alarm system design, especially as new technologies expand the potential number and complexity of alarms. The guiding principle should be patient wellbeing, while taking into consideration the regulatory and liability issues that someti...

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

    Hoško, I.; Zečević, N.; Pavlaković, S.

    2012-01-01

    Every industrial production, particularly chemical processing, demands special attention in conducting the technological process with regard to the security requirements. For this reason, production processes should be continuously monitored by means of control and alarm safety instrumented systems. In the production of nitric acid at Petrokemija d. d., the original alarm safety system was designed as a combination of an electrical relay safety system and transistorized alarm module system. I...

  8. Intelligent alarms detection for the analysis of system fault impact on business

    Pace, C.; Russo, I; Fernández, V.; Britos, Paola Verónica; Rossi, Bibiana D.; García Martínez, Ramón

    1998-01-01

    The tools for fault impact analysis are important for the deployment of critical mission systems. These tools can be also used as a development phase aid. We introduce several concepts related to "business alarms". Business alarms are an approximation to the company's business conceptual scheme driven by the business rules from systems conceptual schemes. In order to specify them we propose the utilization of Knowledge Engineering typical techniques. The object of alarm detection for impa...

  9. A combined dosemeter for passive, long-term integration measurement of radon and its short-lived decay products in air

    Natural radiation exposure of man, and especially the radiation exposure of professionally exposed persons, is predominantly caused by radon (Rn), a gas occurring naturally, and its short-lived decay products (RnDPs). Compared to the short-lived RnDPs, the inhalative radiation load caused by the radon gas itself is smaller in general by more than one order of magnitude. Because of this, and because of the fact that it is not known how much time is spent by professionaly exposed persons and persons from the general population in their spheres of life respectively of work, the development of a personnel dosemeter permitting to establish directly the dose-determining content of RnDPs in air is pre-eminent in order to establish the real, individual radiation exposure of persons, BfS, in cooperation with ULS, has developed, calibrated and tested under different conditions a passive personnel/area dosemeter for combined determination of the RnDP content and Rn concentration in atmosphere. The concordance of the effective measuring times of the dosemeter with the real exposure times of the persons concerned safeguards representative measuring results. The main factor of uncertainty in establishing individual radiation loads on the basis of Rn measurements, the assumption of mean steady-state factors, is thus eliminated. The dosemeter stands out by its matchbox size, simple use, sufficient detection efficiency, and its good value for money. Applications of the dosemeter comprise both routine measurements of large, professionally exposed groups of persons, and measurements of individual persons in areas with increased or varying Rn/RnDP concentrations. The optimum exposure time of the dosemeter is three months. (orig.)

  10. Calibration of PADC-based neutron area dosemeters in the neutron field produced in the treatment room of a medical LINAC

    PADC-based nuclear track detectors have been widely used as convenient ambient dosemeters in many working places. However, due to the large energy dependence of their response in terms of ambient dose equivalent (H∗(10)) and to the diversity of workplace fields in terms of energy distribution, the appropriate calibration of these dosemeters is a delicate task. These are among the reasons why ISO has introduced the 12789 Series of Standards, where the simulated workplace neutron fields are introduced and their use to calibrate neutron dosemeters is recommended. This approach was applied in the present work to the UAB PADC-based nuclear track detectors. As a suitable workplace, the treatment room of a 15 MV Varian CLINAC DHX medical accelerator, located in the Ospedale S. Chiara (Pisa), was chosen. Here the neutron spectra in two points of tests (1.5 m and 2 m from the isocenter) were determined with the INFN-LNF Bonner Sphere Spectrometer equipped with Dysprosium activation foils (Dy-BSS), and the values of H∗(10) were derived on this basis. The PADC dosemeters were exposed in these points. Their workplace specific H*(10) responses were determined and compared with those previously obtained in different simulated workplace or reference (ISO 8529) neutron fields. - Highlights: ► The neutron field of a medical LINAC was used to calibrate PADC neutron dosemeters. ► The neutron spectra were derived with a Dy-foil based Bonner Sphere Spectrometer. ► Workplace specific calibration factor were derived for the PADC dosemeters. ► These factors were compared with those obtained in reference neutron fields

  11. Fiber-optic-coupled dosemeter for remote optical sensing of radiation

    Remote sensing technologies for the detection and measurement of ionizing radiation exposure are of current interest for applications such as patient dose verification during radiotherapy and the monitoring of environmental contaminants. Fiberoptic-based sensing is attractive due to the advantages of small size, low cost, long life and freedom from electromagnetic interference. Several fiberoptic-based radiation sensing systems have been described that utilize radiation induced changes in the optical characteristics of the fiber such as reduced transmission as a result of darkening of the glass, optical phase shifts due to heating, or changes in the birefringence of a polarization-maintaining fiber. The measurement of radiation induced darkening is limited in both sensitivity and dynamic range and requires long fiber lengths. Phase shift measurements require the use of single-mode lasers, phase sensitive interferometric detection, long fiber lengths and complex signal processing techniques. Alternatively, thermoluminescent (TL) phosphor powders have been coated onto fiberoptic cables and remote dosimetry measurements performed using traditional laser heating techniques. The sensitivity is limited by the requirement for a very thin layer of phosphor material, due to problems associated with light scattering and efficient heating by thermal diffusion. In this paper we report the development of an all-optical, fiber-optic-coupled, thermoluminescence dosemeter for remote radiation sensing that offers significant advantages compared to previous technologies. We recently reported the development of an optically transparent, TL glass material having exceptionally good characteristics for traditional dosimetry applications. We also reported a modified TL glass incorporating a rare earth ion dopant in order to absorb light from a semiconductor laser and utilize the absorbed light energy to internally heat the glass and release the trapped electrons. (author)

  12. Dosimetric studies of the eye lens using a new dosemeter – Surveys in interventional radiology departments

    During interventional radiology (IR) and cardiology (IC) procedures, medical staff can receive high doses to their eye lenses. The Retrospective Evaluation of Lens Injuries and Dose study organized in Argentina in 2010 found incipient opacity in 50% of IC physicians and 41% of IC technicians/nurses. These results, added to the recommendations of the International Commission on Radiological Protection, which lowered their former occupational equivalent dose limit for the lens, led us to assess the eye lens dose, Hp(3), during interventional procedures. To this end, a new dosemeter was designed and calibrated at the National Atomic Energy Commission of Argentina to evaluate Hp(3). Personal dose equivalent (Hp(10)), and Hp(3) were assessed for 3 months in two IC and IR departments. An Alderson phantom was used to simulate monthly exposures of five occupational staff members. Hp(3) and Hp(10) were obtained monthly for 14 occupational staff members exposed to 121 IR and IC procedures. We concluded that the annual effective dose and Hp(3) were lower than 0.3 and 10 mSv, respectively and the average cumulative Hp(3) for working life was lower than 400 and 200 mSv for physicians and technicians/scrub nurse, respectively. An occupational annual dose constraint of 0.3 mSv was calculated. - Highlights: • An eye lens dosimeters was designed at the Personal Dosimetry Laboratory of CNEA. • A successful dosimetric survey in two interventional departments was done. • The annual effective dose and the annual eye lens dose are lower than the ICRP dose thresholds. • In order to reduce doses actions should be promoted to maximize radiation protection

  13. Obtention of thermoluminescent efficiencies by means of irradiation of TLD-100 dosemeters with proton beams helium and carbon

    In this work, the advances of a serial of measurements of relative efficiency thermoluminescent of heavy charged particles (PCP) with respect to gamma radiation for TLD-100, dosemeters of LiF: Mg,Ti manufactured by the Harshaw-Bicron company are reported. The PCP are essentials in the implementation of dosimetry associated with medical applications. The measurements before gamma radiation were carrying out using the Vickrad irradiator of the National Institute of Nuclear Research at dose of 1.663 Gy. The measures which are reported about protons, helium and carbon were realized using the Pelletron accelerator of the Physics Institute of the UNAM. (Author)

  14. Determination of kinetic parameters in Tl dosemeters of LiF: Mg, Cu, P + PTFE developed in the ININ

    The objective of this work, is the one of determining the kinetic parameters of the dosemeter of LiF: Mg, Cu, P + Ptfe; starting from the curves Tl obtained at being irradiated with alpha radiation (α), beta (β) and gamma (γ). As like to compare its sensitivity with each radiation type, considering the sensitivity of the TLD-100 as the unit. In the Chapter 1, the fundamental structure of the matter is described, making emphasis in the different radiation types, and their interaction with this. In the Chapter 2, the units are described but used in the dosimetry of the radiation. In the Chapter 3, the basic concepts of the phenomenon of Tl are described and those are explained characteristic of the deconvolution method to determine the kinetics of the one phenomenon. In the Chapter 4, the methodology is detailed that was used in the elaboration of this thesis work, describing the material Tl that were considered like reference, as well as the sources of ionizing radiation, with those that the dosemeters were irradiated and the equipment in the one that the curves Tl was obtained. Reference is made to the software used to carry out the deconvolution of the curves Tl that were obtained in the one experimental development. In the Chapter 5, the obtained results of this study are presented, showing the tables of homogenization of dosemeters and the reading of the same one; they are observed the curves Tl obtained to different radiation doses (alpha, beta and gamma), the intensity Tl in function of the dose. Also they are tabulated, the obtained results in the kinetic parameters of the three different study materials (TLD-100H, USA; TLD-100, USA and LiF: Mg, Cu, P + Ptfe developed in the l.N.l.N). They are analyzed shortly for each material Tl their sensitivity to the ionizing radiation as well as their kinetic parameters. The obtained results showed that the Tl dosemeters of LiF: Mg,Cu,P + Ptfe, they presented a bigger sensitivity that the TLD-100 when being

  15. Development of quality assurance procedures for thermoluminescent CaSO4:Dy-teflon skived tape dosemeter

    CaSO4:Dy-Teflon TLD dosemeter material has been manufactured locally in a 0.4 mm thick continuous tape form. Fourteen batches have been examined for physical thickness, density, spectral transmission, diffuse optical density, beta transmission and TL output per unit area for evolving a procedure for quality assurance of the TLD element for large scale production. With the exception of two batches, the TL output per unit area of the tape for a number of batches lies within ±7% of that for a standard batch. (author)

  16. A Smart Cyber-physical Alarm System and its Application for Assisted Living

    Zhe-Ming Lu

    2013-01-01

    Full Text Available Security issues are increasingly obvious. An automated real-time online alarm system to ensure the safety of property and personality while considering numerous smart Terminal Equipments (TE becomes a major challenge. At the same time, this is representative of novel and emerging alarm system for assisted living in the daily life. Two problems of current alarm system are identified. A smart Cyber-Physical Alarm System (CPAS based approach is proposed to address these problems. A prototype system installed in a house to assist living has been running stably and shows quite promising performance.

  17. Accident alarm equipment for steam generator, especially liquid sodium heated steam generator

    The alarm equipment consists of a system of sensors mounted onto the steam generator and its accessories. Each of the sensors is used for a different accident characteristic, such as the flow of sodium, the acoustic spectrum, the concentration of hydrogen in sodium. The system of sensors is connected to the common accident alarm system. The equipment will not issue the alarm signal if it receives a message from only one sensor, only when the message is confirmed from other sensors. This excludes false alarm. (M.D.)

  18. Advanced alarm system design and human performance: Guidance development and current research

    This paper describes a research program sponsored by the U.S. Nuclear Regulatory Commission to address the human factors engineering (HFE) aspects of nuclear power plant alarm systems. The overall objective of the program is to develop HFE review guidance for advanced alarm systems. Guidance has been developed based on a broad base of technical and research literature. As part of the development effort, aspects of alarm system design for which the technical basis was insufficient to support guidance development were identified and prioritized. Research is currently underway to address the highest priority topics: alarm processing and display characteristics. (author). 29 refs, 2 figs

  19. Development of semiconductor radiation sensors for portable alarm-dosimeter

    Kim, Y. K.; Moon, B. S.; Chung, C. E.; Hong, S. B.; Kim, J. Y.; Kim, J. B.; Han, S. H.; Lee, W. G. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-01-01

    We studied Semiconductor Radiation Sensors for Portable Alarm-Dosimeter. We calculated response functions for gamma energy 0.021, 0.122, 0.662, 0.835, 1.2 MeV using EGS4 codes. When we measured at various distance from source to detector, the detection efficiency of Si semiconductor detector was better than that of GM tube. The linear absorption coefficients of steel and aluminum plate were measured. These experimental results of the response of detector for intensity of radiation field coincide to the theoretical expectation. The count value of Si detector was changed with changing thickness of steel as changing threshold voltage of discriminator, and the linear absorption coefficient increased with increasing threshold voltage. Radiation detection efficiency shows difference at each threshold voltage condition. This results coincided to the theoretical simulation. 33 refs., 27 figs., 8 tabs. (Author)

  20. False alarm recognition in hyperspectral gas plume identification

    Conger, James L. (San Ramon, CA); Lawson, Janice K. (Tracy, CA); Aimonetti, William D. (Livermore, CA)

    2011-03-29

    According to one embodiment, a method for analyzing hyperspectral data includes collecting first hyperspectral data of a scene using a hyperspectral imager during a no-gas period and analyzing the first hyperspectral data using one or more gas plume detection logics. The gas plume detection logic is executed using a low detection threshold, and detects each occurrence of an observed hyperspectral signature. The method also includes generating a histogram for all occurrences of each observed hyperspectral signature which is detected using the gas plume detection logic, and determining a probability of false alarm (PFA) for all occurrences of each observed hyperspectral signature based on the histogram. Possibly at some other time, the method includes collecting second hyperspectral data, and analyzing the second hyperspectral data using the one or more gas plume detection logics and the PFA to determine if any gas is present. Other systems and methods are also included.