Utilization of GSM Module (Sim 900 Based Arduino-Uno for Alarm System and Remote Automatic Door Locking

Directory of Open Access Journals (Sweden)

Fauzi Fauzi

2018-01-01

Full Text Available Sebuah sistem alarm dan pengunci pintu otomatis jarak jauh untuk keamanan rumah telah dibuat. Otomatisasi kunci pintu rumah ini beroperasi dengan menggunakan perintah yang dikirimkan oleh pemilik rumah melalui pesan singkat melalui handphone sehingga keamanan rumah akan tetap dapat dikendalikan meski dari jarak yang jauh. Penelitian ini bertujuan untuk membangun otomatisasi rumah pintar yang mampu melakukan dua hal yakni mengunci pintu dan menyalakan alarm dengan menggunakan mikrokontroler Arduino-uno dan modul GSM. Pengontrolan secara otomatis tersebut cukup kompleks dan memerlukan berbagai komponen yang terintegrasi dengan kemampuan pembacaan masukan, pemrosesan data dan pengontrolan keluaran secara bersamaan dan terprogram.  A remote door automatic alarm and door lock system for home security has been designed. This home door lock automation operates using commands sent by homeowners via short messages from handphone so that home security will remain controllable even from a long distance. This study aims to build smart home automation that can do two things: lock the door and turn on the alarm by using Arduino-uno microcontroller and GSM module. The automatic control is quite complex and requires a variety of integrated components with the ability to read input, data processing and control the output simultaneously and programmed.   Keywords: Arduino, GSM, Automatic Doors, SMS Rerefences Depari, G.S. (1985. Belajar Teori dan Keterampilan Elektronika. Bandung: Armico Daryanto, 2005. Pengetahuan Teknik Elektronika. Erlangga. Jakarta. Session, Kendall Webster, 2003. 1001 Rangkaian Elektronika. PT. Elek Media Komputindo Kelompok Gramedia, Jakarta. Sustrisno, 1986, Elektronika Teori dan penerapanya. Penerbit ITB, Bandung

Locations of criticality alarms and nuclear accident dosimeters at Hanford

International Nuclear Information System (INIS)

1992-08-01

Hanford facilities that contain fissionable materials capable of achieving critical mass are monitored with nuclear accident dosimeters (NADS) in compliance with the requirements of DOE Order 5480.11, Chapter XI, Section 4.c. (DOE 1988). The US Department of Energy (DOE) Richland Field Office (RL) has assigned the responsibility for maintaining and evaluating the Hanford NAD system to the Instrumentation and External Dosimetry (I ampersand ED) Section of Pacific Northwest Laboratory's (PNL's) Health Physics Department. This manual provides a description of the Hanford NAD, criteria and instructions for proper NAD placement, and the locations of these dosimeters onsite

Alarms, Chemical

Science.gov (United States)

cited in applicable qualitative materiel requirements, small development requirements, technical characteristics, and other requirements and documentation that pertain to automatic chemical agent alarms.

A Knowledge-Based Approach to Automatic Detection of Equipment Alarm Sounds in a Neonatal Intensive Care Unit Environment.

Science.gov (United States)

Raboshchuk, Ganna; Nadeu, Climent; Jancovic, Peter; Lilja, Alex Peiro; Kokuer, Munevver; Munoz Mahamud, Blanca; Riverola De Veciana, Ana

2018-01-01

A large number of alarm sounds triggered by biomedical equipment occur frequently in the noisy environment of a neonatal intensive care unit (NICU) and play a key role in providing healthcare. In this paper, our work on the development of an automatic system for detection of acoustic alarms in that difficult environment is presented. Such automatic detection system is needed for the investigation of how a preterm infant reacts to auditory stimuli of the NICU environment and for an improved real-time patient monitoring. The approach presented in this paper consists of using the available knowledge about each alarm class in the design of the detection system. The information about the frequency structure is used in the feature extraction stage, and the time structure knowledge is incorporated at the post-processing stage. Several alternative methods are compared for feature extraction, modeling, and post-processing. The detection performance is evaluated with real data recorded in the NICU of the hospital, and by using both frame-level and period-level metrics. The experimental results show that the inclusion of both spectral and temporal information allows to improve the baseline detection performance by more than 60%.

Operation of Personal Electronic Dosimeters at NRCN

International Nuclear Information System (INIS)

Weinstein, M.; Abraham, A.; Tshuva, A.; German, U.

2004-01-01

In the recent years, electronic personal dosimeters (EPD's) are increasingly being used at NRCN, replacing the old direct reading dosimeters that are still widely used. The most significant advantage of the new dosimeters is the real time alarm in a radiation field exceeding a pre-determined threshold. The EPD dosimeters are more precise and can measure γ, β and x rays of a wide range of energies. In addition, the electronic dosimeters collects and stores the reading at a fixed pattern (every 10 seconds) and keeps the data until it is downloaded from the dosimeter. This feature gives the ability to build a personal time-dependent exposure report for each worker who carries this device and to analyze, identify and measure the exact dose, time and duration of any exposure event he was involved in. Designing and building a personal electronic dosimeter became possible as a result of the massive technological improvements of semi conductor detectors and the minimization processes of microprocessors and low energy electronic devices. The main purpose for personal electronic dosimeters was to monitor on-line doses for radiation workers.A special reader device enables to download data and upload operational settings of the dosimeters. By means of this communication channel, one can save the data acquired by the dosimeter, clear the dosimeter memory and set the dosimeter operational parameters. There are two possible working patterns. The first is to read and set all the dosimeters at a central point, normally a dosimetry laboratory (single reader) and the second and more expensive one, is to build a network of readers covering the plant for obtaining on-line communication

Electronic personal dosimeter heralds a revolution in legal dosimetry

International Nuclear Information System (INIS)

Fletcher, R.

1991-01-01

The Electronic Personal Dosimeter (EPD) developed by Siemens Plessey Controls and the UK's national Radiological Protection Board is approaching the pre-production stage. It provides ''legal'' dosimetry and all the features of a personal alarming dosimeter. The EPD uses solid state semiconductor detectors for gamma and beta radiation and has a dose threshold of about 1μ Sv, with a low energy gamma range down to 20 KeV. It has a multi function liquid crystal display for instant readout and audible and visual alarms. Two separates dose stores are maintained. Short term dose for tactical management and long term dose for approved dosimetry service record keeping. The latter can be reset only by an approved dosimetry service and is maintained on a search memory disk which can be read even if the EPD is destroyed. (UK)

A pocket warning γ-dosimeter with numerical display

International Nuclear Information System (INIS)

Jones, A.R.

1980-09-01

A pocket warning dosimeter is described. It provides alarms (continuous tone and a flashing red light) when a presettable dose has been accumulated in the range .064 - 16.4 rads (0.64 - 164 μGy). This warning level can be selected in nine steps of 2 with a switch inside the dosimeter. The dose rate is indicated by a series of sound pulses whose repetition rate is proportional to the dose rate. At 1 rad/h (10 mGy/h) about 17 pluses/minute are emitted. The accumulated dose up to 20 rads (0.2 Gy) is displayed in steps of 1 mrad (10 μGy) with a liquid crystal display. A red LED lights before battery failure occurs. The effects of changes in temperature, battery voltage, dose rate and photon energy upon dosimeter sensitivity are presented. Finally, the applications of the dosimeter are discussed. (auth)

Display-And-Alarm Circuit For Accelerometer

Science.gov (United States)

Bozeman, Richard J., Jr.

1995-01-01

Compact accelerometer assembly consists of commercial accelerometer retrofit with display-and-alarm circuit. Provides simple means for technician attending machine to monitor vibrations. Also simpifies automatic safety shutdown by providing local alarm or shutdown signal when vibration exceeds preset level.

AN AUTOMATIC CAR ANTI-THEFT ALARM SYSTEM

OpenAIRE

J. A. Enokela; E.J. Ibanga

2007-01-01

The theft of cars and other automobiles by criminals has become so frequent in our society as to be classified as alarming. Most of the thefts are organized by gangs of robbers but sometimes individuals engage in this activity. The result usually, however, is that the persons from whom the vehicles have been stolen are left to grieve as many of these vehicles are never recovered. This paper describes a simple alarm system that can be easily installed in all kinds of vehicles. The system desc...

New Neutron Dosimeter

CERN Multimedia

2001-01-01

CERN has been operating an Individual Dosimetry Service for neutrons for about 35 years. The service was based on nuclear emulsions in the form of film packages which were developed and scanned in the Service. In 1999, the supplier of theses packages informed CERN that they will discontinue production of this material. TIS-RP decided to look for an external service provider for individual neutron dosimetry. After an extensive market survey and an invitation for tender, a supplier that met the stringent technical requirements set up by CERN's host states for personal dosimeters was identified. The new dosimeter is based on a track-etching technique. Neutrons have the capability of damaging plastic material. The microscopic damage centres are revealed by etching them in a strong acid. The resulting etch pits can be automatically counted and their density is proportional to dose equivalent from neutrons. On the technical side, the new dosimeter provides an improved independence of its response from energy and th...

Experimental evaluation of human-system interaction on alarm design

International Nuclear Information System (INIS)

Huang, F.-H.; Lee, Y.-L.; Hwang, S.-L.; Yenn, T.-C.; Yu, Y.-C.; Hsu, C.-C.; Huang, H.-W.

2007-01-01

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

Thermoluminescence dosimeter reader

International Nuclear Information System (INIS)

Robertson, M.E.A.; Marshall, J.; Brabants, J.A.P.; Davies, M.E.

1975-01-01

An electric circuit arrangement is described including a photomultiplier tube and a high voltage source therefor also includes a feedback loop from the output of the tube to the high voltage source, and loop providing automatic gain stabilization for the tube. The arrangement is used in a dosimeter reader to provide sensitivity correction for the reader each time the reader is to be used

Direct reading dosimeter

International Nuclear Information System (INIS)

Thomson, I.

1985-01-01

This invention is a direct reading dosimeter which is light, small enough to be worn on a person, and measures both dose rates and total dose. It is based on a semiconductor sensor. The gate threshold voltage change rather than absolute value is measured and displayed as a direct reading of the dose rate. This is effected by continuously switching the gate of an MOS transistor from positive to negative bias. The output can directly drive a digital readout or trigger an audible alarm. The sensor device can be a MOSFET, bipolar transistor, or MOSFET capacitor which has its electrical characteristics change due to the trapped charge in the insulating layer of the device

Environmental radiation monitoring of nuclear sites by thermoluminescent dosimeters (TLD)

International Nuclear Information System (INIS)

Duftschmid, K.E.; Strachotinsky, Ch.

1978-04-01

The measurement of environmental radiation doses around nuclear facilities requires the detection of few mrem/year. The properties of the automatic TLD-system Harshaw Mod. 2271 for such measurements have been evaluated under practical conditions and optimized techniques derived. The automatic TLD-system is based on LiF dosimeter cards with two crystals providing gamma and beta dose values. Limit of detection defined as three standard deviations of residuel dose is 1,2 mR. Automatic readout combined with electronic data evaluation are especially useful for large monitoring networks. Practical intercomparisons of this dosimeter with bulb-type CaF 2 detectors have been performed showing good agreement of both detector. Although bulb-dosimeters proved to be extremely sensitive with a limit of detection at 0,012 mR which makes them very suitable for very short exposure times, the automatic LiF system is superior in regards of man power requirement if monthly monitoring periods are sufficient. The system has been tested in practice during two international intercomparisons performed by the US Department of Energy - Health and Safety Laboratory New York and the Physikalisch Technische Bundesanstalt Braunschweig, Germany, showing excellent agreement. Furthermore a routine monitoring network consisting of 12 measurement positions around the Research Center Seibersdorf has been operated with this technique since more than two years. (author)

Distributed optical fiber temperature sensor (DOFTS) system applied to automatic temperature alarm of coal mine and tunnel

Science.gov (United States)

Zhang, Zaixuan; Wang, Kequan; Kim, Insoo S.; Wang, Jianfeng; Feng, Haiqi; Guo, Ning; Yu, Xiangdong; Zhou, Bangquan; Wu, Xiaobiao; Kim, Yohee

2000-05-01

The DOFTS system that has applied to temperature automatically alarm system of coal mine and tunnel has been researched. It is a real-time, on line and multi-point measurement system. The wavelength of LD is 1550 nm, on the 6 km optical fiber, 3000 points temperature signal is sampled and the spatial position is certain. Temperature measured region: -50 degree(s)C--100 degree(s)C; measured uncertain value: +/- 3 degree(s)C; temperature resolution: 0.1 degree(s)C; spatial resolution: test, test content and practical test results have been discussed.

The NRPB's new dosimeter and dose record keeping services

International Nuclear Information System (INIS)

Dennis, J.A.; Marshall, T.O.; Shaw, K.B.

1976-01-01

A new automated dosimeter and record keeping service which the National Radiological Protection Board (UK) intends to introduce in 1977 is described. The automated system, based on a thermoluminescent dosimeter, will be linked to a fully computerised record keeping system with automatic printing of dose records and Transfer Records operated at its Headquarters at Harwell. The new system will dispense with much manual labour which in the past has introduced inevitable errors and incurred increasing costs. (U.K.)

A design of ambient dose equivalent dosimeter and its dosimetric performance

International Nuclear Information System (INIS)

Zhao Shian; Ou Xiangming; Li Kaibao

1997-01-01

Objective: To design an ambient dose equivalent dosimeter with digital display for radiation protection, which is based on the definition of the new operational radiation quantity for environmental monitoring-ambient dose equivalent recommended by the International Commission on Radiation Units and Measurements (ICRU) Report 39. Methods: Considering the energy response of the instrument, the inner wall of ionizing chamber is coated with gum graphite added with a bit of metal powder. Results: Using this chamber, measurement of H * (10) for photon radiation with unknown spectrum distribution is possible in the energy range from 47 keV to 230 keV with an uncertainty of better than 5%. The configuration, technology and dosimetric performance of the chamber and automatic functions of the reader are presented. Conclusion: The ambient dose equivalent dosimeter can be used as not only a working reference dosimeter, but also a field dosimeter for radiation protection because the readings are expressed directly in ambient dose equivalent and averaged automatically in the period of measurement. Also, its power is supplied by battery for the portable purpose and the readings are displayed on the screen with light-background for dim field

Automated dose estimation for lost or damaged dosimeters

International Nuclear Information System (INIS)

Thompson, W.L.; Deininger, R.J.

1988-01-01

This paper reports that some dosimetry vendors will compute doses for their customers' lost/damaged dosimeters based upon an average of recent dosimeter readings. However, the vendors usually require authorization from the customer for each such occurrence. Therefore, the tedious task of keeping track of the overdue status of each missing dosimeter and constantly notifying the vendor is still present. Also, depending on the monthly variability of a given person's doses, it may be more valid to use the employee's average dose, his/her highest dose over a recent period, an average dose of other employees with similar job duties for that period, or the maximum permissible dose. Thus, the task of estimating doses for lost/damaged dosimeters cannot be delegated to dosimetry vendor. Instead, the radiation safety department must sue the data supplied by the vendor as input for performing estimates. The process is performed automatically at the Medical Center Hospital of Vermont using a personal computer and a relational database

Alarm handler for the advanced photon source control system

International Nuclear Information System (INIS)

Kraimer, M.R.; Cha, B.K.; Anderson, M.

1991-01-01

The Advanced Photon Source (APS), now under construction at Argonne National Laboratory, will have a control system employing graphics workstations at the operator interface level and VME-based microprocessors operating with a distributed database at the field level. The alarm handler is an application utilizing X-Windows running on one or more operator interface workstations which monitors alarms generated by the VME-based microprocessors. Alarms can be grouped in a hierarchical manner. The operator can monitor, acknowledge, and mask alarms either individually or aggregately. Alarm changes of state and all operator modifications are logged. When alarms occur, display windows are automatically generated conveying system and subsystem relationships and severity. Menus are used to modify the alarm action configuration files and to obtain help. Since alarm groups are defined via an alarm configuration file, the alarm handler is a general purpose application which can be customized to monitor a single subsystem or configured to monitor the entire accelerator complex. 2 refs., 2 figs

Automatically Identifying and Predicting Unplanned Wind Turbine Stoppages Using SCADA and Alarms System Data: Case Study and Results

Science.gov (United States)

Leahy, Kevin; Gallagher, Colm; Bruton, Ken; O'Donovan, Peter; O'Sullivan, Dominic T. J.

2017-11-01

Using 10-minute wind turbine SCADA data for fault prediction offers an attractive way of gaining additional prognostic capabilities without needing to invest in extra hardware. To use these data-driven methods effectively, the historical SCADA data must be labelled with the periods when the turbine was in faulty operation as well the sub-system the fault was attributed to. Manually identifying faults using maintenance logs can be effective, but is also highly time consuming and tedious due to the disparate nature of these logs across manufacturers, operators and even individual maintenance events. Turbine alarm systems can help to identify these periods, but the sheer volume of alarms and false positives generated makes analysing them on an individual basis ineffective. In this work, we present a new method for automatically identifying historical stoppages on the turbine using SCADA and alarms data. Each stoppage is associated with either a fault in one of the turbine’s sub-systems, a routine maintenance activity, a grid-related event or a number of other categories. This is then checked against maintenance logs for accuracy and the labelled data fed into a classifier for predicting when these stoppages will occur. Results show that the automated labelling process correctly identifies each type of stoppage, and can be effectively used for SCADA-based prediction of turbine faults.

Plastic dosimeter

International Nuclear Information System (INIS)

Nagai, Shiro; Matsuda, Kohji.

1988-01-01

The report outlines major features and applications of plastic dosimeters. Some plastic dosimeters, including the CTA and PVC types, detect the response of the plastic material itself to radiations while others, such as pigment-added plastic dosimeters, contain additives as radiation detecting material. Most of these dosimeters make use of color centers produced in the dosimeter by radiations. The PMMA dosimeter is widely used in the field of radiation sterilization of food, feed and medical apparatus. The blue cellophane dosimeter is easy to handle if calibrated appropriately. The rad-color dosimeter serves to determine whether products have been irradiated appropriately. The CTA dosimeter has better damp proofing properties than the blue cellophane type. The pigment-added plastic dosimeter consists of a resin such as nylon, CTA or PVC that contains a dye. Some other plastic dosimeters are also described briefly. Though having many advantages, these plastic dosimeter have disadvantages as well. Some of their major disadvantages, including fading as well as large dependence on dose, temperature, humidity and anviroment, are discussed. (Nogami, K.)

Medical extrapolation chamber dosimeter model XW6012A

International Nuclear Information System (INIS)

Jin Tao; Wang Mi; Wu Jinzheng; Guo Qi

1992-01-01

An extrapolation chamber dosimeter has been developed for clinical dosimetry of electron beams and X-rays from medical linear accelerators. It consists of a new type extrapolation chamber, a water phantom and an intelligent portable instrument. With a thin entrance window and a φ20 mm collecting electrode made of polystyrene, the electrode spacing can be varied from 0.2 to 6 mm. The dosimeter can accomplish dose measurement automatically, and has functions of error self-diagnosis and dose self-recording. The energy range applicable is 0.5-20 MeV, and the dose-rate range 0.02-40 Gy/min. The total uncertainty is 2.7%

Alarm Fatigue vs User Expectations Regarding Context-Aware Alarm Handling in Hospital Environments Using CallMeSmart.

Science.gov (United States)

Solvoll, Terje; Arntsen, Harald; Hartvigsen, Gunnar

2017-01-01

Surveys and research show that mobile communication systems in hospital settings are old and cause frequent interruptions. In the quest to remedy this, an Android based communication system called CallMeSmart tries to encapsulate most of the frequent communication into one hand held device focusing on reducing interruptions and at the same time make the workday easier for healthcare workers. The objective of CallMeSmart is to use context-awareness techniques to automatically monitor the availability of physicians' and nurses', and use this information to prevent or route phone calls, text messages, pages and alarms that would otherwise compromise patient care. In this paper, we present the results from interviewing nurses on alarm fatigue and their expectations regarding context-aware alarm handling using CallMeSmart.

Automatic diagnosis of multiple alarms for reactor-control rooms

International Nuclear Information System (INIS)

Gimmy, K.L.; Nomm, E.

1981-01-01

A system has been developed at the Savannah River Plant to help reactor operators respond to multiple alarms in a developing incident situation. The need for such systems has become evident in recent years, particularly after the three Mile Island incident

Proposal for the award of a blanket purchase contract for the design, supply, installation and maintenance of automatic fire-detection, fire-protection and voice-alarm systems for the Super Proton Synchrotron

CERN Document Server

2017-01-01

Proposal for the award of a blanket purchase contract for the design, supply, installation and maintenance of automatic fire-detection, fire-protection and voice-alarm systems for the Super Proton Synchrotron

A study of reset mode in advanced alarm system simulator

International Nuclear Information System (INIS)

Yenn, T. C.; Hwang, S. L.; Huang, F. H.; Yu, A. C.; Hsu, C. C.; Huang, H. W.

2006-01-01

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)

Expert systems and microwave communication systems alarms processing: A feasibility study

Energy Technology Data Exchange (ETDEWEB)

Tonn, B.; Goeltz, R.; Purucker, S.

1987-07-01

This report presents the results of a feasibility study conducted by Oak Ridge National Laboratory (ORNL) for the Bonneville Power Administration concerning the applicability of Artificial Intelligence (AI) technology to process alarms associated with Bonneville's Microwave Communication System (MCS). Specifically, the discussion focuses on the characteristics of a prototype expert system/database management system (DBMS) configuration capable of intelligently processing alarms, efficiently storing alarm-based historical data, and providing analysis and reporting tools. Such a system has the potential to improve response to critical alarms, increase the information content of a large volume of complicated data, free operators from performing routine analysis, and provide alarm information to operators, field personnel, and management through queries and automatically produced reports.

Pen dosimeters

CERN Multimedia

SC/RP Group

2006-01-01

The Radiation Protection Group has decided to withdraw all pen dosimeters from the main PS and SPS access points. This will be effective as of January 2006. The following changes will be implemented: All persons working in a limited-stay controlled radiation area must wear an operational dosimeter in addition to their personal DIS dosimeter. Any persons not equipped with this additional dosimeter must contact the SC/RP Group, which will make this type of dosimeter available for temporary loan. A notice giving the phone numbers of the SC/RP Group members to contact will be displayed at the former distribution points for the pen dosimeters. Thank you for your cooperation. The SC/RP Group

The alarm system of the SAPHIR detector

International Nuclear Information System (INIS)

Schultz-Coulon, H.C.

1993-06-01

In order to obtain an effective control of the different detector components an alarm system was built and implemented into the data acquisition system of the SAPHIR experiment. It provides an easy way of indicating errors by either adequate library calls or an appropriate hardware signal, both leading to an active alarm. This allows to react directly to any error detected by one of the specific control systems. In addition for selected kinds of errors the data run can be stopped automatically. Concept and construction of this system are described and some examples for its application are given. (orig.)

Changes are detected - cameras and video systems are monitoring the plant site, only rarely giving false alarm

International Nuclear Information System (INIS)

Zeissler, H.

1988-01-01

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.) [de

Composite material dosimeters

Science.gov (United States)

Miller, Steven D.

1996-01-01

The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

Development of portable ESR spectrometer as a reader for alanine dosimeters

International Nuclear Information System (INIS)

Kojima, T.; Haruyama, Y.; Tachibana, H.; Tanaka, R.; Okamoto, J.

1993-01-01

A prototype portable electron spin resonance (ESR) spectrometer was designed and tested, and its feasibility as a reader of alanine dosimeters was studied from the two standpoints of reproducibility of readings and sensitivity sufficient for dosimetry in the absorbed dose range 1-100 kGy. It has two main components: a permanent magnet and resonator; and a unit box with a microwave and auto-frequency control (AFC) circuit, a sweep controller of magnetic field, display, etc. In the present preliminary study, reproducibility values are measured with the same ESR parameters and alanine-polystyrene (alanine-PS) dosimeter at a dose of 1 kGy: repeatedly measuring without removing dosimeter from the cavity; individual measurement with removing and inserting again into the cavity with readjustment of ESR parameters. Alanine/ESR dosimetry using this spectrometer has a measurable dose range from 1 to 100 kGy with relatively high precision within ± 3% (1σ) as a preliminary result. The portable ESR spectrometer may also be modified as an automatic, more precise, dedicated alanine dosimeter reader. (author)

Radiation dosimeter

International Nuclear Information System (INIS)

Lowe, D.

1980-01-01

A radiation dosimeter is described, comprising a thermoluminescent phosphor incorporated in matrix of polyethersulphone. The dosimeter is preferably a thin film formed by spreading a suspension of a powdered phosphor in a solution of polyethersulphone onto a flat surface. The solvent for the polyethersulphone is a mixture of a n-methyl-2-pyrrolidone and xylene in equal proportions. A thin, inert film of polyethersulphone can be cemented to one surface of the dosimeter so as to provide a skin dosimeter. (author)

Dosimeter charging apparatus

International Nuclear Information System (INIS)

Reuter, F.A.; Moorman, Ch.J.

1985-01-01

An apparatus for charging a dosimeter which has a capacitor connected between first and second electrodes and a movable electrode in a chamber electrically connected to the first electrode. The movable electrode deflects varying amounts depending upon the charge present on said capacitor. The charger apparatus includes first and second charger electrodes couplable to the first and second dosimeter electrodes. To charge the dosimeter, it is urged downwardly into a charging socket on the charger apparatus. The second dosimeter electrode, which is the dosimeter housing, is electrically coupled to the second charger electrode through a conductive ring which is urged upwardly by a spring. As the dosimeter is urged into the socket, the ring moves downwardly, in contact with the second charger electrode. As the dosimeter is further urged downwardly, the first dosimeter electrode and first charger electrode contact one another, and an insulator post carrying the first and second charger electrodes is urged downwardly. Downward movement of the post effects the application of a charging potential between the first and second charger electrodes. After the charging potential has been applied, the dosimeter is moved further into the charging socket against the force of a relatively heavy biasing spring until the dosimeter reaches a mechanical stop in the charging socket

Automated Information System (AIS) Alarm System

International Nuclear Information System (INIS)

Hunteman, W.

1997-01-01

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

Automated Information System (AIS) Alarm System

Energy Technology Data Exchange (ETDEWEB)

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.

Assessment of Siemens plessey electronic personal dosimeter

International Nuclear Information System (INIS)

Hirning, C.R.; Lopez, S.; Yuen, P.S.

1994-01-01

This report presents the results of a laboratory assessment of the performance of a new type of personal dosimeter. The Electronic Personal Dosimeter, or EPD, was developed jointly by the National Radiological Protection Board and Siemens Plessey Controls Limited, both of the United Kingdom. Twenty pre-production units of the EPD and a reader were purchased by Ontario Hydro for the assessment. The tests were conducted jointly by Ontario Hydro's Health and Safety Division and AECL Research's Chalk River Laboratories (CRL), with funding from the Candu Owner's Group. A total of 26 tests were conducted, divided between Ontario Hydro and AECL. The test results were compared with the relevant requirements of three standards. In general, the performance of the EPD was found to be quite acceptable. It met most of the relevant requirements of the three standards and most of the design specifications. However, the following deficiencies were found: slow response time; sensitivity to high-frequency EMF; poor resistance to dropping; and an alarm that is not loud enough. In addition, the response of the EPD to low-energy beta rays may be too low for some applications. There were serious problems with the reliability of operation of the pre production EPDs used in these tests. 9 refs., 34 tabs., 20 figs

Assessment of Siemens plessey electronic personal dosimeter

Energy Technology Data Exchange (ETDEWEB)

Hirning, C R; Lopez, S [Ontario Hydro, Toronto, ON (Canada); Yuen, P S [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

1994-01-01

This report presents the results of a laboratory assessment of the performance of a new type of personal dosimeter. The Electronic Personal Dosimeter, or EPD, was developed jointly by the National Radiological Protection Board and Siemens Plessey Controls Limited, both of the United Kingdom. Twenty pre-production units of the EPD and a reader were purchased by Ontario Hydro for the assessment. The tests were conducted jointly by Ontario Hydro`s Health and Safety Division and AECL Research`s Chalk River Laboratories (CRL), with funding from the Candu Owner`s Group. A total of 26 tests were conducted, divided between Ontario Hydro and AECL. The test results were compared with the relevant requirements of three standards. In general, the performance of the EPD was found to be quite acceptable. It met most of the relevant requirements of the three standards and most of the design specifications. However, the following deficiencies were found: slow response time; sensitivity to high-frequency EMF; poor resistance to dropping; and an alarm that is not loud enough. In addition, the response of the EPD to low-energy beta rays may be too low for some applications. There were serious problems with the reliability of operation of the pre production EPDs used in these tests. 9 refs., 34 tabs., 20 figs.

Daily management of individual dosimetry at Bugey nuclear plant

International Nuclear Information System (INIS)

Chassagnette, R.

1981-01-01

The regulatory film-dosimeter is not sufficient to monitor workers' exposure in a radiation environment, as the wearer cannot be informed about the presence of a high-level radiation area or an impending risk of exceeding the permissible doses. Electricite de France and Lab-Instruments have developed a dosimeter fitted with numerical reading, alarm and automatic recording that should help workers to appreciate their working conditions better and thus reduce the doses received during operations [fr

Instrument evaluation no. 17. Wallac automatic alarm dosimeter type RAD21

CERN Document Server

Burgess, P H

1980-01-01

The various radiations encountered in radiological protection cover a wide range of energies and radiation measurements have to be carried out under an equally broad spectrum of environmental conditions. This report is one of a series intended to give information on the performance characteristics of radiological protection instruments, to assist in the selection of appropriate instruments for a given purpose, to interpret the results obtained with such instruments, and, in particular, to know the likely sources and magnitude of errors that might be associated with measurements in the field. The radiation, electrical and environmental characteristics of radiation protection instruments are considered together with those aspects of the construction which make an instrument convenient for routine use. To provide consistent criteria for instrument performance, the range of tests performed on any particular class of instrument, the test methods and the criteria of acceptable performance are based broadly on the a...

Development of Thermoluminescence Dosimeter CaSO4:Dy as Personal and Environmental Dosimeters

International Nuclear Information System (INIS)

Hasnel Sofyan

2009-01-01

Development of personal and environmental dosimeters using material phosphors of CaSO 4 :Dy powder in form capillary glass and disc teflon thermoluminescence (TL) dosimeter have been done. TL dosimeter CaSO 4 :Dy powder used can record dose response less than 0.01 mGy. Fading of TL dosimeter capillary glass after 29 days is 25%. In 1 batch, making of CaSO 4 :Dy powder can obtain 2 groups of dosimeter capillaries with coefficient variance smaller than 10%. This discrepancy caused difference in powder making and reading of the TL dosimeter. TL dosimeter CaSO 4 :Dy teflon disc with dia. 5 mm and 0.8 mm thickness is homogeneous mixture between phosphor powder with dia. 80 to 150 mesh and teflon powder dia. 20 μm. The composition of CaSO 4 :Dy and teflon in TL dosimeter influence sensitivity of the dosimeter. It’ concluded that in order to obtain optimal sensitivity of TL dosimeter, the composition of CaSO 4 :Dy and teflon is 3 and 1 with pressured of disc in 700 MPa. (author).

Tracking and Monitoring with Dosimeter-Enabled ARG-US RFID System - 12009

Energy Technology Data Exchange (ETDEWEB)

Anderson, J.; Lee, H.; De Lurgio, P.; Kearney, C.M.; Craig, B.; Soos, I.H.; Tsai, H.; Liu, Y. [Argonne National Laboratory, Argonne, IL 60439 (United States); Shuler, J. [U.S. Department of Energy, Washington, D.C. 20585 (United States)

2012-07-01

Automated monitoring and tracking of materials with radio frequency identification (RFID) technology can significantly improve both the operating efficiency of radiological facilities and the application of the ALARA (as low as reasonably achievable) principle in them. One such system, called ARG-US, has been developed by Argonne National Laboratory for the U.S. Department of Energy (DOE) Packaging and Certification Program to use in managing sensitive nuclear and radioactive materials. Several ARG-US systems are in various stages of deployment and advanced testing across DOE sites. ARG-US utilizes sensors in the tags to continuously monitor the state of health of the packaging and promptly disseminates alarms to authorized users. In conjunction with global positioning system (GPS) tracking provided by TRANSCOM, the system can also monitor and track packages during transport. A compact dosimeter has been incorporated in the ARG-US tags via an onboard universal asynchronous receiver/transmitter interface. The detector has a wide measurement range for gamma radiation - from 0.1 mSv/h to 8 Sv/h. The detector is able to generate alarms for both high and low radiation and for a high cumulative dose. In a large installation, strategically located dosimeter-enabled tags can yield an accurate, real-time, 2D or 3D dose field map that can be used to enhance facility safety, security, and safeguards. This implementation can also lead to a reduced need for manned surveillance and reduced exposure of personnel to radiation, consistent with the ALARA principle at workplaces. (authors)

Automatic diagnosis of alarms: a system to improve operator emergency response

International Nuclear Information System (INIS)

Olson, H.P.; Gimmy, K.L.; Nomm, E.; Finley, R.H.

1980-01-01

A system is being developed at the Savannah River Plant to help reactor operators respond to multiple alarms in a developing incident situation. The need for such systems has becme evident in recent years, particularly after the Three Mile Island incident

Study on the angular dependence of personal exposure dosimeter - Focus on thermoluminescent dosimeter and photoluminescent dosimeter

International Nuclear Information System (INIS)

Dong, Kyung-Rae; Kweon, Dae Cheol; Chung, Woon-Kwan; Goo, Eun-Hoe; Dieter, Kevin; Choe, Chong-Hwan

2011-01-01

Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of ±90 o at an interval scale of 15 o from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0 o to -90 o , respectively. Therefore, PLDs have a lower angular dependence than TLDs.

Development of alarm handling methods for boiling water reactors

Energy Technology Data Exchange (ETDEWEB)

Yukiharu, Ohga; Hiroshi, Seki; Setsuo, Arita [Power and Industrial Systems R and D Div., Hitachi, Ltd., Hitachi, Ibaraki (Japan)

1997-09-01

A method was developed to select important alarms in two steps: first, selection is based on the physical relationship between the alarms, and second, selection is according to the initial event. An approach combining a neural network and knowledge processing was proposed to identify the event rapidly. A prototype system was evaluated in the Kashiwazaki/Kariwa-4 Nuclear Power Plant during the startup test. The evaluation test confirmed that about 30% of the alarms are selected from among the many activated alarms. The second method, dealing with presentation, supports operators in their selection and confirmation of the required information for plant operation. The method selects and offers plant information in response to plant status changes and operators` demands. The selection procedure is based on the knowledge and data as structured by the plant functional structure; i.e. a means-ends abstraction hierarchy model. A prototype system was evaluated using a BWR simulator. The results showed that appropriate information items are automatically selected according to plant status changes and information on generated alarms is presented to operators together with the related trend graph and system diagram. Answers are generated in reply to the operators` demands and operators can confirm the generated alarms on each plant function, such as systems and components. 8 refs, 10 figs, 2 tabs.

Development of alarm handling methods for boiling water reactors

International Nuclear Information System (INIS)

Ohga Yukiharu; Seki Hiroshi; Arita Setsuo

1997-01-01

A method was developed to select important alarms in two steps: first, selection is based on the physical relationship between the alarms, and second, selection is according to the initial event. An approach combining a neural network and knowledge processing was proposed to identify the event rapidly. A prototype system was evaluated in the Kashiwazaki/Kariwa-4 Nuclear Power Plant during the startup test. The evaluation test confirmed that about 30% of the alarms are selected from among the many activated alarms. The second method, dealing with presentation, supports operators in their selection and confirmation of the required information for plant operation. The method selects and offers plant information in response to plant status changes and operators' demands. The selection procedure is based on the knowledge and data as structured by the plant functional structure; i.e. a means-ends abstraction hierarchy model. A prototype system was evaluated using a BWR simulator. The results showed that appropriate information items are automatically selected according to plant status changes and information on generated alarms is presented to operators together with the related trend graph and system diagram. Answers are generated in reply to the operators' demands and operators can confirm the generated alarms on each plant function, such as systems and components. 8 refs, 10 figs, 2 tabs

Fundamentals of Polymer Gel Dosimeters

Science.gov (United States)

McAuley, Kim B.

2006-12-01

The recent literature on polymer gel dosimetry contains application papers and basic experimental studies involving polymethacrylic-acid-based and polyacrylamide-based gel dosimeters. The basic studies assess the relative merits of these two most commonly used dosimeters, and explore the effects of tetrakis hydroxymethyl phosphonium chloride (THPC) antioxidant on dosimeter performance. Polymer gel dosimeters that contain THPC or other oxygen scavengers are called normoxic dosimeters, because they can be prepared under normal atmospheric conditions, rather than in a glove box that excludes oxygen. In this review, an effort is made to explain some of the underlying chemical phenomena that affect dosimeter performance using THPC, and that lead to differences in behaviour between dosimeters made using the two types of monomer systems. Progress on the development of new more effective and less toxic dosimeters is also reported.

Plant experience with an expert system for alarm diagnosis

International Nuclear Information System (INIS)

Gimmy, K.L.

1986-01-01

An expert system called Diagnosis of Multiple Alarms (DMA) is in routine use at four nuclear reactors operated by the DuPont Company. The system is wired to plant alarm annunciators and does event-tree analysis to see if a pattern exists. Any diagnosis is displayed to the plant operator and the corrective procedure to be followed is also identified. The display is automatically superseded if a higher priority diagnosis is made. The system is integrated with operator training and procedures. Operating results have been positive. DMA has diagnosed several hard-to-locate small leaks. There have been some false diagnosis, and realistic plant environments must be considered in such expert systems. 2 refs., 5 figs

Real-time Alarm Monitoring System for Detecting Driver Fatigue in Wireless Areas

Directory of Open Access Journals (Sweden)

Rongrong Fu

2017-04-01

Full Text Available The purpose of this paper was to develop a real-time alarm monitoring system that can detect the fatigue driving state through wireless communication. The drivers’ electroencephalogram (EEG signals were recorded from occipital electrodes. Seven EEG rhythms with different frequency bands as gamma, hbeta, beta, sigma, alpha, theta and delta waves were extracted. They were simultaneously assessed using relative operating characteristic (ROC curves and grey relational analysis to select one as the fatigue feature. The research results showed that the performance of theta wave was the best one. Therefore, theta wave was used as fatigue feature in the following alarm device. The real-time alarm monitoring system based on the result has been developed, once the threshold was settled by using the data of the first ten minutes driving period. The developed system can detect driver fatigue and give alarm to indicate the onset of fatigue automatically.

Dosimeter design specifications

International Nuclear Information System (INIS)

Anon.

1981-01-01

The combination dosimeter and security credential holder was developed as part of the effort involved to provide an automated readout and thermoluminescent dosimetry capability at Hanford. The holder is designed to accomodate the thermoluminescent dosimeter card, appropriate filters, the security credential and a snap type clip. The body of the holder is ABS plastic (acrylontrile-butadiene-styrene). The dosimeter holder and card is mold casted providing uniformity of construction

Type tests to the automatic thermoluminescent dosimetry system acquired by the CPHR for personal dosimetry

International Nuclear Information System (INIS)

Molina P, D.; Pernas S, R.; Martinez G, A.

2006-01-01

The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF:Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

Composite Resin Dosimeters: A New Concept and Design for a Fibrous Color Dosimeter.

Science.gov (United States)

Kinashi, Kenji; Iwata, Takato; Tsuchida, Hayato; Sakai, Wataru; Tsutsumi, Naoto

2018-04-11

Polystyrene (PS)-based composite microfibers combined with a photochromic spiropyran dye, 1,3,3-trimethylindolino-6'-nitrobenzopyrylospiran (6-nitro BIPS), and a photostimulable phosphor, europium-doped barium fluorochloride (BaFCl:Eu 2+ ), were developed for the detection of X-ray exposure doses on the order of approximately 1 Gy. To produce the PS-based composite microfibers, we employed a forcespinning method that embeds a high concentration of phosphor in PS in a safe, inexpensive, and simple procedure. On the basis of the optimization of the forcespinning process, fibrous color dosimeters with a high radiation dose sensitivity of 1.2-4.4 Gy were fabricated. The color of the dosimeters was found to transition from white to blue in response to X-ray exposure. The optimized fibrous color dosimeter, made from a solution having a PS/6-nitro BIPS/BaFCl:Eu 2+ /C 2 Cl 4 ratio of 7.0/0.21/28.0/28.0 (wt %) and produced with a 290 mm distance between the needle and collectors, a 0.34 mm 23 G needle nozzle, and a spinneret rotational rate of 3000 rpm, exhibited sensitivity to a dose as low as 1.2 Gy. To realize practical applications, we manufactured the optimized fibrous color dosimeter into a clothlike color dosimeter. The clothlike color dosimeter was mounted on a stuffed bear, and its coloring behavior was demonstrated upon X-ray exposure. After exposure with X-ray, a blue colored and shaped in the form of the letter "[Formula: see text]" clearly appeared on the surface of the clothlike color dosimeter. The proposed fibrous color dosimeters having excellent workability will be an unprecedented dosimetry and contributed to all industries utilizing radiation dosimeters. This new fibrous "composite resin dosimeter" should be able to replace traditional, wearable, and individual radiation dose monitoring devices, such as film badges.

Copper doped borate dosimeters revisited

International Nuclear Information System (INIS)

Alajerami, Y.S.M.; Hashim, S.; Ghoshal, S.K.; Bradley, D.A.; Mhareb, M.; Saleh, M.A.

2014-01-01

We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu + and Cu ++ ) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu + ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated technique in borate

Type tests to the automatic system of thermoluminescent dosimetry acquired by the CPHR for personnel dosimetry

International Nuclear Information System (INIS)

Molina P, D.; Pernas S, R.

2005-01-01

The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF: Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

Passive radon daughter dosimeters

International Nuclear Information System (INIS)

McElroy, R.G.C.; Johnson, J.R.

1986-03-01

On the basis of an extensive review of the recent literature concerning passive radon daughter dosimeters, we have reached the following conclusions: 1) Passive dosimeters for measuring radon are available and reliable. 2) There does not presently exist an acceptable passive dosimeter for radon daughters. There is little if any hope for the development of such a device in the foreseeable future. 3) We are pessimistic about the potential of 'semi-passive dosimeters' but are less firm about stating categorically that these devices cannot be developed into a useful radon daughter dosimeter. This report documents and justifies these conclusions. It does not address the question of the worker's acceptance of these devices because at the present time, no device is sufficiently advanced for this question to be meaningful. 118 refs

Copper doped borate dosimeters revisited

Energy Technology Data Exchange (ETDEWEB)

Alajerami, Y.S.M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Department of Medical Radiography, Al-Azhar University, Gaza Strip, Palestine (Country Unknown); Hashim, S., E-mail: suhairul@utm.my [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Oncology Treatment Centre, Sultan Ismail Hospital, 81100 Johor Bahru (Malaysia); Ghoshal, S.K. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mhareb, M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Saleh, M.A. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); National Atomic Energy Commission (NATEC), Sana' a (Yemen)

2014-11-15

We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu{sup +} and Cu{sup ++}) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu{sup +} ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated

Electronic dosimeter characteristics and new developments

International Nuclear Information System (INIS)

Thompson, I.M.G.

1999-01-01

Electronic dosimeters are very much more versatile than existing passive dosimeters such as TLDs and film badges which have previously been the only type of dosimeters approved by national authorities for the legal measurement of doses to occupationally exposed workers. Requirements for the specifications and testing of electronic dosimeters are given in the standards produced by the International Electrotechnical Commission Working Group IEC SC45B/B8. A description is given of these standards and the use of electronic dosimeters as legal dosimeters is discussed. (author)

False Alarms and Overmonitoring: Major Factors in Alarm Fatigue Among Labor Nurses.

Science.gov (United States)

Simpson, Kathleen Rice; Lyndon, Audrey

2018-06-08

Nurses can be exposed to hundreds of alarms during their shift, contributing to alarm fatigue. The purposes were to explore similarities and differences in perceptions of clinical alarms by labor nurses caring for generally healthy women compared with perceptions of adult intensive care unit (ICU) and neonatal ICU nurses caring for critically ill patients and to seek nurses' suggestions for potential improvements. Nurses were asked via focus groups about the utility of clinical alarms from medical devices. There was consensus that false alarms and too many devices generating alarms contributed to alarm fatigue, and most alarms lacked clinical relevance. Nurses identified certain types of alarms that they responded to immediately, but the vast majority of the alarms did not contribute to their clinical assessment or planned nursing care. Monitoring only those patients who need it and only those physiologic values that are warranted, based on patient condition, may decrease alarm burden.

Comparison of alanine dosimeters using silicone as their binder to a commercial, polystyrene-bound, alanine dosimeter

International Nuclear Information System (INIS)

Galindo, S.; Urena-Nunez, F.

1997-01-01

The feasibility of practical boron-containing alanine ESR dosimeters for gamma-neutron mixed field irradiation dosimeters depends in part on whether the γ response characteristics of these silicone-bound dosimeters are comparable to those of a commercially available dosimeter that has been used by the International Atomic Energy Agency (International Dose Assurance Service) as a transfer reference dosimeter. This work presents the results of the comparison of 3 batches of silicone-bound alanine dosimeters. The first batch consists of a mixture of alanine and boric acid; the second, alanine and borax; and the last contains only alanine. Results indicate that γ response characteristics of the silicone-bound samples are comparable to those of the commercial, polystyrene-bound, alanine dosimeter and that silicone has a strong potential as a binding substance for alanine ESR dosimetry. (Author)

Development of a TL personal dosimeter identifiable PA exposure, and comparison with commercial TL dosimeters

International Nuclear Information System (INIS)

Kwon, J.W.; Kim, H.K.; Lee, J.K.; Kim, J.L.

2004-01-01

A single-dosimeter worn on the anterior surface of the body of a worker was found to significantly underestimate the effective dose to the worker when the radiation comes from the back. Several researchers suggested that this sort of underestimation can be corrected to a certain extent by using an extra dosimeter on the back. However, use of multiple dosimeters also has disadvantages such as complication in control or incurrence of extra cost. Instead of the common multi-dosimeter approach, in this study, a single dosimeter introducing asymmetric filters which enabled to identify PA exposure was designed, and its dose evaluation algorithm for AP-PA mixed radiation fields was established. A prototype TL personal dosimeter was designed and constructed. The Monte Carlo simulations were utilized in the design process and verified by experiments. The dosimeter and algorithm were applicable to photon radiation having an effective energy beyond 100 keV in AP-PA mixed radiation fields. A simplified performance test based on ANSI N13.11 showed satisfactory results. Considering that the requirements of the International Electrotechnical Commission (IEC) and the American National Standards Institute (ANSI) with regard to the dosimeter on angular dependency is reinforced, the dosimeter and the dose evaluation algorithm developed in this study provides a useful approach in practical personal dosimetry against inhomogeneous high energy radiation fields. (author)

Alarm filtering and presentation

International Nuclear Information System (INIS)

Bray, M.A.

1989-01-01

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.)

Selfcalibrated alanine/EPR dosimeters. A new generation of solid state/EPR dosimeters

International Nuclear Information System (INIS)

Yordanov, N.D.; Gancheva, V.

1999-01-01

Alanine/EPR dosimeters are well established as secondary, reference dosimeters for high-energy radiation. However, there are various sources of uncertainty in the evaluation of absorbed dose. This arises primarily from the necessity to calibrate each EPR spectrometer and each batch of dosimeters before their use. In order to overcome this disadvantage, a new generation alanine/EPR dosimeter has been developed, and its possibilities as a radiation detector are reported. Principally, it is a mixture of alanine, some quantity of EPR active substance, and a binding material. The EPR active substance, acting as an internal EPR standard, is chosen to have EPR parameters which are independent of the irradiation dose. The simultaneous recording of the spectra of both the sample and the standard under the same experimental conditions and the estimation of the ratio I alanine /I Mn as a function of the absorbed dose strongly reduces the uncertainties. The response of these dosimeters for 60 Co γ-radiation exhibits excellent linearity and reproducibility in the range of absorbed dose, 10 2 - 5 x 10 4 Gy. (author)

Heater design for reading radiation dosimeters

International Nuclear Information System (INIS)

Seidel, J.G.; Felice, P.E.

1982-01-01

The nichrome heating element of a conventional dosimeter reading apparatus has been redesigned to include a flat-bottomed depression big enough to hold a thermoluminescent dosimeter. A thin glass plate is positioned in the recess on top of the dosimeter to retain it in the recess during the heating and reading process. This technique of securing the dosimeter in contact with the heating element avoids physical scratching or damage to the dosimeter

Automatic video surveillance of outdoor scenes using track before detect

DEFF Research Database (Denmark)

Hansen, Morten; Sørensen, Helge Bjarup Dissing; Birkemark, Christian M.

2005-01-01

This paper concerns automatic video surveillance of outdoor scenes using a single camera. The first step in automatic interpretation of the video stream is activity detection based on background subtraction. Usually, this process will generate a large number of false alarms in outdoor scenes due...

Hanford personnel dosimeter supporting studies FY-1981

International Nuclear Information System (INIS)

1982-08-01

This report examined specific functional components of the routine external personnel dosimeter program at Hanford. Components studied included: dosimeter readout; dosimeter calibration; dosimeter field response; dose calibration algorithm; dosimeter design; and TLD chip acceptance procedures. Additional information is also presented regarding the dosimeter response to light- and medium-filtered x-rays, high energy photons and neutrons. This study was conducted to clarify certain data obtained during the FY-1980 studies

Radiation dosimeters for medical use

International Nuclear Information System (INIS)

Risticj, S. Goran

2013-01-01

The several personal radiation dosimeter types for medical use, which look like promising for this kind of application, as pMOS (RADFET) dosimeter, direct ion storage (DIS) dosimeters, thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters, are described, and their advantages and disadvantages are analyzed. The p-channel metal-oxide-semiconductor (pMOS) dosimetric transistors allow dose measurements in vivo in real time, and they are especially important for radiotherapy. Direct ion storage (DIS) dosimeters are a hybrid of ion chamber and floating gate MOSFETs (FGMOSFETs), show very high sensitivity. Radiative processes that happen during the exposure of crystal to radiation are classified as prompt luminescence or radioluminescence (RL). In the case of an emission during stimulation, this phenomenon is referred to thermoluminescence or optically stimulated luminescence depending on whether the stimulation source is heat or light. TL and OSL dosimeters are natural or synthetic materials, which the intensity of emitted light is proportional to the irradiation dose. (Author)

Characteristics of radiophotoluminescent glass dosimeters

Energy Technology Data Exchange (ETDEWEB)

Ito, Masashi; Shiraishi, Akemi; Murakami, Hiroyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-07-01

In Japan Atomic Energy Research Institute, a film badge is recently replaced by a new type radiophotoluminescent (RPL) glass dosimeter for external personal monitoring. Some fundamental characteristics of this dosimeter, such as dose dependence linearity, energy dependence, angular dependence, dose evaluation accuracy at mixed irradiation conditions, fading, etc., were examined at the Facility of Radiation Standard (FRS), JAERI. The results have proved that the RPL glass dosimeter has sufficient characteristics for practical use as a personal dosimeter for all of the items examined. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Davey, E C; Basso, R A; Feher, M P [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

1996-12-31

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.

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

International Nuclear Information System (INIS)

Davey, E.C.; Basso, R.A.; Feher, M.P.

1995-01-01

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

Methods for implementation of in vivo dosimetry (entrance dose) using thermoluminescent dosimeters during radiotherapy treatment with photon beam

International Nuclear Information System (INIS)

Barsanelli, Cristiane

2006-01-01

Selection, calibration procedure to convert TLD signal into absorbed dose and physical characteristics at the thermoluminescent dosimeters, as well as the determination of correction factors and the methodology to determine expected entrance dose, are described in this work. Practical aspects and the utility of entrance dose measures with thermoluminescent dosimeters were investigated, as well as the exactness and the reproducibility of the daily dose release. The entrance dose measures were performed in five patients with diagnosis of breast cancer treated with a 6 MV photon beam. The measured dose and the expected dose values agreed in ± 5%, due to excellent treatment equipment stability, to automatic verification system and the good exactness in the daily treatment adjustment. Good precision can be achieved when the correction factors for each parameter of influence in the dosimeter response are carefully determined and applied to convert the thermoluminescent signal into absorbed dose. The study demonstrates the viability of thermoluminescent dosimeters use for in vivo dosimetry and its utility as part of a quality assurance program in a radiation therapy service. (author)

A Fault Alarm and Diagnosis Method Based on Sensitive Parameters and Support Vector Machine

Science.gov (United States)

Zhang, Jinjie; Yao, Ziyun; Lv, Zhiquan; Zhu, Qunxiong; Xu, Fengtian; Jiang, Zhinong

2015-08-01

Study on the extraction of fault feature and the diagnostic technique of reciprocating compressor is one of the hot research topics in the field of reciprocating machinery fault diagnosis at present. A large number of feature extraction and classification methods have been widely applied in the related research, but the practical fault alarm and the accuracy of diagnosis have not been effectively improved. Developing feature extraction and classification methods to meet the requirements of typical fault alarm and automatic diagnosis in practical engineering is urgent task. The typical mechanical faults of reciprocating compressor are presented in the paper, and the existing data of online monitoring system is used to extract fault feature parameters within 15 types in total; the inner sensitive connection between faults and the feature parameters has been made clear by using the distance evaluation technique, also sensitive characteristic parameters of different faults have been obtained. On this basis, a method based on fault feature parameters and support vector machine (SVM) is developed, which will be applied to practical fault diagnosis. A better ability of early fault warning has been proved by the experiment and the practical fault cases. Automatic classification by using the SVM to the data of fault alarm has obtained better diagnostic accuracy.

Fast-neutron solid-state dosimeter

International Nuclear Information System (INIS)

Kecker, K.H.; Haywood, F.F.; Perdue, P.T.; Thorngate, J.H.

1975-01-01

This patent relates to an improved fast-neutron solid-state dosimeter that does not require separation of materials before it can be read out, that utilizes materials that do not melt or otherwise degrade at about 300 0 C readout temperature, that provides a more efficient dosimeter, and that can be reused. The dosimeters are fabricated by intimately mixing a TL material, such as CaSO 4 :Dy, with a powdered polyphenyl, such as p-sexiphenyl, and hot-pressing the mixture to form pellets, followed by out-gassing in a vacuum furnace at 150 0 C prior to first use dosimeters

Evaluation of discrepancies between thermoluminescent dosimeter and direct-reading dosimeter results

International Nuclear Information System (INIS)

Shaw, K.R.

1993-07-01

Currently at Oak Ridge National Laboratory (ORNL), the responses of thermoluminescent dosimeters (TLDs) and direct-reading dosimeters (DRDs) are not officially compared or the discrepancies investigated. However, both may soon be required due to the new US Department of Energy (DOE) Radiological Control Manual. In the past, unofficial comparisons of the two dosimeters have led to discrepancies of up to 200%. This work was conducted to determine the reasons behind such discrepancies. For tests conducted with the TLDs, the reported dose was most often lower than the delivered dose, while DRDs most often responded higher than the delivered dose. Trends were identified in personnel DRD readings, and ft was concluded that more training and more control of the DRDs could improve their response. TLD responses have already begun to be improved; a new background subtraction method was implemented in April 1993, and a new dose algorithm is being considered. It was concluded that the DOE Radiological Control Manual requirements are reasonable for identifying discrepancies between dosimeter types, and more stringent administrative limits might even be considered

To the attention of all dosimeter users

CERN Multimedia

2005-01-01

Many regular users of CERN personal dosimeters do not respect the safety regulations, which include a compulsory monthly read-out of the dosimeter. Therefore we would like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350.-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short term visitor dosimeter (VCT). This dosimeter has a limited validity period but without for a compulsory periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service Bldg. 24 E 011 http://cern.ch/rp-dosimetry

To the attention of all dosimeter users

CERN Multimedia

Dosimetry Service

2005-01-01

Many regular users of CERN personal dosimeters do not respect the safety regulations, which include the compulsory monthly read-out of the dosimeter. Therefore we would like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350.-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short term visitor dosimeter (VCT). This dosimeter has a limited validity period but without for a compulsory periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service Bld 24 E 011 http://cern.ch/rp-dosimetry

To the attention of all dosimeter users

CERN Multimedia

Dosimetry Service

2006-01-01

Many regular users of CERN personal dosimeters do not respect the safety regulations, which include the compulsory monthly read-out of the dosimeter. We would therefore like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350,-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short-term visitor dosimeter (VCT). This dosimeter has a limited validity period but does not require a periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service - Bldg. 24 E 011 - http://cern.ch/rp-dosimetry

Thermoluminescent dosimeter system

International Nuclear Information System (INIS)

Felice, P.E.; Gonzalez, J.L.; Seidel, J.G.

1979-01-01

An improved thermoluminescent dosimeter system and apparatus for sensing alpha particle emission is described. A thermoluminescent body is sealed between a pair of metallized plastic films. The dosimeter is mounted within a protective inverted cup or a tube closed at one end, which is disposed in a test hole for exposure to radioactive radon gas which is indicaive of uranium deposits

Cell-phone interference with pocket dosimeters

International Nuclear Information System (INIS)

Djajaputra, David; Nehru, Ramasamy; Bruch, Philip M; Ayyangar, Komanduri M; Raman, Natarajan V; Enke, Charles A

2005-01-01

Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag. (note)

Cell-phone interference with pocket dosimeters

Energy Technology Data Exchange (ETDEWEB)

Djajaputra, David; Nehru, Ramasamy; Bruch, Philip M; Ayyangar, Komanduri M; Raman, Natarajan V; Enke, Charles A [Department of Radiation Oncology, University of Nebraska Medical Center, 987521 Nebraska Medical Center, Omaha, NE 68198-7521 (United States)

2005-05-07

Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag. (note)

Flame-sintered ceramic exoelectron dosimeter samples

International Nuclear Information System (INIS)

Petel, M.; Holzapfel, G.

1979-01-01

New techniques for the preparation of integrating solid state dosimeters, particularly exoelectron dosimeters, have been initiated. The procedure consists in melting the powdered dosimeter materials in a hot, fast gas stream and depositing the ceramic layer. The gas stream is generated either through a chemical flame or by an electrical arc plasma. Results will be reported on the system Al 2 O 3 /stainless steel as a first step to a usable exoelectron dosimeter

Bilevel alarm monitoring multiplexer

International Nuclear Information System (INIS)

Johnson, C.S.

1977-06-01

This report describes the operation of the Bilevel Alarm Monitoring Multiplexer used in the Adaptive Intrusion Data System (AIDS) to transfer and control alarm signals being sent to the Nova 2 computer, the Memory Controlled Data Processor, and its own integral Display Panel. The multiplexer can handle 48 alarm channels and format the alarms into binary formats compatible with the destination of the alarm data

Passive dosimeters other than film and TLDs [thermoluminescent dosimeter

International Nuclear Information System (INIS)

Hankins, D.E.

1986-01-01

This presentation will describe CR-39 plastic as a personnel neutron dosimeter. Recent research at LLNL and elsewhere has resulted in the development of a dosimetry system that is superior to any personnel neutron dosimeter previously available. The author describes the features of the dosimetry system and the new etching procedures and techniques in detail. Most of the research was done at the LLNL and has been supported as a part of the DOE Neutron Dosimetry Upgrade Program. 10 refs., 4 figs., 1 tab

Development of electric power transmission line anomaly approaching alarm system. Sodensen ijo sekkin keiho sochi no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kusaba, Masaro; Tabata, Takatoshi; Miyazaki, Shusuke [Kyushu Electric Power Co., Inc., Fukuoka (Japan)

1989-03-30

In order to plan preventive measures from the occurrence of electric power transmission line accident, a power transmission line anomaly approaching alarm system was developed to automatically alarm the operators and surveillants. The surveillance system, composed of camera, surveillance unit proper and alarm receiving portion, generates alarm and indicate hazard to the operators, when animal invades a hazardous area designated on the monitor. Wireless telegraph for the alarm transmission use used frequency around a 322MHz band with the Radio Ray law and preventive measures from noise, taken into consideration. The prototype is characterized by unnecessary ancillary fitting to the surveillance object, rare erroneous operations and high reliability. While the hazardous area can be simply designated, changed and released, as made by volume on the control panel. It is moreover easy to designate, as done by confirming the surveillance object on the display. It is also possible in multidimensional surveillance and easy to use on site. 7 figs.

Neutron dosimeter

International Nuclear Information System (INIS)

Bartko, J.; Schoch, K.F. Jr.; Congedo, T.V.; Anderson, S.L. Jr.

1989-01-01

This patent describes a nuclear reactor. It comprises a reactor core; a thermal shield surrounding the reactor core; a pressure vessel surrounding the thermal shield; a neutron dosimeter positioned outside of the thermal shield, the neutron dosimeter comprising a layer of fissile material and a second layer made of a material having an electrical conductivity which permanently varies as a function of its cumulative ion radiation dose; and means, outside the pressure vessel and electrically connected to the layer of second material, for measuring electrical conductivity of the layer of second material

A new radiochromic dosimeter film

Science.gov (United States)

Sidney, L. N.; Lynch, D. C.; Willet, P. S.

By employing acid-sensitive leuco dyes in a chlorine-containing polymer matrix, a new radiochromic dosimeter film has been developed for gamma, electron beam, and ultraviolet radiation. These dosimeter films undergo a color change from colorless to royal blue, red fuchsia, or black, depending on dye selection, and have been characterized using a visible spectrophotometer over an absorbed dose range of 1 to 100 kGy. The primary features of the film are improved color stability before and after irradiation, whether stored in the dark or under artificial lights, and improved moisture resistance. The effects of absorbed dose, dose rate, and storage conditions on dosimeter performance are discussed. The dosimeter material may be produced as a free film or coated onto a transparent substrate and optionally backed with adhesive. Potential applications for these materials include gamma sterilization indicator films for food and medical products, electron beam dosimeters, and in-line radiation monitors for electron beam and ultraviolet processing.

Evaluation of personal dosimeters

International Nuclear Information System (INIS)

Correa, C. A.

2007-01-01

This work makes a screening of the different types of dosimeters present in the international market, to provide operative dosimetry of individual monitoring to measure Hp(10) and Hp(0,07)-specifically for external radiation gamma and beta, as well as to give knowledge of advances of passive and operative dosimetry, and the changes in the regulatory policy relative to these aspects. The data has been extracted from several providers of dosimeters, and the importance has been stressed in a good election of the dosimeter before its use, as well as the important advances in these equipment. (Author) 14 refs

Improved sample holders for the PMMA dosimeters

International Nuclear Information System (INIS)

Kobayashi, Toshikazu; Sone, Koji; Iso, Katsuaki

1994-01-01

PMMA dosimeters are widely used for high dose dosimetry. Dose is determined by measuring the change in optical density of the irradiated PMMA dosimeter element. Measurement precision depends on the mounting method of a dosimeter element in the sample room of a spectrophotometer. We tried to prepare three types of holders, (holders A, B and C in Figs. 1-3), according to the shape of PMMA dosimeter elements. We measured optical density of the irradiated PMMA dosimeter elements by using the three types of holders. It is revealed that the holder of the type A gives more precise results for the Red 4034 or Gammachrome YR dosimeter than that of the type B. The measurements with a spectrophotometer using the type C holder gives better results for the Red acrylic dosimeter than the case of the measurements by the exclusive reader. (author)

Electronic Personal Dosimeters Open a New Dimension in Radon Dose Management

International Nuclear Information System (INIS)

Streil, T.; Oeser, V.

2001-01-01

Full text: Electronic Radon dosimeters enable the installation of completely automated dose management systems in Radon exposed areas for the first time. In opposition to passive dosimeters, the actual dose value will be displayed online. The alarm function indicates the reaching of the permissible doses and prevents exceeding of given levels. The immediate availability of all user- and measurement information leads to a new level of quality assurance within complex dose management systems. Furthermore, the sequentially stored data give an exact assignment of concentration and dose values to the real time and location. This information is very important for staff planning and the assessment of Radon affected objects (local dosimeters). The measurement of Radon concentration is based on the alpha spectroscopy. The gas diffuses through a membrane into the measurement chamber. Progeny inside the chamber ionised after decay will be collected at the detector surface forced by the electric field. All incoming events will be processed by a Multi Channel Analyser (MCA). A integral spectrum and a record of five peak-areas (each assigned to a single nuclide) at every time step will be stored for computing concentration and dose values. The sensitivity of the device was determined to 0.25 counts/(minkBq/m 3 ). An average concentration of 200 Bq/m 3 during an eight-hours work day gives an error of ±20%. The response time (95% of final value) only depends on half live times of 218 Po and 214 Po (10 minutes using fast mode, 2 hours in slow mode) and is not affected by the diffusion membrane. Further tests at high levels (up to several MBq/m 3 ) were carried out successfully during soil gas and water measurements. (author)

The intelligence of dosimeter for ionization radiation

International Nuclear Information System (INIS)

He Jinglun

1992-01-01

The connection of dosimeter with microcomputer system is described, which has the functions of sampling, data handling, display and printing dose values in legal units of measurement. The accuracy and speed of measurement for dosimeters are also raised, thereby the dosimeters are made to have intelligence and the application range of dosimeter is enlarged

Development of an alarm analysis system based on multi-level flow models for nuclear power plant

International Nuclear Information System (INIS)

Zhang Jiande; Yang Ming; Zhang Zhijian

2008-01-01

An alarm analysis system based on Multi-level Flow Models (MFM) was developed for a PWR NPP. By automatically identifying the primary root causes in complex fault situations, the workload of the operators can be reduced. In addition, because MFM also provides a set of graphical symbols that implies causalities, operators can confirm diagnosis results by semiotic analysis, and hence the understandability of the process of alarm analysis as well as the reliability of maintenance task can be increased. 19 cases of simulation data from RELAP5/MOD2 code were utilized for evaluating the performance of the proposed system. The simulation results show that the proposed alarm analysis system has a good ability to detect and diagnose accidents earlier in time before reactor trip. (authors)

Citizen's dosimeter

Energy Technology Data Exchange (ETDEWEB)

Klemic, Gladys [Naperville, IL; Bailey, Paul [Chicago, IL; Breheny, Cecilia [Yonkers, NY

2008-09-02

The present invention relates to a citizen's dosimeter. More specifically, the invention relates to a small, portable, personal dosimetry device designed to be used in the wake of a event involving a Radiological Dispersal Device (RDD), Improvised Nuclear Device (IND), or other event resulting in the contamination of large area with radioactive material or where on site personal dosimetry is required. The card sized dosimeter generally comprises: a lower card layer, the lower card body having an inner and outer side; a upper card layer, the layer card having an inner and outer side; an optically stimulated luminescent material (OSLM), wherein the OSLM is sandwiched between the inner side of the lower card layer and the inner side of the upper card layer during dosimeter radiation recording, a shutter means for exposing at least one side of the OSLM for dosimeter readout; and an energy compensation filter attached to the outer sides of the lower and upper card layers.

Comprehensive smoke alarm coverage in lower economic status homes: alarm presence, functionality, and placement.

Science.gov (United States)

Sidman, Elanor A; Grossman, David C; Mueller, Beth A

2011-08-01

The objectives of this study are to estimate smoke alarm coverage and adherence with national guidelines in low- to mid-value owner-occupied residences, and to identify resident demographic, behavioral, and building characteristics and other fire and burn safety practices associated with smoke alarm utilization. Baseline visits were conducted with 779 households in King County, Washington, for a randomized trial of smoke alarm functionality. Presence, functionality, features, and location of pre-existing smoke alarms were ascertained by staff observation and testing. Household and building descriptors were collected using questionnaires. Households were classified by presence of smoke alarms, functional alarms, and functional and properly mounted alarms placed in hallways and on each floor but not in recommended avoidance locations. Smoke alarms were present in 89%, and functional units in 78%, of households. Only 6-38% met all assessed functionality and placement recommendations. Homes frequently lacked alarms in any bedrooms or on each floor. Building age, but not renovation status, was associated with all dimensions of smoke alarm coverage; post-1980 constructions were 1.7 times more likely to comply with placement recommendations than were pre-1941 homes (95% CI: 1.1-2.6). Respondent education and race/ethnicity, children wood stoves and fireplaces, number of smoke alarms, recency of smoke alarm testing, carbon monoxide monitors, and fire ladders displayed varying relationships with alarm presence, functionality, and placement. Strategies for maintaining smoke alarms in functional condition and improving compliance with placement recommendations are necessary to achieve universal coverage, and will benefit the majority of households.

Dose measurements in intraoral radiography using thermoluminescent dosimeters

Science.gov (United States)

Azorín, C.; Azorín, J.; Aguirre, F.; Rivera, T.

2015-01-01

The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations.

Dose measurements in intraoral radiography using thermoluminescent dosimeters

International Nuclear Information System (INIS)

Azorín, C; Rivera, T; Azorín, J; Aguirre, F

2015-01-01

The use of X-ray in medicine demands to expose the patient and the professional to the lowest radiation doses available in agreement with ALARA philosophy. The reference level for intraoral dental radiography is 7 mGy and, in Mexico, a number of examinations of this type are performed annually. It is considered that approximately 25% of all the X-rays examinations carried out in our country correspond to intraoral radiographies. In other hand, most of the intraoral X-ray equipment correspond to conventional radiological systems using film, which are developed as much manual as automatically. In this work the results of determining the doses received by the patients in intraoral radiological examinations made with different radiological systems using LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters are presented. In some conventional radiological systems using film, when films are developed manual or automatically, incident kerma up to 10.61 ± 0.74 mGv were determined. These values exceed that reference level suggested by the IAEA and in the Mexican standards for intraoral examinations

Acoustic evaluation of polymer gel dosimeters

International Nuclear Information System (INIS)

Mather, M.L.; De Deene, Y.; Baldock, C.; Whittaker, A.K.

2002-01-01

Advances in radiotherapy treatment techniques such as intensity modulated radiotherapy are placing increasing demands on radiation dosimetry for verification of dose distributions in 3D. In response, polymer gel dosimeters that are capable of recording dose distributions in 3D are currently being developed. Recently, a new technique for evaluation of absorbed dose distributions in these dosimeters using ultrasound was introduced. The current work aims to demonstrate the potential of ultrasound as an evaluation technique for polymer gel dosimeters and to investigate the ultrasound properties of two different dosimeter formulations, PAG and MAGIC gels

Water-resistant alanine-EPR dosimeter alanpol

International Nuclear Information System (INIS)

Peimel-Stuglik, Zofia; Bryl-Sandelewska, Teresa; Mirkowski, Krzysztof; Sartowska, Bozena

2009-01-01

Alanpol-water-resistant alanine-electron paramagnetic resonance (EPR) dosimeter consisted of cheap DL-α-alanine (9.8-27%) suspended in polyethylene matrix was presented. The rods (O=2.8 mm) were extruded from a hot mixture of alanine and low-density polyethylene. No grinding or crushing was used for alanine preparation. An orientation of cylindrical crystals, up to 300 μm long in parallel to the rod axis was responsible for some differences in a shape of EPR signal. These differences had no negative consequences for dosimetric applications. Signal-to-dose dependence was linear up to 10 kGy. Standard deviation of dosimetric answer was up to ±1.8% and up to 2.4% for dosimeters with 9.8% and 27% of DL-α-alanine, respectively. Irradiation temperature coefficient for both dosimeters was equal 0.2%/ deg. C. Hydrophobic properties of polyethylene and small number of alanine crystals located on the surface of the rod led to high resistance of dosimeters to water and humidity. The 24 h soaking of irradiated dosimeters in liquid water-reduced EPR signals by 3-4% and by 2-3% for dosimeters with 27% and 9.8% of DL-α-alanine, respectively. Three month storage time of irradiated dosimeters in room conditions decreases EPR signal for ∼3%.

SDI-100 radiation dosimeter

International Nuclear Information System (INIS)

Zheng Zheng; Zhao Yongfu; Dai Honggui

1995-01-01

An intelligent radiation dosimeter, with such functions as signal collection and data processing, store, print and display, has been developed. Its detector is made of a micro-semiconductor. This dosimeter can be used in laboratories for agricultural 60 Co irradiators, radiotherapeutic facilities and other small and medium-size 60 Co irradiators

Alarming atmospheres

DEFF Research Database (Denmark)

Højlund, Marie; Kinch, Sofie

2014-01-01

Nurses working in the Neuro-Intensive Care Unit at Aarhus University Hospital lack the tools to prepare children for the alarming atmosphere they will enter when visiting a hospitalised relative. The complex soundscape dominated by alarms and sounds from equipment is mentioned as the main stressor...

Radon daughter dosimeter

International Nuclear Information System (INIS)

Durkin, J.

1977-01-01

This patent describes a portable radon daughter dosimeter unit used to measure radon gas alpha daughters in ambient air. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as in uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout displays the result in terms of working level-hours

Radon daughter dosimeter

International Nuclear Information System (INIS)

Durkin, J.

1977-01-01

A portable radon daughter dosimeter unit used to measure Radon gas alpha daughters in ambient air is described. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout diplays the result in terms of working level-hours

Hanford beta-gamma personnel dosimeter prototypes and evaluation

International Nuclear Information System (INIS)

Fix, J.J.; Holbrook, K.L.; Soldat, K.L.

1983-04-01

Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips

The neutron response of a 7 LiF thermoluminescent dosimeter incorporated in the UKAEA criticality dosimeter

International Nuclear Information System (INIS)

Eid, A.M.; Delafield, H.J.

1976-04-01

There are practical advantages in incorporating a 7 LiF thermoluminescent dosimeter (TLD) for the measurement of γ-ray dose, into the personnel criticality dosimeter. This paper investigated the corrections necessary for the inherent direct response of the TLD neutrons, and its enhanced indirect response from prompt γ-rays resulting from neutron interactions with the metallic foils contained in the criticality dosimeter. The response of the TLD to fast fission neutrons was measured to be 0.02 γ rad/n rad. The indirect response of the TLD to thermal neutrons was measured to be 4.8 x 10 -10 rad n -1 cm 2 for dosimeters exposed in free air, and 7 x 10 -10 rad n -1 cm 2 for dosimeters worn on the body respectively. Application of these correction factors to TLD measurements made at International Dosimetry Intercomparisons (sponsored by the I.A.E.A.) gave improved agreement with the values given by other participants. (author)

Silver nitrate based gel dosimeter

International Nuclear Information System (INIS)

Titus, D; Samuel, E J J; Srinivasan, K; Roopan, S M; Madhu, C S

2017-01-01

A new radiochromic gel dosimeter based on silver nitrate and a normoxic gel dosimeter was investigated using UV-Visible spectrophotometry in the clinical dose range. Gamma radiation induced the synthesis of silver nanoparticles in the gel and is confirmed from the UV-Visible spectrum which shows an absorbance peak at around 450 nm. The dose response function of the dosimeter is found to be linear upto12Gy. In addition, the gel samples were found to be stable which were kept under refrigeration. (paper)

Automatic scanning of NTA film neutron dosimeters

CERN Document Server

Müller, R

1999-01-01

At the European Laboratory for Particle Physics CERN, personal neutron monitoring for over 4000 collaborators is performed with Kodak NTA film, one of the few suitable dosemeters in the stray radiation environment of a high energy accelerator. After development, films are scanned with a projection microscope. To overcome this lengthy and strenuous procedure an automated analysis system for the dosemeters has been developed. General purpose image recognition software, tailored to the specific needs with a macro language, analyses the digitised microscope image. This paper reports on the successful automatic scanning of NTA films irradiated with neutrons from a /sup 238/Pu-Be source (E approximately=4 MeV), as well as on the extension of the method to neutrons of higher energies. The question of detection limits is discussed in the light of an application of the method in routine personal neutron monitoring. (9 refs).

Recommendations to alarm systems and lessons learned on alarm system implementation

International Nuclear Information System (INIS)

Soerenssen, Aimar; Veland, Oeystein; Farbrot, Jan Erik; Kaarstad, Magnhild; Seim, Lars Aage; Foerdestroemmen, Nils; Bye, Andreas

2001-11-01

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

Development of an automatic human duress detection system

International Nuclear Information System (INIS)

Greene, E.R.; Davis, J.G.; Tuttle, W.C.

1979-01-01

A method for automatically detecting duress in security personnel utilizes real-time assessment of physiological data (heart rate) to evaluate psychological stress. Using body-worn tape recorders, field data have been collected on 22 Albuquerque police officers (20 male, 2 female) to determine actual heart rate responses in both routine and life-threatening situations. Off-line computer analysis has been applied to the data to determine the speed and reliability with which an alarm could be triggered. Alarm algorithms relating field responses to laboratory collected baseline responses have been developed

Alarm processing - Ways to the future

Energy Technology Data Exchange (ETDEWEB)

Pirus, D [EDF - Septen Service Etudes et Projets Thermiques et Nucleires, Villeurbanne Cedex (France)

1997-09-01

After a brief presentation of the main characteristics an efficient alarm system should have, a presentation of the N4 alarm processing and presentation is described in terms of reduction in alarm occurrence, alarm handling and operator presentation. The EDF experiments on the future alarm processing expected for the next generation of the French nuclear plants are then presented. This alarm system will manage the alarms functionally in order to present to the operators the real consequences on the whole plant of a dedicated alarm and try to imbed deeply the alarm presentation within the operating formats and the procedures. (author).

Alarm processing - Ways to the future

International Nuclear Information System (INIS)

Pirus, D.

1997-01-01

After a brief presentation of the main characteristics an efficient alarm system should have, a presentation of the N4 alarm processing and presentation is described in terms of reduction in alarm occurrence, alarm handling and operator presentation. The EDF experiments on the future alarm processing expected for the next generation of the French nuclear plants are then presented. This alarm system will manage the alarms functionally in order to present to the operators the real consequences on the whole plant of a dedicated alarm and try to imbed deeply the alarm presentation within the operating formats and the procedures. (author)

Radiation dosimeter assembly

International Nuclear Information System (INIS)

Seidel, J.G.

1982-01-01

A technique is disclosed for securing a thermoluminescent radiation dosimeter, used for monitoring underground radon gas in uranium prospecting, to a cup-like support member made of heavy gauge aluminum foil. A metalized film, consisting of an aluminum layer and a high tensile strength plastic layer, covers an aperture in the support members for the dosimeter. The film is secured by a high temperature adhesive to the support member, and both are capable of withstanding an annealing temperature of up to 300 0 C

Performance testing of extremity dosimeters, Study 2

International Nuclear Information System (INIS)

Harty, R.; Reece, W.D.; Hooker, C.D.

1990-04-01

The Health Physics Society Standards Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance with the standard. Pacific Northwest Laboratory (PNL) has conducted two separate evaluations of the performance of extremity dosimeter processors to determine the appropriateness of the draft standard, as well as to obtain information regarding the performance of extremity dosimeters. Based on the information obtained during the facility visits and the results obtained from the performance testing, it was recommended that changes be made to ensure that the draft standard is appropriate for extremity dosimeters. The changes include: subdividing the mixture category and the beta particle category; eliminating the neutron category until appropriate flux-to-dose equivalent conversion factors are derived; and changing the tolerance level for the performance criterion to provide consistency with the performance criterion for whole body dosimeters, and to avoid making the draft standard overly difficult for processors of extremity dosimeters to pass. 20 refs., 10 figs., 6 tabs

New Generation of self-calibrated SS/EPR dosimeters: Alanine/EPR dosimeters

International Nuclear Information System (INIS)

Yordanov, N.D.; Gancheva, V.

1999-01-01

A new type of solid state/EPR dosimeters is described. Principally, it contains radiation sensitive diamagnetic material, some quantity of EPR active, but radiation insensitive, substance (for example Mn 2+ /MgO) and a binding material. In the present case alanine is used as a radiation sensitive substance. With this dosimeter, the EPR spectra of alanine and Mn 2+ are simultaneously recorded and the calibration graph represents the ratio of alanine versus Mn 2+ EPR signal intensity as a function of absorbed dose. In this way the reproducibility of the results is expected to be improved significantly including their intercomparison among different laboratories. Homogeneity of the prepared dosimeters and their behaviour (fading of EPR signals with time, influence of different meteorological conditions) show satisfactory reproducibility and stability with time. Because two different EPR active samples are recorded simultaneously, the influence of some instrument setting parameters (microwave power, modulation amplitude and modulation frequency) on the ratio I alanine /I Mn is also investigated. (author)

A fibre optic dosimeter customised for brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Suchowerska, N. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia)], E-mail: Natalka@email.cs.nsw.gov.au; Lambert, J.; Nakano, T. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia); Law, S. [School of Physics, University of Sydney, NSW 2006 (Australia); Optical Fibre Technology Centre, University of Sydney, 206 National Innovation Centre, Australian Technology Park, Eveleigh, NSW 1430 (Australia); Elsey, J. [Bandwidth Foundry Pty Ltd, Australian Technology Park, NSW, 1430 (Australia); McKenzie, D.R. [School of Physics, University of Sydney, NSW 2006 (Australia)

2007-04-15

In-vivo dosimetry for brachytherapy cancer treatment requires a small dosimeter with a real time readout capability that can be inserted into the patient to determine the dose to critical organs. Fibre optic scintillation dosimeters, consisting of a plastic scintillator coupled to an optical fibre, are a promising dosimeter for this application. We have implemented specific design features to optimise the performance of the dosimeter for specific in-vivo dosimetry during brachytherapy. Two sizes of the BrachyFOD{sup TM} scintillation dosimeter have been developed, with external diameters of approximately 2 and 1 mm. We have determined their important dosimetric characteristics (depth dose relation, angular dependence, energy dependence). We have shown that the background signal created by Cerenkov and fibre fluorescence does not significantly affect the performance in most clinical geometries. The dosimeter design enables readout at less than 0.5 s intervals. The clinical demands of real time in-vivo brachytherapy dosimetry can uniquely be satisfied by the BrachyFOD{sup TM}.

Comparative study of some new EPR dosimeters

International Nuclear Information System (INIS)

Alzimami, K.S.; Maghraby, Ahmed M.; Bradley, D.A.

2014-01-01

Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (W PP ) and peak-to-peak signal height (H PP ). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic. - Highlights: ► Several EPR dosimeters were suggested based on SO 3 − radical. ► Taurine, homotaurine, sulfanilic, and sulfamic acid all possess simple EPR spectra. ► Dosimeters were compared to each other in terms of the dosimetric point of view. ► Energy dependence curves of the selected dosimeters were compared to eachother

Ecological alarm system for Itaipu

Energy Technology Data Exchange (ETDEWEB)

Faehser, L.

1984-05-01

At Itaipu, on the Rio Parana, Brazil and Paraguay are constructing the world's largest hydro-electric power plant with a capacity seven times as high as that of Assuan. An information system is intended to give fair warning in case of threatening ecological conditions. The computer-supported alarm system had four objectives: 1. presentation of the present ecological situation; 2. evaluation of the ecological risks; 3. warning about ecological deficits; 4. suggestions for establishing ecological stability. In a first step the available inventory data concerning soil, topography, vegetation and water were evaluated by expert groups according to their risk grade (0-4) and ecological weight (1-10). The product of these evaluations indicates the ecological deficit (0-40). At a threshold value of 30, the information system automatically signals ecological alarm and locates the centre of danger via computer-plotted maps and tables. The necessary data are supplied periodically by selected measurement stations. Quantification of ecological facts enables the persons who are responsible for decisions at Itaipu to recognize, avoid, or diminish elements of danger even if they have little or no ecological knowledge. The file of data that has been compiled so far should be extended parallel with the development in the Itaipu area. With the help of factor analysis connections of cause and effect can be detected in this extremely complex reservoir system which has hardly been explored yet.

The Best Ever Alarm System Toolkit

International Nuclear Information System (INIS)

Kasemir, Kay; Chen, Xihui; Danilova, Ekaterina N.

2009-01-01

Learning from our experience with the standard Experimental Physics and Industrial Control System (EPICS) alarm handler (ALH) as well as a similar intermediate approach based on script-generated operator screens, we developed the Best Ever Alarm System Toolkit (BEAST). It is based on Java and Eclipse on the Control System Studio (CSS) platform, using a relational database (RDB) to store the configuration and log actions. It employs a Java Message Service (JMS) for communication between the modular pieces of the toolkit, which include an Alarm Server to maintain the current alarm state, an arbitrary number of Alarm Client user interfaces (GUI), and tools to annunciate alarms or log alarm related actions. Web reports allow us to monitor the alarm system performance and spot deficiencies in the alarm configuration. The Alarm Client GUI not only gives the end users various ways to view alarms in tree and table, but also makes it easy to access the guidance information, the related operator displays and other CSS tools. It also allows online configuration to be simply modified from the GUI. Coupled with a good 'alarm philosophy' on how to provide useful alarms, we can finally improve the configuration to achieve an effective alarm system.

Optimal Alarm Systems

Data.gov (United States)

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...

Directional Radiation Dosimeter for Area and Environmental Monitoring

International Nuclear Information System (INIS)

Manzoli, J.E.; Campos, V.P.; Moura, E.S.

2009-01-01

It is presented a dosimeter that is able to measure the photon exposure and the direction from where the radiation came from. Preliminary measurements performed by this new directional radiation dosimeter demonstrate its application. This dosimeter consists of a small lead cube with thermoluminescent discs on each face, placed in well known coordinates. Only one dosimeter of this kind indicates the direction of the radiation beam, if it came from a unique position. This study was conducted inside the radiation room of a Cobalt-60 Gamma Irradiator and the dosimeter indicated the source position

A revival of the alarm system: Making the alarm list useful during incidents

International Nuclear Information System (INIS)

Larsson, J. E.; Oehman, B.; Calzada, A.; Nihlwing, C.; Jokstad, H.; Kristianssen, L. I.; Kvalem, J.; Lind, M.

2006-01-01

In control rooms there are often problems with information overload, which means that the operators may receive more information than they are able to interpret. The most serious information overload occurs in two types of situations. The first is when the operating state of the plant changes, which often gives raise to a shower of alarms and events. Such an alarm shower is expected, but can be dangerous, because it may hide other alarms originating from unrelated faults. The second problem occurs when a fault causes several consequential faults, leading to a so-called alarm cascade. Because the alarms seldom arrive in correct time order, it can be very difficult to analyze such a cascade, and the information overload occurs in exactly the moment when a potentially dangerous situation starts. In an ongoing project, GoalArt and IFE are cooperating in testing and evaluating GoalArt's methods for alarm reduction and root cause analysis. The testing comprises two specific algorithms, root cause analysis and state-based alarm priority. The GoalArt system has been integrated with the HAMBO simulator so that operators can evaluate the algorithms on-line. (authors)

Dosimeter

International Nuclear Information System (INIS)

Thomson, I.

1986-01-01

This invention relates to a dosimeter for measuring ionizing radiation, and particularly to a dosimeter using an insulated gate field effect transistor (IGFET) as a sensor, having substantially improved accuracy. An IGFET is a field effect transistor fabricated on a silicon substrate and having an oxide insulator between the gate electrode and the silicon substrate. The gate electrode can be either metal or polycrystalline silicon dioxide. This invention overcomes previously-noted problems with IGFET sensors - the variation of threshold voltage with temperature, their inherent zero offset which varies from wafer to wafer, and the zero drift in threshold voltage - by measuring the differential threshold between two IGFET sensors exposed to the same radiation, in which one is biased into its conducting region, and the other is biased either off or to a conducting level less than the first. The measured differential threshold voltage between the two transistors will be a measure of the gamma radiation dose

Advances in software development for intelligent interfaces for alarm and emergency management consoles

International Nuclear Information System (INIS)

Moseley, M.R.; Olson, C.E.

1986-01-01

Recent advances in technology allow features like voice synthesis, voice and speech recognition, image understanding, and intelligent data base management to be incorporated in computer driven alarm and emergency management information systems. New software development environments make it possible to do rapid prototyping of custom applications. Three examples using these technologies are discussed. (1) Maximum use is made of high-speed graphics and voice synthesis to implement a state-of-the-art alarm processing and display system with features that make the operator-machine interface efficient and accurate. Although very functional, this system is not portable or flexible; the software would have to be substantially rewritten for other applications. (2) An application generator which has the capability of ''building'' a specific alarm processing and display application in a matter of a few hours, using the site definition developed in the security planning phase to produce the custom application. This package is based on a standardized choice of hardware, within which it is capable of building a system to order, automatically constructing graphics, data tables, alarm prioritization rules, and interfaces to peripherals. (3) A software tool, the User Interface Management System (UIMS), is described which permits rapid prototyping of human-machine interfaces for a variety of applications including emergency management, alarm display and process information display. The object-oriented software of the UIMS achieves rapid prototyping of a new interface by standardizing to a class library of software objects instead of hardware objects

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

Energy Technology Data Exchange (ETDEWEB)

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)

Intercomparison measurements with albedo neutron dosimeters

International Nuclear Information System (INIS)

Alberts, W.G.; Kluge, H.

1994-01-01

Since the introduction of the albedo dosimeter as the official personal neutron dosimeter the dosimetry services concerned have participated in intercomparison measurements at the PTB. Their albedo dosimeters were irradiated in reference fields produced by unmoderated and D 2 O-moderated 252 Cf neutron sources in the standard irradiation facility of the PTB. Six fields with fluences different in energy and angle distribution could be realised in order to determine the response of the albedo dosimeter. The dose equivalent values evaluated by the services were compared with the reference values of the PTB for the directional dose equivalent H'(10). The results turned out to be essentially dependent on the evaluation method and the choice of the calibration factors. (orig.) [de

Personnel neutron dosimeter evaluation and upgrade program

International Nuclear Information System (INIS)

Fix, J.J.; Brackenbush, L.W.; McDonald, J.C.; Roberson, P.L.; Holbrook, K.L.; Endres, G.W.R.; Faust, L.G.

1983-01-01

Evaluation of neutron dosimeters from twelve DOE laboratories involved about 2500 dosimeter irradiations at both PNL and the National Bureau of Standards (NBS) using neutrons of several energies and doses and several irradiations for good statistical analysis. The data and their analyses will be published later. The information evaluates accuracy, precision, lower dose detection, and energy response of dosimeters

The development of an automatic scanning method for CR-39 neutron dosimeter

International Nuclear Information System (INIS)

Tawara, Hiroko; Miyajima, Mitsuhiro; Sasaki, Shin-ichi; Hozumi, Ken-ichi

1989-01-01

A method of measuring low level neutron dose has been developed with CR-39 track detectors using an automatic scanning system. It is composed of the optical microscope with a video camera, an image processor and a personal computer. The focus point of the microscope and the X-Y stage are controlled from the computer. The minimum detectable neutron dose is estimated at 4.6 mrem in the uniform field of neutron with equivalent energy spectrum to Am-Be source from the results of automatic measurements. (author)

Alarm-Processing in Nuclear Power Plants

International Nuclear Information System (INIS)

Otazo, J; Fernandez, R

2000-01-01

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

Security Alarm for Motorcycle

Directory of Open Access Journals (Sweden)

Ismail Ismail

2015-11-01

Full Text Available A security alarm for motorcycle has been developed. This equipment consists of two parts. Part one is as a remote control, where it produces a radio signal with frequency of 37.5 MHz to turn on (activate or to turn off alarm. Part two consists of sensor, receiver to receive signal from part one, and alarm. This part two will be attached to motorcycle while part one will be kept as a key by the owner of motorcycle. This equipment has been tested in the laboratory and it worked well. When part two is activated by pushing the “set button” in part one, then any movement of part two (as a movement of motor cycle by about 20 cm from initial position will cause the alarm sounds continuously. The alarm will be off whenever the “reset button” in part one is pushed. Part one (a remote control can activate part two with a maximum of twelve meter separation apart. This shows that the equipment can be used as a security alarm to prevent the motorcycle to be stolen in the future.

Transportable criticality alarm system

International Nuclear Information System (INIS)

Clem, W.E.

1988-09-01

The Transportable Criticality Alarm System was developed at the Hanford Site in 1982 to comply with the requirements of US Department of Energy Order DOE 5480.1, 12/18/80, and ANSI/ANS-8.3- 1979. The portable unit that it replaced failed to comply with the new requirements in that it did not provide the necessary warning of malfunctions, nor did it provide the Hanford Site standard criticality alarm signal. Modern technology allowed the Transportable Criticality Alarm System to comply with the criticality requirements cited and to incorporate other features that make it more usable, maintainable, and reliable. The Transportable Criticality Alarm System (TCAS) provides temporary criticality coverage in manned areas where the facility criticality alarm system is not operable. This gamma radiation-sensitive system has been in use for the past 6 yr at the Hanford Site. 2 refs., 4 figs., 1 tab

Mexican gems as thermoluminescent dosimeters

International Nuclear Information System (INIS)

Azorin N, J.

1979-01-01

The possibility of using naturally ocurring mexican gems as thermoluminescent dosimeters (TLD) was investigated. Twelve types of gems were irradiated with X and gamma rays in order to determinate their dosimetric properties. Three of these gems showed favorable thermoluminescent characteristics compared with commercial thermoluminescent dosimeters. The plots of their thermoluminescent response as a function of gamma dose are straight lines on full log paper in the dose range 10 -2 to 10 2 Gy. The energy dependence is very strong to low energies of the radiation. Their fading was found to be about 5%/yr. and they may be annealed as reused without loss in sensitivity. Therefore, these gems can be used as X and gamma radiation dosimeters. (author)

Evaluation of personal integrating dosimeters

International Nuclear Information System (INIS)

Correa, C.A.; Bisauta, Mauricio A.

2007-01-01

The objective of this work is to analyze the different types of dosimeters present in the international market that are used to provide personal dose monitoring, specifically for external gamma and beta radiation, Hp(10) and Hp (0,07), as well as to add comments of advances in the field of passive and operative dosimetry, and the changes that are being produced in the regulating policy in other countries regarding the use of this devices. The technical specification of each dosimeter has been extracted of different catalogues of products. To conclude, the importance has been stressed in a proper selection of dosimeters with its advantages and disadvantages before its use. (author) [es

Research on the formula of radiochromic film dosimeters

International Nuclear Information System (INIS)

Li Huazhi; Xiao Zhenhong; Lin Min; Cui Ying; Chen Kesheng; Chen Yundong; Ye Hongsheng; Lin Jingwen

2006-10-01

The formula of radiochromic film dosimeters was studied. Commercially available nylon was used as the matrix, while hexahydroxyethyl pararosaniline cyanide (HPR-CN) and pararosaniline cyanide (PR-CN) that are made in China and other countries were used as the dyes of the dosimeters. the performance of the thin film dosimeters made in CIAE was tested and compared with each other. The formula of the dosimeters was finally confirmed by testing its physical properties and dosimetric characteristics. (authors)

Development and dosimetric evaluation of radiochromic PCDA vesicle gel dosimeters

International Nuclear Information System (INIS)

Sun, P.; Fu, Y.C.; Hu, J.; Hao, N.; Huang, W.; Jiang, B.

2016-01-01

The gel dosimeter has the unique capacity in recording radiation dose distribution in three dimensions (3D), which has the specific advantages in dosimetry measurements where steep dose gradients exist, such as in intensity-modulated radiation therapy (IMRT), brachytherapy and so on. Some 3D dosimeters, such as Fricke gel dosimeters, polymer gel dosimeters, the PRESAGE plastic dosimeters and micelle gel dosimeters have appeared recently. However, there are several disadvantages of these 3D dosimeters limit their application in radiotherapy dose verification. In this study, a novel radiochromic gel dosimeter for 3D dose verification of radiotherapy was developed by dispersing nanovesicles self-assembled by 10,12-pentacosadiynoic acid (PCDA) into the tissue equivalence gel matrix. The characteristics of radiochromic PCDA vesicle gel dosimeters were evaluated. The results indicate that these radiochromic gel dosimeters have good linear dose response to X-ray irradiation in the dose range of 2–100 Gy. In addition, the radiochromic gel dosimeters breakthrough the limitations of the existing gel dosimeters such as diffusion effect, post-radiation effect, and poor forming ability. The response of the gel dosimeter does not show any dose rate dependence, energy dependence and temperature effect, and there was no obvious difference in the gel response between single and cumulative dose of fractional irradiation. Hence, the radiochromic PCDA vesicle gel dosimeters developed in this study could be generally applied to 3D dose verification in radiotherapy. - Highlights: • A novel radiochromic gel dosimeter was developed by dispersing PCDA nanovesicles into the tissue equivalence gel matrix. • This nanovesicle overcomes the dose image blurring caused by the diffusion of monomer molecules. • This nanovesicle limits the polymer chain growth, so as to reduce the post-radiation effect. • The gel matrixes possess excellent tissue equivalence and elastic strength, which

Magnetic field dosimeter development

International Nuclear Information System (INIS)

Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

1980-09-01

In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation

Use of wrist albedo neutron dosimeters

International Nuclear Information System (INIS)

Hankins, D.E.

1983-01-01

We are developing a wrist dosimeter that can be used to measure the exposure at the wrist to x-rays, gamma rays, beta-particles, thermal neutrons and fast neutrons. It consists of a modified Hankins Type albedo neutron dosimeter and also contains three pieces of CR-39 plastic. ABS plastic in the form of an elongated hemisphere provides the beta and low energy x-ray shielding necessary to meet the requirement of depth dose measurements at 1 cm. The dosimeter has a beta window located in the side of the hemisphere oriented towards an object being held in the hands. A TLD 600 is positioned under the 1 cm thick ABS plastic and is used to measure the thermal neutron dose. At present we are using Velcro straps to hold the dosimeter on the inside of the wrist. 9 figures

Object oriented design in the AGSDCS alarm system

International Nuclear Information System (INIS)

Morris, J.T.

1994-01-01

The alarm subsystem of the Alternating Gradient Synchrotron Distributed Control System (AGSDCS) has been redesigned to enhance reliability, flexibility, and ease of maintenance. The alarm system is functionally divided into Alarm Generators, Alarm Displays, and a central Alarm Receiver. The task was simplified by defining a set of C++ classes that could be reused by all components of the alarm system. The AlarmData class represents instances of alarm conditions. The AlarmFilter class is used by both the Alarm Receiver and Alarm Displays to select the alarms that are of interest to a particular user. The AlarmDatabase class is used by the Alarm Receiver to manage the central alarm database. The Alarm Displays use the AlarmDatabase class to manage the local database representing the alarms on their screens. ((orig.))

Evaluation of fading factor and self-dose for glass dosimeter and thermoluminescence dosimeter

International Nuclear Information System (INIS)

Yamasaki, T.; Yamanishi, H.; Miyake, H.; Komura, K.

2000-01-01

The glass dosimeter (GD) and thermoluminescence dosimeter (TLD) are both passive radiation detectors. They are often used for measuring environmental radiation. In order to measure low dose rate preciously, it is important to evaluate decreased dose due to fading and self-dose during the exposure period. We evaluate the fading factor and self-dose of thee passive detectors, GD and TLD. We select Ogoya tunnel for the experiment. The tunnel is suitable field for measuring faded dose and self-dose because it is low cosmic radiation. At the center of the tunnel, the intensity of cosmic ray is reduced to about 1/177 than the outside of the funnel. We prepared two sets of dosimeters. One set consists of five GDs, five TLDs and some pre-irradiated GDs and TLDs that are exposed to standard radiation of 4 mGy by Cs-137. These dosimeters are put in the 10 cm thick lead box in order to shield the terrestrial gamma ray. One set is located at the center of the tunnel and the other is the outside of the funnel. The dosimeters were exposed for ten months, from May 1998 to March 1999. After the exposure, the readers of dosimeters are carried into the funnel to read out the signals promptly as soon as taking out the dosimeters. As a result of the measurement, four kinds of data are taken for GD and TLD respectively. Assumed that the self-dose and cosmic ray are constant during exposure, the four independent unknown quantities, a self-dose a dose due to cosmic ray and a fading coefficient at the center of the tunnel and at the outside, are considered. Therefore four simultaneous equations should be obtained. From these examinations, the faded dose of GD is less than 1%, but that of TLD is about 16% during ten months. The coefficient for compensation of fading of GD and TLD is given as the half of the each value. At the outside of the tunnel, the measured dose rate of cosmic ray that can pass through the 10 cm lead is evaluated to be about 16 nGy/h by both detectors. The self

Personal noise dosimeters: Accuracy and reliability in varied settings

Directory of Open Access Journals (Sweden)

Sheri Lynn Cook-Cunningham

2014-01-01

Full Text Available This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units in both pink noise (PN environments and natural environments (NEs through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3 Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b all dosimeters were within the recommended American National Standard Institute (ANSI SI.25-1991 standard of ±2 dB (A of a reference measurement; and (c all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students. This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured

Automatic patient respiration failure detection system with wireless transmission

Science.gov (United States)

Dimeff, J.; Pope, J. M.

1968-01-01

Automatic respiration failure detection system detects respiration failure in patients with a surgically implanted tracheostomy tube, and actuates an audible and/or visual alarm. The system incorporates a miniature radio transmitter so that the patient is unencumbered by wires yet can be monitored from a remote location.

Floating Gate CMOS Dosimeter With Frequency Output

Science.gov (United States)

Garcia-Moreno, E.; Isern, E.; Roca, M.; Picos, R.; Font, J.; Cesari, J.; Pineda, A.

2012-04-01

This paper presents a gamma radiation dosimeter based on a floating gate sensor. The sensor is coupled with a signal processing circuitry, which furnishes a square wave output signal, the frequency of which depends on the total dose. Like any other floating gate dosimeter, it exhibits zero bias operation and reprogramming capabilities. The dosimeter has been designed in a standard 0.6 m CMOS technology. The whole dosimeter occupies a silicon area of 450 m250 m. The initial sensitivity to a radiation dose is Hz/rad, and to temperature and supply voltage is kHz/°C and 0.067 kHz/mV, respectively. The lowest detectable dose is less than 1 rad.

Neutron dosimeter utilizing CR-39

International Nuclear Information System (INIS)

Souza, H.V.C. de.

1991-05-01

A personnel neutron dosimeter has been developed with discretization in a wide range of energies of real interest, utilizing the CR-39 polymer, to detect recoil protons in the fast range, and alpha particles in the thermal and epithermal ranges, with possibility to be disposed in the IRD/CNEN's conventional film badge suport. They are presented, abstractly, the difficulties and importance of the neutron dosimetry, beyond the general objectives that motivated this work execution. The details of the materials utilized in the dosimeter confection, and the experimental methodology employed to obtain the performance curves are presented. The results about linearity response of the dosimeter with respect to equivalent dose, in a wide range of doses, and about the verified angular dependence are analysed. (author)

Central alarm system replacement in NPP Krsko

International Nuclear Information System (INIS)

Cicvaric, D.; Susnic, M.; Djetelic, N.

2004-01-01

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)

Development of radiation alarm monitor

International Nuclear Information System (INIS)

Myung Jae Song; Myung Chan Lee; Jung Kwan Son

1997-01-01

The Radiation Alarm Monitor is developed domestically in order to protect radiation workers from over exposure. The Radiation Alarm Monitor with microprocessor installed can record the information of radiation field before and after accidents. It can also provide the data to analyze the accident and to set a counterplan. It features a wide detection range of radiation (I OmR/h - I OOR/h), radiation work and data storage, portability, high precision (5%) due to calibration, and adaptation of a powerful alarm system. In order to protect workers from over exposure, light and sound alarm had been designed to initiate when accident occurs such as an unexpected change of radiation field such as radiation rate and accumulated dosed between 90 min. before the alarm and 30 min. after the alarm. In addition, the Radiation Alarm Monitor interfaces with computer so that the accident can be analyzed. After the testing conditions in other countries for the Radiation Alarm Monitor were compared, the most stringent test, ANSI N42. 17-A, was selected. The performance testing was car-ried out under various conditions of temperature, humidity, vibration and electromagnetic wave hindrance by Korea Research Institute of Standards and Science (KRISS). As a result, the Radiation Alan-n Monitor passed all test. Also, for the Radiation Alarm Monitor, environmental adaptability tests under the environmental conditions of NPP sites had been performed. The Radiation Alan-n Monitor had been reviewed by radiation workers at NPPs and their opinions had been collected. Operating procedure will be written and distributed to every NPP sites. Radiation Alarm Monitor will be modified for use under the specific environmental conditions of each site. It will be distributed to NPP sites and will be used by radiation workers

Intercomparison of high energy neutron personnel dosimeters

International Nuclear Information System (INIS)

McDonald, J.C.; Akabani, G.; Loesch, R.M.

1993-03-01

An intercomparison of high-energy neutron personnel dosimeters was performed to evaluate the uniformity of the response characteristics of typical neutron dosimeters presently in use at US Department of Energy (DOE) accelerator facilities. It was necessary to perform an intercomparison because there are no national or international standards for high-energy neutron dosimetry. The testing that is presently under way for the Department of Energy Laboratory Accreditation Program (DOELAP) is limited to the use of neutron sources that range in energy from about 1 keV to 2 MeV. Therefore, the high-energy neutron dosimeters presently in use at DOE accelerator facilities are not being tested effectively. This intercomparison employed neutrons produced by the 9 Be(p,n) 9 B interaction at the University of Washington cyclotron, using 50-MeV protons. The resulting neutron energy spectrum extended to a maximum of approximately 50-MeV, with a mean energy of about 20-MeV. Intercomparison results for currently used dosimeters, including Nuclear Type A (NTA) film, thermoluminescent dosimeter (TLD)-albedo, and track-etch dosimeters (TEDs), indicated a wide variation in response to identical doses of high-energy neutrons. Results of this study will be discussed along with a description of plans for future work

EPR of gamma-irradiated polycrystalline alanine-in-glass dosimeter

International Nuclear Information System (INIS)

Al-Karmi, Anan M.; Morsy, M.A.

2008-01-01

This study attempts to overcome some of the reported discrepancies in alanine-EPR reproducibility that may be related to alanine dosimeter preparation and/or EPR spectrometer settings. The dosimeters were prepared by packing pure polycrystalline L-α-alanine directly as supplied by the manufacturer in glass tubes. This dosimeter production scheme avoids any possible contribution to the EPR signal from a binding material. The dosimeters were irradiated with gamma ray to low-dose ranges typical for medical therapy (0-20 Gy). Special attention has been paid to the study of minimum detectable dose, measurement repeatability and reproducibility, and post-irradiation stability. The dosimeter exhibited a linear dose response in the dose range from 0.1 to 20 Gy. These positive properties favor the polycrystalline alanine-in-glass tube as a radiation dosimeter

Application of Glycine-TTC dosimeter in gamma radiation processing facility

International Nuclear Information System (INIS)

Shinde, S.H.; Mondal, S.; Kulkarni, M.S.

2018-01-01

Glycine-TTC dosimeter was found to have a useful dose range of 5 to 30 kGy using spectro-photometric read-out method. Potential use of this dosimeter was demonstrated by measuring dose-rate in gamma chamber GC 900. The aim of the present study was to verify the performance of this dosimeter in actual industrial processing conditions encountered in radiation processing facility such as Gamma Radiation Processing Plant for Spices (GRPPS), BRIT, Vashi. Accordingly, glycine-TTC dosimeters were irradiated along with routine dosimeter viz. ceric-cerous of GRPPS and reference standard dosimeter viz. alanine EPR

Criticality alarm device

International Nuclear Information System (INIS)

Kasai, Kenji.

1994-01-01

The device of the present invention is utilized, for example, to a reprocessing facility for storing and processing nuclear fuels and measures and controls the nuclear fuel assembly system so as not to exceed criticality. That is, a conventional criticality alarm device applies a predetermined processing to neutron fluxes generated from a nuclear fuel assembly system containing nuclear fuels and outputs an alarm. The device of the present invention comprises (1) a neutron flux supply source for increasing and decreasing neutron fluxes periodically and supplying them to nuclear fuel assemblies, (2) a detector for detecting neutron fluxes in the nuclear fuel assemblies, (3) a critical state judging section for judging the critical state of the nuclear fuel assemblies based on the periodically changing signals obtained from the detector (2) and (4) an alarm section for outputting criticality alarms depending on the result of the judgement. The device of the present invention can accurately recognize the critical state of the nuclear fuel assembly system and can forecast reaching of the nuclear fuel assembly to criticality or prompt neutron critical state. (I.S.)

Type tests to the automatic thermoluminescent dosimetry system acquired by the CPHR for personal dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal

Energy Technology Data Exchange (ETDEWEB)

Molina P, D.; Pernas S, R.; Martinez G, A. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Calle 20 No. 4113 e/41 y 47. Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba)

2006-07-01

The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF:Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

Bronchial dosimeter for radon progeny

Energy Technology Data Exchange (ETDEWEB)

Cheung, T.K.; Yu, K.N.; Nikezic, D.; Haque, A.K.M.M. [City University of Hong Kong, Hong Kong (China); Vucic, D. [Faculty of Technology, University of Nis, Lescovac (Yugoslavia)

2000-05-01

Traditionally, assessments of the bronchial dose from radon progeny were carried out by measuring the unattached fraction (f{sub p}) of potential alpha energy concentration (PAEC), the total PAEC, activity median diameters (AMDs) and equilibrium factor, and then using dosimetric lung models. A breakthrough was proposed by Hopke et al. (1990) to use multiple metal wire screens to mimic the deposition properties of radon progeny in the nasal (N) and tracheobronchial (T-B) regions directly. In particular, they were successful in using four layers of 400-mesh wire screens with a face velocity of 12 cm s{sup -1} for the simulation of radon progeny deposition in the T-B region. Oberstedt and Vanmarcke (1995) carried out precise calibrations for the system, and named the system as the 'bronchial dosimeter'. Based on these, Yu and Guan (1998) proposed a portable bronchial dosimeter similar to a normal measurement system for radon progeny or PAEC and consisted of only a single sampler and employed only one 400-mesh wire screen and one filter. However, all these 'bronchial dosimeters' in fact only determined the fraction of potential alpha energy from radon progeny deposited in the T-B region, which required certain assumptions and calculations to further give the final bronchial dose. In the present work, a true 'bronchial dosimeter' was designed, which consisted of three 400-mesh wire screens and a filter. With a face velocity of 11 cm s{sup -1}, the deposition pattern on the wire screens was found to satisfactorily match the variation of the dose conversion factor (in the unit of mSv/WLM) with the size of radon progeny from 1 to 1000 nm. In this way, this bronchial dosimeter directly gave the bronchial dose from the alpha counts recorded on the wire-screens and the filter paper. With the development of this bronchial dosimeter, the present practice of 'dose estimation' from large-scale radon surveys can be replaced by large

Compton effect thermally activated depolarization dosimeter

Science.gov (United States)

Moran, Paul R.

1978-01-01

A dosimetry technique for high-energy gamma radiation or X-radiation employs the Compton effect in conjunction with radiation-induced thermally activated depolarization phenomena. A dielectric material is disposed between two electrodes which are electrically short circuited to produce a dosimeter which is then exposed to the gamma or X radiation. The gamma or X-radiation impinging on the dosimeter interacts with the dielectric material directly or with the metal composing the electrode to produce Compton electrons which are emitted preferentially in the direction in which the radiation was traveling. A portion of these electrons becomes trapped in the dielectric material, consequently inducing a stable electrical polarization in the dielectric material. Subsequent heating of the exposed dosimeter to the point of onset of ionic conductivity with the electrodes still shorted through an ammeter causes the dielectric material to depolarize, and the depolarization signal so emitted can be measured and is proportional to the dose of radiation received by the dosimeter.

Calibration and testing of the DMG gamma dosimeter

International Nuclear Information System (INIS)

Dolgirev, E.I.

1987-01-01

25-1000 nGy/h (2.5-1000 μrad/h) absorbed dose gamma dosimeter for measuring the efficient equivalent irradiation dose for population is developed. It has two subranges 1000 nGy/h and 250 nGy/h. Results of dosimeter calibration and testing are presented. The dosimeter error for both subranges is less than 10%

CRRES dosimeter simulations

International Nuclear Information System (INIS)

Auchampaugh, G.; Cayton, T.

1993-04-01

Conflicting data have been obtained from electron instruments aboard CRRES (Combined Release and Radiation Effects Satellite). To gain insight and to help in the interpretation of the data, we have calculated electron- and proton-flux and dose response functions for the four domes of the CRRES dosimeters using the Los Alamos Monte Carlo radiation transport codes. The response functions were calculated for electron and proton energies representative of those present in the space radiation environment. We also calculated the response of the dosimeters to a model radiation environment for orbit 607, which occurred on April 1, 1991 and compared the results to the measured values. The electron and proton components of the radiation environment were calculated using the solar maximum versions of the AE8 and AP8 models, namely, AE8MAX and AP8MAX. To facilitate the second task, we wrote two FORTRAN programs (CRRESunderscoreSIMP for AP8MAX and CRRESunderscoreSIME for AE8MAX) to read in a standard CRRES data file and to produce a comparison file of the calculated and measured values for all four dosimeter domes.The FORTRAN code will be available to the Phillips Laboratory for their use in making comparisons to other orbital data

Dose measurement during defectoscopic work using electronic personal dosimeters

International Nuclear Information System (INIS)

Smoldasova, J.

2008-01-01

Personal monitoring of the external radiation of radiation, personnel exposed to sources of ionizing radiation at a workplace is an important task of the radiological protection. Information based on the measured quantities characterizing the level of the exposure of radiation personnel enable to assess the optimum radiological protection at the relevant workplace and ascertain any deviation from the normal operation in time. Different types of personal dosimeters are used to monitor the external radiation of radiation personnel. Basically, there are two types of dosimeters, passive and active (electronic). Passive dosimeters provide information on the dose of exposure after its evaluation, while electronic dosimeters provide this information instantly. The goal of the work is to compare data acquired during different working activities using the DMC 2000 XB electronic dosimeters and the passive film dosimeters currently used at the defectoscopic workplace. (authors)

Reactor Gamma Heat Measurements with Calorimeters and Thermoluminescence Dosimeters

DEFF Research Database (Denmark)

Haack, Karsten; Majborn, Benny

1973-01-01

Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than calorimet......Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than...... calorimeters, but possess advantages such as a small probe size and the possibility of making simultaneous measurements at many different positions. Hence, thermoluminescence dosimeters may constitute a valuable supplement to calorimeters for reactor γ-ray heating measurements....

Role of gel dosimeters in boron neutron capture therapy

International Nuclear Information System (INIS)

Khajeali, Azim; Farajollahi, Ali Reza; Khodadadi, Roghayeh; Kasesaz, Yaser; Khalili, Assef

2015-01-01

Gel dosimeters have acquired a unique status in radiotherapy, especially with the advent of the new techniques in which there is a need for three-dimensional dose measurement with high spatial resolution. One of the techniques in which the use of gel dosimeters has drawn the attention of the researchers is the boron neutron capture therapy. Exploring the history of gel dosimeters, this paper sets out to study their role in the boron neutron capture therapy dosimetric process. - Highlights: • Gel dosimeters have been investigated. • Conventional dosimetric proses of BNCT has been investigated. • Role of gel dosimeters in BNCT has been investigated

Polymer gel dosimeter based on itaconic acid

International Nuclear Information System (INIS)

Mattea, Facundo; Chacón, David

2015-01-01

A new polymeric dosimeter based on itaconic acid and N, N’-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158 cGy/min, 226 cGy min and 298 cGy/min with doses up to 1000 Gy. The dosimeters presented a linear response in the dose range 75–1000 Gy, sensitivities of 0.037 1/Gy at 298 cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species. - Highlights: • A novel polymer gel dosimeters based on itaconic acid is presented and characterized. • The typical linear trend of the dose behavior in a specific dose range was found. • Different gel structures were formed when oxygen and an antioxidant were present. • Absorbed dose is univocally correlated with optic absorbance and Raman spectroscopy. • Itaconic acid appears as a reliable radiation dosimeter that may be further improved.

Fundamental Principles of Alarm Design

DEFF Research Database (Denmark)

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...... 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...

The CANDU alarm analysis tool (CAAT)

Energy Technology Data Exchange (ETDEWEB)

Davey, E C; Feher, M P; Lupton, L R [Control Centre Technology Branch, ON (Canada)

1997-09-01

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.

The CANDU alarm analysis tool (CAAT)

International Nuclear Information System (INIS)

Davey, E.C.; Feher, M.P.; Lupton, L.R.

1997-01-01

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

Type tests to the automatic system of thermoluminescent dosimetry acquired by the CPHR for personnel dosimetry; Pruebas tipo al sistema de dosimetria termoluminiscente automatico adquirido por el CPHR para dosimetria personal

Energy Technology Data Exchange (ETDEWEB)

Molina P, D.; Pernas S, R. [Centro de Proteccion e Higiene de las Radiaciones (CPHR), Calle 20, No. 4113 e/ 41 y 47, Miramar, Ciudad de la Habana (Cuba)]. e-mail: daniel@cphr.edu.cu

2005-07-01

The CPHR individual monitoring service acquired an automatic RADOS TLD system to improve its capacities to satisfy the increasing needs of their national customers. The TLD system consists of: two automatic TLD reader, model DOSACUS, a TLD irradiator and personal dosimeters card including slide and holders. The dosimeters were composed by this personal dosimeters card and LiF: Mg,Cu,P (model GR-200) detectors. These readers provide to detectors a constant temperature readout cycle using hot nitrogen gas. In order to evaluate the performance characteristics of the system, different performance tests recommended by the IEC 1066 standard were carried out. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy dependence, residual signal and fading. The results of the tests showed good performance characteristics of the system. (Author)

Some points of advanced alarm system design

International Nuclear Information System (INIS)

Hollo, E.

1977-01-01

A description of some of the more relevant questions relating to advanced alarm systems for nuclear power plant installations. The development of such alarm systems embodies three main tasks: development of formal alarm handling methods, design of alarm patterns, development of alarm analysis systems. The major aspects of these tests are dealt with and the close relation between the alarm analysis and the plant disturbance analysis procedure is emphasized. (author)

Evaluating alternative responses to safeguards alarms

International Nuclear Information System (INIS)

Al-Ayat, R.A.; Judd, B.R.; McCord, R.K.

1982-01-01

This paper describes a quantitative approach to help evaluate and respond to safeguards alarms. These alarms may be generated internally by a facility's safeguards systems or externally by individuals claiming to have stolen special nuclear material (SNM). This approach can be used to identify the most likely cause of an alarm - theft, hoax, or error - and to evaluate alternative responses to alarms. Possible responses include conducting investigations, initiating measures to recover stolen SNM, and replying to external threats. Based on the results of each alarm investigation step, the evaluation revises the likelihoods of possible causes of an alarm, and uses this information to determine the optimal sequence of further responses. The choice of an optimal sequence of responses takes into consideration the costs and benefits of successful thefts or hoaxes. These results provide an analytical basis for setting priorities and developing contingency plans for responding to safeguards alarms

Space charge dosimeters for extremely low power measurements of radiation in shipping containers

Science.gov (United States)

Britton, Jr; Charles, L [Alcoa, TN; Buckner, Mark A [Oak Ridge, TN; Hanson, Gregory R [Clinton, TN; Bryan, William L [Knoxville, TN

2011-04-26

Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

US progress on the development of CR-39 based neutron dosimeters

International Nuclear Information System (INIS)

Hadlock, D.E.

1987-06-01

Historically at US nuclear facilities, two types of personnel neutron dosimeters have been in routine use: nuclear track emulsion-Type A (NTA) film and thermoluminescent dosimeter (TLD)-albedo. Both of these dosimeters have energy-dependent responses. Therefore, the neutron energy spectra must be known, to interpret the dosimeter results properly. A new state-of-the-art dosimetry system has been developed within the US Department of Energy (US DOE) Personnel Neutron Dosimeter Evaluation and Upgrade Program. This system is called the combination thermoluminescent dosimeter/track etch dosimeter (TLD/TED). This paper briefly describes US DOE research currently being conducted to further enhance the TED portion of the combination TLD/TED system. The research areas involved include dose sensitivity, neutron energy range, specialized radiators, self-developing dosimeters, and neutron spectrometry. 1 fig., 1 tab

X-rays individual dose assessment using TLD dosimeters

International Nuclear Information System (INIS)

Salas, Carlos

2008-01-01

This paper describes the methodology used in Embalse NPP for measuring individual X-ray dose in dentists and radiologists, who work in areas near the plant. Personnel is provided with TLD personal dosimeters for thoracic use, as well as TLD ring dosimeters. This individual X-ray dosimetry is fundamental in order to know the effective energy coming from the radiation field, since the dosimetry factors depend on it. On the other hand, the response of the TLD crystals also depends of the effective energy; this accentuates the problem when assessing the individual dose. The X-ray dosimeter must simultaneously determine the value of the effective energy and the corresponding dose value. The basic principle for determining effective energy is by using at least two different TLD materials covered by filters of different thickness. The TLD materials used have totally energy responses. Therefore, different readouts from each of the crystals are obtained. The ratio between both readouts provides a factor that depends of the effective energy but that is 'independent' from the exposure values irradiated to the dosimeter. The Personal TLD dosimeter currently in use is Bicron-Harshaw. It comprises a carrier model 8807. This carrier contains a card model 2211 which groups two TLD 200 crystals and two TLD 100 crystals. It has internal filters at each side of the TLD 200 crystals. The periodical calibration of these dosimeters consists in the irradiation of some dosimeters with different X-ray energy beams in the National Atomic Energy Commission (CNEA). This dosimeter was used, by the National Regulatory Authority (ARN) in several comparisons, always getting satisfactory results. (author)

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

Directory of Open Access Journals (Sweden)

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.

An Emergency Dosimeter for Neutrons

Energy Technology Data Exchange (ETDEWEB)

Braun, J; Nilsson, R

1960-05-15

A neutron dosimeter suitable for single emergency exposures is described. The dosimeter is furnished with detectors for thermal, epi-thermal and fast neutrons. This means that three of the constants by which the spectrum of the incident neutron flux is approximated, can be determined. The dose calculated from these approximated spectra is compared to the dose from spectra obtained in different standard spectra of types which may be expected in a radiation accident.

Review of Fricke gel dosimeters

International Nuclear Information System (INIS)

Schreiner, L J

2004-01-01

The innovation of adding a gel matrix to the traditional Fricke dosimeter to stabilize geometric information established the field of gel dosimetry for radiation therapy. A discussion of Fricke gels provides an overview of the issues that determine the dose response of all gel dosimeters in general. In this paper we review some of the features of Fricke systems to illustrate these issues and, in addition, to motivate renewed clinical interest in Fricke gels

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

Energy Technology Data Exchange (ETDEWEB)

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)

Fiber-optic dosimeters for radiation therapy

Science.gov (United States)

Li, Enbang; Archer, James

2017-10-01

According to the figures provided by the World Health Organization, cancer is a leading cause of death worldwide, accounting for 8.8 million deaths in 2015. Radiation therapy, which uses x-rays to destroy or injure cancer cells, has become one of the most important modalities to treat the primary cancer or advanced cancer. The newly developed microbeam radiation therapy (MRT), which uses highly collimated, quasi-parallel arrays of x-ray microbeams (typically 50 μm wide and separated by 400 μm) produced by synchrotron sources, represents a new paradigm in radiotherapy and has shown great promise in pre-clinical studies on different animal models. Measurements of the absorbed dose distribution of microbeams are vitally important for clinical acceptance of MRT and for developing quality assurance systems for MRT, hence are a challenging and important task for radiation dosimetry. On the other hand, during the traditional LINAC based radiotherapy and breast cancer brachytherapy, skin dose measurements and treatment planning also require a high spatial resolution, tissue equivalent, on-line dosimeter that is both economical and highly reliable. Such a dosimeter currently does not exist and remains a challenge in the development of radiation dosimetry. High resolution, water equivalent, optical and passive x-ray dosimeters have been developed and constructed by using plastic scintillators and optical fibers. The dosimeters have peak edge-on spatial resolutions ranging from 50 to 500 microns in one dimension, with a 10 micron resolution dosimeter under development. The developed fiber-optic dosimeters have been test with both LINAC and synchrotron x-ray beams. This work demonstrates that water-equivalent and high spatial resolution radiation detection can be achieved with scintillators and optical fiber systems. Among other advantages, the developed fiber-optic probes are also passive, energy independent, and radiation hard.

Silicon Diode Dosimeter for Fast Neutrons

International Nuclear Information System (INIS)

Svansson, L.; Widell, C.O.; Swedberg, P.; Wik, M.

1968-11-01

The change of the current-voltage characteristics of a small silicon diode is used as a measure of fast neutron dose in the Fast Neutron Dosimeter 5422. This change is permanent and therefore it is possible to integrate doses over a long period of time. Doses from some rad up to 1000 rad can be measured and the information stored is not destroyed during readout. Considerable research work in this field has previously been carried out by the Swedish Institute for National Defence in collaboration with the Institute of Semiconductor Research Stockholm. The present investigation has been made in order to establish the possibilities of the dosimeter for practical applications and to study the variations of important parameters as a function of the production process. In particular the following parameters have been studied: - dose sensitivity, - energy dependence; - fading effect; - temperature influence; - maximum measurable dose. In general one might conclude that the dosimeter 5422 well fulfills requirements usually specified for a dosimeter for field service. Temperature influence and fading effect are of little practical importance within the recommended range of measurement

Silicon Diode Dosimeter for Fast Neutrons

Energy Technology Data Exchange (ETDEWEB)

Svansson, L; Widell, C O; Swedberg, P [The Inst. of Semiconductor Researc h, Stockholm (Sweden); Wik, M [The Swedish Institute for National Defence, Sun dbyberg (Sweden)

1968-11-15

The change of the current-voltage characteristics of a small silicon diode is used as a measure of fast neutron dose in the Fast Neutron Dosimeter 5422. This change is permanent and therefore it is possible to integrate doses over a long period of time. Doses from some rad up to 1000 rad can be measured and the information stored is not destroyed during readout. Considerable research work in this field has previously been carried out by the Swedish Institute for National Defence in collaboration with the Institute of Semiconductor Research Stockholm. The present investigation has been made in order to establish the possibilities of the dosimeter for practical applications and to study the variations of important parameters as a function of the production process. In particular the following parameters have been studied: - dose sensitivity, - energy dependence; - fading effect; - temperature influence; - maximum measurable dose. In general one might conclude that the dosimeter 5422 well fulfills requirements usually specified for a dosimeter for field service. Temperature influence and fading effect are of little practical importance within the recommended range of measurement.

Investigation of self-indicating radiation personal dosimeter

International Nuclear Information System (INIS)

Xia Wen; Ye Honsheng; Lin Min; Xu Lijun; Chen Kesheng; Chen Yizhen

2014-01-01

A self-indicating radiation personal dosimeter was investigated using radiation sensitive material diacetylene monomer PCDA, which was a component of the polymerization system. The substrate material, solvent, sensitive material, solution temperature, thickness of film and the preparation method were studied. The dosimeter colour changes from white to blue when exposed 0.1-2.5 Gy, and the linearly dependent coefficient of the exposure response is 0.9998, the stability of absorbency in two weeks after exposure is testified well. It can be used as self-indicating radiation alert personal dosimeter. (authors)

Clinical dosimeter based on diamond detector

International Nuclear Information System (INIS)

Chervjakov, A.M.; Ljalina, L.I.; Ljutina, G.J.; Khrunov, V.S.; Martynov, S.S.; Popov, S.A.

2002-01-01

Full text: Diamond detectors have found application in the relative dosimetry and their parameters have been described elsewhere. Today, the exclusive producer of the diamond detector is the Institute of Physical and Technical Problems, Russia, and exclusive dealer is the PTW-Freiburg. The main features of the diamond detector are good long time stability, suitable range of the energy dependence for photon and electron beams in clinical use, independence of the measured date from temperature and pressure. The high sensitivity per volume unit of the diamond detector (1500 times higher than ionization chamber) allowed using detectors with very small volume (1-5 mm 3 ) and rather simple electronics for ionization current registration. The new dosimeter consists of the diamond detector itself, 40 m registration cable, pre-amplifier, micro-processor block for data handling and absorbed dose calculation using the calibration factor of diamond detector in terms of absorbed dose to water. Dosimeter has the possibility to work with PC using standard RS-232 interface. The main features of the dosimeter are as follows: the range of dose rate measurements for photon, electron and proton beams is within 0.01-1.0 Gy/s; the energy ranges for photons are 0.08-25 MeV, and 4-25 MeV for electrons, with energy dependence no more than ±2%; the main uncertainty of the dose measurements is within ±2%; the pre-irradiation dose for diamond detector is no more than 10 Gy; the sensitive volume of the used diamond detectors is within 1-5 mm 3 ; the weight of the dosimeter no more than 2 kg. The new dosimeter was evaluated at the Central Research Institute of Roentgenology and Radiology, St. Petersburg, Russia to verify its performance. The dosimeter was used as a reference instrument for dose measurements at Cobalt-60 unit, SL75-5 and SL-20 linear accelerators and the test results have shown that the device have met the specifications. It is planned to produce dosimeter as serial device by

Automated analysis of off-line measured gamma-spectra using UniSampo gamma-ray spectrum analysis software including criterias for alarming systems

International Nuclear Information System (INIS)

Nikkinen, M.T.

2005-01-01

In many laboratories the number of measured routine gamma-spectra can be significant and the labour work to review all the data is time consuming and expensive task. In many cases the routine sample does not normally contain radiation above a detectable level, and still the review of the spectra has to be performed. By introducing simple rules for emerging conditions, the review work can be significantly reduced. In one case the need to review the environmental measurement spectra was reduced to less than 1% compared to the original need, which in turn made the review personnel available for more useful functions. Using the UniSampo analysis system, the analysis results of spectra that are causing alarming conditions can be transmitted via e-mail to any address. Some systems are even equipped with the capability to forward these results to hand-portable telephones or pagers. This is a very practical solution for automated environmental monitoring, when the sample spectra are collected automatically and transmitted to central computer for further analysis. Set up of an automatic analysis system, rules for the emerging conditions, technical solutions for an automated alarming system and a generic hypothesis test for the alarming system developed for UniSampo analysis software are described. (author)

Procedure for the delivering of personal short-term visitor dosimeters

CERN Document Server

2016-01-01

Update of the administrative procedure for delivering a personal short-term visitor dosimeter to associated members of CERN’s personnel.   Associated members of the CERN personnel may request a short term visitor dosimeter if working only in Supervised Radiation Areas and for a period of less than two months in a calendar year. Such a dosimeter is delivered without the need to provide the usual regular documents: radiation passport, certificate from the home institute or medical certificate. Periodic verification will ensure that holders of these personal dosimeters do not exceed the maximum allowed personal dose for this type of dosimeter, which is the same as the limit for members of the public at 1 mSv per year. From now on, the two-month period can be spread over a calendar year, offering greater flexibility to users coming to CERN for multiple short periods. Please return unused dosimeters Persons leaving CERN for a period of more than one month should return their dosimeter to the D...

Dose intercomparison study involving Fricke, ethanol chlorobenzene, PMMA and alanine dosimeters

International Nuclear Information System (INIS)

Lanuza, L.G.; Cabalfin, E.G.; Kojima, T.; Tachibana, H.

1999-01-01

A dose intercomparison study was carried out between the Philippine Nuclear Research Institute (PNRI) and Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute (JAERI) to determine reliability of the dosimetry systems being used by PNRI employing ethanol chlorobenzene (ECB), Fricke and alanine dosimeters. The Fricke and ECB dosimeters were prepared at PNRI while the alanine-polystyrene dosimeter was provided by JAERI. Fricke or ECB dosimeters were irradiated together with alanine at PNRI gamma irradiation facilities. Analyses of the Fricke and ECB dosimeters were performed at PNRI while alanine dosimeters were analyzed at JAERI. A comparison study between alanine and polymethylmethacrylate (PMMA, Radix RN15) dosimeters was also undertaken at JAERI. The dosimeters were irradiated together under different irradiation conditions using the gamma irradiation facilities of JAERI and Radia Industry Co. Ltd. (Japan). Evaluations of PMMA and alanine dosimeters were both performed at JAERI. Result of the dose intercomparison of PNRI with the International Atomic Energy Agency through the International Dose Assurance Service (IDAS) is also presented. (author)

Dose intercomparison study involving Fricke, ethanol chlorobenzene, PMMA and alanine dosimeters

Energy Technology Data Exchange (ETDEWEB)

Lanuza, L G; Cabalfin, E G [Philippine Nuclear Research Institute, Quezon City (Philippines); Kojima, T; Tachibana, H [Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research institute, Takasaki (Japan)

1999-03-01

A dose intercomparison study was carried out between the Philippine Nuclear Research Institute (PNRI) and Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute (JAERI) to determine reliability of the dosimetry systems being used by PNRI employing ethanol chlorobenzene (ECB), Fricke and alanine dosimeters. The Fricke and ECB dosimeters were prepared at PNRI while the alanine-polystyrene dosimeter was provided by JAERI. Fricke or ECB dosimeters were irradiated together with alanine at PNRI gamma irradiation facilities. Analyses of the Fricke and ECB dosimeters were performed at PNRI while alanine dosimeters were analyzed at JAERI. A comparison study between alanine and polymethylmethacrylate (PMMA, Radix RN15) dosimeters was also undertaken at JAERI. The dosimeters were irradiated together under different irradiation conditions using the gamma irradiation facilities of JAERI and Radia Industry Co. Ltd. (Japan). Evaluations of PMMA and alanine dosimeters were both performed at JAERI. Result of the dose intercomparison of PNRI with the International Atomic Energy Agency through the International Dose Assurance Service (IDAS) is also presented. (author) 8 refs, 3 figs, 4 tabs

Criticality accident alarm system

International Nuclear Information System (INIS)

Malenfant, R.E.

1991-01-01

The American National Standard ANSI/ANS-8.3-1986, Criticality Accident Alarm System provides guidance for the establishment and maintenance of an alarm system to initiate personnel evacuation in the event of inadvertent criticality. In addition to identifying the physical features of the components of the system, the characteristics of accidents of concern are carefully delineated. Unfortunately, this ANSI Standard has led to considerable confusion in interpretation, and there is evidence that the ''minimum accident of concern'' may not be appropriate. Furthermore, although intended as a guide, the provisions of the standard are being rigorously applied, sometimes with interpretations that are not consistent. Although the standard is clear in the use of absorbed dose in free air of 20 rad, at least one installation has interpreted the requirement to apply to dose in soft tissue. The standard is also clear in specifying the response to both neutrons and gamma rays. An assembly of uranyl fluoride enriched to 5% 235 U was operated to simulate a potential accident. The dose, delivered in a free run excursion 2 m from the surface of the vessel, was greater than 500 rad, without ever exceeding a rate of 20 rad/min, which is the set point for activating an alarm that meets the standard. The presence of an alarm system would not have prevented any of the five major accidents in chemical operations nor is it absolutely certain that the alarms were solely responsible for reducing personnel exposures following the accident. Nevertheless, criticality alarm systems are now the subject of great effort and expense. 13 refs

CVD diamond detectors and dosimeters

International Nuclear Information System (INIS)

Manfredotti, C.; Fizzotti, F.; LoGiudice, A.; Paolini, C.; Oliviero, P.; Vittone, E.; Torino Univ., Torino

2002-01-01

Natural diamond, because of its well-known properties of tissue-equivalence, has recorded a wide spreading use in radiotherapy planning with electron linear accelerators. Artificial diamond dosimeters, as obtained by Chemical Vapour Deposition (CVD) could be capable to offer the same performances and they can be prepared in different volumes and shapes. The dosimeter sensitivity per unit volume may be easily proved to be better than standard ionization microchamber. We have prepared in our laboratory CVD diamond microchamber (diamond tips) in emispherical shape with an external diameter of 200 μm, which can be used both as X-ray beam profilometers and as microdosimeters for small field applications like stereotaxy and also for in vivo applications. These dosimeters, which are obtained on a wire substrate that could be either metallic or SiC or even graphite, display good performances also as ion or synchrotron X-rays detectors

Research, Designing And Manufacture Of Gamma Dosimeter Wireless Data Transfer

International Nuclear Information System (INIS)

Bui Trong Duy; Phan Quoc Minh; Dinh Thi Hien; Ngo Duc Tin; Le Trong Nghia

2013-01-01

The system equipment of wireless data transmission Gamma dosimeter consist of standard RF Gamma dosimeter wireless data transmission and wireless data transceiver connection with a computer via RS232 port. The system is designed based on the PIC processor, Geiger-Muller (GM) counter tube used to measure Gamma radiation and measured results show the equivalent dose rate in microsievert units of the SI system. The data has been displayed on the LCD screen of the meter and at the same time has been sent to the wireless receiving host computer located in the control room at distance of about 300 m via standard RF. The equipment used high-voltage 300-500 VDC. The GM counting tube used as radiation detectors to convert quantum Gamma radiation into electrical impulses, these impulses are counted continuously by microprocessor to compute the counter speed of average dose as well as equivalence dose. The processor automatically set measurement time depends on the different dose rates: In the natural foundation, time is approximately 36 seconds, when the dose rate increases, the time reduced to 1 second. The cumulative dose rate values are displayed on the LCD screen with the unit of measurement for dose rate is µSv/h and µSv for the cumulative dose, the measurement range is set automatically according to the scale of: from 10 to 100 µSv/h. All the electronic components function of low power consumption of about 10 mA plus the consumption of RF module about 20 mA when working in the sending state and 1 mA in standby state. Such devices can operate with type 9 V Alkaline battery placed inside while using portable mode, displaying the results on the LCD screen which does not release data on the host computer. In case meter is fixed to measure continuous for long days, the device will be linked to 9 VDC power, supplied from a rectifier 220 VAC mains to the 9 VDC source. (author)

Ionization smoke detector and alarm system

International Nuclear Information System (INIS)

1974-01-01

An ionization smoke detector particularly suited to residential use is disclosed. The detector is battery-operated and is connected with a non-latching, pulsating alarm circuit. The detector has a sensing chamber formed by a perforated metallic shell and an electrode within which an insulated radiation source is centrally positioned to generate an ionization current for detecting smoke or other similar aerosols. The alarm circuit provides a pulsating alarm signal when smoke levels above a pre-determined value are sensed. The alarm circuit also includes a low voltage detection circuit for sounding the alarm when the end of useful battery life is approaching. (Auth.)

A questionnaire comparison of two alarm systems

International Nuclear Information System (INIS)

Collier, Steven G.

1997-11-01

A questionnaire was developed, based on guidelines for alarm system design given in NUREG/CR-6105. The intentions were both to develop a subjective instrument for rating the effectiveness of alarm systems and to learn lessons on alarm system design from a comparison of two systems. The questionnaire was administered to reactor operations staff at two locations with different alarm systems embedded in a simulation of the same underlying PWR power plant: Loviisa NPP and Halden Man-Machine Laboratory. The questionnaire, considered as a measuring instrument, had good to high reliability and moderate to good content validity. The questionnaire is considered suitable for further use in the shortened form resulting from this study. Further work is also recommended. The degree of reliability and validity also lend a degree of validation to the NUREG guidelines. The questionnaire was able to show differences between ratings of the two alarm systems. The Loviisa system showed more consistency with other control room features and was better at drawing the operators' attention to important alarms. Both systems were not rated particularly well on alarm prioritisation and spurious alarms. The Halden system was better at showing naturally occurring relationships between alarms. Some of these differences may have been due to the subjects' greater familiarity with the Loviisa alarm system. The results nevertheless show that the questionnaire can measure subjective responses to alarm systems. (author)

Calibration of dosimeters at 80-120 keV electron irradiation

DEFF Research Database (Denmark)

Miller, A.; Helt-Hansen, J.

to calibrate thin-film dosimeters (Risø B3 and alanine films) by irradiation at the 80–120 keV electron accelerators. This calibration was compared to a 10MeV calibration, and we show that the radiation response of the dosimeter materials (the radiation chemical yield) is constant at these irradiation energies....... However, dose gradients within the dosimeters, when it is irradiated at low electron energies,mean that calibration function here will depend on both irradiation energy and the required effective point of measurement of the dosimeter. These are general effects that apply to any dosimeter that has a non...

Evaluation of optical fibres as gamma radiation dosimeter

International Nuclear Information System (INIS)

Bohra, Dinesh; Chaudhary, H.S.; Panwar, Lalit; Vaijapurkar, S.G.; Bhatnagar, P.K.; Dasgupta, K.

2005-01-01

Semiconductor base gamma and neutron sensors are the fastest and popular dosimeters and are in competition with Thermoluminescence (TL) and Radio photoluminescence (RPL) dosimeters. All over the world armed forces require a dosimeter which records cumulative doses of ionizing radiations from mcGy to 10 Gy and is readable repeatedly without loss of dose information. TL dosimeters do not meet the criteria and RPL dosimeter meet the expectations and are in use by armed forces. Technologists have used laser as an excitation source to stimulate the glass and have achieved success in recording gamma doses of occupational/accidental span (mcGy to 10 Gy). However synthesizing RPL glass batches with exactly same characteristics predoses is a difficult task. Silicon base phosphorous doped step index multimode optical fibre can be made in a significant quantity and large number of dosimeters from it can be achieved with uniform predose. The radiation induced transmission loss gives a measure of gamma dose which is cumulative, readable repeatedly without loss of information. Assorted composition, core dia optical fibres have been synthesized and evaluated for dose linearity, dose rate independence, fading, length optimization. Here in is described some results of recent experiments and sensitivities achieved. (author)

Characterization of high-sensitivity metal oxide semiconductor field effect transistor dosimeters system and LiF:Mg,Cu,P thermoluminescence dosimeters for use in diagnostic radiology

International Nuclear Information System (INIS)

Dong, S.L.; Chu, T.C.; Lan, G.Y.; Wu, T.H.; Lin, Y.C.; Lee, J.S.

2002-01-01

Monitoring radiation exposure during diagnostic radiographic procedures has recently become an area of interest. In recent years, the LiF:Mg,Cu,P thermoluminescence dosimeter (TLD-100H) and the highly sensitive metal oxide semiconductor field effect transistor (MOSFET) dosimeter were introduced as good candidates for entrance skin dose measurements in diagnostic radiology. In the present study, the TLD-100H and the MOSFET dosimeters were evaluated for sensitivity, linearity, energy, angular dependence, and post-exposure response. Our results indicate that the TLD-100H dosimeter has excellent linearity within diagnostic energy ranges and its sensitivity variations were under 3% at tube potentials from 40 Vp to 125 kVp. Good linearity was also observed with the MOSFET dosimeter, but in low-dose regions the values are less reliable and were found to be a function of the tube potentials. Both dosimeters also presented predictable angular dependence in this study. Our findings suggest that the TLD-100H dosimeter is more appropriate for low-dose diagnostic procedures such as chest and skull projections. The MOSFET dosimeter system is valuable for entrance skin dose measurement with lumbar spine projections and certain fluoroscopic procedures

Fire auto alarm system intelligent trend

International Nuclear Information System (INIS)

Du Chengbao

1997-01-01

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

Hornbills can distinguish between primate alarm calls.

Science.gov (United States)

Rainey, Hugo J.; Zuberbühler, Klaus; Slater, Peter J. B.

2004-01-01

Some mammals distinguish between and respond appropriately to the alarm calls of other mammal and bird species. However, the ability of birds to distinguish between mammal alarm calls has not been investigated. Diana monkeys (Cercopithecus diana) produce different alarm calls to two predators: crowned eagles (Stephanoaetus coronatus) and leopards (Panthera pardus). Yellow-casqued hornbills (Ceratogymna elata) are vulnerable to predation by crowned eagles but are not preyed on by leopards and might therefore be expected to respond to the Diana monkey eagle alarm call but not to the leopard alarm call. We compared responses of hornbills to playback of eagle shrieks, leopard growls, Diana monkey eagle alarm calls and Diana monkey leopard alarm calls and found that they distinguished appropriately between the two predator vocalizations as well as between the two Diana monkey alarm calls. We discuss possible mechanisms leading to these responses. PMID:15209110

Advanced alarm management system

International Nuclear Information System (INIS)

Easter, J.R.

1995-01-01

The Westinghouse Advanced Alarm Management System (AWARE) is one of the Man-Machine Design Interfaces (MMI) which has great flexibility with regard to hardware type and configuration, alarm system concept, plant scope, engineering scope and installation. The AWARE System provides the capability to better manage the quantity prioritization and presentation of real-time process alarm messages in the control room. The messages are specific, precise and dynamic. The AWARE System can provide a large reduction in the number of messages that the control room staff must address at any one time, thus making the alarm message system a useful tool for the operators during situations that normally produce a high volume of messages as well as improving the clarity of the presentation of process abnormalities during small disturbances. The operating staff is now provided with the basis for a better understanding of the current plant state and for taking the appropriate control actions. (2 refs., 3 figs.)

HYBRID ALARM SYSTEMS: COMBINING SPATIAL ALARMS AND ALARM LISTS FOR OPTIMIZED CONTROL ROOM OPERATION

Energy Technology Data Exchange (ETDEWEB)

Ronald L. Boring; J.J. Persensky

2012-07-01

The US Department of Energy (DOE) is sponsoring research, development, and deployment on Light Water Reactor Sustainability (LWRS), in which the Idaho National Laboratory (INL) is working closely with nuclear utilities to develop technologies and solutions to help ensure the safe operational life extension of current nuclear power plants. One of the main areas of focus is control room modernization. Within control room modernization, alarm system upgrades present opportunities to meet the broader goals of the LWRS project in demonstrating the use and safety of the advanced instrumentation and control (I&C) technologies and the short-term and longer term objectives of the plant. In this paper, we review approaches for and human factors issues behind upgrading alarms in the main control room of nuclear power plants.

Personnel ionizing radiation dosimeter

International Nuclear Information System (INIS)

Williams, R.A.

1975-01-01

A dosimeter and method for use by personnel working in an area of mixed ionizing radiation fields for measuring and/or determining the effective energy of x- and gamma radiation; beta, x-, and gamma radiation dose equivalent to the surface of the body; beta, x-, and gamma radiation dose equivalent at a depth in the body; the presence of slow neutron, fast neutron dose equivalent; and orientation of the person wearing the dosimeter to the source of radiation is disclosed. Optionally integrated into this device and method are improved means for determining neutron energy spectrum and absorbed dose from fission gamma and neutron radiation resulting from accidental criticality

Limitations of commonly used thick-element personal dosimeters

International Nuclear Information System (INIS)

Gupta, V.P.

1983-01-01

In the ANSI Standard N13.11, accepted in June 1982, radiation dose depths of 1.0 cm and 0.007 cm in tissue for protection dosimetry have been adopted for deep and shallow dose equivalent estimations respectively. This standard is presently used for a mandatory personnel dosimetry performance testing program in the United States. Estimation of shallow-dose equivalent using a two-element dosimeter is described under the guidelines of this standard and the dosimetry practices followed by most dosimeter processors. A mathematical formulation, correlating a dosimeter response and shallow-dose equivalent factors at different energies, is presented. Also, the performance of a two-element thermoluminescent dosimeter is examined and the shallow-dose equivalent response results, both for the beta particles and photons, are discussed

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

Science.gov (United States)

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

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 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. PMID:25591100

Measurements of SNAC2 area dosimeters placed in different configurations around the PROSPERO reactor and comparison with TRIPOLI-4 calculations

Energy Technology Data Exchange (ETDEWEB)

Rousseau, G.; Chambru, L.; Authier, N. [CEA, Centre de Valduc, 21120 Is-sur-Tille, (France)

2015-07-01

In the context of criticality accident alarm system tests, several experiments were carried out in 2013 on the PROSPERO reactor to study the response to neutron and gamma of different devices and dosimeters, particularly on the SNAC2 dosimeter. This article presents the results of this criticality dosimeter in different configurations, and compares the experimental measurements with the results of calculation performed with the TRIPOLI-4 Monte-Carlo Neutral Particles transport code. PROSPERO is a metallic critical assembly managed by the Criticality, Neutron Science and Measurement Department located at the French CEA Research Center of Valduc. The core, surrounded by a reflector of depleted uranium, is composed of 2 horizontal cylindrical blocks made of a highly enriched uranium alloy which can be placed in contact, and of 4 depleted uranium control rods which allow the reactor to be driven. This reactor, placed in a cell 10 m x 8 m x 6 m high, with 1.4-meter-thick concrete walls, is used as a fast neutron spectrum source and is operated at stable power level in delayed critical state, which can vary from 3 mW to 3 kW. PROSPERO is extensively used for electronic hardening or to study the effect of the neutrons on various materials. The SNAC2 criticality dosimeter is a zone dosimeter allowing the off line measurement of criticality accident neutron doses. This dosimeter consists of the pile up of seven activation foils embedded into a 23 mm diameter x 21 mm height cadmium container. The activation measurement of each foil, using a gamma spectroscopy technique, gives information about the neutron reaction rates. The SNAC2 software allows the spectrum unfolding from these values, taking into account the hypothesis of a particular spectrum shape, in three components: a Maxwell spectrum component for the thermal range, a 1/E component for the epithermal range, and a Watt spectrum component for the high energy range. Moreover, from the neutron spectrum, the SNAC

Reducing false asystole alarms in intensive care.

Science.gov (United States)

Dekimpe, Remi; Heldt, Thomas

2017-07-01

High rates of false monitoring alarms in intensive care can desensitize staff and therefore pose a significant risk to patient safety. Like other critical arrhythmia alarms, asystole alarms require immediate attention by the care providers as a true asystole event can be acutely life threatening. Here, it is illustrated that most false asystole alarms can be attributed to poor signal quality, and we propose and evaluate an algorithm to identify data windows of poor signal quality and thereby help suppress false asystole alarms. The algorithm combines intuitive signal-quality features (degree of signal saturation and baseline wander) and information from other physiological signals that might be available. Algorithm training and testing was performed on the MIMIC II and 2015 PhysioNet/Computing in Cardiology Challenge databases, respectively. The algorithm achieved an alarm specificity of 81.0% and sensitivity of 95.4%, missing only one out of 22 true asystole alarms. On a separate neonatal data set, the algorithm was able to reject 89.7% (890 out of 992) of false asystole alarms while keeping all 22 true events. The results show that the false asystole alarm rate can be significantly reduced through basic signal quality evaluation.

Solid-state personal dosimeter using dose conversion algorithm

International Nuclear Information System (INIS)

Lee, B.J.; Lee, Wanno; Cho, Gyuseong; Chang, S.Y.; Rho, S.R.

2003-01-01

Solid-state personal dosimeters using semiconductor detectors have been widely used because of their simplicity and real time operation. In this paper, a personal dosimeter based on a silicon PIN photodiode has been optimally designed by the Monte Carlo method and also developed. For performance test, the developed dosimeter was irradiated within the energy range between 50 keV and 1.25 MeV, the exposure dose rate between 3 mR/h and 25 R/h. The thickness of 0.2 mm Cu and 1.0 mm Al was selected as an optimal filter by simulation results. For minimizing the non-linear sensitivity on energy, dose conversion algorithm was presented, which was able to consider pulse number as well as pulse amplitude related to absorbed energies. The sensitivities of dosimeters developed by the proposed algorithm and the conventional method were compared and analyzed in detail. When dose conversion algorithm was used, the linearity of sensitivity was better about 38%. This dosimeter will be used for above 65 keV within the relative response of ±10% to 137 Cs

46 CFR 169.732 - Carbon dioxide alarm.

Science.gov (United States)

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.” ...

Practical consequences for the use of a personal dosimeter for fast neutrons based on CR39 exposed up to one year

International Nuclear Information System (INIS)

Boschung, Markus; Fiechtner, Annette; Mayer, Sabine; Wernli, Christian

2008-01-01

Full text: At the Paul Scherrer Institut a personal neutron dosimetry system based on chemically etched CR-39 detectors and automatic track counting is in routine use since 1998. In its original design, the dosimeter is sensitive to thermal neutrons and to neutrons in the energy range from 200 keV up to several MeV. The standard exposition period is 3 months. Recently, a novel concept for individual monitoring was implemented at CERN. In this concept, each worker who possibly enters a radiation zone is equipped with a combined dosimeter for the measurement of personal photon and neutron doses. The dosimeter for photon dose measurement has an instant readout capability and dose measurements are done monthly. The dosimeter for neutron measurement is based on CR-39 detectors and is sensitive to fast neutrons only. The CR-39 detector is only evaluated and a neutron dose determined if the monthly personal photon dose exceeds 2 mSv or if the exposition period of the neutron dosimeter exceeds one year. This novel regime of use of the neutron dosimeter has had some important consequences for its practical implementation. A priori, the wearing period of a neutron dosimeter is not known and can range from 1 month up to 12 or even more months. A good knowledge of the long-term behaviour and characteristics of the detector material is needed. But also organisational and administrative issues have to be considered. The paper will outline the adopted procedure covering not only technical but also organisational aspects. The long-term behaviour of background track density and response to 241 Am-Be over one year are described as well as calibrations performed with 241 Am-Be and 252 Cf sources and in the High-Energy Reference Field Facility at CERN (CERF). The concept of individual monitoring at CERN could be transferred to other locations with high energy accelerators such as PSI and DESY. The experience gained with the neutron dosimeter based on CR-39 since introduction of the

46 CFR 108.627 - Carbon dioxide alarm.

Science.gov (United States)

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 to...

Alarm system for ABWR main control panels

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Yuji; Saito, Koji [Toshiba Corp., Yokohoma (Japan)

1997-09-01

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.

Alarm system for ABWR main control panels

International Nuclear Information System (INIS)

Kobayashi, Yuji; Saito, Koji

1997-01-01

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

A PC based thin film dosimeter system

DEFF Research Database (Denmark)

Miller, A.; Hargittai, P.; Kovacs, A.

2000-01-01

A dosimeter system based on the Riso B3 dosimeter film, an office scanner for use with PC and the associated software is presented. The scanned image is analyzed either with standard software (Paint Shop Pro 5 or Excel) functions or with the computer code "Scanalizer" that allows presentation...

Alarm management a comprehensive guide

CERN Document Server

Hollifield, Bill R

2011-01-01

In this second edition, Alarm Management: A Comprehensive Guide, various problems of alarm systems are covered with precise guidance on how they come about and how to effectively correct them. It is written by individuals with vast experience in the different plants, processes, and environments requiring effective alarm management. The second edition is filled with good examples and explanations of procedures, with practical lists and tips on how one should proceed. It is based on hundreds of successful projects.

Organic liquids as ''activ media'' in a holographic ionizing radiation dosimeter

International Nuclear Information System (INIS)

Nicolau-Rebigan, S.

1979-01-01

Some types of organic liquids for using as activ media in a holographic ionizing radiation dosimeter are presented. One outlined the advantages of the holographic dosimeter comparatively with those of common used dosimeters. One presented the advantages of utilization of the organic liquids comparatively with another chemical systems used in a holographic ionizing radiation dosimeter. (author)

Production of sensitivity and false alarm rate

International Nuclear Information System (INIS)

Han Zijie; Kang Wu; Chu Chengsheng; Hao Fanhua; Liu Xiaoya; Cao Lin; Hu Yongbo; Gong Jian; Xiang Yongchun; Zhang Jianhua; Yang Xiangdong

2007-01-01

The false alarm rate and sensitivity in nuclear material monitoring system are affected by alarm principle. Two different alarm principles are studied with theory and experiment analysis in this paper. Our research shows that theory analysis and experiment result are accordant very much. This study provides technology support for designing better alarm principle in nuclear material monitoring system. (authors)

Radiation measured for ISS-Expedition 12 with different dosimeters

International Nuclear Information System (INIS)

Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Weyland, M.

2007-01-01

Radiation in low Earth orbit (LEO) is mainly from Galactic Cosmic Rays (GCR), solar energetic particles and particles in South Atlantic Anomaly (SAA). These particles' radiation impact to astronauts depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. It is important to investigate the LET spectrum for the radiation field and the influence of radiation on astronauts. At present, the best active dosimeters used for all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors; the best passive dosimeters are thermoluminescence dosimeters (TLDs) or optically stimulated luminescence dosimeters (OSLDs) for low LET and CR-39 plastic nuclear track detectors (PNTDs) for high LET. TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation for space mission Expedition 12 (ISS-11S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the mission with these different dosimeters. This paper introduces the operation principles for these dosimeters, describes the method to combine the results measured by CR-39 PNTDs and TLDs/OSLDs, presents the experimental LET spectra and the radiation quantities

An approved personal dosimetry service based on an electronic dosimeter

International Nuclear Information System (INIS)

Marshall, T.O.; Bartlett, D.T.; Burgess, P.H.; Campbell, J.I.; Hill, C.E.; Pook, E.A.; Sandford, D.J.

1991-01-01

At the Second Conference on Radiation Protection and Dosimetry a paper was presented which, in part, announced the development of an electronic dosimeter to be undertaken in the UK by the National Radiological Protection Board (NRPB) and Siemens Plessey Controls Ltd. This dosimeter was to be of a standard suitable for use as the basis of an approved personal dosimetry service for photon and beta radiations. The project has progressed extremely well and dosimeters and readers are about to become commercially available. The system and the specification of the dosimeter are presented. The NRPB is in the process of applying for approval by the Health and Safety Executive (HSE) to operate as personal monitoring service based on this dosimeter. As part of the approval procedure the dosimeter is being type tested and is also undergoing an HSE performance test and wearer trials. The tests and the wearer trials are described and a summary of the results to date presented. The way in which the service will be organized and operated is described and a comparison is made between the running of the service and others based on passive dosimeters at NRPB

Investigating On Colour Stability Conditions Of Postirradiation Radiochromic Film Dosimeter

International Nuclear Information System (INIS)

Nguyen Nguyet Dieu; Doan Binh; Pham Thu Hong; Cao Van Chung; Nguyen Thanh Duoc

2011-01-01

B3 dosimeter is a thin film with average thickness of 0.0194 mm, which is supplied by the Gex company, the United States. This dosimeter was influenced by many factors: light, temperature, humidity during and after irradiation process. In fact, B3 film dosimeters will be stable under certain conditions such as tightly sealed packs, controlled irradiation and stored temperature after irradiated. Therefore, investigation of the stability effect of postirradiated B3 film dosimeters on the heating temperature, heating time and storing time is carried out before the absorbed dose is read and followed standard reading procedures. When exposed to ionizing radiation, the dosimeters change from colorless to colour. The absorbed doses are read on a Genesys 20 spectrophotometer at a wavelength of 544 nm. Absorbed dose range is investigated from 0.55 to 80 kGy. Experimental results were indicated that colour stability of the postirradiated dosimeters at a temperature of 65 ± 3 o C for 30 minutes and keeping them in desiccator for 5 minutes before read out. Under these conditions, colour stability of B3 film dosimeter has maintained for 3 months. (author)

Interior intrusion alarm systems

International Nuclear Information System (INIS)

Prell, J.A.

1978-01-01

In meeting the requirements for the safeguarding of special nuclear material and the physical protection of licensed facilities, the licensee is required to design a physical security system that will meet minimum performance requirements. An integral part of any physical security system is the interior intrusion alarm system. The purpose of this report is to provide the potential user of an interior intrusion alarm system with information on the various types, components, and performance capabilities available so that he can design and install the optimum alarm system for his particular environment. In addition, maintenance and testing procedures are discussed and recommended which, if followed, will help the user obtain the optimum results from his system

SU-E-T-749: Thorough Calibration of MOSFET Dosimeters

International Nuclear Information System (INIS)

Plenkovich, D; Thomas, J

2015-01-01

Purpose: To improve the accuracy of the MOSFET calibration procedure by performing the measurement several times and calculating the average value of the calibration factor for various photon and electron energies. Methods: The output of three photon and six electron beams of Varian Trilogy linear accelerator SN 5878 was calibrated. Five reinforced standard sensitivity MOSFET dosimeters were placed in the calibration jig and connected to the Reader Module. As the backscatter material was used 7 cm of Virtual Water. The MOSFET dosimeters were covered with 1.5 cm thick bolus for the regular and SRS 6 MV beams, 3 cm bolus for 15 MV beam, 1.5 cm bolus for 6 MeV electron beam, and 2 cm bolus for the electron energies of 9, 12, 15, 18, and 22 MeV. The dosimeters were exposed to 100 MU, and the calibration factor was determined using the mobileMOSFET software. To improve the accuracy of calibration, this procedure was repeated ten times and the calibration factors were averaged. Results: As the number of calibrations was increasing the variability of calibration factors of different dosimeters was decreasing. After ten calibrations, the calibration factors for all five dosimeters were within 1% of one another for all energies, except 6 MV SRS photons and 6 MeV electrons, for which the variability was 2%. Conclusions: The described process results in calibration factors which are almost independent of modality or energy. Once calibrated, the dosimeters may be used for in-vivo dosimetry or for daily verification of the beam output. Measurement of the radiation dose under bolus and scatter to the eye are examples of frequent use of calibrated MOSFET dosimeters. The calibration factor determined for full build-up is used under these circumstances. To the best of our knowledge, such thorough procedure for calibrating MOSFET dosimeters has not been reported previously. Best Medical Canada provided MOSFET dosimeters for this project

Development of bead-type radiophotoluminescence glass dosimeter applicable to various purposes

International Nuclear Information System (INIS)

Sato, F.; Toyota, Y.; Maki, D.; Zushi, N.; Kato, Y.; Yamamoto, T.; Iida, T.

2013-01-01

Bead-type radiophotoluminescence (RPL) glass dosimeters were well fabricated with a gas-particle jet flame system for glass melting-cooling process. A rod of silver-activated phosphate glass was pulverized into micrometer-size particles. Spherical glass particles were formed from the pulverized glass particles in the high-temperature jet flame owing to the surface tension of the glass material. Some groups of spherical glass particles were irradiated with X-rays and their RPL was demonstrably observed for their exposure to UV light. A flexible RPL glass sheet was also made of bead-type RPL glass dosimeters and was useful for radiation imaging. Bead-type RPL glass dosimeters are expected to be used for dose monitoring in highly radioactively-contaminated area. -- Highlights: ► We developed bead-type radiophotoluminescence glass dosimeters. ► Bead-type glass RPL dosimeters are satisfactorily used as radiation dosimeters. ► A flexible RPL glass sheet is made of bead-type RPL glass dosimeters

Light scattering in optical CT scanning of Presage dosimeters

Energy Technology Data Exchange (ETDEWEB)

Xu, Y; Adamovics, J; Cheeseborough, J C; Chao, K S; Wuu, C S, E-mail: yx2010@columbia.ed

2010-11-01

The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS' optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

46 CFR 76.15-30 - Alarms.

Science.gov (United States)

2010-10-01

... than paint and lamp lockers and similar small spaces, shall be fitted with an approved audible alarm in... required to be fitted with a delayed discharge. Such alarms shall be so arranged as to sound during the 20 second delay period prior to the discharge of carbon dioxide into the space, and the alarm shall depend...

Diffusion measurement in ferrous infused gel dosimeters

International Nuclear Information System (INIS)

Zahmatkesh, M. H.; Healy, B. J.

2003-01-01

Background: The compositions of Ferrous sulphate, Agarose and Xylenol orange dye and Ferrous sulphate, Gelatin and Xylenol orange dye in solution of distilled water and sulphuric acid are two tissue-equivalent gel dosimeters. Ionizing radiation causes oxidation of Fe 2+ ion to Fe 3+ ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours after irradiation. Materials and methods: 25 m M sulphuric acid, 0.4 mm ferrous ammonium sulphate, 0.2 mm xylenol orange dye and 1% by weight agarose in distilled water named Agarose and Xylenol orange dye and 0.1 mm ferrous ammonium sulphate, 0.1 mm xylenol orange dye, 50 mm sulphuric acid and 5% by weight gelatin in distilled water named Gelatin and Xylenol orange dye are used as two gel dosimeters. All chemicals were supplied by Sigma Ald ridge Company, Germany. The gels were poured in Perspex casts and were irradiated to a beam of X ray from linear accelerators or X ray machine. Results: In this study diffusion coefficients of Agarose and Xylenol orange dye and Gelatin and Xylenol orange dye dosimeters have been measured through a computer program for different temperature. The ferric ion diffusion coefficient (D) for the Agarose and Xylenol orange dye and Gelatin and Xylenol orange dye dosimeters were measured as (1.19.±0.03) x 10 -2 cm 2 .hr -1 and (0.83±0.03) x 10 -2 cm 2 .hr -1 respectively at room temperature. Conclusion: For both dosimeters the diffusion coefficients decreased with gel storage temperatures down to 6 d ig C . Gelatin and Xylenol orange dye dosimeters have advantage of lower diffusion coefficient for a specified temperature

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

Science.gov (United States)

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

2016-01-11

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. To examine if (1) a change in default alarm settings of the cardiac monitors and (2) in-service nursing education on cardiac monitor use in an ICU would result in reducing alarm rate and in improving nurses' attitudes and practices toward clinical alarms. This quality improvement project took place in a 20-bed transplant/cardiac ICU with a total of 39 nurses. We implemented a unit-wide change of default alarm settings involving 17 parameters of the cardiac monitors. All nurses received an in-service education on monitor use. Alarm data were collected from the audit log of the cardiac monitors 10 weeks before and 10 weeks after the change in monitors' parameters. Nurses' attitudes and practices toward clinical alarms were measured using the Healthcare Technology Foundation National Clinical Alarms Survey, pre- and postintervention. Alarm rate was 87.86 alarms/patient day (a total of 64,500 alarms) at the preintervention period compared to 59.18 alarms/patient day (49,319 alarms) postintervention (P=.01). At baseline, Arterial Blood Pressure (ABP), Pair Premature Ventricular Contractions (PVCs), and Peripheral Capillary Oxygen Saturation (SpO2) alarms were the highest. ABP and SpO2 alarms remained among the top three at the postproject period. Out of the 39 ICU nurses, 24 (62%) provided complete pre- and postproject survey questionnaires. Compared to the preintervention survey, no remarkable changes in the postproject period were reported in nurses' attitudes. Themes in the narrative data were related to poor usability of cardiac monitors and the frequent alarms. The data showed great variation among nurses in terms of changing

Development and underground testing of the α dosimeter: a solid state electronic personal radiation dosimeter for uranium miners

International Nuclear Information System (INIS)

Parkinson, R.N.; Roze, V.; Shepherd, R.

1981-01-01

The αDOSIMETER is a complete, integrated system designed to monitor the immediate worksite of underground miners where the disintegration for radon daughters is a risk to the health of mining personnel. The dosimeter weighing little more than one pound is worn by each miner throughout the entire shift and is powered by the miner's cap lamp battery. After this integration period, the unit is connected to a reading network whereupon the day's data is dumped, calculated and stored. Beginning in July 1980, prototype units were subjected to vigorous underground testing in uranium mines in Canada and the United States and in tin mines in Cornwall, UK. The testing results are summarized and proposals advanced for a typical mine monitoring system utilizing the αDOSIMETER

Site-specific calibration of the Hanford personnel neutron dosimeter

International Nuclear Information System (INIS)

Endres, A.W.; Brackenbush, L.W.; Baumgartner, W.V.; Rathbone, B.A.

1994-10-01

A new personnel dosimetry system, employing a standard Hanford thermoluminescent dosimeter (TLD) and a combination dosimeter with both CR-39 nuclear track and TLD-albedo elements, is being implemented at Hanford. Measurements were made in workplace environments in order to verify the accuracy of the system and establish site-specific factors to account for the differences in dosimeter response between the workplace and calibration laboratory. Neutron measurements were performed using sources at Hanford's Plutonium Finishing Plant under high-scatter conditions to calibrate the new neutron dosimeter design to site-specific neutron spectra. The dosimeter was also calibrated using bare and moderated 252 Cf sources under low-scatter conditions available in the Hanford Calibration Laboratory. Dose equivalent rates in the workplace were calculated from spectrometer measurements using tissue equivalent proportional counter (TEPC) and multisphere spectrometers. The accuracy of the spectrometers was verified by measurements on neutron sources with calibrations directly traceable to the National Institute of Standards and Technology (NIST)

Development of a new type thyroid glands dosimeter

International Nuclear Information System (INIS)

He Lihua; Song Yiyang; Chen Qin; Chen Yannan

2000-01-01

A new dosimeter of 125 I in thyroid gland is described. The dosimeter consists of NaI(Tl) detector and intelligent data recorder. Single-chip-microcomputer is used for data handling. The activity of 125 I in thyroid glands of human being is measured directly, rapidly, and accurately. Furthermore, it can calculate and display the intake, committed dose equivalent and committed effective dose equivalent. The measuring range of 125 I in thyroid glands is 10-2 x 10 6 Bq. The dosimeter has been operating continuously for a long time with high stability

Portable battery-free charger for radiation dosimeters

International Nuclear Information System (INIS)

Manning, F.W.

1984-01-01

This invention is a novel portable charger for dosimeters of the electrometer type. The charger does not require batteries or piezoelectric crystals and is of rugged construction. In a preferred embodiment, the charge includes a housing which carries means for mounting a dosimeter to be charged. The housing also includes contact means for impressing a charging voltage across the mounted dosimeter. Also, the housing carries a trigger for operating a charging system mounted in the housing. The charging system includes a magnetic loop including a permanent magnet for establishing a magnetic field through the loop. A segment of the loop is coupled to the trigger for movement thereby to positions opening and closing the loop. A coil inductively coupled with the loop generates coil-generated voltage pulses when the trigger is operated to open and close the loop. The charging system includes an electrical circuit for impressing voltage pulses from the coil across a capacitor for integrating the pulses and applying the resulting integrated voltage across the above-mentioned contact means for charging the dosimeter

Portable battery-free charger for radiation dosimeters

Science.gov (United States)

Manning, Frank W.

1984-01-01

This invention is a novel portable charger for dosimeters of the electrometer type. The charger does not require batteries or piezoelectric crystals and is of rugged construction. In a preferred embodiment, the charge includes a housing which carries means for mounting a dosimeter to be charged. The housing also includes contact means for impressing a charging voltage across the mounted dosimeter. Also, the housing carries a trigger for operating a charging system mounted in the housing. The charging system includes a magnetic loop including a permanent magnet for establishing a magnetic field through the loop. A segment of the loop is coupled to the trigger for movement thereby to positions opening and closing the loop. A coil inductively coupled with the loop generates coil-generated voltage pulses when the trigger is operated to open and close the loop. The charging system includes an electrical circuit for impressing voltage pulses from the coil across a capacitor for integrating the pulses and applying the resulting integrated voltage across the above-mentioned contact means for charging the dosimeter.

Water-equivalent one-dimensional scintillating fiber-optic dosimeter for measuring therapeutic photon beam

International Nuclear Information System (INIS)

Moon, Jinsoo; Won Jang, Kyoung; Jae Yoo, Wook; Han, Ki-Tek; Park, Jang-Yeon; Lee, Bongsoo

2012-01-01

In this study, we fabricated a one-dimensional scintillating fiber-optic dosimeter, which consists of 9 scintillating fiber-optic dosimeters, septa, and PMMA blocks for measuring surface and percentage depth doses of a therapeutic photon beam. Each dosimeter embedded in the 1-D scintillating fiber-optic dosimeter is composed of square type organic scintillators and plastic optical fibers. Also black PVC films are used as septa to minimize cross-talk between the scintillating fiber-optic dosimeters. To construct a dosimeter system, a 1-D scintillating fiber-optic dosimeter and a CMOS image sensor were combined with 20 m-length plastic optical fibers. Using the dosimeter system, we measured surface and percentage depth doses of 6 and 15 MV photon beams and compared the results with those of EBT films and an ionization chamber. - Highlights: ► Fabrication of a one-dimensional scintillating fiber-optic dosimeter. ► The one-dimensional scintillating fiber-optic dosimeter has 9 scintillating fiber-optic dosimeters. ► Measurements of surface and percentage depth doses of a therapeutic photon beam. ► The results were compared with those of EBT films and an ionization chamber.

Gynecological cancer alarm symptoms:

DEFF Research Database (Denmark)

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...... 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 general......: 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....

Fast fluence measurement for JOYO irradiation field using niobium dosimeter

International Nuclear Information System (INIS)

Ito, Chikara

2004-03-01

Neutron fluence and spectrum are key parameters in various irradiation tests and material surveillance tests so they need to be evaluated accurately. The reactor dosimetry test has been conducted by the multiple foil activation method, and a niobium dosimeter has been developed for measurement of fast neutron fluence in the experimental fast reactor JOYO. The inelastic scattering reaction of 93 Nb has a low threshold energy, about 30 keV, and the energy distribution of reaction cross section is similar to the displacement cross section for iron. Therefore, a niobium dosimeter is suitable for evaluation of the fast neutron fluence and the displacement per atom for iron. Moreover, a niobium dosimeter is suited to measure neutron fluence in long-term irradiation test because 93 Nb, which is produced by the reaction, has a long half-life (16.4 years). This study established a high precision measurement technique using the niobium reaction rate. The effect of self-absorption was decreased by the solution and evaporation to dryness of niobium dosimeter. The dosimeter weight was precisely measured using the inductively coupled plasma mass spectrometer. This technique was applied to JOYO dosimetry. The fast neutron fluences (E > 0.1 MeV) found by measuring the reaction rate in the niobium dosimeter were compared with the values evaluated using the multiple foil activation method. The ratio of measured fast neutron fluences by means of niobium dosimeter and multiple foil activation method range from 0.97 to 1.03 and agree within the experimental uncertainty. The measurement errors of fast neutron fluence by niobium dosimeter range from 4.5% (fuel region) to 10.1% (in-vessel storage rack). As a result of this study, the high precision measurement of fast neutron fluence by niobium dosimeters was confirmed. The accuracy of fast reactor dosimetry will be improved by application of niobium dosimeters to the irradiation tests in the JOYO MK-III core. (author)

The computer system of automatical microscope analysis of mines' individual dosimeters

International Nuclear Information System (INIS)

Zorawski, A.; Hawrynski, M.; Kluszczynski, D.

1988-01-01

The Institute of Occupational Medicine (IOM) carriers on routine investigations on miners' individual exposure to radon and its alpha radioactive daughters in Polish mines [1]. Evaluation of miners' exposure is based on automatic analysis of track detectors by computer SYSTEM RADON. The IOM used detectors of size 2x3 cm cut from Kodak LT115 or LR115 dosimetry foil. The scheme of the system is presented in Fig.1 whereas Table 1 includes specification of its elements

Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

International Nuclear Information System (INIS)

Braunlich, P.F.; Tetzlaff, W.

1989-01-01

Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters are disclosed. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phosphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate. 34 figs

Energy response study of modified CR-39 neutron personnel dosimeter

International Nuclear Information System (INIS)

Sathian, Deepa; Bakshi, A.K.; Datta, D.; Nair, Sreejith S.; Sathian, V.; Mishra, Jitendra; Sen, Meghnath

2018-01-01

Personnel neutron dosimetry is an integral part of radiation protection. No single dosimeter provides the satisfactory energy response, sensitivity, angular dependence characteristics and accuracy necessary to meet the requirement of an ideal personnel neutron dosimeter. The response of a personnel neutron dosimeter is critically dependent upon the energy distribution of the neutron field. CR-39 personnel neutron dosimeters were typically calibrated in the standard neutron field of 252 Cf and 241 Am-Be in our laboratory, although actual neutron fields may vary from the calibration neutron spectrum. Recently the badge cassette of the personnel neutron dosimeter was changed due to frequent damage of the PVC badge used earlier. This paper discusses energy response of CR-39 solid state nuclear track detector loaded in this modified badge cassette as per latest ISO recommendation

Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry.

Science.gov (United States)

Lee, Bongsoo; Kwon, Guwon; Shin, Sang Hun; Kim, Jaeseok; Yoo, Wook Jae; Ji, Young Hoon; Jang, Kyoung Won

2015-11-17

In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter.

Effect of electromagnetic field in fusion facility on electronic personal dosimeter

International Nuclear Information System (INIS)

Yamada, Junya; Kawano, Takao; Uda, Tatsuhiko; Shimo, Michikuni

2010-01-01

The effect of electromagnetic field on electronic personal dosimeters in a nuclear fusion facility was examined in a Magnetic Resonance Imaging (MRI) examination room instead of a nuclear fusion facility. Three types of electronic personal dosimeters, the PDM-111, the 112, and the 117, were used as typical ones. We surveyed the electromagnetic field distribution and dosimeters were placed at locations with various strengths of the electromagnetic field. The natural radiation dose was measured for about one week. We found that while dosimeters were not affected by the electric field, they were affected by the magnetic one. Dosimeters detected radiation levels less sensitively as the magnetic field strength was increased up to 150 mT. The dosimeters underestimated the environmental radiation dose rates by about 10-30% when the magnetic field strength was larger than 150 mT. We assumed that hall-effect caused the reduction in radiation sensitivity. We concluded that the strength of the magnetic field needs to be carefully considered when an electronic personal dosimeter is used for monitoring both personal and area dose in a nuclear fusion facility. (author)

Poison and alarm: the Asian hornet Vespa velutina uses sting venom volatiles as an alarm pheromone.

Science.gov (United States)

Cheng, Ya-Nan; Wen, Ping; Dong, Shi-Hao; Tan, Ken; Nieh, James C

2017-02-15

In colonial organisms, alarm pheromones can provide a key fitness advantage by enhancing colony defence and warning of danger. Learning which species use alarm pheromone and the key compounds involved therefore enhances our understanding of how this important signal has evolved. However, our knowledge of alarm pheromones is more limited in the social wasps and hornets compared with the social bees and ants. Vespa velutina is an economically important and widespread hornet predator that attacks honey bees and humans. This species is native to Asia and has now invaded Europe. Despite growing interest in V. velutina , it was unknown whether it possessed an alarm pheromone. We show that these hornets use sting venom as an alarm pheromone. Sting venom volatiles were strongly attractive to hornet workers and triggered attacks. Two major venom fractions, consisting of monoketones and diketones, also elicited attack. We used gas chromatography coupled to electroantennographic detection (GC-EAD) to isolate 13 known and 3 unknown aliphatic ketones and alcohols in venom that elicited conspicuous hornet antennal activity. Two of the unknown compounds may be an undecen-2-one and an undecene-2,10-dinone. Three major compounds (heptan-2-one, nonan-2-one and undecan-2-one) triggered attacks, but only nonan-2-one did so at biologically relevant levels (10 hornet equivalents). Nonan-2-one thus deserves particular attention. However, the key alarm releasers for V. velutina remain to be identified. Such identification will help to illuminate the evolution and function of alarm compounds in hornets. © 2017. Published by The Company of Biologists Ltd.

UVB DNA dosimeters analyzed by polymerase chain reactors

International Nuclear Information System (INIS)

Yoshida, Hiroko; Regan, J.D.; Florida Inst. of Tech., Melbourne, FL

1997-01-01

Purified bacteriophage λ DNA was dried on a UV-transparent polymer film and served as a UVB dosimeter for personal and ecological applications. Bacteriophage λ DNA was chosen because it is commercially available and inexpensive, and its entire sequence is known. Each dosimeter contained two sets of DNA sandwiched between UV-transparent polymer films, one exposed to solar radiation (experimental) and another protected from UV radiation by black paper (control). The DNA dosimeter was then analyzed by a polymerase chain reaction (PCR) that amplifies a 500 base pair specific region of λ DNA. Photoinduced damage in DNA blocks polymerase from synthesizing a new strand; therefore, the amount of amplified product in UV-exposed DNA was reduced from that found in control DNA. The dried λ DNA dosimeter is compact, robust, safe and transportable, stable over long storage times and provides the total UVB dose integrated over the exposure time. (author)

LOW-COST PERSONNEL DOSIMETER.

Science.gov (United States)

specification was achieved by simplifying and improving the basic Bendix dosimeter design, using plastics for component parts, minimizing direct labor, and making the instrument suitable for automated processing and assembly. (Author)

TMACS test procedure TP001: Alarm management. Revision 6

International Nuclear Information System (INIS)

Scanlan, P.K.

1994-01-01

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

Angular dependence of the nanoDot OSL dosimeter

International Nuclear Information System (INIS)

Kerns, James R.; Kry, Stephen F.; Sahoo, Narayan; Followill, David S.; Ibbott, Geoffrey S.

2011-01-01

Purpose: Optically stimulated luminescent detectors (OSLDs) are quickly gaining popularity as passive dosimeters, with applications in medicine for linac output calibration verification, brachytherapy source verification, treatment plan quality assurance, and clinical dose measurements. With such wide applications, these dosimeters must be characterized for numerous factors affecting their response. The most abundant commercial OSLD is the InLight/OSL system from Landauer, Inc. The purpose of this study was to examine the angular dependence of the nanoDot dosimeter, which is part of the InLight system. Methods: Relative dosimeter response data were taken at several angles in 6 and 18 MV photon beams, as well as a clinical proton beam. These measurements were done within a phantom at a depth beyond the build-up region. To verify the observed angular dependence, additional measurements were conducted as well as Monte Carlo simulations in MCNPX. Results: When irradiated with the incident photon beams parallel to the plane of the dosimeter, the nanoDot response was 4% lower at 6 MV and 3% lower at 18 MV than the response when irradiated with the incident beam normal to the plane of the dosimeter. Monte Carlo simulations at 6 MV showed similar results to the experimental values. Examination of the results in Monte Carlo suggests the cause as partial volume irradiation. In a clinical proton beam, no angular dependence was found. Conclusions: A nontrivial angular response of this OSLD was observed in photon beams. This factor may need to be accounted for when evaluating doses from photon beams incident from a variety of directions.

Systems analysis of a security alarm system

International Nuclear Information System (INIS)

Schiff, A.

1975-01-01

When the Lawrence Livermore Laboratory found that its security alarm system was causing more false alarms and maintenance costs than LLL felt was tolerable, a systems analysis was undertaken to determine what should be done about the situation. This report contains an analysis of security alarm systems in general and ends with a review of the existing Security Alarm Control Console (SACC) and recommendations for its improvement, growth and change. (U.S.)

Nuclear power plant alarm systems: Problems and issues

International Nuclear Information System (INIS)

O'Hara, J.M.; Brown, W.S.

1991-01-01

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

Nuclear power plant alarm systems: Problems and issues

Energy Technology Data Exchange (ETDEWEB)

O' Hara, J.M.; Brown, W.S.

1991-01-01

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.

Polymer gel dosimeter with AQUAJOINT® as hydrogel matrix

Science.gov (United States)

Maeyama, Takuya; Ishida, Yasuhiro; Kudo, Yoshihiro; Fukasaku, Kazuaki; Ishikawa, Kenichi L.; Fukunishi, Nobuhisa

2018-05-01

We report a polymer gel dosimeter based on a new gel matrix (AQUAJOINT®) that is a thermo-irreversible hydrogel formed by mixing two types of water-based liquids at room temperature. Normoxic N-vinylpyrrolidone-based polymer gels were prepared with AQUAJOINT® instead of gelatin. This AQUAJOINT®-based gel dosimeter exhibits a 2.5-fold increase in sensitivity over a gelatin-based gel dosimeter and a linear dose-response in the dose range of 0-8 Gy. This gel has heat resistance in a jar and controlled gel properties such as viscoelastic and mechanical characters, which may be useful for deformable polymer gel dosimetry.

Alanine EPR dosimeter response in proton therapy beams

International Nuclear Information System (INIS)

Gall, K.; Serago, C.; Desrosiers, M.; Bensen, D.

1997-01-01

We report a series of measurements directed to assess the suitability of alanine as a mailable dosimeter for dosimetry quality assurance of proton radiation therapy beams. These measurements include dose-response of alanine at 140 MeV, and comparison of response vs energy with a parallel plate ionization chamber. All irradiations were made at the Harvard Cyclotron Laboratory, and the dosimeters were read at NIST. The results encourage us that alanine could be expected to serve as a mailable dosimeter with systematic error due to differential energy response no greater than 3% when doses of 25 Gy are used. (Author)

Perspectives on use of personal alarms by older fallers

Directory of Open Access Journals (Sweden)

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

Investigating potential physicochemical errors in polymer gel dosimeters

International Nuclear Information System (INIS)

Sedaghat, Mahbod; Lepage, Martin; Bujold, Rachel

2011-01-01

Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

Investigating potential physicochemical errors in polymer gel dosimeters

Energy Technology Data Exchange (ETDEWEB)

Sedaghat, Mahbod; Lepage, Martin [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); Bujold, Rachel, E-mail: martin.lepage@usherbrooke.ca [Service de radio-oncologie, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, QC (Canada)

2011-09-21

Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

Validation of an Innovative Satellite-Based UV Dosimeter

Science.gov (United States)

Morelli, Marco; Masini, Andrea; Simeone, Emilio; Khazova, Marina

2016-08-01

We present an innovative satellite-based UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in-vivo assessment of the erythemal effects on some volunteers having a controlled exposure to solar radiation.Both validations showed that the satellite-based UV dosimeter has a good accuracy and reliability needed for health-related applications.The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. This app will be launched on the global market by siHealth Ltd in May 2016 under the name of "HappySun" and available both for Android and for iOS devices (more info on http://www.happysun.co.uk).Extensive R&D activities are on-going for further improvement of the satellite-based UV dosimeter's accuracy.

Calibration and performance testing of electronic personal dosimeters (EPD)

International Nuclear Information System (INIS)

Banaga, H.A.

2008-04-01

In modern radiation protection practices, active personal dosimeters are becoming absolutely necessary operational tools for satisfying the ALARA principle. The aim of this work was to carry out calibration and performance testing of ten electronic personal dosimeters (EPD) used for the individual monitoring. The EPDs were calibrated in terms of operation radiation protection quantity, personal dose equivalent, Hp (10). Calibrations were carried out at three of x-ray beam qualities described in ISO 4037 namely 60, 100 and 150 kV in addition to Cs-137 gamma ray quality. The calibrations were performed using polymethylmethacrylate (PMMA) phantom with dimensions 20*20*15 cm 3 . Conversion coefficient Hp (10)/K air for the phantom was also calculated. The response and linearity of the dosimeter at the specified energies were also tested. The EPDs tested showed that the calibration coefficient ranged from 0.60 to 1.31 and an equivalent response for the specified energies that ranged from 0.76 to 1.67. The study demonstrated the possibility of using non standard phantom for calibrating dosimeters used for individual monitoring. The dosimeters under study showed a good response in all energies except the response in quality 100 kV. The linearity of the dosimeters was within ±15%, with the exception of the quality 100 kV where this limit was exceeded.(Author)

Performance testing of beta dosimeters used at Department of Energy facilities

International Nuclear Information System (INIS)

Roberson, P.L.; Holbrook, K.L.; Pappin, J.L.

1983-01-01

A performance test based on the American national draft standard N13.11 was conducted for dosimeter systems in use at Department of Energy facilities. The large differences in dosimeter response found were due to use of different calibration source standards and different dosimeter designs. Differences in 90 Sr/ 90 Y calibrations were approximately 20% or less for all but one participant. The differences observed were attributed to variable thicknesses of dosimeter elements and variable source irradiation geometries. Improved beta calibration standards will result if irradiation specifications include acceptable ranges from the depth-dose characteristics. The low-energy beta responses observed were consistent with the thicknesses of dosimeter sensitive elements and overlying filtration

Indoor radon level measurements in Iran using AEOI passive dosimeters

International Nuclear Information System (INIS)

Sohrabi, M.; Solaymanian, A.R.

1988-01-01

A passive radon diffusion dosimeter was developed at the RPD of AEOI for nationwide indoor radon level measurements. Several parameters of the dosimeter were studied. Radon levels were determined in about 250 houses in Ramsar (a high natural radiation area), Tehran, Babolsar and Gonabad. In this paper, the results of some dosimeter parameters as well as radon levels in indoor air are reported

T-Farm complex alarm upgrades

Energy Technology Data Exchange (ETDEWEB)

Roberts, J.B.

1995-01-01

The alarm and controls associated with the T, TX, and TY farms are located in the 242-T control room. The design data for replacement and upgrades of the alarm panels is in this document. This task was canceled previous to the 90% design review point.

Approving of personal dosimeter services

International Nuclear Information System (INIS)

Bergman, K.; Malmqvist, L.

2001-09-01

The Swedish regulation SSI FS 98:5 requires that radiological workers of category A use dosemeters from an approved personal dosimetry service. The regulation also includes certain specific dosimeter requirements, which are based on those presented in the Technical Recommendations by the European Commission (Report EUR 14852 EN, 1994). All services have been tested for their ability to determine Hp(10) and some of them to determine Hp(0.07) at one radiation quality. The test was performed in the interval 0.2 mSv to 100 mSv at three different dose equivalents unknown to the system owner. The 11 services operating in Sweden at the moment use 5 different types of dosimeters. The five unique systems have been tested regarding the angular and energy dependence of the response of the dosimeters. The dosimeters were irradiated to a personal dose equivalent of about 1 mSv at three photon energies and at four angles (0, 20, 40 and 60 deg. resp. ) both vertically and horizontally rotated. Only 2 of the services determine Hp(0.07) for beta and gamma radiation and were tested for this quantity. The test results for Hp(10) are all except two within the trumpet curve. For the unique systems it is shown that the uncertainty related to angular response at a specified energy is within the required ±40 % except for the lowest X-ray quality at 40 kV. The response is more dependent on photon energy than on the direction of the photon radiation and the choice of radiation quality for the calibration is of great importance for the system performance

A new method for defining and managing process alarms and for correcting process operation when an alarm occurs

International Nuclear Information System (INIS)

Brooks, Robin; Thorpe, Richard; Wilson, John

2004-01-01

A new mathematical treatment of alarms that considers them as multi-variable interactions between process variables has provided the first-ever method to calculate values for alarm limits. This has resulted in substantial reductions in false alarms and hence in alarm annunciation rates in field trials. It has also unified alarm management, process control and product quality control into a single mathematical framework so that operations improvement and hence economic benefits are obtained at the same time as increased process safety. Additionally, an algorithm has been developed that advises what changes should be made to Manipulable process variables to clear an alarm. The multi-variable Best Operating Zone at the heart of the method is derived from existing historical data using equation-free methods. It does not require a first-principles process model or an expensive series of process identification experiments. Integral with the method is a new format Process Operator Display that uses only existing variables to fully describe the multi-variable operating space. This combination of features makes it an affordable and maintainable solution for small plants and single items of equipment as well as for the largest plants. In many cases, it also provides the justification for the investments about to be made or already made in process historian systems. Field Trials have been and are being conducted at IneosChlor and Mallinckrodt Chemicals, both in the UK, of the new geometric process control (GPC) method for improving the quality of both process operations and product by providing Process Alarms and Alerts of much high quality than ever before. The paper describes the methods used, including a simple visual method for Alarm Rationalisation that quickly delivers large sets of Consistent Alarm Limits, and the extension to full Alert Management with highlights from the Field Trials to indicate the overall effectiveness of the method in practice

A new method for defining and managing process alarms and for correcting process operation when an alarm occurs

Energy Technology Data Exchange (ETDEWEB)

Brooks, Robin [Curvaceous Software Limited, P.O. Box 43, Gerrards Cross, Bucks SL98UX (United Kingdom)]. E-mail: enquiries@curvaceous.com; Thorpe, Richard [Curvaceous Software Limited, P.O. Box 43, Gerrards Cross, Bucks SL98UX (United Kingdom); Wilson, John [Curvaceous Software Limited, P.O. Box 43, Gerrards Cross, Bucks SL98UX (United Kingdom)

2004-11-11

A new mathematical treatment of alarms that considers them as multi-variable interactions between process variables has provided the first-ever method to calculate values for alarm limits. This has resulted in substantial reductions in false alarms and hence in alarm annunciation rates in field trials. It has also unified alarm management, process control and product quality control into a single mathematical framework so that operations improvement and hence economic benefits are obtained at the same time as increased process safety. Additionally, an algorithm has been developed that advises what changes should be made to Manipulable process variables to clear an alarm. The multi-variable Best Operating Zone at the heart of the method is derived from existing historical data using equation-free methods. It does not require a first-principles process model or an expensive series of process identification experiments. Integral with the method is a new format Process Operator Display that uses only existing variables to fully describe the multi-variable operating space. This combination of features makes it an affordable and maintainable solution for small plants and single items of equipment as well as for the largest plants. In many cases, it also provides the justification for the investments about to be made or already made in process historian systems. Field Trials have been and are being conducted at IneosChlor and Mallinckrodt Chemicals, both in the UK, of the new geometric process control (GPC) method for improving the quality of both process operations and product by providing Process Alarms and Alerts of much high quality than ever before. The paper describes the methods used, including a simple visual method for Alarm Rationalisation that quickly delivers large sets of Consistent Alarm Limits, and the extension to full Alert Management with highlights from the Field Trials to indicate the overall effectiveness of the method in practice.

A new method for defining and managing process alarms and for correcting process operation when an alarm occurs.

Science.gov (United States)

Brooks, Robin; Thorpe, Richard; Wilson, John

2004-11-11

A new mathematical treatment of alarms that considers them as multi-variable interactions between process variables has provided the first-ever method to calculate values for alarm limits. This has resulted in substantial reductions in false alarms and hence in alarm annunciation rates in field trials. It has also unified alarm management, process control and product quality control into a single mathematical framework so that operations improvement and hence economic benefits are obtained at the same time as increased process safety. Additionally, an algorithm has been developed that advises what changes should be made to Manipulable process variables to clear an alarm. The multi-variable Best Operating Zone at the heart of the method is derived from existing historical data using equation-free methods. It does not require a first-principles process model or an expensive series of process identification experiments. Integral with the method is a new format Process Operator Display that uses only existing variables to fully describe the multi-variable operating space. This combination of features makes it an affordable and maintainable solution for small plants and single items of equipment as well as for the largest plants. In many cases, it also provides the justification for the investments about to be made or already made in process historian systems. Field Trials have been and are being conducted at IneosChlor and Mallinckrodt Chemicals, both in the UK, of the new geometric process control (GPC) method for improving the quality of both process operations and product by providing Process Alarms and Alerts of much high quality than ever before. The paper describes the methods used, including a simple visual method for Alarm Rationalisation that quickly delivers large sets of Consistent Alarm Limits, and the extension to full Alert Management with highlights from the Field Trials to indicate the overall effectiveness of the method in practice.

Reactor alarm system development and application issues

Energy Technology Data Exchange (ETDEWEB)

Drexler, J E; Oicese, G O [INVAP S.E. (Argentina)

1997-09-01

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.

Reactor alarm system development and application issues

International Nuclear Information System (INIS)

Drexler, J.E.; Oicese, G.O.

1997-01-01

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

Functional alarming and information retrieval

International Nuclear Information System (INIS)

Goodstein, L.P.

1985-08-01

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)

Sensor fusion for intelligent alarm analysis

International Nuclear Information System (INIS)

Nelson, C.L.; Fitzgerald, D.S.

1996-01-01

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

Water equivalence of polymer gel dosimeters

International Nuclear Information System (INIS)

Sellakumar, P.; James Jebaseelan Samuel, E.; Supe, Sanjay S.

2007-01-01

To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z eff ), electron density (ρ e ), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μ en /ρ) and total stopping power (S/ρ) tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close ( en /ρ for all polymer gels were in close agreement ( tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

Comparison of Panasonic’s Dosimetric System with Gamma-31 Dosimeters

Directory of Open Access Journals (Sweden)

Paweł Urban

2013-01-01

Full Text Available Equipment being used in medical or industrial institutions is often a source of ionizing radiation with different energies and types, which complicates the detection and assessment of doses. Up until now, for dosimetric measurements of ionizing radiation, Gamma-31 dosimeters have been used in the Central Mining Institute for many years. Now, this system will be expanded by a Panasonic system, for which measurement procedures were developed and comparisons with other dosimeters were held. The method is based on a four-element dosimeters UD-802 Panasonic equipped with CaSO and LiBO detectors additionally sheltered by filters of different surface mass. The use of UD-802 dosimeters, in contrast to Gamma-31 dosimeters, permits measuring radiation doses in a different range of photon energy. Consequently, it is possible to obtain a more accurate analysis of the hazards caused by gamma radiation in underground mines. The publication includes a description of the dosimetry system and presents the results of measurements conducted by means of both types of dosimeters. In order to verify the correctness of the indications of the new dosimetry system a series of measurements were carried out, which allowed examining the behaviour of the dosimeters under different environmental conditions. As a place of exposure, the selected laboratories in the Silesian Centre for Environmental Radiometry were chosen, where the work is connected with (TENORM and equipment producing ionizing radiation or containing sources of this type of radiation. Moreover, to observe the dosimeters behaviour in difficult environmental conditions, they were exposed in water treatment plants and an underground potassium salt mine.

Applying AI techniques to improve alarm display effectiveness

International Nuclear Information System (INIS)

Gross, J.M.; Birrer, S.A.; Crosberg, D.R.

1987-01-01

The Alarm Filtering System (AFS) addresses the problem of information overload in a control room during abnormal operations. Since operators can miss vital information during these periods, systems which emphasize important messages are beneficial. AFS uses the artificial intelligence (AI) technique of object-oriented programming to filter and dynamically prioritize alarm messages. When an alarm's status changes, AFS determines the relative importance of that change according to the current process state. AFS bases that relative importance on relationships the newly changed alarm has with other activated alarms. Evaluations of a alarm importance take place without regard to the activation sequence of alarm signals. The United States Department of Energy has applied for a patent on the approach used in this software. The approach was originally developed by EG and G Idaho for a nuclear reactor control room

Characterization of Thymol blue Radiochromic dosimeters for high dose applications

Directory of Open Access Journals (Sweden)

Feras M. Aldweri

2018-03-01

Full Text Available Thymol blue (TB solutions and Thymol blue Polyvinyl Alcohol (TB-PVA films have been introduced as Radiochromic dosimeter for high dose applications. The dosimeters were irradiated with gamma ray (60Co source from 5 to 30 kGy for film, and from 0.150 kGy to 4 kGy for solution. The optical density of unirradiated and irradiated TB solution as well as TB-PVA film dosimeters were studied in terms of absorbance at 434 nm using UV/VIS spectrophotometer. The effects of scan temperature, light pre-gamma irradiation, dose rate, relative humidity and stability of the absorbance of solutions and films after irradiation were investigated. We found the dose sensitivity of TB solution and TB-PVA film dosimeters increases significantly with increases of the absorbed dose as well as with the increases of TB dye concentrations. The useful dose range of developed TB solutions and TB-PVA films dosimeters is in the range 0.125–1 kGy and of 5–20 kGy, respectively. Keywords: Dose sensitivity, Radio-chromic dosimeter, Thymol blue, Absorbance, Concentrations

The LEP alarm system

International Nuclear Information System (INIS)

Tyrrell, M.W.

1992-01-01

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)

46 CFR 97.37-9 - Carbon dioxide alarm.

Science.gov (United States)

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 BEING...

46 CFR 78.47-9 - Carbon dioxide alarm.

Science.gov (United States)

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) [Reserved] ...

46 CFR 196.37-9 - Carbon dioxide alarm.

Science.gov (United States)

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 BEING...

Los Alamos Scientific Laboratory long-range alarm system

International Nuclear Information System (INIS)

DesJardin, R.; Machanik, J.

1980-01-01

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-km 2 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

Advanced alarm systems: Display and processing issues

Energy Technology Data Exchange (ETDEWEB)

O`Hara, J.M. [Brookhaven National Lab., Upton, NY (United States); Wachtel, J.; Perensky, J. [US Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research

1995-05-01

This paper describes a research program sponsored by the US Nuclear Regulatory Commission to address the human factors engineering (HFE) deficiencies associated with nuclear power plant alarm systems. The overall objective of the study is to develop HFE review guidance for alarm systems. In support of this objective, human performance issues needing additional research were identified. Among the important issues were alarm processing strategies and alarm display techniques. This paper will discuss these issues and briefly describe our current research plan to address them.

Speech Alarms Pilot Study

Science.gov (United States)

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.

21 CFR 870.1100 - Blood pressure alarm.

Science.gov (United States)

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 pressure...

Alarm processing system using AI techniques for nuclear power plant

International Nuclear Information System (INIS)

Yang, Joon On; Chang, Soon Heung

1990-01-01

An alarm processing system (APS) has been developed using artificial intelligence (AI) techniques. The alarms of nuclear power plants (NPP's) are classified into the generalized and special alarms. The generalized alarms are also classified into the global and local alarms. For each type of alarms, the specific processing rules are applied to filter and suppress unnecessary and potentially misleading alarms. The local processing are based on 'model-based reasoning.' The global and special alarms are processed by using the general cause-consequence check rules. The priorities of alarms are determined according to the plant state and the consistencies between them

Portable dosimeter

International Nuclear Information System (INIS)

Buffa, A.; Caley, R.; Pfaff, K.

1986-01-01

A simple but very accurate portable dosimeter is described for indicating the intensity of ionizing radiation, comprising, as a unit: (a) a radiation-detection chamber having a pair of parallel, facing, electrically-conducting, radiation-permeable electrodes spaced from each other to define a volume for a gas which is ionized by the radiation when exposed thereto; (b) electric potential supply means connected across the electrodes for attracting the gas ions to the electrodes and transferring their charge to the electrodes; (c) detection circuit means connected across the electrodes and having at least one of high-frequency electromagnetic- and radiation-sensitive components for detecting the charge on the electrodes and indicating therefrom a representation of the intensity of the radiation; (d) radiation shield means surrounding the radiation-sensitive components of the detection circuit means for shielding the latter from the ionizing radiation; (e) electric shield means surrounding the sensitive components of the detection circuit means for shielding the latter from electromagnetic interference including any caused by the ionizing radiation; and (f) ion shield means potting the ion-sensitive components for shielding them from radiation-caused ambient ionization; whereby the entire dosimeter may be assembled as the unit and portably transported into various radiation sources

Advances in the development of Cr-39 based neutron dosimeters

International Nuclear Information System (INIS)

Hadlock, D.E.; Parkhurst, M.A.

1987-12-01

A combination thermoluminescent dosimeter (TLD) and track etch dosimeter (TED), which can be used for detecting neutrons over a wide energy range, has been developed through recent research in passive neutron dosimetery. This dosimeter uses Li-600 TLDs to detect thermal and low energy neutrons reflected from the body, and the TED polymer of CR-39, to detect fast neutrons from proton recoil interactions with the polyethylene radiator or with CR-39 itself. Some form of the combination dosimeter is currently in use at several US Department of Energy (DOE) facilities, and its use is expected to expand over the next year to include all DOE facilities where significant neutron exposures may occur. The extensive research conducted on the TED component over the past six years has continually focused on material improvements, reduction in processing time and dosimeter handling, and ease of sample readout with the goal of automating the process as much as possible. 1 fig

Auditory backup alarms: distance-at-first-detection via in-situ experimentation on alarm design and hearing protection effects.

Science.gov (United States)

Alali, Khaled; Casali, John G

2012-01-01

The purpose of this study was to assess normal hearing listeners' performance in detecting a stationary backup alarm signal and to quantify the linear distance at detection point. Detection distances for 12 participants with normal hearing were measured while they were fitted with 7 hearing protectors and while they were unoccluded (open ear). A standard (narrowband) backup alarm signal and a broadband (pulsed white noise) backup alarm signal from Brigade[1] were used. The method of limits, with distance as the physical measurement variable and threshold detection as the task, was employed to find at which distance the participant could first detect the backup alarms. A within-subject Analysis of Variance (ANOVA) revealed a significant main effect of the listening conditions on the detection distance in feet. Post hoc analyses indicated that the Bilsom L3HV conventional passive earmuff (at 1132.2 ft detection distance) was significantly poorer compared to all other HPDs and the open ear in detection distance achieved, and that there were no statistically-significant differences between the unoccluded ear (1652.3 ft), EB-15-Lo BlastPLGTM (1546.2 ft), EB-15-Hi BlastPLGTM (1543.4 ft), E-A-R/3M Combat ArmsTM earplug-nonlinear, level-dependent state (1507.8 ft), E-A-R/3M HiFiTM earplug (1497.7 ft), and Bilsom ImpactTM dichotic electronic earmuff (1567.2 ft). In addition, the E-A-R/3M Combat ArmsTM earplug-passive steady state resulted in significantly longer detection distances than only the open ear condition, at 1474.1 ft versus 1652.3 ft for the open ear. ANOVA also revealed a significant main effect of the backup alarm type on detection distance. The means were 1600.9 ft for the standard (narrowband) backup alarm signal, and a significantly closer 1379.4 ft was required for the Brigade broadband backup alarm signal. For on-ground workers, it is crucial to detect backup alarm signals as far away as possible rather than at close distances since this will provide them

Stable Chemical Dosimeters for Partial Reconstruction of Nuclear Accident Conditions

Energy Technology Data Exchange (ETDEWEB)

Dvornik, I.; Zec, U.; Baric, M.; Razem, D. [Ruder Boskovic Nuclear Institute, Zagreb, Yugoslavia (Croatia)

1969-10-15

The application of chemical dosimeters, tissue equivalent with respect to gamma rays and neutrons, is proposed for dosimetric topography of the space around nuclear devices in case of accidents. The dosimeters in the form of sealed glass ampoules have sufficient sensitivity and long-term stability and are evaluated or checked directly by conventional spectrophotometry. The sensitivity, expressed as yield per rad, is approximately equal for gamma rays and neutrons. The resolution in both cases is about one rad, and the range is up to several thousand rads. The precision of dosimetry is {+-} 1 rad or {+-} 2%, whichever is higher. In free space and unshielded the dosimeter measures the total rad-absorbed dose delivered by gamma rays and neutrons, i.e. the first collision gamma plus neutron dose. If used on- or in-phantom, especially if several dosimeters are disposed within and around the same phantom, it can give important data about the amount of the neutron component of the dose and about the effective mean energy of incident neutrons. The neutron component of the dose can be directly measured if the gamma dosimeter is used together with the chemical dosimeter. The experiments giving the change of optical density per rad and the radiation chemical yield with respect to the absorbed dose delivered by 14-MeV neutrons are described in detail. The possibility is also mentioned of applying the dosimeter as a very sensitive monitor for thermal neutrons, which is due to the chlorine content of 4.73% and activation to {sup 38}Cl. The opinion is expressed that this dosimeter deserves some attention as a part of future planning and development work on area and personnel accidental dosimetry systems. (author)

Useful and usable alarm systems : recommended properties

International Nuclear Information System (INIS)

Veland, Oeystein; Kaarstad, Magnhild; Seim, Lars Aage; Foerdestroemmen, Nils T.

2001-01-01

This document describes the result of a study on alarm systems conducted by IFE in Halden. The study was initiated by the Norwegian Petroleum Directorate. The objective was to identify and formulate a set of important properties for useful and usable alarm systems. The study is mainly based on review of the latest international recognised guidelines and standards on alarm systems available at the time of writing, with focus on realistic solutions from research and best practice from different industries. In addition, IFE experiences gathered through specification and design of alarm systems and experimental activities in HAMMLAB and bilateral projects, have been utilized where relevant. The document presents a total of 43 recommendations divided into a number of general recommendations and more detailed recommendations on alarm generation, structuring, prioritisation, presentation and handling. (Author)

Automating the personnel dosimeter monitoring program

International Nuclear Information System (INIS)

Compston, M.W.

1982-12-01

The personnel dosimetry monitoring program at the Portsmouth uranium enrichment facility has been improved by using thermoluminescent dosimetry to monitor for ionizing radiation exposure, and by automating most of the operations and all of the associated information handling. A thermoluminescent dosimeter (TLD) card, worn by personnel inside security badges, stores the energy of ionizing radiation. The dosimeters are changed-out periodically and are loaded 150 cards at a time into an automated reader-processor. The resulting data is recorded and filed into a useful form by computer programming developed for this purpose

Design of calibration method in neutron and individual dosimeter

International Nuclear Information System (INIS)

Belkhodia, M.

1984-12-01

Usually albedo dosemeters are calibrated with beam of monoenergetic neutrons. Since neutron energy around neutron sources varies greatly, we applied the calibration method to a mixed field whose energy spectrum lies between 0.025 ev and 10 Mev. The method is based on a mathematical model that deals with the dosimeter response as a function at the neutron energy. The measurements carried out with solid state nuclear track detectors show the dosimeter practical aspect. The albedo dosimeter calibration gave results on good agreement with the international institution recommendations

General methods for alarm reduction; Larmsanering med generella metoder

Energy Technology Data Exchange (ETDEWEB)

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

Chemical dosimeter

International Nuclear Information System (INIS)

Baker, W.B.; Clark, D.G.

1979-01-01

The dosimeter may be carried by individuals e.g. at the belt and serves to monitor for vinyl-chloride vapors in industrial plants and for toxic radon gas and toxic radon gas products in mines. It contains a pump, sucking an air flow through an orifice and a filter, as well as a sensor circuit for detecting low air flow rates and a battery testing circuit. (DG) 891 HP/DG 892 MKO [de

Radiation sensitive polymer gel dosimeters

International Nuclear Information System (INIS)

Lepage, M.; Back, S.A.J.; Baldock, C.; Whittaker, A.K.; Rintoul, L.

2000-01-01

Full text: Radiation sensitive gels are studied for their potential to retain a permanent 3D dose distribution for applications in radiotherapy. Co-monomers dissolved in a tissue-equivalent hydrogel undergo a polymerization reaction upon absorption of ionizing radiation. The polymer formed influences the local spin-spin relaxation time (T 2 ) of the dosimeter that can be determined using magnetic resonance imaging (MRI). The relationship between T2 and the absorbed dose was studied for different initial chemical compositions. The aim was to find a model linking the changes in T 2 with absorbed dose to the initial composition of the dosimeter. It is believed this will help designing new gel dosimeters having desired properties to minimize the uncertainty in the determination of the dose distribution. 1 H, 13 C nuclear magnetic resonance spectroscopy and FT-Raman spectroscopy were used to quantify the amount of monomers still remaining after the absorption of a given dose of radiation. This data is used to model the changes of T2 as a function of the absorbed dose. A model of fast exchange of magnetization between three proton pools was used, where the fraction of protons (f x H ) in the x th pool is obtained from the chemical composition of the dosimeter and the apparent T2 of each pool is determined for a given composition. Initially, the protons are contained in two pools; a mobile (mob), which contains the water protons and the monomers protons, and a gelatin (gela) proton pool. The mobile pool is partially depleted as polymer is formed, the protons are transferred into the polymer (pol) pool. In the figure, the experimental data along with the calculated values are plotted for three different monomer concentrations, with the gelatin concentration fixed. The model is seen to provide a good fit to the experimental data

Object-oriented alarm-filtering system

International Nuclear Information System (INIS)

Corsberg, D.R.; Wilkie, D.

1986-01-01

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. 10 refs

An experimental evaluation of alarm processing and display characteristics

International Nuclear Information System (INIS)

O'Hara, J.; Brown, W.; Hallbert, B.; Skraaning, G.Jr.; Persensky, J.; Wachtel, J.

1998-01-01

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. 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. Numerous strengths

The LLNL CR-39 personnel neutron dosimeter

International Nuclear Information System (INIS)

Hankins, D.E.; Homann, S.; Westermark, J.

1987-01-01

We developed a personnel neutron dosimetry system based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This CR-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. 3 refs., 4 figs

Perfection of the individual photographic emulsion dosimeter

International Nuclear Information System (INIS)

Soudain, G.

1960-01-01

A photographic dosimeter making possible the measurement of γ radiation doses of from 10 mr up to 800 r by means of 3 emulsion bands of varying sensitivity stuck to the same support is described. The dosimeter has also a zone for marking and a test film insensitive to radiation. This requires a photometric measurement by diffuse reflection an d makes it possible to measure doses with an accuracy of 20 per cent. (author) [fr

Dosimetric characteristics of PASSAG as a new polymer gel dosimeter with negligible toxicity

Science.gov (United States)

Farhood, Bagher; Abtahi, Seyed Mohammad Mahdi; Geraily, Ghazale; Ghorbani, Mehdi; Mahdavi, Seied Rabi; Zahmatkesh, Mohammad Hasan

2018-06-01

Despite many advantages of polymer gel dosimeters, their clinical use is only not realized now. Toxicity of polymer gel dosimeters can be considered as one of their main limitations for use in routine clinical applications. In the current study, a new polymer gel dosimeter is introduced with negligible toxicity. For this purpose, 2-Acrylamido-2-Methy-1-PropaneSulfonic acid (AMPS) sodium salt monomer was replaced instead of acrylamide monomer used in PAGAT gel dosimeter by using %6 T and %50 C to the gel formula and the new formulation is called PASSAG (Poly AMPS Sodium Salt and Gelatin) polymer gel dosimeter. The irradiation of gel dosimeters was carried out using a Co-60 therapy machine. MRI technique was used to quantify the dose responses of the PASSAG gel dosimeter. Then, the MRI responses (R2) of the gel dosimeter was analyzed at different dose values, post-irradiation times, and scanning temperatures. The results showed that the new gel formulation has a negligible toxicity and it is also eco-friendly. In addition, carcinogenicity and genetic toxicity tests are negative for the monomer used in PASSAG. The radiological properties of PASSAG gel dosimeter showed that this substance can be considered as a soft tissue/water equivalent material. Furthermore, dosimetric evaluation of the new polymer gel dosimeter revealed an excellent linear R2-dose response in the evaluated dose range (0-15 Gy). The R2-dose sensitivity and dose resolution of PASSAG gel dosimeter were 0.081 s-1Gy-1 (in 0-15 Gy dose range) and 1 Gy (in 0-10 Gy dose range), respectively. Moreover, it was shown that the R2-dose sensitivity and dose resolution of the new gel dosimeter improves over time after irradiation. It was also found that the R2 response of the PASSAG gel dosimeter has less dependency to the 18, 20, and 24 °C scanning temperature in comparison to that of room temperature (22 °C).

Line supervision of alarm communications

International Nuclear Information System (INIS)

Chritton, M.R.

1991-01-01

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

Alarm management for process control a best-practice guide for design, implementation, and use of industrial alarm systems

CERN Document Server

Rothenberg, Douglas H

2014-01-01

No modern industrial enterprise, particularly in such areas as chemical processing, can operate without a secure, and reliable, network of automated monitors and controls. And those operations need alarm systems to alert engineers and managers the moment anything goes wrong or needs attention. This book, by one of the world's leading experts on industrial alarm systems, will provide A to Z coverage of designing, implementing, and maintaining an effective alarm network.

Antioxidant effect of green tea on polymer gel dosimeter

International Nuclear Information System (INIS)

Samuel, E J J; Sathiyaraj, P; Deena, T; Kumar, D S

2015-01-01

Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer

Optimizing the sensitivity and radiological properties of the PRESAGE® dosimeter using metal compounds

International Nuclear Information System (INIS)

Alqathami, Mamdooh; Blencowe, Anton; Qiao, Greg; Adamovics, John; Geso, Moshi

2012-01-01

The aim of this study is to investigate the radiation-modifying effects of incorporating commercially available bismuth-, tin- and zinc-based compounds in the composition of the PRESAGE ® dosimeter, and the feasibility of employing such compounds for radiation dose enhancement. Furthermore, we demonstrate that metal compounds can be included in the formulation to yield water-equivalent PRESAGE ® dosimeters with enhanced dose response. Various concentrations of the metal compounds were added to a newly developed PRESAGE ® formulation and the resulting dosimeters were irradiated with 100 kV and 6 MV photon beams. A comparison between sensitivity and radiological properties of the PRESAGE ® dosimeters with and without the addition of metal compounds was carried out. Optical density changes of the dosimeters before and after irradiation were measured using a spectrophotometer. In general, when metal compounds were incorporated in the composition of the PRESAGE ® dosimeter, the sensitivity of the dosimeters to radiation dose increased depending on the type and concentration of the metal compound, with the bismuth compound showing the highest dose enhancement factor. In addition, these metal compounds were also shown to improve the retention of the post-response absorption value of the PRESAGE ® dosimeter over a period of 2 weeks. Thus, incorporating 1–3 mM (ca. 0.2 wt%) of any of the three investigated metal compounds in the composition of the PRESAGE ® dosimeter is found to be an efficient way to enhance the sensitivity of the dosimeter to radiation dose and stabilize its post-response for longer times. Furthermore, the addition of small amounts of the metal compounds also accelerates the polymerization of the PRESAGE ® dosimeter precursors, significantly reducing the fabrication time. Finally, a novel water-equivalent PRESAGE ® dosimeter formula optimized with metal compounds is proposed for clinical use in both kilovoltage and megavoltage radiotherapy

Development of the newly advanced alarm system for APWR plant

International Nuclear Information System (INIS)

Shimada, Manabu; Yamamoto, Yoshihiro; Tani, Mamoru; Kobashi, Shuichi

1997-01-01

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

Development of the newly advanced alarm system for APWR plant

Energy Technology Data Exchange (ETDEWEB)

Shimada, Manabu; Yamamoto, Yoshihiro; Tani, Mamoru; Kobashi, Shuichi [Kansai Electric Power Co., Inc., Osaka (Japan)

1997-09-01

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.

An NMR relaxometry and gravimetric study of gelatin-free aqueous polyacrylamide dosimeters

International Nuclear Information System (INIS)

Babic, Steven; Schreiner, L John

2006-01-01

In conformal radiation therapy, a high dose of radiation is given to a target volume to increase the probability of cure, and care is taken to minimize the dose to surrounding healthy tissue. The techniques used to achieve this are very complicated and the precise verification of the resulting three-dimensional (3D) dose distribution is required. Polyacrylamide gelatin (PAG) dosimeters with magnetic resonance imaging and optical computed tomography scanning provide the required 3D dosimetry with high spatial resolution. Many basic studies have characterized these chemical dosimeters that polymerize under irradiation. However, the investigation of the fundamental properties of the radiation-induced polymerization in PAG dosimeters is complicated by the presence of the background gelatin matrix. In this work, a gelatin-free model system for the study of the basic radiation-induced polymerization in PAG dosimeters has been developed. Experiments were performed on gelatin-free dosimeters, named aqueous polyacrylamide (APA) dosimeters, containing equal amounts of acrylamide and N,N'-methylene-bisacrylamide. The APA dosimeters were prepared with four different total monomer concentrations (2, 4, 6 and 8% by weight). Nuclear magnetic resonance (NMR) spin-spin and spin-lattice proton relaxation measurements at 20 MHz, and gravimetric analyses performed on all four dosimeters, show a continuous degree of polymerization over the dose range of 0-25 Gy. The developed NMR model explains the relationship observed between the relaxation data and the amount of crosslinked polymer formed at each dose. This model can be extended with gelatin relaxation data to provide a fundamental understanding of radiation-induced polymerization in the conventional PAG dosimeters

Alarm management in gas pipeline plant: a case study

Energy Technology Data Exchange (ETDEWEB)

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)

Alarm criteria in radiation portal monitoring

Energy Technology Data Exchange (ETDEWEB)

Burr, Tom [Los Alamos National Laboratory, Statistical Sciences Group, Mail Stop F600, Los Alamos, NM 87545 (United States)]. E-mail: tburr@lanl.gov; Gattiker, James R. [Los Alamos National Laboratory, Statistical Sciences Group, Mail Stop F600, Los Alamos, NM 87545 (United States); Myers, Kary [Los Alamos National Laboratory, Statistical Sciences Group, Mail Stop F600, Los Alamos, NM 87545 (United States); Tompkins, George [Los Alamos National Laboratory, Risk Analysis and Decision Support Systems, Stop F609, Los Alamos, NM 87545 (United States)

2007-05-15

Gamma detectors at border crossings are intended to detect illicit nuclear material. These detectors collect counts that are used to determine whether to trigger an alarm. Several candidate alarm rules are evaluated, with attention to background suppression caused by the vehicle. Because the count criterion leads to many nuisance alarms and because background suppression by the vehicle is smaller for ratios of counts, analysis of a ratio criterion is included. Detection probability results that consider the effects of 5 factors are given for 2 signal-injection studies, 1 for counts, and 1 for count ratios.

Alarm criteria in radiation portal monitoring

International Nuclear Information System (INIS)

Burr, Tom; Gattiker, James R.; Myers, Kary; Tompkins, George

2007-01-01

Gamma detectors at border crossings are intended to detect illicit nuclear material. These detectors collect counts that are used to determine whether to trigger an alarm. Several candidate alarm rules are evaluated, with attention to background suppression caused by the vehicle. Because the count criterion leads to many nuisance alarms and because background suppression by the vehicle is smaller for ratios of counts, analysis of a ratio criterion is included. Detection probability results that consider the effects of 5 factors are given for 2 signal-injection studies, 1 for counts, and 1 for count ratios

Design, construction and characterization of a dosimeter for neutron radiation

International Nuclear Information System (INIS)

Souto, Eduardo de Brito

2007-01-01

An individual dosimeter for neutron-gamma mixed field dosimetry was design and developed aiming monitoring the increasing number of workers potentially exposed to neutrons. The proposed dosimeter was characterized to an Americium-Beryllium source spectrum and dose range of radiation protection interest (up to 20 mSv). Thermoluminescent albedo dosimetry and nuclear tracks dosimetry, traditional techniques found in the international literature, with materials of low cost and national production, were used. A commercial polycarbonate, named SS-1, was characterized for solid state tack detector application. The chemical etching parameters and the methodology of detectors evaluation were determined. The response of TLD-600, TLD-700 and SS-1 were studied and algorithms for dose calculation of neutron and gamma radiation of Americium- Beryllium sources were proposed. The ratio between thermal, albedo and fast neutrons responses, allows analyzing the spectrum to which the dosimeter was submitted and correcting the track detector response to variations in the radiation incidence angle. The new dosimeter is fully characterized, having sufficient performance to be applied as neutron dosimeter in Brazil. (author)

A personal radio-frequency dosimeter with cumulative-dose recording capabilities

International Nuclear Information System (INIS)

Rochelle, R.W.; Moore, M.R.; Thomas, R.S.; Ewing, P.D.; Hess, R.A.; Hoffheins, B.S.

1990-01-01

The radio-frequency (rf) dosimeter developed by the Oak Ridge National Laboratory is a portable, pocket-sized cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. Features of the rf dosimeter include a frequency range of 30 MHz to 10 GHz and a three-dimensional sensor. Data obtained with the rf dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to 6 months, after which the data are transferred to a computer via the dosimeter's serial port. The rf dosimeter should increase knowledge of the levels of electric fields to which individuals are exposed. 13 refs., 16 figs., 2 tabs

Development and characterization of real-time wide-energy range personal neutron dosimeter

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Takashi; Tsujimura, Norio (Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center); Yamano, Toshiya; Suzuki, Toshikazu; Okamoto, Eisuke

1994-04-01

The authors developed a real-time personal neutron dosimeter which could give neutron dose equivalent over wide energy region from thermal to 10 odd MeV by using 2 silicon detectors, fast neutron sensor and slow neutron sensor. The energy response of this dosimeter was evaluated under thermal neutron field, monoenergetic neutron field between 200 keV and 15 MeV, and moderated [sup 252]Cf neutron field. The neutron dose equivalent was estimated by adding neutron dose equivalent below 1 MeV given by slow neutron sensor and that above 1 MeV by fast neutron sensor. It was verified from various field tests that this dosimeter is able to give neutron dose equivalent within a factor of 2 margin of accuracy in reactor, accelerator, fusion research and nuclear fuel handling facilities. This dosimeter has more than one order higher sensitivity than conventional personal neutron dosimeters and is insensitive to [gamma]-rays up to about 500 mSv/h. This dosimeter will soon be commercially available as a personal dosimeter which gives neutron and [gamma]-ray dose equivalents simultaneously by installing [gamma]-ray silicon sensor. (author).

Dental tissue as a thermoluminescence dosimetry dosimeter

International Nuclear Information System (INIS)

Solaimani, F.; Zahmatkesh, M.H.; Akhlaghpoor, Sh.

2003-01-01

Background: Thermoluminescence dosimetry is one of the dosimetry procedures used widely as routine and personal dosimeters. In order to extend this kind of dosimeters, dental tissue has been examined and was found promising as a Thermoluminescence Dosimetry dosimeter. Materials and Methods: In this study, 70 health teeth were collected. The only criterion, wich was considered for selection of the teeth, was the healthiness of them regardless of age and gender of the donors. All collected samples were washed and cleaned and milled uniformly. The final powder had a uniform grain size between 100-300 micrometer. The sample was divided into four groups. Group A and B were used for measurement of density and investigation of variation of thermoluminescent characteristics with temperature respectively. Groups C and D were used for investigation of variation of thermoluminescent intensity with dose and fading of this intensity with time. In all cases the results obtained with dental tissue were compared to a standard LiF, thermoluminescence dosimetry dosimeter. Results: It was found that, average density of the dental tissue was 1.570 g/cm 3 , which is comparable to density of LiF, which is 1.612g/cm 3 . It was also concluded that the range of 0-300 d ig C , dental tissue has a simple curve with two specific peaks at 140 and 25 d ig C respectively. The experiment also showed that, the variation of relative intensity versus dose is linear in the range of 0.04-0.1 Gy. The fading rate of dental tissue is higher than LiF but still in the acceptable range (14% per month in compare to 5.2% per month). Conclusion: Dental tissue as a natural dosimeter is comparable with Thermoluminescence Dosimetry and can be used in accidental events with a good approximation

Experimental evaluation of a MOSFET dosimeter for proton dose measurements

International Nuclear Information System (INIS)

Kohno, Ryosuke; Nishio, Teiji; Miyagishi, Tomoko; Hirano, Eriko; Hotta, Kenji; Kawashima, Mitsuhiko; Ogino, Takashi

2006-01-01

The metal oxide semiconductor field-effect transistor (MOSFET) dosimeter has been widely studied for use as a dosimeter for patient dose verification. The major advantage of this detector is its size, which acts as a point dosimeter, and also its ease of use. The commercially available TN502RD MOSFET dosimeter manufactured by Thomson and Nielsen has never been used for proton dosimetry. Therefore we used the MOSFET dosimeter for the first time in proton dose measurements. In this study, the MOSFET dosimeter was irradiated with 190 MeV therapeutic proton beams. We experimentally evaluated dose reproducibility, linearity, fading effect, beam intensity dependence and angular dependence for the proton beam. Furthermore, the Bragg curve and spread-out Bragg peak were also measured and the linear-energy transfer (LET) dependence of the MOSFET response was investigated. Many characteristics of the MOSFET response for proton beams were the same as those for photon beams reported in previous papers. However, the angular MOSFET responses at 45, 90, 135, 225, 270 and 315 degrees for proton beams were over-responses of about 15%, and moreover the MOSFET response depended strongly on the LET of the proton beam. This study showed that the angular dependence and LET dependence of the MOSFET response must be considered very carefully for quantitative proton dose evaluations

Definition and means of maintaining the criticality detectors and alarms portion of the PFP safety envelope

International Nuclear Information System (INIS)

White, W.F.

1997-01-01

The Criticality Alarm System (CAS) provides continuous detection for high radiation (criticality) events and automatically initiates an evacuation signal to affected personnel. The Safety Envelope (SE) for PFP includes the necessary equipment and the required procedures to ensure the CAS is capable of performing its intended function. This document provides the definition and means of maintaining the SE for PFP related to the CAS. This document also identifies and provides a justification for those portions of the CAS excluded from the PFP Safety Envelope

A Study on Performance Requirements for Advanced Alarm System

International Nuclear Information System (INIS)

Seong, Duk Hyun; Jeong, Jae Hoon; Sim, Young Rok; Ko, Jong Hyun; Kim, Jung Seon; Jang, Gwi Sook; Park, Geun Ok

2005-01-01

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

Early development and characterization of a DNA-based radiation dosimeter

Science.gov (United States)

Avarmaa, Kirsten A.

It is the priority of first responders to minimize damage to persons and infrastructure in the case of a nuclear emergency due to an accident or deliberate terrorist attack -- if this emergency includes a radioactive hazard, first responders require a simple-to-use, accurate and complete dosimeter for radiation protection purposes in order to minimize the health risk to these individuals and the general population at large. This work consists of the early evaluation of the design and performance of a biologically relevant dosimeter which uses DNA material that can respond to the radiation of any particle type. The construct consists of fluorescently tagged strands of DNA. The signalling components of this dosimeter are also investigated for their sensitivity to radiation damage and light exposure. The dual-labelled dosimeter that is evaluated in this work gave a measurable response to gamma radiation at dose levels of 10 Gy for the given detector design and experimental setup. Further testing outside of this work confirmed this finding and indicated a working range of 100 mGy to 10 Gy using a custom-built fluorimeter as part of a larger CRTI initiative. Characterization of the chromatic components of the dosimeter showed that photobleaching is not expected to have an effect on dosimeter performance, but that radiation can damage the non-DNA signalling components at higher dose levels, although this damage is minimal at lower doses over the expected operating ranges. This work therefore describes the early steps in the quantification of the behaviour of the DNA dosimeter as a potential biologically-based device to measure radiation dose.

Operator Performance Comparison of two VDT-based Alarm Systems

International Nuclear Information System (INIS)

Lee, Hyun-Chul; Oh, In-Suk; Sim, Bong-Shick; Koo, In-Soo; Kim, Jeong-Taek; Lee, Ki-Young; Park, Jong-Kyun

1998-01-01

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)

Dosimetry of blood irradiation using an alanine/ESR dosimeter

International Nuclear Information System (INIS)

Chen, F.; Covas, D.T.; Baffa, O.

2001-01-01

A batch of 80 DL-alanine dosimeters was supplied to Hemocentro of the Hospital and Clinics of Faculdade de Medicina de Ribeirao Preto (HC-FMRP) SP, Brazil for the purpose of quality control of the radiation dose delivered to blood bags. The irradiation was made using two (40x40) cm 2 parallel opposed radiation fields each with 80 cm of source to surface distance in the Radiotherapy Section of HC-FMRP with the 60 Co teletherapy unit. The calculated radiation absorbed dose at the center of the box was 20 Gy. The dosimeter readings were performed using a Varian E-4 ESR Spectrometer operating in X-band. For the 80 dosimeters and over the irradiation volume throughout a blood bag, the minimum and maximum doses were 14 and 23 Gy, respectively. The mean dose was (18±2) Gy (1σ), and the coefficient of variability was 11.1%. Alanine dosimeters demonstrated easy handling, good precision and adequate sensitivity for this application

Framework for analyzing safeguards alarms and response decisions

International Nuclear Information System (INIS)

Al-Ayat, R.A.; Judd, B.R.; McCord, R.K.

1982-01-01

This paper describes a quantitative approach to help evaluate and respond to safeguards alarms. These alrms may be generated internally by a facility's safeguards systems or externally by individuals claiming to possess stolen Special Nuclear Material (SNM). This approach can be used to identify the most likely cause of an alarm - theft, hoax, or error - and to evaluate alternative responses to alarms. Possible responses include conducting investigations, initiating measures to recover stolen SNM, and replying to external threats. Based on the results of each alarm investigation step, the evaluation revises the likelihoods of possible causes of an alarm, and uses this information to determine the optimal sequence of further responses. The choice of an optimal sequence of responses takes into consideration the costs and benefits of successful thefts or hoaxes. These results provide an analytical basis for setting priorities and developing contingency plans for responding to safeguards alarms

Electret dosimeter utilizing gas multiplication

International Nuclear Information System (INIS)

Ikeya, M.; Miki, T.

1980-01-01

It was found that the high electric field around the surface of an electret leads to cascade multiplication of the ionization process in a surrounding gas. Very sensitive charge decay constants of the order of 1mrad, were obtained for electrets composed of polyvinyliden fluoride or teflon polymers. The reduced charge is stable and can be utilized in personnel dosimetry. A simple pocket chamber dosimeter is described consisting of a small speaker or buzzer, a cylindrical chamber filled with air, argon or other gases, a polymer thermoelectret foil and an electrode. The sonic vibration of the foil induces an alternating charge on the electrode which is amplified and detected. The feasibility of this dosimeter and its shock and vibration resistance have been demonstrated. (author)

Monte Carlo simulation experiments on box-type radon dosimeter

International Nuclear Information System (INIS)

Jamil, Khalid; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

2014-01-01

Epidemiological studies show that inhalation of radon gas ( 222 Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the 222 Rn concentrations (Bq/m 3 ) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η int ) and alpha hit efficiency (η hit ). The η int depends upon only on the dimensions of the dosimeter and η hit depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper explains that how radon

Monte Carlo simulation experiments on box-type radon dosimeter

Energy Technology Data Exchange (ETDEWEB)

Jamil, Khalid, E-mail: kjamil@comsats.edu.pk; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

2014-11-11

Epidemiological studies show that inhalation of radon gas ({sup 222}Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the {sup 222}Rn concentrations (Bq/m{sup 3}) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η{sub int}) and alpha hit efficiency (η{sub hit}). The η{sub int} depends upon only on the dimensions of the dosimeter and η{sub hit} depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper

Alarm points for fixed oxygen monitors

International Nuclear Information System (INIS)

Miller, G.C.

1987-05-01

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

Railway automatic safety protection system based on GPS

Directory of Open Access Journals (Sweden)

Fu Hai Juan

2016-01-01

Full Text Available The automatic protection system of railway safety is designed for the railway construction workers to protect alarm, and the safety protection device by using GPS satellite positioning system to acquire location information of the operating point, through the CTC/TDCS system and computer monitoring system for the running of the train position and the arithmetic distance. Achieving timely and continuously forecasts about the distance of the train which is apart from the operating point to prompt the voice alarm of the approaching train. Using digital technology to realize the function of the traditional analog interphone, eliminates the quality problems of the call. With the GSM-R, mobile wireless transmission channel and terminal technology, it overcomes the restrictions of the analog interphone which influenced by communication distance and more problems of blind areas. Finally to achieve practical, convenient, applicable and adaptable design goals.

Angular dependence of the nanoDot OSL dosimeter

OpenAIRE

Kerns, James R.; Kry, Stephen F.; Sahoo, Narayan; Followill, David S.; Ibbott, Geoffrey S.

2011-01-01

Purpose: Optically stimulated luminescent detectors (OSLDs) are quickly gaining popularity as passive dosimeters, with applications in medicine for linac output calibration verification, brachytherapy source verification, treatment plan quality assurance, and clinical dose measurements. With such wide applications, these dosimeters must be characterized for numerous factors affecting their response. The most abundant commercial OSLD is the InLight∕OSL system from Landauer, Inc. The purpose of...

Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

Energy Technology Data Exchange (ETDEWEB)

Stranden, E.; Widmark, A.; Sekse, T. (Buskerud Univ. College, Drammen (Norway))

2008-05-15

Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

International Nuclear Information System (INIS)

Stranden, E.; Widmark, A.; Sekse, T.

2008-01-01

Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

Environmental monitoring by CaSO4:Dy TL dosimeters

International Nuclear Information System (INIS)

Deme, S.; Szabo, P.P.

1975-12-01

The thermoluminescent dosimeters of high sensitivity are useful for monitoring the area near nuclear installations. CaSO 4 :Dy TL dosimeters have high sensitivity and low fading so that by means of them the dose from the background can be measured with an accuracy of 10-20%. An increase of 2 mR in the background can be observed and doses as high as 1000R can be registered with an accuracy of 5%. The measuring method and results are reported here. For two years these CaSO 4 :Dy dosimeters have been successfully used at the site of the Central Research Institute for Physics. (K.A.)

Classification of alarm processing techniques and human performance issues

International Nuclear Information System (INIS)

Kim, I.S.; O'Hara, J.M.

1993-01-01

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

Classification of alarm processing techniques and human performance issues

Energy Technology Data Exchange (ETDEWEB)

Kim, I.S.; O' Hara, J.M.

1993-01-01

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.

Classification of alarm processing techniques and human performance issues

Energy Technology Data Exchange (ETDEWEB)

Kim, I.S.; O`Hara, J.M.

1993-05-01

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.

Automated Calibration of Dosimeters for Diagnostic Radiology

International Nuclear Information System (INIS)

Romero Acosta, A.; Gutierrez Lores, S.

2015-01-01

Calibration of dosimeters for diagnostic radiology includes current and charge measurements, which are often repetitive. However, these measurements are usually done using modern electrometers, which are equipped with an RS-232 interface that enables instrument control from a computer. This paper presents an automated system aimed to the measurements for the calibration of dosimeters used in diagnostic radiology. A software application was developed, in order to achieve the acquisition of the electric charge readings, measured values of the monitor chamber, calculation of the calibration coefficient and issue of a calibration certificate. A primary data record file is filled and stored in the computer hard disk. The calibration method used was calibration by substitution. With this system, a better control over the calibration process is achieved and the need for human intervention is reduced. the automated system will be used in the calibration of dosimeters for diagnostic radiology at the Cuban Secondary Standard Dosimetry Laboratory of the Center for Radiation Protection and Hygiene. (Author)

Alarm handling systems and techniques developed to match operator tasks

International Nuclear Information System (INIS)

Bye, A.; Moum, B.R.

1997-01-01

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

Alarm handling systems and techniques developed to match operator tasks

Energy Technology Data Exchange (ETDEWEB)

Bye, A; Moum, B R [Institutt for Energiteknikk, Halden (Norway). OECD Halden Reaktor Projekt

1997-09-01

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.

An Evidence-Based Approach to Reducing Cardiac Telemetry Alarm Fatigue.

Science.gov (United States)

Srinivasa, Ekta; Mankoo, Jaspreet; Kerr, Charles

2017-08-01

It is estimated that between 80% and 99% of alarms in the clinical areas are in actionable alarms (Gross, Dahl, & Nielson). Alarm management is one of the Joint Commission's National Patient Safety Goals (2014) because sentinel events have directly been linked to the devices generating these alarms. At an acute care facility in Boston, a multidisciplinary team consisting of Nursing, Biomedical Engineers, Patient Safety and Providers was formed to conduct a pilot study on the state of telemetry alarms on a surgical floor. An evidence-based approach was taken utilizing Philips Real-time data exporter alarms tracking software to capture all telemetry alarms during a 43-day time span. Likewise, noise meters were placed near telemetry alarm speakers to track decibel levels within the aforementioned timeframe for 21 days. Analysis of the data showed that clinically insignificant Premature Ventricular Contractions (PVC) alarms accounted for more than 40% of all alarms in the unit within the time span, while also contributing to an average noise level of 58.49 dB. In response to the data, the interdisciplinary team approved to permanently default the settings for PAIR PVC, MULTIFORM PVC, and RUN PVC alarms to off. The results showed a 54% decrease in the rate of alarms per bed per day, and an average noise reduction of 2.3 dB between the two selected noise measurement areas. Organizing a multidisciplinary team provides an effective framework toward analyzing and addressing cardiac telemetry alarm fatigue. Looking at quantitative datasets for clinical care areas through various lenses helps identify opportunities for improvement in regards to highlighting alarms that are not actionable. Pilot changes to alarm parameters can be tested for their environmental impact in the care area. © 2017 Sigma Theta Tau International.

Evaluation of the implementation and use of active personal dosimeters for neutrons in Brazil

International Nuclear Information System (INIS)

Castro B, C. P.; Wagner P, W.; De Souza P, K. C.

2014-08-01

This work was conducted through of a field research based on a questionnaire sent to users of active personal dosimeters. A retrospective study of the last six years was also carried out of the services in the Neutron Metrology Laboratory (2008-2013) referent to the active personal dosimeters, taking into consideration the standards ISO-8529-3 and IEC-61526. The active personal dosimeters are defined as any instrument of individual monitoring with direct reading capacity, used by individuals exposed to ionizing radiation fields. Through research was verified that the active personal dosimeters work associated with other dosimeter types. Considering all dosimeters declared in the questionnaire, only two dosimeters (MGP brand Dmc 2000-GN model and the brand ATOMTEX model AT2503A) have conformity declaration with the international standard IEC-61526: 2005 reported by the manufacturers. (author)

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

International Nuclear Information System (INIS)

Davey, E.; Hickey, D.; Babcock, B.

1997-01-01

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)

Anthracene dosimeter characterization under radiotherapy photons

International Nuclear Information System (INIS)

Czelusniak, Caroline

2011-01-01

New radiotherapy techniques such as intensity-modulated radiation therapy and stereotactic radiosurgery have increased the need for dosimeters that can provide measurements in real time with high spatial resolution. Organic scintillation dosimeters are able to measure with accuracy small radiation fields and fields with high gradients, besides having advantages such as water and soft tissue equivalence and the possibility to be used in vivo. Anthracene is an organic scintillator crystal with the highest known scintillation efficiency among organic scintillation materials. The objective of this work is to characterize the anthracene as a dosimeter under radiotherapy photons energies, analysing its signal against average granulosity, intern capsule diameter, absorbed dose, absorbed dose rate, photon energy and its spatial resolution; with the last one analysed under three methods (edge spread function, line spread function and modulation transfer function). The photons energies used were 1.25 MeV ( 60 Co), 0.661 MeV ( 137 Cs) and X-rays (effective energies of 28.4; 46.5; 48.5; 94.0 e 106.0 keV). The scintillation detection system consisted of an optical fiber with one end attached to the anthracene capsule and the other to a photomultiplier tube maintained by power supply followed by an electrometer. Once Cerenkov radiation occurs in the optical fiber, it was removed from the total scintillation signal trough the subtraction of the signal, taken irradiating the optical fiber without the anthracene attached to one of its extremity. From results obtained, one can infer that the dosimeter signal increases proportionally with average granulosity and intern capsule diameter. The signal is linearly dependent of absorbed dose, linearly dependent of low photons energies and independent for high photons energies, as well as independent of the absorbed dose rate. From the spatial resolution values obtained it was possible to infer that the one obtained through modulation

Use of normoxic polymer gel dosimeters for measuring diagnostic doses on CT scanners

International Nuclear Information System (INIS)

Hill, B; Venning, A J; Baldock, C

2004-01-01

X-ray CT has been used to evaluate polymer gel dosimeters for dose response in the therapeutic dose range. This method of polymer gel dosimeter evaluation has been shown to be useful for instance in the comparison of complex sterotactic field distributions with treatment plans. Image averaging and subtraction techniques are used for noise reduction in polymer gel dosimeters resulting in the delivery of several CT slices across the polymer gel dosimeters. It was a logical progression to evaluate normoxic polymer gel dosimeters with optimized CT scanning protocols. During these investigations it was found that unirradiated regions in irradiated normoxic polymer gel dosimetry phantoms polymerised possibly as a result of the evaluation using CT. This prompted an investigation of the CT diagnostic dose response of the normoxic polymer gel dosimeter in order to determine the dose contribution when evaluated using a CT scanner. Having established that there was an effect on the normoxic polymer gel dosimeter when evaluating with a CT scanner the suitability of these gels in the determination of CT diagnostic dose measurement was further investigated

Computational Human Performance Modeling For Alarm System Design

Energy Technology Data Exchange (ETDEWEB)

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.

Semi-supervised detection of intracranial pressure alarms using waveform dynamics

International Nuclear Information System (INIS)

Scalzo, Fabien; Hu, Xiao

2013-01-01

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)

Comprehensive Angular Response Study of LLNL Panasonic Dosimeter Configurations and Artificial Intelligence Algorithm

Energy Technology Data Exchange (ETDEWEB)

Stone, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-06-30

In April of 2016, the Lawrence Livermore National Laboratory External Dosimetry Program underwent a Department of Energy Laboratory Accreditation Program (DOELAP) on-site assessment. The assessment reported a concern that the study performed in 2013 Angular Dependence Study Panasonic UD-802 and UD-810 Dosimeters LLNL Artificial Intelligence Algorithm was incomplete. Only the responses at ±60° and 0° were evaluated and independent data from dosimeters was not used to evaluate the algorithm. Additionally, other configurations of LLNL dosimeters were not considered in this study. This includes nuclear accident dosimeters (NAD) which are placed in the wells surrounding the TLD in the dosimeter holder.

Internal background build-up measurements in CaF2:Mn thermoluminescent dosimeters

International Nuclear Information System (INIS)

Balasybrahmanyam, V.; Measures, M.P.

1977-01-01

Some problems associated with the internal background build-up (IBB) of CaF 2 :Mn thermoluminescent dosimeters are reported. As a result of an investigation of batches of the EG and G model 15 dosimeter it is considered that measurements using this type of dosimeter are accurate and reproducible once the IBB has been determined. However, the use of the Manufacturer's claimed average of 0.064 mR/day can lead to erroneous results when determining environmental background dose rates. The authors therefore urge a rigid quality control program by the manufacturer and suggest that purchasers should be supplied with IBB information of each batch of dosimeters. Meanwhile each user should be aware of the IBB problem and be extremely cautious when using these dosimeters for environmental monitoring purposes. (U.K.)

Dosimetric Characteristics of Radio-Photoluminescent Glass Dosimeters for Medical Applications: Linearity

Energy Technology Data Exchange (ETDEWEB)

Shehzadi, N. N.; Jeong, J. P.; Kim, B. C.; Kim, I. J.; Yi, C. Y. [Center for Ionizing Radiation, Korea Research Institute of Standards and Science, Seoul (Korea, Republic of)

2017-04-15

Radio-photoluminescent glass dosimeter (GD) has advantage of non-destructive reading process, negligible fading and superior radiation detection characteristics than other personal dosimeters like thermoluminescent dosimeters (TLD) or film dosimeters. In this study, one dosimetric characteristic of GDs, dose linearity was evaluated with two different approaches: one for each set of GDs selected and another for a batch of them using accumulated doses of same set of GDs and GDs in a batch, respectively. Within a dose range upto 10 Gy, not only each set of GDs but also a batch of them showed excellent linearity. Within a dose range upto 10 Gy, not only each set of GDs but also a batch of them showed excellent linearity.

Study on intermediate frequency power supply automatic monitor system

International Nuclear Information System (INIS)

Wang Yuntong; Xu Bin

2007-06-01

A new design project of the automatic monitor system for the intermediate frequency power supply system by using the communication server is put for- ward and the realizing principle method and the key technique are clarified in detail. This system made use of the conversion function with the series communication server's control, realized the data collecting function by the double machine backup and redundancy. The new network system adopted the photoelectric-insulated-communication connect device and the diagnosis technique, increased the anti-interference ability, the communication adopted the technique by the alarm information sending out in first and circularly repeating, the slowly speed is overcame in the original monitor network system, and strengthened the celerity of the monitor system and the reliability of the alarm report. After the new monitor system running, the result shows that the functions is more perfect than the original monitor system, the usage is more convenient, have the higher and dependable stability, the report of alarm is more quickly, and is convenient for the analysis after the trouble, at the same time, the system still have the strong ability and value to expand. (authors)

Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

International Nuclear Information System (INIS)

Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

1991-12-01

Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue

Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

Energy Technology Data Exchange (ETDEWEB)

Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

1991-12-01

Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford`s mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

Energy Technology Data Exchange (ETDEWEB)

Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

1991-12-01

Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

High dose potassium-nitrate chemical dosimeter

International Nuclear Information System (INIS)

Dorda de Cancio, E.M.; Munoz, S.S.

1982-01-01

This dosimeter is used to control 10 kGY-order doses (1 Mrad). Nitrate suffers a radiolitic reduction phenomena, which is related to the given dose. The method to use potassium nitrate as dosimeter is described, as well as effects of the temperature of irradiation, pH, nitrate concentration and post-irradiation stability. Nitrate powder was irradiated at a Semi-Industrial Plant, at Centro Atomico Ezeiza, and also in a Gammacell-220 irradiator. The dose rates used were 2,60 and 1,80 KGY/hour, and the given doses varied between 1,0 and 150 KGY. The uncertainty was +-3% in all the range. (author) [es

Optical dosimeter

International Nuclear Information System (INIS)

Drukaroff, I.; Fishman, R.

1984-01-01

A reflecting optical dosimeter is a thin block of optical material having an input light pipe at one corner and an output light pipe at another corner, arranged so that the light path includes several reflections off the edges of the block to thereby greatly extend its length. In a preferred embodiment, one corner of the block is formed at an angle so that after the light is reflected several times between two opposite edges, it is then reflected several more times between the other two edges

Comparison between dosimeter films and electronic dosimeters results obtained in F-18 production practices at IEN/CNEN

International Nuclear Information System (INIS)

Paulo, Osvaldir; Carlos, Luiz R.J.; Mendes, Milton

2008-01-01

Full text: The aim of the present work is the comparison of the dose rates values obtained from dosimeter films with the values obtained from electronic dosimeters used by radiological protection technician involved in practices with fluorine-18 production in CV-28 cyclotron at IEN/CNEN. The motivation for this work was the increase on the demand of this radiopharmaceutical. Nowadays there is an increase demand on the number of clinics and hospitals which had started to use the technique of radiodiagnostic using positron-emission tomography (PET). Therefore, the produced radionuclide activities (physics quantity) and also the complexity of the practices of radiological protection in the areas of that facility had increased a lot. The conventional statistical methods will be used to evaluate the results obtained in the analysis of the data obtained in the reading of the dosimeters. This comparative method is however a first step to taking decisions regarding radiological protection service. Therefore that the radiometric surveys of routine are taken in consideration, as well as the information from the technician of radiological protection that is working in those areas. All this data will give support to improve and implement methods and practices on the accelerators' facilities. In addition, the use of these electronic dosimeters will makes possible the technician read these dose rates received immediately during the practices and use these information you make decisions. In case of dose rates values to present above the expected the practice will be ploughed. Another point to be considered is that this work will propitiate the future updates of the procedures designated to those practices and to conduct at the radiological protection optimization. (author)

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

International Nuclear Information System (INIS)

Tamaoki, Tetsuo; Yamamoto, Hiroki; Sato, Masuo; Yoshida, Megumu; Kaneko, Tomoko; Terunuma, Seiichi; Takatsuto, Hiroshi; Morimoto, Makoto.

1992-01-01

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)

A Design of Alarm System in a Research Reactor Facility

International Nuclear Information System (INIS)

Park, Jaekwan; Jang, Gwisook; Seo, Sangmun; Suh, Yongsuk

2013-01-01

The digital alarm system has become an indispensable design to process a large amount of alarms of power plants. Korean research reactor operated for decades maintains a hybrid alarm system with both an analog annunciator and a digital alarm display. In this design, several alarms are indicated on an analog panel and digital display, respectively, and it requires more attention and effort of the operators. As proven in power plants, a centralized alarm system design is necessary for a new research reactor. However, the number of alarms and operators in a research reactor is significantly lesser than power plants. Thus, simplification should be considered as an important factor for the operation efficiency. This paper introduces a simplified alarm system. As advances in information technology, fully digitalized alarm systems have been applied to power plants. In a new research reactor, it will be more useful than an analog or hybrid configuration installed in research reactors decades ago. However, the simplification feature should be considered as an important factor because the number of alarms and number of operators in a research reactor is significantly lesser than in power plants

Response characteristics of selected personnel neutron dosimeters

International Nuclear Information System (INIS)

McDonald, J.C.; Fix, J.J.; Hadley, R.T.; Holbrook, K.L.; Yoder, R.C.; Roberson, P.L.; Endres, G.W.R.; Nichols, L.L.; Schwartz, R.B.

1983-09-01

Performance characteristics of selected personnel neutron dosimeters in current use at Department of Energy (DOE) facilities were determined from their evaluation of neutron dose equivalent received after irradiations with specific neutron sources at either the National Bureau of Standards (NBS) or the Pacific Northwest Laboratory (PNL). The characteristics assessed included: lower detection level, energy response, precision and accuracy. It was found that when all of the laboratories employed a common set of calibrations, the overall accuracy was approximately +-20%, which is within uncertainty expected for these dosimeters. For doses above 80 mrem, the accuracy improved to better than 10% when a common calibration was used. Individual differences found in this study may reflect differences in calibration technique rather than differences in the dose rates of actual calibration standards. Second, at dose rates above 100 mrem, the precision for the best participants was generally below +-10% which is also within expected limits for these types of dosimeters. The poorest results had a standard deviation of about +-25%. At the lowest doses, which were sometimes below the lower detection limit, the precision often approached or exceeded +-100%. Third, the lower level of detection for free field 252 Cf neutrons generally ranged between 20 and 50 mrem. Fourth, the energy dependence study provided a characterization of the response of the dosimeters to neutron energies far from the calibration energy. 11 references, 22 figures, 26 tables

Nuclear-power-plant perimeter-intrusion alarm systems

International Nuclear Information System (INIS)

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

46 CFR 78.47-75 - Ventilation alarm failure.

Science.gov (United States)

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Ventilation alarm failure. 78.47-75 Section 78.47-75... Fire and Emergency Equipment, Etc. § 78.47-75 Ventilation alarm failure. (a) The alarm required by § 72... FAILURE IN VEHICULAR SPACE.” (b) [Reserved] [CGFR 66-33, 31 FR 15284, Dec. 6, 1966] ...

The false alarm at Forsmark March 6th 1986

International Nuclear Information System (INIS)

Hultaaker, Oe.

1986-01-01

118 households were interviewed by telephone. Additional interviews were made with the representatives of the nuclear plant, county alarming center, Radio Uppland and the authorities in question. Six out of ten households heard the false alarm. Less than one out of twenty believed that it was an alarm caused by real danger and seven out of ten think that there will be more false alarms. (G.B.)

Alarm criteria for the fixed gamma radiation monitoring stations

International Nuclear Information System (INIS)

Kjelle, P.E.

1987-01-01

For the type of measurement considered here, an alarm based on the dose excess has been shown to be a more certain method of indicating that a true alarm situation exists than an alarm based on the dose-rate exceeding a given dose-rate level. The method offers a number of advantages: Dose-rate levels can be recorded over long periods without any necessity of making manual changes in the alarm level due to seasonal variations in the background level. A relatively low level can be specified without an unnecessary number of false alarms being triggered by gamma-emitting radon daughters. (orig./HP)

Evaluation of performance of metal oxide-silicon semiconductor field effect transistor (MOSFET) dosimeter

International Nuclear Information System (INIS)

Nagashima, Hiroyuki; Sano, Naoki; Nakamura, Osamu

2001-01-01

The JARP level dosimeter is the most suitable for absorbed dose determination in radiotherapy because of its high accuracy. However, in measuring the dose of an extremely small field, a dosimeter with a smaller active region is required. The active region of the MOSFET dosimeter is very small, having a volume of just 0.02 mm 3 . In this study, we evaluated the performance of MOSFET dosimeters with two different sensitivities and examined the usefulness of the MOSFET dosimeter in stereotactic radiosurgery. Using the high-sensitivity MOSFET dosimeter, we were able to reduce the experimental error of absorbed dose (≤±1.8%), and, by correcting the sensitivity, we could use it as a field dosimeter. By turning detectors inside out, we could reduce directional dependence (≤±1.8%). Correction was necessary in the TMR determination because peak depth shifts according to the material of the detector. In the determination of the dose distribution in the penumbra, the resolution of the MOSFET detectors was equal to that of the diamond detector. In the determination of OPF for the extremely small field, better results were obtained with MOSFET than with other small detectors. The high-sensitivity MOSFET dosimeter could properly evaluate the dose of an extremely small field and will be useful in dosimetry of the maximum dose of the field center in stereotactic radiosurgery. (author)

SU-E-T-753: Three-Dimensional Dose Distributions of Incident Proton Particle in the Polymer Gel Dosimeter and the Radiochromic Gel Dosimeter: A Simulation Study with MCNP Code

International Nuclear Information System (INIS)

Park, M; Kim, G; Ji, Y; Kim, K; Park, S; Jung, H

2015-01-01

Purpose: The purpose of this study is to estimate the three-dimensional dose distributions in the polymer and the radiochromic gel dosimeter, and to identify the detectability of both gel dosimeters by comparing with the water phantom in case of irradiating the proton particles. Methods: The normoxic polymer gel and the LCV micelle radiochromic gel were used in this study. The densities of polymer and the radiochromic gel dosimeter were 1.024 and 1.005 g/cm 3 , respectively. The dose distributions of protons in the polymer and radiochromic gel were simulated using Monte Carlo radiation transport code (MCNPX, Los Alamos National Laboratory). The shape of phantom irradiated by proton particles was a hexahedron with the dimension of 12.4 × 12.4 × 15.0 cm 3 . The energies of proton beam were 50, 80, and 140 MeV energies were directed to top of the surface of phantom. The cross-sectional view of proton dose distribution in both gel dosimeters was estimated with the water phantom and evaluated by the gamma evaluation method. In addition, the absorbed dose(Gy) was also calculated for evaluating the proton detectability. Results: The evaluation results show that dose distributions in both gel dosimeters at intermediated section and Bragg-peak region are similar with that of the water phantom. At entrance section, however, inconsistencies of dose distribution are represented, compared with water. The relative absorbed doses in radiochromic and polymer gel dosimeter were represented to be 0.47 % and 2.26 % difference, respectively. These results show that the radiochromic gel dosimeter was better matched than the water phantom in the absorbed dose evaluation. Conclusion: The polymer and the radiochromic gel dosimeter show similar characteristics in dose distributions for the proton beams at intermediate section and Bragg-peak region. Moreover the calculated absorbed dose in both gel dosimeters represents similar tendency by comparing with that in water phantom

Improvement in the accuracy of polymer gel dosimeters using scintillating fibers

International Nuclear Information System (INIS)

Tremblay, Nicolas M; Hubert-Tremblay, Vincent; Bujold, Rachel; Beaulieu, Luc; Lepage, Martin

2010-01-01

We propose a novel method for the absolute calibration of polyacrylamide gel (PAG) dosimeters with one or more reference scintillating fiber dosimeters inserted inside the gel. Four calibrated scintillating fibers were inserted into a cylindrical glass container filled with a PAG dosimeter irradiated with a wedge filtered 6 MV photon beam. Calibration curves using small glass vials containing the same gel as the cylindrical containers were used to obtain a first calibration curve. This calibration curve was then adjusted with the dose measured with one of the scintillating fibers in a low gradient part of the field using different approaches. Among these, it was found that a translation of the gel calibration curve yielded the highest accuracy with PAG dosimeters.

Synthesis and production of potassium dichromate as a secondary standard dosimeter; Investigation of its comparative properties with Fricke and clear perspex dosimeters in comprehensive dose mapping of IR-136 Gamma Irradiator

International Nuclear Information System (INIS)

Taimoori Seechani; Behzad.

1995-01-01

Measurement of the absorbed dose is the principle mode or means of quality control in various application of radiation processing. Specially, the cumulative absorbed dose and its variation in different density product boxes (dose mapping) are often required. Proper discharge of these task would require the use of dosimeters having sufficient degree of accuracy and precision. The secondary standard potassium dichromate dosimeter is synthesized for the first time in Iran. The properties of this dosimeter such as dose response, dose rate dependency, reproducibility, molar extinction coefficient, reduction yield and effect of silver ions on reduction yield of dosimetry solution, irradiation temperature effect as well as pre- and post-irradiation stability of the dosimetry solution have been studied. The comparison of the results of this work with that of the ASTM standard of potassium dichromate has shown very good agreement. The produced dichromate dosimeters were used for comprehensive dose mapping or commissioning of the IR-136 irradiator. The non-uniformity ratio and the isodose lines in various product densities in the IR-136 have been measured. Cumulative dose values were obtained for different rows and levels of the IR-136 irradiator system. The results of dichromate dosimetry, wherever possible, were compared with the response of Fricke and clear perspex dosimeters. At low dose values, the precision of this dosimeter was found to be better than the precision of clear perspex, but about the same as that of Fricke dosimeter. It is thus may be said that this dosimeter has combined the desirable properties of both dosimeter together

Development and characterization of a three-dimensional radiochromic film stack dosimeter for megavoltage photon beam dosimetry.

Science.gov (United States)

McCaw, Travis J; Micka, John A; DeWerd, Larry A

2014-05-01

Three-dimensional (3D) dosimeters are particularly useful for verifying the commissioning of treatment planning and delivery systems, especially with the ever-increasing implementation of complex and conformal radiotherapy techniques such as volumetric modulated arc therapy. However, currently available 3D dosimeters require extensive experience to prepare and analyze, and are subject to large measurement uncertainties. This work aims to provide a more readily implementable 3D dosimeter with the development and characterization of a radiochromic film stack dosimeter for megavoltage photon beam dosimetry. A film stack dosimeter was developed using Gafchromic(®) EBT2 films. The dosimeter consists of 22 films separated by 1 mm-thick spacers. A Virtual Water™ phantom was created that maintains the radial film alignment within a maximum uncertainty of 0.3 mm. The film stack dosimeter was characterized using simulations and measurements of 6 MV fields. The absorbed-dose energy dependence and orientation dependence of the film stack dosimeter were investigated using Monte Carlo simulations. The water equivalence of the dosimeter was determined by comparing percentage-depth-dose (PDD) profiles measured with the film stack dosimeter and simulated using Monte Carlo methods. Film stack dosimeter measurements were verified with thermoluminescent dosimeter (TLD) microcube measurements. The film stack dosimeter was also used to verify the delivery of an intensity-modulated radiation therapy (IMRT) procedure. The absorbed-dose energy response of EBT2 film differs less than 1.5% between the calibration and film stack dosimeter geometries for a 6 MV spectrum. Over a series of beam angles ranging from normal incidence to parallel incidence, the overall variation in the response of the film stack dosimeter is within a range of 2.5%. Relative to the response to a normally incident beam, the film stack dosimeter exhibits a 1% under-response when the beam axis is parallel to the film

Temperature, humidity and time., Combined effects on radiochromic film dosimeters

International Nuclear Information System (INIS)

Abdel-Fattah, A.A.; Miller, A.

1996-01-01

The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 o C for irradiation by 60 Co photons and 10-MeV electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is + 0.25 ± 0.1% per o C for the FWT-60-00 dosimeters and +0.5 ± 0.1% per o C for Riso B3 dosimeters at temperatures between 20 and 50 o C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger dependences. Whenever possible one should use dosimeters sealed in pouches under controlled intermediate humidity conditions (30-50%) or, if that is impractical, one should maintain conditions of calibration as close as possible to the conditions of use. Without that precaution, severe dosimetry errors may result. (author)

Description and evaluation of the Hanford personnel dosimeter program from 1944 through 1989. [Contain Glossary

Energy Technology Data Exchange (ETDEWEB)

Wilson, R.H.; Fix, J.J.; Baumgartner, W.V.; Nichols, L.L.

1990-09-01

This report describes the evolution of personnel dosimeter technology at Hanford since the inception of Hanford operations in 1944. Each of the personnel dosimeter systems used by people working or visiting Hanford is described. In addition, the procedures used to calibrate and calculate dose for each of the dosimeter systems are described. The accuracy of the recorded dose, primarily whole body deep dose, for the different dosimeter systems is evaluated. The evaluation is based on an extensive review of historical literature, as well as a 1989 intercomparison study of all film dosimeters and performance testing of the thermoluminescent dosimeter, also conducted during 1989. 73 refs., 40 figs., 41 tabs.

Resolution of alarms for loss of bulk nuclear material

International Nuclear Information System (INIS)

Eggers, R.F.; Davenport, L.C.

1982-01-01

Under methods of material accountability considered in the NRC's Reform Amendment (Federal Register, 46(175):45144 to 45151 dated September 10, 1981) prompt detection of losses and resolution of alarms play a central role in the day-to-day activities of the Material Control and Accounting (MC and A) System. This paper will discuss the two basic pathways of alarm resolution, namely, verification of the magnitude of the loss indicated by the initial alarm, and detection of deliberate or accidental accounting discrepancies. Progress along these pathways leads to a consensus that either (1) a loss occurred, (2) the original alarm was caused by MC and A error, or (3) the cause of the original alarm is uncertain. Three phases of response will be outlined and an example of response to alarms will be given for a mixed oxide powder processing control unit

Performances of Dose Measurement of Commercial Electronic Dosimeters using Geiger Muller Tube and PIN Diode

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hyunjun; Kim, Chankyu; Kim, Yewon; Kim, Giyoon; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2014-05-15

There are two categories in personal dosimeters, one is passive type dosimeter such as TLD (thermoluminescence dosimeter) and the other is active type dosimeter such as electronic dosimeter can show radiation dose immediately while TLD needs long time to readout its data by heating process. For improving the reliability of measuring dose for any energy of radiations, electronic dosimeter uses energy filter by metal packaging its detector using aluminum or copper, but measured dose of electronic dosimeter with energy filter cannot be completely compensated in wide radiation energy region. So, in this paper, we confirmed the accuracy of dose measurement of two types of commercial EPDs using Geiger Muller tube and PIN diode with CsI(Tl) scintillator in three different energy of radiation field. The experiment results for Cs-137 was almost similar with calculation value in the results of both electronic dosimeters, but, the other experiment values with Na-22 and Co-60 had higher error comparing with Cs-137. These results were caused by optimization of their energy filters. The optimization was depending on its thickness of energy filter. So, the electronic dosimeters have to optimizing the energy filter for increasing the accuracy of dose measurement or the electronic dosimeter using PIN diode with CsI(Tl) scintillator uses the multi-channel discriminator for using its energy information.

TH-CD-201-08: Flexible Dosimeter Bands for Whole-Body Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Kim, T; Fahimian, B; Pratx, G [Department of Radiation Oncology, Stanford University, Palo Alto, CA (United States)

2016-06-15

Purpose: The two commonly used radiotherapy techniques are total body irradiation (TBI) and the total skin irradiation (TSI). In order to ensure the accuracy of the prescription beams, the dose received throughout the entire body must be checked using dosimetry. However, the available number of data points is limited as the dosimeters are manually placed on the patient. We developed a flexible and wearable dosimeter that can collect 1D continuous dose information around the peripheral of the patients’ body, including areas obscured from the beam path. Methods: The flexible dosimeter bands are fabricated by embedding storage phosphor powders in a thin layer of non-toxic silicone based elastomer (PDMS). An additional elastomer layer is formed on top of the phosphor layer to provide additional mechanical support for the dosimeter. Once the curing process is complete, the dosimeter is cut into multiple bands and rolled into spools prior to use. Results: The dose responses are tested using a preclinical cabinet X-ray system, where the readout is performed with a storage phosphor reader. Results show that the dose calibration factor is ∼1400 (A.U./Gy) from the beam center. Also, 1-D dose distribution experiment was performed in water phantoms, where preliminary results demonstrate that the dose in water is indeed attenuated compared to in air. Conclusion: Dose response and high-resolution 1-D dosimetry is demonstrated using the flexible dosimeters. By providing a detailed spatial description of the beam dose profile, we expect that the dosimeter bands may aid in enhancing the current existing modality in dosimetry. Since the dosimeter is flexible (can retract back to its original length), they can be comfortably worn around the patient. Potentially, multiple 1-D dose information can be stitched together and extrapolated to provide a coarse 3-D image of the dose distribution. This work was supported by funding from the Cutaneous Lymphoma Foundation under the CLARIONS

TH-CD-201-08: Flexible Dosimeter Bands for Whole-Body Dosimetry

International Nuclear Information System (INIS)

Kim, T; Fahimian, B; Pratx, G

2016-01-01

Purpose: The two commonly used radiotherapy techniques are total body irradiation (TBI) and the total skin irradiation (TSI). In order to ensure the accuracy of the prescription beams, the dose received throughout the entire body must be checked using dosimetry. However, the available number of data points is limited as the dosimeters are manually placed on the patient. We developed a flexible and wearable dosimeter that can collect 1D continuous dose information around the peripheral of the patients’ body, including areas obscured from the beam path. Methods: The flexible dosimeter bands are fabricated by embedding storage phosphor powders in a thin layer of non-toxic silicone based elastomer (PDMS). An additional elastomer layer is formed on top of the phosphor layer to provide additional mechanical support for the dosimeter. Once the curing process is complete, the dosimeter is cut into multiple bands and rolled into spools prior to use. Results: The dose responses are tested using a preclinical cabinet X-ray system, where the readout is performed with a storage phosphor reader. Results show that the dose calibration factor is ∼1400 (A.U./Gy) from the beam center. Also, 1-D dose distribution experiment was performed in water phantoms, where preliminary results demonstrate that the dose in water is indeed attenuated compared to in air. Conclusion: Dose response and high-resolution 1-D dosimetry is demonstrated using the flexible dosimeters. By providing a detailed spatial description of the beam dose profile, we expect that the dosimeter bands may aid in enhancing the current existing modality in dosimetry. Since the dosimeter is flexible (can retract back to its original length), they can be comfortably worn around the patient. Potentially, multiple 1-D dose information can be stitched together and extrapolated to provide a coarse 3-D image of the dose distribution. This work was supported by funding from the Cutaneous Lymphoma Foundation under the CLARIONS

LLL development of a combined etch track: albedo dosimeter

International Nuclear Information System (INIS)

Griffith, R.V.; Fisher, J.C.; Harder, C.A.

1977-01-01

The addition of polycarbonate sheet to albedo detectors for electrochemical etching provides a simple, inexpensive way to reduce the spectral sensitivity of the personnel dosimeter without losing the albedo features of sensitivity and ease of automation. The ECEP technique also provides the dosimetrist with the potential for identifying conditions of body orientation that might otherwise lead to significant error in dosimeter evaluation

Temperature, humidity and time. Combined effects on radiochromic film dosimeters

DEFF Research Database (Denmark)

Abdel-Fattah, A.A.; Miller, A.

1996-01-01

The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 degrees C for irradiation by Co-60 photons and 10-Me......V electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is +0.......25 +/- 0.1% per degrees C for the FWT-60-00 dosimeters and +0.5 +/- 0.1% per degrees C For Riso B3 dosimeters at temperatures between 20 and 50 degrees C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger...

Adjustable electronic load-alarm relay

International Nuclear Information System (INIS)

Mason, C.H.; Sitton, R.S.

1976-01-01

An improved electronic alarm relay for monitoring the current drawn by an ac motor or other electrical load is described. The circuit is designed to measure the load with high accuracy and to have excellent alarm repeatability. Chattering and arcing of the relay contacts are minimal. The operator can adjust the set point easily and can re-set both the high and the low alarm points by means of one simple adjustment. The relay includes means for generating a signal voltage proportional to the motor current. In a preferred form of the invention a first operational amplifier is provided to generate a first constant reference voltage which is higher than a preselected value of the signal voltage. A second operational amplifier is provided to generate a second constant reference voltage which is lower than the aforementioned preselected value of the signal voltage. A circuit comprising a first resistor serially connected to a second resistor is connected across the outputs of the first and second amplifiers, and the junction of the two resistors is connected to the inverting terminal of the second amplifier. Means are provided to compare the aforementioned signal voltage with both the first and second reference voltages and to actuate an alarm if the signal voltage is higher than the first reference voltage or lower than the second reference voltage

Passive dosimetry: introduction of a new dosimeter based on OSL technology

International Nuclear Information System (INIS)

Archambault, V.; Le Roy, G.; Prugnaud, B.

2005-01-01

A new passive dosimeter based on OSL technology has been introduced on the French market. In this article are described: the technology and the material on which this new detector relied, the dosimeter itself. (author)

Development of colored alumilite dosimeter

Energy Technology Data Exchange (ETDEWEB)

Obara, Kenjiro; Shibanuma, Kiyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yagi, Toshiaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yokoo, Noriko [Radiation Application Development Association, Tokai, Ibaraki (Japan)

2003-03-01

In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50{approx}100 degC), high gamma-ray radiation ({approx}1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10{approx}100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to be approximately 1MGy which is too low to monitor the RH equipment for the ITER. In addition, these conventional dosimeters do not involve sufficient radiation resistance against the high gamma-ray radiation as well as are not easy handling and low cost. Based on the above backgrounds, a new dosimeter with bleaching of an azo group dye to be applied to a radiation monitor has been developed for high gamma-ray radiation use. The colored alumilite dosimeter is composed of the azo group dye (-N=N-) in an anodic oxidation layer of aluminum alloy (Al{sub 2}O{sub 3}). It can monitor the radiation dose by measuring the change of the bleaching of azo dye in the Al{sub 2}O{sub 3} layer due to gamma-ray irradiation. The degree of bleaching is measured as the change of hue (color) and brightness based on the Munsell's colors with a three dimensional universe using spectrophotometer. In the tests, the dependencies such as colors, anodized layer thickness, type of azo

Estimation of personal dose based on the dependent calibration of personal dosimeters in interventional radiology

International Nuclear Information System (INIS)

Mori, Hiroshige; Koshida, Kichiro; Ichikawa, Katsuhiro

2007-01-01

The purpose of present study is, in interventional radiology (IVR), to elucidate the differences between each personal dosimeter, and the dependences and calibrations of area or personal dose by measurement with electronic dosimeters in particular. We compare space dose rate distributions measured by an ionization survey meter with the value measured by personal dosimeter: an optically stimulated luminescence, two fluoroglass, and two electronic dosimeters. Furthermore, with electronic dosimeters, we first measured dose rate, energy, and directional dependences. Secondly, we calibrated the dose rate measured by electronic dosimeters with the results, and estimated these methods with coefficient of determination and Akaike's Information Criterion (AIC). The results, especially in electronic dosimeters, revealed that the dose rate measured fell by energy and directional dependences. In terms of methods of calibration, the method is sufficient for energy dependence, but not for directional dependence, because of the lack of stable calibration. This improvement poses a question for the future. The study suggested that these dependences of the personal dosimeter must be considered when area or personal dose is estimated in IVR. (author)

MO-AB-BRA-04: Radiation Measurements with a DNA Double-Strand-Break Dosimeter

Energy Technology Data Exchange (ETDEWEB)

Obeidat, M; Cline, K; Stathakis, S; Papanikolaou, N; Rasmussen, K; Gutierrez, A; Ha, CS; Lee, SE; Shim, EY; Kirby, N [University of Texas HSC SA, San Antonio, TX (United States)

2016-06-15

Purpose: Many types of dosimeters are used to measure radiation, but none of them directly measures the biological effect of this dose. The purpose here is to create a dosimeter that can measure the probability of double-strand breaks (DSB) for DNA, which is directly related to the biological effect of radiation. Methods: The dosimeter has DNA strands, which are labeled on one end with biotin and on the other with fluorescein. The biotin attaches these strands to magnetic beads. We suspended the DNA dosimeter in phosphate-buffered saline (PBS) as it matches the internal environment of the body. We placed small volumes (50µL) of the DNA dosimeter into tubes and irradiated these samples in a water-equivalent plastic phantom with several doses (three samples per dose). After irradiating the samples, a magnet was placed against the tubes. The fluorescein attached to broken DNA strands was extracted (called the supernatant) and placed into a different tube. The fluorescein on the unbroken strands remained attached to the beads in the tube and was re-suspended with 50µL of PBS. A fluorescence reader was used to measure the fluorescence for both the re-suspended beads and supernatant. To prove that we are measuring DSB, we tested dosimeter response with two different lengths of attached DNA strands (1 and 4 kilo-base pair). Results: The probability of DSB at the dose levels of 5, 10, 25, and 50 Gy were 0.05, 0.08, 0.12, and 0.19, respectively, while the coefficients of variation were 0.14, 0.07, 0.02, and 0.01, respectively. The 4 kilo-base-pair dosimeter produced 5.3 times the response of the 1 kilo-base-pair dosimeter. Conclusion: The DNA dosimeter yields a measurable response to dose that scales with the DNA strand length. The goal now is to refine the dosimeter fabrication to reproducibly create a low coefficient of variation for the lower doses. This work was supported in part by Yarmouk University (Irbid, Jordan) and CPRIT (RP140105)

MO-AB-BRA-04: Radiation Measurements with a DNA Double-Strand-Break Dosimeter

International Nuclear Information System (INIS)

Obeidat, M; Cline, K; Stathakis, S; Papanikolaou, N; Rasmussen, K; Gutierrez, A; Ha, CS; Lee, SE; Shim, EY; Kirby, N

2016-01-01

Purpose: Many types of dosimeters are used to measure radiation, but none of them directly measures the biological effect of this dose. The purpose here is to create a dosimeter that can measure the probability of double-strand breaks (DSB) for DNA, which is directly related to the biological effect of radiation. Methods: The dosimeter has DNA strands, which are labeled on one end with biotin and on the other with fluorescein. The biotin attaches these strands to magnetic beads. We suspended the DNA dosimeter in phosphate-buffered saline (PBS) as it matches the internal environment of the body. We placed small volumes (50µL) of the DNA dosimeter into tubes and irradiated these samples in a water-equivalent plastic phantom with several doses (three samples per dose). After irradiating the samples, a magnet was placed against the tubes. The fluorescein attached to broken DNA strands was extracted (called the supernatant) and placed into a different tube. The fluorescein on the unbroken strands remained attached to the beads in the tube and was re-suspended with 50µL of PBS. A fluorescence reader was used to measure the fluorescence for both the re-suspended beads and supernatant. To prove that we are measuring DSB, we tested dosimeter response with two different lengths of attached DNA strands (1 and 4 kilo-base pair). Results: The probability of DSB at the dose levels of 5, 10, 25, and 50 Gy were 0.05, 0.08, 0.12, and 0.19, respectively, while the coefficients of variation were 0.14, 0.07, 0.02, and 0.01, respectively. The 4 kilo-base-pair dosimeter produced 5.3 times the response of the 1 kilo-base-pair dosimeter. Conclusion: The DNA dosimeter yields a measurable response to dose that scales with the DNA strand length. The goal now is to refine the dosimeter fabrication to reproducibly create a low coefficient of variation for the lower doses. This work was supported in part by Yarmouk University (Irbid, Jordan) and CPRIT (RP140105)

Design and development of a PMOSFET gamma ray dosimeter

International Nuclear Information System (INIS)

Khanna, V.K.; Kumar, A.; Gupta, R.P.; Pandya, A.; Roy, Rajesh

2005-01-01

A P-channel MOSFET chip has been designed for detection of gamma radiations. The chip consists of three MOSFETs of different geometrical parameters for achieving sensitivity to low and high dose ranges. One of the MOSFET structures has a closed geometry to reduce the leakage current. The developed dosimeter being a MOSFET, its IC (Integrated Circuit)-compatibility helps in easy interfacing with readout circuitry. The dosimeter fabrication process is based on metal-gate MOSFET technology with thick gate oxide to increase the effective number of electron-hole pairs generated by the gamma rays impinging on the device. The process for the chip realization has been designed and simulated to achieve the required impurity diffusion profile. The chip has been fabricated using the above process and electrically characterized. The device has been exposed to gamma ray source and its characteristics measured. The change in threshold voltage of the MOSFET after exposure has been used to calculate the sensitivity of the device. The developed dosimeter has potential applications in personnel dosimetry and cancer treatment. This paper describes the basic detection mechanism of the MOSFET, the design approach, and fabrication process of the MOSFET dosimeter. (author)

Angular dependence of response of dosimeters exposed to an extended radioactive source

International Nuclear Information System (INIS)

Manai, K.; Trabelsi, A.; Madouri, F.

2014-01-01

This study was carried out to investigate the exposure angular dependence of dosimeters response when exposed to the extended gamma source of an irradiation facility. Using analytical and Monte Carlo analysis, we show that dosimeters response has no angular dependence as claimed by a previous study. The dose rate formula we derived takes into account the path length of the photons in the dosimeter. Experimental data have been used to validate our analytical and Monte Carlo methods. Furthermore, the effects on the dosimeters responses in relation to their sizes response of their size and geometry and orientation have been investigated and, within statistical errors, no angular dependence was found. - Highlights: • We investigate the exposer angle dependence of dosimeter response to a gamma source. • Analytical and Monte Carlo analyses show no angular dependence as claimed by others. • We derive the dose rate formulae taking into account the path length of photons. • Analytical and Monte Carlo models have been validated using experimental data

Water equivalence of NIPAM based polymer gel dosimeters with enhanced sensitivity for x-ray CT

Science.gov (United States)

Gorjiara, Tina; Hill, Robin; Bosi, Stephen; Kuncic, Zdenka; Baldock, Clive

2013-10-01

Two new formulations of N-isopropylacrylamide (NIPAM) based three dimensional (3D) gel dosimeters have recently been developed with improved sensitivity to x-ray CT readout, one without any co-solvent and the other one with isopropanol co-solvent. The water equivalence of the NIPAM gel dosimeters was investigated using different methods to calculate their radiological properties including: density, electron density, number of electrons per grams, effective atomic number, photon interaction probabilities, mass attenuation and energy absorption coefficients, electron collisional, radiative and total mass stopping powers and electron mass scattering power. Monte Carlo modelling was also used to compare the dose response of these gel dosimeters with water for kilovoltage and megavoltage x-ray beams and for megavoltage electron beams. We found that the density and electron density of the co-solvent free gel dosimeter are more water equivalent with less than a 2.6% difference compared to a 5.7% difference for the isopropanol gel dosimeter. Both the co-solvent free and isopropanol solvent gel dosimeters have lower effective atomic numbers than water, differing by 2.2% and 6.5%, respectively. As a result, their photoelectric absorption interaction probabilities are up to 6% and 19% different from water, respectively. Compton scattering and pair production interaction probabilities of NIPAM gel with isopropanol differ by up to 10% from water while for the co-solvent free gel, the differences are 3%. Mass attenuation and energy absorption coefficients of the co-solvent free gel dosimeter and the isopropanol gel dosimeter are up to 7% and 19% lower than water, respectively. Collisional and total mass stopping powers of both gel dosimeters differ by less than 2% from those of water. The dose response of the co-solvent free gel dosimeter is water equivalent (with x-ray beams over the energy range 180 keV-18 MV, both gel dosimeters have less than 2% discrepancy with water. For

The impact of recent changes in smoke alarm legislation on residential fire injuries and smoke alarm ownership in New South Wales, Australia.

Science.gov (United States)

Harvey, Lara A; Poulos, Roslyn G; Sherker, Shauna

2013-01-01

In 2006, New South Wales (NSW) state legislation changed from requiring smoke alarms in new houses only to all houses. We evaluated the impact of this legislative change on residential fire injury and smoke alarm ownership characteristics. Residential fire injuries for 2002 to 2010 were identified from hospitalization data for all hospitals in NSW. Data relating to smoke alarm ownership and demographic factors were obtained from the NSW Population Health Survey. Negative binomial regression analysis was used to analyze trends over time. Prior to the introduction of universal legislation, hospitalization rates were increasing slightly; however, following the introduction of legislation, hospitalization rates decreased by an estimated 36.2% (95% confidence interval [CI], 16.7-55.8) annually. Smoke alarm ownership increased from 73.3% (95% CI, 72.5-74.2) prelegislation to 93.6% (95% CI, 93.1-94.2) 18 months postlegislation. Thirty percent of households reported testing their alarms regularly. Speaking a language other than English (relative risks [RRs], 1.82; 95% CI, 1.44-2.99), allowing smoking in the home (RR, 1.73; 95% CI, 1.31-2.27), and being part of the most disadvantaged socioeconomic group (RR, 1.47; 95% CI, 1.14-1.91) remain major risk factors for nonownership. Broadening the scope of state legislation has had a positive impact on residential fire-related hospitalizations and smoke alarm ownership. However, it is of concern that the legislation has been the least effective in increasing smoke alarm ownership among non-English-speaking households, in households where smoking is allowed, in low socioeconomic households, and that a high proportion of householders do not test their smoke alarms regularly. Targeted campaigns are needed to reach these high-risk groups and to ensure that smoke alarms are functional.

Do aphid colonies amplify their emission of alarm pheromone?

Science.gov (United States)

Hatano, Eduardo; Kunert, Grit; Bartram, Stefan; Boland, Wilhelm; Gershenzon, Jonathan; Weisser, Wolfgang W

2008-09-01

When aphids are attacked by natural enemies, they emit alarm pheromone to alert conspecifics. For most aphids tested, (E)-beta-farnesene (EBF) is the main, or only, constituent of the alarm pheromone. In response to alarm pheromone, alerted aphids drop off the plant, walk away, or attempt to elude predators. However, under natural conditions, EBF concentration might be low due to the low amounts emitted, to rapid air movement, or to oxidative degradation. To ensure that conspecifics are warned, aphids might conceivably amplify the alarm signal by emitting EBF in response to EBF emitted by other aphids. To examine whether such amplification occurs, we synthesized deuterated EBF (DEBF), which allowed us to differentiate between applied and aphid-derived chemical. Colonies of Acyrthosiphon pisum were treated with DEBF, and headspace volatiles were collected and analyzed for evidence of aphid-derived EBF. No aphid-derived EBF was detected, suggesting that amplification of the alarm signal does not occur. We discuss the disadvantages of alarm signal reinforcement.

Patient characteristics associated with false arrhythmia alarms in intensive care

Directory of Open Access Journals (Sweden)

Harris PR

2017-04-01

Full Text Available Patricia R Harris,1,2 Jessica K Zègre-Hemsey,3,4 Daniel Schindler,5 Yong Bai,6 Michele M Pelter,2,7 Xiao Hu2,8 1Department of Nursing, School of Health and Natural Sciences, Dominican University of California, San Rafael, 2Department of Physiological Nursing, School of Nursing, University of California, San Francisco, CA, 3School of Nursing, 4Department of Emergency Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, 5Intensive Care Unit, The Neuroscience Center, Sutter Eden Medical Center, Castro Valley, 6Hu Research Laboratory, Department of Physiological Nursing, School of Nursing, University of California, San Francisco, 7ECG Monitoring Research Lab, Department of Physiological Nursing, School of Nursing, 8Physiological Nursing and Neurological Surgery, Affiliate Faculty of Institute for Computational Health Sciences Core Faculty UCB/UCSF Joint Bio-Engineering Graduate Program, University of California, San Francisco, CA, USA Introduction: A high rate of false arrhythmia alarms in the intensive care unit (ICU leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective: The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods: This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and

A critical assessment of two types of personal UV dosimeters.

Science.gov (United States)

Seckmeyer, Gunther; Klingebiel, Marcus; Riechelmann, Stefan; Lohse, Insa; McKenzie, Richard L; Liley, J Ben; Allen, Martin W; Siani, Anna-Maria; Casale, Giuseppe R

2012-01-01

Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cut-off filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be over-estimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments. © 2011 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

PNNL Results from 2010 CALIBAN Criticality Accident Dosimeter Intercomparison Exercise

International Nuclear Information System (INIS)

Hill, Robin L.; Conrady, Matthew M.

2011-01-01

This document reports the results of the Hanford personnel nuclear accident dosimeter (PNAD) and fixed nuclear accident dosimeter (FNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on September 20-23, 2010. Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimeter intercomparison exercise at the Commissariat a Energie Atomique (CEA) Valduc Center near Dijon, France on September 20-23, 2010. The intercomparison exercise was funded by the U.S. Department of Energy, Nuclear Criticality Safety Program, with Lawrence Livermore National Laboratory as the lead Laboratory. PNNL was one of six invited DOE Laboratory participants. The other participating Laboratories were: Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Savannah River Site (SRS), the Y-12 National Security Complex at Oak Ridge, and Sandia National Laboratory (SNL). The goals of PNNL's participation in the intercomparison exercise were to test and validate the procedures and algorithm currently used for the Hanford personnel nuclear accident dosimeters (PNADs) on the metallic reactor, CALIBAN, to test exposures to PNADs from the side and from behind a phantom, and to test PNADs that were taken from a historical batch of Hanford PNADs that had varying degrees of degradation of the bare indium foil. Similar testing of the PNADs was done on the Valduc SILENE test reactor in 2009 (Hill and Conrady, 2010). The CALIBAN results are reported here.

Personnel neutron dosimeter for use in a plutonium processing plant

International Nuclear Information System (INIS)

Brunskill, R.T.; Hwang, F.S.W.

1978-01-01

A thermoluminesence dosimeter for personnel neutron dose measurement, which is based on the albedo principle, has been developed at Windscale works. The dosimeter has been calibrated against a 238 Pu/Be neutron source using different degrees of moderation and against a variety of neutron spectra prevailing in different areas of the Plutonium Finishing Plant. The dosimeter consists of two identical parts in which the sensitive elements are graphite discs which have thermoluminescent crystals sealed to the plane faces with a high temperature resin. The graphite discs are supported in teflon washers which fit into a body of tufnol. A circular insert of boronated polythene in each tufnol body provides a thermal neutron absorber for the sensitive element in the other half of the dosimeter. Natural lithium borate was used as the neutron sensitive phosphor and a lithium borate made from isotopes 7 Li (99.9%) and 11 B (99.2%) as the neutron insensitive materials. Neutron-sensitive lithium borate is sealed to one face of each disc and the neutron-insensitive material to the opposite face. The dosimeter is so assembled that the neutron-sensitive faces both lie in the central plane. The design is such that one neutron sensitive face responds to the incident flux of neutron only while the other responds to the albedo flux

Calibration of film dosimeters by means of absorbed dose calorimeters

International Nuclear Information System (INIS)

Nikolaev, S.M.; Vanyushkin, B.M.; Kon'kov, N.G.

1980-01-01

Methods of graduating film dosimeters by means of calorimeters of absorbed doses, are considered. Graduating of film dosimeters at the energies of accelerated electrons from 4 to 10 MeV can be carried out by means of quasiadiabatic calorimeter of local absorption, the absorber thickness of which should not exceed 5-10% of Rsub(e) value, where Rsub(e) - free electron path of the given energy. In this case film is located inside the calorimeter. For graduating films with thickness not less than (0.1-0.2)Rsub(e) it is suggested to use calorimeter of full absorption; then the graduated dosimeters are located in front of the calorimeter. Graduation of films at small energies of electrons is exercised by means of a package of films, approximately Rsub(e) thick. A design of quasiadiabatic calorimeter, intended for graduating dosimeters within the energy range of electron beam from 4 to 10 MeV, is considered. The quasiadiabatic calorimeter is a thin graphite tablet with heater and thermocouple, surrounded by foam plastic thermostating case. Electricity quantity, accumulated during the radiation field pass, is measured in the case of using the quasiadiabatic calorimeter for film graduating. The results of graduating film dosimeters, obtained using film package with Rsub(e) thickness, are presented. The obtained results coincide within 5% limits with the data known beforehand [ru

AI-based alarm processing for a nuclear power plant

International Nuclear Information System (INIS)

Na, N.J.; Kim, I.S.; Hwang, I.K.; Lee, D.Y.; Ham, C.S.

1996-01-01

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

IAEA reference dosimeter: Alanine-ESR

International Nuclear Information System (INIS)

Mehta, K.; Girzikowsky, R.

1999-01-01

Since 1985, the IAEA has been using alanine-ESR as a transfer dosimeter for its dose quality audit service, namely the International Dose Assurance Service. The alanine dosimeters are rod-type containing 70 wt% DL--α-alanine and 30 wt% polystyrene. We have two self-shielded gamma facilities for the calibration of the dosimetry system, where the temperature within the irradiation chamber can be controlled by a specially designed unit. A 4th order polynomial is fitted to the 16 data points in the dose range of 100 Gy to 50 kGy. The measured value of the irradiation temperature coefficient at two dose values (15 and 45 kGy) is 0.23 %/deg. C. Also, the ESR-response was followed for several dosimeters for about 8 months to study the post-irradiation effect. A value of 0.008 %/day was observed for the fading of the response for two dose values (15 and 45 kGy) and three irradiation temperatures (15, 27 and 40 deg. C). The effect of the analysis temperature on the ESR response was also studied. The combined relative uncertainty for the IAEA alanine-ESR dosimetry system is 1.5% (k=1). This includes that transferred from the primary laboratory for the dose rate measurements of the gamma facilities, dosimetry system calibration uncertainties, batch variability and uncertainty in the curve fitting procedure. This value however does not include the contribution due to the irradiation temperature correction which is applied when it differs from that during calibration; this component being specific for each dose measurement. (author)

Methacholine challenge test: Comparison of tidal breathing and dosimeter methods in children.

Science.gov (United States)

Mazi, Ahlam; Lands, Larry C; Zielinski, David

2018-02-01

Methacholine Challenge Test (MCT) is used to confirm, assess the severity and/or rule out asthma. Two MCT methods are described as equivalent by the American Thoracic Society (ATS), the tidal breathing and the dosimeter methods. However, the majority of adult studies suggest that individuals with asthma do not react at the same PC 20 between the two methods. Additionally, the nebulizers used are no longer available and studies suggest current nebulizers are not equivalent to these. Our study investigates the difference in positive MCT tests between three methods in a pediatric population. A retrospective, chart review of all MCT performed with spirometry at the Montreal Children's Hospital from January 2006 to March 2016. A comparison of the percentage positive MCT tests with three methods, tidal breathing, APS dosimeter and dose adjusted DA-dosimeter, was performed at different cutoff points up to 8 mg/mL. A total of 747 subjects performed the tidal breathing method, 920 subjects the APS dosimeter method, and 200 subjects the DA-dosimeter method. At a PC 20 cutoff ≤4 mg/mL, the percentage positive MCT was significantly higher using the tidal breathing method (76.3%) compared to the APS dosimeter (45.1%) and DA-dosimeter (65%) methods (P < 0.0001). The choice of nebulizer and technique significantly impacts the rate of positivity when using MCT to diagnose and assess asthma. Lack of direct comparison of techniques within the same individuals and clinical assessment should be addressed in future studies to standardize MCT methodology in children. © 2017 Wiley Periodicals, Inc.

TH-CD-201-11: Optimizing the Response and Cost of a DNA Double-Strand Break Dosimeter

Energy Technology Data Exchange (ETDEWEB)

Obeidat, M; Cline, K; Stathakis, S; Papanikolaou, N; Rasmussen, K; Gutierrez, A; Ha, CS; Lee, SE; Shim, EY; Kirby, N [University of Texas HSC SA, San Antonio, TX (United States)

2016-06-15

Purpose: A DNA double-strand break (DSB) dosimeter was developed to measure the biological effect of radiation. The goal here is to refine the fabrication method of this dosimeter to reproducibly create a low coefficient of variation (CoV) and reduce the cost for the dosimeter. Methods: Our dosimeter consists of 4 kilo-base pair DNA strands (labeled on one end with biotin and on the other with fluorescein) attached to streptavidin magnetic beads. The final step of the DNA dosimeter fabrication is to suspend these attached beads in phosphate-buffered saline (PBS). The amount of PBS used to suspend the attached beads and the relative volume of the DNA strands to the beads both affect the CoV and dosimeter cost. We diluted the beads attached with DNA in different volumes of PBS (100, 200, and 400 µL) to create different concentrations of the DNA dosimeter. Then we irradiated these dosimeters (50 µL samples) in a water-equivalent plastic phantom at 25 and 50 Gy (three samples per dose) and calculated the CoV for each dosimeter concentration. Also, we used different masses of DNA strands (1, 2, 8, 16, 24, and 32 µg) to attach to the same volume of magnetic beads (100 µL) to explore how this affects the cost of the dosimeter. Results: The lowest CoV was produced for the highest concentration of dosimeter (100 µL of PBS), which created CoV of 2.0 and 1.0% for 25 and 50 Gy, respectively. We found that the lowest production cost for the dosimeter occurs by attaching 16 µg of DNA strands with 100 µL of beads. Conclusion: : We optimized the fabrication of the DNA dosimeter to produce low CoV and cost, but we still need to explore ways to further improve the dosimeter for use at lower doses. This work was supported in part by Yarmouk University (Irbid, Jordan) and CPRIT (RP140105)

Development of neutron dosimeter using CR-39 for measurement of ambient dose equivalent

International Nuclear Information System (INIS)

Maki, Daisuke; Shinozaki, Wakako; Ohguchi, Hiroyuki; Yamamoto, Takayoshi; Nakamura, Takayoshi

2010-01-01

A CR-39 has good advantages such as cumulative type dosimeter, small fading effect and gamma-ray insensitive. Therefore, we developed the wide energy-range environmental neutron dosimeter using eight CR-39s for area monitoring in this study. This dosimeter is made of octagonal columnar polyethylene block which height is 60 mm and bottom side is 25 mm. The dosimeter contains two types of CR-39s for fast neutron detection and slow neutron detection. Four CR-39s for fast neutron detection are used for detection of recoil protons produced by H (n, p) reactions. Four CR-39s for slow neutron detection are used with boron nitride converter to detect alpha-rays produced by 10 B (n, α) 7 Li reactions. Ambient dose equivalent is obtained by adding the number of etch-pits observed in four CR-39s for fast neutron detection to the number of etch-pits observed in four CR-39s for slow neutron detection with appropriate constants respectively. Dosimeters were irradiated with some energetic neutrons and evaluated results of ambient dose equivalent were compared with results from neutron transport calculations. Energy response of dosimeter shows good agreement with neutron fluence to ambient dose equivalent conversion coefficients. Directional dependence of dosimeter is at the same level as the rem-counter. (author)

Investigations of interference between electromagnetic transponders and wireless MOSFET dosimeters: a phantom study.

Science.gov (United States)

Su, Zhong; Zhang, Lisha; Ramakrishnan, V; Hagan, Michael; Anscher, Mitchell

2011-05-01

To evaluate both the Calypso Systems' (Calypso Medical Technologies, Inc., Seattle, WA) localization accuracy in the presence of wireless metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters of dose verification system (DVS, Sicel Technologies, Inc., Morrisville, NC) and the dosimeters' reading accuracy in the presence of wireless electromagnetic transponders inside a phantom. A custom-made, solid-water phantom was fabricated with space for transponders and dosimeters. Two inserts were machined with positioning grooves precisely matching the dimensions of the transponders and dosimeters and were arranged in orthogonal and parallel orientations, respectively. To test the transponder localization accuracy with/without presence of dosimeters (hypothesis 1), multivariate analyses were performed on transponder-derived localization data with and without dosimeters at each preset distance to detect statistically significant localization differences between the control and test sets. To test dosimeter dose-reading accuracy with/without presence of transponders (hypothesis 2), an approach of alternating the transponder presence in seven identical fraction dose (100 cGy) deliveries and measurements was implemented. Two-way analysis of variance was performed to examine statistically significant dose-reading differences between the two groups and the different fractions. A relative-dose analysis method was also used to evaluate transponder impact on dose-reading accuracy after dose-fading effect was removed by a second-order polynomial fit. Multivariate analysis indicated that hypothesis 1 was false; there was a statistically significant difference between the localization data from the control and test sets. However, the upper and lower bounds of the 95% confidence intervals of the localized positional differences between the control and test sets were less than 0.1 mm, which was significantly smaller than the minimum clinical localization resolution of 0

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

Energy Technology Data Exchange (ETDEWEB)

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.

Assessment method to predict the rate of unresolved false alarms

International Nuclear Information System (INIS)

Reardon, P.T.; Eggers, R.F.; Heaberlin, S.W.

1982-06-01

A method has been developed to predict the rate of unresolved false alarms of material loss in a nuclear facility. The computer program DETRES-1 was developed. The program first assigns the true values of control unit components receipts, shipments, beginning and ending inventories. A normal random number generator is used to generate measured values of each component. A loss estimator is calculated from the control unit's measured values. If the loss estimator triggers a detection alarm, a response is simulated. The response simulation is divided into two phases. The first phase is to simulate remeasurement of the components of the detection loss estimator using the same or better measurement methods or inferences from surrounding control units. If this phase of response continues to indicate a material loss, phase of response simulating a production shutdown and comprehensive cleanout is initiated. A new loss estimator is found, and tested against the alarm thresholds. If the estimator value is below the threshold, the original detection alarm is considered resolved; if above the threshold, an unresolved alarm has occurred. A tally is kept of valid alarms, unresolved false alarms, and failure to alarm upon a true loss

Dose response of thin-film dosimeters irradiated with 80-120 keV electrons

DEFF Research Database (Denmark)

Helt-Hansen, J.; Miller, A.; Sharpe, P.

2005-01-01

Thin-film dosimeters (Riso B3 and alanine films) were irradiated at 10 MeV and 80-120 keV electron accelerators, and it has been shown that the radiation response of the dosimeter materials (the radiation chemical yields) are constant at these irradiation energies. However, dose gradients within ...... are present within the dosimeter. (C) 2005 Elsevier Ltd. All rights reserved....

SSDL Preparation for Implementation of the Use of OSL Dosimeters in Malaysia

International Nuclear Information System (INIS)

Sangau, J.K.; Taiman Kadni; Ahmad Bazlie Abdul Kadir

2013-01-01

Since the early 1980's, film badge has been widely used as a device of personal dose monitoring in Malaysia. Secondary Standard Dosimetry Laboratory (SSDL), as a service center for film badge has obtained the supply of personal monitoring film from Agfa Gevaert, Belgium every year. As the uses of film badge have some weaknesses, it has prompted SSDL to find an alternative dosimeter to replace the film badge. Based on the studies that have been conducted, SSDL has selected OSL dosimeter (Optically Stimulated Luminescent Dosimeter) to replace the film badge and is expected to be fully operational by middle of 2015. This paper aims to explain the selection of OSL dosimeter and planning carried out to ensure the success of their application in Malaysia. (author)

DTR, Taut Wire System: An alarm barrier with experience

International Nuclear Information System (INIS)

Kraft, A.J.

1986-01-01

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

Transactions of the criticality alarm systems workshop

International Nuclear Information System (INIS)

1988-01-01

The first Criticality Alarm workshop was held by the US Department of Energy Albuquerque Operations Office in 1985. This second workshop is the first held on an international level. There were 98 persons in attendance. They represented the Department of Energy (DOE) field offices, DOE contractors, the Nuclear Regulatory Commission (NRC), NRC licensees, and agencies in the United Kingdom, France, West Germany, and Japan. Topics were on practices experience, and development. A key value of the workshop was the sharing of critical alarm system experiences, problems, and advances in the state of the art. In addition, several Criticality Alarm Systems (CAS) equipment systems were exhibited. Papers were presented on: nature of criticality accidents; lessons learned from past accidents; application of ANS 8.3 standard; gamma and neutron detection systems; research and development in progress; testing at Oak Ridge and Los Alamos; methods used to place detectors; centralized readout feature; false alarms; trip-point settings; and testing and maintenance. The individual papers have been cataloged separately

Ceramic BeO exoelectron dosimeters for tritium and radon monitoring

International Nuclear Information System (INIS)

Gammage, R.B.

1979-01-01

An environmental monitoring device with BeO ceramic dosimeters can be used to measure 222 Rn in dwellings. Radon diffuses into a porous hemispheric chamber and the radon daughters are electrostatically collected on aluminized Mylar foil covering the BeO dosimeter that records the alpha activity. A 10:1 signal-to-background ratio results from a radon exposure of only pCi-h/l. This high sensitivity makes accurate radon measurement possible within one day, even at near background levels of a few tenths pCi/l. The BeO exoelectron dosimeter is also uniquely suited for monitoring occupational exposure to insoluble tritium gas. At one-fifth the maximum permissible concentration, exposure for 8 hours gives a 10:1 signal-to-background exoelectron response to the low energy beta rays. Compensation for any exoelectron response caused by photon radiation can be made by reading the thermoluminescence. The tritium exposure produces negligible thermoluminescence. Progress in these and other applications is now totally dependent on achieving reliability and long-term stability of the exoelectron dosimeter

Alarm systems a guide to design, management and procurement

CERN Document Server

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.

Provision of dosimeters by official monitoring services for eye lens dose estimation

International Nuclear Information System (INIS)

Engelhardt, J.; Martini, E.

2013-01-01

Recent epidemiological studies are implying that the radio sensitivity of the eye lens is much higher than supposed in the past. International recommendations and standards demand to lower down the annual limit of the eye lens organ dose to 20 mSv. Since about 10 years German monitoring services offer partial-body dosimeters fixed on the head or on glasses for monitoring the eye lens dose. These dosimeters are optimized to measure the (surface) personal dose equivalent H p (0,07) from 0,5 mSv up to 10 Sv, which clearly overestimate the organ dose of the eye lens. With special features like different calibrations partial-body dosimeters should be applicable for legal dosimetry to avoid the development of special H p (3) dosimeters. Accepting the right way for wearing these dosimeters it is important to get the right results. Practical experiences are shown with measuring results and the difficulties of rounding the exact measuring values to discrete dose steps. Closing this article we point to still missing legal basis and open questions regarding to type testing procedures. (orig.)

Liquid polymers for using in a holographic ionizing radiation dosimeter

International Nuclear Information System (INIS)

Nicolau-Rebigan, S.

1979-01-01

Some liquid polymeric systems for using in the holographic ionizing radiation dosimeter are presented. It is shown that the action of radiation on polymers leads to the destruction of the polymeric chains or to perform them, the both processes being applied in radiation dosimetry. Some advantages of the holographic dosimeter are outlined comparatively with those common used. (author)

Design of Interrogation Protocols for Radiation Dose Measurements Using Optically-Stimulated Luminescent Dosimeters.

Science.gov (United States)

Abraham, Sara A; Kearfott, Kimberlee J; Jawad, Ali H; Boria, Andrew J; Buth, Tobias J; Dawson, Alexander S; Eng, Sheldon C; Frank, Samuel J; Green, Crystal A; Jacobs, Mitchell L; Liu, Kevin; Miklos, Joseph A; Nguyen, Hien; Rafique, Muhammad; Rucinski, Blake D; Smith, Travis; Tan, Yanliang

2017-03-01

Optically-stimulated luminescent dosimeters are capable of being interrogated multiple times post-irradiation. Each interrogation removes a fraction of the signal stored within the optically-stimulated luminescent dosimeter. This signal loss must be corrected to avoid systematic errors in estimating the average signal of a series of optically-stimulated luminescent dosimeter interrogations and requires a minimum number of consecutive readings to determine an average signal that is within a desired accuracy of the true signal with a desired statistical confidence. This paper establishes a technical basis for determining the required number of readings for a particular application of these dosimeters when using certain OSL dosimetry systems.

Development of colored alumilite dosimeter

CERN Document Server

Obara, K; Yagi, T; Yokoo, N

2003-01-01

In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50 approx 100 degC), high gamma-ray radiation (approx 1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10 approx 100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to b...

An assessment of radiotherapy dosimeters based on CVD grown diamond

International Nuclear Information System (INIS)

Ramkumar, S.; Buttar, C.M.; Conway, J.; Whitehead, A.J.; Sussman, R.S.; Hill, G.; Walker, S.

2001-01-01

Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemical inertness are some of the characteristics of diamond, which make it well suited for its application as a dosimeter. Recent advances in the synthesis of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper, the response of prototype dosimeters based on two different types (CVD1 and CVD2) of CVD diamond to X-rays. The diamond devices were assessed for sensitivity, dependence of response on dose and dose rate, and compared with a Scanditronix silicon photon diode and a PTW natural diamond dosimeter. The diamond devices of CVD1 type showed an initial increase in response with dose, which saturates after ∼6 Gy. The diamond devices of CVD2 type had a response at low fields ( 1162.8 V/cm), the CVD2-type devices showed polarisation and dose-rate dependence. The sensitivity of the CVD diamond devices varied between 82 and 1300 nC/Gy depending upon the sample type and the applied voltage. The sensitivity of CVD diamond devices was significantly higher than that of natural diamond and silicon dosimeters. The results suggest that CVD diamond devices can be fabricated for successful use in radiotherapy applications

Sensitive color dosimeters using photochromic diarylethenes

International Nuclear Information System (INIS)

Irie, Setsuko; Irie, Masahiro

2008-01-01

Various types of color dosimeters are conveniently used for estimating absorbed dose in the radiation sterilization of biomedical materials. Diarylethenes with heterocyclic aryl groups are extensively studied for the applications to the optoelectronic devices, such as optical memory media and photowitching devices because of their thermally irreversible and fatigue-resistant properties. The colors of diarylethenes never fade in the dark conditions. The thermally stable dithienylethene derivatives are applied to sensitive color dosimeters. Upon γ-irradiation, polystyrene films containing diarylethene derivatives, such as 1,2-bis(2-methyl-5-phenyl-3-thienyl) perfluorocyclopentene 1 or 1,2-bis(2,5-dimethyl-3-thienyl) perfluorocyclopentene 2, and fluorescent metal complexes turned blue or red. Even if the absorbed dose was as small as 10 Gy, a clear color change was observed. (author)

Dynamic alarm response procedures

International Nuclear Information System (INIS)

Martin, J.; Gordon, P.; Fitch, K.

2006-01-01

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 Apache R , IIS R , TclHTTPD, and others. DARP pages can be viewed in any Web browser that supports Javascript and Scalable Vector Graphics (SVG), such as Netscape R , Microsoft Internet Explorer R , Mozilla Firefox R , Opera R , and others. (authors)

Complex programmable logic device based alarm sequencer for nuclear power plants

International Nuclear Information System (INIS)

Khedkar, Ravindra; Solomon, J. Selva; KrishnaKumar, B.

2001-01-01

Complex Programmable Logic Device based Alarm Sequencer is an instrument, which detects alarms, memorizes them and displays the sequences of occurrence of alarms. It caters to sixteen alarm signals and distinguishes the sequence among any two alarms with a time resolution of 1 ms. The system described has been designed for continuous operation in process plants, nuclear power plants etc. The system has been tested and found to be working satisfactorily. (author)

Effect of pH grade on polymer-gel dosimeter and its brachytherapy application

International Nuclear Information System (INIS)

Spevacek, V.; Hrbacek, J.; Dvorak, P.; Cechak, T.; Novotny, J.

2003-01-01

To evaluate impact of pH grade on characteristics of polymer-gel dosimeter and its application in dose distribution verification in brachytherapy. A polymer-gel dosimeter based on radiation induced polymerization and crosslinking of acrylic monomers (acrylic acid, N,N' methylen-bis-acrylamide) was investigated with respect to its pH grade. pH grade of a dosimeter was varied by concentration of natrium hydroxide. Afterwards, dosimeter was split into several samples which were uniformly irradiated with Co-60 gamma rays. The range of doses applied was usually from 0 to 50 Gy with the main interest in region up to 20 Gy. Evaluation of dosimeter dose response was performed using MRI (T2). Dose response curves obtained were evaluated with respect to pH grade as a parameter. In parallel, there was studied temperature resistance (melting temperature) of gels with various pH grade. pH grade modified polymer-gel dosimeter was then used to compare dose distribution calculated with brachytherapy treatment planning system for simple irradiation geometry with Ir-192 HDR source. Additionaly, Monte Carlo calculated data were also included in the brachytherapy study. There was observed effect of pH grade on dose-response curve parameters (slope of linear fit, background response, linear range and maximum measurable dose). In general, the lower pH grade the higher sensitivity. Another positive effect of decreased pH grade is significantly higher maximum measurable dose. Maximum melting temperature of a gel was observed with pH grade between 3.5 and 4. For both higher and lower pH grades the melting temperature was lower. Using pH modified polymer-gel dosimeter simple brachytherapy dose distribution was measured and compared with calculated and Monte Carlo simulated data. There was observed strong dependence of dose-response relationship on pH grade of polymer-gel dosimeter resulting in significant improvement of dosimeter characteristics, namely sensitivity, applicable range of

Characterization of MOSFET dosimeters for low-dose measurements in maxillofacial anthropomorphic phantoms.

Science.gov (United States)

Koivisto, Juha H; Wolff, Jan E; Kiljunen, Timo; Schulze, Dirk; Kortesniemi, Mika

2015-07-08

The aims of this study were to characterize reinforced metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to assess the measurement uncertainty, single exposure low-dose limit with acceptable accuracy, and the number of exposures required to attain the corresponding limit of the thermoluminescent dosimeters (TLD). The second aim was to characterize MOSFET dosimeter sensitivities for two dental photon energy ranges, dose dependency, dose rate dependency, and accumulated dose dependency. A further aim was to compare the performance of MOSFETs with those of TLDs in an anthropomorphic phantom head using a dentomaxillofacial CBCT device. The uncertainty was assessed by exposing 20 MOSFETs and a Barracuda MPD reference dosimeter. The MOSFET dosimeter sensitivities were evaluated for two photon energy ranges (50-90 kVp) using a constant dose and polymethylmethacrylate backscatter material. MOSFET and TLD comparative point-dose measurements were performed on an anthropomorphic phantom that was exposed with a clinical CBCT protocol. The MOSFET single exposure low dose limit (25% uncertainty, k = 2) was 1.69 mGy. An averaging of eight MOSFET exposures was required to attain the corresponding TLD (0.3 mGy) low-dose limit. The sensitivity was 3.09 ± 0.13 mV/mGy independently of the photon energy used. The MOSFET dosimeters did not present dose or dose rate sensitivity but, however, presented a 1% decrease of sensitivity per 1000 mV for accumulated threshold voltages between 8300 mV and 17500 mV. The point doses in an anthropomorphic phantom ranged for MOSFETs between 0.24 mGy and 2.29 mGy and for TLDs between 0.25 and 2.09 mGy, respectively. The mean difference was -8%. The MOSFET dosimeters presented statistically insignificant energy dependency. By averaging multiple exposures, the MOSFET dosimeters can achieve a TLD-comparable low-dose limit and constitute a feasible method for diagnostic dosimetry using anthropomorphic phantoms. However, for single in

Characterization of MOSFET dosimeters for low‐dose measurements in maxillofacial anthropomorphic phantoms

Science.gov (United States)

Wolff, Jan E.; Kiljunen, Timo; Schulze, Dirk; Kortesniemi, Mika

2015-01-01

The aims of this study were to characterize reinforced metal‐oxide‐semiconductor field‐effect transistor (MOSFET) dosimeters to assess the measurement uncertainty, single exposure low‐dose limit with acceptable accuracy, and the number of exposures required to attain the corresponding limit of the thermoluminescent dosimeters (TLD). The second aim was to characterize MOSFET dosimeter sensitivities for two dental photon energy ranges, dose dependency, dose rate dependency, and accumulated dose dependency. A further aim was to compare the performance of MOSFETs with those of TLDs in an anthropomorphic phantom head using a dentomaxillofacial CBCT device. The uncertainty was assessed by exposing 20 MOSFETs and a Barracuda MPD reference dosimeter. The MOSFET dosimeter sensitivities were evaluated for two photon energy ranges (50–90 kVp) using a constant dose and polymethylmethacrylate backscatter material. MOSFET and TLD comparative point‐dose measurements were performed on an anthropomorphic phantom that was exposed with a clinical CBCT protocol. The MOSFET single exposure low dose limit (25% uncertainty, k=2) was 1.69 mGy. An averaging of eight MOSFET exposures was required to attain the corresponding TLD (0.3 mGy) low‐dose limit. The sensitivity was 3.09±0.13 mV/mGy independently of the photon energy used. The MOSFET dosimeters did not present dose or dose rate sensitivity but, however, presented a 1% decrease of sensitivity per 1000 mV for accumulated threshold voltages between 8300 mV and 17500 mV. The point doses in an anthropomorphic phantom ranged for MOSFETs between 0.24 mGy and 2.29 mGy and for TLDs between 0.25 and 2.09 mGy, respectively. The mean difference was −8%. The MOSFET dosimeters presented statistically insignificant energy dependency. By averaging multiple exposures, the MOSFET dosimeters can achieve a TLD‐comparable low‐dose limit and constitute a feasible method for diagnostic dosimetry using anthropomorphic phantoms. However

Design of alarm systems in Swedish nuclear power plants

International Nuclear Information System (INIS)

Thunberg, Anna; Osvalder, Anna-Lisa

2008-04-01

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

Studies on reduction of dosimeter used in the product dose mapping process at Sinagama Plant

International Nuclear Information System (INIS)

Sofian Ibrahim; Syuhada Ramli; Cosmos George; Zarina Mohd Nor; Kamarudin Buyong; Shahidan Yob; Nor Ishadi Ismail; Mohd Sidek Othman; Ahsanulkhaliqin Abdul Wahab; Mohd Khairul Azfar Ramli

2012-01-01

Product dose mapping is the determination of the best product loading configuration which will be used during routine sterilization. In product dose mapping, dosimeters are placed throughout products at strategic locations to determine the zones of minimum and maximum dose. On previous Sinagama's product dose mapping method, a total of 240 unit's ceric-cerous dosimeter been used for a tote. Based on the data obtained from Irradiator Dose Mapping Report in 2004 and data from recent studies, the number of dosimeter to be used in product dose mapping can be reduced to 28 units without sacrificing precision and accuracy of the dose mapping results. This also led changes of the placing dosimeter method from Plane system to Coordinate system. Reduction of 88 % on dosimeters usage will directly reduce the cost of expenses on dosimeter, time and labor. (author)

Contribution of computerization to alarm processing: A French safety view

Energy Technology Data Exchange (ETDEWEB)

Cette, W [CEA Centre d` Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

1997-09-01

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).

Contribution of computerization to alarm processing: A French safety view

International Nuclear Information System (INIS)

Cette, W.

1997-01-01

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)

Behavioral alarm treatment for nocturnal enuresis

Directory of Open Access Journals (Sweden)

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.

Spiny lobsters detect conspecific blood-borne alarm cues exclusively through olfactory sensilla.

Science.gov (United States)

Shabani, Shkelzen; Kamio, Michiya; Derby, Charles D

2008-08-01

When attacked by predators, diverse animals actively or passively release molecules that evoke alarm and related anti-predatory behavior by nearby conspecifics. The actively released molecules are alarm pheromones, whereas the passively released molecules are alarm cues. For example, many insects have alarm-signaling systems that involve active release of alarm pheromones from specialized glands and detection of these signals using specific sensors. Many crustaceans passively release alarm cues, but the nature of the cues, sensors and responses is poorly characterized. Here we show in laboratory and field experiments that injured Caribbean spiny lobsters, Panulirus argus, passively release alarm cues via blood (hemolymph) that induce alarm responses in the form of avoidance and suppression of feeding. These cues are detected exclusively through specific olfactory chemosensors, the aesthetasc sensilla. The alarm cues for Caribbean spiny lobsters are not unique to the species but do show some phylogenetic specificity: P. argus responds primarily with alarm behavior to conspecific blood, but with mixed alarm and appetitive behaviors to blood from the congener Panulirus interruptus, or with appetitive behaviors to blood from the blue crab Callinectes sapidus. This study lays the foundation for future neuroethological studies of alarm cue systems in this and other decapod crustaceans.

Implementation of the Integrated Alarm System for KOMAC facility using EPICS framework and Eclipse

International Nuclear Information System (INIS)

Song, Young-Gi; Kim, Jae-Ha; Kim, Han-Sung; Kwon, Hyeok-Jung; Cho, Yong-Sub

2017-01-01

The alarm detecting layer is the component that monitors alarm signals which are transported to the processing part through message queue. The main purpose of the processing part is to transfer the alarm signals connecting an alarm identification and state of the alarm to database system. The operation interface of system level signal links has been developed by EPICS framework. EPICS tools have been used for monitoring device alarm status. The KOMAC alarm system was developed for offering a user-friendly, intuitive user interface. The alarm system is implemented with EPICS IOC for alarm server, eclipse-mars integrated development tool for alarm viewer, and mariadb for alarm log. The new alarm system supports intuitive user interface on alarm information and alarm history. Alarm view has plans to add login function, user permission on alarm acknowledge, user permission of PV import, search and report function.

Angular dependence of dose equivalent response of an albedo neutron dosimeter

International Nuclear Information System (INIS)

Torres, B.A.; Boswell, E.; Schwartz, R.B.

1994-01-01

The ANSI provides procedures for testing the performance of dosimetry services. Although neutron dose equivalent angular response studies are not now mandated, future standards may well require that such studies be performed. Current studies with an albedo dosimeter will yield information regarding the angular dependence of dose equivalent response for this type of personnel dosimeter. Preliminary data for bare 252 Cf fluences show a marked decrease in dosimeter reading with increasing angle. The response decreased by an approximate factor of four. For the horizontal orientation, the same response was noted from both positive and negative angles. However, for the vertical orientation, the response was unexplainably assymetric. We are also examining the response of the personnel badge in moderated 252 Cf fluences. Responses from the moderated and unmoderated 252 Cf fields and theoretical calculations of the neutron angular response will be compared. This information will assist in building a data base for future comparisons of neutron angular responses with other neutron albedo dosimeters and phantoms

Development of real time personal neutron dosimeter with two silicon detectors

Energy Technology Data Exchange (ETDEWEB)

Nakamura, T.; Tsujimura, N. [Tohoku Univ., Cyclotron and Radioisotope Center, Aoba, Aramaki, Aoba-ku (Japan); Yamano, T. [Tokyo Factory, Fuji Electric Co. Ltd., Tokyo (Japan)

1992-07-01

We developed a real time personal neutron dosimeter by using two types of silicon p-n junction detectors, thermal neutron sensor and fast neutron sensor. The thermal neutron sensor which is {sup 10}B doped n-type silicon with a polyethylene radiator mainly counts neutrons of energy front thermal to I MeV, and the fast neutron sensor which is p-type silicon with a polyethylene radiator is sensitive to neutrons above I MeV. The neutron sensitivity measurements revealed that the dosimeter has a rather flat response for dose equivalent from thermal to 15 MeV, excluding a drop from 50 keV to I MeV. In order to get conversion factor from counts to dose equivalent as accurately as possible, we performed the field test of the dosimeter calibration in several neutron-generating fields. By introducing the two-group dose estimation method, this dosimeter can give the neutron dose equivalent within about 50% errors. (author)

PRESAGE® as a solid 3-D radiation dosimeter: A review article

Science.gov (United States)

Khezerloo, Davood; Nedaie, Hassan Ali; Takavar, Abbas; Zirak, Alireza; Farhood, Bagher; Movahedinejhad, Hadi; Banaee, Nooshin; Ahmadalidokht, Isa; Knuap, Courtney

2017-12-01

Radiation oncology has been rapidly improved by the application of new equipment and techniques. With the advent of new complex and precise radiotherapy techniques such as intensity modulated radiotherapy, stereotactic radiosurgery, and volumetric modulated arc therapy, the demand for an accurate and feasible three-dimensional (3-D) dosimetry system has increased. The most important features of a 3-D dosimeter, apart from being precise, accurate and reproducible, include also its low cost, feasibility, and availability. In 2004 a new generation of solid plastic dosimeters which demonstrate a radiochromic response to ionizing radiation was introduced. PRESAGE® plastic dosimeter lacks the limitations of previous Ferric and polymer plastic 3-D dosimeters such as diffusion, sensitivity to oxygen, fabrication problems, scanning and read out challenges. In this decade, a large number of efforts have been carried out to enhance PRESAGE® structure and scanning methods. This article attempts to review and reflect on the results of these investigations.

Solar UV exposure among outdoor workers in Denmark measured with personal UV-B dosimeters

DEFF Research Database (Denmark)

Grandahl, Kasper; Mortensen, Ole Steen; Sherman, David Zim

2017-01-01

radiation exposure are needed to help resolve this problem. This can be done using personal ultraviolet radiation dosimeters. Methods: We consider technical and practical feasibility of measuring individual solar ultraviolet exposure at work and leisure in professions with different á priori temporal high......-level outdoor worktime, using aluminium gallium nitride (AlGaN) photodiode detector based personal UV-B dosimeters. Essential technical specifications including the spectral and angular responsivity of the dosimeters are described and pre-campaign dosimeter calibration applicability is verified. The scale...... with our specialist knowledge as occupational physicians. Conclusions: Large-scale use of personal UV-B dosimeters for measurement of solar ultraviolet radiation exposure at work and leisure in Denmark is indeed feasible from a technical and practical viewpoint. Samples of exposure data shown support...

Response of TLD-100 LiF dosimeters for X-rays of low energies

International Nuclear Information System (INIS)

Bonzi, E. V.; Mainardi, R. T.

2011-10-01

In diverse practical applications as the existent in radiological clinics, industrial facilities and research laboratories, the solid state dosimeters are used for the measure of the different types of ionizing radiations. At the present time dosimeters are manufactured with different types of materials that present thermoluminescent properties, to the effects of determining the absorbed radiation dose. Under these conditions, the radiation dose is determined integrated in all the range of energies of the beam of X-rays, since it assumes that the response of these dosimeters is lineal with the energy of the photons or radiant particles. Because interest exists in advancing in the development of a determination method in the way of the X-rays spectrum emitted by a tube of those used in diagnostic or therapy, we have measured the response of TLD-100 LiF dosimeters for low energies, minor at 60 keV, for a several group of these dosimeters. (Author)

Toxicity alarm: Case history

International Nuclear Information System (INIS)

Hogan, D.; Retallack, J.

1993-01-01

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

Evaluation of performance of electronic dosimeters for individual monitoring: tests in laboratory

International Nuclear Information System (INIS)

Garzon, W.J.; Khoury, H.J.; Barros, V.S.M. de; Medeiros, R.B.

2015-01-01

Electronic dosimeters based on direct ion storage technology are being widely used in many countries for individual monitoring in many applications of ionizing radiation. However, their use as routine dosimeter has been established in a few countries due to lack of accreditation or intercomparison programs. The objective of this study is to evaluate the performance of two direct íon storage dosimeters model available in the international market: the Miriom-Instadose-1 and RADOS DIS-1 to be eventually accepted for individual monitoring in Brazil. (author)

Alarm inhalation dosemeter for long living radioactive dust due to an uncontrolled release

Science.gov (United States)

Streil, T.; Oeser, V.; Rambousky, R.; Buchholz, F. W.

2008-08-01

MyRIAM is the acronym for My Radioactivity In Air Monitor and points out that the device was designed for personal use to detect any radioactivity in the air at the place and at the moment of danger. The active air sampling process enables a detection limit several orders of magnitude below that of Gamma detectors. Therefore, it is the unique way to detect dangerous exposures in time. Individual protection against inhalation of long living radioactive dust (LLRD) saves human life and health. LLRD may occur in natural environment as well as in case of nuclear accidence or military and terrorist attacks. But in any case, the immediate warning of the population is of great importance. Keep in mind: it is very easy to avoid LLRD inhalation—but you have to recognize the imminent danger. The second requirement of gap-less documentation and reliable assessment of any derived LLRD exposure is building the link to Dosimetry applications. The paper demonstrates the possibility to design small and low cost air samplers, which can be used as personal alarm dosimeters and fulfil the requirements mentioned above. Several test measurements taken by a mobile phone sized MyRIAM, shall be used to demonstrate the correctness of this statement.

Alarm inhalation dosemeter for long living radioactive dust due to an uncontrolled release

International Nuclear Information System (INIS)

Streil, T.; Oeser, V.; Rambousky, R.; Buchholz, F. W.

2008-01-01

MyRIAM is the acronym for My Radioactivity In Air Monitor and points out that the device was designed for personal use to detect any radioactivity in the air at the place and at the moment of danger. The active air sampling process enables a detection limit several orders of magnitude below that of Gamma detectors. Therefore, it is the unique way to detect dangerous exposures in time.Individual protection against inhalation of long living radioactive dust (LLRD) saves human life and health. LLRD may occur in natural environment as well as in case of nuclear accidence or military and terrorist attacks. But in any case, the immediate warning of the population is of great importance. Keep in mind: it is very easy to avoid LLRD inhalation--but you have to recognize the imminent danger. The second requirement of gap-less documentation and reliable assessment of any derived LLRD exposure is building the link to Dosimetry applications.The paper demonstrates the possibility to design small and low cost air samplers, which can be used as personal alarm dosimeters and fulfil the requirements mentioned above.Several test measurements taken by a mobile phone sized MyRIAM, shall be used to demonstrate the correctness of this statement

Stop the Noise: A Quality Improvement Project to Decrease Electrocardiographic Nuisance Alarms.

Science.gov (United States)

Sendelbach, Sue; Wahl, Sharon; Anthony, Anita; Shotts, Pam

2015-08-01

As many as 99% of alarm signals may not need any intervention and can result in patients' deaths. Alarm management is now a Joint Commission National Patient Safety Goal. To reduce the number of nuisance electrocardiographic alarm signals in adult patients on the medical cardiovascular care unit. A quality improvement process was used that included eliminating duplicative alarms, customizing alarms, changing electrocardiography electrodes daily, standardizing skin preparation, and using disposable electrocardiography leads. In the cardiovascular care unit, the mean number of electrocardiographic alarm signals per day decreased from 28.5 (baseline) to 3.29, an 88.5% reduction. Use of a bundled approach to managing alarm signals decreased the mean number of alarm signals in a cardiovascular care unit. ©2015 American Association of Critical-Care Nurses.

Fully automatic CNC machining production system

Directory of Open Access Journals (Sweden)

Lee Jeng-Dao

2017-01-01

Full Text Available Customized manufacturing is increasing years by years. The consumption habits change has been cause the shorter of product life cycle. Therefore, many countries view industry 4.0 as a target to achieve more efficient and more flexible automated production. To develop an automatic loading and unloading CNC machining system via vision inspection is the first step in industrial upgrading. CNC controller is adopted as the main controller to command to the robot, conveyor, and other equipment in this study. Moreover, machine vision systems are used to detect position of material on the conveyor and the edge of the machining material. In addition, Open CNC and SCADA software will be utilized to make real-time monitor, remote system of control, alarm email notification, and parameters collection. Furthermore, RFID has been added to employee classification and management. The machine handshaking has been successfully proposed to achieve automatic vision detect, edge tracing measurement, machining and system parameters collection for data analysis to accomplish industrial automation system integration with real-time monitor.

Electron-energy deposition in skin and thermoluminescence dosimeters

International Nuclear Information System (INIS)

Mei, G.T.Y.

1986-01-01

The primary object of this study was to investigate the relations between dosimeter response and skin dose resulting from beta-particle irradiation. This object was achieved by combining evaluation of beta-source energy spectra, calculation of flux energy spectra, and employment of a Monte-Carlo electron-transport computer program for determination of depth-dose distribution in multislab geometries. Intermediate results from three steps of evaluation were compared individually with experimental data or with other theoretical results and showed excellent agreement. The combined method is applicable for the electron agreement. The combined method is applicable for the electron energy range of 1 keV to 5 MeV for both monoenergetic electrons and energy-distributed electrons. Determination of dosimeter response - skin dose relationships for homogeneous atmospheric beta-particle sources and for two specific configurations of LiF TLD's have been carried out in this study. Information based on these calculations is of value in designing beta-particle dosimeters as well as in assessing potential occupational and public health risks associated with the nuclear power industry

Human factors engineering guidance for the review of advanced alarm systems

International Nuclear Information System (INIS)

O'Hara, J.M.; Brown, W.S.; Higgins, J.C.; Stubler, W.F.

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

Human factors engineering guidance for the review of advanced alarm systems

Energy Technology Data Exchange (ETDEWEB)

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.

Valine-spectrophotometric readout dosimeter (1 Gy-50 kGy)

International Nuclear Information System (INIS)

Nilekani, S.R.; Gupta, B.L.

2005-01-01

In this method 20 mg unirradiated/irradiated L-valine powder [(CH 3 ) 2 CH.NH 2 CH.COOH] is dissolved in 10 ml of a solution containing 4x10 -4 mol dm -3 Fe 2+ and 2.5x10 -4 mol dm -3 xylenol orange (XO) in aerated aqueous 0.060 mol dm -3 sulphuric acid (FX). The plot of absorbance at 550 nm against dose is non linear. A dose of 1-50 kGy can be measured. However, dosimeter can be sensitized in the dose range of 1 to 16 kGy by dissolving 50-mg valine powder in 10 ml of a solution which contains 5x10 -4 mol dm -3 Fe 2+ and 3x10 -4 mol dm -3 XO in aerated aqueous 0.065 mol dm -3 sulphuric acid. The plot of absorbance at 549 nm against dose is non-linear. However, dosimeter shows linear response when 500 mg unirradiated/irradiated L-valine powder is dissolved in 10 ml of a solution containing 7.5x10 -4 mol dm -3 Fe 2+ and 3x10 -4 mol dm -3 XO in aerated aqueous 0.25 mol dm -3 sulphuric acid. The plot of absorbance at 557 nm against dose is linear in the dose range of 20-400Gy and doses down to about 1 Gy can be measured using 10-cm path cells. Response of the dosimeter is independent of irradiation temperature in the temperature range 20-50 deg C. Irradiated valine powder is stable for about 1 month. The reproducibility of the method is better than ±2%. This dosimeter is very useful as transfer dosimeter for food irradiation and radiation sterilization

Ionizing radiation M.O.S. dosimeters: sensibility and stability

International Nuclear Information System (INIS)

Gessinn, F.

1993-12-01

This thesis is a contribution to the study of the ionizing radiation responsivity of P.O.M.S. dosimeters. Unlike the development of processing hardening techniques, our works goal were to increase, on the one hand, the M.O.S. dosimeters sensitivity in order to detect small radiation doses and on the other hand, the stability with time and temperature of the devices, to minimize the absorbed-dose estimation errors. With this aim in mind, an analysis of all processing parameters has been carried out: the M.O.S. dosimeter sensitivity is primarily controlled by the gate oxide thickness and the irradiation electric field. Thus, P.M.O.S. transistors with 1 and 2 μm thick silica layers have been fabricated for our experiments. The radiation response of our devices in the high-field mode satisfactorily fits a D ox 2 power law. The maximum sensitivity achieved (9,2 V/Gy for 2μm devices) is close to the ideal value obtained when considering only an unitary carrier-trapping level, and allows to measure about 10 -2 Gy radiation doses. Read-time stability has been evaluated under bias-temperature stress conditions: experiments underscore slow fading, corresponding to 10 -3 Gy/h. The temperature response has also been studied: the analytical model we have developed predicts M.O.S. transistors threshold voltage variations over the military specifications range [-50 deg. C, + 150 deg. C]. Finally, we have investigated the possibilities of irradiated dosimeters thermal annealing for reusing. It appears clearly that radiation-induced damage annealing is strongly gate bias dependent. Furthermore, dosimeters radiation sensitivity seems not to be affected by successive annealings. (author). 146 refs., 58 figs., 9 tabs

Individual dosimeter for radon and thoron daughters

International Nuclear Information System (INIS)

Chapuis, A.M.; Duport, P.; Zettwoog, P.

1979-01-01

The dosimeter is designed for the continuous measurement of the concentration of α emitters from the uranium 238 and thorium 232 series. It enables the measurement of, firstly the aerosol concentration of 218 Po (Radium A), 214 Po (Radium C') and 212 Po (Thorium C') and secondly the activity of long-lived α emitters in aerosols coming from ore dusts. One light weight version of this dosimeter is autonomous for 18 hours and is designed to measure individual doses, due to inhalation, for workers employed in uranium mines and ore processing plants. An other version using the same sampling head allows the monitoring of air concentrations in working environments. Living quarters, or free air

Alarm reduction with correlation analysis; Larmsanering genom korrelationsanalys

Energy Technology Data Exchange (ETDEWEB)

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

Testing alarm resolution procedures in a fuel fabrication facility

International Nuclear Information System (INIS)

Smith, B.W.; Razvi, J.

1984-07-01

Process monitoring data can be used for generating material loss estimates. The intent of using process control data is to enhance nuclear material control and accounting for the timely detection and resolution of discrepancies. The purpose of an alarm resolution system is to distinguish between system errors and an actual loss of nuclear material. A study has been performed to develop and test a site-specific set of alarm resolution procedures. The results of the study are described and include the frequency of alarms, the causes of alarms, the type of resolution, and the modeling of loss estimates. 3 references, 2 figures, 2 tables

Effect of the shape and size of dosimeters on the response of solid state/EPR dosimetry

International Nuclear Information System (INIS)

Yordanov, Nicola D.; Fabisiak, Slawomir; Lagunov, Oleg

2006-01-01

The influence of the shape and size of dosimeters used in solid state-EPR (SS/EPR) dosimetry on their response is reported. It is shown that for commonly used cylindrical (rod) shaped dosimeters of equal height, prepared of low (ε=<3) dielectric constant materials, linearity between their volume and the EPR response is observed when their diameter varies between 3 and 5mm. Further increase of the dosimeter's diameter is not recommended since the increased penetration of the dosimeter material into the electric component of the microwave field in the EPR cavity increases the dielectric losses and decreases the EPR response. In an attempt to improve the sensitivity of the SS/EPR dosimetry we have prepared and tested new, flat-shaped, dosimeters of low (ε∼2) dielectric constant materials which were found to exhibit: (i) linear EPR response within 1-5mm thickness; (ii) higher sensitivity than cylindrical dosimeters at equal sample volume; (iii) increased by ca. 270% EPR sensitivity at 5mm thickness compared to the cylindrical dosimeters with the same diameter (ca. 1.7 times increased sample volume). Using flat shape dosimeters of suitable size provides 2.7 times higher EPR sensitivity of single estimation

Development study of a quality control for clinical dosimeters of radiotherapy

International Nuclear Information System (INIS)

Damatto, Willian B.; Potiens, Maria P.A.; Santos, Gelson P.; Vivolo, Vitor

2011-01-01

This paper presents the partial results of a scientific initiation which the main objective is the enhancement of the quality system of the dosimeter calibration laboratory (LCI-IPEN) on 60 Co gamma radiation to the International Atomic Energy Agency (IAEA), being this the new protocol denominated Calibration of Reference Dosimeters for External Beam Radiotherapy (Technical Reports Series 469). This paper is an actualization of the protocol Absorbed Dose Determination for External Beam Radiotherapy (Technical Reports Series 398). Therefore, in this paper it will presented the study on the clinical dosimeters composed of electrometer, wires, triaxial connectors, and thimble type ionization chamber - 0.60 cm 3 . (author)

Conceptual design of the SMART dosimeter

Science.gov (United States)

Johnson, Erik B.; Vogel, Sam; Frank, Rebecca; Stoddard, Graham; Vera, Alonzo; Alexander, David; Christian, James

2017-08-01

Active dosimeters for astronauts and space weather monitors are critical tools for mitigating radiation induced health issues or system failure on capital equipment. Commercial spaceflight, deep space flight, and satellites require smarter, smaller, and lower power dosimeters. There are a number of instruments with flight heritage, yet as identified in NASA's roadmaps, these technologies do not lend themselves to a viable solution for active dosimetry for an astronaut, particularly for deep space missions. For future missions, nano- and micro-satellites will require compact instruments that will accurately assess the radiation hazard without consuming major resources on the spacecraft. RMD has developed the methods for growing an advanced scintillation material called phenylcarbazole, which provides pulse shape discrimination between protons and electrons. When used in combination with an anti-coincidence detector system, an assessment of the dose from charged ions and neutral particles can be determined. This is valuable as damage on a system (such as silicon or tissue) is dependent on the particle species. Using this crystal with readout electronics developed in partnership with COSMIAC at the University of New Mexico, the design of the Small Mixed field Autonomous Radiation Tracker (SMART) Dosimeter consists of a low-power analog to digital conversion scheme with low-power digital signal processing algorithms, which are to be implemented within a compact system on a chip, such as the Xilinx Zynq series. A review of the conceptual design is presented.

47 CFR 80.307 - Compulsory use of radiotelegraph auto alarm.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Compulsory use of radiotelegraph auto alarm. 80.307 Section 80.307 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL... Safety Watches § 80.307 Compulsory use of radiotelegraph auto alarm. The radiotelegraph auto alarm...

Mayak Film Dosimeter Response Studies Part III: Application to Worker Dose Assessment

International Nuclear Information System (INIS)

Smetanin, Mikhail; Vasilenko, E. K.; Scherpelz, Robert I.

2007-01-01

This paper describes the methods used to convert individual dosimeter readings for workers to obtain estimates of worker doses received in Mayak facilities. Film dosimeters were used at Mayak PA for worker monitoring from 1948 until 1992. The method requires a determination of the relationship between the absorbed dose in film emulsion and the dose in air under calibration conditions, then an extension of this relationship to exposures in the actual radiation fields of the workplace. Corrections needed to account for actual workplace exposure conditions were determined by modeling with the Monte-Carlo radiation transport computer code MCNP. Correction factors were developed to convert from dosimeter reading to a realistic worker dose. The method was applied as a basis for individual dose reconstruction using film dosimeters in realistic photon spectra and geometries at Mayak PA work areas

46 CFR 28.250 - High water alarms.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...

Radiation Dose Measurement Using Chemical Dosimeters

International Nuclear Information System (INIS)

Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

2010-01-01

The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

Non-specific alarm calls trigger mobbing behavior in Hainan gibbons (Nomascus hainanus).

Science.gov (United States)

Deng, Huaiqing; Gao, Kai; Zhou, Jiang

2016-09-30

Alarm calls are important defensive behaviors. Here, we report the acoustic spectrum characteristics of alarm calls produced by Hainan gibbons (Nomascus hainanus) inhabiting Bawangling National Nature Reserve in Hainan, China. Analysis of call data collected from 2002-2014 shows that alarm calls are emitted by all family group members, except infants. Alarm behavior included simple short alarming calls (7-10 min) followed by longer variable-frequency mobbing calls lasting 5-12 min. The duration of individual alarming and mobbing calls was 0.078 ± 0.014 s and 0.154 ± 0.041 s at frequency ranges of 520-1000 Hz and 690-3920 Hz, respectively. Alarming call duration was positively associated with group size. The alarm calls can trigger mobbing behavior in Hainan gibbons; this is a defense way of social animals, and first report among the primates' species. The system of vocal alarm behavior described in this critically endangered species is simple and effective.

A Nuisance Alarm Data System for evaluation of intrusion detectors

International Nuclear Information System (INIS)

Ream, W.K.

1990-01-01

A Nuisance Alarm Data System (NADS) was developed to gather long-term background alarm data on exterior intrusion detectors as part of their evaluation. Since nuisance alarms play an important part in the selection of intrusion detectors for use at Department of Energy (DOE) facilities, an economical and reliable way to monitor and record these alarms was needed. NADS consists of an IBM personal computer and printer along with other commercial units to communicate with the detectors, to gather weather data, and to record video for assessment. Each alarm, its assessment, and the weather conditions occurring at alarm time are placed into a data base that is used in the evaluation of the detector. The operating software is written in Turbo Pascal for easy maintenance and modification. A portable system, based on the NADS design, has been built and shipped to other DOE locations to do on-site alarm monitoring. This has been valuable for the comparison of different detectors in the on-site environment and for testing new detectors when the appropriate conditions do not exist or cannot be simulated at the Exterior Intrusion Detection Testbed

Reducing hospital noise: a review of medical device alarm management.

Science.gov (United States)

Konkani, Avinash; Oakley, Barbara; Bauld, Thomas J